Put the hack into CppCompileAction and fix nits.

src/main/java/com/google/devtools/build/lib/actions/ExecutionRequirements.java

@@ -260,4 +260,9 @@ public enum WorkerProtocolFormat {
    * "requires-xcode-label:unstable" and "requires-xcode:1.0".
    */
   public static final String REQUIRES_XCODE_LABEL = "requires-xcode-label";
+
+  /**
+   * Requires the execution service do NOT share caches across different workspace.
+   */
+  public static final String DIFFERENTIATE_WORKSPACE_CACHE = "internal-differentiate-workspace-cache";
 }

src/main/java/com/google/devtools/build/lib/actions/Spawns.java

@@ -75,6 +75,12 @@ public static boolean requiresNetwork(Spawn spawn, boolean defaultSandboxDisallo
     return defaultSandboxDisallowNetwork;
   }
 
+  /** Returns whether caches from other workspace can be used for this spawn. */
+  public static boolean shouldDifferentiateWorkspaceCache(Spawn spawn) {
+    return spawn.getExecutionInfo()
+        .containsKey(ExecutionRequirements.DIFFERENTIATE_WORKSPACE_CACHE);
+  }
+
   /**
    * Returns whether a Spawn claims to support being executed with the persistent worker strategy
    * according to its execution info tags.

src/main/java/com/google/devtools/build/lib/remote/RemoteActionContextProvider.java

@@ -31,7 +31,7 @@
 import com.google.devtools.build.lib.remote.common.RemoteExecutionClient;
 import com.google.devtools.build.lib.remote.common.RemotePathResolver;
 import com.google.devtools.build.lib.remote.common.RemotePathResolver.DefaultRemotePathResolver;
-import com.google.devtools.build.lib.remote.common.RemotePathResolver.SiblingExternalLayoutResolver;
+import com.google.devtools.build.lib.remote.common.RemotePathResolver.SiblingRepositoryLayoutResolver;
 import com.google.devtools.build.lib.remote.options.RemoteOptions;
 import com.google.devtools.build.lib.remote.util.DigestUtil;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
@@ -91,7 +91,7 @@ RemotePathResolver createRemotePathResolver() {
     RemotePathResolver remotePathResolver;
     if (buildLanguageOptions != null && buildLanguageOptions.experimentalSiblingRepositoryLayout) {
       RemoteOptions remoteOptions = checkNotNull(env.getOptions().getOptions(RemoteOptions.class));
-      remotePathResolver = new SiblingExternalLayoutResolver(execRoot, remoteOptions.incompatibleRemoteOutputPathsRelativeToInputRoot);
+      remotePathResolver = new SiblingRepositoryLayoutResolver(execRoot, remoteOptions.incompatibleRemoteOutputPathsRelativeToInputRoot);
     } else {
       remotePathResolver = new DefaultRemotePathResolver(execRoot);
     }

src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnRunner.java

@@ -229,7 +229,8 @@ public SpawnResult exec(Spawn spawn, SpawnExecutionContext context)
     maybeWriteParamFilesLocally(spawn);
 
     // Get the remote platform properties.
-    Platform platform = PlatformUtils.getPlatformProto(spawn, remoteOptions);
+    Platform platform = PlatformUtils
+        .getPlatformProto(spawn, remoteOptions, getExtraPlatformProperties(spawn, execRoot));
 
     Command command =
         buildCommand(
@@ -698,16 +699,10 @@ private SpawnResult handleError(
   }
 
   static List<Property> getExtraPlatformProperties(Spawn spawn, Path execRoot) {
-    // Hack on Windows. The included headers dumped by cl.exe in stdout contain absolute paths.
-    // When compiling the file from different workspace, the shared cache will cause header
-    // dependency checking to fail. This was initially fixed by a hack (see
-    // https://github.com/bazelbuild/bazel/issues/9172 for more details), but is broken again due
-    // to cl/356735700. We include workspace name here so action results from different workspaces
-    // on Windows won't be shared.
-    boolean isWindows = System.getProperty("os.name").startsWith("Windows");
-    if (isWindows) {
+    if (Spawns.shouldDifferentiateWorkspaceCache(spawn)) {
       return ImmutableList
-          .of(Property.newBuilder().setName("workspace").setValue(execRoot.getBaseName()).build());
+          .of(Property.newBuilder().setName("bazel-workspace").setValue(execRoot.getBaseName())
+              .build());
     }
 
     return ImmutableList.of();

src/main/java/com/google/devtools/build/lib/remote/common/RemotePathResolver.java

@@ -130,20 +130,20 @@ public Path resolveLocalPath(ActionInput actionInput) {
   }
 
   /**
-   * A {@link RemotePathResolver} used when {@code --experimental_sibling_external_layout} is set.
+   * A {@link RemotePathResolver} used when {@code --experimental_sibling_repository_layout} is set.
    * Use parent directory of {@code execRoot} and set {@code workingDirectory} to the base name of
    * {@code execRoot}.
    *
    * The paths of outputs are relative to {@code workingDirectory} if
    * {@code --incompatible_remote_output_paths_relative_to_input_root} is not set, otherwise,
    * relative to input root.
    */
-  class SiblingExternalLayoutResolver implements RemotePathResolver {
+  class SiblingRepositoryLayoutResolver implements RemotePathResolver {
 
     private final Path execRoot;
     private final boolean incompatibleRemoteOutputPathsRelativeToInputRoot;
 
-    public SiblingExternalLayoutResolver(Path execRoot,
+    public SiblingRepositoryLayoutResolver(Path execRoot,
         boolean incompatibleRemoteOutputPathsRelativeToInputRoot) {
       this.execRoot = execRoot;
       this.incompatibleRemoteOutputPathsRelativeToInputRoot = incompatibleRemoteOutputPathsRelativeToInputRoot;

src/main/java/com/google/devtools/build/lib/remote/merkletree/DirectoryTreeBuilder.java

@@ -62,13 +62,6 @@ static DirectoryTree fromActionInputs(
       throws IOException {
     Map<PathFragment, DirectoryNode> tree = new HashMap<>();
     int numFiles = buildFromActionInputs(inputs, metadataProvider, execRoot, digestUtil, tree);
-    // // Make sure working directory is exists
-    // PathFragment workingDirectory = PathFragment.create(execRoot.getBaseName());
-    // if (!tree.containsKey(workingDirectory)) {
-    //   DirectoryNode dir = new DirectoryNode(workingDirectory.toString());
-    //   tree.put(workingDirectory, dir);
-    //   createParentDirectoriesIfNotExist(workingDirectory, dir, tree);
-    // }
     return new DirectoryTree(tree, numFiles);
   }
 

src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java

@@ -1477,6 +1477,19 @@ protected Spawn createSpawn(Map<String, String> clientEnv) throws ActionExecutio
               .build();
     }
 
+    if (featureConfiguration.isEnabled(CppRuleClasses.PARSE_SHOWINCLUDES)) {
+      // Hack on Windows. The included headers dumped by cl.exe in stdout contain absolute paths.
+      // When compiling the file from different workspace, the shared cache will cause header
+      // dependency checking to fail. This was initially fixed by a hack (see
+      // https://github.com/bazelbuild/bazel/issues/9172 for more details), but is broken again due
+      // to cl/356735700. We require execution service to ignore caches from other workspace.
+      executionInfo =
+          ImmutableMap.<String, String>builderWithExpectedSize(executionInfo.size() + 1)
+              .putAll(executionInfo)
+              .put(ExecutionRequirements.DIFFERENTIATE_WORKSPACE_CACHE, "")
+              .build();
+    }
+
     try {
       return new SimpleSpawn(
           this,

src/test/java/com/google/devtools/build/lib/remote/GrpcCacheClientTest.java

@@ -65,7 +65,7 @@
 import com.google.devtools.build.lib.remote.common.RemoteActionExecutionContext;
 import com.google.devtools.build.lib.remote.common.RemoteCacheClient.ActionKey;
 import com.google.devtools.build.lib.remote.common.RemotePathResolver;
-import com.google.devtools.build.lib.remote.common.RemotePathResolver.SiblingExternalLayoutResolver;
+import com.google.devtools.build.lib.remote.common.RemotePathResolver.SiblingRepositoryLayoutResolver;
 import com.google.devtools.build.lib.remote.grpc.ChannelConnectionFactory;
 import com.google.devtools.build.lib.remote.merkletree.MerkleTree;
 import com.google.devtools.build.lib.remote.options.RemoteOptions;
@@ -402,7 +402,7 @@ public void testDownloadAllResultsForSiblingLayoutAndRelativeToInputRoot() throw
     RemoteOptions remoteOptions = Options.getDefaults(RemoteOptions.class);
     GrpcCacheClient client = newClient(remoteOptions);
     RemoteCache remoteCache = new RemoteCache(client, remoteOptions, DIGEST_UTIL);
-    RemotePathResolver remotePathResolver = new SiblingExternalLayoutResolver(execRoot, true);
+    RemotePathResolver remotePathResolver = new SiblingRepositoryLayoutResolver(execRoot, true);
 
     Digest fooDigest = DIGEST_UTIL.computeAsUtf8("foo-contents");
     Digest barDigest = DIGEST_UTIL.computeAsUtf8("bar-contents");