Re: [Patch] Fortran: Fix reallocation on assignment for kind=4 strings [PR107508]

[Mikael Morin <morin-mikael@orange.fr>]

Hello,

Le 05/11/2022 à 23:28, Tobias Burnus a écrit :
> Prior to the attached patch, there is a problem with realloc on assignment
> with kind=4 characters as the string length was compared with the byte 
> size,
> which was always true.
> 
(...)

> OK for mainline?
> 
The trans-array.c part looks good.
A couple of nits for the trans-expr.cc part:

> diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
> index e7b9211f17e..44c373cc495 100644
> --- a/gcc/fortran/trans-expr.cc
> +++ b/gcc/fortran/trans-expr.cc
> @@ -11236,10 +11236,10 @@ alloc_scalar_allocatable_for_assignment (stmtblock_t *block,
>  
>    if (expr1->ts.type == BT_CHARACTER && expr1->ts.deferred)
>      {
> -      /* Use the rhs string length and the lhs element size.  */
> -      size = string_length;
> -      tmp = TREE_TYPE (gfc_typenode_for_spec (&expr1->ts));
> -      tmp = TYPE_SIZE_UNIT (tmp);
> +      /* Use the rhs string length and the lhs element size. Note that 'size' is
> +	 used below for the string-length comparison, only.  */
> +      size = string_length,
s/,/;/ ?
> +      tmp = TYPE_SIZE_UNIT (gfc_get_char_type (expr2->ts.kind));
Here you are using the rhs element size, which contradicts the comment, 
so there is certainly something to fix here (either the comment or the 
code).

>        size_in_bytes = fold_build2_loc (input_location, MULT_EXPR,
>  				       TREE_TYPE (tmp), tmp,
>  				       fold_convert (TREE_TYPE (tmp), size));

As for the testcase, do you keep the code commented on purpose?
Can some of it be removed or uncommented?

Mikael