// option. This file may not be copied, modified, or distributed
// except according to those terms.
+use std::env;
use std::ffi::OsString;
use std::fs::{self, File};
use std::io::{self, BufWriter};
fn no_whole_archives(&mut self);
fn export_symbols(&mut self, sess: &Session, trans: &CrateTranslation,
tmpdir: &Path);
+ fn try_gold_linker(&mut self);
}
pub struct GnuLinker<'a> {
fn export_symbols(&mut self, _: &Session, _: &CrateTranslation, _: &Path) {
// noop, visibility in object files takes care of this
}
+
+ fn try_gold_linker(&mut self) {
+ // Only use gold under specific conditions that we know work
+
+ let gold_exists = match env::var_os("PATH") {
+ Some(ref env_path) => {
+ env::split_paths(env_path).any(|mut p| {
+ p.push("ld.gold");
+ p.exists()
+ })
+ }
+ None => false
+ };
+ let host_is_linux = cfg!(target_os = "linux");
+ // Defensively prevent trying to use gold for bogus cross-targets.
+ let target_is_host_compatible = {
+ let host_os_is_target_os = self.sess.target.target.target_os == env::consts::OS;
+ let host_arch_is_target_arch = self.sess.target.target.arch == env::consts::ARCH;
+ // Support x86_64->i686 and reverse
+ let host_and_target_are_x86ish =
+ (self.sess.target.target.arch == "x86" ||
+ self.sess.target.target.arch == "x86_64") &&
+ (env::consts::ARCH == "x86" ||
+ env::consts::ARCH == "x86_64");
+ host_os_is_target_os && (host_arch_is_target_arch || host_and_target_are_x86ish)
+ };
+ // We have strong confidence that x86 works, but not much
+ // visibility into other architectures.
+ let target_works_with_gold =
+ self.sess.target.target.arch == "x86" ||
+ self.sess.target.target.arch == "x86_64";
+ let opt_out = self.sess.opts.cg.disable_gold;
+
+ let can_use_gold =
+ gold_exists &&
+ host_is_linux &&
+ target_is_host_compatible &&
+ target_works_with_gold &&
+ !opt_out;
+
+ if can_use_gold {
+ info!("linking with ld.gold");
+ self.cmd.arg("-fuse-ld=gold");
+ } else {
+ info!("linking with ld");
+ }
+ }
}
pub struct MsvcLinker<'a> {
arg.push(path);
self.cmd.arg(&arg);
}
+
+ fn try_gold_linker(&mut self) {}
}