[Bug fortran/98490] Unexpected out of bounds in array constructor with implied do loop

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98490

Paul Thomas <pault at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pault at gcc dot gnu.org

--- Comment #8 from Paul Thomas <pault at gcc dot gnu.org> ---
(In reply to Steve Kargl from comment #7)
> On Sat, Jan 02, 2021 at 04:12:27AM +0000, jvdelisle at charter dot net wrote:
> > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98490
> > 
> > --- Comment #5 from Jerry DeLisle <jvdelisle at charter dot net> ---
> > Patch regresses several test cases.
> >
> 
> This regresses okay.
>  
> diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
> index 14361a10f68..b860f7eaa26 100644
> --- a/gcc/fortran/trans-expr.c
> +++ b/gcc/fortran/trans-expr.c
> @@ -2537,7 +2537,9 @@ gfc_conv_substring (gfc_se * se, gfc_ref * ref, int
> kind,
>    if (!CONSTANT_CLASS_P (tmp) && !DECL_P (tmp))
>      end.expr = gfc_evaluate_now (end.expr, &se->pre);
>  
> -  if (gfc_option.rtcheck & GFC_RTCHECK_BOUNDS)
> +  if ((gfc_option.rtcheck & GFC_RTCHECK_BOUNDS)
> +      && (ref->u.ss.start->symtree
> +   && !ref->u.ss.start->symtree->n.sym->attr.implied_index))
>      {
>        tree nonempty = fold_build2_loc (input_location, LE_EXPR,
> 
> My test program without the dejagnu stuff.
> 
> program test
> 
>    implicit none
>  
>    call sub('Lorem ipsum')
> 
>    contains
> 
>       subroutine sub( text )
>          character(len=*), intent(in) :: text
>          character(len=1), allocatable ::c(:)
>          integer :: i
>          c = [ ( text(i:i), i = 1, len(text) ) ]
>          if (c(1) /= 'L') stop 1
>       end subroutine sub
> 
> end program test

Hi Steve and Jerry,

This is OK to commit to master. I would suggest cherry-picking to 9- and
10-branches too.

Cheers

Paul