qemu/scripts/qapi/commands.py

"""
QAPI command marshaller generator

Copyright IBM, Corp. 2011
Copyright (C) 2014-2018 Red Hat, Inc.

Authors:
 Anthony Liguori <aliguori@us.ibm.com>
 Michael Roth <mdroth@linux.vnet.ibm.com>
 Markus Armbruster <armbru@redhat.com>

This work is licensed under the terms of the GNU GPL, version 2.
See the COPYING file in the top-level directory.
"""

from qapi.common import *


def gen_command_decl(name, arg_type, boxed, ret_type):
    return mcgen('''
%(c_type)s qmp_%(c_name)s(%(params)s);
''',
                 c_type=(ret_type and ret_type.c_type()) or 'void',
                 c_name=c_name(name),
                 params=build_params(arg_type, boxed, 'Error **errp'))


def gen_call(name, arg_type, boxed, ret_type):
    ret = ''

    argstr = ''
    if boxed:
        assert arg_type and not arg_type.is_empty()
        argstr = '&arg, '
    elif arg_type:
        assert not arg_type.variants
        for memb in arg_type.members:
            if memb.optional:
                argstr += 'arg.has_%s, ' % c_name(memb.name)
            argstr += 'arg.%s, ' % c_name(memb.name)

    lhs = ''
    if ret_type:
        lhs = 'retval = '

    ret = mcgen('''

    %(lhs)sqmp_%(c_name)s(%(args)s&err);
''',
                c_name=c_name(name), args=argstr, lhs=lhs)
    if ret_type:
        ret += mcgen('''
    if (err) {
        goto out;
    }

    qmp_marshal_output_%(c_name)s(retval, ret, &err);
''',
                     c_name=ret_type.c_name())
    return ret


def gen_marshal_output(ret_type):
    return mcgen('''

static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out, Error **errp)
{
    Error *err = NULL;
    Visitor *v;

    v = qobject_output_visitor_new(ret_out);
    visit_type_%(c_name)s(v, "unused", &ret_in, &err);
    if (!err) {
        visit_complete(v, ret_out);
    }
    error_propagate(errp, err);
    visit_free(v);
    v = qapi_dealloc_visitor_new();
    visit_type_%(c_name)s(v, "unused", &ret_in, NULL);
    visit_free(v);
}
''',
                 c_type=ret_type.c_type(), c_name=ret_type.c_name())


def build_marshal_proto(name):
    return ('void qmp_marshal_%s(QDict *args, QObject **ret, Error **errp)'
            % c_name(name))


def gen_marshal_decl(name):
    return mcgen('''
%(proto)s;
''',
                 proto=build_marshal_proto(name))


def gen_marshal(name, arg_type, boxed, ret_type):
    have_args = arg_type and not arg_type.is_empty()

    ret = mcgen('''

%(proto)s
{
    Error *err = NULL;
''',
                proto=build_marshal_proto(name))

    if ret_type:
        ret += mcgen('''
    %(c_type)s retval;
''',
                     c_type=ret_type.c_type())

    if have_args:
        visit_members = ('visit_type_%s_members(v, &arg, &err);'
                         % arg_type.c_name())
        ret += mcgen('''
    Visitor *v;
    %(c_name)s arg = {0};

''',
                     c_name=arg_type.c_name())
    else:
        visit_members = ''
        ret += mcgen('''
    Visitor *v = NULL;

    if (args) {
''')
        push_indent()

    ret += mcgen('''
    v = qobject_input_visitor_new(QOBJECT(args));
    visit_start_struct(v, NULL, NULL, 0, &err);
    if (err) {
        goto out;
    }
    %(visit_members)s
    if (!err) {
        visit_check_struct(v, &err);
    }
    visit_end_struct(v, NULL);
    if (err) {
        goto out;
    }
''',
                 visit_members=visit_members)

    if not have_args:
        pop_indent()
        ret += mcgen('''
    }
''')

    ret += gen_call(name, arg_type, boxed, ret_type)

    ret += mcgen('''

out:
    error_propagate(errp, err);
    visit_free(v);
''')

    if have_args:
        visit_members = ('visit_type_%s_members(v, &arg, NULL);'
                         % arg_type.c_name())
    else:
        visit_members = ''
        ret += mcgen('''
    if (args) {
''')
        push_indent()

    ret += mcgen('''
    v = qapi_dealloc_visitor_new();
    visit_start_struct(v, NULL, NULL, 0, NULL);
    %(visit_members)s
    visit_end_struct(v, NULL);
    visit_free(v);
''',
                 visit_members=visit_members)

    if not have_args:
        pop_indent()
        ret += mcgen('''
    }
''')

    ret += mcgen('''
}
''')
    return ret


def gen_register_command(name, success_response):
    options = 'QCO_NO_OPTIONS'
    if not success_response:
        options = 'QCO_NO_SUCCESS_RESP'

    ret = mcgen('''
    qmp_register_command(cmds, "%(name)s",
                         qmp_marshal_%(c_name)s, %(opts)s);
''',
                name=name, c_name=c_name(name),
                opts=options)
    return ret


def gen_registry(registry, prefix):
    ret = mcgen('''

void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds)
{
    QTAILQ_INIT(cmds);

''',
                c_prefix=c_name(prefix, protect=False))
    ret += registry
    ret += mcgen('''
}
''')
    return ret


class QAPISchemaGenCommandVisitor(QAPISchemaVisitor):
    def __init__(self, prefix):
        self._prefix = prefix
        self.decl = None
        self.defn = None
        self._regy = None
        self._visited_ret_types = None

    def visit_begin(self, schema):
        self.decl = ''
        self.defn = ''
        self._regy = ''
        self._visited_ret_types = set()

    def visit_end(self):
        self.defn += gen_registry(self._regy, self._prefix)
        self._regy = None
        self._visited_ret_types = None

    def visit_command(self, name, info, arg_type, ret_type,
                      gen, success_response, boxed):
        if not gen:
            return
        self.decl += gen_command_decl(name, arg_type, boxed, ret_type)
        if ret_type and ret_type not in self._visited_ret_types:
            self._visited_ret_types.add(ret_type)
            self.defn += gen_marshal_output(ret_type)
        self.decl += gen_marshal_decl(name)
        self.defn += gen_marshal(name, arg_type, boxed, ret_type)
        self._regy += gen_register_command(name, success_response)


def gen_commands(schema, output_dir, prefix):
    blurb = ' * Schema-defined QAPI/QMP commands'
    genc = QAPIGenC(blurb, __doc__)
    genh = QAPIGenH(blurb, __doc__)

    genc.add(mcgen('''
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qemu/module.h"
#include "qapi/visitor.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qobject-output-visitor.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/dealloc-visitor.h"
#include "qapi/error.h"
#include "%(prefix)sqapi-types.h"
#include "%(prefix)sqapi-visit.h"
#include "%(prefix)sqmp-commands.h"

''',
                   prefix=prefix))

    genh.add(mcgen('''
#include "%(prefix)sqapi-types.h"
#include "qapi/qmp/dispatch.h"

void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
''',
                   prefix=prefix, c_prefix=c_name(prefix, protect=False)))

    vis = QAPISchemaGenCommandVisitor(prefix)
    schema.visit(vis)
    genc.add(vis.defn)
    genh.add(vis.decl)
    genc.write(output_dir, prefix + 'qmp-marshal.c')
    genh.write(output_dir, prefix + 'qmp-commands.h')