--- /dev/null
+#serial 7 -*- autoconf -*-
+
+dnl From Jim Meyering.
+dnl
+dnl See if the glibc *_unlocked I/O macros are available.
+dnl Use only those *_unlocked macros that are declared.
+dnl
+
+AC_DEFUN([jm_FUNC_GLIBC_UNLOCKED_IO],
+ [AC_CHECK_DECLS(
+ [clearerr_unlocked, feof_unlocked, ferror_unlocked,
+ fflush_unlocked, fgets_unlocked, fputc_unlocked, fputs_unlocked,
+ fread_unlocked, fwrite_unlocked, getc_unlocked,
+ getchar_unlocked, putc_unlocked, putchar_unlocked])])