/**
* Copyright (C) 2010-2017 Gordon Fraser, Andrea Arcuri and EvoSuite
* contributors
*
* This file is part of EvoSuite.
*
* EvoSuite is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation, either version 3.0 of the License, or
* (at your option) any later version.
*
* EvoSuite is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with EvoSuite. If not, see <http://www.gnu.org/licenses/>.
*/
package org.evosuite.graphs.cdg;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Set;
import org.evosuite.coverage.branch.Branch;
import org.evosuite.graphs.EvoSuiteGraph;
import org.evosuite.graphs.cfg.ActualControlFlowGraph;
import org.evosuite.graphs.cfg.BasicBlock;
import org.evosuite.graphs.cfg.BytecodeInstruction;
import org.evosuite.graphs.cfg.ControlDependency;
import org.evosuite.graphs.cfg.ControlFlowEdge;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class ControlDependenceGraph extends EvoSuiteGraph<BasicBlock, ControlFlowEdge> {
private static Logger logger = LoggerFactory.getLogger(ControlDependenceGraph.class);
private final ActualControlFlowGraph cfg;
private final String className;
private final String methodName;
/**
* <p>Constructor for ControlDependenceGraph.</p>
*
* @param cfg a {@link org.evosuite.graphs.cfg.ActualControlFlowGraph} object.
*/
public ControlDependenceGraph(ActualControlFlowGraph cfg) {
super(ControlFlowEdge.class);
this.cfg = cfg;
this.className = cfg.getClassName();
this.methodName = cfg.getMethodName();
computeGraph();
// TODO check sanity
}
/**
* Convenience method redirecting to getControlDependentBranches(BasicBlock)
* if the given instruction is known to this CDG. Otherwise an
* IllegalArgumentException will be thrown.
*
* Should no longer be used: rather ask a BasicBlock for its CDs, so it can
* cache it.
*/
// public Set<ControlDependency>
// getControlDependentBranches(BytecodeInstruction ins) {
// if (ins == null)
// throw new IllegalArgumentException("null not accepted");
// if (!knowsInstruction(ins))
// throw new IllegalArgumentException(
// "instruction not known to this CDG: " + methodName
// + ins.toString());
//
// BasicBlock insBlock = ins.getBasicBlock();
//
// return getControlDependentBranches(insBlock);
// }
/**
* Checks whether this graph knows the given instruction. That is there is a
* BasicBlock in this graph's vertexSet containing the given instruction.
*
* @param ins a {@link org.evosuite.graphs.cfg.BytecodeInstruction} object.
* @return a boolean.
*/
public boolean knowsInstruction(BytecodeInstruction ins) {
return cfg.knowsInstruction(ins);
}
/**
* <p>getControlDependenceDepth</p>
*
* @param dependence a {@link org.evosuite.graphs.cfg.ControlDependency} object.
* @return a int.
*/
public int getControlDependenceDepth(ControlDependency dependence) {
int min = Integer.MAX_VALUE;
for (BasicBlock root : determineEntryPoints()) {
int distance = getDistance(root,
dependence.getBranch().getInstruction().getBasicBlock());
if (distance < min)
min = distance;
}
return min;
}
/**
* <p>getAlternativeBlocks</p>
*
* @param dependency a {@link org.evosuite.graphs.cfg.ControlDependency} object.
* @return a {@link java.util.Set} object.
*/
public Set<BasicBlock> getAlternativeBlocks(ControlDependency dependency) {
Set<BasicBlock> blocks = new HashSet<BasicBlock>();
Branch branch = dependency.getBranch();
BasicBlock block = branch.getInstruction().getBasicBlock();
for (ControlFlowEdge e : outgoingEdgesOf(block)) {
// TODO: Why can this be null?
if (e.getControlDependency() == null
|| e.getControlDependency().equals(dependency))
continue;
BasicBlock next = getEdgeTarget(e);
blocks.add(next);
getReachableBasicBlocks(blocks, next);
// blocks.addAll(getReachableBasicBlocks(next));
}
return blocks;
}
private void getReachableBasicBlocks(Set<BasicBlock> blocks, BasicBlock start) {
for (ControlFlowEdge e : outgoingEdgesOf(start)) {
BasicBlock next = getEdgeTarget(e);
if (!blocks.contains(next)) {
blocks.add(next);
getReachableBasicBlocks(blocks, next);
// blocks.addAll(getReachableBasicBlocks(next));
}
}
// return blocks;
}
/**
* Returns a Set containing all Branches the given BasicBlock is control
* dependent on.
*
* This is for each incoming ControlFlowEdge of the given block within this
* CDG, the branch instruction of that edge will be added to the returned
* set.
*
* @param insBlock a {@link org.evosuite.graphs.cfg.BasicBlock} object.
* @return a {@link java.util.Set} object.
*/
public Set<ControlDependency> getControlDependentBranches(BasicBlock insBlock) {
if (insBlock == null)
throw new IllegalArgumentException("null not accepted");
if (!containsVertex(insBlock))
throw new IllegalArgumentException("unknown block: " + insBlock.getName());
if (insBlock.hasControlDependenciesSet())
return insBlock.getControlDependencies();
Set<ControlDependency> r = retrieveControlDependencies(insBlock,
new LinkedHashSet<>());
return r;
}
private Set<ControlDependency> retrieveControlDependencies(BasicBlock insBlock,
Set<ControlFlowEdge> handled) {
Set<ControlDependency> r = new LinkedHashSet<>();
for (ControlFlowEdge e : incomingEdgesOf(insBlock)) {
if (handled.contains(e))
continue;
handled.add(e);
ControlDependency cd = e.getControlDependency();
if (cd != null)
r.add(cd);
else {
BasicBlock in = getEdgeSource(e);
if (!in.equals(insBlock))
r.addAll(retrieveControlDependencies(in, handled));
}
}
// TODO need RootBranch Object!!!
// TODO the following does not hold! a node can be dependent on the root
// branch AND another branch! TODO !!!
// // sanity check
// if (r.isEmpty()) {
// Set<BasicBlock> insParents = getParents(insBlock);
// if (insParents.size() != 1) {
//
// for (BasicBlock b : insParents)
// logger.error(b.toString());
//
// throw new IllegalStateException(
// "expect instruction dependent on root branch to have exactly one parent in it's CDG namely the EntryBlock: "
// + insBlock.toString());
// }
//
// for (BasicBlock b : insParents)
// if (!b.isEntryBlock() && !getControlDependentBranches(b).isEmpty())
// throw new IllegalStateException(
// "expect instruction dependent on root branch to have exactly one parent in it's CDG namely the EntryBlock"
// + insBlock.toString() + methodName);
// }
return r;
}
/**
* <p>getControlDependentBranchIds</p>
*
* @param ins a {@link org.evosuite.graphs.cfg.BasicBlock} object.
* @return a {@link java.util.Set} object.
*/
public Set<Integer> getControlDependentBranchIds(BasicBlock ins) {
Set<ControlDependency> dependentBranches = getControlDependentBranches(ins);
Set<Integer> r = new LinkedHashSet<>();
for (ControlDependency cd : dependentBranches) {
if (cd == null)
throw new IllegalStateException(
"expect set returned by getControlDependentBranches() not to contain null");
r.add(cd.getBranch().getActualBranchId());
}
// to indicate this is only dependent on root branch,
// meaning entering the method
if (isRootDependent(ins))
r.add(-1);
return r;
}
// /**
// * Determines whether the given Branch has to be evaluated to true or to
// * false in order to reach the given BytecodeInstruction - given the
// * instruction is directly control dependent on the given Branch.
// *
// * In other words this method checks whether there is an incoming
// * ControlFlowEdge to the given instruction's BasicBlock containing the
// * given Branch as it's BranchInstruction and if so, that edges
// * branchExpressionValue is returned. If the given instruction is directly
// * control dependent on the given branch such a ControlFlowEdge must
// exist.
// * Should this assumption be violated an IllegalStateException is thrown.
// *
// * If the given instruction is not known to this CDG or not directly
// control
// * dependent on the given Branch an IllegalArgumentException is thrown.
// */
// public boolean getBranchExpressionValue(BytecodeInstruction ins, Branch
// b) {
// if (ins == null)
// throw new IllegalArgumentException("null given");
// if (!ins.isDirectlyControlDependentOn(b))
// throw new IllegalArgumentException(
// "only allowed to call this method for instructions and their directly control dependent branches");
// if (b == null)
// return true; // root branch special case
//
// BasicBlock insBlock = ins.getBasicBlock();
//
// for (ControlFlowEdge e : incomingEdgesOf(insBlock)) {
// if (e.isExceptionEdge() && !e.hasControlDependency())
// continue;
//
// Branch current = e.getBranchInstruction();
// if (current == null) {
// try {
// BasicBlock in = getEdgeSource(e);
// return getBranchExpressionValue(in.getFirstInstruction(), b);
// } catch (Exception ex) {
// continue;
// }
// } else if (current.equals(b))
// return e.getBranchExpressionValue();
// }
//
// throw new IllegalStateException(
// "expect CDG to contain an incoming edge to the given instructions basic block containing the given branch if isControlDependent() returned true on those two ");
// }
// initialization
/**
* Determines whether the given BytecodeInstruction is directly control
* dependent on the given Branch. It's BasicBlock is control dependent on
* the given Branch.
*
* If b is null, it is assumed to be the root branch.
*
* If the given instruction is not known to this CDG an
* IllegalArgumentException is thrown.
*
* @param ins a {@link org.evosuite.graphs.cfg.BytecodeInstruction} object.
* @param b a {@link org.evosuite.coverage.branch.Branch} object.
* @return a boolean.
*/
public boolean isDirectlyControlDependentOn(BytecodeInstruction ins, Branch b) {
if (ins == null)
throw new IllegalArgumentException("null given");
BasicBlock insBlock = ins.getBasicBlock();
return isDirectlyControlDependentOn(insBlock, b);
}
/**
* Determines whether the given BasicBlock is directly control dependent on
* the given Branch. Meaning within this CDG there is an incoming
* ControlFlowEdge to this instructions BasicBlock holding the given Branch
* as it's branchInstruction.
*
* If b is null, it is assumed to be the root branch.
*
* If the given instruction is not known to this CDG an
* IllegalArgumentException is thrown.
*
* @param insBlock a {@link org.evosuite.graphs.cfg.BasicBlock} object.
* @param b a {@link org.evosuite.coverage.branch.Branch} object.
* @return a boolean.
*/
public boolean isDirectlyControlDependentOn(BasicBlock insBlock, Branch b) {
Set<ControlFlowEdge> incomming = incomingEdgesOf(insBlock);
if (incomming.size() == 1) {
// in methods with a try-catch-block it is possible that there
// are nodes in the CDG that have exactly one parent with an
// edge without a branchInstruction that is a non exceptional
// edge
// should the given instruction be such a node, follow the parents
// until
// you reach one where the above conditions are not met
for (ControlFlowEdge e : incomming) {
if (!e.hasControlDependency() && !e.isExceptionEdge()) {
return isDirectlyControlDependentOn(getEdgeSource(e), b);
}
}
}
boolean isRootDependent = isRootDependent(insBlock);
if (b == null)
return isRootDependent;
if (isRootDependent && b != null)
return false;
for (ControlFlowEdge e : incomming) {
Branch current = e.getBranchInstruction();
if (e.isExceptionEdge()) {
if (current != null)
throw new IllegalStateException(
"expect exception edges to have no BranchInstruction set");
else
continue;
}
if (current == null)
continue;
// throw new IllegalStateException(
// "expect non exceptional ControlFlowEdges whithin the CDG that don't come from EntryBlock to have branchInstructions set "
// + insBlock.toString() + methodName);
if (current.equals(b))
return true;
}
return false;
}
/**
* Checks whether the given instruction is dependent on the root branch of
* it's method
*
* This is the case if the BasicBlock of the given instruction is directly
* adjacent to the EntryBlock
*
* @param ins a {@link org.evosuite.graphs.cfg.BytecodeInstruction} object.
* @return a boolean.
*/
public boolean isRootDependent(BytecodeInstruction ins) {
return isRootDependent(ins.getBasicBlock());
}
/**
* Checks whether the given basicBlock is dependent on the root branch of
* it's method
*
* This is the case if the BasicBlock of the given instruction is directly
* adjacent to the EntryBlock
*
* @param insBlock a {@link org.evosuite.graphs.cfg.BasicBlock} object.
* @return a boolean.
*/
public boolean isRootDependent(BasicBlock insBlock) {
if (isAdjacentToEntryBlock(insBlock))
return true;
for (ControlFlowEdge in : incomingEdgesOf(insBlock)) {
if (in.hasControlDependency())
continue;
BasicBlock inBlock = getEdgeSource(in);
if(inBlock.equals(insBlock))
continue;
if (isRootDependent(inBlock))
return true;
}
return false;
}
/**
* Returns true if the given BasicBlock has an incoming edge from this CDG's
* EntryBlock or is itself the EntryBlock
*
* @param insBlock a {@link org.evosuite.graphs.cfg.BasicBlock} object.
* @return a boolean.
*/
public boolean isAdjacentToEntryBlock(BasicBlock insBlock) {
if (insBlock.isEntryBlock())
return true;
Set<BasicBlock> parents = getParents(insBlock);
for (BasicBlock parent : parents)
if (parent.isEntryBlock())
return true;
return false;
}
// /**
// * If the given instruction is known to this graph, the BasicBlock holding
// * that instruction is returned. Otherwise an IllegalArgumentException
// will
// * be thrown.
// *
// * Just a convenience method that more or less just redirects the call to
// * the CFG
// */
// public BasicBlock getBlockOf(BytecodeInstruction ins) {
// if (ins == null)
// throw new IllegalArgumentException("null given");
// if (!cfg.knowsInstruction(ins))
// throw new IllegalArgumentException("unknown instruction");
//
// BasicBlock insBlock = cfg.getBlockOf(ins);
// if (insBlock == null)
// throw new IllegalStateException(
// "expect CFG to return non-null BasicBlock for instruction it knows");
//
// return insBlock;
// }
// init
private void computeGraph() {
createGraphNodes();
computeControlDependence();
}
private void createGraphNodes() {
// copy CFG nodes
addVertices(cfg);
for (BasicBlock b : vertexSet())
if (b.isExitBlock() && !graph.removeVertex(b)) // TODO refactor
throw new IllegalStateException("internal error building up CDG");
}
private void computeControlDependence() {
ActualControlFlowGraph rcfg = cfg.computeReverseCFG();
DominatorTree<BasicBlock> dt = new DominatorTree<BasicBlock>(rcfg);
for (BasicBlock b : rcfg.vertexSet())
if (!b.isExitBlock()) {
logger.debug("DFs for: " + b.getName());
for (BasicBlock cd : dt.getDominatingFrontiers(b)) {
ControlFlowEdge orig = cfg.getEdge(cd, b);
if (!cd.isEntryBlock() && orig == null) {
// in for loops for example it can happen that cd and b
// were not directly adjacent to each other in the CFG
// but rather there were some intermediate nodes between
// them and the needed information is inside one of the
// edges
// from cd to the first intermediate node. more
// precisely cd is expected to be a branch and to have 2
// outgoing edges, one for evaluating to true (jumping)
// and one for false. one of them can be followed and b
// will eventually be reached, the other one can not be
// followed in that way. TODO TRY!
logger.debug("cd: " + cd.toString());
logger.debug("b: " + b.toString());
// TODO this is just for now! unsafe and probably not
// even correct!
Set<ControlFlowEdge> candidates = cfg.outgoingEdgesOf(cd);
if (candidates.size() < 2)
throw new IllegalStateException("unexpected");
boolean leadToB = false;
boolean skip = false;
for (ControlFlowEdge e : candidates) {
if (!e.hasControlDependency()) {
skip = true;
break;
}
if (cfg.leadsToNode(e, b)) {
if (leadToB)
orig = null;
// throw new
// IllegalStateException("unexpected");
leadToB = true;
orig = e;
}
}
if (skip)
continue;
if (!leadToB)
throw new IllegalStateException("unexpected");
}
if (orig == null)
logger.debug("orig still null!");
if (!addEdge(cd, b, new ControlFlowEdge(orig)))
throw new IllegalStateException(
"internal error while adding CD edge");
logger.debug(" " + cd.getName());
}
}
}
/** {@inheritDoc} */
@Override
public String getName() {
// return "CDG" + graphId + "_" + methodName;
return methodName + "_" + "CDG";
}
/** {@inheritDoc} */
@Override
protected String dotSubFolder() {
return toFileString(className) + "/CDG/";
}
/**
* <p>Getter for the field <code>className</code>.</p>
*
* @return a {@link java.lang.String} object.
*/
public String getClassName() {
return className;
}
/**
* <p>Getter for the field <code>methodName</code>.</p>
*
* @return a {@link java.lang.String} object.
*/
public String getMethodName() {
return methodName;
}
}