fileno error on windows MSYS2 mingw64

[billcxx]

I git clone spdlog and try to build it in the MSYS2 mingw64 terminal on Win10.
cmake configuration is fine but make gives the following error.

$ make
[ 10%] Building CXX object CMakeFiles/spdlog.dir/src/spdlog.cpp.obj
In file included from /home/00010/spdlog/src/spdlog.cpp:12:
/home/00010/spdlog/include/spdlog/details/os-inl.h: In function ‘size_t spdlog::details::os::filesize(FILE*)’:
/home/00010/spdlog/include/spdlog/details/os-inl.h:237:16: error: ‘::fileno’ has not been declared
  237 |     int fd = ::fileno(f);
      |                ^~~~~~
/home/00010/spdlog/include/spdlog/details/os-inl.h: In function ‘bool spdlog::details::os::in_terminal(FILE*)’:
/home/00010/spdlog/include/spdlog/details/os-inl.h:449:21: error: ‘fileno’ was not declared in this scope; did you mean ‘file’?
  449 |     return ::isatty(fileno(file)) != 0;
      |                     ^~~~~~
      |                     file
make[2]: *** [CMakeFiles/spdlog.dir/build.make:76: CMakeFiles/spdlog.dir/src/spdlog.cpp.obj] Error 1
make[1]: *** [CMakeFiles/Makefile2:100: CMakeFiles/spdlog.dir/all] Error 2
make: *** [Makefile:156: all] Error 2

I know this is the same error as in #1581 which is marked as fixed.
I'm not sure if I'm missing any steps in building spdlog in MSYS2 mingw64.

[tt4g]

Yes, it should be fixed.

See the fix commit ccffb6e.
The fix is simple: if CMAKE_SYSTEM_NAME is CYGWIN or MSYS, set CMAKE_CXX_EXTENSIONS=ON.
This is a setting to address the problem that fileno() is not defined unless -std=gnu***, as noted in this comment.

However, if you are using CMake installed on Windows, CMAKE_SYSTEM_NAME will not be CYGWIN or MSYS.
See: #2532, https://gitlab.kitware.com/cmake/cmake/-/issues/24125, https://discourse.cmake.org/t/how-to-check-that-the-current-compiler-is-gcc-msys-when-using-ninja-generator/6698

You are probably using CMake for Windows.
You should install CMake for MSYS or set cmake -DCMAKE_CXX_EXTENSIONS=ON manually on the command line.

[billcxx]

Thanks for the quick reply!

My problem is indeed not using the correct cmake, but slightly different from your guess.

When I install the msys cmake, I install through this command pacman -S cmake which install the msys version of the cmake, not the mingw64 version of the cmake! This matters.

Today, I opened the mingw64 terminal and used the cmake located in /c/msys64/usr/bin/ (this is wrong). The mingw64 cmake should located in /c/msys64/mingw64/bin/, if you have not installed the mingw-w64-x86_64-cmake, the terminal will find the wrong one to use (like in my case, it found the msys cmake). If I switch to the msys terminal and build spdlog from here, everything works.

BTW, when I use the wrong cmake, it gives some warning that System is unknown to cmake.
Hope this will help other msys newbies like me.

[billcxx]

Forget to mention, the same applies to mingw64.
To compile spdlog in mingw64 terminal, you need to install everything in msys2 with the prefix mingw-w64-x86_64

With mingw64, the spdlog library builds fine, but there are some problems when building the example. I guess this is not spdlog's problem, so closing this issue.

FAILED: example/example.exe
cmd.exe /C "cd . && C:\msys64\mingw64\bin\c++.exe -O3 -DNDEBUG  example/CMakeFiles/example.dir/example.cpp.obj -o example\example.exe -Wl,--out-implib,example\libexample.dll.a -Wl,--m
ajor-image-version,0,--minor-image-version,0  libspdlog.a  -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32 && cd ."
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x83c5): undefi
ned reference to `__imp_WSAStartup'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x83df): undefi
ned reference to `__imp_htons'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x8401): undefi
ned reference to `__imp_inet_pton'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x841d): undefi
ned reference to `__imp_socket'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x845a): undefi
ned reference to `__imp_setsockopt'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x86e9): undefi
ned reference to `__imp_WSAGetLastError'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x8714): undefi
ned reference to `__imp_WSAGetLastError'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x8727): undefi
ned reference to `__imp_closesocket'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x8735): undefi
ned reference to `__imp_WSACleanup'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x8755): undefi
ned reference to `__imp_WSAGetLastError'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x875e): undefi
ned reference to `__imp_WSACleanup'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x877e): undefi
ned reference to `__imp_WSAGetLastError'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text+0x8787): undefi
ned reference to `__imp_WSACleanup'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text$_ZN6spdlog5sink
s8udp_sinkISt5mutexE8sink_it_ERKNS_7details7log_msgE[_ZN6spdlog5sinks8udp_sinkISt5mutexE8sink_it_ERKNS_7details7log_msgE]+0x6d): undefined reference to `__imp_sendto'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text$_ZN6spdlog5sink
s8udp_sinkISt5mutexED1Ev[_ZN6spdlog5sinks8udp_sinkISt5mutexED1Ev]+0x1e): undefined reference to `__imp_closesocket'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text$_ZN6spdlog5sink
s8udp_sinkISt5mutexED1Ev[_ZN6spdlog5sinks8udp_sinkISt5mutexED1Ev]+0x2c): undefined reference to `__imp_WSACleanup'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text$_ZN6spdlog5sink
s8udp_sinkISt5mutexED0Ev[_ZN6spdlog5sinks8udp_sinkISt5mutexED0Ev]+0x1e): undefined reference to `__imp_closesocket'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text$_ZN6spdlog5sink
s8udp_sinkISt5mutexED0Ev[_ZN6spdlog5sinks8udp_sinkISt5mutexED0Ev]+0x2c): undefined reference to `__imp_WSACleanup'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text$_ZNSt23_Sp_coun
ted_ptr_inplaceIN6spdlog5sinks8udp_sinkISt5mutexEESaIvELN9__gnu_cxx12_Lock_policyE2EE10_M_disposeEv[_ZNSt23_Sp_counted_ptr_inplaceIN6spdlog5sinks8udp_sinkISt5mutexEESaIvELN9__gnu_cxx1
2_Lock_policyE2EE10_M_disposeEv]+0x3e): undefined reference to `__imp_WSACleanup'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: example/CMakeFiles/example.dir/example.cpp.obj:example.cpp:(.text$_ZNSt23_Sp_coun
ted_ptr_inplaceIN6spdlog5sinks8udp_sinkISt5mutexEESaIvELN9__gnu_cxx12_Lock_policyE2EE10_M_disposeEv[_ZNSt23_Sp_counted_ptr_inplaceIN6spdlog5sinks8udp_sinkISt5mutexEESaIvELN9__gnu_cxx1
2_Lock_policyE2EE10_M_disposeEv]+0x72): undefined reference to `__imp_closesocket'
collect2.exe: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.