Ben Cheng | 6e5a1b6 | 2014-04-08 14:53:42 -0700 | [diff] [blame^] | 1 | # Useful gdb string convenience functions. |
| 2 | # Copyright (C) 2012-2014 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() |