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// Copyright 2014-2015 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.
//! [Flexible target specification.](https://github.com/rust-lang/rfcs/pull/131)
//!
//! Rust targets a wide variety of usecases, and in the interest of flexibility,
//! allows new target triples to be defined in configuration files. Most users
//! will not need to care about these, but this is invaluable when porting Rust
//! to a new platform, and allows for an unprecedented level of control over how
//! the compiler works.
//!
//! # Using custom targets
//!
//! A target triple, as passed via `rustc --target=TRIPLE`, will first be
//! compared against the list of built-in targets. This is to ease distributing
//! rustc (no need for configuration files) and also to hold these built-in
//! targets as immutable and sacred. If `TRIPLE` is not one of the built-in
//! targets, rustc will check if a file named `TRIPLE` exists. If it does, it
//! will be loaded as the target configuration. If the file does not exist,
//! rustc will search each directory in the environment variable
//! `RUST_TARGET_PATH` for a file named `TRIPLE.json`. The first one found will
//! be loaded. If no file is found in any of those directories, a fatal error
//! will be given.
//!
//! Projects defining their own targets should use
//! `--target=path/to/my-awesome-platform.json` instead of adding to
//! `RUST_TARGET_PATH`.
//!
//! # Defining a new target
//!
//! Targets are defined using [JSON](http://json.org/). The `Target` struct in
//! this module defines the format the JSON file should take, though each
//! underscore in the field names should be replaced with a hyphen (`-`) in the
//! JSON file. Some fields are required in every target specification, such as
//! `llvm-target`, `target-endian`, `target-pointer-width`, `data-layout`,
//! `arch`, and `os`. In general, options passed to rustc with `-C` override
//! the target's settings, though `target-feature` and `link-args` will *add*
//! to the list specified by the target, rather than replace.
use serialize::json::{Json, ToJson};
use std::collections::BTreeMap;
use std::default::Default;
use std::io::prelude::*;
use syntax::abi::Abi;
mod android_base;
mod apple_base;
mod apple_ios_base;
mod bitrig_base;
mod dragonfly_base;
mod freebsd_base;
mod linux_base;
mod linux_musl_base;
mod openbsd_base;
mod netbsd_base;
mod solaris_base;
mod windows_base;
mod windows_msvc_base;
pub type TargetResult = Result<Target, String>;
macro_rules! supported_targets {
( $(($triple:expr, $module:ident)),+ ) => (
$(mod $module;)*
/// List of supported targets
const TARGETS: &'static [&'static str] = &[$($triple),*];
fn load_specific(target: &str) -> TargetResult {
match target {
$(
$triple => {
let mut t = try!($module::target());
t.options.is_builtin = true;
// round-trip through the JSON parser to ensure at
// run-time that the parser works correctly
t = try!(Target::from_json(t.to_json()));
debug!("Got builtin target: {:?}", t);
Ok(t)
},
)+
_ => Err(format!("Unable to find target: {}", target))
}
}
pub fn get_targets() -> Box<Iterator<Item=String>> {
Box::new(TARGETS.iter().filter_map(|t| -> Option<String> {
load_specific(t)
.map(|t| t.llvm_target)
.ok()
}))
}
#[cfg(test)]
mod test_json_encode_decode {
use serialize::json::ToJson;
use super::Target;
$(use super::$module;)*
$(
#[test]
fn $module() {
// Grab the TargetResult struct. If we successfully retrieved
// a Target, then the test JSON encoding/decoding can run for this
// Target on this testing platform (i.e., checking the iOS targets
// only on a Mac test platform).
let _ = $module::target().map(|original| {
let as_json = original.to_json();
let parsed = Target::from_json(as_json).unwrap();
assert_eq!(original, parsed);
});
}
)*
}
)
}
supported_targets! {
("x86_64-unknown-linux-gnu", x86_64_unknown_linux_gnu),
("i686-unknown-linux-gnu", i686_unknown_linux_gnu),
("i586-unknown-linux-gnu", i586_unknown_linux_gnu),
("mips-unknown-linux-gnu", mips_unknown_linux_gnu),
("mipsel-unknown-linux-gnu", mipsel_unknown_linux_gnu),
("powerpc-unknown-linux-gnu", powerpc_unknown_linux_gnu),
("powerpc64-unknown-linux-gnu", powerpc64_unknown_linux_gnu),
("powerpc64le-unknown-linux-gnu", powerpc64le_unknown_linux_gnu),
("arm-unknown-linux-gnueabi", arm_unknown_linux_gnueabi),
("arm-unknown-linux-gnueabihf", arm_unknown_linux_gnueabihf),
("arm-unknown-linux-musleabi", arm_unknown_linux_musleabi),
("arm-unknown-linux-musleabihf", arm_unknown_linux_musleabihf),
("armv7-unknown-linux-gnueabihf", armv7_unknown_linux_gnueabihf),
("armv7-unknown-linux-musleabihf", armv7_unknown_linux_musleabihf),
("aarch64-unknown-linux-gnu", aarch64_unknown_linux_gnu),
("x86_64-unknown-linux-musl", x86_64_unknown_linux_musl),
("i686-unknown-linux-musl", i686_unknown_linux_musl),
("mips-unknown-linux-musl", mips_unknown_linux_musl),
("mipsel-unknown-linux-musl", mipsel_unknown_linux_musl),
("i686-linux-android", i686_linux_android),
("arm-linux-androideabi", arm_linux_androideabi),
("armv7-linux-androideabi", armv7_linux_androideabi),
("aarch64-linux-android", aarch64_linux_android),
("i686-unknown-freebsd", i686_unknown_freebsd),
("x86_64-unknown-freebsd", x86_64_unknown_freebsd),
("i686-unknown-dragonfly", i686_unknown_dragonfly),
("x86_64-unknown-dragonfly", x86_64_unknown_dragonfly),
("x86_64-unknown-bitrig", x86_64_unknown_bitrig),
("x86_64-unknown-openbsd", x86_64_unknown_openbsd),
("x86_64-unknown-netbsd", x86_64_unknown_netbsd),
("x86_64-rumprun-netbsd", x86_64_rumprun_netbsd),
("x86_64-apple-darwin", x86_64_apple_darwin),
("i686-apple-darwin", i686_apple_darwin),
("i386-apple-ios", i386_apple_ios),
("x86_64-apple-ios", x86_64_apple_ios),
("aarch64-apple-ios", aarch64_apple_ios),
("armv7-apple-ios", armv7_apple_ios),
("armv7s-apple-ios", armv7s_apple_ios),
("x86_64-sun-solaris", x86_64_sun_solaris),
("x86_64-pc-windows-gnu", x86_64_pc_windows_gnu),
("i686-pc-windows-gnu", i686_pc_windows_gnu),
("x86_64-pc-windows-msvc", x86_64_pc_windows_msvc),
("i686-pc-windows-msvc", i686_pc_windows_msvc),
("i586-pc-windows-msvc", i586_pc_windows_msvc),
("le32-unknown-nacl", le32_unknown_nacl),
("asmjs-unknown-emscripten", asmjs_unknown_emscripten)
}
/// Everything `rustc` knows about how to compile for a specific target.
///
/// Every field here must be specified, and has no default value.
#[derive(PartialEq, Clone, Debug)]
pub struct Target {
/// Target triple to pass to LLVM.
pub llvm_target: String,
/// String to use as the `target_endian` `cfg` variable.
pub target_endian: String,
/// String to use as the `target_pointer_width` `cfg` variable.
pub target_pointer_width: String,
/// OS name to use for conditional compilation.
pub target_os: String,
/// Environment name to use for conditional compilation.
pub target_env: String,
/// Vendor name to use for conditional compilation.
pub target_vendor: String,
/// Architecture to use for ABI considerations. Valid options: "x86",
/// "x86_64", "arm", "aarch64", "mips", "powerpc", and "powerpc64".
pub arch: String,
/// [Data layout](http://llvm.org/docs/LangRef.html#data-layout) to pass to LLVM.
pub data_layout: String,
/// Optional settings with defaults.
pub options: TargetOptions,
}
/// Optional aspects of a target specification.
///
/// This has an implementation of `Default`, see each field for what the default is. In general,
/// these try to take "minimal defaults" that don't assume anything about the runtime they run in.
#[derive(PartialEq, Clone, Debug)]
pub struct TargetOptions {
/// Whether the target is built-in or loaded from a custom target specification.
pub is_builtin: bool,
/// Linker to invoke. Defaults to "cc".
pub linker: String,
/// Archive utility to use when managing archives. Defaults to "ar".
pub ar: String,
/// Linker arguments that are unconditionally passed *before* any
/// user-defined libraries.
pub pre_link_args: Vec<String>,
/// Objects to link before all others, always found within the
/// sysroot folder.
pub pre_link_objects_exe: Vec<String>, // ... when linking an executable
pub pre_link_objects_dll: Vec<String>, // ... when linking a dylib
/// Linker arguments that are unconditionally passed after any
/// user-defined but before post_link_objects. Standard platform
/// libraries that should be always be linked to, usually go here.
pub late_link_args: Vec<String>,
/// Objects to link after all others, always found within the
/// sysroot folder.
pub post_link_objects: Vec<String>,
/// Linker arguments that are unconditionally passed *after* any
/// user-defined libraries.
pub post_link_args: Vec<String>,
/// Default CPU to pass to LLVM. Corresponds to `llc -mcpu=$cpu`. Defaults
/// to "generic".
pub cpu: String,
/// Default target features to pass to LLVM. These features will *always* be
/// passed, and cannot be disabled even via `-C`. Corresponds to `llc
/// -mattr=$features`.
pub features: String,
/// Whether dynamic linking is available on this target. Defaults to false.
pub dynamic_linking: bool,
/// Whether executables are available on this target. iOS, for example, only allows static
/// libraries. Defaults to false.
pub executables: bool,
/// Relocation model to use in object file. Corresponds to `llc
/// -relocation-model=$relocation_model`. Defaults to "pic".
pub relocation_model: String,
/// Code model to use. Corresponds to `llc -code-model=$code_model`. Defaults to "default".
pub code_model: String,
/// Do not emit code that uses the "red zone", if the ABI has one. Defaults to false.
pub disable_redzone: bool,
/// Eliminate frame pointers from stack frames if possible. Defaults to true.
pub eliminate_frame_pointer: bool,
/// Emit each function in its own section. Defaults to true.
pub function_sections: bool,
/// String to prepend to the name of every dynamic library. Defaults to "lib".
pub dll_prefix: String,
/// String to append to the name of every dynamic library. Defaults to ".so".
pub dll_suffix: String,
/// String to append to the name of every executable.
pub exe_suffix: String,
/// String to prepend to the name of every static library. Defaults to "lib".
pub staticlib_prefix: String,
/// String to append to the name of every static library. Defaults to ".a".
pub staticlib_suffix: String,
/// OS family to use for conditional compilation. Valid options: "unix", "windows".
pub target_family: Option<String>,
/// Whether the target toolchain is like OSX's. Only useful for compiling against iOS/OS X, in
/// particular running dsymutil and some other stuff like `-dead_strip`. Defaults to false.
pub is_like_osx: bool,
/// Whether the target toolchain is like Solaris's.
/// Only useful for compiling against Illumos/Solaris,
/// as they have a different set of linker flags. Defaults to false.
pub is_like_solaris: bool,
/// Whether the target toolchain is like Windows'. Only useful for compiling against Windows,
/// only really used for figuring out how to find libraries, since Windows uses its own
/// library naming convention. Defaults to false.
pub is_like_windows: bool,
pub is_like_msvc: bool,
/// Whether the target toolchain is like Android's. Only useful for compiling against Android.
/// Defaults to false.
pub is_like_android: bool,
/// Whether the linker support GNU-like arguments such as -O. Defaults to false.
pub linker_is_gnu: bool,
/// The MinGW toolchain has a known issue that prevents it from correctly
/// handling COFF object files with more than 2^15 sections. Since each weak
/// symbol needs its own COMDAT section, weak linkage implies a large
/// number sections that easily exceeds the given limit for larger
/// codebases. Consequently we want a way to disallow weak linkage on some
/// platforms.
pub allows_weak_linkage: bool,
/// Whether the linker support rpaths or not. Defaults to false.
pub has_rpath: bool,
/// Whether to disable linking to compiler-rt. Defaults to false, as LLVM
/// will emit references to the functions that compiler-rt provides.
pub no_compiler_rt: bool,
/// Whether to disable linking to the default libraries, typically corresponds
/// to `-nodefaultlibs`. Defaults to true.
pub no_default_libraries: bool,
/// Dynamically linked executables can be compiled as position independent
/// if the default relocation model of position independent code is not
/// changed. This is a requirement to take advantage of ASLR, as otherwise
/// the functions in the executable are not randomized and can be used
/// during an exploit of a vulnerability in any code.
pub position_independent_executables: bool,
/// Format that archives should be emitted in. This affects whether we use
/// LLVM to assemble an archive or fall back to the system linker, and
/// currently only "gnu" is used to fall into LLVM. Unknown strings cause
/// the system linker to be used.
pub archive_format: String,
/// Is asm!() allowed? Defaults to true.
pub allow_asm: bool,
/// Whether the target uses a custom unwind resumption routine.
/// By default LLVM lowers `resume` instructions into calls to `_Unwind_Resume`
/// defined in libgcc. If this option is enabled, the target must provide
/// `eh_unwind_resume` lang item.
pub custom_unwind_resume: bool,
/// Default crate for allocation symbols to link against
pub lib_allocation_crate: String,
pub exe_allocation_crate: String,
/// Flag indicating whether ELF TLS (e.g. #[thread_local]) is available for
/// this target.
pub has_elf_tls: bool,
// This is mainly for easy compatibility with emscripten.
// If we give emcc .o files that are actually .bc files it
// will 'just work'.
pub obj_is_bitcode: bool,
/// Maximum integer size in bits that this target can perform atomic
/// operations on.
pub max_atomic_width: u64,
}
impl Default for TargetOptions {
/// Create a set of "sane defaults" for any target. This is still
/// incomplete, and if used for compilation, will certainly not work.
fn default() -> TargetOptions {
TargetOptions {
is_builtin: false,
linker: option_env!("CFG_DEFAULT_LINKER").unwrap_or("cc").to_string(),
ar: option_env!("CFG_DEFAULT_AR").unwrap_or("ar").to_string(),
pre_link_args: Vec::new(),
post_link_args: Vec::new(),
cpu: "generic".to_string(),
features: "".to_string(),
dynamic_linking: false,
executables: false,
relocation_model: "pic".to_string(),
code_model: "default".to_string(),
disable_redzone: false,
eliminate_frame_pointer: true,
function_sections: true,
dll_prefix: "lib".to_string(),
dll_suffix: ".so".to_string(),
exe_suffix: "".to_string(),
staticlib_prefix: "lib".to_string(),
staticlib_suffix: ".a".to_string(),
target_family: None,
is_like_osx: false,
is_like_solaris: false,
is_like_windows: false,
is_like_android: false,
is_like_msvc: false,
linker_is_gnu: false,
allows_weak_linkage: true,
has_rpath: false,
no_compiler_rt: false,
no_default_libraries: true,
position_independent_executables: false,
pre_link_objects_exe: Vec::new(),
pre_link_objects_dll: Vec::new(),
post_link_objects: Vec::new(),
late_link_args: Vec::new(),
archive_format: "gnu".to_string(),
custom_unwind_resume: false,
lib_allocation_crate: "alloc_system".to_string(),
exe_allocation_crate: "alloc_system".to_string(),
allow_asm: true,
has_elf_tls: false,
obj_is_bitcode: false,
max_atomic_width: 0,
}
}
}
impl Target {
/// Given a function ABI, turn "System" into the correct ABI for this target.
pub fn adjust_abi(&self, abi: Abi) -> Abi {
match abi {
Abi::System => {
if self.options.is_like_windows && self.arch == "x86" {
Abi::Stdcall
} else {
Abi::C
}
},
abi => abi
}
}
/// Load a target descriptor from a JSON object.
pub fn from_json(obj: Json) -> TargetResult {
// While ugly, this code must remain this way to retain
// compatibility with existing JSON fields and the internal
// expected naming of the Target and TargetOptions structs.
// To ensure compatibility is retained, the built-in targets
// are round-tripped through this code to catch cases where
// the JSON parser is not updated to match the structs.
let get_req_field = |name: &str| {
match obj.find(name)
.map(|s| s.as_string())
.and_then(|os| os.map(|s| s.to_string())) {
Some(val) => Ok(val),
None => {
return Err(format!("Field {} in target specification is required", name))
}
}
};
let get_opt_field = |name: &str, default: &str| {
obj.find(name).and_then(|s| s.as_string())
.map(|s| s.to_string())
.unwrap_or(default.to_string())
};
let mut base = Target {
llvm_target: try!(get_req_field("llvm-target")),
target_endian: try!(get_req_field("target-endian")),
target_pointer_width: try!(get_req_field("target-pointer-width")),
data_layout: try!(get_req_field("data-layout")),
arch: try!(get_req_field("arch")),
target_os: try!(get_req_field("os")),
target_env: get_opt_field("env", ""),
target_vendor: get_opt_field("vendor", "unknown"),
options: Default::default(),
};
// Default max-atomic-width to target-pointer-width
base.options.max_atomic_width = base.target_pointer_width.parse().unwrap();
macro_rules! key {
($key_name:ident) => ( {
let name = (stringify!($key_name)).replace("_", "-");
obj.find(&name[..]).map(|o| o.as_string()
.map(|s| base.options.$key_name = s.to_string()));
} );
($key_name:ident, bool) => ( {
let name = (stringify!($key_name)).replace("_", "-");
obj.find(&name[..])
.map(|o| o.as_boolean()
.map(|s| base.options.$key_name = s));
} );
($key_name:ident, u64) => ( {
let name = (stringify!($key_name)).replace("_", "-");
obj.find(&name[..])
.map(|o| o.as_u64()
.map(|s| base.options.$key_name = s));
} );
($key_name:ident, list) => ( {
let name = (stringify!($key_name)).replace("_", "-");
obj.find(&name[..]).map(|o| o.as_array()
.map(|v| base.options.$key_name = v.iter()
.map(|a| a.as_string().unwrap().to_string()).collect()
)
);
} );
($key_name:ident, optional) => ( {
let name = (stringify!($key_name)).replace("_", "-");
if let Some(o) = obj.find(&name[..]) {
base.options.$key_name = o
.as_string()
.map(|s| s.to_string() );
}
} );
}
key!(is_builtin, bool);
key!(linker);
key!(ar);
key!(pre_link_args, list);
key!(pre_link_objects_exe, list);
key!(pre_link_objects_dll, list);
key!(late_link_args, list);
key!(post_link_objects, list);
key!(post_link_args, list);
key!(cpu);
key!(features);
key!(dynamic_linking, bool);
key!(executables, bool);
key!(relocation_model);
key!(code_model);
key!(disable_redzone, bool);
key!(eliminate_frame_pointer, bool);
key!(function_sections, bool);
key!(dll_prefix);
key!(dll_suffix);
key!(exe_suffix);
key!(staticlib_prefix);
key!(staticlib_suffix);
key!(target_family, optional);
key!(is_like_osx, bool);
key!(is_like_solaris, bool);
key!(is_like_windows, bool);
key!(is_like_msvc, bool);
key!(is_like_android, bool);
key!(linker_is_gnu, bool);
key!(allows_weak_linkage, bool);
key!(has_rpath, bool);
key!(no_compiler_rt, bool);
key!(no_default_libraries, bool);
key!(position_independent_executables, bool);
key!(archive_format);
key!(allow_asm, bool);
key!(custom_unwind_resume, bool);
key!(lib_allocation_crate);
key!(exe_allocation_crate);
key!(has_elf_tls, bool);
key!(obj_is_bitcode, bool);
key!(max_atomic_width, u64);
Ok(base)
}
/// Search RUST_TARGET_PATH for a JSON file specifying the given target
/// triple. Note that it could also just be a bare filename already, so also
/// check for that. If one of the hardcoded targets we know about, just
/// return it directly.
///
/// The error string could come from any of the APIs called, including
/// filesystem access and JSON decoding.
pub fn search(target: &str) -> Result<Target, String> {
use std::env;
use std::ffi::OsString;
use std::fs::File;
use std::path::{Path, PathBuf};
use serialize::json;
fn load_file(path: &Path) -> Result<Target, String> {
let mut f = File::open(path).map_err(|e| e.to_string())?;
let mut contents = Vec::new();
f.read_to_end(&mut contents).map_err(|e| e.to_string())?;
let obj = json::from_reader(&mut &contents[..])
.map_err(|e| e.to_string())?;
Target::from_json(obj)
}
if let Ok(t) = load_specific(target) {
return Ok(t)
}
let path = Path::new(target);
if path.is_file() {
return load_file(&path);
}
let path = {
let mut target = target.to_string();
target.push_str(".json");
PathBuf::from(target)
};
let target_path = env::var_os("RUST_TARGET_PATH")
.unwrap_or(OsString::new());
// FIXME 16351: add a sane default search path?
for dir in env::split_paths(&target_path) {
let p = dir.join(&path);
if p.is_file() {
return load_file(&p);
}
}
Err(format!("Could not find specification for target {:?}", target))
}
}
impl ToJson for Target {
fn to_json(&self) -> Json {
let mut d = BTreeMap::new();
let default: TargetOptions = Default::default();
macro_rules! target_val {
($attr:ident) => ( {
let name = (stringify!($attr)).replace("_", "-");
d.insert(name.to_string(), self.$attr.to_json());
} );
($attr:ident, $key_name:expr) => ( {
let name = $key_name;
d.insert(name.to_string(), self.$attr.to_json());
} );
}
macro_rules! target_option_val {
($attr:ident) => ( {
let name = (stringify!($attr)).replace("_", "-");
if default.$attr != self.options.$attr {
d.insert(name.to_string(), self.options.$attr.to_json());
}
} );
($attr:ident, $key_name:expr) => ( {
let name = $key_name;
if default.$attr != self.options.$attr {
d.insert(name.to_string(), self.options.$attr.to_json());
}
} );
}
target_val!(llvm_target);
target_val!(target_endian);
target_val!(target_pointer_width);
target_val!(arch);
target_val!(target_os, "os");
target_val!(target_env, "env");
target_val!(target_vendor, "vendor");
target_val!(arch);
target_val!(data_layout);
target_option_val!(is_builtin);
target_option_val!(linker);
target_option_val!(ar);
target_option_val!(pre_link_args);
target_option_val!(pre_link_objects_exe);
target_option_val!(pre_link_objects_dll);
target_option_val!(late_link_args);
target_option_val!(post_link_objects);
target_option_val!(post_link_args);
target_option_val!(cpu);
target_option_val!(features);
target_option_val!(dynamic_linking);
target_option_val!(executables);
target_option_val!(relocation_model);
target_option_val!(code_model);
target_option_val!(disable_redzone);
target_option_val!(eliminate_frame_pointer);
target_option_val!(function_sections);
target_option_val!(dll_prefix);
target_option_val!(dll_suffix);
target_option_val!(exe_suffix);
target_option_val!(staticlib_prefix);
target_option_val!(staticlib_suffix);
target_option_val!(target_family);
target_option_val!(is_like_osx);
target_option_val!(is_like_solaris);
target_option_val!(is_like_windows);
target_option_val!(is_like_msvc);
target_option_val!(is_like_android);
target_option_val!(linker_is_gnu);
target_option_val!(allows_weak_linkage);
target_option_val!(has_rpath);
target_option_val!(no_compiler_rt);
target_option_val!(no_default_libraries);
target_option_val!(position_independent_executables);
target_option_val!(archive_format);
target_option_val!(allow_asm);
target_option_val!(custom_unwind_resume);
target_option_val!(lib_allocation_crate);
target_option_val!(exe_allocation_crate);
target_option_val!(has_elf_tls);
target_option_val!(obj_is_bitcode);
target_option_val!(max_atomic_width);
Json::Object(d)
}
}
fn maybe_jemalloc() -> String {
if cfg!(feature = "jemalloc") {
"alloc_jemalloc".to_string()
} else {
"alloc_system".to_string()
}
}