compiler/rustc_target/src/lib.rs

   1 //! Some stuff used by rustc that doesn't have many dependencies
   2 //!
   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
   8 //! LLVM.
   9
  10 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
  11 #![cfg_attr(not(bootstrap), doc(rust_logo))]
  12 #![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
  13 #![feature(assert_matches)]
  14 #![feature(associated_type_bounds)]
  15 #![feature(exhaustive_patterns)]
  16 #![feature(iter_intersperse)]
  17 #![feature(let_chains)]
  18 #![feature(min_specialization)]
  19 #![feature(never_type)]
  20 #![feature(rustc_attrs)]
  21 #![feature(step_trait)]
  22 #![deny(rustc::untranslatable_diagnostic)]
  23 #![deny(rustc::diagnostic_outside_of_impl)]
  24 #![allow(internal_features)]
  25
  26 use std::path::{Path, PathBuf};
  27
  28 #[macro_use]
  29 extern crate rustc_macros;
  30
  31 #[macro_use]
  32 extern crate tracing;
  33
  34 pub mod abi;
  35 pub mod asm;
  36 pub mod json;
  37 pub mod spec;
  38
  39 #[cfg(test)]
  40 mod tests;
  41
  42 pub use rustc_abi::HashStableContext;
  43
  44 /// The name of rustc's own place to organize libraries.
  45 ///
  46 /// Used to be `rustc`, now the default is `rustlib`.
  47 const RUST_LIB_DIR: &str = "rustlib";
  48
  49 /// Returns a `rustlib` path for this particular target, relative to the provided sysroot.
  50 ///
  51 /// For example: `target_sysroot_path("/usr", "x86_64-unknown-linux-gnu")` =>
  52 /// `"lib*/rustlib/x86_64-unknown-linux-gnu"`.
  53 pub fn target_rustlib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
  54     let libdir = find_libdir(sysroot);
  55     PathBuf::from_iter([
  56         Path::new(libdir.as_ref()),
  57         Path::new(RUST_LIB_DIR),
  58         Path::new(target_triple),
  59     ])
  60 }
  61
  62 /// The name of the directory rustc expects libraries to be located.
  63 fn find_libdir(sysroot: &Path) -> std::borrow::Cow<'static, str> {
  64     // FIXME: This is a quick hack to make the rustc binary able to locate
  65     // Rust libraries in Linux environments where libraries might be installed
  66     // to lib64/lib32. This would be more foolproof by basing the sysroot off
  67     // of the directory where `librustc_driver` is located, rather than
  68     // where the rustc binary is.
  69     // If --libdir is set during configuration to the value other than
  70     // "lib" (i.e., non-default), this value is used (see issue #16552).
  71
  72     #[cfg(target_pointer_width = "64")]
  73     const PRIMARY_LIB_DIR: &str = "lib64";
  74
  75     #[cfg(target_pointer_width = "32")]
  76     const PRIMARY_LIB_DIR: &str = "lib32";
  77
  78     const SECONDARY_LIB_DIR: &str = "lib";
  79
  80     match option_env!("CFG_LIBDIR_RELATIVE") {
  81         None | Some("lib") => {
  82             if sysroot.join(PRIMARY_LIB_DIR).join(RUST_LIB_DIR).exists() {
  83                 PRIMARY_LIB_DIR.into()
  84             } else {
  85                 SECONDARY_LIB_DIR.into()
  86             }
  87         }
  88         Some(libdir) => libdir.into(),
  89     }
  90 }