Python dis.hasjrel方法代码示例

# 需要导入模块: import dis [as 别名]
# 或者: from dis import hasjrel [as 别名]
def apply_labels(self, start=None):
        '''
        Find all JMP REL and ABS bytecode sequences and update the target
        within branch instruction and add xref to the destination.
        '''
        for current in self.nodes(start):
            current.xrefs = []
            current.target = None

        for current in self.nodes(start):
            label = -1
            if current.opcode >= dis.HAVE_ARGUMENT:
                if current.opcode in dis.hasjrel:
                    label = current.addr+current.oparg+current.len()
                elif current.opcode in dis.hasjabs:
                    label = current.oparg

                if label >= 0:
                    if current not in self.bytecodes[label].xrefs:
                        self.bytecodes[label].xrefs.append(current)
                    current.target = self.bytecodes[label]
            current = current.next
        return 

# 需要导入模块: import dis [as 别名]
# 或者: from dis import hasjrel [as 别名]
def patch_opargs(self, start=None):
        '''
        Updates branch instructions to correct offsets after adding or
        deleting bytecode
        '''
        for current in self.nodes(start):
            # No argument, skip to next
            if current.opcode < dis.HAVE_ARGUMENT:
                continue

            # Patch relative offsets
            if current.opcode in dis.hasjrel:
                current.oparg = current.target.addr - \
                                    (current.addr+current.len())

            # Patch absolute offsets
            elif current.opcode in dis.hasjabs:
                current.oparg = current.target.addr 

# 需要导入模块: import dis [as 别名]
# 或者: from dis import hasjrel [as 别名]
def get_followers(self):
        """Get the whole list of followers, including the next block."""
        followers = set(self.next)
        # Blocks that must be emitted *after* this one, because of
        # bytecode offsets (e.g. relative jumps) pointing to them.
        for inst in self.insts:
            if inst[0] in PyFlowGraph.hasjrel:
                followers.add(inst[1])
        return followers 

# 需要导入模块: import dis [as 别名]
# 或者: from dis import hasjrel [as 别名]
def flattenGraph(self):
        """Arrange the blocks in order and resolve jumps"""
        assert self.stage == RAW
        self.insts = insts = []
        pc = 0
        begin = {}
        end = {}
        for b in self.getBlocksInOrder():
            begin[b] = pc
            for inst in b.getInstructions():
                insts.append(inst)
                if len(inst) == 1:
                    pc = pc + 1
                elif inst[0] != "SET_LINENO":
                    # arg takes 2 bytes
                    pc = pc + 3
            end[b] = pc
        pc = 0
        for i in range(len(insts)):
            inst = insts[i]
            if len(inst) == 1:
                pc = pc + 1
            elif inst[0] != "SET_LINENO":
                pc = pc + 3
            opname = inst[0]
            if opname in self.hasjrel:
                oparg = inst[1]
                offset = begin[oparg] - pc
                insts[i] = opname, offset
            elif opname in self.hasjabs:
                insts[i] = opname, begin[inst[1]]
        self.stage = FLAT 

# 需要导入模块: import dis [as 别名]
# 或者: from dis import hasjrel [as 别名]
def jump(self):
        opcode = self.opcode
        if opcode in dis.hasjrel:
            return self[1] + self.arg
        elif opcode in dis.hasjabs:
            return self.code.address(self.arg) 

# 需要导入模块: import dis [as 别名]
# 或者: from dis import hasjrel [as 别名]
def get_target_addr(self):
        '''
        Returns the target address for the current instruction based on the
        current address.
        '''
        rvalue = None
        if self.opcode in dis.hasjrel:
            rvalue = self.addr + self.oparg + self.len()
        if self.opcode in dis.hasjabs:
            rvalue = self.oparg

        return rvalue 

# 需要导入模块: import dis [as 别名]
# 或者: from dis import hasjrel [as 别名]
def flattenGraph(self):
        """Arrange the blocks in order and resolve jumps"""
        assert self.stage == RAW
        self.insts = insts = []
        pc = 0
        begin = {}
        end = {}
        for b in self.getBlocksInOrder():
            begin[b] = pc
            for inst in b.getInstructions():
                insts.append(inst)
                if len(inst) == 1:
                    pc = pc + 1
                elif inst[0] != "SET_LINENO":
                    # arg takes 2 bytes
                    pc = pc + 3
            end[b] = pc
        pc = 0
        for i in range(len(insts)):
            inst = insts[i]
            if len(inst) == 1:
                pc = pc + 1
            elif inst[0] != "SET_LINENO":
                pc = pc + 3
            opname = inst[0]
            if self.hasjrel.has_elt(opname):
                oparg = inst[1]
                offset = begin[oparg] - pc
                insts[i] = opname, offset
            elif self.hasjabs.has_elt(opname):
                insts[i] = opname, begin[inst[1]]
        self.stage = FLAT 

# 需要导入模块: import dis [as 别名]
# 或者: from dis import hasjrel [as 别名]
def _update_label_offsets(code_obj, breakpoint_offset, breakpoint_code_list):
    """
    Update labels for the relative and absolute jump targets
    :param code_obj: code to modify
    :param breakpoint_offset: offset for the inserted code
    :param breakpoint_code_list: size of the inserted code
    :return: bytes sequence with modified labels; list of tuples (resulting offset, list of code instructions) with
    information about all inserted pieces of code
    """
    inserted_code = list()
    # the list with all inserted pieces of code
    inserted_code.append((breakpoint_offset, breakpoint_code_list))
    code_list = list(code_obj)
    j = 0

    while j < len(inserted_code):
        current_offset, current_code_list = inserted_code[j]
        offsets_for_modification = []

        for offset, op, arg in _unpack_opargs(code_list, inserted_code, j):
            if arg is not None:
                if op in dis.hasjrel:
                    # has relative jump target
                    label = offset + 2 + arg
                    if offset < current_offset < label:
                        # change labels for relative jump targets if code was inserted inside
                        offsets_for_modification.append(offset)
                elif op in dis.hasjabs:
                    # change label for absolute jump if code was inserted before it
                    if current_offset < arg:
                        offsets_for_modification.append(offset)
        for i in range(0, len(code_list), 2):
            op = code_list[i]
            if i in offsets_for_modification and op >= dis.HAVE_ARGUMENT:
                new_arg = code_list[i + 1] + len(current_code_list)
                if new_arg <= MAX_BYTE:
                    code_list[i + 1] = new_arg
                else:
                    # handle bytes overflow
                    if i - 2 > 0 and code_list[i - 2] == EXTENDED_ARG and code_list[i - 1] < MAX_BYTE:
                        # if new argument > 255 and EXTENDED_ARG already exists we need to increase it's argument
                        code_list[i - 1] += 1
                    else:
                        # if there isn't EXTENDED_ARG operator yet we have to insert the new operator
                        extended_arg_code = [EXTENDED_ARG, new_arg >> 8]
                        inserted_code.append((i, extended_arg_code))
                    code_list[i + 1] = new_arg & MAX_BYTE

        code_list = code_list[:current_offset] + current_code_list + code_list[current_offset:]

        for k in range(len(inserted_code)):
            offset, inserted_code_list = inserted_code[k]
            if current_offset < offset:
                inserted_code[k] = (offset + len(current_code_list), inserted_code_list)
        j += 1

    return bytes(code_list), inserted_code