Re: [Patch, Fortran] PR 41714: [OOP] ALLOCATE SOURCE= does not properly copy the value from SOURCE

[Janus Weil <janus@gcc.gnu.org>]

>>> It looks OK to me except:
>>>
>>>>        PR fortran/41714
>>>>        * trans-expr.c (gfc_build_memcpy_call): Take care of the case that the
>>>>        call to '__builtin_memcpy' is optimized away (replaced by a direct
>>>>        assignment).
>>>
>>> How the heck does that work?  It comes out as a NOP_EXPR and yet it's
>>> really an assignment..... Is that documented somewhere?
>>
>> That patch looks indeed dubious.  It tests for an implementation detail
>> (the memcpy folder returns (void *) ({ *dst = *src; dst; })).  You should
>> be able to unconditionally fold-convert to void_type_node as in the
>> original code.  Instead tree_annotate_all_with_location should be fixed.
>
> Or rather the FE should not call this function - it assumes that the code
> is already gimplified.

Ok, so you mean one should instead just do the stuff which this
function does, but without the extra checks? Like here:

Index: gcc/fortran/trans.c
===================================================================
--- gcc/fortran/trans.c (Revision 153538)
+++ gcc/fortran/trans.c (Arbeitskopie)
@@ -1282,7 +1282,11 @@ gfc_trans_code (gfc_code * code)
       if (res != NULL_TREE && ! IS_EMPTY_STMT (res))
        {
          if (TREE_CODE (res) == STATEMENT_LIST)
-           tree_annotate_all_with_location (&res, input_location);
+           {
+             tree_stmt_iterator i;
+             for (i = tsi_start (res); !tsi_end_p (i); tsi_next (&i))
+               SET_EXPR_LOCATION (tsi_stmt (i), input_location);
+           }
          else
            SET_EXPR_LOCATION (res, input_location);


Note: Maybe one should rather use 'tree_annotate_one_with_location'
instead of SET_EXPR_LOCATION, but right now this is static in
gimplify.c.

Cheers,
Janus