qemu-patch-raspberry4/scripts/qapi/introspect.py
John Snow 7137a96099 qapi: Prefer explicit relative imports
All of the QAPI include statements are changed to be package-aware, as
explicit relative imports.

A quirk of Python packages is that the name of the package exists only
*outside* of the package. This means that to a module inside of the qapi
folder, there is inherently no such thing as the "qapi" package. The
reason these imports work is because the "qapi" package exists in the
context of the caller -- the execution shim, where sys.path includes a
directory that has a 'qapi' folder in it.

When we write "from qapi import sibling", we are NOT referencing the folder
'qapi', but rather "any package named qapi in sys.path". If you should
so happen to have a 'qapi' package in your path, it will use *that*
package.

When we write "from .sibling import foo", we always reference explicitly
our sibling module; guaranteeing consistency in *where* we are importing
these modules from.

This can be useful when working with virtual environments and packages
in development mode. In development mode, a package is installed as a
series of symlinks that forwards to your same source files. The problem
arises because code quality checkers will follow "import qapi.x" to the
"installed" version instead of the sibling file and -- even though they
are the same file -- they have different module paths, and this causes
cyclic import problems, false positive type mismatch errors, and more.

It can also be useful when dealing with hierarchical packages, e.g. if
we allow qemu.core.qmp, qemu.qapi.parser, etc.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201009161558.107041-6-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-10 11:37:47 +02:00

238 lines
8.3 KiB
Python

"""
QAPI introspection generator
Copyright (C) 2015-2018 Red Hat, Inc.
Authors:
Markus Armbruster <armbru@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 .common import *
from .gen import QAPISchemaMonolithicCVisitor
from .schema import (QAPISchemaArrayType, QAPISchemaBuiltinType,
QAPISchemaType)
def _make_tree(obj, ifcond, features, extra=None):
if extra is None:
extra = {}
if ifcond:
extra['if'] = ifcond
if features:
obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]
if extra:
return (obj, extra)
return obj
def _tree_to_qlit(obj, level=0, suppress_first_indent=False):
def indent(level):
return level * 4 * ' '
if isinstance(obj, tuple):
ifobj, extra = obj
ifcond = extra.get('if')
comment = extra.get('comment')
ret = ''
if comment:
ret += indent(level) + '/* %s */\n' % comment
if ifcond:
ret += gen_if(ifcond)
ret += _tree_to_qlit(ifobj, level)
if ifcond:
ret += '\n' + gen_endif(ifcond)
return ret
ret = ''
if not suppress_first_indent:
ret += indent(level)
if obj is None:
ret += 'QLIT_QNULL'
elif isinstance(obj, str):
ret += 'QLIT_QSTR(' + to_c_string(obj) + ')'
elif isinstance(obj, list):
elts = [_tree_to_qlit(elt, level + 1).strip('\n')
for elt in obj]
elts.append(indent(level + 1) + "{}")
ret += 'QLIT_QLIST(((QLitObject[]) {\n'
ret += '\n'.join(elts) + '\n'
ret += indent(level) + '}))'
elif isinstance(obj, dict):
elts = []
for key, value in sorted(obj.items()):
elts.append(indent(level + 1) + '{ %s, %s }' %
(to_c_string(key),
_tree_to_qlit(value, level + 1, True)))
elts.append(indent(level + 1) + '{}')
ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n'
ret += ',\n'.join(elts) + '\n'
ret += indent(level) + '}))'
elif isinstance(obj, bool):
ret += 'QLIT_QBOOL(%s)' % ('true' if obj else 'false')
else:
assert False # not implemented
if level > 0:
ret += ','
return ret
def to_c_string(string):
return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
class QAPISchemaGenIntrospectVisitor(QAPISchemaMonolithicCVisitor):
def __init__(self, prefix, unmask):
super().__init__(
prefix, 'qapi-introspect',
' * QAPI/QMP schema introspection', __doc__)
self._unmask = unmask
self._schema = None
self._trees = []
self._used_types = []
self._name_map = {}
self._genc.add(mcgen('''
#include "qemu/osdep.h"
#include "%(prefix)sqapi-introspect.h"
''',
prefix=prefix))
def visit_begin(self, schema):
self._schema = schema
def visit_end(self):
# 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):
# Ignore types on first pass; visit_end() will pick up used types
return not isinstance(entity, QAPISchemaType)
def _name(self, name):
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):
# 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)
def _gen_tree(self, name, mtype, obj, ifcond, features):
extra = 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.
extra = {'comment': '"%s" = %s' % (self._name(name), name)}
name = self._name(name)
obj['name'] = name
obj['meta-type'] = mtype
self._trees.append(_make_tree(obj, ifcond, features, extra))
def _gen_member(self, member):
obj = {'name': member.name, 'type': self._use_type(member.type)}
if member.optional:
obj['default'] = None
return _make_tree(obj, member.ifcond, member.features)
def _gen_variants(self, tag_name, variants):
return {'tag': tag_name,
'variants': [self._gen_variant(v) for v in variants]}
def _gen_variant(self, variant):
obj = {'case': variant.name, 'type': self._use_type(variant.type)}
return _make_tree(obj, variant.ifcond, None)
def visit_builtin_type(self, name, info, json_type):
self._gen_tree(name, 'builtin', {'json-type': json_type}, [], None)
def visit_enum_type(self, name, info, ifcond, features, members, prefix):
self._gen_tree(name, 'enum',
{'values': [_make_tree(m.name, m.ifcond, None)
for m in members]},
ifcond, features)
def visit_array_type(self, name, info, ifcond, element_type):
element = self._use_type(element_type)
self._gen_tree('[' + element + ']', 'array', {'element-type': element},
ifcond, None)
def visit_object_type_flat(self, name, info, ifcond, features,
members, variants):
obj = {'members': [self._gen_member(m) for m in members]}
if variants:
obj.update(self._gen_variants(variants.tag_member.name,
variants.variants))
self._gen_tree(name, 'object', obj, ifcond, features)
def visit_alternate_type(self, name, info, ifcond, features, variants):
self._gen_tree(name, 'alternate',
{'members': [
_make_tree({'type': self._use_type(m.type)},
m.ifcond, None)
for m in variants.variants]},
ifcond, features)
def visit_command(self, name, info, ifcond, features,
arg_type, ret_type, gen, success_response, boxed,
allow_oob, allow_preconfig, coroutine):
arg_type = arg_type or self._schema.the_empty_object_type
ret_type = ret_type or self._schema.the_empty_object_type
obj = {'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, info, ifcond, features, arg_type, boxed):
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, output_dir, prefix, opt_unmask):
vis = QAPISchemaGenIntrospectVisitor(prefix, opt_unmask)
schema.visit(vis)
vis.write(output_dir)