// 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.collect.ImmutableList; import com.google.devtools.build.lib.cmdline.Label; import com.google.devtools.build.lib.syntax.Type; import javax.annotation.Nullable; /** * The interface for accessing a {@link Rule}'s attributes. * *
Since what an attribute lookup should return can be ambiguous (e.g. for configurable * attributes, should we return a configuration-resolved value or the original, unresolved * selection expression?), different implementations can apply different policies for how to * fulfill these methods. Calling code can then use the appropriate implementation for whatever * its particular needs are. */ public interface AttributeMap { /** * Returns the name of the rule; this is equivalent to {@code getLabel().getName()}. */ String getName(); /** * Returns the label of the rule. */ Label getLabel(); /** * Returns the value of the named rule attribute, which must be of the given type. This may * be null (for example, for an attribute with no default value that isn't explicitly set in * the rule - see {@link Type#getDefaultValue}). * *
If the rule doesn't have this attribute with the specified type, throws an
* {@link IllegalArgumentException}.
*/
@Nullable
It is probably a good idea to avoid this method in default value and implicit outputs
* computation, because it is confusing that setting an attribute to an empty list (for example)
* is different from not setting it at all.
*/
boolean isAttributeValueExplicitlySpecified(String attributeName);
/**
* An interface which accepts {@link Attribute}s, used by {@link #visitLabels}.
*/
interface AcceptsLabelAttribute {
/**
* Accept a (Label, Attribute) pair describing a dependency edge.
*
* @param label the target node of the (Rule, Label) edge.
* The source node should already be known.
* @param attribute the attribute.
*/
void acceptLabelAttribute(Label label, Attribute attribute);
}
/**
* For all attributes that contain labels in their values (either by *being* a label or
* being a collection that includes labels), visits every label and notifies the
* specified observer at each visit.
*/
void visitLabels(AcceptsLabelAttribute observer);
// TODO(bazel-team): These methods are here to support computed defaults that inherit
// package-level default values. Instead, we should auto-inherit and remove the computed
// defaults. If we really need to give access to package-level defaults, we should come up with
// a more generic interface.
String getPackageDefaultHdrsCheck();
Boolean getPackageDefaultTestOnly();
String getPackageDefaultDeprecation();
ImmutableList