assembler.py 文件源码

def calculate_ins_operands(self):
        """
        Instructions like JUMP_FORWARD & SETUP_LOOP uses the operand to refer to other instructions.
        This reference is an integer denoting the offset/absolute address of the target. This function
        calculates the values of these operand
        """
        logger.debug('Calculating instruction operands.')
        for block in self.bb_ordered:
            addr = block.address
            for ins in block.instruction_iter():
                addr += ins.size
                if ins.opcode in dis.hasjabs:
                    # ins.argval is a BasicBlock
                    ins.arg = ins.argval.address
                    # TODO
                    # We do not generate EXTENDED_ARG opcode at the moment,
                    # hence size of opcode argument can only be 2 bytes
                    assert ins.arg <= 0xFFFF
                elif ins.opcode in dis.hasjrel:
                    ins.arg = ins.argval.address - addr
                    # relative jump can USUALLY go forward
                    assert ins.arg >= 0
                    assert ins.arg <= 0xFFFF