/**
* Pass 3b implements the data flow analysis as described in the Java Virtual Machine
* Specification, Second Edition. Later versions will use LocalVariablesInfo objects to verify if
* the verifier-inferred types and the class file's debug information (LocalVariables attributes)
* match [TODO].
*
* @see org.aspectj.apache.bcel.verifier.statics.LocalVariablesInfo
* @see org.aspectj.apache.bcel.verifier.statics.Pass2Verifier#getLocalVariablesInfo(int)
*/
public VerificationResult do_verify() {
if (!myOwner.doPass3a(method_no).equals(VerificationResult.VR_OK)) {
return VerificationResult.VR_NOTYET;
}
// Pass 3a ran before, so it's safe to assume the JavaClass object is
// in the BCEL repository.
JavaClass jc = Repository.lookupClass(myOwner.getClassName());
ConstantPoolGen constantPoolGen = new ConstantPoolGen(jc.getConstantPool());
// Init Visitors
InstConstraintVisitor icv = new InstConstraintVisitor();
icv.setConstantPoolGen(constantPoolGen);
ExecutionVisitor ev = new ExecutionVisitor();
ev.setConstantPoolGen(constantPoolGen);
Method[] methods = jc.getMethods(); // Method no "method_no" exists, we ran Pass3a before on it!
try {
MethodGen mg = new MethodGen(methods[method_no], myOwner.getClassName(), constantPoolGen);
icv.setMethodGen(mg);
////////////// DFA BEGINS HERE ////////////////
if (!(mg.isAbstract() || mg.isNative())) { // IF mg HAS CODE (See pass 2)
ControlFlowGraph cfg = new ControlFlowGraph(mg);
// Build the initial frame situation for this method.
Frame f = new Frame(mg.getMaxLocals(), mg.getMaxStack());
if (!mg.isStatic()) {
if (mg.getName().equals(Constants.CONSTRUCTOR_NAME)) {
Frame._this = new UninitializedObjectType(new ObjectType(jc.getClassName()));
f.getLocals().set(0, Frame._this);
} else {
Frame._this = null;
f.getLocals().set(0, new ObjectType(jc.getClassName()));
}
}
Type[] argtypes = mg.getArgumentTypes();
int twoslotoffset = 0;
for (int j = 0; j < argtypes.length; j++) {
if (argtypes[j] == Type.SHORT
|| argtypes[j] == Type.BYTE
|| argtypes[j] == Type.CHAR
|| argtypes[j] == Type.BOOLEAN) {
argtypes[j] = Type.INT;
}
f.getLocals().set(twoslotoffset + j + (mg.isStatic() ? 0 : 1), argtypes[j]);
if (argtypes[j].getSize() == 2) {
twoslotoffset++;
f.getLocals().set(twoslotoffset + j + (mg.isStatic() ? 0 : 1), Type.UNKNOWN);
}
}
circulationPump(cfg, cfg.contextOf(mg.getInstructionList().getStart()), f, icv, ev);
}
} catch (VerifierConstraintViolatedException ce) {
ce.extendMessage("Constraint violated in method '" + methods[method_no] + "':\n", "");
return new VerificationResult(VerificationResult.VERIFIED_REJECTED, ce.getMessage());
} catch (RuntimeException re) {
// These are internal errors
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
re.printStackTrace(pw);
throw new AssertionViolatedException(
"Some RuntimeException occured while verify()ing class '"
+ jc.getClassName()
+ "', method '"
+ methods[method_no]
+ "'. Original RuntimeException's stack trace:\n---\n"
+ sw
+ "---\n");
}
return VerificationResult.VR_OK;
}
/**
* The LocalVariables from the current Frame we're operating on.
*
* @see #setFrame(Frame)
*/
private LocalVariables locals() {
return frame.getLocals();
}
/**
* Whenever the outgoing frame situation of an InstructionContext changes, all its successors are
* put [back] into the queue [as if they were unvisited]. The proof of termination is about the
* existence of a fix point of frame merging.
*/
private void circulationPump(
ControlFlowGraph cfg,
InstructionContext start,
Frame vanillaFrame,
InstConstraintVisitor icv,
ExecutionVisitor ev) {
final Random random = new Random();
InstructionContextQueue icq = new InstructionContextQueue();
start.execute(
vanillaFrame,
new ArrayList(),
icv,
ev); // new ArrayList() <=> no Instruction was executed before
// => Top-Level routine (no jsr call before)
icq.add(start, new ArrayList());
// LOOP!
while (!icq.isEmpty()) {
InstructionContext u;
ArrayList ec;
if (!DEBUG) {
int r = random.nextInt(icq.size());
u = icq.getIC(r);
ec = icq.getEC(r);
icq.remove(r);
} else {
u = icq.getIC(0);
ec = icq.getEC(0);
icq.remove(0);
}
ArrayList oldchain = (ArrayList) (ec.clone());
ArrayList newchain = (ArrayList) (ec.clone());
newchain.add(u);
if ((u.getInstruction().getInstruction()) instanceof RET) {
// System.err.println(u);
// We can only follow _one_ successor, the one after the
// JSR that was recently executed.
RET ret = (RET) (u.getInstruction().getInstruction());
ReturnaddressType t =
(ReturnaddressType) u.getOutFrame(oldchain).getLocals().get(ret.getIndex());
InstructionContext theSuccessor = cfg.contextOf(t.getTarget());
// Sanity check
InstructionContext lastJSR = null;
int skip_jsr = 0;
for (int ss = oldchain.size() - 1; ss >= 0; ss--) {
if (skip_jsr < 0) {
throw new AssertionViolatedException("More RET than JSR in execution chain?!");
}
// System.err.println("+"+oldchain.get(ss));
if (((InstructionContext) oldchain.get(ss)).getInstruction().getInstruction()
instanceof JsrInstruction) {
if (skip_jsr == 0) {
lastJSR = (InstructionContext) oldchain.get(ss);
break;
} else {
skip_jsr--;
}
}
if (((InstructionContext) oldchain.get(ss)).getInstruction().getInstruction()
instanceof RET) {
skip_jsr++;
}
}
if (lastJSR == null) {
throw new AssertionViolatedException(
"RET without a JSR before in ExecutionChain?! EC: '" + oldchain + "'.");
}
JsrInstruction jsr = (JsrInstruction) (lastJSR.getInstruction().getInstruction());
if (theSuccessor != (cfg.contextOf(jsr.physicalSuccessor()))) {
throw new AssertionViolatedException(
"RET '"
+ u.getInstruction()
+ "' info inconsistent: jump back to '"
+ theSuccessor
+ "' or '"
+ cfg.contextOf(jsr.physicalSuccessor())
+ "'?");
}
if (theSuccessor.execute(u.getOutFrame(oldchain), newchain, icv, ev)) {
icq.add(theSuccessor, (ArrayList) newchain.clone());
}
} else { // "not a ret"
// Normal successors. Add them to the queue of successors.
InstructionContext[] succs = u.getSuccessors();
for (int s = 0; s < succs.length; s++) {
InstructionContext v = succs[s];
if (v.execute(u.getOutFrame(oldchain), newchain, icv, ev)) {
icq.add(v, (ArrayList) newchain.clone());
}
}
} // end "not a ret"
// Exception Handlers. Add them to the queue of successors.
// [subroutines are never protected; mandated by JustIce]
ExceptionHandler[] exc_hds = u.getExceptionHandlers();
for (int s = 0; s < exc_hds.length; s++) {
InstructionContext v = cfg.contextOf(exc_hds[s].getHandlerStart());
// TODO: the "oldchain" and "newchain" is used to determine the subroutine
// we're in (by searching for the last JSR) by the InstructionContext
// implementation. Therefore, we should not use this chain mechanism
// when dealing with exception handlers.
// Example: a JSR with an exception handler as its successor does not
// mean we're in a subroutine if we go to the exception handler.
// We should address this problem later; by now we simply "cut" the chain
// by using an empty chain for the exception handlers.
// if (v.execute(new Frame(u.getOutFrame(oldchain).getLocals(), new OperandStack
// (u.getOutFrame().getStack().maxStack(), (exc_hds[s].getExceptionType()==null?
// Type.THROWABLE : exc_hds[s].getExceptionType())) ), newchain), icv, ev){
// icq.add(v, (ArrayList) newchain.clone());
if (v.execute(
new Frame(
u.getOutFrame(oldchain).getLocals(),
new OperandStack(
u.getOutFrame(oldchain).getStack().maxStack(),
(exc_hds[s].getExceptionType() == null
? Type.THROWABLE
: exc_hds[s].getExceptionType()))),
new ArrayList(),
icv,
ev)) {
icq.add(v, new ArrayList());
}
}
} // while (!icq.isEmpty()) END
InstructionHandle ih = start.getInstruction();
do {
if ((ih.getInstruction() instanceof ReturnInstruction) && (!(cfg.isDead(ih)))) {
InstructionContext ic = cfg.contextOf(ih);
Frame f =
ic.getOutFrame(
new ArrayList()); // TODO: This is buggy, we check only the top-level return
// instructions this way. Maybe some maniac returns from a method
// when in a subroutine?
LocalVariables lvs = f.getLocals();
for (int i = 0; i < lvs.maxLocals(); i++) {
if (lvs.get(i) instanceof UninitializedObjectType) {
this.addMessage(
"Warning: ReturnInstruction '"
+ ic
+ "' may leave method with an uninitialized object in the local variables array '"
+ lvs
+ "'.");
}
}
OperandStack os = f.getStack();
for (int i = 0; i < os.size(); i++) {
if (os.peek(i) instanceof UninitializedObjectType) {
this.addMessage(
"Warning: ReturnInstruction '"
+ ic
+ "' may leave method with an uninitialized object on the operand stack '"
+ os
+ "'.");
}
}
}
} while ((ih = ih.getNext()) != null);
}
/**
* Whenever the outgoing frame situation of an InstructionContext changes, all its successors are
* put [back] into the queue [as if they were unvisited]. The proof of termination is about the
* existence of a fix point of frame merging.
*/
private void circulationPump(
MethodGen m,
ControlFlowGraph cfg,
InstructionContext start,
Frame vanillaFrame,
InstConstraintVisitor icv,
ExecutionVisitor ev) {
final Random random = new Random();
InstructionContextQueue icq = new InstructionContextQueue();
start.execute(
vanillaFrame,
new ArrayList<InstructionContext>(),
icv,
ev); // new ArrayList() <=> no Instruction was executed before
// => Top-Level routine (no jsr call before)
icq.add(start, new ArrayList<InstructionContext>());
// LOOP!
while (!icq.isEmpty()) {
InstructionContext u;
ArrayList<InstructionContext> ec;
if (!DEBUG) {
int r = random.nextInt(icq.size());
u = icq.getIC(r);
ec = icq.getEC(r);
icq.remove(r);
} else {
u = icq.getIC(0);
ec = icq.getEC(0);
icq.remove(0);
}
@SuppressWarnings("unchecked") // ec is of type ArrayList<InstructionContext>
ArrayList<InstructionContext> oldchain = (ArrayList<InstructionContext>) (ec.clone());
@SuppressWarnings("unchecked") // ec is of type ArrayList<InstructionContext>
ArrayList<InstructionContext> newchain = (ArrayList<InstructionContext>) (ec.clone());
newchain.add(u);
if ((u.getInstruction().getInstruction()) instanceof RET) {
// System.err.println(u);
// We can only follow _one_ successor, the one after the
// JSR that was recently executed.
RET ret = (RET) (u.getInstruction().getInstruction());
ReturnaddressType t =
(ReturnaddressType) u.getOutFrame(oldchain).getLocals().get(ret.getIndex());
InstructionContext theSuccessor = cfg.contextOf(t.getTarget());
// Sanity check
InstructionContext lastJSR = null;
int skip_jsr = 0;
for (int ss = oldchain.size() - 1; ss >= 0; ss--) {
if (skip_jsr < 0) {
throw new AssertionViolatedException("More RET than JSR in execution chain?!");
}
// System.err.println("+"+oldchain.get(ss));
if ((oldchain.get(ss)).getInstruction().getInstruction() instanceof JsrInstruction) {
if (skip_jsr == 0) {
lastJSR = oldchain.get(ss);
break;
}
skip_jsr--;
}
if ((oldchain.get(ss)).getInstruction().getInstruction() instanceof RET) {
skip_jsr++;
}
}
if (lastJSR == null) {
throw new AssertionViolatedException(
"RET without a JSR before in ExecutionChain?! EC: '" + oldchain + "'.");
}
JsrInstruction jsr = (JsrInstruction) (lastJSR.getInstruction().getInstruction());
if (theSuccessor != (cfg.contextOf(jsr.physicalSuccessor()))) {
throw new AssertionViolatedException(
"RET '"
+ u.getInstruction()
+ "' info inconsistent: jump back to '"
+ theSuccessor
+ "' or '"
+ cfg.contextOf(jsr.physicalSuccessor())
+ "'?");
}
if (theSuccessor.execute(u.getOutFrame(oldchain), newchain, icv, ev)) {
@SuppressWarnings(
"unchecked") // newchain is already of type ArrayList<InstructionContext>
ArrayList<InstructionContext> newchainClone =
(ArrayList<InstructionContext>) newchain.clone();
icq.add(theSuccessor, newchainClone);
}
} else { // "not a ret"
// Normal successors. Add them to the queue of successors.
InstructionContext[] succs = u.getSuccessors();
for (InstructionContext v : succs) {
if (v.execute(u.getOutFrame(oldchain), newchain, icv, ev)) {
@SuppressWarnings(
"unchecked") // newchain is already of type ArrayList<InstructionContext>
ArrayList<InstructionContext> newchainClone =
(ArrayList<InstructionContext>) newchain.clone();
icq.add(v, newchainClone);
}
}
} // end "not a ret"
// Exception Handlers. Add them to the queue of successors.
// [subroutines are never protected; mandated by JustIce]
ExceptionHandler[] exc_hds = u.getExceptionHandlers();
for (ExceptionHandler exc_hd : exc_hds) {
InstructionContext v = cfg.contextOf(exc_hd.getHandlerStart());
// TODO: the "oldchain" and "newchain" is used to determine the subroutine
// we're in (by searching for the last JSR) by the InstructionContext
// implementation. Therefore, we should not use this chain mechanism
// when dealing with exception handlers.
// Example: a JSR with an exception handler as its successor does not
// mean we're in a subroutine if we go to the exception handler.
// We should address this problem later; by now we simply "cut" the chain
// by using an empty chain for the exception handlers.
// if (v.execute(new Frame(u.getOutFrame(oldchain).getLocals(), new OperandStack
// (u.getOutFrame().getStack().maxStack(), (exc_hds[s].getExceptionType()==null?
// Type.THROWABLE : exc_hds[s].getExceptionType())) ), newchain), icv, ev){
// icq.add(v, (ArrayList) newchain.clone());
if (v.execute(
new Frame(
u.getOutFrame(oldchain).getLocals(),
new OperandStack(
u.getOutFrame(oldchain).getStack().maxStack(),
(exc_hd.getExceptionType() == null
? Type.THROWABLE
: exc_hd.getExceptionType()))),
new ArrayList<InstructionContext>(),
icv,
ev)) {
icq.add(v, new ArrayList<InstructionContext>());
}
}
} // while (!icq.isEmpty()) END
InstructionHandle ih = start.getInstruction();
do {
if ((ih.getInstruction() instanceof ReturnInstruction) && (!(cfg.isDead(ih)))) {
InstructionContext ic = cfg.contextOf(ih);
Frame f =
ic.getOutFrame(
new ArrayList<
InstructionContext>()); // TODO: This is buggy, we check only the top-level
// return instructions this way. Maybe some maniac
// returns from a method when in a subroutine?
LocalVariables lvs = f.getLocals();
for (int i = 0; i < lvs.maxLocals(); i++) {
if (lvs.get(i) instanceof UninitializedObjectType) {
this.addMessage(
"Warning: ReturnInstruction '"
+ ic
+ "' may leave method with an uninitialized object in the local variables array '"
+ lvs
+ "'.");
}
}
OperandStack os = f.getStack();
for (int i = 0; i < os.size(); i++) {
if (os.peek(i) instanceof UninitializedObjectType) {
this.addMessage(
"Warning: ReturnInstruction '"
+ ic
+ "' may leave method with an uninitialized object on the operand stack '"
+ os
+ "'.");
}
}
// see JVM $4.8.2
// TODO implement all based on stack
Type returnedType = null;
InstructionHandle ihPrev = null;
ihPrev = ih.getPrev();
if (ihPrev != null) {
if (ihPrev.getInstruction() instanceof InvokeInstruction) {
returnedType =
((InvokeInstruction) ihPrev.getInstruction()).getType(m.getConstantPool());
}
if (ihPrev.getInstruction() instanceof LoadInstruction) {
int index = ((LoadInstruction) ihPrev.getInstruction()).getIndex();
returnedType = lvs.get(index);
}
if (ihPrev.getInstruction() instanceof GETFIELD) {
returnedType = ((GETFIELD) ihPrev.getInstruction()).getType(m.getConstantPool());
}
}
if (returnedType != null) {
if (returnedType instanceof ObjectType) {
try {
if (!((ObjectType) returnedType).isAssignmentCompatibleWith(m.getReturnType())) {
throw new StructuralCodeConstraintException(
"Returned type "
+ returnedType
+ " does not match Method's return type "
+ m.getReturnType());
}
} catch (ClassNotFoundException e) {
// dont know what do do now, so raise RuntimeException
throw new RuntimeException(e);
}
} else if (!returnedType.equals(m.getReturnType())) {
throw new StructuralCodeConstraintException(
"Returned type "
+ returnedType
+ " does not match Method's return type "
+ m.getReturnType());
}
}
}
} while ((ih = ih.getNext()) != null);
}
