Separate runfiles middlemen into two layers: one that is a middleman …

…for the files itself, and one that contains this middleman and the runfiles output manifest.

This is in preparation for Windows symlink support in runfiles manifests: on Windows, we'll need the target files created before we can create the runfiles symlinks for them, but we can't do that by adding the current runfiles middleman to the inputs of SymlinkTreeAction because it would create a cycle (output manifest -> SymlinkTreeAction -> runfiles manifest -> MiddlemanAction -> output manifest)

The alternative is to just add the artifacts to the inputs of SymlinkTreeAction, but that would create a bunch of extra edges and, more importantly, reverse edges in the action graph which we don't want.

--
MOS_MIGRATED_REVID=113041344

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

@@ -633,9 +633,7 @@ private static <E> void expandMiddlemanArtifact(Artifact middleman,
     Preconditions.checkArgument(middleman.isMiddlemanArtifact());
     List<Artifact> artifacts = new ArrayList<>();
     middlemanExpander.expand(middleman, artifacts);
-    for (Artifact artifact : artifacts) {
-      output.add(outputFormatter.apply(artifact));
-    }
+    addExpandedArtifacts(artifacts, output, outputFormatter, middlemanExpander);
   }
 
   /**

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

@@ -82,14 +82,15 @@ 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) {
+      ActionOwner owner, Artifact owningArtifact, Iterable<Artifact> inputs, Root middlemanDir,
+      String tag) {
     if (hasExactlyOneInput(inputs)) { // Optimization: No middleman for just one input.
       return Iterables.getOnlyElement(inputs);
     }
     String middlemanPath = owningArtifact == null
        ? Label.print(owner.getLabel())
        : owningArtifact.getRootRelativePath().getPathString();
-    return createMiddleman(owner, middlemanPath, "runfiles", inputs, middlemanDir,
+    return createMiddleman(owner, middlemanPath, tag, inputs, middlemanDir,
         MiddlemanType.RUNFILES_MIDDLEMAN).getFirst();
   }
 

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

@@ -22,7 +22,6 @@
 import com.google.devtools.build.lib.analysis.actions.ActionConstructionContext;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.config.RunUnder;
-import com.google.devtools.build.lib.collect.IterablesChain;
 import com.google.devtools.build.lib.packages.TargetUtils;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.FileSystemUtils;
@@ -112,9 +111,11 @@ private RunfilesSupport(RuleContext ruleContext, Artifact executable, Runfiles r
       throw new IllegalStateException("main program " + executable + " not included in runfiles");
     }
 
+    Artifact artifactsMiddleman = createArtifactsMiddleman(ruleContext, runfiles.getAllArtifacts());
     runfilesInputManifest = createRunfilesInputManifestArtifact(ruleContext);
     this.runfilesManifest = createRunfilesAction(ruleContext, runfiles);
-    this.runfilesMiddleman = createRunfilesMiddleman(ruleContext, runfiles.getAllArtifacts());
+    this.runfilesMiddleman = createRunfilesMiddleman(
+        ruleContext, artifactsMiddleman, runfilesManifest);
     sourcesManifest = createSourceManifest(ruleContext, runfiles);
 
     args = ImmutableList.<String>builder()
@@ -247,15 +248,19 @@ public Artifact getSourceManifest() {
     return sourcesManifest;
   }
 
-  private Artifact createRunfilesMiddleman(ActionConstructionContext context,
+  private Artifact createArtifactsMiddleman(ActionConstructionContext context,
       Iterable<Artifact> allRunfilesArtifacts) {
-    Iterable<Artifact> inputs = IterablesChain.<Artifact>builder()
-        .add(allRunfilesArtifacts)
-        .addElement(runfilesManifest)
-        .build();
     return context.getAnalysisEnvironment().getMiddlemanFactory().createRunfilesMiddleman(
-        context.getActionOwner(), owningExecutable, inputs,
-        context.getConfiguration().getMiddlemanDirectory());
+        context.getActionOwner(), owningExecutable, allRunfilesArtifacts,
+        context.getConfiguration().getMiddlemanDirectory(), "runfiles_artifacts");
+  }
+
+  private Artifact createRunfilesMiddleman(ActionConstructionContext context,
+      Artifact artifactsMiddleman, Artifact outputManifest) {
+    return context.getAnalysisEnvironment().getMiddlemanFactory().createRunfilesMiddleman(
+        context.getActionOwner(), owningExecutable,
+        ImmutableList.of(artifactsMiddleman, outputManifest),
+        context.getConfiguration().getMiddlemanDirectory(), "runfiles");
   }
 
   /**

src/test/java/com/google/devtools/build/lib/exec/MiddlemanActionTest.java

@@ -112,9 +112,11 @@ public void testDifferentExecutablesForRunfilesMiddleman() throws Exception {
 
     analysisEnvironment.clear();
     Artifact middlemanForC = middlemanFactory.createRunfilesMiddleman(
-        NULL_ACTION_OWNER, c, Arrays.asList(c, common), targetConfig.getMiddlemanDirectory());
+        NULL_ACTION_OWNER, c, Arrays.asList(c, common), targetConfig.getMiddlemanDirectory(),
+        "runfiles");
     Artifact middlemanForD = middlemanFactory.createRunfilesMiddleman(
-        NULL_ACTION_OWNER, d, Arrays.asList(d, common), targetConfig.getMiddlemanDirectory());
+        NULL_ACTION_OWNER, d, Arrays.asList(d, common), targetConfig.getMiddlemanDirectory(),
+        "runfiles");
     analysisEnvironment.registerWith(getMutableActionGraph());
 
     MiddlemanAction middlemanActionForC = (MiddlemanAction) getGeneratingAction(middlemanForC);