xref: /qemu/scripts/qapi/visit.py (revision a4a1c70dc759e5b81627e96564f344ab43ea86eb) 
1#
2# QAPI visitor generator
3#
4# Copyright IBM, Corp. 2011
5# Copyright (C) 2014-2016 Red Hat, Inc.
6#
7# Authors:
8#  Anthony Liguori <aliguori@us.ibm.com>
9#  Michael Roth    <mdroth@linux.vnet.ibm.com>
10#  Markus Armbruster <armbru@redhat.com>
11#
12# This work is licensed under the terms of the GNU GPL, version 2.
13# See the COPYING file in the top-level directory.
14
15from qapi import *
16import re
17
18
19def gen_visit_decl(name, scalar=False):
20    c_type = c_name(name) + ' *'
21    if not scalar:
22        c_type += '*'
23    return mcgen('''
24void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
25''',
26                 c_name=c_name(name), c_type=c_type)
27
28
29def gen_visit_members_decl(name):
30    return mcgen('''
31
32void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
33''',
34                 c_name=c_name(name))
35
36
37def gen_visit_object_members(name, base, members, variants):
38    ret = mcgen('''
39
40void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
41{
42    Error *err = NULL;
43
44''',
45                c_name=c_name(name))
46
47    if base:
48        ret += mcgen('''
49    visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, &err);
50    if (err) {
51        goto out;
52    }
53''',
54                     c_type=base.c_name())
55
56    for memb in members:
57        if memb.optional:
58            ret += mcgen('''
59    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
60''',
61                         name=memb.name, c_name=c_name(memb.name))
62            push_indent()
63        ret += mcgen('''
64    visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, &err);
65    if (err) {
66        goto out;
67    }
68''',
69                     c_type=memb.type.c_name(), name=memb.name,
70                     c_name=c_name(memb.name))
71        if memb.optional:
72            pop_indent()
73            ret += mcgen('''
74    }
75''')
76
77    if variants:
78        ret += mcgen('''
79    switch (obj->%(c_name)s) {
80''',
81                     c_name=c_name(variants.tag_member.name))
82
83        for var in variants.variants:
84            ret += mcgen('''
85    case %(case)s:
86        visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
87        break;
88''',
89                         case=c_enum_const(variants.tag_member.type.name,
90                                           var.name,
91                                           variants.tag_member.type.prefix),
92                         c_type=var.type.c_name(), c_name=c_name(var.name))
93
94        ret += mcgen('''
95    default:
96        abort();
97    }
98''')
99
100    # 'goto out' produced for base, for each member, and if variants were
101    # present
102    if base or members or variants:
103        ret += mcgen('''
104
105out:
106''')
107    ret += mcgen('''
108    error_propagate(errp, err);
109}
110''')
111    return ret
112
113
114def gen_visit_list(name, element_type):
115    return mcgen('''
116
117void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
118{
119    Error *err = NULL;
120    %(c_name)s *tail;
121    size_t size = sizeof(**obj);
122
123    visit_start_list(v, name, (GenericList **)obj, size, &err);
124    if (err) {
125        goto out;
126    }
127
128    for (tail = *obj; tail;
129         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
130        visit_type_%(c_elt_type)s(v, NULL, &tail->value, &err);
131        if (err) {
132            break;
133        }
134    }
135
136    if (!err) {
137        visit_check_list(v, &err);
138    }
139    visit_end_list(v, (void **)obj);
140    if (err && visit_is_input(v)) {
141        qapi_free_%(c_name)s(*obj);
142        *obj = NULL;
143    }
144out:
145    error_propagate(errp, err);
146}
147''',
148                 c_name=c_name(name), c_elt_type=element_type.c_name())
149
150
151def gen_visit_enum(name):
152    return mcgen('''
153
154void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
155{
156    int value = *obj;
157    visit_type_enum(v, name, &value, %(c_name)s_lookup, errp);
158    *obj = value;
159}
160''',
161                 c_name=c_name(name))
162
163
164def gen_visit_alternate(name, variants):
165    promote_int = 'true'
166    ret = ''
167    for var in variants.variants:
168        if var.type.alternate_qtype() == 'QTYPE_QINT':
169            promote_int = 'false'
170
171    ret += mcgen('''
172
173void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
174{
175    Error *err = NULL;
176
177    visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
178                          %(promote_int)s, &err);
179    if (err) {
180        goto out;
181    }
182    if (!*obj) {
183        goto out_obj;
184    }
185    switch ((*obj)->type) {
186''',
187                 c_name=c_name(name), promote_int=promote_int)
188
189    for var in variants.variants:
190        ret += mcgen('''
191    case %(case)s:
192''',
193                     case=var.type.alternate_qtype())
194        if isinstance(var.type, QAPISchemaObjectType):
195            ret += mcgen('''
196        visit_start_struct(v, name, NULL, 0, &err);
197        if (err) {
198            break;
199        }
200        visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
201        if (!err) {
202            visit_check_struct(v, &err);
203        }
204        visit_end_struct(v, NULL);
205''',
206                         c_type=var.type.c_name(),
207                         c_name=c_name(var.name))
208        else:
209            ret += mcgen('''
210        visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
211''',
212                         c_type=var.type.c_name(),
213                         c_name=c_name(var.name))
214        ret += mcgen('''
215        break;
216''')
217
218    ret += mcgen('''
219    case QTYPE_NONE:
220        abort();
221    default:
222        error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
223                   "%(name)s");
224    }
225out_obj:
226    visit_end_alternate(v, (void **)obj);
227    if (err && visit_is_input(v)) {
228        qapi_free_%(c_name)s(*obj);
229        *obj = NULL;
230    }
231out:
232    error_propagate(errp, err);
233}
234''',
235                 name=name, c_name=c_name(name))
236
237    return ret
238
239
240def gen_visit_object(name, base, members, variants):
241    return mcgen('''
242
243void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
244{
245    Error *err = NULL;
246
247    visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
248    if (err) {
249        goto out;
250    }
251    if (!*obj) {
252        goto out_obj;
253    }
254    visit_type_%(c_name)s_members(v, *obj, &err);
255    if (err) {
256        goto out_obj;
257    }
258    visit_check_struct(v, &err);
259out_obj:
260    visit_end_struct(v, (void **)obj);
261    if (err && visit_is_input(v)) {
262        qapi_free_%(c_name)s(*obj);
263        *obj = NULL;
264    }
265out:
266    error_propagate(errp, err);
267}
268''',
269                 c_name=c_name(name))
270
271
272class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
273    def __init__(self):
274        self.decl = None
275        self.defn = None
276        self._btin = None
277
278    def visit_begin(self, schema):
279        self.decl = ''
280        self.defn = ''
281        self._btin = guardstart('QAPI_VISIT_BUILTIN')
282
283    def visit_end(self):
284        # To avoid header dependency hell, we always generate
285        # declarations for built-in types in our header files and
286        # simply guard them.  See also do_builtins (command line
287        # option -b).
288        self._btin += guardend('QAPI_VISIT_BUILTIN')
289        self.decl = self._btin + self.decl
290        self._btin = None
291
292    def visit_enum_type(self, name, info, values, prefix):
293        # Special case for our lone builtin enum type
294        # TODO use something cleaner than existence of info
295        if not info:
296            self._btin += gen_visit_decl(name, scalar=True)
297            if do_builtins:
298                self.defn += gen_visit_enum(name)
299        else:
300            self.decl += gen_visit_decl(name, scalar=True)
301            self.defn += gen_visit_enum(name)
302
303    def visit_array_type(self, name, info, element_type):
304        decl = gen_visit_decl(name)
305        defn = gen_visit_list(name, element_type)
306        if isinstance(element_type, QAPISchemaBuiltinType):
307            self._btin += decl
308            if do_builtins:
309                self.defn += defn
310        else:
311            self.decl += decl
312            self.defn += defn
313
314    def visit_object_type(self, name, info, base, members, variants):
315        # Nothing to do for the special empty builtin
316        if name == 'q_empty':
317            return
318        self.decl += gen_visit_members_decl(name)
319        self.defn += gen_visit_object_members(name, base, members, variants)
320        # TODO Worth changing the visitor signature, so we could
321        # directly use rather than repeat type.is_implicit()?
322        if not name.startswith('q_'):
323            # only explicit types need an allocating visit
324            self.decl += gen_visit_decl(name)
325            self.defn += gen_visit_object(name, base, members, variants)
326
327    def visit_alternate_type(self, name, info, variants):
328        self.decl += gen_visit_decl(name)
329        self.defn += gen_visit_alternate(name, variants)
330
331# If you link code generated from multiple schemata, you want only one
332# instance of the code for built-in types.  Generate it only when
333# do_builtins, enabled by command line option -b.  See also
334# QAPISchemaGenVisitVisitor.visit_end().
335do_builtins = False
336
337(input_file, output_dir, do_c, do_h, prefix, opts) = \
338    parse_command_line("b", ["builtins"])
339
340for o, a in opts:
341    if o in ("-b", "--builtins"):
342        do_builtins = True
343
344c_comment = '''
345/*
346 * schema-defined QAPI visitor functions
347 *
348 * Copyright IBM, Corp. 2011
349 *
350 * Authors:
351 *  Anthony Liguori   <aliguori@us.ibm.com>
352 *
353 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
354 * See the COPYING.LIB file in the top-level directory.
355 *
356 */
357'''
358h_comment = '''
359/*
360 * schema-defined QAPI visitor functions
361 *
362 * Copyright IBM, Corp. 2011
363 *
364 * Authors:
365 *  Anthony Liguori   <aliguori@us.ibm.com>
366 *
367 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
368 * See the COPYING.LIB file in the top-level directory.
369 *
370 */
371'''
372
373(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
374                            'qapi-visit.c', 'qapi-visit.h',
375                            c_comment, h_comment)
376
377fdef.write(mcgen('''
378#include "qemu/osdep.h"
379#include "qemu-common.h"
380#include "qapi/error.h"
381#include "%(prefix)sqapi-visit.h"
382''',
383                 prefix=prefix))
384
385fdecl.write(mcgen('''
386#include "qapi/visitor.h"
387#include "qapi/qmp/qerror.h"
388#include "%(prefix)sqapi-types.h"
389
390''',
391                  prefix=prefix))
392
393schema = QAPISchema(input_file)
394gen = QAPISchemaGenVisitVisitor()
395schema.visit(gen)
396fdef.write(gen.defn)
397fdecl.write(gen.decl)
398
399close_output(fdef, fdecl)
400