modulegraph.py 文件源码

def get_instructions(code):
        """
        Iterator parsing the bytecode into easy-usable minimal emulation of
        Python 3.4 `dis.Instruction` instances.
        """

        # shortcuts
        HAVE_ARGUMENT = dis.HAVE_ARGUMENT
        EXTENDED_ARG = dis.EXTENDED_ARG

        class Instruction:
            # Minimal emulation of Python 3.4 dis.Instruction
            def __init__(self, opcode, oparg):
                self.opname = dis.opname[opcode]
                self.arg = oparg
                # opcode, argval, argrepr, offset, is_jump_target and
                # starts_line are not used by our code, so we leave them away
                # here.

        code = code.co_code
        extended_arg = 0
        i = 0
        n = len(code)
        while i < n:
            c = code[i]
            i = i + 1
            op = _cOrd(c)
            if op >= HAVE_ARGUMENT:
                oparg = _cOrd(code[i]) + _cOrd(code[i + 1]) * 256 + extended_arg
                extended_arg = 0
                i += 2
                if op == EXTENDED_ARG:
                    extended_arg = oparg*65536
            else:
                oparg = None
            yield Instruction(op, oparg)


#FIXME: Leverage this rather than magic numbers below.