qemu-patch-raspberry4/scripts/qapi-visit.py
Eric Blake 1158bb2a05 qapi: Add parameter to visit_end_*
Rather than making the dealloc visitor track of stack of pointers
remembered during visit_start_* in order to free them during
visit_end_*, it's a lot easier to just make all callers pass the
same pointer to visit_end_*.  The generated code has access to the
same pointer, while all other users are doing virtual walks and
can pass NULL.  The dealloc visitor is then greatly simplified.

All three visit_end_*() functions intentionally take a void**,
even though the visit_start_*() functions differ between void**,
GenericList**, and GenericAlternate**.  This is done for several
reasons: when doing a virtual walk, passing NULL doesn't care
what the type is, but when doing a generated walk, we already
have to cast the caller's specific FOO* to call visit_start,
while using void** lets us use visit_end without a cast. Also,
an upcoming patch will add a clone visitor that wants to use
the same implementation for all three visit_end callbacks,
which is made easier if all three share the same signature.

For visitors with already track per-object state (the QMP visitors
via a stack, and the string visitors which do not allow nesting),
add an assertion that the caller is indeed passing the same
pointer to paired calls.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-4-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00

393 lines
10 KiB
Python

#
# QAPI visitor generator
#
# Copyright IBM, Corp. 2011
# Copyright (C) 2014-2016 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 import *
import re
def gen_visit_decl(name, scalar=False):
c_type = c_name(name) + ' *'
if not scalar:
c_type += '*'
return mcgen('''
void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
''',
c_name=c_name(name), c_type=c_type)
def gen_visit_members_decl(name):
return mcgen('''
void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
''',
c_name=c_name(name))
def gen_visit_object_members(name, base, members, variants):
ret = mcgen('''
void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
{
Error *err = NULL;
''',
c_name=c_name(name))
if base:
ret += mcgen('''
visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, &err);
''',
c_type=base.c_name())
ret += gen_err_check()
for memb in members:
if memb.optional:
ret += mcgen('''
if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
''',
name=memb.name, c_name=c_name(memb.name))
push_indent()
ret += mcgen('''
visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, &err);
''',
c_type=memb.type.c_name(), name=memb.name,
c_name=c_name(memb.name))
ret += gen_err_check()
if memb.optional:
pop_indent()
ret += mcgen('''
}
''')
if variants:
ret += mcgen('''
switch (obj->%(c_name)s) {
''',
c_name=c_name(variants.tag_member.name))
for var in variants.variants:
ret += mcgen('''
case %(case)s:
visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
break;
''',
case=c_enum_const(variants.tag_member.type.name,
var.name,
variants.tag_member.type.prefix),
c_type=var.type.c_name(), c_name=c_name(var.name))
ret += mcgen('''
default:
abort();
}
''')
# 'goto out' produced for base, for each member, and if variants were
# present
if base or members or variants:
ret += mcgen('''
out:
''')
ret += mcgen('''
error_propagate(errp, err);
}
''')
return ret
def gen_visit_list(name, element_type):
return mcgen('''
void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
{
Error *err = NULL;
%(c_name)s *tail;
size_t size = sizeof(**obj);
visit_start_list(v, name, (GenericList **)obj, size, &err);
if (err) {
goto out;
}
for (tail = *obj; tail;
tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
visit_type_%(c_elt_type)s(v, NULL, &tail->value, &err);
if (err) {
break;
}
}
visit_end_list(v, (void **)obj);
if (err && visit_is_input(v)) {
qapi_free_%(c_name)s(*obj);
*obj = NULL;
}
out:
error_propagate(errp, err);
}
''',
c_name=c_name(name), c_elt_type=element_type.c_name())
def gen_visit_enum(name):
return mcgen('''
void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
{
int value = *obj;
visit_type_enum(v, name, &value, %(c_name)s_lookup, errp);
*obj = value;
}
''',
c_name=c_name(name))
def gen_visit_alternate(name, variants):
promote_int = 'true'
ret = ''
for var in variants.variants:
if var.type.alternate_qtype() == 'QTYPE_QINT':
promote_int = 'false'
ret += mcgen('''
void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
{
Error *err = NULL;
visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
%(promote_int)s, &err);
if (err) {
goto out;
}
if (!*obj) {
goto out_obj;
}
switch ((*obj)->type) {
''',
c_name=c_name(name), promote_int=promote_int)
for var in variants.variants:
ret += mcgen('''
case %(case)s:
''',
case=var.type.alternate_qtype())
if isinstance(var.type, QAPISchemaObjectType):
ret += mcgen('''
visit_start_struct(v, name, NULL, 0, &err);
if (err) {
break;
}
visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
if (!err) {
visit_check_struct(v, &err);
}
visit_end_struct(v, NULL);
''',
c_type=var.type.c_name(),
c_name=c_name(var.name))
else:
ret += mcgen('''
visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
''',
c_type=var.type.c_name(),
c_name=c_name(var.name))
ret += mcgen('''
break;
''')
ret += mcgen('''
case QTYPE_NONE:
abort();
default:
error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"%(name)s");
}
out_obj:
visit_end_alternate(v, (void **)obj);
if (err && visit_is_input(v)) {
qapi_free_%(c_name)s(*obj);
*obj = NULL;
}
out:
error_propagate(errp, err);
}
''',
name=name, c_name=c_name(name))
return ret
def gen_visit_object(name, base, members, variants):
return mcgen('''
void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
{
Error *err = NULL;
visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
if (err) {
goto out;
}
if (!*obj) {
goto out_obj;
}
visit_type_%(c_name)s_members(v, *obj, &err);
if (err) {
goto out_obj;
}
visit_check_struct(v, &err);
out_obj:
visit_end_struct(v, (void **)obj);
if (err && visit_is_input(v)) {
qapi_free_%(c_name)s(*obj);
*obj = NULL;
}
out:
error_propagate(errp, err);
}
''',
c_name=c_name(name))
class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
def __init__(self):
self.decl = None
self.defn = None
self._btin = None
def visit_begin(self, schema):
self.decl = ''
self.defn = ''
self._btin = guardstart('QAPI_VISIT_BUILTIN')
def visit_end(self):
# To avoid header dependency hell, we always generate
# declarations for built-in types in our header files and
# simply guard them. See also do_builtins (command line
# option -b).
self._btin += guardend('QAPI_VISIT_BUILTIN')
self.decl = self._btin + self.decl
self._btin = None
def visit_enum_type(self, name, info, values, prefix):
# Special case for our lone builtin enum type
# TODO use something cleaner than existence of info
if not info:
self._btin += gen_visit_decl(name, scalar=True)
if do_builtins:
self.defn += gen_visit_enum(name)
else:
self.decl += gen_visit_decl(name, scalar=True)
self.defn += gen_visit_enum(name)
def visit_array_type(self, name, info, element_type):
decl = gen_visit_decl(name)
defn = gen_visit_list(name, element_type)
if isinstance(element_type, QAPISchemaBuiltinType):
self._btin += decl
if do_builtins:
self.defn += defn
else:
self.decl += decl
self.defn += defn
def visit_object_type(self, name, info, base, members, variants):
# Nothing to do for the special empty builtin
if name == 'q_empty':
return
self.decl += gen_visit_members_decl(name)
self.defn += gen_visit_object_members(name, base, members, variants)
# TODO Worth changing the visitor signature, so we could
# directly use rather than repeat type.is_implicit()?
if not name.startswith('q_'):
# only explicit types need an allocating visit
self.decl += gen_visit_decl(name)
self.defn += gen_visit_object(name, base, members, variants)
def visit_alternate_type(self, name, info, variants):
self.decl += gen_visit_decl(name)
self.defn += gen_visit_alternate(name, variants)
# If you link code generated from multiple schemata, you want only one
# instance of the code for built-in types. Generate it only when
# do_builtins, enabled by command line option -b. See also
# QAPISchemaGenVisitVisitor.visit_end().
do_builtins = False
(input_file, output_dir, do_c, do_h, prefix, opts) = \
parse_command_line("b", ["builtins"])
for o, a in opts:
if o in ("-b", "--builtins"):
do_builtins = True
c_comment = '''
/*
* schema-defined QAPI visitor functions
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
'''
h_comment = '''
/*
* schema-defined QAPI visitor functions
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
'''
(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
'qapi-visit.c', 'qapi-visit.h',
c_comment, h_comment)
fdef.write(mcgen('''
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qapi/error.h"
#include "%(prefix)sqapi-visit.h"
''',
prefix=prefix))
fdecl.write(mcgen('''
#include "qapi/visitor.h"
#include "qapi/qmp/qerror.h"
#include "%(prefix)sqapi-types.h"
''',
prefix=prefix))
schema = QAPISchema(input_file)
gen = QAPISchemaGenVisitVisitor()
schema.visit(gen)
fdef.write(gen.defn)
fdecl.write(gen.decl)
close_output(fdef, fdecl)