1 files changed, 51 insertions, 0 deletions
diff --git a/acinclude.m4 b/acinclude.m4
index 59a9359..cd2b903 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -111,3 +111,54 @@ AC_DEFUN(AC_STRUCT_ST_MTIM_NSEC,
   fi
  ]
 )
+
+
+dnl ---------------------------------------------------------------------------
+dnl This will be in the next version of autoconf; take this out then!
+
+# make_FUNC_SETVBUF_REVERSED
+# ------------------------
+AC_DEFUN([make_FUNC_SETVBUF_REVERSED],
+[AC_REQUIRE([AC_C_PROTOTYPES])dnl
+AC_CACHE_CHECK(whether setvbuf arguments are reversed,
+  ac_cv_func_setvbuf_reversed,
+  [ac_cv_func_setvbuf_reversed=no
+   AC_LINK_IFELSE(
+     [AC_LANG_PROGRAM(
+	[[#include <stdio.h>
+#	  if PROTOTYPES
+	   int (setvbuf) (FILE *, int, char *, size_t);
+#	  endif]],
+	[[char buf; return setvbuf (stdout, _IOLBF, &buf, 1);]])],
+     [AC_LINK_IFELSE(
+	[AC_LANG_PROGRAM(
+	   [[#include <stdio.h>
+#	     if PROTOTYPES
+	      int (setvbuf) (FILE *, int, char *, size_t);
+#	     endif]],
+	   [[char buf; return setvbuf (stdout, &buf, _IOLBF, 1);]])],
+	[# It compiles and links either way, so it must not be declared
+	 # with a prototype and most likely this is a K&R C compiler.
+	 # Try running it.
+	 AC_RUN_IFELSE(
+	   [AC_LANG_PROGRAM(
+	      [[#include <stdio.h>]],
+	      [[/* This call has the arguments reversed.
+		   A reversed system may check and see that the address of buf
+		   is not _IOLBF, _IONBF, or _IOFBF, and return nonzero.  */
+		char buf;
+		if (setvbuf (stdout, _IOLBF, &buf, 1) != 0)
+		  exit (1);
+		putchar ('\r');
+		exit (0); /* Non-reversed systems SEGV here.  */]])],
+	   ac_cv_func_setvbuf_reversed=yes,
+	   rm -f core core.* *.core,
+	   [[: # Assume setvbuf is not reversed when cross-compiling.]])]
+	ac_cv_func_setvbuf_reversed=yes)])])
+if test $ac_cv_func_setvbuf_reversed = yes; then
+  AC_DEFINE(SETVBUF_REVERSED, 1,
+            [Define to 1 if the `setvbuf' function takes the buffering type as
+             its second argument and the buffer pointer as the third, as on
+             System V before release 3.])
+fi
+])# make_FUNC_SETVBUF_REVERSED