qemu/scripts/qapi-introspect.py
Eric Blake 48825ca419 qapi: Plumb in 'boxed' to qapi generator lower levels
The next patch will add support for passing a qapi union type
as the 'data' of a command.  But to do that, the user function
for implementing the command, as called by the generated
marshal command, must take the corresponding C struct as a
single boxed pointer, rather than a breakdown into one
parameter per member.  Even without a union, being able to use
a C struct rather than a list of parameters can make it much
easier to handle coding with QAPI.

This patch adds the internal plumbing of a 'boxed' flag
associated with each command and event.  In several cases,
this means adding indentation, with one new dead branch and
the remaining branch being the original code more deeply
nested; this was done so that the new implementation in the
next patch is easier to review without also being mixed with
indentation changes.

For this patch, no behavior or generated output changes, other
than the testsuite outputting the value of the new flag
(always False for now).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1468468228-27827-9-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Identifier box renamed to boxed in two places]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-19 13:21:08 +02:00

220 lines
7.1 KiB
Python

#
# QAPI introspection generator
#
# Copyright (C) 2015-2016 Red Hat, Inc.
#
# Authors:
# 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 *
# Caveman's json.dumps() replacement (we're stuck at Python 2.4)
# TODO try to use json.dumps() once we get unstuck
def to_json(obj, level=0):
if obj is None:
ret = 'null'
elif isinstance(obj, str):
ret = '"' + obj.replace('"', r'\"') + '"'
elif isinstance(obj, list):
elts = [to_json(elt, level + 1)
for elt in obj]
ret = '[' + ', '.join(elts) + ']'
elif isinstance(obj, dict):
elts = ['"%s": %s' % (key.replace('"', r'\"'),
to_json(obj[key], level + 1))
for key in sorted(obj.keys())]
ret = '{' + ', '.join(elts) + '}'
else:
assert False # not implemented
if level == 1:
ret = '\n' + ret
return ret
def to_c_string(string):
return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
class QAPISchemaGenIntrospectVisitor(QAPISchemaVisitor):
def __init__(self, unmask):
self._unmask = unmask
self.defn = None
self.decl = None
self._schema = None
self._jsons = None
self._used_types = None
self._name_map = None
def visit_begin(self, schema):
self._schema = schema
self._jsons = []
self._used_types = []
self._name_map = {}
def visit_end(self):
# visit the types that are actually used
jsons = self._jsons
self._jsons = []
for typ in self._used_types:
typ.visit(self)
# generate C
# TODO can generate awfully long lines
jsons.extend(self._jsons)
name = prefix + 'qmp_schema_json'
self.decl = mcgen('''
extern const char %(c_name)s[];
''',
c_name=c_name(name))
lines = to_json(jsons).split('\n')
c_string = '\n '.join([to_c_string(line) for line in lines])
self.defn = mcgen('''
const char %(c_name)s[] = %(c_string)s;
''',
c_name=c_name(name),
c_string=c_string)
self._schema = None
self._jsons = None
self._used_types = None
self._name_map = None
def visit_needed(self, entity):
# Ignore types on first pass; visit_end() will pick up used types
return not isinstance(entity, QAPISchemaType)
def _name(self, name):
if self._unmask:
return name
if name not in self._name_map:
self._name_map[name] = '%d' % len(self._name_map)
return self._name_map[name]
def _use_type(self, typ):
# Map the various integer types to plain int
if typ.json_type() == 'int':
typ = self._schema.lookup_type('int')
elif (isinstance(typ, QAPISchemaArrayType) and
typ.element_type.json_type() == 'int'):
typ = self._schema.lookup_type('intList')
# Add type to work queue if new
if typ not in self._used_types:
self._used_types.append(typ)
# Clients should examine commands and events, not types. Hide
# type names to reduce the temptation. Also saves a few
# characters.
if isinstance(typ, QAPISchemaBuiltinType):
return typ.name
if isinstance(typ, QAPISchemaArrayType):
return '[' + self._use_type(typ.element_type) + ']'
return self._name(typ.name)
def _gen_json(self, name, mtype, obj):
if mtype not in ('command', 'event', 'builtin', 'array'):
name = self._name(name)
obj['name'] = name
obj['meta-type'] = mtype
self._jsons.append(obj)
def _gen_member(self, member):
ret = {'name': member.name, 'type': self._use_type(member.type)}
if member.optional:
ret['default'] = None
return ret
def _gen_variants(self, tag_name, variants):
return {'tag': tag_name,
'variants': [self._gen_variant(v) for v in variants]}
def _gen_variant(self, variant):
return {'case': variant.name, 'type': self._use_type(variant.type)}
def visit_builtin_type(self, name, info, json_type):
self._gen_json(name, 'builtin', {'json-type': json_type})
def visit_enum_type(self, name, info, values, prefix):
self._gen_json(name, 'enum', {'values': values})
def visit_array_type(self, name, info, element_type):
element = self._use_type(element_type)
self._gen_json('[' + element + ']', 'array', {'element-type': element})
def visit_object_type_flat(self, name, info, members, variants):
obj = {'members': [self._gen_member(m) for m in members]}
if variants:
obj.update(self._gen_variants(variants.tag_member.name,
variants.variants))
self._gen_json(name, 'object', obj)
def visit_alternate_type(self, name, info, variants):
self._gen_json(name, 'alternate',
{'members': [{'type': self._use_type(m.type)}
for m in variants.variants]})
def visit_command(self, name, info, arg_type, ret_type,
gen, success_response, boxed):
arg_type = arg_type or self._schema.the_empty_object_type
ret_type = ret_type or self._schema.the_empty_object_type
self._gen_json(name, 'command',
{'arg-type': self._use_type(arg_type),
'ret-type': self._use_type(ret_type)})
def visit_event(self, name, info, arg_type, boxed):
arg_type = arg_type or self._schema.the_empty_object_type
self._gen_json(name, 'event', {'arg-type': self._use_type(arg_type)})
# Debugging aid: unmask QAPI schema's type names
# We normally mask them, because they're not QMP wire ABI
opt_unmask = False
(input_file, output_dir, do_c, do_h, prefix, opts) = \
parse_command_line("u", ["unmask-non-abi-names"])
for o, a in opts:
if o in ("-u", "--unmask-non-abi-names"):
opt_unmask = True
c_comment = '''
/*
* QAPI/QMP schema introspection
*
* Copyright (C) 2015 Red Hat, Inc.
*
* 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 = '''
/*
* QAPI/QMP schema introspection
*
* Copyright (C) 2015 Red Hat, Inc.
*
* 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,
'qmp-introspect.c', 'qmp-introspect.h',
c_comment, h_comment)
fdef.write(mcgen('''
#include "qemu/osdep.h"
#include "%(prefix)sqmp-introspect.h"
''',
prefix=prefix))
schema = QAPISchema(input_file)
gen = QAPISchemaGenIntrospectVisitor(opt_unmask)
schema.visit(gen)
fdef.write(gen.defn)
fdecl.write(gen.decl)
close_output(fdef, fdecl)