Struct Initialize with string failed?

[jungjin09]

Hi,
this code runs fine in debug mode but in release mode, i get an error as soon as i get out of the loop. (I'm using vs2022-v143-msvc14.32)

struct functioninfo
{
	std::wstring var;
	std::wstring name;
	std::vector<std::wstring> vec;
};

for(unsigned i=0;i<1;++i)
{
	functioninfo func_finfo{ std::wstring{},std::wstring{L"abc"},{} };
}

The error I get is: Exception thrown: read access violation.
this was 0x6300620061.

Program crash when call: _Destroy_range(_Myfirst, _Mylast, _Al);

_CONSTEXPR20 void _Tidy() noexcept { // free all storage
        auto& _Al         = _Getal();
        auto& _My_data    = _Mypair._Myval2;
        pointer& _Myfirst = _My_data._Myfirst;
        pointer& _Mylast  = _My_data._Mylast;
        pointer& _Myend   = _My_data._Myend;

        _My_data._Orphan_all();

        if (_Myfirst) { // destroy and deallocate old array
            _Destroy_range(_Myfirst, _Mylast, _Al);
            _ASAN_VECTOR_REMOVE;
            _Al.deallocate(_Myfirst, static_cast<size_type>(_Myend - _Myfirst));

            _Myfirst = nullptr;
            _Mylast  = nullptr;
            _Myend   = nullptr;
        }
    }

then,
xstring
line4632

_CONSTEXPR20 void _Tidy_deallocate() noexcept { // initialize buffer, deallocating any storage
        _Mypair._Myval2._Orphan_all();
        **if (_Mypair._Myval2._Large_string_engaged()) {** 
            const pointer _Ptr = _Mypair._Myval2._Bx._Ptr;
            auto& _Al          = _Getal();
            _Destroy_in_place(_Mypair._Myval2._Bx._Ptr);
            _Al.deallocate(_Ptr, _Mypair._Myval2._Myres + 1);
        }

#if _HAS_CXX20
        if (_STD is_constant_evaluated()) {
            _Mypair._Myval2._Bx._Ptr = nullptr;
            _Mypair._Myval2._Mysize  = 0;
            _Mypair._Myval2._Myres   = 0;
        } else
#endif // _HAS_CXX20
        {
            _Mypair._Myval2._Mysize = 0;
            _Mypair._Myval2._Myres  = _BUF_SIZE - 1;
            // the _Traits::assign is last so the codegen doesn't think the char write can alias this
            _Traits::assign(_Mypair._Myval2._Bx._Buf[0], _Elem());
        }
    }

I searched many post but couldn't find the answer.
Is it a certain c++ setting that turns things upside down?
I hope someone can help me find the cause.

Thanks you.

[CaseyCarter]

The error I get is: Exception thrown: read access violation.
this was 0x6300620061.

This is notably the result of interpreting L"abc" as a 64-bit pointer.

I'm not able to reproduce this. Do you have a complete cpp file and/or VS solution that reproduces the bad behavior?

[jungjin09]

Hi,
it's hard to reproduce the problem because it seems to be related to this 3rd library.
after many change setting msvc, v142.. still same error, the code worked after disabling the feature in project setting:
c/c++ optimization/whole program optimization.
I think that's the only way for me right now.

Thank you for your help.

[frederick-vs-ja]

It seems that SSO buffer is sometimes misinterpreted.
Looks like some kind of ABI incompatibility, possibly related to #1502 and #1735.

[StephanTLavavej]

Please let us know if you're able to distill this down to a self-contained test case - otherwise we'll need to close this as not reproducible. Thanks for reporting it!

[jungjin09]

Hi, finally I found the cause.
after checking, I have 2 structs with the same name but different member located on 2 different cpp files.

In unknown way connected. after the end of running, error appeared as image.
problem has been resolved.