Expose the j2objc configuration fragment, with field dead_code_report, matching build flag --j2objc_dead_code_report.

RELNOTES: The 'j2objc' configuration fragment is exposed to Skylark.
PiperOrigin-RevId: 189630012

2 files changed, 21 insertions, 6 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 5a65d0b48e..3870556daa 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
@@ -111,7 +111,7 @@ public class J2ObjcAspect extends NativeAspectClass implements ConfiguredAspectF
       LabelLateBoundDefault.fromTargetConfiguration(
           J2ObjcConfiguration.class,
           null,
-          (rule, attributes, j2objcConfig) -> j2objcConfig.deadCodeReport().orNull());
+          (rule, attributes, j2objcConfig) -> j2objcConfig.deadCodeReport());
 
   /** Adds additional attribute aspects and attributes to the given AspectDefinition.Builder. */
   protected AspectDefinition.Builder addAdditionalAttributes(AspectDefinition.Builder builder) {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcConfiguration.java
index d71ce599c9..f57e901765 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcConfiguration.java
@@ -15,7 +15,6 @@
 package com.google.devtools.build.lib.rules.objc;
 
 import com.google.common.base.Joiner;
-import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration.Fragment;
@@ -28,8 +27,12 @@ import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import java.util.Collections;
 import java.util.List;
+import javax.annotation.Nullable;
 
 /**
  * A J2ObjC transpiler configuration fragment containing J2ObjC translation flags. This
@@ -38,6 +41,11 @@ import java.util.List;
  */
 @AutoCodec
 @Immutable
+@SkylarkModule(
+    name = "j2objc",
+    category = SkylarkModuleCategory.CONFIGURATION_FRAGMENT,
+    doc = "A configuration fragment for j2Objc."
+)
 public class J2ObjcConfiguration extends Fragment {
   /**
    * Always-on flags for J2ObjC translation. These flags are always used when invoking the J2ObjC
@@ -91,7 +99,7 @@ public class J2ObjcConfiguration extends Fragment {
   private final List<String> translationFlags;
   private final boolean removeDeadCode;
   private final boolean experimentalJ2ObjcHeaderMap;
-  private final Optional<Label> deadCodeReport;
+  @Nullable private final Label deadCodeReport;
 
   J2ObjcConfiguration(J2ObjcCommandLineOptions j2ObjcOptions) {
     this(
@@ -102,7 +110,7 @@ public class J2ObjcConfiguration extends Fragment {
             .build(),
         j2ObjcOptions.removeDeadCode,
         j2ObjcOptions.experimentalJ2ObjcHeaderMap,
-        Optional.fromNullable(j2ObjcOptions.deadCodeReport));
+        j2ObjcOptions.deadCodeReport);
   }
 
   @AutoCodec.Instantiator
@@ -110,7 +118,7 @@ public class J2ObjcConfiguration extends Fragment {
       List<String> translationFlags,
       boolean removeDeadCode,
       boolean experimentalJ2ObjcHeaderMap,
-      Optional<Label> deadCodeReport) {
+      Label deadCodeReport) {
     this.translationFlags = translationFlags;
     this.removeDeadCode = removeDeadCode;
     this.experimentalJ2ObjcHeaderMap = experimentalJ2ObjcHeaderMap;
@@ -131,8 +139,15 @@ public class J2ObjcConfiguration extends Fragment {
   /**
    * Returns the label of the dead code report generated by ProGuard for J2ObjC to eliminate dead
    * code. The dead Java code in the report will not be translated to Objective-C code.
+   *
+   * Returns null if no such report was requested.
    */
-  public Optional<Label> deadCodeReport() {
+  @Nullable
+  @SkylarkCallable(name = "dead_code_report", structField = true,
+      doc = "The label of the dead code report generated by ProGuard for dead code elimination, "
+          + "or <code>None</code> if no such report was requested.",
+      allowReturnNones = true)
+  public Label deadCodeReport() {
     return deadCodeReport;
   }