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/*
* Copyright 2008 The Closure Compiler Authors.
*
* 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.javascript.jscomp.disambiguate;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.MoreObjects;
import com.google.errorprone.annotations.DoNotCall;
import com.google.javascript.jscomp.colors.Color;
import java.util.BitSet;
import java.util.LinkedHashMap;
import org.jspecify.nullness.Nullable;
/**
* A struct representing a {@link Color} for use in ambiguation.
*
* Each instance pairs a Color with additional information computed by/for optimizations.
*
*
Note: this design now depends on the implementation of Color to preserve invariants about
* recursive Colors. The node factory can't be depended on for post-processing Colors without losing
* type safety.
*/
final class ColorGraphNode {
private final Color color;
private final LinkedHashMap associatedProps =
new LinkedHashMap<>();
private final int index;
private final BitSet subtypeIndices = new BitSet();
/**
* Reasons a property name became associated with a type.
*
* This information is only used for debugging. It doesn't affect the behaviour of the pass.
*/
enum PropAssociation {
/** Because of an access in the AST (e.g. foo.prop) */
AST,
/**
* Because the type system recorded such an association, without any reason visible in the AST.
* Usually this means the relevant AST segment has been optimized away by an earlier pass.
*/
TYPE_SYSTEM,
/** Because it was inherited from a supertype in the type graph */
SUPERTYPE
}
static ColorGraphNode create(Color single, int index) {
checkNotNull(single);
checkArgument(index >= 0);
return new ColorGraphNode(single, index);
}
@VisibleForTesting
static ColorGraphNode createForTesting(int index) {
checkArgument(index < 0); // All test nodes have negative indexs to differentiate them.
return new ColorGraphNode(null, index);
}
private ColorGraphNode(@Nullable Color single, int index) {
this.index = index;
this.color = single;
}
Color getColor() {
return checkNotNull(this.color);
}
/**
* An ID used to efficiently construct a unique name for any cluster this node becomes the
* represenative of.
*/
int getIndex() {
return this.index;
}
/** The set of properties that that might be accessed from this type. */
LinkedHashMap getAssociatedProps() {
return this.associatedProps;
}
/** The IDs of other ColorGraphNodes that have been found to be subtypes of this type. */
BitSet getSubtypeIndices() {
return this.subtypeIndices;
}
@Override
@DoNotCall // For debugging only.
public String toString() {
return MoreObjects.toStringHelper(this)
.add("index", this.index)
.add("color", this.color)
.toString();
}
}