Clang upgrade to 20.1.0 in meta-clang

[kraj]

This is for information, since chromium builds will be directly impacted. There is PR for upgrading clang from 19 -> 20 in meta-clang right now under test, I have chroumium-ozone-wayland builds working for x86_64 but would appreciate any help in testing other chromium configs that you might be interested in and giving feedback on how it goes with clang20

[OldManYellsAtCloud]

Just wanted to look at some Firefox issues with clang20, but I have faced 2 problems with the latest meta-clang when I tried to compile wasi-sdk.

1. By default, it fails with the following error:

| CMake Error at /yocto/walnascar/build/tmp/work/x86_64-linux/wasi-sdk-native/git/toolchain.cmake:11 (find_program):
|   Could not find CMAKE_AR using the following names: llvm-ar

I kinda recall some similar mesa issues, though I might be mistaken... anyway. I can get over this if I add llvm-native to the dependencies.

2. Once I get over the first issue, I get a second one (during configure):

|     Run Build Command(s): ninja -v cmTC_193c7
|     [1/2] /yocto/walnascar/build/tmp/work/x86_64-linux/wasi-sdk-native/git/recipe-sysroot-native/usr/bin/clang   -isystem/yocto/walnascar/build/tmp/work/x86_64-linux/wasi-sdk-native/git/recipe-sysroot-native/usr/include -O2 -pipe -o CMakeFiles/cmTC_193c7.dir/testCCompiler.c.o -c /yocto/walnascar/build/tmp/work/x86_64-linux/wasi-sdk-native/git/build/CMakeFiles/CMakeScratch/TryCompile-fe8oht/testCCompiler.c
|     FAILED: CMakeFiles/cmTC_193c7.dir/testCCompiler.c.o
|     /yocto/walnascar/build/tmp/work/x86_64-linux/wasi-sdk-native/git/recipe-sysroot-native/usr/bin/clang   -isystem/yocto/walnascar/build/tmp/work/x86_64-linux/wasi-sdk-native/git/recipe-sysroot-native/usr/include -O2 -pipe -o CMakeFiles/cmTC_193c7.dir/testCCompiler.c.o -c /yocto/walnascar/build/tmp/work/x86_64-linux/wasi-sdk-native/git/build/CMakeFiles/CMakeScratch/TryCompile-fe8oht/testCCompiler.c
|     /yocto/walnascar/build/tmp/work/x86_64-linux/wasi-sdk-native/git/recipe-sysroot-native/usr/bin/clang: symbol lookup error: /yocto/walnascar/build/tmp/work/x86_64-linux/wasi-sdk-native/git/recipe-sysroot-native/usr/bin/clang: undefined symbol: LLVMInitializeAArch64TargetInfo, version LLVM_20.1
|     ninja: build stopped: subcommand failed.

Before I'd dive into it, wanted to ask if maybe you have any idea from top of your head about undefined LLVMInitializeAArch64TargetInfo... or maybe I should stay in clang19 until clang20 gets into oe-core?

[kraj]

I think it is due to llvm doing clang builds also in core, I have patches in flight to fix this such that whole clang is in core then we can just use it in meta-clang. if you are interested to try it out use

https://git.yoctoproject.org/poky-contrib/log/?h=kraj/clang-merge-2

and

kraj/meta-clang#1088

applied to clang master branch

[OldManYellsAtCloud]

Thanks. Unfortunately when I try to clone the poky-contrib repo, I get only error 500. Not sure if the server is being hammered again, or it just requires special permission. Anyway, after I applied your latest clang patches from the oe-core mailing list I managed to compile wasi-sdk successfully, without meta-clang and without doing anything extra. Thanks for the hint.

[kraj]

Thanks. Unfortunately when I try to clone the poky-contrib repo, I get only error 500. Not sure if the server is being hammered again, or it just requires special permission. Anyway, after I applied your latest clang patches from the oe-core mailing list I managed to compile wasi-sdk successfully, without meta-clang and without doing anything extra. Thanks for the hint.

Yeah the link usually says web.git.yoctoproject.org to mitigate the hammers, so you have to manually remove web. from the URI