xref: /openbmc/qemu/scripts/qapi/introspect.py (revision 84cf09915fdaba38a5d5f21baff38e94dd98607f)
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 .common import (
14    c_name,
15    gen_endif,
16    gen_if,
17    mcgen,
18)
19from .gen import QAPISchemaMonolithicCVisitor
20from .schema import (
21    QAPISchemaArrayType,
22    QAPISchemaBuiltinType,
23    QAPISchemaType,
24)
25
26
27def _make_tree(obj, ifcond, extra=None):
28    if extra is None:
29        extra = {}
30    if ifcond:
31        extra['if'] = ifcond
32    return (obj, extra)
33
34
35def _tree_to_qlit(obj, level=0, dict_value=False):
36
37    def indent(level):
38        return level * 4 * ' '
39
40    if isinstance(obj, tuple):
41        ifobj, extra = obj
42        ifcond = extra.get('if')
43        comment = extra.get('comment')
44
45        # NB: _tree_to_qlit is called recursively on the values of a
46        # key:value pair; those values can't be decorated with
47        # comments or conditionals.
48        msg = "dict values cannot have attached comments or if-conditionals."
49        assert not dict_value, msg
50
51        ret = ''
52        if comment:
53            ret += indent(level) + '/* %s */\n' % comment
54        if ifcond:
55            ret += gen_if(ifcond)
56        ret += _tree_to_qlit(ifobj, level)
57        if ifcond:
58            ret += '\n' + gen_endif(ifcond)
59        return ret
60
61    ret = ''
62    if not dict_value:
63        ret += indent(level)
64    if obj is None:
65        ret += 'QLIT_QNULL'
66    elif isinstance(obj, str):
67        ret += 'QLIT_QSTR(' + to_c_string(obj) + ')'
68    elif isinstance(obj, list):
69        elts = [_tree_to_qlit(elt, level + 1).strip('\n')
70                for elt in obj]
71        elts.append(indent(level + 1) + "{}")
72        ret += 'QLIT_QLIST(((QLitObject[]) {\n'
73        ret += '\n'.join(elts) + '\n'
74        ret += indent(level) + '}))'
75    elif isinstance(obj, dict):
76        elts = []
77        for key, value in sorted(obj.items()):
78            elts.append(indent(level + 1) + '{ %s, %s }' %
79                        (to_c_string(key),
80                         _tree_to_qlit(value, level + 1, True)))
81        elts.append(indent(level + 1) + '{}')
82        ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n'
83        ret += ',\n'.join(elts) + '\n'
84        ret += indent(level) + '}))'
85    elif isinstance(obj, bool):
86        ret += 'QLIT_QBOOL(%s)' % ('true' if obj else 'false')
87    else:
88        assert False                # not implemented
89    if level > 0:
90        ret += ','
91    return ret
92
93
94def to_c_string(string):
95    return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
96
97
98class QAPISchemaGenIntrospectVisitor(QAPISchemaMonolithicCVisitor):
99
100    def __init__(self, prefix, unmask):
101        super().__init__(
102            prefix, 'qapi-introspect',
103            ' * QAPI/QMP schema introspection', __doc__)
104        self._unmask = unmask
105        self._schema = None
106        self._trees = []
107        self._used_types = []
108        self._name_map = {}
109        self._genc.add(mcgen('''
110#include "qemu/osdep.h"
111#include "%(prefix)sqapi-introspect.h"
112
113''',
114                             prefix=prefix))
115
116    def visit_begin(self, schema):
117        self._schema = schema
118
119    def visit_end(self):
120        # visit the types that are actually used
121        for typ in self._used_types:
122            typ.visit(self)
123        # generate C
124        name = c_name(self._prefix, protect=False) + 'qmp_schema_qlit'
125        self._genh.add(mcgen('''
126#include "qapi/qmp/qlit.h"
127
128extern const QLitObject %(c_name)s;
129''',
130                             c_name=c_name(name)))
131        self._genc.add(mcgen('''
132const QLitObject %(c_name)s = %(c_string)s;
133''',
134                             c_name=c_name(name),
135                             c_string=_tree_to_qlit(self._trees)))
136        self._schema = None
137        self._trees = []
138        self._used_types = []
139        self._name_map = {}
140
141    def visit_needed(self, entity):
142        # Ignore types on first pass; visit_end() will pick up used types
143        return not isinstance(entity, QAPISchemaType)
144
145    def _name(self, name):
146        if self._unmask:
147            return name
148        if name not in self._name_map:
149            self._name_map[name] = '%d' % len(self._name_map)
150        return self._name_map[name]
151
152    def _use_type(self, typ):
153        assert self._schema is not None
154
155        # Map the various integer types to plain int
156        if typ.json_type() == 'int':
157            typ = self._schema.lookup_type('int')
158        elif (isinstance(typ, QAPISchemaArrayType) and
159              typ.element_type.json_type() == 'int'):
160            typ = self._schema.lookup_type('intList')
161        # Add type to work queue if new
162        if typ not in self._used_types:
163            self._used_types.append(typ)
164        # Clients should examine commands and events, not types.  Hide
165        # type names as integers to reduce the temptation.  Also, it
166        # saves a few characters on the wire.
167        if isinstance(typ, QAPISchemaBuiltinType):
168            return typ.name
169        if isinstance(typ, QAPISchemaArrayType):
170            return '[' + self._use_type(typ.element_type) + ']'
171        return self._name(typ.name)
172
173    @staticmethod
174    def _gen_features(features):
175        return [_make_tree(f.name, f.ifcond) for f in features]
176
177    def _gen_tree(self, name, mtype, obj, ifcond, features):
178        extra = None
179        if mtype not in ('command', 'event', 'builtin', 'array'):
180            if not self._unmask:
181                # Output a comment to make it easy to map masked names
182                # back to the source when reading the generated output.
183                extra = {'comment': '"%s" = %s' % (self._name(name), name)}
184            name = self._name(name)
185        obj['name'] = name
186        obj['meta-type'] = mtype
187        if features:
188            obj['features'] = self._gen_features(features)
189        self._trees.append(_make_tree(obj, ifcond, extra))
190
191    def _gen_member(self, member):
192        obj = {'name': member.name, 'type': self._use_type(member.type)}
193        if member.optional:
194            obj['default'] = None
195        if member.features:
196            obj['features'] = self._gen_features(member.features)
197        return _make_tree(obj, member.ifcond)
198
199    def _gen_variants(self, tag_name, variants):
200        return {'tag': tag_name,
201                'variants': [self._gen_variant(v) for v in variants]}
202
203    def _gen_variant(self, variant):
204        obj = {'case': variant.name, 'type': self._use_type(variant.type)}
205        return _make_tree(obj, variant.ifcond)
206
207    def visit_builtin_type(self, name, info, json_type):
208        self._gen_tree(name, 'builtin', {'json-type': json_type}, [], None)
209
210    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
211        self._gen_tree(name, 'enum',
212                       {'values': [_make_tree(m.name, m.ifcond, None)
213                                   for m in members]},
214                       ifcond, features)
215
216    def visit_array_type(self, name, info, ifcond, element_type):
217        element = self._use_type(element_type)
218        self._gen_tree('[' + element + ']', 'array', {'element-type': element},
219                       ifcond, None)
220
221    def visit_object_type_flat(self, name, info, ifcond, features,
222                               members, variants):
223        obj = {'members': [self._gen_member(m) for m in members]}
224        if variants:
225            obj.update(self._gen_variants(variants.tag_member.name,
226                                          variants.variants))
227
228        self._gen_tree(name, 'object', obj, ifcond, features)
229
230    def visit_alternate_type(self, name, info, ifcond, features, variants):
231        self._gen_tree(name, 'alternate',
232                       {'members': [
233                           _make_tree({'type': self._use_type(m.type)},
234                                      m.ifcond, None)
235                           for m in variants.variants]},
236                       ifcond, features)
237
238    def visit_command(self, name, info, ifcond, features,
239                      arg_type, ret_type, gen, success_response, boxed,
240                      allow_oob, allow_preconfig, coroutine):
241        assert self._schema is not None
242
243        arg_type = arg_type or self._schema.the_empty_object_type
244        ret_type = ret_type or self._schema.the_empty_object_type
245        obj = {'arg-type': self._use_type(arg_type),
246               'ret-type': self._use_type(ret_type)}
247        if allow_oob:
248            obj['allow-oob'] = allow_oob
249        self._gen_tree(name, 'command', obj, ifcond, features)
250
251    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
252        assert self._schema is not None
253        arg_type = arg_type or self._schema.the_empty_object_type
254        self._gen_tree(name, 'event', {'arg-type': self._use_type(arg_type)},
255                       ifcond, features)
256
257
258def gen_introspect(schema, output_dir, prefix, opt_unmask):
259    vis = QAPISchemaGenIntrospectVisitor(prefix, opt_unmask)
260    schema.visit(vis)
261    vis.write(output_dir)
262