Re: [Patch] Fortran: List-directed read - accept again tab as alternative to space as separator [PR114304]

[Jerry D <jvdelisle2@gmail.com>]

On 4/8/24 2:53 AM, Tobias Burnus wrote:
> Jerry D wrote:
>> See attached updated patch.
> 
> It turned rather quickly out that this patch – committed as r14-9822-g93adf88cc6744a – caused regressions.
> 
> Namely, real-world code use tab(s) as separator instead of spaces.
> 
> [For instance, PR114304 which contains a named-list input file from SPEC CPU 2017; that example uses tabs before the '=' sign, but the issue is more generic.]
> 
> I think the ISO Fortran standard only permits spaces, but as it feels natural and is widely supported, tabs are used and should remain supported.
> 
> It is not quite clear how '\r' are or should be handled, but as eat_spaces did use it, I thought I would add one testcase using them as well.
> 
> That test is not affected by my change; it did work before with GCC and still does – but it does fail with ifort/ifx/flang. I have not thought deeply whether it should be supported or not – and 
> looking at the libgfortran source file, it often but (→ testcase) not consistently requires that an \n follows the \r.
> 
> OK for mainline? [And: When the previous patch gets backported, this surely needs to be included as well.]
> 
> Tobias

Good catch. I did not even think about tabs.

OK to commit and I will take care of it when I do the backport to 13.

Thanks!

Jerry