We already have several places that want to visit all the members of an implicit object within a larger context (simple union variant, event with anonymous data, command with anonymous arguments struct); and will be adding another one soon (the ability to declare an anonymous base for a flat union). Having a C struct declared for these implicit types, along with a visit_type_FOO_members() helper function, will make for fewer special cases in our generator. We do not, however, need qapi_free_FOO() or visit_type_FOO() functions for implicit types, because they should not be used directly outside of the generated code. This is done by adding a conditional in visit_object_type() for both qapi-types.py and qapi-visit.py based on the object name. The comparison of "name.startswith('q_')" is a bit hacky (it's basically duplicating what .is_implicit() already uses), but beats changing the signature of the visit_object_type() callback to pass a new 'implicit' flag. The hack should be temporary: we are considering adding a future patch that consolidates the narrow visit_object_type(..., base, local_members, variants) and visit_object_type_flat(..., all_members, variants) [where different sets of information are already broken out, and the QAPISchemaObjectType is no longer available] into a broader visit_object_type(obj_type) [where the visitor can query the needed fields from obj_type directly]. Also, now that we WANT to output C code for implicits, we no longer need the visit_needed() filter, leaving 'q_empty' as the only object still needing a special case. Remember, 'q_empty' is the only built-in generated object, which means that without a special case it would be emitted in multiple files (the main qapi-types.h and in qga-qapi-types.h) causing compilation failure due to redefinition. But since it has no members, it's easier to just avoid an attempt to visit that particular type; since gen_object() is called recursively, we also prime the objects_seen set to cover any recursion into the empty type. The patch relies on the changed naming of implicit types in the previous patch. It is a bit unfortunate that the generated struct names and visit_type_FOO_members() don't match normal naming conventions, but it's not too bad, since they will only be used in generated code. The generated code grows substantially in size: the implicit '-wrapper' types must be emitted in qapi-types.h before any union can include an unboxed member of that type. Arguably, the '-args' types could be emitted in a private header for just qapi-visit.c and qmp-marshal.c, rather than polluting qapi-types.h; but adding complexity to the generator to split the output location according to role doesn't seem worth the maintenance costs. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1458254921-17042-6-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
313 lines
8.3 KiB
Python
313 lines
8.3 KiB
Python
#
|
|
# QAPI types generator
|
|
#
|
|
# Copyright IBM, Corp. 2011
|
|
# Copyright (c) 2013-2016 Red Hat Inc.
|
|
#
|
|
# Authors:
|
|
# Anthony Liguori <aliguori@us.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 *
|
|
|
|
|
|
# variants must be emitted before their container; track what has already
|
|
# been output
|
|
objects_seen = set()
|
|
|
|
|
|
def gen_fwd_object_or_array(name):
|
|
return mcgen('''
|
|
|
|
typedef struct %(c_name)s %(c_name)s;
|
|
''',
|
|
c_name=c_name(name))
|
|
|
|
|
|
def gen_array(name, element_type):
|
|
return mcgen('''
|
|
|
|
struct %(c_name)s {
|
|
%(c_name)s *next;
|
|
%(c_type)s value;
|
|
};
|
|
''',
|
|
c_name=c_name(name), c_type=element_type.c_type())
|
|
|
|
|
|
def gen_struct_members(members):
|
|
ret = ''
|
|
for memb in members:
|
|
if memb.optional:
|
|
ret += mcgen('''
|
|
bool has_%(c_name)s;
|
|
''',
|
|
c_name=c_name(memb.name))
|
|
ret += mcgen('''
|
|
%(c_type)s %(c_name)s;
|
|
''',
|
|
c_type=memb.type.c_type(), c_name=c_name(memb.name))
|
|
return ret
|
|
|
|
|
|
def gen_object(name, base, members, variants):
|
|
if name in objects_seen:
|
|
return ''
|
|
objects_seen.add(name)
|
|
|
|
ret = ''
|
|
if variants:
|
|
for v in variants.variants:
|
|
if isinstance(v.type, QAPISchemaObjectType):
|
|
ret += gen_object(v.type.name, v.type.base,
|
|
v.type.local_members, v.type.variants)
|
|
|
|
ret += mcgen('''
|
|
|
|
struct %(c_name)s {
|
|
''',
|
|
c_name=c_name(name))
|
|
|
|
if base:
|
|
ret += mcgen('''
|
|
/* Members inherited from %(c_name)s: */
|
|
''',
|
|
c_name=base.c_name())
|
|
ret += gen_struct_members(base.members)
|
|
ret += mcgen('''
|
|
/* Own members: */
|
|
''')
|
|
ret += gen_struct_members(members)
|
|
|
|
if variants:
|
|
ret += gen_variants(variants)
|
|
|
|
# Make sure that all structs have at least one member; this avoids
|
|
# potential issues with attempting to malloc space for zero-length
|
|
# structs in C, and also incompatibility with C++ (where an empty
|
|
# struct is size 1).
|
|
if not (base and base.members) and not members and not variants:
|
|
ret += mcgen('''
|
|
char qapi_dummy_for_empty_struct;
|
|
''')
|
|
|
|
ret += mcgen('''
|
|
};
|
|
''')
|
|
|
|
return ret
|
|
|
|
|
|
def gen_upcast(name, base):
|
|
# C makes const-correctness ugly. We have to cast away const to let
|
|
# this function work for both const and non-const obj.
|
|
return mcgen('''
|
|
|
|
static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
|
|
{
|
|
return (%(base)s *)obj;
|
|
}
|
|
''',
|
|
c_name=c_name(name), base=base.c_name())
|
|
|
|
|
|
def gen_variants(variants):
|
|
ret = mcgen('''
|
|
union { /* union tag is @%(c_name)s */
|
|
''',
|
|
c_name=c_name(variants.tag_member.name))
|
|
|
|
for var in variants.variants:
|
|
# Ugly special case for simple union TODO get rid of it
|
|
simple_union_type = var.simple_union_type()
|
|
if simple_union_type:
|
|
typ = simple_union_type.c_type()
|
|
else:
|
|
typ = var.type.c_unboxed_type()
|
|
ret += mcgen('''
|
|
%(c_type)s %(c_name)s;
|
|
''',
|
|
c_type=typ,
|
|
c_name=c_name(var.name))
|
|
|
|
ret += mcgen('''
|
|
} u;
|
|
''')
|
|
|
|
return ret
|
|
|
|
|
|
def gen_type_cleanup_decl(name):
|
|
ret = mcgen('''
|
|
|
|
void qapi_free_%(c_name)s(%(c_name)s *obj);
|
|
''',
|
|
c_name=c_name(name))
|
|
return ret
|
|
|
|
|
|
def gen_type_cleanup(name):
|
|
ret = mcgen('''
|
|
|
|
void qapi_free_%(c_name)s(%(c_name)s *obj)
|
|
{
|
|
QapiDeallocVisitor *qdv;
|
|
Visitor *v;
|
|
|
|
if (!obj) {
|
|
return;
|
|
}
|
|
|
|
qdv = qapi_dealloc_visitor_new();
|
|
v = qapi_dealloc_get_visitor(qdv);
|
|
visit_type_%(c_name)s(v, NULL, &obj, NULL);
|
|
qapi_dealloc_visitor_cleanup(qdv);
|
|
}
|
|
''',
|
|
c_name=c_name(name))
|
|
return ret
|
|
|
|
|
|
class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
|
|
def __init__(self):
|
|
self.decl = None
|
|
self.defn = None
|
|
self._fwdecl = None
|
|
self._btin = None
|
|
|
|
def visit_begin(self, schema):
|
|
# gen_object() is recursive, ensure it doesn't visit the empty type
|
|
objects_seen.add(schema.the_empty_object_type.name)
|
|
self.decl = ''
|
|
self.defn = ''
|
|
self._fwdecl = ''
|
|
self._btin = guardstart('QAPI_TYPES_BUILTIN')
|
|
|
|
def visit_end(self):
|
|
self.decl = self._fwdecl + self.decl
|
|
self._fwdecl = None
|
|
# 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_TYPES_BUILTIN')
|
|
self.decl = self._btin + self.decl
|
|
self._btin = None
|
|
|
|
def _gen_type_cleanup(self, name):
|
|
self.decl += gen_type_cleanup_decl(name)
|
|
self.defn += gen_type_cleanup(name)
|
|
|
|
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_enum(name, values, prefix)
|
|
if do_builtins:
|
|
self.defn += gen_enum_lookup(name, values, prefix)
|
|
else:
|
|
self._fwdecl += gen_enum(name, values, prefix)
|
|
self.defn += gen_enum_lookup(name, values, prefix)
|
|
|
|
def visit_array_type(self, name, info, element_type):
|
|
if isinstance(element_type, QAPISchemaBuiltinType):
|
|
self._btin += gen_fwd_object_or_array(name)
|
|
self._btin += gen_array(name, element_type)
|
|
self._btin += gen_type_cleanup_decl(name)
|
|
if do_builtins:
|
|
self.defn += gen_type_cleanup(name)
|
|
else:
|
|
self._fwdecl += gen_fwd_object_or_array(name)
|
|
self.decl += gen_array(name, element_type)
|
|
self._gen_type_cleanup(name)
|
|
|
|
def visit_object_type(self, name, info, base, members, variants):
|
|
# Nothing to do for the special empty builtin
|
|
if name == 'q_empty':
|
|
return
|
|
self._fwdecl += gen_fwd_object_or_array(name)
|
|
self.decl += gen_object(name, base, members, variants)
|
|
if base:
|
|
self.decl += gen_upcast(name, base)
|
|
# TODO Worth changing the visitor signature, so we could
|
|
# directly use rather than repeat type.is_implicit()?
|
|
if not name.startswith('q_'):
|
|
# implicit types won't be directly allocated/freed
|
|
self._gen_type_cleanup(name)
|
|
|
|
def visit_alternate_type(self, name, info, variants):
|
|
self._fwdecl += gen_fwd_object_or_array(name)
|
|
self.decl += gen_object(name, None, [variants.tag_member], variants)
|
|
self._gen_type_cleanup(name)
|
|
|
|
# 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
|
|
# QAPISchemaGenTypeVisitor.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 = '''
|
|
/*
|
|
* deallocation functions for schema-defined QAPI types
|
|
*
|
|
* Copyright IBM, Corp. 2011
|
|
*
|
|
* Authors:
|
|
* Anthony Liguori <aliguori@us.ibm.com>
|
|
* Michael Roth <mdroth@linux.vnet.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 types
|
|
*
|
|
* 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-types.c', 'qapi-types.h',
|
|
c_comment, h_comment)
|
|
|
|
fdef.write(mcgen('''
|
|
#include "qemu/osdep.h"
|
|
#include "qapi/dealloc-visitor.h"
|
|
#include "%(prefix)sqapi-types.h"
|
|
#include "%(prefix)sqapi-visit.h"
|
|
''',
|
|
prefix=prefix))
|
|
|
|
# To avoid circular headers, use only typedefs.h here, not qobject.h
|
|
fdecl.write(mcgen('''
|
|
#include "qemu/typedefs.h"
|
|
'''))
|
|
|
|
schema = QAPISchema(input_file)
|
|
gen = QAPISchemaGenTypeVisitor()
|
|
schema.visit(gen)
|
|
fdef.write(gen.defn)
|
|
fdecl.write(gen.decl)
|
|
|
|
close_output(fdef, fdecl)
|