xref: /qemu/scripts/qapi/visit.py (revision c978bd5226f1ed73456ac468a7ed50af3d24dc84) 
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 qapi.common import *
17from qapi.gen import QAPISchemaModularCVisitor, ifcontext
18from qapi.schema import QAPISchemaObjectType
19
20
21def gen_visit_decl(name, scalar=False):
22    c_type = c_name(name) + ' *'
23    if not scalar:
24        c_type += '*'
25    return mcgen('''
26void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
27''',
28                 c_name=c_name(name), c_type=c_type)
29
30
31def gen_visit_members_decl(name):
32    return mcgen('''
33
34void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
35''',
36                 c_name=c_name(name))
37
38
39def gen_visit_object_members(name, base, members, variants):
40    ret = mcgen('''
41
42void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
43{
44    Error *err = NULL;
45
46''',
47                c_name=c_name(name))
48
49    if base:
50        ret += mcgen('''
51    visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, &err);
52    if (err) {
53        goto out;
54    }
55''',
56                     c_type=base.c_name())
57
58    for memb in members:
59        ret += gen_if(memb.ifcond)
60        if memb.optional:
61            ret += mcgen('''
62    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
63''',
64                         name=memb.name, c_name=c_name(memb.name))
65            push_indent()
66        ret += mcgen('''
67    visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, &err);
68    if (err) {
69        goto out;
70    }
71''',
72                     c_type=memb.type.c_name(), name=memb.name,
73                     c_name=c_name(memb.name))
74        if memb.optional:
75            pop_indent()
76            ret += mcgen('''
77    }
78''')
79        ret += gen_endif(memb.ifcond)
80
81    if variants:
82        ret += mcgen('''
83    switch (obj->%(c_name)s) {
84''',
85                     c_name=c_name(variants.tag_member.name))
86
87        for var in variants.variants:
88            case_str = c_enum_const(variants.tag_member.type.name,
89                                    var.name,
90                                    variants.tag_member.type.prefix)
91            ret += gen_if(var.ifcond)
92            if var.type.name == 'q_empty':
93                # valid variant and nothing to do
94                ret += mcgen('''
95    case %(case)s:
96        break;
97''',
98                             case=case_str)
99            else:
100                ret += mcgen('''
101    case %(case)s:
102        visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
103        break;
104''',
105                             case=case_str,
106                             c_type=var.type.c_name(), c_name=c_name(var.name))
107
108            ret += gen_endif(var.ifcond)
109        ret += mcgen('''
110    default:
111        abort();
112    }
113''')
114
115    # 'goto out' produced for base, for each member, and if variants were
116    # present
117    if base or members or variants:
118        ret += mcgen('''
119
120out:
121''')
122    ret += mcgen('''
123    error_propagate(errp, err);
124}
125''')
126    return ret
127
128
129def gen_visit_list(name, element_type):
130    return mcgen('''
131
132void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
133{
134    Error *err = NULL;
135    %(c_name)s *tail;
136    size_t size = sizeof(**obj);
137
138    visit_start_list(v, name, (GenericList **)obj, size, &err);
139    if (err) {
140        goto out;
141    }
142
143    for (tail = *obj; tail;
144         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
145        visit_type_%(c_elt_type)s(v, NULL, &tail->value, &err);
146        if (err) {
147            break;
148        }
149    }
150
151    if (!err) {
152        visit_check_list(v, &err);
153    }
154    visit_end_list(v, (void **)obj);
155    if (err && visit_is_input(v)) {
156        qapi_free_%(c_name)s(*obj);
157        *obj = NULL;
158    }
159out:
160    error_propagate(errp, err);
161}
162''',
163                 c_name=c_name(name), c_elt_type=element_type.c_name())
164
165
166def gen_visit_enum(name):
167    return mcgen('''
168
169void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
170{
171    int value = *obj;
172    visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
173    *obj = value;
174}
175''',
176                 c_name=c_name(name))
177
178
179def gen_visit_alternate(name, variants):
180    ret = mcgen('''
181
182void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
183{
184    Error *err = NULL;
185
186    visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
187                          &err);
188    if (err) {
189        goto out;
190    }
191    if (!*obj) {
192        /* incomplete */
193        assert(visit_is_dealloc(v));
194        goto out_obj;
195    }
196    switch ((*obj)->type) {
197''',
198                c_name=c_name(name))
199
200    for var in variants.variants:
201        ret += gen_if(var.ifcond)
202        ret += mcgen('''
203    case %(case)s:
204''',
205                     case=var.type.alternate_qtype())
206        if isinstance(var.type, QAPISchemaObjectType):
207            ret += mcgen('''
208        visit_start_struct(v, name, NULL, 0, &err);
209        if (err) {
210            break;
211        }
212        visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
213        if (!err) {
214            visit_check_struct(v, &err);
215        }
216        visit_end_struct(v, NULL);
217''',
218                         c_type=var.type.c_name(),
219                         c_name=c_name(var.name))
220        else:
221            ret += mcgen('''
222        visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
223''',
224                         c_type=var.type.c_name(),
225                         c_name=c_name(var.name))
226        ret += mcgen('''
227        break;
228''')
229        ret += gen_endif(var.ifcond)
230
231    ret += mcgen('''
232    case QTYPE_NONE:
233        abort();
234    default:
235        error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
236                   "%(name)s");
237        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
238        g_free(*obj);
239        *obj = NULL;
240    }
241out_obj:
242    visit_end_alternate(v, (void **)obj);
243    if (err && visit_is_input(v)) {
244        qapi_free_%(c_name)s(*obj);
245        *obj = NULL;
246    }
247out:
248    error_propagate(errp, err);
249}
250''',
251                 name=name, c_name=c_name(name))
252
253    return ret
254
255
256def gen_visit_object(name, base, members, variants):
257    return mcgen('''
258
259void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
260{
261    Error *err = NULL;
262
263    visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
264    if (err) {
265        goto out;
266    }
267    if (!*obj) {
268        /* incomplete */
269        assert(visit_is_dealloc(v));
270        goto out_obj;
271    }
272    visit_type_%(c_name)s_members(v, *obj, &err);
273    if (err) {
274        goto out_obj;
275    }
276    visit_check_struct(v, &err);
277out_obj:
278    visit_end_struct(v, (void **)obj);
279    if (err && visit_is_input(v)) {
280        qapi_free_%(c_name)s(*obj);
281        *obj = NULL;
282    }
283out:
284    error_propagate(errp, err);
285}
286''',
287                 c_name=c_name(name))
288
289
290class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
291
292    def __init__(self, prefix):
293        super().__init__(
294            prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
295            ' * Built-in QAPI visitors', __doc__)
296
297    def _begin_system_module(self, name):
298        self._genc.preamble_add(mcgen('''
299#include "qemu/osdep.h"
300#include "qapi/error.h"
301#include "qapi/qapi-builtin-visit.h"
302'''))
303        self._genh.preamble_add(mcgen('''
304#include "qapi/visitor.h"
305#include "qapi/qapi-builtin-types.h"
306
307'''))
308
309    def _begin_user_module(self, name):
310        types = self._module_basename('qapi-types', name)
311        visit = self._module_basename('qapi-visit', name)
312        self._genc.preamble_add(mcgen('''
313#include "qemu/osdep.h"
314#include "qapi/error.h"
315#include "qapi/qmp/qerror.h"
316#include "%(visit)s.h"
317''',
318                                      visit=visit))
319        self._genh.preamble_add(mcgen('''
320#include "qapi/qapi-builtin-visit.h"
321#include "%(types)s.h"
322
323''',
324                                      types=types))
325
326    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
327        with ifcontext(ifcond, self._genh, self._genc):
328            self._genh.add(gen_visit_decl(name, scalar=True))
329            self._genc.add(gen_visit_enum(name))
330
331    def visit_array_type(self, name, info, ifcond, element_type):
332        with ifcontext(ifcond, self._genh, self._genc):
333            self._genh.add(gen_visit_decl(name))
334            self._genc.add(gen_visit_list(name, element_type))
335
336    def visit_object_type(self, name, info, ifcond, features,
337                          base, members, variants):
338        # Nothing to do for the special empty builtin
339        if name == 'q_empty':
340            return
341        with ifcontext(ifcond, self._genh, self._genc):
342            self._genh.add(gen_visit_members_decl(name))
343            self._genc.add(gen_visit_object_members(name, base,
344                                                    members, variants))
345            # TODO Worth changing the visitor signature, so we could
346            # directly use rather than repeat type.is_implicit()?
347            if not name.startswith('q_'):
348                # only explicit types need an allocating visit
349                self._genh.add(gen_visit_decl(name))
350                self._genc.add(gen_visit_object(name, base, members, variants))
351
352    def visit_alternate_type(self, name, info, ifcond, features, variants):
353        with ifcontext(ifcond, self._genh, self._genc):
354            self._genh.add(gen_visit_decl(name))
355            self._genc.add(gen_visit_alternate(name, variants))
356
357
358def gen_visit(schema, output_dir, prefix, opt_builtins):
359    vis = QAPISchemaGenVisitVisitor(prefix)
360    schema.visit(vis)
361    vis.write(output_dir, opt_builtins)
362