Add a deprecation warning to objc_xcodeproj

--
PiperOrigin-RevId: 144127414
MOS_MIGRATED_REVID=144127414
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcXcodeproj.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcXcodeproj.java
index 0c6730f..4679e0e 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcXcodeproj.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcXcodeproj.java
@@ -32,6 +32,9 @@
   @Override
   public ConfiguredTarget create(RuleContext ruleContext)
       throws InterruptedException, RuleErrorException {
+    ruleContext.ruleWarning("This rule is deprecated, and is not supported by Skylark rules. "
+        + "Please use Tulsi (https://tulsi.bazel.build/) to manage Xcode projects.");
+
     NestedSetBuilder<Artifact> filesToBuild = NestedSetBuilder.stableOrder();
     new XcodeSupport(ruleContext)
         .addFilesToBuild(filesToBuild)
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcXcodeprojRule.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcXcodeprojRule.java
index e259875..7857a6f 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcXcodeprojRule.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcXcodeprojRule.java
@@ -78,6 +78,9 @@
 
 /*<!-- #BLAZE_RULE (NAME = objc_xcodeproj, TYPE = OTHER, FAMILY = Objective-C) -->
 
+<p>This rule is deprecated, and is not supported by Skylark rules. Please use
+<a href="https://tulsi.bazel.build/">Tulsi</a> to manage Xcode projects.</p>
+
 <p>This rule combines build information about several objc targets (and all their transitive
 dependencies) into a single Xcode project file, for use in developing on a Mac.</p>