test stage 1 in separate job

src/ci/docker/scripts/x86_64-gnu-llvm.sh

@@ -18,27 +18,6 @@ if [ "$READ_ONLY_SRC" = "0" ]; then
     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
-
-    # Run the `mir-opt` tests again but this time for a 32-bit target.
-    # This enforces that tests using `// EMIT_MIR_FOR_EACH_BIT_WIDTH` have
-    # both 32-bit and 64-bit outputs updated by the PR author, before
-    # the PR is approved and tested for merging.
-    # It will also detect tests lacking `// EMIT_MIR_FOR_EACH_BIT_WIDTH`,
-    # despite having different output on 32-bit vs 64-bit targets.
-    ../x.py --stage 1 test tests/mir-opt --host='' --target=i686-unknown-linux-gnu
-
-    # Run `ui-fulldeps` in `--stage=1`, which actually uses the stage0
-    # compiler, and is sensitive to the addition of new flags.
-    ../x.py --stage 1 test tests/ui-fulldeps
-
-    # Rebuild the stdlib with the size optimizations enabled and run tests again.
-    RUSTFLAGS_NOT_BOOTSTRAP="--cfg feature=\"optimize_for_size\"" ../x.py --stage 1 test \
-        library/std library/alloc library/core
-fi
-
 # NOTE: intentionally uses all of `x.py`, `x`, and `x.ps1` to make sure they all work on Linux.
 ../x.py --stage 2 test --skip src/tools/tidy
 

src/ci/docker/scripts/x86_64-gnu-llvm1.sh

@@ -18,16 +18,6 @@ if [ "$READ_ONLY_SRC" = "0" ]; then
     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 tests \
-      --skip coverage-map \
-      --skip coverage-run \
-      --skip library \
-      --skip tidyselftest
-fi
-
 ../x.py --stage 2 test \
   --skip tests \
   --skip coverage-map \

src/ci/docker/scripts/x86_64-gnu-llvm2.sh

@@ -18,29 +18,6 @@ if [ "$READ_ONLY_SRC" = "0" ]; then
     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 compiler \
-      --skip src
-
-    # Run the `mir-opt` tests again but this time for a 32-bit target.
-    # This enforces that tests using `// EMIT_MIR_FOR_EACH_BIT_WIDTH` have
-    # both 32-bit and 64-bit outputs updated by the PR author, before
-    # the PR is approved and tested for merging.
-    # It will also detect tests lacking `// EMIT_MIR_FOR_EACH_BIT_WIDTH`,
-    # despite having different output on 32-bit vs 64-bit targets.
-    ../x.py --stage 1 test tests/mir-opt --host='' --target=i686-unknown-linux-gnu
-
-    # Run `ui-fulldeps` in `--stage=1`, which actually uses the stage0
-    # compiler, and is sensitive to the addition of new flags.
-    ../x.py --stage 1 test tests/ui-fulldeps
-
-    # Rebuild the stdlib with the size optimizations enabled and run tests again.
-    RUSTFLAGS_NOT_BOOTSTRAP="--cfg feature=\"optimize_for_size\"" ../x.py --stage 1 test \
-        library/std library/alloc library/core
-fi
-
 ../x.py --stage 2 test \
   --skip compiler \
   --skip src

src/ci/docker/scripts/x86_64-gnu-llvm3.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+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
+
+##### Test stage 1 #####
+
+../x.py --stage 1 test --skip src/tools/tidy
+
+# Run the `mir-opt` tests again but this time for a 32-bit target.
+# This enforces that tests using `// EMIT_MIR_FOR_EACH_BIT_WIDTH` have
+# both 32-bit and 64-bit outputs updated by the PR author, before
+# the PR is approved and tested for merging.
+# It will also detect tests lacking `// EMIT_MIR_FOR_EACH_BIT_WIDTH`,
+# despite having different output on 32-bit vs 64-bit targets.
+../x.py --stage 1 test tests/mir-opt --host='' --target=i686-unknown-linux-gnu
+
+# Run `ui-fulldeps` in `--stage=1`, which actually uses the stage0
+# compiler, and is sensitive to the addition of new flags.
+../x.py --stage 1 test tests/ui-fulldeps
+
+# Rebuild the stdlib with the size optimizations enabled and run tests again.
+RUSTFLAGS_NOT_BOOTSTRAP="--cfg feature=\"optimize_for_size\"" ../x.py --stage 1 test \
+    library/std library/alloc library/core

src/ci/github-actions/jobs.yml

@@ -314,24 +314,32 @@ auto:
     <<: *job-linux-8c
 
   # The x86_64-gnu-llvm-19 job is split into multiple jobs to run tests in parallel.
-  # x86_64-gnu-llvm-19-1 skips tests that run in x86_64-gnu-llvm-19-2.
+  # x86_64-gnu-llvm-19-1 skips tests that run in x86_64-gnu-llvm-19-{2,3}.
   - image: x86_64-gnu-llvm-19-1
     env:
       RUST_BACKTRACE: 1
       IMAGE: x86_64-gnu-llvm-19
       DOCKER_SCRIPT: x86_64-gnu-llvm1.sh
     <<: *job-linux-4c
 
-  # Skip tests that run in x86_64-gnu-llvm-19-2
+  # Skip tests that run in x86_64-gnu-llvm-19-{1,3}
   - image: x86_64-gnu-llvm-19-2
     env:
       RUST_BACKTRACE: 1
       IMAGE: x86_64-gnu-llvm-19
       DOCKER_SCRIPT: x86_64-gnu-llvm2.sh
     <<: *job-linux-4c
 
+  # Skip tests that run in x86_64-gnu-llvm-19-{1,2}
+  - image: x86_64-gnu-llvm-19-3
+    env:
+      RUST_BACKTRACE: 1
+      IMAGE: x86_64-gnu-llvm-19
+      DOCKER_SCRIPT: x86_64-gnu-llvm3.sh
+    <<: *job-linux-4c
+
   # The x86_64-gnu-llvm-18 job is split into multiple jobs to run tests in parallel.
-  # x86_64-gnu-llvm-18-1 skips tests that run in x86_64-gnu-llvm-18-2.
+  # x86_64-gnu-llvm-18-1 skips tests that run in x86_64-gnu-llvm-18-{2,3}.
   - image: x86_64-gnu-llvm-18-1
     env:
       RUST_BACKTRACE: 1
@@ -340,7 +348,7 @@ auto:
       DOCKER_SCRIPT: x86_64-gnu-llvm1.sh
     <<: *job-linux-4c
 
-  # Skip tests that run in x86_64-gnu-llvm-18-2
+  # Skip tests that run in x86_64-gnu-llvm-18-{1,3}
   - image: x86_64-gnu-llvm-18-2
     env:
       RUST_BACKTRACE: 1
@@ -349,6 +357,15 @@ auto:
       DOCKER_SCRIPT: x86_64-gnu-llvm2.sh
     <<: *job-linux-4c
 
+  # Skip tests that run in x86_64-gnu-llvm-18-{1,2}
+  - image: x86_64-gnu-llvm-18-3
+    env:
+      RUST_BACKTRACE: 1
+      READ_ONLY_SRC: "0"
+      IMAGE: x86_64-gnu-llvm-18
+      DOCKER_SCRIPT: x86_64-gnu-llvm3.sh
+    <<: *job-linux-4c
+
   - image: x86_64-gnu-nopt
     <<: *job-linux-4c