Fixing issue with external j2objc protos (reattempt at #4058)

This is a re-attempt at https://github.com/bazelbuild/bazel/pull/4058 which got reverted via https://github.com/bazelbuild/bazel/issues/4780

#4780 was being caused because cc plugin and j2objc plugin used different paths for outputs. I also manually verified that this works for both external cc_proto_librarys and external j2objc java_proto_libraries.

The output files are created without a repository, but the expected
filenames have them

This resolves issues when having a proto_library from an external build
file.

cc @c-parsons @pmbethe09

Closes #4793.

PiperOrigin-RevId: 190950452

1 files changed, 13 insertions, 9 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcAspect.java b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcAspect.java
index 7f325a3016..c12faf2e1c 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcAspect.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcAspect.java
@@ -630,11 +630,10 @@ public class J2ObjcAspect extends NativeAspectClass implements ConfiguredAspectF
             .addAll(outputClassMappingFiles)
             .build();
 
+    String genfilesPath = getProtoOutputRoot(ruleContext).getPathString();
+
     String langPluginParameter =
-        String.format(
-            "%s:%s",
-            Joiner.on(',').join(J2OBJC_PLUGIN_PARAMS),
-            ruleContext.getConfiguration().getGenfilesFragment().getPathString());
+        String.format("%s:%s", Joiner.on(',').join(J2OBJC_PLUGIN_PARAMS), genfilesPath);
 
     SupportData supportData = base.getProvider(ProtoSupportDataProvider.class).getSupportData();
 
@@ -744,11 +743,8 @@ public class J2ObjcAspect extends NativeAspectClass implements ConfiguredAspectF
 
   private static J2ObjcSource protoJ2ObjcSource(
       RuleContext ruleContext, ImmutableList<Artifact> protoSources) {
-    PathFragment objcFileRootExecPath =
-        ruleContext
-            .getConfiguration()
-            .getGenfilesDirectory(ruleContext.getRule().getRepository())
-            .getExecPath();
+    PathFragment objcFileRootExecPath = getProtoOutputRoot(ruleContext);
+
     Iterable<PathFragment> headerSearchPaths =
         J2ObjcLibrary.j2objcSourceHeaderSearchPaths(
             ruleContext, objcFileRootExecPath, protoSources);
@@ -762,6 +758,14 @@ public class J2ObjcAspect extends NativeAspectClass implements ConfiguredAspectF
         headerSearchPaths);
   }
 
+  private static PathFragment getProtoOutputRoot(RuleContext ruleContext) {
+    return ruleContext
+        .getConfiguration()
+        .getGenfilesFragment()
+        .getRelative(
+            ruleContext.getLabel().getPackageIdentifier().getRepository().getPathUnderExecRoot());
+  }
+
   private static boolean isProtoRule(ConfiguredTarget base) {
     return base.getProvider(ProtoSourcesProvider.class) != null;
   }