[Bug fortran/114827] Valgrind reports errors with class(*) assignment

["anlauf at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114827

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2024-04-24
           Keywords|                            |wrong-code

--- Comment #5 from anlauf at gcc dot gnu.org ---
Confirmed.

Two data points which give a hint what might be wrong:

1) the valgrind error count at runtime depends on the string length passed
   to foo.  I get no errors for a string of length 1.

2) the dump-tree of subroutine foo looks suspicious:

    if (b->_data == 0B)
      {
        b->_data = __builtin_malloc (MAX_EXPR <(unsigned long)
rhs.1._vptr->_size, 1>);

It looks like _size comes from:

  static struct __vtype_CHARACTER_1_ __vtab_CHARACTER_1_ = {._hash=85893463,
._size=1, ._extends=0B, ._def_init=0B, ._copy=__copy_character_1, ._final=0B};

and is always 1.  On the other hand, subroutine run sets:

        class.2._vptr = (struct __vtype__STAR * {ref-all})
&__vtab_CHARACTER_1_;
        class.2._data = (void *) &"fubarfubarfubarfubarfubarfu"[1]{lb: 1 sz:
1};
        class.2._len = 27;

but _len is used in foo for the _copy, but not for the allocation.

Thus the size allocated needs to be fixed.

Changing the character argument to use kind=4, I see that _size seems to
represent the element size.

The allocation size thus should be changed to (_size * _len).

Need to find the place where this happens...  Anyone?