+/* Convert GNU_EXPR, a pointer to a VMS descriptor, to GNU_TYPE, a regular
+ pointer or fat pointer type. GNU_EXPR_ALT_TYPE is the alternate (32-bit)
+ pointer type of GNU_EXPR. BY_REF is true if the result is to be used by
+ reference. GNAT_SUBPROG is the subprogram to which the VMS descriptor is
+ passed. */
+extern tree convert_vms_descriptor (tree gnu_type, tree gnu_expr,
+ tree gnu_expr_alt_type, bool by_ref,
+ Entity_Id gnat_subprog);
+
+/* Indicate that we need to take the address of T and that it therefore
+ should not be allocated in a register. Returns true if successful. */
+extern bool gnat_mark_addressable (tree t);
+
+/* Save EXP for later use or reuse. This is equivalent to save_expr in tree.c
+ but we know how to handle our own nodes. */
+extern tree gnat_save_expr (tree exp);
+
+/* Protect EXP for immediate reuse. This is a variant of gnat_save_expr that
+ is optimized under the assumption that EXP's value doesn't change before
+ its subsequent reuse(s) except through its potential reevaluation. */
+extern tree gnat_protect_expr (tree exp);
+
+/* This is equivalent to stabilize_reference in tree.c but we know how to
+ handle our own nodes and we take extra arguments. FORCE says whether to
+ force evaluation of everything. We set SUCCESS to true unless we walk
+ through something we don't know how to stabilize. */
+extern tree gnat_stabilize_reference (tree ref, bool force, bool *success);