xref: /openbmc/qemu/scripts/qapi/types.py (revision a495eba0) 
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 (
20    QAPISchemaModularCVisitor,
21    gen_special_features,
22    ifcontext,
23)
24from .schema import (
25    QAPISchema,
26    QAPISchemaEnumMember,
27    QAPISchemaFeature,
28    QAPISchemaIfCond,
29    QAPISchemaObjectType,
30    QAPISchemaObjectTypeMember,
31    QAPISchemaType,
32    QAPISchemaVariants,
33)
34from .source import QAPISourceInfo
35
36
37# variants must be emitted before their container; track what has already
38# been output
39objects_seen = set()
40
41
42def gen_enum_lookup(name: str,
43                    members: List[QAPISchemaEnumMember],
44                    prefix: Optional[str] = None) -> str:
45    max_index = c_enum_const(name, '_MAX', prefix)
46    feats = ''
47    ret = mcgen('''
48
49const QEnumLookup %(c_name)s_lookup = {
50    .array = (const char *const[]) {
51''',
52                c_name=c_name(name))
53    for memb in members:
54        ret += memb.ifcond.gen_if()
55        index = c_enum_const(name, memb.name, prefix)
56        ret += mcgen('''
57        [%(index)s] = "%(name)s",
58''',
59                     index=index, name=memb.name)
60        ret += memb.ifcond.gen_endif()
61
62        special_features = gen_special_features(memb.features)
63        if special_features != '0':
64            feats += mcgen('''
65        [%(index)s] = %(special_features)s,
66''',
67                           index=index, special_features=special_features)
68
69    if feats:
70        ret += mcgen('''
71    },
72    .special_features = (const unsigned char[%(max_index)s]) {
73''',
74                     max_index=max_index)
75        ret += feats
76
77    ret += mcgen('''
78    },
79    .size = %(max_index)s
80};
81''',
82                 max_index=max_index)
83    return ret
84
85
86def gen_enum(name: str,
87             members: List[QAPISchemaEnumMember],
88             prefix: Optional[str] = None) -> str:
89    # append automatically generated _MAX value
90    enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
91
92    ret = mcgen('''
93
94typedef enum %(c_name)s {
95''',
96                c_name=c_name(name))
97
98    for memb in enum_members:
99        ret += memb.ifcond.gen_if()
100        ret += mcgen('''
101    %(c_enum)s,
102''',
103                     c_enum=c_enum_const(name, memb.name, prefix))
104        ret += memb.ifcond.gen_endif()
105
106    ret += mcgen('''
107} %(c_name)s;
108''',
109                 c_name=c_name(name))
110
111    ret += mcgen('''
112
113#define %(c_name)s_str(val) \\
114    qapi_enum_lookup(&%(c_name)s_lookup, (val))
115
116extern const QEnumLookup %(c_name)s_lookup;
117''',
118                 c_name=c_name(name))
119    return ret
120
121
122def gen_fwd_object_or_array(name: str) -> str:
123    return mcgen('''
124
125typedef struct %(c_name)s %(c_name)s;
126''',
127                 c_name=c_name(name))
128
129
130def gen_array(name: str, element_type: QAPISchemaType) -> str:
131    return mcgen('''
132
133struct %(c_name)s {
134    %(c_name)s *next;
135    %(c_type)s value;
136};
137''',
138                 c_name=c_name(name), c_type=element_type.c_type())
139
140
141def gen_struct_members(members: List[QAPISchemaObjectTypeMember]) -> str:
142    ret = ''
143    for memb in members:
144        ret += memb.ifcond.gen_if()
145        if memb.optional:
146            ret += mcgen('''
147    bool has_%(c_name)s;
148''',
149                         c_name=c_name(memb.name))
150        ret += mcgen('''
151    %(c_type)s %(c_name)s;
152''',
153                     c_type=memb.type.c_type(), c_name=c_name(memb.name))
154        ret += memb.ifcond.gen_endif()
155    return ret
156
157
158def gen_object(name: str, ifcond: QAPISchemaIfCond,
159               base: Optional[QAPISchemaObjectType],
160               members: List[QAPISchemaObjectTypeMember],
161               variants: Optional[QAPISchemaVariants]) -> str:
162    if name in objects_seen:
163        return ''
164    objects_seen.add(name)
165
166    ret = ''
167    for var in variants.variants if variants else ():
168        obj = var.type
169        if not isinstance(obj, QAPISchemaObjectType):
170            continue
171        ret += gen_object(obj.name, obj.ifcond, obj.base,
172                          obj.local_members, obj.variants)
173
174    ret += mcgen('''
175
176''')
177    ret += ifcond.gen_if()
178    ret += mcgen('''
179struct %(c_name)s {
180''',
181                 c_name=c_name(name))
182
183    if base:
184        if not base.is_implicit():
185            ret += mcgen('''
186    /* Members inherited from %(c_name)s: */
187''',
188                         c_name=base.c_name())
189        ret += gen_struct_members(base.members)
190        if not base.is_implicit():
191            ret += mcgen('''
192    /* Own members: */
193''')
194    ret += gen_struct_members(members)
195
196    if variants:
197        ret += gen_variants(variants)
198
199    # Make sure that all structs have at least one member; this avoids
200    # potential issues with attempting to malloc space for zero-length
201    # structs in C, and also incompatibility with C++ (where an empty
202    # struct is size 1).
203    if (not base or base.is_empty()) and not members and not variants:
204        ret += mcgen('''
205    char qapi_dummy_for_empty_struct;
206''')
207
208    ret += mcgen('''
209};
210''')
211    ret += ifcond.gen_endif()
212
213    return ret
214
215
216def gen_upcast(name: str, base: QAPISchemaObjectType) -> str:
217    # C makes const-correctness ugly.  We have to cast away const to let
218    # this function work for both const and non-const obj.
219    return mcgen('''
220
221static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
222{
223    return (%(base)s *)obj;
224}
225''',
226                 c_name=c_name(name), base=base.c_name())
227
228
229def gen_variants(variants: QAPISchemaVariants) -> str:
230    ret = mcgen('''
231    union { /* union tag is @%(c_name)s */
232''',
233                c_name=c_name(variants.tag_member.name))
234
235    for var in variants.variants:
236        if var.type.name == 'q_empty':
237            continue
238        ret += var.ifcond.gen_if()
239        ret += mcgen('''
240        %(c_type)s %(c_name)s;
241''',
242                     c_type=var.type.c_unboxed_type(),
243                     c_name=c_name(var.name))
244        ret += var.ifcond.gen_endif()
245
246    ret += mcgen('''
247    } u;
248''')
249
250    return ret
251
252
253def gen_type_cleanup_decl(name: str) -> str:
254    ret = mcgen('''
255
256void qapi_free_%(c_name)s(%(c_name)s *obj);
257G_DEFINE_AUTOPTR_CLEANUP_FUNC(%(c_name)s, qapi_free_%(c_name)s)
258''',
259                c_name=c_name(name))
260    return ret
261
262
263def gen_type_cleanup(name: str) -> str:
264    ret = mcgen('''
265
266void qapi_free_%(c_name)s(%(c_name)s *obj)
267{
268    Visitor *v;
269
270    if (!obj) {
271        return;
272    }
273
274    v = qapi_dealloc_visitor_new();
275    visit_type_%(c_name)s(v, NULL, &obj, NULL);
276    visit_free(v);
277}
278''',
279                c_name=c_name(name))
280    return ret
281
282
283class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
284
285    def __init__(self, prefix: str):
286        super().__init__(
287            prefix, 'qapi-types', ' * Schema-defined QAPI types',
288            ' * Built-in QAPI types', __doc__)
289
290    def _begin_builtin_module(self) -> None:
291        self._genc.preamble_add(mcgen('''
292#include "qemu/osdep.h"
293#include "qapi/dealloc-visitor.h"
294#include "qapi/qapi-builtin-types.h"
295#include "qapi/qapi-builtin-visit.h"
296'''))
297        self._genh.preamble_add(mcgen('''
298#include "qapi/util.h"
299'''))
300
301    def _begin_user_module(self, name: str) -> None:
302        types = self._module_basename('qapi-types', name)
303        visit = self._module_basename('qapi-visit', name)
304        self._genc.preamble_add(mcgen('''
305#include "qemu/osdep.h"
306#include "qapi/dealloc-visitor.h"
307#include "%(types)s.h"
308#include "%(visit)s.h"
309''',
310                                      types=types, visit=visit))
311        self._genh.preamble_add(mcgen('''
312#include "qapi/qapi-builtin-types.h"
313'''))
314
315    def visit_begin(self, schema: QAPISchema) -> None:
316        # gen_object() is recursive, ensure it doesn't visit the empty type
317        objects_seen.add(schema.the_empty_object_type.name)
318
319    def _gen_type_cleanup(self, name: str) -> None:
320        self._genh.add(gen_type_cleanup_decl(name))
321        self._genc.add(gen_type_cleanup(name))
322
323    def visit_enum_type(self,
324                        name: str,
325                        info: Optional[QAPISourceInfo],
326                        ifcond: QAPISchemaIfCond,
327                        features: List[QAPISchemaFeature],
328                        members: List[QAPISchemaEnumMember],
329                        prefix: Optional[str]) -> None:
330        with ifcontext(ifcond, self._genh, self._genc):
331            self._genh.preamble_add(gen_enum(name, members, prefix))
332            self._genc.add(gen_enum_lookup(name, members, prefix))
333
334    def visit_array_type(self,
335                         name: str,
336                         info: Optional[QAPISourceInfo],
337                         ifcond: QAPISchemaIfCond,
338                         element_type: QAPISchemaType) -> None:
339        with ifcontext(ifcond, self._genh, self._genc):
340            self._genh.preamble_add(gen_fwd_object_or_array(name))
341            self._genh.add(gen_array(name, element_type))
342            self._gen_type_cleanup(name)
343
344    def visit_object_type(self,
345                          name: str,
346                          info: Optional[QAPISourceInfo],
347                          ifcond: QAPISchemaIfCond,
348                          features: List[QAPISchemaFeature],
349                          base: Optional[QAPISchemaObjectType],
350                          members: List[QAPISchemaObjectTypeMember],
351                          variants: Optional[QAPISchemaVariants]) -> None:
352        # Nothing to do for the special empty builtin
353        if name == 'q_empty':
354            return
355        with ifcontext(ifcond, self._genh):
356            self._genh.preamble_add(gen_fwd_object_or_array(name))
357        self._genh.add(gen_object(name, ifcond, base, members, variants))
358        with ifcontext(ifcond, self._genh, self._genc):
359            if base and not base.is_implicit():
360                self._genh.add(gen_upcast(name, base))
361            # TODO Worth changing the visitor signature, so we could
362            # directly use rather than repeat type.is_implicit()?
363            if not name.startswith('q_'):
364                # implicit types won't be directly allocated/freed
365                self._gen_type_cleanup(name)
366
367    def visit_alternate_type(self,
368                             name: str,
369                             info: Optional[QAPISourceInfo],
370                             ifcond: QAPISchemaIfCond,
371                             features: List[QAPISchemaFeature],
372                             variants: QAPISchemaVariants) -> None:
373        with ifcontext(ifcond, self._genh):
374            self._genh.preamble_add(gen_fwd_object_or_array(name))
375        self._genh.add(gen_object(name, ifcond, None,
376                                  [variants.tag_member], variants))
377        with ifcontext(ifcond, self._genh, self._genc):
378            self._gen_type_cleanup(name)
379
380
381def gen_types(schema: QAPISchema,
382              output_dir: str,
383              prefix: str,
384              opt_builtins: bool) -> None:
385    vis = QAPISchemaGenTypeVisitor(prefix)
386    schema.visit(vis)
387    vis.write(output_dir, opt_builtins)
388