Auto merge of #142234 - matthiaskrgr:rollup-kg5wibu, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #141751 (Remap compiler vs non-compiler sources differently (bootstrap side))
 - #142160 (Only allow `bootstrap` cfg in rustc & related)
 - #142191 (early return in trait detection for non-trait item)
 - #142211 (Do not checkout GCC submodule for the tidy job)
 - #142218 (CI: rfl: move job forward to Linux v6.16-rc1)
 - #142224 (Avoid a gratuitous 10s wait in a stress test)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -3494,7 +3494,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             continue;
                         }
                         trait_in_other_version_found = self
-                            .detect_and_explain_multiple_crate_versions(
+                            .detect_and_explain_multiple_crate_versions_of_trait_item(
                                 err,
                                 pick.item.def_id,
                                 rcvr.hir_id,
@@ -3701,12 +3701,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // same crate.
 
             let rcvr_ty = self.node_ty_opt(ty.hir_id);
-            trait_in_other_version_found = self.detect_and_explain_multiple_crate_versions(
-                err,
-                assoc.def_id,
-                ty.hir_id,
-                rcvr_ty,
-            );
+            trait_in_other_version_found = self
+                .detect_and_explain_multiple_crate_versions_of_trait_item(
+                    err,
+                    assoc.def_id,
+                    ty.hir_id,
+                    rcvr_ty,
+                );
         }
         if !trait_in_other_version_found
             && self.suggest_valid_traits(err, item_name, valid_out_of_scope_traits, true)
@@ -4098,7 +4099,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    fn detect_and_explain_multiple_crate_versions(
+    fn detect_and_explain_multiple_crate_versions_of_trait_item(
         &self,
         err: &mut Diag<'_>,
         item_def_id: DefId,
@@ -4111,6 +4112,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return false;
         }
         let trait_def_id = self.tcx.parent(item_def_id);
+        if !self.tcx.is_trait(trait_def_id) {
+            return false;
+        }
         let krate = self.tcx.crate_name(trait_def_id.krate);
         let name = self.tcx.item_name(trait_def_id);
         let candidates: Vec<_> = traits

library/core/src/iter/sources/generator.rs

@@ -20,7 +20,7 @@
 /// ```
 #[unstable(feature = "iter_macro", issue = "none", reason = "generators are unstable")]
 #[allow_internal_unstable(coroutines, iter_from_coroutine)]
-#[cfg_attr(not(bootstrap), rustc_builtin_macro)]
+#[rustc_builtin_macro]
 pub macro iter($($t:tt)*) {
     /* compiler-builtin */
 }

library/std/tests/sync/mpmc.rs

@@ -462,8 +462,8 @@ fn oneshot_single_thread_recv_timeout() {
 #[test]
 fn stress_recv_timeout_two_threads() {
     let (tx, rx) = channel();
-    let stress = stress_factor() + 100;
-    let timeout = Duration::from_millis(100);
+    let stress = stress_factor() + 50;
+    let timeout = Duration::from_millis(5);
 
     thread::spawn(move || {
         for i in 0..stress {
@@ -475,18 +475,23 @@ fn stress_recv_timeout_two_threads() {
     });
 
     let mut recv_count = 0;
+    let mut got_timeout = false;
     loop {
         match rx.recv_timeout(timeout) {
             Ok(n) => {
                 assert_eq!(n, 1usize);
                 recv_count += 1;
             }
-            Err(RecvTimeoutError::Timeout) => continue,
+            Err(RecvTimeoutError::Timeout) => {
+                got_timeout = true;
+                continue;
+            }
             Err(RecvTimeoutError::Disconnected) => break,
         }
     }
 
     assert_eq!(recv_count, stress);
+    assert!(got_timeout);
 }
 
 #[test]

library/std/tests/sync/mpsc.rs

@@ -425,8 +425,8 @@ fn oneshot_single_thread_recv_timeout() {
 #[test]
 fn stress_recv_timeout_two_threads() {
     let (tx, rx) = channel();
-    let stress = stress_factor() + 100;
-    let timeout = Duration::from_millis(100);
+    let stress = stress_factor() + 50;
+    let timeout = Duration::from_millis(5);
 
     thread::spawn(move || {
         for i in 0..stress {
@@ -438,18 +438,23 @@ fn stress_recv_timeout_two_threads() {
     });
 
     let mut recv_count = 0;
+    let mut got_timeout = false;
     loop {
         match rx.recv_timeout(timeout) {
             Ok(n) => {
                 assert_eq!(n, 1usize);
                 recv_count += 1;
             }
-            Err(RecvTimeoutError::Timeout) => continue,
+            Err(RecvTimeoutError::Timeout) => {
+                got_timeout = true;
+                continue;
+            }
             Err(RecvTimeoutError::Disconnected) => break,
         }
     }
 
     assert_eq!(recv_count, stress);
+    assert!(got_timeout);
 }
 
 #[test]

src/bootstrap/src/core/builder/cargo.rs

@@ -11,7 +11,7 @@ use crate::utils::build_stamp;
 use crate::utils::helpers::{self, LldThreads, check_cfg_arg, linker_args, linker_flags};
 use crate::{
     BootstrapCommand, CLang, Compiler, Config, DocTests, DryRun, EXTRA_CHECK_CFGS, GitRepo, Mode,
-    TargetSelection, command, prepare_behaviour_dump_dir, t,
+    RemapScheme, TargetSelection, command, prepare_behaviour_dump_dir, t,
 };
 
 /// Represents flag values in `String` form with whitespace delimiter to pass it to the compiler
@@ -636,6 +636,15 @@ impl Builder<'_> {
         for (restricted_mode, name, values) in EXTRA_CHECK_CFGS {
             if restricted_mode.is_none() || *restricted_mode == Some(mode) {
                 rustflags.arg(&check_cfg_arg(name, *values));
+
+                if *name == "bootstrap" {
+                    // Cargo doesn't pass RUSTFLAGS to proc_macros:
+                    // https://github.com/rust-lang/cargo/issues/4423
+                    // Thus, if we are on stage 0, we explicitly set `--cfg=bootstrap`.
+                    // We also declare that the flag is expected, which we need to do to not
+                    // get warnings about it being unexpected.
+                    hostflags.arg(check_cfg_arg(name, *values));
+                }
             }
         }
 
@@ -645,13 +654,6 @@ impl Builder<'_> {
         if stage == 0 {
             hostflags.arg("--cfg=bootstrap");
         }
-        // Cargo doesn't pass RUSTFLAGS to proc_macros:
-        // https://github.com/rust-lang/cargo/issues/4423
-        // Thus, if we are on stage 0, we explicitly set `--cfg=bootstrap`.
-        // We also declare that the flag is expected, which we need to do to not
-        // get warnings about it being unexpected.
-        hostflags.arg("-Zunstable-options");
-        hostflags.arg("--check-cfg=cfg(bootstrap)");
 
         // FIXME: It might be better to use the same value for both `RUSTFLAGS` and `RUSTDOCFLAGS`,
         // but this breaks CI. At the very least, stage0 `rustdoc` needs `--cfg bootstrap`. See
@@ -920,13 +922,46 @@ impl Builder<'_> {
             hostflags.arg(format!("-Ctarget-feature={sign}crt-static"));
         }
 
-        if let Some(map_to) = self.build.debuginfo_map_to(GitRepo::Rustc) {
-            let map = format!("{}={}", self.build.src.display(), map_to);
-            cargo.env("RUSTC_DEBUGINFO_MAP", map);
+        // `rustc` needs to know the remapping scheme, in order to know how to reverse it (unremap)
+        // later. Two env vars are set and made available to the compiler
+        //
+        // - `CFG_VIRTUAL_RUST_SOURCE_BASE_DIR`: `rust-src` remap scheme (`NonCompiler`)
+        // - `CFG_VIRTUAL_RUSTC_DEV_SOURCE_BASE_DIR`: `rustc-dev` remap scheme (`Compiler`)
+        //
+        // Keep this scheme in sync with `rustc_metadata::rmeta::decoder`'s
+        // `try_to_translate_virtual_to_real`.
+        //
+        // `RUSTC_DEBUGINFO_MAP` is used to pass through to the underlying rustc
+        // `--remap-path-prefix`.
+        match mode {
+            Mode::Rustc | Mode::Codegen => {
+                if let Some(ref map_to) =
+                    self.build.debuginfo_map_to(GitRepo::Rustc, RemapScheme::NonCompiler)
+                {
+                    cargo.env("CFG_VIRTUAL_RUST_SOURCE_BASE_DIR", map_to);
+                }
 
-            // `rustc` needs to know the virtual `/rustc/$hash` we're mapping to,
-            // in order to opportunistically reverse it later.
-            cargo.env("CFG_VIRTUAL_RUST_SOURCE_BASE_DIR", map_to);
+                if let Some(ref map_to) =
+                    self.build.debuginfo_map_to(GitRepo::Rustc, RemapScheme::Compiler)
+                {
+                    // When building compiler sources, we want to apply the compiler remap scheme.
+                    cargo.env(
+                        "RUSTC_DEBUGINFO_MAP",
+                        format!("{}={}", self.build.src.display(), map_to),
+                    );
+                    cargo.env("CFG_VIRTUAL_RUSTC_DEV_SOURCE_BASE_DIR", map_to);
+                }
+            }
+            Mode::Std | Mode::ToolBootstrap | Mode::ToolRustc | Mode::ToolStd => {
+                if let Some(ref map_to) =
+                    self.build.debuginfo_map_to(GitRepo::Rustc, RemapScheme::NonCompiler)
+                {
+                    cargo.env(
+                        "RUSTC_DEBUGINFO_MAP",
+                        format!("{}={}", self.build.src.display(), map_to),
+                    );
+                }
+            }
         }
 
         if self.config.rust_remap_debuginfo {

src/bootstrap/src/lib.rs

@@ -81,7 +81,10 @@ const LLD_FILE_NAMES: &[&str] = &["ld.lld", "ld64.lld", "lld-link", "wasm-ld"];
 /// (Mode restriction, config name, config values (if any))
 #[expect(clippy::type_complexity)] // It's fine for hard-coded list and type is explained above.
 const EXTRA_CHECK_CFGS: &[(Option<Mode>, &str, Option<&[&'static str]>)] = &[
-    (None, "bootstrap", None),
+    (Some(Mode::Rustc), "bootstrap", None),
+    (Some(Mode::Codegen), "bootstrap", None),
+    (Some(Mode::ToolRustc), "bootstrap", None),
+    (Some(Mode::ToolStd), "bootstrap", None),
     (Some(Mode::Rustc), "llvm_enzyme", None),
     (Some(Mode::Codegen), "llvm_enzyme", None),
     (Some(Mode::ToolRustc), "llvm_enzyme", None),
@@ -272,6 +275,16 @@ impl Mode {
     }
 }
 
+/// When `rust.rust_remap_debuginfo` is requested, the compiler needs to know how to
+/// opportunistically unremap compiler vs non-compiler sources. We use two schemes,
+/// [`RemapScheme::Compiler`] and [`RemapScheme::NonCompiler`].
+pub enum RemapScheme {
+    /// The [`RemapScheme::Compiler`] scheme will remap to `/rustc-dev/{hash}`.
+    Compiler,
+    /// The [`RemapScheme::NonCompiler`] scheme will remap to `/rustc/{hash}`.
+    NonCompiler,
+}
+
 #[derive(Debug, Hash, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 pub enum CLang {
     C,
@@ -1217,15 +1230,32 @@ Executed at: {executed_at}"#,
         })
     }
 
-    fn debuginfo_map_to(&self, which: GitRepo) -> Option<String> {
+    fn debuginfo_map_to(&self, which: GitRepo, remap_scheme: RemapScheme) -> Option<String> {
         if !self.config.rust_remap_debuginfo {
             return None;
         }
 
         match which {
             GitRepo::Rustc => {
                 let sha = self.rust_sha().unwrap_or(&self.version);
-                Some(format!("/rustc/{sha}"))
+
+                match remap_scheme {
+                    RemapScheme::Compiler => {
+                        // For compiler sources, remap via `/rustc-dev/{sha}` to allow
+                        // distinguishing between compiler sources vs library sources, since
+                        // `rustc-dev` dist component places them under
+                        // `$sysroot/lib/rustlib/rustc-src/rust` as opposed to `rust-src`'s
+                        // `$sysroot/lib/rustlib/src/rust`.
+                        //
+                        // Keep this scheme in sync with `rustc_metadata::rmeta::decoder`'s
+                        // `try_to_translate_virtual_to_real`.
+                        Some(format!("/rustc-dev/{sha}"))
+                    }
+                    RemapScheme::NonCompiler => {
+                        // For non-compiler sources, use `/rustc/{sha}` remapping scheme.
+                        Some(format!("/rustc/{sha}"))
+                    }
+                }
             }
             GitRepo::Llvm => Some(String::from("/rustc/llvm")),
         }
@@ -1292,7 +1322,7 @@ Executed at: {executed_at}"#,
             base.push("-fno-omit-frame-pointer".into());
         }
 
-        if let Some(map_to) = self.debuginfo_map_to(which) {
+        if let Some(map_to) = self.debuginfo_map_to(which, RemapScheme::NonCompiler) {
             let map = format!("{}={}", self.src.display(), map_to);
             let cc = self.cc(target);
             if cc.ends_with("clang") || cc.ends_with("gcc") {

src/ci/docker/scripts/rfl-build.sh

@@ -2,8 +2,7 @@
 
 set -euo pipefail
 
-# https://github.com/Rust-for-Linux/linux/issues/1163
-LINUX_VERSION=3ca02fc80cc4fdac63aaa6796642f1e07be591d6
+LINUX_VERSION=v6.16-rc1
 
 # Build rustc, rustdoc, cargo, clippy-driver and rustfmt
 ../x.py build --stage 2 library rustdoc clippy rustfmt

src/ci/github-actions/jobs.yml

@@ -129,6 +129,10 @@ pr:
   - name: mingw-check-tidy
     continue_on_error: true
     free_disk: false
+    env:
+      # This submodule is expensive to checkout, and it should not be needed for
+      # tidy. This speeds up the PR CI job by ~1 minute.
+      SKIP_SUBMODULES: src/gcc
     <<: *job-linux-4c
   - name: x86_64-gnu-llvm-19
     env:

src/ci/scripts/checkout-submodules.sh

@@ -55,7 +55,11 @@ for i in ${!modules[@]}; do
         bg_pids[${i}]=$!
         continue
     else
+      # Submodule paths contained in SKIP_SUBMODULES (comma-separated list) will not be
+      # checked out.
+      if [ -z "${SKIP_SUBMODULES:-}" ] || [[ ! ",$SKIP_SUBMODULES," = *",$module,"* ]]; then
         use_git="$use_git $module"
+      fi
     fi
 done
 retry sh -c "git submodule deinit -f $use_git && \