On Thu, 06 Mar 2014 19:54:33 +0800
Wenchao Xia <wenchaoq...@gmail.com> wrote:
> 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?
I do. Please, respin 07/10 only and send it as a reply to this thread.
> >> + if not enum_define:
> >> + add_enum('%sKind' % expr['union'])
> >> +
> >> try:
> >> check_exprs(schema)
> >> except QAPIExprError, e:
> > [...]
>
