[AOSP-pick] Enumerate all currently used cache directories.

base/src/com/google/idea/blaze/base/qsync/ProjectLoader.java

@@ -153,9 +153,10 @@ public QuerySyncProject loadProject(BlazeContext context) throws BuildException
     ProjectProtoTransform.Registry projectTransformRegistry = new Registry();
     SnapshotHolder graph = new SnapshotHolder();
     graph.addListener((c, i) -> projectModificationTracker.incModificationCount());
+    Path buildCachePath = getBuildCachePath(project);
     BuildArtifactCache artifactCache =
         BuildArtifactCache.create(
-            ideProjectBasePath.resolve(".buildcache"),
+          buildCachePath,
             createArtifactFetcher(),
             executor,
             QuerySyncManager.getInstance(project).cacheCleanRequest());
@@ -266,6 +267,10 @@ public QuerySyncProject loadProject(BlazeContext context) throws BuildException
     return querySyncProject;
   }
 
+  public static Path getBuildCachePath(Project project) {
+    return Paths.get(checkNotNull(project.getBasePath())).resolve(".buildcache");
+  }
+
   private ParallelPackageReader createWorkspaceRelativePackageReader() {
     return new ParallelPackageReader(executor, new PackageStatementParser());
   }

base/src/com/google/idea/blaze/base/sync/data/BlazeDataStorage.java

@@ -15,17 +15,26 @@
  */
 package com.google.idea.blaze.base.sync.data;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.idea.blaze.base.logging.LoggedDirectoryProvider;
+import com.google.idea.blaze.base.model.primitives.WorkspaceRoot;
+import com.google.idea.blaze.base.qsync.ProjectLoader;
 import com.google.idea.blaze.base.settings.Blaze;
 import com.google.idea.blaze.base.settings.BlazeImportSettings;
 import com.google.idea.blaze.base.settings.BlazeImportSettingsManager;
+import com.google.idea.blaze.qsync.deps.ArtifactDirectories;
+import com.google.idea.blaze.qsync.project.ProjectPath;
 import com.intellij.openapi.application.ApplicationInfo;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.application.PathManager;
 import com.intellij.openapi.project.Project;
 import java.io.File;
+import java.nio.file.Path;
+import java.util.Collection;
 import java.util.Optional;
 
 /** Defines where we store our blaze project data. */
@@ -66,6 +75,28 @@ private static File getProjectConfigurationDir() {
     return new File(PathManager.getSystemPath(), "blaze/projects").getAbsoluteFile();
   }
 
+  /**
+   * DO NOT USE: Returns a best-effort list of all project data directories used by the IDE.
+   */
+  public static Collection<Path> getMaybeAllProjectDataDirs(Project project) {
+    BlazeImportSettings importSettings = BlazeImportSettingsManager.getInstance(project)
+      .getImportSettings();
+    if (importSettings == null) {
+      throw new IllegalStateException("BlazeImportSettings unavailable");
+    }
+    final var pathResolver =
+      ProjectPath.Resolver.create(
+        WorkspaceRoot.fromImportSettings(importSettings).path(),
+        Path.of(
+          importSettings
+            .getProjectDataDirectory()));
+    return ImmutableList.of(
+      getProjectDataDir(importSettings).toPath(),
+      pathResolver.resolve(ArtifactDirectories.ROOT),
+      ProjectLoader.getBuildCachePath(project)
+    );
+  }
+
   /**
    * Configuration which includes the plugin's own project-specific data directory (used for
    * artifacts related to IntelliJ's project setup - module configurations, locally cached jars,

querysync/java/com/google/idea/blaze/qsync/deps/ArtifactDirectories.java

@@ -21,7 +21,7 @@
 /** Static helpers for managing directories in the project artifact store. */
 public class ArtifactDirectories {
 
-  private static final ProjectPath ROOT = ProjectPath.projectRelative(".bazel");
+  public static final ProjectPath ROOT = ProjectPath.projectRelative(".bazel");
 
   /**
    * By default, all project artifacts go in this directory, at a path matching their bazel output