}
// Emit the relevant instructions for this instantiation, translating
// labels and jump targets as we go:
for (int i = 0, c = instructions.size(); i < c; i++) {
AbstractInsnNode insn = instructions.get(i);
Instantiation owner = instant.findOwner(i);
// Always remap labels:
if (insn.getType() == AbstractInsnNode.LABEL) {
// Translate labels into their renamed equivalents.
// Avoid adding the same label more than once. Note
// that because we own this instruction the gotoTable
// and the rangeTable will always agree.
LabelNode ilbl = (LabelNode) insn;
LabelNode remap = instant.rangeLabel(ilbl);
if (LOGGING) {
log("Translating lbl #" + i + ":" + ilbl + " to " + remap);
}
if (remap != duplbl) {
newInstructions.add(remap);
duplbl = remap;
}
continue;
}
// We don't want to emit instructions that were already
// emitted by a subroutine higher on the stack. Note that
// it is still possible for a given instruction to be
// emitted twice because it may belong to two subroutines
// that do not invoke each other.
if (owner != instant) {
continue;
}
if (LOGGING) {
log("Emitting inst #" + i);
}
if (insn.getOpcode() == RET) {
// Translate RET instruction(s) to a jump to the return label
// for the appropriate instantiation. The problem is that the
// subroutine may "fall through" to the ret of a parent
// subroutine; therefore, to find the appropriate ret label we
// find the lowest subroutine on the stack that claims to own
// this instruction. See the class javadoc comment for an
// explanation on why this technique is safe (note: it is only
// safe if the input is verifiable).
LabelNode retlabel = null;
for (Instantiation p = instant; p != null; p = p.previous) {
if (p.subroutine.ownsInstruction(i)) {
retlabel = p.returnLabel;
}
}
if (retlabel == null) {
// This is only possible if the mainSubroutine owns a RET
// instruction, which should never happen for verifiable
// code.
throw new RuntimeException("Instruction #" + i
+ " is a RET not owned by any subroutine");
}
newInstructions.add(new JumpInsnNode(GOTO, retlabel));
} else if (insn.getOpcode() == JSR) {
LabelNode lbl = ((JumpInsnNode) insn).label;
Subroutine sub = (Subroutine) subroutineHeads.get(lbl);
Instantiation newinst = new Instantiation(instant, sub);
LabelNode startlbl = newinst.gotoLabel(lbl);
if (LOGGING) {
log(" Creating instantiation of subr " + sub);
}
// Rather than JSRing, we will jump to the inline version and
// push NULL for what was once the return value. This hack
// allows us to avoid doing any sort of data flow analysis to
// figure out which instructions manipulate the old return value
// pointer which is now known to be unneeded.
newInstructions.add(new InsnNode(ACONST_NULL));
newInstructions.add(new JumpInsnNode(GOTO, startlbl));
newInstructions.add(newinst.returnLabel);
// Insert this new instantiation into the queue to be emitted
// later.
worklist.add(newinst);
} else {
newInstructions.add(insn.clone(instant));
}
}
// Emit try/catch blocks that are relevant to this method.
for (Iterator it = tryCatchBlocks.iterator(); it.hasNext();) {