Rollup merge of rust-lang#137612 - Kobzol:bootstrap-2024, r=onur-ozkan

Update bootstrap to edition 2024

The stage0 compiler now supports edition 2024, so we can update bootstrap to it. I manually reviewed all the changes from `cargo fix --edition` and reverted most of them (`if let` -> `matches` changes and two unneeded usages of `use <>`).

r? `@onur-ozkan`

src/bootstrap/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "bootstrap"
 version = "0.0.0"
-edition = "2021"
+edition = "2024"
 build = "build.rs"
 default-run = "bootstrap"
 

src/bootstrap/src/bin/sccache-plus-cl.rs

@@ -4,8 +4,13 @@ use std::process::{self, Command};
 fn main() {
     let target = env::var("SCCACHE_TARGET").unwrap();
     // Locate the actual compiler that we're invoking
-    env::set_var("CC", env::var_os("SCCACHE_CC").unwrap());
-    env::set_var("CXX", env::var_os("SCCACHE_CXX").unwrap());
+
+    // SAFETY: we're in main, there are no other threads
+    unsafe {
+        env::set_var("CC", env::var_os("SCCACHE_CC").unwrap());
+        env::set_var("CXX", env::var_os("SCCACHE_CXX").unwrap());
+    }
+
     let mut cfg = cc::Build::new();
     cfg.cargo_metadata(false)
         .out_dir("/")

src/bootstrap/src/core/build_steps/format.rs

@@ -27,7 +27,7 @@ fn rustfmt(
     rustfmt: &Path,
     paths: &[PathBuf],
     check: bool,
-) -> impl FnMut(bool) -> RustfmtStatus {
+) -> impl FnMut(bool) -> RustfmtStatus + use<> {
     let mut cmd = Command::new(rustfmt);
     // Avoid the submodule config paths from coming into play. We only allow a single global config
     // for the workspace for now.

src/bootstrap/src/utils/cc_detect/tests.rs

@@ -9,20 +9,24 @@ use crate::{Build, Config, Flags};
 fn test_cc2ar_env_specific() {
     let triple = "x86_64-unknown-linux-gnu";
     let key = "AR_x86_64_unknown_linux_gnu";
-    env::set_var(key, "custom-ar");
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::set_var(key, "custom-ar") };
     let target = TargetSelection::from_user(triple);
     let cc = Path::new("/usr/bin/clang");
     let default_ar = PathBuf::from("default-ar");
     let result = cc2ar(cc, target, default_ar);
-    env::remove_var(key);
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var(key) };
     assert_eq!(result, Some(PathBuf::from("custom-ar")));
 }
 
 #[test]
 fn test_cc2ar_musl() {
     let triple = "x86_64-unknown-linux-musl";
-    env::remove_var("AR_x86_64_unknown_linux_musl");
-    env::remove_var("AR");
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR_x86_64_unknown_linux_musl") };
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR") };
     let target = TargetSelection::from_user(triple);
     let cc = Path::new("/usr/bin/clang");
     let default_ar = PathBuf::from("default-ar");
@@ -33,8 +37,10 @@ fn test_cc2ar_musl() {
 #[test]
 fn test_cc2ar_openbsd() {
     let triple = "x86_64-unknown-openbsd";
-    env::remove_var("AR_x86_64_unknown_openbsd");
-    env::remove_var("AR");
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR_x86_64_unknown_openbsd") };
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR") };
     let target = TargetSelection::from_user(triple);
     let cc = Path::new("/usr/bin/cc");
     let default_ar = PathBuf::from("default-ar");
@@ -45,8 +51,10 @@ fn test_cc2ar_openbsd() {
 #[test]
 fn test_cc2ar_vxworks() {
     let triple = "armv7-wrs-vxworks";
-    env::remove_var("AR_armv7_wrs_vxworks");
-    env::remove_var("AR");
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR_armv7_wrs_vxworks") };
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR") };
     let target = TargetSelection::from_user(triple);
     let cc = Path::new("/usr/bin/clang");
     let default_ar = PathBuf::from("default-ar");
@@ -57,8 +65,10 @@ fn test_cc2ar_vxworks() {
 #[test]
 fn test_cc2ar_nto_i586() {
     let triple = "i586-unknown-nto-something";
-    env::remove_var("AR_i586_unknown_nto_something");
-    env::remove_var("AR");
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR_i586_unknown_nto_something") };
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR") };
     let target = TargetSelection::from_user(triple);
     let cc = Path::new("/usr/bin/clang");
     let default_ar = PathBuf::from("default-ar");
@@ -69,8 +79,10 @@ fn test_cc2ar_nto_i586() {
 #[test]
 fn test_cc2ar_nto_aarch64() {
     let triple = "aarch64-unknown-nto-something";
-    env::remove_var("AR_aarch64_unknown_nto_something");
-    env::remove_var("AR");
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR_aarch64_unknown_nto_something") };
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR") };
     let target = TargetSelection::from_user(triple);
     let cc = Path::new("/usr/bin/clang");
     let default_ar = PathBuf::from("default-ar");
@@ -81,8 +93,10 @@ fn test_cc2ar_nto_aarch64() {
 #[test]
 fn test_cc2ar_nto_x86_64() {
     let triple = "x86_64-unknown-nto-something";
-    env::remove_var("AR_x86_64_unknown_nto_something");
-    env::remove_var("AR");
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR_x86_64_unknown_nto_something") };
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR") };
     let target = TargetSelection::from_user(triple);
     let cc = Path::new("/usr/bin/clang");
     let default_ar = PathBuf::from("default-ar");
@@ -94,8 +108,10 @@ fn test_cc2ar_nto_x86_64() {
 #[should_panic(expected = "Unknown architecture, cannot determine archiver for Neutrino QNX")]
 fn test_cc2ar_nto_unknown() {
     let triple = "powerpc-unknown-nto-something";
-    env::remove_var("AR_powerpc_unknown_nto_something");
-    env::remove_var("AR");
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR_powerpc_unknown_nto_something") };
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::remove_var("AR") };
     let target = TargetSelection::from_user(triple);
     let cc = Path::new("/usr/bin/clang");
     let default_ar = PathBuf::from("default-ar");
@@ -177,7 +193,8 @@ fn test_default_compiler_wasi() {
     let build = Build::new(Config { ..Config::parse(Flags::parse(&["check".to_owned()])) });
     let target = TargetSelection::from_user("wasm32-wasi");
     let wasi_sdk = PathBuf::from("/wasi-sdk");
-    env::set_var("WASI_SDK_PATH", &wasi_sdk);
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe { env::set_var("WASI_SDK_PATH", &wasi_sdk) };
     let mut cfg = cc::Build::new();
     if let Some(result) = default_compiler(&mut cfg, Language::C, target.clone(), &build) {
         let expected = {
@@ -190,7 +207,10 @@ fn test_default_compiler_wasi() {
             "default_compiler should return a compiler path for wasi target when WASI_SDK_PATH is set"
         );
     }
-    env::remove_var("WASI_SDK_PATH");
+    // SAFETY: bootstrap tests run on a single thread
+    unsafe {
+        env::remove_var("WASI_SDK_PATH");
+    }
 }
 
 #[test]

src/bootstrap/src/utils/helpers.rs

@@ -286,7 +286,7 @@ pub fn output(cmd: &mut Command) -> String {
 /// to finish and then return its output. This allows the spawned process
 /// to do work without immediately blocking bootstrap.
 #[track_caller]
-pub fn start_process(cmd: &mut Command) -> impl FnOnce() -> String {
+pub fn start_process(cmd: &mut Command) -> impl FnOnce() -> String + use<> {
     let child = match cmd.stderr(Stdio::inherit()).stdout(Stdio::piped()).spawn() {
         Ok(child) => child,
         Err(e) => fail(&format!("failed to execute command: {cmd:?}\nERROR: {e}")),

src/bootstrap/src/utils/job.rs

@@ -7,7 +7,9 @@ pub unsafe fn setup(_build: &mut crate::Build) {}
 #[cfg(all(unix, not(target_os = "haiku")))]
 pub unsafe fn setup(build: &mut crate::Build) {
     if build.config.low_priority {
-        libc::setpriority(libc::PRIO_PGRP as _, 0, 10);
+        unsafe {
+            libc::setpriority(libc::PRIO_PGRP as _, 0, 10);
+        }
     }
 }