Add an event for source directory encountered in a build.

PiperOrigin-RevId: 437843565

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

@@ -275,6 +275,10 @@ private SkyValue createSourceValue(Artifact artifact, Environment env)
       return new MissingArtifactValue(artifact);
     }
 
+    if (fileValue.isDirectory()) {
+      env.getListener().post(SourceDirectoryEvent.create(artifact.getExecPath()));
+    }
+
     if (!fileValue.isDirectory() || !TrackSourceDirectoriesFlag.trackSourceDirectories()) {
       FileArtifactValue metadata;
       try {

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

@@ -614,6 +614,16 @@ java_library(
     ],
 )
 
+java_library(
+    name = "source_directory_event",
+    srcs = ["SourceDirectoryEvent.java"],
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib/events",
+        "//src/main/java/com/google/devtools/build/lib/vfs:pathfragment",
+        "//third_party:auto_value",
+    ],
+)
+
 java_library(
     name = "artifact_function",
     srcs = ["ArtifactFunction.java"],
@@ -625,6 +635,7 @@ java_library(
         ":metadata_consumer_for_metrics",
         ":recursive_filesystem_traversal",
         ":runfiles_artifact_value",
+        ":source_directory_event",
         ":track_source_directories_flag",
         ":tree_artifact_value",
         "//src/main/java/com/google/devtools/build/lib/actions",

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

@@ -0,0 +1,29 @@
+// Copyright 2015 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.auto.value.AutoValue;
+import com.google.devtools.build.lib.events.ExtendedEventHandler.ProgressLike;
+import com.google.devtools.build.lib.vfs.PathFragment;
+
+/** Event issued when a source directory is encountered in {@link ArtifactFunction}. */
+@AutoValue
+public abstract class SourceDirectoryEvent implements ProgressLike {
+  public abstract PathFragment execPath();
+
+  public static SourceDirectoryEvent create(PathFragment execPath) {
+    return new AutoValue_SourceDirectoryEvent(execPath);
+  }
+}