rust-lang · bors · Aug 15, 2025 · Aug 14, 2025 · Jul 20, 2025 · Aug 14, 2025
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -223,6 +223,11 @@ jobs:
           cd src/ci/citool
           CARGO_INCREMENTAL=0 CARGO_TARGET_DIR=../../../build/citool cargo build
 
+      - name: wait for Windows disk cleanup to finish
+        if: ${{ matrix.free_disk && startsWith(matrix.os, 'windows-') }}
+        run: |
+          python3 src/ci/scripts/free-disk-space-windows-wait.py
+
       - name: run the build
         run: |
           set +e

diff --git a/bootstrap.example.toml b/bootstrap.example.toml
@@ -9,7 +9,7 @@
 # a custom configuration file can also be specified with `--config` to the build
 # system.
 #
-# Note that the following are equivelent, for more details see <https://toml.io/en/v1.0.0>.
+# Note that the following are equivalent, for more details see <https://toml.io/en/v1.0.0>.
 #
 #     build.verbose = 1
 #
@@ -345,9 +345,9 @@
 # want to use vendoring. See https://forge.rust-lang.org/infra/other-installation-methods.html#source-code.
 #build.vendor = if "is a tarball source" && "vendor" dir exists && ".cargo/config.toml" file exists { true } else { false }
 
-# Typically the build system will build the Rust compiler twice. The second
-# compiler, however, will simply use its own libraries to link against. If you
-# would rather to perform a full bootstrap, compiling the compiler three times,
+# If you build the compiler more than twice (stage3+) or the standard library more than once
+# (stage 2+), the third compiler and second library will get uplifted from stage2 and stage1,
+# respectively. If you would like to disable this uplifting, and rather perform a full bootstrap,
 # then you can set this option to true.
 #
 # This is only useful for verifying that rustc generates reproducible builds.
@@ -482,7 +482,7 @@
 # Use `--extra-checks=''` to temporarily disable all extra checks.
 #
 # Automatically enabled in the "tools" profile.
-# Set to the empty string to force disable (recommeded for hdd systems).
+# Set to the empty string to force disable (recommended for hdd systems).
 #build.tidy-extra-checks = ""
 
 # Indicates whether ccache is used when building certain artifacts (e.g. LLVM).

diff --git a/compiler/rustc_lint/src/drop_forget_useless.rs b/compiler/rustc_lint/src/drop_forget_useless.rs
@@ -151,7 +151,7 @@ impl<'tcx> LateLintPass<'tcx> for DropForgetUseless {
                     && let Node::Stmt(stmt) = node
                     && let StmtKind::Semi(e) = stmt.kind
                     && e.hir_id == expr.hir_id
-                    && let Some(arg_span) = arg.span.find_ancestor_inside(expr.span)
+                    && let Some(arg_span) = arg.span.find_ancestor_inside_same_ctxt(expr.span)
                 {
                     UseLetUnderscoreIgnoreSuggestion::Suggestion {
                         start_span: expr.span.shrink_to_lo().until(arg_span),

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
@@ -2847,16 +2847,27 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         // This is the location used by the `rustc-dev` `rustup` component.
         real_source_base_dir("lib/rustlib/rustc-src/rust", "compiler/rustc/src/main.rs");
 
-    let mut search_paths = vec![];
-    for s in &matches.opt_strs("L") {
-        search_paths.push(SearchPath::from_cli_opt(
-            sysroot.path(),
-            &target_triple,
-            early_dcx,
-            s,
-            unstable_opts.unstable_options,
-        ));
-    }
+    // We eagerly scan all files in each passed -L path. If the same directory is passed multiple
+    // times, and the directory contains a lot of files, this can take a lot of time.
+    // So we remove -L paths that were passed multiple times, and keep only the first occurrence.
+    // We still have to keep the original order of the -L arguments.
+    let search_paths: Vec<SearchPath> = {
+        let mut seen_search_paths = FxHashSet::default();
+        let search_path_matches: Vec<String> = matches.opt_strs("L");
+        search_path_matches
+            .iter()
+            .filter(|p| seen_search_paths.insert(*p))
+            .map(|path| {
+                SearchPath::from_cli_opt(
+                    sysroot.path(),
+                    &target_triple,
+                    early_dcx,
+                    &path,
+                    unstable_opts.unstable_options,
+                )
+            })
+            .collect()
+    };
 
     let working_dir = std::env::current_dir().unwrap_or_else(|e| {
         early_dcx.early_fatal(format!("Current directory is invalid: {e}"));

diff --git a/library/std/src/sys/pal/unix/thread.rs b/library/std/src/sys/pal/unix/thread.rs
@@ -77,7 +77,18 @@ impl Thread {
                     let page_size = os::page_size();
                     let stack_size =
                         (stack_size + page_size - 1) & (-(page_size as isize - 1) as usize - 1);
-                    assert_eq!(libc::pthread_attr_setstacksize(attr.as_mut_ptr(), stack_size), 0);
+
+                    // Some libc implementations, e.g. musl, place an upper bound
+                    // on the stack size, in which case we can only gracefully return
+                    // an error here.
+                    if libc::pthread_attr_setstacksize(attr.as_mut_ptr(), stack_size) != 0 {
+                        assert_eq!(libc::pthread_attr_destroy(attr.as_mut_ptr()), 0);
+                        drop(Box::from_raw(data));
+                        return Err(io::const_error!(
+                            io::ErrorKind::InvalidInput,
+                            "invalid stack size"
+                        ));
+                    }
                 }
             };
         }

diff --git a/library/std/src/sys/pal/windows/c/bindings.txt b/library/std/src/sys/pal/windows/c/bindings.txt
@@ -2158,6 +2158,7 @@ GetCurrentDirectoryW
 GetCurrentProcess
 GetCurrentProcessId
 GetCurrentThread
+GetCurrentThreadId
 GetEnvironmentStringsW
 GetEnvironmentVariableW
 GetExitCodeProcess
@@ -2185,7 +2186,6 @@ GetSystemInfo
 GetSystemTimeAsFileTime
 GetSystemTimePreciseAsFileTime
 GetTempPathW
-GetThreadId
 GetUserProfileDirectoryW
 GetWindowsDirectoryW
 HANDLE

diff --git a/library/std/src/sys/pal/windows/c/windows_sys.rs b/library/std/src/sys/pal/windows/c/windows_sys.rs
@@ -38,6 +38,7 @@ windows_targets::link!("kernel32.dll" "system" fn GetCurrentDirectoryW(nbufferle
 windows_targets::link!("kernel32.dll" "system" fn GetCurrentProcess() -> HANDLE);
 windows_targets::link!("kernel32.dll" "system" fn GetCurrentProcessId() -> u32);
 windows_targets::link!("kernel32.dll" "system" fn GetCurrentThread() -> HANDLE);
+windows_targets::link!("kernel32.dll" "system" fn GetCurrentThreadId() -> u32);
 windows_targets::link!("kernel32.dll" "system" fn GetEnvironmentStringsW() -> PWSTR);
 windows_targets::link!("kernel32.dll" "system" fn GetEnvironmentVariableW(lpname : PCWSTR, lpbuffer : PWSTR, nsize : u32) -> u32);
 windows_targets::link!("kernel32.dll" "system" fn GetExitCodeProcess(hprocess : HANDLE, lpexitcode : *mut u32) -> BOOL);
@@ -61,7 +62,6 @@ windows_targets::link!("kernel32.dll" "system" fn GetSystemInfo(lpsysteminfo : *
 windows_targets::link!("kernel32.dll" "system" fn GetSystemTimeAsFileTime(lpsystemtimeasfiletime : *mut FILETIME));
 windows_targets::link!("kernel32.dll" "system" fn GetSystemTimePreciseAsFileTime(lpsystemtimeasfiletime : *mut FILETIME));
 windows_targets::link!("kernel32.dll" "system" fn GetTempPathW(nbufferlength : u32, lpbuffer : PWSTR) -> u32);
-windows_targets::link!("kernel32.dll" "system" fn GetThreadId(thread : HANDLE) -> u32);
 windows_targets::link!("userenv.dll" "system" fn GetUserProfileDirectoryW(htoken : HANDLE, lpprofiledir : PWSTR, lpcchsize : *mut u32) -> BOOL);
 windows_targets::link!("kernel32.dll" "system" fn GetWindowsDirectoryW(lpbuffer : PWSTR, usize : u32) -> u32);
 windows_targets::link!("kernel32.dll" "system" fn InitOnceBeginInitialize(lpinitonce : *mut INIT_ONCE, dwflags : u32, fpending : *mut BOOL, lpcontext : *mut *mut core::ffi::c_void) -> BOOL);

diff --git a/library/std/src/sys/pal/windows/thread.rs b/library/std/src/sys/pal/windows/thread.rs
@@ -129,7 +129,7 @@ impl Thread {
 
 pub(crate) fn current_os_id() -> Option<u64> {
     // SAFETY: FFI call with no preconditions.
-    let id: u32 = unsafe { c::GetThreadId(c::GetCurrentThread()) };
+    let id: u32 = unsafe { c::GetCurrentThreadId() };
 
     // A return value of 0 indicates failed lookup.
     if id == 0 { None } else { Some(id.into()) }

diff --git a/src/bootstrap/Cargo.lock b/src/bootstrap/Cargo.lock
@@ -48,7 +48,6 @@ dependencies = [
  "clap",
  "clap_complete",
  "cmake",
- "fd-lock",
  "home",
  "ignore",
  "insta",
@@ -268,17 +267,6 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
-[[package]]
-name = "fd-lock"
-version = "4.0.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ce92ff622d6dadf7349484f42c93271a0d49b7cc4d466a936405bacbe10aa78"
-dependencies = [
- "cfg-if",
- "rustix",
- "windows-sys 0.59.0",
-]
-
 [[package]]
 name = "filetime"
 version = "0.2.25"
@@ -759,13 +747,12 @@ dependencies = [
 
 [[package]]
 name = "tar"
-version = "0.4.43"
+version = "0.4.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c65998313f8e17d0d553d28f91a0df93e4dbbbf770279c7bc21ca0f09ea1a1f6"
+checksum = "1d863878d212c87a19c1a610eb53bb01fe12951c0501cf5a0d65f724914a667a"
 dependencies = [
  "filetime",
  "libc",
- "xattr",
 ]
 
 [[package]]
@@ -1147,16 +1134,6 @@ dependencies = [
  "bitflags",
 ]
 
-[[package]]
-name = "xattr"
-version = "1.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d65cbf2f12c15564212d48f4e3dfb87923d25d611f2aed18f4cb23f0413d89e"
-dependencies = [
- "libc",
- "rustix",
-]
-
 [[package]]
 name = "xz2"
 version = "0.1.7"

diff --git a/src/bootstrap/Cargo.toml b/src/bootstrap/Cargo.toml
@@ -38,7 +38,6 @@ cmake = "=0.1.54"
 build_helper = { path = "../build_helper" }
 clap = { version = "4.4", default-features = false, features = ["std", "usage", "help", "derive", "error-context"] }
 clap_complete = "4.4"
-fd-lock = "4.0"
 home = "0.5"
 ignore = "0.4"
 libc = "0.2"
@@ -51,7 +50,7 @@ serde = "1.0"
 serde_derive = "1.0"
 serde_json = "1.0"
 sha2 = "0.10"
-tar = "0.4"
+tar = { version = "0.4.44", default-features = false }
 termcolor = "1.4"
 toml = "0.5"
 walkdir = "2.4"

diff --git a/src/bootstrap/src/bin/main.rs b/src/bootstrap/src/bin/main.rs
@@ -5,8 +5,8 @@
 //! parent directory, and otherwise documentation can be found throughout the `build`
 //! directory in each respective module.
 
-use std::fs::{self, OpenOptions};
-use std::io::{self, BufRead, BufReader, IsTerminal, Write};
+use std::fs::{self, OpenOptions, TryLockError};
+use std::io::{self, BufRead, BufReader, IsTerminal, Read, Write};
 use std::path::Path;
 use std::str::FromStr;
 use std::time::Instant;
@@ -39,38 +39,34 @@ fn main() {
     let config = Config::parse(flags);
 
     let mut build_lock;
-    let _build_lock_guard;
 
     if !config.bypass_bootstrap_lock {
         // Display PID of process holding the lock
         // PID will be stored in a lock file
         let lock_path = config.out.join("lock");
-        let pid = fs::read_to_string(&lock_path);
-
-        build_lock = fd_lock::RwLock::new(t!(fs::OpenOptions::new()
+        build_lock = t!(fs::OpenOptions::new()
+            .read(true)
             .write(true)
-            .truncate(true)
             .create(true)
-            .open(&lock_path)));
-        _build_lock_guard = match build_lock.try_write() {
-            Ok(mut lock) => {
-                t!(lock.write(process::id().to_string().as_ref()));
-                lock
+            .truncate(false)
+            .open(&lock_path));
+        t!(build_lock.try_lock().or_else(|e| {
+            if let TryLockError::Error(e) = e {
+                return Err(e);
             }
-            err => {
-                drop(err);
-                // #135972: We can reach this point when the lock has been taken,
-                // but the locker has not yet written its PID to the file
-                if let Some(pid) = pid.ok().filter(|pid| !pid.is_empty()) {
-                    println!("WARNING: build directory locked by process {pid}, waiting for lock");
-                } else {
-                    println!("WARNING: build directory locked, waiting for lock");
-                }
-                let mut lock = t!(build_lock.write());
-                t!(lock.write(process::id().to_string().as_ref()));
-                lock
+            let mut pid = String::new();
+            t!(build_lock.read_to_string(&mut pid));
+            // #135972: We can reach this point when the lock has been taken,
+            // but the locker has not yet written its PID to the file
+            if !pid.is_empty() {
+                println!("WARNING: build directory locked by process {pid}, waiting for lock");
+            } else {
+                println!("WARNING: build directory locked, waiting for lock");
             }
-        };
+            build_lock.lock()
+        }));
+        t!(build_lock.set_len(0));
+        t!(build_lock.write_all(process::id().to_string().as_bytes()));
     }
 
     // check_version warnings are not printed during setup, or during CI