misc,tests: Split testlib CI Tests to one dir-per-job

This splits the CI Tests to one job per sub-directory in "tests/gem5"
via a matrix.

Advantages:
* We can utilize more runners to run the quick tests. This should mean
  tests run quicker.
* This approach does not require editing of the workflow as more tests
  are added or taken away.
* There is now an output artifact for each directory in "tests/gem5"
  instead of one for the entriety of every quick test in "tests".

In addition:
* The artifact retention for the test outputs has been increased to 30 days.
* The output test artifacts have been renamed to be more descriptive of
  the job, run, attempt, directory run, and the status.
* The 'tar' step has been removed. GitHub's 'action/artifact' can handle
  directories.

Change-Id: I5b3132b424e3769d81d9cd75db2a8c59dbe4a7e5

.github/workflows/ci-tests.yaml

@@ -46,27 +46,6 @@ jobs:
             "curl -Lo $f https://gerrit-review.googlesource.com/tools/hooks/commit-msg ; chmod +x $f\n Then amend the commit with git commit --amend --no-edit, and update your pull request."
           exit 1
 
-  build-gem5:
-    runs-on: [self-hosted, linux, x64, build]
-    if: github.event.pull_request.draft == false
-    container: ghcr.io/gem5/ubuntu-22.04_all-dependencies:latest
-    needs: [pre-commit, check-for-change-id] # only runs if pre-commit and change-id passes
-    outputs:
-      artifactname: ${{ steps.name.outputs.test }}
-    steps:
-      - uses: actions/checkout@v3
-      - id: name
-        run: echo "test=$(date +"%Y-%m-%d_%H.%M.%S")-artifact" >> $GITHUB_OUTPUT
-
-      - name: Build gem5
-        run: |
-          scons build/ALL/gem5.opt -j $(nproc)
-      - uses: actions/upload-artifact@v3
-        with:
-          name: ${{ steps.name.outputs.test }}
-          path: build/ALL/gem5.opt
-      - run: echo "This job's status is ${{ job.status }}."
-
   unittests-all-opt:
     runs-on: [self-hosted, linux, x64, run]
     if: github.event.pull_request.draft == false
@@ -80,39 +59,122 @@ jobs:
         run: scons build/ALL/unittests.opt -j $(nproc)
       - run: echo "This job's status is ${{ job.status }}."
 
-  testlib-quick:
+  testlib-quick-matrix:
+    runs-on: [self-hosted, linux, x64, run]
+    if: github.event.pull_request.draft == false
+    # In order to make sure the environment is exactly the same, we run in
+    # the same container we use to build gem5 and run the testlib tests. This
+    container: ghcr.io/gem5/ubuntu-22.04_all-dependencies:latest
+    needs: [pre-commit, check-for-change-id]
+    steps:
+      - uses: actions/checkout@v3
+
+      # Unfortunately the 'ubunutu-latest' image doesn't have jq installed.
+      # We therefore need to install it as a step here.
+      - name: Install jq
+        run: apt install -y jq
+
+      - name: Get directories for testlib-quick
+        working-directory: "${{ github.workspace }}/tests"
+        id: dir-matrix
+        run: echo "test-dirs-matrix=$(find gem5/* -type d -maxdepth 0 | jq -ncR '[inputs]')" >>$GITHUB_OUTPUT
+
+      - name: Get the build targets for testlib-quick-gem5-builds
+        working-directory: "${{ github.workspace }}/tests"
+        id: build-matrix
+        run: echo "build-matrix=$(./main.py list --build-targets -q | jq -ncR '[inputs]')" >>$GITHUB_OUTPUT
+
+    outputs:
+        build-matrix: ${{ steps.build-matrix.outputs.build-matrix }}
+        test-dirs-matrix: ${{ steps.dir-matrix.outputs.test-dirs-matrix }}
+
+  testlib-quick-gem5-builds:
+    runs-on: [self-hosted, linux, x64, build]
+    if: github.event.pull_request.draft == false
+    container: ghcr.io/gem5/ubuntu-22.04_all-dependencies:latest
+    needs: [pre-commit, check-for-change-id, testlib-quick-matrix]
+    strategy:
+      matrix:
+        build-target: ${{ fromJson(needs.testlib-quick-matrix.outputs.build-matrix) }}
+    steps:
+      - uses: actions/checkout@v3
+      - name: Build gem5
+        run: scons ${{ matrix.build-target }} -j $(nproc)
+
+        # Upload the gem5 binary as an artifact.
+        # Note: the "achor.txt" file is a hack to make sure the paths are
+        # preserverd in the artifact. The upload-artifact action finds the
+        # closest common directory and uploads everything relative to that.
+        # E.g., if we upload "build/ARM/gem5.opt" and "build/RISCV/gem5.opt"
+        # Then upload-artifact will upload "ARM/gem5.opt" and "RISCV/gem5.opt",
+        # stripping the "build" directory. By adding the "anchor.txt" file, we
+        # ensure the "build" directory is preserved.
+      - run: echo "anchor" > anchor.txt
+      - uses: actions/upload-artifact@v3
+        with:
+          name: ci-tests-${{ github.run_number }}-testlib-quick-all-gem5-builds
+          path: |
+            build/*/gem5.*
+            anchor.txt
+          retention-days: 7
+
+  testlib-quick-execution:
     runs-on: [self-hosted, linux, x64, run]
     if: github.event.pull_request.draft == false
     container: ghcr.io/gem5/ubuntu-22.04_all-dependencies:latest
-    needs: [pre-commit, build-gem5, check-for-change-id]
+    needs: [pre-commit, check-for-change-id, testlib-quick-matrix, testlib-quick-gem5-builds]
     timeout-minutes: 360     # 6 hours
+    strategy:
+      fail-fast: false
+      matrix:
+        test-dir: ${{ fromJson(needs.testlib-quick-matrix.outputs.test-dirs-matrix) }}
     steps:
       - name: Clean runner
         run:
           rm -rf ./* || true
           rm -rf ./.??* || true
           rm -rf ~/.cache || true
+
+        # Checkout the repository then download the gem5.opt artifact.
       - uses: actions/checkout@v3
       - uses: actions/download-artifact@v3
         with:
-          name: ${{needs.build-gem5.outputs.artifactname}}
-          path: build/ALL
-      - run: chmod u+x build/ALL/gem5.opt
-      - name: The TestLib CI Tests
-        working-directory: ${{ github.workspace }}/tests
-        run: ./main.py run --skip-build -vv
-      - name: create zip of results
-        if: success() || failure()
+          name: ci-tests-${{ github.run_number }}-testlib-quick-all-gem5-builds
+
+        # Check that the gem5.opt artifact exists and is executable.
+      - name: Chmod gem5.{opt,debug,fast} to be executable
         run: |
-          apt-get -y install zip
-          zip -r output.zip tests/testing-results
-      - name: upload zip
+          find . -name "gem5.opt" -exec chmod u+x {} \;
+          find . -name "gem5.debug" -exec chmod u+x {} \;
+          find . -name "gem5.fast" -exec chmod u+x {} \;
+
+        # Run the testlib quick tests in the given directory.
+      - name: Run "tests/${{ matrix.test-dir }}" TestLib quick tests
+        id: run-tests
+        working-directory: ${{ github.workspace }}/tests
+        run: ./main.py run --skip-build -vv ${{ matrix.test-dir }}
+
+        # Get the basename of the matrix.test-dir path (to name the artifact).
+      - name: Sanatize test-dir for artifact name
+        id: sanitize-test-dir
+        if: success() || failure()
+        run: echo "sanatized-test-dir=$(echo '${{ matrix.test-dir }}' | sed 's/\//-/g')" >> $GITHUB_OUTPUT
+
+        # Upload the tests/testing-results directory as an artifact.
+      - name: Upload test results
         if: success() || failure()
         uses: actions/upload-artifact@v3
-        env:
-          MY_STEP_VAR: ${{github.job}}_COMMIT.${{github.sha}}_RUN.${{github.run_id}}_ATTEMPT.${{github.run_attempt}}
         with:
-          name: ${{ env.MY_STEP_VAR }}
-          path: output.zip
-          retention-days: 7
+          name: ci-tests-run-${{ github.run_number }}-attempt-${{ github.run_attempt }}-testlib-quick-${{ steps.sanitize-test-dir.outputs.sanatized-test-dir }}-status-${{ steps.run-tests.outcome }}-output
+          path: tests/testing-results
+          retention-days: 30
+
+  testlib-quick:
+    # It is 'testlib-quick' which needs to pass for the pull request to be
+    # merged. The 'testlib-quick-execution' is a matrix job which runs all the
+    # the testlib quick tests. This job is therefore a stub which will pass if
+    # all the testlib-quick-execution jobs pass.
+    runs-on: [self-hosted, linux, x64, run]
+    needs: testlib-quick-execution
+    steps:
       - run: echo "This job's status is ${{ job.status }}."