-AC_CHECK_FUNCS(putc_unlocked fputc_unlocked fputs_unlocked \
- fwrite_unlocked fprintf_unlocked)
-AC_CHECK_DECLS([abort, basename, errno, getopt, putc_unlocked, fputc_unlocked,
- fputs_unlocked, fwrite_unlocked, fprintf_unlocked])
+define(libcpp_UNLOCKED_FUNCS, clearerr_unlocked feof_unlocked dnl
+ ferror_unlocked fflush_unlocked fgetc_unlocked fgets_unlocked dnl
+ fileno_unlocked fprintf_unlocked fputc_unlocked fputs_unlocked dnl
+ fread_unlocked fwrite_unlocked getchar_unlocked getc_unlocked dnl
+ putchar_unlocked putc_unlocked)
+AC_CHECK_FUNCS(libcpp_UNLOCKED_FUNCS)
+AC_CHECK_DECLS([abort, asprintf, basename(char *), errno, getopt, vasprintf])
+AC_CHECK_DECLS(m4_split(m4_normalize(libcpp_UNLOCKED_FUNCS)))