Re: [Qemu-devel] [PATCH v5 28/28] qapi: Drop support for inline nested types

[Markus Armbruster]

Eric Blake <address@hidden> writes:

> A future patch will be using a 'name':{dictionary} entry in the
> QAPI schema to specify a default value for an optional argument;
> but existing use of inline nested structs conflicts with that goal.
> Now that all commands have been changed to avoid inline nested
> structs, nuke support for them, and turn it into a hard error.
> Update the testsuite to reflect tighter parsing rules.
>
> Signed-off-by: Eric Blake <address@hidden>
> ---
>  scripts/qapi-commands.py                     |  8 +++---
>  scripts/qapi-event.py                        |  4 +--
>  scripts/qapi-types.py                        |  9 ++-----
>  scripts/qapi-visit.py                        | 37 
> ++++------------------------
>  scripts/qapi.py                              | 18 +++++---------
>  tests/qapi-schema/event-nest-struct.err      |  2 +-
>  tests/qapi-schema/nested-struct-data.err     |  1 +
>  tests/qapi-schema/nested-struct-data.exit    |  2 +-
>  tests/qapi-schema/nested-struct-data.json    |  2 +-
>  tests/qapi-schema/nested-struct-data.out     |  3 ---
>  tests/qapi-schema/nested-struct-returns.err  |  1 +
>  tests/qapi-schema/nested-struct-returns.exit |  2 +-
>  tests/qapi-schema/nested-struct-returns.json |  2 +-
>  tests/qapi-schema/nested-struct-returns.out  |  3 ---
>  14 files changed, 26 insertions(+), 68 deletions(-)
>
> diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
> index 053ba85..db81044 100644
> --- a/scripts/qapi-commands.py
> +++ b/scripts/qapi-commands.py
> @@ -28,7 +28,7 @@ def type_visitor(name):
>
>  def generate_command_decl(name, args, ret_type):
>      arglist=""
> -    for argname, argtype, optional, structured in parse_args(args):
> +    for argname, argtype, optional in parse_args(args):
>          argtype = c_type(argtype, is_param=True)
>          if optional:
>              arglist += "bool has_%s, " % c_var(argname)
> @@ -53,7 +53,7 @@ def gen_sync_call(name, args, ret_type, indent=0):
>      retval=""
>      if ret_type:
>          retval = "retval = "
> -    for argname, argtype, optional, structured in parse_args(args):
> +    for argname, argtype, optional in parse_args(args):
>          if optional:
>              arglist += "has_%s, " % c_var(argname)
>          arglist += "%s, " % (c_var(argname))
> @@ -96,7 +96,7 @@ Visitor *v;
>  def gen_visitor_input_vars_decl(args):
>      ret = ""
>      push_indent()
> -    for argname, argtype, optional, structured in parse_args(args):
> +    for argname, argtype, optional in parse_args(args):
>          if optional:
>              ret += mcgen('''
>  bool has_%(argname)s = false;
> @@ -139,7 +139,7 @@ v = qapi_dealloc_get_visitor(md);
>  v = qmp_input_get_visitor(mi);
>  ''')
>
> -    for argname, argtype, optional, structured in parse_args(args):
> +    for argname, argtype, optional in parse_args(args):
>          if optional:
>              ret += mcgen('''
>  visit_optional(v, &has_%(c_name)s, "%(name)s", %(errp)s);
> diff --git a/scripts/qapi-event.py b/scripts/qapi-event.py
> index 601e307..47dc041 100644
> --- a/scripts/qapi-event.py
> +++ b/scripts/qapi-event.py
> @@ -21,7 +21,7 @@ def _generate_event_api_name(event_name, params):
>      l = len(api_name)
>
>      if params:
> -        for argname, argentry, optional, structured in parse_args(params):
> +        for argname, argentry, optional in parse_args(params):
>              if optional:
>                  api_name += "bool has_%s,\n" % c_var(argname)
>                  api_name += "".ljust(l)
> @@ -93,7 +93,7 @@ def generate_event_implement(api_name, event_name, params):
>  """,
>                  event_name = event_name)
>
> -        for argname, argentry, optional, structured in parse_args(params):
> +        for argname, argentry, optional in parse_args(params):
>              if optional:
>                  ret += mcgen("""
>      if (has_%(var)s) {
> diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
> index 9c8d68c..4789528 100644
> --- a/scripts/qapi-types.py
> +++ b/scripts/qapi-types.py
> @@ -63,18 +63,13 @@ typedef struct %(name)sList
>  def generate_struct_fields(members):
>      ret = ''
>
> -    for argname, argentry, optional, structured in parse_args(members):
> +    for argname, argentry, optional in parse_args(members):
>          if optional:
>              ret += mcgen('''
>      bool has_%(c_name)s;
>  ''',
>                           c_name=c_var(argname))
> -        if structured:
> -            push_indent()
> -            ret += generate_struct({ "field": argname, "data": argentry})
> -            pop_indent()
> -        else:
> -            ret += mcgen('''
> +        ret += mcgen('''
>      %(c_type)s %(c_name)s;
>  ''',
>                       c_type=c_type(argentry), c_name=c_var(argname))
> diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
> index 3e11089..10b08c6 100644
> --- a/scripts/qapi-visit.py
> +++ b/scripts/qapi-visit.py
> @@ -51,27 +51,6 @@ def generate_visit_struct_fields(name, field_prefix, 
> fn_prefix, members, base =
>      else:
>          full_name = "%s_%s" % (name, fn_prefix)
>
> -    for argname, argentry, optional, structured in parse_args(members):
> -        if structured:
> -            if not fn_prefix:
> -                nested_fn_prefix = argname
> -            else:
> -                nested_fn_prefix = "%s_%s" % (fn_prefix, argname)
> -
> -            nested_field_prefix = "%s%s." % (field_prefix, argname)
> -            ret += generate_visit_struct_fields(name, nested_field_prefix,
> -                                                nested_fn_prefix, argentry)
> -            ret += mcgen('''
> -
> -static void visit_type_%(full_name)s_field_%(c_name)s(Visitor *m, %(name)s 
> **obj, Error **errp)
> -{
> -''',
> -                         name=name, full_name=full_name, 
> c_name=c_var(argname))
> -            ret += generate_visit_struct_body(full_name, argname, argentry)
> -            ret += mcgen('''
> -}
> -''')
> -
>      if base:
>          ret += generate_visit_implicit_struct(base)
>
> @@ -94,7 +73,7 @@ if (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):
> +    for argname, argentry, optional in parse_args(members):
>          if optional:
>              ret += mcgen('''
>  visit_optional(m, &(*obj)->%(c_prefix)shas_%(c_name)s, "%(name)s", &err);
> @@ -104,18 +83,12 @@ if (!err && (*obj)->%(prefix)shas_%(c_name)s) {
>                           c_name=c_var(argname), name=argname)
>              push_indent()
>
> -        if structured:
> -            ret += mcgen('''
> -visit_type_%(full_name)s_field_%(c_name)s(m, obj, &err);
> -''',
> -                         full_name=full_name, c_name=c_var(argname))
> -        else:
> -            ret += mcgen('''
> +        ret += mcgen('''
>  visit_type_%(type)s(m, &(*obj)->%(c_prefix)s%(c_name)s, "%(name)s", &err);
>  ''',
> -                         c_prefix=c_var(field_prefix), prefix=field_prefix,
> -                         type=type_name(argentry), c_name=c_var(argname),
> -                         name=argname)
> +                     c_prefix=c_var(field_prefix), prefix=field_prefix,
> +                     type=type_name(argentry), c_name=c_var(argname),
> +                     name=argname)
>
>          if optional:
>              pop_indent()
> diff --git a/scripts/qapi.py b/scripts/qapi.py
> index 800e8e4..8e5b4ad 100644
> --- a/scripts/qapi.py
> +++ b/scripts/qapi.py
> @@ -368,11 +368,13 @@ def check_type(expr_info, source, data, allow_array = 
> False,
>      for (key, value) in data.items():
>          check_name(expr_info, "Member of %s" % source, key,
>                     allow_optional=allow_optional)
> +        # Todo: allow dictionaries to represent default values of
> +        # an optional argument.
>          check_type(expr_info, "Member '%s' of %s" % (key, source), value,
>                     allow_array=True,
>                     allowed_metas=['built-in', 'union', 'alternate', 'struct',
>                                    'enum'],
> -                   allow_dict=True, allow_optional=True, 
> allow_star=allow_star)
> +                   allow_dict=False, allow_star=allow_star)

check_type() uses allow_optional only when allow_dict.  Okay.

>
>  def check_command(expr, expr_info):
>      name = expr['command']
> @@ -404,13 +406,6 @@ def check_event(expr, expr_info):
>      check_type(expr_info, "'data' for event '%s'" % name,
>                 expr.get('data'), allowed_metas=['union', 'struct'],
>                 allow_optional=True)
> -    if params:
> -        for argname, argentry, optional, structured in parse_args(params):
> -            if structured:
> -                raise QAPIExprError(expr_info,
> -                                    "Nested structure define in event is not 
> "
> -                                    "supported, event '%s', argname '%s'"
> -                                    % (expr['event'], argname))
>
>  def check_union(expr, expr_info):
>      name = expr['union']
> @@ -667,13 +662,12 @@ def parse_args(typeinfo):
>          argname = member
>          argentry = typeinfo[member]
>          optional = False
> -        structured = False
>          if member.startswith('*'):
>              argname = member[1:]
>              optional = True
> -        if isinstance(argentry, OrderedDict):
> -            structured = True
> -        yield (argname, argentry, optional, structured)
> +        # Todo: allow argentry to be OrderedDict, for providing the
> +        # value of an optional argument.
> +        yield (argname, argentry, optional)
>
>  def de_camel_case(name):
>      new_name = ''
> diff --git a/tests/qapi-schema/event-nest-struct.err 
> b/tests/qapi-schema/event-nest-struct.err
> index 91bde1c..5a42701 100644
> --- a/tests/qapi-schema/event-nest-struct.err
> +++ b/tests/qapi-schema/event-nest-struct.err
> @@ -1 +1 @@
> -tests/qapi-schema/event-nest-struct.json:1: Nested structure define in event 
> is not supported, event 'EVENT_A', argname 'a'
> +tests/qapi-schema/event-nest-struct.json:1: Member 'a' of 'data' for event 
> 'EVENT_A' should be a type name
> diff --git a/tests/qapi-schema/nested-struct-data.err 
> b/tests/qapi-schema/nested-struct-data.err
> index e69de29..da767ba 100644
> --- a/tests/qapi-schema/nested-struct-data.err
> +++ b/tests/qapi-schema/nested-struct-data.err
> @@ -0,0 +1 @@
> +tests/qapi-schema/nested-struct-data.json:2: Member 'a' of 'data' for 
> command 'foo' should be a type name
> diff --git a/tests/qapi-schema/nested-struct-data.exit 
> b/tests/qapi-schema/nested-struct-data.exit
> index 573541a..d00491f 100644
> --- a/tests/qapi-schema/nested-struct-data.exit
> +++ b/tests/qapi-schema/nested-struct-data.exit
> @@ -1 +1 @@
> -0
> +1
> diff --git a/tests/qapi-schema/nested-struct-data.json 
> b/tests/qapi-schema/nested-struct-data.json
> index 0247c8c..3d52d2b 100644
> --- a/tests/qapi-schema/nested-struct-data.json
> +++ b/tests/qapi-schema/nested-struct-data.json
> @@ -1,4 +1,4 @@
> -# FIXME: inline subtypes collide with our desired future use of defaults

Seen only now: I'd mark this TODO rather than FIXME in PATCH 19, because
it's not actually broken.  Only if you respin anyway, of course.

> +# inline subtypes collide with our desired future use of defaults
>  { 'command': 'foo',
>    'data': { 'a' : { 'string' : 'str', 'integer': 'int' }, 'b' : 'str' },
>    'returns': {} }
> diff --git a/tests/qapi-schema/nested-struct-data.out 
> b/tests/qapi-schema/nested-struct-data.out
> index 999cbb8..e69de29 100644
> --- a/tests/qapi-schema/nested-struct-data.out
> +++ b/tests/qapi-schema/nested-struct-data.out
> @@ -1,3 +0,0 @@
> -[OrderedDict([('command', 'foo'), ('data', OrderedDict([('a', 
> OrderedDict([('string', 'str'), ('integer', 'int')])), ('b', 'str')])), 
> ('returns', OrderedDict())])]
> -[]
> -[]
> diff --git a/tests/qapi-schema/nested-struct-returns.err 
> b/tests/qapi-schema/nested-struct-returns.err
> index e69de29..5238d07 100644
> --- a/tests/qapi-schema/nested-struct-returns.err
> +++ b/tests/qapi-schema/nested-struct-returns.err
> @@ -0,0 +1 @@
> +tests/qapi-schema/nested-struct-returns.json:2: Member 'a' of 'returns' for 
> command 'foo' should be a type name
> diff --git a/tests/qapi-schema/nested-struct-returns.exit 
> b/tests/qapi-schema/nested-struct-returns.exit
> index 573541a..d00491f 100644
> --- a/tests/qapi-schema/nested-struct-returns.exit
> +++ b/tests/qapi-schema/nested-struct-returns.exit
> @@ -1 +1 @@
> -0
> +1
> diff --git a/tests/qapi-schema/nested-struct-returns.json 
> b/tests/qapi-schema/nested-struct-returns.json
> index 5a46840..d2cd047 100644
> --- a/tests/qapi-schema/nested-struct-returns.json
> +++ b/tests/qapi-schema/nested-struct-returns.json
> @@ -1,3 +1,3 @@
> -# FIXME: inline subtypes collide with our desired future use of defaults
> +# inline subtypes collide with our desired future use of defaults
>  { 'command': 'foo',
>    'returns': { 'a' : { 'string' : 'str', 'integer': 'int' }, 'b' : 'str' } }
> diff --git a/tests/qapi-schema/nested-struct-returns.out 
> b/tests/qapi-schema/nested-struct-returns.out
> index c53d23b..e69de29 100644
> --- a/tests/qapi-schema/nested-struct-returns.out
> +++ b/tests/qapi-schema/nested-struct-returns.out
> @@ -1,3 +0,0 @@
> -[OrderedDict([('command', 'foo'), ('returns', OrderedDict([('a', 
> OrderedDict([('string', 'str'), ('integer', 'int')])), ('b', 'str')]))])]
> -[]
> -[]

Reviewed-by: Markus Armbruster <address@hidden>