rust/crates/project_model/src/sysroot.rs
2021-07-19 21:20:10 +03:00

210 lines
6.7 KiB
Rust

//! Loads "sysroot" crate.
//!
//! One confusing point here is that normally sysroot is a bunch of `.rlib`s,
//! but we can't process `.rlib` and need source code instead. The source code
//! is typically installed with `rustup component add rust-src` command.
use std::{convert::TryFrom, env, fs, ops, path::PathBuf, process::Command};
use anyhow::{format_err, Result};
use la_arena::{Arena, Idx};
use paths::{AbsPath, AbsPathBuf};
use crate::{utf8_stdout, ManifestPath};
#[derive(Default, Debug, Clone, Eq, PartialEq)]
pub struct Sysroot {
crates: Arena<SysrootCrateData>,
}
pub(crate) type SysrootCrate = Idx<SysrootCrateData>;
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct SysrootCrateData {
pub name: String,
pub root: ManifestPath,
pub deps: Vec<SysrootCrate>,
}
impl ops::Index<SysrootCrate> for Sysroot {
type Output = SysrootCrateData;
fn index(&self, index: SysrootCrate) -> &SysrootCrateData {
&self.crates[index]
}
}
impl Sysroot {
pub fn public_deps(&self) -> impl Iterator<Item = (&'static str, SysrootCrate)> + '_ {
// core is added as a dependency before std in order to
// mimic rustcs dependency order
["core", "alloc", "std"].iter().filter_map(move |&it| Some((it, self.by_name(it)?)))
}
pub fn proc_macro(&self) -> Option<SysrootCrate> {
self.by_name("proc_macro")
}
pub fn crates<'a>(&'a self) -> impl Iterator<Item = SysrootCrate> + ExactSizeIterator + 'a {
self.crates.iter().map(|(id, _data)| id)
}
pub fn discover(dir: &AbsPath) -> Result<Sysroot> {
log::debug!("Discovering sysroot for {}", dir.display());
let sysroot_dir = discover_sysroot_dir(dir)?;
let sysroot_src_dir = discover_sysroot_src_dir(&sysroot_dir, dir)?;
let res = Sysroot::load(&sysroot_src_dir)?;
Ok(res)
}
pub fn discover_rustc(cargo_toml: &ManifestPath) -> Option<ManifestPath> {
log::debug!("Discovering rustc source for {}", cargo_toml.display());
let current_dir = cargo_toml.parent();
discover_sysroot_dir(current_dir).ok().and_then(|sysroot_dir| get_rustc_src(&sysroot_dir))
}
pub fn load(sysroot_src_dir: &AbsPath) -> Result<Sysroot> {
let mut sysroot = Sysroot { crates: Arena::default() };
for path in SYSROOT_CRATES.trim().lines() {
let name = path.split('/').last().unwrap();
let root = [format!("{}/src/lib.rs", path), format!("lib{}/lib.rs", path)]
.iter()
.map(|it| sysroot_src_dir.join(it))
.filter_map(|it| ManifestPath::try_from(it).ok())
.find(|it| fs::metadata(it).is_ok());
if let Some(root) = root {
sysroot.crates.alloc(SysrootCrateData {
name: name.into(),
root,
deps: Vec::new(),
});
}
}
if let Some(std) = sysroot.by_name("std") {
for dep in STD_DEPS.trim().lines() {
if let Some(dep) = sysroot.by_name(dep) {
sysroot.crates[std].deps.push(dep)
}
}
}
if let Some(alloc) = sysroot.by_name("alloc") {
if let Some(core) = sysroot.by_name("core") {
sysroot.crates[alloc].deps.push(core);
}
}
if let Some(proc_macro) = sysroot.by_name("proc_macro") {
if let Some(std) = sysroot.by_name("std") {
sysroot.crates[proc_macro].deps.push(std);
}
}
if sysroot.by_name("core").is_none() {
let var_note = if env::var_os("RUST_SRC_PATH").is_some() {
" (`RUST_SRC_PATH` might be incorrect, try unsetting it)"
} else {
""
};
anyhow::bail!(
"could not find libcore in sysroot path `{}`{}",
sysroot_src_dir.as_ref().display(),
var_note,
);
}
Ok(sysroot)
}
fn by_name(&self, name: &str) -> Option<SysrootCrate> {
let (id, _data) = self.crates.iter().find(|(_id, data)| data.name == name)?;
Some(id)
}
}
fn discover_sysroot_dir(current_dir: &AbsPath) -> Result<AbsPathBuf> {
let mut rustc = Command::new(toolchain::rustc());
rustc.current_dir(current_dir).args(&["--print", "sysroot"]);
log::debug!("Discovering sysroot by {:?}", rustc);
let stdout = utf8_stdout(rustc)?;
Ok(AbsPathBuf::assert(PathBuf::from(stdout)))
}
fn discover_sysroot_src_dir(
sysroot_path: &AbsPathBuf,
current_dir: &AbsPath,
) -> Result<AbsPathBuf> {
if let Ok(path) = env::var("RUST_SRC_PATH") {
let path = AbsPathBuf::try_from(path.as_str())
.map_err(|path| format_err!("RUST_SRC_PATH must be absolute: {}", path.display()))?;
let core = path.join("core");
if fs::metadata(&core).is_ok() {
log::debug!("Discovered sysroot by RUST_SRC_PATH: {}", path.display());
return Ok(path);
}
log::debug!("RUST_SRC_PATH is set, but is invalid (no core: {:?}), ignoring", core);
}
get_rust_src(sysroot_path)
.or_else(|| {
let mut rustup = Command::new(toolchain::rustup());
rustup.current_dir(current_dir).args(&["component", "add", "rust-src"]);
utf8_stdout(rustup).ok()?;
get_rust_src(sysroot_path)
})
.ok_or_else(|| {
format_err!(
"\
can't load standard library from sysroot
{}
(discovered via `rustc --print sysroot`)
try installing the Rust source the same way you installed rustc",
sysroot_path.display(),
)
})
}
fn get_rustc_src(sysroot_path: &AbsPath) -> Option<ManifestPath> {
let rustc_src = sysroot_path.join("lib/rustlib/rustc-src/rust/compiler/rustc/Cargo.toml");
let rustc_src = ManifestPath::try_from(rustc_src).ok()?;
log::debug!("Checking for rustc source code: {}", rustc_src.display());
if fs::metadata(&rustc_src).is_ok() {
Some(rustc_src)
} else {
None
}
}
fn get_rust_src(sysroot_path: &AbsPath) -> Option<AbsPathBuf> {
// Try the new path first since the old one still exists.
let rust_src = sysroot_path.join("lib/rustlib/src/rust");
log::debug!("Checking sysroot (looking for `library` and `src` dirs): {}", rust_src.display());
["library", "src"].iter().map(|it| rust_src.join(it)).find(|it| fs::metadata(it).is_ok())
}
const SYSROOT_CRATES: &str = "
alloc
core
panic_abort
panic_unwind
proc_macro
profiler_builtins
std
stdarch/crates/std_detect
term
test
unwind";
const STD_DEPS: &str = "
alloc
core
panic_abort
panic_unwind
profiler_builtins
std_detect
term
test
unwind";