Re: [libvirt] [PATCH 4/5] util: XML: Introduce automatic reset of XPath's current node

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(a)redhat.com&gt; > --- > 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, } ?