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# Useful gdb string convenience functions.
# Copyright (C) 2012-2013 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""$_memeq, $_strlen, $_streq, $_regex"""
import gdb
import re
class _MemEq(gdb.Function):
"""$_memeq - compare bytes of memory
Usage:
$_memeq(a, b, len)
Returns:
True if len bytes at a and b compare equally.
"""
def __init__(self):
super(_MemEq, self).__init__("_memeq")
def invoke(self, a, b, length):
if length < 0:
raise ValueError("length must be non-negative")
if length == 0:
return True
# The argument(s) to vector are [low_bound,]high_bound.
byte_vector = gdb.lookup_type("char").vector(length - 1)
ptr_byte_vector = byte_vector.pointer()
a_ptr = a.reinterpret_cast(ptr_byte_vector)
b_ptr = b.reinterpret_cast(ptr_byte_vector)
return a_ptr.dereference() == b_ptr.dereference()
class _StrLen(gdb.Function):
"""$_strlen - compute string length
Usage:
$_strlen(a)
Returns:
Length of string a, assumed to be a string in the current language.
"""
def __init__(self):
super(_StrLen, self).__init__("_strlen")
def invoke(self, a):
s = a.string()
return len(s)
class _StrEq(gdb.Function):
"""$_streq - check string equality
Usage:
$_streq(a, b)
Returns:
True if a and b are identical strings in the current language.
Example (amd64-linux):
catch syscall open
cond $bpnum $_streq((char*) $rdi, "foo")
"""
def __init__(self):
super(_StrEq, self).__init__("_streq")
def invoke(self, a, b):
return a.string() == b.string()
class _RegEx(gdb.Function):
"""$_regex - check if a string matches a regular expression
Usage:
$_regex(string, regex)
Returns:
True if string str (in the current language) matches the
regular expression regex.
"""
def __init__(self):
super(_RegEx, self).__init__("_regex")
def invoke(self, string, regex):
s = string.string()
r = re.compile(regex.string())
return bool(r.match(s))
# GDB will import us automagically via gdb/__init__.py.
_MemEq()
_StrLen()
_StrEq()
_RegEx()
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