[clang] Reland "[clang][modules] Print library module manifest path." (PR #82160)

[Chuanqi Xu via cfe-commits]

ChuanqiXu9 wrote:

> @ChuanqiXu9 since you suggested this test approach

It looks like that I failed to understand VE is under X86 also...

> do you know whether this is the expected behavior of -sysroot ?

I am not sure. This is surprising to me too.



> The point is to build libraries and test clang at once. The `TC.getFilePaths` is constructed from following items in `ToolChain::ToolChain`
> 
> 1. `BUILD/bin/../lib/x86_64-unknown-linux-gnu`
> 2. `%t/Inputs/usr/lib/x86_64-linux-gnu`
> 3. `%t/Inputs/usr/lib`
> 
> Yes. It contains 1st item at run time if you build libraries. As a result, `GetStdModuleManifestPath` find `BUILD/bin/../lib/x86_64-unknown-linux-gnu/libc++.so` first. However, `modules.json` is at `%t/Inputs/usr/lib/x86_64-linux-gnu/modules.json`.
> 
> Hope this helps you.

It looks like this is not special to VE but reproducible for every constructing the clang and libc++ at once. So  I'll try to look at it if I can reproduce it locally.

https://github.com/llvm/llvm-project/pull/82160