CMake build of boost::context generates wrong command line for assembler when clang is used on Windows

[s13n]

I integrated boost into my CMake project using FetchContent, and it builds fine when using the MSVC compiler, but when using the clang-cl 19.1.5 compiler I get the following error when assembler sources are compiled for boost::context:

  FAILED: _deps/boost-build/libs/context/CMakeFiles/boost_context.dir/src/asm/make_x86_64_ms_pe_masm.asm.obj 
  C:\PROGRA~1\MICROS~2\2022\COMMUN~1\VC\Tools\MSVC\1444~1.352\bin\Hostx86\x64\ml64.exe -DBOOST_CONTEXT_DYN_LINK="" -DBOOST_CONTEXT_EXPORT=EXPORT -DBOOST_CONTEXT_NO_LIB="" -DBOOST_CONTEXT_SOURCE="" -DBOOST_ERROR_CODE_HEADER_ONLY -DBOOST_PROCESS_USE_STD_FS -DBOOST_SYSTEM_USE_UTF8 -Dboost_context_EXPORTS [...] /nologo /quiet -Wno-unused-command-line-argument -c -Fo _deps\boost-build\libs\context\CMakeFiles\boost_context.dir\src\asm\make_x86_64_ms_pe_masm.asm.obj [...]_deps\boost-src\libs\context\src\asm\make_x86_64_ms_pe_masm.asm
  Microsoft (R) Macro Assembler (x64) Version 14.44.35217.0
  
  Copyright (C) Microsoft Corporation.  All rights reserved.
  
  
  
[...]build\x64-clang-Debug\MASM : fatal error A1013: invalid numerical command-line argument : /W

Apparently, command line options are mixed up between different tool versions, or perhaps the wrong assembler is being called.

I used boost 1.88, but it happens with multiple recent versions. I am using Windows 11 on x86-64.

The project compiles successfully with clang on Linux.

[pdimov]

That's weird.

The -Wno-unused-command-line-argument has been added by #288, but a further PR, #294, makes sure to apply it only when BOOST_CONTEXT_ASSEMBLER is not "masm" (which it should be under clang-cl).

It's not clear why the logic doesn't work correctly in your case. What is BOOST_CONTEXT_ASSEMBLER?

[pdimov]

Ah, I see. #288 is in 1.88, but #294 is in 1.89. So this has been fixed in 1.89.

[s13n]

Confirming that it was solved in 1.89.0! My builds succeed with the latest boost version. Thanks!