1 //! Some stuff used by rustc that doesn't have many dependencies
3 //! Originally extracted from rustc::back, which was nominally the
4 //! compiler 'backend', though LLVM is rustc's backend, so rustc_target
5 //! is really just odds-and-ends relating to code gen and linking.
6 //! This crate mostly exists to make rustc smaller, so we might put
7 //! more 'stuff' here in the future. It does not have a dependency on
10 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
11 #![feature(bool_to_option)]
13 #![feature(never_type)]
14 #![feature(associated_type_bounds)]
15 #![feature(exhaustive_patterns)]
16 #![feature(min_specialization)]
18 use std::path::{Path, PathBuf};
21 extern crate rustc_macros;
33 /// Requirements for a `StableHashingContext` to be used in this crate.
34 /// This is a hack to allow using the `HashStable_Generic` derive macro
35 /// instead of implementing everything in `rustc_middle`.
36 pub trait HashStableContext {}
38 /// The name of rustc's own place to organize libraries.
40 /// Used to be `rustc`, now the default is `rustlib`.
41 const RUST_LIB_DIR: &str = "rustlib";
43 /// Returns a `rustlib` path for this particular target, relative to the provided sysroot.
45 /// For example: `target_sysroot_path("/usr", "x86_64-unknown-linux-gnu")` =>
46 /// `"lib*/rustlib/x86_64-unknown-linux-gnu"`.
47 pub fn target_rustlib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
48 let libdir = find_libdir(sysroot);
49 std::array::IntoIter::new([
50 Path::new(libdir.as_ref()),
51 Path::new(RUST_LIB_DIR),
52 Path::new(target_triple),
57 /// The name of the directory rustc expects libraries to be located.
58 fn find_libdir(sysroot: &Path) -> std::borrow::Cow<'static, str> {
59 // FIXME: This is a quick hack to make the rustc binary able to locate
60 // Rust libraries in Linux environments where libraries might be installed
61 // to lib64/lib32. This would be more foolproof by basing the sysroot off
62 // of the directory where `librustc_driver` is located, rather than
63 // where the rustc binary is.
64 // If --libdir is set during configuration to the value other than
65 // "lib" (i.e., non-default), this value is used (see issue #16552).
67 #[cfg(target_pointer_width = "64")]
68 const PRIMARY_LIB_DIR: &str = "lib64";
70 #[cfg(target_pointer_width = "32")]
71 const PRIMARY_LIB_DIR: &str = "lib32";
73 const SECONDARY_LIB_DIR: &str = "lib";
75 match option_env!("CFG_LIBDIR_RELATIVE") {
76 None | Some("lib") => {
77 if sysroot.join(PRIMARY_LIB_DIR).join(RUST_LIB_DIR).exists() {
78 PRIMARY_LIB_DIR.into()
80 SECONDARY_LIB_DIR.into()
83 Some(libdir) => libdir.into(),