Introduces a registry of native providers to the BuildConfiguration, which can be added to by fragments. Uses the registry to enable native access to TranstiveProviderInstances from Skylark. In particular, makes ObjcProvider accessible to skylark rule implementations.

--
MOS_MIGRATED_REVID=121390911

13 files changed, 333 insertions, 363 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java
index a39737ce7c..be01445b3b 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java
@@ -21,6 +21,7 @@ import static com.google.devtools.build.lib.packages.RuleClass.Builder.RuleClass
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
+import com.google.common.collect.ImmutableBiMap;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
@@ -106,6 +107,9 @@ public class ConfiguredRuleClassProvider implements RuleClassProvider {
     private ImmutableList.Builder<Class<?>> skylarkModules =
         ImmutableList.<Class<?>>builder().addAll(SkylarkModules.MODULES);
     private final List<Class<? extends FragmentOptions>> buildOptions = Lists.newArrayList();
+    private ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>>
+        registeredSkylarkProviders = ImmutableBiMap.of();
+ 
 
     public void addWorkspaceFilePrefix(String contents) {
       defaultWorkspaceFilePrefix.append(contents);
@@ -198,6 +202,16 @@ public class ConfiguredRuleClassProvider implements RuleClassProvider {
       return this;
     }
 
+    /**
+     * Registers a map that indicates which keys in structs returned by skylark rules should be
+     * interpreted as native TransitiveInfoProvider instances of type (map value).
+     */
+    public Builder setSkylarkProviderRegistry(
+        ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>> providers) {
+      this.registeredSkylarkProviders = providers;
+      return this;
+    }
+
     private RuleConfiguredTargetFactory createFactory(
         Class<? extends RuleConfiguredTargetFactory> factoryClass) {
       try {
@@ -274,7 +288,8 @@ public class ConfiguredRuleClassProvider implements RuleClassProvider {
           prerequisiteValidator,
           skylarkAccessibleTopLevels,
           skylarkModules.build(),
-          buildOptions);
+          buildOptions,
+          registeredSkylarkProviders);
     }
 
     @Override
@@ -373,6 +388,9 @@ public class ConfiguredRuleClassProvider implements RuleClassProvider {
   private final Environment.Frame globals;
 
   private final List<Class<? extends FragmentOptions>> buildOptions;
+  
+  private final ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>>
+      registeredSkylarkProviders;
 
   private ConfiguredRuleClassProvider(
       Label preludeLabel,
@@ -391,7 +409,8 @@ public class ConfiguredRuleClassProvider implements RuleClassProvider {
       PrerequisiteValidator prerequisiteValidator,
       ImmutableMap<String, Object> skylarkAccessibleJavaClasses,
       ImmutableList<Class<?>> skylarkModules,
-      List<Class<? extends FragmentOptions>> buildOptions) {
+      List<Class<? extends FragmentOptions>> buildOptions,
+      ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>> registeredSkylarkProviders) {
     this.preludeLabel = preludeLabel;
     this.runfilesPrefix = runfilesPrefix;
     this.toolsRepository = toolsRepository;
@@ -408,6 +427,7 @@ public class ConfiguredRuleClassProvider implements RuleClassProvider {
     this.prerequisiteValidator = prerequisiteValidator;
     this.globals = createGlobals(skylarkAccessibleJavaClasses, skylarkModules);
     this.buildOptions = buildOptions;
+    this.registeredSkylarkProviders = registeredSkylarkProviders;
   }
 
   public PrerequisiteValidator getPrerequisiteValidator() {
@@ -507,6 +527,19 @@ public class ConfiguredRuleClassProvider implements RuleClassProvider {
   }
 
   /**
+   * Returns a map that indicates which keys in structs returned by skylark rules should be
+   * interpreted as native TransitiveInfoProvider instances of type (map value).
+   *
+   * <p>That is, if this map contains "dummy" -> DummyProvider.class, a "dummy" entry in a skylark
+   * rule implementations returned struct will be exported from that ConfiguredTarget as a
+   * DummyProvider.
+   */
+  public ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>>
+      getRegisteredSkylarkProviders() {
+    return this.registeredSkylarkProviders;
+  }
+  
+  /**
    * Creates a BuildOptions class for the given options taken from an optionsProvider.
    */
   public BuildOptions createBuildOptions(OptionsClassProvider optionsProvider) {
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredTargetFactory.java b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredTargetFactory.java
index 06f6c87404..39a0e674ff 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredTargetFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredTargetFactory.java
@@ -221,15 +221,21 @@ public final class ConfiguredTargetFactory {
       ListMultimap<Attribute, ConfiguredTarget> prerequisiteMap,
       Set<ConfigMatchingProvider> configConditions) throws InterruptedException {
     // Visibility computation and checking is done for every rule.
-    RuleContext ruleContext = new RuleContext.Builder(env, rule, null,
-        configuration, hostConfiguration,
-        ruleClassProvider.getPrerequisiteValidator(),
-        rule.getRuleClassObject().getConfigurationFragmentPolicy())
-        .setVisibility(convertVisibility(prerequisiteMap, env.getEventHandler(), rule, null))
-        .setPrerequisites(prerequisiteMap)
-        .setConfigConditions(configConditions)
-        .setUniversalFragment(ruleClassProvider.getUniversalFragment())
-        .build();
+    RuleContext ruleContext =
+        new RuleContext.Builder(
+                env,
+                rule,
+                null,
+                configuration,
+                hostConfiguration,
+                ruleClassProvider.getPrerequisiteValidator(),
+                rule.getRuleClassObject().getConfigurationFragmentPolicy())
+            .setVisibility(convertVisibility(prerequisiteMap, env.getEventHandler(), rule, null))
+            .setPrerequisites(prerequisiteMap)
+            .setConfigConditions(configConditions)
+            .setUniversalFragment(ruleClassProvider.getUniversalFragment())
+            .setSkylarkProvidersRegistry(ruleClassProvider.getRegisteredSkylarkProviders())
+            .build();
     if (ruleContext.hasErrors()) {
       return null;
     }
@@ -252,7 +258,9 @@ public final class ConfiguredTargetFactory {
     if (rule.getRuleClassObject().isSkylarkExecutable()) {
       // TODO(bazel-team): maybe merge with RuleConfiguredTargetBuilder?
       return SkylarkRuleConfiguredTargetBuilder.buildRule(
-          ruleContext, rule.getRuleClassObject().getConfiguredTargetFunction());
+          ruleContext,
+          rule.getRuleClassObject().getConfiguredTargetFunction(),
+          ruleClassProvider.getRegisteredSkylarkProviders());
     } else {
       RuleClass.ConfiguredTargetFactory<ConfiguredTarget, RuleContext> factory =
           rule.getRuleClassObject().<ConfiguredTarget, RuleContext>getConfiguredTargetFactory();
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/RuleConfiguredTargetBuilder.java b/src/main/java/com/google/devtools/build/lib/analysis/RuleConfiguredTargetBuilder.java
index 853fdf7caf..ab7bdafd8e 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/RuleConfiguredTargetBuilder.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/RuleConfiguredTargetBuilder.java
@@ -43,6 +43,7 @@ import com.google.devtools.build.lib.syntax.EvalException;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.util.Preconditions;
 
+import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -124,9 +125,29 @@ public final class RuleConfiguredTargetBuilder {
       add(OutputGroupProvider.class, new OutputGroupProvider(outputGroups.build()));
     }
 
-
+    addRegisteredProvidersToSkylarkProviders();
+      
     return new RuleConfiguredTarget(ruleContext, skylarkProviders.build(), providers);
   }
+  
+  /**
+   * Adds skylark providers from a skylark provider registry, and checks for collisions.
+   */
+  private void addRegisteredProvidersToSkylarkProviders() {
+    Map<String, Object> nativeSkylarkProviders = new HashMap<>();
+    for (Entry<Class<? extends TransitiveInfoProvider>, TransitiveInfoProvider> entry :
+        providers.entrySet()) {
+      if (ruleContext.getSkylarkProviderRegistry().containsValue(entry.getKey())) {
+        String skylarkName = ruleContext.getSkylarkProviderRegistry().inverse().get(entry.getKey());
+        nativeSkylarkProviders.put(skylarkName, entry.getValue());
+      }
+    }
+    try {
+      skylarkProviders.putAll(nativeSkylarkProviders);
+    } catch (IllegalArgumentException e) {
+      ruleContext.ruleError("Collision caused by duplicate skylark providers: " + e.getMessage());
+    }
+  }
 
   /**
    * Like getFilesToBuild(), except that it also includes the runfiles middleman, if any.
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
index 9c85ce9949..faa4f2c441 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
@@ -18,6 +18,7 @@ import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Joiner;
 import com.google.common.base.Predicate;
 import com.google.common.base.Predicates;
+import com.google.common.collect.ImmutableBiMap;
 import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableListMultimap;
@@ -151,7 +152,9 @@ public final class RuleContext extends TargetContext
   private final ConfigurationFragmentPolicy configurationFragmentPolicy;
   private final Class<? extends BuildConfiguration.Fragment> universalFragment;
   private final ErrorReporter reporter;
-
+  private final ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>>
+      skylarkProviderRegistry;
+  
   private ActionOwner actionOwner;
 
   /* lazily computed cache for Make variables, computed from the above. See get... method */
@@ -178,6 +181,7 @@ public final class RuleContext extends TargetContext
     this.features = getEnabledFeatures();
     this.ruleClassNameForLogging = ruleClassNameForLogging;
     this.aspectAttributes = aspectAttributes;
+    this.skylarkProviderRegistry = builder.skylarkProviderRegistry;
     this.hostConfiguration = builder.hostConfiguration;
     reporter = builder.reporter;
   }
@@ -269,6 +273,15 @@ public final class RuleContext extends TargetContext
   }
 
   /**
+   * Returns a map that indicates which providers should be exported to skylark under the key
+   * (map key).  These provider types will also be exportable by skylark rules under (map key).
+   */
+  public ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>>
+      getSkylarkProviderRegistry() {
+    return skylarkProviderRegistry;
+  }
+  
+  /**
    * Returns whether this instance is known to have errors at this point during analysis. Do not
    * call this method after the initializationHook has returned.
    */
@@ -1307,6 +1320,7 @@ public final class RuleContext extends TargetContext
     private Set<ConfigMatchingProvider> configConditions;
     private NestedSet<PackageSpecification> visibility;
     private ImmutableMap<String, Attribute> aspectAttributes;
+    private ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>> skylarkProviderRegistry;
 
     Builder(
         AnalysisEnvironment env,
@@ -1393,6 +1407,16 @@ public final class RuleContext extends TargetContext
       return this;
     }
 
+    /**
+     * Sets a map that indicates which providers should be exported to skylark under the key
+     * (map key).  These provider types will also be exportable by skylark rules under (map key).
+     */
+    Builder setSkylarkProvidersRegistry(
+        ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>> skylarkProviderRegistry) {
+      this.skylarkProviderRegistry = skylarkProviderRegistry;
+      return this;
+    }
+
     private boolean validateFilesetEntry(FilesetEntry filesetEntry, ConfiguredTarget src) {
       if (src.getProvider(FilesetProvider.class) != null) {
         return true;
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java
index 674a88107e..f2f909a4a0 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java
@@ -16,6 +16,7 @@ package com.google.devtools.build.lib.bazel.rules;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Functions;
+import com.google.common.collect.ImmutableBiMap;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.analysis.BaseRuleClasses;
@@ -23,6 +24,7 @@ import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider;
 import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider.PrerequisiteValidator;
 import com.google.devtools.build.lib.analysis.ConfiguredTarget;
 import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.config.BuildOptions;
 import com.google.devtools.build.lib.analysis.config.ConfigRuleClasses;
@@ -129,6 +131,7 @@ import com.google.devtools.build.lib.rules.objc.ObjcFrameworkRule;
 import com.google.devtools.build.lib.rules.objc.ObjcImportRule;
 import com.google.devtools.build.lib.rules.objc.ObjcLibraryRule;
 import com.google.devtools.build.lib.rules.objc.ObjcProtoLibraryRule;
+import com.google.devtools.build.lib.rules.objc.ObjcProvider;
 import com.google.devtools.build.lib.rules.objc.ObjcRuleClasses;
 import com.google.devtools.build.lib.rules.objc.ObjcXcodeprojRule;
 import com.google.devtools.build.lib.rules.proto.BazelProtoLibraryRule;
@@ -241,10 +244,19 @@ public class BazelRuleClassProvider {
   /**
    * Java objects accessible from Skylark rule implementations using this module.
    */
-  public static final ImmutableMap<String, Object> skylarkBuiltinJavaObects =
+  public static final ImmutableMap<String, Object> SKYLARK_BUILT_IN_JAVA_OBJECTS =
       ImmutableMap.of(
           "android_common", new AndroidSkylarkCommon(),
           "apple_common", new AppleSkylarkCommon());
+  /**
+   * Native provider types registered for use in skylark.  If these provider types are exported
+   * by native rules, they will be made accessible to dependent skylark rules. They also can
+   * be exported by skylark rules under the name (map key).
+   */
+  private static final ImmutableBiMap<String, Class<? extends TransitiveInfoProvider>>
+      SKYLARK_PROVIDERS_TO_REGISTER =
+          ImmutableBiMap.<String, Class<? extends TransitiveInfoProvider>>of(
+              ObjcProvider.OBJC_SKYLARK_PROVIDER_NAME, ObjcProvider.class);
 
   public static void setup(ConfiguredRuleClassProvider.Builder builder) {
     builder
@@ -256,7 +268,8 @@ public class BazelRuleClassProvider {
         .setRunfilesPrefix("__main__")
         .setToolsRepository(TOOLS_REPOSITORY)
         .setPrerequisiteValidator(new BazelPrerequisiteValidator())
-        .setSkylarkAccessibleTopLevels(skylarkBuiltinJavaObects);
+        .setSkylarkAccessibleTopLevels(SKYLARK_BUILT_IN_JAVA_OBJECTS)
+        .setSkylarkProviderRegistry(SKYLARK_PROVIDERS_TO_REGISTER);
 
     builder.addBuildOptions(BUILD_OPTIONS);
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleConfiguredTargetBuilder.java b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleConfiguredTargetBuilder.java
index 263fc49468..0cc409fd74 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleConfiguredTargetBuilder.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleConfiguredTargetBuilder.java
@@ -23,6 +23,7 @@ import com.google.devtools.build.lib.analysis.Runfiles;
 import com.google.devtools.build.lib.analysis.RunfilesProvider;
 import com.google.devtools.build.lib.analysis.RunfilesSupport;
 import com.google.devtools.build.lib.analysis.SkylarkProviderValidationUtil;
+import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.events.Location;
@@ -60,9 +61,14 @@ import java.util.Map;
 public final class SkylarkRuleConfiguredTargetBuilder {
 
   /**
-   * Create a Rule Configured Target from the ruleContext and the ruleImplementation.
+   * Create a Rule Configured Target from the ruleContext and the ruleImplementation.  The
+   * registeredProviderTypes map indicates which keys in structs returned by skylark rules
+   * should be interpreted as native TransitiveInfoProvider instances of type (map value).
    */
-  public static ConfiguredTarget buildRule(RuleContext ruleContext, BaseFunction ruleImplementation)
+  public static ConfiguredTarget buildRule(
+      RuleContext ruleContext,
+      BaseFunction ruleImplementation,
+      Map<String, Class<? extends TransitiveInfoProvider>> registeredProviderTypes)
       throws InterruptedException {
     String expectFailure = ruleContext.attributes().get("expect_failure", Type.STRING);
     try (Mutability mutability = Mutability.create("configured target")) {
@@ -90,7 +96,8 @@ public final class SkylarkRuleConfiguredTargetBuilder {
         ruleContext.ruleError("Expected failure not found: " + expectFailure);
         return null;
       }
-      ConfiguredTarget configuredTarget = createTarget(ruleContext, target);
+      ConfiguredTarget configuredTarget =
+          createTarget(ruleContext, target, registeredProviderTypes);
       SkylarkProviderValidationUtil.checkOrphanArtifacts(ruleContext);
       return configuredTarget;
     } catch (EvalException e) {
@@ -131,7 +138,10 @@ public final class SkylarkRuleConfiguredTargetBuilder {
 
   // TODO(bazel-team): this whole defaulting - overriding executable, runfiles and files_to_build
   // is getting out of hand. Clean this whole mess up.
-  private static ConfiguredTarget createTarget(RuleContext ruleContext, Object target)
+  private static ConfiguredTarget createTarget(
+      RuleContext ruleContext,
+      Object target,
+      Map<String, Class<? extends TransitiveInfoProvider>> registeredProviderTypes)
       throws EvalException {
     Artifact executable = getExecutable(ruleContext, target);
     RuleConfiguredTargetBuilder builder = new RuleConfiguredTargetBuilder(ruleContext);
@@ -142,7 +152,7 @@ public final class SkylarkRuleConfiguredTargetBuilder {
       filesToBuild.add(executable);
     }
     builder.setFilesToBuild(filesToBuild.build());
-    return addStructFields(ruleContext, builder, target, executable);
+    return addStructFields(ruleContext, builder, target, executable, registeredProviderTypes);
   }
 
   private static Artifact getExecutable(RuleContext ruleContext, Object target)
@@ -206,8 +216,12 @@ public final class SkylarkRuleConfiguredTargetBuilder {
     }
   }
 
-  private static ConfiguredTarget addStructFields(RuleContext ruleContext,
-      RuleConfiguredTargetBuilder builder, Object target, Artifact executable)
+  private static ConfiguredTarget addStructFields(
+      RuleContext ruleContext,
+      RuleConfiguredTargetBuilder builder,
+      Object target,
+      Artifact executable,
+      Map<String, Class<? extends TransitiveInfoProvider>> registeredProviderTypes)
       throws EvalException {
     Location loc = null;
     Runfiles statelessRunfiles = null;
@@ -268,6 +282,10 @@ public final class SkylarkRuleConfiguredTargetBuilder {
                   InstrumentedFilesCollector.NO_METADATA_COLLECTOR,
                   Collections.<Artifact>emptySet());
           builder.addProvider(InstrumentedFilesProvider.class, instrumentedFilesProvider);
+        } else if (registeredProviderTypes.containsKey(key)) {
+          Class<? extends TransitiveInfoProvider> providerType = registeredProviderTypes.get(key);
+          TransitiveInfoProvider provider = cast(key, struct, providerType, loc);
+          builder.addProvider(providerType, provider);
         } else if (!key.equals("executable")) {
           // We handled executable already.
           builder.addSkylarkTransitiveInfo(key, struct.getValue(key), loc);
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/AppleSkylarkCommon.java b/src/main/java/com/google/devtools/build/lib/rules/objc/AppleSkylarkCommon.java
index f77e8ba1b7..a8d9931cd6 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/AppleSkylarkCommon.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/AppleSkylarkCommon.java
@@ -14,9 +14,18 @@
 
 package com.google.devtools.build.lib.rules.objc;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.devtools.build.lib.rules.apple.AppleToolchain;
+import com.google.devtools.build.lib.rules.objc.ObjcProvider.Key;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature.Param;
+import com.google.devtools.build.lib.syntax.BuiltinFunction;
+import com.google.devtools.build.lib.syntax.SkylarkDict;
+import com.google.devtools.build.lib.syntax.SkylarkSignatureProcessor;
+
+import java.util.Map.Entry;
 
 /**
  * A class that exposes apple rule implementation internals to skylark.
@@ -26,6 +35,25 @@ import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
   doc = "Functions for skylark to access internals of the apple rule implementations."
 )
 public class AppleSkylarkCommon {
+ 
+  @VisibleForTesting
+  public static final String BAD_KEY_ERROR = "Argument %s not a recognized key or 'providers'.";
+
+  @VisibleForTesting
+  public static final String BAD_SET_TYPE_ERROR =
+      "Value for key %s must be a set of %s, instead found set of %s.";
+
+  @VisibleForTesting
+  public static final String BAD_PROVIDERS_ITER_ERROR =
+      "Value for argument 'providers' must be a list of ObjcProvider instances, instead found %s.";
+
+  @VisibleForTesting
+  public static final String BAD_PROVIDERS_ELEM_ERROR =
+      "Value for argument 'providers' must be a list of ObjcProvider instances, instead found "
+          + "iterable with %s.";
+
+  @VisibleForTesting
+  public static final String NOT_SET_ERROR = "Value for key %s must be a set, instead found %s.";
   
   @SkylarkCallable(
       name = "apple_toolchain",
@@ -34,14 +62,46 @@ public class AppleSkylarkCommon {
   public AppleToolchain getAppleToolchain() {
     return new AppleToolchain();
   }
-  
-  @SkylarkCallable(
-      name = "keys",
-      doc = "Retrieves ObjcProvider keys",
-      structField = true
+
+  @SkylarkSignature(
+    name = "new_objc_provider",
+    objectType = AppleSkylarkCommon.class,
+    returnType = ObjcProvider.class,
+    doc = "Creates a new ObjcProvider instance.",
+    mandatoryPositionals = {
+      @Param(name = "self", type = AppleSkylarkCommon.class, doc = "The apple_common instance.")
+    },
+    extraKeywords = {
+      @Param(
+        name = "kwargs",
+        type = SkylarkDict.class,
+        defaultValue = "{}",
+        doc = "Dictionary of arguments"
+      )
+    }
   )
-  public SkylarkKeyStore getKeys() {
-    return new SkylarkKeyStore();
-  } 
+  public static final BuiltinFunction NEW_OBJC_PROVIDER =
+      new BuiltinFunction("new_objc_provider") {
+        @SuppressWarnings("unused")
+        // This method is registered statically for skylark, and never called directly.
+        public ObjcProvider invoke(AppleSkylarkCommon self, SkylarkDict<String, Object> kwargs) {
+          ObjcProvider.Builder resultBuilder = new ObjcProvider.Builder();
+          for (Entry<String, Object> entry : kwargs.entrySet()) {
+            Key<?> key = ObjcProvider.getSkylarkKeyForString(entry.getKey());
+            if (key != null) {
+              resultBuilder.addElementsFromSkylark(key, entry.getValue());
+            } else if (entry.getKey().equals("providers")) {
+              resultBuilder.addProvidersFromSkylark(entry.getValue());
+            } else {
+              throw new IllegalArgumentException(String.format(BAD_KEY_ERROR, entry.getKey()));
+            }
+          }
+          return resultBuilder.build();
+        }
+      };
+
+  static {
+    SkylarkSignatureProcessor.configureSkylarkFunctions(AppleSkylarkCommon.class);
+  }
 }
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/BinaryLinkingTargetFactory.java b/src/main/java/com/google/devtools/build/lib/rules/objc/BinaryLinkingTargetFactory.java
index 442a847494..d06a374f07 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/BinaryLinkingTargetFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/BinaryLinkingTargetFactory.java
@@ -27,7 +27,6 @@ import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
 import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder;
 import com.google.devtools.build.lib.analysis.RuleContext;
 import com.google.devtools.build.lib.analysis.RunfilesSupport;
-import com.google.devtools.build.lib.analysis.SkylarkProviders;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
 import com.google.devtools.build.lib.rules.apple.AppleConfiguration;
@@ -38,7 +37,6 @@ import com.google.devtools.build.lib.rules.objc.ObjcCommon.CompilationAttributes
 import com.google.devtools.build.lib.rules.objc.ObjcCommon.ResourceAttributes;
 import com.google.devtools.build.lib.rules.objc.ReleaseBundlingSupport.LinkedBinary;
 import com.google.devtools.build.lib.rules.test.InstrumentedFilesProvider;
-import com.google.devtools.build.lib.syntax.ClassObject.SkylarkClassObject;
 
 /**
  * Implementation for rules that link binaries.
@@ -173,10 +171,7 @@ abstract class BinaryLinkingTargetFactory implements RuleConfiguredTargetFactory
             .addProvider(ObjcProvider.class, objcProvider)
             .addProvider(
                 InstrumentedFilesProvider.class,
-                compilationSupport.getInstrumentedFilesProvider(common))
-            .addSkylarkTransitiveInfo(
-                ObjcProvider.OBJC_SKYLARK_PROVIDER_NAME,
-                common.getObjcProvider().toSkylarkProvider());
+                compilationSupport.getInstrumentedFilesProvider(common));
     if (xcTestAppProvider.isPresent()) {
       // TODO(bazel-team): Stop exporting an XcTestAppProvider once objc_binary no longer creates an
       // application bundle.
@@ -222,8 +217,6 @@ abstract class BinaryLinkingTargetFactory implements RuleConfiguredTargetFactory
             .setHasModuleMap()
             .setLinkedBinary(intermediateArtifacts.strippedSingleArchitectureBinary());
 
-    builder.addDepObjcProviders(createSkylarkObjcProviders(ruleContext));
-    
     if (ObjcRuleClasses.objcConfiguration(ruleContext).generateDebugSymbols()
         || ObjcRuleClasses.objcConfiguration(ruleContext).generateDsym()) {
       builder.addDebugArtifacts(DsymOutputType.APP);
@@ -237,25 +230,6 @@ abstract class BinaryLinkingTargetFactory implements RuleConfiguredTargetFactory
   }
 
   /**
-   * Constructs an ObjcProvider instance for each skylark objc provider in this target's
-   * dependencies.
-   */
-  private Iterable<ObjcProvider> createSkylarkObjcProviders(RuleContext ruleContext) {
-     ImmutableList.Builder<ObjcProvider> skylarkProviderListBuilder = ImmutableList.builder();
-    for (SkylarkProviders skylarkProviders :
-        ruleContext.getPrerequisites("deps", Mode.TARGET, SkylarkProviders.class)) {
-      Object objcSkylarkProvider =
-          skylarkProviders.getValue(ObjcProvider.OBJC_SKYLARK_PROVIDER_TO_EXPORT_NAME);
-      if (objcSkylarkProvider != null) {
-        ObjcProvider objcProviderFromSkylark =
-            ObjcProvider.fromSkylarkProvider((SkylarkClassObject) objcSkylarkProvider);
-        skylarkProviderListBuilder.add(objcProviderFromSkylark);
-      }
-    }
-    return skylarkProviderListBuilder.build();
-  }
-  
-  /**
    * Performs additional configuration of the target. The default implementation does nothing, but
    * subclasses may override it to add logic.
    */
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcLibrary.java b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcLibrary.java
index c2dce23cbb..fd37871cc8 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcLibrary.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcLibrary.java
@@ -82,8 +82,6 @@ public class J2ObjcLibrary implements RuleConfiguredTargetFactory {
             J2ObjcMappingFileProvider.class, ObjcRuleClasses.j2ObjcMappingFileProvider(ruleContext))
         .addProvider(ObjcProvider.class, objcProvider)
         .addProvider(XcodeProvider.class, xcodeProviderBuilder.build())
-        .addSkylarkTransitiveInfo(
-            ObjcProvider.OBJC_SKYLARK_PROVIDER_NAME, objcProvider.toSkylarkProvider())
         .build();
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcLibrary.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcLibrary.java
index 991a6d83be..aad16f1e1b 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcLibrary.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcLibrary.java
@@ -143,8 +143,6 @@ public class ObjcLibrary implements RuleConfiguredTargetFactory {
         .addProvider(
             CcLinkParamsProvider.class,
             new CcLinkParamsProvider(new ObjcLibraryCcLinkParamsStore(common)))
-        .addSkylarkTransitiveInfo(
-            ObjcProvider.OBJC_SKYLARK_PROVIDER_NAME, common.getObjcProvider().toSkylarkProvider())
         .build();
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoLibrary.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoLibrary.java
index e46d8204ec..c7b115f79a 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoLibrary.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoLibrary.java
@@ -64,8 +64,6 @@ public class ObjcProtoLibrary implements RuleConfiguredTargetFactory {
     return ObjcRuleClasses.ruleConfiguredTarget(ruleContext, filesToBuild.build())
         .addProvider(XcodeProvider.class, xcodeProviderBuilder.build())
         .addProvider(ObjcProvider.class, common.getObjcProvider())
-        .addSkylarkTransitiveInfo(
-            ObjcProvider.OBJC_SKYLARK_PROVIDER_NAME, common.getObjcProvider().toSkylarkProvider())
         .build();
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java
index 91f5c1fca2..92ddc73b3f 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java
@@ -28,10 +28,10 @@ import com.google.devtools.build.lib.collect.nestedset.Order;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.rules.cpp.CppModuleMap;
 import com.google.devtools.build.lib.rules.cpp.LinkerInputs;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.syntax.ClassObject.SkylarkClassObject;
 import com.google.devtools.build.lib.syntax.SkylarkNestedSet;
+import com.google.devtools.build.lib.syntax.SkylarkType;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.xcode.xcodegen.proto.XcodeGenProtos.TargetControl;
@@ -44,29 +44,19 @@ import java.util.Map;
  * deps that are needed for building Objective-C rules.
  */
 @Immutable
-public final class ObjcProvider implements TransitiveInfoProvider {
+@SkylarkModule(name = "ObjcProvider", doc = "A provider for compilation and linking of objc.")
+public final class ObjcProvider extends SkylarkClassObject implements TransitiveInfoProvider {
 
   /**
-   * The name skylark dependents can use to access a Skylark provider containing information
-   * from a target's ObjcProvider.
+   * The skylark struct key name for a rule implementation to use when exporting an ObjcProvider.
    */
   public static final String OBJC_SKYLARK_PROVIDER_NAME = "objc";
 
   /**
-   * The name skylark dependents can use to export a native objc provider to depending native
-   * rules.
-   *
-   * <p>This constant must be different from OBJC_SKYLARK_PROVIDER_NAME to prevent skylark rules
-   * from automatically exporting the ObjcProvider provided to them by dependents.  This can
-   * lead to duplicate symbol linker errors.
-   */
-  public static final String OBJC_SKYLARK_PROVIDER_TO_EXPORT_NAME = "objc_export";
-
-  /**
    * Represents one of the things this provider can provide transitively. Things are provided as
    * {@link NestedSet}s of type E.
    */
-  @SkylarkModule(name = "Key", doc = "An ObjcProvider key.")
+  @Immutable
   public static class Key<E> {
     private final Order order;
     private final String skylarkKeyName;
@@ -81,7 +71,6 @@ public final class ObjcProvider implements TransitiveInfoProvider {
     /**
      * Returns the name of the collection represented by this key in the Skylark provider.
      */
-    @SkylarkCallable(name = "name", structField = true)
     public String getSkylarkKeyName() {
       return skylarkKeyName;
     }
@@ -95,6 +84,7 @@ public final class ObjcProvider implements TransitiveInfoProvider {
   }
 
   public static final Key<Artifact> LIBRARY = new Key<>(LINK_ORDER, "library", Artifact.class);
+  
   public static final Key<Artifact> IMPORTED_LIBRARY =
       new Key<>(LINK_ORDER, "imported_library", Artifact.class);
 
@@ -339,6 +329,51 @@ public final class ObjcProvider implements TransitiveInfoProvider {
 
   // Items which should not be propagated to dependents.
   private final ImmutableMap<Key<?>, NestedSet<?>> nonPropagatedItems;
+  /**
+   * All keys in ObjcProvider that will be passed in the corresponding Skylark provider.
+   */
+  // Only keys for Artifact or primitive types can be in the Skylark provider, as other types
+  // are not supported as Skylark types.
+  // Note: This list is only required to support objcprovider <-> skylarkprovider conversion, which
+  // will be removed in favor of native skylark ObjcProvider access once that is implemented.
+  static final ImmutableList<Key<?>> KEYS_FOR_SKYLARK =
+      ImmutableList.<Key<?>>of(
+          LIBRARY,
+          IMPORTED_LIBRARY,
+          LINKED_BINARY,
+          FORCE_LOAD_LIBRARY,
+          HEADER,
+          SOURCE,
+          DEFINE,
+          ASSET_CATALOG,
+          SDK_DYLIB,
+          XCDATAMODEL,
+          MODULE_MAP,
+          MERGE_ZIP,
+          FRAMEWORK_FILE,
+          DEBUG_SYMBOLS,
+          DEBUG_SYMBOLS_PLIST,
+          BREAKPAD_FILE,
+          STORYBOARD,
+          XIB,
+          STRINGS,
+          LINKOPT,
+          J2OBJC_LIBRARY,
+          ROOT_MERGE_ZIP);
+
+  /**
+   * Returns the skylark key for the given string, or null if no such key exists or is available
+   * to Skylark.
+   */
+  static Key<?> getSkylarkKeyForString(String keyName) {
+    Key<?> result = null;
+    for (Key<?> candidateKey : KEYS_FOR_SKYLARK) {
+      if (candidateKey.getSkylarkKeyName().equals(keyName)) {
+        return candidateKey;
+      }
+    }
+    return null;
+  }
 
   // Items which should be passed to strictly direct dependers, but not transitive dependers.
   private final ImmutableMap<Key<?>, NestedSet<?>> strictDependencyItems;
@@ -346,7 +381,9 @@ public final class ObjcProvider implements TransitiveInfoProvider {
   private ObjcProvider(
       ImmutableMap<Key<?>, NestedSet<?>> items,
       ImmutableMap<Key<?>, NestedSet<?>> nonPropagatedItems,
-      ImmutableMap<Key<?>, NestedSet<?>> strictDependencyItems) {
+      ImmutableMap<Key<?>, NestedSet<?>> strictDependencyItems,
+      ImmutableMap<String, Object> skylarkFields) {
+    super(skylarkFields, "ObjcProvider field %s could not be instantiated");
     this.items = Preconditions.checkNotNull(items);
     this.nonPropagatedItems = Preconditions.checkNotNull(nonPropagatedItems);
     this.strictDependencyItems = Preconditions.checkNotNull(strictDependencyItems);
@@ -387,35 +424,6 @@ public final class ObjcProvider implements TransitiveInfoProvider {
   }
 
   /**
-   * Returns a {@code SkylarkClassObject} containing values from this provider that is suitable
-   * for a skylark provider.
-   */
-  public SkylarkClassObject toSkylarkProvider() {
-    ImmutableMap.Builder<String, Object> providerBuilder = ImmutableMap.<String, Object>builder();
-    for (Key<?> key : SkylarkKeyStore.KEYS_FOR_SKYLARK) {
-      providerBuilder.put(key.getSkylarkKeyName(), new SkylarkNestedSet(key.getType(), get(key)));
-    }
-    return new SkylarkClassObject(providerBuilder.build(), "No such attribute '%s'");
-  }
-
-  /**
-   * Returns an {@code ObjcProvider} from a given skylark provider.  For each candidate key
-   * in the ObjcProvider, will check the given skylark provider to see if that key is represented
-   * in the returned struct.
-   */
-  public static ObjcProvider fromSkylarkProvider(SkylarkClassObject skylarkProvider) {
-    Builder builder = new Builder();
-    for (Key<?> key : SkylarkKeyStore.KEYS_FOR_SKYLARK) {
-      SkylarkNestedSet skylarkSet =
-          (SkylarkNestedSet) skylarkProvider.getValue(key.getSkylarkKeyName());
-      if (skylarkSet != null) {
-        builder.uncheckedAddAll(key, skylarkSet.getSet(key.getType()), builder.items);
-      }
-    }
-    return builder.build();
-  }
-
-  /**
    * A builder for this context with an API that is optimized for collecting information from
    * several transitive dependencies.
    */
@@ -576,20 +584,83 @@ public final class ObjcProvider implements TransitiveInfoProvider {
       return this;
     }
 
+    /**
+     * Add elements in toAdd with the given key from skylark.  An error is thrown if toAdd is not
+     * an appropriate SkylarkNestedSet.
+     */
+    void addElementsFromSkylark(Key<?> key, Object toAdd) {
+      if (!(toAdd instanceof SkylarkNestedSet)) {
+        throw new IllegalArgumentException(
+            String.format(
+                AppleSkylarkCommon.NOT_SET_ERROR, key.getSkylarkKeyName(), toAdd.getClass()));
+      } else if (!((SkylarkNestedSet) toAdd).getContentType().canBeCastTo(key.getType())) {
+        throw new IllegalArgumentException(
+            String.format(
+                AppleSkylarkCommon.BAD_SET_TYPE_ERROR,
+                key.getSkylarkKeyName(),
+                key.getType(),
+                ((SkylarkNestedSet) toAdd).getContentType().getType()));
+      } else {
+        uncheckedAddAll(key, (SkylarkNestedSet) toAdd, this.items);
+      }
+    }
+
+    /**
+     * Adds the given providers from skylark.  An error is thrown if toAdd is not an iterable of
+     * ObjcProvider instances.
+     */
+    @SuppressWarnings("unchecked")
+    void addProvidersFromSkylark(Object toAdd) {
+      if (!(toAdd instanceof Iterable)) {
+        throw new IllegalArgumentException(
+            String.format(AppleSkylarkCommon.BAD_PROVIDERS_ITER_ERROR, toAdd.getClass()));
+      } else {
+        Iterable<Object> toAddIterable = (Iterable<Object>) toAdd;
+        for (Object toAddObject : toAddIterable) {
+          if (!(toAddObject instanceof ObjcProvider)) {
+            throw new IllegalArgumentException(
+                String.format(AppleSkylarkCommon.BAD_PROVIDERS_ELEM_ERROR, toAddObject.getClass()));
+          } else {
+            this.addTransitiveAndPropagate((ObjcProvider) toAddObject);
+          }
+        }
+      }
+    }
+    
     public ObjcProvider build() {
-      ImmutableMap.Builder<Key<?>, NestedSet<?>> propagated = new ImmutableMap.Builder<>();
+      ImmutableMap.Builder<Key<?>, NestedSet<?>> propagatedBuilder = new ImmutableMap.Builder<>();
       for (Map.Entry<Key<?>, NestedSetBuilder<?>> typeEntry : items.entrySet()) {
-        propagated.put(typeEntry.getKey(), typeEntry.getValue().build());
+        propagatedBuilder.put(typeEntry.getKey(), typeEntry.getValue().build());
       }
-      ImmutableMap.Builder<Key<?>, NestedSet<?>> nonPropagated = new ImmutableMap.Builder<>();
+      ImmutableMap.Builder<Key<?>, NestedSet<?>> nonPropagatedBuilder =
+          new ImmutableMap.Builder<>();
       for (Map.Entry<Key<?>, NestedSetBuilder<?>> typeEntry : nonPropagatedItems.entrySet()) {
-        nonPropagated.put(typeEntry.getKey(), typeEntry.getValue().build());
+        nonPropagatedBuilder.put(typeEntry.getKey(), typeEntry.getValue().build());
       }
-      ImmutableMap.Builder<Key<?>, NestedSet<?>> strictDependency = new ImmutableMap.Builder<>();
+      ImmutableMap.Builder<Key<?>, NestedSet<?>> strictDependencyBuilder =
+          new ImmutableMap.Builder<>();
       for (Map.Entry<Key<?>, NestedSetBuilder<?>> typeEntry : strictDependencyItems.entrySet()) {
-        strictDependency.put(typeEntry.getKey(), typeEntry.getValue().build());
+        strictDependencyBuilder.put(typeEntry.getKey(), typeEntry.getValue().build());
+      }
+
+      ImmutableMap<Key<?>, NestedSet<?>> propagated = propagatedBuilder.build();
+      ImmutableMap<Key<?>, NestedSet<?>> nonPropagated = nonPropagatedBuilder.build();
+      ImmutableMap<Key<?>, NestedSet<?>> strictDependency = strictDependencyBuilder.build();
+
+      ImmutableMap.Builder<String, Object> skylarkFields = new ImmutableMap.Builder<>();
+      for (Key<?> key : KEYS_FOR_SKYLARK) {
+        SkylarkType type = SkylarkType.of(key.getType());
+        if (items.containsKey(key)) {
+          skylarkFields.put(
+              key.getSkylarkKeyName(), SkylarkNestedSet.of(type, propagated.get(key)));
+        }
+        if (strictDependency.containsKey(key)) {
+          skylarkFields.put(
+              key.getSkylarkKeyName(), SkylarkNestedSet.of(type, strictDependency.get(key)));
+        }
       }
-      return new ObjcProvider(propagated.build(), nonPropagated.build(), strictDependency.build());
+
+      return new ObjcProvider(propagated, nonPropagated, strictDependency, skylarkFields.build());
     }
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/SkylarkKeyStore.java b/src/main/java/com/google/devtools/build/lib/rules/objc/SkylarkKeyStore.java
deleted file mode 100644
index 0b99bdcdc1..0000000000
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/SkylarkKeyStore.java
+++ /dev/null
@@ -1,246 +0,0 @@
-// Copyright 2016 The Bazel Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//    http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package com.google.devtools.build.lib.rules.objc;
-
-import com.google.common.collect.ImmutableList;
-import com.google.devtools.build.lib.actions.Artifact;
-import com.google.devtools.build.lib.rules.objc.ObjcProvider.Key;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
-
-/**
- * A container for valid ObjcProvider keys, to be provided to skylark.
- */
-@SkylarkModule(
-  name = "objc_provider_keys_store",
-  doc = "A container for valid ObjcProvider keys."
-)
-public class SkylarkKeyStore {
-  
-  @SkylarkCallable(
-      name = "library",
-      doc = "Returns a key that gives libraries in this target"
-  )
-  public static Key<Artifact> getLibrary() {
-    return ObjcProvider.LIBRARY;
-  }
-  
-  @SkylarkCallable(
-      name = "imported_library",
-      doc = "Returns a key that gives imported libraries in this target"
-  )
-  public static Key<Artifact> getImportedLibrary() {
-    return ObjcProvider.IMPORTED_LIBRARY;
-  }
-  
-  @SkylarkCallable(
-      name = "linked_binary",
-      doc = "Returns a key that gives single-architecture linked binaries to "
-          + "be combined into a multi-architecture binary"
-  )
-  public static Key<Artifact> getLinkedBinary() {
-    return ObjcProvider.LINKED_BINARY;
-  }
-  
-  @SkylarkCallable(
-      name = "force_load_library",
-      doc = "Returns a key that  gives libraries to laod with the "
-          + "'-force_load' flag."
-  )
-  public static Key<Artifact> getForceLoadLibrary() {
-    return ObjcProvider.FORCE_LOAD_LIBRARY;
-  }
-  
-  @SkylarkCallable(
-      name = "header",
-      doc = "Returns a key that gives all header files."
-  )
-  public static Key<Artifact> getHeader() {
-    return ObjcProvider.HEADER;
-  }
- 
-  @SkylarkCallable(
-      name = "source",
-      doc = "Returns a key that gives all source files."
-  )
-  public static Key<Artifact> getSource() {
-    return ObjcProvider.SOURCE;
-  }
-
-  @SkylarkCallable(
-      name = "define",
-      doc = "Returns a key that  gives all values in 'defines' attributes."
-  )
-  public static Key<String> getDefine() {
-    return ObjcProvider.DEFINE;
-  }
-
-  @SkylarkCallable(
-      name = "asset_catalog",
-      doc = "Returns the 'ASSET_CATALOG' key."
-  )
-  public static Key<Artifact> getAssetCatalog() {
-    return ObjcProvider.ASSET_CATALOG;
-  }
-  
-  @SkylarkCallable(
-      name = "sdk_dylib",
-      doc = "Returns the 'SDK_DYLIB' key."
-  )
-  public static Key<String> getSdkDylib() {
-    return ObjcProvider.SDK_DYLIB;
-  }
-  
-  @SkylarkCallable(
-      name = "xcdatamodel",
-      doc = "Returns the 'XCDATAMODEL' key."
-  )
-  public static Key<Artifact> getXcDataModel() {
-    return ObjcProvider.XCDATAMODEL;
-  }
-
-  @SkylarkCallable(
-      name = "module_map",
-      doc = "Returns a key that gives clang module maps."
-  )
-  public static Key<Artifact> getModuleMap() {
-    return ObjcProvider.MODULE_MAP;
-  }
-
-  @SkylarkCallable(
-      name = "merge_zip",
-      doc = "Returns a key that gives zips to include in the bundle."
-  )
-  public static Key<Artifact> getMergeZip() {
-    return ObjcProvider.MERGE_ZIP;
-  }
-
-  @SkylarkCallable(
-      name = "root_merge_zip",
-      doc = "Returns a key that gives zips to include outside the bundle."
-  )
-  public static Key<Artifact> getRootMergeZip() {
-    return ObjcProvider.ROOT_MERGE_ZIP;
-  }
-
-  @SkylarkCallable(
-      name = "framework_file",
-      doc = "Returns a key that gives .framework files to be included in "
-          + "compilation and linking."
-  )
-  public static Key<Artifact> getFrameworkFile() {
-    return ObjcProvider.FRAMEWORK_FILE;
-  }
-
-  @SkylarkCallable(
-      name = "debug_symbols",
-      doc = "Returns a key that gives an artifact containing debug symbol "
-          + "information."
-  )
-  public static Key<Artifact> getDebugSymbols() {
-    return ObjcProvider.DEBUG_SYMBOLS;
-  }
-
-  @SkylarkCallable(
-      name = "debug_symbols_plist",
-      doc = "Returns a key that gives an artifact containing the plist "
-          + "on debug symbols."
-  )
-  public static Key<Artifact> getDebugSymbolsPlist() {
-    return ObjcProvider.DEBUG_SYMBOLS_PLIST;
-  }
-  
-  @SkylarkCallable(
-      name = "breakpad_file",
-      doc = "Returns a key that gives the generated breakpad file for crash "
-          + "reporting."
-  )
-  public static Key<Artifact> getBreakpadFile() {
-    return ObjcProvider.BREAKPAD_FILE;
-  }
-  
-  @SkylarkCallable(
-      name = "storyboard",
-      doc = "Returns a key that gives artifacts for storyboard sources."
-  )
-  public static Key<Artifact> getStoryboard() {
-    return ObjcProvider.STORYBOARD;
-  }
-
-  @SkylarkCallable(
-      name = "xib",
-      doc = "Returns a key that gives artifacts for .xib file sources."
-  )
-  public static Key<Artifact> getXib() {
-    return ObjcProvider.XIB;
-  }
-
-  @SkylarkCallable(
-      name = "strings",
-      doc = "Returns a key that gives artifacts for strings source files."
-  )
-  public static Key<Artifact> getStrings() {
-    return ObjcProvider.STRINGS;
-  }
-  
-  @SkylarkCallable(
-      name = "linkopt",
-      doc = "Returns a key that gives linking options from dependencies."
-  )
-  public static Key<String> getLinkopt() {
-    return ObjcProvider.LINKOPT;
-  }
- 
-  @SkylarkCallable(
-      name = "j2objc_library",
-      doc = "Returns a key that gives static libraries that are built from "
-          + "J2ObjC-translated Java code."
-  )
-  public static Key<Artifact> getJ2ObjcLibrary() {
-    return ObjcProvider.J2OBJC_LIBRARY;
-  }
-  
-  /**
-   * All keys in ObjcProvider that will be passed in the corresponding Skylark provider.
-   */
-  // Only keys for Artifact or primitive types can be in the Skylark provider, as other types
-  // are not supported as Skylark types.
-  // Note: This list is only required to support objcprovider <-> skylarkprovider conversion, which
-  // will be removed in favor of native skylark ObjcProvider access once that is implemented.
-  static final ImmutableList<ObjcProvider.Key<?>> KEYS_FOR_SKYLARK =
-      ImmutableList.<ObjcProvider.Key<?>>of(
-          ObjcProvider.LIBRARY,
-          ObjcProvider.IMPORTED_LIBRARY,
-          ObjcProvider.LINKED_BINARY,
-          ObjcProvider.FORCE_LOAD_LIBRARY,
-          ObjcProvider.HEADER,
-          ObjcProvider.SOURCE,
-          ObjcProvider.DEFINE,
-          ObjcProvider.ASSET_CATALOG,
-          ObjcProvider.SDK_DYLIB,
-          ObjcProvider.XCDATAMODEL,
-          ObjcProvider.MODULE_MAP,
-          ObjcProvider.MERGE_ZIP,
-          ObjcProvider.FRAMEWORK_FILE,
-          ObjcProvider.DEBUG_SYMBOLS,
-          ObjcProvider.DEBUG_SYMBOLS_PLIST,
-          ObjcProvider.BREAKPAD_FILE,
-          ObjcProvider.STORYBOARD,
-          ObjcProvider.XIB,
-          ObjcProvider.STRINGS,
-          ObjcProvider.LINKOPT,
-          ObjcProvider.J2OBJC_LIBRARY,
-          ObjcProvider.ROOT_MERGE_ZIP);
-}