-extern const char *ctf_str_add (ctf_file_t *, const char *);
-extern const char *ctf_str_add_ref (ctf_file_t *, const char *, uint32_t *ref);
-extern const char *ctf_str_add_external (ctf_file_t *, const char *, uint32_t offset);
+extern uint32_t ctf_str_add (ctf_file_t *, const char *);
+extern uint32_t ctf_str_add_ref (ctf_file_t *, const char *, uint32_t *ref);
+extern int ctf_str_add_external (ctf_file_t *, const char *, uint32_t offset);
+extern void ctf_str_remove_ref (ctf_file_t *, const char *, uint32_t *ref);