proguard.analysis.datastructure.callgraph.Node Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of proguard-core Show documentation
Show all versions of proguard-core Show documentation
ProGuardCORE is a free library to read, analyze, modify, and write Java class files.
/*
* ProGuardCORE -- library to process Java bytecode.
*
* Copyright (c) 2002-2021 Guardsquare NV
*
* 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 proguard.analysis.datastructure.callgraph;
import java.util.*;
import proguard.analysis.datastructure.CodeLocation;
import proguard.classfile.ClassPool;
import proguard.classfile.MethodSignature;
/**
* Represents a node in a sub-callgraph, e.g. only the incoming or the outgoing callgraph for a
* specific method. See {@link CallGraph#reconstructCallGraph(ClassPool, MethodSignature)} for more
* details. The reconstruction process makes sure that there are no loops in the graph.
*
* @author Samuel Hopstock
*/
public class Node {
public final MethodSignature signature;
public final Set predecessors = new HashSet<>();
/**
* The {@link CodeLocation}s containing the calls in this node's predecessors that lead here. If
* the call graph is traversed strictly in successor direction, there is exactly one incoming call
* per node, except for the root, which has none.
*/
public final Set incomingCallLocations = new HashSet<>();
/**
* The {@link CodeLocation}s containing the calls in this node that lead to its successors. If the
* call graph is traversed strictly in predecessor direction, there is exactly one outgoing call
* per node, except for the root, which has none.
*/
public final Set outgoingCallLocations = new HashSet<>();
public final Set successors = new HashSet<>();
public boolean isTruncated = false;
public Node(MethodSignature signature) {
this.signature = signature;
}
/**
* Checks if this node or any successors corresponds to a specific {@link MethodSignature}.
*
* @param signature The {@link MethodSignature} to look for
* @return true if this node or any of its transitive successors represents the target location
*/
public boolean successorsContain(MethodSignature signature) {
if (this.signature.equals(signature)) {
return true;
}
return successors.stream().anyMatch(s -> s.successorsContain(signature));
}
/**
* Checks if this node or any predecessors corresponds to a specific {@link MethodSignature}.
*
* @param signature The {@link MethodSignature} to look for
* @return true if this node or any of its transitive predecessors represents the target location
*/
public boolean predecessorsContain(MethodSignature signature) {
if (this.signature.equals(signature)) {
return true;
}
return predecessors.stream().anyMatch(s -> s.predecessorsContain(signature));
}
/**
* Calculate the distance between this node and its furthest successor.
*
* @return The distance (number of hops in the graph)
*/
public int getSuccessorDepth() {
if (successors.isEmpty()) {
return 0;
}
return successors.stream().mapToInt(s -> s.getSuccessorDepth() + 1).max().getAsInt();
}
/**
* Calculate the distance between this node and its furthest predecessor.
*
* @return The distance (number of hops in the graph)
*/
public int getPredecessorDepth() {
if (predecessors.isEmpty()) {
return 0;
}
return predecessors.stream().mapToInt(s -> s.getSuccessorDepth() + 1).max().getAsInt();
}
/** Get all predecessors of this node. */
public Set getAllPredecessors() {
Set predecessors = new HashSet<>();
List worklist = new ArrayList<>();
worklist.add(this);
while (!worklist.isEmpty()) {
Node curr = worklist.remove(0);
predecessors.add(curr);
worklist.addAll(curr.predecessors);
}
return predecessors;
}
/** Get the predecessor leaf nodes in the call sub-graph represented by this node. */
public Set getFurthestPredecessors() {
return getLeafNodes(true);
}
/** Get the successor leaf nodes in the call sub-graph represented by this node. */
public Set getFurthestSuccessors() {
return getLeafNodes(false);
}
/**
* Get the leaf nodes of the call sub-graph represented by this node.
*
* @param predecessors If true, we're looking for the furthest predecessors of this node,
* otherwise for the furthest successors.
* @return The set of leaf nodes in this sub-graph.
*/
private Set getLeafNodes(boolean predecessors) {
Set leafNodes = new HashSet<>();
List worklist = new ArrayList<>();
worklist.add(this);
while (!worklist.isEmpty()) {
Node curr = worklist.remove(0);
Set next = predecessors ? curr.predecessors : curr.successors;
if (next.isEmpty()) {
leafNodes.add(curr);
} else {
worklist.addAll(next);
}
}
return leafNodes;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
Node that = (Node) o;
return Objects.equals(signature, that.signature);
}
@Override
public int hashCode() {
return Objects.hash(signature);
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy