xref: /openbmc/qemu/scripts/qapi/introspect.py (revision d4c5b429fd18d30f2e23aef6e944fe40f2319024)
1"""
2QAPI introspection generator
3
4Copyright (C) 2015-2018 Red Hat, Inc.
5
6Authors:
7 Markus Armbruster <armbru@redhat.com>
8
9This work is licensed under the terms of the GNU GPL, version 2.
10See the COPYING file in the top-level directory.
11"""
12
13from typing import Optional
14
15from .common import (
16    c_name,
17    gen_endif,
18    gen_if,
19    mcgen,
20)
21from .gen import QAPISchemaMonolithicCVisitor
22from .schema import (
23    QAPISchemaArrayType,
24    QAPISchemaBuiltinType,
25    QAPISchemaType,
26)
27
28
29def _make_tree(obj, ifcond, comment=None):
30    extra = {
31        'if': ifcond,
32        'comment': comment
33    }
34    return (obj, extra)
35
36
37def _tree_to_qlit(obj, level=0, dict_value=False):
38
39    def indent(level):
40        return level * 4 * ' '
41
42    if isinstance(obj, tuple):
43        ifobj, extra = obj
44        ifcond = extra.get('if')
45        comment = extra.get('comment')
46
47        # NB: _tree_to_qlit is called recursively on the values of a
48        # key:value pair; those values can't be decorated with
49        # comments or conditionals.
50        msg = "dict values cannot have attached comments or if-conditionals."
51        assert not dict_value, msg
52
53        ret = ''
54        if comment:
55            ret += indent(level) + '/* %s */\n' % comment
56        if ifcond:
57            ret += gen_if(ifcond)
58        ret += _tree_to_qlit(ifobj, level)
59        if ifcond:
60            ret += '\n' + gen_endif(ifcond)
61        return ret
62
63    ret = ''
64    if not dict_value:
65        ret += indent(level)
66    if obj is None:
67        ret += 'QLIT_QNULL'
68    elif isinstance(obj, str):
69        ret += 'QLIT_QSTR(' + to_c_string(obj) + ')'
70    elif isinstance(obj, list):
71        elts = [_tree_to_qlit(elt, level + 1).strip('\n')
72                for elt in obj]
73        elts.append(indent(level + 1) + "{}")
74        ret += 'QLIT_QLIST(((QLitObject[]) {\n'
75        ret += '\n'.join(elts) + '\n'
76        ret += indent(level) + '}))'
77    elif isinstance(obj, dict):
78        elts = []
79        for key, value in sorted(obj.items()):
80            elts.append(indent(level + 1) + '{ %s, %s }' %
81                        (to_c_string(key),
82                         _tree_to_qlit(value, level + 1, True)))
83        elts.append(indent(level + 1) + '{}')
84        ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n'
85        ret += ',\n'.join(elts) + '\n'
86        ret += indent(level) + '}))'
87    elif isinstance(obj, bool):
88        ret += 'QLIT_QBOOL(%s)' % ('true' if obj else 'false')
89    else:
90        assert False                # not implemented
91    if level > 0:
92        ret += ','
93    return ret
94
95
96def to_c_string(string):
97    return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
98
99
100class QAPISchemaGenIntrospectVisitor(QAPISchemaMonolithicCVisitor):
101
102    def __init__(self, prefix, unmask):
103        super().__init__(
104            prefix, 'qapi-introspect',
105            ' * QAPI/QMP schema introspection', __doc__)
106        self._unmask = unmask
107        self._schema = None
108        self._trees = []
109        self._used_types = []
110        self._name_map = {}
111        self._genc.add(mcgen('''
112#include "qemu/osdep.h"
113#include "%(prefix)sqapi-introspect.h"
114
115''',
116                             prefix=prefix))
117
118    def visit_begin(self, schema):
119        self._schema = schema
120
121    def visit_end(self):
122        # visit the types that are actually used
123        for typ in self._used_types:
124            typ.visit(self)
125        # generate C
126        name = c_name(self._prefix, protect=False) + 'qmp_schema_qlit'
127        self._genh.add(mcgen('''
128#include "qapi/qmp/qlit.h"
129
130extern const QLitObject %(c_name)s;
131''',
132                             c_name=c_name(name)))
133        self._genc.add(mcgen('''
134const QLitObject %(c_name)s = %(c_string)s;
135''',
136                             c_name=c_name(name),
137                             c_string=_tree_to_qlit(self._trees)))
138        self._schema = None
139        self._trees = []
140        self._used_types = []
141        self._name_map = {}
142
143    def visit_needed(self, entity):
144        # Ignore types on first pass; visit_end() will pick up used types
145        return not isinstance(entity, QAPISchemaType)
146
147    def _name(self, name):
148        if self._unmask:
149            return name
150        if name not in self._name_map:
151            self._name_map[name] = '%d' % len(self._name_map)
152        return self._name_map[name]
153
154    def _use_type(self, typ):
155        assert self._schema is not None
156
157        # Map the various integer types to plain int
158        if typ.json_type() == 'int':
159            typ = self._schema.lookup_type('int')
160        elif (isinstance(typ, QAPISchemaArrayType) and
161              typ.element_type.json_type() == 'int'):
162            typ = self._schema.lookup_type('intList')
163        # Add type to work queue if new
164        if typ not in self._used_types:
165            self._used_types.append(typ)
166        # Clients should examine commands and events, not types.  Hide
167        # type names as integers to reduce the temptation.  Also, it
168        # saves a few characters on the wire.
169        if isinstance(typ, QAPISchemaBuiltinType):
170            return typ.name
171        if isinstance(typ, QAPISchemaArrayType):
172            return '[' + self._use_type(typ.element_type) + ']'
173        return self._name(typ.name)
174
175    @staticmethod
176    def _gen_features(features):
177        return [_make_tree(f.name, f.ifcond) for f in features]
178
179    def _gen_tree(self, name, mtype, obj, ifcond, features):
180        comment: Optional[str] = None
181        if mtype not in ('command', 'event', 'builtin', 'array'):
182            if not self._unmask:
183                # Output a comment to make it easy to map masked names
184                # back to the source when reading the generated output.
185                comment = f'"{self._name(name)}" = {name}'
186            name = self._name(name)
187        obj['name'] = name
188        obj['meta-type'] = mtype
189        if features:
190            obj['features'] = self._gen_features(features)
191        self._trees.append(_make_tree(obj, ifcond, comment))
192
193    def _gen_member(self, member):
194        obj = {'name': member.name, 'type': self._use_type(member.type)}
195        if member.optional:
196            obj['default'] = None
197        if member.features:
198            obj['features'] = self._gen_features(member.features)
199        return _make_tree(obj, member.ifcond)
200
201    def _gen_variants(self, tag_name, variants):
202        return {'tag': tag_name,
203                'variants': [self._gen_variant(v) for v in variants]}
204
205    def _gen_variant(self, variant):
206        obj = {'case': variant.name, 'type': self._use_type(variant.type)}
207        return _make_tree(obj, variant.ifcond)
208
209    def visit_builtin_type(self, name, info, json_type):
210        self._gen_tree(name, 'builtin', {'json-type': json_type}, [], None)
211
212    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
213        self._gen_tree(name, 'enum',
214                       {'values': [_make_tree(m.name, m.ifcond, None)
215                                   for m in members]},
216                       ifcond, features)
217
218    def visit_array_type(self, name, info, ifcond, element_type):
219        element = self._use_type(element_type)
220        self._gen_tree('[' + element + ']', 'array', {'element-type': element},
221                       ifcond, None)
222
223    def visit_object_type_flat(self, name, info, ifcond, features,
224                               members, variants):
225        obj = {'members': [self._gen_member(m) for m in members]}
226        if variants:
227            obj.update(self._gen_variants(variants.tag_member.name,
228                                          variants.variants))
229
230        self._gen_tree(name, 'object', obj, ifcond, features)
231
232    def visit_alternate_type(self, name, info, ifcond, features, variants):
233        self._gen_tree(name, 'alternate',
234                       {'members': [
235                           _make_tree({'type': self._use_type(m.type)},
236                                      m.ifcond, None)
237                           for m in variants.variants]},
238                       ifcond, features)
239
240    def visit_command(self, name, info, ifcond, features,
241                      arg_type, ret_type, gen, success_response, boxed,
242                      allow_oob, allow_preconfig, coroutine):
243        assert self._schema is not None
244
245        arg_type = arg_type or self._schema.the_empty_object_type
246        ret_type = ret_type or self._schema.the_empty_object_type
247        obj = {'arg-type': self._use_type(arg_type),
248               'ret-type': self._use_type(ret_type)}
249        if allow_oob:
250            obj['allow-oob'] = allow_oob
251        self._gen_tree(name, 'command', obj, ifcond, features)
252
253    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
254        assert self._schema is not None
255        arg_type = arg_type or self._schema.the_empty_object_type
256        self._gen_tree(name, 'event', {'arg-type': self._use_type(arg_type)},
257                       ifcond, features)
258
259
260def gen_introspect(schema, output_dir, prefix, opt_unmask):
261    vis = QAPISchemaGenIntrospectVisitor(prefix, opt_unmask)
262    schema.visit(vis)
263    vis.write(output_dir)
264