1 files changed, 32 insertions, 0 deletions
diff --git a/gl/m4/wmemchr.m4 b/gl/m4/wmemchr.m4
new file mode 100644
index 0000000..62bd89c
--- /dev/null
+++ b/gl/m4/wmemchr.m4
@@ -0,0 +1,32 @@
+# wmemchr.m4 serial 4
+dnl Copyright (C) 2011-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_WMEMCHR],
+[
+  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
+  dnl We cannot use AC_CHECK_FUNCS here, because the MSVC 9 header files
+  dnl provide this function as an inline function definition.
+  AC_CACHE_CHECK([for wmemchr], [gl_cv_func_wmemchr],
+    [AC_LINK_IFELSE(
+       [AC_LANG_PROGRAM([[
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be included
+   before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+]],
+          [[return ! wmemchr ((const wchar_t *) 0, (wchar_t) ' ', 0);]])
+       ],
+       [gl_cv_func_wmemchr=yes],
+       [gl_cv_func_wmemchr=no])
+    ])
+  if test $gl_cv_func_wmemchr = no; then
+    HAVE_WMEMCHR=0
+  fi
+])