xref: /openbmc/qemu/scripts/qapi/introspect.py (revision fb0bc835e56b894cbc7236294921e5393c786ad8)
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 qapi.common import *
14
15
16# Caveman's json.dumps() replacement (we're stuck at Python 2.4)
17# TODO try to use json.dumps() once we get unstuck
18def to_json(obj, level=0):
19    if obj is None:
20        ret = 'null'
21    elif isinstance(obj, str):
22        ret = '"' + obj.replace('"', r'\"') + '"'
23    elif isinstance(obj, list):
24        elts = [to_json(elt, level + 1)
25                for elt in obj]
26        ret = '[' + ', '.join(elts) + ']'
27    elif isinstance(obj, dict):
28        elts = ['"%s": %s' % (key.replace('"', r'\"'),
29                              to_json(obj[key], level + 1))
30                for key in sorted(obj.keys())]
31        ret = '{' + ', '.join(elts) + '}'
32    else:
33        assert False                # not implemented
34    if level == 1:
35        ret = '\n' + ret
36    return ret
37
38
39def to_c_string(string):
40    return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
41
42
43class QAPISchemaGenIntrospectVisitor(QAPISchemaVisitor):
44    def __init__(self, prefix, unmask):
45        self._prefix = prefix
46        self._unmask = unmask
47        self.defn = None
48        self.decl = None
49        self._schema = None
50        self._jsons = None
51        self._used_types = None
52        self._name_map = None
53
54    def visit_begin(self, schema):
55        self._schema = schema
56        self._jsons = []
57        self._used_types = []
58        self._name_map = {}
59
60    def visit_end(self):
61        # visit the types that are actually used
62        jsons = self._jsons
63        self._jsons = []
64        for typ in self._used_types:
65            typ.visit(self)
66        # generate C
67        # TODO can generate awfully long lines
68        jsons.extend(self._jsons)
69        name = c_name(self._prefix, protect=False) + 'qmp_schema_json'
70        self.decl = mcgen('''
71extern const char %(c_name)s[];
72''',
73                          c_name=c_name(name))
74        lines = to_json(jsons).split('\n')
75        c_string = '\n    '.join([to_c_string(line) for line in lines])
76        self.defn = mcgen('''
77const char %(c_name)s[] = %(c_string)s;
78''',
79                          c_name=c_name(name),
80                          c_string=c_string)
81        self._schema = None
82        self._jsons = None
83        self._used_types = None
84        self._name_map = None
85
86    def visit_needed(self, entity):
87        # Ignore types on first pass; visit_end() will pick up used types
88        return not isinstance(entity, QAPISchemaType)
89
90    def _name(self, name):
91        if self._unmask:
92            return name
93        if name not in self._name_map:
94            self._name_map[name] = '%d' % len(self._name_map)
95        return self._name_map[name]
96
97    def _use_type(self, typ):
98        # Map the various integer types to plain int
99        if typ.json_type() == 'int':
100            typ = self._schema.lookup_type('int')
101        elif (isinstance(typ, QAPISchemaArrayType) and
102              typ.element_type.json_type() == 'int'):
103            typ = self._schema.lookup_type('intList')
104        # Add type to work queue if new
105        if typ not in self._used_types:
106            self._used_types.append(typ)
107        # Clients should examine commands and events, not types.  Hide
108        # type names to reduce the temptation.  Also saves a few
109        # characters.
110        if isinstance(typ, QAPISchemaBuiltinType):
111            return typ.name
112        if isinstance(typ, QAPISchemaArrayType):
113            return '[' + self._use_type(typ.element_type) + ']'
114        return self._name(typ.name)
115
116    def _gen_json(self, name, mtype, obj):
117        if mtype not in ('command', 'event', 'builtin', 'array'):
118            name = self._name(name)
119        obj['name'] = name
120        obj['meta-type'] = mtype
121        self._jsons.append(obj)
122
123    def _gen_member(self, member):
124        ret = {'name': member.name, 'type': self._use_type(member.type)}
125        if member.optional:
126            ret['default'] = None
127        return ret
128
129    def _gen_variants(self, tag_name, variants):
130        return {'tag': tag_name,
131                'variants': [self._gen_variant(v) for v in variants]}
132
133    def _gen_variant(self, variant):
134        return {'case': variant.name, 'type': self._use_type(variant.type)}
135
136    def visit_builtin_type(self, name, info, json_type):
137        self._gen_json(name, 'builtin', {'json-type': json_type})
138
139    def visit_enum_type(self, name, info, values, prefix):
140        self._gen_json(name, 'enum', {'values': values})
141
142    def visit_array_type(self, name, info, element_type):
143        element = self._use_type(element_type)
144        self._gen_json('[' + element + ']', 'array', {'element-type': element})
145
146    def visit_object_type_flat(self, name, info, members, variants):
147        obj = {'members': [self._gen_member(m) for m in members]}
148        if variants:
149            obj.update(self._gen_variants(variants.tag_member.name,
150                                          variants.variants))
151        self._gen_json(name, 'object', obj)
152
153    def visit_alternate_type(self, name, info, variants):
154        self._gen_json(name, 'alternate',
155                       {'members': [{'type': self._use_type(m.type)}
156                                    for m in variants.variants]})
157
158    def visit_command(self, name, info, arg_type, ret_type,
159                      gen, success_response, boxed):
160        arg_type = arg_type or self._schema.the_empty_object_type
161        ret_type = ret_type or self._schema.the_empty_object_type
162        self._gen_json(name, 'command',
163                       {'arg-type': self._use_type(arg_type),
164                        'ret-type': self._use_type(ret_type)})
165
166    def visit_event(self, name, info, arg_type, boxed):
167        arg_type = arg_type or self._schema.the_empty_object_type
168        self._gen_json(name, 'event', {'arg-type': self._use_type(arg_type)})
169
170
171def gen_introspect(schema, output_dir, prefix, opt_unmask):
172    blurb = ' * QAPI/QMP schema introspection'
173    genc = QAPIGenC(blurb, __doc__)
174    genh = QAPIGenH(blurb, __doc__)
175
176    genc.add(mcgen('''
177#include "qemu/osdep.h"
178#include "%(prefix)sqmp-introspect.h"
179
180''',
181                   prefix=prefix))
182
183    vis = QAPISchemaGenIntrospectVisitor(prefix, opt_unmask)
184    schema.visit(vis)
185    genc.add(vis.defn)
186    genh.add(vis.decl)
187    genc.write(output_dir, prefix + 'qmp-introspect.c')
188    genh.write(output_dir, prefix + 'qmp-introspect.h')
189