private static String lookupSwitch(CodeIterator iter, int pos) {
StringBuffer buffer = new StringBuffer("lookupswitch {\n");
int index = (pos & ~3) + 4;
// default
buffer.append("\t\tdefault: ").append(pos + iter.s32bitAt(index)).append("\n");
int npairs = iter.s32bitAt(index += 4);
int end = npairs * 8 + (index += 4);
for (; index < end; index += 8) {
int match = iter.s32bitAt(index);
int target = iter.s32bitAt(index + 4) + pos;
buffer.append("\t\t").append(match).append(": ").append(target).append("\n");
}
buffer.setCharAt(buffer.length() - 1, '}');
return buffer.toString();
}
private static String tableSwitch(CodeIterator iter, int pos) {
StringBuffer buffer = new StringBuffer("tableswitch {\n");
int index = (pos & ~3) + 4;
// default
buffer.append("\t\tdefault: ").append(pos + iter.s32bitAt(index)).append("\n");
int low = iter.s32bitAt(index += 4);
int high = iter.s32bitAt(index += 4);
int end = (high - low + 1) * 4 + (index += 4);
// Offset table
for (int key = low; index < end; index += 4, key++) {
int target = iter.s32bitAt(index) + pos;
buffer.append("\t\t").append(key).append(": ").append(target).append("\n");
}
buffer.setCharAt(buffer.length() - 1, '}');
return buffer.toString();
}
/** Gets a string representation of the bytecode instruction at the specified position. */
public static String instructionString(CodeIterator iter, int pos, ConstPool pool) {
int opcode = iter.byteAt(pos);
if (opcode > opcodes.length || opcode < 0)
throw new IllegalArgumentException("Invalid opcode, opcode: " + opcode + " pos: " + pos);
String opstring = opcodes[opcode];
switch (opcode) {
case BIPUSH:
return opstring + " " + iter.byteAt(pos + 1);
case SIPUSH:
return opstring + " " + iter.s16bitAt(pos + 1);
case LDC:
return opstring + " " + ldc(pool, iter.byteAt(pos + 1));
case LDC_W:
case LDC2_W:
return opstring + " " + ldc(pool, iter.u16bitAt(pos + 1));
case ILOAD:
case LLOAD:
case FLOAD:
case DLOAD:
case ALOAD:
case ISTORE:
case LSTORE:
case FSTORE:
case DSTORE:
case ASTORE:
return opstring + " " + iter.byteAt(pos + 1);
case IFEQ:
case IFGE:
case IFGT:
case IFLE:
case IFLT:
case IFNE:
case IFNONNULL:
case IFNULL:
case IF_ACMPEQ:
case IF_ACMPNE:
case IF_ICMPEQ:
case IF_ICMPGE:
case IF_ICMPGT:
case IF_ICMPLE:
case IF_ICMPLT:
case IF_ICMPNE:
return opstring + " " + (iter.s16bitAt(pos + 1) + pos);
case IINC:
return opstring + " " + iter.byteAt(pos + 1);
case GOTO:
case JSR:
return opstring + " " + (iter.s16bitAt(pos + 1) + pos);
case RET:
return opstring + " " + iter.byteAt(pos + 1);
case TABLESWITCH:
return tableSwitch(iter, pos);
case LOOKUPSWITCH:
return lookupSwitch(iter, pos);
case GETSTATIC:
case PUTSTATIC:
case GETFIELD:
case PUTFIELD:
return opstring + " " + fieldInfo(pool, iter.u16bitAt(pos + 1));
case INVOKEVIRTUAL:
case INVOKESPECIAL:
case INVOKESTATIC:
return opstring + " " + methodInfo(pool, iter.u16bitAt(pos + 1));
case INVOKEINTERFACE:
return opstring + " " + interfaceMethodInfo(pool, iter.u16bitAt(pos + 1));
case INVOKEDYNAMIC:
return opstring + " " + iter.u16bitAt(pos + 1);
case NEW:
return opstring + " " + classInfo(pool, iter.u16bitAt(pos + 1));
case NEWARRAY:
return opstring + " " + arrayInfo(iter.byteAt(pos + 1));
case ANEWARRAY:
case CHECKCAST:
return opstring + " " + classInfo(pool, iter.u16bitAt(pos + 1));
case WIDE:
return wide(iter, pos);
case MULTIANEWARRAY:
return opstring + " " + classInfo(pool, iter.u16bitAt(pos + 1));
case GOTO_W:
case JSR_W:
return opstring + " " + (iter.s32bitAt(pos + 1) + pos);
default:
return opstring;
}
}