xref: /qemu/scripts/qapi/visit.py (revision b2a3cbb8) 
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    if base:
75        ret += mcgen('''
76    if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) {
77        return false;
78    }
79''',
80                     c_type=base.c_name())
81
82    for memb in members:
83        ret += memb.ifcond.gen_if()
84        if memb.optional:
85            ret += mcgen('''
86    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
87''',
88                         name=memb.name, c_name=c_name(memb.name))
89            indent.increase()
90        special_features = gen_special_features(memb.features)
91        if special_features != '0':
92            ret += mcgen('''
93    if (visit_policy_reject(v, "%(name)s", %(special_features)s, errp)) {
94        return false;
95    }
96    if (!visit_policy_skip(v, "%(name)s", %(special_features)s)) {
97''',
98                         name=memb.name, special_features=special_features)
99            indent.increase()
100        ret += mcgen('''
101    if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) {
102        return false;
103    }
104''',
105                     c_type=memb.type.c_name(), name=memb.name,
106                     c_name=c_name(memb.name))
107        if special_features != '0':
108            indent.decrease()
109            ret += mcgen('''
110    }
111''')
112        if memb.optional:
113            indent.decrease()
114            ret += mcgen('''
115    }
116''')
117        ret += memb.ifcond.gen_endif()
118
119    if variants:
120        tag_member = variants.tag_member
121        assert isinstance(tag_member.type, QAPISchemaEnumType)
122
123        ret += mcgen('''
124    switch (obj->%(c_name)s) {
125''',
126                     c_name=c_name(tag_member.name))
127
128        for var in variants.variants:
129            case_str = c_enum_const(tag_member.type.name, var.name,
130                                    tag_member.type.prefix)
131            ret += var.ifcond.gen_if()
132            if var.type.name == 'q_empty':
133                # valid variant and nothing to do
134                ret += mcgen('''
135    case %(case)s:
136        break;
137''',
138                             case=case_str)
139            else:
140                ret += mcgen('''
141    case %(case)s:
142        return visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, errp);
143''',
144                             case=case_str,
145                             c_type=var.type.c_name(), c_name=c_name(var.name))
146
147            ret += var.ifcond.gen_endif()
148        ret += mcgen('''
149    default:
150        abort();
151    }
152''')
153
154    ret += mcgen('''
155    return true;
156}
157''')
158    return ret
159
160
161def gen_visit_list(name: str, element_type: QAPISchemaType) -> str:
162    return mcgen('''
163
164bool visit_type_%(c_name)s(Visitor *v, const char *name,
165                 %(c_name)s **obj, Error **errp)
166{
167    bool ok = false;
168    %(c_name)s *tail;
169    size_t size = sizeof(**obj);
170
171    if (!visit_start_list(v, name, (GenericList **)obj, size, errp)) {
172        return false;
173    }
174
175    for (tail = *obj; tail;
176         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
177        if (!visit_type_%(c_elt_type)s(v, NULL, &tail->value, errp)) {
178            goto out_obj;
179        }
180    }
181
182    ok = visit_check_list(v, errp);
183out_obj:
184    visit_end_list(v, (void **)obj);
185    if (!ok && visit_is_input(v)) {
186        qapi_free_%(c_name)s(*obj);
187        *obj = NULL;
188    }
189    return ok;
190}
191''',
192                 c_name=c_name(name), c_elt_type=element_type.c_name())
193
194
195def gen_visit_enum(name: str) -> str:
196    return mcgen('''
197
198bool visit_type_%(c_name)s(Visitor *v, const char *name,
199                 %(c_name)s *obj, Error **errp)
200{
201    int value = *obj;
202    bool ok = visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
203    *obj = value;
204    return ok;
205}
206''',
207                 c_name=c_name(name))
208
209
210def gen_visit_alternate(name: str, variants: QAPISchemaVariants) -> str:
211    ret = mcgen('''
212
213bool visit_type_%(c_name)s(Visitor *v, const char *name,
214                 %(c_name)s **obj, Error **errp)
215{
216    bool ok = false;
217
218    if (!visit_start_alternate(v, name, (GenericAlternate **)obj,
219                               sizeof(**obj), errp)) {
220        return false;
221    }
222    if (!*obj) {
223        /* incomplete */
224        assert(visit_is_dealloc(v));
225        ok = true;
226        goto out_obj;
227    }
228    switch ((*obj)->type) {
229''',
230                c_name=c_name(name))
231
232    for var in variants.variants:
233        ret += var.ifcond.gen_if()
234        ret += mcgen('''
235    case %(case)s:
236''',
237                     case=var.type.alternate_qtype())
238        if isinstance(var.type, QAPISchemaObjectType):
239            ret += mcgen('''
240        if (!visit_start_struct(v, name, NULL, 0, errp)) {
241            break;
242        }
243        if (visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, errp)) {
244            ok = visit_check_struct(v, errp);
245        }
246        visit_end_struct(v, NULL);
247''',
248                         c_type=var.type.c_name(),
249                         c_name=c_name(var.name))
250        else:
251            ret += mcgen('''
252        ok = visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, errp);
253''',
254                         c_type=var.type.c_name(),
255                         c_name=c_name(var.name))
256        ret += mcgen('''
257        break;
258''')
259        ret += var.ifcond.gen_endif()
260
261    ret += mcgen('''
262    case QTYPE_NONE:
263        abort();
264    default:
265        assert(visit_is_input(v));
266        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
267                   "%(name)s");
268        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
269        g_free(*obj);
270        *obj = NULL;
271    }
272out_obj:
273    visit_end_alternate(v, (void **)obj);
274    if (!ok && visit_is_input(v)) {
275        qapi_free_%(c_name)s(*obj);
276        *obj = NULL;
277    }
278    return ok;
279}
280''',
281                 name=name, c_name=c_name(name))
282
283    return ret
284
285
286def gen_visit_object(name: str) -> str:
287    return mcgen('''
288
289bool visit_type_%(c_name)s(Visitor *v, const char *name,
290                 %(c_name)s **obj, Error **errp)
291{
292    bool ok = false;
293
294    if (!visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), errp)) {
295        return false;
296    }
297    if (!*obj) {
298        /* incomplete */
299        assert(visit_is_dealloc(v));
300        ok = true;
301        goto out_obj;
302    }
303    if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
304        goto out_obj;
305    }
306    ok = visit_check_struct(v, errp);
307out_obj:
308    visit_end_struct(v, (void **)obj);
309    if (!ok && visit_is_input(v)) {
310        qapi_free_%(c_name)s(*obj);
311        *obj = NULL;
312    }
313    return ok;
314}
315''',
316                 c_name=c_name(name))
317
318
319class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
320
321    def __init__(self, prefix: str):
322        super().__init__(
323            prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
324            ' * Built-in QAPI visitors', __doc__)
325
326    def _begin_builtin_module(self) -> None:
327        self._genc.preamble_add(mcgen('''
328#include "qemu/osdep.h"
329#include "qapi/error.h"
330#include "qapi/qapi-builtin-visit.h"
331'''))
332        self._genh.preamble_add(mcgen('''
333#include "qapi/visitor.h"
334#include "qapi/qapi-builtin-types.h"
335
336'''))
337
338    def _begin_user_module(self, name: str) -> None:
339        types = self._module_basename('qapi-types', name)
340        visit = self._module_basename('qapi-visit', name)
341        self._genc.preamble_add(mcgen('''
342#include "qemu/osdep.h"
343#include "qapi/error.h"
344#include "qapi/qmp/qerror.h"
345#include "%(visit)s.h"
346''',
347                                      visit=visit))
348        self._genh.preamble_add(mcgen('''
349#include "qapi/qapi-builtin-visit.h"
350#include "%(types)s.h"
351
352''',
353                                      types=types))
354
355    def visit_enum_type(self,
356                        name: str,
357                        info: Optional[QAPISourceInfo],
358                        ifcond: QAPISchemaIfCond,
359                        features: List[QAPISchemaFeature],
360                        members: List[QAPISchemaEnumMember],
361                        prefix: Optional[str]) -> None:
362        with ifcontext(ifcond, self._genh, self._genc):
363            self._genh.add(gen_visit_decl(name, scalar=True))
364            self._genc.add(gen_visit_enum(name))
365
366    def visit_array_type(self,
367                         name: str,
368                         info: Optional[QAPISourceInfo],
369                         ifcond: QAPISchemaIfCond,
370                         element_type: QAPISchemaType) -> None:
371        with ifcontext(ifcond, self._genh, self._genc):
372            self._genh.add(gen_visit_decl(name))
373            self._genc.add(gen_visit_list(name, element_type))
374
375    def visit_object_type(self,
376                          name: str,
377                          info: Optional[QAPISourceInfo],
378                          ifcond: QAPISchemaIfCond,
379                          features: List[QAPISchemaFeature],
380                          base: Optional[QAPISchemaObjectType],
381                          members: List[QAPISchemaObjectTypeMember],
382                          variants: Optional[QAPISchemaVariants]) -> None:
383        # Nothing to do for the special empty builtin
384        if name == 'q_empty':
385            return
386        with ifcontext(ifcond, self._genh, self._genc):
387            self._genh.add(gen_visit_members_decl(name))
388            self._genc.add(gen_visit_object_members(name, base,
389                                                    members, variants))
390            # TODO Worth changing the visitor signature, so we could
391            # directly use rather than repeat type.is_implicit()?
392            if not name.startswith('q_'):
393                # only explicit types need an allocating visit
394                self._genh.add(gen_visit_decl(name))
395                self._genc.add(gen_visit_object(name))
396
397    def visit_alternate_type(self,
398                             name: str,
399                             info: Optional[QAPISourceInfo],
400                             ifcond: QAPISchemaIfCond,
401                             features: List[QAPISchemaFeature],
402                             variants: QAPISchemaVariants) -> None:
403        with ifcontext(ifcond, self._genh, self._genc):
404            self._genh.add(gen_visit_decl(name))
405            self._genc.add(gen_visit_alternate(name, variants))
406
407
408def gen_visit(schema: QAPISchema,
409              output_dir: str,
410              prefix: str,
411              opt_builtins: bool) -> None:
412    vis = QAPISchemaGenVisitVisitor(prefix)
413    schema.visit(vis)
414    vis.write(output_dir, opt_builtins)
415