xref: /openbmc/qemu/scripts/qapi/types.py (revision 7d87775f) 
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    QAPISchemaAlternatives,
27    QAPISchemaBranches,
28    QAPISchemaEnumMember,
29    QAPISchemaFeature,
30    QAPISchemaIfCond,
31    QAPISchemaObjectType,
32    QAPISchemaObjectTypeMember,
33    QAPISchemaType,
34    QAPISchemaVariants,
35)
36from .source import QAPISourceInfo
37
38
39# variants must be emitted before their container; track what has already
40# been output
41objects_seen = set()
42
43
44def gen_enum_lookup(name: str,
45                    members: List[QAPISchemaEnumMember],
46                    prefix: Optional[str] = None) -> str:
47    max_index = c_enum_const(name, '_MAX', prefix)
48    feats = ''
49    ret = mcgen('''
50
51const QEnumLookup %(c_name)s_lookup = {
52    .array = (const char *const[]) {
53''',
54                c_name=c_name(name))
55    for memb in members:
56        ret += memb.ifcond.gen_if()
57        index = c_enum_const(name, memb.name, prefix)
58        ret += mcgen('''
59        [%(index)s] = "%(name)s",
60''',
61                     index=index, name=memb.name)
62        ret += memb.ifcond.gen_endif()
63
64        special_features = gen_special_features(memb.features)
65        if special_features != '0':
66            feats += mcgen('''
67        [%(index)s] = %(special_features)s,
68''',
69                           index=index, special_features=special_features)
70
71    if feats:
72        ret += mcgen('''
73    },
74    .special_features = (const unsigned char[%(max_index)s]) {
75''',
76                     max_index=max_index)
77        ret += feats
78
79    ret += mcgen('''
80    },
81    .size = %(max_index)s
82};
83''',
84                 max_index=max_index)
85    return ret
86
87
88def gen_enum(name: str,
89             members: List[QAPISchemaEnumMember],
90             prefix: Optional[str] = None) -> str:
91    # append automatically generated _MAX value
92    enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
93
94    ret = mcgen('''
95
96typedef enum %(c_name)s {
97''',
98                c_name=c_name(name))
99
100    for memb in enum_members:
101        ret += memb.ifcond.gen_if()
102        ret += mcgen('''
103    %(c_enum)s,
104''',
105                     c_enum=c_enum_const(name, memb.name, prefix))
106        ret += memb.ifcond.gen_endif()
107
108    ret += mcgen('''
109} %(c_name)s;
110''',
111                 c_name=c_name(name))
112
113    ret += mcgen('''
114
115#define %(c_name)s_str(val) \\
116    qapi_enum_lookup(&%(c_name)s_lookup, (val))
117
118extern const QEnumLookup %(c_name)s_lookup;
119''',
120                 c_name=c_name(name))
121    return ret
122
123
124def gen_fwd_object_or_array(name: str) -> str:
125    return mcgen('''
126
127typedef struct %(c_name)s %(c_name)s;
128''',
129                 c_name=c_name(name))
130
131
132def gen_array(name: str, element_type: QAPISchemaType) -> str:
133    return mcgen('''
134
135struct %(c_name)s {
136    %(c_name)s *next;
137    %(c_type)s value;
138};
139''',
140                 c_name=c_name(name), c_type=element_type.c_type())
141
142
143def gen_struct_members(members: List[QAPISchemaObjectTypeMember]) -> str:
144    ret = ''
145    for memb in members:
146        ret += memb.ifcond.gen_if()
147        if memb.need_has():
148            ret += mcgen('''
149    bool has_%(c_name)s;
150''',
151                         c_name=c_name(memb.name))
152        ret += mcgen('''
153    %(c_type)s %(c_name)s;
154''',
155                     c_type=memb.type.c_type(), c_name=c_name(memb.name))
156        ret += memb.ifcond.gen_endif()
157    return ret
158
159
160def gen_object(name: str, ifcond: QAPISchemaIfCond,
161               base: Optional[QAPISchemaObjectType],
162               members: List[QAPISchemaObjectTypeMember],
163               variants: Optional[QAPISchemaVariants]) -> str:
164    if name in objects_seen:
165        return ''
166    objects_seen.add(name)
167
168    ret = ''
169    for var in variants.variants if variants else ():
170        obj = var.type
171        if not isinstance(obj, QAPISchemaObjectType):
172            continue
173        ret += gen_object(obj.name, obj.ifcond, obj.base,
174                          obj.local_members, obj.branches)
175
176    ret += mcgen('''
177
178''')
179    ret += ifcond.gen_if()
180    ret += mcgen('''
181struct %(c_name)s {
182''',
183                 c_name=c_name(name))
184
185    if base:
186        if not base.is_implicit():
187            ret += mcgen('''
188    /* Members inherited from %(c_name)s: */
189''',
190                         c_name=base.c_name())
191        ret += gen_struct_members(base.members)
192        if not base.is_implicit():
193            ret += mcgen('''
194    /* Own members: */
195''')
196    ret += gen_struct_members(members)
197
198    if variants:
199        ret += gen_variants(variants)
200
201    # Make sure that all structs have at least one member; this avoids
202    # potential issues with attempting to malloc space for zero-length
203    # structs in C, and also incompatibility with C++ (where an empty
204    # struct is size 1).
205    if (not base or base.is_empty()) and not members and not variants:
206        ret += mcgen('''
207    char qapi_dummy_for_empty_struct;
208''')
209
210    ret += mcgen('''
211};
212''')
213    ret += ifcond.gen_endif()
214
215    return ret
216
217
218def gen_upcast(name: str, base: QAPISchemaObjectType) -> str:
219    # C makes const-correctness ugly.  We have to cast away const to let
220    # this function work for both const and non-const obj.
221    return mcgen('''
222
223static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
224{
225    return (%(base)s *)obj;
226}
227''',
228                 c_name=c_name(name), base=base.c_name())
229
230
231def gen_variants(variants: QAPISchemaVariants) -> str:
232    ret = mcgen('''
233    union { /* union tag is @%(c_name)s */
234''',
235                c_name=c_name(variants.tag_member.name))
236
237    for var in variants.variants:
238        if var.type.name == 'q_empty':
239            continue
240        ret += var.ifcond.gen_if()
241        ret += mcgen('''
242        %(c_type)s %(c_name)s;
243''',
244                     c_type=var.type.c_unboxed_type(),
245                     c_name=c_name(var.name))
246        ret += var.ifcond.gen_endif()
247
248    ret += mcgen('''
249    } u;
250''')
251
252    return ret
253
254
255def gen_type_cleanup_decl(name: str) -> str:
256    ret = mcgen('''
257
258void qapi_free_%(c_name)s(%(c_name)s *obj);
259G_DEFINE_AUTOPTR_CLEANUP_FUNC(%(c_name)s, qapi_free_%(c_name)s)
260''',
261                c_name=c_name(name))
262    return ret
263
264
265def gen_type_cleanup(name: str) -> str:
266    ret = mcgen('''
267
268void qapi_free_%(c_name)s(%(c_name)s *obj)
269{
270    Visitor *v;
271
272    if (!obj) {
273        return;
274    }
275
276    v = qapi_dealloc_visitor_new();
277    visit_type_%(c_name)s(v, NULL, &obj, NULL);
278    visit_free(v);
279}
280''',
281                c_name=c_name(name))
282    return ret
283
284
285class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
286
287    def __init__(self, prefix: str):
288        super().__init__(
289            prefix, 'qapi-types', ' * Schema-defined QAPI types',
290            ' * Built-in QAPI types', __doc__)
291
292    def _begin_builtin_module(self) -> None:
293        self._genc.preamble_add(mcgen('''
294#include "qemu/osdep.h"
295#include "qapi/dealloc-visitor.h"
296#include "qapi/qapi-builtin-types.h"
297#include "qapi/qapi-builtin-visit.h"
298'''))
299        self._genh.preamble_add(mcgen('''
300#include "qapi/util.h"
301'''))
302
303    def _begin_user_module(self, name: str) -> None:
304        types = self._module_basename('qapi-types', name)
305        visit = self._module_basename('qapi-visit', name)
306        self._genc.preamble_add(mcgen('''
307#include "qemu/osdep.h"
308#include "qapi/dealloc-visitor.h"
309#include "%(types)s.h"
310#include "%(visit)s.h"
311''',
312                                      types=types, visit=visit))
313        self._genh.preamble_add(mcgen('''
314#include "qapi/qapi-builtin-types.h"
315'''))
316
317    def visit_begin(self, schema: QAPISchema) -> None:
318        # gen_object() is recursive, ensure it doesn't visit the empty type
319        objects_seen.add(schema.the_empty_object_type.name)
320
321    def _gen_type_cleanup(self, name: str) -> None:
322        self._genh.add(gen_type_cleanup_decl(name))
323        self._genc.add(gen_type_cleanup(name))
324
325    def visit_enum_type(self,
326                        name: str,
327                        info: Optional[QAPISourceInfo],
328                        ifcond: QAPISchemaIfCond,
329                        features: List[QAPISchemaFeature],
330                        members: List[QAPISchemaEnumMember],
331                        prefix: Optional[str]) -> None:
332        with ifcontext(ifcond, self._genh, self._genc):
333            self._genh.preamble_add(gen_enum(name, members, prefix))
334            self._genc.add(gen_enum_lookup(name, members, prefix))
335
336    def visit_array_type(self,
337                         name: str,
338                         info: Optional[QAPISourceInfo],
339                         ifcond: QAPISchemaIfCond,
340                         element_type: QAPISchemaType) -> None:
341        with ifcontext(ifcond, self._genh, self._genc):
342            self._genh.preamble_add(gen_fwd_object_or_array(name))
343            self._genh.add(gen_array(name, element_type))
344            self._gen_type_cleanup(name)
345
346    def visit_object_type(self,
347                          name: str,
348                          info: Optional[QAPISourceInfo],
349                          ifcond: QAPISchemaIfCond,
350                          features: List[QAPISchemaFeature],
351                          base: Optional[QAPISchemaObjectType],
352                          members: List[QAPISchemaObjectTypeMember],
353                          branches: Optional[QAPISchemaBranches]) -> None:
354        # Nothing to do for the special empty builtin
355        if name == 'q_empty':
356            return
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, base, members, branches))
360        with ifcontext(ifcond, self._genh, self._genc):
361            if base and not base.is_implicit():
362                self._genh.add(gen_upcast(name, base))
363            # TODO Worth changing the visitor signature, so we could
364            # directly use rather than repeat type.is_implicit()?
365            if not name.startswith('q_'):
366                # implicit types won't be directly allocated/freed
367                self._gen_type_cleanup(name)
368
369    def visit_alternate_type(self,
370                             name: str,
371                             info: Optional[QAPISourceInfo],
372                             ifcond: QAPISchemaIfCond,
373                             features: List[QAPISchemaFeature],
374                             alternatives: QAPISchemaAlternatives) -> None:
375        with ifcontext(ifcond, self._genh):
376            self._genh.preamble_add(gen_fwd_object_or_array(name))
377        self._genh.add(gen_object(name, ifcond, None,
378                                  [alternatives.tag_member], alternatives))
379        with ifcontext(ifcond, self._genh, self._genc):
380            self._gen_type_cleanup(name)
381
382
383def gen_types(schema: QAPISchema,
384              output_dir: str,
385              prefix: str,
386              opt_builtins: bool) -> None:
387    vis = QAPISchemaGenTypeVisitor(prefix)
388    schema.visit(vis)
389    vis.write(output_dir, opt_builtins)
390