Bug 282276 – [Win] Cross-compiling the Windows port from Linux

• Status: NEW
• Component: CMake

[Ian Grunert]

It would make it easier for more WebKit maintainers to fix Windows build issues. It's more likely that contributors have a Linux dev environment setup than a Windows one.

Windows compiles under clang-cl now, and links with lld-link, so no MASM.exe to worry about.

We'll need something like https://github.com/Jake-Shadle/xwin to download the Microsoft CRT headers and libraries, and Windows SDK headers and libraries - we might want to integrate it into the existing script that downloads WebKitRequirements and put the files in WebKitLibraries.

Use the /vctoolsdir and /winsdkdir flags for clang-cl to point at the CRT and SDK directories, which should expand out into the required compilation / linker flags.

Some CMake changes will be needed to duct tape these pieces together - in particular the /vctoolsdir and /winsdkdir flags.

Might require some changes to Scripts like build-webkit etc.

----

Running the MiniBrowser / jsc via wine might need other changes, but being able to build would be the first step.

[Fujii Hironori]

glandium.org » Blog Archive » Standing up the Cross-Compilation of Firefox for Windows on Linux
https://glandium.org/blog/?p=4020

[Radar WebKit Bug Importer]

<rdar://problem/139306427>

[Ian Grunert]

We'd have to switch vcpkg to compile it's dependencies using clang-cl as well.

Building icu with clang-cl seems to fail:

```
[554/556] C:\WINDOWS\system32\cmd.exe /C "cd /D S:\WebKit\WebKitBuild\Debug\vcpkg_installed\vcpkg\blds\icu\x64-windows-webkit-dbg && S:\WebKit\WebKitBuild\Debug\vcpkg_installed\vcpkg\blds\icu\x64-windows-webkit-dbg\bin\pkgdata -f -v -c -s S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/build/icudt77l -d S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out -e icudt77 -T S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/tmp -p icudt77l -m dll -L icudt S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/tmp/icudata.lst && "C:\Program Files\CMake\bin\cmake.exe" -E touch S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/icudata_asm_file_stamp"
FAILED: data/out/tmp/icudt77l_dat.obj data/out/icudata_asm_file_stamp S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/tmp/icudt77l_dat.obj S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/icudata_asm_file_stamp 
C:\WINDOWS\system32\cmd.exe /C "cd /D S:\WebKit\WebKitBuild\Debug\vcpkg_installed\vcpkg\blds\icu\x64-windows-webkit-dbg && S:\WebKit\WebKitBuild\Debug\vcpkg_installed\vcpkg\blds\icu\x64-windows-webkit-dbg\bin\pkgdata -f -v -c -s S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/build/icudt77l -d S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out -e icudt77 -T S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/tmp -p icudt77l -m dll -L icudt S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/tmp/icudata.lst && "C:\Program Files\CMake\bin\cmake.exe" -E touch S:/WebKit/WebKitBuild/Debug/vcpkg_installed/vcpkg/blds/icu/x64-windows-webkit-dbg/data/out/icudata_asm_file_stamp"
ninja: build stopped: subcommand failed.
```

Might work after icu is updated past 78.1:

https://unicode-org.atlassian.net/browse/ICU-23151

[Ian Grunert]

https://github.com/mstorsjo/msvc-wine

This might be able to run MSVC on Linux via wine to solve the vcpkg problem (as well as solving the problem of downloading the required headers and libraries)

[Ian Grunert]

Pull request: https://github.com/WebKit/WebKit/pull/57907