Splitting InsnList into basic blocks

Question

In the ASM Tree API, I have an InsnList, containing a list of instructions in a method.

I want to split this up into basic blocks: a sequence of instructions such that each instruction except the last one has exactly one successor, and such that no instruction except the first one can be the target of a jump.

How would I accomplish this?

Answer 1

In Java 7+ stack frames will be included in the method opcodes. Iterate through a method's InsnList and make blocks split by each FrameInsn.

Example:

List<InsnList> l = Lists.newList();
InsnList il = new InsnList();
for (AbstractInsnNode ain : method.instructions.toArray()) {
    if (ain.getType == AbstractInsnNode.FRAME){
        l.add(il);
        il = new InsnList();
    } else {
        il.add(ain);
    }
}