queue = new int[n];
top = 0;
// computes exception handlers for each instruction
for (int i = 0; i < m.tryCatchBlocks.size(); ++i) {
TryCatchBlockNode tcb = (TryCatchBlockNode) m.tryCatchBlocks.get(i);
int begin = insns.indexOf(tcb.start);
int end = insns.indexOf(tcb.end);
for (int j = begin; j < end; ++j) {
List insnHandlers = handlers[j];
if (insnHandlers == null) {
insnHandlers = new ArrayList();
handlers[j] = insnHandlers;
}
insnHandlers.add(tcb);
}
}
// computes the subroutine for each instruction:
Subroutine main = new Subroutine(null, m.maxLocals, null);
List subroutineCalls = new ArrayList();
Map subroutineHeads = new HashMap();
findSubroutine(0, main, subroutineCalls);
while (!subroutineCalls.isEmpty()) {
JumpInsnNode jsr = (JumpInsnNode) subroutineCalls.remove(0);
Subroutine sub = (Subroutine) subroutineHeads.get(jsr.label);
if (sub == null) {
sub = new Subroutine(jsr.label, m.maxLocals, jsr);
subroutineHeads.put(jsr.label, sub);
findSubroutine(insns.indexOf(jsr.label), sub, subroutineCalls);
} else {
sub.callers.add(jsr);
}
}
for (int i = 0; i < n; ++i) {
if (subroutines[i] != null && subroutines[i].start == null) {
subroutines[i] = null;
}
}
// initializes the data structures for the control flow analysis
Frame current = newFrame(m.maxLocals, m.maxStack);
Frame handler = newFrame(m.maxLocals, m.maxStack);
current.setReturn(interpreter.newValue(Type.getReturnType(m.desc)));
Type[] args = Type.getArgumentTypes(m.desc);
int local = 0;
if ((m.access & ACC_STATIC) == 0) {
Type ctype = Type.getObjectType(owner);
current.setLocal(local++, interpreter.newValue(ctype));
}
for (int i = 0; i < args.length; ++i) {
current.setLocal(local++, interpreter.newValue(args[i]));
if (args[i].getSize() == 2) {
current.setLocal(local++, interpreter.newValue(null));
}
}
while (local < m.maxLocals) {
current.setLocal(local++, interpreter.newValue(null));
}
merge(0, current, null);
// control flow analysis
while (top > 0) {
int insn = queue[--top];
Frame f = frames[insn];
Subroutine subroutine = subroutines[insn];
queued[insn] = false;
AbstractInsnNode insnNode = null;
try {
insnNode = m.instructions.get(insn);
int insnOpcode = insnNode.getOpcode();
int insnType = insnNode.getType();
if (insnType == AbstractInsnNode.LABEL
|| insnType == AbstractInsnNode.LINE
|| insnType == AbstractInsnNode.FRAME) {
merge(insn + 1, f, subroutine);
newControlFlowEdge(insn, insn + 1);
} else {
current.init(f).execute(insnNode, interpreter);
subroutine = subroutine == null ? null : subroutine.copy();
if (insnNode instanceof JumpInsnNode) {
JumpInsnNode j = (JumpInsnNode) insnNode;
if (insnOpcode != GOTO && insnOpcode != JSR) {
merge(insn + 1, current, subroutine);
newControlFlowEdge(insn, insn + 1);
}
int jump = insns.indexOf(j.label);
if (insnOpcode == JSR) {
merge(jump, current, new Subroutine(j.label,
m.maxLocals, j));
} else {
merge(jump, current, subroutine);
}
newControlFlowEdge(insn, jump);
} else if (insnNode instanceof LookupSwitchInsnNode) {
LookupSwitchInsnNode lsi = (LookupSwitchInsnNode) insnNode;
int jump = insns.indexOf(lsi.dflt);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
for (int j = 0; j < lsi.labels.size(); ++j) {
LabelNode label = (LabelNode) lsi.labels.get(j);
jump = insns.indexOf(label);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
}
} else if (insnNode instanceof TableSwitchInsnNode) {
TableSwitchInsnNode tsi = (TableSwitchInsnNode) insnNode;
int jump = insns.indexOf(tsi.dflt);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
for (int j = 0; j < tsi.labels.size(); ++j) {
LabelNode label = (LabelNode) tsi.labels.get(j);
jump = insns.indexOf(label);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
}
} else if (insnOpcode == RET) {
if (subroutine == null) {
throw new AnalyzerException(insnNode,
"RET instruction outside of a sub routine");
}
for (int i = 0; i < subroutine.callers.size(); ++i) {
Object caller = subroutine.callers.get(i);
int call = insns.indexOf((AbstractInsnNode) caller);
if (frames[call] != null) {
merge(call + 1, frames[call], current,
subroutines[call], subroutine.access);
newControlFlowEdge(insn, call + 1);
}
}
} else if (insnOpcode != ATHROW
&& (insnOpcode < IRETURN || insnOpcode > RETURN)) {
if (subroutine != null) {
if (insnNode instanceof VarInsnNode) {
int var = ((VarInsnNode) insnNode).var;
subroutine.access[var] = true;
if (insnOpcode == LLOAD || insnOpcode == DLOAD
|| insnOpcode == LSTORE
|| insnOpcode == DSTORE) {
subroutine.access[var + 1] = true;
}
} else if (insnNode instanceof IincInsnNode) {
int var = ((IincInsnNode) insnNode).var;
subroutine.access[var] = true;
}
}
merge(insn + 1, current, subroutine);
newControlFlowEdge(insn, insn + 1);
}
}
List insnHandlers = handlers[insn];
if (insnHandlers != null) {
for (int i = 0; i < insnHandlers.size(); ++i) {
TryCatchBlockNode tcb = (TryCatchBlockNode) insnHandlers
.get(i);
Type type;
if (tcb.type == null) {
type = Type.getObjectType("java/lang/Throwable");
} else {