[PATCH] D37631: [libFuzzer] Support using libc++

[Petr Hosek via Phabricator via llvm-commits]

phosek added a comment.

In https://reviews.llvm.org/D37631#876650, @vitalybuka wrote:

> So actually if LLVM_ENABLE_LIBCXX=NO it already builds libfuzzer with libc++. There are issues with tests. We need to add --stdlib=libc++ there and maybe rpath.


The problem is that this only covers the case when compiler-rt is in llvm/projects, when built as part of llvm/runtimes we currently don't set `LLVM_ENABLE_LIBCXX` (although maybe we should when it's available).

>> After thinking about it a bit more, I think `LLVM_ENABLE_LIBCXX` is fine for this purpose. The only question is whether you want to have separate toggle, e.g. for testing? Maybe we could keep the separate option but set `LLVM_ENABLE_LIBCXX` as its default value?
> 
> We should not test different variations of cmake flags and environments using cmake itself. This can get complicated very quickly.
>  Unless we are going to ship both fuzzer versions. Are we?

Ideally no.

> We have tests and we can just make them work with any value of  LLVM_ENABLE_LIBCXX. 
>  Then we just add another step into build bot config.
>  WDYT?

Yeah, that' what I was thinking. I can update the lit configuration to use -lc++ even on Linux if `LLVM_ENABLE_LIBCXX` is set so we get coverage on bots. Is that fine with you?


Repository:
  rL LLVM

https://reviews.llvm.org/D37631