+extern const char *dump_base_name;
+extern const char *aux_base_name;
+extern const char *aux_info_file_name;
+extern const char *asm_file_name;
+extern bool exit_after_options;
+extern bool version_flag;
+
+extern int target_flags_explicit;
+
+/* See toplev.c. */
+extern int flag_loop_optimize;
+extern int flag_crossjumping;
+extern int flag_if_conversion;
+extern int flag_if_conversion2;
+extern int flag_keep_static_consts;
+extern int flag_peel_loops;
+extern int flag_rerun_cse_after_loop;
+extern int flag_thread_jumps;
+extern int flag_tracer;
+extern int flag_unroll_loops;
+extern int flag_unroll_all_loops;
+extern int flag_unswitch_loops;
+extern int flag_cprop_registers;
+extern int time_report;
+extern int flag_new_regalloc;
+extern int flag_tree_based_profiling;
+
+/* Things to do with target switches. */
+extern void display_target_options (void);
+extern void print_version (FILE *, const char *);
+extern void set_target_switch (const char *);
+extern void * default_get_pch_validity (size_t *);
+extern const char * default_pch_valid_p (const void *, size_t);
+
+/* The hashtable, so that the C front ends can pass it to cpplib. */
+extern struct ht *ident_hash;
+
+/* This function can be used by targets to set the flags originally
+ implied by -ffast-math and -fno-fast-math. */
+
+extern void set_fast_math_flags (int);
+
+/* Handle -d switch. */
+extern void decode_d_option (const char *);
+
+/* Return true iff flags are set as if -ffast-math. */
+extern bool fast_math_flags_set_p (void);
+
+/* The following functions accept a wide integer argument. Rather
+ than having to cast on every function call, we use a macro instead. */
+
+#ifndef exact_log2
+#define exact_log2(N) exact_log2_wide ((unsigned HOST_WIDE_INT) (N))
+#define floor_log2(N) floor_log2_wide ((unsigned HOST_WIDE_INT) (N))
+#endif
+extern int exact_log2_wide (unsigned HOST_WIDE_INT);
+extern int floor_log2_wide (unsigned HOST_WIDE_INT);
+
+/* Functions used to get and set GCC's notion of in what directory
+ compilation was started. */
+
+extern const char *get_src_pwd (void);
+extern bool set_src_pwd (const char *);