Commit 25a0d9c9 authored by Eric Blake's avatar Eric Blake Committed by Markus Armbruster
Browse files

qapi: Use predicate callback to determine visit filtering 



Previously, qapi-types and qapi-visit filtered out implicit
objects during visit_object_type() by using 'info' (works since
implicit objects do not [yet] have associated info); meanwhile
qapi-introspect filtered out all schema types on the first pass
by returning a python type from visit_begin(), which was then
used at a distance in QAPISchema.visit() to do the filtering.

Rather than keeping these ad hoc approaches, add a new visitor
callback visit_needed() which returns False to skip a given
entity, and which defaults to True unless overridden.  Use the
new mechanism to simplify all three filtering visitors.

No change to the generated code.

Suggested-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-2-git-send-email-eblake@redhat.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
parent d08ac81a

scripts/qapi-introspect.py

+4 −1
Original line number Diff line number Diff line
@@ -54,7 +54,6 @@ class QAPISchemaGenIntrospectVisitor(QAPISchemaVisitor): 
        self._jsons = []

        self._used_types = []

        self._name_map = {}

        return QAPISchemaType   # don't visit types for now



    def visit_end(self):

        # visit the types that are actually used
@@ -82,6 +81,10 @@ const char %(c_name)s[] = %(c_string)s; 
        self._used_types = None

        self._name_map = None



    def visit_needed(self, entity):

        # Ignore types on first pass; visit_end() will pick up used types

        return not isinstance(entity, QAPISchemaType)



    def _name(self, name):

        if self._unmask:

            return name

scripts/qapi-types.py

+11 −8
Original line number Diff line number Diff line
@@ -233,6 +233,10 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor): 
        self.decl = self._btin + self.decl

        self._btin = None



    def visit_needed(self, entity):

        # Visit everything except implicit objects

        return not isinstance(entity, QAPISchemaObjectType) or entity.info



    def _gen_type_cleanup(self, name):

        self.decl += gen_type_cleanup_decl(name)

        self.defn += gen_type_cleanup(name)
@@ -254,7 +258,6 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor): 
            self._gen_type_cleanup(name)



    def visit_object_type(self, name, info, base, members, variants):

        if info:

        self._fwdecl += gen_fwd_object_or_array(name)

        if variants:

            assert not members      # not implemented

scripts/qapi-visit.py

+10 −7
Original line number Diff line number Diff line
@@ -335,6 +335,10 @@ class QAPISchemaGenVisitVisitor(QAPISchemaVisitor): 
        self.decl = self._btin + self.decl

        self._btin = None



    def visit_needed(self, entity):

        # Visit everything except implicit objects

        return not isinstance(entity, QAPISchemaObjectType) or entity.info



    def visit_enum_type(self, name, info, values, prefix):

        self.decl += gen_visit_decl(name, scalar=True)

        self.defn += gen_visit_enum(name)
@@ -351,7 +355,6 @@ class QAPISchemaGenVisitVisitor(QAPISchemaVisitor): 
            self.defn += defn



    def visit_object_type(self, name, info, base, members, variants):

        if info:

        self.decl += gen_visit_decl(name)

        if variants:

            assert not members      # not implemented

scripts/qapi.py

+8 −4
Original line number Diff line number Diff line
@@ -811,6 +811,10 @@ class QAPISchemaVisitor(object): 
    def visit_end(self):

        pass



    def visit_needed(self, entity):

        # Default to visiting everything

        return True



    def visit_builtin_type(self, name, info, json_type):

        pass
@@ -1304,10 +1308,10 @@ class QAPISchema(object): 
            ent.check(self)



    def visit(self, visitor):

        ignore = visitor.visit_begin(self)

        for name in sorted(self._entity_dict.keys()):

            if not ignore or not isinstance(self._entity_dict[name], ignore):

                self._entity_dict[name].visit(visitor)

        visitor.visit_begin(self)

        for (name, entity) in sorted(self._entity_dict.items()):

            if visitor.visit_needed(entity):

                entity.visit(visitor)

        visitor.visit_end()