"""
QAPI introspection generator
Copyright (C) 2015-2021 Red Hat, Inc.
Authors:
Markus Armbruster <armbru@redhat.com>
John Snow <jsnow@redhat.com>
This work is licensed under the terms of the GNU GPL, version 2.
See the COPYING file in the top-level directory.
"""
from typing import (
Any,
Dict,
Generic,
Iterable,
List,
Optional,
Sequence,
Tuple,
TypeVar,
Union,
)
from .common import (
c_name,
gen_endif,
gen_if,
mcgen,
)
from .gen import QAPISchemaMonolithicCVisitor
from .schema import (
QAPISchema,
QAPISchemaArrayType,
QAPISchemaBuiltinType,
QAPISchemaEntity,
QAPISchemaEnumMember,
QAPISchemaFeature,
QAPISchemaObjectType,
QAPISchemaObjectTypeMember,
QAPISchemaType,
QAPISchemaVariant,
QAPISchemaVariants,
)
from .source import QAPISourceInfo
# This module constructs a tree data structure that is used to
# generate the introspection information for QEMU. It is shaped
# like a JSON value.
#
# A complexity over JSON is that our values may or may not be annotated.
#
# Un-annotated values may be:
# Scalar: str, bool, None.
# Non-scalar: List, Dict
# _value = Union[str, bool, None, Dict[str, JSONValue], List[JSONValue]]
#
# With optional annotations, the type of all values is:
# JSONValue = Union[_Value, Annotated[_Value]]
#
# Sadly, mypy does not support recursive types; so the _Stub alias is used to
# mark the imprecision in the type model where we'd otherwise use JSONValue.
_Stub = Any
_Scalar = Union[str, bool, None]
_NonScalar = Union[Dict[str, _Stub], List[_Stub]]
_Value = Union[_Scalar, _NonScalar]
JSONValue = Union[_Value, 'Annotated[_Value]']
# These types are based on structures defined in QEMU's schema, so we
# lack precise types for them here. Python 3.6 does not offer
# TypedDict constructs, so they are broadly typed here as simple
# Python Dicts.
SchemaInfo = Dict[str, object]
SchemaInfoObject = Dict[str, object]
SchemaInfoObjectVariant = Dict[str, object]
SchemaInfoObjectMember = Dict[str, object]
SchemaInfoCommand = Dict[str, object]
_ValueT = TypeVar('_ValueT', bound=_Value)
class Annotated(Generic[_ValueT]):
"""
Annotated generally contains a SchemaInfo-like type (as a dict),
But it also used to wrap comments/ifconds around scalar leaf values,
for the benefit of features and enums.
"""
# TODO: Remove after Python 3.7 adds @dataclass:
# pylint: disable=too-few-public-methods
def __init__(self, value: _ValueT, ifcond: Iterable[str],
comment: Optional[str] = None):
self.value = value
self.comment: Optional[str] = comment
self.ifcond: Tuple[str, ...] = tuple(ifcond)
def _tree_to_qlit(obj: JSONValue,
level: int = 0,
dict_value: bool = False) -> str:
"""
Convert the type tree into a QLIT C string, recursively.
:param obj: The value to convert.
This value may not be Annotated when dict_value is True.
:param level: The indentation level for this particular value.
:param dict_value: True when the value being processed belongs to a
dict key; which suppresses the output indent.
"""
def indent(level: int) -> str:
return level * 4 * ' '
if isinstance(obj, Annotated):
# NB: _tree_to_qlit is called recursively on the values of a
# key:value pair; those values can't be decorated with
# comments or conditionals.
msg = "dict values cannot have attached comments or if-conditionals."
assert not dict_value, msg
ret = ''
if obj.comment:
ret += indent(level) + f"/* {obj.comment} */\n"
if obj.ifcond:
ret += gen_if(obj.ifcond)
ret += _tree_to_qlit(obj.value, level)
if obj.ifcond:
ret += '\n' + gen_endif(obj.ifcond)
return ret
ret = ''
if not dict_value:
ret += indent(level)
# Scalars:
if obj is None:
ret += 'QLIT_QNULL'
elif isinstance(obj, str):
ret += f"QLIT_QSTR({to_c_string(obj)})"
elif isinstance(obj, bool):
ret += f"QLIT_QBOOL({str(obj).lower()})"
# Non-scalars:
elif isinstance(obj, list):
ret += 'QLIT_QLIST(((QLitObject[]) {\n'
for value in obj:
ret += _tree_to_qlit(value, level + 1).strip('\n') + '\n'
ret += indent(level + 1) + '{}\n'
ret += indent(level) + '}))'
elif isinstance(obj, dict):
ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n'
for key, value in sorted(obj.items()):
ret += indent(level + 1) + "{{ {:s}, {:s} }},\n".format(
to_c_string(key),
_tree_to_qlit(value, level + 1, dict_value=True)
)
ret += indent(level + 1) + '{}\n'
ret += indent(level) + '}))'
else:
raise NotImplementedError(
f"type '{type(obj).__name__}' not implemented"
)
if level > 0:
ret += ','
return ret
def to_c_string(string: str) -> str:
return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
class QAPISchemaGenIntrospectVisitor(QAPISchemaMonolithicCVisitor):
def __init__(self, prefix: str, unmask: bool):
super().__init__(
prefix, 'qapi-introspect',
' * QAPI/QMP schema introspection', __doc__)
self._unmask = unmask
self._schema: Optional[QAPISchema] = None
self._trees: List[Annotated[SchemaInfo]] = []
self._used_types: List[QAPISchemaType] = []
self._name_map: Dict[str, str] = {}
self._genc.add(mcgen('''
#include "qemu/osdep.h"
#include "%(prefix)sqapi-introspect.h"
''',
prefix=prefix))
def visit_begin(self, schema: QAPISchema) -> None:
self._schema = schema
def visit_end(self) -> None:
# visit the types that are actually used
for typ in self._used_types:
typ.visit(self)
# generate C
name = c_name(self._prefix, protect=False) + 'qmp_schema_qlit'
self._genh.add(mcgen('''
#include "qapi/qmp/qlit.h"
extern const QLitObject %(c_name)s;
''',
c_name=c_name(name)))
self._genc.add(mcgen('''
const QLitObject %(c_name)s = %(c_string)s;
''',
c_name=c_name(name),
c_string=_tree_to_qlit(self._trees)))
self._schema = None
self._trees = []
self._used_types = []
self._name_map = {}
def visit_needed(self, entity: QAPISchemaEntity) -> bool:
# Ignore types on first pass; visit_end() will pick up used types
return not isinstance(entity, QAPISchemaType)
def _name(self, name: str) -> str:
if self._unmask:
return name
if name not in self._name_map:
self._name_map[name] = '%d' % len(self._name_map)
return self._name_map[name]
def _use_type(self, typ: QAPISchemaType) -> str:
assert self._schema is not None
# Map the various integer types to plain int
if typ.json_type() == 'int':
typ = self._schema.lookup_type('int')
elif (isinstance(typ, QAPISchemaArrayType) and
typ.element_type.json_type() == 'int'):
typ = self._schema.lookup_type('intList')
# Add type to work queue if new
if typ not in self._used_types:
self._used_types.append(typ)
# Clients should examine commands and events, not types. Hide
# type names as integers to reduce the temptation. Also, it
# saves a few characters on the wire.
if isinstance(typ, QAPISchemaBuiltinType):
return typ.name
if isinstance(typ, QAPISchemaArrayType):
return '[' + self._use_type(typ.element_type) + ']'
return self._name(typ.name)
@staticmethod
def _gen_features(features: Sequence[QAPISchemaFeature]
) -> List[Annotated[str]]:
return [Annotated(f.name, f.ifcond) for f in features]
def _gen_tree(self, name: str, mtype: str, obj: Dict[str, object],
ifcond: Sequence[str] = (),
features: Sequence[QAPISchemaFeature] = ()) -> None:
"""
Build and append a SchemaInfo object to self._trees.
:param name: The SchemaInfo's name.
:param mtype: The SchemaInfo's meta-type.
:param obj: Additional SchemaInfo members, as appropriate for
the meta-type.
:param ifcond: Conditionals to apply to the SchemaInfo.
:param features: The SchemaInfo's features.
Will be omitted from the output if empty.
"""
comment: Optional[str] = None
if mtype not in ('command', 'event', 'builtin', 'array'):
if not self._unmask:
# Output a comment to make it easy to map masked names
# back to the source when reading the generated output.
comment = f'"{self._name(name)}" = {name}'
name = self._name(name)
obj['name'] = name
obj['meta-type'] = mtype
if features:
obj['features'] = self._gen_features(features)
self._trees.append(Annotated(obj, ifcond, comment))
def _gen_member(self, member: QAPISchemaObjectTypeMember
) -> Annotated[SchemaInfoObjectMember]:
obj: SchemaInfoObjectMember = {
'name': member.name,
'type': self._use_type(member.type)
}
if member.optional:
obj['default'] = None
if member.features:
obj['features'] = self._gen_features(member.features)
return Annotated(obj, member.ifcond)
def _gen_variant(self, variant: QAPISchemaVariant
) -> Annotated[SchemaInfoObjectVariant]:
obj: SchemaInfoObjectVariant = {
'case': variant.name,
'type': self._use_type(variant.type)
}
return Annotated(obj, variant.ifcond)
def visit_builtin_type(self, name: str, info: Optional[QAPISourceInfo],
json_type: str) -> None:
self._gen_tree(name, 'builtin', {'json-type': json_type})
def visit_enum_type(self, name: str, info: Optional[QAPISourceInfo],
ifcond: Sequence[str],
features: List[QAPISchemaFeature],
members: List[QAPISchemaEnumMember],
prefix: Optional[str]) -> None:
self._gen_tree(
name, 'enum',
{'values': [Annotated(m.name, m.ifcond) for m in members]},
ifcond, features
)
def visit_array_type(self, name: str, info: Optional[QAPISourceInfo],
ifcond: Sequence[str],
element_type: QAPISchemaType) -> None:
element = self._use_type(element_type)
self._gen_tree('[' + element + ']', 'array', {'element-type': element},
ifcond)
def visit_object_type_flat(self, name: str, info: Optional[QAPISourceInfo],
ifcond: Sequence[str],
features: List[QAPISchemaFeature],
members: List[QAPISchemaObjectTypeMember],
variants: Optional[QAPISchemaVariants]) -> None:
obj: SchemaInfoObject = {
'members': [self._gen_member(m) for m in members]
}
if variants:
obj['tag'] = variants.tag_member.name
obj['variants'] = [self._gen_variant(v) for v in variants.variants]
self._gen_tree(name, 'object', obj, ifcond, features)
def visit_alternate_type(self, name: str, info: Optional[QAPISourceInfo],
ifcond: Sequence[str],
features: List[QAPISchemaFeature],
variants: QAPISchemaVariants) -> None:
self._gen_tree(
name, 'alternate',
{'members': [Annotated({'type': self._use_type(m.type)},
m.ifcond)
for m in variants.variants]},
ifcond, features
)
def visit_command(self, name: str, info: Optional[QAPISourceInfo],
ifcond: Sequence[str],
features: List[QAPISchemaFeature],
arg_type: Optional[QAPISchemaObjectType],
ret_type: Optional[QAPISchemaType], gen: bool,
success_response: bool, boxed: bool, allow_oob: bool,
allow_preconfig: bool, coroutine: bool) -> None:
assert self._schema is not None
arg_type = arg_type or self._schema.the_empty_object_type
ret_type = ret_type or self._schema.the_empty_object_type
obj: SchemaInfoCommand = {
'arg-type': self._use_type(arg_type),
'ret-type': self._use_type(ret_type)
}
if allow_oob:
obj['allow-oob'] = allow_oob
self._gen_tree(name, 'command', obj, ifcond, features)
def visit_event(self, name: str, info: Optional[QAPISourceInfo],
ifcond: Sequence[str], features: List[QAPISchemaFeature],
arg_type: Optional[QAPISchemaObjectType],
boxed: bool) -> None:
assert self._schema is not None
arg_type = arg_type or self._schema.the_empty_object_type
self._gen_tree(name, 'event', {'arg-type': self._use_type(arg_type)},
ifcond, features)
def gen_introspect(schema: QAPISchema, output_dir: str, prefix: str,
opt_unmask: bool) -> None:
vis = QAPISchemaGenIntrospectVisitor(prefix, opt_unmask)
schema.visit(vis)
vis.write(output_dir)
