Introduces experimental_objc_library. This rule builds objc code with the c++ rule implementation backend and an OSX crosstool.

--
MOS_MIGRATED_REVID=119660101

4 files changed, 279 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibrary.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibrary.java
new file mode 100644
index 0000000000..4b214acd76
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibrary.java
@@ -0,0 +1,83 @@
+// 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.Sets;
+import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.analysis.ConfiguredTarget;
+import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
+import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
+import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
+import com.google.devtools.build.lib.rules.cpp.CcLibraryHelper;
+import com.google.devtools.build.lib.rules.cpp.CcToolchainFeatures.FeatureConfiguration;
+import com.google.devtools.build.lib.rules.cpp.CcToolchainProvider;
+import com.google.devtools.build.lib.rules.objc.ObjcCommon.CompilationAttributes;
+
+import java.util.Collection;
+
+/**
+ * Implementation for experimental_objc_library.
+ */
+public class ExperimentalObjcLibrary implements RuleConfiguredTargetFactory {
+
+  @Override
+  public ConfiguredTarget create(RuleContext ruleContext) throws InterruptedException {
+
+    CompilationArtifacts compilationArtifacts =
+        CompilationSupport.compilationArtifacts(ruleContext);
+    CompilationAttributes compilationAttributes = new CompilationAttributes(ruleContext);
+
+    ObjcCommon common = common(ruleContext, compilationAttributes, compilationArtifacts);
+
+    CcToolchainProvider toolchain =
+        ruleContext
+            .getPrerequisite(":cc_toolchain", Mode.TARGET)
+            .getProvider(CcToolchainProvider.class);
+    FeatureConfiguration featureConfiguration = toolchain.getFeatures().getFeatureConfiguration();
+
+    Collection<Artifact> sources = Sets.newHashSet(compilationArtifacts.getSrcs());
+    Collection<Artifact> privateHdrs = Sets.newHashSet(compilationArtifacts.getPrivateHdrs());
+    Collection<Artifact> publicHdrs = Sets.newHashSet(compilationAttributes.hdrs());
+
+    CcLibraryHelper helper =
+        new CcLibraryHelper(ruleContext, ObjcCppSemantics.INSTANCE, featureConfiguration)
+            .addSources(sources)
+            .addSources(privateHdrs)
+            .enableCompileProviders()
+            .addPublicHeaders(publicHdrs)
+            .addDeps(ruleContext.getPrerequisites("deps", Mode.TARGET));
+
+    CcLibraryHelper.Info info = helper.build();
+
+    NestedSetBuilder<Artifact> filesToBuild =
+        NestedSetBuilder.<Artifact>stableOrder().addAll(common.getCompiledArchive().asSet());
+
+    return ObjcRuleClasses.ruleConfiguredTarget(ruleContext, filesToBuild.build())
+        .addProviders(info.getProviders())
+        .build();
+  }
+
+  private ObjcCommon common(
+      RuleContext ruleContext,
+      CompilationAttributes compilationAttributes,
+      CompilationArtifacts compilationArtifacts) {
+    return new ObjcCommon.Builder(ruleContext)
+        .setCompilationAttributes(compilationAttributes)
+        .setCompilationArtifacts(compilationArtifacts)
+        .addDepObjcProviders(ruleContext.getPrerequisites("deps", Mode.TARGET, ObjcProvider.class))
+        .build();
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibraryRule.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibraryRule.java
new file mode 100644
index 0000000000..77c70f65de
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibraryRule.java
@@ -0,0 +1,53 @@
+// 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.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.RuleClass;
+import com.google.devtools.build.lib.packages.RuleClass.Builder;
+import com.google.devtools.build.lib.packages.RuleClass.PackageNameConstraint;
+import com.google.devtools.build.lib.rules.apple.AppleConfiguration;
+import com.google.devtools.build.lib.rules.cpp.CppConfiguration;
+
+/**
+ * Rule definition for experimental_objc_library.
+ */
+public class ExperimentalObjcLibraryRule implements RuleDefinition {
+  @Override
+  public RuleClass build(Builder builder, RuleDefinitionEnvironment env) {
+    return builder
+        .requiresConfigurationFragments(
+            ObjcConfiguration.class, AppleConfiguration.class, CppConfiguration.class)
+        // experimental_objc_library should only occur in bazel test code.  We use the /objc
+        // directory for tests.
+        .setValidityPredicate(new PackageNameConstraint(1, "objc"))
+        .build();
+  }
+
+  @Override
+  public Metadata getMetadata() {
+    return RuleDefinition.Metadata.builder()
+        .name("experimental_objc_library")
+        .factoryClass(ExperimentalObjcLibrary.class)
+        .ancestors(
+            BaseRuleClasses.BaseRule.class,
+            ObjcRuleClasses.LinkingRule.class,
+            ObjcRuleClasses.AlwaysLinkRule.class,
+            ObjcRuleClasses.CrosstoolRule.class)
+        .build();
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCppSemantics.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCppSemantics.java
new file mode 100644
index 0000000000..30afe9dcc4
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCppSemantics.java
@@ -0,0 +1,76 @@
+// 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.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.actions.Root;
+import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.rules.cpp.CppCompilationContext.Builder;
+import com.google.devtools.build.lib.rules.cpp.CppCompileActionBuilder;
+import com.google.devtools.build.lib.rules.cpp.CppCompileActionContext;
+import com.google.devtools.build.lib.rules.cpp.CppConfiguration;
+import com.google.devtools.build.lib.rules.cpp.CppConfiguration.HeadersCheckingMode;
+import com.google.devtools.build.lib.rules.cpp.CppHelper;
+import com.google.devtools.build.lib.rules.cpp.CppSemantics;
+import com.google.devtools.build.lib.vfs.PathFragment;
+
+/**
+ * CppSemantics for objc builds.
+ */
+public class ObjcCppSemantics implements CppSemantics {
+  
+  // We make CppSemantics a singleton object for efficiency and consistency, since we expect
+  // any instance to be identical.
+  public static final CppSemantics INSTANCE = new ObjcCppSemantics();
+
+  @Override
+  public PathFragment getEffectiveSourcePath(Artifact source) {
+    return source.getRootRelativePath();
+  }
+
+  @Override
+  public void finalizeCompileActionBuilder(
+      RuleContext ruleContext, CppCompileActionBuilder actionBuilder) {
+    actionBuilder.setCppConfiguration(ruleContext.getFragment(CppConfiguration.class));
+    actionBuilder.setActionContext(CppCompileActionContext.class);
+    // Because Bazel does not support include scanning, we need the entire crosstool filegroup,
+    // including header files, as opposed to just the "compile" filegroup.
+    actionBuilder.addTransitiveMandatoryInputs(CppHelper.getToolchain(ruleContext).getCrosstool());
+    actionBuilder.setShouldScanIncludes(false);
+  }
+
+  
+  @Override
+  public void setupCompilationContext(RuleContext ruleContext, Builder contextBuilder) {
+    // For objc builds, no extra setup is required.
+  }
+
+  @Override
+  public HeadersCheckingMode determineHeadersCheckingMode(RuleContext ruleContext) {
+    // Currently, objc builds do not enforce strict deps.  To begin enforcing strict deps in objc,
+    // switch this flag to STRICT.
+    return HeadersCheckingMode.WARN;
+  }
+
+  @Override
+  public boolean needsIncludeScanning(RuleContext ruleContext) {
+    return false;
+  }
+
+  @Override
+  public Root getGreppedIncludesDirectory(RuleContext ruleContext) {
+    return null;
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcRuleClasses.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcRuleClasses.java
index ef9e07911a..634c535156 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcRuleClasses.java
@@ -53,6 +53,7 @@ import com.google.devtools.build.lib.rules.apple.AppleConfiguration;
 import com.google.devtools.build.lib.rules.apple.AppleToolchain;
 import com.google.devtools.build.lib.rules.apple.AppleToolchain.RequiresXcodeConfigRule;
 import com.google.devtools.build.lib.rules.apple.Platform;
+import com.google.devtools.build.lib.rules.cpp.CppConfiguration;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.util.FileType;
 import com.google.devtools.build.lib.util.FileTypeSet;
@@ -125,12 +126,50 @@ public class ObjcRuleClasses {
     return !ASSEMBLY_SOURCES.matches(sourceArtifact.getFilename());
   }
 
-
   @VisibleForTesting
   static final Iterable<SdkFramework> AUTOMATIC_SDK_FRAMEWORKS = ImmutableList.of(
       new SdkFramework("Foundation"), new SdkFramework("UIKit"));
 
   /**
+   * Label of a filegroup that contains all crosstool and grte files for all configurations,
+   * as specified on the command-line.
+   *
+   * <p> Since this is the loading-phase default for the :cc_toolchain attribute of rules
+   * using the crosstool, it must contain in its transitive closure the computer value
+   * of that attribute under the default configuration.
+   */
+  public static final String CROSSTOOL_LABEL = "//tools/defaults:crosstool";
+
+  /**
+   * Late-bound attribute giving the CcToolchain for CROSSTOOL_LABEL.
+   *
+   * TODO(cpeyser): Use AppleCcToolchain instead of CcToolchain once released.
+   */
+  public static final LateBoundLabel<BuildConfiguration> APPLE_TOOLCHAIN =
+      new LateBoundLabel<BuildConfiguration>(CROSSTOOL_LABEL, CppConfiguration.class) {
+        @Override
+        public Label getDefault(
+            Rule rule, AttributeMap attributes, BuildConfiguration configuration) {
+          return configuration.getFragment(CppConfiguration.class).getCcToolchainRuleLabel();
+        }
+      };
+
+  /**
+   * A null value for the lipo context colletor.  Objc builds do not use a lipo context collector.
+   */
+  // TODO(b/28084560): Allow :lipo_context_collector not to be set instead of having a null 
+  // instance.
+  public static final LateBoundLabel<BuildConfiguration> NULL_LIPO_CONTEXT_COLLECTOR =
+      new LateBoundLabel<BuildConfiguration>() {
+        @Override
+        public Label getDefault(
+            Rule rule, AttributeMap attributes, BuildConfiguration configuration) {
+          return null;
+        }
+      };
+      
+      
+  /**
    * Creates a new spawn action builder with apple environment variables set that are typically
    * needed by the apple toolchain. This should be used to start to build spawn actions that, in
    * order to run, require both a darwin architecture and a collection of environment variables
@@ -510,6 +549,31 @@ public class ObjcRuleClasses {
   }
 
   /**
+   * Common attributes for {@code objc_*} rules that depend on a crosstool.
+   */
+  public static class CrosstoolRule implements RuleDefinition {
+
+    @Override
+    public RuleClass build(Builder builder, RuleDefinitionEnvironment env) {
+      return builder
+          .add(attr(":cc_toolchain", LABEL).value(APPLE_TOOLCHAIN))
+          .add(
+              attr(":lipo_context_collector", LABEL)
+                  .value(NULL_LIPO_CONTEXT_COLLECTOR)
+                  .skipPrereqValidatorCheck())
+          .build();
+    }
+
+    @Override
+    public Metadata getMetadata() {
+      return RuleDefinition.Metadata.builder()
+          .name("$objc_crosstool_rule")
+          .type(RuleClassType.ABSTRACT)
+          .build();
+    }
+  }
+
+  /**
    * Common attributes for {@code objc_*} rules that can be input to compilation (i.e. can be
    * dependencies of other compiling rules).
    */
@@ -592,7 +656,8 @@ public class ObjcRuleClasses {
             "cc_library",
             "cc_inc_library",
             "ios_framework",
-            "swift_library");
+            "swift_library",
+            "experimental_objc_library");
 
     @Override
     public RuleClass build(Builder builder, RuleDefinitionEnvironment env) {