1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523
//! # Cargo-Sysroot
//!
//! Compiles the Rust sysroot crates, core, compiler_builtins, and alloc.
use anyhow::{anyhow, Context, Error, Result};
use cargo_toml2::{
from_path,
to_path,
CargoToml,
Dependency,
DependencyFull,
Package,
Patches,
TargetConfig,
Workspace,
};
use std::{
collections::BTreeMap,
env,
ffi::OsString,
fs,
path::{Path, PathBuf},
process::Command,
};
mod util;
pub use util::get_rust_src;
/// The sysroot crates to build.
///
/// See [`build_sysroot_with`] for details.
#[derive(Debug, Copy, Clone)]
pub enum Sysroot {
/// The core crate. Provides core functionality.
///
/// This does **not** include [`Sysroot::CompilerBuiltins`],
/// which is what you probably want unless your target
/// needs special handling.
Core,
/// Compiler-builtins crate.
///
/// This implies [`Sysroot::Core`].
CompilerBuiltins,
/// The alloc crate. Gives you a heap, and things to put on it.
///
/// This implies [`Sysroot::Core`], and [`Sysroot::CompilerBuiltins`].
Alloc,
/// The standard library. Gives you an operating system.
///
/// This implies [`Sysroot::Alloc`], [`Sysroot::Core`], and
/// [`Sysroot::CompilerBuiltins`].
Std,
}
/// Features to enable when building the sysroot crates
///
/// See [`SysrootBuilder::features`] for usage.
#[derive(Debug, Copy, Clone, PartialOrd, PartialEq, Ord, Eq)]
pub enum Features {
/// This enables the `mem` feature of [`compiler_builtins`][1],
/// which will provide memory related intrinsics such as `memcpy`.
///
/// [1]: https://github.com/rust-lang/compiler-builtins
CompilerBuiltinsMem,
/// This enables the `c` feature of [`compiler_builtins`][1],
/// which enables compilation of `C` code and may result in more
/// optimized implementations, and fills in the rare unimplemented
/// intrinsics.
///
/// [1]: https://github.com/rust-lang/compiler-builtins
CompilerBuiltinsC,
/// This enables the `no-asm` feature of [`compiler_builtins`][1],
/// which disables any implementations which use
/// inline assembly and fall back to pure Rust versions (if available).
///
/// [1]: https://github.com/rust-lang/compiler-builtins
// TODO: Would only work on the [`Sysroot::CompilerBuiltins`] target,
// as it's not exported through alloc, but could be forced by
// adding compiler_builtins as an explicit dependency and enabling it,
// relying on features collapsing.
CompilerBuiltinsNoAsm,
}
/// A builder interface for constructing the Sysroot
///
/// See the individual methods for more details on what this means
/// and what defaults exist.
#[derive(Debug, Clone)]
pub struct SysrootBuilder {
/// Manifest to use for cargo profiles
manifest: Option<PathBuf>,
/// Output directory, where the built sysroot will be anchored.
output: PathBuf,
/// Target triple/json to build for
target: Option<PathBuf>,
/// The rust sources to use
rust_src: Option<PathBuf>,
/// Which crates to include in the sysroot
sysroot_crate: Sysroot,
/// What custom features to enable, if any. See [`Features`] for details.
features: Vec<Features>,
/// Custom flags to pass to rustc.
rustc_flags: Vec<OsString>,
}
impl SysrootBuilder {
/// New [`SysrootBuilder`].
///
/// `sysroot_crate` specifies which libraries to build as part of
/// the sysroot. See [`Sysroot`] for more details.
pub fn new(sysroot_crate: Sysroot) -> Self {
Self {
manifest: Default::default(),
output: PathBuf::from(".").join("target").join("sysroot"),
target: Default::default(),
// Set in [`SysrootBuilder::build`] since `new` can't error.
rust_src: Default::default(),
sysroot_crate,
features: Vec::with_capacity(3),
rustc_flags: Default::default(),
}
}
/// Set path to the `Cargo.toml` of the project requiring a custom sysroot.
///
/// If provided, any [Cargo Profile's][1] in the provided manifest
/// will be copied into the sysroot crate being compiled.
///
/// If not provided, profiles use their default settings.
///
/// By default this will be `None`.
///
/// [1]: https://doc.rust-lang.org/stable/cargo/reference/profiles.html
pub fn manifest(&mut self, manifest: PathBuf) -> &mut Self {
self.manifest = Some(manifest);
self
}
/// Set where the sysroot directory will be placed.
///
/// By default this is `./target/sysroot`.
pub fn output(&mut self, output: PathBuf) -> &mut Self {
self.output = output;
self
}
/// The target to compile *for*. This can be a target-triple,
/// or a [JSON Target Specification][1].
///
/// By default this is `None`, and if not set when
/// [`SysrootBuilder::build`] is called, will cause an error.
///
/// [1]: https://doc.rust-lang.org/rustc/targets/custom.html
pub fn target(&mut self, target: PathBuf) -> &mut Self {
self.target = Some(target);
self
}
/// The rust source directory. These are used to compile the sysroot.
///
/// By default this uses the `rust-src` component from the
/// current `rustup` toolchain.
pub fn rust_src(&mut self, rust_src: PathBuf) -> &mut Self {
self.rust_src = Some(rust_src);
self
}
/// Which features to enable.
///
/// This *adds* to, not *replaces*, any previous calls to this method.
///
/// By default this is empty.
///
/// See [`Features`] for details.
pub fn features(&mut self, features: &[Features]) -> &mut Self {
self.features.extend_from_slice(features);
// TODO: Should?? Not??
self.features.sort_unstable();
self.features.dedup();
self
}
/// Custom flags to pass to **all** `rustc` compiler invocations.
///
/// This *adds* to, not *replaces*, any previous calls to this method.
///
/// By default this is empty.
///
/// # Internal
///
/// This will use the `RUSTFLAGS` to ensure flags are set for all
/// invocations.
///
/// Flags passed to this method will be *appended*
/// to any existing `RUSTFLAGS`.
pub fn rustc_flags<I, S>(&mut self, flags: I) -> &mut Self
where
I: IntoIterator<Item = S>,
S: Into<OsString>,
{
self.rustc_flags.extend(flags.into_iter().map(Into::into));
self
}
/// Build the Sysroot, and return a path suitable to pass to rustc.
///
/// # Errors
///
/// - [`SysrootBuilder::target`] was not called
/// - If `manifest` is provided and does not exist
/// - If `target` is a JSON specification, but doesn't exist.
/// - If the `rust_src` directory does not exist, or could not be detected.
/// - If the sysroot cannot be setup, or fails to compile
pub fn build(&self) -> Result<PathBuf> {
let target = match &self.target {
Some(t) => t,
None => return Err(anyhow!("SysrootBuilder::target was not called")),
};
if let Some(manifest) = &self.manifest {
if !manifest.exists() {
return Err(anyhow!(
"Provided manifest did not exist. Path: {}",
manifest.display()
));
}
}
// If `target` has an extension, assume target spec...
if target.extension().is_some() {
// ...and check if it exists.
if !target.exists() {
return Err(anyhow!(
"Provided JSON Target Specification did not exist: {}",
target.display()
));
}
}
let rust_src = match &self.rust_src {
Some(s) => {
if !s.exists() {
return Err(anyhow!(
"The provided rust-src directory did not exist: {}",
s.display()
));
}
s.clone()
}
None => {
let src = util::get_rust_src().context("Could not detect appropriate rust-src")?;
if !src.exists() {
return Err(anyhow!("Rust-src component not installed?"));
}
src
}
};
fs::create_dir_all(&self.output).context("Couldn't create sysroot output directory")?;
fs::create_dir_all(artifact_dir(&self.output, target)?)
.context("Failed to setup sysroot directory structure")?;
let sysroot_cargo_toml = generate_sysroot_cargo_toml(&SysrootBuilder {
// HACK: So it can see auto-detected rust-src.
rust_src: Some(rust_src),
..self.clone()
})?;
build_alloc(&sysroot_cargo_toml, &self).context("Failed to build sysroot")?;
// Copy host tools to the new sysroot, so that stuff like proc-macros and
// testing can work.
util::copy_host_tools(&self.output).context("Couldn't copy host tools to sysroot")?;
Ok(self.output.canonicalize().with_context(|| {
format!(
"Couldn't get canonical path to sysroot: {}",
self.output.display()
)
})?)
}
}
/// Generate a Cargo.toml for building the sysroot crates
///
/// Should ONLY be called by [`SysrootBuilder::build`].
///
/// See [`build_sysroot_with`].
fn generate_sysroot_cargo_toml(builder: &SysrootBuilder) -> Result<PathBuf> {
fs::write(
builder.output.join("lib.rs"),
"#![feature(no_core)]\n#![no_core]",
)?;
let toml = CargoToml {
package: Package {
name: "Sysroot".into(),
version: "0.0.0".into(),
authors: vec!["The Rust Project Developers".into(), "DianaNites".into()],
edition: Some("2018".into()),
autotests: Some(false),
autobenches: Some(false),
..Default::default()
},
lib: Some(TargetConfig {
name: Some("sysroot".into()),
path: Some("lib.rs".into()),
..Default::default()
}),
workspace: Some(Workspace::default()),
dependencies: Some({
let mut deps = BTreeMap::new();
match builder.sysroot_crate {
Sysroot::Core => {
deps.insert(
"core".into(),
Dependency::Full(DependencyFull {
path: Some(builder.rust_src.as_ref().unwrap().join("core")),
..Default::default()
}),
);
}
Sysroot::CompilerBuiltins => {
deps.insert(
"compiler_builtins".into(),
Dependency::Full(DependencyFull {
version: Some("0.1".into()),
features: {
let mut f = vec!["rustc-dep-of-std".into()];
if builder.features.contains(&Features::CompilerBuiltinsMem) {
f.push("mem".into());
}
Some(f)
},
..Default::default()
}),
);
}
Sysroot::Alloc => {
deps.insert(
"alloc".into(),
Dependency::Full(DependencyFull {
path: Some(builder.rust_src.as_ref().unwrap().join("alloc")),
features: if builder.features.contains(&Features::CompilerBuiltinsMem) {
Some(vec!["compiler-builtins-mem".into()])
} else {
None
},
..Default::default()
}),
);
}
Sysroot::Std => {
deps.insert(
"std".into(),
Dependency::Full(DependencyFull {
path: Some(builder.rust_src.as_ref().unwrap().join("std")),
features: if builder.features.contains(&Features::CompilerBuiltinsMem) {
Some(vec!["compiler-builtins-mem".into()])
} else {
None
},
..Default::default()
}),
);
}
}
deps
}),
patch: Some(Patches {
sources: if let Sysroot::Core = builder.sysroot_crate {
BTreeMap::new()
} else {
let mut sources = BTreeMap::new();
sources.insert("crates-io".into(), {
let mut x = BTreeMap::new();
x.insert(
"rustc-std-workspace-core".to_string(),
Dependency::Full(DependencyFull {
path: Some(
builder
.rust_src
.as_ref()
.unwrap()
.join("rustc-std-workspace-core"),
),
..Default::default()
}),
);
x
});
sources
},
}),
profile: {
match &builder.manifest {
Some(manifest) => {
let toml: CargoToml =
from_path(manifest).with_context(|| manifest.display().to_string())?;
toml.profile
}
None => None,
}
},
..Default::default()
};
let path = builder.output.join("Cargo.toml");
to_path(&path, &toml).context("Failed writing sysroot Cargo.toml")?;
Ok(path)
}
/// The entry-point for building the alloc crate, which builds all the others
///
/// Should ONLY be called by [`SysrootBuilder::build`].
fn build_alloc(alloc_cargo_toml: &Path, builder: &SysrootBuilder) -> Result<()> {
let path = alloc_cargo_toml;
let triple = builder.target.as_ref().unwrap();
let target_dir = builder.output.join("target");
// TODO: Eat output if up to date? Always? On error?
let exit = Command::new(env::var_os("CARGO").unwrap_or_else(|| "cargo".into()))
.arg("rustc")
.arg("--release")
.arg("--target")
// If it doesn't work, assume it's a builtin path?
.arg(&triple.canonicalize().unwrap_or_else(|_| triple.into()))
.arg("--target-dir")
.arg(&target_dir)
.arg("--manifest-path")
.arg(path)
.arg("--") // Pass to rustc directly.
.arg("-Z")
// The rust build system only passes this for rustc? xbuild passes this for alloc. 🤷♀️
.arg("force-unstable-if-unmarked")
.env("RUSTFLAGS", {
let mut env = OsString::new();
if let Some(exist) = std::env::var_os("RUSTFLAGS") {
env.push(exist);
}
for flag in &builder.rustc_flags {
env.push(" ");
env.push(flag)
}
env
})
// Causes clippy to leak output
// See #6
.env_remove("RUSTC_WORKSPACE_WRAPPER")
.status()
.context("Couldn't find/run cargo command")?;
if !exit.success() {
return Err(anyhow!(
"Failed to build sysroot: Exit code {}",
exit.code()
.map(|i| i.to_string())
.unwrap_or_else(|| "Killed by signal".to_string())
));
}
// Copy artifacts to sysroot.
for entry in fs::read_dir(
target_dir
.join(
&triple
.file_stem()
.context("Failed to parse target triple")?,
)
.join("release")
.join("deps"),
)
.context("Failure to read artifact directory")?
{
let entry = entry?;
let name = entry
.file_name()
.into_string()
.map_err(|e| Error::msg(e.to_string_lossy().to_string()))
.context("Invalid Unicode in path")?;
if name.starts_with("lib") {
let out = artifact_dir(&builder.output, &triple)?.join(name);
fs::copy(entry.path(), &out).with_context(|| {
format!(
"Copying sysroot artifact from {} to {} failed",
entry.path().display(),
out.display()
)
})?;
}
}
Ok(())
}
/// The output artifact directory
///
/// Not part of the public API.
fn artifact_dir(sysroot_dir: &Path, target: &Path) -> Result<PathBuf> {
Ok(sysroot_dir
.join("lib")
.join("rustlib")
.join(target.file_stem().context("Invalid Target Specification")?)
.join("lib"))
}
/// Clean up generated sysroot artifacts.
///
/// Should be called before [`build_sysroot`] if you want this behavior.
pub fn clean_artifacts(sysroot_dir: &Path) -> Result<()> {
// Clean-up old artifacts
match remove_dir_all::remove_dir_all(sysroot_dir) {
Ok(_) => (),
Err(e) if e.kind() == std::io::ErrorKind::NotFound => (),
e => e.context("Couldn't clean sysroot artifacts")?,
};
Ok(())
}