xref: /qemu/scripts/qapi/types.py (revision 2ebb09f34ffff152dda6d2b5d9a2348f3fefc6d3) 
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_features, ifcontext
20from .schema import (
21    QAPISchema,
22    QAPISchemaAlternatives,
23    QAPISchemaBranches,
24    QAPISchemaEnumMember,
25    QAPISchemaFeature,
26    QAPISchemaIfCond,
27    QAPISchemaObjectType,
28    QAPISchemaObjectTypeMember,
29    QAPISchemaType,
30    QAPISchemaVariants,
31)
32from .source import QAPISourceInfo
33
34
35# variants must be emitted before their container; track what has already
36# been output
37objects_seen = set()
38
39
40def gen_enum_lookup(name: str,
41                    members: List[QAPISchemaEnumMember],
42                    prefix: Optional[str] = None) -> str:
43    max_index = c_enum_const(name, '_MAX', prefix)
44    feats = ''
45    ret = mcgen('''
46
47const QEnumLookup %(c_name)s_lookup = {
48    .array = (const char *const[]) {
49''',
50                c_name=c_name(name))
51    for memb in members:
52        ret += memb.ifcond.gen_if()
53        index = c_enum_const(name, memb.name, prefix)
54        ret += mcgen('''
55        [%(index)s] = "%(name)s",
56''',
57                     index=index, name=memb.name)
58        ret += memb.ifcond.gen_endif()
59
60        features = gen_features(memb.features)
61        if features != '0':
62            feats += mcgen('''
63        [%(index)s] = %(features)s,
64''',
65                           index=index, features=features)
66
67    if feats:
68        ret += mcgen('''
69    },
70    .features = (const uint64_t[%(max_index)s]) {
71''',
72                     max_index=max_index)
73        ret += feats
74
75    ret += mcgen('''
76    },
77    .size = %(max_index)s
78};
79''',
80                 max_index=max_index)
81    return ret
82
83
84def gen_enum(name: str,
85             members: List[QAPISchemaEnumMember],
86             prefix: Optional[str] = None) -> str:
87    # append automatically generated _MAX value
88    enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
89
90    ret = mcgen('''
91
92typedef enum %(c_name)s {
93''',
94                c_name=c_name(name))
95
96    for memb in enum_members:
97        ret += memb.ifcond.gen_if()
98        ret += mcgen('''
99    %(c_enum)s,
100''',
101                     c_enum=c_enum_const(name, memb.name, prefix))
102        ret += memb.ifcond.gen_endif()
103
104    ret += mcgen('''
105} %(c_name)s;
106''',
107                 c_name=c_name(name))
108
109    ret += mcgen('''
110
111#define %(c_name)s_str(val) \\
112    qapi_enum_lookup(&%(c_name)s_lookup, (val))
113
114extern const QEnumLookup %(c_name)s_lookup;
115''',
116                 c_name=c_name(name))
117    return ret
118
119
120def gen_fwd_object_or_array(name: str) -> str:
121    return mcgen('''
122
123typedef struct %(c_name)s %(c_name)s;
124''',
125                 c_name=c_name(name))
126
127
128def gen_array(name: str, element_type: QAPISchemaType) -> str:
129    return mcgen('''
130
131struct %(c_name)s {
132    %(c_name)s *next;
133    %(c_type)s value;
134};
135''',
136                 c_name=c_name(name), c_type=element_type.c_type())
137
138
139def gen_struct_members(members: List[QAPISchemaObjectTypeMember]) -> str:
140    ret = ''
141    for memb in members:
142        ret += memb.ifcond.gen_if()
143        if memb.need_has():
144            ret += mcgen('''
145    bool has_%(c_name)s;
146''',
147                         c_name=c_name(memb.name))
148        ret += mcgen('''
149    %(c_type)s %(c_name)s;
150''',
151                     c_type=memb.type.c_type(), c_name=c_name(memb.name))
152        ret += memb.ifcond.gen_endif()
153    return ret
154
155
156def gen_object(name: str, ifcond: QAPISchemaIfCond,
157               base: Optional[QAPISchemaObjectType],
158               members: List[QAPISchemaObjectTypeMember],
159               variants: Optional[QAPISchemaVariants]) -> str:
160    if name in objects_seen:
161        return ''
162    objects_seen.add(name)
163
164    ret = ''
165    for var in variants.variants if variants else ():
166        obj = var.type
167        if not isinstance(obj, QAPISchemaObjectType):
168            continue
169        ret += gen_object(obj.name, obj.ifcond, obj.base,
170                          obj.local_members, obj.branches)
171
172    ret += mcgen('''
173
174''')
175    ret += ifcond.gen_if()
176    ret += mcgen('''
177struct %(c_name)s {
178''',
179                 c_name=c_name(name))
180
181    if base:
182        if not base.is_implicit():
183            ret += mcgen('''
184    /* Members inherited from %(c_name)s: */
185''',
186                         c_name=base.c_name())
187        ret += gen_struct_members(base.members)
188        if not base.is_implicit():
189            ret += mcgen('''
190    /* Own members: */
191''')
192    ret += gen_struct_members(members)
193
194    if variants:
195        ret += gen_variants(variants)
196
197    # Make sure that all structs have at least one member; this avoids
198    # potential issues with attempting to malloc space for zero-length
199    # structs in C, and also incompatibility with C++ (where an empty
200    # struct is size 1).
201    if (not base or base.is_empty()) and not members and not variants:
202        ret += mcgen('''
203    char qapi_dummy_for_empty_struct;
204''')
205
206    ret += mcgen('''
207};
208''')
209    ret += ifcond.gen_endif()
210
211    return ret
212
213
214def gen_upcast(name: str, base: QAPISchemaObjectType) -> str:
215    # C makes const-correctness ugly.  We have to cast away const to let
216    # this function work for both const and non-const obj.
217    return mcgen('''
218
219static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
220{
221    return (%(base)s *)obj;
222}
223''',
224                 c_name=c_name(name), base=base.c_name())
225
226
227def gen_variants(variants: QAPISchemaVariants) -> str:
228    ret = mcgen('''
229    union { /* union tag is @%(c_name)s */
230''',
231                c_name=c_name(variants.tag_member.name))
232
233    for var in variants.variants:
234        if var.type.name == 'q_empty':
235            continue
236        ret += var.ifcond.gen_if()
237        ret += mcgen('''
238        %(c_type)s %(c_name)s;
239''',
240                     c_type=var.type.c_unboxed_type(),
241                     c_name=c_name(var.name))
242        ret += var.ifcond.gen_endif()
243
244    ret += mcgen('''
245    } u;
246''')
247
248    return ret
249
250
251def gen_type_cleanup_decl(name: str) -> str:
252    ret = mcgen('''
253
254void qapi_free_%(c_name)s(%(c_name)s *obj);
255G_DEFINE_AUTOPTR_CLEANUP_FUNC(%(c_name)s, qapi_free_%(c_name)s)
256''',
257                c_name=c_name(name))
258    return ret
259
260
261def gen_type_cleanup(name: str) -> str:
262    ret = mcgen('''
263
264void qapi_free_%(c_name)s(%(c_name)s *obj)
265{
266    Visitor *v;
267
268    if (!obj) {
269        return;
270    }
271
272    v = qapi_dealloc_visitor_new();
273    visit_type_%(c_name)s(v, NULL, &obj, NULL);
274    visit_free(v);
275}
276''',
277                c_name=c_name(name))
278    return ret
279
280
281class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
282
283    def __init__(self, prefix: str):
284        super().__init__(
285            prefix, 'qapi-types', ' * Schema-defined QAPI types',
286            ' * Built-in QAPI types', __doc__)
287
288    def _begin_builtin_module(self) -> None:
289        self._genc.preamble_add(mcgen('''
290#include "qemu/osdep.h"
291#include "qapi/dealloc-visitor.h"
292#include "qapi/qapi-builtin-types.h"
293#include "qapi/qapi-builtin-visit.h"
294'''))
295        self._genh.preamble_add(mcgen('''
296#include "qapi/util.h"
297'''))
298
299    def _begin_user_module(self, name: str) -> None:
300        types = self._module_basename('qapi-types', name)
301        visit = self._module_basename('qapi-visit', name)
302        self._genc.preamble_add(mcgen('''
303#include "qemu/osdep.h"
304#include "qapi/dealloc-visitor.h"
305#include "%(types)s.h"
306#include "%(visit)s.h"
307#include "%(prefix)sqapi-features.h"
308''',
309                                      types=types, visit=visit,
310                                      prefix=self._prefix))
311        self._genh.preamble_add(mcgen('''
312#include "qapi/qapi-builtin-types.h"
313''',
314                                      prefix=self._prefix))
315
316    def visit_begin(self, schema: QAPISchema) -> None:
317        # gen_object() is recursive, ensure it doesn't visit the empty type
318        objects_seen.add(schema.the_empty_object_type.name)
319
320    def _gen_type_cleanup(self, name: str) -> None:
321        self._genh.add(gen_type_cleanup_decl(name))
322        self._genc.add(gen_type_cleanup(name))
323
324    def visit_enum_type(self,
325                        name: str,
326                        info: Optional[QAPISourceInfo],
327                        ifcond: QAPISchemaIfCond,
328                        features: List[QAPISchemaFeature],
329                        members: List[QAPISchemaEnumMember],
330                        prefix: Optional[str]) -> None:
331        with ifcontext(ifcond, self._genh, self._genc):
332            self._genh.preamble_add(gen_enum(name, members, prefix))
333            self._genc.add(gen_enum_lookup(name, members, prefix))
334
335    def visit_array_type(self,
336                         name: str,
337                         info: Optional[QAPISourceInfo],
338                         ifcond: QAPISchemaIfCond,
339                         element_type: QAPISchemaType) -> None:
340        with ifcontext(ifcond, self._genh, self._genc):
341            self._genh.preamble_add(gen_fwd_object_or_array(name))
342            self._genh.add(gen_array(name, element_type))
343            self._gen_type_cleanup(name)
344
345    def visit_object_type(self,
346                          name: str,
347                          info: Optional[QAPISourceInfo],
348                          ifcond: QAPISchemaIfCond,
349                          features: List[QAPISchemaFeature],
350                          base: Optional[QAPISchemaObjectType],
351                          members: List[QAPISchemaObjectTypeMember],
352                          branches: Optional[QAPISchemaBranches]) -> None:
353        # Nothing to do for the special empty builtin
354        if name == 'q_empty':
355            return
356        with ifcontext(ifcond, self._genh):
357            self._genh.preamble_add(gen_fwd_object_or_array(name))
358        self._genh.add(gen_object(name, ifcond, base, members, branches))
359        with ifcontext(ifcond, self._genh, self._genc):
360            if base and not base.is_implicit():
361                self._genh.add(gen_upcast(name, base))
362            # TODO Worth changing the visitor signature, so we could
363            # directly use rather than repeat type.is_implicit()?
364            if not name.startswith('q_'):
365                # implicit types won't be directly allocated/freed
366                self._gen_type_cleanup(name)
367
368    def visit_alternate_type(self,
369                             name: str,
370                             info: Optional[QAPISourceInfo],
371                             ifcond: QAPISchemaIfCond,
372                             features: List[QAPISchemaFeature],
373                             alternatives: QAPISchemaAlternatives) -> None:
374        with ifcontext(ifcond, self._genh):
375            self._genh.preamble_add(gen_fwd_object_or_array(name))
376        self._genh.add(gen_object(name, ifcond, None,
377                                  [alternatives.tag_member], alternatives))
378        with ifcontext(ifcond, self._genh, self._genc):
379            self._gen_type_cleanup(name)
380
381
382def gen_types(schema: QAPISchema,
383              output_dir: str,
384              prefix: str,
385              opt_builtins: bool) -> None:
386    vis = QAPISchemaGenTypeVisitor(prefix)
387    schema.visit(vis)
388    vis.write(output_dir, opt_builtins)
389