-
-/* Build the result of __builtin_offsetof. TYPE is the first argument to
- offsetof, i.e. a type. LIST is a tree_list that encodes component and
- array references; PURPOSE is set for the former and VALUE is set for
- the later. */
-
-tree
-build_offsetof (tree type, tree list)
-{
- tree t;
-
- /* Build "*(type *)0". */
- t = convert (build_pointer_type (type), null_pointer_node);
- t = build_indirect_ref (t, "");
-
- /* Build COMPONENT and ARRAY_REF expressions as needed. */
- for (list = nreverse (list); list ; list = TREE_CHAIN (list))
- if (TREE_PURPOSE (list))
- t = build_component_ref (t, TREE_PURPOSE (list));
- else
- t = build_array_ref (t, TREE_VALUE (list));
-
- /* Finalize the offsetof expression. For now all we need to do is take
- the address of the expression we created, and cast that to an integer
- type; this mirrors the traditional macro implementation of offsetof. */
- t = build_unary_op (ADDR_EXPR, t, 0);
- return convert (size_type_node, t);
-}