Have clang output .d dependency files during ObjcCompile.

These are not currently used by anything.  The next step is for bazel to read these files and use them to check the declared dependencies for correctness.

RELNOTES:

--
MOS_MIGRATED_REVID=103023531

1 files changed, 8 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/IntermediateArtifacts.java b/src/main/java/com/google/devtools/build/lib/rules/objc/IntermediateArtifacts.java
index ff6b573aee..59f9b07f67 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/IntermediateArtifacts.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/IntermediateArtifacts.java
@@ -72,7 +72,7 @@ final class IntermediateArtifacts {
             ruleContext.getConfiguration().getBinDirectory());
     return artifact;
   }
-  
+
   /**
    * Returns a derived artifact in the bin directory obtained by appending some extension to the end
    * of the given {@link PathFragment}.
@@ -332,4 +332,11 @@ final class IntermediateArtifacts {
   public Artifact runnerScript() {
     return appendExtension("_runner.sh");
   }
+
+  /**
+   * Dependency file that is generated when compiling the {@code source} artifact.
+   */
+  public Artifact dotdFile(Artifact source) {
+     return inUniqueObjsDir(source, ".d");
+  }
 }