[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
                 CC|                            |burnus at gcc dot gnu.org,
                   |                            |pault at gcc dot gnu.org
   Target Milestone|---                         |4.6.1
            Summary|ICE on array assignment     |[4.6/4.7 Regression] ICE on
                   |statement with allocatable  |array assignment statement
                   |LHS                         |with allocatable LHS

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-03-30 11:55:51 UTC ---
(In reply to comment #0)
> Disabling the possibility of "allocate-on-assignment" by changing
[...]

Or simply use: -fno-realloc-lhs


With my - admittedly not clean - tree, that gives the following valgrind
output:

Invalid read of size 8
    at 0x56B13A: get_std_lbound (trans-array.c:6825)
    by 0x573E88: gfc_alloc_allocatable_for_assignment (trans-array.c:7083)
    by 0x58EBDB: gfc_trans_assignment_1 (trans-expr.c:6186)

That's the lines:

6822      else if (expr->expr_type == EXPR_VARIABLE)
6823        {
6824          tmp = TREE_TYPE (expr->symtree->n.sym->backend_decl);
6825          return GFC_TYPE_ARRAY_LBOUND(tmp, dim);

The issue is that
  TYPE_LANG_SPECIFIC (tmp) == tmp->type.lang_specific == NULL
and, thus, accessing TYPE_LANG_SPECIFIC(node)->lbound[dim]  gives an ICE.

The issue is that for "mmv%h0" the proper backend is not:
  expr->symtree->n.sym->backend_decl
but rather
  expr->ref->u.c->component->backend_decl