[PATCH] Fortran: make STAT/LSTAT/FSTAT intrinsics generic [PR82480]

[Harald Anlauf]

On 9/9/25 21:41, Jakub Jelinek wrote:
> On Tue, Sep 09, 2025 at 09:32:41PM +0200, Harald Anlauf wrote:
>> Running the related tests under valgrind did not reveal anything.
>> The maybe-uninitialized errors are bogus.
> 
> They aren't, because the compiler doesn't know that those 17 or how many
> calls in between
>    switch (code->resolved_isym->id)
> and
>    if (code->resolved_isym->id == GFC_ISYM_FSTAT)
> later on don't change code->resolved_isym or code->resolved_isym->id
> (which is passed to the function, so escaped, any function compiler doesn't
> know anything about could have access to that through global variables in
> theory).

Oh.  Coming from Fortran, I did not consider that anyone would write
such code (except when doing I/O or communication)...

> I think if the code did
>    auto id = code->resolved_isym->id;
>    switch (id)
>      {
>      case GFC_ISYM_FSTAT:
>        ...
>        break;
>      case GFC_ISYM_LSTAT:
>      case GFC_ISYM_STAT:
>        ...
>        break;
>      default:
>        gcc_unreachable ();
>      }
> ...
>    switch (id)
> ...
>    if (id == GFC_ISYM_FSTAT)
>      tmp = build_call_expr_loc (input_location, tmp, 3, unit, vals,
>                                 stat ? arg3 : null_pointer_node);
>    else
>      tmp = build_call_expr_loc (input_location, tmp, 4, name, vals,
>                                 stat ? arg3 : null_pointer_node, slen);
> then it wouldn't have the uninit warnings.
> 
> 	Jakub
> 
> 

I see.  The corresponding patch would have been slightly longer...