+extern tree c_expr_to_decl (tree, bool *, bool *);
+extern tree c_begin_omp_parallel (void);
+extern tree c_finish_omp_parallel (tree, tree);
+extern tree c_begin_omp_task (void);
+extern tree c_finish_omp_task (tree, tree);
+extern tree c_finish_omp_clauses (tree);