Eric Blake <ebl...@redhat.com> writes:
> Upcoming patches will be adding several contexts where we want
> to handle the visit of an implicit type (an anonymous base type,
> or an anonymous branch of a flat union) by directly inlining
> the visit of each member of the implicit type. The work is made
> easier by factoring out a new helper, gen_visit_members_call(),
> so that the caller doesn't need to care whether the type it is
> visiting is implicit or normal.
>
> For now, the only implicit type we encounter are the branches
> of a simple union; the initial implementation of the helper
> method is hard-coded to that usage, but it gets us one step
> closer to completely dropping the hack of simple_union_type().
>
> Generated output is unchanged.
>
> Signed-off-by: Eric Blake <ebl...@redhat.com>
>
> ---
> v2: retitle, rebase to s/fields/members/ changes
> ---
> scripts/qapi-visit.py | 42 ++++++++++++++++++++++++------------------
> 1 file changed, 24 insertions(+), 18 deletions(-)
>
> diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
> index a712e9a..dbae00c 100644
> --- a/scripts/qapi-visit.py
> +++ b/scripts/qapi-visit.py
> @@ -34,6 +34,25 @@ void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s
> *obj, Error **errp);
> c_name=c_name(name))
>
>
> +def gen_visit_members_call(typ, c_name):
The actual arguments of c_name are C expressions, not names.
> + ret = ''
> + assert isinstance(typ, QAPISchemaObjectType)
> + if typ.is_implicit():
> + # TODO ugly special case for simple union
> + assert len(typ.members) == 1
> + assert not typ.variants
This is an inlined and simplified version of simple_union_type().
Violation of DRY, acceptable if temporary, but could use a comment.
> + ret += mcgen('''
> + visit_type_%(c_type)s(v, "data", %(c_name)s, &err);
> +''',
> + c_type=typ.members[0].type.c_name(), c_name=c_name)
> + else:
> + ret += mcgen('''
> + visit_type_%(c_type)s_members(v, %(c_name)s, &err);
> +''',
> + c_type=typ.c_name(), c_name=c_name)
> + return ret
> +
> +
> def gen_visit_object_members(name, base, members, variants):
> ret = mcgen('''
>
> @@ -45,10 +64,7 @@ void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s
> *obj, Error **errp)
> c_name=c_name(name))
>
> if base:
> - ret += mcgen('''
> - visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, &err);
> -''',
> - c_type=base.c_name())
> + ret += gen_visit_members_call(base, '(%s *)obj' % base.c_name())
> ret += gen_err_check()
>
> ret += gen_visit_members(members, prefix='obj->')
> @@ -60,26 +76,16 @@ void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s
> *obj, Error **errp)
> c_name=c_name(variants.tag_member.name))
>
> for var in variants.variants:
> - # TODO ugly special case for simple union
> - simple_union_type = var.simple_union_type()
> ret += mcgen('''
> case %(case)s:
> ''',
> case=c_enum_const(variants.tag_member.type.name,
> var.name,
> variants.tag_member.type.prefix))
> - if simple_union_type:
> - ret += mcgen('''
> - visit_type_%(c_type)s(v, "data", &obj->u.%(c_name)s, &err);
> -''',
> - c_type=simple_union_type.c_name(),
> - c_name=c_name(var.name))
> - else:
> - ret += mcgen('''
> - visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
> -''',
> - c_type=var.type.c_name(),
> - c_name=c_name(var.name))
> + push_indent()
> + ret += gen_visit_members_call(var.type,
> + '&obj->u.' + c_name(var.name))
> + pop_indent()
> ret += mcgen('''
> break;
> ''')
Not an improvement on its own. Need to review more patches before I can
more.
