Report completion of a target together with failed actions

Report the completion of all targets together with the root causes on the build
event stream. To do so, have TargetCompleteEvent and ActionExecutedEvent be
instances of BuildEvent; however, ignore an ActionExecutedEvent in the
BuildEventStreamer if the execution was successful.

By this change we get, for the first time, a build event stream that is naturally
closed, i.e., without Aborted events closing up lose ends. Add a test asserting
this property.

--
Change-Id: Ie90dd52ee80deb0fdabdce1da551935522880a1a
Reviewed-on: https://bazel-review.googlesource.com/#/c/6279
MOS_MIGRATED_REVID=137273002

1 files changed, 8 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BuildEventStreamer.java b/src/main/java/com/google/devtools/build/lib/runtime/BuildEventStreamer.java
index 6329d41676..819e2f3c32 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BuildEventStreamer.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BuildEventStreamer.java
@@ -16,6 +16,7 @@ package com.google.devtools.build.lib.runtime;
 
 import com.google.common.collect.Sets;
 import com.google.common.eventbus.Subscribe;
+import com.google.devtools.build.lib.actions.ActionExecutedEvent;
 import com.google.devtools.build.lib.analysis.NoBuildEvent;
 import com.google.devtools.build.lib.buildeventstream.AbortedEvent;
 import com.google.devtools.build.lib.buildeventstream.BuildEvent;
@@ -146,6 +147,13 @@ public class BuildEventStreamer implements EventHandler {
 
   @Subscribe
   public void buildEvent(BuildEvent event) {
+    if (event instanceof ActionExecutedEvent) {
+      // We ignore events about action executions if the execution succeeded.
+      if (((ActionExecutedEvent) event).getException() == null) {
+        return;
+      }
+    }
+
     post(event);
   }
 }