BitSet getBasicBlocks() {
if (basicBlocks == null) {
Instruction[] code = mi.getInstructions();
BitSet bb = new BitSet(code.length);
bb.set(0); // first insn is always a bb start
// first, look at the insn type
for (int i = 0; i < code.length; i++) {
Instruction insn = code[i];
if (insn instanceof IfInstruction) {
IfInstruction ifInsn = (IfInstruction) insn;
Instruction tgt = ifInsn.getTarget();
bb.set(tgt.getInstructionIndex());
tgt = ifInsn.getNext();
bb.set(tgt.getInstructionIndex());
} else if (insn instanceof GOTO) {
Instruction tgt = ((GOTO) insn).getTarget();
bb.set(tgt.getInstructionIndex());
} else if (insn instanceof InvokeInstruction) {
// hmm, this might be a bit too conservative, but who says we
// don't jump out of a caller into a handler, or even that we
// ever return from the call?
Instruction tgt = insn.getNext();
bb.set(tgt.getInstructionIndex());
}
}
// and now look at the handlers (every first insn is a bb start)
ExceptionHandler[] handlers = mi.getExceptions();
if (handlers != null) {
for (int i = 0; i < handlers.length; i++) {
Instruction tgt = mi.getInstructionAt(handlers[i].getHandler());
bb.set(tgt.getInstructionIndex());
}
}
basicBlocks = bb;
/** dump
* System.out.println();
* System.out.println(mi.getFullName());
* for (int i=0; i<code.length; i++) {
* System.out.print(String.format("%1$2d %2$c ",i, bb.get(i) ? '>' : ' '));
* System.out.println(code[i]);
* }
**/
}
return basicBlocks;
}
BitSet getHandlerStarts() {
BitSet b = new BitSet(mi.getInstructions().length);
ExceptionHandler[] handler = mi.getExceptions();
if (handler != null) {
for (int i = 0; i < handler.length; i++) {
Instruction hs = mi.getInstructionAt(handler[i].getHandler());
b.set(hs.getInstructionIndex());
}
}
return b;
}