qapi-types/visit.py: Inheritance for structs

This introduces a new 'base' key for struct definitions that refers to
another struct type. On the JSON level, the fields of the base type are
included directly into the same namespace as the fields of the defined
type, like with unions. On the C level, a pointer to a struct of the
base type is included.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Kevin Wolf 2013-09-19 11:56:36 +02:00
parent 14d36307ff
commit 622f557f5a
3 changed files with 37 additions and 2 deletions

View file

@ -17,7 +17,7 @@ import os
import getopt
import errno
def generate_visit_struct_fields(name, field_prefix, fn_prefix, members):
def generate_visit_struct_fields(name, field_prefix, fn_prefix, members, base = None):
substructs = []
ret = ''
full_name = name if not fn_prefix else "%s_%s" % (name, fn_prefix)
@ -42,6 +42,19 @@ static void visit_type_%(full_name)s_fields(Visitor *m, %(name)s ** obj, Error *
name=name, full_name=full_name)
push_indent()
if base:
ret += mcgen('''
visit_start_implicit_struct(m, obj ? (void**) &(*obj)->%(c_name)s : NULL, sizeof(%(type)s), &err);
if (!err) {
visit_type_%(type)s_fields(m, obj ? &(*obj)->%(c_prefix)s%(c_name)s : NULL, &err);
error_propagate(errp, err);
err = NULL;
visit_end_implicit_struct(m, &err);
}
''',
c_prefix=c_var(field_prefix),
type=type_name(base), c_name=c_var('base'))
for argname, argentry, optional, structured in parse_args(members):
if optional:
ret += mcgen('''
@ -124,8 +137,9 @@ def generate_visit_struct(expr):
name = expr['type']
members = expr['data']
base = expr.get('base')
ret = generate_visit_struct_fields(name, "", "", members)
ret = generate_visit_struct_fields(name, "", "", members, base)
ret += mcgen('''