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[CMake][WinMsvc] Replace MSVC_BASE/WINSDK_BASE with LLVM_WINSYSROOT
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Authored by ychen on Jan 20 2022, 9:16 PM.

Details

Summary
  • Using LLVM_WINSYSROOT would pick up DIA SDK path automatically, otherwise llvm-pdbutil has no DIA support.
  • Add MSVC_VER to specify VC tools version.
  • Make MSVC_VER/WINSDK_VER optional. If not specified, use the highest version number like the driver does.

Diff Detail

Event Timeline

ychen created this revision.Jan 20 2022, 9:16 PM
ychen requested review of this revision.Jan 20 2022, 9:16 PM
Herald added a project: Restricted Project. · View Herald TranscriptJan 20 2022, 9:16 PM

/winsysroot is somewhat new, but I suppose that's fine (?)

Looks fine to me (haven't tried it though). The only real question below is where and how winsysroot gets added as flag :)

llvm/cmake/platforms/WinMsvc.cmake
212

clang does this internally if they're not defined. Maybe add -vctoolsversion only if MSVC_VER is defined, and -winsdkversion only if WINSDK_VER is defined?

217

MSVC_VER and WINSDK_VER are optional, so you probably should only check for the sysroot

221

given that this is only set to check for existence, maybe this variable (and the check against it) isn't needed?

223

same here

266

Do you want to add /winsysroot down here too? Or how is that flag getting added?

288

FWIW in Chromium we build our lld-link against libxml2 (with almost everything disabled) these days, and it can do /manifest handling without mt.exe if build that way.

ychen added a comment.Jan 21 2022, 2:20 PM

Thanks for the review!

llvm/cmake/platforms/WinMsvc.cmake
212

yeah, considered that. Later I found out I still need MSVC_VER and WINSDK_VER to specify libpath for the linker. Guess we need to wait until lld-link accepts /winsysroot...

217

same. Optional for the user, still need it to specify linker libpath.

266
288

Thanks for the info. I'll try removing it locally.

ychen added inline comments.Jan 21 2022, 3:07 PM
llvm/cmake/platforms/WinMsvc.cmake
288

Oh, okay. It seems LLVM Windows release build does not link libxml2 yet. Is it possible to upstream your code (https://chromium.googlesource.com/chromium/src/+/66ff126e39334b72ec6f23b6d28a60e7efbbc019/tools/clang/scripts/build.py#281) to llvm/utils/release/build_llvm_package.bat so the release lld-link works with /manifest?

thakis accepted this revision.Jan 22 2022, 8:33 AM

Lg for now; once lld-link supports the flag we can make it nicer :)

llvm/cmake/platforms/WinMsvc.cmake
212

Someone over here is working on that :)

288

I wasn't aware of that script. That seems like a good thing to do, yes.

This revision is now accepted and ready to land.Jan 22 2022, 8:33 AM
smeenai added inline comments.Mar 4 2022, 4:20 PM
llvm/cmake/platforms/WinMsvc.cmake
266

Not all parts of LLVM's build call HandleLLVMOptions, e.g. compiler-rt doesn't. We should add the flag explicitly to handle those cases as well (and I don't think having it specified twice should cause any harm). I'll put up a patch.

Herald added a project: Restricted Project. · View Herald TranscriptMar 4 2022, 4:20 PM

In case of Visual Studio 2019/2022, Windows SDK are installed outside of MSVS directory

C:\Program Files (x86)\Windows Kits\10

In case of Visual Studio 2019/2022, Windows SDK are installed outside of MSVS directory

C:\Program Files (x86)\Windows Kits\10

I believe that was the case for earlier versions as well (at least 2015 and 2017), but this is intended for cross-compilation, so the idea was that you'd arrange the SDK and VC directories in the layout expected by /winsysroot.