gdb/python/lib/gdb/function/strfns.py

   1 # Useful gdb string convenience functions.
   2 # Copyright (C) 2012-2016 Free Software Foundation, Inc.
   3
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 """$_memeq, $_strlen, $_streq, $_regex"""
  18
  19 import gdb
  20 import re
  21
  22
  23 class _MemEq(gdb.Function):
  24   """$_memeq - compare bytes of memory
  25
  26 Usage:
  27   $_memeq(a, b, len)
  28
  29 Returns:
  30   True if len bytes at a and b compare equally.
  31 """
  32   def __init__(self):
  33     super(_MemEq, self).__init__("_memeq")
  34
  35   def invoke(self, a, b, length):
  36     if length < 0:
  37       raise ValueError("length must be non-negative")
  38     if length == 0:
  39       return True
  40     # The argument(s) to vector are [low_bound,]high_bound.
  41     byte_vector = gdb.lookup_type("char").vector(length - 1)
  42     ptr_byte_vector = byte_vector.pointer()
  43     a_ptr = a.reinterpret_cast(ptr_byte_vector)
  44     b_ptr = b.reinterpret_cast(ptr_byte_vector)
  45     return a_ptr.dereference() == b_ptr.dereference()
  46
  47
  48 class _StrLen(gdb.Function):
  49   """$_strlen - compute string length
  50
  51 Usage:
  52   $_strlen(a)
  53
  54 Returns:
  55   Length of string a, assumed to be a string in the current language.
  56 """
  57   def __init__(self):
  58     super(_StrLen, self).__init__("_strlen")
  59
  60   def invoke(self, a):
  61     s = a.string()
  62     return len(s)
  63
  64
  65 class _StrEq(gdb.Function):
  66   """$_streq - check string equality
  67
  68 Usage:
  69   $_streq(a, b)
  70
  71 Returns:
  72   True if a and b are identical strings in the current language.
  73
  74 Example (amd64-linux):
  75   catch syscall open
  76   cond $bpnum $_streq((char*) $rdi, "foo")
  77 """
  78   def __init__(self):
  79     super(_StrEq, self).__init__("_streq")
  80
  81   def invoke(self, a, b):
  82     return a.string() == b.string()
  83
  84
  85 class _RegEx(gdb.Function):
  86   """$_regex - check if a string matches a regular expression
  87
  88 Usage:
  89   $_regex(string, regex)
  90
  91 Returns:
  92   True if string str (in the current language) matches the
  93   regular expression regex.
  94 """
  95   def __init__(self):
  96     super(_RegEx, self).__init__("_regex")
  97
  98   def invoke(self, string, regex):
  99     s = string.string()
 100     r = re.compile(regex.string())
 101     return bool(r.match(s))
 102
 103
 104 # GDB will import us automagically via gdb/__init__.py.
 105 _MemEq()
 106 _StrLen()
 107 _StrEq()
 108 _RegEx()