Bug 111073 - [13/14/15 regression] False-positive -Wstringop-overflow when building gdb from trunk with -D_GLIBCXX_ASSERTIONS
Summary: [13/14/15 regression] False-positive -Wstringop-overflow when building gdb fr...
Status: UNCONFIRMED
Alias: None
Product: gcc
Classification: Unclassified
Component: tree-optimization (show other bugs)
Version: 14.0
: P2 normal
Target Milestone: 13.4
Assignee: Not yet assigned to anyone
URL:
Keywords: diagnostic
Depends on:
Blocks: Wstringop-overflow
  Show dependency treegraph
 
Reported: 2023-08-19 06:48 UTC by Sam James
Modified: 2024-05-21 09:16 UTC (History)
4 users (show)

See Also:
Host:
Target:
Build:
Known to work:
Known to fail:
Last reconfirmed:


Attachments
infcall.ii.xz (329.16 KB, application/x-xz)
2023-08-19 06:48 UTC, Sam James
Details

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Description Sam James 2023-08-19 06:48:42 UTC
Created attachment 55762 [details]
infcall.ii.xz

12.3.1 20230818 is OK, but 13.2.1 20230812 and 14.0.0 20230813 aren't.

I filed this over at gdb first: https://sourceware.org/bugzilla/show_bug.cgi?id=30780.

```
$ g++-14 -x c++    -I. -I. -I./config -DLOCALEDIR="\"/usr/local/share/locale\"" -DHAVE_CONFIG_H -I./../include/opcode -I../bfd -I./../bfd -I./../include -I./../readline/readline/.. -I./../zlib  -I../libdecnumber -I./../libdecnumber  -I./../gnulib/import -I../gnulib/import -I./.. -I.. -I./../libbacktrace/ -I../libbacktrace/ -DTUI=1    -I/usr/include/python3.12 -I/usr/include/python3.12   -I./.. -pthread    -Wall -Wpointer-arith -Wno-unused -Wunused-value -Wunused-variable -Wunused-function -Wno-switch -Wno-char-subscripts -Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable -Wno-sign-compare -Wno-error=maybe-uninitialized -Wno-mismatched-tags -Wsuggest-override -Wimplicit-fallthrough=3 -Wduplicated-cond -Wshadow=local -Wdeprecated-copy -Wdeprecated-copy-dtor -Wredundant-move -Wmissing-declarations -Wstrict-null-sentinel -Wformat -Wformat-nonliteral -Werror -g -O2     -c -o infcall.o -MT infcall.o -MMD -MP -MF ./.deps/infcall.Tpo infcall.c
In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/hashtable_policy.h:36,
                 from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/hashtable.h:35,
                 from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/unordered_map.h:33,
                 from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/unordered_map:41,
                 from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/functional:63,
                 from ./../gdbsupport/ptid.h:35,
                 from ./../gdbsupport/common-defs.h:206,
                 from defs.h:26,
                 from infcall.c:20:
In static member function ‘static _Up* std::__copy_move<_IsMove, true, std::random_access_iterator_tag>::__copy_m(_Tp*, _Tp*, _Up*) [with _Tp = value*; _Up = value*; bool _IsMove = false]’,
    inlined from ‘_OI std::__copy_move_a2(_II, _II, _OI) [with bool _IsMove = false; _II = value**; _OI = value**]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_algobase.h:506:30,
    inlined from ‘_OI std::__copy_move_a1(_II, _II, _OI) [with bool _IsMove = false; _II = value**; _OI = value**]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_algobase.h:533:42,
    inlined from ‘_OI std::__copy_move_a(_II, _II, _OI) [with bool _IsMove = false; _II = value**; _OI = value**]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_algobase.h:540:31,
    inlined from ‘_OI std::copy(_II, _II, _OI) [with _II = value**; _OI = value**]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_algobase.h:633:7,
    inlined from ‘static _ForwardIterator std::__uninitialized_copy<true>::__uninit_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = value**; _ForwardIterator = value**]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_uninitialized.h:147:27,
    inlined from ‘_ForwardIterator std::uninitialized_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = value**; _ForwardIterator = value**]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_uninitialized.h:185:15,
    inlined from ‘_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, allocator<_Tp>&) [with _InputIterator = value**; _ForwardIterator = value**; _Tp = value*]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_uninitialized.h:373:37,
    inlined from ‘void std::vector<_Tp, _Alloc>::_M_range_insert(iterator, _ForwardIterator, _ForwardIterator, std::forward_iterator_tag) [with _ForwardIterator = value**; _Tp = value*; _Alloc = std::allocator<value*>]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/vector.tcc:884:38,
    inlined from ‘std::vector<_Tp, _Alloc>::iterator std::vector<_Tp, _Alloc>::insert(const_iterator, _InputIterator, _InputIterator) [with _InputIterator = value**; <template-parameter-2-2> = void; _Tp = value*; _Alloc = std::allocator<value*>]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_vector.h:1486:19,
    inlined from ‘value* call_function_by_hand_dummy(value*, type*, gdb::array_view<value*>, void (*)(void*, int), void*)’ at infcall.c:1239:23:
/usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_algobase.h:437:30: error: ‘void* __builtin_memmove(void*, const void*, long unsigned int)’ writing 9 or more bytes into a region of size 0 overflows the destination [-Werror=stringop-overflow=]
  437 |             __builtin_memmove(__result, __first, sizeof(_Tp) * _Num);
      |             ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/x86_64-pc-linux-gnu/bits/c++allocator.h:33,
                 from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/allocator.h:46,
                 from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/alloc_traits.h:39,
                 from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/ext/alloc_traits.h:34,
                 from /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/hashtable_policy.h:39:
In member function ‘_Tp* std::__new_allocator<_Tp>::allocate(size_type, const void*) [with _Tp = value*]’,
    inlined from ‘static _Tp* std::allocator_traits<std::allocator<_Tp1> >::allocate(allocator_type&, size_type) [with _Tp = value*]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/alloc_traits.h:482:28,
    inlined from ‘std::_Vector_base<_Tp, _Alloc>::pointer std::_Vector_base<_Tp, _Alloc>::_M_allocate(std::size_t) [with _Tp = value*; _Alloc = std::allocator<value*>]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_vector.h:378:33,
    inlined from ‘void std::vector<_Tp, _Alloc>::_M_range_insert(iterator, _ForwardIterator, _ForwardIterator, std::forward_iterator_tag) [with _ForwardIterator = value**; _Tp = value*; _Alloc = std::allocator<value*>]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/vector.tcc:875:40,
    inlined from ‘std::vector<_Tp, _Alloc>::iterator std::vector<_Tp, _Alloc>::insert(const_iterator, _InputIterator, _InputIterator) [with _InputIterator = value**; <template-parameter-2-2> = void; _Tp = value*; _Alloc = std::allocator<value*>]’ at /usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_vector.h:1486:19,
    inlined from ‘value* call_function_by_hand_dummy(value*, type*, gdb::array_view<value*>, void (*)(void*, int), void*)’ at infcall.c:1239:23:
/usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/new_allocator.h:151:55: note: at offset [-9223372036854775808, -1] into destination object of size [8, 9223372036854775800] allocated by ‘operator new’
  151 |         return static_cast<_Tp*>(_GLIBCXX_OPERATOR_NEW(__n * sizeof(_Tp)));
      |                                                       ^
cc1plus: all warnings being treated as errors
```
Comment 1 Sam James 2023-08-19 06:49:25 UTC
I can reproduce it with:
```
$ g++-14 -c infcall.ii -O2 -Werror=stringop-overflow
[...]
/usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_algobase.h:437:30: error: ‘void* __builtin_memmove(void*, const void*, long unsigned int)’ writing 9 or more bytes into a region of size 0 overflows the destination [-Werror=stringop-overflow=]
  437 |             __builtin_memmove(__result, __first, sizeof(_Tp) * _Num);
      |             ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[...]
```
Comment 2 Sam James 2023-08-19 06:51:20 UTC
Oh, interesting. It needs -D_GLIBCXX_ASSERTIONS (which my gcc has on by default) to trigger.
Comment 3 Jakub Jelinek 2024-05-21 09:16:37 UTC
GCC 13.3 is being released, retargeting bugs to GCC 13.4.