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# -*- coding: utf-8 -*-
#
# Copyright © 2009 Red Hat, Inc.
#
# This software is licensed to you under the GNU Lesser General Public
# License, version 2.1 (LGPLv2.1). There is NO WARRANTY for this software,
# express or implied, including the implied warranties of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. You should have received a copy of
# LGPLv2.1 along with this software; if not, see
# http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt
#
# Red Hat trademarks are not licensed under LGPLv2.1. No permission is
# granted to use or replicate Red Hat trademarks that are incorporated in
# this software or its documentation.
#
# Red Hat Author(s): David Hugh Malcolm <dmalcolm@redhat.com>
"""
Hooks for validating CPython extension source code
"""
class CExtensionError(Exception):
# Base class for errors discovered by static analysis in C extension code
def __init__(self, location):
self.location = location
def __str__(self):
return '%s:%s:%s:%s' % (self.location.file,
self.location.line,
self.location.current_element,
self._get_desc())
def _get_desc(self):
# Hook for additional descriptive text about the error
raise NotImplementedError
class FormatStringError(CExtensionError):
def __init__(self, location, format_string):
CExtensionError.__init__(self, location)
self.format_string = format_string
class UnknownFormatChar(FormatStringError):
def __init__(self, location, format_string, ch):
FormatStringError.__init__(self, location, format_string)
self.ch = ch
def _get_desc(self):
return "unknown format char in \"%s\": '%s'" % (self.format_string, self.ch)
class UnhandledCode(UnknownFormatChar):
def _get_desc(self):
return "unhandled format code in \"%s\": '%s' (FIXME)" % (self.format_string, self.ch)
def get_types(location, strfmt):
"""
Generate a list of C type names from a PyArg_ParseTuple format string
Compare to Python/getargs.c:vgetargs1
FIXME: only implements a subset of the various cases; no tuples yet etc
"""
result = []
i = 0
while i < len(strfmt):
c = strfmt[i]
i += 1
if i < len(strfmt):
next = strfmt[i]
else:
next = None
if c in ['(', ')']:
continue
if c in [':', ';']:
break
if c =='|':
continue
# From convertsimple:
simple = {'b':'char',
'B':'char',
'h':'short',
'H':'short',
'i':'int',
'I':'int',
'n':'Py_ssize_t',
'l':'long',
'k':'unsigned long',
'L':'PY_LONG_LONG',
'K':'unsigned PY_LONG_LONG',
'f':'float',
'd':'double',
'D':'Py_complex',
'c':'char',
}
if c in simple:
result.append(simple[c] + ' *')
elif c in ['s', 'z']: # string, possibly NULL/None
if next == '#':
if True: # FIXME: is PY_SSIZE_T_CLEAN defined?
result += ['const char * *', 'Py_ssize_t *']
else:
result += ['const char * *', 'int *']
i += 1
elif next == '*':
result.append('Py_buffer *')
i += 1
else:
result.append('const char * *')
# FIXME: seeing lots of (const char**) versus (char**) mismatches here
# do we care?
elif c == 'e':
if next in ['s', 't']:
result += ['const char *', 'char * *']
i += 1
if i < len(strfmt):
if strfmt[i] == '#':
result.append('int *')
i+=1
elif c == 'S':
result.append('PyObject * *')
elif c == 'U':
result.append('PyObject * *')
elif c == 'O': # object
if next == '!':
result += ['PyTypeObject *', 'PyObject * *']
i += 1
elif next == '?':
raise UnhandledCode(location, strfmt, c + next) # FIXME
elif next == '&':
# FIXME: can't really handle this case as is, fixing for fcntmodule.c
result += ['int ( PyObject * object , int * target )', # converter
'int *'] # FIXME, anything
i += 1
else:
result.append('PyObject * *')
elif c == 'w':
if next == '#':
result += ['char * *', 'Py_ssize_t *']
i += 1
elif next == '*':
result.append('Py_buffer *')
i += 1
else:
result.append('char * *')
elif c == 't':
if next == '#':
result += ['char * *', 'int *']
i += 1
else:
raise UnknownFormatChar(location, strfmt, c)
return result
class WrongNumberOfVars(FormatStringError):
def __init__(self, location, format_string, exp_types, num_args):
FormatStringError.__init__(self, location, format_string)
self.exp_types = exp_types
self.num_args = num_args
class NotEnoughVars(WrongNumberOfVars):
def _get_desc(self):
return 'Not enough arguments in "%s" : expected %i (%s), but got %i' % (
self.format_string,
len(self.exp_types),
self.exp_types,
self.num_args)
class TooManyVars(WrongNumberOfVars):
def _get_desc(self):
return 'Too many arguments in "%s": expected %i (%s), but got %i' % (
self.format_string,
len(self.exp_types),
self.exp_types,
self.num_args)
class MismatchingType(FormatStringError):
def __init__(self, location, format_string, arg_num, exp_type, actual_type):
super(self.__class__, self).__init__(location, format_string)
self.arg_num = arg_num
self.exp_type = exp_type
self.actual_type = actual_type
def _get_desc(self):
return 'Mismatching type of argument %i in "%s": expected "%s" but got "%s"' % (
self.arg_num,
self.format_string,
self.exp_type,
self.actual_type)
def strip_prefix(t, prefix):
if t.startswith(prefix):
return t[len(prefix):]
else:
return t
def simplify_type(t):
# do we really care about char/const char mismatches?:
t = strip_prefix(t, 'signed ')
t = strip_prefix(t, 'unsigned ')
t = strip_prefix(t, 'const ')
return t
def type_equality(t1, t2):
t1 = simplify_type(t1)
t2 = simplify_type(t2)
return t1 == t2
def validate_type(location, format_string, index, actual_num_args, actual_type):
if False:
print 'validate_types(%s, %s, %s, %s, %s)' % (
repr(location),
repr(format_string),
repr(index),
repr(actual_num_args),
repr(actual_type))
try:
exp_types = get_types(location, format_string[1:-1]) # strip leading and trailing " chars
if actual_num_args < len(exp_types):
raise NotEnoughVars(location, format_string, exp_types, actual_num_args)
if actual_num_args > len(exp_types):
raise TooManyVars(location, format_string, exp_types, actual_num_args)
exp_type = exp_types[index]
if not type_equality(exp_type, actual_type):
raise MismatchingType(location, format_string, index+1, exp_type, actual_type)
except CExtensionError, err:
print err
if False:
print 'validate_types(%s, %s, %s, %s, %s)' % (
repr(location),
repr(format_string),
repr(index),
repr(actual_num_args),
repr(actual_type))
return 1
return 0
import unittest
class TestArgParsing(unittest.TestCase):
def assert_args(self, arg_str, exp_result):
result = get_types(None, arg_str)
self.assertEquals(result, exp_result)
def test_simple_cases(self):
self.assert_args('c',
['char *'])
def test_socketmodule_socket_htons(self):
self.assert_args('i:htons',
['int *'])
def test_fcntlmodule_fcntl_flock(self):
# FIXME: somewhat broken, we can't know what the converter callback is
self.assert_args("O&i:flock",
['int ( PyObject * object , int * target )',
'int *',
'int *'])
def test_posixmodule_listdir(self):
self.assert_args("et#:listdir",
['const char *', 'char * *', 'int *'])
def test_bsddb_DBSequence_set_range(self):
self.assert_args("(LL):set_range",
['PY_LONG_LONG *', 'PY_LONG_LONG *'])
if __name__ == '__main__':
unittest.main()
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