xref: /qemu/scripts/qapi/visit.py (revision c261394978d000000a095d7b4986226d0a4a551c) 
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 *
16
17
18def gen_visit_decl(name, scalar=False):
19    c_type = c_name(name) + ' *'
20    if not scalar:
21        c_type += '*'
22    return mcgen('''
23void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
24''',
25                 c_name=c_name(name), c_type=c_type)
26
27
28def gen_visit_members_decl(name):
29    return mcgen('''
30
31void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
32''',
33                 c_name=c_name(name))
34
35
36def gen_visit_object_members(name, base, members, variants):
37    ret = mcgen('''
38
39void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
40{
41    Error *err = NULL;
42
43''',
44                c_name=c_name(name))
45
46    if base:
47        ret += mcgen('''
48    visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, &err);
49    if (err) {
50        goto out;
51    }
52''',
53                     c_type=base.c_name())
54
55    for memb in members:
56        if memb.optional:
57            ret += mcgen('''
58    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
59''',
60                         name=memb.name, c_name=c_name(memb.name))
61            push_indent()
62        ret += mcgen('''
63    visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, &err);
64    if (err) {
65        goto out;
66    }
67''',
68                     c_type=memb.type.c_name(), name=memb.name,
69                     c_name=c_name(memb.name))
70        if memb.optional:
71            pop_indent()
72            ret += mcgen('''
73    }
74''')
75
76    if variants:
77        ret += mcgen('''
78    switch (obj->%(c_name)s) {
79''',
80                     c_name=c_name(variants.tag_member.name))
81
82        for var in variants.variants:
83            ret += mcgen('''
84    case %(case)s:
85        visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
86        break;
87''',
88                         case=c_enum_const(variants.tag_member.type.name,
89                                           var.name,
90                                           variants.tag_member.type.prefix),
91                         c_type=var.type.c_name(), c_name=c_name(var.name))
92
93        ret += mcgen('''
94    default:
95        abort();
96    }
97''')
98
99    # 'goto out' produced for base, for each member, and if variants were
100    # present
101    if base or members or variants:
102        ret += mcgen('''
103
104out:
105''')
106    ret += mcgen('''
107    error_propagate(errp, err);
108}
109''')
110    return ret
111
112
113def gen_visit_list(name, element_type):
114    return mcgen('''
115
116void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
117{
118    Error *err = NULL;
119    %(c_name)s *tail;
120    size_t size = sizeof(**obj);
121
122    visit_start_list(v, name, (GenericList **)obj, size, &err);
123    if (err) {
124        goto out;
125    }
126
127    for (tail = *obj; tail;
128         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
129        visit_type_%(c_elt_type)s(v, NULL, &tail->value, &err);
130        if (err) {
131            break;
132        }
133    }
134
135    if (!err) {
136        visit_check_list(v, &err);
137    }
138    visit_end_list(v, (void **)obj);
139    if (err && visit_is_input(v)) {
140        qapi_free_%(c_name)s(*obj);
141        *obj = NULL;
142    }
143out:
144    error_propagate(errp, err);
145}
146''',
147                 c_name=c_name(name), c_elt_type=element_type.c_name())
148
149
150def gen_visit_enum(name):
151    return mcgen('''
152
153void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
154{
155    int value = *obj;
156    visit_type_enum(v, name, &value, %(c_name)s_lookup, errp);
157    *obj = value;
158}
159''',
160                 c_name=c_name(name))
161
162
163def gen_visit_alternate(name, variants):
164    promote_int = 'true'
165    ret = ''
166    for var in variants.variants:
167        if var.type.alternate_qtype() == 'QTYPE_QINT':
168            promote_int = 'false'
169
170    ret += mcgen('''
171
172void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
173{
174    Error *err = NULL;
175
176    visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
177                          %(promote_int)s, &err);
178    if (err) {
179        goto out;
180    }
181    if (!*obj) {
182        goto out_obj;
183    }
184    switch ((*obj)->type) {
185''',
186                 c_name=c_name(name), promote_int=promote_int)
187
188    for var in variants.variants:
189        ret += mcgen('''
190    case %(case)s:
191''',
192                     case=var.type.alternate_qtype())
193        if isinstance(var.type, QAPISchemaObjectType):
194            ret += mcgen('''
195        visit_start_struct(v, name, NULL, 0, &err);
196        if (err) {
197            break;
198        }
199        visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
200        if (!err) {
201            visit_check_struct(v, &err);
202        }
203        visit_end_struct(v, NULL);
204''',
205                         c_type=var.type.c_name(),
206                         c_name=c_name(var.name))
207        else:
208            ret += mcgen('''
209        visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
210''',
211                         c_type=var.type.c_name(),
212                         c_name=c_name(var.name))
213        ret += mcgen('''
214        break;
215''')
216
217    ret += mcgen('''
218    case QTYPE_NONE:
219        abort();
220    default:
221        error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
222                   "%(name)s");
223    }
224out_obj:
225    visit_end_alternate(v, (void **)obj);
226    if (err && visit_is_input(v)) {
227        qapi_free_%(c_name)s(*obj);
228        *obj = NULL;
229    }
230out:
231    error_propagate(errp, err);
232}
233''',
234                 name=name, c_name=c_name(name))
235
236    return ret
237
238
239def gen_visit_object(name, base, members, variants):
240    return mcgen('''
241
242void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
243{
244    Error *err = NULL;
245
246    visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
247    if (err) {
248        goto out;
249    }
250    if (!*obj) {
251        goto out_obj;
252    }
253    visit_type_%(c_name)s_members(v, *obj, &err);
254    if (err) {
255        goto out_obj;
256    }
257    visit_check_struct(v, &err);
258out_obj:
259    visit_end_struct(v, (void **)obj);
260    if (err && visit_is_input(v)) {
261        qapi_free_%(c_name)s(*obj);
262        *obj = NULL;
263    }
264out:
265    error_propagate(errp, err);
266}
267''',
268                 c_name=c_name(name))
269
270
271class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
272    def __init__(self):
273        self.decl = None
274        self.defn = None
275        self._btin = None
276
277    def visit_begin(self, schema):
278        self.decl = ''
279        self.defn = ''
280        self._btin = guardstart('QAPI_VISIT_BUILTIN')
281
282    def visit_end(self):
283        # To avoid header dependency hell, we always generate
284        # declarations for built-in types in our header files and
285        # simply guard them.  See also do_builtins (command line
286        # option -b).
287        self._btin += guardend('QAPI_VISIT_BUILTIN')
288        self.decl = self._btin + self.decl
289        self._btin = None
290
291    def visit_enum_type(self, name, info, values, prefix):
292        # Special case for our lone builtin enum type
293        # TODO use something cleaner than existence of info
294        if not info:
295            self._btin += gen_visit_decl(name, scalar=True)
296            if do_builtins:
297                self.defn += gen_visit_enum(name)
298        else:
299            self.decl += gen_visit_decl(name, scalar=True)
300            self.defn += gen_visit_enum(name)
301
302    def visit_array_type(self, name, info, element_type):
303        decl = gen_visit_decl(name)
304        defn = gen_visit_list(name, element_type)
305        if isinstance(element_type, QAPISchemaBuiltinType):
306            self._btin += decl
307            if do_builtins:
308                self.defn += defn
309        else:
310            self.decl += decl
311            self.defn += defn
312
313    def visit_object_type(self, name, info, base, members, variants):
314        # Nothing to do for the special empty builtin
315        if name == 'q_empty':
316            return
317        self.decl += gen_visit_members_decl(name)
318        self.defn += gen_visit_object_members(name, base, members, variants)
319        # TODO Worth changing the visitor signature, so we could
320        # directly use rather than repeat type.is_implicit()?
321        if not name.startswith('q_'):
322            # only explicit types need an allocating visit
323            self.decl += gen_visit_decl(name)
324            self.defn += gen_visit_object(name, base, members, variants)
325
326    def visit_alternate_type(self, name, info, variants):
327        self.decl += gen_visit_decl(name)
328        self.defn += gen_visit_alternate(name, variants)
329
330# If you link code generated from multiple schemata, you want only one
331# instance of the code for built-in types.  Generate it only when
332# do_builtins, enabled by command line option -b.  See also
333# QAPISchemaGenVisitVisitor.visit_end().
334do_builtins = False
335
336(input_file, output_dir, do_c, do_h, prefix, opts) = \
337    parse_command_line('b', ['builtins'])
338
339for o, a in opts:
340    if o in ('-b', '--builtins'):
341        do_builtins = True
342
343c_comment = '''
344/*
345 * schema-defined QAPI visitor functions
346 *
347 * Copyright IBM, Corp. 2011
348 *
349 * Authors:
350 *  Anthony Liguori   <aliguori@us.ibm.com>
351 *
352 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
353 * See the COPYING.LIB file in the top-level directory.
354 *
355 */
356'''
357h_comment = '''
358/*
359 * schema-defined QAPI visitor functions
360 *
361 * Copyright IBM, Corp. 2011
362 *
363 * Authors:
364 *  Anthony Liguori   <aliguori@us.ibm.com>
365 *
366 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
367 * See the COPYING.LIB file in the top-level directory.
368 *
369 */
370'''
371
372(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
373                            'qapi-visit.c', 'qapi-visit.h',
374                            c_comment, h_comment)
375
376fdef.write(mcgen('''
377#include "qemu/osdep.h"
378#include "qemu-common.h"
379#include "qapi/error.h"
380#include "%(prefix)sqapi-visit.h"
381''',
382                 prefix=prefix))
383
384fdecl.write(mcgen('''
385#include "qapi/visitor.h"
386#include "qapi/qmp/qerror.h"
387#include "%(prefix)sqapi-types.h"
388
389''',
390                  prefix=prefix))
391
392schema = QAPISchema(input_file)
393gen = QAPISchemaGenVisitVisitor()
394schema.visit(gen)
395fdef.write(gen.defn)
396fdecl.write(gen.decl)
397
398close_output(fdef, fdecl)
399