xref: /qemu/scripts/qapi/visit.py (revision 5af8263d40c698c47befd4c0bed3d6c452b56d82) 
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 .common import (
17    c_enum_const,
18    c_name,
19    gen_endif,
20    gen_if,
21    mcgen,
22    pop_indent,
23    push_indent,
24)
25from .gen import QAPISchemaModularCVisitor, ifcontext
26from .schema import QAPISchemaObjectType
27
28
29def gen_visit_decl(name, scalar=False):
30    c_type = c_name(name) + ' *'
31    if not scalar:
32        c_type += '*'
33    return mcgen('''
34bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
35''',
36                 c_name=c_name(name), c_type=c_type)
37
38
39def gen_visit_members_decl(name):
40    return mcgen('''
41
42bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
43''',
44                 c_name=c_name(name))
45
46
47def gen_visit_object_members(name, base, members, variants):
48    ret = mcgen('''
49
50bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
51{
52''',
53                c_name=c_name(name))
54
55    if base:
56        ret += mcgen('''
57    if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) {
58        return false;
59    }
60''',
61                     c_type=base.c_name())
62
63    for memb in members:
64        ret += gen_if(memb.ifcond)
65        if memb.optional:
66            ret += mcgen('''
67    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
68''',
69                         name=memb.name, c_name=c_name(memb.name))
70            push_indent()
71        ret += mcgen('''
72    if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) {
73        return false;
74    }
75''',
76                     c_type=memb.type.c_name(), name=memb.name,
77                     c_name=c_name(memb.name))
78        if memb.optional:
79            pop_indent()
80            ret += mcgen('''
81    }
82''')
83        ret += gen_endif(memb.ifcond)
84
85    if variants:
86        ret += mcgen('''
87    switch (obj->%(c_name)s) {
88''',
89                     c_name=c_name(variants.tag_member.name))
90
91        for var in variants.variants:
92            case_str = c_enum_const(variants.tag_member.type.name,
93                                    var.name,
94                                    variants.tag_member.type.prefix)
95            ret += gen_if(var.ifcond)
96            if var.type.name == 'q_empty':
97                # valid variant and nothing to do
98                ret += mcgen('''
99    case %(case)s:
100        break;
101''',
102                             case=case_str)
103            else:
104                ret += mcgen('''
105    case %(case)s:
106        return visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, errp);
107''',
108                             case=case_str,
109                             c_type=var.type.c_name(), c_name=c_name(var.name))
110
111            ret += gen_endif(var.ifcond)
112        ret += mcgen('''
113    default:
114        abort();
115    }
116''')
117
118    ret += mcgen('''
119    return true;
120}
121''')
122    return ret
123
124
125def gen_visit_list(name, element_type):
126    return mcgen('''
127
128bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
129{
130    bool ok = false;
131    %(c_name)s *tail;
132    size_t size = sizeof(**obj);
133
134    if (!visit_start_list(v, name, (GenericList **)obj, size, errp)) {
135        return false;
136    }
137
138    for (tail = *obj; tail;
139         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
140        if (!visit_type_%(c_elt_type)s(v, NULL, &tail->value, errp)) {
141            goto out_obj;
142        }
143    }
144
145    ok = visit_check_list(v, errp);
146out_obj:
147    visit_end_list(v, (void **)obj);
148    if (!ok && visit_is_input(v)) {
149        qapi_free_%(c_name)s(*obj);
150        *obj = NULL;
151    }
152    return ok;
153}
154''',
155                 c_name=c_name(name), c_elt_type=element_type.c_name())
156
157
158def gen_visit_enum(name):
159    return mcgen('''
160
161bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
162{
163    int value = *obj;
164    bool ok = visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
165    *obj = value;
166    return ok;
167}
168''',
169                 c_name=c_name(name))
170
171
172def gen_visit_alternate(name, variants):
173    ret = mcgen('''
174
175bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
176{
177    bool ok = false;
178
179    if (!visit_start_alternate(v, name, (GenericAlternate **)obj,
180                               sizeof(**obj), errp)) {
181        return false;
182    }
183    if (!*obj) {
184        /* incomplete */
185        assert(visit_is_dealloc(v));
186        ok = true;
187        goto out_obj;
188    }
189    switch ((*obj)->type) {
190''',
191                c_name=c_name(name))
192
193    for var in variants.variants:
194        ret += gen_if(var.ifcond)
195        ret += mcgen('''
196    case %(case)s:
197''',
198                     case=var.type.alternate_qtype())
199        if isinstance(var.type, QAPISchemaObjectType):
200            ret += mcgen('''
201        if (!visit_start_struct(v, name, NULL, 0, errp)) {
202            break;
203        }
204        if (visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, errp)) {
205            ok = visit_check_struct(v, errp);
206        }
207        visit_end_struct(v, NULL);
208''',
209                         c_type=var.type.c_name(),
210                         c_name=c_name(var.name))
211        else:
212            ret += mcgen('''
213        ok = visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, errp);
214''',
215                         c_type=var.type.c_name(),
216                         c_name=c_name(var.name))
217        ret += mcgen('''
218        break;
219''')
220        ret += gen_endif(var.ifcond)
221
222    ret += mcgen('''
223    case QTYPE_NONE:
224        abort();
225    default:
226        assert(visit_is_input(v));
227        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
228                   "%(name)s");
229        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
230        g_free(*obj);
231        *obj = NULL;
232    }
233out_obj:
234    visit_end_alternate(v, (void **)obj);
235    if (!ok && visit_is_input(v)) {
236        qapi_free_%(c_name)s(*obj);
237        *obj = NULL;
238    }
239    return ok;
240}
241''',
242                 name=name, c_name=c_name(name))
243
244    return ret
245
246
247def gen_visit_object(name, base, members, variants):
248    return mcgen('''
249
250bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
251{
252    bool ok = false;
253
254    if (!visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), errp)) {
255        return false;
256    }
257    if (!*obj) {
258        /* incomplete */
259        assert(visit_is_dealloc(v));
260        ok = true;
261        goto out_obj;
262    }
263    if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
264        goto out_obj;
265    }
266    ok = visit_check_struct(v, errp);
267out_obj:
268    visit_end_struct(v, (void **)obj);
269    if (!ok && visit_is_input(v)) {
270        qapi_free_%(c_name)s(*obj);
271        *obj = NULL;
272    }
273    return ok;
274}
275''',
276                 c_name=c_name(name))
277
278
279class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
280
281    def __init__(self, prefix):
282        super().__init__(
283            prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
284            ' * Built-in QAPI visitors', __doc__)
285
286    def _begin_system_module(self, name):
287        self._genc.preamble_add(mcgen('''
288#include "qemu/osdep.h"
289#include "qapi/error.h"
290#include "qapi/qapi-builtin-visit.h"
291'''))
292        self._genh.preamble_add(mcgen('''
293#include "qapi/visitor.h"
294#include "qapi/qapi-builtin-types.h"
295
296'''))
297
298    def _begin_user_module(self, name):
299        types = self._module_basename('qapi-types', name)
300        visit = self._module_basename('qapi-visit', name)
301        self._genc.preamble_add(mcgen('''
302#include "qemu/osdep.h"
303#include "qapi/error.h"
304#include "qapi/qmp/qerror.h"
305#include "%(visit)s.h"
306''',
307                                      visit=visit))
308        self._genh.preamble_add(mcgen('''
309#include "qapi/qapi-builtin-visit.h"
310#include "%(types)s.h"
311
312''',
313                                      types=types))
314
315    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
316        with ifcontext(ifcond, self._genh, self._genc):
317            self._genh.add(gen_visit_decl(name, scalar=True))
318            self._genc.add(gen_visit_enum(name))
319
320    def visit_array_type(self, name, info, ifcond, element_type):
321        with ifcontext(ifcond, self._genh, self._genc):
322            self._genh.add(gen_visit_decl(name))
323            self._genc.add(gen_visit_list(name, element_type))
324
325    def visit_object_type(self, name, info, ifcond, features,
326                          base, members, variants):
327        # Nothing to do for the special empty builtin
328        if name == 'q_empty':
329            return
330        with ifcontext(ifcond, self._genh, self._genc):
331            self._genh.add(gen_visit_members_decl(name))
332            self._genc.add(gen_visit_object_members(name, base,
333                                                    members, variants))
334            # TODO Worth changing the visitor signature, so we could
335            # directly use rather than repeat type.is_implicit()?
336            if not name.startswith('q_'):
337                # only explicit types need an allocating visit
338                self._genh.add(gen_visit_decl(name))
339                self._genc.add(gen_visit_object(name, base, members, variants))
340
341    def visit_alternate_type(self, name, info, ifcond, features, variants):
342        with ifcontext(ifcond, self._genh, self._genc):
343            self._genh.add(gen_visit_decl(name))
344            self._genc.add(gen_visit_alternate(name, variants))
345
346
347def gen_visit(schema, output_dir, prefix, opt_builtins):
348    vis = QAPISchemaGenVisitVisitor(prefix)
349    schema.visit(vis)
350    vis.write(output_dir, opt_builtins)
351