/*
* @see com.ibm.wala.cfg.ControlFlowGraph#getProgramCounter(int)
*/
public int getProgramCounter(int index) {
try {
return method.getBytecodeIndex(index);
} catch (InvalidClassFileException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
return -1;
}
}
public IInstruction[] getInstructions() {
try {
return method.getInstructions();
} catch (InvalidClassFileException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
return null;
}
}
/*
* @see com.ibm.wala.classLoader.IClass#getDeclaredMethods()
*/
@Override
public Collection<IMethod> getDeclaredMethods() {
try {
computeMethodMapIfNeeded();
} catch (InvalidClassFileException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
}
return Collections.unmodifiableCollection(methodMap.values());
}
private ExceptionHandler[] getExceptionHandlers() {
ExceptionHandler[][] handlers;
try {
handlers = method.getHandlers();
} catch (InvalidClassFileException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
handlers = null;
}
ExceptionHandler[] hs = handlers[getLastInstructionIndex()];
return hs;
}
/*
* @see com.ibm.wala.classLoader.IClass#getMethod(com.ibm.wala.types.Selector)
*/
@Override
public IMethod getMethod(Selector selector) {
try {
computeMethodMapIfNeeded();
} catch (InvalidClassFileException e1) {
e1.printStackTrace();
Assertions.UNREACHABLE();
}
// my methods + cached parent stuff
IMethod result = methodMap.get(selector);
if (result != null) {
return result;
}
if (inheritCache != null) {
result = inheritCache.get(selector);
if (result != null) {
return result;
}
}
// check parent, caching if found
if (!selector.equals(MethodReference.clinitSelector)
&& !selector.equals(MethodReference.initSelector)) {
IClass superclass = getSuperclass();
if (superclass != null) {
IMethod inherit = superclass.getMethod(selector);
if (inherit != null) {
if (inheritCache == null) {
inheritCache = new BimodalMap<Selector, IMethod>(5);
}
inheritCache.put(selector, inherit);
return inherit;
}
}
}
// didn't find it yet. special logic for interfaces
if (isInterface() || isAbstract()) {
final Iterator<IClass> it = getAllImplementedInterfaces().iterator();
// try each superinterface
while (it.hasNext()) {
IClass k = it.next();
result = k.getMethod(selector);
if (result != null) {
return result;
}
}
}
return null;
}
/**
* Add any exceptional edges generated by the last instruction in a basic block.
*
* @param last the last instruction in a basic block.
*/
protected void addExceptionalEdges(IInstruction last) {
IClassHierarchy cha = getMethod().getClassHierarchy();
if (last.isPEI()) {
Collection<TypeReference> exceptionTypes = null;
boolean goToAllHandlers = false;
ExceptionHandler[] hs = getExceptionHandlers();
if (last instanceof ThrowInstruction) {
// this class does not have the type information needed
// to determine what the athrow throws. So, add an
// edge to all reachable handlers. Better information can
// be obtained later with SSA type propagation.
// TODO: consider pruning to only the exception types that
// this method either catches or allocates, since these are
// the only types that can flow to an athrow.
goToAllHandlers = true;
} else {
if (hs != null && hs.length > 0) {
IClassLoader loader = getMethod().getDeclaringClass().getClassLoader();
BytecodeLanguage l = (BytecodeLanguage) loader.getLanguage();
exceptionTypes = l.getImplicitExceptionTypes(last);
if (last instanceof IInvokeInstruction) {
IInvokeInstruction call = (IInvokeInstruction) last;
exceptionTypes = HashSetFactory.make(exceptionTypes);
MethodReference target =
MethodReference.findOrCreate(
l,
loader.getReference(),
call.getClassType(),
call.getMethodName(),
call.getMethodSignature());
try {
exceptionTypes.addAll(l.inferInvokeExceptions(target, cha));
} catch (InvalidClassFileException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
}
}
}
}
if (hs != null && hs.length > 0) {
// found a handler for this PEI
// create a mutable copy
if (!goToAllHandlers) {
exceptionTypes = HashSetFactory.make(exceptionTypes);
}
// this var gets set to false if goToAllHandlers is true but some enclosing exception
// handler catches all
// exceptions. in such a case, we need not add an exceptional edge to the method exit
boolean needEdgeToExitForAllHandlers = true;
for (int j = 0; j < hs.length; j++) {
if (DEBUG) {
System.err.println(" handler " + hs[j]);
}
BasicBlock b = getBlockForInstruction(hs[j].getHandler());
if (DEBUG) {
System.err.println(" target " + b);
}
if (goToAllHandlers) {
// add an edge to the catch block.
if (DEBUG) {
System.err.println(" gotoAllHandlers " + b);
}
addExceptionalEdgeTo(b);
// if the handler catches all exceptions, we don't need to add an edge to the exit or
// any other handlers
if (hs[j].getCatchClass() == null) {
needEdgeToExitForAllHandlers = false;
break;
}
} else {
TypeReference caughtException = null;
if (hs[j].getCatchClass() != null) {
ClassLoaderReference loader =
ShrikeCFG.this.getMethod().getDeclaringClass().getReference().getClassLoader();
caughtException = ShrikeUtil.makeTypeReference(loader, hs[j].getCatchClass());
if (DEBUG) {
System.err.println(" caughtException " + caughtException);
}
IClass caughtClass = cha.lookupClass(caughtException);
if (caughtClass == null) {
// conservatively add the edge, and raise a warning
addExceptionalEdgeTo(b);
Warnings.add(FailedExceptionResolutionWarning.create(caughtException));
// null out caughtException, to avoid attempting to process it
caughtException = null;
}
} else {
if (DEBUG) {
System.err.println(" catchClass() == null");
}
// hs[j].getCatchClass() == null.
// this means that the handler catches all exceptions.
// add the edge and null out all types
if (!exceptionTypes.isEmpty()) {
addExceptionalEdgeTo(b);
exceptionTypes.clear();
caughtException = null;
}
}
if (caughtException != null) {
IClass caughtClass = cha.lookupClass(caughtException);
// the set "caught" should be the set of exceptions that MUST
// have been caught by the handlers in scope
ArrayList<TypeReference> caught =
new ArrayList<TypeReference>(exceptionTypes.size());
// check if we should add an edge to the catch block.
for (TypeReference t : exceptionTypes) {
if (t != null) {
IClass klass = cha.lookupClass(t);
if (klass == null) {
Warnings.add(FailedExceptionResolutionWarning.create(caughtException));
// conservatively add an edge
addExceptionalEdgeTo(b);
} else {
boolean subtype1 = cha.isSubclassOf(klass, caughtClass);
if (subtype1 || cha.isSubclassOf(caughtClass, klass)) {
// add the edge and null out the type from the array
addExceptionalEdgeTo(b);
if (subtype1) {
caught.add(t);
}
}
}
}
}
exceptionTypes.removeAll(caught);
}
}
}
// if needed, add an edge to the exit block.
if ((exceptionTypes == null && needEdgeToExitForAllHandlers)
|| (exceptionTypes != null && !exceptionTypes.isEmpty())) {
BasicBlock exit = exit();
addExceptionalEdgeTo(exit);
}
} else {
// found no handler for this PEI ... link to the exit block.
BasicBlock exit = exit();
addExceptionalEdgeTo(exit);
}
}
}
private void makeBasicBlocks() {
ExceptionHandler[][] handlers;
try {
handlers = method.getHandlers();
} catch (InvalidClassFileException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
handlers = null;
}
boolean[] r = new boolean[getInstructions().length];
boolean[] catchers = new boolean[getInstructions().length];
// we initially start with both the entry and exit block.
int blockCount = 2;
// Compute r so r[i] == true iff instruction i begins a basic block.
// While doing so count the number of blocks.
r[0] = true;
IInstruction[] instructions = getInstructions();
for (int i = 0; i < instructions.length; i++) {
int[] targets = instructions[i].getBranchTargets();
// if there are any targets, then break the basic block here.
// also break the basic block after a return
if (targets.length > 0 || !instructions[i].isFallThrough()) {
if (i + 1 < instructions.length && !r[i + 1]) {
r[i + 1] = true;
blockCount++;
}
}
for (int j = 0; j < targets.length; j++) {
if (!r[targets[j]]) {
r[targets[j]] = true;
blockCount++;
}
}
if (instructions[i].isPEI()) {
ExceptionHandler[] hs = handlers[i];
// break the basic block here.
if (i + 1 < instructions.length && !r[i + 1]) {
r[i + 1] = true;
blockCount++;
}
if (hs != null && hs.length > 0) {
for (int j = 0; j < hs.length; j++) {
exceptionHandlers.add(hs[j]);
if (!r[hs[j].getHandler()]) {
// we have not discovered the catch block yet.
// form a new basic block
r[hs[j].getHandler()] = true;
blockCount++;
}
catchers[hs[j].getHandler()] = true;
}
}
}
}
BasicBlock entry = new BasicBlock(-1);
addNode(entry);
int j = 1;
for (int i = 0; i < r.length; i++) {
if (r[i]) {
BasicBlock b = new BasicBlock(i);
addNode(b);
if (catchers[i]) {
setCatchBlock(j);
}
j++;
}
}
BasicBlock exit = new BasicBlock(-1);
addNode(exit);
}