Remove support for ProtocolBuffers2.

PiperOrigin-RevId: 171013687

6 files changed, 38 insertions, 480 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoAspect.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoAspect.java
index 6a13ac18cc..5d74c1bf94 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoAspect.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoAspect.java
@@ -62,11 +62,10 @@ public class ObjcProtoAspect extends NativeAspectClass implements ConfiguredAspe
 
     ProtoAttributes attributes = new ProtoAttributes(ruleContext);
 
-    // If the rule has the portable_proto_filters or uses_protobuf, it must be an objc_proto_library
-    // configured to use the third party protobuf library, in contrast with the PB2 internal
-    // library. Only the third party library is enabled to propagate the protos with this aspect.
-    // Validation for the correct target attributes is done in ProtoSupport.java.
-    if (attributes.requiresProtobuf()) {
+    // If this current target is an objc_proto_library, only then read the protos and portable
+    // filters it has configured in the attributes and add them to the ObjcProtoProvider.Builder
+    // instance. Validation for the correct target attributes is already done in ProtoSupport.java.
+    if (attributes.isObjcProtoLibrary()) {
 
       // Gather up all the dependency protos depended by this target.
       Iterable<ProtoSourcesProvider> protoProviders =
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 412968ece2..5a3f00553a 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
@@ -31,18 +31,8 @@ public class ObjcProtoLibrary implements RuleConfiguredTargetFactory {
   @Override
   public ConfiguredTarget create(final RuleContext ruleContext)
       throws InterruptedException, RuleErrorException {
-
-    ProtoAttributes attributes = new ProtoAttributes(ruleContext);
-    attributes.validate();
-
-    if (attributes.requiresProtobuf()) {
-      return createProtobufTarget(ruleContext);
-    } else {
-      ruleContext.ruleWarning("The usage of objc_proto_library without the portable_proto_filters "
-          + "attribute has been deprecated with a deadline to migrate set to June 30th. Please "
-          + "refer to b/37274743 for more information.");
-      return createProtocolBuffers2Target(ruleContext);
-    }
+    new ProtoAttributes(ruleContext).validate();
+    return createProtobufTarget(ruleContext);
   }
 
   private ConfiguredTarget createProtobufTarget(RuleContext ruleContext)
@@ -96,19 +86,4 @@ public class ObjcProtoLibrary implements RuleConfiguredTargetFactory {
 
     return portableProtoFilters.build();
   }
-
-  private ConfiguredTarget createProtocolBuffers2Target(RuleContext ruleContext)
-      throws InterruptedException, RuleErrorException {
-    NestedSetBuilder<Artifact> filesToBuild = NestedSetBuilder.stableOrder();
-
-    ProtocolBuffers2Support protoSupport =
-        new ProtocolBuffers2Support(ruleContext)
-            .registerGenerationActions()
-            .registerCompilationActions()
-            .addFilesToBuild(filesToBuild);
-
-    return ObjcRuleClasses.ruleConfiguredTarget(ruleContext, filesToBuild.build())
-        .addNativeDeclaredProvider(protoSupport.getObjcProvider())
-        .build();
-  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoLibraryRule.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoLibraryRule.java
index bddb0a9a85..5a209c878e 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoLibraryRule.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoLibraryRule.java
@@ -28,8 +28,6 @@ import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.analysis.BaseRuleClasses;
 import com.google.devtools.build.lib.analysis.RuleDefinition;
 import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
-import com.google.devtools.build.lib.packages.Attribute.ComputedDefault;
-import com.google.devtools.build.lib.packages.AttributeMap;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.packages.RuleClass.Builder;
 import com.google.devtools.build.lib.rules.apple.AppleConfiguration;
@@ -40,12 +38,9 @@ import com.google.devtools.build.lib.util.FileType;
 /**
  * Rule definition for objc_proto_library.
  *
- * This is a temporary rule until it is better known how to support proto_library rules.
+ * <p>This is a temporary rule until it is better known how to support proto_library rules.
  */
 public class ObjcProtoLibraryRule implements RuleDefinition {
-  static final String OPTIONS_FILE_ATTR = "options_file";
-  static final String USE_OBJC_HEADER_NAMES_ATTR = "use_objc_header_names";
-  static final String PER_PROTO_INCLUDES_ATTR = "per_proto_includes";
   static final String PORTABLE_PROTO_FILTERS_ATTR = "portable_proto_filters";
   static final String USES_PROTOBUF_ATTR = "uses_protobuf";
 
@@ -54,9 +49,8 @@ public class ObjcProtoLibraryRule implements RuleDefinition {
   /**
    * Returns a newly built rule definition for objc_proto_library.
    *
-   * @param objcProtoAspect Aspect that traverses the dependency graph through the deps attribute
-   *                        to gather all proto files and portable filters depended by
-   *                        objc_proto_library targets using the new protobuf compiler/library.
+   * @param objcProtoAspect Aspect that traverses the dependency graph through the deps attribute to
+   *     gather all proto files and portable filters depended by objc_proto_library targets.
    */
   public ObjcProtoLibraryRule(ObjcProtoAspect objcProtoAspect) {
     this.objcProtoAspect = objcProtoAspect;
@@ -68,33 +62,19 @@ public class ObjcProtoLibraryRule implements RuleDefinition {
         .requiresConfigurationFragments(
             CppConfiguration.class, ObjcConfiguration.class, AppleConfiguration.class)
         /* <!-- #BLAZE_RULE(objc_proto_library).ATTRIBUTE(deps) -->
-        The directly depended upon proto_library rules.
+        The directly depended upon proto_library and objc_proto_library rules.
         <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
         .override(
             attr("deps", LABEL_LIST)
-                // Support for files in deps is for backwards compatibility.
-                .allowedRuleClasses("proto_library", "filegroup", "objc_proto_library")
+                .allowedRuleClasses("proto_library", "objc_proto_library")
                 .aspect(objcProtoAspect)
                 .legacyAllowAnyFileType())
-        /* <!-- #BLAZE_RULE(objc_proto_library).ATTRIBUTE(options_file) -->
-        Optional options file to apply to protos which affects compilation (e.g. class
-        whitelist/blacklist settings).
-        <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
-        .add(attr(OPTIONS_FILE_ATTR, LABEL).legacyAllowAnyFileType().singleArtifact().cfg(HOST))
-        /* <!-- #BLAZE_RULE(objc_proto_library).ATTRIBUTE(use_objc_header_names) -->
-        If true, output headers with .pbobjc.h, rather than .pb.h.
-        <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
-        .add(attr(USE_OBJC_HEADER_NAMES_ATTR, BOOLEAN).value(false))
-        /* <!-- #BLAZE_RULE(objc_proto_library).ATTRIBUTE(per_proto_includes) -->
-        If true, always add all directories to objc_library includes.
-        <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
-        .add(attr(PER_PROTO_INCLUDES_ATTR, BOOLEAN).value(false))
         /* <!-- #BLAZE_RULE(objc_proto_library).ATTRIBUTE(uses_protobuf) -->
         Whether to use the new protobuf compiler and runtime for this target. If you enable this
         option without passing portable_proto_filters, it will generate a filter file for all the
         protos that passed through proto_library targets as deps.
         <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
-        .add(attr(USES_PROTOBUF_ATTR, BOOLEAN).value(false))
+        .add(attr(USES_PROTOBUF_ATTR, BOOLEAN).value(true))
         /* <!-- #BLAZE_RULE(objc_proto_library).ATTRIBUTE(portable_proto_filters) -->
         List of portable proto filters to be passed on to the protobuf compiler. This attribute
         cannot be used together with the options_file, output_cpp, per_proto_includes and
@@ -110,42 +90,16 @@ public class ObjcProtoLibraryRule implements RuleDefinition {
                 .allowedFileTypes(FileType.of(".py"), FileType.of(".sh"))
                 .cfg(HOST)
                 .singleArtifact()
-                .value(
-                    new ComputedDefault(PORTABLE_PROTO_FILTERS_ATTR, USES_PROTOBUF_ATTR) {
-                      @Override
-                      public Object getDefault(AttributeMap rule) {
-                        return usesProtobuf(rule)
-                            ? env.getToolsLabel("//tools/objc:protobuf_compiler_wrapper")
-                            : env.getToolsLabel("//tools/objc:compile_protos");
-                      }
-                    }))
+                .value(env.getToolsLabel("//tools/objc:protobuf_compiler_wrapper")))
         .add(
             attr(PROTO_COMPILER_SUPPORT_ATTR, LABEL)
                 .legacyAllowAnyFileType()
                 .cfg(HOST)
-                .value(
-                    new ComputedDefault(PORTABLE_PROTO_FILTERS_ATTR, USES_PROTOBUF_ATTR) {
-                      @Override
-                      public Object getDefault(AttributeMap rule) {
-                        return usesProtobuf(rule)
-                            ? env.getToolsLabel("//tools/objc:protobuf_compiler_support")
-                            : env.getToolsLabel("//tools/objc:proto_support");
-                      }
-                    }))
+                .value(env.getToolsLabel("//tools/objc:protobuf_compiler_support")))
         .add(
             attr(PROTO_LIB_ATTR, LABEL)
                 .allowedRuleClasses("objc_library")
-                .value(
-                    new ComputedDefault(PORTABLE_PROTO_FILTERS_ATTR, USES_PROTOBUF_ATTR) {
-                      @Override
-                      public Object getDefault(AttributeMap rule) {
-                        if (usesProtobuf(rule)) {
-                          return env.getLabel("//external:objc_protobuf_lib");
-                        } else {
-                          return env.getLabel("//external:objc_proto_lib");
-                        }
-                      }
-                    }))
+                .value(env.getToolsLabel("//tools/objc:protobuf_lib")))
         .add(
             ProtoSourceFileBlacklist.blacklistFilegroupAttribute(
                 PROTOBUF_WELL_KNOWN_TYPES,
@@ -159,21 +113,18 @@ public class ObjcProtoLibraryRule implements RuleDefinition {
     return RuleDefinition.Metadata.builder()
         .name("objc_proto_library")
         .factoryClass(ObjcProtoLibrary.class)
-        .ancestors(BaseRuleClasses.RuleBase.class, ObjcRuleClasses.LibtoolRule.class,
-            ObjcRuleClasses.XcrunRule.class, ObjcRuleClasses.CrosstoolRule.class)
+        .ancestors(
+            BaseRuleClasses.RuleBase.class,
+            ObjcRuleClasses.LibtoolRule.class,
+            ObjcRuleClasses.XcrunRule.class,
+            ObjcRuleClasses.CrosstoolRule.class)
         .build();
   }
-
-  static boolean usesProtobuf(AttributeMap attributes) {
-    return attributes.isAttributeValueExplicitlySpecified(
-            ObjcProtoLibraryRule.PORTABLE_PROTO_FILTERS_ATTR)
-        || attributes.get(ObjcProtoLibraryRule.USES_PROTOBUF_ATTR, BOOLEAN);
-  }
 }
 
 /*<!-- #BLAZE_RULE (NAME = objc_proto_library, TYPE = LIBRARY, FAMILY = Objective-C) -->
 
-<p>This rule produces a static library from the given proto_library dependencies, after applying an
-options file.</p>
+<p>This rule generates ObjC headers for the proto files given through the proto_library and
+objc_proto_library dependencies.</p>
 
 <!-- #END_BLAZE_RULE -->*/
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ProtoAttributes.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ProtoAttributes.java
index 890a37cb01..d525817d69 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ProtoAttributes.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ProtoAttributes.java
@@ -16,17 +16,13 @@ package com.google.devtools.build.lib.rules.objc;
 
 import static com.google.common.base.CaseFormat.LOWER_UNDERSCORE;
 import static com.google.common.base.CaseFormat.UPPER_CAMEL;
-import static com.google.devtools.build.lib.packages.BuildType.LABEL;
 import static com.google.devtools.build.lib.packages.BuildType.LABEL_LIST;
-import static com.google.devtools.build.lib.syntax.Type.BOOLEAN;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.CharMatcher;
-import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.actions.Artifact;
-import com.google.devtools.build.lib.analysis.PrerequisiteArtifacts;
 import com.google.devtools.build.lib.analysis.RuleContext;
 import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
 import com.google.devtools.build.lib.analysis.configuredtargets.AbstractConfiguredTarget;
@@ -36,8 +32,6 @@ import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.packages.RuleClass.ConfiguredTargetFactory.RuleErrorException;
 import com.google.devtools.build.lib.rules.proto.ProtoSourceFileBlacklist;
 import com.google.devtools.build.lib.rules.proto.ProtoSourcesProvider;
-import com.google.devtools.build.lib.syntax.Type;
-import com.google.devtools.build.lib.util.FileType;
 import java.util.ArrayList;
 
 /** Common rule attributes used by an objc_proto_library. */
@@ -51,43 +45,12 @@ final class ProtoAttributes {
       ImmutableSet.of("url", "http", "https");
 
   @VisibleForTesting
-  static final String FILES_NOT_ALLOWED_ERROR =
-      "Using files and filegroups in objc_proto_library with portable_proto_filters is not "
-          + "allowed. Please wrap the files inside a proto_library target.";
-
-  @VisibleForTesting
-  static final String FILES_DEPRECATED_WARNING =
-      "Using files and filegroups in objc_proto_library is deprecated";
-
-  @VisibleForTesting
-  static final String NO_PROTOS_ERROR =
-      "no protos to compile - a non-empty deps attribute is required";
-
-  @VisibleForTesting
-  static final String PROTOBUF_ATTRIBUTES_NOT_EXCLUSIVE_ERROR =
-      "The portable_proto_filters and uses_protobuf attributes are incompatible with the "
-          + "options_file, output_cpp, per_proto_includes and use_objc_header_names attributes.";
-
-  @VisibleForTesting
   static final String PORTABLE_PROTO_FILTERS_EMPTY_ERROR =
       "The portable_proto_filters attribute can't be empty";
 
   @VisibleForTesting
-  static final String OBJC_PROTO_LIB_DEP_IN_PROTOCOL_BUFFERS2_DEPS_ERROR =
-      "Protocol Buffers 2 objc_proto_library targets can't depend on other objc_proto_library "
-          + "targets. Please migrate your Protocol Buffers 2 objc_proto_library targets to use the "
-          + "portable_proto_filters attribute.";
-
-  @VisibleForTesting
-  static final String PROTOCOL_BUFFERS2_IN_PROTOBUF_DEPS_ERROR =
-      "Protobuf objc_proto_library targets can't depend on Protocol Buffers 2 objc_proto_library "
-          + "targets. Please migrate your Protocol Buffers 2 objc_proto_library targets to use the "
-          + "portable_proto_filters attribute.";
-
-  @VisibleForTesting
-  static final String USES_PROTOBUF_CANT_BE_SPECIFIED_AS_FALSE =
-      "objc_proto_library targets can't specify the uses_protobuf attribute to false when also "
-          + "specifying portable_proto_filters.";
+  static final String NO_PROTOS_ERROR =
+      "no protos to compile - a non-empty deps attribute is required";
 
   private final RuleContext ruleContext;
 
@@ -112,80 +75,21 @@ final class ProtoAttributes {
    * </ul>
    */
   public void validate() throws RuleErrorException {
-    PrerequisiteArtifacts prerequisiteArtifacts =
-        ruleContext.getPrerequisiteArtifacts("deps", Mode.TARGET);
-    ImmutableList<Artifact> protoFiles = prerequisiteArtifacts.filter(FileType.of(".proto")).list();
-
-    if (hasPortableProtoFilters()
-        && ruleContext
-            .attributes()
-            .isAttributeValueExplicitlySpecified(ObjcProtoLibraryRule.USES_PROTOBUF_ATTR)
-        && !ruleContext.attributes().get(ObjcProtoLibraryRule.USES_PROTOBUF_ATTR, BOOLEAN)) {
-      ruleContext.throwWithAttributeError(
-          ObjcProtoLibraryRule.USES_PROTOBUF_ATTR, USES_PROTOBUF_CANT_BE_SPECIFIED_AS_FALSE);
-    }
-
-    if (requiresProtobuf()) {
-      if (!protoFiles.isEmpty()) {
-        ruleContext.throwWithAttributeError("deps", FILES_NOT_ALLOWED_ERROR);
-      }
-      if (getProtoFiles().isEmpty() && !hasObjcProtoLibraryDependencies()) {
-        ruleContext.throwWithAttributeError("deps", NO_PROTOS_ERROR);
-      }
-      if (getPortableProtoFilters().isEmpty() && !usesProtobuf()) {
-        ruleContext.throwWithAttributeError(
-            ObjcProtoLibraryRule.PORTABLE_PROTO_FILTERS_ATTR, PORTABLE_PROTO_FILTERS_EMPTY_ERROR);
-      }
-      if (usesObjcHeaderNames()
-          || needsPerProtoIncludes()
-          || getOptionsFile().isPresent()) {
-        ruleContext.throwWithRuleError(PROTOBUF_ATTRIBUTES_NOT_EXCLUSIVE_ERROR);
-      }
-      if (hasPB2Dependencies()) {
-        ruleContext.throwWithAttributeError("deps", PROTOCOL_BUFFERS2_IN_PROTOBUF_DEPS_ERROR);
-      }
-    } else {
-      if (!protoFiles.isEmpty()) {
-        ruleContext.attributeWarning("deps", FILES_DEPRECATED_WARNING);
-      }
-      if (getProtoFiles().isEmpty()) {
-        ruleContext.throwWithAttributeError("deps", NO_PROTOS_ERROR);
-      }
-      if (hasObjcProtoLibraryDependencies()) {
-        ruleContext.throwWithAttributeError(
-            "deps", OBJC_PROTO_LIB_DEP_IN_PROTOCOL_BUFFERS2_DEPS_ERROR);
-      }
-    }
-  }
-
-  /** Returns whether the generated header files should have be of type pb.h or pbobjc.h. */
-  boolean usesObjcHeaderNames() {
-    if (ruleContext
-        .attributes()
-        .has(ObjcProtoLibraryRule.USE_OBJC_HEADER_NAMES_ATTR, Type.BOOLEAN)) {
-      return ruleContext
-          .attributes()
-          .get(ObjcProtoLibraryRule.USE_OBJC_HEADER_NAMES_ATTR, Type.BOOLEAN);
+    if (getProtoFiles().isEmpty() && !hasObjcProtoLibraryDependencies()) {
+      ruleContext.throwWithAttributeError("deps", NO_PROTOS_ERROR);
     }
-    return false;
-  }
-
-  /** Returns whether the includes should include each of the proto generated headers. */
-  boolean needsPerProtoIncludes() {
-    if (ruleContext.attributes().has(ObjcProtoLibraryRule.PER_PROTO_INCLUDES_ATTR, Type.BOOLEAN)) {
-      return ruleContext
-          .attributes()
-          .get(ObjcProtoLibraryRule.PER_PROTO_INCLUDES_ATTR, Type.BOOLEAN);
+    if (hasPortableProtoFilters() && getPortableProtoFilters().isEmpty()) {
+      ruleContext.throwWithAttributeError(
+          ObjcProtoLibraryRule.PORTABLE_PROTO_FILTERS_ATTR, PORTABLE_PROTO_FILTERS_EMPTY_ERROR);
     }
-    return false;
   }
 
-  /** Returns whether this target configures the uses_protobuf attribute. */
-  boolean usesProtobuf() {
-    if (ruleContext.attributes().has(ObjcProtoLibraryRule.USES_PROTOBUF_ATTR, Type.BOOLEAN)) {
-      return ruleContext.attributes().get(ObjcProtoLibraryRule.USES_PROTOBUF_ATTR, Type.BOOLEAN);
-    }
-    return false;
+  /**
+   * Returns whether the target is an objc_proto_library. It does so by making sure that the
+   * portable_proto_filters attribute exists in this target's attributes (even if it's empty).
+   */
+  boolean isObjcProtoLibrary() {
+    return ruleContext.attributes().has(ObjcProtoLibraryRule.PORTABLE_PROTO_FILTERS_ATTR);
   }
 
   /** Returns whether to use the protobuf library instead of the PB2 library. */
@@ -195,15 +99,6 @@ final class ProtoAttributes {
         .isAttributeValueExplicitlySpecified(ObjcProtoLibraryRule.PORTABLE_PROTO_FILTERS_ATTR);
   }
 
-  /**
-   * Returns whether the target requires the use of protobuf or not. This is a convenience method to
-   * check that either the {@code portable_proto_filters} or the {@code uses_protobuf} attributes
-   * were passed.
-   */
-  boolean requiresProtobuf() {
-    return hasPortableProtoFilters() || usesProtobuf();
-  }
-
   /** Returns the list of portable proto filters. */
   ImmutableList<Artifact> getPortableProtoFilters() {
     if (ruleContext
@@ -223,19 +118,9 @@ final class ProtoAttributes {
         .list();
   }
 
-  /** Returns the options file, or {@link Optional#absent} if it was not specified. */
-  Optional<Artifact> getOptionsFile() {
-    if (ruleContext.attributes().has(ObjcProtoLibraryRule.OPTIONS_FILE_ATTR, LABEL)) {
-      return Optional.fromNullable(
-          ruleContext.getPrerequisiteArtifact(ObjcProtoLibraryRule.OPTIONS_FILE_ATTR, Mode.HOST));
-    }
-    return Optional.absent();
-  }
-
   /** Returns the list of proto files to compile. */
   NestedSet<Artifact> getProtoFiles() {
     return NestedSetBuilder.<Artifact>stableOrder()
-        .addAll(getProtoDepsFiles())
         .addTransitive(getProtoDepsSources())
         .build();
   }
@@ -353,25 +238,6 @@ final class ProtoAttributes {
     return artifacts.build();
   }
 
-  /**
-   * Returns the list of proto files that were added directly into the deps attributes. This way of
-   * specifying the protos is deprecated, and displays a warning when the target does so.
-   */
-  private ImmutableList<Artifact> getProtoDepsFiles() {
-    PrerequisiteArtifacts prerequisiteArtifacts =
-        ruleContext.getPrerequisiteArtifacts("deps", Mode.TARGET);
-    return prerequisiteArtifacts.filter(FileType.of(".proto")).list();
-  }
-
-  private boolean hasPB2Dependencies() {
-    for (TransitiveInfoCollection dep : ruleContext.getPrerequisites("deps", Mode.TARGET)) {
-      if (isObjcProtoLibrary(dep) && !hasProtobufProvider(dep)) {
-        return true;
-      }
-    }
-    return false;
-  }
-
   private boolean hasObjcProtoLibraryDependencies() {
     for (TransitiveInfoCollection dep : ruleContext.getPrerequisites("deps", Mode.TARGET)) {
       if (isObjcProtoLibrary(dep)) {
@@ -390,8 +256,4 @@ final class ProtoAttributes {
       return false;
     }
   }
-
-  private boolean hasProtobufProvider(TransitiveInfoCollection dependency) {
-    return dependency.getProvider(ObjcProtoProvider.class) != null;
-  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ProtobufSupport.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ProtobufSupport.java
index 348890eda1..4c7bb87400 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ProtobufSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ProtobufSupport.java
@@ -528,10 +528,9 @@ final class ProtobufSupport {
   }
 
   private boolean isLinkingTarget() {
-    // Since this is the ProtobufSupport helper class, check whether the current target has
-    // configured the protobuf attributes. If not, it's not an objc_proto_library rule, so it must
-    // be a linking rule (e.g. apple_binary).
-    return !attributes.requiresProtobuf();
+    // Since this is the ProtobufSupport helper class, check whether the current target is
+    // an objc_proto_library. If not, it must be a linking rule (e.g. apple_binary).
+    return !attributes.isObjcProtoLibrary();
   }
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ProtocolBuffers2Support.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ProtocolBuffers2Support.java
deleted file mode 100644
index 1a4b2fbdb6..0000000000
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ProtocolBuffers2Support.java
+++ /dev/null
@@ -1,228 +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.common.collect.ImmutableSet;
-import com.google.common.collect.Iterables;
-import com.google.common.collect.Ordering;
-import com.google.devtools.build.lib.actions.Artifact;
-import com.google.devtools.build.lib.analysis.RuleContext;
-import com.google.devtools.build.lib.analysis.actions.CustomCommandLine;
-import com.google.devtools.build.lib.analysis.actions.FileWriteAction;
-import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTarget.Mode;
-import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
-import com.google.devtools.build.lib.packages.RuleClass.ConfiguredTargetFactory.RuleErrorException;
-import com.google.devtools.build.lib.vfs.FileSystemUtils;
-import com.google.devtools.build.lib.vfs.PathFragment;
-
-/**
- * Support for generating Objective C proto static libraries that registers actions which generate
- * and compile the Objective C protos by using the deprecated ProtocolBuffers2 library and compiler.
- *
- * <p>Methods on this class can be called in any order without impacting the result.
- */
-final class ProtocolBuffers2Support {
-
-  private static final String UNIQUE_DIRECTORY_NAME = "_generated_protos";
-
-  private final RuleContext ruleContext;
-  private final ProtoAttributes attributes;
-
-  /**
-   * Creates a new proto support for the ProtocolBuffers2 library.
-   *
-   * @param ruleContext context this proto library is constructed in
-   */
-  public ProtocolBuffers2Support(RuleContext ruleContext) {
-    this.ruleContext = ruleContext;
-    this.attributes = new ProtoAttributes(ruleContext);
-  }
-
-  /**
-   * Register the proto generation actions. These actions generate the ObjC/CPP code to be compiled
-   * by this rule.
-   */
-  public ProtocolBuffers2Support registerGenerationActions() throws InterruptedException {
-    ruleContext.registerAction(
-        FileWriteAction.create(
-            ruleContext,
-            getProtoInputsFile(),
-            getProtoInputsFileContents(
-                attributes.filterWellKnownProtos(attributes.getProtoFiles())),
-            false));
-
-    ruleContext.registerAction(
-        ObjcRuleClasses.spawnOnDarwinActionBuilder()
-            .setMnemonic("GenObjcPB2Protos")
-            .addInput(attributes.getProtoCompiler())
-            .addInputs(attributes.getProtoCompilerSupport())
-            .addInput(getProtoInputsFile())
-            .addTransitiveInputs(attributes.getProtoFiles())
-            .addInputs(attributes.getOptionsFile().asSet())
-            .addOutputs(getGeneratedProtoOutputs(getHeaderExtension()))
-            .addOutputs(getGeneratedProtoOutputs(getSourceExtension()))
-            .setExecutable(PathFragment.create("/usr/bin/python"))
-            .addCommandLine(getGenerationCommandLine())
-            .build(ruleContext));
-    return this;
-  }
-
-  /**
-   * Registers the actions that will compile the generated code.
-   */
-  public ProtocolBuffers2Support registerCompilationActions()
-      throws RuleErrorException, InterruptedException {
-    CompilationSupport compilationSupport =
-        new CompilationSupport.Builder()
-            .setRuleContext(ruleContext)
-            .doNotUseDeps()
-            .doNotUsePch()
-            .build();
-
-    compilationSupport.registerCompileAndArchiveActions(getCommon());
-    return this;
-  }
-
-  /** Adds the generated files to the set of files to be output when this rule is built. */
-  public ProtocolBuffers2Support addFilesToBuild(NestedSetBuilder<Artifact> filesToBuild)
-      throws InterruptedException {
-    filesToBuild
-        .addAll(getGeneratedProtoOutputs(getHeaderExtension()))
-        .addAll(getGeneratedProtoOutputs(getSourceExtension()))
-        .addAll(getCompilationArtifacts().getArchive().asSet());
-    return this;
-  }
-
-  /** Returns the ObjcProvider for this target. */
-  public ObjcProvider getObjcProvider() {
-    return getCommon().getObjcProvider();
-  }
-
-  private String getHeaderExtension() {
-    return ".pb" + (attributes.usesObjcHeaderNames() ? "objc.h" : ".h");
-  }
-
-  private String getSourceExtension() {
-    return ".pb.m";
-  }
-
-  private ObjcCommon getCommon() {
-    return new ObjcCommon.Builder(ruleContext)
-        .setIntermediateArtifacts(new IntermediateArtifacts(ruleContext, ""))
-        .setHasModuleMap()
-        .setCompilationArtifacts(getCompilationArtifacts())
-        .addIncludes(getIncludes())
-        .addDepObjcProviders(
-            ruleContext.getPrerequisites(
-                ObjcRuleClasses.PROTO_LIB_ATTR, Mode.TARGET, ObjcProvider.SKYLARK_CONSTRUCTOR))
-        .build();
-  }
-
-  private CompilationArtifacts getCompilationArtifacts() {
-    Iterable<Artifact> generatedSources = getGeneratedProtoOutputs(getSourceExtension());
-    return new CompilationArtifacts.Builder()
-        .setIntermediateArtifacts(new IntermediateArtifacts(ruleContext, ""))
-        .addAdditionalHdrs(getGeneratedProtoOutputs(getHeaderExtension()))
-        .addAdditionalHdrs(generatedSources)
-        .addNonArcSrcs(generatedSources)
-        .build();
-  }
-
-  private Artifact getProtoInputsFile() {
-    return ruleContext.getUniqueDirectoryArtifact(
-        "_protos", "_proto_input_files", ruleContext.getConfiguration().getGenfilesDirectory());
-  }
-
-  private String getProtoInputsFileContents(Iterable<Artifact> outputProtos) {
-    // Sort the file names to make the remote action key independent of the precise deps structure.
-    // compile_protos.py will sort the input list anyway.
-    Iterable<Artifact> sorted = Ordering.natural().immutableSortedCopy(outputProtos);
-    return Artifact.joinExecPaths("\n", sorted);
-  }
-
-  private CustomCommandLine getGenerationCommandLine() {
-    CustomCommandLine.Builder commandLineBuilder =
-        new CustomCommandLine.Builder()
-            .addExecPath(attributes.getProtoCompiler())
-            .add("--input-file-list")
-            .addExecPath(getProtoInputsFile())
-            .add("--output-dir")
-            .addDynamicString(getWorkspaceRelativeOutputDir().getSafePathString())
-            .add("--working-dir")
-            .add(".");
-
-    if (attributes.getOptionsFile().isPresent()) {
-      commandLineBuilder
-          .add("--compiler-options-path")
-          .addExecPath(attributes.getOptionsFile().get());
-    }
-
-    if (attributes.usesObjcHeaderNames()) {
-      commandLineBuilder.add("--use-objc-header-names");
-    }
-    return commandLineBuilder.build();
-  }
-
-  public ImmutableSet<PathFragment> getIncludes() {
-    ImmutableSet.Builder<PathFragment> searchPathEntriesBuilder =
-        new ImmutableSet.Builder<PathFragment>().add(getWorkspaceRelativeOutputDir());
-
-    if (attributes.needsPerProtoIncludes()) {
-      PathFragment generatedProtoDir = PathFragment.create(
-          getWorkspaceRelativeOutputDir(), ruleContext.getLabel().getPackageFragment());
-
-      searchPathEntriesBuilder
-          .add(generatedProtoDir)
-          .addAll(
-              Iterables.transform(
-                  getGeneratedProtoOutputs(getHeaderExtension()),
-                  input -> input.getExecPath().getParentDirectory()));
-    }
-
-    return searchPathEntriesBuilder.build();
-  }
-
-  private PathFragment getWorkspaceRelativeOutputDir() {
-    // Generate sources in a package-and-rule-scoped directory; adds both the
-    // package-and-rule-scoped directory and the header-containing-directory to the include path
-    // of dependers.
-    PathFragment rootRelativeOutputDir = ruleContext.getUniqueDirectory(UNIQUE_DIRECTORY_NAME);
-
-    return PathFragment.create(
-        ruleContext.getBinOrGenfilesDirectory().getExecPath(), rootRelativeOutputDir);
-  }
-
-  private Iterable<Artifact> getGeneratedProtoOutputs(String extension) {
-    ImmutableList.Builder<Artifact> builder = new ImmutableList.Builder<>();
-    for (Artifact protoFile : attributes.filterWellKnownProtos(attributes.getProtoFiles())) {
-      String protoFileName = FileSystemUtils.removeExtension(protoFile.getFilename());
-      String generatedOutputName = attributes.getGeneratedProtoFilename(protoFileName, false);
-
-      PathFragment generatedFilePath = PathFragment.create(
-          protoFile.getRootRelativePath().getParentDirectory(),
-          PathFragment.create(generatedOutputName));
-
-      PathFragment outputFile = FileSystemUtils.appendExtension(generatedFilePath, extension);
-
-      if (outputFile != null) {
-        builder.add(
-            ruleContext.getUniqueDirectoryArtifact(
-                UNIQUE_DIRECTORY_NAME, outputFile, ruleContext.getBinOrGenfilesDirectory()));
-      }
-    }
-    return builder.build();
-  }
-}