[Lldb-commits] [PATCH] D130689: [LLVM] Update C++ standard to 17

Mon Aug 8 04:01:56 PDT 2022

aaron.ballman added a comment.

In D130689#3705131 <https://reviews.llvm.org/D130689#3705131>, @royjacobson wrote:

> This seems to have been more disruptive than expected, since an existing CMakeCache.txt can make LLVM compile in previous C++14 configuration. This seems to make some of the bots fail in a way that makes the patches making use of C++17 features seem at fault.
>
> See:
> https://github.com/llvm/llvm-project/commit/ede96de751224487aea122af8bfb4e82bc54840b#commitcomment-80507826
> https://reviews.llvm.org/rG32fd0b7fd5ab
>
> How would you feel about adding something like
>
>   #if defined(__cplusplus) && __cplusplus < 201703L
>   #error "LLVM requires at least C++17"
>   #endif
>
> to some central header, to make this switch more visible?

FWIW, that revert was not necessarily due to cmake cache issues (though those issues may exist, I haven't checked). I reverted that change because it broke the build for me locally as well as caused some bots to go red. My local build definitely rebuilt the cache and still failed.

https://lab.llvm.org/buildbot/#/builders/127/builds/33955 (build with revert, passing)
https://lab.llvm.org/buildbot/#/builders/127/builds/33954 (previous build, failing due to compile errors)

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D130689/new/

https://reviews.llvm.org/D130689