Need a hint or more likely help

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

All, consider this simple code:

  module foo
    contains
      subroutine bar 
        character(len=:), allocatable :: s(:)
        call bah(s)
     end subroutine bar
  end module foo

If one compiles with -fdump-tree-original, one see (with some pruning)

  void bar ()
  {
    integer(kind=8) .s;
    struct array01_character(kind=1) s;

The above two lines seem to be ok.

    bitsizetype D.4319;
    sizetype D.4320;

    try
      {
        D.4319 = (bitsizetype) (sizetype) NON_LVALUE_EXPR <.s> * 8;
        D.4320 = (sizetype) NON_LVALUE_EXPR <.s>;
        s.data = 0B;
        s.dtype = {.elem_len=(unsigned long) .s, .version=0, .rank=1, .type=6};
        bah ((character(kind=1)[0:][1:.s] * restrict) s.data, .s);
    }

This is bad. .s is undefined.  I've trace this to trans-array.cc:11531

  if (sym->ts.type == BT_CHARACTER
      && !INTEGER_CST_P (sym->ts.u.cl->backend_decl))
    {
      gfc_conv_string_length (sym->ts.u.cl, NULL, &init);
      gfc_trans_vla_type_sizes (sym, &init);

The problem here is that sym->ts.u.cl->length == NULL.  If I change
the conditional to 

  if (sym->ts.type == BT_CHARACTER
      && sym->ts.u.cl->length
      && !INTEGER_CST_P (sym->ts.u.cl->backend_decl))

then the option -fdump-tree-original produces

  void bar ()
  {
    integer(kind=8) .s;
    struct array01_character(kind=1) s;

    try
      {
        s.data = 0B;
        s.dtype = {.elem_len=(unsigned long) .s, .version=0, .rank=1, .type=6};
        bah ((character(kind=1)[0:][1:.s] * restrict) s.data, .s);
      }

which looks good except I don't know what the reference to .s here
means.  Is this correct or should we set .s to zero by artificially
setting sym->ts.u.cl->length to, say, zero length?

-- 
Steve