Auto merge of #18317 - lnicola:sync-from-rust, r=Veykril

minor: sync from downstream

14 files changed, 112 insertions, 15 deletions

diff --git a/src/ci/docker/host-x86_64/dist-loongarch64-linux/Dockerfile b/src/ci/docker/host-x86_64/dist-loongarch64-linux/Dockerfile
index 865a9e32fa9..71eb72686b0 100644
--- a/src/ci/docker/host-x86_64/dist-loongarch64-linux/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-loongarch64-linux/Dockerfile
@@ -47,6 +47,7 @@ ENV RUST_CONFIGURE_ARGS \
       --enable-extended \
       --enable-full-tools \
       --enable-profiler \
+      --enable-sanitizers \
       --disable-docs
 
 ENV SCRIPT python3 ../x.py dist --host $HOSTS --target $TARGETS
diff --git a/src/ci/docker/host-x86_64/dist-loongarch64-musl/Dockerfile b/src/ci/docker/host-x86_64/dist-loongarch64-musl/Dockerfile
index 62dbfaaa673..5081f25e567 100644
--- a/src/ci/docker/host-x86_64/dist-loongarch64-musl/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-loongarch64-musl/Dockerfile
@@ -29,6 +29,7 @@ ENV RUST_CONFIGURE_ARGS \
       --enable-extended \
       --enable-full-tools \
       --enable-profiler \
+      --enable-sanitizers \
       --disable-docs \
       --set target.loongarch64-unknown-linux-musl.crt-static=false \
       --musl-root-loongarch64=/x-tools/loongarch64-unknown-linux-musl/loongarch64-unknown-linux-musl/sysroot/usr
diff --git a/src/ci/docker/host-x86_64/mingw-check/Dockerfile b/src/ci/docker/host-x86_64/mingw-check/Dockerfile
index 571378774be..0f8ebb987c3 100644
--- a/src/ci/docker/host-x86_64/mingw-check/Dockerfile
+++ b/src/ci/docker/host-x86_64/mingw-check/Dockerfile
@@ -46,7 +46,8 @@ ENV RUN_CHECK_WITH_PARALLEL_QUERIES 1
 # Check library crates on all tier 1 targets.
 # We disable optimized compiler built-ins because that requires a C toolchain for the target.
 # We also skip the x86_64-unknown-linux-gnu target as it is well-tested by other jobs.
-ENV SCRIPT python3 ../x.py check --stage 0 --set build.optimized-compiler-builtins=false core alloc std --target=aarch64-unknown-linux-gnu,i686-pc-windows-msvc,i686-unknown-linux-gnu,x86_64-apple-darwin,x86_64-pc-windows-gnu,x86_64-pc-windows-msvc && \
+ENV SCRIPT \
+           python3 ../x.py check --stage 0 --set build.optimized-compiler-builtins=false core alloc std --target=aarch64-unknown-linux-gnu,i686-pc-windows-msvc,i686-unknown-linux-gnu,x86_64-apple-darwin,x86_64-pc-windows-gnu,x86_64-pc-windows-msvc && \
            /scripts/check-default-config-profiles.sh && \
            python3 ../x.py check --target=i686-pc-windows-gnu --host=i686-pc-windows-gnu && \
            python3 ../x.py clippy bootstrap -Dwarnings && \
diff --git a/src/ci/docker/host-x86_64/x86_64-fuchsia/Dockerfile b/src/ci/docker/host-x86_64/x86_64-fuchsia/Dockerfile
index ba3e8bdb687..0cae83a85b3 100644
--- a/src/ci/docker/host-x86_64/x86_64-fuchsia/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-fuchsia/Dockerfile
@@ -58,6 +58,9 @@ RUN mkdir -p $RUST_INSTALL_DIR/etc
 # Fuchsia only supports LLVM.
 ENV CODEGEN_BACKENDS llvm
 
+# download-rustc is not allowed for `x install`
+ENV NO_DOWNLOAD_CI_RUSTC 1
+
 ENV RUST_CONFIGURE_ARGS \
   --prefix=$RUST_INSTALL_DIR \
   --sysconfdir=etc \
@@ -70,6 +73,7 @@ ENV RUST_CONFIGURE_ARGS \
   --set target.x86_64-unknown-fuchsia.ar=/usr/local/bin/llvm-ar \
   --set target.x86_64-unknown-fuchsia.ranlib=/usr/local/bin/llvm-ranlib \
   --set target.x86_64-unknown-fuchsia.linker=/usr/local/bin/ld.lld
+
 ENV SCRIPT \
     python3 ../x.py install --target $TARGETS compiler/rustc library/std clippy && \
     bash ../src/ci/docker/host-x86_64/x86_64-fuchsia/build-fuchsia.sh
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile
index 145f41f21e1..17fc1a57492 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile
@@ -84,6 +84,7 @@ ENV RUST_CONFIGURE_ARGS \
   --enable-new-symbol-mangling
 
 ENV HOST_TARGET x86_64-unknown-linux-gnu
+ENV FORCE_CI_RUSTC 1
 
 COPY host-x86_64/dist-x86_64-linux/shared.sh /scripts/
 COPY host-x86_64/dist-x86_64-linux/build-gccjit.sh /scripts/
diff --git a/src/ci/docker/run.sh b/src/ci/docker/run.sh
index fad4b5af095..28487bce482 100755
--- a/src/ci/docker/run.sh
+++ b/src/ci/docker/run.sh
@@ -343,6 +343,7 @@ docker \
   --env PR_CI_JOB \
   --env OBJDIR_ON_HOST="$objdir" \
   --env CODEGEN_BACKENDS \
+  --env DISABLE_CI_RUSTC_IF_INCOMPATIBLE="$DISABLE_CI_RUSTC_IF_INCOMPATIBLE" \
   --init \
   --rm \
   rust-ci \
diff --git a/src/ci/docker/scripts/emscripten.sh b/src/ci/docker/scripts/emscripten.sh
index 3f5e2c6ff1d..8b2b39ee162 100644
--- a/src/ci/docker/scripts/emscripten.sh
+++ b/src/ci/docker/scripts/emscripten.sh
@@ -20,5 +20,5 @@ exit 1
 
 git clone https://github.com/emscripten-core/emsdk.git /emsdk-portable
 cd /emsdk-portable
-hide_output ./emsdk install 2.0.5
-./emsdk activate 2.0.5
+hide_output ./emsdk install 3.1.68
+./emsdk activate 3.1.68
diff --git a/src/ci/docker/scripts/fuchsia-test-runner.py b/src/ci/docker/scripts/fuchsia-test-runner.py
index a5458b8645d..1aa9a4a1794 100755
--- a/src/ci/docker/scripts/fuchsia-test-runner.py
+++ b/src/ci/docker/scripts/fuchsia-test-runner.py
@@ -193,18 +193,38 @@ class TestEnvironment:
             stderr=subprocess.STDOUT,
         )
         if process.returncode:
-            self.env_logger.error(
-                f"llvm-readelf failed for binary {binary} with output {process.stdout}"
+            e = f"llvm-readelf failed for binary {binary} with output {process.stdout}"
+            self.env_logger.error(e)
+            raise Exception(e)
+
+        try:
+            elf_output = json.loads(process.stdout)
+        except Exception as e:
+            e.add_note(f"Failed to read JSON from llvm-readelf for binary {binary}")
+            e.add_note(f"stdout: {process.stdout}")
+            raise
+
+        try:
+            note_sections = elf_output[0]["NoteSections"]
+        except Exception as e:
+            e.add_note(
+                f'Failed to read "NoteSections" from llvm-readelf for binary {binary}'
             )
-            raise Exception(f"Unreadable build-id for binary {binary}")
-        data = json.loads(process.stdout)
-        if len(data) != 1:
-            raise Exception(f"Unreadable output from llvm-readelf for binary {binary}")
-        notes = data[0]["Notes"]
-        for note in notes:
-            note_section = note["NoteSection"]
-            if note_section["Name"] == ".note.gnu.build-id":
-                return note_section["Note"]["Build ID"]
+            e.add_note(f"elf_output: {elf_output}")
+            raise
+
+        for entry in note_sections:
+            try:
+                note_section = entry["NoteSection"]
+                if note_section["Name"] == ".note.gnu.build-id":
+                    return note_section["Notes"][0]["Build ID"]
+            except Exception as e:
+                e.add_note(
+                    f'Failed to read ".note.gnu.build-id" from NoteSections \
+                        entry in llvm-readelf for binary {binary}'
+                )
+                e.add_note(f"NoteSections: {note_sections}")
+                raise
         raise Exception(f"Build ID not found for binary {binary}")
 
     def generate_buildid_dir(
diff --git a/src/ci/docker/scripts/rfl-build.sh b/src/ci/docker/scripts/rfl-build.sh
index 8011e07e92e..27dbfc6040c 100755
--- a/src/ci/docker/scripts/rfl-build.sh
+++ b/src/ci/docker/scripts/rfl-build.sh
@@ -2,7 +2,7 @@
 
 set -euo pipefail
 
-LINUX_VERSION=4c7864e81d8bbd51036dacf92fb0a400e13aaeee
+LINUX_VERSION=v6.12-rc2
 
 # Build rustc, rustdoc, cargo, clippy-driver and rustfmt
 ../x.py build --stage 2 library rustdoc clippy rustfmt
diff --git a/src/ci/docker/scripts/x86_64-gnu-llvm.sh b/src/ci/docker/scripts/x86_64-gnu-llvm.sh
index 98290f5a72c..dea38b6fd2a 100755
--- a/src/ci/docker/scripts/x86_64-gnu-llvm.sh
+++ b/src/ci/docker/scripts/x86_64-gnu-llvm.sh
@@ -2,6 +2,22 @@
 
 set -ex
 
+if [ "$READ_ONLY_SRC" = "0" ]; then
+    # `core::builder::tests::ci_rustc_if_unchanged_logic` bootstrap test ensures that
+    # "download-rustc=if-unchanged" logic don't use CI rustc while there are changes on
+    # compiler and/or library. Here we are adding a dummy commit on compiler and running
+    # that test to make sure we never download CI rustc with a change on the compiler tree.
+    echo "" >> ../compiler/rustc/src/main.rs
+    git config --global user.email "dummy@dummy.com"
+    git config --global user.name "dummy"
+    git add ../compiler/rustc/src/main.rs
+    git commit -m "test commit for rust.download-rustc=if-unchanged logic"
+    DISABLE_CI_RUSTC_IF_INCOMPATIBLE=0 ../x.py test bootstrap \
+        -- core::builder::tests::ci_rustc_if_unchanged_logic
+    # Revert the dummy commit
+    git reset --hard HEAD~1
+fi
+
 # Only run the stage 1 tests on merges, not on PR CI jobs.
 if [[ -z "${PR_CI_JOB}" ]]; then
     ../x.py --stage 1 test --skip src/tools/tidy
diff --git a/src/ci/github-actions/jobs.yml b/src/ci/github-actions/jobs.yml
index 6379f1ade1c..8f49f623afa 100644
--- a/src/ci/github-actions/jobs.yml
+++ b/src/ci/github-actions/jobs.yml
@@ -92,6 +92,8 @@ pr:
   - image: x86_64-gnu-llvm-18
     env:
       ENABLE_GCC_CODEGEN: "1"
+      # We are adding (temporarily) a dummy commit on the compiler
+      READ_ONLY_SRC: "0"
     <<: *job-linux-16c
   - image: x86_64-gnu-tools
     <<: *job-linux-16c
@@ -259,6 +261,7 @@ auto:
   - image: x86_64-gnu-llvm-18
     env:
       RUST_BACKTRACE: 1
+      READ_ONLY_SRC: "0"
     <<: *job-linux-8c
 
   - image: x86_64-gnu-nopt
diff --git a/src/ci/run.sh b/src/ci/run.sh
index c8201d9bcfd..3962c354c10 100755
--- a/src/ci/run.sh
+++ b/src/ci/run.sh
@@ -52,6 +52,13 @@ if [ "$CI" != "" ]; then
     RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set change-id=99999999"
 fi
 
+# If runner uses an incompatible option and `FORCE_CI_RUSTC` is not defined,
+# switch to in-tree rustc.
+if [ "$FORCE_CI_RUSTC" == "" ]; then
+    echo 'debug: `DISABLE_CI_RUSTC_IF_INCOMPATIBLE` configured.'
+    DISABLE_CI_RUSTC_IF_INCOMPATIBLE=1
+fi
+
 if ! isCI || isCiBranch auto || isCiBranch beta || isCiBranch try || isCiBranch try-perf || \
   isCiBranch automation/bors/try; then
     RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set build.print-step-timings --enable-verbose-tests"
@@ -169,10 +176,16 @@ else
   if [ "$NO_DOWNLOAD_CI_LLVM" = "" ]; then
     RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set llvm.download-ci-llvm=if-unchanged"
   else
+    # CI rustc requires CI LLVM to be enabled (see https://github.com/rust-lang/rust/issues/123586).
+    NO_DOWNLOAD_CI_RUSTC=1
     # When building for CI we want to use the static C++ Standard library
     # included with LLVM, since a dynamic libstdcpp may not be available.
     RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set llvm.static-libstdcpp"
   fi
+
+  if [ "$NO_DOWNLOAD_CI_RUSTC" = "" ]; then
+    RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set rust.download-rustc=if-unchanged"
+  fi
 fi
 
 if [ "$ENABLE_GCC_CODEGEN" = "1" ]; then
diff --git a/src/ci/scripts/setup-upstream-remote.sh b/src/ci/scripts/setup-upstream-remote.sh
new file mode 100755
index 00000000000..52b4c98a890
--- /dev/null
+++ b/src/ci/scripts/setup-upstream-remote.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+# In CI environments, bootstrap is forced to use the remote upstream based
+# on "git_repository" and "nightly_branch" values from src/stage0 file.
+# This script configures the remote as it may not exist by default.
+
+set -euo pipefail
+IFS=$'\n\t'
+
+ci_dir=$(cd $(dirname $0) && pwd)/..
+source "$ci_dir/shared.sh"
+
+git_repository=$(parse_stage0_file_by_key "git_repository")
+nightly_branch=$(parse_stage0_file_by_key "nightly_branch")
+
+# Configure "rust-lang/rust" upstream remote only when it's not origin.
+if [ -z "$(git config remote.origin.url | grep $git_repository)" ]; then
+    echo "Configuring https://github.com/$git_repository remote as upstream."
+    git remote add upstream "https://github.com/$git_repository"
+    REMOTE_NAME="upstream"
+else
+    REMOTE_NAME="origin"
+fi
+
+git fetch $REMOTE_NAME $nightly_branch
diff --git a/src/ci/shared.sh b/src/ci/shared.sh
index 2b0a10e4d08..1e6a008a5de 100644
--- a/src/ci/shared.sh
+++ b/src/ci/shared.sh
@@ -136,3 +136,15 @@ function releaseChannel {
         echo $RUST_CI_OVERRIDE_RELEASE_CHANNEL
     fi
 }
+
+# Parse values from src/stage0 file by key
+function parse_stage0_file_by_key {
+    local key="$1"
+    local file="$ci_dir/../stage0"
+    local value=$(awk -F= '{a[$1]=$2} END {print(a["'$key'"])}' $file)
+    if [ -z "$value" ]; then
+        echo "ERROR: Key '$key' not found in '$file'."
+        exit 1
+    fi
+    echo "$value"
+}