Lib/dis.py

   1 # Disassembler
   2
   3 import sys
   4 import string
   5
   6 def dis():
   7         tb = sys.last_traceback
   8         while tb.tb_next: tb = tb.tb_next
   9         distb(tb)
  10
  11 def distb(tb):
  12         disassemble(tb.tb_frame.f_code, tb.tb_lasti)
  13
  14 def disco(co):
  15         disassemble(co, -1)
  16
  17 def disassemble(co, lasti):
  18         code = co.co_code
  19         labels = findlabels(code)
  20         n = len(code)
  21         i = 0
  22         while i < n:
  23                 c = code[i]
  24                 op = ord(c)
  25                 if op == SET_LINENO and i > 0: print # Extra blank line
  26                 if i == lasti: print '-->',
  27                 else: print '   ',
  28                 if i in labels: print '>>',
  29                 else: print '  ',
  30                 print string.rjust(`i`, 4),
  31                 print string.ljust(opname[op], 15),
  32                 i = i+1
  33                 if op >= HAVE_ARGUMENT:
  34                         oparg = ord(code[i]) + ord(code[i+1])*256
  35                         i = i+2
  36                         print string.rjust(`oparg`, 5),
  37                         if op in hasconst:
  38                                 print '(' + `co.co_consts[oparg]` + ')',
  39                         elif op in hasname:
  40                                 print '(' + co.co_names[oparg] + ')',
  41                         elif op in hasjrel:
  42                                 print '(to ' + `i + oparg` + ')',
  43                 print
  44
  45 def findlabels(code):
  46         labels = []
  47         n = len(code)
  48         i = 0
  49         while i < n:
  50                 c = code[i]
  51                 op = ord(c)
  52                 i = i+1
  53                 if op >= HAVE_ARGUMENT:
  54                         oparg = ord(code[i]) + ord(code[i+1])*256
  55                         i = i+2
  56                         label = -1
  57                         if op in hasjrel:
  58                                 label = i+oparg
  59                         elif op in hasjabs:
  60                                 label = oparg
  61                         if label >= 0:
  62                                 if label not in labels:
  63                                         labels.append(label)
  64         return labels
  65
  66 hasconst = []
  67 hasname = []
  68 hasjrel = []
  69 hasjabs = []
  70
  71 opname = [''] * 256
  72 for op in range(256): opname[op] = '<' + `op` + '>'
  73
  74 def def_op(name, op):
  75         opname[op] = name
  76
  77 def name_op(name, op):
  78         opname[op] = name
  79         hasname.append(op)
  80
  81 def jrel_op(name, op):
  82         opname[op] = name
  83         hasjrel.append(op)
  84
  85 def jabs_op(name, op):
  86         opname[op] = name
  87         hasjabs.append(op)
  88
  89 # Instruction opcodes for compiled code
  90
  91 def_op('STOP_CODE', 0)
  92 def_op('POP_TOP', 1)
  93 def_op('ROT_TWO', 2)
  94 def_op('ROT_THREE', 3)
  95 def_op('DUP_TOP', 4)
  96
  97 def_op('UNARY_POSITIVE', 10)
  98 def_op('UNARY_NEGATIVE', 11)
  99 def_op('UNARY_NOT', 12)
 100 def_op('UNARY_CONVERT', 13)
 101 def_op('UNARY_CALL', 14)
 102 def_op('UNARY_INVERT', 15)
 103
 104 def_op('BINARY_MULTIPLY', 20)
 105 def_op('BINARY_DIVIDE', 21)
 106 def_op('BINARY_MODULO', 22)
 107 def_op('BINARY_ADD', 23)
 108 def_op('BINARY_SUBTRACT', 24)
 109 def_op('BINARY_SUBSCR', 25)
 110 def_op('BINARY_CALL', 26)
 111
 112 def_op('SLICE+0', 30)
 113 def_op('SLICE+1', 31)
 114 def_op('SLICE+2', 32)
 115 def_op('SLICE+3', 33)
 116
 117 def_op('STORE_SLICE+0', 40)
 118 def_op('STORE_SLICE+1', 41)
 119 def_op('STORE_SLICE+2', 42)
 120 def_op('STORE_SLICE+3', 43)
 121
 122 def_op('DELETE_SLICE+0', 50)
 123 def_op('DELETE_SLICE+1', 51)
 124 def_op('DELETE_SLICE+2', 52)
 125 def_op('DELETE_SLICE+3', 53)
 126
 127 def_op('STORE_SUBSCR', 60)
 128 def_op('DELETE_SUBSCR', 61)
 129
 130 def_op('PRINT_EXPR', 70)
 131 def_op('PRINT_ITEM', 71)
 132 def_op('PRINT_NEWLINE', 72)
 133
 134 def_op('BREAK_LOOP', 80)
 135 def_op('RAISE_EXCEPTION', 81)
 136 def_op('LOAD_LOCALS', 82)
 137 def_op('RETURN_VALUE', 83)
 138 def_op('LOAD_GLOBALS', 84)
 139 def_op('EXEC_STMT', 85)
 140 def_op('BUILD_FUNCTION', 86)
 141 def_op('POP_BLOCK', 87)
 142 def_op('END_FINALLY', 88)
 143 def_op('BUILD_CLASS', 89)
 144
 145 HAVE_ARGUMENT = 90              # Opcodes from here have an argument:
 146
 147 name_op('STORE_NAME', 90)       # Index in name list
 148 name_op('DELETE_NAME', 91)      # ""
 149 def_op('UNPACK_TUPLE', 92)      # Number of tuple items
 150 def_op('UNPACK_LIST', 93)       # Number of list items
 151 def_op('UNPACK_ARG', 94)        # Number of arguments expected
 152 name_op('STORE_ATTR', 95)       # Index in name list
 153 name_op('DELETE_ATTR', 96)      # ""
 154 name_op('STORE_GLOBAL', 97)     # ""
 155 name_op('DELETE_GLOBAL', 98)    # ""
 156 name_op('UNPACK_VARARG', 99)    # Minimal number of arguments
 157
 158 def_op('LOAD_CONST', 100)       # Index in const list
 159 hasconst.append(100)
 160 name_op('LOAD_NAME', 101)       # Index in name list
 161 def_op('BUILD_TUPLE', 102)      # Number of tuple items
 162 def_op('BUILD_LIST', 103)       # Number of list items
 163 def_op('BUILD_MAP', 104)        # Always zero for now
 164 name_op('LOAD_ATTR', 105)       # Index in name list
 165 def_op('COMPARE_OP', 106)       # Comparison operator
 166 name_op('IMPORT_NAME', 107)     # Index in name list
 167 name_op('IMPORT_FROM', 108)     # Index in name list
 168
 169 jrel_op('JUMP_FORWARD', 110)    # Number of bytes to skip
 170 jrel_op('JUMP_IF_FALSE', 111)   # ""
 171 jrel_op('JUMP_IF_TRUE', 112)    # ""
 172 jabs_op('JUMP_ABSOLUTE', 113)   # Target byte offset from beginning of code
 173 jrel_op('FOR_LOOP', 114)        # Number of bytes to skip
 174
 175 name_op('LOAD_LOCAL', 115)      # Index in name list
 176 name_op('LOAD_GLOBAL', 116)     # Index in name list
 177 def_op('SET_FUNC_ARGS', 117)    # Argcount
 178
 179 jrel_op('SETUP_LOOP', 120)      # Distance to target address
 180 jrel_op('SETUP_EXCEPT', 121)    # ""
 181 jrel_op('SETUP_FINALLY', 122)   # ""
 182
 183 def_op('RESERVE_FAST', 123)     # Number of local variables
 184 hasconst.append(123)
 185 def_op('LOAD_FAST', 124)        # Local variable number
 186 def_op('STORE_FAST', 125)       # Local variable number
 187 def_op('DELETE_FAST', 126)      # Local variable number
 188
 189 def_op('SET_LINENO', 127)       # Current line number
 190 SET_LINENO = 127