commit 3c1c8e9cb2d73657422c59872c53b55febf5f5d1
author lberki <lberki@google.com> Thu Jul 13 12:25:47 2017 +0200
committer László Csomor <laszlocsomor@google.com> Fri Jul 14 10:49:19 2017 +0200
tree 6ba5ffa5a75c3dd7eb33ea0e280e227679314157
parent 7ced4c04b0f93ad0952e98f1c279406975f7011c

Add a toolchains= attribute to *_binary, *_test, cc_library and extra_action rules to declare which Make variables they need.

The idea is that they would depend on the future java_runtime_alias / cc_toolchain_alias and similar rules and thus Bazel will know which Make variables they actually need instead of pulling in the whole BuildConfiguration and also making it possible to compute these Make variables during analysis instead of configuration creation.

RELNOTES: None.
PiperOrigin-RevId: 161785868

src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java b/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java
index 2396c3e..b455376 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java
@@ -48,6 +48,7 @@
 import com.google.devtools.build.lib.packages.RuleClass.Builder;
 import com.google.devtools.build.lib.packages.RuleClass.Builder.RuleClassType;
 import com.google.devtools.build.lib.packages.TestSize;
+import com.google.devtools.build.lib.rules.MakeVariableProvider;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.util.FileTypeSet;
 import java.util.List;
@@ -156,7 +157,7 @@
       return RuleDefinition.Metadata.builder()
           .name("$test_base_rule")
           .type(RuleClassType.ABSTRACT)
-          .ancestors(RootRule.class)
+          .ancestors(RootRule.class, MakeVariableExpandingRule.class)
           .build();
     }
   }
@@ -266,6 +267,33 @@
   }
 
   /**
+   * A rule that contains a {@code variables=} attribute to allow referencing Make variables.
+   */
+  public static final class MakeVariableExpandingRule implements RuleDefinition {
+    @Override
+    public RuleClass build(Builder builder, RuleDefinitionEnvironment env) {
+      return builder
+          /* <!-- #BLAZE_RULE($make_variable_expanding_rule).ATTRIBUTE(toolchains) -->
+          The set of toolchains that supply <a href="${link make-variables}">"Make variables"</a>
+          that this target can use in some of its attributes. Some rules have toolchains whose Make
+          variables they can use by default.
+          <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
+          .add(attr("toolchains", LABEL_LIST)
+              .allowedFileTypes(FileTypeSet.NO_FILE)
+              .mandatoryProviders(ImmutableList.of(MakeVariableProvider.SKYLARK_CONSTRUCTOR.id())))
+          .build();
+    }
+
+    @Override
+    public Metadata getMetadata() {
+      return RuleDefinition.Metadata.builder()
+          .name("$make_variable_expanding_rule")
+          .type(RuleClassType.ABSTRACT)
+          .build();
+    }
+  }
+
+  /**
    * Common ancestor class for some rules.
    */
   public static final class RuleBase implements RuleDefinition {
@@ -311,7 +339,7 @@
       return RuleDefinition.Metadata.builder()
           .name("$binary_base_rule")
           .type(RuleClassType.ABSTRACT)
-          .ancestors(RootRule.class)
+          .ancestors(RootRule.class, MakeVariableExpandingRule.class)
           .build();
     }
   }