/**
* Remove from instruction `prev' to instruction `next' both contained in this list. Throws
* TargetLostException when one of the removed instruction handles is still being targeted.
*
* @param prev where to start deleting (predecessor, exclusive)
* @param next where to end deleting (successor, exclusive)
*/
private void remove(InstructionHandle prev, InstructionHandle next) throws TargetLostException {
InstructionHandle first, last; // First and last deleted instruction
if ((prev == null) && (next == null)) {
first = start;
last = end;
start = end = null;
} else {
if (prev == null) { // At start of list
first = start;
start = next;
} else {
first = prev.next;
prev.next = next;
}
if (next == null) { // At end of list
last = end;
end = prev;
} else {
last = next.prev;
next.prev = prev;
}
}
first.prev = null; // Completely separated from rest of list
last.next = null;
List<InstructionHandle> target_vec = new ArrayList<InstructionHandle>();
for (InstructionHandle ih = first; ih != null; ih = ih.next) {
ih.getInstruction().dispose(); // e.g. BranchInstructions release their targets
}
StringBuilder buf = new StringBuilder("{ ");
for (InstructionHandle ih = first; ih != null; ih = next) {
next = ih.next;
length--;
if (ih.hasTargeters()) { // Still got targeters?
target_vec.add(ih);
buf.append(ih.toString(true) + " ");
ih.next = ih.prev = null;
} else {
ih.dispose();
}
}
buf.append("}");
if (!target_vec.isEmpty()) {
InstructionHandle[] targeted = new InstructionHandle[target_vec.size()];
target_vec.toArray(targeted);
throw new TargetLostException(targeted, buf.toString());
}
}
/**
* Replace instruction ih in list il with the instructions in new_il. If new_il is null, do
* nothing
*/
protected static void replace_instructions(
InstructionList il, InstructionHandle ih, InstructionList new_il) {
if ((new_il == null) || new_il.isEmpty()) return;
// If there is only one new instruction, just replace it in the handle
if (new_il.getLength() == 1) {
ih.setInstruction(new_il.getEnd().getInstruction());
return;
}
// Get the start and end instruction of the new instructions
InstructionHandle new_end = new_il.getEnd();
InstructionHandle new_start = il.insert(ih, new_il);
// Move all of the branches from the old instruction to the new start
il.redirectBranches(ih, new_start);
// Move other targets to the new instuctions.
if (ih.hasTargeters()) {
for (InstructionTargeter it : ih.getTargeters()) {
if (it instanceof LineNumberGen) {
it.updateTarget(ih, new_start);
} else if (it instanceof LocalVariableGen) {
it.updateTarget(ih, new_end);
} else if (it instanceof CodeExceptionGen) {
CodeExceptionGen exc = (CodeExceptionGen) it;
if (exc.getStartPC() == ih) exc.updateTarget(ih, new_start);
else if (exc.getEndPC() == ih) exc.updateTarget(ih, new_end);
else if (exc.getHandlerPC() == ih) exc.setHandlerPC(new_start);
else System.out.printf("Malformed CodeException: %s%n", exc);
} else {
System.out.printf("unexpected target %s%n", it);
}
}
}
// Remove the old handle. There should be no targeters left to it.
try {
il.delete(ih);
} catch (Exception e) {
throw new Error("Can't delete instruction", e);
}
}
