// Copyright 2014 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.packages; import com.google.common.base.Function; import com.google.devtools.build.lib.events.Location; import java.util.BitSet; /** * Provides attribute setting and retrieval for a Rule. Encapsulating attribute access * here means it can be passed around independently of the Rule itself. In particular, * it can be consumed by independent {@link AttributeMap} instances that can apply * varying kinds of logic for determining the "value" of an attribute. For example, * a configurable attribute's "value" may be a { config --> value } dictionary * or a configuration-bound lookup on that dictionary, depending on the context in * which it's requested. * *
This class provides the lowest-level access to attribute information. It is *not*
* intended to be a robust public interface, but rather just an input to {@link AttributeMap}
* instances. Use those instances for all domain-level attribute access.
*/
public class AttributeContainer {
private final RuleClass ruleClass;
// Attribute values, keyed by attribute index:
private final Object[] attributeValues;
// Whether an attribute value has been set explicitly in the BUILD file, keyed by attribute index.
private final BitSet attributeValueExplicitlySpecified;
// Attribute locations, keyed by attribute index:
private final Location[] attributeLocations;
/**
* Create a container for a rule of the given rule class.
*/
public AttributeContainer(RuleClass ruleClass) {
this(ruleClass, new Location[ruleClass.getAttributeCount()]);
}
AttributeContainer(RuleClass ruleClass, Location[] locations) {
this.ruleClass = ruleClass;
this.attributeValues = new Object[ruleClass.getAttributeCount()];
this.attributeValueExplicitlySpecified = new BitSet(ruleClass.getAttributeCount());
this.attributeLocations = locations;
}
/**
* Returns an attribute value by instance, or null on no match.
*/
public Object getAttr(Attribute attribute) {
return getAttr(attribute.getName());
}
/**
* Returns an attribute value by name, or null on no match.
*/
public Object getAttr(String attrName) {
Integer idx = ruleClass.getAttributeIndex(attrName);
return idx != null ? attributeValues[idx] : null;
}
/**
* Returns true iff the given attribute exists for this rule and its value
* is explicitly set in the BUILD file (as opposed to its default value).
*/
public boolean isAttributeValueExplicitlySpecified(Attribute attribute) {
return isAttributeValueExplicitlySpecified(attribute.getName());
}
public boolean isAttributeValueExplicitlySpecified(String attributeName) {
Integer idx = ruleClass.getAttributeIndex(attributeName);
return idx != null && attributeValueExplicitlySpecified.get(idx);
}
/**
* Returns the location of the attribute definition for this rule, or null if not found.
*/
public Location getAttributeLocation(String attrName) {
Integer idx = ruleClass.getAttributeIndex(attrName);
return idx != null ? attributeLocations[idx] : null;
}
Object getAttributeValue(int index) {
return attributeValues[index];
}
void setAttributeValue(Attribute attribute, Object value, boolean explicit) {
Integer index = ruleClass.getAttributeIndex(attribute.getName());
attributeValues[index] = value;
attributeValueExplicitlySpecified.set(index, explicit);
}
void setAttributeValueByName(String attrName, Object value) {
Integer index = ruleClass.getAttributeIndex(attrName);
attributeValues[index] = value;
attributeValueExplicitlySpecified.set(index);
}
void setAttributeLocation(int attrIndex, Location location) {
attributeLocations[attrIndex] = location;
}
void setAttributeLocation(Attribute attribute, Location location) {
Integer index = ruleClass.getAttributeIndex(attribute.getName());
attributeLocations[index] = location;
}
public static final Function