xref: /openbmc/qemu/scripts/qapi/types.py (revision c2387413) 
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, Sequence
17
18from .common import (
19    c_enum_const,
20    c_name,
21    gen_endif,
22    gen_if,
23    mcgen,
24)
25from .gen import QAPISchemaModularCVisitor, ifcontext
26from .schema import (
27    QAPISchema,
28    QAPISchemaEnumMember,
29    QAPISchemaFeature,
30    QAPISchemaObjectType,
31    QAPISchemaObjectTypeMember,
32    QAPISchemaType,
33    QAPISchemaVariants,
34)
35from .source import QAPISourceInfo
36
37
38# variants must be emitted before their container; track what has already
39# been output
40objects_seen = set()
41
42
43def gen_enum_lookup(name: str,
44                    members: List[QAPISchemaEnumMember],
45                    prefix: Optional[str] = None) -> str:
46    ret = mcgen('''
47
48const QEnumLookup %(c_name)s_lookup = {
49    .array = (const char *const[]) {
50''',
51                c_name=c_name(name))
52    for memb in members:
53        ret += gen_if(memb.ifcond)
54        index = c_enum_const(name, memb.name, prefix)
55        ret += mcgen('''
56        [%(index)s] = "%(name)s",
57''',
58                     index=index, name=memb.name)
59        ret += gen_endif(memb.ifcond)
60
61    ret += mcgen('''
62    },
63    .size = %(max_index)s
64};
65''',
66                 max_index=c_enum_const(name, '_MAX', prefix))
67    return ret
68
69
70def gen_enum(name: str,
71             members: List[QAPISchemaEnumMember],
72             prefix: Optional[str] = None) -> str:
73    # append automatically generated _MAX value
74    enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
75
76    ret = mcgen('''
77
78typedef enum %(c_name)s {
79''',
80                c_name=c_name(name))
81
82    for memb in enum_members:
83        ret += gen_if(memb.ifcond)
84        ret += mcgen('''
85    %(c_enum)s,
86''',
87                     c_enum=c_enum_const(name, memb.name, prefix))
88        ret += gen_endif(memb.ifcond)
89
90    ret += mcgen('''
91} %(c_name)s;
92''',
93                 c_name=c_name(name))
94
95    ret += mcgen('''
96
97#define %(c_name)s_str(val) \\
98    qapi_enum_lookup(&%(c_name)s_lookup, (val))
99
100extern const QEnumLookup %(c_name)s_lookup;
101''',
102                 c_name=c_name(name))
103    return ret
104
105
106def gen_fwd_object_or_array(name: str) -> str:
107    return mcgen('''
108
109typedef struct %(c_name)s %(c_name)s;
110''',
111                 c_name=c_name(name))
112
113
114def gen_array(name: str, element_type: QAPISchemaType) -> str:
115    return mcgen('''
116
117struct %(c_name)s {
118    %(c_name)s *next;
119    %(c_type)s value;
120};
121''',
122                 c_name=c_name(name), c_type=element_type.c_type())
123
124
125def gen_struct_members(members: List[QAPISchemaObjectTypeMember]) -> str:
126    ret = ''
127    for memb in members:
128        ret += gen_if(memb.ifcond)
129        if memb.optional:
130            ret += mcgen('''
131    bool has_%(c_name)s;
132''',
133                         c_name=c_name(memb.name))
134        ret += mcgen('''
135    %(c_type)s %(c_name)s;
136''',
137                     c_type=memb.type.c_type(), c_name=c_name(memb.name))
138        ret += gen_endif(memb.ifcond)
139    return ret
140
141
142def gen_object(name: str, ifcond: Sequence[str],
143               base: Optional[QAPISchemaObjectType],
144               members: List[QAPISchemaObjectTypeMember],
145               variants: Optional[QAPISchemaVariants]) -> str:
146    if name in objects_seen:
147        return ''
148    objects_seen.add(name)
149
150    ret = ''
151    for var in variants.variants if variants else ():
152        obj = var.type
153        if not isinstance(obj, QAPISchemaObjectType):
154            continue
155        ret += gen_object(obj.name, obj.ifcond, obj.base,
156                          obj.local_members, obj.variants)
157
158    ret += mcgen('''
159
160''')
161    ret += gen_if(ifcond)
162    ret += mcgen('''
163struct %(c_name)s {
164''',
165                 c_name=c_name(name))
166
167    if base:
168        if not base.is_implicit():
169            ret += mcgen('''
170    /* Members inherited from %(c_name)s: */
171''',
172                         c_name=base.c_name())
173        ret += gen_struct_members(base.members)
174        if not base.is_implicit():
175            ret += mcgen('''
176    /* Own members: */
177''')
178    ret += gen_struct_members(members)
179
180    if variants:
181        ret += gen_variants(variants)
182
183    # Make sure that all structs have at least one member; this avoids
184    # potential issues with attempting to malloc space for zero-length
185    # structs in C, and also incompatibility with C++ (where an empty
186    # struct is size 1).
187    if (not base or base.is_empty()) and not members and not variants:
188        ret += mcgen('''
189    char qapi_dummy_for_empty_struct;
190''')
191
192    ret += mcgen('''
193};
194''')
195    ret += gen_endif(ifcond)
196
197    return ret
198
199
200def gen_upcast(name: str, base: QAPISchemaObjectType) -> str:
201    # C makes const-correctness ugly.  We have to cast away const to let
202    # this function work for both const and non-const obj.
203    return mcgen('''
204
205static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
206{
207    return (%(base)s *)obj;
208}
209''',
210                 c_name=c_name(name), base=base.c_name())
211
212
213def gen_variants(variants: QAPISchemaVariants) -> str:
214    ret = mcgen('''
215    union { /* union tag is @%(c_name)s */
216''',
217                c_name=c_name(variants.tag_member.name))
218
219    for var in variants.variants:
220        if var.type.name == 'q_empty':
221            continue
222        ret += gen_if(var.ifcond)
223        ret += mcgen('''
224        %(c_type)s %(c_name)s;
225''',
226                     c_type=var.type.c_unboxed_type(),
227                     c_name=c_name(var.name))
228        ret += gen_endif(var.ifcond)
229
230    ret += mcgen('''
231    } u;
232''')
233
234    return ret
235
236
237def gen_type_cleanup_decl(name: str) -> str:
238    ret = mcgen('''
239
240void qapi_free_%(c_name)s(%(c_name)s *obj);
241G_DEFINE_AUTOPTR_CLEANUP_FUNC(%(c_name)s, qapi_free_%(c_name)s)
242''',
243                c_name=c_name(name))
244    return ret
245
246
247def gen_type_cleanup(name: str) -> str:
248    ret = mcgen('''
249
250void qapi_free_%(c_name)s(%(c_name)s *obj)
251{
252    Visitor *v;
253
254    if (!obj) {
255        return;
256    }
257
258    v = qapi_dealloc_visitor_new();
259    visit_type_%(c_name)s(v, NULL, &obj, NULL);
260    visit_free(v);
261}
262''',
263                c_name=c_name(name))
264    return ret
265
266
267class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
268
269    def __init__(self, prefix: str):
270        super().__init__(
271            prefix, 'qapi-types', ' * Schema-defined QAPI types',
272            ' * Built-in QAPI types', __doc__)
273
274    def _begin_builtin_module(self) -> None:
275        self._genc.preamble_add(mcgen('''
276#include "qemu/osdep.h"
277#include "qapi/dealloc-visitor.h"
278#include "qapi/qapi-builtin-types.h"
279#include "qapi/qapi-builtin-visit.h"
280'''))
281        self._genh.preamble_add(mcgen('''
282#include "qapi/util.h"
283'''))
284
285    def _begin_user_module(self, name: str) -> None:
286        types = self._module_basename('qapi-types', name)
287        visit = self._module_basename('qapi-visit', name)
288        self._genc.preamble_add(mcgen('''
289#include "qemu/osdep.h"
290#include "qapi/dealloc-visitor.h"
291#include "%(types)s.h"
292#include "%(visit)s.h"
293''',
294                                      types=types, visit=visit))
295        self._genh.preamble_add(mcgen('''
296#include "qapi/qapi-builtin-types.h"
297'''))
298
299    def visit_begin(self, schema: QAPISchema) -> None:
300        # gen_object() is recursive, ensure it doesn't visit the empty type
301        objects_seen.add(schema.the_empty_object_type.name)
302
303    def _gen_type_cleanup(self, name: str) -> None:
304        self._genh.add(gen_type_cleanup_decl(name))
305        self._genc.add(gen_type_cleanup(name))
306
307    def visit_enum_type(self,
308                        name: str,
309                        info: Optional[QAPISourceInfo],
310                        ifcond: Sequence[str],
311                        features: List[QAPISchemaFeature],
312                        members: List[QAPISchemaEnumMember],
313                        prefix: Optional[str]) -> None:
314        with ifcontext(ifcond, self._genh, self._genc):
315            self._genh.preamble_add(gen_enum(name, members, prefix))
316            self._genc.add(gen_enum_lookup(name, members, prefix))
317
318    def visit_array_type(self,
319                         name: str,
320                         info: Optional[QAPISourceInfo],
321                         ifcond: Sequence[str],
322                         element_type: QAPISchemaType) -> None:
323        with ifcontext(ifcond, self._genh, self._genc):
324            self._genh.preamble_add(gen_fwd_object_or_array(name))
325            self._genh.add(gen_array(name, element_type))
326            self._gen_type_cleanup(name)
327
328    def visit_object_type(self,
329                          name: str,
330                          info: Optional[QAPISourceInfo],
331                          ifcond: Sequence[str],
332                          features: List[QAPISchemaFeature],
333                          base: Optional[QAPISchemaObjectType],
334                          members: List[QAPISchemaObjectTypeMember],
335                          variants: Optional[QAPISchemaVariants]) -> None:
336        # Nothing to do for the special empty builtin
337        if name == 'q_empty':
338            return
339        with ifcontext(ifcond, self._genh):
340            self._genh.preamble_add(gen_fwd_object_or_array(name))
341        self._genh.add(gen_object(name, ifcond, base, members, variants))
342        with ifcontext(ifcond, self._genh, self._genc):
343            if base and not base.is_implicit():
344                self._genh.add(gen_upcast(name, base))
345            # TODO Worth changing the visitor signature, so we could
346            # directly use rather than repeat type.is_implicit()?
347            if not name.startswith('q_'):
348                # implicit types won't be directly allocated/freed
349                self._gen_type_cleanup(name)
350
351    def visit_alternate_type(self,
352                             name: str,
353                             info: Optional[QAPISourceInfo],
354                             ifcond: Sequence[str],
355                             features: List[QAPISchemaFeature],
356                             variants: QAPISchemaVariants) -> None:
357        with ifcontext(ifcond, self._genh):
358            self._genh.preamble_add(gen_fwd_object_or_array(name))
359        self._genh.add(gen_object(name, ifcond, None,
360                                  [variants.tag_member], variants))
361        with ifcontext(ifcond, self._genh, self._genc):
362            self._gen_type_cleanup(name)
363
364
365def gen_types(schema: QAPISchema,
366              output_dir: str,
367              prefix: str,
368              opt_builtins: bool) -> None:
369    vis = QAPISchemaGenTypeVisitor(prefix)
370    schema.visit(vis)
371    vis.write(output_dir, opt_builtins)
372