support -lc++ on windows for the msvc ABI

[SpexGuy]

On Windows, zig c++ empty_file.cpp fails with this error:

C:\Users\Martin\Projects\Zig-ImGui>zig c++ test.cpp
zig: warning: argument unused during compilation: '-nostdinc++' [-Wunused-command-line-argument]
zig: warning: argument unused during compilation: '-nostdinc++' [-Wunused-command-line-argument]
zig: warning: argument unused during compilation: '-nostdinc++' [-Wunused-command-line-argument]
zig: warning: argument unused during compilation: '-nostdinc++' [-Wunused-command-line-argument]
zig: warning: argument unused during compilation: '-nostdinc++' [-Wunused-command-line-argument]
In file included from C:\Program Files\Zig\Current\lib\zig\libcxxabi\src/cxa_aux_runtime.cpp:14:
In file included from C:\Program Files\Zig\Current\lib\zig\libcxx\include\typeinfo:72:
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.23.28105\include\vcruntime_typeinfo.h:115:10: error:
      target of using declaration conflicts with declaration already in scope
        using ::type_info;
                ^
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.23.28105\include\vcruntime_typeinfo.h:65:7: note:
      target of using declaration
class type_info
      ^
C:\Program Files\Zig\Current\lib\zig\libcxxabi\include\cxxabi.h:29:27: note: conflicting declaration
class _LIBCXXABI_TYPE_VIS type_info; // forward declaration
                          ^
1 error generated.

The following command failed:
C:\Program Files\Zig\Current\zig.exe clang -c -nostdinc -nostdinc++ -fno-spell-checking -target x86_64-unknown-windows-msvc -isystem C:\Program Files\Zig\Current\lib\zig\include -isystem C:\Program Files (x86)\Windows Kits\10\Include\10.0.18362.0\ucrt -isystem C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.23.28105\include -isystem C:\Program Files (x86)\Windows Kits\10\Include\10.0.18362.0\ucrt\..\um -isystem C:\Program Files (x86)\Windows Kits\10\Include\10.0.18362.0\ucrt\..\shared -Xclang -target-cpu -Xclang skylake -Xclang -target-feature -Xclang -3dnow,-3dnowa,+64bit,+adx,+aes,+avx,+avx2,-avx512bf16,-avx512bitalg,-avx512bw,-avx512cd,-avx512dq,-avx512er,-avx512f,-avx512ifma,-avx512pf,-avx512vbmi,-avx512vbmi2,-avx512vl,-avx512vnni,-avx512vp2intersect,-avx512vpopcntdq,+bmi,+bmi2,-branchfusion,-cldemote,+clflushopt,-clwb,-clzero,+cmov,+cx16,+cx8,-enqcmd,+ermsb,+f16c,-false-deps-lzcnt-tzcnt,+false-deps-popcnt,-fast-11bytenop,-fast-15bytenop,-fast-bextr,+fast-gather,-fast-hops,-fast-lzcnt,+fast-scalar-fsqrt,-fast-scalar-shift-masks,+fast-shld-rotate,+fast-variable-shuffle,+fast-vector-fsqrt,-fast-vector-shift-masks,+fma,-fma4,+fsgsbase,+fxsr,-gfni,-idivl-to-divb,+idivq-to-divl,+invpcid,-lea-sp,-lea-uses-ag,-lwp,+lzcnt,+macrofusion,+merge-to-threeway-branch,+mmx,+movbe,-movdir64b,-movdiri,-mpx,-mwaitx,+nopl,-pad-short-functions,+pclmul,-pconfig,-pku,+popcnt,-prefer-128-bit,-prefer-256-bit,-prefer-mask-registers,-prefetchwt1,+prfchw,-ptwrite,-rdpid,+rdrnd,+rdseed,-retpoline,-retpoline-external-thunk,-retpoline-indirect-branches,-retpoline-indirect-calls,+rtm,+sahf,+sgx,-sha,-shstk,+slow-3ops-lea,-slow-incdec,-slow-lea,-slow-pmaddwd,-slow-pmulld,-slow-shld,-slow-two-mem-ops,-slow-unaligned-mem-16,-slow-unaligned-mem-32,-soft-float,+sse,-sse-unaligned-mem,+sse2,+sse3,+sse4.1,+sse4.2,-sse4a,+ssse3,-tbm,-use-aa,-use-glm-div-sqrt-costs,-vaes,-vpclmulqdq,+vzeroupper,-waitpkg,-wbnoinvd,+x87,-xop,+xsave,+xsavec,+xsaveopt,+xsaves -MD -MV -MF C:\Users\Martin\AppData\Local\zig\stage1\tmp\mNdq4h1lx5Zr-cxa_aux_runtime.obj.d -fno-omit-frame-pointer -D_DEBUG -Og -fstack-protector-strong --param ssp-buffer-size=4 -o C:\Users\Martin\AppData\Local\zig\stage1\tmp\mNdq4h1lx5Zr-cxa_aux_runtime.obj C:\Program Files\Zig\Current\lib\zig\libcxxabi\src/cxa_aux_runtime.cpp -DHAVE___CXA_THREAD_ATEXIT_IMPL -D_LIBCPP_DISABLE_EXTERN_TEMPLATE -D_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS -D_LIBCXXABI_BUILDING_LIBRARY -D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS -D_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS -I C:\Program Files\Zig\Current\lib\zig\libcxxabi\include -I C:\Program Files\Zig\Current\lib\zig\libcxx\include -O3 -DNDEBUG -nostdinc++ -fstrict-aliasing -funwind-tables -D_DEBUG -UNDEBUG -std=c++11

The same error is observed when building pub fn main() void {} with zig build-exe -lc++.

Adding --target=native-native-gnu seems to fix it.

[alexnask]

The issue appears to be that we try to compile libcxxabi when using the MSVC c++ stdlib, I assume this is just wrong.

[kubkon]

I don't think this is still an issue. @SpexGuy would you mind double checking that the error is now a linking error stating the lack of _WinMain export? I actually would have expected _main undefined rather than _WinMain meaning we probably set subsystem to Windows by default rather than console.

[SpexGuy]

This doesn't seem to be fixed, but some things have rearranged. Since we changed to the mingw abi by default, you need to use this command now to reproduce:
zig c++ -target native-native-msvc empty_file.cpp

We compile libc files in parallel now, so the error message is considerably harder to read as errors from many files are interleaved. I've attached the result of running this command:
master_stderr.txt