[Libsysio-commit] HEAD: libsysio/include sysio-cmn.h

[Lee W. <lw...@us...>]

Update of /cvsroot/libsysio/libsysio/include
In directory sc8-pr-cvs6.sourceforge.net:/tmp/cvs-serv355/include

Modified Files:
	sysio-cmn.h 
Log Message:


Oops. Need to add changes supporting CONTAINER macro for the new
tree abstraction support.


Index: sysio-cmn.h
===================================================================
RCS file: /cvsroot/libsysio/libsysio/include/sysio-cmn.h,v
retrieving revision 1.18
retrieving revision 1.19
diff -u -w -b -B -p -r1.18 -r1.19
--- sysio-cmn.h	20 Aug 2007 19:12:08 -0000	1.18
+++ sysio-cmn.h	21 Sep 2007 19:36:59 -0000	1.19
@@ -83,6 +83,18 @@ struct intnl_xtvec;
 struct iovec;
 
 /*
+ * Return offset to given member of given structure or union.
+ */
+#define OFFSETOF(type, _mbr) \
+	((size_t )&((struct type *)0)->_mbr)
+
+/*
+ * Return ptr to record containing the passed member.
+ */
+#define CONTAINER(type, _mbr, ptr) \
+	(struct type *)((ptrdiff_t )(ptr) - OFFSETOF(type, _mbr))
+
+/*
  * Symbol composition.
  */
 #define _PREPEND_HELPER(p, x) \