[PATCH] D126907: Deferred Concept Instantiation Implementation Take 2

Mon Aug 22 09:17:48 PDT 2022

aaron.ballman added a comment.

In D126907#3739750 <https://reviews.llvm.org/D126907#3739750>, @Mordante wrote:

> In D126907#3738383 <https://reviews.llvm.org/D126907#3738383>, @erichkeane wrote:
>
>> There was a test I dealt with previously where a ton of the header files were run with modules enabled (and an auto generated files), so I'm shocked to find there is MORE differences here.  @ldionne : This is another example where trying to test libcxx is particularly difficult to do apparently.
>
> I disagree; testing libcxx is easy.

FWIW, that's not been my experience. I can't even get libcxx to build for me on Windows with Visual Studio cmake integration, let alone test it. These are the results I got when I tried again today from the instructions from the website:

  CMake Error in F:/source/llvm-project/libcxx/benchmarks/CMakeLists.txt:
    No known features for CXX compiler

    "Clang"

    version 16.0.0.

  CMake Generate step failed.  Build files cannot be regenerated correctly.
  FAILED: runtimes/runtimes-stamps/runtimes-configure 

That said, I recall at one point I was able to get libcxx to build for me, but then I ran into issues getting the tests to run (and we document this on the website: "Building with Visual Studio currently does not permit running tests."). The result is that I stopped trying to build or test libcxx locally ages ago and I rely entirely on the bots to tell me if something's gone wrong.

> Unfortunately what's missing is good documentation explaining how to test different configurations. A similar libc++ related issue came up in another Clang review recently where the libc++ CI setup was unclear. Afterwards I had a talk with @aaron.ballman and I agreed to improve the documentation. While improving the documentation I noticed some issues with our CI setup. So before publishing documentation that doesn't reflect reality, I first wanted to fix these issues. While testing my fixes I ran into the build failure due to this patch. So now we're at a full circle.

And I greatly appreciate the improvements that have been going on here!

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D126907/new/

https://reviews.llvm.org/D126907