"sandwich" rlibs between native deps in linker order (#1333)
"sandwich" rlibs between two sections of native dependencies in linker order
diff --git a/rust/private/rustc.bzl b/rust/private/rustc.bzl
index 47fc576..0c70aa9 100644
--- a/rust/private/rustc.bzl
+++ b/rust/private/rustc.bzl
@@ -1301,8 +1301,26 @@
modifiers = ""
if experimental_use_whole_archive_for_native_deps:
modifiers = ":+whole-archive"
+
+ # To ensure appropriate linker library argument order, in the presence
+ # of both native libraries that depend on rlibs and rlibs that depend
+ # on native libraries, we use an approach where we "sandwich" the
+ # rust libraries between two similar sections of all of native
+ # libraries:
+ # n1 n2 ... r1 r2 ... n1 n2 ...
+ # A B C
+ # This way any dependency from a native library to a rust library
+ # is resolved from A to B, and any dependency from a rust library to
+ # a native one is resolved from B to C.
+ # The question of resolving dependencies from a native library from A
+ # to any rust library is addressed in a different place, where we
+ # create symlinks to the rlibs, pretending they are native libraries,
+ # and adding references to these symlinks in the native section A.
+ # We rely in the behavior of -Clink-arg to put the linker args
+ # at the end of the linker invocation constructed by rustc.
return [
"-lstatic%s=%s" % (modifiers, get_lib_name(artifact)),
+ "-Clink-arg=-l%s" % get_lib_name(artifact),
]
elif _is_dylib(lib):
return [
diff --git a/test/unit/native_deps/native_deps_test.bzl b/test/unit/native_deps/native_deps_test.bzl
index a1161fa..202cf09 100644
--- a/test/unit/native_deps/native_deps_test.bzl
+++ b/test/unit/native_deps/native_deps_test.bzl
@@ -30,6 +30,7 @@
assert_argv_contains_prefix_suffix(env, action, "-Lnative=", "/native_deps")
assert_argv_contains(env, action, "--crate-type=cdylib")
assert_argv_contains(env, action, "-lstatic=native_dep")
+ assert_argv_contains(env, action, "-Clink-arg=-lnative_dep")
assert_argv_contains_prefix(env, action, "--codegen=linker=")
return analysistest.end(env)
@@ -40,6 +41,7 @@
assert_argv_contains_prefix_suffix(env, action, "-Lnative=", "/native_deps")
assert_argv_contains(env, action, "--crate-type=staticlib")
assert_argv_contains(env, action, "-lstatic=native_dep")
+ assert_argv_contains(env, action, "-Clink-arg=-lnative_dep")
assert_argv_contains_prefix(env, action, "--codegen=linker=")
return analysistest.end(env)
@@ -51,6 +53,7 @@
assert_argv_contains_prefix_suffix(env, action, "-Lnative=", "/native_deps")
assert_argv_contains(env, action, "--crate-type=proc-macro")
assert_argv_contains(env, action, "-lstatic=native_dep")
+ assert_argv_contains(env, action, "-Clink-arg=-lnative_dep")
assert_argv_contains_prefix(env, action, "--codegen=linker=")
return analysistest.end(env)
@@ -60,6 +63,7 @@
action = tut.actions[0]
assert_argv_contains_prefix_suffix(env, action, "-Lnative=", "/native_deps")
assert_argv_contains(env, action, "-lstatic=native_dep")
+ assert_argv_contains(env, action, "-Clink-arg=-lnative_dep")
assert_argv_contains_prefix(env, action, "--codegen=linker=")
return analysistest.end(env)