Add CcHostToolchainAliasRule.

RELNOTES:none
PiperOrigin-RevId: 196477775

3 files changed, 48 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/CcRules.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/CcRules.java
index e971deaefc..b21b211871 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/CcRules.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/CcRules.java
@@ -23,6 +23,7 @@ import com.google.devtools.build.lib.bazel.rules.cpp.BazelCcLibraryRule;
 import com.google.devtools.build.lib.bazel.rules.cpp.BazelCcTestRule;
 import com.google.devtools.build.lib.bazel.rules.cpp.BazelCppRuleClasses;
 import com.google.devtools.build.lib.rules.core.CoreRules;
+import com.google.devtools.build.lib.rules.cpp.CcHostToolchainAliasRule;
 import com.google.devtools.build.lib.rules.cpp.CcImportRule;
 import com.google.devtools.build.lib.rules.cpp.CcModule;
 import com.google.devtools.build.lib.rules.cpp.CcToolchainAliasRule;
@@ -56,6 +57,7 @@ public class CcRules implements RuleSet {
     builder.addRuleDefinition(new CcToolchainRule());
     builder.addRuleDefinition(new CcToolchainSuiteRule());
     builder.addRuleDefinition(new CcToolchainAliasRule());
+    builder.addRuleDefinition(new CcHostToolchainAliasRule());
     builder.addRuleDefinition(new CcImportRule());
     builder.addRuleDefinition(new CcToolchainTypeRule());
     builder.addRuleDefinition(new BazelCppRuleClasses.CcLinkingRule());
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcHostToolchainAliasRule.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcHostToolchainAliasRule.java
new file mode 100644
index 0000000000..f9ae51299c
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcHostToolchainAliasRule.java
@@ -0,0 +1,38 @@
+// Copyright 2017 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.cpp;
+
+import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
+import com.google.devtools.build.lib.analysis.config.HostTransition;
+import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.packages.Attribute;
+import com.google.devtools.build.lib.rules.LateBoundAlias.CommonAliasRule;
+
+/** Implementation of the {@code cc_toolchain_alias} rule. */
+public class CcHostToolchainAliasRule extends CommonAliasRule {
+
+  public CcHostToolchainAliasRule() {
+    super(
+        "cc_host_toolchain_alias",
+        CppRuleClasses::ccHostToolchainAttribute,
+        CppConfiguration.class);
+  }
+
+  @Override
+  protected Attribute.Builder<Label> makeAttribute(RuleDefinitionEnvironment environment) {
+    Attribute.Builder<Label> builder = super.makeAttribute(environment);
+    return builder.cfg(HostTransition.INSTANCE);
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java
index 0bd153d958..da10c03d71 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java
@@ -90,6 +90,14 @@ public class CppRuleClasses {
         (rules, attributes, cppConfig) -> cppConfig.getCcToolchainRuleLabel());
   }
 
+  public static LabelLateBoundDefault<CppConfiguration> ccHostToolchainAttribute(
+      RuleDefinitionEnvironment env) {
+    return LabelLateBoundDefault.fromHostConfiguration(
+        CppConfiguration.class,
+        env.getToolsLabel(CROSSTOOL_LABEL),
+        (rules, attributes, cppConfig) -> cppConfig.getCcToolchainRuleLabel());
+  }
+
   public static Label ccToolchainTypeAttribute(RuleDefinitionEnvironment env) {
     return env.getToolsLabel(CppHelper.TOOLCHAIN_TYPE_LABEL);
   }