-extern void detect_coding P_ ((struct coding_system *, unsigned char *, int));
-extern void detect_eol P_ ((struct coding_system *, unsigned char *, int));
-extern int conversion_buffer_size;
-extern char *conversion_buffer;
-extern char *get_conversion_buffer P_ ((int));
+extern void detect_coding P_ ((struct coding_system *, const unsigned char *,
+ int));
+extern void detect_eol P_ ((struct coding_system *, const unsigned char *,
+ int));