δΊ 2014/3/6 16:25, Markus Armbruster ει:
> Wenchao Xia <wenchaoq...@gmail.com> writes:
>
>> By default, any union will automatically generate a enum type as
>> "[UnionName]Kind" in C code, and it is duplicated when the discriminator
>> is specified as a pre-defined enum type in schema. After this patch,
>> the pre-defined enum type will be really used as the switch case
>> condition in generated C code, if discriminator is an enum field.
>>
>> Signed-off-by: Wenchao Xia <wenchaoq...@gmail.com>
>> Reviewed-by: Eric Blake <ebl...@redhat.com>
>> ---
>> docs/qapi-code-gen.txt | 8 ++++-
>> scripts/qapi-types.py | 18 +++++++++---
>> scripts/qapi-visit.py | 29 +++++++++++++------
>> scripts/qapi.py | 32
>> +++++++++++++++++++++-
>> tests/Makefile | 2 +-
>> tests/qapi-schema/flat-union-reverse-define.exit | 1 +
>> tests/qapi-schema/flat-union-reverse-define.json | 17 +++++++++++
>> tests/qapi-schema/flat-union-reverse-define.out | 9 ++++++
>> 8 files changed, 99 insertions(+), 17 deletions(-)
>> create mode 100644 tests/qapi-schema/flat-union-reverse-define.err
>> create mode 100644 tests/qapi-schema/flat-union-reverse-define.exit
>> create mode 100644 tests/qapi-schema/flat-union-reverse-define.json
>> create mode 100644 tests/qapi-schema/flat-union-reverse-define.out
>>
>> diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt
>> index 0728f36..a2e7921 100644
>> --- a/docs/qapi-code-gen.txt
>> +++ b/docs/qapi-code-gen.txt
>> @@ -123,11 +123,15 @@ And it looks like this on the wire:
>>
>> Flat union types avoid the nesting on the wire. They are used whenever a
>> specific field of the base type is declared as the discriminator ('type' is
>> -then no longer generated). The discriminator must always be a string field.
>> +then no longer generated). The discriminator can be a string field or a
>> +predefined enum field. If it is a string field, a hidden enum type will be
>> +generated as "[UNION_NAME]Kind". If it is an enum field, a compile time
>> check
>> +will be done to verify the correctness. It is recommended to use an enum
>> field.
>> The above example can then be modified as follows:
>>
>> + { 'enum': 'BlockdevDriver', 'data': [ 'raw', 'qcow2' ] }
>> { 'type': 'BlockdevCommonOptions',
>> - 'data': { 'driver': 'str', 'readonly': 'bool' } }
>> + 'data': { 'driver': 'BlockdevDriver', 'readonly': 'bool' } }
>> { 'union': 'BlockdevOptions',
>> 'base': 'BlockdevCommonOptions',
>> 'discriminator': 'driver',
>> diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
>> index 5885bac..10864ef 100644
>> --- a/scripts/qapi-types.py
>> +++ b/scripts/qapi-types.py
>> @@ -201,14 +201,21 @@ def generate_union(expr):
>> base = expr.get('base')
>> discriminator = expr.get('discriminator')
>>
>> + enum_define = discriminator_find_enum_define(expr)
>> + if enum_define:
>> + discriminator_type_name = enum_define['enum_name']
>> + else:
>> + discriminator_type_name = '%sKind' % (name)
>> +
>> ret = mcgen('''
>> struct %(name)s
>> {
>> - %(name)sKind kind;
>> + %(discriminator_type_name)s kind;
>> union {
>> void *data;
>> ''',
>> - name=name)
>> + name=name,
>> + discriminator_type_name=discriminator_type_name)
>>
>> for key in typeinfo:
>> ret += mcgen('''
>> @@ -389,8 +396,11 @@ for expr in exprs:
>> fdef.write(generate_enum_lookup(expr['enum'], expr['data']))
>> elif expr.has_key('union'):
>> ret += generate_fwd_struct(expr['union'], expr['data']) + "\n"
>> - ret += generate_enum('%sKind' % expr['union'], expr['data'].keys())
>> - fdef.write(generate_enum_lookup('%sKind' % expr['union'],
>> expr['data'].keys()))
>> + enum_define = discriminator_find_enum_define(expr)
>> + if not enum_define:
>> + ret += generate_enum('%sKind' % expr['union'],
>> expr['data'].keys())
>> + fdef.write(generate_enum_lookup('%sKind' % expr['union'],
>> + expr['data'].keys()))
>> if expr.get('discriminator') == {}:
>> fdef.write(generate_anon_union_qtypes(expr))
>> else:
>> diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
>> index 0baaf60..45ce3a9 100644
>> --- a/scripts/qapi-visit.py
>> +++ b/scripts/qapi-visit.py
>> @@ -259,10 +259,16 @@ def generate_visit_union(expr):
>> assert not base
>> return generate_visit_anon_union(name, members)
>>
>> - # There will always be a discriminator in the C switch code, by default
>> it
>> - # is an enum type generated silently as "'%sKind' % (name)"
>> - ret = generate_visit_enum('%sKind' % name, members.keys())
>> - disc_type = '%sKind' % (name)
>> + enum_define = discriminator_find_enum_define(expr)
>> + if enum_define:
>> + # Use the enum type as discriminator
>> + ret = ""
>> + disc_type = enum_define['enum_name']
>> + else:
>> + # There will always be a discriminator in the C switch code, by
>> default it
>> + # is an enum type generated silently as "'%sKind' % (name)"
>> + ret = generate_visit_enum('%sKind' % name, members.keys())
>> + disc_type = '%sKind' % (name)
>>
>> if base:
>> base_fields = find_struct(base)['data']
>> @@ -298,15 +304,16 @@ void visit_type_%(name)s(Visitor *m, %(name)s ** obj,
>> const char *name, Error **
>> pop_indent()
>>
>> if not discriminator:
>> - desc_type = "type"
>> + disc_key = "type"
>> else:
>> - desc_type = discriminator
>> + disc_key = discriminator
>> ret += mcgen('''
>> - visit_type_%(name)sKind(m, &(*obj)->kind, "%(type)s", &err);
>> + visit_type_%(disc_type)s(m, &(*obj)->kind, "%(disc_key)s", &err);
>> if (!err) {
>> switch ((*obj)->kind) {
>> ''',
>> - name=name, type=desc_type)
>> + disc_type = disc_type,
>> + disc_key = disc_key)
>>
>> for key in members:
>> if not discriminator:
>> @@ -517,7 +524,11 @@ for expr in exprs:
>> ret += generate_visit_list(expr['union'], expr['data'])
>> fdef.write(ret)
>>
>> - ret = generate_decl_enum('%sKind' % expr['union'],
>> expr['data'].keys())
>> + enum_define = discriminator_find_enum_define(expr)
>> + ret = ""
>> + if not enum_define:
>> + ret = generate_decl_enum('%sKind' % expr['union'],
>> + expr['data'].keys())
>> ret += generate_declaration(expr['union'], expr['data'])
>> fdecl.write(ret)
>> elif expr.has_key('enum'):
>> diff --git a/scripts/qapi.py b/scripts/qapi.py
>> index eebc8a7..0a504c4 100644
>> --- a/scripts/qapi.py
>> +++ b/scripts/qapi.py
>> @@ -180,6 +180,25 @@ def find_base_fields(base):
>> return None
>> return base_struct_define['data']
>>
>> +# Return the discriminator enum define if discriminator is specified as an
>> +# enum type, otherwise return None.
>> +def discriminator_find_enum_define(expr):
>> + base = expr.get('base')
>> + discriminator = expr.get('discriminator')
>> +
>> + if not (discriminator and base):
>> + return None
>> +
>> + base_fields = find_base_fields(base)
>> + if not base_fields:
>> + return None
>> +
>> + discriminator_type = base_fields.get(discriminator)
>> + if not discriminator_type:
>> + return None
>> +
>> + return find_enum(discriminator_type)
>> +
>> def check_union(expr, expr_info):
>> name = expr['union']
>> base = expr.get('base')
>> @@ -254,11 +273,22 @@ def parse_schema(fp):
>> add_enum(expr['enum'], expr['data'])
>> elif expr.has_key('union'):
>> add_union(expr)
>> - add_enum('%sKind' % expr['union'])
>> elif expr.has_key('type'):
>> add_struct(expr)
>> exprs.append(expr)
>>
>> + # Try again for hidden UnionKind enum
>> + for expr_elem in schema.exprs:
>> + expr = expr_elem['expr']
>> + if expr.has_key('union'):
>> + try:
>> + enum_define = discriminator_find_enum_define(expr)
>> + except QAPIExprError, e:
>> + print >>sys.stderr, e
>> + exit(1)
> How can we get QAPIExprError here?
>
Ops, for this version Exception wouldn't happen, I forgot
to remove the "try except". It should be simply:
+ # Try again for hidden UnionKind enum
+ for expr_elem in schema.exprs:
+ expr = expr_elem['expr']
+ if expr.has_key('union'):
+ enum_define = discriminator_find_enum_define(expr)
Luiz, do you mind apply this series and correct above directly?
>> + if not enum_define:
>> + add_enum('%sKind' % expr['union'])
>> +
>> try:
>> check_exprs(schema)
>> except QAPIExprError, e:
> [...]
