[flang-commits] [flang] [flang] Generate valid IR on GOTO DO body (PR #66084)

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vdonaldson wrote:

> Your test program works fine with this patch

@luporl Thanks for verifying that your patch addresses this test variant.

I discussed this compiler crash issue with several other engineers at nvidia. Although the executable generated for these test cases with your patch will avoid the compiler crash, the vast majority of such nonconformant tests will crash at runtime. We believe it would be preferable to handle this as some other compilers do by turning the current warning into a hard error. I have filed an internal issue to do that not only for DO loops, but also for most if not all other constructs as well. ASSOCIATE constructs for example are similar to DO loops in that they would most likely crash at runtime after taking a nonconformant branch. One question is whether or not to make an exception for IF/ELSE IF/ELSE sequences, which might occur in old f66/f77 code and are more likely to be benign and not crash at runtime.

My recommendation now is to put this PR on hold pending a probable error message fix.

Again, thanks for working on the problem.

https://github.com/llvm/llvm-project/pull/66084