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

   1 # Useful gdb string convenience functions.
   2 # Copyright (C) 2012-2025 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, $_regex"""
  18
  19 import re
  20
  21 import gdb
  22
  23
  24 class _MemEq(gdb.Function):
  25     """$_memeq - compare bytes of memory.
  26
  27     Usage: $_memeq (A, B, LEN)
  28
  29     Returns:
  30       True if LEN bytes at A and B compare equally."""
  31
  32     def __init__(self):
  33         super(_MemEq, self).__init__("_memeq")
  34
  35     def invoke(self, a, b, length):
  36         if length < 0:
  37             raise ValueError("length must be non-negative")
  38         if length == 0:
  39             return True
  40         # The argument(s) to vector are [low_bound,]high_bound.
  41         byte_vector = gdb.lookup_type("char").vector(length - 1)
  42         ptr_byte_vector = byte_vector.pointer()
  43         a_ptr = a.reinterpret_cast(ptr_byte_vector)
  44         b_ptr = b.reinterpret_cast(ptr_byte_vector)
  45         return a_ptr.dereference() == b_ptr.dereference()
  46
  47
  48 class _StrLen(gdb.Function):
  49     """$_strlen - compute string length.
  50
  51     Usage: $_strlen (A)
  52
  53     Returns:
  54       Length of string A, assumed to be a string in the current language."""
  55
  56     def __init__(self):
  57         super(_StrLen, self).__init__("_strlen")
  58
  59     def invoke(self, a):
  60         s = a.string()
  61         return len(s)
  62
  63
  64 class _StrEq(gdb.Function):
  65     """$_streq - check string equality.
  66
  67     Usage: $_streq (A, B)
  68
  69     Returns:
  70       True if A and B are identical strings in the current language.
  71
  72     Example (amd64-linux):
  73       catch syscall open
  74       cond $bpnum $_streq((char*) $rdi, "foo")"""
  75
  76     def __init__(self):
  77         super(_StrEq, self).__init__("_streq")
  78
  79     def invoke(self, a, b):
  80         return a.string() == b.string()
  81
  82
  83 class _RegEx(gdb.Function):
  84     """$_regex - check if a string matches a regular expression.
  85
  86     Usage: $_regex (STRING, REGEX)
  87
  88     Returns:
  89       True if string STRING (in the current language) matches the
  90       regular expression REGEX."""
  91
  92     def __init__(self):
  93         super(_RegEx, self).__init__("_regex")
  94
  95     def invoke(self, string, regex):
  96         s = string.string()
  97         r = re.compile(regex.string())
  98         return bool(r.match(s))
  99
 100
 101 # GDB will import us automagically via gdb/__init__.py.
 102 _MemEq()
 103 _StrLen()
 104 _StrEq()
 105 _RegEx()