/** Write the exceptions table */
void writeExceptions(
Environment env, DataOutputStream out, ConstantPool tab, Instruction first, Instruction last)
throws IOException {
for (Instruction inst = first; inst != last.next; inst = inst.next) {
if (inst.opc == opc_try) {
TryData td = (TryData) inst.value;
writeExceptions(env, out, tab, inst.next, td.getEndLabel());
for (Enumeration e = td.catches.elements(); e.hasMoreElements(); ) {
CatchData cd = (CatchData) e.nextElement();
// System.out.println("EXCEPTION: " + env.getSource() + ", pc=" + inst.pc + ", end=" +
// td.getEndLabel().pc + ", hdl=" + cd.getLabel().pc + ", tp=" + cd.getType());
out.writeShort(inst.pc);
out.writeShort(td.getEndLabel().pc);
out.writeShort(cd.getLabel().pc);
if (cd.getType() != null) {
out.writeShort(tab.index(cd.getType()));
} else {
out.writeShort(0);
}
}
inst = td.getEndLabel();
}
}
}
/** Optimize instructions and mark those that can be reached */
void optimize(Environment env, Label lbl) {
lbl.pc = REACHED;
for (Instruction inst = lbl.next; inst != null; inst = inst.next) {
switch (inst.pc) {
case NOTREACHED:
inst.optimize(env);
inst.pc = REACHED;
break;
case REACHED:
return;
case NEEDED:
break;
}
switch (inst.opc) {
case opc_label:
case opc_dead:
if (inst.pc == REACHED) {
inst.pc = NOTREACHED;
}
break;
case opc_ifeq:
case opc_ifne:
case opc_ifgt:
case opc_ifge:
case opc_iflt:
case opc_ifle:
case opc_if_icmpeq:
case opc_if_icmpne:
case opc_if_icmpgt:
case opc_if_icmpge:
case opc_if_icmplt:
case opc_if_icmple:
case opc_if_acmpeq:
case opc_if_acmpne:
case opc_ifnull:
case opc_ifnonnull:
optimize(env, (Label) inst.value);
break;
case opc_goto:
optimize(env, (Label) inst.value);
return;
case opc_jsr:
optimize(env, (Label) inst.value);
break;
case opc_ret:
case opc_return:
case opc_ireturn:
case opc_lreturn:
case opc_freturn:
case opc_dreturn:
case opc_areturn:
case opc_athrow:
return;
case opc_tableswitch:
case opc_lookupswitch:
{
SwitchData sw = (SwitchData) inst.value;
optimize(env, sw.defaultLabel);
for (Enumeration e = sw.tab.elements(); e.hasMoreElements(); ) {
optimize(env, (Label) e.nextElement());
}
return;
}
case opc_try:
{
TryData td = (TryData) inst.value;
td.getEndLabel().pc = NEEDED;
for (Enumeration e = td.catches.elements(); e.hasMoreElements(); ) {
CatchData cd = (CatchData) e.nextElement();
optimize(env, cd.getLabel());
}
break;
}
}
}
}
