#  Copyright (c) 2016 by Rocky Bernstein
"""
Python 2.4 bytecode scanner/deparser

This overlaps Python's 2.4's dis module, but it can be run from
Python 3 and other versions of Python. Also, we save token
information for later use in deparsing.
"""

import uncompyle6.scanners.scanner25 as scan
import uncompyle6.scanners.scanner2 as scan2

# bytecode verification, verify(), uses JUMP_OPs from here
from xdis.opcodes import opcode_24
JUMP_OPs = opcode_24.JUMP_OPs

# We base this off of 2.6 instead of the other way around
# because we cleaned things up this way.
# The history is that 2.7 support is the cleanest,
# then from that we got 2.6 and so on.
class Scanner24(scan.Scanner25):
    def __init__(self, show_asm):
        scan2.Scanner2.__init__(self, 2.4, show_asm)
        self.stmt_opcodes = frozenset([
            self.opc.SETUP_LOOP,       self.opc.BREAK_LOOP,
            self.opc.SETUP_FINALLY,    self.opc.END_FINALLY,
            self.opc.SETUP_EXCEPT,     self.opc.POP_BLOCK,
            self.opc.STORE_FAST,       self.opc.DELETE_FAST,
            self.opc.STORE_DEREF,      self.opc.STORE_GLOBAL,
            self.opc.DELETE_GLOBAL,    self.opc.STORE_NAME,
            self.opc.DELETE_NAME,      self.opc.STORE_ATTR,
            self.opc.DELETE_ATTR,      self.opc.STORE_SUBSCR,
            self.opc.DELETE_SUBSCR,    self.opc.RETURN_VALUE,
            self.opc.RAISE_VARARGS,    self.opc.POP_TOP,
            self.opc.PRINT_EXPR,       self.opc.PRINT_ITEM,
            self.opc.PRINT_NEWLINE,    self.opc.PRINT_ITEM_TO,
            self.opc.PRINT_NEWLINE_TO, self.opc.CONTINUE_LOOP,
            self.opc.JUMP_ABSOLUTE,    self.opc.EXEC_STMT,
        ])

        # "setup" opcodes
        self.setup_ops = frozenset([
            self.opc.SETUP_EXCEPT, self.opc.SETUP_FINALLY,
            ])

        # opcodes with expect a variable number pushed values whose
        # count is in the opcode. For parsing we generally change the
        # opcode name to include that number.
        self.varargs_ops = frozenset([
            self.opc.BUILD_LIST,           self.opc.BUILD_TUPLE,
            self.opc.BUILD_SLICE,          self.opc.UNPACK_SEQUENCE,
            self.opc.MAKE_FUNCTION,        self.opc.CALL_FUNCTION,
            self.opc.MAKE_CLOSURE,         self.opc.CALL_FUNCTION_VAR,
            self.opc.CALL_FUNCTION_KW,     self.opc.CALL_FUNCTION_VAR_KW,
            self.opc.DUP_TOPX,             self.opc.RAISE_VARARGS])

        # opcodes that store values into a variable
        self.designator_ops = frozenset([
            self.opc.STORE_FAST,    self.opc.STORE_NAME,
            self.opc.STORE_GLOBAL,  self.opc.STORE_DEREF,   self.opc.STORE_ATTR,
            self.opc.STORE_SLICE_0, self.opc.STORE_SLICE_1, self.opc.STORE_SLICE_2,
            self.opc.STORE_SLICE_3, self.opc.STORE_SUBSCR,  self.opc.UNPACK_SEQUENCE,
            self.opc.JA
        ])
        # Python 2.7 has POP_JUMP_IF_{TRUE,FALSE}_OR_POP but < 2.7 doesn't
        # Add an empty set make processing more uniform.
        self.pop_jump_if_or_pop = frozenset([])
        return