xref: /openbmc/qemu/scripts/qapi/visit.py (revision 4921d0a7) 
1"""
2QAPI visitor generator
3
4Copyright IBM, Corp. 2011
5Copyright (C) 2014-2018 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.
13See the COPYING file in the top-level directory.
14"""
15
16from typing import List, Optional
17
18from .common import (
19    c_enum_const,
20    c_name,
21    indent,
22    mcgen,
23)
24from .gen import (
25    QAPISchemaModularCVisitor,
26    gen_special_features,
27    ifcontext,
28)
29from .schema import (
30    QAPISchema,
31    QAPISchemaEnumMember,
32    QAPISchemaEnumType,
33    QAPISchemaFeature,
34    QAPISchemaIfCond,
35    QAPISchemaObjectType,
36    QAPISchemaObjectTypeMember,
37    QAPISchemaType,
38    QAPISchemaVariants,
39)
40from .source import QAPISourceInfo
41
42
43def gen_visit_decl(name: str, scalar: bool = False) -> str:
44    c_type = c_name(name) + ' *'
45    if not scalar:
46        c_type += '*'
47    return mcgen('''
48
49bool visit_type_%(c_name)s(Visitor *v, const char *name,
50                 %(c_type)sobj, Error **errp);
51''',
52                 c_name=c_name(name), c_type=c_type)
53
54
55def gen_visit_members_decl(name: str) -> str:
56    return mcgen('''
57
58bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
59''',
60                 c_name=c_name(name))
61
62
63def gen_visit_object_members(name: str,
64                             base: Optional[QAPISchemaObjectType],
65                             members: List[QAPISchemaObjectTypeMember],
66                             variants: Optional[QAPISchemaVariants]) -> str:
67    ret = mcgen('''
68
69bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
70{
71''',
72                c_name=c_name(name))
73
74    sep = ''
75    for memb in members:
76        if memb.optional and not memb.need_has():
77            ret += memb.ifcond.gen_if()
78            ret += mcgen('''
79    bool has_%(c_name)s = !!obj->%(c_name)s;
80''',
81                         c_name=c_name(memb.name))
82            sep = '\n'
83            ret += memb.ifcond.gen_endif()
84    ret += sep
85
86    if base:
87        ret += mcgen('''
88    if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) {
89        return false;
90    }
91''',
92                     c_type=base.c_name())
93
94    for memb in members:
95        ret += memb.ifcond.gen_if()
96        if memb.optional:
97            has = 'has_' + c_name(memb.name)
98            if memb.need_has():
99                has = 'obj->' + has
100            ret += mcgen('''
101    if (visit_optional(v, "%(name)s", &%(has)s)) {
102''',
103                         name=memb.name, has=has)
104            indent.increase()
105        special_features = gen_special_features(memb.features)
106        if special_features != '0':
107            ret += mcgen('''
108    if (visit_policy_reject(v, "%(name)s", %(special_features)s, errp)) {
109        return false;
110    }
111    if (!visit_policy_skip(v, "%(name)s", %(special_features)s)) {
112''',
113                         name=memb.name, special_features=special_features)
114            indent.increase()
115        ret += mcgen('''
116    if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) {
117        return false;
118    }
119''',
120                     c_type=memb.type.c_name(), name=memb.name,
121                     c_name=c_name(memb.name))
122        if special_features != '0':
123            indent.decrease()
124            ret += mcgen('''
125    }
126''')
127        if memb.optional:
128            indent.decrease()
129            ret += mcgen('''
130    }
131''')
132        ret += memb.ifcond.gen_endif()
133
134    if variants:
135        tag_member = variants.tag_member
136        assert isinstance(tag_member.type, QAPISchemaEnumType)
137
138        ret += mcgen('''
139    switch (obj->%(c_name)s) {
140''',
141                     c_name=c_name(tag_member.name))
142
143        for var in variants.variants:
144            case_str = c_enum_const(tag_member.type.name, var.name,
145                                    tag_member.type.prefix)
146            ret += var.ifcond.gen_if()
147            if var.type.name == 'q_empty':
148                # valid variant and nothing to do
149                ret += mcgen('''
150    case %(case)s:
151        break;
152''',
153                             case=case_str)
154            else:
155                ret += mcgen('''
156    case %(case)s:
157        return visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, errp);
158''',
159                             case=case_str,
160                             c_type=var.type.c_name(), c_name=c_name(var.name))
161
162            ret += var.ifcond.gen_endif()
163        ret += mcgen('''
164    default:
165        abort();
166    }
167''')
168
169    ret += mcgen('''
170    return true;
171}
172''')
173    return ret
174
175
176def gen_visit_list(name: str, element_type: QAPISchemaType) -> str:
177    return mcgen('''
178
179bool visit_type_%(c_name)s(Visitor *v, const char *name,
180                 %(c_name)s **obj, Error **errp)
181{
182    bool ok = false;
183    %(c_name)s *tail;
184    size_t size = sizeof(**obj);
185
186    if (!visit_start_list(v, name, (GenericList **)obj, size, errp)) {
187        return false;
188    }
189
190    for (tail = *obj; tail;
191         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
192        if (!visit_type_%(c_elt_type)s(v, NULL, &tail->value, errp)) {
193            goto out_obj;
194        }
195    }
196
197    ok = visit_check_list(v, errp);
198out_obj:
199    visit_end_list(v, (void **)obj);
200    if (!ok && visit_is_input(v)) {
201        qapi_free_%(c_name)s(*obj);
202        *obj = NULL;
203    }
204    return ok;
205}
206''',
207                 c_name=c_name(name), c_elt_type=element_type.c_name())
208
209
210def gen_visit_enum(name: str) -> str:
211    return mcgen('''
212
213bool visit_type_%(c_name)s(Visitor *v, const char *name,
214                 %(c_name)s *obj, Error **errp)
215{
216    int value = *obj;
217    bool ok = visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
218    *obj = value;
219    return ok;
220}
221''',
222                 c_name=c_name(name))
223
224
225def gen_visit_alternate(name: str, variants: QAPISchemaVariants) -> str:
226    ret = mcgen('''
227
228bool visit_type_%(c_name)s(Visitor *v, const char *name,
229                 %(c_name)s **obj, Error **errp)
230{
231    bool ok = false;
232
233    if (!visit_start_alternate(v, name, (GenericAlternate **)obj,
234                               sizeof(**obj), errp)) {
235        return false;
236    }
237    if (!*obj) {
238        /* incomplete */
239        assert(visit_is_dealloc(v));
240        ok = true;
241        goto out_obj;
242    }
243    switch ((*obj)->type) {
244''',
245                c_name=c_name(name))
246
247    for var in variants.variants:
248        ret += var.ifcond.gen_if()
249        ret += mcgen('''
250    case %(case)s:
251''',
252                     case=var.type.alternate_qtype())
253        if isinstance(var.type, QAPISchemaObjectType):
254            ret += mcgen('''
255        if (!visit_start_struct(v, name, NULL, 0, errp)) {
256            break;
257        }
258        if (visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, errp)) {
259            ok = visit_check_struct(v, errp);
260        }
261        visit_end_struct(v, NULL);
262''',
263                         c_type=var.type.c_name(),
264                         c_name=c_name(var.name))
265        else:
266            ret += mcgen('''
267        ok = visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, errp);
268''',
269                         c_type=var.type.c_name(),
270                         c_name=c_name(var.name))
271        ret += mcgen('''
272        break;
273''')
274        ret += var.ifcond.gen_endif()
275
276    ret += mcgen('''
277    case QTYPE_NONE:
278        abort();
279    default:
280        assert(visit_is_input(v));
281        error_setg(errp, "Invalid parameter type for '%%s', expected: %(name)s",
282                         name ? name : "null");
283        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
284        g_free(*obj);
285        *obj = NULL;
286    }
287out_obj:
288    visit_end_alternate(v, (void **)obj);
289    if (!ok && visit_is_input(v)) {
290        qapi_free_%(c_name)s(*obj);
291        *obj = NULL;
292    }
293    return ok;
294}
295''',
296                 name=name, c_name=c_name(name))
297
298    return ret
299
300
301def gen_visit_object(name: str) -> str:
302    return mcgen('''
303
304bool visit_type_%(c_name)s(Visitor *v, const char *name,
305                 %(c_name)s **obj, Error **errp)
306{
307    bool ok = false;
308
309    if (!visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), errp)) {
310        return false;
311    }
312    if (!*obj) {
313        /* incomplete */
314        assert(visit_is_dealloc(v));
315        ok = true;
316        goto out_obj;
317    }
318    if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
319        goto out_obj;
320    }
321    ok = visit_check_struct(v, errp);
322out_obj:
323    visit_end_struct(v, (void **)obj);
324    if (!ok && visit_is_input(v)) {
325        qapi_free_%(c_name)s(*obj);
326        *obj = NULL;
327    }
328    return ok;
329}
330''',
331                 c_name=c_name(name))
332
333
334class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
335
336    def __init__(self, prefix: str):
337        super().__init__(
338            prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
339            ' * Built-in QAPI visitors', __doc__)
340
341    def _begin_builtin_module(self) -> None:
342        self._genc.preamble_add(mcgen('''
343#include "qemu/osdep.h"
344#include "qapi/error.h"
345#include "qapi/qapi-builtin-visit.h"
346'''))
347        self._genh.preamble_add(mcgen('''
348#include "qapi/visitor.h"
349#include "qapi/qapi-builtin-types.h"
350
351'''))
352
353    def _begin_user_module(self, name: str) -> None:
354        types = self._module_basename('qapi-types', name)
355        visit = self._module_basename('qapi-visit', name)
356        self._genc.preamble_add(mcgen('''
357#include "qemu/osdep.h"
358#include "qapi/error.h"
359#include "%(visit)s.h"
360''',
361                                      visit=visit))
362        self._genh.preamble_add(mcgen('''
363#include "qapi/qapi-builtin-visit.h"
364#include "%(types)s.h"
365
366''',
367                                      types=types))
368
369    def visit_enum_type(self,
370                        name: str,
371                        info: Optional[QAPISourceInfo],
372                        ifcond: QAPISchemaIfCond,
373                        features: List[QAPISchemaFeature],
374                        members: List[QAPISchemaEnumMember],
375                        prefix: Optional[str]) -> None:
376        with ifcontext(ifcond, self._genh, self._genc):
377            self._genh.add(gen_visit_decl(name, scalar=True))
378            self._genc.add(gen_visit_enum(name))
379
380    def visit_array_type(self,
381                         name: str,
382                         info: Optional[QAPISourceInfo],
383                         ifcond: QAPISchemaIfCond,
384                         element_type: QAPISchemaType) -> None:
385        with ifcontext(ifcond, self._genh, self._genc):
386            self._genh.add(gen_visit_decl(name))
387            self._genc.add(gen_visit_list(name, element_type))
388
389    def visit_object_type(self,
390                          name: str,
391                          info: Optional[QAPISourceInfo],
392                          ifcond: QAPISchemaIfCond,
393                          features: List[QAPISchemaFeature],
394                          base: Optional[QAPISchemaObjectType],
395                          members: List[QAPISchemaObjectTypeMember],
396                          variants: Optional[QAPISchemaVariants]) -> None:
397        # Nothing to do for the special empty builtin
398        if name == 'q_empty':
399            return
400        with ifcontext(ifcond, self._genh, self._genc):
401            self._genh.add(gen_visit_members_decl(name))
402            self._genc.add(gen_visit_object_members(name, base,
403                                                    members, variants))
404            # TODO Worth changing the visitor signature, so we could
405            # directly use rather than repeat type.is_implicit()?
406            if not name.startswith('q_'):
407                # only explicit types need an allocating visit
408                self._genh.add(gen_visit_decl(name))
409                self._genc.add(gen_visit_object(name))
410
411    def visit_alternate_type(self,
412                             name: str,
413                             info: Optional[QAPISourceInfo],
414                             ifcond: QAPISchemaIfCond,
415                             features: List[QAPISchemaFeature],
416                             variants: QAPISchemaVariants) -> None:
417        with ifcontext(ifcond, self._genh, self._genc):
418            self._genh.add(gen_visit_decl(name))
419            self._genc.add(gen_visit_alternate(name, variants))
420
421
422def gen_visit(schema: QAPISchema,
423              output_dir: str,
424              prefix: str,
425              opt_builtins: bool) -> None:
426    vis = QAPISchemaGenVisitVisitor(prefix)
427    schema.visit(vis)
428    vis.write(output_dir, opt_builtins)
429