ci: report skipped membrowse targets as identical

2 files changed, 56 insertions, 4 deletions

diff --git a/.github/workflows/membrowse-report.yml b/.github/workflows/membrowse-report.yml
index 79c88db841..d7877e6058 100644
--- a/.github/workflows/membrowse-report.yml
+++ b/.github/workflows/membrowse-report.yml
@@ -42,6 +42,8 @@ jobs:
     outputs:
       matrix: ${{ steps.set-matrix.outputs.matrix }}
       target_count: ${{ steps.set-matrix.outputs.target_count }}
+      skipped_matrix: ${{ steps.set-matrix.outputs.skipped_matrix }}
+      skipped_count: ${{ steps.set-matrix.outputs.skipped_count }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v5
@@ -177,3 +179,38 @@ jobs:
           verbose: INFO
           # Uncomment to allow CI to pass even when memory budgets are exceeded
           # dont_fail_on_alerts: true
+
+  # Targets not affected by this push are not rebuilt, but their binaries are
+  # unchanged. Report them as identical (metadata-only, no build) so every
+  # target keeps an unbroken per-commit chain instead of a hole on each commit
+  # that only touched other BSPs. Only runs on push to master; PRs are transient
+  # and keep the build-affected-only behavior above.
+  mark-identical:
+    needs: load-targets
+    if: ${{ github.event_name == 'push' && needs.load-targets.outputs.skipped_count != '0' }}
+    runs-on: ubuntu-22.04
+    strategy:
+      fail-fast: false
+      matrix:
+        include: ${{ fromJson(needs.load-targets.outputs.skipped_matrix) }}
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+
+      - name: Mark MemBrowse report identical
+        # Non-fatal: an identical upload needs the parent commit to already have
+        # a report for this target. Right after adoption some parents predate
+        # this job and the upload is rejected; it self-heals once the target is
+        # next built (a full report needs no parent) and every later commit is
+        # covered. Don't fail the run over that transient window.
+        continue-on-error: true
+        uses: membrowse/membrowse-action@v1
+        with:
+          target_name: ${{ matrix.target_name }}
+          identical: true
+          api_key: ${{ secrets.MEMBROWSE_API_KEY }}
+          api_url: ${{ vars.MEMBROWSE_API_URL }}
+          verbose: INFO
diff --git a/tools/ci/membrowse_filter_targets.py b/tools/ci/membrowse_filter_targets.py
index 626adade8e..67afa71f78 100644
--- a/tools/ci/membrowse_filter_targets.py
+++ b/tools/ci/membrowse_filter_targets.py
@@ -79,13 +79,20 @@ def select_targets(targets, changed_files):
     return selected
 
 
-def write_github_output(matrix, output_path):
+def skipped_targets(targets, selected_targets):
+    selected_names = {target["target_name"] for target in selected_targets}
+    return [target for target in targets if target["target_name"] not in selected_names]
+
+
+def write_github_output(selected, skipped, output_path):
     if not output_path:
         return
 
     with open(output_path, "a", encoding="utf-8") as output:
-        output.write("matrix={}\n".format(json.dumps(matrix, separators=(",", ":"))))
-        output.write("target_count={}\n".format(len(matrix)))
+        output.write("matrix={}\n".format(json.dumps(selected, separators=(",", ":"))))
+        output.write("target_count={}\n".format(len(selected)))
+        output.write("skipped_matrix={}\n".format(json.dumps(skipped, separators=(",", ":"))))
+        output.write("skipped_count={}\n".format(len(skipped)))
 
 
 def main():
@@ -99,6 +106,10 @@ def main():
 
     changed_files = read_changed_files(args.changed_files)
     selected_targets = select_targets(targets, changed_files)
+    # Targets not affected by this change are built by nobody, but their
+    # binaries are unchanged, so they are reported as identical (metadata-only)
+    # to keep every target's per-commit chain unbroken. See membrowse-report.yml.
+    unselected_targets = skipped_targets(targets, selected_targets)
 
     print("Changed files:")
     for changed_file in changed_files:
@@ -108,8 +119,12 @@ def main():
     for target in selected_targets:
         print("  {}".format(target["target_name"]))
 
+    print("Skipped MemBrowse targets (reported as identical):")
+    for target in unselected_targets:
+        print("  {}".format(target["target_name"]))
+
     print("Selected {}/{} MemBrowse targets".format(len(selected_targets), len(targets)))
-    write_github_output(selected_targets, os.getenv("GITHUB_OUTPUT"))
+    write_github_output(selected_targets, unselected_targets, os.getenv("GITHUB_OUTPUT"))
 
 
 if __name__ == "__main__":