BEP: Report pattern expansion failures

If expanding a pattern fails, report this on the build event protocol;
also include details of what happened.

--
Change-Id: I2bc9caf7c085911b80551d7892cc34f5e9961c7b
Reviewed-on: https://cr.bazel.build/8795
PiperOrigin-RevId: 148894326
MOS_MIGRATED_REVID=148894326

2 files changed, 30 insertions, 3 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/buildeventstream/BuildEventId.java b/src/main/java/com/google/devtools/build/lib/buildeventstream/BuildEventId.java
index 467d6f2b20..3a89fa5aeb 100644
--- a/src/main/java/com/google/devtools/build/lib/buildeventstream/BuildEventId.java
+++ b/src/main/java/com/google/devtools/build/lib/buildeventstream/BuildEventId.java
@@ -84,15 +84,30 @@ public final class BuildEventId implements Serializable {
         BuildEventStreamProtos.BuildEventId.newBuilder().setStarted(startedId).build());
   }
 
-  public static BuildEventId targetPatternExpanded(List<String> targetPattern) {
+  private static BuildEventId targetPatternExpanded(List<String> targetPattern, boolean skipped) {
     BuildEventStreamProtos.BuildEventId.PatternExpandedId patternId =
         BuildEventStreamProtos.BuildEventId.PatternExpandedId.newBuilder()
             .addAllPattern(targetPattern)
             .build();
-    return new BuildEventId(
-        BuildEventStreamProtos.BuildEventId.newBuilder().setPattern(patternId).build());
+    BuildEventStreamProtos.BuildEventId.Builder builder =
+        BuildEventStreamProtos.BuildEventId.newBuilder();
+    if (skipped) {
+      builder.setPatternSkipped(patternId);
+    } else {
+      builder.setPattern(patternId);
+    }
+    return new BuildEventId(builder.build());
   }
 
+  public static BuildEventId targetPatternExpanded(List<String> targetPattern) {
+    return targetPatternExpanded(targetPattern, false);
+  }
+
+  public static BuildEventId targetPatternSkipped(List<String> targetPattern) {
+    return targetPatternExpanded(targetPattern, true);
+  }
+
+
   public static BuildEventId targetCompleted(Label target) {
     BuildEventStreamProtos.BuildEventId.TargetCompletedId targetId =
         BuildEventStreamProtos.BuildEventId.TargetCompletedId.newBuilder()
diff --git a/src/main/java/com/google/devtools/build/lib/buildeventstream/proto/build_event_stream.proto b/src/main/java/com/google/devtools/build/lib/buildeventstream/proto/build_event_stream.proto
index 1ff9d6a021..9d6af941f8 100644
--- a/src/main/java/com/google/devtools/build/lib/buildeventstream/proto/build_event_stream.proto
+++ b/src/main/java/com/google/devtools/build/lib/buildeventstream/proto/build_event_stream.proto
@@ -51,6 +51,10 @@ message BuildEventId {
 
   // Identifier of an event indicating that a target pattern has been expanded
   // further.
+  // Messages of this shape are also used to describe parts of a pattern that
+  // have been skipped for some reason, if the actual expasion was still carried
+  // out (e.g., if keep_going is set). In this case, the pattern_skipped choice
+  // in the id field is to be made.
   message PatternExpandedId {
     repeated string pattern = 1;
   }
@@ -94,6 +98,7 @@ message BuildEventId {
     ProgressId progress = 2;
     BuildStartedId started = 3;
     PatternExpandedId pattern = 4;
+    PatternExpandedId pattern_skipped = 10;
     TargetCompletedId target_completed = 5;
     ActionCompletedId action_completed = 6;
     TestResultId test_result = 8;
@@ -135,6 +140,12 @@ message Aborted {
   string description = 2;
 }
 
+// Payload of an event indicating that an expected event will not come, as
+// something went wrong when attempting to load the corresponding package.
+message LoadingFailure {
+  string details = 1;
+}
+
 // Payload of an event indicating the beginning of a new build. Usually, events
 // of those type start a new build-event stream. The target pattern requested
 // to be build is contained in one of the announced child events; it is an
@@ -273,6 +284,7 @@ message BuildEvent {
   oneof payload {
     Progress progress = 3;
     Aborted aborted = 4;
+    LoadingFailure loading_failed = 11;
     BuildStarted started = 5;
     PatternExpanded expanded = 6;
     ActionExecuted action = 7;