xref: /qemu/scripts/qapi/commands.py (revision b21e2380) 
1"""
2QAPI command marshaller 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 typing import (
17    Dict,
18    List,
19    Optional,
20    Set,
21)
22
23from .common import c_name, mcgen
24from .gen import (
25    QAPIGenC,
26    QAPISchemaModularCVisitor,
27    build_params,
28    gen_special_features,
29    ifcontext,
30)
31from .schema import (
32    QAPISchema,
33    QAPISchemaFeature,
34    QAPISchemaIfCond,
35    QAPISchemaObjectType,
36    QAPISchemaType,
37)
38from .source import QAPISourceInfo
39
40
41def gen_command_decl(name: str,
42                     arg_type: Optional[QAPISchemaObjectType],
43                     boxed: bool,
44                     ret_type: Optional[QAPISchemaType]) -> str:
45    return mcgen('''
46%(c_type)s qmp_%(c_name)s(%(params)s);
47''',
48                 c_type=(ret_type and ret_type.c_type()) or 'void',
49                 c_name=c_name(name),
50                 params=build_params(arg_type, boxed, 'Error **errp'))
51
52
53def gen_call(name: str,
54             arg_type: Optional[QAPISchemaObjectType],
55             boxed: bool,
56             ret_type: Optional[QAPISchemaType],
57             gen_tracing: bool) -> str:
58    ret = ''
59
60    argstr = ''
61    if boxed:
62        assert arg_type
63        argstr = '&arg, '
64    elif arg_type:
65        assert not arg_type.variants
66        for memb in arg_type.members:
67            if memb.optional:
68                argstr += 'arg.has_%s, ' % c_name(memb.name)
69            argstr += 'arg.%s, ' % c_name(memb.name)
70
71    lhs = ''
72    if ret_type:
73        lhs = 'retval = '
74
75    name = c_name(name)
76    upper = name.upper()
77
78    if gen_tracing:
79        ret += mcgen('''
80
81    if (trace_event_get_state_backends(TRACE_QMP_ENTER_%(upper)s)) {
82        g_autoptr(GString) req_json = qobject_to_json(QOBJECT(args));
83
84        trace_qmp_enter_%(name)s(req_json->str);
85    }
86    ''',
87                     upper=upper, name=name)
88
89    ret += mcgen('''
90
91    %(lhs)sqmp_%(name)s(%(args)s&err);
92''',
93                 name=name, args=argstr, lhs=lhs)
94
95    ret += mcgen('''
96    if (err) {
97''')
98
99    if gen_tracing:
100        ret += mcgen('''
101        trace_qmp_exit_%(name)s(error_get_pretty(err), false);
102''',
103                     name=name)
104
105    ret += mcgen('''
106        error_propagate(errp, err);
107        goto out;
108    }
109''')
110
111    if ret_type:
112        ret += mcgen('''
113
114    qmp_marshal_output_%(c_name)s(retval, ret, errp);
115''',
116                     c_name=ret_type.c_name())
117
118    if gen_tracing:
119        if ret_type:
120            ret += mcgen('''
121
122    if (trace_event_get_state_backends(TRACE_QMP_EXIT_%(upper)s)) {
123        g_autoptr(GString) ret_json = qobject_to_json(*ret);
124
125        trace_qmp_exit_%(name)s(ret_json->str, true);
126    }
127    ''',
128                         upper=upper, name=name)
129        else:
130            ret += mcgen('''
131
132    trace_qmp_exit_%(name)s("{}", true);
133    ''',
134                         name=name)
135
136    return ret
137
138
139def gen_marshal_output(ret_type: QAPISchemaType) -> str:
140    return mcgen('''
141
142static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
143                                QObject **ret_out, Error **errp)
144{
145    Visitor *v;
146
147    v = qobject_output_visitor_new_qmp(ret_out);
148    if (visit_type_%(c_name)s(v, "unused", &ret_in, errp)) {
149        visit_complete(v, ret_out);
150    }
151    visit_free(v);
152    v = qapi_dealloc_visitor_new();
153    visit_type_%(c_name)s(v, "unused", &ret_in, NULL);
154    visit_free(v);
155}
156''',
157                 c_type=ret_type.c_type(), c_name=ret_type.c_name())
158
159
160def build_marshal_proto(name: str) -> str:
161    return ('void qmp_marshal_%s(QDict *args, QObject **ret, Error **errp)'
162            % c_name(name))
163
164
165def gen_marshal_decl(name: str) -> str:
166    return mcgen('''
167%(proto)s;
168''',
169                 proto=build_marshal_proto(name))
170
171
172def gen_trace(name: str) -> str:
173    return mcgen('''
174qmp_enter_%(name)s(const char *json) "%%s"
175qmp_exit_%(name)s(const char *result, bool succeeded) "%%s %%d"
176''',
177                 name=c_name(name))
178
179
180def gen_marshal(name: str,
181                arg_type: Optional[QAPISchemaObjectType],
182                boxed: bool,
183                ret_type: Optional[QAPISchemaType],
184                gen_tracing: bool) -> str:
185    have_args = boxed or (arg_type and not arg_type.is_empty())
186    if have_args:
187        assert arg_type is not None
188        arg_type_c_name = arg_type.c_name()
189
190    ret = mcgen('''
191
192%(proto)s
193{
194    Error *err = NULL;
195    bool ok = false;
196    Visitor *v;
197''',
198                proto=build_marshal_proto(name))
199
200    if ret_type:
201        ret += mcgen('''
202    %(c_type)s retval;
203''',
204                     c_type=ret_type.c_type())
205
206    if have_args:
207        ret += mcgen('''
208    %(c_name)s arg = {0};
209''',
210                     c_name=arg_type_c_name)
211
212    ret += mcgen('''
213
214    v = qobject_input_visitor_new_qmp(QOBJECT(args));
215    if (!visit_start_struct(v, NULL, NULL, 0, errp)) {
216        goto out;
217    }
218''')
219
220    if have_args:
221        ret += mcgen('''
222    if (visit_type_%(c_arg_type)s_members(v, &arg, errp)) {
223        ok = visit_check_struct(v, errp);
224    }
225''',
226                     c_arg_type=arg_type_c_name)
227    else:
228        ret += mcgen('''
229    ok = visit_check_struct(v, errp);
230''')
231
232    ret += mcgen('''
233    visit_end_struct(v, NULL);
234    if (!ok) {
235        goto out;
236    }
237''')
238
239    ret += gen_call(name, arg_type, boxed, ret_type, gen_tracing)
240
241    ret += mcgen('''
242
243out:
244    visit_free(v);
245''')
246
247    ret += mcgen('''
248    v = qapi_dealloc_visitor_new();
249    visit_start_struct(v, NULL, NULL, 0, NULL);
250''')
251
252    if have_args:
253        ret += mcgen('''
254    visit_type_%(c_arg_type)s_members(v, &arg, NULL);
255''',
256                     c_arg_type=arg_type_c_name)
257
258    ret += mcgen('''
259    visit_end_struct(v, NULL);
260    visit_free(v);
261''')
262
263    ret += mcgen('''
264}
265''')
266    return ret
267
268
269def gen_register_command(name: str,
270                         features: List[QAPISchemaFeature],
271                         success_response: bool,
272                         allow_oob: bool,
273                         allow_preconfig: bool,
274                         coroutine: bool) -> str:
275    options = []
276
277    if not success_response:
278        options += ['QCO_NO_SUCCESS_RESP']
279    if allow_oob:
280        options += ['QCO_ALLOW_OOB']
281    if allow_preconfig:
282        options += ['QCO_ALLOW_PRECONFIG']
283    if coroutine:
284        options += ['QCO_COROUTINE']
285
286    ret = mcgen('''
287    qmp_register_command(cmds, "%(name)s",
288                         qmp_marshal_%(c_name)s, %(opts)s, %(feats)s);
289''',
290                name=name, c_name=c_name(name),
291                opts=' | '.join(options) or 0,
292                feats=gen_special_features(features))
293    return ret
294
295
296class QAPISchemaGenCommandVisitor(QAPISchemaModularCVisitor):
297    def __init__(self, prefix: str, gen_tracing: bool):
298        super().__init__(
299            prefix, 'qapi-commands',
300            ' * Schema-defined QAPI/QMP commands', None, __doc__,
301            gen_tracing=gen_tracing)
302        self._visited_ret_types: Dict[QAPIGenC, Set[QAPISchemaType]] = {}
303        self._gen_tracing = gen_tracing
304
305    def _begin_user_module(self, name: str) -> None:
306        self._visited_ret_types[self._genc] = set()
307        commands = self._module_basename('qapi-commands', name)
308        types = self._module_basename('qapi-types', name)
309        visit = self._module_basename('qapi-visit', name)
310        self._genc.add(mcgen('''
311#include "qemu/osdep.h"
312#include "qapi/compat-policy.h"
313#include "qapi/visitor.h"
314#include "qapi/qmp/qdict.h"
315#include "qapi/dealloc-visitor.h"
316#include "qapi/error.h"
317#include "%(visit)s.h"
318#include "%(commands)s.h"
319
320''',
321                             commands=commands, visit=visit))
322
323        if self._gen_tracing and commands != 'qapi-commands':
324            self._genc.add(mcgen('''
325#include "qapi/qmp/qjson.h"
326#include "trace/trace-%(nm)s_trace_events.h"
327''',
328                                 nm=c_name(commands, protect=False)))
329            # We use c_name(commands, protect=False) to turn '-' into '_', to
330            # match .underscorify() in trace/meson.build
331
332        self._genh.add(mcgen('''
333#include "%(types)s.h"
334
335''',
336                             types=types))
337
338    def visit_begin(self, schema: QAPISchema) -> None:
339        self._add_module('./init', ' * QAPI Commands initialization')
340        self._genh.add(mcgen('''
341#include "qapi/qmp/dispatch.h"
342
343void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
344''',
345                             c_prefix=c_name(self._prefix, protect=False)))
346        self._genc.add(mcgen('''
347#include "qemu/osdep.h"
348#include "%(prefix)sqapi-commands.h"
349#include "%(prefix)sqapi-init-commands.h"
350
351void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds)
352{
353    QTAILQ_INIT(cmds);
354
355''',
356                             prefix=self._prefix,
357                             c_prefix=c_name(self._prefix, protect=False)))
358
359    def visit_end(self) -> None:
360        with self._temp_module('./init'):
361            self._genc.add(mcgen('''
362}
363'''))
364
365    def visit_command(self,
366                      name: str,
367                      info: Optional[QAPISourceInfo],
368                      ifcond: QAPISchemaIfCond,
369                      features: List[QAPISchemaFeature],
370                      arg_type: Optional[QAPISchemaObjectType],
371                      ret_type: Optional[QAPISchemaType],
372                      gen: bool,
373                      success_response: bool,
374                      boxed: bool,
375                      allow_oob: bool,
376                      allow_preconfig: bool,
377                      coroutine: bool) -> None:
378        if not gen:
379            return
380        # FIXME: If T is a user-defined type, the user is responsible
381        # for making this work, i.e. to make T's condition the
382        # conjunction of the T-returning commands' conditions.  If T
383        # is a built-in type, this isn't possible: the
384        # qmp_marshal_output_T() will be generated unconditionally.
385        if ret_type and ret_type not in self._visited_ret_types[self._genc]:
386            self._visited_ret_types[self._genc].add(ret_type)
387            with ifcontext(ret_type.ifcond,
388                           self._genh, self._genc):
389                self._genc.add(gen_marshal_output(ret_type))
390        with ifcontext(ifcond, self._genh, self._genc):
391            self._genh.add(gen_command_decl(name, arg_type, boxed, ret_type))
392            self._genh.add(gen_marshal_decl(name))
393            self._genc.add(gen_marshal(name, arg_type, boxed, ret_type,
394                                       self._gen_tracing))
395            if self._gen_tracing:
396                self._gen_trace_events.add(gen_trace(name))
397        with self._temp_module('./init'):
398            with ifcontext(ifcond, self._genh, self._genc):
399                self._genc.add(gen_register_command(
400                    name, features, success_response, allow_oob,
401                    allow_preconfig, coroutine))
402
403
404def gen_commands(schema: QAPISchema,
405                 output_dir: str,
406                 prefix: str,
407                 gen_tracing: bool) -> None:
408    vis = QAPISchemaGenCommandVisitor(prefix, gen_tracing)
409    schema.visit(vis)
410    vis.write(output_dir)
411