Re: [Patch] Fortran: Avoid SAVE_EXPR for deferred-len char types

[Steve Kargl <sgk@troutmask.apl.washington.edu>]

On Mon, Feb 20, 2023 at 07:56:14AM +0100, Tobias Burnus wrote:
> On 17.02.23 17:27, Steve Kargl wrote:
> > On Fri, Feb 17, 2023 at 12:13:52PM +0100, Tobias Burnus wrote:
> > > OK for mainline?
> > Short version: no.
> 
> Would you mind to write a reasoning beyond only a single word?
> 
> > > subroutine foo(n)
> > >    integer :: n
> > >    integer :: array(n*5)
> > >    integer :: my_len
> > >    ...
> > >    my_len = 5
> > >    block
> > >      character(len=my_len, kind=4) :: str
> > > 
> > >      my_len = 99
> > >      print *, len(str)  ! still shows 5 - not 99
> > >    end block
> > > end
> > Are you sure about the above comment?
> 
> Yes - for three reasons:
> * On the what-feels-right side: It does not make any sense to print
>   any other value than 5 given that 'str' has been declared with len = 5.
> * On the GCC side, the SAVE_EXPR ensures that the length is evaluated
>   early and then "saved" to ensure its original value is available
> * The quoted text from the standard implies that this is what
>   should happen.

Your comment in the above code suggest to me that you
expected 99.  Of course, the print statement should
produce 5 and that is what gfortran does.  If your patch
only effects deferred character types, why are you including
a useless code example.

-- 
steve