Make runfiles tree creation on Windows depend on the artifacts of the…

… actual runfiles.

This is necessary because the plan for Windows calls for knowing if the target of the symlink is a directory or a file, thus, we cannot create runfiles trees before the artifacts in them are built. This probably comes with a performance hit due to the extra scheduling constraints.

This makes almost every test pass save:

- test_tmpdir in bazel_test_test, which I hereby dismiss as a fluke
- test_http_archive_tgz in external_integration_test (Maybe a permissions issue due to copying things?)
- A bunch of test in external_correctness_test, probably related to the fact that since we are copying things, we don't notice changes to the original files.

--
MOS_MIGRATED_REVID=113050025

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

@@ -23,6 +23,8 @@
 
 import java.util.Iterator;
 
+import javax.annotation.Nullable;
+
 /**
  * A factory to create middleman objects.
  */
@@ -82,8 +84,8 @@ public Artifact createAggregatingMiddleman(
    * @param middlemanDir the directory in which to place the middleman.
    */
   public Artifact createRunfilesMiddleman(
-      ActionOwner owner, Artifact owningArtifact, Iterable<Artifact> inputs, Root middlemanDir,
-      String tag) {
+      ActionOwner owner, @Nullable Artifact owningArtifact, Iterable<Artifact> inputs,
+      Root middlemanDir, String tag) {
     if (hasExactlyOneInput(inputs)) { // Optimization: No middleman for just one input.
       return Iterables.getOnlyElement(inputs);
     }

src/main/java/com/google/devtools/build/lib/analysis/RunfilesSupport.java

@@ -113,7 +113,7 @@ private RunfilesSupport(RuleContext ruleContext, Artifact executable, Runfiles r
 
     Artifact artifactsMiddleman = createArtifactsMiddleman(ruleContext, runfiles.getAllArtifacts());
     runfilesInputManifest = createRunfilesInputManifestArtifact(ruleContext);
-    this.runfilesManifest = createRunfilesAction(ruleContext, runfiles);
+    this.runfilesManifest = createRunfilesAction(ruleContext, runfiles, artifactsMiddleman);
     this.runfilesMiddleman = createRunfilesMiddleman(
         ruleContext, artifactsMiddleman, runfilesManifest);
     sourcesManifest = createSourceManifest(ruleContext, runfiles);
@@ -272,7 +272,8 @@ private Artifact createRunfilesMiddleman(ActionConstructionContext context,
    * generated files, etc.) into a single tree, so that programs can access them
    * using the workspace-relative name.
    */
-  private Artifact createRunfilesAction(ActionConstructionContext context, Runfiles runfiles) {
+  private Artifact createRunfilesAction(ActionConstructionContext context, Runfiles runfiles,
+      Artifact artifactsMiddleman) {
     // Compute the names of the runfiles directory and its MANIFEST file.
     Artifact inputManifest = getRunfilesInputManifest();
     context.getAnalysisEnvironment().registerAction(
@@ -292,7 +293,8 @@ private Artifact createRunfilesAction(ActionConstructionContext context, Runfile
     Artifact outputManifest = context.getDerivedArtifact(
         outputManifestPath, config.getBinDirectory());
     context.getAnalysisEnvironment().registerAction(new SymlinkTreeAction(
-        context.getActionOwner(), inputManifest, outputManifest, /*filesetTree=*/false));
+        context.getActionOwner(), inputManifest, artifactsMiddleman, outputManifest,
+        /*filesetTree=*/false));
     return outputManifest;
   }
 

src/main/java/com/google/devtools/build/lib/analysis/SymlinkTreeAction.java

@@ -24,6 +24,8 @@
 import com.google.devtools.build.lib.util.Fingerprint;
 import com.google.devtools.build.lib.util.Preconditions;
 
+import javax.annotation.Nullable;
+
 /**
  * Action responsible for the symlink tree creation.
  * Used to generate runfiles and fileset symlink farms.
@@ -40,22 +42,36 @@ public class SymlinkTreeAction extends AbstractAction {
    * Creates SymlinkTreeAction instance.
    *
    * @param owner action owner
-   * @param inputManifest exec path to the input runfiles manifest
-   * @param outputManifest exec path to the generated symlink tree manifest
+   * @param inputManifest the input runfiles manifest
+   * @param artifactMiddleman the middleman artifact representing all the files the symlinks
+   *                          point to (on Windows we need to know if the target of a "symlink" is
+   *                          a directory or a file so we need to build it before)
+   * @param outputManifest the generated symlink tree manifest
    *                       (must have "MANIFEST" base name). Symlink tree root
    *                       will be set to the artifact's parent directory.
    * @param filesetTree true if this is fileset symlink tree,
    *                    false if this is a runfiles symlink tree.
    */
-  public SymlinkTreeAction(ActionOwner owner, Artifact inputManifest, Artifact outputManifest,
-      boolean filesetTree) {
-    super(owner, ImmutableList.of(inputManifest), ImmutableList.of(outputManifest));
+  public SymlinkTreeAction(ActionOwner owner, Artifact inputManifest,
+      @Nullable Artifact artifactMiddleman, Artifact outputManifest, boolean filesetTree) {
+    super(owner, computeInputs(inputManifest, artifactMiddleman), ImmutableList.of(outputManifest));
     Preconditions.checkArgument(outputManifest.getPath().getBaseName().equals("MANIFEST"));
     this.inputManifest = inputManifest;
     this.outputManifest = outputManifest;
     this.filesetTree = filesetTree;
   }
 
+  private static ImmutableList<Artifact> computeInputs(
+      Artifact inputManifest, Artifact artifactMiddleman) {
+    ImmutableList.Builder<Artifact> result = ImmutableList.<Artifact>builder()
+        .add(inputManifest);
+    if (artifactMiddleman != null
+        && !artifactMiddleman.getPath().getFileSystem().supportsSymbolicLinksNatively()) {
+      result.add(artifactMiddleman);
+    }
+    return result.build();
+  }
+
   public Artifact getInputManifest() {
     return inputManifest;
   }

src/main/java/com/google/devtools/build/lib/rules/android/NativeLibs.java

@@ -151,8 +151,13 @@ public Artifact createApkBuilderSymlinks(RuleContext ruleContext) {
             .addRootSymlinks(symlinks)
             .build());
     Artifact outputManifest = AndroidBinary.getDxArtifact(ruleContext, "native_symlinks/MANIFEST");
+    Artifact nativeLibsMiddleman =
+        ruleContext.getAnalysisEnvironment().getMiddlemanFactory().createRunfilesMiddleman(
+            ruleContext.getActionOwner(), null, symlinks.values(),
+            ruleContext.getConfiguration().getMiddlemanDirectory(), "android_native_libs");
+
     ruleContext.registerAction(new SymlinkTreeAction(
-        ruleContext.getActionOwner(), inputManifest, outputManifest, false));
+        ruleContext.getActionOwner(), inputManifest, nativeLibsMiddleman, outputManifest, false));
     return outputManifest;
   }