[flang-commits] [flang] [flang] Implement IERRNO intrinsic (PR #124281)

[Tom Eccles via flang-commits]

https://github.com/tblah commented:

Thank you for adding this.

I think for something so simple as this you could get away with implementing this as a library procedure instead of a full-on intrinsic because the call to the runtime doesn't need any wrapping.

In short, you don't need the changes in `intrinsics.cpp` or `intrinsicCall.cpp` etc. Just add a `FORTRAN_PROCEDURE_NAME(ierrno)` to the runtime. Then flang can lower this as a generic unresolved function call which is then provided by the runtime.

For example see `ACCESS()`: https://github.com/llvm/llvm-project/pull/88517

https://github.com/llvm/llvm-project/pull/124281