qemu/scripts/qapi/expr.py

369 lines
12 KiB
Python

# -*- coding: utf-8 -*-
#
# Check (context-free) QAPI schema expression structure
#
# Copyright IBM, Corp. 2011
# Copyright (c) 2013-2019 Red Hat Inc.
#
# Authors:
# Anthony Liguori <aliguori@us.ibm.com>
# Markus Armbruster <armbru@redhat.com>
# Eric Blake <eblake@redhat.com>
# Marc-André Lureau <marcandre.lureau@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 collections import OrderedDict
import re
from .common import c_name
from .error import QAPISemError
# Names must be letters, numbers, -, and _. They must start with letter,
# except for downstream extensions which must start with __RFQDN_.
# Dots are only valid in the downstream extension prefix.
valid_name = re.compile(r'^(__[a-zA-Z0-9.-]+_)?'
'[a-zA-Z][a-zA-Z0-9_-]*$')
def check_name_is_str(name, info, source):
if not isinstance(name, str):
raise QAPISemError(info, "%s requires a string name" % source)
def check_name_str(name, info, source,
allow_optional=False, enum_member=False,
permit_upper=False):
membername = name
if allow_optional and name.startswith('*'):
membername = name[1:]
# Enum members can start with a digit, because the generated C
# code always prefixes it with the enum name
if enum_member and membername[0].isdigit():
membername = 'D' + membername
# Reserve the entire 'q_' namespace for c_name(), and for 'q_empty'
# and 'q_obj_*' implicit type names.
if not valid_name.match(membername) or \
c_name(membername, False).startswith('q_'):
raise QAPISemError(info, "%s has an invalid name" % source)
if not permit_upper and name.lower() != name:
raise QAPISemError(
info, "%s uses uppercase in name" % source)
assert not membername.startswith('*')
def check_defn_name_str(name, info, meta):
check_name_str(name, info, meta, permit_upper=True)
if name.endswith('Kind') or name.endswith('List'):
raise QAPISemError(
info, "%s name should not end in '%s'" % (meta, name[-4:]))
def check_keys(value, info, source, required, optional):
def pprint(elems):
return ', '.join("'" + e + "'" for e in sorted(elems))
missing = set(required) - set(value)
if missing:
raise QAPISemError(
info,
"%s misses key%s %s"
% (source, 's' if len(missing) > 1 else '',
pprint(missing)))
allowed = set(required + optional)
unknown = set(value) - allowed
if unknown:
raise QAPISemError(
info,
"%s has unknown key%s %s\nValid keys are %s."
% (source, 's' if len(unknown) > 1 else '',
pprint(unknown), pprint(allowed)))
def check_flags(expr, info):
for key in ['gen', 'success-response']:
if key in expr and expr[key] is not False:
raise QAPISemError(
info, "flag '%s' may only use false value" % key)
for key in ['boxed', 'allow-oob', 'allow-preconfig', 'coroutine']:
if key in expr and expr[key] is not True:
raise QAPISemError(
info, "flag '%s' may only use true value" % key)
if 'allow-oob' in expr and 'coroutine' in expr:
# This is not necessarily a fundamental incompatibility, but
# we don't have a use case and the desired semantics isn't
# obvious. The simplest solution is to forbid it until we get
# a use case for it.
raise QAPISemError(info, "flags 'allow-oob' and 'coroutine' "
"are incompatible")
def check_if(expr, info, source):
def check_if_str(ifcond, info):
if not isinstance(ifcond, str):
raise QAPISemError(
info,
"'if' condition of %s must be a string or a list of strings"
% source)
if ifcond.strip() == '':
raise QAPISemError(
info,
"'if' condition '%s' of %s makes no sense"
% (ifcond, source))
ifcond = expr.get('if')
if ifcond is None:
return
if isinstance(ifcond, list):
if ifcond == []:
raise QAPISemError(
info, "'if' condition [] of %s is useless" % source)
for elt in ifcond:
check_if_str(elt, info)
else:
check_if_str(ifcond, info)
expr['if'] = [ifcond]
def normalize_members(members):
if isinstance(members, OrderedDict):
for key, arg in members.items():
if isinstance(arg, dict):
continue
members[key] = {'type': arg}
def check_type(value, info, source,
allow_array=False, allow_dict=False):
if value is None:
return
# Array type
if isinstance(value, list):
if not allow_array:
raise QAPISemError(info, "%s cannot be an array" % source)
if len(value) != 1 or not isinstance(value[0], str):
raise QAPISemError(info,
"%s: array type must contain single type name" %
source)
return
# Type name
if isinstance(value, str):
return
# Anonymous type
if not allow_dict:
raise QAPISemError(info, "%s should be a type name" % source)
if not isinstance(value, OrderedDict):
raise QAPISemError(info,
"%s should be an object or type name" % source)
permit_upper = allow_dict in info.pragma.name_case_whitelist
# value is a dictionary, check that each member is okay
for (key, arg) in value.items():
key_source = "%s member '%s'" % (source, key)
check_name_str(key, info, key_source,
allow_optional=True, permit_upper=permit_upper)
if c_name(key, False) == 'u' or c_name(key, False).startswith('has_'):
raise QAPISemError(info, "%s uses reserved name" % key_source)
check_keys(arg, info, key_source, ['type'], ['if', 'features'])
check_if(arg, info, key_source)
check_features(arg.get('features'), info)
check_type(arg['type'], info, key_source, allow_array=True)
def check_features(features, info):
if features is None:
return
if not isinstance(features, list):
raise QAPISemError(info, "'features' must be an array")
features[:] = [f if isinstance(f, dict) else {'name': f}
for f in features]
for f in features:
source = "'features' member"
assert isinstance(f, dict)
check_keys(f, info, source, ['name'], ['if'])
check_name_is_str(f['name'], info, source)
source = "%s '%s'" % (source, f['name'])
check_name_str(f['name'], info, source)
check_if(f, info, source)
def check_enum(expr, info):
name = expr['enum']
members = expr['data']
prefix = expr.get('prefix')
if not isinstance(members, list):
raise QAPISemError(info, "'data' must be an array")
if prefix is not None and not isinstance(prefix, str):
raise QAPISemError(info, "'prefix' must be a string")
permit_upper = name in info.pragma.name_case_whitelist
members[:] = [m if isinstance(m, dict) else {'name': m}
for m in members]
for member in members:
source = "'data' member"
check_keys(member, info, source, ['name'], ['if'])
check_name_is_str(member['name'], info, source)
source = "%s '%s'" % (source, member['name'])
check_name_str(member['name'], info, source,
enum_member=True, permit_upper=permit_upper)
check_if(member, info, source)
def check_struct(expr, info):
name = expr['struct']
members = expr['data']
check_type(members, info, "'data'", allow_dict=name)
check_type(expr.get('base'), info, "'base'")
def check_union(expr, info):
name = expr['union']
base = expr.get('base')
discriminator = expr.get('discriminator')
members = expr['data']
if discriminator is None: # simple union
if base is not None:
raise QAPISemError(info, "'base' requires 'discriminator'")
else: # flat union
check_type(base, info, "'base'", allow_dict=name)
if not base:
raise QAPISemError(info, "'discriminator' requires 'base'")
check_name_is_str(discriminator, info, "'discriminator'")
for (key, value) in members.items():
source = "'data' member '%s'" % key
check_name_str(key, info, source)
check_keys(value, info, source, ['type'], ['if'])
check_if(value, info, source)
check_type(value['type'], info, source, allow_array=not base)
def check_alternate(expr, info):
members = expr['data']
if not members:
raise QAPISemError(info, "'data' must not be empty")
for (key, value) in members.items():
source = "'data' member '%s'" % key
check_name_str(key, info, source)
check_keys(value, info, source, ['type'], ['if'])
check_if(value, info, source)
check_type(value['type'], info, source)
def check_command(expr, info):
args = expr.get('data')
rets = expr.get('returns')
boxed = expr.get('boxed', False)
if boxed and args is None:
raise QAPISemError(info, "'boxed': true requires 'data'")
check_type(args, info, "'data'", allow_dict=not boxed)
check_type(rets, info, "'returns'", allow_array=True)
def check_event(expr, info):
args = expr.get('data')
boxed = expr.get('boxed', False)
if boxed and args is None:
raise QAPISemError(info, "'boxed': true requires 'data'")
check_type(args, info, "'data'", allow_dict=not boxed)
def check_exprs(exprs):
for expr_elem in exprs:
expr = expr_elem['expr']
info = expr_elem['info']
doc = expr_elem.get('doc')
if 'include' in expr:
continue
if 'enum' in expr:
meta = 'enum'
elif 'union' in expr:
meta = 'union'
elif 'alternate' in expr:
meta = 'alternate'
elif 'struct' in expr:
meta = 'struct'
elif 'command' in expr:
meta = 'command'
elif 'event' in expr:
meta = 'event'
else:
raise QAPISemError(info, "expression is missing metatype")
name = expr[meta]
check_name_is_str(name, info, "'%s'" % meta)
info.set_defn(meta, name)
check_defn_name_str(name, info, meta)
if doc:
if doc.symbol != name:
raise QAPISemError(
info, "documentation comment is for '%s'" % doc.symbol)
doc.check_expr(expr)
elif info.pragma.doc_required:
raise QAPISemError(info,
"documentation comment required")
if meta == 'enum':
check_keys(expr, info, meta,
['enum', 'data'], ['if', 'features', 'prefix'])
check_enum(expr, info)
elif meta == 'union':
check_keys(expr, info, meta,
['union', 'data'],
['base', 'discriminator', 'if', 'features'])
normalize_members(expr.get('base'))
normalize_members(expr['data'])
check_union(expr, info)
elif meta == 'alternate':
check_keys(expr, info, meta,
['alternate', 'data'], ['if', 'features'])
normalize_members(expr['data'])
check_alternate(expr, info)
elif meta == 'struct':
check_keys(expr, info, meta,
['struct', 'data'], ['base', 'if', 'features'])
normalize_members(expr['data'])
check_struct(expr, info)
elif meta == 'command':
check_keys(expr, info, meta,
['command'],
['data', 'returns', 'boxed', 'if', 'features',
'gen', 'success-response', 'allow-oob',
'allow-preconfig', 'coroutine'])
normalize_members(expr.get('data'))
check_command(expr, info)
elif meta == 'event':
check_keys(expr, info, meta,
['event'], ['data', 'boxed', 'if', 'features'])
normalize_members(expr.get('data'))
check_event(expr, info)
else:
assert False, 'unexpected meta type'
check_if(expr, info, meta)
check_features(expr.get('features'), info)
check_flags(expr, info)
return exprs