re PR fortran/51073 (_gfortran_caf_register incorrectly assumes malloc(0) returns non-NULL)

2011-11-14  Tobias Burnus  <burnus@net-b.de>

        PR fortran/51073
        * trans-decl.c (generate_coarray_sym_init): Handle zero-sized
        * arrays.

From-SVN: r181348

gcc/fortran/ChangeLog

+2011-11-14  Tobias Burnus  <burnus@net-b.de>
+
+	PR fortran/51073
+	* trans-decl.c (generate_coarray_sym_init): Handle zero-sized arrays.
+
 2011-11-09  Tobias Burnus  <burnus@net-b.de>
 
 	* symbol.c (clear_sym_mark, traverse_ns): Remove functions.

gcc/fortran/trans-decl.c

@@ -4234,12 +4234,16 @@ generate_coarray_sym_init (gfc_symbol *sym)
 
   size = TYPE_SIZE_UNIT (gfc_get_element_type (TREE_TYPE (decl)));
 
+  /* Ensure that we do not have size=0 for zero-sized arrays.  */ 
+  size = fold_build2_loc (input_location, MAX_EXPR, size_type_node,
+			  fold_convert (size_type_node, size),
+			  build_int_cst (size_type_node, 1));
+
   if (GFC_TYPE_ARRAY_RANK (TREE_TYPE (decl)))
     {
       tmp = GFC_TYPE_ARRAY_SIZE (TREE_TYPE (decl));
       size = fold_build2_loc (input_location, MULT_EXPR, size_type_node,
-			      fold_convert (size_type_node, tmp),
-			      fold_convert (size_type_node, size));
+			      fold_convert (size_type_node, tmp), size);
     }
 
   gcc_assert (GFC_TYPE_ARRAY_CAF_TOKEN (TREE_TYPE (decl)) != NULL_TREE);