MinGW32 compilation errors

[Lastique]

Looks like 44582f3 and possibly some other recent commits broke MinGW32 builds of Boost.Filesystem:

gcc.compile.c++ bin.v2\libs\filesystem\build\gcc-5\debug\cxxstd-11-iso\threadapi-win32\threading-multi\visibility-hidden\codecvt_error_category.o
In file included from ./boost/system/detail/append_int.hpp:8:0,
                 from ./boost/system/detail/error_condition.hpp:18,
                 from ./boost/system/detail/error_category_impl.hpp:14,
                 from ./boost/system/error_category.hpp:11,
                 from ./boost/filesystem/detail/path_traits.hpp:25,
                 from libs/filesystem/src/codecvt_error_category.cpp:18:
./boost/system/detail/snprintf.hpp:22:12: error: 'std::snprintf' has not been declared
 using std::snprintf;
            ^

In file included from ./boost/system/detail/error_category_impl.hpp:79:0,
                 from ./boost/system/error_category.hpp:11,
                 from ./boost/filesystem/detail/path_traits.hpp:25,
                 from libs/filesystem/src/codecvt_error_category.cpp:18:
./boost/system/detail/mutex.hpp: At global scope:
./boost/system/detail/mutex.hpp:84:12: error: 'std::mutex' has not been declared
 using std::mutex;
            ^

https://ci.appveyor.com/project/Lastique/filesystem/builds/48983852/job/2cgottx8b8ckwac0?fullLog=true#L376

Is this platform no longer supported?

[Lastique]

BTW, there is boost/core/snprintf.hpp in Boost.Core with snprintf emulation.

[pdimov]

I suspect that nobody is using the plain MinGW (as opposed to mingw-w64) anymore, but I have no way to know for sure.

For the time being I've removed (the old) MinGW from my Appveyor. We'll see if anyone (apart from you) notices.

[pdimov]

BTW, there is boost/core/snprintf.hpp in Boost.Core with snprintf emulation.

Yeah, there was an snprintf.hpp here too, before I removed it. :-)

[marakew]

using msvc and C++20 the same issues with _snprintf

D:\T60\git\boost_\libs\system\include\boost/system/detail/snprintf.hpp(22): error C2039: '_snprintf': is not a member of 'std'
D:\Program Files (x86)\Microsoft Visual Studio\2019\EnterprisePreview\VC\Tools\MSVC\14.29.30133\include\functional(31): note: see declaration of 'std'
D:\T60\git\boost_\libs\system\include\boost/system/detail/snprintf.hpp(22): error C2873: '_snprintf': symbol cannot be used in a using-declaration
D:\T60\git\boost_\libs\system\include\boost/system/detail/append_int.hpp(23): error C2039: '_snprintf': is not a member of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/append_int.hpp(17): note: see declaration of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/system_category_message_win32.hpp(33): error C2039: '_snprintf': is not a member of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/system_category_message_win32.hpp(28): note: see declaration of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/interop_category.hpp(58): error C2039: '_snprintf': is not a member of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/interop_category.hpp(24): note: see declaration of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/error_code.hpp(266): error C2039: '_snprintf': is not a member of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/std_category.hpp(25): note: see declaration of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/error_code.hpp(272): error C2039: '_snprintf': is not a member of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/std_category.hpp(25): note: see declaration of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/error_category_impl.hpp(61): error C2039: '_snprintf': is not a member of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/std_category.hpp(25): note: see declaration of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/error_category_impl.hpp(67): error C2039: '_snprintf': is not a member of 'boost::system::detail'
D:\T60\git\boost_\libs\system\include\boost/system/detail/std_category.hpp(25): note: see declaration of 'boost::system::detail'

[marakew]

look at there
nlohmann/json#1408 (comment)

[Lastique]

@marakew This looks like snprintf is defined as a macro somewhere and gets replaced to _snprintf. Boost.System doesn't do this, and I'm fairly sure MSVC standard library also doesn't, so you should review your library dependencies and report this to the developers of the offending library.

In any case, this is not the issue that was reported here.

[marakew]

i think remove "using std::snprintf;" solve this there non sense use std::snprintf inside boost::system::detail

[pdimov]

D:\T60\git\boost_\libs\system\include\boost/system/detail/snprintf.hpp(22): error C2039: '_snprintf': is not a member of 'std'

You have #define snprintf _snprintf somewhere. This is no longer needed on a recent MSVC (VS2015 and later) and needs to be removed.

[marakew]

drop "using std::snprintf" will be better solution

[Lastique]

drop "using std::snprintf" will be better solution

This is not a solution at all. Any std::snprintf or boost::core::snprintf calls will remain broken.

[marakew]

not and how this was work before commit mention above ?

[pdimov]

It will be more convenient for me because it will avoid bug reports such as yours, so I may well do that, but it's not a better solution overall, because you'll keep encountering these issues in other libraries until you fix your code to remove the #define.

[Lastique]

not and how this was work before commit mention above ?

As long as you have the define, it didn't work and it won't work except by accident. Removing the define is the only solution.

Note that snprintf and _snprintf are not equivalent. So the correctness of the define is questionable to begin with.