xref: /openbmc/qemu/scripts/qapi/types.py (revision fc309207) 
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 typing import List, Optional
17
18from .common import c_enum_const, c_name, mcgen
19from .gen import QAPISchemaModularCVisitor, gen_special_features, ifcontext
20from .schema import (
21    QAPISchema,
22    QAPISchemaEnumMember,
23    QAPISchemaFeature,
24    QAPISchemaIfCond,
25    QAPISchemaObjectType,
26    QAPISchemaObjectTypeMember,
27    QAPISchemaType,
28    QAPISchemaVariants,
29)
30from .source import QAPISourceInfo
31
32
33# variants must be emitted before their container; track what has already
34# been output
35objects_seen = set()
36
37
38def gen_enum_lookup(name: str,
39                    members: List[QAPISchemaEnumMember],
40                    prefix: Optional[str] = None) -> str:
41    max_index = c_enum_const(name, '_MAX', prefix)
42    feats = ''
43    ret = mcgen('''
44
45const QEnumLookup %(c_name)s_lookup = {
46    .array = (const char *const[]) {
47''',
48                c_name=c_name(name))
49    for memb in members:
50        ret += memb.ifcond.gen_if()
51        index = c_enum_const(name, memb.name, prefix)
52        ret += mcgen('''
53        [%(index)s] = "%(name)s",
54''',
55                     index=index, name=memb.name)
56        ret += memb.ifcond.gen_endif()
57
58        special_features = gen_special_features(memb.features)
59        if special_features != '0':
60            feats += mcgen('''
61        [%(index)s] = %(special_features)s,
62''',
63                           index=index, special_features=special_features)
64
65    if feats:
66        ret += mcgen('''
67    },
68    .special_features = (const unsigned char[%(max_index)s]) {
69''',
70                     max_index=max_index)
71        ret += feats
72
73    ret += mcgen('''
74    },
75    .size = %(max_index)s
76};
77''',
78                 max_index=max_index)
79    return ret
80
81
82def gen_enum(name: str,
83             members: List[QAPISchemaEnumMember],
84             prefix: Optional[str] = None) -> str:
85    # append automatically generated _MAX value
86    enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
87
88    ret = mcgen('''
89
90typedef enum %(c_name)s {
91''',
92                c_name=c_name(name))
93
94    for memb in enum_members:
95        ret += memb.ifcond.gen_if()
96        ret += mcgen('''
97    %(c_enum)s,
98''',
99                     c_enum=c_enum_const(name, memb.name, prefix))
100        ret += memb.ifcond.gen_endif()
101
102    ret += mcgen('''
103} %(c_name)s;
104''',
105                 c_name=c_name(name))
106
107    ret += mcgen('''
108
109#define %(c_name)s_str(val) \\
110    qapi_enum_lookup(&%(c_name)s_lookup, (val))
111
112extern const QEnumLookup %(c_name)s_lookup;
113''',
114                 c_name=c_name(name))
115    return ret
116
117
118def gen_fwd_object_or_array(name: str) -> str:
119    return mcgen('''
120
121typedef struct %(c_name)s %(c_name)s;
122''',
123                 c_name=c_name(name))
124
125
126def gen_array(name: str, element_type: QAPISchemaType) -> str:
127    return mcgen('''
128
129struct %(c_name)s {
130    %(c_name)s *next;
131    %(c_type)s value;
132};
133''',
134                 c_name=c_name(name), c_type=element_type.c_type())
135
136
137def gen_struct_members(members: List[QAPISchemaObjectTypeMember]) -> str:
138    ret = ''
139    for memb in members:
140        ret += memb.ifcond.gen_if()
141        if memb.optional:
142            ret += mcgen('''
143    bool has_%(c_name)s;
144''',
145                         c_name=c_name(memb.name))
146        ret += mcgen('''
147    %(c_type)s %(c_name)s;
148''',
149                     c_type=memb.type.c_type(), c_name=c_name(memb.name))
150        ret += memb.ifcond.gen_endif()
151    return ret
152
153
154def gen_object(name: str, ifcond: QAPISchemaIfCond,
155               base: Optional[QAPISchemaObjectType],
156               members: List[QAPISchemaObjectTypeMember],
157               variants: Optional[QAPISchemaVariants]) -> str:
158    if name in objects_seen:
159        return ''
160    objects_seen.add(name)
161
162    ret = ''
163    for var in variants.variants if variants else ():
164        obj = var.type
165        if not isinstance(obj, QAPISchemaObjectType):
166            continue
167        ret += gen_object(obj.name, obj.ifcond, obj.base,
168                          obj.local_members, obj.variants)
169
170    ret += mcgen('''
171
172''')
173    ret += ifcond.gen_if()
174    ret += mcgen('''
175struct %(c_name)s {
176''',
177                 c_name=c_name(name))
178
179    if base:
180        if not base.is_implicit():
181            ret += mcgen('''
182    /* Members inherited from %(c_name)s: */
183''',
184                         c_name=base.c_name())
185        ret += gen_struct_members(base.members)
186        if not base.is_implicit():
187            ret += mcgen('''
188    /* Own members: */
189''')
190    ret += gen_struct_members(members)
191
192    if variants:
193        ret += gen_variants(variants)
194
195    # Make sure that all structs have at least one member; this avoids
196    # potential issues with attempting to malloc space for zero-length
197    # structs in C, and also incompatibility with C++ (where an empty
198    # struct is size 1).
199    if (not base or base.is_empty()) and not members and not variants:
200        ret += mcgen('''
201    char qapi_dummy_for_empty_struct;
202''')
203
204    ret += mcgen('''
205};
206''')
207    ret += ifcond.gen_endif()
208
209    return ret
210
211
212def gen_upcast(name: str, base: QAPISchemaObjectType) -> str:
213    # C makes const-correctness ugly.  We have to cast away const to let
214    # this function work for both const and non-const obj.
215    return mcgen('''
216
217static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
218{
219    return (%(base)s *)obj;
220}
221''',
222                 c_name=c_name(name), base=base.c_name())
223
224
225def gen_variants(variants: QAPISchemaVariants) -> str:
226    ret = mcgen('''
227    union { /* union tag is @%(c_name)s */
228''',
229                c_name=c_name(variants.tag_member.name))
230
231    for var in variants.variants:
232        if var.type.name == 'q_empty':
233            continue
234        ret += var.ifcond.gen_if()
235        ret += mcgen('''
236        %(c_type)s %(c_name)s;
237''',
238                     c_type=var.type.c_unboxed_type(),
239                     c_name=c_name(var.name))
240        ret += var.ifcond.gen_endif()
241
242    ret += mcgen('''
243    } u;
244''')
245
246    return ret
247
248
249def gen_type_cleanup_decl(name: str) -> str:
250    ret = mcgen('''
251
252void qapi_free_%(c_name)s(%(c_name)s *obj);
253G_DEFINE_AUTOPTR_CLEANUP_FUNC(%(c_name)s, qapi_free_%(c_name)s)
254''',
255                c_name=c_name(name))
256    return ret
257
258
259def gen_type_cleanup(name: str) -> str:
260    ret = mcgen('''
261
262void qapi_free_%(c_name)s(%(c_name)s *obj)
263{
264    Visitor *v;
265
266    if (!obj) {
267        return;
268    }
269
270    v = qapi_dealloc_visitor_new();
271    visit_type_%(c_name)s(v, NULL, &obj, NULL);
272    visit_free(v);
273}
274''',
275                c_name=c_name(name))
276    return ret
277
278
279class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
280
281    def __init__(self, prefix: str):
282        super().__init__(
283            prefix, 'qapi-types', ' * Schema-defined QAPI types',
284            ' * Built-in QAPI types', __doc__)
285
286    def _begin_builtin_module(self) -> None:
287        self._genc.preamble_add(mcgen('''
288#include "qemu/osdep.h"
289#include "qapi/dealloc-visitor.h"
290#include "qapi/qapi-builtin-types.h"
291#include "qapi/qapi-builtin-visit.h"
292'''))
293        self._genh.preamble_add(mcgen('''
294#include "qapi/util.h"
295'''))
296
297    def _begin_user_module(self, name: str) -> None:
298        types = self._module_basename('qapi-types', name)
299        visit = self._module_basename('qapi-visit', name)
300        self._genc.preamble_add(mcgen('''
301#include "qemu/osdep.h"
302#include "qapi/dealloc-visitor.h"
303#include "%(types)s.h"
304#include "%(visit)s.h"
305''',
306                                      types=types, visit=visit))
307        self._genh.preamble_add(mcgen('''
308#include "qapi/qapi-builtin-types.h"
309'''))
310
311    def visit_begin(self, schema: QAPISchema) -> None:
312        # gen_object() is recursive, ensure it doesn't visit the empty type
313        objects_seen.add(schema.the_empty_object_type.name)
314
315    def _gen_type_cleanup(self, name: str) -> None:
316        self._genh.add(gen_type_cleanup_decl(name))
317        self._genc.add(gen_type_cleanup(name))
318
319    def visit_enum_type(self,
320                        name: str,
321                        info: Optional[QAPISourceInfo],
322                        ifcond: QAPISchemaIfCond,
323                        features: List[QAPISchemaFeature],
324                        members: List[QAPISchemaEnumMember],
325                        prefix: Optional[str]) -> None:
326        with ifcontext(ifcond, self._genh, self._genc):
327            self._genh.preamble_add(gen_enum(name, members, prefix))
328            self._genc.add(gen_enum_lookup(name, members, prefix))
329
330    def visit_array_type(self,
331                         name: str,
332                         info: Optional[QAPISourceInfo],
333                         ifcond: QAPISchemaIfCond,
334                         element_type: QAPISchemaType) -> None:
335        with ifcontext(ifcond, self._genh, self._genc):
336            self._genh.preamble_add(gen_fwd_object_or_array(name))
337            self._genh.add(gen_array(name, element_type))
338            self._gen_type_cleanup(name)
339
340    def visit_object_type(self,
341                          name: str,
342                          info: Optional[QAPISourceInfo],
343                          ifcond: QAPISchemaIfCond,
344                          features: List[QAPISchemaFeature],
345                          base: Optional[QAPISchemaObjectType],
346                          members: List[QAPISchemaObjectTypeMember],
347                          variants: Optional[QAPISchemaVariants]) -> None:
348        # Nothing to do for the special empty builtin
349        if name == 'q_empty':
350            return
351        with ifcontext(ifcond, self._genh):
352            self._genh.preamble_add(gen_fwd_object_or_array(name))
353        self._genh.add(gen_object(name, ifcond, base, members, variants))
354        with ifcontext(ifcond, self._genh, self._genc):
355            if base and not base.is_implicit():
356                self._genh.add(gen_upcast(name, base))
357            # TODO Worth changing the visitor signature, so we could
358            # directly use rather than repeat type.is_implicit()?
359            if not name.startswith('q_'):
360                # implicit types won't be directly allocated/freed
361                self._gen_type_cleanup(name)
362
363    def visit_alternate_type(self,
364                             name: str,
365                             info: Optional[QAPISourceInfo],
366                             ifcond: QAPISchemaIfCond,
367                             features: List[QAPISchemaFeature],
368                             variants: QAPISchemaVariants) -> None:
369        with ifcontext(ifcond, self._genh):
370            self._genh.preamble_add(gen_fwd_object_or_array(name))
371        self._genh.add(gen_object(name, ifcond, None,
372                                  [variants.tag_member], variants))
373        with ifcontext(ifcond, self._genh, self._genc):
374            self._gen_type_cleanup(name)
375
376
377def gen_types(schema: QAPISchema,
378              output_dir: str,
379              prefix: str,
380              opt_builtins: bool) -> None:
381    vis = QAPISchemaGenTypeVisitor(prefix)
382    schema.visit(vis)
383    vis.write(output_dir, opt_builtins)
384