@@ -136,23 +136,10 @@ struct %(c_name)s {
if base:
ret += gen_struct_fields([], base)
else:
- # TODO As a hack, we emit both 'kind' and 'type'. Ultimately, we
- # want to use only 'type', but the conversion is large enough to
- # require staging over several commits.
- ret += mcgen('''
- union {
- %(c_type)s kind;
- %(c_type)s type;
- };
-''',
- c_type=c_name(variants.tag_member.type.name))
+ ret += gen_struct_field(variants.tag_member.name,
+ variants.tag_member.type,
+ False)
- # TODO As a hack, we emit the union twice, once as an anonymous union
- # and once as a named union. Ultimately, we want to use only the
- # named union version (as it avoids conflicts between tag values as
- # branch names competing with non-variant QMP names), but the conversion
- # is large enough to require staging over several commits.
- tmp = ''
# FIXME: What purpose does data serve, besides preventing a union that
# has a branch named 'data'? We use it in qapi-visit.py to decide
# whether to bypass the switch statement if visiting the discriminator
@@ -161,7 +148,7 @@ struct %(c_name)s {
# should not be any data leaks even without a data pointer. Or, if
# 'data' is merely added to guarantee we don't have an empty union,
# shouldn't we enforce that at .json parse time?
- tmp += mcgen('''
+ ret += mcgen('''
union { /* union tag is @%(c_name)s */
void *data;
''',
@@ -170,17 +157,14 @@ struct %(c_name)s {
for var in variants.variants:
# Ugly special case for simple union TODO get rid of it
typ = var.simple_union_type() or var.type
- tmp += mcgen('''
+ ret += mcgen('''
%(c_type)s %(c_name)s;
''',
c_type=typ.c_type(),
c_name=c_name(var.name))
- ret += tmp
- ret += ' ' + '\n '.join(tmp.split('\n'))
ret += mcgen('''
} u;
- };
};
''')
@@ -113,10 +113,8 @@
# should still be valid as a type or union branch name. And although
# '*Kind' and '*List' are forbidden as type names, they should not be
# forbidden as a member or branch name.
-# TODO - we temporarily do not support 'u' as branch name, while converting
-# code to use the new union layout
{ 'struct': 'has_a', 'data': { 'MyKind': 'int', 'MyList': ['int'] } }
-{ 'union': 'u', 'data': { 'u8': 'uint8', 'myKind': 'has_a',
+{ 'union': 'u', 'data': { 'u': 'uint8', 'myKind': 'has_a',
'myList': 'has_a' } }
# testing commands
@@ -202,10 +202,10 @@ object has_a
member MyKind: int optional=False
member MyList: intList optional=False
object u
- case u8: :obj-uint8-wrapper
+ case u: :obj-uint8-wrapper
case myKind: :obj-has_a-wrapper
case myList: :obj-has_a-wrapper
-enum uKind ['u8', 'myKind', 'myList']
+enum uKind ['u', 'myKind', 'myList']
command user_def_cmd None -> None
gen=True success_response=True
command user_def_cmd1 :obj-user_def_cmd1-arg -> None
We have two issues with our qapi union layout: 1) Even though the QMP wire format spells the tag 'type', the C code spells it 'kind', requiring some hacks in the generator. 2) The C struct uses an anonymous union, which places all tag values in the same namespace as all non-variant members. This leads to spurious collisions if a tag value matches a QMP name. This patch is the back end for a series that converts to a saner qapi union layout. Now that all clients have been converted to use 'type' and 'obj->u.value', we can drop the temporary support for 'kind' and 'obj->value', and undo the temporary restriction against 'u' as a branch name. Given a simple union qapi type: { 'union':'Foo', 'data': { 'a':'int', 'b':'bool' } } this is the overall effect, when compared to the state before this series of patches: | struct Foo { |- FooKind kind; |- union { /* union tag is @kind */ |+ FooKind type; |+ union { /* union tag is @type */ | void *data; | int64_t a; | bool b; |- }; |+ } u; | }; Note, however, that we do not rename the generated enum, which is still 'FooKind'. A further patch could generate implicit enums as 'FooType', but that causes more churn to C code, and gets harder since the generator already reserved the '*Kind' namespace, but there are already QMP constructs with '*Type' naming which means we cannot easily reserve it for qapi. Signed-off-by: Eric Blake <eblake@redhat.com> --- v9: new patch, but incorporates parts of v5 31/46 and Markus' RFC: http://lists.gnu.org/archive/html/qemu-devel/2015-10/msg02236.html --- scripts/qapi-types.py | 26 +++++--------------------- tests/qapi-schema/qapi-schema-test.json | 4 +--- tests/qapi-schema/qapi-schema-test.out | 4 ++-- 3 files changed, 8 insertions(+), 26 deletions(-)