i#1973 musl: Add CI workflow (#7197)

The workflow constructs an Alpine Linux chroot environment in place and
build DynamoRIO in it, serving as compatibility verification against
musl. Tests are disabled in CI since only half of them pass.

Issue: #1973

.github/workflows/ci-x86.yml

@@ -333,3 +333,84 @@ jobs:
           See more details on github.com/DynamoRIO/dynamorio/actions/runs/${{github.run_id}}
         to: [email protected]
         from: Github Action CI
+
+  # 64-bit Linux build with gcc and musl.
+  # TODO i#1973: Fix failing cases and enable tests in CI.
+  x86-64-alpine-3_21:
+    runs-on: ubuntu-22.04
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: true
+        path: ${{ github.workspace }}/DynamoRIO
+
+    # Cancel any prior runs for a PR (but do not cancel master branch runs).
+    - uses: n1hility/cancel-previous-runs@v2
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+      if: ${{ github.event_name == 'pull_request' }}
+
+    - run: git fetch --no-tags --depth=1 origin master
+      working-directory: ${{ github.workspace }}/DynamoRIO
+
+    # Create an Alpine Linux 3.21.2 chroot environment for building
+    - name: Create Build Environment
+      run: |
+        curl -L https://dl-cdn.alpinelinux.org/v3.21/main/x86_64/apk-tools-static-2.14.6-r2.apk | \
+        tar xzv sbin/apk.static
+
+        sudo mkdir -p alpine-root/etc/apk
+        echo "https://dl-cdn.alpinelinux.org/v3.21/main/" | \
+        sudo tee alpine-root/etc/apk/repositories
+        # Meta-package build-base simplifies dependencies, but it pulls in
+        # fortify-headers. Alpine ships an out-of-date version whose headers
+        # contain unnecessary includes, causing naming conflicts.
+        # TODO i#1973: simplify dependency with build-base after fixing
+        # the compatibility problem.
+        # Supply --allow-untrusted since we're creating a rootfs from scratch
+        # thus don't have any public key available.
+        sudo sbin/apk.static -p alpine-root -U --initdb --allow-untrusted add \
+          alpine-base binutils bash cmake doxygen file g++ git libunwind-dev \
+          lz4-dev lz4-static linux-headers make musl-dev musl-libintl perl \
+          patch xz-dev zlib-dev zlib-static
+
+        cd alpine-root
+        sudo mount -o bind /dev/ dev
+        sudo mount -t proc proc proc
+        sudo mount -t sysfs sys sys
+        sudo mount -o bind ${{ github.workspace }}/DynamoRIO root
+
+    - name: Run Suite
+      working-directory: ${{ github.workspace }}
+      run: |
+        sudo --preserve-env=CI_TRIGGER,CI_BRANCH,DYNAMORIO_MUSL \
+          chroot alpine-root sh -c 'cd &&
+                                    ./suite/runsuite_wrapper.pl automated_ci 64_only'
+      env:
+        DYNAMORIO_MUSL: yes
+        CI_TRIGGER: ${{ github.event_name }}
+        CI_BRANCH: ${{ github.ref }}
+
+    - name: Send failure mail to dynamorio-devs
+      if: failure() && github.ref == 'refs/heads/master'
+      uses: dawidd6/action-send-mail@v2
+      with:
+        server_address: smtp.gmail.com
+        server_port: 465
+        username: ${{secrets.DYNAMORIO_NOTIFICATION_EMAIL_USERNAME}}
+        password: ${{secrets.DYNAMORIO_NOTIFICATION_EMAIL_PASSWORD}}
+        subject: |
+          [${{github.repository}}] ${{github.workflow}} FAILED
+          on ${{github.event_name}} at ${{github.ref}}
+        body: |
+          Github Actions CI workflow run FAILED!
+          Workflow: ${{github.workflow}}/x86-32-ubuntu22
+          Repository: ${{github.repository}}
+          Branch ref: ${{github.ref}}
+          SHA: ${{github.sha}}
+          Triggering actor: ${{github.actor}}
+          Triggering event: ${{github.event_name}}
+          Run Id: ${{github.run_id}}
+          See more details on github.com/DynamoRIO/dynamorio/actions/runs/${{github.run_id}}
+        to: [email protected]
+        from: Github Action CI

suite/runsuite.cmake

@@ -107,9 +107,16 @@ set(build_tests "BUILD_TESTS:BOOL=ON")
 if (arg_automated_ci)
   # XXX i#1801, i#1962: under clang we have several failing tests.  Until those are
   # fixed, our CI clang suite only builds and does not run tests.
-  if (UNIX AND NOT APPLE AND "$ENV{DYNAMORIO_CLANG}" MATCHES "yes")
-    set(run_tests OFF)
-    message("Detected a CI clang suite: disabling running of tests")
+  # TODO i#1973: our musl port passes only half of the tests. Enable tests in CI
+  # when it's ready.
+  if (UNIX AND NOT APPLE)
+    if ("$ENV{DYNAMORIO_CLANG}" MATCHES "yes")
+        set(run_tests OFF)
+        message("Detected a CI clang suite: disabling running of tests")
+    elseif ("$ENV{DYNAMORIO_MUSL}" MATCHES "yes")
+        set(run_tests OFF)
+        message("Detected a CI musl suite: disabling running of tests")
+    endif ()
   endif ()
   if ("$ENV{CI_TARGET}" STREQUAL "package")
     # We don't want flaky tests to derail package deployment.  We've already run