xref: /qemu/scripts/qapi/types.py (revision 9277d81f) 
1"""
2QAPI types generator
3
4Copyright IBM, Corp. 2011
5Copyright (c) 2013-2018 Red Hat Inc.
6
7Authors:
8 Anthony Liguori <aliguori@us.ibm.com>
9 Michael Roth <mdroth@linux.vnet.ibm.com>
10 Markus Armbruster <armbru@redhat.com>
11
12This work is licensed under the terms of the GNU GPL, version 2.
13# See the COPYING file in the top-level directory.
14"""
15
16from qapi.common import *
17
18
19# variants must be emitted before their container; track what has already
20# been output
21objects_seen = set()
22
23
24def gen_fwd_object_or_array(name):
25    return mcgen('''
26
27typedef struct %(c_name)s %(c_name)s;
28''',
29                 c_name=c_name(name))
30
31
32def gen_array(name, element_type):
33    return mcgen('''
34
35struct %(c_name)s {
36    %(c_name)s *next;
37    %(c_type)s value;
38};
39''',
40                 c_name=c_name(name), c_type=element_type.c_type())
41
42
43def gen_struct_members(members):
44    ret = ''
45    for memb in members:
46        if memb.optional:
47            ret += mcgen('''
48    bool has_%(c_name)s;
49''',
50                         c_name=c_name(memb.name))
51        ret += mcgen('''
52    %(c_type)s %(c_name)s;
53''',
54                     c_type=memb.type.c_type(), c_name=c_name(memb.name))
55    return ret
56
57
58def gen_object(name, ifcond, base, members, variants):
59    if name in objects_seen:
60        return ''
61    objects_seen.add(name)
62
63    ret = ''
64    if variants:
65        for v in variants.variants:
66            if isinstance(v.type, QAPISchemaObjectType):
67                ret += gen_object(v.type.name, v.type.ifcond, v.type.base,
68                                  v.type.local_members, v.type.variants)
69
70    ret += mcgen('''
71
72''')
73    ret += gen_if(ifcond)
74    ret += mcgen('''
75struct %(c_name)s {
76''',
77                 c_name=c_name(name))
78
79    if base:
80        if not base.is_implicit():
81            ret += mcgen('''
82    /* Members inherited from %(c_name)s: */
83''',
84                         c_name=base.c_name())
85        ret += gen_struct_members(base.members)
86        if not base.is_implicit():
87            ret += mcgen('''
88    /* Own members: */
89''')
90    ret += gen_struct_members(members)
91
92    if variants:
93        ret += gen_variants(variants)
94
95    # Make sure that all structs have at least one member; this avoids
96    # potential issues with attempting to malloc space for zero-length
97    # structs in C, and also incompatibility with C++ (where an empty
98    # struct is size 1).
99    if (not base or base.is_empty()) and not members and not variants:
100        ret += mcgen('''
101    char qapi_dummy_for_empty_struct;
102''')
103
104    ret += mcgen('''
105};
106''')
107    ret += gen_endif(ifcond)
108
109    return ret
110
111
112def gen_upcast(name, base):
113    # C makes const-correctness ugly.  We have to cast away const to let
114    # this function work for both const and non-const obj.
115    return mcgen('''
116
117static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
118{
119    return (%(base)s *)obj;
120}
121''',
122                 c_name=c_name(name), base=base.c_name())
123
124
125def gen_variants(variants):
126    ret = mcgen('''
127    union { /* union tag is @%(c_name)s */
128''',
129                c_name=c_name(variants.tag_member.name))
130
131    for var in variants.variants:
132        if var.type.name == 'q_empty':
133            continue
134        ret += mcgen('''
135        %(c_type)s %(c_name)s;
136''',
137                     c_type=var.type.c_unboxed_type(),
138                     c_name=c_name(var.name))
139
140    ret += mcgen('''
141    } u;
142''')
143
144    return ret
145
146
147def gen_type_cleanup_decl(name):
148    ret = mcgen('''
149
150void qapi_free_%(c_name)s(%(c_name)s *obj);
151''',
152                c_name=c_name(name))
153    return ret
154
155
156def gen_type_cleanup(name):
157    ret = mcgen('''
158
159void qapi_free_%(c_name)s(%(c_name)s *obj)
160{
161    Visitor *v;
162
163    if (!obj) {
164        return;
165    }
166
167    v = qapi_dealloc_visitor_new();
168    visit_type_%(c_name)s(v, NULL, &obj, NULL);
169    visit_free(v);
170}
171''',
172                c_name=c_name(name))
173    return ret
174
175
176class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
177
178    def __init__(self, prefix):
179        QAPISchemaModularCVisitor.__init__(
180            self, prefix, 'qapi-types', ' * Schema-defined QAPI types',
181            __doc__)
182        self._add_module(None, ' * Built-in QAPI types')
183        self._genc.preamble_add(mcgen('''
184#include "qemu/osdep.h"
185#include "qapi/dealloc-visitor.h"
186#include "qapi/qapi-builtin-types.h"
187#include "qapi/qapi-builtin-visit.h"
188'''))
189        self._genh.preamble_add(mcgen('''
190#include "qapi/util.h"
191'''))
192
193    def _begin_module(self, name):
194        types = self._module_basename('qapi-types', name)
195        visit = self._module_basename('qapi-visit', name)
196        self._genc.preamble_add(mcgen('''
197#include "qemu/osdep.h"
198#include "qapi/dealloc-visitor.h"
199#include "%(types)s.h"
200#include "%(visit)s.h"
201''',
202                                      types=types, visit=visit))
203        self._genh.preamble_add(mcgen('''
204#include "qapi/qapi-builtin-types.h"
205'''))
206
207    def visit_begin(self, schema):
208        # gen_object() is recursive, ensure it doesn't visit the empty type
209        objects_seen.add(schema.the_empty_object_type.name)
210
211    def _gen_type_cleanup(self, name):
212        self._genh.add(gen_type_cleanup_decl(name))
213        self._genc.add(gen_type_cleanup(name))
214
215    def visit_enum_type(self, name, info, ifcond, values, prefix):
216        with ifcontext(ifcond, self._genh, self._genc):
217            self._genh.preamble_add(gen_enum(name, values, prefix))
218            self._genc.add(gen_enum_lookup(name, values, prefix))
219
220    def visit_array_type(self, name, info, ifcond, element_type):
221        with ifcontext(ifcond, self._genh, self._genc):
222            self._genh.preamble_add(gen_fwd_object_or_array(name))
223            self._genh.add(gen_array(name, element_type))
224            self._gen_type_cleanup(name)
225
226    def visit_object_type(self, name, info, ifcond, base, members, variants):
227        # Nothing to do for the special empty builtin
228        if name == 'q_empty':
229            return
230        with ifcontext(ifcond, self._genh):
231            self._genh.preamble_add(gen_fwd_object_or_array(name))
232        self._genh.add(gen_object(name, ifcond, base, members, variants))
233        with ifcontext(ifcond, self._genh, self._genc):
234            if base and not base.is_implicit():
235                self._genh.add(gen_upcast(name, base))
236            # TODO Worth changing the visitor signature, so we could
237            # directly use rather than repeat type.is_implicit()?
238            if not name.startswith('q_'):
239                # implicit types won't be directly allocated/freed
240                self._gen_type_cleanup(name)
241
242    def visit_alternate_type(self, name, info, ifcond, variants):
243        with ifcontext(ifcond, self._genh):
244            self._genh.preamble_add(gen_fwd_object_or_array(name))
245        self._genh.add(gen_object(name, ifcond, None,
246                                  [variants.tag_member], variants))
247        with ifcontext(ifcond, self._genh, self._genc):
248            self._gen_type_cleanup(name)
249
250
251def gen_types(schema, output_dir, prefix, opt_builtins):
252    vis = QAPISchemaGenTypeVisitor(prefix)
253    schema.visit(vis)
254    vis.write(output_dir, opt_builtins)
255