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

1 files changed, 66 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/PatternExpandingError.java b/src/main/java/com/google/devtools/build/lib/skyframe/PatternExpandingError.java
new file mode 100644
index 0000000000..fd273e7fee
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/PatternExpandingError.java
@@ -0,0 +1,66 @@
+// Copyright 2016 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.skyframe;
+
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.buildeventstream.BuildEvent;
+import com.google.devtools.build.lib.buildeventstream.BuildEventId;
+import com.google.devtools.build.lib.buildeventstream.BuildEventStreamProtos;
+import com.google.devtools.build.lib.buildeventstream.GenericBuildEvent;
+import com.google.devtools.build.lib.buildeventstream.PathConverter;
+import java.util.Collection;
+import java.util.List;
+
+/** Event reporting about failure to expand a target pattern properly. */
+public final class PatternExpandingError implements BuildEvent {
+
+  private final List<String> pattern;
+  private final String message;
+  private final boolean skipped;
+
+  private PatternExpandingError(List<String> pattern, String message, boolean skipped) {
+    this.pattern = pattern;
+    this.message = message;
+    this.skipped = skipped;
+  }
+
+  public static PatternExpandingError failed(List<String> pattern, String message) {
+    return new PatternExpandingError(pattern, message, false);
+  }
+
+  public static PatternExpandingError skipped(String term, String message) {
+    return new PatternExpandingError(ImmutableList.of(term), message, true);
+  }
+
+  @Override
+  public BuildEventId getEventId() {
+    if (skipped) {
+      return BuildEventId.targetPatternSkipped(pattern);
+    } else {
+      return BuildEventId.targetPatternExpanded(pattern);
+    }
+  }
+
+  @Override
+  public Collection<BuildEventId> getChildrenEvents() {
+    return ImmutableList.<BuildEventId>of();
+  }
+
+  @Override
+  public BuildEventStreamProtos.BuildEvent asStreamProto(PathConverter pathConverter) {
+    BuildEventStreamProtos.LoadingFailure failure =
+        BuildEventStreamProtos.LoadingFailure.newBuilder().setDetails(message).build();
+    return GenericBuildEvent.protoChaining(this).setLoadingFailed(failure).build();
+  }
+}