Support CMake on Windows with Clang and MinGW headers

[papadokolos]

System info:

• Sublime Text version: Version 3.2.2, Build 3211
• Which system are you on: Windows 7 64 bit
• Clang version: 10.0.0
• gcc version : 8.1.0 (i686-posix-dwarf-rev0, Built by MinGW-W64 project)

What happens:

I want to use EasyClangComplete for a CMake based project on Windows.
My goal is to use Clang compiler with MinGW (mingw-w64) headers.

In order to achieve that, I had to fulfill the following requirements:

1. Clang should get the flag -target i686-pc-windows-gnu when compiling.
2. CMake should get the flags -DCMAKE_CXX_COMPILER=clang++, -DCMAKE_CXX_FLAGS="-target i686-pc-windows-gnu" and -G "MinGW Makefiles" when executed.
3. EasyClangComplete needs to add support for two things:
   • Parsing a UNC (non posix) path in the generated compilation database
   • Treat -target as a flag

My current approach - Internal modifications

I successfully got it working by making the following modifications to EasyClangComplete's source code.

Diff view

Example compile_commands.json

Here is an example for such a generated compilation database:

[
{
  "directory": "C:/Users/Secret/AppData/Local/Temp/EasyClangComplete/cmake_builds/afeee6ac216a4e3cad7a41f5cf6958c1",
  "command": "C:\\PROGRA~1\\LLVM\\bin\\CLANG_~1.EXE    -target i686-pc-windows-gnu -g   -Wall -Wextra -Wpedantic -Werror -std=c++14 -o CMakeFiles\\space-age.dir\\space_age_test.cpp.obj -c C:\\Users\\Secret\\Exercism\\cpp\\space-age\\space_age_test.cpp",
  "file": "C:/Users/Secret/Exercism/cpp/space-age/space_age_test.cpp"
},
{
  "directory": "C:/Users/Secret/AppData/Local/Temp/EasyClangComplete/cmake_builds/afeee6ac216a4e3cad7a41f5cf6958c1",
  "command": "C:\\PROGRA~1\\LLVM\\bin\\CLANG_~1.EXE    -target i686-pc-windows-gnu -g   -Wall -Wextra -Wpedantic -Werror -std=c++14 -o CMakeFiles\\space-age.dir\\space_age.cpp.obj -c C:\\Users\\Secret\\Exercism\\cpp\\space-age\\space_age.cpp",
  "file": "C:/Users/Secret/Exercism/cpp/space-age/space_age.cpp"
},
{
  "directory": "C:/Users/Secret/AppData/Local/Temp/EasyClangComplete/cmake_builds/afeee6ac216a4e3cad7a41f5cf6958c1",
  "command": "C:\\PROGRA~1\\LLVM\\bin\\CLANG_~1.EXE    -target i686-pc-windows-gnu -g   -Wall -Wextra -Wpedantic -Werror -std=c++14 -o CMakeFiles\\space-age.dir\\test\\tests-main.cpp.obj -c C:\\Users\\Secret\\Exercism\\cpp\\space-age\\test\\tests-main.cpp",
  "file": "C:/Users/Secret/Exercism/cpp/space-age/test/tests-main.cpp"
}
]

Reaching out for help:

I would love to hear your opinion. How would you implement support for this?
I might be able to make a PR for this myself, but first I would like to get an idea of how big is this task 😉

[niosus]

From your changes the only non-trivial one is the change to posix in the shlex. All the others, you can already pass to cmake, see flag_sources in the documentation. I am also a bit unsure what adding -target gets you. The flags there are the flags that clang supports, are you sure this change is necessary?

[papadokolos]

Thanks for the tip on flag_sources! 😄

shlex

Regarding shlex, would it be appropriate to make the posix boolean value determined by the condition sys,platform != "wind32"?

-target

I need -target to be recognized as a flag by ECC, otherwise it isn't being passed to Clang compiler. Adding -target to SEPARABLE_PREFIXES makes it work (perhaps there is a better way?).

From the comment above SEPARABLE_PREFIXES:

# Generated from clang -help with regex: ([-/][\w-]+)\s<\w+>\s
SEPARABLE_PREFIXES = set([

When I execute clang -help, I get a long list of flags, including -target. The list is considerabely larger than SEPARABLE_PREFIXES. So it seems that many clang flags are missing. Also, applying the provided regex pattern on clang -help output yields inaccurate results, at least within Sublime Find (with regex enabled).

[stale]

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[niosus]

This seems to be an easy fix, I think I'll be able to look into this soon. Ping.