This is a long-standing problem in clang/llvm since the diagnostic/help messages are hard-coded in cpp/td code.
I created a plugin for dynamic linked clang/LLVM to translate diagnostic/help messages in English into other languages. This is convenient for users because they don’t need to rebuild the whole Clang project.
GitHub link: GitHub - dtcxzyw/clang-i18n: Clang wrapper with i18n support Clang国际化支持插件
This is just a weekend project, but I think it may be helpful for someone
Currently, only the Chinese translation is available. It just takes several hours to finish the EN to CN translation with the aid of LLM. All kinds of contributions are welcome.
Enjoy yourself!