Add isConfigMatcher property to rule classes.

BuildConfiguration currently depends directly on the name of a rule class
to see if it is config_setting. This creates a circular dependency between
ConfigSetting and BuildConfiguration.

As ConfigSetting is being moved to rules/config, this circular dependency
will no longer work. This replaces the name special case for a special
property of the rule class, which only config_setting should set.

RELNOTES: None.

PiperOrigin-RevId: 151871084

4 files changed, 27 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java b/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java
index 5c479ee495..60c0e207da 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java
@@ -1952,8 +1952,7 @@ public final class BuildConfiguration {
     // from these transitions, since their *purpose* is to do computation on the owning
     // rule's configuration.
     // TODO(bazel-team): don't require special casing here. This is far too hackish.
-    if (toTarget instanceof Rule
-        && ((Rule) toTarget).getRuleClass().equals(ConfigRuleClasses.ConfigSettingRule.RULE_NAME)) {
+    if (toTarget instanceof Rule && ((Rule) toTarget).getRuleClassObject().isConfigMatcher()) {
       transitionApplier.applyTransition(Attribute.ConfigurationTransition.NONE); // Unnecessary.
       return;
     }
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/ConfigRuleClasses.java b/src/main/java/com/google/devtools/build/lib/analysis/config/ConfigRuleClasses.java
index c6f5cd450c..7df805c4d5 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/ConfigRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/ConfigRuleClasses.java
@@ -147,6 +147,7 @@ public class ConfigRuleClasses {
           <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
           .add(attr(SETTINGS_ATTRIBUTE, STRING_DICT).mandatory()
               .nonconfigurable(NONCONFIGURABLE_ATTRIBUTE_REASON))
+          .setIsConfigMatcherForConfigSettingOnly()
           .build();
     }
 
diff --git a/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java b/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
index 1a2dbb2127..37bc246916 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
@@ -484,6 +484,7 @@ public class RuleClass {
     private boolean binaryOutput = true;
     private boolean workspaceOnly = false;
     private boolean outputsDefaultExecutable = false;
+    private boolean isConfigMatcher = false;
     private ImplicitOutputsFunction implicitOutputsFunction = ImplicitOutputsFunction.NONE;
     private Configurator<?, ?> configurator = NO_CHANGE;
     private RuleTransitionFactory transitionFactory;
@@ -599,6 +600,7 @@ public class RuleClass {
           workspaceOnly,
           outputsDefaultExecutable,
           implicitOutputsFunction,
+          isConfigMatcher,
           configurator,
           transitionFactory,
           configuredTargetFactory,
@@ -969,6 +971,17 @@ public class RuleClass {
     }
 
     /**
+     * Causes rules of this type to be evaluated with the parent's configuration, always, so that
+     * rules which match against parts of the configuration will behave as expected.
+     *
+     * <p>This is only intended for use by {@code config_setting} - other rules should not use this!
+     */
+    public Builder setIsConfigMatcherForConfigSettingOnly() {
+      this.isConfigMatcher = true;
+      return this;
+    }
+
+    /**
      * Returns an Attribute.Builder object which contains a replica of the
      * same attribute in the parent rule if exists.
      *
@@ -999,6 +1012,7 @@ public class RuleClass {
   private final boolean binaryOutput;
   private final boolean workspaceOnly;
   private final boolean outputsDefaultExecutable;
+  private final boolean isConfigMatcher;
 
   /**
    * A (unordered) mapping from attribute names to small integers indexing into
@@ -1115,6 +1129,7 @@ public class RuleClass {
       boolean workspaceOnly,
       boolean outputsDefaultExecutable,
       ImplicitOutputsFunction implicitOutputsFunction,
+      boolean isConfigMatcher,
       Configurator<?, ?> configurator,
       RuleTransitionFactory transitionFactory,
       ConfiguredTargetFactory<?, ?> configuredTargetFactory,
@@ -1137,6 +1152,7 @@ public class RuleClass {
     this.publicByDefault = publicByDefault;
     this.binaryOutput = binaryOutput;
     this.implicitOutputsFunction = implicitOutputsFunction;
+    this.isConfigMatcher = isConfigMatcher;
     this.configurator = Preconditions.checkNotNull(configurator);
     this.transitionFactory = transitionFactory;
     this.configuredTargetFactory = configuredTargetFactory;
@@ -1343,6 +1359,14 @@ public class RuleClass {
   }
 
   /**
+   * Returns true if rules of this type should be evaluated with the parent's configuration so that
+   * they can match on aspects of it.
+   */
+  public boolean isConfigMatcher() {
+    return isConfigMatcher;
+  }
+
+  /**
    * Creates a new {@link Rule} {@code r} where {@code r.getPackage()} is the {@link Package}
    * associated with {@code pkgBuilder}.
    *
diff --git a/src/test/java/com/google/devtools/build/lib/packages/RuleClassTest.java b/src/test/java/com/google/devtools/build/lib/packages/RuleClassTest.java
index 08c86ee6b7..38a8e0ab3c 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/RuleClassTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/RuleClassTest.java
@@ -887,6 +887,7 @@ public class RuleClassTest extends PackageLoadingTestCase {
         workspaceOnly,
         outputsDefaultExecutable,
         implicitOutputsFunction,
+        /*isConfigMatcher=*/ false,
         configurator,
         transitionFactory,
         configuredTargetFactory,