Enable rules to transition based on their Rule objects.
This begins to allow for cases where a rule sets configuration
based on its attributes, such as where a rule attribute names
flags and their values - sort of a reverse select.
There are no such cases yet, but they're coming!
--
PiperOrigin-RevId: 150648357
MOS_MIGRATED_REVID=150648357
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 eeacba5..1a2dbb2 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
@@ -445,6 +445,22 @@
}
}
+ /**
+ * A RuleTransitionFactory which always returns the same transition.
+ */
+ private static final class FixedTransitionFactory implements RuleTransitionFactory {
+ private final Transition transition;
+
+ private FixedTransitionFactory(Transition transition) {
+ this.transition = transition;
+ }
+
+ @Override
+ public Transition buildTransitionFor(Rule rule) {
+ return transition;
+ }
+ }
+
/** List of required attributes for normal rules, name and type. */
public static final ImmutableList<Attribute> REQUIRED_ATTRIBUTES_FOR_NORMAL_RULES =
ImmutableList.of(attr("tags", Type.STRING_LIST).build());
@@ -470,7 +486,7 @@
private boolean outputsDefaultExecutable = false;
private ImplicitOutputsFunction implicitOutputsFunction = ImplicitOutputsFunction.NONE;
private Configurator<?, ?> configurator = NO_CHANGE;
- private Transition transition;
+ private RuleTransitionFactory transitionFactory;
private ConfiguredTargetFactory<?, ?> configuredTargetFactory = null;
private PredicateWithMessage<Rule> validityPredicate =
PredicatesWithMessage.<Rule>alwaysTrue();
@@ -584,7 +600,7 @@
outputsDefaultExecutable,
implicitOutputsFunction,
configurator,
- transition,
+ transitionFactory,
configuredTargetFactory,
validityPredicate,
preferredDependencyPredicate,
@@ -718,8 +734,9 @@
public Builder cfg(Configurator<?, ?> configurator) {
Preconditions.checkState(type != RuleClassType.ABSTRACT,
"Setting not inherited property (cfg) of abstract rule class '%s'", name);
- Preconditions.checkState(transition == null,
- "Property cfg cannot be set to both a configurator and a transition");
+ Preconditions.checkState(this.transitionFactory == null && this.configurator == NO_CHANGE,
+ "Property cfg has already been set");
+ Preconditions.checkNotNull(configurator);
this.configurator = configurator;
return this;
}
@@ -734,9 +751,20 @@
public Builder cfg(Transition transition) {
Preconditions.checkState(type != RuleClassType.ABSTRACT,
"Setting not inherited property (cfg) of abstract rule class '%s'", name);
- Preconditions.checkState(configurator == NO_CHANGE,
- "Property cfg cannot be set to both a configurator and a transition");
- this.transition = transition;
+ Preconditions.checkState(this.transitionFactory == null && this.configurator == NO_CHANGE,
+ "Property cfg has already been set");
+ Preconditions.checkNotNull(transition);
+ this.transitionFactory = new FixedTransitionFactory(transition);
+ return this;
+ }
+
+ public Builder cfg(RuleTransitionFactory transitionFactory) {
+ Preconditions.checkState(type != RuleClassType.ABSTRACT,
+ "Setting not inherited property (cfg) of abstract rule class '%s'", name);
+ Preconditions.checkState(this.transitionFactory == null && this.configurator == NO_CHANGE,
+ "Property cfg has already been set");
+ Preconditions.checkNotNull(transitionFactory);
+ this.transitionFactory = transitionFactory;
return this;
}
@@ -1000,12 +1028,10 @@
private final Configurator<?, ?> configurator;
/**
- * A configuration transition that should be applied on any edge of the configured target graph
- * that leads into a target of this rule class.
- *
- * <p>This transition must be a PatchTransition, but that class is not accessible in this package.
+ * A factory which will produce a configuration transition that should be applied on any edge of
+ * the configured target graph that leads into a target of this rule class.
*/
- private final Transition transition;
+ private final RuleTransitionFactory transitionFactory;
/**
* The factory that creates configured targets from this rule.
@@ -1090,7 +1116,7 @@
boolean outputsDefaultExecutable,
ImplicitOutputsFunction implicitOutputsFunction,
Configurator<?, ?> configurator,
- Transition transition,
+ RuleTransitionFactory transitionFactory,
ConfiguredTargetFactory<?, ?> configuredTargetFactory,
PredicateWithMessage<Rule> validityPredicate,
Predicate<String> preferredDependencyPredicate,
@@ -1112,7 +1138,7 @@
this.binaryOutput = binaryOutput;
this.implicitOutputsFunction = implicitOutputsFunction;
this.configurator = Preconditions.checkNotNull(configurator);
- this.transition = transition;
+ this.transitionFactory = transitionFactory;
this.configuredTargetFactory = configuredTargetFactory;
this.validityPredicate = validityPredicate;
this.preferredDependencyPredicate = preferredDependencyPredicate;
@@ -1182,8 +1208,8 @@
return (Configurator<C, R>) configurator;
}
- public Transition getTransition() {
- return transition;
+ public RuleTransitionFactory getTransitionFactory() {
+ return transitionFactory;
}
@SuppressWarnings("unchecked")
