Add CoverageActionsFinishedId to the build_event_stream proto.

With Skymeld, the coverage actions are run _after_ the analysis & execution
phase, since this is the earliest place where we can 1) have the list of analyzed
tests and 2) request for a Skyframe evaluation.

Unfortunately, this means that the info about the coverage artifacts would be
missing in the BEP message triggered by the `TargetCompleteEvents`, which are sent
at the end of the analysis & execution phase.

This CL fixes that by adding an empty `CoverageActionsFinishedId`, which is listed
as a `#postedAfter()` event of `TargetCompleteEvent`. This ensures that all info
regarding the coverage artifacts is availble by the time we convert the
`TargetCompleteEvent` to a BEP message.

PiperOrigin-RevId: 534809359
Change-Id: Iabde183433a8492d9f009e7b235990efe7fc7069

src/main/java/com/google/devtools/build/lib/BUILD

@@ -336,6 +336,7 @@ java_library(
         "//src/main/java/com/google/devtools/build/lib/analysis:provider_collection",
         "//src/main/java/com/google/devtools/build/lib/analysis:server_directories",
         "//src/main/java/com/google/devtools/build/lib/analysis:template_expansion_exception",
+        "//src/main/java/com/google/devtools/build/lib/analysis:test/coverage_action_finished_event",
         "//src/main/java/com/google/devtools/build/lib/analysis:test/coverage_report_action_factory",
         "//src/main/java/com/google/devtools/build/lib/analysis:top_level_artifact_context",
         "//src/main/java/com/google/devtools/build/lib/analysis:transitive_info_collection",

src/main/java/com/google/devtools/build/lib/analysis/BUILD

@@ -2627,6 +2627,16 @@ java_library(
     ],
 )
 
+java_library(
+    name = "test/coverage_action_finished_event",
+    srcs = ["test/CoverageActionFinishedEvent.java"],
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib/buildeventstream",
+        "//src/main/java/com/google/devtools/build/lib/buildeventstream/proto:build_event_stream_java_proto",
+        "//third_party:guava",
+    ],
+)
+
 java_library(
     name = "test/execution_info",
     srcs = ["test/ExecutionInfo.java"],

src/main/java/com/google/devtools/build/lib/analysis/TargetCompleteEvent.java

@@ -151,7 +151,6 @@ private TargetCompleteEvent(
       postedAfterBuilder.add(cause.getIdProto());
     }
     detailedExitCode = mostImportantDetailedExitCode;
-    this.postedAfter = postedAfterBuilder.build();
     this.completionContext = completionContext;
     this.outputs = outputs;
     this.isTest = isTest;
@@ -174,10 +173,12 @@ private TargetCompleteEvent(
           instrumentedFilesProvider.getBaselineCoverageArtifacts();
       if (!baselineCoverageArtifacts.isEmpty()) {
         this.baselineCoverageArtifacts = baselineCoverageArtifacts;
+        postedAfterBuilder.add(BuildEventIdUtil.coverageActionsFinished());
       } else {
         this.baselineCoverageArtifacts = null;
       }
     }
+    this.postedAfter = postedAfterBuilder.build();
     this.tags = targetAndData.getRuleTags();
   }
 

src/main/java/com/google/devtools/build/lib/analysis/test/CoverageActionFinishedEvent.java

@@ -0,0 +1,47 @@
+// Copyright 2023 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.lib.analysis.test;
+
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.buildeventstream.BuildEvent;
+import com.google.devtools.build.lib.buildeventstream.BuildEventContext;
+import com.google.devtools.build.lib.buildeventstream.BuildEventIdUtil;
+import com.google.devtools.build.lib.buildeventstream.BuildEventStreamProtos;
+import com.google.devtools.build.lib.buildeventstream.BuildEventStreamProtos.BuildEventId;
+import com.google.devtools.build.lib.buildeventstream.GenericBuildEvent;
+import java.util.Collection;
+
+/**
+ * Signal that the coverage actions are finished. Only used as a prerequisite for {@link
+ * com.google.devtools.build.lib.analysis.TargetCompleteEvent} in Skymeld mode.
+ */
+public class CoverageActionFinishedEvent implements BuildEvent {
+
+  @Override
+  public BuildEventStreamProtos.BuildEvent asStreamProto(BuildEventContext context)
+      throws InterruptedException {
+    return GenericBuildEvent.protoChaining(this).build();
+  }
+
+  @Override
+  public BuildEventId getEventId() {
+    return BuildEventIdUtil.coverageActionsFinished();
+  }
+
+  @Override
+  public Collection<BuildEventId> getChildrenEvents() {
+    return ImmutableList.of();
+  }
+}

src/main/java/com/google/devtools/build/lib/buildeventstream/BuildEventIdUtil.java

@@ -130,6 +130,12 @@ public static BuildEventId targetConfigured(Label label) {
     return BuildEventId.newBuilder().setTargetConfigured(configuredId).build();
   }
 
+  public static BuildEventId coverageActionsFinished() {
+    return BuildEventId.newBuilder()
+        .setCoverageActionsFinished(BuildEventId.CoverageActionsFinishedId.getDefaultInstance())
+        .build();
+  }
+
   public static BuildEventId aspectConfigured(Label label, String aspect) {
     BuildEventId.TargetConfiguredId configuredId =
         BuildEventId.TargetConfiguredId.newBuilder()

src/main/java/com/google/devtools/build/lib/buildeventstream/proto/build_event_stream.proto

@@ -223,6 +223,9 @@ message BuildEventId {
   // Identifier of an event providing convenience symlinks information.
   message ConvenienceSymlinksIdentifiedId {}
 
+  // Identifier of an event signalling that the coverage actions are finished.
+  message CoverageActionsFinishedId {}
+
   oneof id {
     UnknownBuildEventId unknown = 1;
     ProgressId progress = 2;
@@ -250,6 +253,7 @@ message BuildEventId {
     WorkspaceConfigId workspace = 23;
     BuildMetadataId build_metadata = 24;
     ConvenienceSymlinksIdentifiedId convenience_symlinks_identified = 25;
+    CoverageActionsFinishedId coverage_actions_finished = 27;
   }
 }
 

src/main/java/com/google/devtools/build/lib/buildtool/SkyframeBuilder.java

@@ -30,6 +30,7 @@
 import com.google.devtools.build.lib.actions.TestExecException;
 import com.google.devtools.build.lib.analysis.ConfiguredTarget;
 import com.google.devtools.build.lib.analysis.TopLevelArtifactContext;
+import com.google.devtools.build.lib.analysis.test.CoverageActionFinishedEvent;
 import com.google.devtools.build.lib.analysis.test.TestProvider;
 import com.google.devtools.build.lib.bugreport.BugReporter;
 import com.google.devtools.build.lib.buildtool.buildevent.ExecutionProgressReceiverAvailableEvent;
@@ -119,6 +120,9 @@ public void buildArtifacts(
     skyframeExecutor
         .getEventBus()
         .post(new ExecutionProgressReceiverAvailableEvent(executionProgressReceiver));
+    // When not in Skymeld mode, TargetCompleteEvents don't need to be held back.
+    // See {@link CoverageActionFinishedEvent}.
+    skyframeExecutor.getEventBus().post(new CoverageActionFinishedEvent());
 
     List<DetailedExitCode> detailedExitCodes = new ArrayList<>();
     EvaluationResult<?> result;

src/main/java/com/google/devtools/build/lib/skyframe/BUILD

@@ -265,6 +265,7 @@ java_library(
         "//src/main/java/com/google/devtools/build/lib/analysis:target_and_configuration",
         "//src/main/java/com/google/devtools/build/lib/analysis:template_expansion_exception",
         "//src/main/java/com/google/devtools/build/lib/analysis:test/analysis_failure_propagation_exception",
+        "//src/main/java/com/google/devtools/build/lib/analysis:test/coverage_action_finished_event",
         "//src/main/java/com/google/devtools/build/lib/analysis:toolchain_collection",
         "//src/main/java/com/google/devtools/build/lib/analysis:toolchain_context",
         "//src/main/java/com/google/devtools/build/lib/analysis:top_level_artifact_context",

src/main/java/com/google/devtools/build/lib/skyframe/SkyframeBuildView.java

@@ -66,6 +66,7 @@
 import com.google.devtools.build.lib.analysis.config.ConfigConditions;
 import com.google.devtools.build.lib.analysis.config.StarlarkTransitionCache;
 import com.google.devtools.build.lib.analysis.test.AnalysisFailurePropagationException;
+import com.google.devtools.build.lib.analysis.test.CoverageActionFinishedEvent;
 import com.google.devtools.build.lib.bugreport.BugReport;
 import com.google.devtools.build.lib.bugreport.BugReporter;
 import com.google.devtools.build.lib.buildeventstream.BuildEventStreamProtos.BuildMetrics.BuildGraphMetrics;
@@ -660,6 +661,7 @@ public SkyframeAnalysisResult analyzeAndExecuteTargets(
                           buildResultListener.getAnalyzedTargets(),
                           buildResultListener.getAnalyzedTests())),
                   keepGoing);
+          eventBus.post(new CoverageActionFinishedEvent());
           if (additionalArtifactsResult.hasError()) {
             detailedExitCodes.add(
                 SkyframeErrorProcessor.processErrors(