Move ASan CI job to reusable-san.yml

This refactors the CI configuration for ASan to deduplicate some logic,
and bring it together with the other sanitzers.

As a sideeffect, it will also run `--with-pydebug` and build with the
Clang compiler.

Author: StanFromIreland

.github/workflows/build.yml

@@ -481,53 +481,6 @@ jobs:
     if: fromJSON(needs.build-context.outputs.run-tests)
     uses: ./.github/workflows/reusable-test-lazy-imports-all.yml
 
-  build-asan:
-    name: 'Address sanitizer'
-    runs-on: ${{ matrix.os }}
-    timeout-minutes: 60
-    needs: build-context
-    if: needs.build-context.outputs.run-ubuntu == 'true'
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-26.04]
-    env:
-      OPENSSL_VER: 3.5.9
-      PYTHONSTRICTEXTENSIONBUILD: 1
-      ASAN_OPTIONS: detect_leaks=0:allocator_may_return_null=1:handle_segv=0
-    steps:
-    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-      with:
-        persist-credentials: false
-    - name: Runner image version
-      run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
-    - name: Register gcc problem matcher
-      run: echo "::add-matcher::.github/problem-matchers/gcc.json"
-    - name: Install dependencies
-      run: sudo ./.github/workflows/posix-deps-apt.sh
-    - name: Configure OpenSSL env vars
-      run: |
-        echo "MULTISSL_DIR=${GITHUB_WORKSPACE}/multissl" >> "$GITHUB_ENV"
-        echo "OPENSSL_DIR=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}" >> "$GITHUB_ENV"
-        echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> "$GITHUB_ENV"
-    - name: 'Restore OpenSSL build'
-      id: cache-openssl
-      uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
-      with:
-        path: ./multissl/openssl/${{ env.OPENSSL_VER }}
-        key: ${{ matrix.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
-    - name: Install OpenSSL
-      if: steps.cache-openssl.outputs.cache-hit != 'true'
-      run: python3 Tools/ssl/multissltests.py --steps=library --base-directory "$MULTISSL_DIR" --openssl "$OPENSSL_VER" --system Linux
-    - name: Configure CPython
-      run: ./configure --config-cache --with-address-sanitizer --without-pymalloc --with-openssl="$OPENSSL_DIR"
-    - name: Build CPython
-      run: make -j4
-    - name: Display build info
-      run: make pythoninfo
-    - name: Tests
-      run: xvfb-run make ci
-
   build-san:
     # ${{ '' } is a hack to nest jobs under the same sidebar category.
     name: Sanitizers${{ '' }}  # zizmor: ignore[obfuscation]
@@ -544,6 +497,9 @@ jobs:
         sanitizer:
         - TSan
         include:
+        - check-name: Address
+          sanitizer: ASan
+          free-threading: false
         - check-name: Undefined behavior
           sanitizer: UBSan
           free-threading: false
@@ -657,7 +613,6 @@ jobs:
     - build-wasi
     - test-hypothesis
     - test-lazy-imports-all
-    - build-asan
     - build-san
     - cross-build-linux
     - cifuzz
@@ -704,7 +659,6 @@ jobs:
             build-ubuntu-installed,
             build-ubuntu-ssltests,
             test-hypothesis,
-            build-asan,
             build-san,
             cross-build-linux,
             '

.github/workflows/reusable-san.yml

@@ -43,6 +43,15 @@ jobs:
         # please update the versions in `Tools/pixi-packages/variants.yaml` too.
         echo "CC=clang" >> "$GITHUB_ENV"
         echo "CXX=clang++" >> "$GITHUB_ENV"
+    - name: ASan option setup
+      if: inputs.sanitizer == 'ASan'
+      run: |
+        echo "MULTISSL_DIR=${GITHUB_WORKSPACE}/multissl" >> "$GITHUB_ENV"
+        echo "OPENSSL_DIR=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}" >> "$GITHUB_ENV"
+        echo "ASAN_OPTIONS=${SAN_LOG_OPTION} detect_leaks=0 allocator_may_return_null=1 handle_segv=0" >> "$GITHUB_ENV"
+        echo "PYTHONSTRICTEXTENSIONBUILD=1" >> "$GITHUB_ENV"
+      env:
+        SAN_LOG_OPTION: log_path=${{ github.workspace }}/san_log
     - name: TSan option setup
       if: inputs.sanitizer == 'TSan'
       run: |
@@ -88,24 +97,27 @@ jobs:
     - name: Add ccache to PATH
       run: |
         echo "PATH=/usr/lib/ccache:$PATH" >> "$GITHUB_ENV"
-    - name: 'Restore OpenSSL build (TSan)'
+    - name: 'Restore OpenSSL build'
       id: cache-openssl
-      if: inputs.sanitizer == 'TSan'
+      if: inputs.sanitizer == 'TSan' || inputs.sanitizer == 'ASan'
       uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
       with:
         path: ./multissl/openssl/${{ env.OPENSSL_VER }}
-        key: ${{ env.IMAGE_OS_VERSION }}-multissl-openssl-tsan-${{ env.OPENSSL_VER }}
-    - name: Install OpenSSL (TSan)
+        key: >-
+          ${{ env.IMAGE_OS_VERSION }}-multissl-openssl-${{
+            inputs.sanitizer == 'TSan' && 'tsan-' || ''
+          }}${{ env.OPENSSL_VER }}
+    - name: Install OpenSSL
       if: >-
-        inputs.sanitizer == 'TSan'
+        (inputs.sanitizer == 'TSan' || inputs.sanitizer == 'ASan')
         && steps.cache-openssl.outputs.cache-hit != 'true'
       run: >-
         python3 Tools/ssl/multissltests.py
         --steps=library
         --base-directory="${MULTISSL_DIR}"
         --openssl="${OPENSSL_VER}"
         --system=Linux
-        --tsan
+        ${{ inputs.sanitizer == 'TSan' && '--tsan' || '' }}
     # gh-157958: -O2 instead of the pydebug default -Og to avoid a clang 21
     # compile-time blowup on some interpreter files.
     # (https://github.com/llvm/llvm-project/issues/179695)
@@ -117,14 +129,20 @@ jobs:
         --config-cache
         OPT="-O2 -g"
         ${{
-          inputs.sanitizer == 'TSan'
+          inputs.sanitizer == 'ASan'
+          && '--with-address-sanitizer --without-pymalloc'
+          || inputs.sanitizer == 'TSan'
           && '--with-thread-sanitizer'
           || inputs.sanitizer == 'MSan'
           && '--with-memory-sanitizer'
           || '--with-undefined-behavior-sanitizer --with-strict-overflow'
         }}
         ${{ inputs.sanitizer == 'MSan' && '--with-assertions' || '--with-pydebug' }}
-        ${{ inputs.sanitizer == 'TSan' && '--with-openssl="$OPENSSL_DIR" --with-openssl-rpath=auto' || '' }}
+        ${{
+          (inputs.sanitizer == 'TSan' || inputs.sanitizer == 'ASan')
+          && '--with-openssl="$OPENSSL_DIR" --with-openssl-rpath=auto'
+          || ''
+        }}
         ${{ inputs.free-threading && '--disable-gil' || '' }}
     - name: Build CPython
       run: make -j4