AC_CHECK_FUNCS([memmove setenv],
[],[AC_MSG_ERROR([function is required])])
AC_CHECK_FUNCS([execvpe])
+dnl These are not in POSIX.
+AC_CHECK_FUNCS([fwrite_unlocked fputs_unlocked fputc_unlocked])
dnl Thanks to gperftools' configure.ac (https://code.google.com/p/gperftools).
AC_MSG_CHECKING([for __builtin_expect])
* failures when used in our hook macros below. */
/* In glibc, real fwrite_unlocked() is called in macro. */
-#undef fwrite_unlocked
+#ifdef HAVE_FWRITE_UNLOCKED
+# undef fwrite_unlocked
+#endif
/* In Clang when compiling with hardening flags (fortify) on Debian Wheezy. */
#undef printf
#undef fprintf
FILE *, stream, int, flag, char const *, format, va_list, ap)
/* unlocked_stdio(3), only functions from above are hooked */
+#ifdef HAVE_FWRITE_UNLOCKED
HOOK_FILE4(size_t, fwrite_unlocked, stream,
void const *, ptr, size_t, size, size_t, nmemb, FILE *, stream)
+#endif
+#ifdef HAVE_FPUTS_UNLOCKED
HOOK_FILE2(int, fputs_unlocked, stream,
char const *, s, FILE *, stream)
+#endif
+#ifdef HAVE_FPUTC_UNLOCKED
HOOK_FILE2(int, fputc_unlocked, stream,
int, c, FILE *, stream)
+#endif
HOOK_FILE2(int, putc_unlocked, stream,
int, c, FILE *, stream)
HOOK_FILE1(int, putchar_unlocked, stdout,