Allow repository rules to provide default bindings for external labels.
The idea is that an android_sdk_repository rule would by default bind @external:android/sdk to itself, thus avoiding an unnecessary roundtrip through //tools/android:sdk . If we then also eventually bind that external label to something, we can avoid having the //tools/android:sdk rule altogether.
--
MOS_MIGRATED_REVID=96285812
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 d2c1f56..05ad52a 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
@@ -20,10 +20,13 @@
import static com.google.devtools.build.lib.packages.Type.LABEL_LIST;
import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Function;
+import com.google.common.base.Functions;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Ordering;
import com.google.devtools.build.lib.events.EventHandler;
@@ -91,6 +94,8 @@
*/
@Immutable
public final class RuleClass {
+ public static final Function<? super Rule, Map<String, Label>> NO_EXTERNAL_BINDINGS =
+ Functions.<Map<String, Label>>constant(ImmutableMap.<String, Label>of());
/**
* A constraint for the package name of the Rule instances.
*/
@@ -428,6 +433,8 @@
private Predicate<String> preferredDependencyPredicate = Predicates.alwaysFalse();
private List<Class<?>> advertisedProviders = new ArrayList<>();
private BaseFunction configuredTargetFunction = null;
+ private Function<? super Rule, Map<String, Label>> externalBindingsFunction =
+ NO_EXTERNAL_BINDINGS;
private SkylarkEnvironment ruleDefinitionEnvironment = null;
private Set<Class<?>> configurationFragments = new LinkedHashSet<>();
private boolean failIfMissingConfigurationFragment;
@@ -510,10 +517,13 @@
== (configuredTargetFactory == null && configuredTargetFunction == null));
Preconditions.checkState(skylarkExecutable == (configuredTargetFunction != null));
Preconditions.checkState(skylarkExecutable == (ruleDefinitionEnvironment != null));
+ Preconditions.checkState(workspaceOnly || externalBindingsFunction == NO_EXTERNAL_BINDINGS);
+
return new RuleClass(name, skylarkExecutable, documented, publicByDefault, binaryOutput,
workspaceOnly, outputsDefaultExecutable, implicitOutputsFunction, configurator,
configuredTargetFactory, validityPredicate, preferredDependencyPredicate,
ImmutableSet.copyOf(advertisedProviders), configuredTargetFunction,
+ externalBindingsFunction,
ruleDefinitionEnvironment, configurationFragments, failIfMissingConfigurationFragment,
supportsConstraintChecking, attributes.values().toArray(new Attribute[0]));
}
@@ -688,6 +698,11 @@
return this;
}
+ public Builder setExternalBindingsFunction(Function<? super Rule, Map<String, Label>> func) {
+ this.externalBindingsFunction = func;
+ return this;
+ }
+
/**
* Sets the rule definition environment. Meant for Skylark usage.
*/
@@ -841,6 +856,11 @@
@Nullable private final BaseFunction configuredTargetFunction;
/**
+ * Returns the extra bindings a workspace function adds to the WORKSPACE file.
+ */
+ private final Function<? super Rule, Map<String, Label>> externalBindingsFunction;
+
+ /**
* The Skylark rule definition environment of this RuleClass.
* Null for non Skylark executable RuleClasses.
*/
@@ -900,6 +920,7 @@
PredicateWithMessage<Rule> validityPredicate, Predicate<String> preferredDependencyPredicate,
ImmutableSet<Class<?>> advertisedProviders,
@Nullable BaseFunction configuredTargetFunction,
+ Function<? super Rule, Map<String, Label>> externalBindingsFunction,
@Nullable SkylarkEnvironment ruleDefinitionEnvironment,
Set<Class<?>> allowedConfigurationFragments, boolean failIfMissingConfigurationFragment,
boolean supportsConstraintChecking,
@@ -917,6 +938,7 @@
this.preferredDependencyPredicate = preferredDependencyPredicate;
this.advertisedProviders = advertisedProviders;
this.configuredTargetFunction = configuredTargetFunction;
+ this.externalBindingsFunction = externalBindingsFunction;
this.ruleDefinitionEnvironment = ruleDefinitionEnvironment;
// Do not make a defensive copy as builder does that already
this.attributes = attributes;
@@ -1512,6 +1534,14 @@
}
/**
+ * Returns a function that computes the external bindings a repository function contributes to
+ * the WORKSPACE file.
+ */
+ public Function<? super Rule, Map<String, Label>> getExternalBindingsFunction() {
+ return externalBindingsFunction;
+ }
+
+ /**
* Returns this RuleClass's rule definition environment.
*/
@Nullable public SkylarkEnvironment getRuleDefinitionEnvironment() {
