[3.14] Forward-port 'check-abi' CI job from 3.13

.github/workflows/build.yml

@@ -43,6 +43,53 @@ jobs:
     if: fromJSON(needs.build-context.outputs.run-docs)
     uses: ./.github/workflows/reusable-docs.yml
 
+  check-abi:
+    name: 'Check if the ABI has changed'
+    runs-on: ubuntu-22.04  # 24.04 causes spurious errors
+    needs: build-context
+    if: needs.build-context.outputs.run-tests == 'true'
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
+      - name: Install dependencies
+        run: |
+            sudo ./.github/workflows/posix-deps-apt.sh
+            sudo apt-get install -yq abigail-tools
+      - name: Build CPython
+        env:
+          CFLAGS: -g3 -O0
+        run: |
+          # Build Python with the libpython dynamic library
+          ./configure --enable-shared
+          make -j4
+      - name: Check for changes in the ABI
+        id: check
+        run: |
+          if ! make check-abidump; then
+            echo "Generated ABI file is not up to date."
+            echo "Please add the release manager of this branch as a reviewer of this PR."
+            echo ""
+            echo "The up to date ABI file should be attached to this build as an artifact."
+            echo ""
+            echo "To learn more about this check: https://devguide.python.org/getting-started/setup-building/index.html#regenerate-the-abi-dump"
+            echo ""
+            exit 1
+          fi
+      - name: Generate updated ABI files
+        if: ${{ failure() && steps.check.conclusion == 'failure' }}
+        run: |
+          make regen-abidump
+      - uses: actions/upload-artifact@v4
+        name: Publish updated ABI files
+        if: ${{ failure() && steps.check.conclusion == 'failure' }}
+        with:
+          name: abi-data
+          path: ./Doc/data/*.abi
+
   check-autoconf-regen:
     name: 'Check if Autoconf files are up to date'
     # Don't use ubuntu-latest but a specific version to make the job

.gitignore

@@ -170,6 +170,3 @@ Python/frozen_modules/MANIFEST
 # Ignore ./python binary on Unix but still look into ./Python/ directory.
 /python
 !/Python/
-
-# main branch only: ABI files are not checked/maintained.
-Doc/data/python*.abi