xref: /qemu/scripts/qapi/visit.py (revision fa274ed6fb788866ed3a2cfd54a2ddf78f04f2c0) 
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    visit_end_list(v, (void **)obj);
137    if (err && visit_is_input(v)) {
138        qapi_free_%(c_name)s(*obj);
139        *obj = NULL;
140    }
141out:
142    error_propagate(errp, err);
143}
144''',
145                 c_name=c_name(name), c_elt_type=element_type.c_name())
146
147
148def gen_visit_enum(name):
149    return mcgen('''
150
151void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
152{
153    int value = *obj;
154    visit_type_enum(v, name, &value, %(c_name)s_lookup, errp);
155    *obj = value;
156}
157''',
158                 c_name=c_name(name))
159
160
161def gen_visit_alternate(name, variants):
162    promote_int = 'true'
163    ret = ''
164    for var in variants.variants:
165        if var.type.alternate_qtype() == 'QTYPE_QINT':
166            promote_int = 'false'
167
168    ret += mcgen('''
169
170void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
171{
172    Error *err = NULL;
173
174    visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
175                          %(promote_int)s, &err);
176    if (err) {
177        goto out;
178    }
179    if (!*obj) {
180        goto out_obj;
181    }
182    switch ((*obj)->type) {
183''',
184                 c_name=c_name(name), promote_int=promote_int)
185
186    for var in variants.variants:
187        ret += mcgen('''
188    case %(case)s:
189''',
190                     case=var.type.alternate_qtype())
191        if isinstance(var.type, QAPISchemaObjectType):
192            ret += mcgen('''
193        visit_start_struct(v, name, NULL, 0, &err);
194        if (err) {
195            break;
196        }
197        visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
198        if (!err) {
199            visit_check_struct(v, &err);
200        }
201        visit_end_struct(v, NULL);
202''',
203                         c_type=var.type.c_name(),
204                         c_name=c_name(var.name))
205        else:
206            ret += mcgen('''
207        visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
208''',
209                         c_type=var.type.c_name(),
210                         c_name=c_name(var.name))
211        ret += mcgen('''
212        break;
213''')
214
215    ret += mcgen('''
216    case QTYPE_NONE:
217        abort();
218    default:
219        error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
220                   "%(name)s");
221    }
222out_obj:
223    visit_end_alternate(v, (void **)obj);
224    if (err && visit_is_input(v)) {
225        qapi_free_%(c_name)s(*obj);
226        *obj = NULL;
227    }
228out:
229    error_propagate(errp, err);
230}
231''',
232                 name=name, c_name=c_name(name))
233
234    return ret
235
236
237def gen_visit_object(name, base, members, variants):
238    return mcgen('''
239
240void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
241{
242    Error *err = NULL;
243
244    visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
245    if (err) {
246        goto out;
247    }
248    if (!*obj) {
249        goto out_obj;
250    }
251    visit_type_%(c_name)s_members(v, *obj, &err);
252    if (err) {
253        goto out_obj;
254    }
255    visit_check_struct(v, &err);
256out_obj:
257    visit_end_struct(v, (void **)obj);
258    if (err && visit_is_input(v)) {
259        qapi_free_%(c_name)s(*obj);
260        *obj = NULL;
261    }
262out:
263    error_propagate(errp, err);
264}
265''',
266                 c_name=c_name(name))
267
268
269class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
270    def __init__(self):
271        self.decl = None
272        self.defn = None
273        self._btin = None
274
275    def visit_begin(self, schema):
276        self.decl = ''
277        self.defn = ''
278        self._btin = guardstart('QAPI_VISIT_BUILTIN')
279
280    def visit_end(self):
281        # To avoid header dependency hell, we always generate
282        # declarations for built-in types in our header files and
283        # simply guard them.  See also do_builtins (command line
284        # option -b).
285        self._btin += guardend('QAPI_VISIT_BUILTIN')
286        self.decl = self._btin + self.decl
287        self._btin = None
288
289    def visit_enum_type(self, name, info, values, prefix):
290        # Special case for our lone builtin enum type
291        # TODO use something cleaner than existence of info
292        if not info:
293            self._btin += gen_visit_decl(name, scalar=True)
294            if do_builtins:
295                self.defn += gen_visit_enum(name)
296        else:
297            self.decl += gen_visit_decl(name, scalar=True)
298            self.defn += gen_visit_enum(name)
299
300    def visit_array_type(self, name, info, element_type):
301        decl = gen_visit_decl(name)
302        defn = gen_visit_list(name, element_type)
303        if isinstance(element_type, QAPISchemaBuiltinType):
304            self._btin += decl
305            if do_builtins:
306                self.defn += defn
307        else:
308            self.decl += decl
309            self.defn += defn
310
311    def visit_object_type(self, name, info, base, members, variants):
312        # Nothing to do for the special empty builtin
313        if name == 'q_empty':
314            return
315        self.decl += gen_visit_members_decl(name)
316        self.defn += gen_visit_object_members(name, base, members, variants)
317        # TODO Worth changing the visitor signature, so we could
318        # directly use rather than repeat type.is_implicit()?
319        if not name.startswith('q_'):
320            # only explicit types need an allocating visit
321            self.decl += gen_visit_decl(name)
322            self.defn += gen_visit_object(name, base, members, variants)
323
324    def visit_alternate_type(self, name, info, variants):
325        self.decl += gen_visit_decl(name)
326        self.defn += gen_visit_alternate(name, variants)
327
328# If you link code generated from multiple schemata, you want only one
329# instance of the code for built-in types.  Generate it only when
330# do_builtins, enabled by command line option -b.  See also
331# QAPISchemaGenVisitVisitor.visit_end().
332do_builtins = False
333
334(input_file, output_dir, do_c, do_h, prefix, opts) = \
335    parse_command_line("b", ["builtins"])
336
337for o, a in opts:
338    if o in ("-b", "--builtins"):
339        do_builtins = True
340
341c_comment = '''
342/*
343 * schema-defined QAPI visitor functions
344 *
345 * Copyright IBM, Corp. 2011
346 *
347 * Authors:
348 *  Anthony Liguori   <aliguori@us.ibm.com>
349 *
350 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
351 * See the COPYING.LIB file in the top-level directory.
352 *
353 */
354'''
355h_comment = '''
356/*
357 * schema-defined QAPI visitor functions
358 *
359 * Copyright IBM, Corp. 2011
360 *
361 * Authors:
362 *  Anthony Liguori   <aliguori@us.ibm.com>
363 *
364 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
365 * See the COPYING.LIB file in the top-level directory.
366 *
367 */
368'''
369
370(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
371                            'qapi-visit.c', 'qapi-visit.h',
372                            c_comment, h_comment)
373
374fdef.write(mcgen('''
375#include "qemu/osdep.h"
376#include "qemu-common.h"
377#include "qapi/error.h"
378#include "%(prefix)sqapi-visit.h"
379''',
380                 prefix=prefix))
381
382fdecl.write(mcgen('''
383#include "qapi/visitor.h"
384#include "qapi/qmp/qerror.h"
385#include "%(prefix)sqapi-types.h"
386
387''',
388                  prefix=prefix))
389
390schema = QAPISchema(input_file)
391gen = QAPISchemaGenVisitVisitor()
392schema.visit(gen)
393fdef.write(gen.defn)
394fdecl.write(gen.decl)
395
396close_output(fdef, fdecl)
397