On 2/26/19 11:08 AM, Peter Krempa wrote:
Quite a few parts modify the XPath context current node to shif the
shift
scope and allow easier queries. This also means that the node needs to be restored afterwards.
Introduce a macro based on 'VIR_AUTOCLEAN' which adds a local structure on the stack remembering the original node along with a function which will make sure that the node is reset when the local structure leaves scope.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> --- src/libvirt_private.syms | 1 + src/util/virxml.c | 10 ++++++++++ src/util/virxml.h | 22 ++++++++++++++++++++++ 3 files changed, 33 insertions(+)
Nice idea.
+/** + * VIR_XPATH_NODE_AUTORESTORE: + * @ctxt: XML XPath context pointer + * + * This macro ensures that when the scope where it's used ends @ctxt's current
Reads better with s/ends/ends,/
+ * node pointer is reset to the original value when this macro was used. + */ +# define VIR_XPATH_NODE_AUTORESTORE(ctxt) \ + VIR_AUTOCLEAN(virXPathContextNodeSave) ctxt ## CtxtSave = {(ctxt), (ctxt)->node}
Worth using C99 syntax as in { .ctxt = (ctxt), .node = (ctxt)->node, } ? -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org