https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95039
Bug ID: 95039
Summary: GCC 10 Analyzer and ‘‘result_decl’ not supported by
dump_expr
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: analyzer
Assignee: dmalcolm at gcc dot gnu.org
Reporter: noloader at gmail dot com
Target Milestone: ---
Created attachment 48498
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48498&action=edit
Preprocessed source file ecp.ii
Hi Everyone,
I'm trying out the analyzer on a C++ project. I'm working on Fedora 32 with GCC
10.
$ gcc --version
gcc (GCC) 10.0.1 20200430 (Red Hat 10.0.1-0.14)
Here's what I am seeing:
‘std::_Vector_base<CryptoPP::WindowSlider,
std::allocator<CryptoPP::WindowSlider> >::_M_allocate’
|......
| 346 | return __n != 0 ? _Tr::allocate(_M_impl, __n) : pointer();
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | | |
| | |
(5) ...to here
| | |
(6) ‘‘result_decl’ not supported by dump_expr<expression error>’ is NULL
| | (4) following ‘false’ branch (when ‘__n ==
0’)...
The odd thing (to me) is, std::allocate related functions seem to be analyzed
as returning NULL. But in C++ a failed allocation throws, it does not return
NULL.
It is fairly easy to duplicate with live code. Unfortunately, I am not sure
what is needed for a reproducer based on the error message. (I tired to
duplicate with a toy example using std::vector, but no joy). It can be
duplicated with live code using:
$ git clone https://github.com/weidai11/cryptopp.git
$ cd cryptopp
$ CXXFLAGS="-DNDEBUG -g2 -O3 -fanalyzer -save-temps" make ecp.o
...
<Lots of Analyzer output>
Attached is the output with a -save-temps.
This may be related to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94034.
==========
In file included from ecp.h:10,
from ecp.cpp:7:
integer.h: In static member function ‘static void std::_Destroy_aux<<anonymous>
>::__destroy(_ForwardIterator, _ForwardIterator) [with _ForwardIterator =
CryptoPP::WindowSlider*; bool <anonymous> = false]’:
integer.h:49:20: warning: dereference of NULL ‘__first’ [CWE-690]
[-Wanalyzer-null-dereference]
49 | class CRYPTOPP_DLL Integer : private InitializeInteger, public
ASN1Object
| ^~~~~~~
‘std::vector<_Tp, _Alloc>::pointer std::vector<_Tp,
_Alloc>::_M_allocate_and_copy(std::vector<_Tp, _Alloc>::size_type,
_ForwardIterator, _ForwardIterator) [with _ForwardIterator = const
CryptoPP::WindowSlider*; _Tp = CryptoPP::WindowSlider; _Alloc =
std::allocator<CryptoPP::WindowSlider>]’: events 1-2
|
|/usr/include/c++/10/bits/stl_vector.h:1508:2:
| 1508 | _M_allocate_and_copy(size_type __n,
| | ^~~~~~~~~~~~~~~~~~~~
| | |
| | (1) entry to
‘std::vector<CryptoPP::WindowSlider>::_M_allocate_and_copy<const
CryptoPP::WindowSlider*>’
|......
| 1511 | pointer __result = this->_M_allocate(__n);
| | ~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (2) calling
‘std::_Vector_base<CryptoPP::WindowSlider,
std::allocator<CryptoPP::WindowSlider> >::_M_allocate’ from
‘std::vector<CryptoPP::WindowSlider>::_M_allocate_and_copy<const
CryptoPP::WindowSlider*>’
|
+--> ‘std::_Vector_base<_Tp, _Alloc>::pointer std::_Vector_base<_Tp,
_Alloc>::_M_allocate(std::size_t) [with _Tp = CryptoPP::WindowSlider; _Alloc =
std::allocator<CryptoPP::WindowSlider>]’: events 3-6
|
| 343 | _M_allocate(size_t __n)
| | ^~~~~~~~~~~
| | |
| | (3) entry to
‘std::_Vector_base<CryptoPP::WindowSlider,
std::allocator<CryptoPP::WindowSlider> >::_M_allocate’
|......
| 346 | return __n != 0 ? _Tr::allocate(_M_impl, __n) : pointer();
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | | |
| | |
(5) ...to here
| | |
(6) ‘‘result_decl’ not supported by dump_expr<expression error>’ is NULL
| | (4) following ‘false’ branch (when ‘__n ==
0’)...
|
<------+
|
‘std::vector<_Tp, _Alloc>::pointer std::vector<_Tp,
_Alloc>::_M_allocate_and_copy(std::vector<_Tp, _Alloc>::size_type,
_ForwardIterator, _ForwardIterator) [with _ForwardIterator = const
CryptoPP::WindowSlider*; _Tp = CryptoPP::WindowSlider; _Alloc =
std::allocator<CryptoPP::WindowSlider>]’: event 7
|
| 1511 | pointer __result = this->_M_allocate(__n);
| | ~~~~~~~~~~~~~~~~~^~~~~
| | |
| | (7) return of NULL to
‘std::vector<CryptoPP::WindowSlider>::_M_allocate_and_copy<const
CryptoPP::WindowSlider*>’ from ‘std::_Vector_base<CryptoPP::WindowSlider,
std::allocator<CryptoPP::WindowSlider> >::_M_allocate’
|
‘std::vector<_Tp, _Alloc>::pointer std::vector<_Tp,
_Alloc>::_M_allocate_and_copy(std::vector<_Tp, _Alloc>::size_type,
_ForwardIterator, _ForwardIterator) [with _ForwardIterator = const
CryptoPP::WindowSlider*; _Tp = CryptoPP::WindowSlider; _Alloc =
std::allocator<CryptoPP::WindowSlider>]’: event 8
|
|/usr/include/c++/10/bits/stl_uninitialized.h:150:15:
| 147 | return std::__uninitialized_copy<__is_trivial(_ValueType1)
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| 148 | && __is_trivial(_ValueType2)
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| 149 | && __assignable>::
| | ~~~~~~~~~~~~~~~~~~
| 150 | __uninit_copy(__first, __last, __result);
| | ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (8) calling
‘std::__uninitialized_copy<false>::__uninit_copy<const CryptoPP::WindowSlider*,
CryptoPP::WindowSlider*>’ from
‘std::vector<CryptoPP::WindowSlider>::_M_allocate_and_copy<const
CryptoPP::WindowSlider*>’
|
+--> ‘static _ForwardIterator
std::__uninitialized_copy<_TrivialValueTypes>::__uninit_copy(_InputIterator,
_InputIterator, _ForwardIterator) [with _InputIterator = const
CryptoPP::WindowSlider*; _ForwardIterator = CryptoPP::WindowSlider*; bool
_TrivialValueTypes = false]’: events 9-10
|
| 84 | __uninit_copy(_InputIterator __first,
_InputIterator __last,
| | ^~~~~~~~~~~~~
| | |
| | (9) entry to
‘std::__uninitialized_copy<false>::__uninit_copy<const CryptoPP::WindowSlider*,
CryptoPP::WindowSlider*>’
|......
| 90 | for (; __first != __last; ++__first, (void)++__cur)
| | ~~~~~~~~~~~~~~~~~
| | |
| | (10) following ‘false’ branch (when
‘__first != __last’)...
|
‘static _ForwardIterator
std::__uninitialized_copy<_TrivialValueTypes>::__uninit_copy(_InputIterator,
_InputIterator, _ForwardIterator) [with _InputIterator = const
CryptoPP::WindowSlider*; _ForwardIterator = CryptoPP::WindowSlider*; bool
_TrivialValueTypes = false]’: event 11
|
|/usr/include/c++/10/bits/move.h:49:5:
| 49 | __addressof(_Tp& __r) _GLIBCXX_NOEXCEPT
| | ^~~~~~~~~~~
| | |
| | (11) ...to here
|
‘static _ForwardIterator
std::__uninitialized_copy<_TrivialValueTypes>::__uninit_copy(_InputIterator,
_InputIterator, _ForwardIterator) [with _InputIterator = const
CryptoPP::WindowSlider*; _ForwardIterator = CryptoPP::WindowSlider*; bool
_TrivialValueTypes = false]’: event 12
|
|/usr/include/c++/10/bits/stl_uninitialized.h:90:23:
| 90 | for (; __first != __last; ++__first, (void)++__cur)
| | ~~~~~~~~^~~~~~~~~
| | |
| | (12) following ‘false’ branch (when
‘__first != __last’)...
|
‘static _ForwardIterator
std::__uninitialized_copy<_TrivialValueTypes>::__uninit_copy(_InputIterator,
_InputIterator, _ForwardIterator) [with _InputIterator = const
CryptoPP::WindowSlider*; _ForwardIterator = CryptoPP::WindowSlider*; bool
_TrivialValueTypes = false]’: event 13
|
|/usr/include/c++/10/bits/move.h:49:5:
| 49 | __addressof(_Tp& __r) _GLIBCXX_NOEXCEPT
| | ^~~~~~~~~~~
| | |
| | (13) ...to here
|
‘static _ForwardIterator
std::__uninitialized_copy<_TrivialValueTypes>::__uninit_copy(_InputIterator,
_InputIterator, _ForwardIterator) [with _InputIterator = const
CryptoPP::WindowSlider*; _ForwardIterator = CryptoPP::WindowSlider*; bool
_TrivialValueTypes = false]’: event 14
|
|/usr/include/c++/10/bits/stl_construct.h:185:11:
| 184 |
std::_Destroy_aux<__has_trivial_destructor(_Value_type)>::
| |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| 185 | __destroy(__first, __last);
| | ~~~~~~~~~^~~~~~~~~~~~~~~~~
| | |
| | (14) calling
‘std::_Destroy_aux<false>::__destroy<CryptoPP::WindowSlider*>’ from
‘std::__uninitialized_copy<false>::__uninit_copy<const CryptoPP::WindowSlider*,
CryptoPP::WindowSlider*>’
|
+--> ‘static void std::_Destroy_aux<<anonymous>
>::__destroy(_ForwardIterator, _ForwardIterator) [with _ForwardIterator =
CryptoPP::WindowSlider*; bool <anonymous> = false]’: events 15-16
|
| 149 | __destroy(_ForwardIterator __first,
_ForwardIterator __last)
| | ^~~~~~~~~
| | |
| | (15) entry to
‘std::_Destroy_aux<false>::__destroy<CryptoPP::WindowSlider*>’
| 150 | {
| 151 | for (; __first != __last; ++__first)
| | ~~~~~~~~~~~~~~~~~
| | |
| | (16) following ‘false’ branch
(when ‘__first != __last’)...
|
‘static void std::_Destroy_aux<<anonymous>
>::__destroy(_ForwardIterator, _ForwardIterator) [with _ForwardIterator =
CryptoPP::WindowSlider*; bool <anonymous> = false]’: event 17
|
|/usr/include/c++/10/bits/move.h:49:5:
| 49 | __addressof(_Tp& __r) _GLIBCXX_NOEXCEPT
| | ^~~~~~~~~~~
| | |
| | (17) ...to here
|
‘static void std::_Destroy_aux<<anonymous>
>::__destroy(_ForwardIterator, _ForwardIterator) [with _ForwardIterator =
CryptoPP::WindowSlider*; bool <anonymous> = false]’: event 18
|
|integer.h:49:20:
| 49 | class CRYPTOPP_DLL Integer : private
InitializeInteger, public ASN1Object
| | ^~~~~~~
| | |
| | (18) calling
‘CryptoPP::SecBlock<long unsigned int, CryptoPP::AllocatorWithCleanup<long
unsigned int, true> >::~SecBlock’ from
‘std::_Destroy_aux<false>::__destroy<CryptoPP::WindowSlider*>’
|
+--> ‘CryptoPP::SecBlock<T, A>::~SecBlock() [with T = long
unsigned int; A = CryptoPP::AllocatorWithCleanup<long unsigned int, true>]’:
event 19
|
|secblock.h:772:2:
| 772 | ~SecBlock()
| | ^
| | |
| | (19) entry to ‘CryptoPP::SecBlock<long
unsigned int, CryptoPP::AllocatorWithCleanup<long unsigned int, true>
>::~SecBlock’
|
‘CryptoPP::SecBlock<T, A>::~SecBlock() [with T = long
unsigned int; A = CryptoPP::AllocatorWithCleanup<long unsigned int, true>]’:
event 20
|
|misc.h:633:15:
| 633 | return b < a ? b : a;
| | ~~~~~~^~~~~~~
| | |
| | (20) following ‘true’ branch...
|
‘CryptoPP::SecBlock<T, A>::~SecBlock() [with T = long
unsigned int; A = CryptoPP::AllocatorWithCleanup<long unsigned int, true>]’:
events 21-23
|
|secblock.h:773:36:
| 233 | if (ptr)
| | ~~
| | |
| | (22) following ‘false’ branch...
|......
| 773 | {m_alloc.deallocate(m_ptr, STDMIN(m_size,
m_mark));}
| |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
| | | |
| | | (21) ...to
here
| | (23) ...to here
|
<------+
|
‘static void std::_Destroy_aux<<anonymous>
>::__destroy(_ForwardIterator, _ForwardIterator) [with _ForwardIterator =
CryptoPP::WindowSlider*; bool <anonymous> = false]’: events 24-25
|
|integer.h:49:20:
| 49 | class CRYPTOPP_DLL Integer : private
InitializeInteger, public ASN1Object
| | ^~~~~~~
| | |
| | (24) returning to
‘std::_Destroy_aux<false>::__destroy<CryptoPP::WindowSlider*>’ from
‘CryptoPP::SecBlock<long unsigned int, CryptoPP::AllocatorWithCleanup<long
unsigned int, true> >::~SecBlock’
| | (25) dereference of NULL
‘__first’
|
