lambda implicit copy capture triggered from within an OpenMP critical section crashes

[carrardt]

Bugzilla Link	50560
Version	12.0
OS	Linux
Attachments	files generated during crash + console log + command line + original source
CC	@zygoloid

Extended Description

// the following code crashes clang (llvm project 12.0.0)
int main()
{
  for(int i=0;i<3;i++)
  {
    auto mylambda = [=](int& x)
    { 
#     pragma omp critical
      x+=i;
    };
    mylambda(i);
  }
  return 0;
}

[llvmbot]

@llvm/issue-subscribers-openmp

[hainest]

I've encountered this with a slightly smaller reproducer. I've tried in all versions from 7 to 17, and only clang-12 is affected.

int foo(int id) {
  return [id]() {
    #pragma omp critical
    {
      return id;
    }
  }();
}

preprocess-source.txt
run-script.txt
stacktrace.txt

Likely the same as #49321.

[Endilll]

@hainest If this has been fixed in 13, it would be nice to leave a Compiler Explorer link and close both issues. Can you prepare a Compiler Explorer reproducer? Unfortunately, we can't just paste in our cc1 run scripts there.

[hainest]

@Endilll Here's a godbolt link.

[Endilll]

Thank you!
Confirmed to not reproduce anymore even on assertion builds.