[Xen-devel] [PATCH] libxc: provide XENCTRL_HAS_XC_INTERFACE feature test macro

[Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>]

# HG changeset patch
# User Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
# Date 1296140344 0
# Node ID f346343cb9786978767e219c2bf8c116a169f6f2
# Parent  48008a2cbc1ed12696cd129d83196f3e04f6ab1b
libxc: provide XENCTRL_HAS_XC_INTERFACE feature test macro

This makes it easier for out-of-tree callers to tell which version of
the libxc interface this version of xenctrl.h provides.

Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Acked-by: Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx>
Committed-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>

diff -r 48008a2cbc1e -r f346343cb978 tools/libxc/xenctrl.h
--- a/tools/libxc/xenctrl.h     Thu Jan 27 11:31:46 2011 +0000
+++ b/tools/libxc/xenctrl.h     Thu Jan 27 14:59:04 2011 +0000
@@ -86,6 +86,16 @@
 #else
 #error "Define barriers"
 #endif
+
+
+#define XENCTRL_HAS_XC_INTERFACE 1
+/* In Xen 4.0 and earlier, xc_interface_open and xc_evtchn_open would
+ * both return ints being the file descriptor.  In 4.1 and later, they
+ * return an xc_interface* and xc_evtchn*, respectively - ie, a
+ * pointer to an opaque struct.  This #define is provided in 4.1 and
+ * later, allowing out-of-tree callers to more easily distinguish
+ * between, and be compatible with, both versions.
+ */
 
 
 /*

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