rust/compiler/rustc_target/src/lib.rs
2022-02-19 17:27:43 +01:00

88 lines
2.9 KiB
Rust

//! Some stuff used by rustc that doesn't have many dependencies
//!
//! Originally extracted from rustc::back, which was nominally the
//! compiler 'backend', though LLVM is rustc's backend, so rustc_target
//! is really just odds-and-ends relating to code gen and linking.
//! This crate mostly exists to make rustc smaller, so we might put
//! more 'stuff' here in the future. It does not have a dependency on
//! LLVM.
#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
#![feature(bool_to_option)]
#![feature(let_else)]
#![feature(nll)]
#![feature(never_type)]
#![feature(associated_type_bounds)]
#![feature(exhaustive_patterns)]
#![feature(min_specialization)]
#![feature(step_trait)]
use std::iter::FromIterator;
use std::path::{Path, PathBuf};
#[macro_use]
extern crate rustc_macros;
#[macro_use]
extern crate tracing;
pub mod abi;
pub mod asm;
pub mod spec;
#[cfg(test)]
mod tests;
/// Requirements for a `StableHashingContext` to be used in this crate.
/// This is a hack to allow using the `HashStable_Generic` derive macro
/// instead of implementing everything in `rustc_middle`.
pub trait HashStableContext {}
/// The name of rustc's own place to organize libraries.
///
/// Used to be `rustc`, now the default is `rustlib`.
const RUST_LIB_DIR: &str = "rustlib";
/// Returns a `rustlib` path for this particular target, relative to the provided sysroot.
///
/// For example: `target_sysroot_path("/usr", "x86_64-unknown-linux-gnu")` =>
/// `"lib*/rustlib/x86_64-unknown-linux-gnu"`.
pub fn target_rustlib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
let libdir = find_libdir(sysroot);
PathBuf::from_iter([
Path::new(libdir.as_ref()),
Path::new(RUST_LIB_DIR),
Path::new(target_triple),
])
}
/// The name of the directory rustc expects libraries to be located.
fn find_libdir(sysroot: &Path) -> std::borrow::Cow<'static, str> {
// FIXME: This is a quick hack to make the rustc binary able to locate
// Rust libraries in Linux environments where libraries might be installed
// to lib64/lib32. This would be more foolproof by basing the sysroot off
// of the directory where `librustc_driver` is located, rather than
// where the rustc binary is.
// If --libdir is set during configuration to the value other than
// "lib" (i.e., non-default), this value is used (see issue #16552).
#[cfg(target_pointer_width = "64")]
const PRIMARY_LIB_DIR: &str = "lib64";
#[cfg(target_pointer_width = "32")]
const PRIMARY_LIB_DIR: &str = "lib32";
const SECONDARY_LIB_DIR: &str = "lib";
match option_env!("CFG_LIBDIR_RELATIVE") {
None | Some("lib") => {
if sysroot.join(PRIMARY_LIB_DIR).join(RUST_LIB_DIR).exists() {
PRIMARY_LIB_DIR.into()
} else {
SECONDARY_LIB_DIR.into()
}
}
Some(libdir) => libdir.into(),
}
}