[flang-commits] [flang] [llvm] [flang] Enumeration Type: (PR 3/5) Intrinsics + I/O + Modules (PR #193235)

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@@ -2976,7 +2988,7 @@ bool IntrinsicProcTable::Implementation::IsIntrinsicFunction(
   }
   // special cases
   return name == "__builtin_c_loc" || name == "__builtin_c_devloc" ||
-      name == "null";
+      name == "null" || name == "next" || name == "previous";
----------------
MattPD wrote:

Should recognizing `next`/`previous` as intrinsic names here be gated behind the enumeration-type feature? As written they are reserved for every compilation, including default (pre-F2023) mode, so a reference to an implicit-external procedure named `next` or `previous` fails to compile:
```fortran
program p
  integer :: i
  i = next(5)      ! compiled without -fenumeration-type
end program
```
The compiler reports `error: Internal error: Expression analysis failed on: ... Name = 'next'`, whereas the same program with any other name (`foo(5)`) compiles cleanly as an implicit external. The internal error also appears with `-fenumeration-type` enabled whenever the argument is not an enumeration type, because the enum dispatch returns `nullopt` without emitting a diagnostic. Would gating the `next`/`previous` recognition behind `LanguageFeature::EnumerationType`, plus a proper "argument must be of enumeration type" diagnostic for the non-enum case, be reasonable?

https://github.com/llvm/llvm-project/pull/193235