Re: [PATCH, fortran] Fix Bug 124543 - INQUIRE: Sometimes returns incorrect values

Hi Jerry,

thanks for your efforts!

I played with the testcase, threw the NAG compiler on it, and
found a few minor nits:

1)

! Make sure there is no file with the name we will be using
   open (lun, file=lfn, status='old', iostat=iostat)
   if (iostat /= 0) then
     close (lun, status='delete')
   end if

Here the logic seems backwards to me: you want to delete an
existing file.  It should rather read:

   if (iostat == 0) then
...

2)

   inquire (file=lfn, id=id, pending=pending, recl=recl)  ! SEGV at 
run-time w/gfortran

This crashes with NAG, because there is *no* pending asynchronous
transfer.

I recommend to replace that with

   inquire (file=lfn, id=id, pending=pending, recl=recl,iostat=iostat)

and I also wonder if we should set iostat to non-zero (like NAG) and
test it with:

   if (iostat == 0) stop 80

(This fails after your patch).

Similarly later on:

   inquire (unit=lun, id=id, pending=pending, recl=recl,iostat=iostat)
   if (iostat == 0) stop 123


The other differences I saw may be issues with NAG or an interpretation
issue.

So the patch is OK with the above addressed and suitably resolved.

Thanks,
Harald


On 3/29/26 04:38, Jerry D wrote:
> Hello All,
> 
> The attached patch fixes numerous return values or missing checks.
> 
> There were at least two places where we segfaulted on checking a 
> gfc_unit value when the unit did not exist.
> 
> I have not implemented inquire (unit=lun, leading_zero=leading_zero) 
> since this is rather new and I prefer to add it after this patch. It is 
> one of those examples of a new feature added that does not have a lot of 
> value AFAICT. It will require some front-end work.
> 
> The new test case is very busy. It is not too difficult to adjust if we 
> miss anything there.
> 
> Regression tested on X86_64.
> 
> OK for mainline?
> 
> Regards,
> 
> Jerry
> -----
>      fortran: Fix several issues with INQUIRE and unconnected units.
> 
>              PR libfortran/124543
> 
>      libgfortran/ChangeLog:
> 
>              * io/inquire.c (inquire_via_unit): Fix return value for
>              NAMED. Add check for ACTION. Fix return values for
>              ENCODING, PENDING, READ, WRITE, READWRITE.
>              (inquire_via_filename): Add checks for ACTION, DELIM,
>              ASYNCHRONOUS, and PENDING. Fix return value for
>              ENCODING.
>              * io/unix.c (inquire_access): Change return value from no
>              to unknown.
> 
>      gcc/testsuite/ChangeLog:
> 
>              * gfortran.dg/pr124543.f90: New test.
>