Rollup merge of #56746 - pnkfelix:issue-56537-add-test-of-closure-using-region-from-containing-fn, r=nikomatsakis

Add test of current behavior (infer free region within closure body)

This behavior was previously not encoded in our test suite.

it is pretty important that we test this behavior. In particular, in #56537  I had proposed expanding the lifetime elision rules so that they would apply to some of the cases encoded in this test, which would cause them to start failing to compile successfully (because the lifetime attached to the return type would start being treated as connected to the lifetime on the input parameter to the lambda expression, which is explicitly *not* what the code wants in this particular case).

In other words, I am trying to ensure that anyone who tries such experiments with lifetime elision in the future quickly finds out why we don't support lifetime elision on lambda expressions (at least not in the naive manner described on #56537).
diff --git a/.gitmodules b/.gitmodules
index 3fc6e45..70164d4 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -5,9 +5,6 @@
 [submodule "src/rust-installer"]
 	path = src/tools/rust-installer
 	url = https://github.com/rust-lang/rust-installer.git
-[submodule "src/liblibc"]
-	path = src/liblibc
-	url = https://github.com/rust-lang/libc.git
 [submodule "src/doc/nomicon"]
 	path = src/doc/nomicon
 	url = https://github.com/rust-lang-nursery/nomicon.git
@@ -23,9 +20,6 @@
 [submodule "src/tools/rls"]
 	path = src/tools/rls
 	url = https://github.com/rust-lang-nursery/rls.git
-[submodule "src/libcompiler_builtins"]
-	path = src/libcompiler_builtins
-	url = https://github.com/rust-lang-nursery/compiler-builtins.git
 [submodule "src/tools/clippy"]
 	path = src/tools/clippy
 	url = https://github.com/rust-lang-nursery/rust-clippy.git
@@ -35,9 +29,6 @@
 [submodule "src/tools/miri"]
 	path = src/tools/miri
 	url = https://github.com/solson/miri.git
-[submodule "src/dlmalloc"]
-	path = src/dlmalloc
-	url = https://github.com/alexcrichton/dlmalloc-rs.git
 [submodule "src/doc/rust-by-example"]
 	path = src/doc/rust-by-example
 	url = https://github.com/rust-lang/rust-by-example.git
@@ -67,6 +58,3 @@
 [submodule "src/doc/edition-guide"]
 	path = src/doc/edition-guide
 	url = https://github.com/rust-lang-nursery/edition-guide
-[submodule "src/rust-sgx"]
-	path = src/rust-sgx
-	url = https://github.com/fortanix/rust-sgx
diff --git a/Cargo.lock b/Cargo.lock
index c3c8812..be4a1c2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -15,9 +15,9 @@
 name = "alloc"
 version = "0.0.0"
 dependencies = [
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
- "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -81,7 +81,7 @@
 
 [[package]]
 name = "backtrace"
-version = "0.3.9"
+version = "0.3.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "backtrace-sys 0.1.24 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -407,10 +407,11 @@
 
 [[package]]
 name = "compiler_builtins"
-version = "0.0.0"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cc 1.0.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "core 0.0.0",
+ "rustc-std-workspace-core 1.0.0",
 ]
 
 [[package]]
@@ -456,7 +457,7 @@
 name = "core"
 version = "0.0.0"
 dependencies = [
- "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -658,10 +659,12 @@
 
 [[package]]
 name = "dlmalloc"
-version = "0.0.0"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "compiler_builtins 0.0.0",
- "core 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-std-workspace-core 1.0.0",
 ]
 
 [[package]]
@@ -725,7 +728,7 @@
 version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "backtrace 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -733,7 +736,7 @@
 version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "backtrace 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -748,7 +751,7 @@
 version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "backtrace 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "failure_derive 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -814,10 +817,11 @@
 
 [[package]]
 name = "fortanix-sgx-abi"
-version = "0.0.0"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "compiler_builtins 0.0.0",
- "core 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-std-workspace-core 1.0.0",
 ]
 
 [[package]]
@@ -1140,16 +1144,11 @@
 
 [[package]]
 name = "libc"
-version = "0.0.0"
-dependencies = [
- "compiler_builtins 0.0.0",
- "core 0.0.0",
-]
-
-[[package]]
-name = "libc"
 version = "0.2.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rustc-std-workspace-core 1.0.0",
+]
 
 [[package]]
 name = "libgit2-sys"
@@ -1520,9 +1519,9 @@
 name = "panic_abort"
 version = "0.0.0"
 dependencies = [
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
- "libc 0.0.0",
+ "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1530,9 +1529,9 @@
 version = "0.0.0"
 dependencies = [
  "alloc 0.0.0",
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
- "libc 0.0.0",
+ "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
  "unwind 0.0.0",
 ]
 
@@ -1683,7 +1682,7 @@
 version = "0.0.0"
 dependencies = [
  "cc 1.0.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
 ]
 
@@ -1814,7 +1813,7 @@
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1836,7 +1835,7 @@
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1861,7 +1860,7 @@
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2061,7 +2060,7 @@
 version = "0.0.0"
 dependencies = [
  "arena 0.0.0",
- "backtrace 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "chalk-engine 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2243,6 +2242,13 @@
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "rustc-std-workspace-core"
+version = "1.0.0"
+dependencies = [
+ "core 0.0.0",
+]
+
+[[package]]
 name = "rustc-workspace-hack"
 version = "1.0.0"
 dependencies = [
@@ -2284,7 +2290,7 @@
  "alloc 0.0.0",
  "build_helper 0.1.0",
  "cmake 0.1.33 (registry+https://github.com/rust-lang/crates.io-index)",
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
 ]
 
@@ -2479,7 +2485,7 @@
  "alloc 0.0.0",
  "build_helper 0.1.0",
  "cmake 0.1.33 (registry+https://github.com/rust-lang/crates.io-index)",
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
 ]
 
@@ -2531,7 +2537,7 @@
  "alloc 0.0.0",
  "build_helper 0.1.0",
  "cmake 0.1.33 (registry+https://github.com/rust-lang/crates.io-index)",
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
 ]
 
@@ -2644,7 +2650,7 @@
  "alloc 0.0.0",
  "build_helper 0.1.0",
  "cmake 0.1.33 (registry+https://github.com/rust-lang/crates.io-index)",
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
 ]
 
@@ -2877,15 +2883,15 @@
  "alloc 0.0.0",
  "build_helper 0.1.0",
  "cc 1.0.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
- "dlmalloc 0.0.0",
- "fortanix-sgx-abi 0.0.0",
- "libc 0.0.0",
+ "dlmalloc 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fortanix-sgx-abi 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
  "panic_abort 0.0.0",
  "panic_unwind 0.0.0",
  "profiler_builtins 0.0.0",
- "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_asan 0.0.0",
  "rustc_lsan 0.0.0",
  "rustc_msan 0.0.0",
@@ -3217,9 +3223,9 @@
 name = "unwind"
 version = "0.0.0"
 dependencies = [
- "compiler_builtins 0.0.0",
+ "compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
- "libc 0.0.0",
+ "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -3374,7 +3380,7 @@
 "checksum arrayvec 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)" = "a1e964f9e24d588183fcb43503abda40d288c8657dfc27311516ce2f05675aef"
 "checksum assert_cli 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "98589b0e465a6c510d95fceebd365bb79bedece7f6e18a480897f2015f85ec51"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
-"checksum backtrace 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "89a47830402e9981c5c41223151efcced65a0510c13097c769cede7efb34782a"
+"checksum backtrace 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)" = "18b65ea1161bfb2dd6da6fade5edd4dbd08fba85012123dd333d2fd1b90b2782"
 "checksum backtrace-sys 0.1.24 (registry+https://github.com/rust-lang/crates.io-index)" = "c66d56ac8dabd07f6aacdaf633f4b8262f5b3601a810a0dcddffd5c22c69daa0"
 "checksum bit-set 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6f1efcc46c18245a69c38fcc5cc650f16d3a59d034f3106e9ed63748f695730a"
 "checksum bit-vec 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4440d5cb623bb7390ae27fec0bb6c61111969860f8e3ae198bfa0663645e67cf"
@@ -3397,6 +3403,7 @@
 "checksum colored 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b0aa3473e85a3161b59845d6096b289bb577874cafeaf75ea1b1beaa6572c7fc"
 "checksum commoncrypto 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d056a8586ba25a1e4d61cb090900e495952c7886786fc55f909ab2f819b69007"
 "checksum commoncrypto-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1fed34f46747aa73dfaa578069fd8279d2818ade2b55f38f22a9401c7f4083e2"
+"checksum compiler_builtins 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "8ad611263b9f31bdb66e66227d3b781600fd1e68d5deee29b23f5e2ac9cb4892"
 "checksum compiletest_rs 0.3.17 (registry+https://github.com/rust-lang/crates.io-index)" = "89747fe073b7838343bd2c2445e7a7c2e0d415598f8925f0fa9205b9cdfc48cb"
 "checksum core-foundation 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4e2640d6d0bf22e82bed1b73c6aef8d5dd31e5abe6666c57e6d45e2649f4f887"
 "checksum core-foundation-sys 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e7ca8a5221364ef15ce201e8ed2f609fc312682a8f4e0e3d4aa5879764e0fa3b"
@@ -3418,6 +3425,7 @@
 "checksum diff 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "3c2b69f912779fbb121ceb775d74d51e915af17aaebc38d28a592843a2dd0a3a"
 "checksum difference 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "524cbf6897b527295dff137cec09ecf3a05f4fddffd7dfcd1585403449e74198"
 "checksum directories 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "72d337a64190607d4fcca2cb78982c5dd57f4916e19696b48a575fa746b6cb0f"
+"checksum dlmalloc 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4c46c65de42b063004b31c67a98abe071089b289ff0919c660ed7ff4f59317f8"
 "checksum either 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3be565ca5c557d7f59e7cfcf1844f9e3033650c929c6566f511e8005f205c1d0"
 "checksum elasticlunr-rs 2.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "a99a310cd1f9770e7bf8e48810c7bcbb0e078c8fb23a8c7bcf0da4c2bf61a455"
 "checksum ena 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f56c93cc076508c549d9bb747f79aa9b4eb098be7b8cad8830c3137ef52d1e00"
@@ -3434,6 +3442,7 @@
 "checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
 "checksum foreign-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f6f339eb8adc052cd2ca78910fda869aefa38d22d5cb648e6485e4d3fc06f3b1"
 "checksum foreign-types-shared 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "00b0228411908ca8685dba7fc2cdd70ec9990a6e753e89b6ac91a84c40fbaf4b"
+"checksum fortanix-sgx-abi 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "26105e20b4c3f7a319db1376b54ac9a46e5761e949405553375095d05a0cee4d"
 "checksum fs2 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "9564fc758e15025b46aa6643b1b77d047d1a56a1aea6e01002ac0c7026876213"
 "checksum fs_extra 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5f2a4a2034423744d2cc7ca2068453168dcdb82c438419e639a26bd87839c674"
 "checksum fst 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d94485a00b1827b861dd9d1a2cc9764f9044d4c535514c0760a5a2012ef3399f"
diff --git a/Cargo.toml b/Cargo.toml
index b763caa..667c557 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -65,6 +65,10 @@
 # here
 rustc-workspace-hack = { path = 'src/tools/rustc-workspace-hack' }
 
+# See comments in `tools/rustc-std-workspace-core/README.md` for what's going on
+# here
+rustc-std-workspace-core = { path = 'src/tools/rustc-std-workspace-core' }
+
 [patch."https://github.com/rust-lang/rust-clippy"]
 clippy_lints = { path = "src/tools/clippy/clippy_lints" }
 rustc_tools_util = { path = "src/tools/clippy/rustc_tools_util" }
diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 7dc64db..32f3e57 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -684,6 +684,11 @@
             .env("RUSTDOC_REAL", self.rustdoc(host))
             .env("RUSTDOC_CRATE_VERSION", self.rust_version())
             .env("RUSTC_BOOTSTRAP", "1");
+
+        // Remove make-related flags that can cause jobserver problems.
+        cmd.env_remove("MAKEFLAGS");
+        cmd.env_remove("MFLAGS");
+
         if let Some(linker) = self.linker(host) {
             cmd.env("RUSTC_TARGET_LINKER", linker);
         }
diff --git a/src/bootstrap/channel.rs b/src/bootstrap/channel.rs
index 88b6925..878b6ed 100644
--- a/src/bootstrap/channel.rs
+++ b/src/bootstrap/channel.rs
@@ -24,7 +24,7 @@
 use config::Config;
 
 // The version number
-pub const CFG_RELEASE_NUM: &str = "1.32.0";
+pub const CFG_RELEASE_NUM: &str = "1.33.0";
 
 pub struct GitInfo {
     inner: Option<Info>,
diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index 2e792b6..689d053 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -152,11 +152,12 @@
 
     if builder.no_std(target) == Some(true) {
         // for no-std targets we only compile a few no_std crates
-        cargo.arg("--features").arg("c mem")
+        cargo
             .args(&["-p", "alloc"])
-            .args(&["-p", "compiler_builtins"])
             .arg("--manifest-path")
-            .arg(builder.src.join("src/rustc/compiler_builtins_shim/Cargo.toml"));
+            .arg(builder.src.join("src/liballoc/Cargo.toml"))
+            .arg("--features")
+            .arg("compiler-builtins-mem");
     } else {
         let features = builder.std_features();
 
diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index 1ae494b..f03eefb 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -857,12 +857,9 @@
         // (essentially libstd and all of its path dependencies)
         let std_src_dirs = [
             "src/build_helper",
-            "src/dlmalloc",
             "src/liballoc",
             "src/libbacktrace",
-            "src/libcompiler_builtins",
             "src/libcore",
-            "src/liblibc",
             "src/libpanic_abort",
             "src/libpanic_unwind",
             "src/librustc_asan",
@@ -871,21 +868,15 @@
             "src/librustc_tsan",
             "src/libstd",
             "src/libunwind",
-            "src/rustc/compiler_builtins_shim",
-            "src/rustc/libc_shim",
-            "src/rustc/dlmalloc_shim",
-            "src/rustc/fortanix-sgx-abi_shim",
             "src/libtest",
             "src/libterm",
             "src/libprofiler_builtins",
             "src/stdsimd",
             "src/libproc_macro",
-        ];
-        let std_src_dirs_exclude = [
-            "src/libcompiler_builtins/compiler-rt/test",
+            "src/tools/rustc-std-workspace-core",
         ];
 
-        copy_src_dirs(builder, &std_src_dirs[..], &std_src_dirs_exclude[..], &dst_src);
+        copy_src_dirs(builder, &std_src_dirs[..], &[], &dst_src);
         for file in src_files.iter() {
             builder.copy(&builder.src.join(file), &dst_src.join(file));
         }
@@ -909,7 +900,7 @@
     }
 }
 
-const CARGO_VENDOR_VERSION: &str = "0.1.19";
+const CARGO_VENDOR_VERSION: &str = "0.1.22";
 
 #[derive(Debug, PartialOrd, Ord, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct PlainSourceTarball;
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index c31db48..c879291 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -1134,10 +1134,10 @@
             let krate = &self.crates[&krate];
             if krate.is_local(self) {
                 ret.push(krate);
-                for dep in &krate.deps {
-                    if visited.insert(dep) && dep != "build_helper" {
-                        list.push(*dep);
-                    }
+            }
+            for dep in &krate.deps {
+                if visited.insert(dep) && dep != "build_helper" {
+                    list.push(*dep);
                 }
             }
         }
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index ca9894f..dc061fe 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -1558,10 +1558,7 @@
         let builder = run.builder;
         run = run.krate("test");
         for krate in run.builder.in_tree_crates("std") {
-            if krate.is_local(&run.builder)
-                && !(krate.name.starts_with("rustc_") && krate.name.ends_with("san"))
-                && krate.name != "dlmalloc"
-            {
+            if !(krate.name.starts_with("rustc_") && krate.name.ends_with("san")) {
                 run = run.path(krate.local_path(&builder).to_str().unwrap());
             }
         }
diff --git a/src/build_helper/lib.rs b/src/build_helper/lib.rs
index 0cbb080..a580a87 100644
--- a/src/build_helper/lib.rs
+++ b/src/build_helper/lib.rs
@@ -224,14 +224,12 @@
 // Timestamps are created automatically when the result of `native_lib_boilerplate` goes out
 // of scope, so all the build actions should be completed until then.
 pub fn native_lib_boilerplate(
-    src_name: &str,
+    src_dir: &Path,
     out_name: &str,
     link_name: &str,
     search_subdir: &str,
 ) -> Result<NativeLibBoilerplate, ()> {
-    let current_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
-    let src_dir = current_dir.join("..").join(src_name);
-    rerun_if_changed_anything_in_dir(&src_dir);
+    rerun_if_changed_anything_in_dir(src_dir);
 
     let out_dir = env::var_os("RUSTBUILD_NATIVE_DIR").unwrap_or_else(||
         env::var_os("OUT_DIR").unwrap());
@@ -248,9 +246,9 @@
     );
 
     let timestamp = out_dir.join("rustbuild.timestamp");
-    if !up_to_date(Path::new("build.rs"), &timestamp) || !up_to_date(&src_dir, &timestamp) {
+    if !up_to_date(Path::new("build.rs"), &timestamp) || !up_to_date(src_dir, &timestamp) {
         Ok(NativeLibBoilerplate {
-            src_dir: src_dir,
+            src_dir: src_dir.to_path_buf(),
             out_dir: out_dir,
         })
     } else {
@@ -279,8 +277,11 @@
     } else {
         format!("static={}", link_name)
     };
+    // The source for `compiler-rt` comes from the `compiler-builtins` crate, so
+    // load our env var set by cargo to find the source code.
+    let dir = env::var_os("DEP_COMPILER_RT_COMPILER_RT").unwrap();
     let lib = native_lib_boilerplate(
-        "libcompiler_builtins/compiler-rt",
+        dir.as_ref(),
         sanitizer_name,
         &to_link,
         search_path,
diff --git a/src/ci/docker/dist-various-1/Dockerfile b/src/ci/docker/dist-various-1/Dockerfile
index c7e6af2..4f8a3c0 100644
--- a/src/ci/docker/dist-various-1/Dockerfile
+++ b/src/ci/docker/dist-various-1/Dockerfile
@@ -52,8 +52,8 @@
     CXX=arm-linux-gnueabi-g++ CXXFLAGS="-march=armv6 -marm" \
     bash musl.sh arm && \
     env \
-    CC=arm-linux-gnueabihf-gcc CFLAGS="-march=armv6 -marm" \
-    CXX=arm-linux-gnueabihf-g++ CXXFLAGS="-march=armv6 -marm" \
+    CC=arm-linux-gnueabihf-gcc CFLAGS="-march=armv6 -marm -mfpu=vfp" \
+    CXX=arm-linux-gnueabihf-g++ CXXFLAGS="-march=armv6 -marm -mfpu=vfp" \
     bash musl.sh armhf && \
     env \
     CC=arm-linux-gnueabihf-gcc CFLAGS="-march=armv7-a" \
diff --git a/src/dlmalloc b/src/dlmalloc
deleted file mode 160000
index de99f4b..0000000
--- a/src/dlmalloc
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit de99f4b0c886f5916cd1a146464276d65bef61b8
diff --git a/src/doc/rustc/src/codegen-options/index.md b/src/doc/rustc/src/codegen-options/index.md
index 4fc5f42..94f2104 100644
--- a/src/doc/rustc/src/codegen-options/index.md
+++ b/src/doc/rustc/src/codegen-options/index.md
@@ -22,6 +22,13 @@
 This flag lets you append multiple extra arguments to the linker invocation. The
 options should be separated by spaces.
 
+## linker-flavor
+
+This flag lets you control the linker flavor used by `rustc`. If a linker is given with the
+`-C linker` flag described above then the linker flavor is inferred from the value provided. If no
+linker is given then the linker flavor is used to determine the linker to use. Every `rustc` target
+defaults to some linker flavor.
+
 ## link-dead-code
 
 Normally, the linker will remove dead code. This flag disables this behavior.
diff --git a/src/doc/unstable-book/src/compiler-flags/linker-flavor.md b/src/doc/unstable-book/src/compiler-flags/linker-flavor.md
deleted file mode 100644
index 3965960..0000000
--- a/src/doc/unstable-book/src/compiler-flags/linker-flavor.md
+++ /dev/null
@@ -1,61 +0,0 @@
-# `linker-flavor`
-
-The tracking issue for this feature is: None
-
-------------------------
-
-Every `rustc` target defaults to some linker. For example, Linux targets default
-to gcc. In some cases, you may want to override the default; you can do that
-with the unstable CLI argument: `-Z linker-flavor`.
-
-Here how you would use this flag to link a Rust binary for the
-`thumbv7m-none-eabi` using LLD instead of GCC.
-
-``` text
-$ xargo rustc --target thumbv7m-none-eabi -- \
-    -C linker=ld.lld \
-    -Z linker-flavor=ld \
-    -Z print-link-args | tr ' ' '\n'
-"ld.lld"
-"-L"
-"$SYSROOT/lib/rustlib/thumbv7m-none-eabi/lib"
-"$PWD/target/thumbv7m-none-eabi/debug/deps/app-512e9dbf385f233c.0.o"
-"-o"
-"$PWD/target/thumbv7m-none-eabi/debug/deps/app-512e9dbf385f233c"
-"--gc-sections"
-"-L"
-"$PWD/target/thumbv7m-none-eabi/debug/deps"
-"-L"
-"$PWD/target/debug/deps"
-"-L"
-"$SYSROOT/lib/rustlib/thumbv7m-none-eabi/lib"
-"-Bstatic"
-"$SYSROOT/lib/rustlib/thumbv7m-none-eabi/lib/libcore-e1ccb7dfb1cb9ebb.rlib"
-"-Bdynamic"
-```
-
-Whereas the default is:
-
-``` text
-$ xargo rustc --target thumbv7m-none-eabi -- \
-    -C link-arg=-nostartfiles \
-    -Z print-link-args | tr ' ' '\n'
-"arm-none-eabi-gcc"
-"-L"
-"$SYSROOT/lib/rustlib/thumbv7m-none-eabi/lib"
-"$PWD/target/thumbv7m-none-eabi/debug/deps/app-961e39416baa38d9.0.o"
-"-o"
-"$PWD/target/thumbv7m-none-eabi/debug/deps/app-961e39416baa38d9"
-"-Wl,--gc-sections"
-"-nodefaultlibs"
-"-L"
-"$PWD/target/thumbv7m-none-eabi/debug/deps"
-"-L"
-"$PWD/target/debug/deps"
-"-L"
-"$SYSROOT/lib/rustlib/thumbv7m-none-eabi/lib"
-"-Wl,-Bstatic"
-"$SYSROOT/lib/rustlib/thumbv7m-none-eabi/lib/libcore-e1ccb7dfb1cb9ebb.rlib"
-"-nostartfiles"
-"-Wl,-Bdynamic"
-```
diff --git a/src/etc/gdb_rust_pretty_printing.py b/src/etc/gdb_rust_pretty_printing.py
index a376c85..f02c7d8 100755
--- a/src/etc/gdb_rust_pretty_printing.py
+++ b/src/etc/gdb_rust_pretty_printing.py
@@ -9,6 +9,7 @@
 # except according to those terms.
 
 import gdb
+import re
 import sys
 import debugger_pretty_printers_common as rustpp
 
@@ -20,6 +21,16 @@
 
 rust_enabled = 'set language rust' in gdb.execute('complete set language ru', to_string = True)
 
+# The btree pretty-printers fail in a confusing way unless
+# https://sourceware.org/bugzilla/show_bug.cgi?id=21763 is fixed.
+# This fix went in 8.1, so check for that.
+# See https://github.com/rust-lang/rust/issues/56730
+gdb_81 = False
+_match = re.match('([0-9]+)\\.([0-9]+)', gdb.VERSION)
+if _match:
+    if int(_match.group(1)) > 8 or (int(_match.group(1)) == 8 and int(_match.group(2)) >= 1):
+        gdb_81 = True
+
 #===============================================================================
 # GDB Pretty Printing Module for Rust
 #===============================================================================
@@ -110,10 +121,10 @@
     if type_kind == rustpp.TYPE_KIND_STD_VECDEQUE:
         return RustStdVecDequePrinter(val)
 
-    if type_kind == rustpp.TYPE_KIND_STD_BTREESET:
+    if type_kind == rustpp.TYPE_KIND_STD_BTREESET and gdb_81:
         return RustStdBTreeSetPrinter(val)
 
-    if type_kind == rustpp.TYPE_KIND_STD_BTREEMAP:
+    if type_kind == rustpp.TYPE_KIND_STD_BTREEMAP and gdb_81:
         return RustStdBTreeMapPrinter(val)
 
     if type_kind == rustpp.TYPE_KIND_STD_STRING:
diff --git a/src/liballoc/Cargo.toml b/src/liballoc/Cargo.toml
index 642a43d..b2eb356 100644
--- a/src/liballoc/Cargo.toml
+++ b/src/liballoc/Cargo.toml
@@ -11,10 +11,10 @@
 
 [dependencies]
 core = { path = "../libcore" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+compiler_builtins = { version = "0.1.0", features = ['rustc-dep-of-std'] }
 
 [dev-dependencies]
-rand = "0.5"
+rand = "0.6"
 
 [[test]]
 name = "collectionstests"
@@ -28,3 +28,6 @@
 name = "vec_deque_append_bench"
 path = "../liballoc/benches/vec_deque_append.rs"
 harness = false
+
+[features]
+compiler-builtins-mem = ['compiler_builtins/mem']
diff --git a/src/liballoc/collections/vec_deque.rs b/src/liballoc/collections/vec_deque.rs
index c0adeca..0c5926f 100644
--- a/src/liballoc/collections/vec_deque.rs
+++ b/src/liballoc/collections/vec_deque.rs
@@ -1026,7 +1026,10 @@
             iter: Iter {
                 tail: drain_tail,
                 head: drain_head,
-                ring: unsafe { self.buffer_as_mut_slice() },
+                // Crucially, we only create shared references from `self` here and read from
+                // it.  We do not write to `self` nor reborrow to a mutable reference.
+                // Hence the raw pointer we created above, for `deque`, remains valid.
+                ring: unsafe { self.buffer_as_slice() },
             },
         }
     }
diff --git a/src/liballoc/tests/binary_heap.rs b/src/liballoc/tests/binary_heap.rs
index b0d8fa6..536291d 100644
--- a/src/liballoc/tests/binary_heap.rs
+++ b/src/liballoc/tests/binary_heap.rs
@@ -14,7 +14,7 @@
 use std::panic::{self, AssertUnwindSafe};
 use std::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
 
-use rand::{thread_rng, Rng};
+use rand::{thread_rng, seq::SliceRandom};
 
 #[test]
 fn test_iterator() {
@@ -332,7 +332,7 @@
             let panic_item = PanicOrd(i, true);
 
             // heapify the sane items
-            rng.shuffle(&mut panic_ords);
+            panic_ords.shuffle(&mut rng);
             let mut heap = BinaryHeap::from(panic_ords);
             let inner_data;
 
diff --git a/src/liballoc/tests/slice.rs b/src/liballoc/tests/slice.rs
index 787e495..6f31e6c 100644
--- a/src/liballoc/tests/slice.rs
+++ b/src/liballoc/tests/slice.rs
@@ -18,7 +18,7 @@
 use std::sync::atomic::{ATOMIC_USIZE_INIT, AtomicUsize};
 use std::thread;
 
-use rand::{Rng, RngCore, thread_rng};
+use rand::{Rng, RngCore, thread_rng, seq::SliceRandom};
 use rand::distributions::Standard;
 
 fn square(n: usize) -> usize {
@@ -459,7 +459,7 @@
     for i in 0..v.len() {
         v[i] = i as i32;
     }
-    v.sort_by(|_, _| *rng.choose(&[Less, Equal, Greater]).unwrap());
+    v.sort_by(|_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
     v.sort();
     for i in 0..v.len() {
         assert_eq!(v[i], i as i32);
diff --git a/src/liballoc/tests/str.rs b/src/liballoc/tests/str.rs
index 683ce2b..9ad8ad1 100644
--- a/src/liballoc/tests/str.rs
+++ b/src/liballoc/tests/str.rs
@@ -1514,9 +1514,9 @@
 
 #[test]
 fn trim_ws() {
-    assert_eq!(" \t  a \t  ".trim_left_matches(|c: char| c.is_whitespace()),
+    assert_eq!(" \t  a \t  ".trim_start_matches(|c: char| c.is_whitespace()),
                     "a \t  ");
-    assert_eq!(" \t  a \t  ".trim_right_matches(|c: char| c.is_whitespace()),
+    assert_eq!(" \t  a \t  ".trim_end_matches(|c: char| c.is_whitespace()),
                " \t  a");
     assert_eq!(" \t  a \t  ".trim_start_matches(|c: char| c.is_whitespace()),
                     "a \t  ");
@@ -1524,9 +1524,9 @@
                " \t  a");
     assert_eq!(" \t  a \t  ".trim_matches(|c: char| c.is_whitespace()),
                     "a");
-    assert_eq!(" \t   \t  ".trim_left_matches(|c: char| c.is_whitespace()),
+    assert_eq!(" \t   \t  ".trim_start_matches(|c: char| c.is_whitespace()),
                          "");
-    assert_eq!(" \t   \t  ".trim_right_matches(|c: char| c.is_whitespace()),
+    assert_eq!(" \t   \t  ".trim_end_matches(|c: char| c.is_whitespace()),
                "");
     assert_eq!(" \t   \t  ".trim_start_matches(|c: char| c.is_whitespace()),
                          "");
diff --git a/src/libcompiler_builtins b/src/libcompiler_builtins
deleted file mode 160000
index 10f4f35..0000000
--- a/src/libcompiler_builtins
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 10f4f35f9670bb29715a8c1ec01284852d47ed35
diff --git a/src/libcore/Cargo.toml b/src/libcore/Cargo.toml
index 7fd61f0..fa2ab11 100644
--- a/src/libcore/Cargo.toml
+++ b/src/libcore/Cargo.toml
@@ -20,7 +20,7 @@
 path = "../libcore/benches/lib.rs"
 
 [dev-dependencies]
-rand = "0.5"
+rand = "0.6"
 
 [features]
 # Make panics and failed asserts immediately abort without formatting any message
diff --git a/src/libcore/ffi.rs b/src/libcore/ffi.rs
index d7a112e..899fae9 100644
--- a/src/libcore/ffi.rs
+++ b/src/libcore/ffi.rs
@@ -1,7 +1,6 @@
 #![stable(feature = "", since = "1.30.0")]
 
 #![allow(non_camel_case_types)]
-#![cfg_attr(stage0, allow(dead_code))]
 
 //! Utilities related to FFI bindings.
 
@@ -123,7 +122,6 @@
                      all supported platforms",
            issue = "27745")]
 #[repr(transparent)]
-#[cfg(not(stage0))]
 pub struct VaList<'a>(&'a mut VaListImpl);
 
 // The VaArgSafe trait needs to be used in public interfaces, however, the trait
@@ -173,7 +171,6 @@
            issue = "27745")]
 impl<T> sealed_trait::VaArgSafe for *const T {}
 
-#[cfg(not(stage0))]
 impl<'a> VaList<'a> {
     /// Advance to the next arg.
     #[unstable(feature = "c_variadic",
@@ -208,7 +205,6 @@
     }
 }
 
-#[cfg(not(stage0))]
 extern "rust-intrinsic" {
     /// Destroy the arglist `ap` after initialization with `va_start` or
     /// `va_copy`.
diff --git a/src/libcore/intrinsics.rs b/src/libcore/intrinsics.rs
index eebb98b..b94d5b4 100644
--- a/src/libcore/intrinsics.rs
+++ b/src/libcore/intrinsics.rs
@@ -718,7 +718,6 @@
     pub fn uninit<T>() -> T;
 
     /// Moves a value out of scope without running drop glue.
-    #[cfg(not(stage0))]
     pub fn forget<T: ?Sized>(_: T);
 
     /// Reinterprets the bits of a value of one type as another type.
@@ -1476,14 +1475,12 @@
     /// The stabilized versions of this intrinsic are available on the integer
     /// primitives via the `rotate_left` method. For example,
     /// [`std::u32::rotate_left`](../../std/primitive.u32.html#method.rotate_left)
-    #[cfg(not(stage0))]
     pub fn rotate_left<T>(x: T, y: T) -> T;
 
     /// Performs rotate right.
     /// The stabilized versions of this intrinsic are available on the integer
     /// primitives via the `rotate_right` method. For example,
     /// [`std::u32::rotate_right`](../../std/primitive.u32.html#method.rotate_right)
-    #[cfg(not(stage0))]
     pub fn rotate_right<T>(x: T, y: T) -> T;
 
     /// Returns (a + b) mod 2<sup>N</sup>, where N is the width of T in bits.
diff --git a/src/libcore/marker.rs b/src/libcore/marker.rs
index 0d43f92..d3d1612 100644
--- a/src/libcore/marker.rs
+++ b/src/libcore/marker.rs
@@ -640,15 +640,15 @@
 #[unstable(feature = "pin", issue = "49150")]
 pub auto trait Unpin {}
 
-/// A type which does not implement `Unpin`.
+/// A marker type which does not implement `Unpin`.
 ///
-/// If a type contains a `Pinned`, it will not implement `Unpin` by default.
+/// If a type contains a `PhantomPinned`, it will not implement `Unpin` by default.
 #[unstable(feature = "pin", issue = "49150")]
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
-pub struct Pinned;
+pub struct PhantomPinned;
 
 #[unstable(feature = "pin", issue = "49150")]
-impl !Unpin for Pinned {}
+impl !Unpin for PhantomPinned {}
 
 #[unstable(feature = "pin", issue = "49150")]
 impl<'a, T: ?Sized + 'a> Unpin for &'a T {}
diff --git a/src/libcore/mem.rs b/src/libcore/mem.rs
index 06754f1..afd9fcb 100644
--- a/src/libcore/mem.rs
+++ b/src/libcore/mem.rs
@@ -149,7 +149,6 @@
 ///
 /// [`forget`]: fn.forget.html
 #[inline]
-#[cfg(not(stage0))]
 #[unstable(feature = "forget_unsized", issue = "0")]
 pub fn forget_unsized<T: ?Sized>(t: T) {
     unsafe { intrinsics::forget(t) }
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index 13b4221..4acf3a1 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -2330,12 +2330,7 @@
             #[rustc_const_unstable(feature = "const_int_rotate")]
             #[inline]
             pub const fn rotate_left(self, n: u32) -> Self {
-                #[cfg(not(stage0))] {
-                    unsafe { intrinsics::rotate_left(self, n as $SelfT) }
-                }
-                #[cfg(stage0)] {
-                    (self << (n % $BITS)) | (self >> (($BITS - (n % $BITS)) % $BITS))
-                }
+                unsafe { intrinsics::rotate_left(self, n as $SelfT) }
             }
         }
 
@@ -2360,12 +2355,7 @@
             #[rustc_const_unstable(feature = "const_int_rotate")]
             #[inline]
             pub const fn rotate_right(self, n: u32) -> Self {
-                #[cfg(not(stage0))] {
-                    unsafe { intrinsics::rotate_right(self, n as $SelfT) }
-                }
-                #[cfg(stage0)] {
-                    (self >> (n % $BITS)) | (self << (($BITS - (n % $BITS)) % $BITS))
-                }
+                unsafe { intrinsics::rotate_right(self, n as $SelfT) }
             }
         }
 
diff --git a/src/libcore/ops/unsize.rs b/src/libcore/ops/unsize.rs
index 4d9a40a..e86a392 100644
--- a/src/libcore/ops/unsize.rs
+++ b/src/libcore/ops/unsize.rs
@@ -93,7 +93,7 @@
 /// {}
 /// ```
 #[unstable(feature = "dispatch_from_dyn", issue = "0")]
-#[cfg_attr(not(stage0), lang = "dispatch_from_dyn")]
+#[lang = "dispatch_from_dyn"]
 pub trait DispatchFromDyn<T> {
     // Empty.
 }
diff --git a/src/libcore/pin.rs b/src/libcore/pin.rs
index aa51555..0ad6e8c 100644
--- a/src/libcore/pin.rs
+++ b/src/libcore/pin.rs
@@ -7,23 +7,33 @@
 //! since moving an object with pointers to itself will invalidate them,
 //! which could cause undefined behavior.
 //!
-//! In order to prevent objects from moving, they must be pinned
-//! by wrapping a pointer to the data in the [`Pin`] type. A pointer wrapped
-//! in a `Pin` is otherwise equivalent to its normal version, e.g., `Pin<Box<T>>`
-//! and `Box<T>` work the same way except that the first is pinning the value
-//! of `T` in place.
+//! By default, all types in Rust are movable. Rust allows passing all types by-value,
+//! and common smart-pointer types such as `Box`, `Rc`, and `&mut` allow replacing and
+//! moving the values they contain. In order to prevent objects from moving, they must
+//! be pinned by wrapping a pointer to the data in the [`Pin`] type.
+//! Doing this prohibits moving the value behind the pointer.
+//! For example, `Pin<Box<T>>` functions much like a regular `Box<T>`,
+//! but doesn't allow moving `T`. The pointer value itself (the `Box`) can still be moved,
+//! but the value behind it cannot.
 //!
-//! First of all, these are pointer types because pinned data mustn't be passed around by value
-//! (that would change its location in memory).
-//! Secondly, since data can be moved out of `&mut` and `Box` with functions such as [`swap`],
-//! which causes their contents to swap places in memory,
-//! we need dedicated types that prohibit such operations.
+//! Since data can be moved out of `&mut` and `Box` with functions such as [`swap`],
+//! changing the location of the underlying data, [`Pin`] prohibits accessing the
+//! underlying pointer type (the `&mut` or `Box`) directly, and provides its own set of
+//! APIs for accessing and using the value. [`Pin`] also guarantees that no other
+//! functions will move the pointed-to value. This allows for the creation of
+//! self-references and other special behaviors that are only possible for unmovable
+//! values.
 //!
-//! However, these restrictions are usually not necessary,
-//! so most types implement the [`Unpin`] auto-trait,
-//! which indicates that the type can be moved out safely.
-//! Doing so removes the limitations of pinning types,
-//! making them the same as their non-pinning counterparts.
+//! However, these restrictions are usually not necessary. Many types are always freely
+//! movable. These types implement the [`Unpin`] auto-trait, which nullifies the affect
+//! of [`Pin`]. For `T: Unpin`, `Pin<Box<T>>` and `Box<T>` function identically, as do
+//! `Pin<&mut T>` and `&mut T`.
+//!
+//! Note that pinning and `Unpin` only affect the pointed-to type. For example, whether
+//! or not `Box<T>` is `Unpin` has no affect on the behavior of `Pin<Box<T>>`. Similarly,
+//! `Pin<Box<T>>` and `Pin<&mut T>` are always `Unpin` themselves, even though the
+//! `T` underneath them isn't, because the pointers in `Pin<Box<_>>` and `Pin<&mut _>`
+//! are always freely movable, even if the data they point to isn't.
 //!
 //! [`Pin`]: struct.Pin.html
 //! [`Unpin`]: trait.Unpin.html
@@ -36,7 +46,7 @@
 //! #![feature(pin)]
 //!
 //! use std::pin::Pin;
-//! use std::marker::Pinned;
+//! use std::marker::PhantomPinned;
 //! use std::ptr::NonNull;
 //!
 //! // This is a self-referential struct since the slice field points to the data field.
@@ -47,7 +57,7 @@
 //! struct Unmovable {
 //!     data: String,
 //!     slice: NonNull<String>,
-//!     _pin: Pinned,
+//!     _pin: PhantomPinned,
 //! }
 //!
 //! impl Unmovable {
@@ -60,7 +70,7 @@
 //!             // we only create the pointer once the data is in place
 //!             // otherwise it will have already moved before we even started
 //!             slice: NonNull::dangling(),
-//!             _pin: Pinned,
+//!             _pin: PhantomPinned,
 //!         };
 //!         let mut boxed = Box::pinned(res);
 //!
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index b11ae30..f61e582 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -2848,14 +2848,14 @@
 #[unstable(feature = "ptr_internals", issue = "0")]
 impl<'a, T: ?Sized> From<&'a mut T> for Unique<T> {
     fn from(reference: &'a mut T) -> Self {
-        Unique { pointer: unsafe { NonZero(reference as _) }, _marker: PhantomData }
+        Unique { pointer: unsafe { NonZero(reference as *mut T) }, _marker: PhantomData }
     }
 }
 
 #[unstable(feature = "ptr_internals", issue = "0")]
 impl<'a, T: ?Sized> From<&'a T> for Unique<T> {
     fn from(reference: &'a T) -> Self {
-        Unique { pointer: unsafe { NonZero(reference as _) }, _marker: PhantomData }
+        Unique { pointer: unsafe { NonZero(reference as *const T) }, _marker: PhantomData }
     }
 }
 
@@ -3058,7 +3058,7 @@
 impl<'a, T: ?Sized> From<&'a mut T> for NonNull<T> {
     #[inline]
     fn from(reference: &'a mut T) -> Self {
-        NonNull { pointer: unsafe { NonZero(reference as _) } }
+        NonNull { pointer: unsafe { NonZero(reference as *mut T) } }
     }
 }
 
@@ -3066,6 +3066,6 @@
 impl<'a, T: ?Sized> From<&'a T> for NonNull<T> {
     #[inline]
     fn from(reference: &'a T) -> Self {
-        NonNull { pointer: unsafe { NonZero(reference as _) } }
+        NonNull { pointer: unsafe { NonZero(reference as *const T) } }
     }
 }
diff --git a/src/libcore/sync/atomic.rs b/src/libcore/sync/atomic.rs
index 27eeb04..060983a 100644
--- a/src/libcore/sync/atomic.rs
+++ b/src/libcore/sync/atomic.rs
@@ -1940,7 +1940,7 @@
     8,
     u64 AtomicU64 ATOMIC_U64_INIT
 }
-#[cfg(all(not(stage0), target_has_atomic = "128"))]
+#[cfg(target_has_atomic = "128")]
 atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
@@ -1954,7 +1954,7 @@
     16,
     i128 AtomicI128 ATOMIC_I128_INIT
 }
-#[cfg(all(not(stage0), target_has_atomic = "128"))]
+#[cfg(target_has_atomic = "128")]
 atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
diff --git a/src/libcore/tests/num/flt2dec/random.rs b/src/libcore/tests/num/flt2dec/random.rs
index 95dfcb5..21a7c9f 100644
--- a/src/libcore/tests/num/flt2dec/random.rs
+++ b/src/libcore/tests/num/flt2dec/random.rs
@@ -18,7 +18,8 @@
 use core::num::flt2dec::strategy::grisu::format_shortest_opt;
 use core::num::flt2dec::{decode, DecodableFloat, FullDecoded, Decoded};
 
-use rand::{FromEntropy, XorShiftRng};
+use rand::FromEntropy;
+use rand::rngs::SmallRng;
 use rand::distributions::{Distribution, Uniform};
 
 pub fn decode_finite<T: DecodableFloat>(v: T) -> Decoded {
@@ -71,7 +72,10 @@
 pub fn f32_random_equivalence_test<F, G>(f: F, g: G, k: usize, n: usize)
         where F: FnMut(&Decoded, &mut [u8]) -> Option<(usize, i16)>,
               G: FnMut(&Decoded, &mut [u8]) -> (usize, i16) {
-    let mut rng = XorShiftRng::from_entropy();
+    if cfg!(target_os = "emscripten") {
+        return // using rng pulls in i128 support, which doesn't work
+    }
+    let mut rng = SmallRng::from_entropy();
     let f32_range = Uniform::new(0x0000_0001u32, 0x7f80_0000);
     iterate("f32_random_equivalence_test", k, n, f, g, |_| {
         let x = f32::from_bits(f32_range.sample(&mut rng));
@@ -82,7 +86,10 @@
 pub fn f64_random_equivalence_test<F, G>(f: F, g: G, k: usize, n: usize)
         where F: FnMut(&Decoded, &mut [u8]) -> Option<(usize, i16)>,
               G: FnMut(&Decoded, &mut [u8]) -> (usize, i16) {
-    let mut rng = XorShiftRng::from_entropy();
+    if cfg!(target_os = "emscripten") {
+        return // using rng pulls in i128 support, which doesn't work
+    }
+    let mut rng = SmallRng::from_entropy();
     let f64_range = Uniform::new(0x0000_0000_0000_0001u64, 0x7ff0_0000_0000_0000);
     iterate("f64_random_equivalence_test", k, n, f, g, |_| {
         let x = f64::from_bits(f64_range.sample(&mut rng));
diff --git a/src/libcore/tests/slice.rs b/src/libcore/tests/slice.rs
index dba5a43..4f00ebe 100644
--- a/src/libcore/tests/slice.rs
+++ b/src/libcore/tests/slice.rs
@@ -1024,11 +1024,11 @@
 fn sort_unstable() {
     use core::cmp::Ordering::{Equal, Greater, Less};
     use core::slice::heapsort;
-    use rand::{FromEntropy, Rng, XorShiftRng};
+    use rand::{FromEntropy, Rng, rngs::SmallRng, seq::SliceRandom};
 
     let mut v = [0; 600];
     let mut tmp = [0; 600];
-    let mut rng = XorShiftRng::from_entropy();
+    let mut rng = SmallRng::from_entropy();
 
     for len in (2..25).chain(500..510) {
         let v = &mut v[0..len];
@@ -1073,7 +1073,7 @@
     for i in 0..v.len() {
         v[i] = i as i32;
     }
-    v.sort_unstable_by(|_, _| *rng.choose(&[Less, Equal, Greater]).unwrap());
+    v.sort_unstable_by(|_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
     v.sort_unstable();
     for i in 0..v.len() {
         assert_eq!(v[i], i as i32);
diff --git a/src/liblibc b/src/liblibc
deleted file mode 160000
index 5b40375..0000000
--- a/src/liblibc
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 5b403753da9ec8ff501adf34cb6d63b319b4a3ae
diff --git a/src/libpanic_abort/Cargo.toml b/src/libpanic_abort/Cargo.toml
index 633d273..e304e61 100644
--- a/src/libpanic_abort/Cargo.toml
+++ b/src/libpanic_abort/Cargo.toml
@@ -11,5 +11,5 @@
 
 [dependencies]
 core = { path = "../libcore" }
-libc = { path = "../rustc/libc_shim" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+libc = { version = "0.2", default-features = false }
+compiler_builtins = "0.1.0"
diff --git a/src/libpanic_unwind/Cargo.toml b/src/libpanic_unwind/Cargo.toml
index 74aaa4d..c9fce62 100644
--- a/src/libpanic_unwind/Cargo.toml
+++ b/src/libpanic_unwind/Cargo.toml
@@ -12,6 +12,6 @@
 [dependencies]
 alloc = { path = "../liballoc" }
 core = { path = "../libcore" }
-libc = { path = "../rustc/libc_shim" }
+libc = { version = "0.2", default-features = false }
 unwind = { path = "../libunwind" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+compiler_builtins = "0.1.0"
diff --git a/src/libprofiler_builtins/Cargo.toml b/src/libprofiler_builtins/Cargo.toml
index 79192fb..7c95cf0 100644
--- a/src/libprofiler_builtins/Cargo.toml
+++ b/src/libprofiler_builtins/Cargo.toml
@@ -13,7 +13,7 @@
 
 [dependencies]
 core = { path = "../libcore" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+compiler_builtins = { version = "0.1.0", features = ['rustc-dep-of-std'] }
 
 [build-dependencies]
 cc = "1.0.1"
diff --git a/src/libprofiler_builtins/build.rs b/src/libprofiler_builtins/build.rs
index 8d6c7d6..db72ce7 100644
--- a/src/libprofiler_builtins/build.rs
+++ b/src/libprofiler_builtins/build.rs
@@ -56,9 +56,15 @@
         cfg.define("COMPILER_RT_HAS_UNAME", Some("1"));
     }
 
+    // The source for `compiler-rt` comes from the `compiler-builtins` crate, so
+    // load our env var set by cargo to find the source code.
+    let root = env::var_os("DEP_COMPILER_RT_COMPILER_RT").unwrap();
+    let root = Path::new(&root);
+
     for src in profile_sources {
-        cfg.file(Path::new("../libcompiler_builtins/compiler-rt/lib/profile").join(src));
+        cfg.file(root.join("lib").join("profile").join(src));
     }
 
+    cfg.warnings(false);
     cfg.compile("profiler-rt");
 }
diff --git a/src/librustc/ich/impls_ty.rs b/src/librustc/ich/impls_ty.rs
index e6a7c20..56da6b7 100644
--- a/src/librustc/ich/impls_ty.rs
+++ b/src/librustc/ich/impls_ty.rs
@@ -338,7 +338,7 @@
 );
 
 impl_stable_hash_for!(
-    impl<'tcx, M> for enum mir::interpret::AllocType<'tcx, M> [ mir::interpret::AllocType ] {
+    impl<'tcx> for enum mir::interpret::AllocKind<'tcx> [ mir::interpret::AllocKind ] {
         Function(instance),
         Static(def_id),
         Memory(mem),
diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index a09d167..b7759a8 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -463,7 +463,7 @@
                     Ok(ref s) => {
                         // FIXME(Manishearth) ideally the emitting code
                         // can tell us whether or not this is global
-                        let opt_colon = if s.trim_left().starts_with("::") {
+                        let opt_colon = if s.trim_start().starts_with("::") {
                             ""
                         } else {
                             "::"
diff --git a/src/librustc/mir/interpret/error.rs b/src/librustc/mir/interpret/error.rs
index 289f693..8b16aaf 100644
--- a/src/librustc/mir/interpret/error.rs
+++ b/src/librustc/mir/interpret/error.rs
@@ -183,50 +183,14 @@
 impl<'tcx> EvalError<'tcx> {
     pub fn print_backtrace(&mut self) {
         if let Some(ref mut backtrace) = self.backtrace {
-            eprintln!("{}", print_backtrace(&mut *backtrace));
+            print_backtrace(&mut *backtrace);
         }
     }
 }
 
-fn print_backtrace(backtrace: &mut Backtrace) -> String {
-    use std::fmt::Write;
-
+fn print_backtrace(backtrace: &mut Backtrace) {
     backtrace.resolve();
-
-    let mut trace_text = "\n\nAn error occurred in miri:\n".to_string();
-    write!(trace_text, "backtrace frames: {}\n", backtrace.frames().len()).unwrap();
-    'frames: for (i, frame) in backtrace.frames().iter().enumerate() {
-        if frame.symbols().is_empty() {
-            write!(trace_text, "  {}: no symbols\n", i).unwrap();
-        }
-        let mut first = true;
-        for symbol in frame.symbols() {
-            if first {
-                write!(trace_text, "  {}: ", i).unwrap();
-                first = false;
-            } else {
-                let len = i.to_string().len();
-                write!(trace_text, "  {}  ", " ".repeat(len)).unwrap();
-            }
-            if let Some(name) = symbol.name() {
-                write!(trace_text, "{}\n", name).unwrap();
-            } else {
-                write!(trace_text, "<unknown>\n").unwrap();
-            }
-            write!(trace_text, "           at ").unwrap();
-            if let Some(file_path) = symbol.filename() {
-                write!(trace_text, "{}", file_path.display()).unwrap();
-            } else {
-                write!(trace_text, "<unknown_file>").unwrap();
-            }
-            if let Some(line) = symbol.lineno() {
-                write!(trace_text, ":{}\n", line).unwrap();
-            } else {
-                write!(trace_text, "\n").unwrap();
-            }
-        }
-    }
-    trace_text
+    eprintln!("\n\nAn error occurred in miri:\n{:?}", backtrace);
 }
 
 impl<'tcx> From<EvalErrorKind<'tcx, u64>> for EvalError<'tcx> {
@@ -238,7 +202,7 @@
 
                 if val == "immediate" {
                     // Print it now
-                    eprintln!("{}", print_backtrace(&mut backtrace));
+                    print_backtrace(&mut backtrace);
                     None
                 } else {
                     Some(Box::new(backtrace))
diff --git a/src/librustc/mir/interpret/mod.rs b/src/librustc/mir/interpret/mod.rs
index 9369b6e..d54a1c9 100644
--- a/src/librustc/mir/interpret/mod.rs
+++ b/src/librustc/mir/interpret/mod.rs
@@ -41,7 +41,6 @@
 use ty::layout::{self, Size};
 use middle::region;
 use std::io;
-use std::hash::Hash;
 use rustc_serialize::{Encoder, Decodable, Encodable};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::{Lock as Mutex, HashMapExt};
@@ -90,7 +89,7 @@
 impl ::rustc_serialize::UseSpecializedDecodable for AllocId {}
 
 #[derive(RustcDecodable, RustcEncodable)]
-enum AllocKind {
+enum AllocDiscriminant {
     Alloc,
     Fn,
     Static,
@@ -104,23 +103,23 @@
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
     alloc_id: AllocId,
 ) -> Result<(), E::Error> {
-    let alloc_type: AllocType<'tcx, &'tcx Allocation> =
+    let alloc_kind: AllocKind<'tcx> =
         tcx.alloc_map.lock().get(alloc_id).expect("no value for AllocId");
-    match alloc_type {
-        AllocType::Memory(alloc) => {
+    match alloc_kind {
+        AllocKind::Memory(alloc) => {
             trace!("encoding {:?} with {:#?}", alloc_id, alloc);
-            AllocKind::Alloc.encode(encoder)?;
+            AllocDiscriminant::Alloc.encode(encoder)?;
             alloc.encode(encoder)?;
         }
-        AllocType::Function(fn_instance) => {
+        AllocKind::Function(fn_instance) => {
             trace!("encoding {:?} with {:#?}", alloc_id, fn_instance);
-            AllocKind::Fn.encode(encoder)?;
+            AllocDiscriminant::Fn.encode(encoder)?;
             fn_instance.encode(encoder)?;
         }
-        AllocType::Static(did) => {
+        AllocKind::Static(did) => {
             // referring to statics doesn't need to know about their allocations,
             // just about its DefId
-            AllocKind::Static.encode(encoder)?;
+            AllocDiscriminant::Static.encode(encoder)?;
             did.encode(encoder)?;
         }
     }
@@ -189,10 +188,10 @@
         let idx = decoder.read_u32()? as usize;
         let pos = self.state.data_offsets[idx] as usize;
 
-        // Decode the AllocKind now so that we know if we have to reserve an
+        // Decode the AllocDiscriminant now so that we know if we have to reserve an
         // AllocId.
         let (alloc_kind, pos) = decoder.with_position(pos, |decoder| {
-            let alloc_kind = AllocKind::decode(decoder)?;
+            let alloc_kind = AllocDiscriminant::decode(decoder)?;
             Ok((alloc_kind, decoder.position()))
         })?;
 
@@ -208,7 +207,7 @@
                 ref mut entry @ State::Empty => {
                     // We are allowed to decode
                     match alloc_kind {
-                        AllocKind::Alloc => {
+                        AllocDiscriminant::Alloc => {
                             // If this is an allocation, we need to reserve an
                             // AllocId so we can decode cyclic graphs.
                             let alloc_id = decoder.tcx().alloc_map.lock().reserve();
@@ -217,7 +216,7 @@
                                 alloc_id);
                             Some(alloc_id)
                         },
-                        AllocKind::Fn | AllocKind::Static => {
+                        AllocDiscriminant::Fn | AllocDiscriminant::Static => {
                             // Fns and statics cannot be cyclic and their AllocId
                             // is determined later by interning
                             *entry = State::InProgressNonAlloc(
@@ -251,15 +250,15 @@
         // Now decode the actual data
         let alloc_id = decoder.with_position(pos, |decoder| {
             match alloc_kind {
-                AllocKind::Alloc => {
+                AllocDiscriminant::Alloc => {
                     let allocation = <&'tcx Allocation as Decodable>::decode(decoder)?;
                     // We already have a reserved AllocId.
                     let alloc_id = alloc_id.unwrap();
                     trace!("decoded alloc {:?} {:#?}", alloc_id, allocation);
-                    decoder.tcx().alloc_map.lock().set_id_same_memory(alloc_id, allocation);
+                    decoder.tcx().alloc_map.lock().set_alloc_id_same_memory(alloc_id, allocation);
                     Ok(alloc_id)
                 },
-                AllocKind::Fn => {
+                AllocDiscriminant::Fn => {
                     assert!(alloc_id.is_none());
                     trace!("creating fn alloc id");
                     let instance = ty::Instance::decode(decoder)?;
@@ -267,7 +266,7 @@
                     let alloc_id = decoder.tcx().alloc_map.lock().create_fn_alloc(instance);
                     Ok(alloc_id)
                 },
-                AllocKind::Static => {
+                AllocDiscriminant::Static => {
                     assert!(alloc_id.is_none());
                     trace!("creating extern static alloc id at");
                     let did = DefId::decode(decoder)?;
@@ -292,39 +291,42 @@
 }
 
 #[derive(Debug, Clone, Eq, PartialEq, Hash, RustcDecodable, RustcEncodable)]
-pub enum AllocType<'tcx, M> {
+pub enum AllocKind<'tcx> {
     /// The alloc id is used as a function pointer
     Function(Instance<'tcx>),
     /// The alloc id points to a "lazy" static variable that did not get computed (yet).
     /// This is also used to break the cycle in recursive statics.
     Static(DefId),
     /// The alloc id points to memory
-    Memory(M)
+    Memory(&'tcx Allocation),
 }
 
-pub struct AllocMap<'tcx, M> {
+pub struct AllocMap<'tcx> {
     /// Lets you know what an AllocId refers to
-    id_to_type: FxHashMap<AllocId, AllocType<'tcx, M>>,
+    id_to_kind: FxHashMap<AllocId, AllocKind<'tcx>>,
 
-    /// Used to ensure that functions and statics only get one associated AllocId
-    type_interner: FxHashMap<AllocType<'tcx, M>, AllocId>,
+    /// Used to ensure that statics only get one associated AllocId
+    type_interner: FxHashMap<AllocKind<'tcx>, AllocId>,
 
     /// The AllocId to assign to the next requested id.
     /// Always incremented, never gets smaller.
     next_id: AllocId,
 }
 
-impl<'tcx, M: fmt::Debug + Eq + Hash + Clone> AllocMap<'tcx, M> {
+impl<'tcx> AllocMap<'tcx> {
     pub fn new() -> Self {
         AllocMap {
-            id_to_type: Default::default(),
+            id_to_kind: Default::default(),
             type_interner: Default::default(),
             next_id: AllocId(0),
         }
     }
 
-    /// obtains a new allocation ID that can be referenced but does not
+    /// Obtains a new allocation ID that can be referenced but does not
     /// yet have an allocation backing it.
+    ///
+    /// Make sure to call `set_alloc_id_memory` or `set_alloc_id_same_memory` before returning such
+    /// an `AllocId` from a query.
     pub fn reserve(
         &mut self,
     ) -> AllocId {
@@ -337,53 +339,73 @@
         next
     }
 
-    fn intern(&mut self, alloc_type: AllocType<'tcx, M>) -> AllocId {
-        if let Some(&alloc_id) = self.type_interner.get(&alloc_type) {
+    fn intern(&mut self, alloc_kind: AllocKind<'tcx>) -> AllocId {
+        if let Some(&alloc_id) = self.type_interner.get(&alloc_kind) {
             return alloc_id;
         }
         let id = self.reserve();
-        debug!("creating alloc_type {:?} with id {}", alloc_type, id);
-        self.id_to_type.insert(id, alloc_type.clone());
-        self.type_interner.insert(alloc_type, id);
+        debug!("creating alloc_kind {:?} with id {}", alloc_kind, id);
+        self.id_to_kind.insert(id, alloc_kind.clone());
+        self.type_interner.insert(alloc_kind, id);
         id
     }
 
-    // FIXME: Check if functions have identity. If not, we should not intern these,
-    // but instead create a new id per use.
-    // Alternatively we could just make comparing function pointers an error.
+    /// Functions cannot be identified by pointers, as asm-equal functions can get deduplicated
+    /// by the linker and functions can be duplicated across crates.
+    /// We thus generate a new `AllocId` for every mention of a function. This means that
+    /// `main as fn() == main as fn()` is false, while `let x = main as fn(); x == x` is true.
     pub fn create_fn_alloc(&mut self, instance: Instance<'tcx>) -> AllocId {
-        self.intern(AllocType::Function(instance))
+        let id = self.reserve();
+        self.id_to_kind.insert(id, AllocKind::Function(instance));
+        id
     }
 
-    pub fn get(&self, id: AllocId) -> Option<AllocType<'tcx, M>> {
-        self.id_to_type.get(&id).cloned()
+    /// Returns `None` in case the `AllocId` is dangling. An `EvalContext` can still have a
+    /// local `Allocation` for that `AllocId`, but having such an `AllocId` in a constant is
+    /// illegal and will likely ICE.
+    /// This function exists to allow const eval to detect the difference between evaluation-
+    /// local dangling pointers and allocations in constants/statics.
+    pub fn get(&self, id: AllocId) -> Option<AllocKind<'tcx>> {
+        self.id_to_kind.get(&id).cloned()
     }
 
-    pub fn unwrap_memory(&self, id: AllocId) -> M {
+    /// Panics if the `AllocId` does not refer to an `Allocation`
+    pub fn unwrap_memory(&self, id: AllocId) -> &'tcx Allocation {
         match self.get(id) {
-            Some(AllocType::Memory(mem)) => mem,
+            Some(AllocKind::Memory(mem)) => mem,
             _ => bug!("expected allocation id {} to point to memory", id),
         }
     }
 
+    /// Generate an `AllocId` for a static or return a cached one in case this function has been
+    /// called on the same static before.
     pub fn intern_static(&mut self, static_id: DefId) -> AllocId {
-        self.intern(AllocType::Static(static_id))
+        self.intern(AllocKind::Static(static_id))
     }
 
-    pub fn allocate(&mut self, mem: M) -> AllocId {
+    /// Intern the `Allocation` and return a new `AllocId`, even if there's already an identical
+    /// `Allocation` with a different `AllocId`.
+    // FIXME: is this really necessary? Can we ensure `FOO` and `BAR` being different after codegen
+    // in `static FOO: u32 = 42; static BAR: u32 = 42;` even if they reuse the same allocation
+    // inside rustc?
+    pub fn allocate(&mut self, mem: &'tcx Allocation) -> AllocId {
         let id = self.reserve();
-        self.set_id_memory(id, mem);
+        self.set_alloc_id_memory(id, mem);
         id
     }
 
-    pub fn set_id_memory(&mut self, id: AllocId, mem: M) {
-        if let Some(old) = self.id_to_type.insert(id, AllocType::Memory(mem)) {
+    /// Freeze an `AllocId` created with `reserve` by pointing it at an `Allocation`. Trying to
+    /// call this function twice, even with the same `Allocation` will ICE the compiler.
+    pub fn set_alloc_id_memory(&mut self, id: AllocId, mem: &'tcx Allocation) {
+        if let Some(old) = self.id_to_kind.insert(id, AllocKind::Memory(mem)) {
             bug!("tried to set allocation id {}, but it was already existing as {:#?}", id, old);
         }
     }
 
-    pub fn set_id_same_memory(&mut self, id: AllocId, mem: M) {
-       self.id_to_type.insert_same(id, AllocType::Memory(mem));
+    /// Freeze an `AllocId` created with `reserve` by pointing it at an `Allocation`. May be called
+    /// twice for the same `(AllocId, Allocation)` pair.
+    fn set_alloc_id_same_memory(&mut self, id: AllocId, mem: &'tcx Allocation) {
+        self.id_to_kind.insert_same(id, AllocKind::Memory(mem));
     }
 }
 
diff --git a/src/librustc/mir/interpret/value.rs b/src/librustc/mir/interpret/value.rs
index 500bd47..b8d4c5a 100644
--- a/src/librustc/mir/interpret/value.rs
+++ b/src/librustc/mir/interpret/value.rs
@@ -18,7 +18,7 @@
 /// Represents the result of a raw const operation, pre-validation.
 #[derive(Copy, Clone, Debug, Eq, PartialEq, RustcEncodable, RustcDecodable, Hash)]
 pub struct RawConst<'tcx> {
-    // the value lives here, at offset 0, and that allocation definitely is a `AllocType::Memory`
+    // the value lives here, at offset 0, and that allocation definitely is a `AllocKind::Memory`
     // (so you can use `AllocMap::unwrap_memory`).
     pub alloc_id: AllocId,
     pub ty: Ty<'tcx>,
diff --git a/src/librustc/mir/mod.rs b/src/librustc/mir/mod.rs
index b7a4295..68b5c3e 100644
--- a/src/librustc/mir/mod.rs
+++ b/src/librustc/mir/mod.rs
@@ -2637,7 +2637,7 @@
                 if let Ref(_, &ty::TyS { sty: Str, .. }, _) = ty.sty {
                     return ty::tls::with(|tcx| {
                         let alloc = tcx.alloc_map.lock().get(ptr.alloc_id);
-                        if let Some(interpret::AllocType::Memory(alloc)) = alloc {
+                        if let Some(interpret::AllocKind::Memory(alloc)) = alloc {
                             assert_eq!(len as usize as u128, len);
                             let slice =
                                 &alloc.bytes[(ptr.offset.bytes() as usize)..][..(len as usize)];
diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs
index 750b7f1..b58d80e 100644
--- a/src/librustc/session/config.rs
+++ b/src/librustc/session/config.rs
@@ -14,7 +14,7 @@
 use std::str::FromStr;
 
 use session::{early_error, early_warn, Session};
-use session::search_paths::SearchPaths;
+use session::search_paths::SearchPath;
 
 use rustc_target::spec::{LinkerFlavor, PanicStrategy, RelroLevel};
 use rustc_target::spec::{Target, TargetTriple};
@@ -374,7 +374,7 @@
         lint_cap: Option<lint::Level> [TRACKED],
         describe_lints: bool [UNTRACKED],
         output_types: OutputTypes [TRACKED],
-        search_paths: SearchPaths [UNTRACKED],
+        search_paths: Vec<SearchPath> [UNTRACKED],
         libs: Vec<(String, Option<String>, Option<cstore::NativeLibraryKind>)> [TRACKED],
         maybe_sysroot: Option<PathBuf> [TRACKED],
 
@@ -593,7 +593,7 @@
             lint_cap: None,
             describe_lints: false,
             output_types: OutputTypes(BTreeMap::new()),
-            search_paths: SearchPaths::new(),
+            search_paths: vec![],
             maybe_sysroot: None,
             target_triple: TargetTriple::from_triple(host_triple()),
             test: false,
@@ -1135,6 +1135,8 @@
         "enable incremental compilation"),
     default_linker_libraries: Option<bool> = (None, parse_opt_bool, [UNTRACKED],
         "allow the linker to link its default libraries"),
+    linker_flavor: Option<LinkerFlavor> = (None, parse_linker_flavor, [UNTRACKED],
+                                           "Linker flavor"),
 }
 
 options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
@@ -1297,8 +1299,6 @@
         "pass `-install_name @rpath/...` to the macOS linker"),
     sanitizer: Option<Sanitizer> = (None, parse_sanitizer, [TRACKED],
                                     "Use a sanitizer"),
-    linker_flavor: Option<LinkerFlavor> = (None, parse_linker_flavor, [UNTRACKED],
-                                           "Linker flavor"),
     fuel: Option<(String, u64)> = (None, parse_optimization_fuel, [TRACKED],
         "set the optimization fuel quota for a crate"),
     print_fuel: Option<String> = (None, parse_opt_string, [TRACKED],
@@ -2115,9 +2115,9 @@
         }
     };
 
-    let mut search_paths = SearchPaths::new();
+    let mut search_paths = vec![];
     for s in &matches.opt_strs("L") {
-        search_paths.add_path(&s[..], error_format);
+        search_paths.push(SearchPath::from_cli_opt(&s[..], error_format));
     }
 
     let libs = matches
@@ -2535,6 +2535,7 @@
     use session::config::{build_configuration, build_session_options_and_crate_config};
     use session::config::{LtoCli, CrossLangLto};
     use session::build_session;
+    use session::search_paths::SearchPath;
     use std::collections::{BTreeMap, BTreeSet};
     use std::iter::FromIterator;
     use std::path::PathBuf;
@@ -2790,48 +2791,48 @@
 
         // Reference
         v1.search_paths
-            .add_path("native=abc", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("native=abc", super::ErrorOutputType::Json(false)));
         v1.search_paths
-            .add_path("crate=def", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("crate=def", super::ErrorOutputType::Json(false)));
         v1.search_paths
-            .add_path("dependency=ghi", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("dependency=ghi", super::ErrorOutputType::Json(false)));
         v1.search_paths
-            .add_path("framework=jkl", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("framework=jkl", super::ErrorOutputType::Json(false)));
         v1.search_paths
-            .add_path("all=mno", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("all=mno", super::ErrorOutputType::Json(false)));
 
         v2.search_paths
-            .add_path("native=abc", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("native=abc", super::ErrorOutputType::Json(false)));
         v2.search_paths
-            .add_path("dependency=ghi", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("dependency=ghi", super::ErrorOutputType::Json(false)));
         v2.search_paths
-            .add_path("crate=def", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("crate=def", super::ErrorOutputType::Json(false)));
         v2.search_paths
-            .add_path("framework=jkl", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("framework=jkl", super::ErrorOutputType::Json(false)));
         v2.search_paths
-            .add_path("all=mno", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("all=mno", super::ErrorOutputType::Json(false)));
 
         v3.search_paths
-            .add_path("crate=def", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("crate=def", super::ErrorOutputType::Json(false)));
         v3.search_paths
-            .add_path("framework=jkl", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("framework=jkl", super::ErrorOutputType::Json(false)));
         v3.search_paths
-            .add_path("native=abc", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("native=abc", super::ErrorOutputType::Json(false)));
         v3.search_paths
-            .add_path("dependency=ghi", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("dependency=ghi", super::ErrorOutputType::Json(false)));
         v3.search_paths
-            .add_path("all=mno", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("all=mno", super::ErrorOutputType::Json(false)));
 
         v4.search_paths
-            .add_path("all=mno", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("all=mno", super::ErrorOutputType::Json(false)));
         v4.search_paths
-            .add_path("native=abc", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("native=abc", super::ErrorOutputType::Json(false)));
         v4.search_paths
-            .add_path("crate=def", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("crate=def", super::ErrorOutputType::Json(false)));
         v4.search_paths
-            .add_path("dependency=ghi", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("dependency=ghi", super::ErrorOutputType::Json(false)));
         v4.search_paths
-            .add_path("framework=jkl", super::ErrorOutputType::Json(false));
+            .push(SearchPath::from_cli_opt("framework=jkl", super::ErrorOutputType::Json(false)));
 
         assert!(v1.dep_tracking_hash() == v2.dep_tracking_hash());
         assert!(v1.dep_tracking_hash() == v3.dep_tracking_hash());
diff --git a/src/librustc/session/filesearch.rs b/src/librustc/session/filesearch.rs
index 8159c65..c204556 100644
--- a/src/librustc/session/filesearch.rs
+++ b/src/librustc/session/filesearch.rs
@@ -12,13 +12,12 @@
 
 pub use self::FileMatch::*;
 
-use rustc_data_structures::fx::FxHashSet;
 use std::borrow::Cow;
 use std::env;
 use std::fs;
 use std::path::{Path, PathBuf};
 
-use session::search_paths::{SearchPaths, PathKind};
+use session::search_paths::{SearchPath, PathKind};
 use rustc_fs_util::fix_windows_verbatim_for_gcc;
 
 #[derive(Copy, Clone)]
@@ -30,31 +29,19 @@
 // A module for searching for libraries
 
 pub struct FileSearch<'a> {
-    pub sysroot: &'a Path,
-    pub search_paths: &'a SearchPaths,
-    pub triple: &'a str,
-    pub kind: PathKind,
+    sysroot: &'a Path,
+    triple: &'a str,
+    search_paths: &'a [SearchPath],
+    tlib_path: &'a SearchPath,
+    kind: PathKind,
 }
 
 impl<'a> FileSearch<'a> {
-    pub fn for_each_lib_search_path<F>(&self, mut f: F) where
-        F: FnMut(&Path, PathKind)
-    {
-        let mut visited_dirs = FxHashSet::default();
-        visited_dirs.reserve(self.search_paths.paths.len() + 1);
-        for (path, kind) in self.search_paths.iter(self.kind) {
-            f(path, kind);
-            visited_dirs.insert(path.to_path_buf());
-        }
-
-        debug!("filesearch: searching lib path");
-        let tlib_path = make_target_lib_path(self.sysroot,
-                                             self.triple);
-        if !visited_dirs.contains(&tlib_path) {
-            f(&tlib_path, PathKind::All);
-        }
-
-        visited_dirs.insert(tlib_path);
+    pub fn search_paths(&self) -> impl Iterator<Item = &'a SearchPath> {
+        let kind = self.kind;
+        self.search_paths.iter()
+            .filter(move |sp| sp.kind.matches(kind))
+            .chain(std::iter::once(self.tlib_path))
     }
 
     pub fn get_lib_path(&self) -> PathBuf {
@@ -64,14 +51,8 @@
     pub fn search<F>(&self, mut pick: F)
         where F: FnMut(&Path, PathKind) -> FileMatch
     {
-        self.for_each_lib_search_path(|lib_search_path, kind| {
-            debug!("searching {}", lib_search_path.display());
-            let files = match fs::read_dir(lib_search_path) {
-                Ok(files) => files,
-                Err(..) => return,
-            };
-            let files = files.filter_map(|p| p.ok().map(|s| s.path()))
-                             .collect::<Vec<_>>();
+        for search_path in self.search_paths() {
+            debug!("searching {}", search_path.dir.display());
             fn is_rlib(p: &Path) -> bool {
                 p.extension() == Some("rlib".as_ref())
             }
@@ -79,11 +60,11 @@
             // an rlib and a dylib we only read one of the files of
             // metadata, so in the name of speed, bring all rlib files to
             // the front of the search list.
-            let files1 = files.iter().filter(|p| is_rlib(p));
-            let files2 = files.iter().filter(|p| !is_rlib(p));
+            let files1 = search_path.files.iter().filter(|p| is_rlib(p));
+            let files2 = search_path.files.iter().filter(|p| !is_rlib(p));
             for path in files1.chain(files2) {
                 debug!("testing {}", path.display());
-                let maybe_picked = pick(path, kind);
+                let maybe_picked = pick(path, search_path.kind);
                 match maybe_picked {
                     FileMatches => {
                         debug!("picked {}", path.display());
@@ -93,29 +74,30 @@
                     }
                 }
             }
-        });
+        }
     }
 
     pub fn new(sysroot: &'a Path,
                triple: &'a str,
-               search_paths: &'a SearchPaths,
-               kind: PathKind) -> FileSearch<'a> {
+               search_paths: &'a Vec<SearchPath>,
+               tlib_path: &'a SearchPath,
+               kind: PathKind)
+               -> FileSearch<'a> {
         debug!("using sysroot = {}, triple = {}", sysroot.display(), triple);
         FileSearch {
             sysroot,
-            search_paths,
             triple,
+            search_paths,
+            tlib_path,
             kind,
         }
     }
 
-    // Returns a list of directories where target-specific dylibs might be located.
-    pub fn get_dylib_search_paths(&self) -> Vec<PathBuf> {
-        let mut paths = Vec::new();
-        self.for_each_lib_search_path(|lib_search_path, _| {
-            paths.push(lib_search_path.to_path_buf());
-        });
-        paths
+    // Returns just the directories within the search paths.
+    pub fn search_path_dirs(&self) -> Vec<PathBuf> {
+        self.search_paths()
+            .map(|sp| sp.dir.to_path_buf())
+            .collect()
     }
 
     // Returns a list of directories where target-specific tool binaries are located.
@@ -138,8 +120,7 @@
     p
 }
 
-fn make_target_lib_path(sysroot: &Path,
-                        target_triple: &str) -> PathBuf {
+pub fn make_target_lib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
     sysroot.join(&relative_target_lib_path(sysroot, target_triple))
 }
 
diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index d1dd745..12b5646 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -19,8 +19,8 @@
 use lint::builtin::BuiltinLintDiagnostics;
 use middle::allocator::AllocatorKind;
 use middle::dependency_format;
-use session::search_paths::PathKind;
 use session::config::{OutputType, Lto};
+use session::search_paths::{PathKind, SearchPath};
 use util::nodemap::{FxHashMap, FxHashSet};
 use util::common::{duration_to_secs_str, ErrorReported};
 use util::common::ProfileQueriesMsg;
@@ -48,7 +48,7 @@
 use std::env;
 use std::fmt;
 use std::io::Write;
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 use std::time::Duration;
 use std::sync::mpsc;
 use std::sync::atomic::{AtomicUsize, Ordering};
@@ -64,12 +64,15 @@
     pub target: config::Config,
     pub host: Target,
     pub opts: config::Options,
+    pub host_tlib_path: SearchPath,
+    /// This is `None` if the host and target are the same.
+    pub target_tlib_path: Option<SearchPath>,
     pub parse_sess: ParseSess,
     /// For a library crate, this is always none
     pub entry_fn: Once<Option<(NodeId, Span, config::EntryFnType)>>,
     pub plugin_registrar_fn: Once<Option<ast::NodeId>>,
     pub proc_macro_decls_static: Once<Option<ast::NodeId>>,
-    pub default_sysroot: Option<PathBuf>,
+    pub sysroot: PathBuf,
     /// The name of the root source file of the crate, in the local file system.
     /// `None` means that there is no source file.
     pub local_crate_source_file: Option<PathBuf>,
@@ -694,27 +697,22 @@
         )
     }
 
-    pub fn sysroot<'a>(&'a self) -> &'a Path {
-        match self.opts.maybe_sysroot {
-            Some(ref sysroot) => sysroot,
-            None => self.default_sysroot
-                        .as_ref()
-                        .expect("missing sysroot and default_sysroot in Session"),
-        }
-    }
     pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
         filesearch::FileSearch::new(
-            self.sysroot(),
+            &self.sysroot,
             self.opts.target_triple.triple(),
             &self.opts.search_paths,
+            // target_tlib_path==None means it's the same as host_tlib_path.
+            self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
             kind,
         )
     }
     pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
         filesearch::FileSearch::new(
-            self.sysroot(),
+            &self.sysroot,
             config::host_triple(),
             &self.opts.search_paths,
+            &self.host_tlib_path,
             kind,
         )
     }
@@ -1109,9 +1107,18 @@
     let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
 
     let p_s = parse::ParseSess::with_span_handler(span_diagnostic, source_map);
-    let default_sysroot = match sopts.maybe_sysroot {
-        Some(_) => None,
-        None => Some(filesearch::get_or_default_sysroot()),
+    let sysroot = match &sopts.maybe_sysroot {
+        Some(sysroot) => sysroot.clone(),
+        None => filesearch::get_or_default_sysroot(),
+    };
+
+    let host_triple = config::host_triple();
+    let target_triple = sopts.target_triple.triple();
+    let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
+    let target_tlib_path = if host_triple == target_triple {
+        None
+    } else {
+        Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
     };
 
     let file_path_mapping = sopts.file_path_mapping();
@@ -1142,12 +1149,14 @@
         target: target_cfg,
         host,
         opts: sopts,
+        host_tlib_path,
+        target_tlib_path,
         parse_sess: p_s,
         // For a library crate, this is always none
         entry_fn: Once::new(),
         plugin_registrar_fn: Once::new(),
         proc_macro_decls_static: Once::new(),
-        default_sysroot,
+        sysroot,
         local_crate_source_file,
         working_dir,
         lint_store: RwLock::new(lint::LintStore::new()),
diff --git a/src/librustc/session/search_paths.rs b/src/librustc/session/search_paths.rs
index 6b0a8a0..5c44a07 100644
--- a/src/librustc/session/search_paths.rs
+++ b/src/librustc/session/search_paths.rs
@@ -8,18 +8,15 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::slice;
 use std::path::{Path, PathBuf};
 use session::{early_error, config};
+use session::filesearch::make_target_lib_path;
 
 #[derive(Clone, Debug)]
-pub struct SearchPaths {
-    crate paths: Vec<(PathKind, PathBuf)>,
-}
-
-pub struct Iter<'a> {
-    kind: PathKind,
-    iter: slice::Iter<'a, (PathKind, PathBuf)>,
+pub struct SearchPath {
+    pub kind: PathKind,
+    pub dir: PathBuf,
+    pub files: Vec<PathBuf>,
 }
 
 #[derive(Eq, PartialEq, Clone, Copy, Debug, PartialOrd, Ord, Hash)]
@@ -32,12 +29,17 @@
     All,
 }
 
-impl SearchPaths {
-    pub fn new() -> SearchPaths {
-        SearchPaths { paths: Vec::new() }
+impl PathKind {
+    pub fn matches(&self, kind: PathKind) -> bool {
+        match (self, kind) {
+            (PathKind::All, _) | (_, PathKind::All) => true,
+            _ => *self == kind,
+        }
     }
+}
 
-    pub fn add_path(&mut self, path: &str, output: config::ErrorOutputType) {
+impl SearchPath {
+    pub fn from_cli_opt(path: &str, output: config::ErrorOutputType) -> Self {
         let (kind, path) = if path.starts_with("native=") {
             (PathKind::Native, &path["native=".len()..])
         } else if path.starts_with("crate=") {
@@ -54,34 +56,28 @@
         if path.is_empty() {
             early_error(output, "empty search path given via `-L`");
         }
-        self.paths.push((kind, PathBuf::from(path)));
+
+        let dir = PathBuf::from(path);
+        Self::new(kind, dir)
     }
 
-    pub fn iter(&self, kind: PathKind) -> Iter<'_> {
-        Iter { kind: kind, iter: self.paths.iter() }
+    pub fn from_sysroot_and_triple(sysroot: &Path, triple: &str) -> Self {
+        Self::new(PathKind::All, make_target_lib_path(sysroot, triple))
     }
-}
 
-impl<'a> Iterator for Iter<'a> {
-    type Item = (&'a Path, PathKind);
-
-    fn next(&mut self) -> Option<(&'a Path, PathKind)> {
-        loop {
-            match *self.iter.next()? {
-                (kind, ref p) if self.kind == PathKind::All ||
-                                  kind == PathKind::All ||
-                                  kind == self.kind => {
-                    return Some((p, kind))
-                }
-                _ => {}
+    fn new(kind: PathKind, dir: PathBuf) -> Self {
+        // Get the files within the directory.
+        let files = match std::fs::read_dir(&dir) {
+            Ok(files) => {
+                files.filter_map(|p| {
+                    p.ok().map(|s| s.path())
+                })
+                .collect::<Vec<_>>()
             }
-        }
-    }
+            Err(..) => vec![],
+        };
 
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        // This iterator will never return more elements than the base iterator;
-        // but it can ignore all the remaining elements.
-        let (_, upper) = self.iter.size_hint();
-        (0, upper)
+        SearchPath { kind, dir, files }
     }
 }
+
diff --git a/src/librustc/traits/specialize/specialization_graph.rs b/src/librustc/traits/specialize/specialization_graph.rs
index 22221e0..b0ca2f6 100644
--- a/src/librustc/traits/specialize/specialization_graph.rs
+++ b/src/librustc/traits/specialize/specialization_graph.rs
@@ -132,10 +132,12 @@
             simplified_self,
         );
 
-        for possible_sibling in match simplified_self {
-            Some(sty) => self.filtered(sty),
-            None => self.iter(),
-        } {
+        let possible_siblings = match simplified_self {
+            Some(sty) => PotentialSiblings::Filtered(self.filtered(sty)),
+            None => PotentialSiblings::Unfiltered(self.iter()),
+        };
+
+        for possible_sibling in possible_siblings {
             debug!(
                 "insert: impl_def_id={:?}, simplified_self={:?}, possible_sibling={:?}",
                 impl_def_id,
@@ -222,14 +224,37 @@
         Ok(Inserted::BecameNewSibling(last_lint))
     }
 
-    fn iter(&mut self) -> Box<dyn Iterator<Item = DefId> + '_> {
+    fn iter(&mut self) -> impl Iterator<Item = DefId> + '_ {
         let nonblanket = self.nonblanket_impls.iter_mut().flat_map(|(_, v)| v.iter());
-        Box::new(self.blanket_impls.iter().chain(nonblanket).cloned())
+        self.blanket_impls.iter().chain(nonblanket).cloned()
     }
 
-    fn filtered(&mut self, sty: SimplifiedType) -> Box<dyn Iterator<Item = DefId> + '_> {
+    fn filtered(&mut self, sty: SimplifiedType) -> impl Iterator<Item = DefId> + '_ {
         let nonblanket = self.nonblanket_impls.entry(sty).or_default().iter();
-        Box::new(self.blanket_impls.iter().chain(nonblanket).cloned())
+        self.blanket_impls.iter().chain(nonblanket).cloned()
+    }
+}
+
+// A custom iterator used by Children::insert
+enum PotentialSiblings<I, J>
+    where I: Iterator<Item = DefId>,
+          J: Iterator<Item = DefId>
+{
+    Unfiltered(I),
+    Filtered(J)
+}
+
+impl<I, J> Iterator for PotentialSiblings<I, J>
+    where I: Iterator<Item = DefId>,
+          J: Iterator<Item = DefId>
+{
+    type Item = DefId;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match *self {
+            PotentialSiblings::Unfiltered(ref mut iter) => iter.next(),
+            PotentialSiblings::Filtered(ref mut iter) => iter.next()
+        }
     }
 }
 
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index a3db3a0..e27d734 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -946,7 +946,7 @@
     /// Stores the value of constants (and deduplicates the actual memory)
     allocation_interner: Lock<FxHashMap<&'tcx Allocation, ()>>,
 
-    pub alloc_map: Lock<interpret::AllocMap<'tcx, &'tcx Allocation>>,
+    pub alloc_map: Lock<interpret::AllocMap<'tcx>>,
 
     layout_interner: Lock<FxHashMap<&'tcx LayoutDetails, ()>>,
 
diff --git a/src/librustc/util/profiling.rs b/src/librustc/util/profiling.rs
index 1e648c4..c2bfa62 100644
--- a/src/librustc/util/profiling.rs
+++ b/src/librustc/util/profiling.rs
@@ -62,11 +62,15 @@
             }
 
             fn print(&self, lock: &mut StderrLock<'_>) {
-                writeln!(lock, "| Phase            | Time (ms)      | Queries        | Hits (%) |")
+                writeln!(lock, "| Phase            | Time (ms)      \
+                                | Time (%) | Queries        | Hits (%)")
                     .unwrap();
-                writeln!(lock, "| ---------------- | -------------- | -------------- | -------- |")
+                writeln!(lock, "| ---------------- | -------------- \
+                                | -------- | -------------- | --------")
                     .unwrap();
 
+                let total_time = ($(self.times.$name + )* 0) as f32;
+
                 $(
                     let (hits, total) = self.query_counts.$name;
                     let (hits, total) = if total > 0 {
@@ -78,11 +82,12 @@
 
                     writeln!(
                         lock,
-                        "| {0: <16} | {1: <14} | {2: <14} | {3: <8} |",
+                        "| {0: <16} | {1: <14} | {2: <8.2} | {3: <14} | {4: <8}",
                         stringify!($name),
                         self.times.$name / 1_000_000,
+                        ((self.times.$name as f32) / total_time) * 100.0,
                         total,
-                        hits
+                        hits,
                     ).unwrap();
                 )*
             }
diff --git a/src/librustc_asan/Cargo.toml b/src/librustc_asan/Cargo.toml
index 734564c..836caf2 100644
--- a/src/librustc_asan/Cargo.toml
+++ b/src/librustc_asan/Cargo.toml
@@ -16,4 +16,4 @@
 [dependencies]
 alloc = { path = "../liballoc" }
 core = { path = "../libcore" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+compiler_builtins = "0.1.0"
diff --git a/src/librustc_codegen_llvm/attributes.rs b/src/librustc_codegen_llvm/attributes.rs
index ffe5e12..48e0a3a 100644
--- a/src/librustc_codegen_llvm/attributes.rs
+++ b/src/librustc_codegen_llvm/attributes.rs
@@ -15,14 +15,16 @@
 use rustc::hir::def_id::{DefId, LOCAL_CRATE};
 use rustc::session::Session;
 use rustc::session::config::Sanitizer;
-use rustc::ty::TyCtxt;
+use rustc::ty::{self, TyCtxt, PolyFnSig};
 use rustc::ty::layout::HasTyCtxt;
 use rustc::ty::query::Providers;
+use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_data_structures::sync::Lrc;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_target::spec::PanicStrategy;
 use rustc_codegen_ssa::traits::*;
 
+use abi::Abi;
 use attributes;
 use llvm::{self, Attribute};
 use llvm::AttributePlace::Function;
@@ -60,7 +62,7 @@
 
 /// Tell LLVM whether the function can or cannot unwind.
 #[inline]
-pub fn unwind(val: &'ll Value, can_unwind: bool) {
+fn unwind(val: &'ll Value, can_unwind: bool) {
     Attribute::NoUnwind.toggle_llfn(Function, val, !can_unwind);
 }
 
@@ -129,8 +131,7 @@
 }
 
 pub fn apply_target_cpu_attr(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
-    let cpu = llvm_util::target_cpu(cx.tcx.sess);
-    let target_cpu = CString::new(cpu).unwrap();
+    let target_cpu = SmallCStr::new(llvm_util::target_cpu(cx.tcx.sess));
     llvm::AddFunctionAttrStringValue(
             llfn,
             llvm::AttributePlace::Function,
@@ -150,9 +151,10 @@
 /// Composite function which sets LLVM attributes for function depending on its AST (`#[attribute]`)
 /// attributes.
 pub fn from_fn_attrs(
-    cx: &CodegenCx<'ll, '_>,
+    cx: &CodegenCx<'ll, 'tcx>,
     llfn: &'ll Value,
     id: Option<DefId>,
+    sig: PolyFnSig<'tcx>,
 ) {
     let codegen_fn_attrs = id.map(|id| cx.tcx.codegen_fn_attrs(id))
         .unwrap_or_else(|| CodegenFnAttrs::new());
@@ -194,37 +196,42 @@
             llvm::AttributePlace::ReturnValue, llfn);
     }
 
-    let can_unwind = if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::UNWIND) {
-        Some(true)
+    unwind(llfn, if cx.tcx.sess.panic_strategy() != PanicStrategy::Unwind {
+        // In panic=abort mode we assume nothing can unwind anywhere, so
+        // optimize based on this!
+        false
+    } else if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::UNWIND) {
+        // If a specific #[unwind] attribute is present, use that
+        true
     } else if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_ALLOCATOR_NOUNWIND) {
-        Some(false)
-
-    // Perhaps questionable, but we assume that anything defined
-    // *in Rust code* may unwind. Foreign items like `extern "C" {
-    // fn foo(); }` are assumed not to unwind **unless** they have
-    // a `#[unwind]` attribute.
-    } else if id.map(|id| !cx.tcx.is_foreign_item(id)).unwrap_or(false) {
-        Some(true)
-    } else {
-        None
-    };
-
-    match can_unwind {
-        Some(false) => attributes::unwind(llfn, false),
-        Some(true) if cx.tcx.sess.panic_strategy() == PanicStrategy::Unwind => {
-            attributes::unwind(llfn, true);
+        // Special attribute for allocator functions, which can't unwind
+        false
+    } else if let Some(id) = id {
+        let sig = cx.tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
+        if cx.tcx.is_foreign_item(id) {
+            // Foreign items like `extern "C" { fn foo(); }` are assumed not to
+            // unwind
+            false
+        } else if sig.abi != Abi::Rust && sig.abi != Abi::RustCall {
+            // Any items defined in Rust that *don't* have the `extern` ABI are
+            // defined to not unwind. We insert shims to abort if an unwind
+            // happens to enforce this.
+            false
+        } else {
+            // Anything else defined in Rust is assumed that it can possibly
+            // unwind
+            true
         }
-        Some(true) | None => {}
-    }
+    } else {
+        // assume this can possibly unwind, avoiding the application of a
+        // `nounwind` attribute below.
+        true
+    });
 
     // Always annotate functions with the target-cpu they are compiled for.
     // Without this, ThinLTO won't inline Rust functions into Clang generated
     // functions (because Clang annotates functions this way too).
-    // NOTE: For now we just apply this if -Zcross-lang-lto is specified, since
-    //       it introduce a little overhead and isn't really necessary otherwise.
-    if cx.tcx.sess.opts.debugging_opts.cross_lang_lto.enabled() {
-        apply_target_cpu_attr(cx, llfn);
-    }
+    apply_target_cpu_attr(cx, llfn);
 
     let features = llvm_target_features(cx.tcx.sess)
         .map(|s| s.to_string())
diff --git a/src/librustc_codegen_llvm/back/link.rs b/src/librustc_codegen_llvm/back/link.rs
index 9e100a1..f1c0464 100644
--- a/src/librustc_codegen_llvm/back/link.rs
+++ b/src/librustc_codegen_llvm/back/link.rs
@@ -212,12 +212,7 @@
 }
 
 fn archive_search_paths(sess: &Session) -> Vec<PathBuf> {
-    let mut search = Vec::new();
-    sess.target_filesearch(PathKind::Native).for_each_lib_search_path(|path, _| {
-        search.push(path.to_path_buf());
-    });
-
-    search
+    sess.target_filesearch(PathKind::Native).search_path_dirs()
 }
 
 fn archive_config<'a>(sess: &'a Session,
@@ -1024,11 +1019,10 @@
     // where extern libraries might live, based on the
     // addl_lib_search_paths
     if sess.opts.cg.rpath {
-        let sysroot = sess.sysroot();
         let target_triple = sess.opts.target_triple.triple();
         let mut get_install_prefix_lib_path = || {
             let install_prefix = option_env!("CFG_PREFIX").expect("CFG_PREFIX");
-            let tlib = filesearch::relative_target_lib_path(sysroot, target_triple);
+            let tlib = filesearch::relative_target_lib_path(&sess.sysroot, target_triple);
             let mut path = PathBuf::from(install_prefix);
             path.push(&tlib);
 
@@ -1068,12 +1062,13 @@
 fn add_local_native_libraries(cmd: &mut dyn Linker,
                               sess: &Session,
                               codegen_results: &CodegenResults) {
-    sess.target_filesearch(PathKind::All).for_each_lib_search_path(|path, k| {
-        match k {
-            PathKind::Framework => { cmd.framework_path(path); }
-            _ => { cmd.include_path(&fix_windows_verbatim_for_gcc(path)); }
+    let filesearch = sess.target_filesearch(PathKind::All);
+    for search_path in filesearch.search_paths() {
+        match search_path.kind {
+            PathKind::Framework => { cmd.framework_path(&search_path.dir); }
+            _ => { cmd.include_path(&fix_windows_verbatim_for_gcc(&search_path.dir)); }
         }
-    });
+    }
 
     let relevant_libs = codegen_results.crate_info.used_libraries.iter().filter(|l| {
         relevant_lib(sess, l)
diff --git a/src/librustc_codegen_llvm/callee.rs b/src/librustc_codegen_llvm/callee.rs
index f13eeb6..87185a2 100644
--- a/src/librustc_codegen_llvm/callee.rs
+++ b/src/librustc_codegen_llvm/callee.rs
@@ -94,7 +94,7 @@
         if instance.def.is_inline(tcx) {
             attributes::inline(cx, llfn, attributes::InlineAttr::Hint);
         }
-        attributes::from_fn_attrs(cx, llfn, Some(instance.def.def_id()));
+        attributes::from_fn_attrs(cx, llfn, Some(instance.def.def_id()), sig);
 
         let instance_def_id = instance.def_id();
 
diff --git a/src/librustc_codegen_llvm/common.rs b/src/librustc_codegen_llvm/common.rs
index 55f286e..ad14ca7 100644
--- a/src/librustc_codegen_llvm/common.rs
+++ b/src/librustc_codegen_llvm/common.rs
@@ -21,7 +21,7 @@
 use rustc_codegen_ssa::traits::*;
 
 use rustc::ty::layout::{HasDataLayout, LayoutOf, self, TyLayout, Size};
-use rustc::mir::interpret::{Scalar, AllocType, Allocation};
+use rustc::mir::interpret::{Scalar, AllocKind, Allocation};
 use consts::const_alloc_to_llvm;
 use rustc_codegen_ssa::mir::place::PlaceRef;
 
@@ -316,9 +316,9 @@
                 }
             },
             Scalar::Ptr(ptr) => {
-                let alloc_type = self.tcx.alloc_map.lock().get(ptr.alloc_id);
-                let base_addr = match alloc_type {
-                    Some(AllocType::Memory(alloc)) => {
+                let alloc_kind = self.tcx.alloc_map.lock().get(ptr.alloc_id);
+                let base_addr = match alloc_kind {
+                    Some(AllocKind::Memory(alloc)) => {
                         let init = const_alloc_to_llvm(self, alloc);
                         if alloc.mutability == Mutability::Mutable {
                             self.static_addr_of_mut(init, alloc.align, None)
@@ -326,10 +326,10 @@
                             self.static_addr_of(init, alloc.align, None)
                         }
                     }
-                    Some(AllocType::Function(fn_instance)) => {
+                    Some(AllocKind::Function(fn_instance)) => {
                         self.get_fn(fn_instance)
                     }
-                    Some(AllocType::Static(def_id)) => {
+                    Some(AllocKind::Static(def_id)) => {
                         assert!(self.tcx.is_static(def_id).is_some());
                         self.get_static(def_id)
                     }
diff --git a/src/librustc_codegen_llvm/context.rs b/src/librustc_codegen_llvm/context.rs
index 6c90937..0bd6146 100644
--- a/src/librustc_codegen_llvm/context.rs
+++ b/src/librustc_codegen_llvm/context.rs
@@ -409,7 +409,6 @@
         ));
 
         let llfn = self.declare_fn("rust_eh_unwind_resume", sig);
-        attributes::unwind(llfn, true);
         attributes::apply_target_cpu_attr(self, llfn);
         unwresume.set(Some(llfn));
         llfn
diff --git a/src/librustc_codegen_llvm/declare.rs b/src/librustc_codegen_llvm/declare.rs
index c23aab4..2964f2e 100644
--- a/src/librustc_codegen_llvm/declare.rs
+++ b/src/librustc_codegen_llvm/declare.rs
@@ -26,8 +26,7 @@
 use rustc::ty::layout::LayoutOf;
 use rustc::session::config::Sanitizer;
 use rustc_data_structures::small_c_str::SmallCStr;
-use rustc_target::spec::PanicStrategy;
-use abi::{Abi, FnType, FnTypeExt};
+use abi::{FnType, FnTypeExt};
 use attributes;
 use context::CodegenCx;
 use type_::Type;
@@ -86,10 +85,6 @@
         _ => {},
     }
 
-    if cx.tcx.sess.panic_strategy() != PanicStrategy::Unwind {
-        attributes::unwind(llfn, false);
-    }
-
     attributes::non_lazy_bind(cx.sess(), llfn);
 
     llfn
@@ -132,10 +127,6 @@
             llvm::Attribute::NoReturn.apply_llfn(Function, llfn);
         }
 
-        if sig.abi != Abi::Rust && sig.abi != Abi::RustCall {
-            attributes::unwind(llfn, false);
-        }
-
         fty.apply_attrs_llfn(llfn);
 
         llfn
diff --git a/src/librustc_codegen_llvm/intrinsic.rs b/src/librustc_codegen_llvm/intrinsic.rs
index 59608b1..8b26ada 100644
--- a/src/librustc_codegen_llvm/intrinsic.rs
+++ b/src/librustc_codegen_llvm/intrinsic.rs
@@ -1081,7 +1081,7 @@
         Abi::Rust
     ));
     let llfn = cx.define_internal_fn(name, rust_fn_sig);
-    attributes::from_fn_attrs(cx, llfn, None);
+    attributes::from_fn_attrs(cx, llfn, None, rust_fn_sig);
     let bx = Builder::new_block(cx, llfn, "entry-block");
     codegen(bx);
     llfn
@@ -1171,6 +1171,27 @@
     );
     let arg_tys = sig.inputs();
 
+    if name == "simd_select_bitmask" {
+        let in_ty = arg_tys[0];
+        let m_len = match in_ty.sty {
+            // Note that this `.unwrap()` crashes for isize/usize, that's sort
+            // of intentional as there's not currently a use case for that.
+            ty::Int(i) => i.bit_width().unwrap(),
+            ty::Uint(i) => i.bit_width().unwrap(),
+            _ => return_error!("`{}` is not an integral type", in_ty),
+        };
+        require_simd!(arg_tys[1], "argument");
+        let v_len = arg_tys[1].simd_size(tcx);
+        require!(m_len == v_len,
+                 "mismatched lengths: mask length `{}` != other vector length `{}`",
+                 m_len, v_len
+        );
+        let i1 = bx.type_i1();
+        let i1xn = bx.type_vector(i1, m_len as u64);
+        let m_i1s = bx.bitcast(args[0].immediate(), i1xn);
+        return Ok(bx.select(m_i1s, args[1].immediate(), args[2].immediate()));
+    }
+
     // every intrinsic takes a SIMD vector as its first argument
     require_simd!(arg_tys[0], "input");
     let in_ty = arg_tys[0];
diff --git a/src/librustc_codegen_llvm/llvm_util.rs b/src/librustc_codegen_llvm/llvm_util.rs
index fdb6373..12109ae 100644
--- a/src/librustc_codegen_llvm/llvm_util.rs
+++ b/src/librustc_codegen_llvm/llvm_util.rs
@@ -124,6 +124,7 @@
 ];
 
 const X86_WHITELIST: &[(&str, Option<&str>)] = &[
+    ("adx", Some("adx_target_feature")),
     ("aes", None),
     ("avx", None),
     ("avx2", None),
diff --git a/src/librustc_codegen_llvm/mono_item.rs b/src/librustc_codegen_llvm/mono_item.rs
index 1d5bcc4..9c69d7d 100644
--- a/src/librustc_codegen_llvm/mono_item.rs
+++ b/src/librustc_codegen_llvm/mono_item.rs
@@ -82,7 +82,12 @@
         if instance.def.is_inline(self.tcx) {
             attributes::inline(self, lldecl, attributes::InlineAttr::Hint);
         }
-        attributes::from_fn_attrs(self, lldecl, Some(instance.def.def_id()));
+        attributes::from_fn_attrs(
+            self,
+            lldecl,
+            Some(instance.def.def_id()),
+            mono_sig,
+        );
 
         self.instances.borrow_mut().insert(instance, lldecl);
     }
diff --git a/src/librustc_codegen_ssa/Cargo.toml b/src/librustc_codegen_ssa/Cargo.toml
index 7b1c7cf..5099449 100644
--- a/src/librustc_codegen_ssa/Cargo.toml
+++ b/src/librustc_codegen_ssa/Cargo.toml
@@ -16,7 +16,7 @@
 rustc-demangle = "0.1.4"
 memmap = "0.6"
 log = "0.4.5"
-libc = "0.2.43"
+libc = "0.2.44"
 jobserver = "0.1.11"
 
 serialize = { path = "../libserialize" }
diff --git a/src/librustc_codegen_ssa/back/link.rs b/src/librustc_codegen_ssa/back/link.rs
index 24a70dc..59102e0 100644
--- a/src/librustc_codegen_ssa/back/link.rs
+++ b/src/librustc_codegen_ssa/back/link.rs
@@ -192,11 +192,7 @@
 
     // linker and linker flavor specified via command line have precedence over what the target
     // specification specifies
-    if let Some(ret) = infer_from(
-        sess,
-        sess.opts.cg.linker.clone(),
-        sess.opts.debugging_opts.linker_flavor,
-    ) {
+    if let Some(ret) = infer_from(sess, sess.opts.cg.linker.clone(), sess.opts.cg.linker_flavor) {
         return ret;
     }
 
diff --git a/src/librustc_codegen_ssa/back/linker.rs b/src/librustc_codegen_ssa/back/linker.rs
index 2f92c42..4960c89 100644
--- a/src/librustc_codegen_ssa/back/linker.rs
+++ b/src/librustc_codegen_ssa/back/linker.rs
@@ -606,8 +606,7 @@
         self.cmd.arg("/DEBUG");
 
         // This will cause the Microsoft linker to embed .natvis info into the PDB file
-        let sysroot = self.sess.sysroot();
-        let natvis_dir_path = sysroot.join("lib\\rustlib\\etc");
+        let natvis_dir_path = self.sess.sysroot.join("lib\\rustlib\\etc");
         if let Ok(natvis_dir) = fs::read_dir(&natvis_dir_path) {
             // LLVM 5.0.0's lld-link frontend doesn't yet recognize, and chokes
             // on, the /NATVIS:... flags.  LLVM 6 (or earlier) should at worst ignore
diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index f2edcdc..b26d81b 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -975,7 +975,7 @@
         let mut old_path = OsString::new();
         if cfg!(windows) {
             old_path = env::var_os("PATH").unwrap_or(old_path);
-            let mut new_path = sess.host_filesearch(PathKind::All).get_dylib_search_paths();
+            let mut new_path = sess.host_filesearch(PathKind::All).search_path_dirs();
             for path in env::split_paths(&old_path) {
                 if !new_path.contains(&path) {
                     new_path.push(path);
diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs
index 39777e0..41c9b22 100644
--- a/src/librustc_driver/lib.rs
+++ b/src/librustc_driver/lib.rs
@@ -1042,7 +1042,7 @@
                     targets.sort();
                     println!("{}", targets.join("\n"));
                 },
-                Sysroot => println!("{}", sess.sysroot().display()),
+                Sysroot => println!("{}", sess.sysroot.display()),
                 TargetSpec => println!("{}", sess.target.target.to_json().pretty()),
                 FileNames | CrateName => {
                     let input = input.unwrap_or_else(||
diff --git a/src/librustc_errors/emitter.rs b/src/librustc_errors/emitter.rs
index ae9f6a5..7bd0f0f 100644
--- a/src/librustc_errors/emitter.rs
+++ b/src/librustc_errors/emitter.rs
@@ -1262,7 +1262,7 @@
 
                         // Do not underline the leading...
                         let start = part.snippet.len()
-                            .saturating_sub(part.snippet.trim_left().len());
+                            .saturating_sub(part.snippet.trim_start().len());
                         // ...or trailing spaces. Account for substitutions containing unicode
                         // characters.
                         let sub_len = part.snippet.trim().chars().fold(0, |acc, ch| {
diff --git a/src/librustc_lint/lib.rs b/src/librustc_lint/lib.rs
index b1e44ea..66364ff 100644
--- a/src/librustc_lint/lib.rs
+++ b/src/librustc_lint/lib.rs
@@ -376,7 +376,7 @@
     store.register_removed("resolve_trait_on_defaulted_unit",
         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
     store.register_removed("private_no_mangle_fns",
-        "no longer an warning, #[no_mangle] functions always exported");
+        "no longer a warning, #[no_mangle] functions always exported");
     store.register_removed("private_no_mangle_statics",
-        "no longer an warning, #[no_mangle] statics always exported");
+        "no longer a warning, #[no_mangle] statics always exported");
 }
diff --git a/src/librustc_lint/nonstandard_style.rs b/src/librustc_lint/nonstandard_style.rs
index 13be50e..e071c34 100644
--- a/src/librustc_lint/nonstandard_style.rs
+++ b/src/librustc_lint/nonstandard_style.rs
@@ -167,7 +167,7 @@
     fn to_snake_case(mut str: &str) -> String {
         let mut words = vec![];
         // Preserve leading underscores
-        str = str.trim_left_matches(|c: char| {
+        str = str.trim_start_matches(|c: char| {
             if c == '_' {
                 words.push(String::new());
                 true
@@ -199,7 +199,7 @@
             if ident.is_empty() {
                 return true;
             }
-            let ident = ident.trim_left_matches('\'');
+            let ident = ident.trim_start_matches('\'');
             let ident = ident.trim_matches('_');
 
             let mut allow_underscore = true;
diff --git a/src/librustc_llvm/build.rs b/src/librustc_llvm/build.rs
index 7d01ed5..ce48208 100644
--- a/src/librustc_llvm/build.rs
+++ b/src/librustc_llvm/build.rs
@@ -192,11 +192,11 @@
             // On MSVC llvm-config will print the full name to libraries, but
             // we're only interested in the name part
             let name = Path::new(lib).file_name().unwrap().to_str().unwrap();
-            name.trim_right_matches(".lib")
+            name.trim_end_matches(".lib")
         } else if lib.ends_with(".lib") {
             // Some MSVC libraries just come up with `.lib` tacked on, so chop
             // that off
-            lib.trim_right_matches(".lib")
+            lib.trim_end_matches(".lib")
         } else {
             continue;
         };
diff --git a/src/librustc_lsan/Cargo.toml b/src/librustc_lsan/Cargo.toml
index 2573825..a8e11df 100644
--- a/src/librustc_lsan/Cargo.toml
+++ b/src/librustc_lsan/Cargo.toml
@@ -16,4 +16,4 @@
 [dependencies]
 alloc = { path = "../liballoc" }
 core = { path = "../libcore" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+compiler_builtins = "0.1.0"
diff --git a/src/librustc_metadata/locator.rs b/src/librustc_metadata/locator.rs
index 1f298f6..f01ed9e 100644
--- a/src/librustc_metadata/locator.rs
+++ b/src/librustc_metadata/locator.rs
@@ -678,7 +678,7 @@
             // candidates are all canonicalized, so we canonicalize the sysroot
             // as well.
             if let Some((ref prev, _)) = ret {
-                let sysroot = self.sess.sysroot();
+                let sysroot = &self.sess.sysroot;
                 let sysroot = sysroot.canonicalize()
                                      .unwrap_or_else(|_| sysroot.to_path_buf());
                 if prev.starts_with(&sysroot) {
diff --git a/src/librustc_mir/borrow_check/move_errors.rs b/src/librustc_mir/borrow_check/move_errors.rs
index db60017..fb93c41 100644
--- a/src/librustc_mir/borrow_check/move_errors.rs
+++ b/src/librustc_mir/borrow_check/move_errors.rs
@@ -426,13 +426,13 @@
                     .span_to_snippet(pat_span)
                     .unwrap();
                 if pat_snippet.starts_with('&') {
-                    let pat_snippet = pat_snippet[1..].trim_left();
+                    let pat_snippet = pat_snippet[1..].trim_start();
                     let suggestion;
                     let to_remove;
                     if pat_snippet.starts_with("mut")
                         && pat_snippet["mut".len()..].starts_with(Pattern_White_Space)
                     {
-                        suggestion = pat_snippet["mut".len()..].trim_left();
+                        suggestion = pat_snippet["mut".len()..].trim_start();
                         to_remove = "&mut";
                     } else {
                         suggestion = pat_snippet;
diff --git a/src/librustc_mir/build/matches/simplify.rs b/src/librustc_mir/build/matches/simplify.rs
index cfea357..328b330 100644
--- a/src/librustc_mir/build/matches/simplify.rs
+++ b/src/librustc_mir/build/matches/simplify.rs
@@ -26,6 +26,10 @@
 use build::matches::{Ascription, Binding, MatchPair, Candidate};
 use hair::*;
 use rustc::mir::*;
+use rustc::ty;
+use rustc::ty::layout::{Integer, IntegerExt, Size};
+use syntax::attr::{SignedInt, UnsignedInt};
+use rustc::hir::RangeEnd;
 
 use std::mem;
 
@@ -62,6 +66,7 @@
                                  match_pair: MatchPair<'pat, 'tcx>,
                                  candidate: &mut Candidate<'pat, 'tcx>)
                                  -> Result<(), MatchPair<'pat, 'tcx>> {
+        let tcx = self.hir.tcx();
         match *match_pair.pattern.kind {
             PatternKind::AscribeUserType { ref subpattern, ref user_ty, user_ty_span } => {
                 candidate.ascriptions.push(Ascription {
@@ -104,7 +109,34 @@
                 Err(match_pair)
             }
 
-            PatternKind::Range { .. } => {
+            PatternKind::Range { lo, hi, ty, end } => {
+                let range = match ty.sty {
+                    ty::Char => {
+                        Some(('\u{0000}' as u128, '\u{10FFFF}' as u128, Size::from_bits(32)))
+                    }
+                    ty::Int(ity) => {
+                        // FIXME(49937): refactor these bit manipulations into interpret.
+                        let size = Integer::from_attr(&tcx, SignedInt(ity)).size();
+                        let min = 1u128 << (size.bits() - 1);
+                        let max = (1u128 << (size.bits() - 1)) - 1;
+                        Some((min, max, size))
+                    }
+                    ty::Uint(uty) => {
+                        // FIXME(49937): refactor these bit manipulations into interpret.
+                        let size = Integer::from_attr(&tcx, UnsignedInt(uty)).size();
+                        let max = !0u128 >> (128 - size.bits());
+                        Some((0, max, size))
+                    }
+                    _ => None,
+                };
+                if let Some((min, max, sz)) = range {
+                    if let (Some(lo), Some(hi)) = (lo.val.try_to_bits(sz), hi.val.try_to_bits(sz)) {
+                        if lo <= min && (hi > max || hi == max && end == RangeEnd::Included) {
+                            // Irrefutable pattern match.
+                            return Ok(());
+                        }
+                    }
+                }
                 Err(match_pair)
             }
 
diff --git a/src/librustc_mir/build/mod.rs b/src/librustc_mir/build/mod.rs
index b0601b3..ab52d9b 100644
--- a/src/librustc_mir/build/mod.rs
+++ b/src/librustc_mir/build/mod.rs
@@ -628,12 +628,7 @@
     // unwind anyway. Don't stop them.
     let attrs = &tcx.get_attrs(fn_def_id);
     match attr::find_unwind_attr(Some(tcx.sess.diagnostic()), attrs) {
-        None => {
-            // FIXME(rust-lang/rust#48251) -- Had to disable
-            // abort-on-panic for backwards compatibility reasons.
-            false
-        }
-
+        None => true,
         Some(UnwindAttr::Allowed) => false,
         Some(UnwindAttr::Aborts) => true,
     }
diff --git a/src/librustc_mir/hair/pattern/_match.rs b/src/librustc_mir/hair/pattern/_match.rs
index 4c77350..5cfcc16 100644
--- a/src/librustc_mir/hair/pattern/_match.rs
+++ b/src/librustc_mir/hair/pattern/_match.rs
@@ -178,11 +178,11 @@
 
 use rustc::hir::def_id::DefId;
 use rustc::hir::RangeEnd;
-use rustc::ty::{self, Ty, TyCtxt, TypeFoldable};
-use rustc::ty::layout::{Integer, IntegerExt, VariantIdx};
+use rustc::ty::{self, Ty, TyCtxt, TypeFoldable, Const};
+use rustc::ty::layout::{Integer, IntegerExt, VariantIdx, Size};
 
 use rustc::mir::Field;
-use rustc::mir::interpret::ConstValue;
+use rustc::mir::interpret::{ConstValue, Pointer, Scalar};
 use rustc::util::common::ErrorReported;
 
 use syntax::attr::{SignedInt, UnsignedInt};
@@ -200,14 +200,60 @@
 pub fn expand_pattern<'a, 'tcx>(cx: &MatchCheckCtxt<'a, 'tcx>, pat: Pattern<'tcx>)
                                 -> &'a Pattern<'tcx>
 {
-    cx.pattern_arena.alloc(LiteralExpander.fold_pattern(&pat))
+    cx.pattern_arena.alloc(LiteralExpander { tcx: cx.tcx }.fold_pattern(&pat))
 }
 
-struct LiteralExpander;
-impl<'tcx> PatternFolder<'tcx> for LiteralExpander {
+struct LiteralExpander<'a, 'tcx> {
+    tcx: TyCtxt<'a, 'tcx, 'tcx>
+}
+
+impl<'a, 'tcx> LiteralExpander<'a, 'tcx> {
+    /// Derefs `val` and potentially unsizes the value if `crty` is an array and `rty` a slice.
+    ///
+    /// `crty` and `rty` can differ because you can use array constants in the presence of slice
+    /// patterns. So the pattern may end up being a slice, but the constant is an array. We convert
+    /// the array to a slice in that case.
+    fn fold_const_value_deref(
+        &mut self,
+        val: ConstValue<'tcx>,
+        // the pattern's pointee type
+        rty: Ty<'tcx>,
+        // the constant's pointee type
+        crty: Ty<'tcx>,
+    ) -> ConstValue<'tcx> {
+        match (val, &crty.sty, &rty.sty) {
+            // the easy case, deref a reference
+            (ConstValue::Scalar(Scalar::Ptr(p)), x, y) if x == y => ConstValue::ByRef(
+                p.alloc_id,
+                self.tcx.alloc_map.lock().unwrap_memory(p.alloc_id),
+                p.offset,
+            ),
+            // unsize array to slice if pattern is array but match value or other patterns are slice
+            (ConstValue::Scalar(Scalar::Ptr(p)), ty::Array(t, n), ty::Slice(u)) => {
+                assert_eq!(t, u);
+                ConstValue::ScalarPair(
+                    Scalar::Ptr(p),
+                    n.val.try_to_scalar().unwrap(),
+                )
+            },
+            // fat pointers stay the same
+            (ConstValue::ScalarPair(..), _, _) => val,
+            // FIXME(oli-obk): this is reachable for `const FOO: &&&u32 = &&&42;` being used
+            _ => bug!("cannot deref {:#?}, {} -> {}", val, crty, rty),
+        }
+    }
+}
+
+impl<'a, 'tcx> PatternFolder<'tcx> for LiteralExpander<'a, 'tcx> {
     fn fold_pattern(&mut self, pat: &Pattern<'tcx>) -> Pattern<'tcx> {
         match (&pat.ty.sty, &*pat.kind) {
-            (&ty::Ref(_, rty, _), &PatternKind::Constant { ref value }) => {
+            (
+                &ty::Ref(_, rty, _),
+                &PatternKind::Constant { value: Const {
+                    val,
+                    ty: ty::TyS { sty: ty::Ref(_, crty, _), .. },
+                } },
+            ) => {
                 Pattern {
                     ty: pat.ty,
                     span: pat.span,
@@ -215,7 +261,11 @@
                         subpattern: Pattern {
                             ty: rty,
                             span: pat.span,
-                            kind: box PatternKind::Constant { value: value.clone() },
+                            kind: box PatternKind::Constant { value: Const::from_const_value(
+                                self.tcx,
+                                self.fold_const_value_deref(*val, rty, crty),
+                                rty,
+                            ) },
                         }
                     }
                 }
@@ -732,15 +782,17 @@
     for row in patterns {
         match *row.kind {
             PatternKind::Constant { value } => {
-                if let Some(ptr) = value.to_ptr() {
-                    let is_array_ptr = value.ty
-                        .builtin_deref(true)
-                        .and_then(|t| t.ty.builtin_index())
-                        .map_or(false, |t| t == cx.tcx.types.u8);
-                    if is_array_ptr {
-                        let alloc = cx.tcx.alloc_map.lock().unwrap_memory(ptr.alloc_id);
-                        max_fixed_len = cmp::max(max_fixed_len, alloc.bytes.len() as u64);
-                    }
+                // extract the length of an array/slice from a constant
+                match (value.val, &value.ty.sty) {
+                    (_, ty::Array(_, n)) => max_fixed_len = cmp::max(
+                        max_fixed_len,
+                        n.unwrap_usize(cx.tcx),
+                    ),
+                    (ConstValue::ScalarPair(_, n), ty::Slice(_)) => max_fixed_len = cmp::max(
+                        max_fixed_len,
+                        n.to_usize(&cx.tcx).unwrap(),
+                    ),
+                    _ => {},
                 }
             }
             PatternKind::Slice { ref prefix, slice: None, ref suffix } => {
@@ -1348,28 +1400,62 @@
     }
 }
 
-fn slice_pat_covered_by_constructor<'tcx>(
+// checks whether a constant is equal to a user-written slice pattern. Only supports byte slices,
+// meaning all other types will compare unequal and thus equal patterns often do not cause the
+// second pattern to lint about unreachable match arms.
+fn slice_pat_covered_by_const<'tcx>(
     tcx: TyCtxt<'_, 'tcx, '_>,
     _span: Span,
-    ctor: &Constructor,
+    const_val: &ty::Const<'tcx>,
     prefix: &[Pattern<'tcx>],
     slice: &Option<Pattern<'tcx>>,
     suffix: &[Pattern<'tcx>]
 ) -> Result<bool, ErrorReported> {
-    let data: &[u8] = match *ctor {
-        ConstantValue(const_val) => {
-            let val = match const_val.val {
-                ConstValue::Unevaluated(..) |
-                ConstValue::ByRef(..) => bug!("unexpected ConstValue: {:?}", const_val),
-                ConstValue::Scalar(val) | ConstValue::ScalarPair(val, _) => val,
-            };
-            if let Ok(ptr) = val.to_ptr() {
-                tcx.alloc_map.lock().unwrap_memory(ptr.alloc_id).bytes.as_ref()
-            } else {
-                bug!("unexpected non-ptr ConstantValue")
+    let data: &[u8] = match (const_val.val, &const_val.ty.sty) {
+        (ConstValue::ByRef(id, alloc, offset), ty::Array(t, n)) => {
+            if *t != tcx.types.u8 {
+                // FIXME(oli-obk): can't mix const patterns with slice patterns and get
+                // any sort of exhaustiveness/unreachable check yet
+                // This solely means that we don't lint about unreachable patterns, even if some
+                // are definitely unreachable.
+                return Ok(false);
             }
-        }
-        _ => bug!()
+            let ptr = Pointer::new(id, offset);
+            let n = n.assert_usize(tcx).unwrap();
+            alloc.get_bytes(&tcx, ptr, Size::from_bytes(n)).unwrap()
+        },
+        // a slice fat pointer to a zero length slice
+        (ConstValue::ScalarPair(Scalar::Bits { .. }, n), ty::Slice(t)) => {
+            if *t != tcx.types.u8 {
+                // FIXME(oli-obk): can't mix const patterns with slice patterns and get
+                // any sort of exhaustiveness/unreachable check yet
+                // This solely means that we don't lint about unreachable patterns, even if some
+                // are definitely unreachable.
+                return Ok(false);
+            }
+            assert_eq!(n.to_usize(&tcx).unwrap(), 0);
+            &[]
+        },
+        //
+        (ConstValue::ScalarPair(Scalar::Ptr(ptr), n), ty::Slice(t)) => {
+            if *t != tcx.types.u8 {
+                // FIXME(oli-obk): can't mix const patterns with slice patterns and get
+                // any sort of exhaustiveness/unreachable check yet
+                // This solely means that we don't lint about unreachable patterns, even if some
+                // are definitely unreachable.
+                return Ok(false);
+            }
+            let n = n.to_usize(&tcx).unwrap();
+            tcx.alloc_map
+                .lock()
+                .unwrap_memory(ptr.alloc_id)
+                .get_bytes(&tcx, ptr, Size::from_bytes(n))
+                .unwrap()
+        },
+        _ => bug!(
+            "slice_pat_covered_by_const: {:#?}, {:#?}, {:#?}, {:#?}",
+            const_val, prefix, slice, suffix,
+        ),
     };
 
     let pat_len = prefix.len() + suffix.len();
@@ -1675,22 +1761,23 @@
                     // necessarily point to memory, they are usually just integers. The only time
                     // they should be pointing to memory is when they are subslices of nonzero
                     // slices
-                    let (opt_ptr, n, ty) = match value.ty.builtin_deref(false).unwrap().ty.sty {
-                        ty::TyKind::Array(t, n) => (value.to_ptr(), n.unwrap_usize(cx.tcx), t),
-                        ty::TyKind::Slice(t) => {
-                            match value.val {
-                                ConstValue::ScalarPair(ptr, n) => (
-                                    ptr.to_ptr().ok(),
-                                    n.to_bits(cx.tcx.data_layout.pointer_size).unwrap() as u64,
-                                    t,
-                                ),
-                                _ => span_bug!(
-                                    pat.span,
-                                    "slice pattern constant must be scalar pair but is {:?}",
-                                    value,
-                                ),
-                            }
-                        },
+                    let (opt_ptr, n, ty) = match (value.val, &value.ty.sty) {
+                        (ConstValue::ByRef(id, alloc, offset), ty::TyKind::Array(t, n)) => (
+                            Some((
+                                Pointer::new(id, offset),
+                                alloc,
+                            )),
+                            n.unwrap_usize(cx.tcx),
+                            t,
+                        ),
+                        (ConstValue::ScalarPair(ptr, n), ty::TyKind::Slice(t)) => (
+                            ptr.to_ptr().ok().map(|ptr| (
+                                ptr,
+                                cx.tcx.alloc_map.lock().unwrap_memory(ptr.alloc_id),
+                            )),
+                            n.to_bits(cx.tcx.data_layout.pointer_size).unwrap() as u64,
+                            t,
+                        ),
                         _ => span_bug!(
                             pat.span,
                             "unexpected const-val {:?} with ctor {:?}",
@@ -1702,8 +1789,7 @@
                         // convert a constant slice/array pattern to a list of patterns.
                         match (n, opt_ptr) {
                             (0, _) => Some(SmallVec::new()),
-                            (_, Some(ptr)) => {
-                                let alloc = cx.tcx.alloc_map.lock().unwrap_memory(ptr.alloc_id);
+                            (_, Some((ptr, alloc))) => {
                                 let layout = cx.tcx.layout_of(cx.param_env.and(ty)).ok()?;
                                 (0..n).map(|i| {
                                     let ptr = ptr.offset(layout.size * i, &cx.tcx).ok()?;
@@ -1766,10 +1852,8 @@
                         None
                     }
                 }
-                ConstantValue(..) => {
-                    match slice_pat_covered_by_constructor(
-                        cx.tcx, pat.span, constructor, prefix, slice, suffix
-                            ) {
+                ConstantValue(cv) => {
+                    match slice_pat_covered_by_const(cx.tcx, pat.span, cv, prefix, slice, suffix) {
                         Ok(true) => Some(smallvec![]),
                         Ok(false) => None,
                         Err(ErrorReported) => None
diff --git a/src/librustc_mir/hair/pattern/mod.rs b/src/librustc_mir/hair/pattern/mod.rs
index d695a64..ddd6a70 100644
--- a/src/librustc_mir/hair/pattern/mod.rs
+++ b/src/librustc_mir/hair/pattern/mod.rs
@@ -1259,34 +1259,32 @@
         }
     }
 
-    if let ty::Ref(_, rty, _) = ty.value.sty {
-        if let ty::Str = rty.sty {
-            match (a.val, b.val) {
-                (
-                    ConstValue::ScalarPair(
-                        Scalar::Ptr(ptr_a),
-                        len_a,
-                    ),
-                    ConstValue::ScalarPair(
-                        Scalar::Ptr(ptr_b),
-                        len_b,
-                    ),
-                ) if ptr_a.offset.bytes() == 0 && ptr_b.offset.bytes() == 0 => {
-                    if let Ok(len_a) = len_a.to_bits(tcx.data_layout.pointer_size) {
-                        if let Ok(len_b) = len_b.to_bits(tcx.data_layout.pointer_size) {
-                            if len_a == len_b {
-                                let map = tcx.alloc_map.lock();
-                                let alloc_a = map.unwrap_memory(ptr_a.alloc_id);
-                                let alloc_b = map.unwrap_memory(ptr_b.alloc_id);
-                                if alloc_a.bytes.len() as u128 == len_a {
-                                    return from_bool(alloc_a == alloc_b);
-                                }
+    if let ty::Str = ty.value.sty {
+        match (a.val, b.val) {
+            (
+                ConstValue::ScalarPair(
+                    Scalar::Ptr(ptr_a),
+                    len_a,
+                ),
+                ConstValue::ScalarPair(
+                    Scalar::Ptr(ptr_b),
+                    len_b,
+                ),
+            ) if ptr_a.offset.bytes() == 0 && ptr_b.offset.bytes() == 0 => {
+                if let Ok(len_a) = len_a.to_bits(tcx.data_layout.pointer_size) {
+                    if let Ok(len_b) = len_b.to_bits(tcx.data_layout.pointer_size) {
+                        if len_a == len_b {
+                            let map = tcx.alloc_map.lock();
+                            let alloc_a = map.unwrap_memory(ptr_a.alloc_id);
+                            let alloc_b = map.unwrap_memory(ptr_b.alloc_id);
+                            if alloc_a.bytes.len() as u128 == len_a {
+                                return from_bool(alloc_a == alloc_b);
                             }
                         }
                     }
                 }
-                _ => (),
             }
+            _ => (),
         }
     }
 
diff --git a/src/librustc_mir/interpret/intrinsics.rs b/src/librustc_mir/interpret/intrinsics.rs
index bbee6e0..cbe2e25 100644
--- a/src/librustc_mir/interpret/intrinsics.rs
+++ b/src/librustc_mir/interpret/intrinsics.rs
@@ -103,7 +103,7 @@
                     if bits == 0 {
                         return err!(Intrinsic(format!("{} called on 0", intrinsic_name)));
                     }
-                    numeric_intrinsic(intrinsic_name.trim_right_matches("_nonzero"), bits, kind)?
+                    numeric_intrinsic(intrinsic_name.trim_end_matches("_nonzero"), bits, kind)?
                 } else {
                     numeric_intrinsic(intrinsic_name, bits, kind)?
                 };
diff --git a/src/librustc_mir/interpret/memory.rs b/src/librustc_mir/interpret/memory.rs
index e32abb9..420fe26 100644
--- a/src/librustc_mir/interpret/memory.rs
+++ b/src/librustc_mir/interpret/memory.rs
@@ -29,7 +29,7 @@
 
 use super::{
     Pointer, AllocId, Allocation, GlobalId, AllocationExtra,
-    EvalResult, Scalar, EvalErrorKind, AllocType, PointerArithmetic,
+    EvalResult, Scalar, EvalErrorKind, AllocKind, PointerArithmetic,
     Machine, AllocMap, MayLeak, ErrorHandled, InboundsCheck,
 };
 
@@ -204,12 +204,12 @@
             None => {
                 // Deallocating static memory -- always an error
                 return match self.tcx.alloc_map.lock().get(ptr.alloc_id) {
-                    Some(AllocType::Function(..)) => err!(DeallocatedWrongMemoryKind(
+                    Some(AllocKind::Function(..)) => err!(DeallocatedWrongMemoryKind(
                         "function".to_string(),
                         format!("{:?}", kind),
                     )),
-                    Some(AllocType::Static(..)) |
-                    Some(AllocType::Memory(..)) => err!(DeallocatedWrongMemoryKind(
+                    Some(AllocKind::Static(..)) |
+                    Some(AllocKind::Memory(..)) => err!(DeallocatedWrongMemoryKind(
                         "static".to_string(),
                         format!("{:?}", kind),
                     )),
@@ -326,15 +326,15 @@
     ) -> EvalResult<'tcx, Cow<'tcx, Allocation<M::PointerTag, M::AllocExtra>>> {
         let alloc = tcx.alloc_map.lock().get(id);
         let def_id = match alloc {
-            Some(AllocType::Memory(mem)) => {
+            Some(AllocKind::Memory(mem)) => {
                 // We got tcx memory. Let the machine figure out whether and how to
                 // turn that into memory with the right pointer tag.
                 return Ok(M::adjust_static_allocation(mem, memory_extra))
             }
-            Some(AllocType::Function(..)) => {
+            Some(AllocKind::Function(..)) => {
                 return err!(DerefFunctionPointer)
             }
-            Some(AllocType::Static(did)) => {
+            Some(AllocKind::Static(did)) => {
                 did
             }
             None =>
@@ -435,8 +435,8 @@
         }
         // Could also be a fn ptr or extern static
         match self.tcx.alloc_map.lock().get(id) {
-            Some(AllocType::Function(..)) => (Size::ZERO, Align::from_bytes(1).unwrap()),
-            Some(AllocType::Static(did)) => {
+            Some(AllocKind::Function(..)) => (Size::ZERO, Align::from_bytes(1).unwrap()),
+            Some(AllocKind::Static(did)) => {
                 // The only way `get` couldn't have worked here is if this is an extern static
                 assert!(self.tcx.is_foreign_item(did));
                 // Use size and align of the type
@@ -459,7 +459,7 @@
         }
         trace!("reading fn ptr: {}", ptr.alloc_id);
         match self.tcx.alloc_map.lock().get(ptr.alloc_id) {
-            Some(AllocType::Function(instance)) => Ok(instance),
+            Some(AllocKind::Function(instance)) => Ok(instance),
             _ => Err(EvalErrorKind::ExecuteMemory.into()),
         }
     }
@@ -557,16 +557,16 @@
                 Err(()) => {
                     // static alloc?
                     match self.tcx.alloc_map.lock().get(id) {
-                        Some(AllocType::Memory(alloc)) => {
+                        Some(AllocKind::Memory(alloc)) => {
                             self.dump_alloc_helper(
                                 &mut allocs_seen, &mut allocs_to_print,
                                 msg, alloc, " (immutable)".to_owned()
                             );
                         }
-                        Some(AllocType::Function(func)) => {
+                        Some(AllocKind::Function(func)) => {
                             trace!("{} {}", msg, func);
                         }
-                        Some(AllocType::Static(did)) => {
+                        Some(AllocKind::Static(did)) => {
                             trace!("{} {:?}", msg, did);
                         }
                         None => {
@@ -638,7 +638,7 @@
         // ensure llvm knows not to put this into immutable memory
         alloc.mutability = mutability;
         let alloc = self.tcx.intern_const_alloc(alloc);
-        self.tcx.alloc_map.lock().set_id_memory(alloc_id, alloc);
+        self.tcx.alloc_map.lock().set_alloc_id_memory(alloc_id, alloc);
         // recurse into inner allocations
         for &(_, alloc) in alloc.relocations.values() {
             // FIXME: Reusing the mutability here is likely incorrect.  It is originally
diff --git a/src/librustc_mir/interpret/validity.rs b/src/librustc_mir/interpret/validity.rs
index 4f17373..c7bfea8 100644
--- a/src/librustc_mir/interpret/validity.rs
+++ b/src/librustc_mir/interpret/validity.rs
@@ -17,7 +17,7 @@
 use rustc::ty;
 use rustc_data_structures::fx::FxHashSet;
 use rustc::mir::interpret::{
-    Scalar, AllocType, EvalResult, EvalErrorKind,
+    Scalar, AllocKind, EvalResult, EvalErrorKind,
 };
 
 use super::{
@@ -388,7 +388,7 @@
                             "integer pointer in non-ZST reference", self.path);
                         // Skip validation entirely for some external statics
                         let alloc_kind = self.ecx.tcx.alloc_map.lock().get(ptr.alloc_id);
-                        if let Some(AllocType::Static(did)) = alloc_kind {
+                        if let Some(AllocKind::Static(did)) = alloc_kind {
                             // `extern static` cannot be validated as they have no body.
                             // FIXME: Statics from other crates are also skipped.
                             // They might be checked at a different type, but for now we
diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index c962a24..a6239a8 100644
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -197,7 +197,7 @@
 use rustc::mir::{self, Location, Promoted};
 use rustc::mir::visit::Visitor as MirVisitor;
 use rustc::mir::mono::MonoItem;
-use rustc::mir::interpret::{Scalar, GlobalId, AllocType, ErrorHandled};
+use rustc::mir::interpret::{Scalar, GlobalId, AllocKind, ErrorHandled};
 
 use monomorphize::{self, Instance};
 use rustc::util::nodemap::{FxHashSet, FxHashMap, DefIdMap};
@@ -1161,22 +1161,22 @@
     alloc_id: AllocId,
     output: &mut Vec<MonoItem<'tcx>>,
 ) {
-    let alloc_type = tcx.alloc_map.lock().get(alloc_id);
-    match alloc_type {
-        Some(AllocType::Static(did)) => {
+    let alloc_kind = tcx.alloc_map.lock().get(alloc_id);
+    match alloc_kind {
+        Some(AllocKind::Static(did)) => {
             let instance = Instance::mono(tcx, did);
             if should_monomorphize_locally(tcx, &instance) {
                 trace!("collecting static {:?}", did);
                 output.push(MonoItem::Static(did));
             }
         }
-        Some(AllocType::Memory(alloc)) => {
+        Some(AllocKind::Memory(alloc)) => {
             trace!("collecting {:?} with {:#?}", alloc_id, alloc);
             for &((), inner) in alloc.relocations.values() {
                 collect_miri(tcx, inner, output);
             }
         },
-        Some(AllocType::Function(fn_instance)) => {
+        Some(AllocKind::Function(fn_instance)) => {
             if should_monomorphize_locally(tcx, &fn_instance) {
                 trace!("collecting {:?} with {:#?}", alloc_id, fn_instance);
                 output.push(create_fn_mono_item(fn_instance));
diff --git a/src/librustc_msan/Cargo.toml b/src/librustc_msan/Cargo.toml
index 2916567..78c39d0 100644
--- a/src/librustc_msan/Cargo.toml
+++ b/src/librustc_msan/Cargo.toml
@@ -16,4 +16,4 @@
 [dependencies]
 alloc = { path = "../liballoc" }
 core = { path = "../libcore" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+compiler_builtins = "0.1.0"
diff --git a/src/librustc_resolve/diagnostics.rs b/src/librustc_resolve/diagnostics.rs
index 2681295..7730239 100644
--- a/src/librustc_resolve/diagnostics.rs
+++ b/src/librustc_resolve/diagnostics.rs
@@ -295,9 +295,8 @@
 Erroneous code example:
 
 ```compile_fail,E0259
-# #![feature(libc)]
 extern crate core;
-extern crate libc as core;
+extern crate std as core;
 
 fn main() {}
 ```
@@ -308,9 +307,8 @@
 Correct example:
 
 ```
-# #![feature(libc)]
 extern crate core;
-extern crate libc as other_name;
+extern crate std as other_name;
 
 fn main() {}
 ```
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index ebd2c87..e449fec 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -3010,6 +3010,7 @@
         // Visit all direct subpatterns of this pattern.
         let outer_pat_id = pat.id;
         pat.walk(&mut |pat| {
+            debug!("resolve_pattern pat={:?} node={:?}", pat, pat.node);
             match pat.node {
                 PatKind::Ident(bmode, ident, ref opt_pat) => {
                     // First try to resolve the identifier as some existing
@@ -3166,6 +3167,7 @@
                  format!("not found in {}", mod_str),
                  item_span)
             };
+
             let code = DiagnosticId::Error(code.into());
             let mut err = this.session.struct_span_err_with_code(base_span, &base_msg, code);
 
@@ -3189,11 +3191,22 @@
                 return (err, Vec::new());
             }
             if is_self_value(path, ns) {
+                debug!("smart_resolve_path_fragment E0424 source:{:?}", source);
+
                 __diagnostic_used!(E0424);
                 err.code(DiagnosticId::Error("E0424".into()));
-                err.span_label(span, format!("`self` value is a keyword \
-                                               only available in \
-                                               methods with `self` parameter"));
+                err.span_label(span, match source {
+                    PathSource::Pat => {
+                        format!("`self` value is a keyword \
+                                and may not be bound to \
+                                variables or shadowed")
+                    }
+                    _ => {
+                        format!("`self` value is a keyword \
+                                only available in methods \
+                                with `self` parameter")
+                    }
+                });
                 return (err, Vec::new());
             }
 
diff --git a/src/librustc_tsan/Cargo.toml b/src/librustc_tsan/Cargo.toml
index baadb64..f061827 100644
--- a/src/librustc_tsan/Cargo.toml
+++ b/src/librustc_tsan/Cargo.toml
@@ -16,4 +16,4 @@
 [dependencies]
 alloc = { path = "../liballoc" }
 core = { path = "../libcore" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+compiler_builtins = "0.1.0"
diff --git a/src/librustc_typeck/check/demand.rs b/src/librustc_typeck/check/demand.rs
index f4f6b3d..db4b686 100644
--- a/src/librustc_typeck/check/demand.rs
+++ b/src/librustc_typeck/check/demand.rs
@@ -123,7 +123,7 @@
                         let sole_field_ty = sole_field.ty(self.tcx, substs);
                         if self.can_coerce(expr_ty, sole_field_ty) {
                             let variant_path = self.tcx.item_path_str(variant.did);
-                            Some(variant_path.trim_left_matches("std::prelude::v1::").to_string())
+                            Some(variant_path.trim_start_matches("std::prelude::v1::").to_string())
                         } else {
                             None
                         }
@@ -519,7 +519,7 @@
                 let suffix_suggestion = format!(
                     "{}{}{}{}",
                     if needs_paren { "(" } else { "" },
-                    src.trim_right_matches(&checked_ty.to_string()),
+                    src.trim_end_matches(&checked_ty.to_string()),
                     expected_ty,
                     if needs_paren { ")" } else { "" },
                 );
diff --git a/src/librustc_typeck/check/intrinsic.rs b/src/librustc_typeck/check/intrinsic.rs
index 5c0eef5..a40e56d 100644
--- a/src/librustc_typeck/check/intrinsic.rs
+++ b/src/librustc_typeck/check/intrinsic.rs
@@ -435,7 +435,8 @@
         "simd_insert" => (2, vec![param(0), tcx.types.u32, param(1)], param(0)),
         "simd_extract" => (2, vec![param(0), tcx.types.u32], param(1)),
         "simd_cast" => (2, vec![param(0)], param(1)),
-        "simd_select" => (2, vec![param(0), param(1), param(1)], param(1)),
+        "simd_select" |
+        "simd_select_bitmask" => (2, vec![param(0), param(1), param(1)], param(1)),
         "simd_reduce_all" | "simd_reduce_any" => (1, vec![param(0)], tcx.types.bool),
         "simd_reduce_add_ordered" | "simd_reduce_mul_ordered"
             => (2, vec![param(0), param(1)], param(1)),
diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index f4d05c6..b421f07 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -20,7 +20,7 @@
 use rustc::session::config::{CodegenOptions, DebuggingOptions, ErrorOutputType, Externs};
 use rustc::session::config::{nightly_options, build_codegen_options, build_debugging_options,
                              get_cmd_lint_options};
-use rustc::session::search_paths::SearchPaths;
+use rustc::session::search_paths::SearchPath;
 use rustc_driver;
 use rustc_target::spec::TargetTriple;
 use syntax::edition::Edition;
@@ -46,7 +46,7 @@
     /// How to format errors and warnings.
     pub error_format: ErrorOutputType,
     /// Library search paths to hand to the compiler.
-    pub libs: SearchPaths,
+    pub libs: Vec<SearchPath>,
     /// The list of external crates to link against.
     pub externs: Externs,
     /// List of `cfg` flags to hand to the compiler. Always includes `rustdoc`.
@@ -295,10 +295,9 @@
         }
         let input = PathBuf::from(&matches.free[0]);
 
-        let mut libs = SearchPaths::new();
-        for s in &matches.opt_strs("L") {
-            libs.add_path(s, error_format);
-        }
+        let libs = matches.opt_strs("L").iter()
+            .map(|s| SearchPath::from_cli_opt(s, error_format))
+            .collect();
         let externs = match parse_externs(&matches) {
             Ok(ex) => ex,
             Err(err) => {
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index 047d355..b85342f 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -51,7 +51,7 @@
 use passes;
 
 pub use rustc::session::config::{Input, Options, CodegenOptions};
-pub use rustc::session::search_paths::SearchPaths;
+pub use rustc::session::search_paths::SearchPath;
 
 pub type ExternalPaths = FxHashMap<DefId, (Vec<String>, clean::TypeKind)>;
 
diff --git a/src/librustdoc/html/layout.rs b/src/librustdoc/html/layout.rs
index 6ce02c3..37ff693 100644
--- a/src/librustdoc/html/layout.rs
+++ b/src/librustdoc/html/layout.rs
@@ -54,6 +54,7 @@
     <link rel=\"stylesheet\" type=\"text/css\" href=\"{root_path}light{suffix}.css\" \
           id=\"themeStyle\">\
     <script src=\"{root_path}storage{suffix}.js\"></script>\
+    <noscript><link rel=\"stylesheet\" href=\"{root_path}noscript{suffix}.css\"></noscript>\
     {css_extension}\
     {favicon}\
     {in_header}\
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 00ca4fe..536ea39 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -806,6 +806,10 @@
 }
 
 pub fn plain_summary_line(md: &str) -> String {
+    plain_summary_line_full(md, false)
+}
+
+pub fn plain_summary_line_full(md: &str, limit_length: bool) -> String {
     struct ParserWrapper<'a> {
         inner: Parser<'a>,
         is_in: isize,
@@ -852,7 +856,21 @@
             s.push_str(&t);
         }
     }
-    s
+    if limit_length && s.chars().count() > 60 {
+        let mut len = 0;
+        let mut ret = s.split_whitespace()
+                       .take_while(|p| {
+                           // + 1 for the added character after the word.
+                           len += p.chars().count() + 1;
+                           len < 60
+                       })
+                       .collect::<Vec<_>>()
+                       .join(" ");
+        ret.push('…');
+        ret
+    } else {
+        s
+    }
 }
 
 pub fn markdown_links(md: &str) -> Vec<(String, Option<Range<usize>>)> {
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 8d7942a..c9f3aa0 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -698,7 +698,7 @@
                 ty: item.type_(),
                 name: item.name.clone().unwrap(),
                 path: fqp[..fqp.len() - 1].join("::"),
-                desc: plain_summary_line(item.doc_value()),
+                desc: plain_summary_line_short(item.doc_value()),
                 parent: Some(did),
                 parent_idx: None,
                 search_type: get_index_search_type(&item),
@@ -736,7 +736,7 @@
     }
 
     let crate_doc = krate.module.as_ref().map(|module| {
-        plain_summary_line(module.doc_value())
+        plain_summary_line_short(module.doc_value())
     }).unwrap_or(String::new());
 
     let mut crate_data = BTreeMap::new();
@@ -772,6 +772,9 @@
     write_minify(cx.dst.join(&format!("settings{}.css", cx.shared.resource_suffix)),
                  static_files::SETTINGS_CSS,
                  options.enable_minification)?;
+    write_minify(cx.dst.join(&format!("noscript{}.css", cx.shared.resource_suffix)),
+                 static_files::NOSCRIPT_CSS,
+                 options.enable_minification)?;
 
     // To avoid "light.css" to be overwritten, we'll first run over the received themes and only
     // then we'll run over the "official" styles.
@@ -865,9 +868,8 @@
     }
 
     {
-        let mut data = format!("var resourcesSuffix = \"{}\";\n",
-                               cx.shared.resource_suffix);
-        data.push_str(static_files::STORAGE_JS);
+        let mut data = static_files::STORAGE_JS.to_owned();
+        data.push_str(&format!("var resourcesSuffix = \"{}\";", cx.shared.resource_suffix));
         write_minify(cx.dst.join(&format!("storage{}.js", cx.shared.resource_suffix)),
                      &data,
                      options.enable_minification)?;
@@ -1481,7 +1483,7 @@
                             ty: item.type_(),
                             name: s.to_string(),
                             path: path.join("::"),
-                            desc: plain_summary_line(item.doc_value()),
+                            desc: plain_summary_line_short(item.doc_value()),
                             parent,
                             parent_idx: None,
                             search_type: get_index_search_type(&item),
@@ -1512,7 +1514,8 @@
             clean::FunctionItem(..) | clean::ModuleItem(..) |
             clean::ForeignFunctionItem(..) | clean::ForeignStaticItem(..) |
             clean::ConstantItem(..) | clean::StaticItem(..) |
-            clean::UnionItem(..) | clean::ForeignTypeItem | clean::MacroItem(..)
+            clean::UnionItem(..) | clean::ForeignTypeItem |
+            clean::MacroItem(..) | clean::ProcMacroItem(..)
             if !self.stripped_mod => {
                 // Re-exported items mean that the same id can show up twice
                 // in the rustdoc ast that we're looking at. We know,
@@ -1673,7 +1676,7 @@
                                 ty: item.type_(),
                                 name: item_name.to_string(),
                                 path: path.clone(),
-                                desc: plain_summary_line(item.doc_value()),
+                                desc: plain_summary_line_short(item.doc_value()),
                                 parent: None,
                                 parent_idx: None,
                                 search_type: get_index_search_type(&item),
@@ -2388,7 +2391,13 @@
 #[inline]
 fn plain_summary_line(s: Option<&str>) -> String {
     let line = shorter(s).replace("\n", " ");
-    markdown::plain_summary_line(&line[..])
+    markdown::plain_summary_line_full(&line[..], false)
+}
+
+#[inline]
+fn plain_summary_line_short(s: Option<&str>) -> String {
+    let line = shorter(s).replace("\n", " ");
+    markdown::plain_summary_line_full(&line[..], true)
 }
 
 fn document(w: &mut fmt::Formatter, cx: &Context, item: &clean::Item) -> fmt::Result {
@@ -3006,6 +3015,22 @@
     // Trait documentation
     document(w, cx, it)?;
 
+    fn write_small_section_header(
+        w: &mut fmt::Formatter,
+        id: &str,
+        title: &str,
+        extra_content: &str,
+    ) -> fmt::Result {
+        write!(w, "
+            <h2 id='{0}' class='small-section-header'>\
+              {1}<a href='#{0}' class='anchor'></a>\
+            </h2>{2}", id, title, extra_content)
+    }
+
+    fn write_loading_content(w: &mut fmt::Formatter, extra_content: &str) -> fmt::Result {
+        write!(w, "{}<span class='loading-content'>Loading content...</span>", extra_content)
+    }
+
     fn trait_item(w: &mut fmt::Formatter, cx: &Context, m: &clean::Item, t: &clean::Item)
                   -> fmt::Result {
         let name = m.name.as_ref().unwrap();
@@ -3026,74 +3051,45 @@
     }
 
     if !types.is_empty() {
-        write!(w, "
-            <h2 id='associated-types' class='small-section-header'>
-              Associated Types<a href='#associated-types' class='anchor'></a>
-            </h2>
-            <div class='methods'>
-        ")?;
+        write_small_section_header(w, "associated-types", "Associated Types",
+                                   "<div class='methods'>")?;
         for t in &types {
             trait_item(w, cx, *t, it)?;
         }
-        write!(w, "</div>")?;
+        write_loading_content(w, "</div>")?;
     }
 
     if !consts.is_empty() {
-        write!(w, "
-            <h2 id='associated-const' class='small-section-header'>
-              Associated Constants<a href='#associated-const' class='anchor'></a>
-            </h2>
-            <div class='methods'>
-        ")?;
+        write_small_section_header(w, "associated-const", "Associated Constants",
+                                   "<div class='methods'>")?;
         for t in &consts {
             trait_item(w, cx, *t, it)?;
         }
-        write!(w, "</div>")?;
+        write_loading_content(w, "</div>")?;
     }
 
     // Output the documentation for each function individually
     if !required.is_empty() {
-        write!(w, "
-            <h2 id='required-methods' class='small-section-header'>
-              Required Methods<a href='#required-methods' class='anchor'></a>
-            </h2>
-            <div class='methods'>
-        ")?;
+        write_small_section_header(w, "required-methods", "Required methods",
+                                   "<div class='methods'>")?;
         for m in &required {
             trait_item(w, cx, *m, it)?;
         }
-        write!(w, "</div>")?;
+        write_loading_content(w, "</div>")?;
     }
     if !provided.is_empty() {
-        write!(w, "
-            <h2 id='provided-methods' class='small-section-header'>
-              Provided Methods<a href='#provided-methods' class='anchor'></a>
-            </h2>
-            <div class='methods'>
-        ")?;
+        write_small_section_header(w, "provided-methods", "Provided methods",
+                                   "<div class='methods'>")?;
         for m in &provided {
             trait_item(w, cx, *m, it)?;
         }
-        write!(w, "</div>")?;
+        write_loading_content(w, "</div>")?;
     }
 
     // If there are methods directly on this trait object, render them here.
     render_assoc_items(w, cx, it, it.def_id, AssocItemRender::All)?;
 
     let cache = cache();
-    let impl_header = "\
-        <h2 id='implementors' class='small-section-header'>\
-          Implementors<a href='#implementors' class='anchor'></a>\
-        </h2>\
-        <div class='item-list' id='implementors-list'>\
-    ";
-
-    let synthetic_impl_header = "\
-        <h2 id='synthetic-implementors' class='small-section-header'>\
-          Auto implementors<a href='#synthetic-implementors' class='anchor'></a>\
-        </h2>\
-        <div class='item-list' id='synthetic-implementors-list'>\
-    ";
 
     let mut synthetic_types = Vec::new();
 
@@ -3130,11 +3126,7 @@
         concrete.sort_by(compare_impl);
 
         if !foreign.is_empty() {
-            write!(w, "
-                <h2 id='foreign-impls' class='small-section-header'>
-                  Implementations on Foreign Types<a href='#foreign-impls' class='anchor'></a>
-                </h2>
-            ")?;
+            write_small_section_header(w, "foreign-impls", "Implementations on Foreign Types", "")?;
 
             for implementor in foreign {
                 let assoc_link = AssocItemLink::GotoSource(
@@ -3145,33 +3137,38 @@
                             RenderMode::Normal, implementor.impl_item.stable_since(), false,
                             None)?;
             }
+            write_loading_content(w, "")?;
         }
 
-        write!(w, "{}", impl_header)?;
+        write_small_section_header(w, "implementors", "Implementors",
+                                   "<div class='item-list' id='implementors-list'>")?;
         for implementor in concrete {
             render_implementor(cx, implementor, w, &implementor_dups)?;
         }
-        write!(w, "</div>")?;
+        write_loading_content(w, "</div>")?;
 
         if t.auto {
-            write!(w, "{}", synthetic_impl_header)?;
+            write_small_section_header(w, "synthetic-implementors", "Auto implementors",
+                                       "<div class='item-list' id='synthetic-implementors-list'>")?;
             for implementor in synthetic {
                 synthetic_types.extend(
                     collect_paths_for_type(implementor.inner_impl().for_.clone())
                 );
                 render_implementor(cx, implementor, w, &implementor_dups)?;
             }
-            write!(w, "</div>")?;
+            write_loading_content(w, "</div>")?;
         }
     } else {
         // even without any implementations to write in, we still want the heading and list, so the
         // implementors javascript file pulled in below has somewhere to write the impls into
-        write!(w, "{}", impl_header)?;
-        write!(w, "</div>")?;
+        write_small_section_header(w, "implementors", "Implementors",
+                                   "<div class='item-list' id='implementors-list'>")?;
+        write_loading_content(w, "</div>")?;
 
         if t.auto {
-            write!(w, "{}", synthetic_impl_header)?;
-            write!(w, "</div>")?;
+            write_small_section_header(w, "synthetic-implementors", "Auto implementors",
+                                       "<div class='item-list' id='synthetic-implementors-list'>")?;
+            write_loading_content(w, "</div>")?;
         }
     }
     write!(w, r#"<script type="text/javascript">window.inlined_types=new Set({});</script>"#,
diff --git a/src/librustdoc/html/static/main.js b/src/librustdoc/html/static/main.js
index 1869969..51714c3 100644
--- a/src/librustdoc/html/static/main.js
+++ b/src/librustdoc/html/static/main.js
@@ -30,6 +30,27 @@
     };
 }
 
+if (!DOMTokenList.prototype.add) {
+    DOMTokenList.prototype.add = function(className) {
+        if (className && !hasClass(this, className)) {
+            if (this.className && this.className.length > 0) {
+                this.className += " " + className;
+            } else {
+                this.className = className;
+            }
+        }
+    };
+}
+
+if (!DOMTokenList.prototype.remove) {
+    DOMTokenList.prototype.remove = function(className) {
+        if (className && this.className) {
+            this.className = (" " + this.className + " ").replace(" " + className + " ", " ")
+                                                         .trim();
+        }
+    };
+}
+
 (function() {
     "use strict";
 
@@ -61,7 +82,7 @@
                      "attr",
                      "derive"];
 
-    var search_input = document.getElementsByClassName('search-input')[0];
+    var search_input = document.getElementsByClassName("search-input")[0];
 
     // On the search screen, so you remain on the last tab you opened.
     //
@@ -75,9 +96,9 @@
     var titleBeforeSearch = document.title;
 
     function getPageId() {
-        var id = document.location.href.split('#')[1];
+        var id = document.location.href.split("#")[1];
         if (id) {
-            return id.split('?')[0].split('&')[0];
+            return id.split("?")[0].split("&")[0];
         }
         return null;
     }
@@ -87,9 +108,9 @@
         if (elems) {
             addClass(elems, "show-it");
         }
-        var sidebar = document.getElementsByClassName('sidebar')[0];
+        var sidebar = document.getElementsByClassName("sidebar")[0];
         if (sidebar) {
-            addClass(sidebar, 'mobile');
+            addClass(sidebar, "mobile");
             var filler = document.getElementById("sidebar-filler");
             if (!filler) {
                 var div = document.createElement("div");
@@ -108,13 +129,13 @@
         if (elems) {
             removeClass(elems, "show-it");
         }
-        var sidebar = document.getElementsByClassName('sidebar')[0];
-        removeClass(sidebar, 'mobile');
+        var sidebar = document.getElementsByClassName("sidebar")[0];
+        removeClass(sidebar, "mobile");
         var filler = document.getElementById("sidebar-filler");
         if (filler) {
             filler.remove();
         }
-        document.getElementsByTagName("body")[0].style.marginTop = '';
+        document.getElementsByTagName("body")[0].style.marginTop = "";
         var themePicker = document.getElementsByClassName("theme-picker");
         if (themePicker && themePicker.length > 0) {
             themePicker[0].style.display = null;
@@ -125,8 +146,8 @@
     var TY_PRIMITIVE = itemTypes.indexOf("primitive");
     var TY_KEYWORD = itemTypes.indexOf("keyword");
 
-    onEach(document.getElementsByClassName('js-only'), function(e) {
-        removeClass(e, 'js-only');
+    onEachLazy(document.getElementsByClassName("js-only"), function(e) {
+        removeClass(e, "js-only");
     });
 
     function getQueryStringParams() {
@@ -145,16 +166,19 @@
           window.history && typeof window.history.pushState === "function";
     }
 
+    var main = document.getElementById("main");
+
     function highlightSourceLines(ev) {
         // If we're in mobile mode, we should add the sidebar in any case.
         hideSidebar();
+        var elem;
         var search = document.getElementById("search");
         var i, from, to, match = window.location.hash.match(/^#?(\d+)(?:-(\d+))?$/);
         if (match) {
             from = parseInt(match[1], 10);
             to = Math.min(50000, parseInt(match[2] || match[1], 10));
             from = Math.min(from, to);
-            var elem = document.getElementById(from);
+            elem = document.getElementById(from);
             if (!elem) {
                 return;
             }
@@ -164,22 +188,22 @@
                     x.scrollIntoView();
                 }
             }
-            onEach(document.getElementsByClassName('line-numbers'), function(e) {
-                onEach(e.getElementsByTagName('span'), function(i_e) {
-                    removeClass(i_e, 'line-highlighted');
+            onEachLazy(document.getElementsByClassName("line-numbers"), function(e) {
+                onEachLazy(e.getElementsByTagName("span"), function(i_e) {
+                    removeClass(i_e, "line-highlighted");
                 });
             });
             for (i = from; i <= to; ++i) {
-                addClass(document.getElementById(i), 'line-highlighted');
+                addClass(document.getElementById(i), "line-highlighted");
             }
         } else if (ev !== null && search && !hasClass(search, "hidden") && ev.newURL) {
             addClass(search, "hidden");
-            removeClass(document.getElementById("main"), "hidden");
-            var hash = ev.newURL.slice(ev.newURL.indexOf('#') + 1);
+            removeClass(main, "hidden");
+            var hash = ev.newURL.slice(ev.newURL.indexOf("#") + 1);
             if (browserSupportsHistoryApi()) {
                 history.replaceState(hash, "", "?search=#" + hash);
             }
-            var elem = document.getElementById(hash);
+            elem = document.getElementById(hash);
             if (elem) {
                 elem.scrollIntoView();
             }
@@ -190,7 +214,7 @@
         var elem = document.getElementById(id);
         if (elem && isHidden(elem)) {
             var h3 = elem.parentNode.previousSibling;
-            if (h3 && h3.tagName !== 'H3') {
+            if (h3 && h3.tagName !== "H3") {
                 h3 = h3.previousSibling; // skip div.docblock
             }
 
@@ -236,7 +260,7 @@
                 removeClass(help, "hidden");
                 addClass(document.body, "blur");
             }
-        } else if (!hasClass(help, "hidden")) {
+        } else if (hasClass(help, "hidden") === false) {
             ev.preventDefault();
             addClass(help, "hidden");
             removeClass(document.body, "blur");
@@ -246,12 +270,12 @@
     function handleEscape(ev, help) {
         hideModal();
         var search = document.getElementById("search");
-        if (!hasClass(help, "hidden")) {
+        if (hasClass(help, "hidden") === false) {
             displayHelp(false, ev);
-        } else if (!hasClass(search, "hidden")) {
+        } else if (hasClass(search, "hidden") === false) {
             ev.preventDefault();
             addClass(search, "hidden");
-            removeClass(document.getElementById("main"), "hidden");
+            removeClass(main, "hidden");
             document.title = titleBeforeSearch;
         }
         defocusSearchBar();
@@ -305,26 +329,27 @@
             if (elem && elem.tagName === tagName) {
                 return elem;
             }
-        } while (elem = elem.parentNode);
+            elem = elem.parentNode;
+        } while (elem);
         return null;
     }
 
     document.onkeypress = handleShortcut;
     document.onkeydown = handleShortcut;
     document.onclick = function(ev) {
-        if (hasClass(ev.target, 'collapse-toggle')) {
+        if (hasClass(ev.target, "collapse-toggle")) {
             collapseDocs(ev.target, "toggle");
-        } else if (hasClass(ev.target.parentNode, 'collapse-toggle')) {
+        } else if (hasClass(ev.target.parentNode, "collapse-toggle")) {
             collapseDocs(ev.target.parentNode, "toggle");
-        } else if (ev.target.tagName === 'SPAN' && hasClass(ev.target.parentNode, 'line-numbers')) {
+        } else if (ev.target.tagName === "SPAN" && hasClass(ev.target.parentNode, "line-numbers")) {
             var prev_id = 0;
 
             var set_fragment = function(name) {
                 if (browserSupportsHistoryApi()) {
-                    history.replaceState(null, null, '#' + name);
+                    history.replaceState(null, null, "#" + name);
                     window.hashchange();
                 } else {
-                    location.replace('#' + name);
+                    location.replace("#" + name);
                 }
             };
 
@@ -337,31 +362,31 @@
                     cur_id = tmp;
                 }
 
-                set_fragment(prev_id + '-' + cur_id);
+                set_fragment(prev_id + "-" + cur_id);
             } else {
                 prev_id = cur_id;
 
                 set_fragment(cur_id);
             }
-        } else if (!hasClass(document.getElementById("help"), "hidden")) {
+        } else if (hasClass(document.getElementById("help"), "hidden") === false) {
             addClass(document.getElementById("help"), "hidden");
             removeClass(document.body, "blur");
         } else {
             // Making a collapsed element visible on onhashchange seems
             // too late
-            var a = findParentElement(ev.target, 'A');
+            var a = findParentElement(ev.target, "A");
             if (a && a.hash) {
-                expandSection(a.hash.replace(/^#/, ''));
+                expandSection(a.hash.replace(/^#/, ""));
             }
         }
     };
 
-    var x = document.getElementsByClassName('version-selector');
+    var x = document.getElementsByClassName("version-selector");
     if (x.length > 0) {
         x[0].onchange = function() {
             var i, match,
                 url = document.location.href,
-                stripped = '',
+                stripped = "",
                 len = rootPath.match(/\.\.\//g).length + 1;
 
             for (i = 0; i < len; ++i) {
@@ -372,7 +397,7 @@
                 url = url.substring(0, url.length - match[0].length);
             }
 
-            url += '/' + document.getElementsByClassName('version-selector')[0].value + stripped;
+            url += "/" + document.getElementsByClassName("version-selector")[0].value + stripped;
 
             document.location.href = url;
         };
@@ -428,7 +453,7 @@
         // where you start trying to do a search, and the index loads, and
         // suddenly your search is gone!
         if (search_input.value === "") {
-            search_input.value = params.search || '';
+            search_input.value = params.search || "";
         }
 
         /**
@@ -441,7 +466,8 @@
          */
         function execQuery(query, searchWords, filterCrates) {
             function itemTypeFromName(typename) {
-                for (var i = 0; i < itemTypes.length; ++i) {
+                var length = itemTypes.length;
+                for (var i = 0; i < length; ++i) {
                     if (itemTypes[i] === typename) {
                         return i;
                     }
@@ -455,7 +481,8 @@
                 results = {}, results_in_args = {}, results_returned = {},
                 split = valLower.split("::");
 
-            for (var z = 0; z < split.length; ++z) {
+            var length = split.length;
+            for (var z = 0; z < length; ++z) {
                 if (split[z] === "") {
                     split.splice(z, 1);
                     z -= 1;
@@ -464,7 +491,8 @@
 
             function transformResults(results, isType) {
                 var out = [];
-                for (i = 0; i < results.length; ++i) {
+                var length = results.length;
+                for (var i = 0; i < length; ++i) {
                     if (results[i].id > -1) {
                         var obj = searchIndex[results[i].id];
                         obj.lev = results[i].lev;
@@ -473,7 +501,7 @@
                             obj.displayPath = pathSplitter(res[0]);
                             obj.fullPath = obj.displayPath + obj.name;
                             // To be sure than it some items aren't considered as duplicate.
-                            obj.fullPath += '|' + obj.ty;
+                            obj.fullPath += "|" + obj.ty;
                             obj.href = res[1];
                             out.push(obj);
                             if (out.length >= MAX_RESULTS) {
@@ -493,8 +521,9 @@
                     }
                 }
                 results = ar;
+                var i;
                 var nresults = results.length;
-                for (var i = 0; i < nresults; ++i) {
+                for (i = 0; i < nresults; ++i) {
                     results[i].word = searchWords[results[i].id];
                     results[i].item = searchIndex[results[i].id] || {};
                 }
@@ -552,8 +581,8 @@
                     }
 
                     // sort by description (no description goes later)
-                    a = (aaa.item.desc === '');
-                    b = (bbb.item.desc === '');
+                    a = (aaa.item.desc === "");
+                    b = (bbb.item.desc === "");
                     if (a !== b) { return a - b; }
 
                     // sort by type (later occurrence in `itemTypes` goes later)
@@ -570,7 +599,8 @@
                     return 0;
                 });
 
-                for (var i = 0; i < results.length; ++i) {
+                var length = results.length;
+                for (i = 0; i < length; ++i) {
                     var result = results[i];
 
                     // this validation does not make sense when searching by types
@@ -592,10 +622,10 @@
 
             function extractGenerics(val) {
                 val = val.toLowerCase();
-                if (val.indexOf('<') !== -1) {
-                    var values = val.substring(val.indexOf('<') + 1, val.lastIndexOf('>'));
+                if (val.indexOf("<") !== -1) {
+                    var values = val.substring(val.indexOf("<") + 1, val.lastIndexOf(">"));
                     return {
-                        name: val.substring(0, val.indexOf('<')),
+                        name: val.substring(0, val.indexOf("<")),
                         generics: values.split(/\s*,\s*/),
                     };
                 }
@@ -617,9 +647,11 @@
                         var done = 0;
                         // We need to find the type that matches the most to remove it in order
                         // to move forward.
-                        for (var y = 0; y < val.generics.length; ++y) {
+                        var vlength = val.generics.length;
+                        for (var y = 0; y < vlength; ++y) {
                             var lev = { pos: -1, lev: MAX_LEV_DISTANCE + 1};
-                            for (var x = 0; x < elems.length; ++x) {
+                            var elength = elems.length;
+                            for (var x = 0; x < elength; ++x) {
                                 var tmp_lev = levenshtein(elems[x], val.generics[y]);
                                 if (tmp_lev < lev.lev) {
                                     lev.lev = tmp_lev;
@@ -644,6 +676,7 @@
             // Check for type name and type generics (if any).
             function checkType(obj, val, literalSearch) {
                 var lev_distance = MAX_LEV_DISTANCE + 1;
+                var x;
                 if (obj[NAME] === val.name) {
                     if (literalSearch === true) {
                         if (val.generics && val.generics.length !== 0) {
@@ -651,7 +684,6 @@
                                   obj[GENERICS_DATA].length >= val.generics.length) {
                                 var elems = obj[GENERICS_DATA].slice(0);
                                 var allFound = true;
-                                var x;
 
                                 for (var y = 0; allFound === true && y < val.generics.length; ++y) {
                                     allFound = false;
@@ -685,7 +717,8 @@
                 // Names didn't match so let's check if one of the generic types could.
                 if (literalSearch === true) {
                      if (obj.length > GENERICS_DATA && obj[GENERICS_DATA].length > 0) {
-                        for (var x = 0; x < obj[GENERICS_DATA].length; ++x) {
+                        var length = obj[GENERICS_DATA].length;
+                        for (x = 0; x < length; ++x) {
                             if (obj[GENERICS_DATA][x] === val.name) {
                                 return true;
                             }
@@ -693,13 +726,13 @@
                     }
                     return false;
                 }
-                var lev_distance = Math.min(levenshtein(obj[NAME], val.name),
-                                            lev_distance);
+                lev_distance = Math.min(levenshtein(obj[NAME], val.name), lev_distance);
                 if (lev_distance <= MAX_LEV_DISTANCE) {
                     lev_distance = Math.min(checkGenerics(obj, val), lev_distance);
                 } else if (obj.length > GENERICS_DATA && obj[GENERICS_DATA].length > 0) {
                     // We can check if the type we're looking for is inside the generics!
-                    for (var x = 0; x < obj[GENERICS_DATA].length; ++x) {
+                    var olength = obj[GENERICS_DATA].length;
+                    for (x = 0; x < olength; ++x) {
                         lev_distance = Math.min(levenshtein(obj[GENERICS_DATA][x], val.name),
                                                 lev_distance);
                     }
@@ -714,7 +747,8 @@
 
                 if (obj && obj.type && obj.type[INPUTS_DATA] &&
                       obj.type[INPUTS_DATA].length > 0) {
-                    for (var i = 0; i < obj.type[INPUTS_DATA].length; i++) {
+                    var length = obj.type[INPUTS_DATA].length;
+                    for (var i = 0; i < length; i++) {
                         var tmp = checkType(obj.type[INPUTS_DATA][i], val, literalSearch);
                         if (literalSearch === true && tmp === true) {
                             return true;
@@ -755,16 +789,18 @@
                     path.push(ty.parent.name.toLowerCase());
                 }
 
-                if (contains.length > path.length) {
+                var length = path.length;
+                var clength = contains.length;
+                if (clength > length) {
                     return MAX_LEV_DISTANCE + 1;
                 }
-                for (var i = 0; i < path.length; ++i) {
-                    if (i + contains.length > path.length) {
+                for (var i = 0; i < length; ++i) {
+                    if (i + clength > length) {
                         break;
                     }
                     var lev_total = 0;
                     var aborted = false;
-                    for (var x = 0; x < contains.length; ++x) {
+                    for (var x = 0; x < clength; ++x) {
                         var lev = levenshtein(path[i + x], contains[x]);
                         if (lev > MAX_LEV_DISTANCE) {
                             aborted = true;
@@ -773,7 +809,7 @@
                         lev_total += lev;
                     }
                     if (aborted === false) {
-                        ret_lev = Math.min(ret_lev, Math.round(lev_total / contains.length));
+                        ret_lev = Math.min(ret_lev, Math.round(lev_total / clength));
                     }
                 }
                 return ret_lev;
@@ -810,18 +846,23 @@
 
             // quoted values mean literal search
             var nSearchWords = searchWords.length;
+            var i;
+            var ty;
+            var fullId;
+            var returned;
+            var in_args;
             if ((val.charAt(0) === "\"" || val.charAt(0) === "'") &&
                 val.charAt(val.length - 1) === val.charAt(0))
             {
                 val = extractGenerics(val.substr(1, val.length - 2));
-                for (var i = 0; i < nSearchWords; ++i) {
+                for (i = 0; i < nSearchWords; ++i) {
                     if (filterCrates !== undefined && searchIndex[i].crate !== filterCrates) {
                         continue;
                     }
-                    var in_args = findArg(searchIndex[i], val, true);
-                    var returned = checkReturned(searchIndex[i], val, true);
-                    var ty = searchIndex[i];
-                    var fullId = generateId(ty);
+                    in_args = findArg(searchIndex[i], val, true);
+                    returned = checkReturned(searchIndex[i], val, true);
+                    ty = searchIndex[i];
+                    fullId = generateId(ty);
 
                     if (searchWords[i] === val.name) {
                         // filter type: ... queries
@@ -866,27 +907,27 @@
                 var input = parts[0];
                 // sort inputs so that order does not matter
                 var inputs = input.split(",").map(trimmer).sort();
-                for (var i = 0; i < inputs.length; ++i) {
+                for (i = 0; i < inputs.length; ++i) {
                     inputs[i] = extractGenerics(inputs[i]);
                 }
                 var output = extractGenerics(parts[1]);
 
-                for (var i = 0; i < nSearchWords; ++i) {
+                for (i = 0; i < nSearchWords; ++i) {
                     if (filterCrates !== undefined && searchIndex[i].crate !== filterCrates) {
                         continue;
                     }
                     var type = searchIndex[i].type;
-                    var ty = searchIndex[i];
+                    ty = searchIndex[i];
                     if (!type) {
                         continue;
                     }
-                    var fullId = generateId(ty);
+                    fullId = generateId(ty);
 
                     // allow searching for void (no output) functions as well
                     var typeOutput = type.length > OUTPUT_DATA ? type[OUTPUT_DATA].name : "";
-                    var returned = checkReturned(ty, output, true);
+                    returned = checkReturned(ty, output, true);
                     if (output.name === "*" || returned === true) {
-                        var in_args = false;
+                        in_args = false;
                         var module = false;
 
                         if (input === "*") {
@@ -946,14 +987,16 @@
                 var contains = paths.slice(0, paths.length > 1 ? paths.length - 1 : 1);
 
                 for (j = 0; j < nSearchWords; ++j) {
-                    var ty = searchIndex[j];
+                    var lev;
+                    var lev_distance;
+                    ty = searchIndex[j];
                     if (!ty || (filterCrates !== undefined && ty.crate !== filterCrates)) {
                         continue;
                     }
                     var lev_distance;
                     var lev_add = 0;
                     if (paths.length > 1) {
-                        var lev = checkPath(contains, paths[paths.length - 1], ty);
+                        lev = checkPath(contains, paths[paths.length - 1], ty);
                         if (lev > MAX_LEV_DISTANCE) {
                             continue;
                         } else if (lev > 0) {
@@ -961,12 +1004,12 @@
                         }
                     }
 
-                    var returned = MAX_LEV_DISTANCE + 1;
-                    var in_args = MAX_LEV_DISTANCE + 1;
+                    returned = MAX_LEV_DISTANCE + 1;
+                    in_args = MAX_LEV_DISTANCE + 1;
                     var index = -1;
                     // we want lev results to go lower than others
-                    var lev = MAX_LEV_DISTANCE + 1;
-                    var fullId = generateId(ty);
+                    lev = MAX_LEV_DISTANCE + 1;
+                    fullId = generateId(ty);
 
                     if (searchWords[j].indexOf(split[i]) > -1 ||
                         searchWords[j].indexOf(val) > -1 ||
@@ -1042,14 +1085,14 @@
             }
 
             var ret = {
-                'in_args': sortResults(results_in_args, true),
-                'returned': sortResults(results_returned, true),
-                'others': sortResults(results),
+                "in_args": sortResults(results_in_args, true),
+                "returned": sortResults(results_returned, true),
+                "others": sortResults(results),
             };
             if (ALIASES && ALIASES[window.currentCrate] &&
                     ALIASES[window.currentCrate][query.raw]) {
                 var aliases = ALIASES[window.currentCrate][query.raw];
-                for (var i = 0; i < aliases.length; ++i) {
+                for (i = 0; i < aliases.length; ++i) {
                     aliases[i].is_alias = true;
                     aliases[i].alias = query.raw;
                     aliases[i].path = aliases[i].p;
@@ -1057,9 +1100,9 @@
                     aliases[i].displayPath = pathSplitter(res[0]);
                     aliases[i].fullPath = aliases[i].displayPath + aliases[i].name;
                     aliases[i].href = res[1];
-                    ret['others'].unshift(aliases[i]);
-                    if (ret['others'].length > MAX_RESULTS) {
-                        ret['others'].pop();
+                    ret.others.unshift(aliases[i]);
+                    if (ret.others.length > MAX_RESULTS) {
+                        ret.others.pop();
                     }
                 }
             }
@@ -1106,7 +1149,7 @@
 
             matches = query.match(/^(fn|mod|struct|enum|trait|type|const|macro)\s*:\s*/i);
             if (matches) {
-                type = matches[1].replace(/^const$/, 'constant');
+                type = matches[1].replace(/^const$/, "constant");
                 query = query.substring(matches[0].length);
             }
 
@@ -1124,38 +1167,38 @@
             var click_func = function(e) {
                 var el = e.target;
                 // to retrieve the real "owner" of the event.
-                while (el.tagName !== 'TR') {
+                while (el.tagName !== "TR") {
                     el = el.parentNode;
                 }
-                var dst = e.target.getElementsByTagName('a');
+                var dst = e.target.getElementsByTagName("a");
                 if (dst.length < 1) {
                     return;
                 }
                 dst = dst[0];
                 if (window.location.pathname === dst.pathname) {
-                    addClass(document.getElementById('search'), 'hidden');
-                    removeClass(document.getElementById('main'), 'hidden');
+                    addClass(document.getElementById("search"), "hidden");
+                    removeClass(main, "hidden");
                     document.location.href = dst.href;
                 }
             };
             var mouseover_func = function(e) {
                 var el = e.target;
                 // to retrieve the real "owner" of the event.
-                while (el.tagName !== 'TR') {
+                while (el.tagName !== "TR") {
                     el = el.parentNode;
                 }
                 clearTimeout(hoverTimeout);
                 hoverTimeout = setTimeout(function() {
-                    onEach(document.getElementsByClassName('search-results'), function(e) {
-                        onEach(e.getElementsByClassName('result'), function(i_e) {
-                            removeClass(i_e, 'highlighted');
+                    onEachLazy(document.getElementsByClassName("search-results"), function(e) {
+                        onEachLazy(e.getElementsByClassName("result"), function(i_e) {
+                            removeClass(i_e, "highlighted");
                         });
                     });
-                    addClass(el, 'highlighted');
+                    addClass(el, "highlighted");
                 }, 20);
             };
-            onEach(document.getElementsByClassName('search-results'), function(e) {
-                onEach(e.getElementsByClassName('result'), function(i_e) {
+            onEachLazy(document.getElementsByClassName("search-results"), function(e) {
+                onEachLazy(e.getElementsByClassName("result"), function(i_e) {
                     i_e.onclick = click_func;
                     i_e.onmouseover = mouseover_func;
                 });
@@ -1167,8 +1210,8 @@
                 var actives = [[], [], []];
                 // "current" is used to know which tab we're looking into.
                 var current = 0;
-                onEach(document.getElementsByClassName('search-results'), function(e) {
-                    onEach(e.getElementsByClassName('highlighted'), function(e) {
+                onEachLazy(document.getElementsByClassName("search-results"), function(e) {
+                    onEachLazy(e.getElementsByClassName("highlighted"), function(e) {
                         actives[current].push(e);
                     });
                     current += 1;
@@ -1180,25 +1223,25 @@
                         return;
                     }
 
-                    addClass(actives[currentTab][0].previousElementSibling, 'highlighted');
-                    removeClass(actives[currentTab][0], 'highlighted');
+                    addClass(actives[currentTab][0].previousElementSibling, "highlighted");
+                    removeClass(actives[currentTab][0], "highlighted");
                 } else if (e.which === 40) { // down
                     if (!actives[currentTab].length) {
-                        var results = document.getElementsByClassName('search-results');
+                        var results = document.getElementsByClassName("search-results");
                         if (results.length > 0) {
-                            var res = results[currentTab].getElementsByClassName('result');
+                            var res = results[currentTab].getElementsByClassName("result");
                             if (res.length > 0) {
-                                addClass(res[0], 'highlighted');
+                                addClass(res[0], "highlighted");
                             }
                         }
                     } else if (actives[currentTab][0].nextElementSibling) {
-                        addClass(actives[currentTab][0].nextElementSibling, 'highlighted');
-                        removeClass(actives[currentTab][0], 'highlighted');
+                        addClass(actives[currentTab][0].nextElementSibling, "highlighted");
+                        removeClass(actives[currentTab][0], "highlighted");
                     }
                 } else if (e.which === 13) { // return
                     if (actives[currentTab].length) {
                         document.location.href =
-                            actives[currentTab][0].getElementsByTagName('a')[0].href;
+                            actives[currentTab][0].getElementsByTagName("a")[0].href;
                     }
                 } else if (e.which === 9) { // tab
                     if (e.shiftKey) {
@@ -1210,11 +1253,11 @@
                 } else if (e.which === 16) { // shift
                     // Does nothing, it's just to avoid losing "focus" on the highlighted element.
                 } else if (e.which === 27) { // escape
-                    removeClass(actives[currentTab][0], 'highlighted');
-                    search_input.value = '';
+                    removeClass(actives[currentTab][0], "highlighted");
+                    search_input.value = "";
                     defocusSearchBar();
                 } else if (actives[currentTab].length > 0) {
-                    removeClass(actives[currentTab][0], 'highlighted');
+                    removeClass(actives[currentTab][0], "highlighted");
                 }
             };
         }
@@ -1225,46 +1268,46 @@
             var type = itemTypes[item.ty];
             var name = item.name;
 
-            if (type === 'mod') {
-                displayPath = item.path + '::';
-                href = rootPath + item.path.replace(/::/g, '/') + '/' +
-                       name + '/index.html';
+            if (type === "mod") {
+                displayPath = item.path + "::";
+                href = rootPath + item.path.replace(/::/g, "/") + "/" +
+                       name + "/index.html";
             } else if (type === "primitive" || type === "keyword") {
                 displayPath = "";
-                href = rootPath + item.path.replace(/::/g, '/') +
-                       '/' + type + '.' + name + '.html';
+                href = rootPath + item.path.replace(/::/g, "/") +
+                       "/" + type + "." + name + ".html";
             } else if (type === "externcrate") {
                 displayPath = "";
-                href = rootPath + name + '/index.html';
+                href = rootPath + name + "/index.html";
             } else if (item.parent !== undefined) {
                 var myparent = item.parent;
-                var anchor = '#' + type + '.' + name;
+                var anchor = "#" + type + "." + name;
                 var parentType = itemTypes[myparent.ty];
                 if (parentType === "primitive") {
-                    displayPath = myparent.name + '::';
+                    displayPath = myparent.name + "::";
                 } else {
-                    displayPath = item.path + '::' + myparent.name + '::';
+                    displayPath = item.path + "::" + myparent.name + "::";
                 }
-                href = rootPath + item.path.replace(/::/g, '/') +
-                       '/' + parentType +
-                       '.' + myparent.name +
-                       '.html' + anchor;
+                href = rootPath + item.path.replace(/::/g, "/") +
+                       "/" + parentType +
+                       "." + myparent.name +
+                       ".html" + anchor;
             } else {
-                displayPath = item.path + '::';
-                href = rootPath + item.path.replace(/::/g, '/') +
-                       '/' + type + '.' + name + '.html';
+                displayPath = item.path + "::";
+                href = rootPath + item.path.replace(/::/g, "/") +
+                       "/" + type + "." + name + ".html";
             }
             return [displayPath, href];
         }
 
         function escape(content) {
-            var h1 = document.createElement('h1');
+            var h1 = document.createElement("h1");
             h1.textContent = content;
             return h1.innerHTML;
         }
 
         function pathSplitter(path) {
-            var tmp = '<span>' + path.replace(/::/g, '::</span><span>');
+            var tmp = "<span>" + path.replace(/::/g, "::</span><span>");
             if (tmp.endsWith("<span>")) {
                 return tmp.slice(0, tmp.length - 6);
             }
@@ -1272,16 +1315,16 @@
         }
 
         function addTab(array, query, display) {
-            var extraStyle = '';
+            var extraStyle = "";
             if (display === false) {
-                extraStyle = ' style="display: none;"';
+                extraStyle = " style=\"display: none;\"";
             }
 
-            var output = '';
+            var output = "";
             var duplicates = {};
             var length = 0;
             if (array.length > 0) {
-                output = '<table class="search-results"' + extraStyle + '>';
+                output = "<table class=\"search-results\"" + extraStyle + ">";
 
                 array.forEach(function(item) {
                     var name, type;
@@ -1297,50 +1340,50 @@
                     }
                     length += 1;
 
-                    output += '<tr class="' + type + ' result"><td>' +
-                              '<a href="' + item.href + '">' +
+                    output += "<tr class=\"" + type + " result\"><td>" +
+                              "<a href=\"" + item.href + "\">" +
                               (item.is_alias === true ?
-                               ('<span class="alias"><b>' + item.alias + ' </b></span><span ' +
-                                  'class="grey"><i>&nbsp;- see&nbsp;</i></span>') : '') +
-                              item.displayPath + '<span class="' + type + '">' +
-                              name + '</span></a></td><td>' +
-                              '<a href="' + item.href + '">' +
-                              '<span class="desc">' + escape(item.desc) +
-                              '&nbsp;</span></a></td></tr>';
+                               ("<span class=\"alias\"><b>" + item.alias + " </b></span><span " +
+                                  "class=\"grey\"><i>&nbsp;- see&nbsp;</i></span>") : "") +
+                              item.displayPath + "<span class=\"" + type + "\">" +
+                              name + "</span></a></td><td>" +
+                              "<a href=\"" + item.href + "\">" +
+                              "<span class=\"desc\">" + escape(item.desc) +
+                              "&nbsp;</span></a></td></tr>";
                 });
-                output += '</table>';
+                output += "</table>";
             } else {
-                output = '<div class="search-failed"' + extraStyle + '>No results :(<br/>' +
-                    'Try on <a href="https://duckduckgo.com/?q=' +
-                    encodeURIComponent('rust ' + query.query) +
-                    '">DuckDuckGo</a>?<br/><br/>' +
-                    'Or try looking in one of these:<ul><li>The <a ' +
-                    'href="https://doc.rust-lang.org/reference/index.html">Rust Reference</a> for' +
-                    ' technical details about the language.</li><li><a ' +
-                    'href="https://doc.rust-lang.org/rust-by-example/index.html">Rust By Example' +
-                    '</a> for expository code examples.</a></li><li>The <a ' +
-                    'href="https://doc.rust-lang.org/book/index.html">Rust Book</a> for ' +
-                    'introductions to language features and the language itself.</li><li><a ' +
-                    'href="https://docs.rs">Docs.rs</a> for documentation of crates released on ' +
-                    '<a href="https://crates.io/">crates.io</a>.</li></ul></div>';
+                output = "<div class=\"search-failed\"" + extraStyle + ">No results :(<br/>" +
+                    "Try on <a href=\"https://duckduckgo.com/?q=" +
+                    encodeURIComponent("rust " + query.query) +
+                    "\">DuckDuckGo</a>?<br/><br/>" +
+                    "Or try looking in one of these:<ul><li>The <a " +
+                    "href=\"https://doc.rust-lang.org/reference/index.html\">Rust Reference</a> " +
+                    " for technical details about the language.</li><li><a " +
+                    "href=\"https://doc.rust-lang.org/rust-by-example/index.html\">Rust By " +
+                    "Example</a> for expository code examples.</a></li><li>The <a " +
+                    "href=\"https://doc.rust-lang.org/book/index.html\">Rust Book</a> for " +
+                    "introductions to language features and the language itself.</li><li><a " +
+                    "href=\"https://docs.rs\">Docs.rs</a> for documentation of crates released on" +
+                    " <a href=\"https://crates.io/\">crates.io</a>.</li></ul></div>";
             }
             return [output, length];
         }
 
         function makeTabHeader(tabNb, text, nbElems) {
             if (currentTab === tabNb) {
-                return '<div class="selected">' + text +
-                       ' <div class="count">(' + nbElems + ')</div></div>';
+                return "<div class=\"selected\">" + text +
+                       " <div class=\"count\">(" + nbElems + ")</div></div>";
             }
-            return '<div>' + text + ' <div class="count">(' + nbElems + ')</div></div>';
+            return "<div>" + text + " <div class=\"count\">(" + nbElems + ")</div></div>";
         }
 
-        function showResults(results, filterCrates) {
-            if (results['others'].length === 1 &&
-                getCurrentValue('rustdoc-go-to-only-result') === "true") {
-                var elem = document.createElement('a');
-                elem.href = results['others'][0].href;
-                elem.style.display = 'none';
+        function showResults(results) {
+            if (results.others.length === 1 &&
+                getCurrentValue("rustdoc-go-to-only-result") === "true") {
+                var elem = document.createElement("a");
+                elem.href = results.others[0].href;
+                elem.style.display = "none";
                 // For firefox, we need the element to be in the DOM so it can be clicked.
                 document.body.appendChild(elem);
                 elem.click();
@@ -1349,39 +1392,34 @@
 
             currentResults = query.id;
 
-            var ret_others = addTab(results['others'], query);
-            var ret_in_args = addTab(results['in_args'], query, false);
-            var ret_returned = addTab(results['returned'], query, false);
+            var ret_others = addTab(results.others, query);
+            var ret_in_args = addTab(results.in_args, query, false);
+            var ret_returned = addTab(results.returned, query, false);
 
-            var filter = "";
-            if (filterCrates !== undefined) {
-                filter = " (in <b>" + filterCrates + "</b> crate)";
-            }
-
-            var output = '<h1>Results for ' + escape(query.query) +
-                (query.type ? ' (type: ' + escape(query.type) + ')' : '') + filter + '</h1>' +
-                '<div id="titles">' +
+            var output = "<h1>Results for " + escape(query.query) +
+                (query.type ? " (type: " + escape(query.type) + ")" : "") + "</h1>" +
+                "<div id=\"titles\">" +
                 makeTabHeader(0, "In Names", ret_others[1]) +
                 makeTabHeader(1, "In Parameters", ret_in_args[1]) +
                 makeTabHeader(2, "In Return Types", ret_returned[1]) +
-                '</div><div id="results">' +
-                ret_others[0] + ret_in_args[0] + ret_returned[0] + '</div>';
+                "</div><div id=\"results\">" +
+                ret_others[0] + ret_in_args[0] + ret_returned[0] + "</div>";
 
-            addClass(document.getElementById('main'), 'hidden');
-            var search = document.getElementById('search');
-            removeClass(search, 'hidden');
+            addClass(main, "hidden");
+            var search = document.getElementById("search");
+            removeClass(search, "hidden");
             search.innerHTML = output;
-            var tds = search.getElementsByTagName('td');
+            var tds = search.getElementsByTagName("td");
             var td_width = 0;
             if (tds.length > 0) {
                 td_width = tds[0].offsetWidth;
             }
             var width = search.offsetWidth - 40 - td_width;
-            onEach(search.getElementsByClassName('desc'), function(e) {
-                e.style.width = width + 'px';
+            onEachLazy(search.getElementsByClassName("desc"), function(e) {
+                e.style.width = width + "px";
             });
             initSearchNav();
-            var elems = document.getElementById('titles').childNodes;
+            var elems = document.getElementById("titles").childNodes;
             elems[0].onclick = function() { printTab(0); };
             elems[1].onclick = function() { printTab(1); };
             elems[2].onclick = function() { printTab(2); };
@@ -1389,74 +1427,74 @@
         }
 
         function execSearch(query, searchWords, filterCrates) {
+            function getSmallest(arrays, positions, notDuplicates) {
+                var start = null;
+
+                for (var it = 0; it < positions.length; ++it) {
+                    if (arrays[it].length > positions[it] &&
+                        (start === null || start > arrays[it][positions[it]].lev) &&
+                        !notDuplicates[arrays[it][positions[it]].fullPath]) {
+                        start = arrays[it][positions[it]].lev;
+                    }
+                }
+                return start;
+            }
+
+            function mergeArrays(arrays) {
+                var ret = [];
+                var positions = [];
+                var notDuplicates = {};
+
+                for (var x = 0; x < arrays.length; ++x) {
+                    positions.push(0);
+                }
+                while (ret.length < MAX_RESULTS) {
+                    var smallest = getSmallest(arrays, positions, notDuplicates);
+
+                    if (smallest === null) {
+                        break;
+                    }
+                    for (x = 0; x < arrays.length && ret.length < MAX_RESULTS; ++x) {
+                        if (arrays[x].length > positions[x] &&
+                                arrays[x][positions[x]].lev === smallest &&
+                                !notDuplicates[arrays[x][positions[x]].fullPath]) {
+                            ret.push(arrays[x][positions[x]]);
+                            notDuplicates[arrays[x][positions[x]].fullPath] = true;
+                            positions[x] += 1;
+                        }
+                    }
+                }
+                return ret;
+            }
+
             var queries = query.raw.split(",");
             var results = {
-                'in_args': [],
-                'returned': [],
-                'others': [],
+                "in_args": [],
+                "returned": [],
+                "others": [],
             };
 
             for (var i = 0; i < queries.length; ++i) {
-                var query = queries[i].trim();
+                query = queries[i].trim();
                 if (query.length !== 0) {
                     var tmp = execQuery(getQuery(query), searchWords, filterCrates);
 
-                    results['in_args'].push(tmp['in_args']);
-                    results['returned'].push(tmp['returned']);
-                    results['others'].push(tmp['others']);
+                    results.in_args.push(tmp.in_args);
+                    results.returned.push(tmp.returned);
+                    results.others.push(tmp.others);
                 }
             }
             if (queries.length > 1) {
-                function getSmallest(arrays, positions, notDuplicates) {
-                    var start = null;
-
-                    for (var it = 0; it < positions.length; ++it) {
-                        if (arrays[it].length > positions[it] &&
-                            (start === null || start > arrays[it][positions[it]].lev) &&
-                            !notDuplicates[arrays[it][positions[it]].fullPath]) {
-                            start = arrays[it][positions[it]].lev;
-                        }
-                    }
-                    return start;
-                }
-
-                function mergeArrays(arrays) {
-                    var ret = [];
-                    var positions = [];
-                    var notDuplicates = {};
-
-                    for (var x = 0; x < arrays.length; ++x) {
-                        positions.push(0);
-                    }
-                    while (ret.length < MAX_RESULTS) {
-                        var smallest = getSmallest(arrays, positions, notDuplicates);
-
-                        if (smallest === null) {
-                            break;
-                        }
-                        for (x = 0; x < arrays.length && ret.length < MAX_RESULTS; ++x) {
-                            if (arrays[x].length > positions[x] &&
-                                    arrays[x][positions[x]].lev === smallest &&
-                                    !notDuplicates[arrays[x][positions[x]].fullPath]) {
-                                ret.push(arrays[x][positions[x]]);
-                                notDuplicates[arrays[x][positions[x]].fullPath] = true;
-                                positions[x] += 1;
-                            }
-                        }
-                    }
-                    return ret;
-                }
-
                 return {
-                    'in_args': mergeArrays(results['in_args']),
-                    'returned': mergeArrays(results['returned']),
-                    'others': mergeArrays(results['others']),
+                    "in_args": mergeArrays(results.in_args),
+                    "returned": mergeArrays(results.returned),
+                    "others": mergeArrays(results.others),
                 };
             } else {
                 return {
-                    'in_args': results['in_args'][0],
-                    'returned': results['returned'][0],
-                    'others': results['others'][0],
+                    "in_args": results.in_args[0],
+                    "returned": results.returned[0],
+                    "others": results.others[0],
                 };
             }
         }
@@ -1508,6 +1546,8 @@
         function buildIndex(rawSearchIndex) {
             searchIndex = [];
             var searchWords = [];
+            var i;
+
             for (var crate in rawSearchIndex) {
                 if (!rawSearchIndex.hasOwnProperty(crate)) { continue; }
 
@@ -1534,7 +1574,7 @@
 
                 // convert `paths` into an object form
                 var len = paths.length;
-                for (var i = 0; i < len; ++i) {
+                for (i = 0; i < len; ++i) {
                     paths[i] = {ty: paths[i][0], name: paths[i][1]};
                 }
 
@@ -1545,9 +1585,9 @@
                 // operation that is cached for the life of the page state so that
                 // all other search operations have access to this cached data for
                 // faster analysis operations
-                var len = items.length;
+                len = items.length;
                 var lastPath = "";
-                for (var i = 0; i < len; ++i) {
+                for (i = 0; i < len; ++i) {
                     var rawRow = items[i];
                     var row = {crate: crate, ty: rawRow[0], name: rawRow[1],
                                path: rawRow[2] || lastPath, desc: rawRow[3],
@@ -1573,13 +1613,12 @@
                     if (browserSupportsHistoryApi()) {
                         history.replaceState("", "std - Rust", "?search=");
                     }
-                    var main = document.getElementById('main');
-                    if (hasClass(main, 'content')) {
-                        removeClass(main, 'hidden');
+                    if (hasClass(main, "content")) {
+                        removeClass(main, "hidden");
                     }
-                    var search_c = document.getElementById('search');
-                    if (hasClass(search_c, 'content')) {
-                        addClass(search_c, 'hidden');
+                    var search_c = document.getElementById("search");
+                    if (hasClass(search_c, "content")) {
+                        addClass(search_c, "hidden");
                     }
                 } else {
                     searchTimeout = setTimeout(search, 500);
@@ -1620,13 +1659,12 @@
                     // When browsing back from search results the main page
                     // visibility must be reset.
                     if (!params.search) {
-                        var main = document.getElementById('main');
-                        if (hasClass(main, 'content')) {
-                            removeClass(main, 'hidden');
+                        if (hasClass(main, "content")) {
+                            removeClass(main, "hidden");
                         }
-                        var search_c = document.getElementById('search');
-                        if (hasClass(search_c, 'content')) {
-                            addClass(search_c, 'hidden');
+                        var search_c = document.getElementById("search");
+                        if (hasClass(search_c, "content")) {
+                            addClass(search_c, "hidden");
                         }
                     }
                     // Revert to the previous title manually since the History
@@ -1643,9 +1681,9 @@
                     if (params.search) {
                         search_input.value = params.search;
                     } else {
-                        search_input.value = '';
+                        search_input.value = "";
                     }
-                    // Some browsers fire 'onpopstate' for every page load
+                    // Some browsers fire "onpopstate" for every page load
                     // (Chrome), while others fire the event only when actually
                     // popping a state (Firefox), which is why search() is
                     // called both here and at the end of the startSearch()
@@ -1660,13 +1698,13 @@
         startSearch();
 
         // Draw a convenient sidebar of known crates if we have a listing
-        if (rootPath === '../' || rootPath === "./") {
-            var sidebar = document.getElementsByClassName('sidebar-elems')[0];
+        if (rootPath === "../" || rootPath === "./") {
+            var sidebar = document.getElementsByClassName("sidebar-elems")[0];
             if (sidebar) {
-                var div = document.createElement('div');
-                div.className = 'block crate';
-                div.innerHTML = '<h3>Crates</h3>';
-                var ul = document.createElement('ul');
+                var div = document.createElement("div");
+                div.className = "block crate";
+                div.innerHTML = "<h3>Crates</h3>";
+                var ul = document.createElement("ul");
                 div.appendChild(ul);
 
                 var crates = [];
@@ -1678,17 +1716,17 @@
                 }
                 crates.sort();
                 for (var i = 0; i < crates.length; ++i) {
-                    var klass = 'crate';
+                    var klass = "crate";
                     if (rootPath !== "./" && crates[i] === window.currentCrate) {
-                        klass += ' current';
+                        klass += " current";
                     }
-                    var link = document.createElement('a');
-                    link.href = rootPath + crates[i] + '/index.html';
+                    var link = document.createElement("a");
+                    link.href = rootPath + crates[i] + "/index.html";
                     link.title = rawSearchIndex[crates[i]].doc;
                     link.className = klass;
                     link.textContent = crates[i];
 
-                    var li = document.createElement('li');
+                    var li = document.createElement("li");
                     li.appendChild(link);
                     ul.appendChild(li);
                 }
@@ -1701,41 +1739,44 @@
 
     // delayed sidebar rendering.
     function initSidebarItems(items) {
-        var sidebar = document.getElementsByClassName('sidebar-elems')[0];
+        var sidebar = document.getElementsByClassName("sidebar-elems")[0];
         var current = window.sidebarCurrent;
 
         function block(shortty, longty) {
             var filtered = items[shortty];
-            if (!filtered) { return; }
+            if (!filtered) {
+                return;
+            }
 
-            var div = document.createElement('div');
-            div.className = 'block ' + shortty;
-            var h3 = document.createElement('h3');
+            var div = document.createElement("div");
+            div.className = "block " + shortty;
+            var h3 = document.createElement("h3");
             h3.textContent = longty;
             div.appendChild(h3);
-            var ul = document.createElement('ul');
+            var ul = document.createElement("ul");
 
-            for (var i = 0; i < filtered.length; ++i) {
+            var length = filtered.length;
+            for (var i = 0; i < length; ++i) {
                 var item = filtered[i];
                 var name = item[0];
                 var desc = item[1]; // can be null
 
                 var klass = shortty;
                 if (name === current.name && shortty === current.ty) {
-                    klass += ' current';
+                    klass += " current";
                 }
                 var path;
-                if (shortty === 'mod') {
-                    path = name + '/index.html';
+                if (shortty === "mod") {
+                    path = name + "/index.html";
                 } else {
-                    path = shortty + '.' + name + '.html';
+                    path = shortty + "." + name + ".html";
                 }
-                var link = document.createElement('a');
+                var link = document.createElement("a");
                 link.href = current.relpath + path;
                 link.title = desc;
                 link.className = klass;
                 link.textContent = name;
-                var li = document.createElement('li');
+                var li = document.createElement("li");
                 li.appendChild(link);
                 ul.appendChild(li);
             }
@@ -1763,22 +1804,25 @@
     window.initSidebarItems = initSidebarItems;
 
     window.register_implementors = function(imp) {
-        var implementors = document.getElementById('implementors-list');
-        var synthetic_implementors = document.getElementById('synthetic-implementors-list');
+        var implementors = document.getElementById("implementors-list");
+        var synthetic_implementors = document.getElementById("synthetic-implementors-list");
 
         var libs = Object.getOwnPropertyNames(imp);
-        for (var i = 0; i < libs.length; ++i) {
+        var llength = libs.length;
+        for (var i = 0; i < llength; ++i) {
             if (libs[i] === currentCrate) { continue; }
             var structs = imp[libs[i]];
 
+            var slength = structs.length;
             struct_loop:
-            for (var j = 0; j < structs.length; ++j) {
+            for (var j = 0; j < slength; ++j) {
                 var struct = structs[j];
 
                 var list = struct.synthetic ? synthetic_implementors : implementors;
 
                 if (struct.synthetic) {
-                    for (var k = 0; k < struct.types.length; k++) {
+                    var stlength = struct.types.length;
+                    for (var k = 0; k < stlength; k++) {
                         if (window.inlined_types.has(struct.types[k])) {
                             continue struct_loop;
                         }
@@ -1786,21 +1830,22 @@
                     }
                 }
 
-                var code = document.createElement('code');
+                var code = document.createElement("code");
                 code.innerHTML = struct.text;
 
-                var x = code.getElementsByTagName('a');
-                for (var k = 0; k < x.length; k++) {
-                    var href = x[k].getAttribute('href');
-                    if (href && href.indexOf('http') !== 0) {
-                        x[k].setAttribute('href', rootPath + href);
+                var x = code.getElementsByTagName("a");
+                var xlength = x.length;
+                for (var it = 0; it < xlength; it++) {
+                    var href = x[it].getAttribute("href");
+                    if (href && href.indexOf("http") !== 0) {
+                        x[it].setAttribute("href", rootPath + href);
                     }
                 }
-                var display = document.createElement('h3');
+                var display = document.createElement("h3");
                 addClass(display, "impl");
-                display.innerHTML = '<span class="in-band"><table class="table-display"><tbody>\
-                    <tr><td><code>' + code.outerHTML + '</code></td><td></td></tr></tbody></table>\
-                    </span>';
+                display.innerHTML = "<span class=\"in-band\"><table class=\"table-display\">" +
+                    "<tbody><tr><td><code>" + code.outerHTML + "</code></td><td></td></tr>" +
+                    "</tbody></table></span>";
                 list.appendChild(display);
             }
         }
@@ -1816,47 +1861,49 @@
         }
         // button will collapse the section
         // note that this text is also set in the HTML template in render.rs
-        return "\u2212"; // "\u2212" is '−' minus sign
+        return "\u2212"; // "\u2212" is "−" minus sign
     }
 
     function onEveryMatchingChild(elem, className, func) {
         if (elem && className && func) {
-            for (var i = 0; i < elem.childNodes.length; i++) {
-                if (hasClass(elem.childNodes[i], className)) {
-                    func(elem.childNodes[i]);
+            var length = elem.childNodes.length;
+            var nodes = elem.childNodes;
+            for (var i = 0; i < length; ++i) {
+                if (hasClass(nodes[i], className)) {
+                    func(nodes[i]);
                 } else {
-                    onEveryMatchingChild(elem.childNodes[i], className, func);
+                    onEveryMatchingChild(nodes[i], className, func);
                 }
             }
         }
     }
 
     function toggleAllDocs(pageId, fromAutoCollapse) {
-        var toggle = document.getElementById("toggle-all-docs");
-        if (!toggle) {
+        var innerToggle = document.getElementById("toggle-all-docs");
+        if (!innerToggle) {
             return;
         }
-        if (hasClass(toggle, "will-expand")) {
+        if (hasClass(innerToggle, "will-expand")) {
             updateLocalStorage("rustdoc-collapse", "false");
-            removeClass(toggle, "will-expand");
-            onEveryMatchingChild(toggle, "inner", function(e) {
+            removeClass(innerToggle, "will-expand");
+            onEveryMatchingChild(innerToggle, "inner", function(e) {
                 e.innerHTML = labelForToggleButton(false);
             });
-            toggle.title = "collapse all docs";
+            innerToggle.title = "collapse all docs";
             if (fromAutoCollapse !== true) {
-                onEach(document.getElementsByClassName("collapse-toggle"), function(e) {
+                onEachLazy(document.getElementsByClassName("collapse-toggle"), function(e) {
                     collapseDocs(e, "show");
                 });
             }
         } else {
             updateLocalStorage("rustdoc-collapse", "true");
-            addClass(toggle, "will-expand");
-            onEveryMatchingChild(toggle, "inner", function(e) {
+            addClass(innerToggle, "will-expand");
+            onEveryMatchingChild(innerToggle, "inner", function(e) {
                 e.innerHTML = labelForToggleButton(true);
             });
-            toggle.title = "expand all docs";
+            innerToggle.title = "expand all docs";
             if (fromAutoCollapse !== true) {
-                onEach(document.getElementsByClassName("collapse-toggle"), function(e) {
+                onEachLazy(document.getElementsByClassName("collapse-toggle"), function(e) {
                     collapseDocs(e, "hide", pageId);
                 });
             }
@@ -1870,27 +1917,58 @@
 
         function adjustToggle(arg) {
             return function(e) {
-                if (hasClass(e, 'toggle-label')) {
+                if (hasClass(e, "toggle-label")) {
                     if (arg) {
-                        e.style.display = 'inline-block';
+                        e.style.display = "inline-block";
                     } else {
-                        e.style.display = 'none';
+                        e.style.display = "none";
                     }
                 }
-                if (hasClass(e, 'inner')) {
+                if (hasClass(e, "inner")) {
                     e.innerHTML = labelForToggleButton(arg);
                 }
             };
-        };
+        }
 
-        if (!hasClass(toggle.parentNode, "impl")) {
-            var relatedDoc = toggle.parentNode.nextElementSibling;
+        function implHider(addOrRemove) {
+            return function(n) {
+                var is_method = hasClass(n, "method");
+                if (is_method || hasClass(n, "type")) {
+                    if (is_method === true) {
+                        if (addOrRemove) {
+                            addClass(n, "hidden-by-impl-hider");
+                        } else {
+                            removeClass(n, "hidden-by-impl-hider");
+                        }
+                    }
+                    var ns = n.nextElementSibling;
+                    while (true) {
+                        if (ns && (
+                                hasClass(ns, "docblock") ||
+                                hasClass(ns, "stability"))) {
+                            if (addOrRemove) {
+                                addClass(ns, "hidden-by-impl-hider");
+                            } else {
+                                removeClass(ns, "hidden-by-impl-hider");
+                            }
+                            ns = ns.nextElementSibling;
+                            continue;
+                        }
+                        break;
+                    }
+                }
+            };
+        }
+
+        var relatedDoc;
+        var action = mode;
+        if (hasClass(toggle.parentNode, "impl") === false) {
+            relatedDoc = toggle.parentNode.nextElementSibling;
             if (hasClass(relatedDoc, "stability")) {
                 relatedDoc = relatedDoc.nextElementSibling;
             }
             if (hasClass(relatedDoc, "docblock") || hasClass(relatedDoc, "sub-variant")) {
-                var action = mode;
-                if (action === "toggle") {
+                if (mode === "toggle") {
                     if (hasClass(relatedDoc, "hidden-by-usual-hider")) {
                         action = "show";
                     } else {
@@ -1899,67 +1977,35 @@
                 }
                 if (action === "hide") {
                     addClass(relatedDoc, "hidden-by-usual-hider");
-                    onEach(toggle.childNodes, adjustToggle(true));
-                    addClass(toggle.parentNode, 'collapsed');
+                    onEachLazy(toggle.childNodes, adjustToggle(true));
+                    addClass(toggle.parentNode, "collapsed");
                 } else if (action === "show") {
                     removeClass(relatedDoc, "hidden-by-usual-hider");
-                    removeClass(toggle.parentNode, 'collapsed');
-                    onEach(toggle.childNodes, adjustToggle(false));
+                    removeClass(toggle.parentNode, "collapsed");
+                    onEachLazy(toggle.childNodes, adjustToggle(false));
                 }
             }
         } else {
             // we are collapsing the impl block
-            function implHider(addOrRemove) {
-                return function(n) {
-                    var is_method = hasClass(n, "method");
-                    if (is_method || hasClass(n, "type")) {
-                        if (is_method === true) {
-                            if (addOrRemove) {
-                                addClass(n, "hidden-by-impl-hider");
-                            } else {
-                                removeClass(n, "hidden-by-impl-hider");
-                            }
-                        }
-                        var ns = n.nextElementSibling;
-                        while (true) {
-                            if (ns && (
-                                    hasClass(ns, "docblock") ||
-                                    hasClass(ns, "stability"))) {
-                                if (addOrRemove) {
-                                    addClass(ns, "hidden-by-impl-hider");
-                                } else {
-                                    removeClass(ns, "hidden-by-impl-hider");
-                                }
-                                ns = ns.nextElementSibling;
-                                continue;
-                            }
-                            break;
-                        }
-                    }
-                }
-            }
 
             var parentElem = toggle.parentNode;
-            var relatedDoc = parentElem;
+            relatedDoc = parentElem;
             var docblock = relatedDoc.nextElementSibling;
 
-            while (!hasClass(relatedDoc, "impl-items")) {
+            while (hasClass(relatedDoc, "impl-items") === false) {
                 relatedDoc = relatedDoc.nextElementSibling;
             }
 
-            if ((!relatedDoc && !hasClass(docblock, "docblock")) ||
-                (pageId && onEach(relatedDoc.childNodes, function(e) {
-                    return e.id === pageId;
-                }) === true)) {
+            if ((!relatedDoc && hasClass(docblock, "docblock") === false) ||
+                (pageId && document.getElementById(pageId))) {
                 return;
             }
 
             // Hide all functions, but not associated types/consts
 
-            var action = mode;
-            if (action === "toggle") {
+            if (mode === "toggle") {
                 if (hasClass(relatedDoc, "fns-now-collapsed") ||
-                    hasClass(docblock,  "hidden-by-impl-hider")) {
+                    hasClass(docblock, "hidden-by-impl-hider")) {
                     action = "show";
                 } else {
                     action = "hide";
@@ -1969,13 +2015,25 @@
             if (action === "show") {
                 removeClass(relatedDoc, "fns-now-collapsed");
                 removeClass(docblock, "hidden-by-usual-hider");
-                onEach(toggle.childNodes, adjustToggle(false));
-                onEach(relatedDoc.childNodes, implHider(false));
+                onEachLazy(toggle.childNodes, adjustToggle(false));
+                onEachLazy(relatedDoc.childNodes, implHider(false));
             } else if (action === "hide") {
                 addClass(relatedDoc, "fns-now-collapsed");
                 addClass(docblock, "hidden-by-usual-hider");
-                onEach(toggle.childNodes, adjustToggle(true));
-                onEach(relatedDoc.childNodes, implHider(true));
+                onEachLazy(toggle.childNodes, adjustToggle(true));
+                onEachLazy(relatedDoc.childNodes, implHider(true));
+            }
+        }
+    }
+
+    function collapser(e, collapse) {
+        // inherent impl ids are like "impl" or impl-<number>'.
+        // they will never be hidden by default.
+        var n = e.parentElement;
+        if (n.id.match(/^impl(?:-\d+)?$/) === null) {
+            // Automatically minimize all non-inherent impls
+            if (collapse || hasClass(n, "impl")) {
+                collapseDocs(e, "hide", pageId);
             }
         }
     }
@@ -1983,88 +2041,112 @@
     function autoCollapse(pageId, collapse) {
         if (collapse) {
             toggleAllDocs(pageId, true);
-        }
-        var collapser = function(e) {
-                // inherent impl ids are like 'impl' or impl-<number>'.
-                // they will never be hidden by default.
-                var n = e.parentElement;
-                if (n.id.match(/^impl(?:-\d+)?$/) === null) {
-                    // Automatically minimize all non-inherent impls
-                    if (collapse || hasClass(n, 'impl')) {
-                        collapseDocs(e, "hide", pageId);
-                    }
-                }
-        };
-        if (getCurrentValue('rustdoc-trait-implementations') !== "false") {
-            var impl_list = document.getElementById('implementations-list');
+        } else if (getCurrentValue("rustdoc-trait-implementations") !== "false") {
+            var impl_list = document.getElementById("implementations-list");
 
             if (impl_list !== null) {
-                onEach(impl_list.getElementsByClassName("collapse-toggle"), collapser);
-            }
-        }
-        if (getCurrentValue('rustdoc-method-docs') !== "false") {
-            var implItems = document.getElementsByClassName('impl-items');
-
-            if (implItems && implItems.length > 0) {
-                onEach(implItems, function(elem) {
-                    onEach(elem.getElementsByClassName("collapse-toggle"), collapser);
+                onEachLazy(impl_list.getElementsByClassName("collapse-toggle"), function(e) {
+                    collapser(e, collapse);
                 });
             }
         }
     }
 
-    var x = document.getElementById('toggle-all-docs');
-    if (x) {
-        x.onclick = toggleAllDocs;
+    var toggles = document.getElementById("toggle-all-docs");
+    if (toggles) {
+        toggles.onclick = toggleAllDocs;
     }
 
     function insertAfter(newNode, referenceNode) {
         referenceNode.parentNode.insertBefore(newNode, referenceNode.nextSibling);
     }
 
-    function checkIfThereAreMethods(elems) {
-        var areThereMethods = false;
-
-        onEach(elems, function(e) {
-            if (hasClass(e, "method")) {
-                areThereMethods = true;
-                return true;
-            }
-        });
-        return areThereMethods;
+    function createSimpleToggle(sectionIsCollapsed) {
+        var toggle = document.createElement("a");
+        toggle.href = "javascript:void(0)";
+        toggle.className = "collapse-toggle";
+        toggle.innerHTML = "[<span class=\"inner\">" + labelForToggleButton(sectionIsCollapsed) +
+                           "</span>]";
+        return toggle;
     }
 
-    var toggle = document.createElement('a');
-    toggle.href = 'javascript:void(0)';
-    toggle.className = 'collapse-toggle';
-    toggle.innerHTML = "[<span class='inner'>" + labelForToggleButton(false) + "</span>]";
+    var toggle = createSimpleToggle(false);
 
     var func = function(e) {
         var next = e.nextElementSibling;
-        if (hasClass(e, 'impl') && next && hasClass(next, 'docblock')) {
+        if (!next) {
+            return;
+        }
+        if (hasClass(next, "docblock") ||
+            (hasClass(next, "stability") &&
+             hasClass(next.nextElementSibling, "docblock"))) {
+            insertAfter(toggle.cloneNode(true), e.childNodes[e.childNodes.length - 1]);
+        }
+    };
+
+    var funcImpl = function(e) {
+        var next = e.nextElementSibling;
+        if (next && hasClass(next, "docblock")) {
             next = next.nextElementSibling;
         }
         if (!next) {
             return;
         }
-        if ((hasClass(e, 'method') || hasClass(e, 'associatedconstant') ||
-             checkIfThereAreMethods(next.childNodes)) &&
-            (hasClass(next, 'docblock') ||
-             hasClass(e, 'impl') ||
-             (hasClass(next, 'stability') &&
-              hasClass(next.nextElementSibling, 'docblock')))) {
+        if (next.getElementsByClassName("method").length > 0 && hasClass(e, "impl")) {
             insertAfter(toggle.cloneNode(true), e.childNodes[e.childNodes.length - 1]);
         }
     };
-    onEach(document.getElementsByClassName('method'), func);
-    onEach(document.getElementsByClassName('associatedconstant'), func);
-    onEach(document.getElementsByClassName('impl'), func);
-    onEach(document.getElementsByClassName('impl-items'), function(e) {
-        onEach(e.getElementsByClassName('associatedconstant'), func);
-        var hiddenElems = e.getElementsByClassName('hidden');
+
+    onEachLazy(document.getElementsByClassName("method"), func);
+    onEachLazy(document.getElementsByClassName("associatedconstant"), func);
+    onEachLazy(document.getElementsByClassName("impl"), funcImpl);
+    var impl_call = function() {};
+    if (getCurrentValue("rustdoc-method-docs") !== "false") {
+        impl_call = function(e, newToggle, pageId) {
+            if (e.id.match(/^impl(?:-\d+)?$/) === null) {
+                // Automatically minimize all non-inherent impls
+                if (hasClass(e, "impl")) {
+                    collapseDocs(newToggle, "hide", pageId);
+                }
+            }
+        };
+    }
+    var pageId = getPageId();
+    var newToggle = document.createElement("a");
+    newToggle.href = "javascript:void(0)";
+    newToggle.className = "collapse-toggle hidden-default collapsed";
+    newToggle.innerHTML = "[<span class=\"inner\">" + labelForToggleButton(true) +
+                          "</span>] Show hidden undocumented items";
+    function toggleClicked() {
+        if (hasClass(this, "collapsed")) {
+            removeClass(this, "collapsed");
+            onEachLazy(this.parentNode.getElementsByClassName("hidden"), function(x) {
+                if (hasClass(x, "content") === false) {
+                    removeClass(x, "hidden");
+                    addClass(x, "x");
+                }
+            }, true);
+            this.innerHTML = "[<span class=\"inner\">" + labelForToggleButton(false) +
+                             "</span>] Hide undocumented items";
+        } else {
+            addClass(this, "collapsed");
+            onEachLazy(this.parentNode.getElementsByClassName("x"), function(x) {
+                if (hasClass(x, "content") === false) {
+                    addClass(x, "hidden");
+                    removeClass(x, "x");
+                }
+            }, true);
+            this.innerHTML = "[<span class=\"inner\">" + labelForToggleButton(true) +
+                             "</span>] Show hidden undocumented items";
+        }
+    }
+    onEachLazy(document.getElementsByClassName("impl-items"), function(e) {
+        onEachLazy(e.getElementsByClassName("associatedconstant"), func);
+        var hiddenElems = e.getElementsByClassName("hidden");
         var needToggle = false;
 
-        for (var i = 0; i < hiddenElems.length; ++i) {
+        var hlength = hiddenElems.length;
+        for (var i = 0; i < hlength; ++i) {
             if (hasClass(hiddenElems[i], "content") === false &&
                 hasClass(hiddenElems[i], "docblock") === false) {
                 needToggle = true;
@@ -2072,46 +2154,21 @@
             }
         }
         if (needToggle === true) {
-            var newToggle = document.createElement('a');
-            newToggle.href = 'javascript:void(0)';
-            newToggle.className = 'collapse-toggle hidden-default collapsed';
-            newToggle.innerHTML = "[<span class='inner'>" + labelForToggleButton(true) + "</span>" +
-                                  "] Show hidden undocumented items";
-            newToggle.onclick = function() {
-                if (hasClass(this, "collapsed")) {
-                    removeClass(this, "collapsed");
-                    onEach(this.parentNode.getElementsByClassName("hidden"), function(x) {
-                        if (hasClass(x, "content") === false) {
-                            removeClass(x, "hidden");
-                            addClass(x, "x");
-                        }
-                    }, true);
-                    this.innerHTML = "[<span class='inner'>" + labelForToggleButton(false) +
-                                     "</span>] Hide undocumented items"
-                } else {
-                    addClass(this, "collapsed");
-                    onEach(this.parentNode.getElementsByClassName("x"), function(x) {
-                        if (hasClass(x, "content") === false) {
-                            addClass(x, "hidden");
-                            removeClass(x, "x");
-                        }
-                    }, true);
-                    this.innerHTML = "[<span class='inner'>" + labelForToggleButton(true) +
-                                     "</span>] Show hidden undocumented items";
-                }
-            };
-            e.insertBefore(newToggle, e.firstChild);
+            var inner_toggle = newToggle.cloneNode(true);
+            inner_toggle.onclick = toggleClicked;
+            e.insertBefore(inner_toggle, e.firstChild);
+            impl_call(e, inner_toggle, pageId);
         }
     });
 
     function createToggle(otherMessage, fontSize, extraClass, show) {
-        var span = document.createElement('span');
-        span.className = 'toggle-label';
+        var span = document.createElement("span");
+        span.className = "toggle-label";
         if (show) {
-            span.style.display = 'none';
+            span.style.display = "none";
         }
         if (!otherMessage) {
-            span.innerHTML = '&nbsp;Expand&nbsp;description';
+            span.innerHTML = "&nbsp;Expand&nbsp;description";
         } else {
             span.innerHTML = otherMessage;
         }
@@ -2123,13 +2180,13 @@
         var mainToggle = toggle.cloneNode(true);
         mainToggle.appendChild(span);
 
-        var wrapper = document.createElement('div');
-        wrapper.className = 'toggle-wrapper';
+        var wrapper = document.createElement("div");
+        wrapper.className = "toggle-wrapper";
         if (!show) {
-            addClass(wrapper, 'collapsed');
-            var inner = mainToggle.getElementsByClassName('inner');
+            addClass(wrapper, "collapsed");
+            var inner = mainToggle.getElementsByClassName("inner");
             if (inner && inner.length > 0) {
-                inner[0].innerHTML = '+';
+                inner[0].innerHTML = "+";
             }
         }
         if (extraClass) {
@@ -2139,21 +2196,21 @@
         return wrapper;
     }
 
-    var showItemDeclarations = getCurrentValue('rustdoc-item-declarations') === "false";
+    var showItemDeclarations = getCurrentValue("rustdoc-item-declarations") === "false";
     function buildToggleWrapper(e) {
-        if (hasClass(e, 'autohide')) {
+        if (hasClass(e, "autohide")) {
             var wrap = e.previousElementSibling;
-            if (wrap && hasClass(wrap, 'toggle-wrapper')) {
-                var toggle = wrap.childNodes[0];
-                var extra = e.childNodes[0].tagName === 'H3';
+            if (wrap && hasClass(wrap, "toggle-wrapper")) {
+                var inner_toggle = wrap.childNodes[0];
+                var extra = e.childNodes[0].tagName === "H3";
 
-                e.style.display = 'none';
-                addClass(wrap, 'collapsed');
-                onEach(toggle.getElementsByClassName('inner'), function(e) {
+                e.style.display = "none";
+                addClass(wrap, "collapsed");
+                onEachLazy(inner_toggle.getElementsByClassName("inner"), function(e) {
                     e.innerHTML = labelForToggleButton(true);
                 });
-                onEach(toggle.getElementsByClassName('toggle-label'), function(e) {
-                    e.style.display = 'inline-block';
+                onEachLazy(inner_toggle.getElementsByClassName("toggle-label"), function(e) {
+                    e.style.display = "inline-block";
                     if (extra === true) {
                         i_e.innerHTML = " Show " + e.childNodes[0].innerHTML;
                     }
@@ -2161,28 +2218,28 @@
             }
         }
         if (e.parentNode.id === "main") {
-            var otherMessage = '';
+            var otherMessage = "";
             var fontSize;
             var extraClass;
 
             if (hasClass(e, "type-decl")) {
                 fontSize = "20px";
-                otherMessage = '&nbsp;Show&nbsp;declaration';
+                otherMessage = "&nbsp;Show&nbsp;declaration";
                 if (showItemDeclarations === false) {
-                    extraClass = 'collapsed';
+                    extraClass = "collapsed";
                 }
             } else if (hasClass(e, "sub-variant")) {
-                otherMessage = '&nbsp;Show&nbsp;fields';
+                otherMessage = "&nbsp;Show&nbsp;fields";
             } else if (hasClass(e, "non-exhaustive")) {
-                otherMessage = '&nbsp;This&nbsp;';
+                otherMessage = "&nbsp;This&nbsp;";
                 if (hasClass(e, "non-exhaustive-struct")) {
-                    otherMessage += 'struct';
+                    otherMessage += "struct";
                 } else if (hasClass(e, "non-exhaustive-enum")) {
-                    otherMessage += 'enum';
+                    otherMessage += "enum";
                 } else if (hasClass(e, "non-exhaustive-type")) {
-                    otherMessage += 'type';
+                    otherMessage += "type";
                 }
-                otherMessage += '&nbsp;is&nbsp;marked&nbsp;as&nbsp;non-exhaustive';
+                otherMessage += "&nbsp;is&nbsp;marked&nbsp;as&nbsp;non-exhaustive";
             } else if (hasClass(e.childNodes[0], "impl-items")) {
                 extraClass = "marg-left";
             }
@@ -2199,21 +2256,8 @@
         }
     }
 
-    onEach(document.getElementsByClassName('docblock'), buildToggleWrapper);
-    onEach(document.getElementsByClassName('sub-variant'), buildToggleWrapper);
-
-    function createToggleWrapper(tog) {
-        var span = document.createElement('span');
-        span.className = 'toggle-label';
-        span.style.display = 'none';
-        span.innerHTML = '&nbsp;Expand&nbsp;attributes';
-        tog.appendChild(span);
-
-        var wrapper = document.createElement('div');
-        wrapper.className = 'toggle-wrapper toggle-attributes';
-        wrapper.appendChild(tog);
-        return wrapper;
-    }
+    onEachLazy(document.getElementsByClassName("docblock"), buildToggleWrapper);
+    onEachLazy(document.getElementsByClassName("sub-variant"), buildToggleWrapper);
 
     // In the search display, allows to switch between tabs.
     function printTab(nb) {
@@ -2221,24 +2265,37 @@
             currentTab = nb;
         }
         var nb_copy = nb;
-        onEach(document.getElementById('titles').childNodes, function(elem) {
+        onEachLazy(document.getElementById("titles").childNodes, function(elem) {
             if (nb_copy === 0) {
-                addClass(elem, 'selected');
+                addClass(elem, "selected");
             } else {
-                removeClass(elem, 'selected');
+                removeClass(elem, "selected");
             }
             nb_copy -= 1;
         });
-        onEach(document.getElementById('results').childNodes, function(elem) {
+        onEachLazy(document.getElementById("results").childNodes, function(elem) {
             if (nb === 0) {
-                elem.style.display = '';
+                elem.style.display = "";
             } else {
-                elem.style.display = 'none';
+                elem.style.display = "none";
             }
             nb -= 1;
         });
     }
 
+    function createToggleWrapper(tog) {
+        var span = document.createElement("span");
+        span.className = "toggle-label";
+        span.style.display = "none";
+        span.innerHTML = "&nbsp;Expand&nbsp;attributes";
+        tog.appendChild(span);
+
+        var wrapper = document.createElement("div");
+        wrapper.className = "toggle-wrapper toggle-attributes";
+        wrapper.appendChild(tog);
+        return wrapper;
+    }
+
     // To avoid checking on "rustdoc-item-attributes" value on every loop...
     var itemAttributesFunc = function() {};
     if (getCurrentValue("rustdoc-item-attributes") !== "false") {
@@ -2246,8 +2303,9 @@
             collapseDocs(x.previousSibling.childNodes[0], "toggle");
         };
     }
-    onEach(document.getElementById('main').getElementsByClassName('attributes'), function(i_e) {
-        i_e.parentNode.insertBefore(createToggleWrapper(toggle.cloneNode(true)), i_e);
+    var attributesToggle = createToggleWrapper(createSimpleToggle(false));
+    onEachLazy(main.getElementsByClassName("attributes"), function(i_e) {
+        i_e.parentNode.insertBefore(attributesToggle.cloneNode(true), i_e);
         itemAttributesFunc(i_e);
     });
 
@@ -2255,45 +2313,45 @@
     var lineNumbersFunc = function() {};
     if (getCurrentValue("rustdoc-line-numbers") === "true") {
         lineNumbersFunc = function(x) {
-            var count = x.textContent.split('\n').length;
+            var count = x.textContent.split("\n").length;
             var elems = [];
             for (var i = 0; i < count; ++i) {
                 elems.push(i + 1);
             }
-            var node = document.createElement('pre');
-            addClass(node, 'line-number');
-            node.innerHTML = elems.join('\n');
+            var node = document.createElement("pre");
+            addClass(node, "line-number");
+            node.innerHTML = elems.join("\n");
             x.parentNode.insertBefore(node, x);
         };
     }
-    onEach(document.getElementsByClassName('rust-example-rendered'), function(e) {
-        if (hasClass(e, 'compile_fail')) {
+    onEachLazy(document.getElementsByClassName("rust-example-rendered"), function(e) {
+        if (hasClass(e, "compile_fail")) {
             e.addEventListener("mouseover", function(event) {
-                this.parentElement.previousElementSibling.childNodes[0].style.color = '#f00';
+                this.parentElement.previousElementSibling.childNodes[0].style.color = "#f00";
             });
             e.addEventListener("mouseout", function(event) {
-                this.parentElement.previousElementSibling.childNodes[0].style.color = '';
+                this.parentElement.previousElementSibling.childNodes[0].style.color = "";
             });
-        } else if (hasClass(e, 'ignore')) {
+        } else if (hasClass(e, "ignore")) {
             e.addEventListener("mouseover", function(event) {
-                this.parentElement.previousElementSibling.childNodes[0].style.color = '#ff9200';
+                this.parentElement.previousElementSibling.childNodes[0].style.color = "#ff9200";
             });
             e.addEventListener("mouseout", function(event) {
-                this.parentElement.previousElementSibling.childNodes[0].style.color = '';
+                this.parentElement.previousElementSibling.childNodes[0].style.color = "";
             });
         }
         lineNumbersFunc(e);
     });
 
     function showModal(content) {
-        var modal = document.createElement('div');
+        var modal = document.createElement("div");
         modal.id = "important";
-        addClass(modal, 'modal');
-        modal.innerHTML = '<div class="modal-content"><div class="close" id="modal-close">✕</div>' +
-                          '<div class="whiter"></div><span class="docblock">' + content +
-                          '</span></div>';
-        document.getElementsByTagName('body')[0].appendChild(modal);
-        document.getElementById('modal-close').onclick = hideModal;
+        addClass(modal, "modal");
+        modal.innerHTML = "<div class=\"modal-content\"><div class=\"close\" id=\"modal-close\">✕" +
+                          "</div><div class=\"whiter\"></div><span class=\"docblock\">" + content +
+                          "</span></div>";
+        document.getElementsByTagName("body")[0].appendChild(modal);
+        document.getElementById("modal-close").onclick = hideModal;
         modal.onclick = hideModal;
     }
 
@@ -2304,7 +2362,7 @@
         }
     }
 
-    onEach(document.getElementsByClassName('important-traits'), function(e) {
+    onEachLazy(document.getElementsByClassName("important-traits"), function(e) {
         e.onclick = function() {
             showModal(e.lastElementChild.innerHTML);
         };
@@ -2312,7 +2370,7 @@
 
     function putBackSearch(search_input) {
         if (search_input.value !== "") {
-            addClass(document.getElementById("main"), "hidden");
+            addClass(main, "hidden");
             removeClass(document.getElementById("search"), "hidden");
             if (browserSupportsHistoryApi()) {
                 history.replaceState(search_input.value,
@@ -2330,16 +2388,16 @@
 
     var params = getQueryStringParams();
     if (params && params.search) {
-        addClass(document.getElementById("main"), "hidden");
+        addClass(main, "hidden");
         var search = document.getElementById("search");
         removeClass(search, "hidden");
-        search.innerHTML = '<h3 style="text-align: center;">Loading search results...</h3>';
+        search.innerHTML = "<h3 style=\"text-align: center;\">Loading search results...</h3>";
     }
 
     var sidebar_menu = document.getElementsByClassName("sidebar-menu")[0];
     if (sidebar_menu) {
         sidebar_menu.onclick = function() {
-            var sidebar = document.getElementsByClassName('sidebar')[0];
+            var sidebar = document.getElementsByClassName("sidebar")[0];
             if (hasClass(sidebar, "mobile") === true) {
                 hideSidebar();
             } else {
@@ -2355,7 +2413,18 @@
     autoCollapse(getPageId(), getCurrentValue("rustdoc-collapse") === "true");
 
     if (window.location.hash && window.location.hash.length > 0) {
-        expandSection(window.location.hash.replace(/^#/, ''));
+        expandSection(window.location.hash.replace(/^#/, ""));
+    }
+
+    if (main) {
+        onEachLazy(main.getElementsByClassName("loading-content"), function(e) {
+            e.remove();
+        });
+        onEachLazy(main.childNodes, function(e) {
+            if (e.tagName === "H2" || e.tagName === "H3") {
+                e.nextElementSibling.style.display = "block";
+            }
+        });
     }
 
     function addSearchOptions(crates) {
@@ -2394,10 +2463,10 @@
 
 // Sets the focus on the search bar at the top of the page
 function focusSearchBar() {
-    document.getElementsByClassName('search-input')[0].focus();
+    document.getElementsByClassName("search-input")[0].focus();
 }
 
 // Removes the focus from the search bar
 function defocusSearchBar() {
-    document.getElementsByClassName('search-input')[0].blur();
+    document.getElementsByClassName("search-input")[0].blur();
 }
diff --git a/src/librustdoc/html/static/noscript.css b/src/librustdoc/html/static/noscript.css
new file mode 100644
index 0000000..f4de75f
--- /dev/null
+++ b/src/librustdoc/html/static/noscript.css
@@ -0,0 +1,19 @@
+/**
+ * Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+ * file at the top-level directory of this distribution and at
+ * http://rust-lang.org/COPYRIGHT.
+ *
+ * Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+ * http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+ * <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+ * option. This file may not be copied, modified, or distributed
+ * except according to those terms.
+ */
+
+#main > h2 + div, #main > h2 + h3, #main > h3 + div {
+	display: block;
+}
+
+.loading-content {
+	display: none;
+}
diff --git a/src/librustdoc/html/static/rustdoc.css b/src/librustdoc/html/static/rustdoc.css
index cd5a8a7..d1336b1 100644
--- a/src/librustdoc/html/static/rustdoc.css
+++ b/src/librustdoc/html/static/rustdoc.css
@@ -368,6 +368,10 @@
 #main > .docblock h2 { font-size: 1.15em; }
 #main > .docblock h3, #main > .docblock h4, #main > .docblock h5 { font-size: 1em; }
 
+#main > h2 + div, #main > h2 + h3, #main > h3 + div {
+	display: none;
+}
+
 .docblock h1 { font-size: 1em; }
 .docblock h2 { font-size: 0.95em; }
 .docblock h3, .docblock h4, .docblock h5 { font-size: 0.9em; }
diff --git a/src/librustdoc/html/static/storage.js b/src/librustdoc/html/static/storage.js
index e8f0c03..d1c377b 100644
--- a/src/librustdoc/html/static/storage.js
+++ b/src/librustdoc/html/static/storage.js
@@ -19,55 +19,38 @@
 var savedHref = [];
 
 function hasClass(elem, className) {
-    if (elem && className && elem.className) {
-        var elemClass = elem.className;
-        var start = elemClass.indexOf(className);
-        if (start === -1) {
-            return false;
-        } else if (elemClass.length === className.length) {
-            return true;
-        } else {
-            if (start > 0 && elemClass[start - 1] !== ' ') {
-                return false;
-            }
-            var end = start + className.length;
-            return !(end < elemClass.length && elemClass[end] !== ' ');
-        }
-    }
-    return false;
+    return elem && elem.classList && elem.classList.contains(className);
 }
 
 function addClass(elem, className) {
-    if (elem && className && !hasClass(elem, className)) {
-        if (elem.className && elem.className.length > 0) {
-            elem.className += ' ' + className;
-        } else {
-            elem.className = className;
-        }
+    if (!elem || !elem.classList) {
+        return;
     }
+    elem.classList.add(className);
 }
 
 function removeClass(elem, className) {
-    if (elem && className && elem.className) {
-        elem.className = (" " + elem.className + " ").replace(" " + className + " ", " ")
-                                                     .trim();
+    if (!elem || !elem.classList) {
+        return;
     }
+    elem.classList.remove(className);
 }
 
 function isHidden(elem) {
-    return (elem.offsetParent === null)
+    return elem.offsetParent === null;
 }
 
 function onEach(arr, func, reversed) {
     if (arr && arr.length > 0 && func) {
+        var length = arr.length;
         if (reversed !== true) {
-            for (var i = 0; i < arr.length; ++i) {
+            for (var i = 0; i < length; ++i) {
                 if (func(arr[i]) === true) {
                     return true;
                 }
             }
         } else {
-            for (var i = arr.length - 1; i >= 0; --i) {
+            for (var i = length - 1; i >= 0; --i) {
                 if (func(arr[i]) === true) {
                     return true;
                 }
@@ -77,6 +60,13 @@
     return false;
 }
 
+function onEachLazy(lazyArray, func, reversed) {
+    return onEach(
+        Array.prototype.slice.call(lazyArray),
+        func,
+        reversed);
+}
+
 function usableLocalStorage() {
     // Check if the browser supports localStorage at all:
     if (typeof(Storage) === "undefined") {
@@ -133,8 +123,8 @@
     });
     if (found === true) {
         styleElem.href = newHref;
-        updateLocalStorage('rustdoc-theme', newTheme);
+        updateLocalStorage("rustdoc-theme", newTheme);
     }
 }
 
-switchTheme(currentTheme, mainTheme, getCurrentValue('rustdoc-theme') || 'light');
+switchTheme(currentTheme, mainTheme, getCurrentValue("rustdoc-theme") || "light");
diff --git a/src/librustdoc/html/static_files.rs b/src/librustdoc/html/static_files.rs
index a485fac..f71b2a8 100644
--- a/src/librustdoc/html/static_files.rs
+++ b/src/librustdoc/html/static_files.rs
@@ -23,6 +23,9 @@
 /// The file contents of `settings.css`, responsible for the items on the settings page.
 pub static SETTINGS_CSS: &'static str = include_str!("static/settings.css");
 
+/// The file contents of the `noscript.css` file, used in case JS isn't supported or is disabled.
+pub static NOSCRIPT_CSS: &'static str = include_str!("static/noscript.css");
+
 /// The file contents of `normalize.css`, included to even out standard elements between browser
 /// implementations.
 pub static NORMALIZE_CSS: &'static str = include_str!("static/normalize.css");
diff --git a/src/librustdoc/markdown.rs b/src/librustdoc/markdown.rs
index e0e0be7..504567e 100644
--- a/src/librustdoc/markdown.rs
+++ b/src/librustdoc/markdown.rs
@@ -35,7 +35,7 @@
     for line in s.lines() {
         if line.starts_with("# ") || line.starts_with("%") {
             // trim the whitespace after the symbol
-            metadata.push(line[1..].trim_left());
+            metadata.push(line[1..].trim_start());
             count += line.len() + 1;
         } else {
             return (metadata, &s[count..]);
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 29062ba..2e8bfd8 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -294,23 +294,23 @@
                      "trait@", "union@"].iter()
                                       .find(|p| link.starts_with(**p)) {
                     kind = PathKind::Type;
-                    link.trim_left_matches(prefix)
+                    link.trim_start_matches(prefix)
                 } else if let Some(prefix) =
                     ["const@", "static@",
                      "value@", "function@", "mod@",
                      "fn@", "module@", "method@"]
                         .iter().find(|p| link.starts_with(**p)) {
                     kind = PathKind::Value;
-                    link.trim_left_matches(prefix)
+                    link.trim_start_matches(prefix)
                 } else if link.ends_with("()") {
                     kind = PathKind::Value;
-                    link.trim_right_matches("()")
+                    link.trim_end_matches("()")
                 } else if link.starts_with("macro@") {
                     kind = PathKind::Macro;
-                    link.trim_left_matches("macro@")
+                    link.trim_start_matches("macro@")
                 } else if link.ends_with('!') {
                     kind = PathKind::Macro;
-                    link.trim_right_matches('!')
+                    link.trim_end_matches('!')
                 } else {
                     &link[..]
                 }.trim();
diff --git a/src/librustdoc/passes/unindent_comments.rs b/src/librustdoc/passes/unindent_comments.rs
index 6d875c1..5c565bf 100644
--- a/src/librustdoc/passes/unindent_comments.rs
+++ b/src/librustdoc/passes/unindent_comments.rs
@@ -95,7 +95,7 @@
     });
 
     if !lines.is_empty() {
-        let mut unindented = vec![ lines[0].trim_left().to_string() ];
+        let mut unindented = vec![ lines[0].trim_start().to_string() ];
         unindented.extend_from_slice(&lines[1..].iter().map(|&line| {
             if line.chars().all(|c| c.is_whitespace()) {
                 line.to_string()
diff --git a/src/librustdoc/test.rs b/src/librustdoc/test.rs
index be9327c..50acde6 100644
--- a/src/librustdoc/test.rs
+++ b/src/librustdoc/test.rs
@@ -21,7 +21,7 @@
 use rustc::hir::intravisit;
 use rustc::session::{self, CompileIncomplete, config};
 use rustc::session::config::{OutputType, OutputTypes, Externs, CodegenOptions};
-use rustc::session::search_paths::{SearchPaths, PathKind};
+use rustc::session::search_paths::{SearchPath, PathKind};
 use syntax::ast;
 use syntax::source_map::SourceMap;
 use syntax::edition::Edition;
@@ -187,7 +187,7 @@
 }
 
 fn run_test(test: &str, cratename: &str, filename: &FileName, line: usize,
-            cfgs: Vec<String>, libs: SearchPaths,
+            cfgs: Vec<String>, libs: Vec<SearchPath>,
             cg: CodegenOptions, externs: Externs,
             should_panic: bool, no_run: bool, as_test_harness: bool,
             compile_fail: bool, mut error_codes: Vec<String>, opts: &TestOptions,
@@ -556,7 +556,7 @@
     names: Vec<String>,
 
     cfgs: Vec<String>,
-    libs: SearchPaths,
+    libs: Vec<SearchPath>,
     cg: CodegenOptions,
     externs: Externs,
     use_headers: bool,
@@ -571,7 +571,7 @@
 }
 
 impl Collector {
-    pub fn new(cratename: String, cfgs: Vec<String>, libs: SearchPaths, cg: CodegenOptions,
+    pub fn new(cratename: String, cfgs: Vec<String>, libs: Vec<SearchPath>, cg: CodegenOptions,
                externs: Externs, use_headers: bool, opts: TestOptions,
                maybe_sysroot: Option<PathBuf>, source_map: Option<Lrc<SourceMap>>,
                filename: Option<PathBuf>, linker: Option<PathBuf>, edition: Edition) -> Collector {
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index 004be1c..287984c 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -424,10 +424,11 @@
             hir::ItemKind::Use(ref path, kind) => {
                 let is_glob = kind == hir::UseKind::Glob;
 
-                // Struct and variant constructors always show up alongside their definitions, we've
-                // already processed them so just discard these.
+                // Struct and variant constructors and proc macro stubs always show up alongside
+                // their definitions, we've already processed them so just discard these.
                 match path.def {
-                    Def::StructCtor(..) | Def::VariantCtor(..) | Def::SelfCtor(..) => return,
+                    Def::StructCtor(..) | Def::VariantCtor(..) | Def::SelfCtor(..) |
+                    Def::Macro(_, MacroKind::ProcMacroStub) => return,
                     _ => {}
                 }
 
diff --git a/src/libserialize/json.rs b/src/libserialize/json.rs
index 9439dc7..b0884e1 100644
--- a/src/libserialize/json.rs
+++ b/src/libserialize/json.rs
@@ -3493,7 +3493,7 @@
 
         // Helper function for counting indents
         fn indents(source: &str) -> usize {
-            let trimmed = source.trim_left_matches(' ');
+            let trimmed = source.trim_start_matches(' ');
             source.len() - trimmed.len()
         }
 
diff --git a/src/libstd/Cargo.toml b/src/libstd/Cargo.toml
index 274d5be..41e778b 100644
--- a/src/libstd/Cargo.toml
+++ b/src/libstd/Cargo.toml
@@ -17,13 +17,13 @@
 panic_unwind = { path = "../libpanic_unwind", optional = true }
 panic_abort = { path = "../libpanic_abort" }
 core = { path = "../libcore" }
-libc = { path = "../rustc/libc_shim" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+libc = { version = "0.2.44", default-features = false, features = ['rustc-dep-of-std'] }
+compiler_builtins = { version = "0.1.1" }
 profiler_builtins = { path = "../libprofiler_builtins", optional = true }
 unwind = { path = "../libunwind" }
 
 [dev-dependencies]
-rand = "0.5"
+rand = "0.6.1"
 
 [target.x86_64-apple-darwin.dependencies]
 rustc_asan = { path = "../librustc_asan" }
@@ -36,10 +36,10 @@
 rustc_tsan = { path = "../librustc_tsan" }
 
 [target.'cfg(any(all(target_arch = "wasm32", not(target_os = "emscripten")), target_env = "sgx"))'.dependencies]
-dlmalloc = { path = '../rustc/dlmalloc_shim' }
+dlmalloc = { version = "0.1", features = ['rustc-dep-of-std'] }
 
 [target.x86_64-fortanix-unknown-sgx.dependencies]
-fortanix-sgx-abi = { path = "../rustc/fortanix-sgx-abi_shim" }
+fortanix-sgx-abi = { version = "0.3.1", features = ['rustc-dep-of-std'] }
 
 [build-dependencies]
 cc = "1.0"
diff --git a/src/libstd/build.rs b/src/libstd/build.rs
index 9d6e8c4..7143de5 100644
--- a/src/libstd/build.rs
+++ b/src/libstd/build.rs
@@ -68,7 +68,6 @@
         println!("cargo:rustc-link-lib=advapi32");
         println!("cargo:rustc-link-lib=ws2_32");
         println!("cargo:rustc-link-lib=userenv");
-        println!("cargo:rustc-link-lib=shell32");
     } else if target.contains("fuchsia") {
         println!("cargo:rustc-link-lib=zircon");
         println!("cargo:rustc-link-lib=fdio");
@@ -82,7 +81,12 @@
 }
 
 fn build_libbacktrace(target: &str) -> Result<(), ()> {
-    let native = native_lib_boilerplate("libbacktrace", "libbacktrace", "backtrace", "")?;
+    let native = native_lib_boilerplate(
+        "../libbacktrace".as_ref(),
+        "libbacktrace",
+        "backtrace",
+        "",
+    )?;
 
     let mut build = cc::Build::new();
     build
diff --git a/src/libstd/error.rs b/src/libstd/error.rs
index a9b2711..e5c5ab8 100644
--- a/src/libstd/error.rs
+++ b/src/libstd/error.rs
@@ -533,6 +533,7 @@
         Error::description(&**self)
     }
 
+    #[allow(deprecated)]
     fn cause(&self) -> Option<&dyn Error> {
         Error::cause(&**self)
     }
diff --git a/src/libstd/ffi/mod.rs b/src/libstd/ffi/mod.rs
index 99da73a..7e15539 100644
--- a/src/libstd/ffi/mod.rs
+++ b/src/libstd/ffi/mod.rs
@@ -72,32 +72,32 @@
 //!
 //! * **From Rust to C:** [`CString`] represents an owned, C-friendly
 //! string: it is nul-terminated, and has no internal nul characters.
-//! Rust code can create a `CString` out of a normal string (provided
+//! Rust code can create a [`CString`] out of a normal string (provided
 //! that the string doesn't have nul characters in the middle), and
-//! then use a variety of methods to obtain a raw `*mut u8` that can
+//! then use a variety of methods to obtain a raw `*mut `[`u8`] that can
 //! then be passed as an argument to functions which use the C
 //! conventions for strings.
 //!
 //! * **From C to Rust:** [`CStr`] represents a borrowed C string; it
-//! is what you would use to wrap a raw `*const u8` that you got from
-//! a C function. A `CStr` is guaranteed to be a nul-terminated array
-//! of bytes. Once you have a `CStr`, you can convert it to a Rust
-//! `&str` if it's valid UTF-8, or lossily convert it by adding
+//! is what you would use to wrap a raw `*const `[`u8`] that you got from
+//! a C function. A [`CStr`] is guaranteed to be a nul-terminated array
+//! of bytes. Once you have a [`CStr`], you can convert it to a Rust
+//! [`&str`][`str`] if it's valid UTF-8, or lossily convert it by adding
 //! replacement characters.
 //!
 //! [`OsString`] and [`OsStr`] are useful when you need to transfer
 //! strings to and from the operating system itself, or when capturing
-//! the output of external commands. Conversions between `OsString`,
-//! `OsStr` and Rust strings work similarly to those for [`CString`]
+//! the output of external commands. Conversions between [`OsString`],
+//! [`OsStr`] and Rust strings work similarly to those for [`CString`]
 //! and [`CStr`].
 //!
 //! * [`OsString`] represents an owned string in whatever
 //! representation the operating system prefers. In the Rust standard
 //! library, various APIs that transfer strings to/from the operating
-//! system use `OsString` instead of plain strings. For example,
+//! system use [`OsString`] instead of plain strings. For example,
 //! [`env::var_os()`] is used to query environment variables; it
-//! returns an `Option<OsString>`. If the environment variable exists
-//! you will get a `Some(os_string)`, which you can *then* try to
+//! returns an [`Option`]`<`[`OsString`]`>`. If the environment variable
+//! exists you will get a [`Some`]`(os_string)`, which you can *then* try to
 //! convert to a Rust string. This yields a [`Result<>`], so that
 //! your code can detect errors in case the environment variable did
 //! not in fact contain valid Unicode data.
@@ -105,7 +105,7 @@
 //! * [`OsStr`] represents a borrowed reference to a string in a
 //! format that can be passed to the operating system. It can be
 //! converted into an UTF-8 Rust string slice in a similar way to
-//! `OsString`.
+//! [`OsString`].
 //!
 //! # Conversions
 //!
@@ -131,7 +131,7 @@
 //! Additionally, on Windows [`OsString`] implements the
 //! `std::os::windows:ffi::`[`OsStringExt`][windows.OsStringExt]
 //! trait, which provides a [`from_wide`] method. The result of this
-//! method is an `OsString` which can be round-tripped to a Windows
+//! method is an [`OsString`] which can be round-tripped to a Windows
 //! string losslessly.
 //!
 //! [`String`]: ../string/struct.String.html
@@ -160,6 +160,8 @@
 //! [`collect`]: ../iter/trait.Iterator.html#method.collect
 //! [windows.OsStringExt]: ../os/windows/ffi/trait.OsStringExt.html
 //! [`from_wide`]: ../os/windows/ffi/trait.OsStringExt.html#tymethod.from_wide
+//! [`Option`]: ../option/enum.Option.html
+//! [`Some`]: ../option/enum.Option.html#variant.Some
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
@@ -174,7 +176,6 @@
 #[stable(feature = "raw_os", since = "1.1.0")]
 pub use core::ffi::c_void;
 
-#[cfg(not(stage0))]
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
diff --git a/src/libstd/ffi/os_str.rs b/src/libstd/ffi/os_str.rs
index 8289721..766142f 100644
--- a/src/libstd/ffi/os_str.rs
+++ b/src/libstd/ffi/os_str.rs
@@ -536,17 +536,42 @@
     ///
     /// # Examples
     ///
-    /// Calling `to_string_lossy` on an `OsStr` with valid unicode:
+    /// Calling `to_string_lossy` on an `OsStr` with invalid unicode:
     ///
     /// ```
-    /// use std::ffi::OsStr;
+    /// // Note, due to differences in how Unix and Windows represent strings,
+    /// // we are forced to complicate this example, setting up example `OsStr`s
+    /// // with different source data and via different platform extensions.
+    /// // Understand that in reality you could end up with such example invalid
+    /// // sequences simply through collecting user command line arguments, for
+    /// // example.
     ///
-    /// let os_str = OsStr::new("foo");
-    /// assert_eq!(os_str.to_string_lossy(), "foo");
+    /// #[cfg(any(unix, target_os = "redox"))] {
+    ///     use std::ffi::OsStr;
+    ///     use std::os::unix::ffi::OsStrExt;
+    ///
+    ///     // Here, the values 0x66 and 0x6f correspond to 'f' and 'o'
+    ///     // respectively. The value 0x80 is a lone continuation byte, invalid
+    ///     // in a UTF-8 sequence.
+    ///     let source = [0x66, 0x6f, 0x80, 0x6f];
+    ///     let os_str = OsStr::from_bytes(&source[..]);
+    ///
+    ///     assert_eq!(os_str.to_string_lossy(), "fo�o");
+    /// }
+    /// #[cfg(windows)] {
+    ///     use std::ffi::OsString;
+    ///     use std::os::windows::prelude::*;
+    ///
+    ///     // Here the values 0x0066 and 0x006f correspond to 'f' and 'o'
+    ///     // respectively. The value 0xD800 is a lone surrogate half, invalid
+    ///     // in a UTF-16 sequence.
+    ///     let source = [0x0066, 0x006f, 0xD800, 0x006f];
+    ///     let os_string = OsString::from_wide(&source[..]);
+    ///     let os_str = os_string.as_os_str();
+    ///
+    ///     assert_eq!(os_str.to_string_lossy(), "fo�o");
+    /// }
     /// ```
-    ///
-    /// Had `os_str` contained invalid unicode, the `to_string_lossy` call might
-    /// have returned `"fo�"`.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn to_string_lossy(&self) -> Cow<str> {
         self.inner.to_string_lossy()
diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs
index b6a0ce6..d581ba1 100644
--- a/src/libstd/fs.rs
+++ b/src/libstd/fs.rs
@@ -2089,7 +2089,7 @@
     use fs::{self, File, OpenOptions};
     use io::{ErrorKind, SeekFrom};
     use path::Path;
-    use rand::{StdRng, FromEntropy, RngCore};
+    use rand::{rngs::StdRng, FromEntropy, RngCore};
     use str;
     use sys_common::io::test::{TempDir, tmpdir};
     use thread;
diff --git a/src/libstd/io/error.rs b/src/libstd/io/error.rs
index 32e2996..d3844eb 100644
--- a/src/libstd/io/error.rs
+++ b/src/libstd/io/error.rs
@@ -555,6 +555,7 @@
         }
     }
 
+    #[allow(deprecated)]
     fn cause(&self) -> Option<&dyn error::Error> {
         match self.repr {
             Repr::Os(..) => None,
diff --git a/src/libstd/io/lazy.rs b/src/libstd/io/lazy.rs
index c2aaeb9..24965ff 100644
--- a/src/libstd/io/lazy.rs
+++ b/src/libstd/io/lazy.rs
@@ -26,7 +26,6 @@
 unsafe impl<T> Sync for Lazy<T> {}
 
 impl<T> Lazy<T> {
-    #[unstable(feature = "sys_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn new() -> Lazy<T> {
         Lazy {
             lock: Mutex::new(),
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 90c8eaf..0febbe5 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -271,6 +271,7 @@
 #![feature(libc)]
 #![feature(link_args)]
 #![feature(linkage)]
+#![cfg_attr(not(stage0), feature(min_const_unsafe_fn))]
 #![feature(needs_panic_runtime)]
 #![feature(never_type)]
 #![feature(nll)]
@@ -317,10 +318,6 @@
 
 #![default_lib_allocator]
 
-#[cfg(stage0)]
-#[global_allocator]
-static ALLOC: alloc::System = alloc::System;
-
 // Explicitly import the prelude. The compiler uses this same unstable attribute
 // to import the prelude implicitly when building crates that depend on std.
 #[prelude_import]
diff --git a/src/libstd/panic.rs b/src/libstd/panic.rs
index 099b4d6..3eacc7a 100644
--- a/src/libstd/panic.rs
+++ b/src/libstd/panic.rs
@@ -264,7 +264,7 @@
 #[cfg(target_has_atomic = "64")]
 #[unstable(feature = "integer_atomics", issue = "32976")]
 impl RefUnwindSafe for atomic::AtomicI64 {}
-#[cfg(all(not(stage0), target_has_atomic = "128"))]
+#[cfg(target_has_atomic = "128")]
 #[unstable(feature = "integer_atomics", issue = "32976")]
 impl RefUnwindSafe for atomic::AtomicI128 {}
 
@@ -283,7 +283,7 @@
 #[cfg(target_has_atomic = "64")]
 #[unstable(feature = "integer_atomics", issue = "32976")]
 impl RefUnwindSafe for atomic::AtomicU64 {}
-#[cfg(all(not(stage0), target_has_atomic = "128"))]
+#[cfg(target_has_atomic = "128")]
 #[unstable(feature = "integer_atomics", issue = "32976")]
 impl RefUnwindSafe for atomic::AtomicU128 {}
 
diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs
index 6b47ba6..b6180fb 100644
--- a/src/libstd/panicking.rs
+++ b/src/libstd/panicking.rs
@@ -209,7 +209,8 @@
             if let Some(format) = log_backtrace {
                 let _ = backtrace::print(err, format);
             } else if FIRST_PANIC.compare_and_swap(true, false, Ordering::SeqCst) {
-                let _ = writeln!(err, "note: Run with `RUST_BACKTRACE=1` for a backtrace.");
+                let _ = writeln!(err, "note: Run with `RUST_BACKTRACE=1` \
+                                       environment variable to display a backtrace.");
             }
         }
     };
diff --git a/src/libstd/primitive_docs.rs b/src/libstd/primitive_docs.rs
index 3b2366a..7c1654f 100644
--- a/src/libstd/primitive_docs.rs
+++ b/src/libstd/primitive_docs.rs
@@ -426,7 +426,7 @@
 /// ## 3. Get it from C.
 ///
 /// ```
-/// # #![feature(libc)]
+/// # #![feature(rustc_private)]
 /// extern crate libc;
 ///
 /// use std::mem;
diff --git a/src/libstd/sys/cloudabi/condvar.rs b/src/libstd/sys/cloudabi/condvar.rs
index ccf848a..3229d98 100644
--- a/src/libstd/sys/cloudabi/condvar.rs
+++ b/src/libstd/sys/cloudabi/condvar.rs
@@ -13,7 +13,7 @@
 use sync::atomic::{AtomicU32, Ordering};
 use sys::cloudabi::abi;
 use sys::mutex::{self, Mutex};
-use sys::time::dur2intervals;
+use sys::time::checked_dur2intervals;
 use time::Duration;
 
 extern "C" {
@@ -114,6 +114,8 @@
 
         // Call into the kernel to wait on the condition variable.
         let condvar = self.condvar.get();
+        let timeout = checked_dur2intervals(&dur)
+            .expect("overflow converting duration to nanoseconds");
         let subscriptions = [
             abi::subscription {
                 type_: abi::eventtype::CONDVAR,
@@ -132,7 +134,7 @@
                 union: abi::subscription_union {
                     clock: abi::subscription_clock {
                         clock_id: abi::clockid::MONOTONIC,
-                        timeout: dur2intervals(&dur),
+                        timeout,
                         ..mem::zeroed()
                     },
                 },
diff --git a/src/libstd/sys/cloudabi/thread.rs b/src/libstd/sys/cloudabi/thread.rs
index a76e1fa..1773214 100644
--- a/src/libstd/sys/cloudabi/thread.rs
+++ b/src/libstd/sys/cloudabi/thread.rs
@@ -16,7 +16,7 @@
 use mem;
 use ptr;
 use sys::cloudabi::abi;
-use sys::time::dur2intervals;
+use sys::time::checked_dur2intervals;
 use sys_common::thread::*;
 use time::Duration;
 
@@ -70,13 +70,15 @@
     }
 
     pub fn sleep(dur: Duration) {
+        let timeout = checked_dur2intervals(&dur)
+            .expect("overflow converting duration to nanoseconds");
         unsafe {
             let subscription = abi::subscription {
                 type_: abi::eventtype::CLOCK,
                 union: abi::subscription_union {
                     clock: abi::subscription_clock {
                         clock_id: abi::clockid::MONOTONIC,
-                        timeout: dur2intervals(&dur),
+                        timeout,
                         ..mem::zeroed()
                     },
                 },
diff --git a/src/libstd/sys/cloudabi/time.rs b/src/libstd/sys/cloudabi/time.rs
index a442d1e..c9fea18 100644
--- a/src/libstd/sys/cloudabi/time.rs
+++ b/src/libstd/sys/cloudabi/time.rs
@@ -19,15 +19,10 @@
     t: abi::timestamp,
 }
 
-fn checked_dur2intervals(dur: &Duration) -> Option<abi::timestamp> {
+pub fn checked_dur2intervals(dur: &Duration) -> Option<abi::timestamp> {
     dur.as_secs()
-        .checked_mul(NSEC_PER_SEC)
-        .and_then(|nanos| nanos.checked_add(dur.subsec_nanos() as abi::timestamp))
-}
-
-pub fn dur2intervals(dur: &Duration) -> abi::timestamp {
-    checked_dur2intervals(dur)
-        .expect("overflow converting duration to nanoseconds")
+        .checked_mul(NSEC_PER_SEC)?
+        .checked_add(dur.subsec_nanos() as abi::timestamp)
 }
 
 impl Instant {
@@ -47,20 +42,16 @@
         Duration::new(diff / NSEC_PER_SEC, (diff % NSEC_PER_SEC) as u32)
     }
 
-    pub fn add_duration(&self, other: &Duration) -> Instant {
-        Instant {
-            t: self.t
-                .checked_add(dur2intervals(other))
-                .expect("overflow when adding duration to instant"),
-        }
+    pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> {
+        Some(Instant {
+            t: self.t.checked_add(checked_dur2intervals(other)?)?,
+        })
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> Instant {
-        Instant {
-            t: self.t
-                .checked_sub(dur2intervals(other))
-                .expect("overflow when subtracting duration from instant"),
-        }
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> {
+        Some(Instant {
+            t: self.t.checked_sub(checked_dur2intervals(other)?)?,
+        })
     }
 }
 
@@ -95,23 +86,16 @@
         }
     }
 
-    pub fn add_duration(&self, other: &Duration) -> SystemTime {
-        self.checked_add_duration(other)
-            .expect("overflow when adding duration to instant")
-    }
-
     pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
-        checked_dur2intervals(other)
-            .and_then(|d| self.t.checked_add(d))
-            .map(|t| SystemTime {t})
+        Some(SystemTime {
+            t: self.t.checked_add(checked_dur2intervals(other)?)?,
+        })
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> SystemTime {
-        SystemTime {
-            t: self.t
-                .checked_sub(dur2intervals(other))
-                .expect("overflow when subtracting duration from instant"),
-        }
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
+        Some(SystemTime {
+            t: self.t.checked_sub(checked_dur2intervals(other)?)?,
+        })
     }
 }
 
diff --git a/src/libstd/sys/redox/time.rs b/src/libstd/sys/redox/time.rs
index beff8d2..cb2eab5 100644
--- a/src/libstd/sys/redox/time.rs
+++ b/src/libstd/sys/redox/time.rs
@@ -41,10 +41,6 @@
         }
     }
 
-    fn add_duration(&self, other: &Duration) -> Timespec {
-        self.checked_add_duration(other).expect("overflow when adding duration to time")
-    }
-
     fn checked_add_duration(&self, other: &Duration) -> Option<Timespec> {
         let mut secs = other
             .as_secs()
@@ -67,27 +63,25 @@
         })
     }
 
-    fn sub_duration(&self, other: &Duration) -> Timespec {
+    fn checked_sub_duration(&self, other: &Duration) -> Option<Timespec> {
         let mut secs = other
             .as_secs()
             .try_into() // <- target type would be `i64`
             .ok()
-            .and_then(|secs| self.t.tv_sec.checked_sub(secs))
-            .expect("overflow when subtracting duration from time");
+            .and_then(|secs| self.t.tv_sec.checked_sub(secs))?;
 
         // Similar to above, nanos can't overflow.
         let mut nsec = self.t.tv_nsec as i32 - other.subsec_nanos() as i32;
         if nsec < 0 {
             nsec += NSEC_PER_SEC as i32;
-            secs = secs.checked_sub(1).expect("overflow when subtracting \
-                                               duration from time");
+            secs = secs.checked_sub(1)?;
         }
-        Timespec {
+        Some(Timespec {
             t: syscall::TimeSpec {
                 tv_sec: secs,
                 tv_nsec: nsec as i32,
             },
-        }
+        })
     }
 }
 
@@ -150,12 +144,12 @@
         })
     }
 
-    pub fn add_duration(&self, other: &Duration) -> Instant {
-        Instant { t: self.t.add_duration(other) }
+    pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> {
+        Some(Instant { t: self.t.checked_add_duration(other)? })
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> Instant {
-        Instant { t: self.t.sub_duration(other) }
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> {
+        Some(Instant { t: self.t.checked_sub_duration(other)? })
     }
 }
 
@@ -178,16 +172,12 @@
         self.t.sub_timespec(&other.t)
     }
 
-    pub fn add_duration(&self, other: &Duration) -> SystemTime {
-        SystemTime { t: self.t.add_duration(other) }
-    }
-
     pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
-        self.t.checked_add_duration(other).map(|t| SystemTime { t })
+        Some(SystemTime { t: self.t.checked_add_duration(other)? })
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> SystemTime {
-        SystemTime { t: self.t.sub_duration(other) }
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
+        Some(SystemTime { t: self.t.checked_sub_duration(other)? })
     }
 }
 
diff --git a/src/libstd/sys/sgx/abi/mem.rs b/src/libstd/sys/sgx/abi/mem.rs
index 508f2ff..bf32c71 100644
--- a/src/libstd/sys/sgx/abi/mem.rs
+++ b/src/libstd/sys/sgx/abi/mem.rs
@@ -34,13 +34,6 @@
     base
 }
 
-pub fn is_enclave_range(p: *const u8, len: usize) -> bool {
-    let start=p as u64;
-    let end=start + (len as u64);
-    start >= image_base() &&
-        end <= image_base() + (unsafe { ENCLAVE_SIZE } as u64) // unsafe ok: link-time constant
-}
-
 pub fn is_user_range(p: *const u8, len: usize) -> bool {
     let start=p as u64;
     let end=start + (len as u64);
diff --git a/src/libstd/sys/sgx/abi/usercalls/mod.rs b/src/libstd/sys/sgx/abi/usercalls/mod.rs
index 2bc32c9..d1d180e 100644
--- a/src/libstd/sys/sgx/abi/usercalls/mod.rs
+++ b/src/libstd/sys/sgx/abi/usercalls/mod.rs
@@ -33,14 +33,6 @@
     }
 }
 
-pub fn read_alloc(fd: Fd) -> IoResult<Vec<u8>> {
-    unsafe {
-        let mut userbuf = alloc::User::<ByteBuffer>::uninitialized();
-        raw::read_alloc(fd, userbuf.as_raw_mut_ptr()).from_sgx_result()?;
-        Ok(copy_user_buffer(&userbuf))
-    }
-}
-
 pub fn write(fd: Fd, buf: &[u8]) -> IoResult<usize> {
     unsafe {
         let userbuf = alloc::User::new_from_enclave(buf);
diff --git a/src/libstd/sys/sgx/condvar.rs b/src/libstd/sys/sgx/condvar.rs
index d3e8165..940f50f 100644
--- a/src/libstd/sys/sgx/condvar.rs
+++ b/src/libstd/sys/sgx/condvar.rs
@@ -18,7 +18,6 @@
 }
 
 impl Condvar {
-    #[unstable(feature = "sgx_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn new() -> Condvar {
         Condvar { inner: SpinMutex::new(WaitVariable::new(())) }
     }
diff --git a/src/libstd/sys/sgx/mutex.rs b/src/libstd/sys/sgx/mutex.rs
index 6633611..994cf91 100644
--- a/src/libstd/sys/sgx/mutex.rs
+++ b/src/libstd/sys/sgx/mutex.rs
@@ -20,7 +20,6 @@
 
 // Implementation according to “Operating Systems: Three Easy Pieces”, chapter 28
 impl Mutex {
-    #[unstable(feature = "sgx_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn new() -> Mutex {
         Mutex { inner: SpinMutex::new(WaitVariable::new(false)) }
     }
@@ -79,7 +78,6 @@
 }
 
 impl ReentrantMutex {
-    #[unstable(feature = "sgx_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn uninitialized() -> ReentrantMutex {
         ReentrantMutex {
             inner: SpinMutex::new(WaitVariable::new(ReentrantLock { owner: None, count: 0 }))
diff --git a/src/libstd/sys/sgx/rwlock.rs b/src/libstd/sys/sgx/rwlock.rs
index 7b6970b..a1551db 100644
--- a/src/libstd/sys/sgx/rwlock.rs
+++ b/src/libstd/sys/sgx/rwlock.rs
@@ -21,7 +21,6 @@
 //unsafe impl Sync for RWLock {} // FIXME
 
 impl RWLock {
-    #[unstable(feature = "sgx_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn new() -> RWLock {
         RWLock {
             readers: SpinMutex::new(WaitVariable::new(None)),
diff --git a/src/libstd/sys/sgx/time.rs b/src/libstd/sys/sgx/time.rs
index b01c992..196e1a9 100644
--- a/src/libstd/sys/sgx/time.rs
+++ b/src/libstd/sys/sgx/time.rs
@@ -28,12 +28,12 @@
         self.0 - other.0
     }
 
-    pub fn add_duration(&self, other: &Duration) -> Instant {
-        Instant(self.0 + *other)
+    pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> {
+        Some(Instant(self.0.checked_add(*other)?))
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> Instant {
-        Instant(self.0 - *other)
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> {
+        Some(Instant(self.0.checked_sub(*other)?))
     }
 }
 
@@ -47,15 +47,11 @@
         self.0.checked_sub(other.0).ok_or_else(|| other.0 - self.0)
     }
 
-    pub fn add_duration(&self, other: &Duration) -> SystemTime {
-        SystemTime(self.0 + *other)
-    }
-
     pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
-        self.0.checked_add(*other).map(|d| SystemTime(d))
+        Some(SystemTime(self.0.checked_add(*other)?))
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> SystemTime {
-        SystemTime(self.0 - *other)
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
+        Some(SystemTime(self.0.checked_sub(*other)?))
     }
 }
diff --git a/src/libstd/sys/sgx/waitqueue.rs b/src/libstd/sys/sgx/waitqueue.rs
index ec1135b..ef0def1 100644
--- a/src/libstd/sys/sgx/waitqueue.rs
+++ b/src/libstd/sys/sgx/waitqueue.rs
@@ -50,7 +50,6 @@
 }
 
 impl<T> WaitVariable<T> {
-    #[unstable(feature = "sgx_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn new(var: T) -> Self {
         WaitVariable {
             queue: WaitQueue::new(),
@@ -137,7 +136,6 @@
 }
 
 impl WaitQueue {
-    #[unstable(feature = "sgx_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn new() -> Self {
         WaitQueue {
             inner: UnsafeList::new()
@@ -255,7 +253,6 @@
     }
 
     impl<T> UnsafeList<T> {
-        #[unstable(feature = "sgx_internals", issue = "0")] // FIXME: min_const_fn
         pub const fn new() -> Self {
             unsafe {
                 UnsafeList {
diff --git a/src/libstd/sys/unix/ext/fs.rs b/src/libstd/sys/unix/ext/fs.rs
index 7e65bbd..af2f199 100644
--- a/src/libstd/sys/unix/ext/fs.rs
+++ b/src/libstd/sys/unix/ext/fs.rs
@@ -348,7 +348,7 @@
     /// # Examples
     ///
     /// ```no_run
-    /// # #![feature(libc)]
+    /// # #![feature(rustc_private)]
     /// extern crate libc;
     /// use std::fs::OpenOptions;
     /// use std::os::unix::fs::OpenOptionsExt;
diff --git a/src/libstd/sys/unix/time.rs b/src/libstd/sys/unix/time.rs
index 1f9539c..8f8aaa8 100644
--- a/src/libstd/sys/unix/time.rs
+++ b/src/libstd/sys/unix/time.rs
@@ -42,10 +42,6 @@
         }
     }
 
-    fn add_duration(&self, other: &Duration) -> Timespec {
-        self.checked_add_duration(other).expect("overflow when adding duration to time")
-    }
-
     fn checked_add_duration(&self, other: &Duration) -> Option<Timespec> {
         let mut secs = other
             .as_secs()
@@ -68,27 +64,25 @@
         })
     }
 
-    fn sub_duration(&self, other: &Duration) -> Timespec {
+    fn checked_sub_duration(&self, other: &Duration) -> Option<Timespec> {
         let mut secs = other
             .as_secs()
             .try_into() // <- target type would be `libc::time_t`
             .ok()
-            .and_then(|secs| self.t.tv_sec.checked_sub(secs))
-            .expect("overflow when subtracting duration from time");
+            .and_then(|secs| self.t.tv_sec.checked_sub(secs))?;
 
         // Similar to above, nanos can't overflow.
         let mut nsec = self.t.tv_nsec as i32 - other.subsec_nanos() as i32;
         if nsec < 0 {
             nsec += NSEC_PER_SEC as i32;
-            secs = secs.checked_sub(1).expect("overflow when subtracting \
-                                               duration from time");
+            secs = secs.checked_sub(1)?;
         }
-        Timespec {
+        Some(Timespec {
             t: libc::timespec {
                 tv_sec: secs,
                 tv_nsec: nsec as _,
             },
-        }
+        })
     }
 }
 
@@ -165,18 +159,16 @@
             Duration::new(nanos / NSEC_PER_SEC, (nanos % NSEC_PER_SEC) as u32)
         }
 
-        pub fn add_duration(&self, other: &Duration) -> Instant {
-            Instant {
-                t: self.t.checked_add(dur2intervals(other))
-                       .expect("overflow when adding duration to instant"),
-            }
+        pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> {
+            Some(Instant {
+                t: self.t.checked_add(checked_dur2intervals(other)?)?,
+            })
         }
 
-        pub fn sub_duration(&self, other: &Duration) -> Instant {
-            Instant {
-                t: self.t.checked_sub(dur2intervals(other))
-                       .expect("overflow when subtracting duration from instant"),
-            }
+        pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> {
+            Some(Instant {
+                t: self.t.checked_sub(checked_dur2intervals(other)?)?,
+            })
         }
     }
 
@@ -199,16 +191,12 @@
             self.t.sub_timespec(&other.t)
         }
 
-        pub fn add_duration(&self, other: &Duration) -> SystemTime {
-            SystemTime { t: self.t.add_duration(other) }
-        }
-
         pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
-            self.t.checked_add_duration(other).map(|t| SystemTime { t })
+            Some(SystemTime { t: self.t.checked_add_duration(other)? })
         }
 
-        pub fn sub_duration(&self, other: &Duration) -> SystemTime {
-            SystemTime { t: self.t.sub_duration(other) }
+        pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
+            Some(SystemTime { t: self.t.checked_sub_duration(other)? })
         }
     }
 
@@ -236,12 +224,12 @@
         }
     }
 
-    fn dur2intervals(dur: &Duration) -> u64 {
+    fn checked_dur2intervals(dur: &Duration) -> Option<u64> {
+        let nanos = dur.as_secs()
+            .checked_mul(NSEC_PER_SEC)?
+            .checked_add(dur.subsec_nanos() as u64)?;
         let info = info();
-        let nanos = dur.as_secs().checked_mul(NSEC_PER_SEC).and_then(|nanos| {
-            nanos.checked_add(dur.subsec_nanos() as u64)
-        }).expect("overflow converting duration to nanoseconds");
-        mul_div_u64(nanos, info.denom as u64, info.numer as u64)
+        Some(mul_div_u64(nanos, info.denom as u64, info.numer as u64))
     }
 
     fn info() -> &'static libc::mach_timebase_info {
@@ -299,12 +287,12 @@
             })
         }
 
-        pub fn add_duration(&self, other: &Duration) -> Instant {
-            Instant { t: self.t.add_duration(other) }
+        pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> {
+            Some(Instant { t: self.t.checked_add_duration(other)? })
         }
 
-        pub fn sub_duration(&self, other: &Duration) -> Instant {
-            Instant { t: self.t.sub_duration(other) }
+        pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> {
+            Some(Instant { t: self.t.checked_sub_duration(other)? })
         }
     }
 
@@ -327,16 +315,12 @@
             self.t.sub_timespec(&other.t)
         }
 
-        pub fn add_duration(&self, other: &Duration) -> SystemTime {
-            SystemTime { t: self.t.add_duration(other) }
-        }
-
         pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
-            self.t.checked_add_duration(other).map(|t| SystemTime { t })
+            Some(SystemTime { t: self.t.checked_add_duration(other)? })
         }
 
-        pub fn sub_duration(&self, other: &Duration) -> SystemTime {
-            SystemTime { t: self.t.sub_duration(other) }
+        pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
+            Some(SystemTime { t: self.t.checked_sub_duration(other)? })
         }
     }
 
diff --git a/src/libstd/sys/wasm/time.rs b/src/libstd/sys/wasm/time.rs
index 991e817..cc56773 100644
--- a/src/libstd/sys/wasm/time.rs
+++ b/src/libstd/sys/wasm/time.rs
@@ -28,12 +28,12 @@
         self.0 - other.0
     }
 
-    pub fn add_duration(&self, other: &Duration) -> Instant {
-        Instant(self.0 + *other)
+    pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> {
+        Some(Instant(self.0.checked_add(*other)?))
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> Instant {
-        Instant(self.0 - *other)
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> {
+        Some(Instant(self.0.checked_sub(*other)?))
     }
 }
 
@@ -47,15 +47,11 @@
         self.0.checked_sub(other.0).ok_or_else(|| other.0 - self.0)
     }
 
-    pub fn add_duration(&self, other: &Duration) -> SystemTime {
-        SystemTime(self.0 + *other)
-    }
-
     pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
-        self.0.checked_add(*other).map(|d| SystemTime(d))
+        Some(SystemTime(self.0.checked_add(*other)?))
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> SystemTime {
-        SystemTime(self.0 - *other)
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
+        Some(SystemTime(self.0.checked_sub(*other)?))
     }
 }
diff --git a/src/libstd/sys/windows/args.rs b/src/libstd/sys/windows/args.rs
index 4784633..9e9198e 100644
--- a/src/libstd/sys/windows/args.rs
+++ b/src/libstd/sys/windows/args.rs
@@ -11,12 +11,14 @@
 #![allow(dead_code)] // runtime init functions not used during testing
 
 use os::windows::prelude::*;
+use sys::windows::os::current_exe;
 use sys::c;
-use slice;
-use ops::Range;
 use ffi::OsString;
-use libc::{c_int, c_void};
 use fmt;
+use vec;
+use core::iter;
+use slice;
+use path::PathBuf;
 
 pub unsafe fn init(_argc: isize, _argv: *const *const u8) { }
 
@@ -24,20 +26,146 @@
 
 pub fn args() -> Args {
     unsafe {
-        let mut nArgs: c_int = 0;
-        let lpCmdLine = c::GetCommandLineW();
-        let szArgList = c::CommandLineToArgvW(lpCmdLine, &mut nArgs);
+        let lp_cmd_line = c::GetCommandLineW();
+        let parsed_args_list = parse_lp_cmd_line(
+            lp_cmd_line as *const u16,
+            || current_exe().map(PathBuf::into_os_string).unwrap_or_else(|_| OsString::new()));
 
-        // szArcList can be NULL if CommandLinToArgvW failed,
-        // but in that case nArgs is 0 so we won't actually
-        // try to read a null pointer
-        Args { cur: szArgList, range: 0..(nArgs as isize) }
+        Args { parsed_args_list: parsed_args_list.into_iter() }
     }
 }
 
+/// Implements the Windows command-line argument parsing algorithm.
+///
+/// Microsoft's documentation for the Windows CLI argument format can be found at
+/// <https://docs.microsoft.com/en-us/previous-versions//17w5ykft(v=vs.85)>.
+///
+/// Windows includes a function to do this in shell32.dll,
+/// but linking with that DLL causes the process to be registered as a GUI application.
+/// GUI applications add a bunch of overhead, even if no windows are drawn. See
+/// <https://randomascii.wordpress.com/2018/12/03/a-not-called-function-can-cause-a-5x-slowdown/>.
+///
+/// This function was tested for equivalence to the shell32.dll implementation in
+/// Windows 10 Pro v1803, using an exhaustive test suite available at
+/// <https://gist.github.com/notriddle/dde431930c392e428055b2dc22e638f5> or
+/// <https://paste.gg/p/anonymous/47d6ed5f5bd549168b1c69c799825223>.
+unsafe fn parse_lp_cmd_line<F: Fn() -> OsString>(lp_cmd_line: *const u16, exe_name: F)
+                                                 -> Vec<OsString> {
+    const BACKSLASH: u16 = '\\' as u16;
+    const QUOTE: u16 = '"' as u16;
+    const TAB: u16 = '\t' as u16;
+    const SPACE: u16 = ' ' as u16;
+    let mut ret_val = Vec::new();
+    if lp_cmd_line.is_null() || *lp_cmd_line == 0 {
+        ret_val.push(exe_name());
+        return ret_val;
+    }
+    let mut cmd_line = {
+        let mut end = 0;
+        while *lp_cmd_line.offset(end) != 0 {
+            end += 1;
+        }
+        slice::from_raw_parts(lp_cmd_line, end as usize)
+    };
+    // The executable name at the beginning is special.
+    cmd_line = match cmd_line[0] {
+        // The executable name ends at the next quote mark,
+        // no matter what.
+        QUOTE => {
+            let args = {
+                let mut cut = cmd_line[1..].splitn(2, |&c| c == QUOTE);
+                if let Some(exe) = cut.next() {
+                    ret_val.push(OsString::from_wide(exe));
+                }
+                cut.next()
+            };
+            if let Some(args) = args {
+                args
+            } else {
+                return ret_val;
+            }
+        }
+        // Implement quirk: when they say whitespace here,
+        // they include the entire ASCII control plane:
+        // "However, if lpCmdLine starts with any amount of whitespace, CommandLineToArgvW
+        // will consider the first argument to be an empty string. Excess whitespace at the
+        // end of lpCmdLine is ignored."
+        0...SPACE => {
+            ret_val.push(OsString::new());
+            &cmd_line[1..]
+        },
+        // The executable name ends at the next whitespace,
+        // no matter what.
+        _ => {
+            let args = {
+                let mut cut = cmd_line.splitn(2, |&c| c > 0 && c <= SPACE);
+                if let Some(exe) = cut.next() {
+                    ret_val.push(OsString::from_wide(exe));
+                }
+                cut.next()
+            };
+            if let Some(args) = args {
+                args
+            } else {
+                return ret_val;
+            }
+        }
+    };
+    let mut cur = Vec::new();
+    let mut in_quotes = false;
+    let mut was_in_quotes = false;
+    let mut backslash_count: usize = 0;
+    for &c in cmd_line {
+        match c {
+            // backslash
+            BACKSLASH => {
+                backslash_count += 1;
+                was_in_quotes = false;
+            },
+            QUOTE if backslash_count % 2 == 0 => {
+                cur.extend(iter::repeat(b'\\' as u16).take(backslash_count / 2));
+                backslash_count = 0;
+                if was_in_quotes {
+                    cur.push('"' as u16);
+                    was_in_quotes = false;
+                } else {
+                    was_in_quotes = in_quotes;
+                    in_quotes = !in_quotes;
+                }
+            }
+            QUOTE if backslash_count % 2 != 0 => {
+                cur.extend(iter::repeat(b'\\' as u16).take(backslash_count / 2));
+                backslash_count = 0;
+                was_in_quotes = false;
+                cur.push(b'"' as u16);
+            }
+            SPACE | TAB if !in_quotes => {
+                cur.extend(iter::repeat(b'\\' as u16).take(backslash_count));
+                if !cur.is_empty() || was_in_quotes {
+                    ret_val.push(OsString::from_wide(&cur[..]));
+                    cur.truncate(0);
+                }
+                backslash_count = 0;
+                was_in_quotes = false;
+            }
+            _ => {
+                cur.extend(iter::repeat(b'\\' as u16).take(backslash_count));
+                backslash_count = 0;
+                was_in_quotes = false;
+                cur.push(c);
+            }
+        }
+    }
+    cur.extend(iter::repeat(b'\\' as u16).take(backslash_count));
+    // include empty quoted strings at the end of the arguments list
+    if !cur.is_empty() || was_in_quotes || in_quotes {
+        ret_val.push(OsString::from_wide(&cur[..]));
+    }
+    ret_val
+}
+
 pub struct Args {
-    range: Range<isize>,
-    cur: *mut *mut u16,
+    parsed_args_list: vec::IntoIter<OsString>,
 }
 
 pub struct ArgsInnerDebug<'a> {
@@ -46,19 +174,7 @@
 
 impl<'a> fmt::Debug for ArgsInnerDebug<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.write_str("[")?;
-        let mut first = true;
-        for i in self.args.range.clone() {
-            if !first {
-                f.write_str(", ")?;
-            }
-            first = false;
-
-            // Here we do allocation which could be avoided.
-            fmt::Debug::fmt(&unsafe { os_string_from_ptr(*self.args.cur.offset(i)) }, f)?;
-        }
-        f.write_str("]")?;
-        Ok(())
+        self.args.parsed_args_list.as_slice().fmt(f)
     }
 }
 
@@ -70,38 +186,82 @@
     }
 }
 
-unsafe fn os_string_from_ptr(ptr: *mut u16) -> OsString {
-    let mut len = 0;
-    while *ptr.offset(len) != 0 { len += 1; }
-
-    // Push it onto the list.
-    let ptr = ptr as *const u16;
-    let buf = slice::from_raw_parts(ptr, len as usize);
-    OsStringExt::from_wide(buf)
-}
-
 impl Iterator for Args {
     type Item = OsString;
-    fn next(&mut self) -> Option<OsString> {
-        self.range.next().map(|i| unsafe { os_string_from_ptr(*self.cur.offset(i)) } )
-    }
-    fn size_hint(&self) -> (usize, Option<usize>) { self.range.size_hint() }
+    fn next(&mut self) -> Option<OsString> { self.parsed_args_list.next() }
+    fn size_hint(&self) -> (usize, Option<usize>) { self.parsed_args_list.size_hint() }
 }
 
 impl DoubleEndedIterator for Args {
-    fn next_back(&mut self) -> Option<OsString> {
-        self.range.next_back().map(|i| unsafe { os_string_from_ptr(*self.cur.offset(i)) } )
-    }
+    fn next_back(&mut self) -> Option<OsString> { self.parsed_args_list.next_back() }
 }
 
 impl ExactSizeIterator for Args {
-    fn len(&self) -> usize { self.range.len() }
+    fn len(&self) -> usize { self.parsed_args_list.len() }
 }
 
-impl Drop for Args {
-    fn drop(&mut self) {
-        // self.cur can be null if CommandLineToArgvW previously failed,
-        // but LocalFree ignores NULL pointers
-        unsafe { c::LocalFree(self.cur as *mut c_void); }
+#[cfg(test)]
+mod tests {
+    use sys::windows::args::*;
+    use ffi::OsString;
+
+    fn chk(string: &str, parts: &[&str]) {
+        let mut wide: Vec<u16> = OsString::from(string).encode_wide().collect();
+        wide.push(0);
+        let parsed = unsafe {
+            parse_lp_cmd_line(wide.as_ptr() as *const u16, || OsString::from("TEST.EXE"))
+        };
+        let expected: Vec<OsString> = parts.iter().map(|k| OsString::from(k)).collect();
+        assert_eq!(parsed.as_slice(), expected.as_slice());
+    }
+
+    #[test]
+    fn empty() {
+        chk("", &["TEST.EXE"]);
+        chk("\0", &["TEST.EXE"]);
+    }
+
+    #[test]
+    fn single_words() {
+        chk("EXE one_word", &["EXE", "one_word"]);
+        chk("EXE a", &["EXE", "a"]);
+        chk("EXE 😅", &["EXE", "😅"]);
+        chk("EXE 😅🤦", &["EXE", "😅🤦"]);
+    }
+
+    #[test]
+    fn official_examples() {
+        chk(r#"EXE "abc" d e"#, &["EXE", "abc", "d", "e"]);
+        chk(r#"EXE a\\\b d"e f"g h"#, &["EXE", r#"a\\\b"#, "de fg", "h"]);
+        chk(r#"EXE a\\\"b c d"#, &["EXE", r#"a\"b"#, "c", "d"]);
+        chk(r#"EXE a\\\\"b c" d e"#, &["EXE", r#"a\\b c"#, "d", "e"]);
+    }
+
+    #[test]
+    fn whitespace_behavior() {
+        chk(r#" test"#, &["", "test"]);
+        chk(r#"  test"#, &["", "test"]);
+        chk(r#" test test2"#, &["", "test", "test2"]);
+        chk(r#" test  test2"#, &["", "test", "test2"]);
+        chk(r#"test test2 "#, &["test", "test2"]);
+        chk(r#"test  test2 "#, &["test", "test2"]);
+        chk(r#"test "#, &["test"]);
+    }
+
+    #[test]
+    fn genius_quotes() {
+        chk(r#"EXE "" """#, &["EXE", "", ""]);
+        chk(r#"EXE "" """"#, &["EXE", "", "\""]);
+        chk(
+            r#"EXE "this is """all""" in the same argument""#,
+            &["EXE", "this is \"all\" in the same argument"]
+        );
+        chk(r#"EXE "a"""#, &["EXE", "a\""]);
+        chk(r#"EXE "a"" a"#, &["EXE", "a\"", "a"]);
+        // quotes cannot be escaped in command names
+        chk(r#""EXE" check"#, &["EXE", "check"]);
+        chk(r#""EXE check""#, &["EXE check"]);
+        chk(r#""EXE """for""" check"#, &["EXE ", r#"for""#, "check"]);
+        chk(r#""EXE \"for\" check"#, &[r#"EXE \"#, r#"for""#,  "check"]);
     }
 }
diff --git a/src/libstd/sys/windows/c.rs b/src/libstd/sys/windows/c.rs
index c84874a..fa21f45 100644
--- a/src/libstd/sys/windows/c.rs
+++ b/src/libstd/sys/windows/c.rs
@@ -1035,9 +1035,6 @@
 
     pub fn SetLastError(dwErrCode: DWORD);
     pub fn GetCommandLineW() -> *mut LPCWSTR;
-    pub fn LocalFree(ptr: *mut c_void);
-    pub fn CommandLineToArgvW(lpCmdLine: *mut LPCWSTR,
-                              pNumArgs: *mut c_int) -> *mut *mut u16;
     pub fn GetTempPathW(nBufferLength: DWORD,
                         lpBuffer: LPCWSTR) -> DWORD;
     pub fn OpenProcessToken(ProcessHandle: HANDLE,
diff --git a/src/libstd/sys/windows/os.rs b/src/libstd/sys/windows/os.rs
index 2be30e6..84ef62e 100644
--- a/src/libstd/sys/windows/os.rs
+++ b/src/libstd/sys/windows/os.rs
@@ -76,7 +76,7 @@
         match String::from_utf16(&buf[..res]) {
             Ok(mut msg) => {
                 // Trim trailing CRLF inserted by FormatMessageW
-                let len = msg.trim_right().len();
+                let len = msg.trim_end().len();
                 msg.truncate(len);
                 msg
             },
diff --git a/src/libstd/sys/windows/time.rs b/src/libstd/sys/windows/time.rs
index c809a0b..bb2c97e 100644
--- a/src/libstd/sys/windows/time.rs
+++ b/src/libstd/sys/windows/time.rs
@@ -68,30 +68,27 @@
         Duration::new(nanos / NANOS_PER_SEC, (nanos % NANOS_PER_SEC) as u32)
     }
 
-    pub fn add_duration(&self, other: &Duration) -> Instant {
+    pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> {
         let freq = frequency() as u64;
-        let t = other.as_secs().checked_mul(freq).and_then(|i| {
-            (self.t as u64).checked_add(i)
-        }).and_then(|i| {
-            i.checked_add(mul_div_u64(other.subsec_nanos() as u64, freq,
-                                      NANOS_PER_SEC))
-        }).expect("overflow when adding duration to time");
-        Instant {
+        let t = other.as_secs()
+            .checked_mul(freq)?
+            .checked_add(mul_div_u64(other.subsec_nanos() as u64, freq, NANOS_PER_SEC))?
+            .checked_add(self.t as u64)?;
+        Some(Instant {
             t: t as c::LARGE_INTEGER,
-        }
+        })
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> Instant {
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> {
         let freq = frequency() as u64;
         let t = other.as_secs().checked_mul(freq).and_then(|i| {
             (self.t as u64).checked_sub(i)
         }).and_then(|i| {
-            i.checked_sub(mul_div_u64(other.subsec_nanos() as u64, freq,
-                                      NANOS_PER_SEC))
-        }).expect("overflow when subtracting duration from time");
-        Instant {
+            i.checked_sub(mul_div_u64(other.subsec_nanos() as u64, freq, NANOS_PER_SEC))
+        })?;
+        Some(Instant {
             t: t as c::LARGE_INTEGER,
-        }
+        })
     }
 }
 
@@ -127,20 +124,14 @@
         }
     }
 
-    pub fn add_duration(&self, other: &Duration) -> SystemTime {
-        self.checked_add_duration(other).expect("overflow when adding duration to time")
-    }
-
     pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
-        checked_dur2intervals(other)
-            .and_then(|d| self.intervals().checked_add(d))
-            .map(|i| SystemTime::from_intervals(i))
+        let intervals = self.intervals().checked_add(checked_dur2intervals(other)?)?;
+        Some(SystemTime::from_intervals(intervals))
     }
 
-    pub fn sub_duration(&self, other: &Duration) -> SystemTime {
-        let intervals = self.intervals().checked_sub(dur2intervals(other))
-                            .expect("overflow when subtracting from time");
-        SystemTime::from_intervals(intervals)
+    pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
+        let intervals = self.intervals().checked_sub(checked_dur2intervals(other)?)?;
+        Some(SystemTime::from_intervals(intervals))
     }
 }
 
@@ -184,16 +175,12 @@
     }
 }
 
-fn checked_dur2intervals(d: &Duration) -> Option<i64> {
-    d.as_secs()
-        .checked_mul(INTERVALS_PER_SEC)
-        .and_then(|i| i.checked_add(d.subsec_nanos() as u64 / 100))
-        .and_then(|i| i.try_into().ok())
-}
-
-fn dur2intervals(d: &Duration) -> i64 {
-    checked_dur2intervals(d)
-        .expect("overflow when converting duration to intervals")
+fn checked_dur2intervals(dur: &Duration) -> Option<i64> {
+    dur.as_secs()
+        .checked_mul(INTERVALS_PER_SEC)?
+        .checked_add(dur.subsec_nanos() as u64 / 100)?
+        .try_into()
+        .ok()
 }
 
 fn intervals2dur(intervals: u64) -> Duration {
diff --git a/src/libstd/sys_common/condvar.rs b/src/libstd/sys_common/condvar.rs
index 16bf080..b6f29dd 100644
--- a/src/libstd/sys_common/condvar.rs
+++ b/src/libstd/sys_common/condvar.rs
@@ -25,7 +25,6 @@
     ///
     /// Behavior is undefined if the condition variable is moved after it is
     /// first used with any of the functions below.
-    #[unstable(feature = "sys_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn new() -> Condvar { Condvar(imp::Condvar::new()) }
 
     /// Prepares the condition variable for use.
diff --git a/src/libstd/sys_common/mutex.rs b/src/libstd/sys_common/mutex.rs
index 8768423..c6d531c 100644
--- a/src/libstd/sys_common/mutex.rs
+++ b/src/libstd/sys_common/mutex.rs
@@ -27,7 +27,6 @@
     /// Also, until `init` is called, behavior is undefined if this
     /// mutex is ever used reentrantly, i.e., `raw_lock` or `try_lock`
     /// are called by the thread currently holding the lock.
-    #[unstable(feature = "sys_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn new() -> Mutex { Mutex(imp::Mutex::new()) }
 
     /// Prepare the mutex for use.
diff --git a/src/libstd/sys_common/rwlock.rs b/src/libstd/sys_common/rwlock.rs
index a430c25..71a4f01 100644
--- a/src/libstd/sys_common/rwlock.rs
+++ b/src/libstd/sys_common/rwlock.rs
@@ -22,7 +22,6 @@
     ///
     /// Behavior is undefined if the reader-writer lock is moved after it is
     /// first used with any of the functions below.
-    #[unstable(feature = "sys_internals", issue = "0")] // FIXME: min_const_fn
     pub const fn new() -> RWLock { RWLock(imp::RWLock::new()) }
 
     /// Acquires shared access to the underlying lock, blocking the current
diff --git a/src/libstd/time.rs b/src/libstd/time.rs
index 6678104..63cede7 100644
--- a/src/libstd/time.rs
+++ b/src/libstd/time.rs
@@ -208,6 +208,22 @@
     pub fn elapsed(&self) -> Duration {
         Instant::now() - *self
     }
+
+    /// Returns `Some(t)` where `t` is the time `self + duration` if `t` can be represented as
+    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
+    /// otherwise.
+    #[unstable(feature = "time_checked_add", issue = "55940")]
+    pub fn checked_add(&self, duration: Duration) -> Option<Instant> {
+        self.0.checked_add_duration(&duration).map(|t| Instant(t))
+    }
+
+    /// Returns `Some(t)` where `t` is the time `self - duration` if `t` can be represented as
+    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
+    /// otherwise.
+    #[unstable(feature = "time_checked_add", issue = "55940")]
+    pub fn checked_sub(&self, duration: Duration) -> Option<Instant> {
+        self.0.checked_sub_duration(&duration).map(|t| Instant(t))
+    }
 }
 
 #[stable(feature = "time2", since = "1.8.0")]
@@ -215,7 +231,8 @@
     type Output = Instant;
 
     fn add(self, other: Duration) -> Instant {
-        Instant(self.0.add_duration(&other))
+        self.checked_add(other)
+            .expect("overflow when adding duration to instant")
     }
 }
 
@@ -231,7 +248,8 @@
     type Output = Instant;
 
     fn sub(self, other: Duration) -> Instant {
-        Instant(self.0.sub_duration(&other))
+        self.checked_sub(other)
+            .expect("overflow when subtracting duration from instant")
     }
 }
 
@@ -365,6 +383,14 @@
     pub fn checked_add(&self, duration: Duration) -> Option<SystemTime> {
         self.0.checked_add_duration(&duration).map(|t| SystemTime(t))
     }
+
+    /// Returns `Some(t)` where `t` is the time `self - duration` if `t` can be represented as
+    /// `SystemTime` (which means it's inside the bounds of the underlying data structure), `None`
+    /// otherwise.
+    #[unstable(feature = "time_checked_add", issue = "55940")]
+    pub fn checked_sub(&self, duration: Duration) -> Option<SystemTime> {
+        self.0.checked_sub_duration(&duration).map(|t| SystemTime(t))
+    }
 }
 
 #[stable(feature = "time2", since = "1.8.0")]
@@ -372,7 +398,8 @@
     type Output = SystemTime;
 
     fn add(self, dur: Duration) -> SystemTime {
-        SystemTime(self.0.add_duration(&dur))
+        self.checked_add(dur)
+            .expect("overflow when adding duration to instant")
     }
 }
 
@@ -388,7 +415,8 @@
     type Output = SystemTime;
 
     fn sub(self, dur: Duration) -> SystemTime {
-        SystemTime(self.0.sub_duration(&dur))
+        self.checked_sub(dur)
+            .expect("overflow when subtracting duration from instant")
     }
 }
 
@@ -521,6 +549,20 @@
 
         let second = Duration::new(1, 0);
         assert_almost_eq!(a - second + second, a);
+        assert_almost_eq!(a.checked_sub(second).unwrap().checked_add(second).unwrap(), a);
+
+        // checked_add_duration will not panic on overflow
+        let mut maybe_t = Some(Instant::now());
+        let max_duration = Duration::from_secs(u64::max_value());
+        // in case `Instant` can store `>= now + max_duration`.
+        for _ in 0..2 {
+            maybe_t = maybe_t.and_then(|t| t.checked_add(max_duration));
+        }
+        assert_eq!(maybe_t, None);
+
+        // checked_add_duration calculates the right time and will work for another year
+        let year = Duration::from_secs(60 * 60 * 24 * 365);
+        assert_eq!(a + year, a.checked_add(year).unwrap());
     }
 
     #[test]
@@ -557,6 +599,7 @@
                            .duration(), second);
 
         assert_almost_eq!(a - second + second, a);
+        assert_almost_eq!(a.checked_sub(second).unwrap().checked_add(second).unwrap(), a);
 
         // A difference of 80 and 800 years cannot fit inside a 32-bit time_t
         if !(cfg!(unix) && ::mem::size_of::<::libc::time_t>() <= 4) {
diff --git a/src/libsyntax/diagnostics/plugin.rs b/src/libsyntax/diagnostics/plugin.rs
index 1229db9..3b88767 100644
--- a/src/libsyntax/diagnostics/plugin.rs
+++ b/src/libsyntax/diagnostics/plugin.rs
@@ -141,6 +141,7 @@
     ])
 }
 
+#[allow(deprecated)]
 pub fn expand_build_diagnostic_array<'cx>(ecx: &'cx mut ExtCtxt,
                                           span: Span,
                                           token_tree: &[TokenTree])
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index eb71003..10c451e 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -15,7 +15,7 @@
 use early_buffered_lints::{BufferedEarlyLint, BufferedEarlyLintId};
 use source_map::{SourceMap, FilePathMapping};
 use syntax_pos::{Span, SourceFile, FileName, MultiSpan};
-use errors::{Handler, ColorConfig, Diagnostic, DiagnosticBuilder};
+use errors::{FatalError, Level, Handler, ColorConfig, Diagnostic, DiagnosticBuilder};
 use feature_gate::UnstableFeatures;
 use parse::parser::Parser;
 use ptr::P;
@@ -192,6 +192,14 @@
     source_file_to_parser(sess, file_to_source_file(sess, path, None))
 }
 
+/// Create a new parser, returning buffered diagnostics if the file doesn't
+/// exist or from lexing the initial token stream.
+pub fn maybe_new_parser_from_file<'a>(sess: &'a ParseSess, path: &Path)
+    -> Result<Parser<'a>, Vec<Diagnostic>> {
+    let file = try_file_to_source_file(sess, path, None).map_err(|db| vec![db])?;
+    maybe_source_file_to_parser(sess, file)
+}
+
 /// Given a session, a crate config, a path, and a span, add
 /// the file at the given path to the source_map, and return a parser.
 /// On an error, use the given span as the source of the problem.
@@ -237,17 +245,30 @@
 // base abstractions
 
 /// Given a session and a path and an optional span (for error reporting),
+/// add the path to the session's source_map and return the new source_file or
+/// error when a file can't be read.
+fn try_file_to_source_file(sess: &ParseSess, path: &Path, spanopt: Option<Span>)
+                   -> Result<Lrc<SourceFile>, Diagnostic> {
+    sess.source_map().load_file(path)
+    .map_err(|e| {
+        let msg = format!("couldn't read {}: {}", path.display(), e);
+        let mut diag = Diagnostic::new(Level::Fatal, &msg);
+        if let Some(sp) = spanopt {
+            diag.set_span(sp);
+        }
+        diag
+    })
+}
+
+/// Given a session and a path and an optional span (for error reporting),
 /// add the path to the session's source_map and return the new source_file.
 fn file_to_source_file(sess: &ParseSess, path: &Path, spanopt: Option<Span>)
                    -> Lrc<SourceFile> {
-    match sess.source_map().load_file(path) {
+    match try_file_to_source_file(sess, path, spanopt) {
         Ok(source_file) => source_file,
-        Err(e) => {
-            let msg = format!("couldn't read {}: {}", path.display(), e);
-            match spanopt {
-                Some(sp) => sess.span_diagnostic.span_fatal(sp, &msg).raise(),
-                None => sess.span_diagnostic.fatal(&msg).raise()
-            }
+        Err(d) => {
+            DiagnosticBuilder::new_diagnostic(&sess.span_diagnostic, d).emit();
+            FatalError.raise();
         }
     }
 }
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index 8e4d3c0..ed74665 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -207,6 +207,10 @@
     Eof,
 }
 
+// `Token` is used a lot. Make sure it doesn't unintentionally get bigger.
+#[cfg(target_arch = "x86_64")]
+static_assert!(MEM_SIZE_OF_STATEMENT: mem::size_of::<Token>() == 16);
+
 impl Token {
     pub fn interpolated(nt: Nonterminal) -> Token {
         Token::Interpolated(Lrc::new((nt, LazyTokenStream::new())))
diff --git a/src/libsyntax/source_map.rs b/src/libsyntax/source_map.rs
index 4500812..9a34312 100644
--- a/src/libsyntax/source_map.rs
+++ b/src/libsyntax/source_map.rs
@@ -579,7 +579,7 @@
         match self.span_to_prev_source(sp) {
             Err(_) => None,
             Ok(source) => source.split('\n').last().map(|last_line| {
-                last_line.len() - last_line.trim_left().len()
+                last_line.len() - last_line.trim_start().len()
             })
         }
     }
@@ -593,7 +593,7 @@
     /// if no character could be found or if an error occurred while retrieving the code snippet.
     pub fn span_extend_to_prev_char(&self, sp: Span, c: char) -> Span {
         if let Ok(prev_source) = self.span_to_prev_source(sp) {
-            let prev_source = prev_source.rsplit(c).nth(0).unwrap_or("").trim_left();
+            let prev_source = prev_source.rsplit(c).nth(0).unwrap_or("").trim_start();
             if !prev_source.is_empty() && !prev_source.contains('\n') {
                 return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
             }
@@ -613,7 +613,7 @@
         for ws in &[" ", "\t", "\n"] {
             let pat = pat.to_owned() + ws;
             if let Ok(prev_source) = self.span_to_prev_source(sp) {
-                let prev_source = prev_source.rsplit(&pat).nth(0).unwrap_or("").trim_left();
+                let prev_source = prev_source.rsplit(&pat).nth(0).unwrap_or("").trim_start();
                 if !prev_source.is_empty() && (!prev_source.contains('\n') || accept_newlines) {
                     return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
                 }
@@ -627,7 +627,7 @@
     pub fn span_until_char(&self, sp: Span, c: char) -> Span {
         match self.span_to_snippet(sp) {
             Ok(snippet) => {
-                let snippet = snippet.split(c).nth(0).unwrap_or("").trim_right();
+                let snippet = snippet.split(c).nth(0).unwrap_or("").trim_end();
                 if !snippet.is_empty() && !snippet.contains('\n') {
                     sp.with_hi(BytePos(sp.lo().0 + snippet.len() as u32))
                 } else {
diff --git a/src/libsyntax_pos/lib.rs b/src/libsyntax_pos/lib.rs
index 8b7ffa4..9aafb9f 100644
--- a/src/libsyntax_pos/lib.rs
+++ b/src/libsyntax_pos/lib.rs
@@ -24,10 +24,13 @@
 #![feature(nll)]
 #![feature(non_exhaustive)]
 #![feature(optin_builtin_traits)]
+#![feature(rustc_attrs)]
 #![feature(specialization)]
+#![feature(step_trait)]
 #![cfg_attr(not(stage0), feature(stdsimd))]
 
 extern crate arena;
+#[macro_use]
 extern crate rustc_data_structures;
 
 #[macro_use]
diff --git a/src/libsyntax_pos/symbol.rs b/src/libsyntax_pos/symbol.rs
index 05c5387..b720db8 100644
--- a/src/libsyntax_pos/symbol.rs
+++ b/src/libsyntax_pos/symbol.rs
@@ -14,6 +14,7 @@
 
 use arena::DroplessArena;
 use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::indexed_vec::Idx;
 use serialize::{Decodable, Decoder, Encodable, Encoder};
 
 use std::fmt;
@@ -57,7 +58,7 @@
     }
 
     pub fn without_first_quote(self) -> Ident {
-        Ident::new(Symbol::intern(self.as_str().trim_left_matches('\'')), self.span)
+        Ident::new(Symbol::intern(self.as_str().trim_start_matches('\'')), self.span)
     }
 
     /// "Normalize" ident for use in comparisons using "item hygiene".
@@ -143,9 +144,18 @@
     }
 }
 
-/// A symbol is an interned or gensymed string.
+/// A symbol is an interned or gensymed string. The use of newtype_index! means
+/// that Option<Symbol> only takes up 4 bytes, because newtype_index! reserves
+/// the last 256 values for tagging purposes.
+///
+/// Note that Symbol cannot be a newtype_index! directly because it implements
+/// fmt::Debug, Encodable, and Decodable in special ways.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct Symbol(u32);
+pub struct Symbol(SymbolIndex);
+
+newtype_index! {
+    pub struct SymbolIndex { .. }
+}
 
 // The interner is pointed to by a thread local value which is only set on the main thread
 // with parallelization is disabled. So we don't allow `Symbol` to transfer between threads
@@ -156,6 +166,10 @@
 impl !Sync for Symbol { }
 
 impl Symbol {
+    const fn new(n: u32) -> Self {
+        Symbol(SymbolIndex::from_u32_const(n))
+    }
+
     /// Maps a string to its interned representation.
     pub fn intern(string: &str) -> Self {
         with_interner(|interner| interner.intern(string))
@@ -189,7 +203,7 @@
     }
 
     pub fn as_u32(self) -> u32 {
-        self.0
+        self.0.as_u32()
     }
 }
 
@@ -197,7 +211,7 @@
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let is_gensymed = with_interner(|interner| interner.is_gensymed(*self));
         if is_gensymed {
-            write!(f, "{}({})", self, self.0)
+            write!(f, "{}({:?})", self, self.0)
         } else {
             write!(f, "{}", self)
         }
@@ -229,6 +243,9 @@
 }
 
 // The `&'static str`s in this type actually point into the arena.
+//
+// Note that normal symbols are indexed upward from 0, and gensyms are indexed
+// downward from SymbolIndex::MAX_AS_U32.
 #[derive(Default)]
 pub struct Interner {
     arena: DroplessArena,
@@ -243,7 +260,7 @@
         for &string in init {
             if string == "" {
                 // We can't allocate empty strings in the arena, so handle this here.
-                let name = Symbol(this.strings.len() as u32);
+                let name = Symbol::new(this.strings.len() as u32);
                 this.names.insert("", name);
                 this.strings.push("");
             } else {
@@ -258,7 +275,7 @@
             return name;
         }
 
-        let name = Symbol(self.strings.len() as u32);
+        let name = Symbol::new(self.strings.len() as u32);
 
         // `from_utf8_unchecked` is safe since we just allocated a `&str` which is known to be
         // UTF-8.
@@ -276,10 +293,10 @@
     }
 
     pub fn interned(&self, symbol: Symbol) -> Symbol {
-        if (symbol.0 as usize) < self.strings.len() {
+        if (symbol.0.as_usize()) < self.strings.len() {
             symbol
         } else {
-            self.interned(self.gensyms[(!0 - symbol.0) as usize])
+            self.interned(self.gensyms[(SymbolIndex::MAX_AS_U32 - symbol.0.as_u32()) as usize])
         }
     }
 
@@ -290,17 +307,17 @@
 
     fn gensymed(&mut self, symbol: Symbol) -> Symbol {
         self.gensyms.push(symbol);
-        Symbol(!0 - self.gensyms.len() as u32 + 1)
+        Symbol::new(SymbolIndex::MAX_AS_U32 - self.gensyms.len() as u32 + 1)
     }
 
     fn is_gensymed(&mut self, symbol: Symbol) -> bool {
-        symbol.0 as usize >= self.strings.len()
+        symbol.0.as_usize() >= self.strings.len()
     }
 
     pub fn get(&self, symbol: Symbol) -> &str {
-        match self.strings.get(symbol.0 as usize) {
+        match self.strings.get(symbol.0.as_usize()) {
             Some(string) => string,
-            None => self.get(self.gensyms[(!0 - symbol.0) as usize]),
+            None => self.get(self.gensyms[(SymbolIndex::MAX_AS_U32 - symbol.0.as_u32()) as usize]),
         }
     }
 }
@@ -324,7 +341,7 @@
         $(
             #[allow(non_upper_case_globals)]
             pub const $konst: Keyword = Keyword {
-                ident: Ident::with_empty_ctxt(super::Symbol($index))
+                ident: Ident::with_empty_ctxt(super::Symbol::new($index))
             };
         )*
 
@@ -709,19 +726,19 @@
     fn interner_tests() {
         let mut i: Interner = Interner::default();
         // first one is zero:
-        assert_eq!(i.intern("dog"), Symbol(0));
+        assert_eq!(i.intern("dog"), Symbol::new(0));
         // re-use gets the same entry:
-        assert_eq!(i.intern("dog"), Symbol(0));
+        assert_eq!(i.intern("dog"), Symbol::new(0));
         // different string gets a different #:
-        assert_eq!(i.intern("cat"), Symbol(1));
-        assert_eq!(i.intern("cat"), Symbol(1));
+        assert_eq!(i.intern("cat"), Symbol::new(1));
+        assert_eq!(i.intern("cat"), Symbol::new(1));
         // dog is still at zero
-        assert_eq!(i.intern("dog"), Symbol(0));
-        assert_eq!(i.gensym("zebra"), Symbol(4294967295));
-        // gensym of same string gets new number :
-        assert_eq!(i.gensym("zebra"), Symbol(4294967294));
+        assert_eq!(i.intern("dog"), Symbol::new(0));
+        assert_eq!(i.gensym("zebra"), Symbol::new(SymbolIndex::MAX_AS_U32));
+        // gensym of same string gets new number:
+        assert_eq!(i.gensym("zebra"), Symbol::new(SymbolIndex::MAX_AS_U32 - 1));
         // gensym of *existing* string gets new number:
-        assert_eq!(i.gensym("dog"), Symbol(4294967293));
+        assert_eq!(i.gensym("dog"), Symbol::new(SymbolIndex::MAX_AS_U32 - 2));
     }
 
     #[test]
diff --git a/src/libunwind/Cargo.toml b/src/libunwind/Cargo.toml
index 4760461..2577d6d 100644
--- a/src/libunwind/Cargo.toml
+++ b/src/libunwind/Cargo.toml
@@ -13,5 +13,5 @@
 
 [dependencies]
 core = { path = "../libcore" }
-libc = { path = "../rustc/libc_shim" }
-compiler_builtins = { path = "../rustc/compiler_builtins_shim" }
+libc = { version = "0.2.43", features = ['rustc-dep-of-std'], default-features = false }
+compiler_builtins = "0.1.0"
diff --git a/src/rust-sgx b/src/rust-sgx
deleted file mode 160000
index 9656260..0000000
--- a/src/rust-sgx
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 9656260888095f44830641ca7bb3da609a793451
diff --git a/src/rustc/compiler_builtins_shim/Cargo.toml b/src/rustc/compiler_builtins_shim/Cargo.toml
deleted file mode 100644
index 9804177..0000000
--- a/src/rustc/compiler_builtins_shim/Cargo.toml
+++ /dev/null
@@ -1,40 +0,0 @@
-[package]
-name = "compiler_builtins"
-authors = ["The Rust Project Developers"]
-version = "0.0.0"
-build = "../../libcompiler_builtins/build.rs"
-
-[lib]
-path = "../../libcompiler_builtins/src/lib.rs"
-test = false
-doctest = false
-
-[dependencies]
-# Specify the path to libcore; at the time of writing, removing this shim in
-# favor of using compiler-builtins from git results in a compilation failure:
-#
-# Building stage0 std artifacts (x86_64-apple-darwin -> x86_64-apple-darwin)
-#    Compiling compiler_builtins v0.1.0 (https://github.com/rust-lang-nursery/compiler-builtins.git#23f14d3f)
-# error[E0463]: can't find crate for `core`
-#
-# error: aborting due to previous error
-#
-# error: Could not compile `compiler_builtins`.
-#
-# Caused by:
-#   process didn't exit successfully: `/Users/tamird/src/rust/build/bootstrap/debug/rustc --crate-name compiler_builtins /Users/tamird/.cargo/git/checkouts/compiler-builtins-ec094dc45a0179c8/23f14d3/src/lib.rs --error-format json --crate-type lib --emit=dep-info,link -C opt-level=2 --cfg feature="c" --cfg feature="compiler-builtins" --cfg feature="default" --cfg feature="gcc" -C metadata=876d429e8d7eae1f -C extra-filename=-876d429e8d7eae1f --out-dir /Users/tamird/src/rust/build/x86_64-apple-darwin/stage0-std/x86_64-apple-darwin/release/deps --target x86_64-apple-darwin -L dependency=/Users/tamird/src/rust/build/x86_64-apple-darwin/stage0-std/x86_64-apple-darwin/release/deps -L dependency=/Users/tamird/src/rust/build/x86_64-apple-darwin/stage0-std/release/deps --cap-lints allow -L native=/Users/tamird/src/rust/build/x86_64-apple-darwin/stage0-std/x86_64-apple-darwin/release/build/compiler_builtins-f18fab55928102ad/out -l static=compiler-rt` (exit code: 101)
-# thread 'main' panicked at 'command did not execute successfully: "/Users/tamird/src/rust/build/x86_64-apple-darwin/stage0/bin/cargo" "build" "-j" "4" "--target" "x86_64-apple-darwin" "--release" "--features" "panic-unwind jemalloc backtrace" "--manifest-path" "/Users/tamird/src/rust/src/libstd/Cargo.toml" "--message-format" "json"
-# expected success, got: exit code: 101', src/bootstrap/compile.rs:883:8
-#
-# See https://github.com/rust-lang/rfcs/pull/1133.
-core = { path = "../../libcore" }
-
-[build-dependencies]
-cc = "1.0.1"
-
-[features]
-c = []
-default = ["rustbuild", "compiler-builtins"]
-mem = []
-rustbuild = []
-compiler-builtins = []
diff --git a/src/rustc/compiler_builtins_shim/build.rs b/src/rustc/compiler_builtins_shim/build.rs
deleted file mode 100644
index b37543e..0000000
--- a/src/rustc/compiler_builtins_shim/build.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// This file is left intentionally empty (and not removed) to avoid an issue
-// where this crate is always considered dirty due to compiler-builtins'
-// `cargo:rerun-if-changed=build.rs` directive; since the path is relative, it
-// refers to this file when this shim crate is being built, and the absence of
-// this file is considered by cargo to be equivalent to it having changed.
diff --git a/src/rustc/dlmalloc_shim/Cargo.toml b/src/rustc/dlmalloc_shim/Cargo.toml
deleted file mode 100644
index b6f8550..0000000
--- a/src/rustc/dlmalloc_shim/Cargo.toml
+++ /dev/null
@@ -1,14 +0,0 @@
-[package]
-name = "dlmalloc"
-version = "0.0.0"
-authors = ["The Rust Project Developers"]
-
-[lib]
-path = "../../dlmalloc/src/lib.rs"
-test = false
-bench = false
-doc = false
-
-[dependencies]
-core = { path = "../../libcore" }
-compiler_builtins = { path = "../../rustc/compiler_builtins_shim" }
diff --git a/src/rustc/fortanix-sgx-abi_shim/Cargo.toml b/src/rustc/fortanix-sgx-abi_shim/Cargo.toml
deleted file mode 100644
index fd81d3d..0000000
--- a/src/rustc/fortanix-sgx-abi_shim/Cargo.toml
+++ /dev/null
@@ -1,14 +0,0 @@
-[package]
-name = "fortanix-sgx-abi"
-version = "0.0.0"
-authors = ["The Rust Project Developers"]
-
-[lib]
-path = "../../rust-sgx/fortanix-sgx-abi/src/lib.rs"
-test = false
-bench = false
-doc = false
-
-[dependencies]
-core = { path = "../../libcore" }
-compiler_builtins = { path = "../../rustc/compiler_builtins_shim" }
diff --git a/src/rustc/libc_shim/Cargo.toml b/src/rustc/libc_shim/Cargo.toml
deleted file mode 100644
index ee037ac..0000000
--- a/src/rustc/libc_shim/Cargo.toml
+++ /dev/null
@@ -1,40 +0,0 @@
-[package]
-name = "libc"
-version = "0.0.0"
-authors = ["The Rust Project Developers"]
-
-[lib]
-name = "libc"
-path = "../../liblibc/src/lib.rs"
-test = false
-bench = false
-doc = false
-
-[dependencies]
-# Specify the path to libcore; at the time of writing, removing this shim in
-# favor of using libc from git results in a compilation failure:
-#
-# Building stage0 std artifacts (x86_64-apple-darwin -> x86_64-apple-darwin)
-#    Compiling libc v0.0.0 (file:///Users/tamird/src/rust/src/rustc/libc_shim)
-# error[E0463]: can't find crate for `core`
-#
-# error: aborting due to previous error
-#
-# error: Could not compile `libc`.
-#
-# Caused by:
-#   process didn't exit successfully: `/Users/tamird/src/rust/build/bootstrap/debug/rustc --crate-name libc src/rustc/libc_shim/../../liblibc/src/lib.rs --error-format json --crate-type lib --emit=dep-info,link -C opt-level=2 --cfg feature="default" --cfg feature="no_std" --cfg feature="stdbuild" -C metadata=d758f87058112d7d -C extra-filename=-d758f87058112d7d --out-dir /Users/tamird/src/rust/build/x86_64-apple-darwin/stage0-std/x86_64-apple-darwin/release/deps --target x86_64-apple-darwin -L dependency=/Users/tamird/src/rust/build/x86_64-apple-darwin/stage0-std/x86_64-apple-darwin/release/deps -L dependency=/Users/tamird/src/rust/build/x86_64-apple-darwin/stage0-std/release/deps` (exit code: 101)
-# thread 'main' panicked at 'command did not execute successfully: "/Users/tamird/src/rust/build/x86_64-apple-darwin/stage0/bin/cargo" "build" "-j" "4" "--target" "x86_64-apple-darwin" "--release" "--features" "panic-unwind jemalloc backtrace" "--manifest-path" "/Users/tamird/src/rust/src/libstd/Cargo.toml" "--message-format" "json"
-# expected success, got: exit code: 101', src/bootstrap/compile.rs:883:8
-#
-# See https://github.com/rust-lang/rfcs/pull/1133.
-core = { path = "../../libcore" }
-compiler_builtins = { path = "../compiler_builtins_shim" }
-
-
-[features]
-# Certain parts of libc are conditionally compiled differently than when used
-# outside rustc. See https://github.com/rust-lang/libc/search?l=Rust&q=stdbuild&type=&utf8=%E2%9C%93.
-stdbuild = []
-default = ["stdbuild", "align"]
-align = []
diff --git a/src/stage0.txt b/src/stage0.txt
index 9326e22..843ecae 100644
--- a/src/stage0.txt
+++ b/src/stage0.txt
@@ -12,7 +12,7 @@
 # source tarball for a stable release you'll likely see `1.x.0` for rustc and
 # `0.x.0` for Cargo where they were released on `date`.
 
-date: 2018-10-30
+date: 2018-12-09
 rustc: beta
 cargo: beta
 
diff --git a/src/test/codegen/nounwind-extern.rs b/src/test/codegen/nounwind-extern.rs
new file mode 100644
index 0000000..ed07cf1
--- /dev/null
+++ b/src/test/codegen/nounwind-extern.rs
@@ -0,0 +1,16 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-flags: -O
+
+#![crate_type = "lib"]
+
+// CHECK: Function Attrs: norecurse nounwind
+pub extern fn foo() {}
diff --git a/src/test/codegen/simd-intrinsic-generic-select.rs b/src/test/codegen/simd-intrinsic-generic-select.rs
index 8a64d74..24a4b2b 100644
--- a/src/test/codegen/simd-intrinsic-generic-select.rs
+++ b/src/test/codegen/simd-intrinsic-generic-select.rs
@@ -21,10 +21,15 @@
 
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
+pub struct f32x8(f32, f32, f32, f32, f32, f32, f32, f32);
+
+#[repr(simd)]
+#[derive(Copy, Clone, PartialEq, Debug)]
 pub struct b8x4(pub i8, pub i8, pub i8, pub i8);
 
 extern "platform-intrinsic" {
     fn simd_select<T, U>(x: T, a: U, b: U) -> U;
+    fn simd_select_bitmask<T, U>(x: T, a: U, b: U) -> U;
 }
 
 // CHECK-LABEL: @select
@@ -33,3 +38,10 @@
     // CHECK: select <4 x i1>
     simd_select(m, a, b)
 }
+
+// CHECK-LABEL: @select_bitmask
+#[no_mangle]
+pub unsafe fn select_bitmask(m: i8, a: f32x8, b: f32x8) -> f32x8 {
+    // CHECK: select <8 x i1>
+    simd_select_bitmask(m, a, b)
+}
diff --git a/src/test/compile-fail/issue-10755.rs b/src/test/compile-fail/issue-10755.rs
index 57915bc..bb77748 100644
--- a/src/test/compile-fail/issue-10755.rs
+++ b/src/test/compile-fail/issue-10755.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// compile-flags: -C linker=llllll -Z linker-flavor=ld
+// compile-flags: -C linker=llllll -C linker-flavor=ld
 // error-pattern: linker `llllll` not found
 
 fn main() {
diff --git a/src/test/compile-fail/nolink-with-link-args.rs b/src/test/compile-fail/nolink-with-link-args.rs
index 6dfd74f..95f827e 100644
--- a/src/test/compile-fail/nolink-with-link-args.rs
+++ b/src/test/compile-fail/nolink-with-link-args.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 // error-pattern:aFdEfSeVEE
-// compile-flags: -Z linker-flavor=ld
+// compile-flags: -C linker-flavor=ld
 
 /* We're testing that link_args are indeed passed when nolink is specified.
 So we try to compile with junk link_args and make sure they are visible in
diff --git a/src/test/debuginfo/pretty-std-collections.rs b/src/test/debuginfo/pretty-std-collections.rs
index a51be37..350b30d 100644
--- a/src/test/debuginfo/pretty-std-collections.rs
+++ b/src/test/debuginfo/pretty-std-collections.rs
@@ -13,7 +13,11 @@
 // ignore-freebsd: gdb package too new
 // ignore-android: FIXME(#10381)
 // compile-flags:-g
-// min-gdb-version 7.7
+
+// The pretty printers being tested here require the patch from
+// https://sourceware.org/bugzilla/show_bug.cgi?id=21763
+// min-gdb-version 8.1
+
 // min-lldb-version: 310
 
 // === GDB TESTS ===================================================================================
diff --git a/src/test/incremental/foreign.rs b/src/test/incremental/foreign.rs
index dbdebef..648e89b 100644
--- a/src/test/incremental/foreign.rs
+++ b/src/test/incremental/foreign.rs
@@ -13,7 +13,7 @@
 
 // revisions: rpass1
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-make-fulldeps/c-link-to-rust-va-list-fn/checkrust.rs b/src/test/run-make-fulldeps/c-link-to-rust-va-list-fn/checkrust.rs
index 90ad601..0254c7c 100644
--- a/src/test/run-make-fulldeps/c-link-to-rust-va-list-fn/checkrust.rs
+++ b/src/test/run-make-fulldeps/c-link-to-rust-va-list-fn/checkrust.rs
@@ -10,7 +10,7 @@
 
 #![crate_type = "staticlib"]
 #![feature(c_variadic)]
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-make-fulldeps/issue-25581/test.rs b/src/test/run-make-fulldeps/issue-25581/test.rs
index 6717d16..b084092 100644
--- a/src/test/run-make-fulldeps/issue-25581/test.rs
+++ b/src/test/run-make-fulldeps/issue-25581/test.rs
@@ -8,14 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(libc)]
-
-extern crate libc;
-
 #[link(name = "test", kind = "static")]
 extern {
-    fn slice_len(s: &[u8]) -> libc::size_t;
-    fn slice_elem(s: &[u8], idx: libc::size_t) -> u8;
+    fn slice_len(s: &[u8]) -> usize;
+    fn slice_elem(s: &[u8], idx: usize) -> u8;
 }
 
 fn main() {
diff --git a/src/test/run-make-fulldeps/issue-26006/in/time/lib.rs b/src/test/run-make-fulldeps/issue-26006/in/time/lib.rs
index b1d07d5..1427250 100644
--- a/src/test/run-make-fulldeps/issue-26006/in/time/lib.rs
+++ b/src/test/run-make-fulldeps/issue-26006/in/time/lib.rs
@@ -7,7 +7,7 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-#![feature(libc)]
+#![feature(rustc_private)]
 extern crate libc;
 
 fn main(){}
diff --git a/src/test/run-make-fulldeps/libtest-json/output.json b/src/test/run-make-fulldeps/libtest-json/output.json
index 80e75c8..2b831ea 100644
--- a/src/test/run-make-fulldeps/libtest-json/output.json
+++ b/src/test/run-make-fulldeps/libtest-json/output.json
@@ -2,7 +2,7 @@
 { "type": "test", "event": "started", "name": "a" }
 { "type": "test", "name": "a", "event": "ok" }
 { "type": "test", "event": "started", "name": "b" }
-{ "type": "test", "name": "b", "event": "failed", "stdout": "thread 'main' panicked at 'assertion failed: false', f.rs:18:5\nnote: Run with `RUST_BACKTRACE=1` for a backtrace.\n" }
+{ "type": "test", "name": "b", "event": "failed", "stdout": "thread 'main' panicked at 'assertion failed: false', f.rs:18:5\nnote: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.\n" }
 { "type": "test", "event": "started", "name": "c" }
 { "type": "test", "name": "c", "event": "ok" }
 { "type": "test", "event": "started", "name": "d" }
diff --git a/src/test/run-make-fulldeps/link-path-order/main.rs b/src/test/run-make-fulldeps/link-path-order/main.rs
index f3502e8..4d38dc8 100644
--- a/src/test/run-make-fulldeps/link-path-order/main.rs
+++ b/src/test/run-make-fulldeps/link-path-order/main.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-make-fulldeps/tools.mk b/src/test/run-make-fulldeps/tools.mk
index 3de358f..7939928 100644
--- a/src/test/run-make-fulldeps/tools.mk
+++ b/src/test/run-make-fulldeps/tools.mk
@@ -76,7 +76,7 @@
 # Extra flags needed to compile a working executable with the standard library
 ifdef IS_WINDOWS
 ifdef IS_MSVC
-	EXTRACFLAGS := ws2_32.lib userenv.lib shell32.lib advapi32.lib
+	EXTRACFLAGS := ws2_32.lib userenv.lib advapi32.lib
 else
 	EXTRACFLAGS := -lws2_32 -luserenv
 endif
diff --git a/src/test/run-pass-valgrind/osx-frameworks.rs b/src/test/run-pass-valgrind/osx-frameworks.rs
index 468a20d..afa9374 100644
--- a/src/test/run-pass-valgrind/osx-frameworks.rs
+++ b/src/test/run-pass-valgrind/osx-frameworks.rs
@@ -11,7 +11,7 @@
 // no-prefer-dynamic
 // pretty-expanded FIXME #23616
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/abort-on-c-abi.rs b/src/test/run-pass/abort-on-c-abi.rs
index 17b2ee3..12b5b78 100644
--- a/src/test/run-pass/abort-on-c-abi.rs
+++ b/src/test/run-pass/abort-on-c-abi.rs
@@ -15,14 +15,11 @@
 // ignore-cloudabi no env and process
 // ignore-emscripten no processes
 
-#![feature(unwind_attributes)]
-
 use std::{env, panic};
 use std::io::prelude::*;
 use std::io;
 use std::process::{Command, Stdio};
 
-#[unwind(aborts)]
 extern "C" fn panic_in_ffi() {
     panic!("Test");
 }
diff --git a/src/test/run-pass/anon-extern-mod.rs b/src/test/run-pass/anon-extern-mod.rs
index 16ca7bc..daa2bd6 100644
--- a/src/test/run-pass/anon-extern-mod.rs
+++ b/src/test/run-pass/anon-extern-mod.rs
@@ -11,7 +11,7 @@
 // pretty-expanded FIXME #23616
 // ignore-wasm32-bare no libc to test ffi with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/array-slice-vec/vec-macro-no-std.rs b/src/test/run-pass/array-slice-vec/vec-macro-no-std.rs
index 5091674..7a90a02 100644
--- a/src/test/run-pass/array-slice-vec/vec-macro-no-std.rs
+++ b/src/test/run-pass/array-slice-vec/vec-macro-no-std.rs
@@ -12,7 +12,7 @@
 
 // ignore-emscripten no no_std executables
 
-#![feature(lang_items, start, libc, alloc)]
+#![feature(lang_items, start, rustc_private, alloc)]
 #![no_std]
 
 extern crate std as other;
diff --git a/src/test/run-pass/auxiliary/anon-extern-mod-cross-crate-1.rs b/src/test/run-pass/auxiliary/anon-extern-mod-cross-crate-1.rs
index 741ce35..6b464c5 100644
--- a/src/test/run-pass/auxiliary/anon-extern-mod-cross-crate-1.rs
+++ b/src/test/run-pass/auxiliary/anon-extern-mod-cross-crate-1.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 #![crate_name="anonexternmod"]
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/auxiliary/check_static_recursion_foreign_helper.rs b/src/test/run-pass/auxiliary/check_static_recursion_foreign_helper.rs
index cd36a8e..4d1acf3 100644
--- a/src/test/run-pass/auxiliary/check_static_recursion_foreign_helper.rs
+++ b/src/test/run-pass/auxiliary/check_static_recursion_foreign_helper.rs
@@ -10,7 +10,7 @@
 
 // Helper definition for test/run-pass/check-static-recursion-foreign.rs.
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 #![crate_name = "check_static_recursion_foreign_helper"]
 #![crate_type = "lib"]
diff --git a/src/test/run-pass/auxiliary/foreign_lib.rs b/src/test/run-pass/auxiliary/foreign_lib.rs
index cef3627..465feb8 100644
--- a/src/test/run-pass/auxiliary/foreign_lib.rs
+++ b/src/test/run-pass/auxiliary/foreign_lib.rs
@@ -10,7 +10,7 @@
 
 #![crate_name="foreign_lib"]
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 pub mod rustrt {
     extern crate libc;
diff --git a/src/test/run-pass/c-stack-as-value.rs b/src/test/run-pass/c-stack-as-value.rs
index df4989d..1f29a52 100644
--- a/src/test/run-pass/c-stack-as-value.rs
+++ b/src/test/run-pass/c-stack-as-value.rs
@@ -11,7 +11,7 @@
 // pretty-expanded FIXME #23616
 // ignore-wasm32-bare no libc to test ffi with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 mod rustrt {
     extern crate libc;
diff --git a/src/test/run-pass/c-stack-returning-int64.rs b/src/test/run-pass/c-stack-returning-int64.rs
index 56a0437..7dd3b9a 100644
--- a/src/test/run-pass/c-stack-returning-int64.rs
+++ b/src/test/run-pass/c-stack-returning-int64.rs
@@ -10,7 +10,7 @@
 
 // ignore-wasm32-bare no libc to test with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/check-static-recursion-foreign.rs b/src/test/run-pass/check-static-recursion-foreign.rs
index a95870c..15f509a 100644
--- a/src/test/run-pass/check-static-recursion-foreign.rs
+++ b/src/test/run-pass/check-static-recursion-foreign.rs
@@ -16,7 +16,7 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(custom_attribute, libc)]
+#![feature(custom_attribute, rustc_private)]
 
 extern crate check_static_recursion_foreign_helper;
 extern crate libc;
diff --git a/src/test/run-pass/command-before-exec.rs b/src/test/run-pass/command-before-exec.rs
index 5d8bc31..b78fa84 100644
--- a/src/test/run-pass/command-before-exec.rs
+++ b/src/test/run-pass/command-before-exec.rs
@@ -13,7 +13,7 @@
 // ignore-cloudabi no processes
 // ignore-emscripten no processes
 
-#![feature(process_exec, libc)]
+#![feature(process_exec, rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/consts/auxiliary/anon-extern-mod-cross-crate-1.rs b/src/test/run-pass/consts/auxiliary/anon-extern-mod-cross-crate-1.rs
index 741ce35..6b464c5 100644
--- a/src/test/run-pass/consts/auxiliary/anon-extern-mod-cross-crate-1.rs
+++ b/src/test/run-pass/consts/auxiliary/anon-extern-mod-cross-crate-1.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 #![crate_name="anonexternmod"]
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/core-run-destroy.rs b/src/test/run-pass/core-run-destroy.rs
index 51e26ff..9023326 100644
--- a/src/test/run-pass/core-run-destroy.rs
+++ b/src/test/run-pass/core-run-destroy.rs
@@ -20,7 +20,7 @@
 // memory, which makes for some *confusing* logs. That's why these are here
 // instead of in std.
 
-#![feature(libc, duration)]
+#![feature(rustc_private, duration)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/cross-crate/auxiliary/anon-extern-mod-cross-crate-1.rs b/src/test/run-pass/cross-crate/auxiliary/anon-extern-mod-cross-crate-1.rs
index 741ce35..6b464c5 100644
--- a/src/test/run-pass/cross-crate/auxiliary/anon-extern-mod-cross-crate-1.rs
+++ b/src/test/run-pass/cross-crate/auxiliary/anon-extern-mod-cross-crate-1.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 #![crate_name="anonexternmod"]
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/ctfe/references.rs b/src/test/run-pass/ctfe/references.rs
index 946ed24..421f354 100644
--- a/src/test/run-pass/ctfe/references.rs
+++ b/src/test/run-pass/ctfe/references.rs
@@ -28,6 +28,7 @@
         _ => panic!("c"),
     }
 
+    #[allow(unreachable_patterns)]
     match &43 {
         &42 => panic!(),
         BOO => panic!(),
diff --git a/src/test/run-pass/env-funky-keys.rs b/src/test/run-pass/env-funky-keys.rs
index 12e1cbe..7e7899c 100644
--- a/src/test/run-pass/env-funky-keys.rs
+++ b/src/test/run-pass/env-funky-keys.rs
@@ -16,7 +16,7 @@
 // ignore-emscripten no execve
 // no-prefer-dynamic
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/env-null-vars.rs b/src/test/run-pass/env-null-vars.rs
index 9a46199..cdbecf1 100644
--- a/src/test/run-pass/env-null-vars.rs
+++ b/src/test/run-pass/env-null-vars.rs
@@ -15,7 +15,7 @@
 
 // issue-53200
 
-#![feature(libc)]
+#![feature(rustc_private)]
 extern crate libc;
 
 use std::env;
diff --git a/src/test/run-pass/extern/auxiliary/extern-crosscrate-source.rs b/src/test/run-pass/extern/auxiliary/extern-crosscrate-source.rs
index 150dffe..d20d9db 100644
--- a/src/test/run-pass/extern/auxiliary/extern-crosscrate-source.rs
+++ b/src/test/run-pass/extern/auxiliary/extern-crosscrate-source.rs
@@ -10,7 +10,7 @@
 
 #![crate_name="externcallback"]
 #![crate_type = "lib"]
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/extern/extern-call-deep.rs b/src/test/run-pass/extern/extern-call-deep.rs
index 6e8d94b..12df0f3 100644
--- a/src/test/run-pass/extern/extern-call-deep.rs
+++ b/src/test/run-pass/extern/extern-call-deep.rs
@@ -10,8 +10,9 @@
 
 // run-pass
 // ignore-wasm32-bare no libc to test ffi with
+// ignore-emscripten blows the JS stack
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/extern/extern-call-deep2.rs b/src/test/run-pass/extern/extern-call-deep2.rs
index 28157c5..8cb0477 100644
--- a/src/test/run-pass/extern/extern-call-deep2.rs
+++ b/src/test/run-pass/extern/extern-call-deep2.rs
@@ -12,7 +12,7 @@
 #![allow(unused_must_use)]
 // ignore-emscripten no threads support
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 use std::thread;
diff --git a/src/test/run-pass/extern/extern-call-indirect.rs b/src/test/run-pass/extern/extern-call-indirect.rs
index 1badb10..d20721f 100644
--- a/src/test/run-pass/extern/extern-call-indirect.rs
+++ b/src/test/run-pass/extern/extern-call-indirect.rs
@@ -11,7 +11,7 @@
 // run-pass
 // ignore-wasm32-bare no libc to test ffi with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/extern/extern-call-scrub.rs b/src/test/run-pass/extern/extern-call-scrub.rs
index ea18069..5e158c2 100644
--- a/src/test/run-pass/extern/extern-call-scrub.rs
+++ b/src/test/run-pass/extern/extern-call-scrub.rs
@@ -16,7 +16,7 @@
 
 // ignore-emscripten no threads support
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 use std::thread;
diff --git a/src/test/run-pass/extern/extern-crosscrate.rs b/src/test/run-pass/extern/extern-crosscrate.rs
index c6fccbe..b99e27a 100644
--- a/src/test/run-pass/extern/extern-crosscrate.rs
+++ b/src/test/run-pass/extern/extern-crosscrate.rs
@@ -12,7 +12,7 @@
 // aux-build:extern-crosscrate-source.rs
 // ignore-wasm32-bare no libc to test ffi with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate externcallback;
 extern crate libc;
diff --git a/src/test/run-pass/fds-are-cloexec.rs b/src/test/run-pass/fds-are-cloexec.rs
index a5ae0ae..33e64d8 100644
--- a/src/test/run-pass/fds-are-cloexec.rs
+++ b/src/test/run-pass/fds-are-cloexec.rs
@@ -14,7 +14,7 @@
 // ignore-emscripten no processes
 // ignore-haiku
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/foreign/auxiliary/foreign_lib.rs b/src/test/run-pass/foreign/auxiliary/foreign_lib.rs
index cef3627..465feb8 100644
--- a/src/test/run-pass/foreign/auxiliary/foreign_lib.rs
+++ b/src/test/run-pass/foreign/auxiliary/foreign_lib.rs
@@ -10,7 +10,7 @@
 
 #![crate_name="foreign_lib"]
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 pub mod rustrt {
     extern crate libc;
diff --git a/src/test/run-pass/foreign/foreign-call-no-runtime.rs b/src/test/run-pass/foreign/foreign-call-no-runtime.rs
index 4837f78..e35ec88 100644
--- a/src/test/run-pass/foreign/foreign-call-no-runtime.rs
+++ b/src/test/run-pass/foreign/foreign-call-no-runtime.rs
@@ -11,7 +11,7 @@
 // run-pass
 // ignore-emscripten no threads support
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/foreign/foreign-fn-linkname.rs b/src/test/run-pass/foreign/foreign-fn-linkname.rs
index 7587660..8fe90b7 100644
--- a/src/test/run-pass/foreign/foreign-fn-linkname.rs
+++ b/src/test/run-pass/foreign/foreign-fn-linkname.rs
@@ -11,7 +11,7 @@
 // run-pass
 // ignore-wasm32-bare no libc to test ffi with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 use std::ffi::CString;
diff --git a/src/test/run-pass/foreign/foreign-no-abi.rs b/src/test/run-pass/foreign/foreign-no-abi.rs
index 1d35f08..49ddd09 100644
--- a/src/test/run-pass/foreign/foreign-no-abi.rs
+++ b/src/test/run-pass/foreign/foreign-no-abi.rs
@@ -14,7 +14,7 @@
 // ignore-wasm32-bare no libc to test ffi with
 // pretty-expanded FIXME #23616
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 mod rustrt {
     extern crate libc;
diff --git a/src/test/run-pass/foreign/foreign2.rs b/src/test/run-pass/foreign/foreign2.rs
index bd6c8e6..f8942bc 100644
--- a/src/test/run-pass/foreign/foreign2.rs
+++ b/src/test/run-pass/foreign/foreign2.rs
@@ -13,7 +13,7 @@
 // ignore-wasm32-bare no libc to test ffi with
 // pretty-expanded FIXME #23616
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/invalid_const_promotion.rs b/src/test/run-pass/invalid_const_promotion.rs
index 0f354e1..3b8a265 100644
--- a/src/test/run-pass/invalid_const_promotion.rs
+++ b/src/test/run-pass/invalid_const_promotion.rs
@@ -15,7 +15,7 @@
 // compile-flags: -C debug_assertions=yes
 
 #![stable(feature = "rustc", since = "1.0.0")]
-#![feature(const_fn, libc, staged_api, rustc_attrs)]
+#![feature(const_fn, rustc_private, staged_api, rustc_attrs)]
 #![allow(const_err)]
 
 extern crate libc;
diff --git a/src/test/run-pass/issues/issue-13259-windows-tcb-trash.rs b/src/test/run-pass/issues/issue-13259-windows-tcb-trash.rs
index de18e09..9c983ea 100644
--- a/src/test/run-pass/issues/issue-13259-windows-tcb-trash.rs
+++ b/src/test/run-pass/issues/issue-13259-windows-tcb-trash.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 // run-pass
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/issues/issue-2214.rs b/src/test/run-pass/issues/issue-2214.rs
index 8329847..f3795c2 100644
--- a/src/test/run-pass/issues/issue-2214.rs
+++ b/src/test/run-pass/issues/issue-2214.rs
@@ -11,7 +11,7 @@
 // run-pass
 // ignore-wasm32-bare no libc to test ffi with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/issues/issue-30490.rs b/src/test/run-pass/issues/issue-30490.rs
index 500999c..47f60fb 100644
--- a/src/test/run-pass/issues/issue-30490.rs
+++ b/src/test/run-pass/issues/issue-30490.rs
@@ -18,7 +18,7 @@
 // where the descriptors to inherit were already stdio descriptors.
 // This test checks to avoid that regression.
 
-#![cfg_attr(unix, feature(libc))]
+#![cfg_attr(unix, feature(rustc_private))]
 #![cfg_attr(windows, allow(unused_imports))]
 
 #[cfg(unix)]
diff --git a/src/test/run-pass/issues/issue-3656.rs b/src/test/run-pass/issues/issue-3656.rs
index 63b2740..99a7244 100644
--- a/src/test/run-pass/issues/issue-3656.rs
+++ b/src/test/run-pass/issues/issue-3656.rs
@@ -19,7 +19,7 @@
 // pretty-expanded FIXME #23616
 // ignore-wasm32-bare no libc to test with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 use libc::{c_uint, uint32_t, c_void};
diff --git a/src/test/run-pass/multi-panic.rs b/src/test/run-pass/multi-panic.rs
index 2e6e109..03e58fc 100644
--- a/src/test/run-pass/multi-panic.rs
+++ b/src/test/run-pass/multi-panic.rs
@@ -17,7 +17,8 @@
     let mut it = err.lines();
 
     assert_eq!(it.next().map(|l| l.starts_with("thread '<unnamed>' panicked at")), Some(true));
-    assert_eq!(it.next(), Some("note: Run with `RUST_BACKTRACE=1` for a backtrace."));
+    assert_eq!(it.next(), Some("note: Run with `RUST_BACKTRACE=1` \
+                                environment variable to display a backtrace."));
     assert_eq!(it.next().map(|l| l.starts_with("thread 'main' panicked at")), Some(true));
     assert_eq!(it.next(), None);
 }
diff --git a/src/test/run-pass/no-stdio.rs b/src/test/run-pass/no-stdio.rs
index d342417..2f5bfbb 100644
--- a/src/test/run-pass/no-stdio.rs
+++ b/src/test/run-pass/no-stdio.rs
@@ -12,7 +12,7 @@
 // ignore-cloudabi no processes
 // ignore-emscripten no processes
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/out-of-stack.rs b/src/test/run-pass/out-of-stack.rs
index cd0f7cd..1c714e7 100644
--- a/src/test/run-pass/out-of-stack.rs
+++ b/src/test/run-pass/out-of-stack.rs
@@ -16,7 +16,7 @@
 // ignore-emscripten no processes
 
 #![feature(asm)]
-#![feature(libc)]
+#![feature(rustc_private)]
 
 #[cfg(unix)]
 extern crate libc;
diff --git a/src/test/run-pass/rfcs/rfc-1014-2.rs b/src/test/run-pass/rfcs/rfc-1014-2.rs
index 7fbc0d1..257c7f5 100644
--- a/src/test/run-pass/rfcs/rfc-1014-2.rs
+++ b/src/test/run-pass/rfcs/rfc-1014-2.rs
@@ -11,7 +11,7 @@
 // run-pass
 #![allow(dead_code)]
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/rfcs/rfc-1014.rs b/src/test/run-pass/rfcs/rfc-1014.rs
index d101c3c..578a7f4 100644
--- a/src/test/run-pass/rfcs/rfc-1014.rs
+++ b/src/test/run-pass/rfcs/rfc-1014.rs
@@ -13,7 +13,7 @@
 // ignore-cloudabi stdout does not map to file descriptor 1 by default
 // ignore-wasm32-bare no libc
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/segfault-no-out-of-stack.rs b/src/test/run-pass/segfault-no-out-of-stack.rs
index a85fe67..961b802 100644
--- a/src/test/run-pass/segfault-no-out-of-stack.rs
+++ b/src/test/run-pass/segfault-no-out-of-stack.rs
@@ -12,7 +12,7 @@
 // ignore-cloudabi can't run commands
 // ignore-emscripten can't run commands
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/signal-alternate-stack-cleanup.rs b/src/test/run-pass/signal-alternate-stack-cleanup.rs
index ad099f8..a79ab20 100644
--- a/src/test/run-pass/signal-alternate-stack-cleanup.rs
+++ b/src/test/run-pass/signal-alternate-stack-cleanup.rs
@@ -16,7 +16,7 @@
 // ignore-wasm32-bare no libc
 // ignore-windows
 
-#![feature(libc)]
+#![feature(rustc_private)]
 extern crate libc;
 
 use libc::*;
diff --git a/src/test/run-pass/simd/simd-intrinsic-generic-select.rs b/src/test/run-pass/simd/simd-intrinsic-generic-select.rs
index 590a299..74b99ca 100644
--- a/src/test/run-pass/simd/simd-intrinsic-generic-select.rs
+++ b/src/test/run-pass/simd/simd-intrinsic-generic-select.rs
@@ -28,6 +28,10 @@
 
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
+struct u32x8(u32, u32, u32, u32, u32, u32, u32, u32);
+
+#[repr(simd)]
+#[derive(Copy, Clone, PartialEq, Debug)]
 struct f32x4(pub f32, pub f32, pub f32, pub f32);
 
 #[repr(simd)]
@@ -36,6 +40,7 @@
 
 extern "platform-intrinsic" {
     fn simd_select<T, U>(x: T, a: U, b: U) -> U;
+    fn simd_select_bitmask<T, U>(x: T, a: U, b: U) -> U;
 }
 
 fn main() {
@@ -146,4 +151,29 @@
         let e = b8x4(t, f, t, t);
         assert_eq!(r, e);
     }
+
+    unsafe {
+        let a = u32x8(0, 1, 2, 3, 4, 5, 6, 7);
+        let b = u32x8(8, 9, 10, 11, 12, 13, 14, 15);
+
+        let r: u32x8 = simd_select_bitmask(0u8, a, b);
+        let e = b;
+        assert_eq!(r, e);
+
+        let r: u32x8 = simd_select_bitmask(0xffu8, a, b);
+        let e = a;
+        assert_eq!(r, e);
+
+        let r: u32x8 = simd_select_bitmask(0b01010101u8, a, b);
+        let e = u32x8(0, 9, 2, 11, 4, 13, 6, 15);
+        assert_eq!(r, e);
+
+        let r: u32x8 = simd_select_bitmask(0b10101010u8, a, b);
+        let e = u32x8(8, 1, 10, 3, 12, 5, 14, 7);
+        assert_eq!(r, e);
+
+        let r: u32x8 = simd_select_bitmask(0b11110000u8, a, b);
+        let e = u32x8(8, 9, 10, 11, 4, 5, 6, 7);
+        assert_eq!(r, e);
+    }
 }
diff --git a/src/test/run-pass/statics/static-mut-foreign.rs b/src/test/run-pass/statics/static-mut-foreign.rs
index d9e43dd..460d66a 100644
--- a/src/test/run-pass/statics/static-mut-foreign.rs
+++ b/src/test/run-pass/statics/static-mut-foreign.rs
@@ -15,7 +15,7 @@
 
 // ignore-wasm32-bare no libc to test ffi with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/run-pass/wait-forked-but-failed-child.rs b/src/test/run-pass/wait-forked-but-failed-child.rs
index dc47108..d822b67 100644
--- a/src/test/run-pass/wait-forked-but-failed-child.rs
+++ b/src/test/run-pass/wait-forked-but-failed-child.rs
@@ -11,7 +11,7 @@
 // ignore-cloudabi no processes
 // ignore-emscripten no processes
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/rustdoc-ui/failed-doctest-output.stdout b/src/test/rustdoc-ui/failed-doctest-output.stdout
index cd19099..bd6fa1f 100644
--- a/src/test/rustdoc-ui/failed-doctest-output.stdout
+++ b/src/test/rustdoc-ui/failed-doctest-output.stdout
@@ -13,13 +13,13 @@
   | ^^ not found in this scope
 
 thread '$DIR/failed-doctest-output.rs - OtherStruct (line 27)' panicked at 'couldn't compile the test', src/librustdoc/test.rs:326:13
-note: Run with `RUST_BACKTRACE=1` for a backtrace.
+note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
 
 ---- $DIR/failed-doctest-output.rs - SomeStruct (line 21) stdout ----
 thread '$DIR/failed-doctest-output.rs - SomeStruct (line 21)' panicked at 'test executable failed:
 
 thread 'main' panicked at 'oh no', $DIR/failed-doctest-output.rs:3:1
-note: Run with `RUST_BACKTRACE=1` for a backtrace.
+note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
 
 ', src/librustdoc/test.rs:361:17
 
diff --git a/src/test/rustdoc/proc-macro.rs b/src/test/rustdoc/proc-macro.rs
index 23d0d00..05d64f8 100644
--- a/src/test/rustdoc/proc-macro.rs
+++ b/src/test/rustdoc/proc-macro.rs
@@ -61,3 +61,16 @@
 pub fn some_derive(_item: TokenStream) -> TokenStream {
     TokenStream::new()
 }
+
+// @has some_macros/foo/index.html
+pub mod foo {
+    // @has - '//code' 'pub use some_proc_macro;'
+    // @has - '//a/@href' '../../some_macros/macro.some_proc_macro.html'
+    pub use some_proc_macro;
+    // @has - '//code' 'pub use some_proc_attr;'
+    // @has - '//a/@href' '../../some_macros/attr.some_proc_attr.html'
+    pub use some_proc_attr;
+    // @has - '//code' 'pub use some_derive;'
+    // @has - '//a/@href' '../../some_macros/derive.SomeDerive.html'
+    pub use some_derive;
+}
diff --git a/src/test/ui/error-codes/E0259.rs b/src/test/ui/error-codes/E0259.rs
index 5a47541..b3e633a 100644
--- a/src/test/ui/error-codes/E0259.rs
+++ b/src/test/ui/error-codes/E0259.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(alloc, libc)]
+#![feature(alloc, rustc_private)]
 #![allow(unused_extern_crates)]
 
 extern crate alloc;
diff --git a/src/test/ui/error-codes/E0424.rs b/src/test/ui/error-codes/E0424.rs
index 445d0c5..20d42da 100644
--- a/src/test/ui/error-codes/E0424.rs
+++ b/src/test/ui/error-codes/E0424.rs
@@ -19,4 +19,5 @@
 }
 
 fn main () {
+    let self = "self"; //~ ERROR E0424
 }
diff --git a/src/test/ui/error-codes/E0424.stderr b/src/test/ui/error-codes/E0424.stderr
index a1b7a5f..5eccd7d 100644
--- a/src/test/ui/error-codes/E0424.stderr
+++ b/src/test/ui/error-codes/E0424.stderr
@@ -4,6 +4,12 @@
 LL |         self.bar(); //~ ERROR E0424
    |         ^^^^ `self` value is a keyword only available in methods with `self` parameter
 
-error: aborting due to previous error
+error[E0424]: expected unit struct/variant or constant, found module `self`
+  --> $DIR/E0424.rs:22:9
+   |
+LL |     let self = "self"; //~ ERROR E0424
+   |         ^^^^ `self` value is a keyword and may not be bound to variables or shadowed
+
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0424`.
diff --git a/src/test/ui/extern/extern-const.fixed b/src/test/ui/extern/extern-const.fixed
index dca5698..fb17934 100644
--- a/src/test/ui/extern/extern-const.fixed
+++ b/src/test/ui/extern/extern-const.fixed
@@ -7,7 +7,7 @@
 // run-rustfix
 // ignore-wasm32 no external library to link to.
 // compile-flags: -g -Z continue-parse-after-error
-#![feature(libc)]
+#![feature(rustc_private)]
 extern crate libc;
 
 #[link(name = "rust_test_helpers", kind = "static")]
diff --git a/src/test/ui/extern/extern-const.rs b/src/test/ui/extern/extern-const.rs
index 07dbe54..f2585f5 100644
--- a/src/test/ui/extern/extern-const.rs
+++ b/src/test/ui/extern/extern-const.rs
@@ -7,7 +7,7 @@
 // run-rustfix
 // ignore-wasm32 no external library to link to.
 // compile-flags: -g -Z continue-parse-after-error
-#![feature(libc)]
+#![feature(rustc_private)]
 extern crate libc;
 
 #[link(name = "rust_test_helpers", kind = "static")]
diff --git a/src/test/ui/feature-gates/feature-gate-linker-flavor.rs b/src/test/ui/feature-gates/feature-gate-linker-flavor.rs
deleted file mode 100644
index 56ede01..0000000
--- a/src/test/ui/feature-gates/feature-gate-linker-flavor.rs
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// This is a fake compile fail test as there's no way to generate a
-// `#![feature(linker_flavor)]` error. The only reason we have a `linker_flavor`
-// feature gate is to be able to document `-Z linker-flavor` in the unstable
-// book
-
-#[used]
-//~^ ERROR attribute must be applied to a `static` variable
-fn foo() {}
-
-fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-linker-flavor.stderr b/src/test/ui/feature-gates/feature-gate-linker-flavor.stderr
deleted file mode 100644
index 7019a66..0000000
--- a/src/test/ui/feature-gates/feature-gate-linker-flavor.stderr
+++ /dev/null
@@ -1,8 +0,0 @@
-error: attribute must be applied to a `static` variable
-  --> $DIR/feature-gate-linker-flavor.rs:16:1
-   |
-LL | #[used]
-   | ^^^^^^^
-
-error: aborting due to previous error
-
diff --git a/src/test/ui/issues/issue-1251.rs b/src/test/ui/issues/issue-1251.rs
index b42404c..125f6e1 100644
--- a/src/test/ui/issues/issue-1251.rs
+++ b/src/test/ui/issues/issue-1251.rs
@@ -14,7 +14,7 @@
 // pretty-expanded FIXME #23616
 // ignore-wasm32-bare no libc to test ffi with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 #![crate_id="rust_get_test_int"]
 
diff --git a/src/test/ui/issues/issue-22034.rs b/src/test/ui/issues/issue-22034.rs
index 2708de2..bee324f 100644
--- a/src/test/ui/issues/issue-22034.rs
+++ b/src/test/ui/issues/issue-22034.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/ui/issues/issue-37887.stderr b/src/test/ui/issues/issue-37887.stderr
index 48fb6c2..7a5a5cd 100644
--- a/src/test/ui/issues/issue-37887.stderr
+++ b/src/test/ui/issues/issue-37887.stderr
@@ -4,13 +4,13 @@
 LL |     use libc::*; //~ ERROR unresolved import
    |         ^^^^ maybe a missing `extern crate libc;`?
 
-error[E0658]: use of unstable library feature 'libc': use `libc` from crates.io (see issue #27783)
+error[E0658]: use of unstable library feature 'rustc_private': this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via `Cargo.toml` instead? (see issue #27812)
   --> $DIR/issue-37887.rs:12:5
    |
 LL |     extern crate libc; //~ ERROR use of unstable
    |     ^^^^^^^^^^^^^^^^^^
    |
-   = help: add #![feature(libc)] to the crate attributes to enable
+   = help: add #![feature(rustc_private)] to the crate attributes to enable
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/lint/lint-ctypes.rs b/src/test/ui/lint/lint-ctypes.rs
index e09aaba..4c9f1f9 100644
--- a/src/test/ui/lint/lint-ctypes.rs
+++ b/src/test/ui/lint/lint-ctypes.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 #![deny(improper_ctypes)]
-#![feature(libc)]
+#![feature(rustc_private)]
 
 #![allow(private_in_public)]
 
diff --git a/src/test/ui/lint/lint-unexported-no-mangle.stderr b/src/test/ui/lint/lint-unexported-no-mangle.stderr
index 063915d..1df2d7b 100644
--- a/src/test/ui/lint/lint-unexported-no-mangle.stderr
+++ b/src/test/ui/lint/lint-unexported-no-mangle.stderr
@@ -1,8 +1,8 @@
-warning: lint `private_no_mangle_fns` has been removed: `no longer an warning, #[no_mangle] functions always exported`
+warning: lint `private_no_mangle_fns` has been removed: `no longer a warning, #[no_mangle] functions always exported`
    |
    = note: requested on the command line with `-F private_no_mangle_fns`
 
-warning: lint `private_no_mangle_statics` has been removed: `no longer an warning, #[no_mangle] statics always exported`
+warning: lint `private_no_mangle_statics` has been removed: `no longer a warning, #[no_mangle] statics always exported`
    |
    = note: requested on the command line with `-F private_no_mangle_statics`
 
diff --git a/src/test/ui/non-copyable-void.rs b/src/test/ui/non-copyable-void.rs
index 63e5f96..3599190 100644
--- a/src/test/ui/non-copyable-void.rs
+++ b/src/test/ui/non-copyable-void.rs
@@ -10,7 +10,7 @@
 
 // ignore-wasm32-bare no libc to test ffi with
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 extern crate libc;
 
diff --git a/src/test/ui/pattern/const-pat-ice.rs b/src/test/ui/pattern/const-pat-ice.rs
new file mode 100644
index 0000000..6496a2a
--- /dev/null
+++ b/src/test/ui/pattern/const-pat-ice.rs
@@ -0,0 +1,13 @@
+// failure-status: 101
+
+// This is a repro test for an ICE in our pattern handling of constants.
+
+const FOO: &&&u32 = &&&42;
+
+fn main() {
+    match unimplemented!() {
+        &&&42 => {},
+        FOO => {},
+        _ => {},
+    }
+}
diff --git a/src/test/ui/pattern/irrefutable-exhaustive-integer-binding.rs b/src/test/ui/pattern/irrefutable-exhaustive-integer-binding.rs
new file mode 100644
index 0000000..ff06588
--- /dev/null
+++ b/src/test/ui/pattern/irrefutable-exhaustive-integer-binding.rs
@@ -0,0 +1,8 @@
+// run-pass
+
+fn main() {
+    let -2147483648..=2147483647 = 1;
+    let 0..=255 = 0u8;
+    let -128..=127 = 0i8;
+    let '\u{0000}'..='\u{10FFFF}' = 'v';
+}
diff --git a/src/test/ui/pattern/slice-pattern-const-2.rs b/src/test/ui/pattern/slice-pattern-const-2.rs
index 6f9501d..6cfef11 100644
--- a/src/test/ui/pattern/slice-pattern-const-2.rs
+++ b/src/test/ui/pattern/slice-pattern-const-2.rs
@@ -1,4 +1,4 @@
-// compile-pass
+#![deny(unreachable_patterns)]
 
 fn main() {
     let s = &[0x00; 4][..]; //Slice of any value
@@ -6,19 +6,26 @@
     match s {
         MAGIC_TEST => (),
         [0x00, 0x00, 0x00, 0x00] => (),
-        [4, 5, 6, 7] => (), // this should warn
+        [4, 5, 6, 7] => (), //~ ERROR unreachable pattern
         _ => (),
     }
     match s {
         [0x00, 0x00, 0x00, 0x00] => (),
         MAGIC_TEST => (),
-        [4, 5, 6, 7] => (), // this should warn
+        [4, 5, 6, 7] => (), //~ ERROR unreachable pattern
         _ => (),
     }
     match s {
         [0x00, 0x00, 0x00, 0x00] => (),
         [4, 5, 6, 7] => (),
-        MAGIC_TEST => (), // this should warn
+        MAGIC_TEST => (), // FIXME(oli-obk): this should warn, but currently does not
+        _ => (),
+    }
+    const FOO: [u32; 1] = [4];
+    match [99] {
+        [0x00] => (),
+        [4] => (),
+        FOO => (), //~ ERROR unreachable pattern
         _ => (),
     }
 }
diff --git a/src/test/ui/pattern/slice-pattern-const-2.stderr b/src/test/ui/pattern/slice-pattern-const-2.stderr
new file mode 100644
index 0000000..95651cc
--- /dev/null
+++ b/src/test/ui/pattern/slice-pattern-const-2.stderr
@@ -0,0 +1,26 @@
+error: unreachable pattern
+  --> $DIR/slice-pattern-const-2.rs:9:9
+   |
+LL |         [4, 5, 6, 7] => (), //~ ERROR unreachable pattern
+   |         ^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/slice-pattern-const-2.rs:1:9
+   |
+LL | #![deny(unreachable_patterns)]
+   |         ^^^^^^^^^^^^^^^^^^^^
+
+error: unreachable pattern
+  --> $DIR/slice-pattern-const-2.rs:15:9
+   |
+LL |         [4, 5, 6, 7] => (), //~ ERROR unreachable pattern
+   |         ^^^^^^^^^^^^
+
+error: unreachable pattern
+  --> $DIR/slice-pattern-const-2.rs:28:9
+   |
+LL |         FOO => (), //~ ERROR unreachable pattern
+   |         ^^^
+
+error: aborting due to 3 previous errors
+
diff --git a/src/test/ui/pattern/slice-pattern-const-3.rs b/src/test/ui/pattern/slice-pattern-const-3.rs
index e7a30ce..8805c43 100644
--- a/src/test/ui/pattern/slice-pattern-const-3.rs
+++ b/src/test/ui/pattern/slice-pattern-const-3.rs
@@ -1,4 +1,4 @@
-// compile-pass
+#![deny(unreachable_patterns)]
 
 fn main() {
     let s = &["0x00"; 4][..]; //Slice of any value
@@ -6,19 +6,26 @@
     match s {
         MAGIC_TEST => (),
         ["0x00", "0x00", "0x00", "0x00"] => (),
-        ["4", "5", "6", "7"] => (), // this should warn
+        ["4", "5", "6", "7"] => (), // FIXME(oli-obk): this should warn, but currently does not
         _ => (),
     }
     match s {
         ["0x00", "0x00", "0x00", "0x00"] => (),
         MAGIC_TEST => (),
-        ["4", "5", "6", "7"] => (), // this should warn
+        ["4", "5", "6", "7"] => (), // FIXME(oli-obk): this should warn, but currently does not
         _ => (),
     }
     match s {
         ["0x00", "0x00", "0x00", "0x00"] => (),
         ["4", "5", "6", "7"] => (),
-        MAGIC_TEST => (), // this should warn
+        MAGIC_TEST => (), // FIXME(oli-obk): this should warn, but currently does not
+        _ => (),
+    }
+    const FOO: [&str; 1] = ["boo"];
+    match ["baa"] {
+        ["0x00"] => (),
+        ["boo"] => (),
+        FOO => (), //~ ERROR unreachable pattern
         _ => (),
     }
 }
diff --git a/src/test/ui/pattern/slice-pattern-const-3.stderr b/src/test/ui/pattern/slice-pattern-const-3.stderr
new file mode 100644
index 0000000..531bbbc
--- /dev/null
+++ b/src/test/ui/pattern/slice-pattern-const-3.stderr
@@ -0,0 +1,14 @@
+error: unreachable pattern
+  --> $DIR/slice-pattern-const-3.rs:28:9
+   |
+LL |         FOO => (), //~ ERROR unreachable pattern
+   |         ^^^
+   |
+note: lint level defined here
+  --> $DIR/slice-pattern-const-3.rs:1:9
+   |
+LL | #![deny(unreachable_patterns)]
+   |         ^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/pattern/slice-pattern-const.rs b/src/test/ui/pattern/slice-pattern-const.rs
index d353f6c..f0a0451 100644
--- a/src/test/ui/pattern/slice-pattern-const.rs
+++ b/src/test/ui/pattern/slice-pattern-const.rs
@@ -1,4 +1,4 @@
-//compile-pass
+#![deny(unreachable_patterns)]
 
 fn main() {
     let s = &[0x00; 4][..]; //Slice of any value
@@ -6,19 +6,42 @@
     match s {
         MAGIC_TEST => (),
         [0x00, 0x00, 0x00, 0x00] => (),
-        [84, 69, 83, 84] => (), // this should warn
+        [84, 69, 83, 84] => (), //~ ERROR unreachable pattern
         _ => (),
     }
     match s {
         [0x00, 0x00, 0x00, 0x00] => (),
         MAGIC_TEST => (),
-        [84, 69, 83, 84] => (), // this should warn
+        [84, 69, 83, 84] => (), //~ ERROR unreachable pattern
         _ => (),
     }
     match s {
         [0x00, 0x00, 0x00, 0x00] => (),
         [84, 69, 83, 84] => (),
-        MAGIC_TEST => (), // this should warn
+        MAGIC_TEST => (), //~ ERROR unreachable pattern
         _ => (),
     }
+    const FOO: [u8; 1] = [4];
+    match [99] {
+        [0x00] => (),
+        [4] => (),
+        FOO => (), //~ ERROR unreachable pattern
+        _ => (),
+    }
+    const BAR: &[u8; 1] = &[4];
+    match &[99] {
+        [0x00] => (),
+        [4] => (),
+        BAR => (), //~ ERROR unreachable pattern
+        b"a" => (),
+        _ => (),
+    }
+
+    const BOO: &[u8; 0] = &[];
+    match &[] {
+        [] => (),
+        BOO => (), //~ ERROR unreachable pattern
+        b"" => (), //~ ERROR unreachable pattern
+        _ => (), //~ ERROR unreachable pattern
+    }
 }
diff --git a/src/test/ui/pattern/slice-pattern-const.stderr b/src/test/ui/pattern/slice-pattern-const.stderr
new file mode 100644
index 0000000..412e015
--- /dev/null
+++ b/src/test/ui/pattern/slice-pattern-const.stderr
@@ -0,0 +1,56 @@
+error: unreachable pattern
+  --> $DIR/slice-pattern-const.rs:9:9
+   |
+LL |         [84, 69, 83, 84] => (), //~ ERROR unreachable pattern
+   |         ^^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/slice-pattern-const.rs:1:9
+   |
+LL | #![deny(unreachable_patterns)]
+   |         ^^^^^^^^^^^^^^^^^^^^
+
+error: unreachable pattern
+  --> $DIR/slice-pattern-const.rs:15:9
+   |
+LL |         [84, 69, 83, 84] => (), //~ ERROR unreachable pattern
+   |         ^^^^^^^^^^^^^^^^
+
+error: unreachable pattern
+  --> $DIR/slice-pattern-const.rs:21:9
+   |
+LL |         MAGIC_TEST => (), //~ ERROR unreachable pattern
+   |         ^^^^^^^^^^
+
+error: unreachable pattern
+  --> $DIR/slice-pattern-const.rs:28:9
+   |
+LL |         FOO => (), //~ ERROR unreachable pattern
+   |         ^^^
+
+error: unreachable pattern
+  --> $DIR/slice-pattern-const.rs:35:9
+   |
+LL |         BAR => (), //~ ERROR unreachable pattern
+   |         ^^^
+
+error: unreachable pattern
+  --> $DIR/slice-pattern-const.rs:43:9
+   |
+LL |         BOO => (), //~ ERROR unreachable pattern
+   |         ^^^
+
+error: unreachable pattern
+  --> $DIR/slice-pattern-const.rs:44:9
+   |
+LL |         b"" => (), //~ ERROR unreachable pattern
+   |         ^^^
+
+error: unreachable pattern
+  --> $DIR/slice-pattern-const.rs:45:9
+   |
+LL |         _ => (), //~ ERROR unreachable pattern
+   |         ^
+
+error: aborting due to 8 previous errors
+
diff --git a/src/test/ui/simd-intrinsic/simd-intrinsic-generic-select.rs b/src/test/ui/simd-intrinsic/simd-intrinsic-generic-select.rs
index d74d681..2a2d35e 100644
--- a/src/test/ui/simd-intrinsic/simd-intrinsic-generic-select.rs
+++ b/src/test/ui/simd-intrinsic/simd-intrinsic-generic-select.rs
@@ -33,6 +33,7 @@
 
 extern "platform-intrinsic" {
     fn simd_select<T, U>(x: T, a: U, b: U) -> U;
+    fn simd_select_bitmask<T, U>(x: T, a: U, b: U) -> U;
 }
 
 fn main() {
@@ -52,5 +53,14 @@
 
         simd_select(z, z, z);
         //~^ ERROR mask element type is `f32`, expected `i_`
+
+        simd_select_bitmask(0u8, x, x);
+        //~^ ERROR mask length `8` != other vector length `4`
+
+        simd_select_bitmask(0.0f32, x, x);
+        //~^ ERROR `f32` is not an integral type
+
+        simd_select_bitmask("x", x, x);
+        //~^ ERROR `&str` is not an integral type
     }
 }
diff --git a/src/test/ui/simd-intrinsic/simd-intrinsic-generic-select.stderr b/src/test/ui/simd-intrinsic/simd-intrinsic-generic-select.stderr
index 61e4202..584f3d5 100644
--- a/src/test/ui/simd-intrinsic/simd-intrinsic-generic-select.stderr
+++ b/src/test/ui/simd-intrinsic/simd-intrinsic-generic-select.stderr
@@ -1,21 +1,39 @@
 error[E0511]: invalid monomorphization of `simd_select` intrinsic: mismatched lengths: mask length `8` != other vector length `4`
-  --> $DIR/simd-intrinsic-generic-select.rs:47:9
+  --> $DIR/simd-intrinsic-generic-select.rs:48:9
    |
 LL |         simd_select(m8, x, x);
    |         ^^^^^^^^^^^^^^^^^^^^^
 
 error[E0511]: invalid monomorphization of `simd_select` intrinsic: mask element type is `u32`, expected `i_`
-  --> $DIR/simd-intrinsic-generic-select.rs:50:9
+  --> $DIR/simd-intrinsic-generic-select.rs:51:9
    |
 LL |         simd_select(x, x, x);
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error[E0511]: invalid monomorphization of `simd_select` intrinsic: mask element type is `f32`, expected `i_`
-  --> $DIR/simd-intrinsic-generic-select.rs:53:9
+  --> $DIR/simd-intrinsic-generic-select.rs:54:9
    |
 LL |         simd_select(z, z, z);
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 3 previous errors
+error[E0511]: invalid monomorphization of `simd_select_bitmask` intrinsic: mismatched lengths: mask length `8` != other vector length `4`
+  --> $DIR/simd-intrinsic-generic-select.rs:57:9
+   |
+LL |         simd_select_bitmask(0u8, x, x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0511]: invalid monomorphization of `simd_select_bitmask` intrinsic: `f32` is not an integral type
+  --> $DIR/simd-intrinsic-generic-select.rs:60:9
+   |
+LL |         simd_select_bitmask(0.0f32, x, x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0511]: invalid monomorphization of `simd_select_bitmask` intrinsic: `&str` is not an integral type
+  --> $DIR/simd-intrinsic-generic-select.rs:63:9
+   |
+LL |         simd_select_bitmask("x", x, x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0511`.
diff --git a/src/test/ui/unnecessary-extern-crate.rs b/src/test/ui/unnecessary-extern-crate.rs
index 110cfef..4eb3c3d 100644
--- a/src/test/ui/unnecessary-extern-crate.rs
+++ b/src/test/ui/unnecessary-extern-crate.rs
@@ -11,7 +11,7 @@
 // edition:2018
 
 #![deny(unused_extern_crates)]
-#![feature(alloc, test, libc, crate_visibility_modifier)]
+#![feature(alloc, test, rustc_private, crate_visibility_modifier)]
 
 extern crate libc;
 //~^ ERROR unused extern crate
diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
index 896b380..ea6c711 100644
--- a/src/tools/build-manifest/src/main.rs
+++ b/src/tools/build-manifest/src/main.rs
@@ -621,8 +621,10 @@
         let asc = self.output.join(format!("{}.asc", filename));
         println!("signing: {:?}", path);
         let mut cmd = Command::new("gpg");
-        cmd.arg("--no-tty")
+        cmd.arg("--pinentry-mode=loopback")
+            .arg("--no-tty")
             .arg("--yes")
+            .arg("--batch")
             .arg("--passphrase-fd").arg("0")
             .arg("--personal-digest-preferences").arg("SHA512")
             .arg("--armor")
diff --git a/src/tools/cargo b/src/tools/cargo
index 28fb200..2cf1f5d 160000
--- a/src/tools/cargo
+++ b/src/tools/cargo
@@ -1 +1 @@
-Subproject commit 28fb20034a5bb42ea589664de2617dd1840506d3
+Subproject commit 2cf1f5dda2f7ed84e94c4d32f643e0f1f15352f0
diff --git a/src/tools/clippy b/src/tools/clippy
index a3c77f6..b7a431e 160000
--- a/src/tools/clippy
+++ b/src/tools/clippy
@@ -1 +1 @@
-Subproject commit a3c77f6ad1c1c185e561e9cd7fdec7db569169d1
+Subproject commit b7a431ea1ddb96a396921bf9b5f2f6d8690cd474
diff --git a/src/tools/compiletest/src/main.rs b/src/tools/compiletest/src/main.rs
index 65f6bff..9aefd15 100644
--- a/src/tools/compiletest/src/main.rs
+++ b/src/tools/compiletest/src/main.rs
@@ -511,7 +511,11 @@
     test::TestOpts {
         filter: config.filter.clone(),
         filter_exact: config.filter_exact,
-        run_ignored: config.run_ignored,
+        run_ignored: if config.run_ignored {
+            test::RunIgnored::Yes
+        } else {
+            test::RunIgnored::No
+        },
         format: if config.quiet {
             test::OutputFormat::Terse
         } else {
diff --git a/src/tools/rustc-std-workspace-core/Cargo.toml b/src/tools/rustc-std-workspace-core/Cargo.toml
new file mode 100644
index 0000000..f000d63
--- /dev/null
+++ b/src/tools/rustc-std-workspace-core/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "rustc-std-workspace-core"
+version = "1.0.0"
+authors = ["Alex Crichton <alex@alexcrichton.com>"]
+license = 'MIT/Apache-2.0'
+description = """
+Hack for the compiler's own build system
+"""
+
+[lib]
+path = "lib.rs"
+
+[dependencies]
+core = { path = "../../libcore" }
diff --git a/src/tools/rustc-std-workspace-core/README.md b/src/tools/rustc-std-workspace-core/README.md
new file mode 100644
index 0000000..9c2b1fa
--- /dev/null
+++ b/src/tools/rustc-std-workspace-core/README.md
@@ -0,0 +1,29 @@
+# The `rustc-std-workspace-core` crate
+
+This crate is a shim and empty crate which simply depends on `libcore` and
+reexports all of its contents. The crate is the crux of empowering the standard
+library to depend on crates from crates.io
+
+Crates on crates.io that the standard library depend on the
+`rustc-std-workspace-core` crate from crates.io. On crates.io, however, this
+crate is empty. We use `[patch]` to override it to this crate in this
+repository. As a result, crates on crates.io will draw a dependency edge to
+`libcore`, the version defined in this repository. That should draw all the
+dependency edges to ensure Cargo builds crates successfully!
+
+Note that crates on crates.io need to depend on this crate with the name `core`
+for everything to work correctly. To do that they can use:
+
+```toml
+core = { version = "1.0.0", optional = true, package = 'rustc-std-workspace-core' }
+```
+
+Through the use of the `package` key the crate is renamed to `core`, meaning
+it'll look like
+
+```
+--extern core=.../librustc_std_workspace_core-XXXXXXX.rlib
+```
+
+when Cargo invokes the compiler, satisfying the implicit `extern crate core`
+directive injected by the compiler.
diff --git a/src/tools/rustc-std-workspace-core/lib.rs b/src/tools/rustc-std-workspace-core/lib.rs
new file mode 100644
index 0000000..e2946fe
--- /dev/null
+++ b/src/tools/rustc-std-workspace-core/lib.rs
@@ -0,0 +1,6 @@
+#![feature(no_core)]
+#![no_core]
+
+extern crate core;
+
+pub use core::*;
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index e275892..2b5cff6 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -53,6 +53,7 @@
     "bytesize",           // Apache-2.0, cargo
     "im-rc",              // MPL-2.0+, cargo
     "adler32",            // BSD-3-Clause AND Zlib, cargo dep that isn't used
+    "fortanix-sgx-abi",   // MPL-2.0+, libstd but only for sgx target
 ];
 
 /// Which crates to check against the whitelist?
diff --git a/src/tools/tidy/src/lib.rs b/src/tools/tidy/src/lib.rs
index 53db589..614d205 100644
--- a/src/tools/tidy/src/lib.rs
+++ b/src/tools/tidy/src/lib.rs
@@ -56,15 +56,11 @@
 
 fn filter_dirs(path: &Path) -> bool {
     let skip = [
-        "src/dlmalloc",
         "src/llvm",
         "src/llvm-emscripten",
         "src/libbacktrace",
-        "src/libcompiler_builtins",
         "src/librustc_data_structures/owning_ref",
-        "src/compiler-rt",
-        "src/liblibc",
-        "src/rt/hoedown",
+        "src/vendor",
         "src/tools/cargo",
         "src/tools/clang",
         "src/tools/rls",
diff --git a/src/tools/tidy/src/pal.rs b/src/tools/tidy/src/pal.rs
index 822db25..acf7202 100644
--- a/src/tools/tidy/src/pal.rs
+++ b/src/tools/tidy/src/pal.rs
@@ -26,7 +26,6 @@
 //! exceptions:
 //!
 //! - core may not have platform-specific code
-//! - libcompiler_builtins may have platform-specific code
 //! - libpanic_abort may have platform-specific code
 //! - libpanic_unwind may have platform-specific code
 //! - libunwind may have platform-specific code
@@ -50,8 +49,6 @@
 // Paths that may contain platform-specific code
 const EXCEPTION_PATHS: &[&str] = &[
     // std crates
-    "src/libcompiler_builtins",
-    "src/liblibc",
     "src/libpanic_abort",
     "src/libpanic_unwind",
     "src/libunwind",