MSVC 12: Warnings

[Naios]

On: 3a5573a

2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 48 bytes will be overrun; 4 bytes will be written starting at offset 48
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 24 bytes will be overrun; 4 bytes will be written starting at offset 24
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 72 bytes will be overrun; 4 bytes will be written starting at offset 72
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 72 bytes will be overrun; 4 bytes will be written starting at offset 72
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 48 bytes will be overrun; 4 bytes will be written starting at offset 48
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 72 bytes will be overrun; 4 bytes will be written starting at offset 72
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 24 bytes will be overrun; 4 bytes will be written starting at offset 24
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 96 bytes will be overrun; 4 bytes will be written starting at offset 96
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 24 bytes will be overrun; 4 bytes will be written starting at offset 24
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 72 bytes will be overrun; 4 bytes will be written starting at offset 72
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 48 bytes will be overrun; 4 bytes will be written starting at offset 48
2>c:\source\trinitycore335\dep\cppformat\format.h(2711): warning C4789: buffer 'array' of size 96 bytes will be overrun; 4 bytes will be written starting at offset 96

[vitaut]

Thanks for reporting. Could you by any chance give an example that triggers the warnings?

[amc522]

I get these same warnings when just compiling format.cc. Currently compiling with Visual Studio (12) 2013. I only get these errors when compiling for 64bit with /W4. I believe it has to do with the #define FMT_VARIADIC_ definition. I get warnings about the constant expression being evaluated
if (sizeof...(Args) > fmt::ArgList::MAX_PACKED_ARGS)
If the compiler does not remove the code inside that if block, then this line:
array[sizeof...(Args)].type = Arg::NONE;
will still be evaluated even though it will never be hit. That statement would cause a warning about going out of the array bounds.

So I dont think there is any bad or dangerous code. The compiler is reading more into it than it has to. I wrapped all the FMT_VARIADIC declarations in the following.

#ifdef _MSC_VER
# pragma warning(push)
# pragma warning(disable: 4127)
# pragma warning(disable: 4789)
#endif
...
#ifdef _MSC_VER
# pragma warning(pop)
#endif

I dont know what the right solution is though.

[Naios]

Naios/TrinityCore@f218d80 produces a lot of warnings with the latest cppformat (rev 3a5573a).

Probably every log message which is calling fmt::sprintf produces a warning for example:

TC_LOG_INFO("sql.updates", "Updating %s database...", DBUpdater<T>::GetTableName().c_str());

[vitaut]

I think d238799 should fix these warnings. Unfortunately I couldn't verify the fix as the warnings are not reported in the AppVeyor build even with /W4. Thanks @amc522 and @Naios.

[amc522]

Yep, that fixed the warnings. Just tested with x86 and x64 in Visual Studio 2013 and the warnings no longer appear. Thanks!

[vitaut]

Thank you for the confirmation, @amc522.