Re: [PATCH] Fortran: use name of array component in runtime error message [PR30802]

[Harald Anlauf <anlauf@gmx.de>]

Am 28.01.24 um 22:43 schrieb Steve Kargl:
> On Sun, Jan 28, 2024 at 08:56:24PM +0100, Harald Anlauf wrote:
>>
>> Am 28.01.24 um 12:39 schrieb Mikael Morin:
>>> Le 24/01/2024 à 22:39, Harald Anlauf a écrit :
>>>> Dear all,
>>>>
>>>> this patch is actually only a followup fix to generate the proper name
>>>> of an array reference in derived-type components for the runtime error
>>>> message generated for the bounds-checking code.  Without the proper
>>>> part ref, not only a user may get confused: I was, too...
>>>>
>>>> The testcase is compile-only, as it is only important to check the
>>>> strings used in the error messages.
>>>>
>>>> Regtested on x86_64-pc-linux-gnu.  OK for mainline?
>>>>
>>>
>>> the change proper looks good, and is an improvement.  But I'm a little
>>> concerned by the production of references like in the test x1%vv%z which
>>> could be confusing and is strictly speaking invalid fortran (multiple
>>> non-scalar components).  Did you consider generating x1%vv(?,?)%zz or
>>> x1%vv(...)%z or similar?
>>
>> yes, that seems very reasonable, given that this is what NAG does.
>>
>> We also have spurious %_data in some error messages that I'll try
>> to get rid off.
>>
>
> I haven't looked at the patch, but sometimes (if not always) things
> like _data are marked with attr.artificial.  You might see if this
> will help with suppressing spurious messages.

I was talking about the generated format strings of runtime error
messages.

program p
   implicit none
   type t
      real :: zzz(10) = 42
   end type t
   class(t), allocatable :: xx(:)
   integer :: j
   j = 0
   allocate (t :: xx(1))
   print *, xx(1)% zzz(j)
end

This is generating the following error at runtime since at least gcc-7:

Fortran runtime error: Index '0' of dimension 1 of array 'xx%_data%zzz'
below lower bound of 1

I believe you were recalling bogus warnings at compile time.
There are no warnings here, and there shouldn't.