xref: /qemu/scripts/qapi/visit.py (revision f9734d5d) 
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    gen_endif,
22    gen_if,
23    indent,
24    mcgen,
25)
26from .gen import QAPISchemaModularCVisitor, ifcontext
27from .schema import (
28    QAPISchema,
29    QAPISchemaEnumMember,
30    QAPISchemaEnumType,
31    QAPISchemaFeature,
32    QAPISchemaIfCond,
33    QAPISchemaObjectType,
34    QAPISchemaObjectTypeMember,
35    QAPISchemaType,
36    QAPISchemaVariants,
37)
38from .source import QAPISourceInfo
39
40
41def gen_visit_decl(name: str, scalar: bool = False) -> str:
42    c_type = c_name(name) + ' *'
43    if not scalar:
44        c_type += '*'
45    return mcgen('''
46
47bool visit_type_%(c_name)s(Visitor *v, const char *name,
48                 %(c_type)sobj, Error **errp);
49''',
50                 c_name=c_name(name), c_type=c_type)
51
52
53def gen_visit_members_decl(name: str) -> str:
54    return mcgen('''
55
56bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
57''',
58                 c_name=c_name(name))
59
60
61def gen_visit_object_members(name: str,
62                             base: Optional[QAPISchemaObjectType],
63                             members: List[QAPISchemaObjectTypeMember],
64                             variants: Optional[QAPISchemaVariants]) -> str:
65    ret = mcgen('''
66
67bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
68{
69''',
70                c_name=c_name(name))
71
72    if base:
73        ret += mcgen('''
74    if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) {
75        return false;
76    }
77''',
78                     c_type=base.c_name())
79
80    for memb in members:
81        deprecated = 'deprecated' in [f.name for f in memb.features]
82        ret += gen_if(memb.ifcond.cgen())
83        if memb.optional:
84            ret += mcgen('''
85    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
86''',
87                         name=memb.name, c_name=c_name(memb.name))
88            indent.increase()
89        if deprecated:
90            ret += mcgen('''
91    if (!visit_deprecated_accept(v, "%(name)s", errp)) {
92        return false;
93    }
94    if (visit_deprecated(v, "%(name)s")) {
95''',
96                         name=memb.name)
97            indent.increase()
98        ret += mcgen('''
99    if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) {
100        return false;
101    }
102''',
103                     c_type=memb.type.c_name(), name=memb.name,
104                     c_name=c_name(memb.name))
105        if deprecated:
106            indent.decrease()
107            ret += mcgen('''
108    }
109''')
110        if memb.optional:
111            indent.decrease()
112            ret += mcgen('''
113    }
114''')
115        ret += gen_endif(memb.ifcond.cgen())
116
117    if variants:
118        tag_member = variants.tag_member
119        assert isinstance(tag_member.type, QAPISchemaEnumType)
120
121        ret += mcgen('''
122    switch (obj->%(c_name)s) {
123''',
124                     c_name=c_name(tag_member.name))
125
126        for var in variants.variants:
127            case_str = c_enum_const(tag_member.type.name, var.name,
128                                    tag_member.type.prefix)
129            ret += gen_if(var.ifcond.cgen())
130            if var.type.name == 'q_empty':
131                # valid variant and nothing to do
132                ret += mcgen('''
133    case %(case)s:
134        break;
135''',
136                             case=case_str)
137            else:
138                ret += mcgen('''
139    case %(case)s:
140        return visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, errp);
141''',
142                             case=case_str,
143                             c_type=var.type.c_name(), c_name=c_name(var.name))
144
145            ret += gen_endif(var.ifcond.cgen())
146        ret += mcgen('''
147    default:
148        abort();
149    }
150''')
151
152    ret += mcgen('''
153    return true;
154}
155''')
156    return ret
157
158
159def gen_visit_list(name: str, element_type: QAPISchemaType) -> str:
160    return mcgen('''
161
162bool visit_type_%(c_name)s(Visitor *v, const char *name,
163                 %(c_name)s **obj, Error **errp)
164{
165    bool ok = false;
166    %(c_name)s *tail;
167    size_t size = sizeof(**obj);
168
169    if (!visit_start_list(v, name, (GenericList **)obj, size, errp)) {
170        return false;
171    }
172
173    for (tail = *obj; tail;
174         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
175        if (!visit_type_%(c_elt_type)s(v, NULL, &tail->value, errp)) {
176            goto out_obj;
177        }
178    }
179
180    ok = visit_check_list(v, errp);
181out_obj:
182    visit_end_list(v, (void **)obj);
183    if (!ok && visit_is_input(v)) {
184        qapi_free_%(c_name)s(*obj);
185        *obj = NULL;
186    }
187    return ok;
188}
189''',
190                 c_name=c_name(name), c_elt_type=element_type.c_name())
191
192
193def gen_visit_enum(name: str) -> str:
194    return mcgen('''
195
196bool visit_type_%(c_name)s(Visitor *v, const char *name,
197                 %(c_name)s *obj, Error **errp)
198{
199    int value = *obj;
200    bool ok = visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
201    *obj = value;
202    return ok;
203}
204''',
205                 c_name=c_name(name))
206
207
208def gen_visit_alternate(name: str, variants: QAPISchemaVariants) -> str:
209    ret = mcgen('''
210
211bool visit_type_%(c_name)s(Visitor *v, const char *name,
212                 %(c_name)s **obj, Error **errp)
213{
214    bool ok = false;
215
216    if (!visit_start_alternate(v, name, (GenericAlternate **)obj,
217                               sizeof(**obj), errp)) {
218        return false;
219    }
220    if (!*obj) {
221        /* incomplete */
222        assert(visit_is_dealloc(v));
223        ok = true;
224        goto out_obj;
225    }
226    switch ((*obj)->type) {
227''',
228                c_name=c_name(name))
229
230    for var in variants.variants:
231        ret += gen_if(var.ifcond.cgen())
232        ret += mcgen('''
233    case %(case)s:
234''',
235                     case=var.type.alternate_qtype())
236        if isinstance(var.type, QAPISchemaObjectType):
237            ret += mcgen('''
238        if (!visit_start_struct(v, name, NULL, 0, errp)) {
239            break;
240        }
241        if (visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, errp)) {
242            ok = visit_check_struct(v, errp);
243        }
244        visit_end_struct(v, NULL);
245''',
246                         c_type=var.type.c_name(),
247                         c_name=c_name(var.name))
248        else:
249            ret += mcgen('''
250        ok = visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, errp);
251''',
252                         c_type=var.type.c_name(),
253                         c_name=c_name(var.name))
254        ret += mcgen('''
255        break;
256''')
257        ret += gen_endif(var.ifcond.cgen())
258
259    ret += mcgen('''
260    case QTYPE_NONE:
261        abort();
262    default:
263        assert(visit_is_input(v));
264        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
265                   "%(name)s");
266        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
267        g_free(*obj);
268        *obj = NULL;
269    }
270out_obj:
271    visit_end_alternate(v, (void **)obj);
272    if (!ok && visit_is_input(v)) {
273        qapi_free_%(c_name)s(*obj);
274        *obj = NULL;
275    }
276    return ok;
277}
278''',
279                 name=name, c_name=c_name(name))
280
281    return ret
282
283
284def gen_visit_object(name: str) -> str:
285    return mcgen('''
286
287bool visit_type_%(c_name)s(Visitor *v, const char *name,
288                 %(c_name)s **obj, Error **errp)
289{
290    bool ok = false;
291
292    if (!visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), errp)) {
293        return false;
294    }
295    if (!*obj) {
296        /* incomplete */
297        assert(visit_is_dealloc(v));
298        ok = true;
299        goto out_obj;
300    }
301    if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
302        goto out_obj;
303    }
304    ok = visit_check_struct(v, errp);
305out_obj:
306    visit_end_struct(v, (void **)obj);
307    if (!ok && visit_is_input(v)) {
308        qapi_free_%(c_name)s(*obj);
309        *obj = NULL;
310    }
311    return ok;
312}
313''',
314                 c_name=c_name(name))
315
316
317class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
318
319    def __init__(self, prefix: str):
320        super().__init__(
321            prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
322            ' * Built-in QAPI visitors', __doc__)
323
324    def _begin_builtin_module(self) -> None:
325        self._genc.preamble_add(mcgen('''
326#include "qemu/osdep.h"
327#include "qapi/error.h"
328#include "qapi/qapi-builtin-visit.h"
329'''))
330        self._genh.preamble_add(mcgen('''
331#include "qapi/visitor.h"
332#include "qapi/qapi-builtin-types.h"
333
334'''))
335
336    def _begin_user_module(self, name: str) -> None:
337        types = self._module_basename('qapi-types', name)
338        visit = self._module_basename('qapi-visit', name)
339        self._genc.preamble_add(mcgen('''
340#include "qemu/osdep.h"
341#include "qapi/error.h"
342#include "qapi/qmp/qerror.h"
343#include "%(visit)s.h"
344''',
345                                      visit=visit))
346        self._genh.preamble_add(mcgen('''
347#include "qapi/qapi-builtin-visit.h"
348#include "%(types)s.h"
349
350''',
351                                      types=types))
352
353    def visit_enum_type(self,
354                        name: str,
355                        info: Optional[QAPISourceInfo],
356                        ifcond: QAPISchemaIfCond,
357                        features: List[QAPISchemaFeature],
358                        members: List[QAPISchemaEnumMember],
359                        prefix: Optional[str]) -> None:
360        with ifcontext(ifcond, self._genh, self._genc):
361            self._genh.add(gen_visit_decl(name, scalar=True))
362            self._genc.add(gen_visit_enum(name))
363
364    def visit_array_type(self,
365                         name: str,
366                         info: Optional[QAPISourceInfo],
367                         ifcond: QAPISchemaIfCond,
368                         element_type: QAPISchemaType) -> None:
369        with ifcontext(ifcond, self._genh, self._genc):
370            self._genh.add(gen_visit_decl(name))
371            self._genc.add(gen_visit_list(name, element_type))
372
373    def visit_object_type(self,
374                          name: str,
375                          info: Optional[QAPISourceInfo],
376                          ifcond: QAPISchemaIfCond,
377                          features: List[QAPISchemaFeature],
378                          base: Optional[QAPISchemaObjectType],
379                          members: List[QAPISchemaObjectTypeMember],
380                          variants: Optional[QAPISchemaVariants]) -> None:
381        # Nothing to do for the special empty builtin
382        if name == 'q_empty':
383            return
384        with ifcontext(ifcond, self._genh, self._genc):
385            self._genh.add(gen_visit_members_decl(name))
386            self._genc.add(gen_visit_object_members(name, base,
387                                                    members, variants))
388            # TODO Worth changing the visitor signature, so we could
389            # directly use rather than repeat type.is_implicit()?
390            if not name.startswith('q_'):
391                # only explicit types need an allocating visit
392                self._genh.add(gen_visit_decl(name))
393                self._genc.add(gen_visit_object(name))
394
395    def visit_alternate_type(self,
396                             name: str,
397                             info: Optional[QAPISourceInfo],
398                             ifcond: QAPISchemaIfCond,
399                             features: List[QAPISchemaFeature],
400                             variants: QAPISchemaVariants) -> None:
401        with ifcontext(ifcond, self._genh, self._genc):
402            self._genh.add(gen_visit_decl(name))
403            self._genc.add(gen_visit_alternate(name, variants))
404
405
406def gen_visit(schema: QAPISchema,
407              output_dir: str,
408              prefix: str,
409              opt_builtins: bool) -> None:
410    vis = QAPISchemaGenVisitVisitor(prefix)
411    schema.visit(vis)
412    vis.write(output_dir, opt_builtins)
413