Commit 29637a6e authored Dec 01, 2015 by Eric Blake Committed by Markus Armbruster Dec 17, 2015

qapi: Shorter visits of optional fields



For less code, reflect the determined boolean value of an optional
visit back to the caller instead of making the caller read the
boolean after the fact.

The resulting generated code has the following diff:

|-    visit_optional(v, &has_fdset_id, "fdset-id");
|-    if (has_fdset_id) {
|+    if (visit_optional(v, &has_fdset_id, "fdset-id")) {
|         visit_type_int(v, &fdset_id, "fdset-id", &err);
|         if (err) {
|             goto out;
|         }
|     }

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

parent 5cdc8831

include/qapi/visitor.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -41,9 +41,9 @@ void visit_end_list(Visitor v, Error *errp);
		* Check if an optional member @name of an object needs visiting.
		* For input visitors, set *@present according to whether the
		* corresponding visit_type_*() needs calling; for other visitors,
		* leave *@present unchanged.
		* leave @present unchanged. Return @present for convenience.
		*/
		void visit_optional(Visitor v, bool present, const char *name);
		bool visit_optional(Visitor v, bool present, const char *name);

		/**
		* Determine the qtype of the item @name in the current object visit.

qapi/qapi-visit-core.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -73,11 +73,12 @@ void visit_end_union(Visitor v, bool data_present, Error *errp)
		}
		}

		void visit_optional(Visitor v, bool present, const char *name)
		bool visit_optional(Visitor v, bool present, const char *name)
		{
		if (v->optional) {
		v->optional(v, present, name);
		}
		return *present;
		}

		void visit_get_next_type(Visitor v, QType type, bool promote_int,

scripts/qapi.py

+1 −2

Original line number	Diff line number	Diff line
		@@ -1656,8 +1656,7 @@ def gen_visit_fields(members, prefix='', need_cast=False, skiperr=False):
		for memb in members:
		if memb.optional:
		ret += mcgen('''
		visit_optional(v, &%(prefix)shas_%(c_name)s, "%(name)s");
		if (%(prefix)shas_%(c_name)s) {
		if (visit_optional(v, &%(prefix)shas_%(c_name)s, "%(name)s")) {
		''',
		prefix=prefix, c_name=c_name(memb.name),
		name=memb.name, errp=errparg)