qemu-e2k/scripts/qapi.py
Eric Blake bac5429ccb qapi: Detect base class loops
It should be fairly obvious that qapi base classes need to
form an acyclic graph, since QMP cannot specify the same
key more than once, while base classes are included as flat
members alongside other members added by the child.  But the
old check_member_clash() parser function was not prepared to
check for this, and entered an infinite recursion (at least
until Python gives up, complaining about nesting too deep).

Now that check_member_clash() has been recently removed,
attempts at self-inheritance trigger an assertion failure
introduced by commit ac88219a.  The obvious fix is to turn
the assertion into a conditional.

This patch includes both the tests (base-cycle-direct and
base-cycle-indirect) and the fix, since the .err file output
for the unfixed case is not useful (particularly when it was
warning about unbounded recursion, as that limit may be
platform-specific).

We don't need to worry about cycles in flat unions (neither
the base type nor the type of a variant can be a union) nor
in alternates (alternate branches cannot themselves be an
alternate).  But if we later allow a union type as a variant,
we will still be okay, as QAPISchemaObjectTypeVariants.check()
triggers the same QAPISchemaObjectType.check() that will
detect any loops.

Likewise, we need not worry about the case of diamond
inheritance where the same class is used for a flat union base
class and one of its variants; either both uses will introduce
a collision in trying to insert the same member name twice, or
the shared type is empty and changes nothing.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-16-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:29 +01:00

1781 lines
59 KiB
Python

#
# QAPI helper library
#
# Copyright IBM, Corp. 2011
# Copyright (c) 2013-2015 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.
import re
from ordereddict import OrderedDict
import errno
import getopt
import os
import sys
import string
builtin_types = {
'str': 'QTYPE_QSTRING',
'int': 'QTYPE_QINT',
'number': 'QTYPE_QFLOAT',
'bool': 'QTYPE_QBOOL',
'int8': 'QTYPE_QINT',
'int16': 'QTYPE_QINT',
'int32': 'QTYPE_QINT',
'int64': 'QTYPE_QINT',
'uint8': 'QTYPE_QINT',
'uint16': 'QTYPE_QINT',
'uint32': 'QTYPE_QINT',
'uint64': 'QTYPE_QINT',
'size': 'QTYPE_QINT',
'any': None, # any QType possible, actually
'QType': 'QTYPE_QSTRING',
}
# Whitelist of commands allowed to return a non-dictionary
returns_whitelist = [
# From QMP:
'human-monitor-command',
'qom-get',
'query-migrate-cache-size',
'query-tpm-models',
'query-tpm-types',
'ringbuf-read',
# From QGA:
'guest-file-open',
'guest-fsfreeze-freeze',
'guest-fsfreeze-freeze-list',
'guest-fsfreeze-status',
'guest-fsfreeze-thaw',
'guest-get-time',
'guest-set-vcpus',
'guest-sync',
'guest-sync-delimited',
]
# Whitelist of entities allowed to violate case conventions
case_whitelist = [
# From QMP:
'ACPISlotType', # DIMM, visible through query-acpi-ospm-status
'CpuInfoBase', # CPU, visible through query-cpu
'CpuInfoMIPS', # PC, visible through query-cpu
'CpuInfoTricore', # PC, visible through query-cpu
'InputAxis', # TODO: drop when x-input-send-event is fixed
'InputButton', # TODO: drop when x-input-send-event is fixed
'QapiErrorClass', # all members, visible through errors
'UuidInfo', # UUID, visible through query-uuid
'X86CPURegister32', # all members, visible indirectly through qom-get
]
enum_types = []
struct_types = []
union_types = []
events = []
all_names = {}
#
# Parsing the schema into expressions
#
def error_path(parent):
res = ""
while parent:
res = ("In file included from %s:%d:\n" % (parent['file'],
parent['line'])) + res
parent = parent['parent']
return res
class QAPISchemaError(Exception):
def __init__(self, schema, msg):
Exception.__init__(self)
self.fname = schema.fname
self.msg = msg
self.col = 1
self.line = schema.line
for ch in schema.src[schema.line_pos:schema.pos]:
if ch == '\t':
self.col = (self.col + 7) % 8 + 1
else:
self.col += 1
self.info = schema.incl_info
def __str__(self):
return error_path(self.info) + \
"%s:%d:%d: %s" % (self.fname, self.line, self.col, self.msg)
class QAPIExprError(Exception):
def __init__(self, expr_info, msg):
Exception.__init__(self)
assert expr_info
self.info = expr_info
self.msg = msg
def __str__(self):
return error_path(self.info['parent']) + \
"%s:%d: %s" % (self.info['file'], self.info['line'], self.msg)
class QAPISchemaParser(object):
def __init__(self, fp, previously_included=[], incl_info=None):
abs_fname = os.path.abspath(fp.name)
fname = fp.name
self.fname = fname
previously_included.append(abs_fname)
self.incl_info = incl_info
self.src = fp.read()
if self.src == '' or self.src[-1] != '\n':
self.src += '\n'
self.cursor = 0
self.line = 1
self.line_pos = 0
self.exprs = []
self.accept()
while self.tok is not None:
expr_info = {'file': fname, 'line': self.line,
'parent': self.incl_info}
expr = self.get_expr(False)
if isinstance(expr, dict) and "include" in expr:
if len(expr) != 1:
raise QAPIExprError(expr_info,
"Invalid 'include' directive")
include = expr["include"]
if not isinstance(include, str):
raise QAPIExprError(expr_info,
"Value of 'include' must be a string")
incl_abs_fname = os.path.join(os.path.dirname(abs_fname),
include)
# catch inclusion cycle
inf = expr_info
while inf:
if incl_abs_fname == os.path.abspath(inf['file']):
raise QAPIExprError(expr_info, "Inclusion loop for %s"
% include)
inf = inf['parent']
# skip multiple include of the same file
if incl_abs_fname in previously_included:
continue
try:
fobj = open(incl_abs_fname, 'r')
except IOError, e:
raise QAPIExprError(expr_info,
'%s: %s' % (e.strerror, include))
exprs_include = QAPISchemaParser(fobj, previously_included,
expr_info)
self.exprs.extend(exprs_include.exprs)
else:
expr_elem = {'expr': expr,
'info': expr_info}
self.exprs.append(expr_elem)
def accept(self):
while True:
self.tok = self.src[self.cursor]
self.pos = self.cursor
self.cursor += 1
self.val = None
if self.tok == '#':
self.cursor = self.src.find('\n', self.cursor)
elif self.tok in "{}:,[]":
return
elif self.tok == "'":
string = ''
esc = False
while True:
ch = self.src[self.cursor]
self.cursor += 1
if ch == '\n':
raise QAPISchemaError(self,
'Missing terminating "\'"')
if esc:
if ch == 'b':
string += '\b'
elif ch == 'f':
string += '\f'
elif ch == 'n':
string += '\n'
elif ch == 'r':
string += '\r'
elif ch == 't':
string += '\t'
elif ch == 'u':
value = 0
for _ in range(0, 4):
ch = self.src[self.cursor]
self.cursor += 1
if ch not in "0123456789abcdefABCDEF":
raise QAPISchemaError(self,
'\\u escape needs 4 '
'hex digits')
value = (value << 4) + int(ch, 16)
# If Python 2 and 3 didn't disagree so much on
# how to handle Unicode, then we could allow
# Unicode string defaults. But most of QAPI is
# ASCII-only, so we aren't losing much for now.
if not value or value > 0x7f:
raise QAPISchemaError(self,
'For now, \\u escape '
'only supports non-zero '
'values up to \\u007f')
string += chr(value)
elif ch in "\\/'\"":
string += ch
else:
raise QAPISchemaError(self,
"Unknown escape \\%s" % ch)
esc = False
elif ch == "\\":
esc = True
elif ch == "'":
self.val = string
return
else:
string += ch
elif self.src.startswith("true", self.pos):
self.val = True
self.cursor += 3
return
elif self.src.startswith("false", self.pos):
self.val = False
self.cursor += 4
return
elif self.src.startswith("null", self.pos):
self.val = None
self.cursor += 3
return
elif self.tok == '\n':
if self.cursor == len(self.src):
self.tok = None
return
self.line += 1
self.line_pos = self.cursor
elif not self.tok.isspace():
raise QAPISchemaError(self, 'Stray "%s"' % self.tok)
def get_members(self):
expr = OrderedDict()
if self.tok == '}':
self.accept()
return expr
if self.tok != "'":
raise QAPISchemaError(self, 'Expected string or "}"')
while True:
key = self.val
self.accept()
if self.tok != ':':
raise QAPISchemaError(self, 'Expected ":"')
self.accept()
if key in expr:
raise QAPISchemaError(self, 'Duplicate key "%s"' % key)
expr[key] = self.get_expr(True)
if self.tok == '}':
self.accept()
return expr
if self.tok != ',':
raise QAPISchemaError(self, 'Expected "," or "}"')
self.accept()
if self.tok != "'":
raise QAPISchemaError(self, 'Expected string')
def get_values(self):
expr = []
if self.tok == ']':
self.accept()
return expr
if self.tok not in "{['tfn":
raise QAPISchemaError(self, 'Expected "{", "[", "]", string, '
'boolean or "null"')
while True:
expr.append(self.get_expr(True))
if self.tok == ']':
self.accept()
return expr
if self.tok != ',':
raise QAPISchemaError(self, 'Expected "," or "]"')
self.accept()
def get_expr(self, nested):
if self.tok != '{' and not nested:
raise QAPISchemaError(self, 'Expected "{"')
if self.tok == '{':
self.accept()
expr = self.get_members()
elif self.tok == '[':
self.accept()
expr = self.get_values()
elif self.tok in "'tfn":
expr = self.val
self.accept()
else:
raise QAPISchemaError(self, 'Expected "{", "[" or string')
return expr
#
# Semantic analysis of schema expressions
# TODO fold into QAPISchema
# TODO catching name collisions in generated code would be nice
#
def find_base_fields(base):
base_struct_define = find_struct(base)
if not base_struct_define:
return None
return base_struct_define['data']
# Return the qtype of an alternate branch, or None on error.
def find_alternate_member_qtype(qapi_type):
if qapi_type in builtin_types:
return builtin_types[qapi_type]
elif find_struct(qapi_type):
return "QTYPE_QDICT"
elif find_enum(qapi_type):
return "QTYPE_QSTRING"
elif find_union(qapi_type):
return "QTYPE_QDICT"
return None
# Return the discriminator enum define if discriminator is specified as an
# enum type, otherwise return None.
def discriminator_find_enum_define(expr):
base = expr.get('base')
discriminator = expr.get('discriminator')
if not (discriminator and base):
return None
base_fields = find_base_fields(base)
if not base_fields:
return None
discriminator_type = base_fields.get(discriminator)
if not discriminator_type:
return None
return find_enum(discriminator_type)
# 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('^(__[a-zA-Z0-9.-]+_)?'
'[a-zA-Z][a-zA-Z0-9_-]*$')
def check_name(expr_info, source, name, allow_optional=False,
enum_member=False):
global valid_name
membername = name
if not isinstance(name, str):
raise QAPIExprError(expr_info,
"%s requires a string name" % source)
if name.startswith('*'):
membername = name[1:]
if not allow_optional:
raise QAPIExprError(expr_info,
"%s does not allow optional name '%s'"
% (source, name))
# 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()
if not valid_name.match(membername) or \
c_name(membername, False).startswith('q_'):
raise QAPIExprError(expr_info,
"%s uses invalid name '%s'" % (source, name))
def add_name(name, info, meta, implicit=False):
global all_names
check_name(info, "'%s'" % meta, name)
# FIXME should reject names that differ only in '_' vs. '.'
# vs. '-', because they're liable to clash in generated C.
if name in all_names:
raise QAPIExprError(info,
"%s '%s' is already defined"
% (all_names[name], name))
if not implicit and (name.endswith('Kind') or name.endswith('List')):
raise QAPIExprError(info,
"%s '%s' should not end in '%s'"
% (meta, name, name[-4:]))
all_names[name] = meta
def add_struct(definition, info):
global struct_types
name = definition['struct']
add_name(name, info, 'struct')
struct_types.append(definition)
def find_struct(name):
global struct_types
for struct in struct_types:
if struct['struct'] == name:
return struct
return None
def add_union(definition, info):
global union_types
name = definition['union']
add_name(name, info, 'union')
union_types.append(definition)
def find_union(name):
global union_types
for union in union_types:
if union['union'] == name:
return union
return None
def add_enum(name, info, enum_values=None, implicit=False):
global enum_types
add_name(name, info, 'enum', implicit)
enum_types.append({"enum_name": name, "enum_values": enum_values})
def find_enum(name):
global enum_types
for enum in enum_types:
if enum['enum_name'] == name:
return enum
return None
def is_enum(name):
return find_enum(name) is not None
def check_type(expr_info, source, value, allow_array=False,
allow_dict=False, allow_optional=False,
allow_metas=[]):
global all_names
if value is None:
return
# Check if array type for value is okay
if isinstance(value, list):
if not allow_array:
raise QAPIExprError(expr_info,
"%s cannot be an array" % source)
if len(value) != 1 or not isinstance(value[0], str):
raise QAPIExprError(expr_info,
"%s: array type must contain single type name"
% source)
value = value[0]
# Check if type name for value is okay
if isinstance(value, str):
if value not in all_names:
raise QAPIExprError(expr_info,
"%s uses unknown type '%s'"
% (source, value))
if not all_names[value] in allow_metas:
raise QAPIExprError(expr_info,
"%s cannot use %s type '%s'"
% (source, all_names[value], value))
return
if not allow_dict:
raise QAPIExprError(expr_info,
"%s should be a type name" % source)
if not isinstance(value, OrderedDict):
raise QAPIExprError(expr_info,
"%s should be a dictionary or type name" % source)
# value is a dictionary, check that each member is okay
for (key, arg) in value.items():
check_name(expr_info, "Member of %s" % source, key,
allow_optional=allow_optional)
if c_name(key, False) == 'u' or c_name(key, False).startswith('has_'):
raise QAPIExprError(expr_info,
"Member of %s uses reserved name '%s'"
% (source, key))
# Todo: allow dictionaries to represent default values of
# an optional argument.
check_type(expr_info, "Member '%s' of %s" % (key, source), arg,
allow_array=True,
allow_metas=['built-in', 'union', 'alternate', 'struct',
'enum'])
def check_command(expr, expr_info):
name = expr['command']
check_type(expr_info, "'data' for command '%s'" % name,
expr.get('data'), allow_dict=True, allow_optional=True,
allow_metas=['struct'])
returns_meta = ['union', 'struct']
if name in returns_whitelist:
returns_meta += ['built-in', 'alternate', 'enum']
check_type(expr_info, "'returns' for command '%s'" % name,
expr.get('returns'), allow_array=True,
allow_optional=True, allow_metas=returns_meta)
def check_event(expr, expr_info):
global events
name = expr['event']
events.append(name)
check_type(expr_info, "'data' for event '%s'" % name,
expr.get('data'), allow_dict=True, allow_optional=True,
allow_metas=['struct'])
def check_union(expr, expr_info):
name = expr['union']
base = expr.get('base')
discriminator = expr.get('discriminator')
members = expr['data']
# Two types of unions, determined by discriminator.
# With no discriminator it is a simple union.
if discriminator is None:
enum_define = None
allow_metas = ['built-in', 'union', 'alternate', 'struct', 'enum']
if base is not None:
raise QAPIExprError(expr_info,
"Simple union '%s' must not have a base"
% name)
# Else, it's a flat union.
else:
# The object must have a string member 'base'.
check_type(expr_info, "'base' for union '%s'" % name,
base, allow_metas=['struct'])
if not base:
raise QAPIExprError(expr_info,
"Flat union '%s' must have a base"
% name)
base_fields = find_base_fields(base)
assert base_fields
# The value of member 'discriminator' must name a non-optional
# member of the base struct.
check_name(expr_info, "Discriminator of flat union '%s'" % name,
discriminator)
discriminator_type = base_fields.get(discriminator)
if not discriminator_type:
raise QAPIExprError(expr_info,
"Discriminator '%s' is not a member of base "
"struct '%s'"
% (discriminator, base))
enum_define = find_enum(discriminator_type)
allow_metas = ['struct']
# Do not allow string discriminator
if not enum_define:
raise QAPIExprError(expr_info,
"Discriminator '%s' must be of enumeration "
"type" % discriminator)
# Check every branch
for (key, value) in members.items():
check_name(expr_info, "Member of union '%s'" % name, key)
# Each value must name a known type
check_type(expr_info, "Member '%s' of union '%s'" % (key, name),
value, allow_array=not base, allow_metas=allow_metas)
# If the discriminator names an enum type, then all members
# of 'data' must also be members of the enum type.
if enum_define:
if key not in enum_define['enum_values']:
raise QAPIExprError(expr_info,
"Discriminator value '%s' is not found in "
"enum '%s'" %
(key, enum_define["enum_name"]))
def check_alternate(expr, expr_info):
name = expr['alternate']
members = expr['data']
types_seen = {}
# Check every branch
for (key, value) in members.items():
check_name(expr_info, "Member of alternate '%s'" % name, key)
# Ensure alternates have no type conflicts.
check_type(expr_info, "Member '%s' of alternate '%s'" % (key, name),
value,
allow_metas=['built-in', 'union', 'struct', 'enum'])
qtype = find_alternate_member_qtype(value)
assert qtype
if qtype in types_seen:
raise QAPIExprError(expr_info,
"Alternate '%s' member '%s' can't "
"be distinguished from member '%s'"
% (name, key, types_seen[qtype]))
types_seen[qtype] = key
def check_enum(expr, expr_info):
name = expr['enum']
members = expr.get('data')
prefix = expr.get('prefix')
if not isinstance(members, list):
raise QAPIExprError(expr_info,
"Enum '%s' requires an array for 'data'" % name)
if prefix is not None and not isinstance(prefix, str):
raise QAPIExprError(expr_info,
"Enum '%s' requires a string for 'prefix'" % name)
for member in members:
check_name(expr_info, "Member of enum '%s'" % name, member,
enum_member=True)
def check_struct(expr, expr_info):
name = expr['struct']
members = expr['data']
check_type(expr_info, "'data' for struct '%s'" % name, members,
allow_dict=True, allow_optional=True)
check_type(expr_info, "'base' for struct '%s'" % name, expr.get('base'),
allow_metas=['struct'])
def check_keys(expr_elem, meta, required, optional=[]):
expr = expr_elem['expr']
info = expr_elem['info']
name = expr[meta]
if not isinstance(name, str):
raise QAPIExprError(info,
"'%s' key must have a string value" % meta)
required = required + [meta]
for (key, value) in expr.items():
if key not in required and key not in optional:
raise QAPIExprError(info,
"Unknown key '%s' in %s '%s'"
% (key, meta, name))
if (key == 'gen' or key == 'success-response') and value is not False:
raise QAPIExprError(info,
"'%s' of %s '%s' should only use false value"
% (key, meta, name))
for key in required:
if key not in expr:
raise QAPIExprError(info,
"Key '%s' is missing from %s '%s'"
% (key, meta, name))
def check_exprs(exprs):
global all_names
# Learn the types and check for valid expression keys
for builtin in builtin_types.keys():
all_names[builtin] = 'built-in'
for expr_elem in exprs:
expr = expr_elem['expr']
info = expr_elem['info']
if 'enum' in expr:
check_keys(expr_elem, 'enum', ['data'], ['prefix'])
add_enum(expr['enum'], info, expr['data'])
elif 'union' in expr:
check_keys(expr_elem, 'union', ['data'],
['base', 'discriminator'])
add_union(expr, info)
elif 'alternate' in expr:
check_keys(expr_elem, 'alternate', ['data'])
add_name(expr['alternate'], info, 'alternate')
elif 'struct' in expr:
check_keys(expr_elem, 'struct', ['data'], ['base'])
add_struct(expr, info)
elif 'command' in expr:
check_keys(expr_elem, 'command', [],
['data', 'returns', 'gen', 'success-response'])
add_name(expr['command'], info, 'command')
elif 'event' in expr:
check_keys(expr_elem, 'event', [], ['data'])
add_name(expr['event'], info, 'event')
else:
raise QAPIExprError(expr_elem['info'],
"Expression is missing metatype")
# Try again for hidden UnionKind enum
for expr_elem in exprs:
expr = expr_elem['expr']
if 'union' in expr:
if not discriminator_find_enum_define(expr):
add_enum('%sKind' % expr['union'], expr_elem['info'],
implicit=True)
elif 'alternate' in expr:
add_enum('%sKind' % expr['alternate'], expr_elem['info'],
implicit=True)
# Validate that exprs make sense
for expr_elem in exprs:
expr = expr_elem['expr']
info = expr_elem['info']
if 'enum' in expr:
check_enum(expr, info)
elif 'union' in expr:
check_union(expr, info)
elif 'alternate' in expr:
check_alternate(expr, info)
elif 'struct' in expr:
check_struct(expr, info)
elif 'command' in expr:
check_command(expr, info)
elif 'event' in expr:
check_event(expr, info)
else:
assert False, 'unexpected meta type'
return exprs
#
# Schema compiler frontend
#
class QAPISchemaEntity(object):
def __init__(self, name, info):
assert isinstance(name, str)
self.name = name
# For explicitly defined entities, info points to the (explicit)
# definition. For builtins (and their arrays), info is None.
# For implicitly defined entities, info points to a place that
# triggered the implicit definition (there may be more than one
# such place).
self.info = info
def c_name(self):
return c_name(self.name)
def check(self, schema):
pass
def is_implicit(self):
return not self.info
def visit(self, visitor):
pass
class QAPISchemaVisitor(object):
def visit_begin(self, schema):
pass
def visit_end(self):
pass
def visit_needed(self, entity):
# Default to visiting everything
return True
def visit_builtin_type(self, name, info, json_type):
pass
def visit_enum_type(self, name, info, values, prefix):
pass
def visit_array_type(self, name, info, element_type):
pass
def visit_object_type(self, name, info, base, members, variants):
pass
def visit_object_type_flat(self, name, info, members, variants):
pass
def visit_alternate_type(self, name, info, variants):
pass
def visit_command(self, name, info, arg_type, ret_type,
gen, success_response):
pass
def visit_event(self, name, info, arg_type):
pass
class QAPISchemaType(QAPISchemaEntity):
def c_type(self, is_param=False):
return c_name(self.name) + pointer_suffix
def c_null(self):
return 'NULL'
def json_type(self):
pass
def alternate_qtype(self):
json2qtype = {
'string': 'QTYPE_QSTRING',
'number': 'QTYPE_QFLOAT',
'int': 'QTYPE_QINT',
'boolean': 'QTYPE_QBOOL',
'object': 'QTYPE_QDICT'
}
return json2qtype.get(self.json_type())
class QAPISchemaBuiltinType(QAPISchemaType):
def __init__(self, name, json_type, c_type, c_null):
QAPISchemaType.__init__(self, name, None)
assert not c_type or isinstance(c_type, str)
assert json_type in ('string', 'number', 'int', 'boolean', 'null',
'value')
self._json_type_name = json_type
self._c_type_name = c_type
self._c_null_val = c_null
def c_name(self):
return self.name
def c_type(self, is_param=False):
if is_param and self.name == 'str':
return 'const ' + self._c_type_name
return self._c_type_name
def c_null(self):
return self._c_null_val
def json_type(self):
return self._json_type_name
def visit(self, visitor):
visitor.visit_builtin_type(self.name, self.info, self.json_type())
class QAPISchemaEnumType(QAPISchemaType):
def __init__(self, name, info, values, prefix):
QAPISchemaType.__init__(self, name, info)
for v in values:
assert isinstance(v, QAPISchemaMember)
v.set_owner(name)
assert prefix is None or isinstance(prefix, str)
self.values = values
self.prefix = prefix
def check(self, schema):
seen = {}
for v in self.values:
v.check_clash(self.info, seen)
def is_implicit(self):
# See QAPISchema._make_implicit_enum_type()
return self.name.endswith('Kind')
def c_type(self, is_param=False):
return c_name(self.name)
def member_names(self):
return [v.name for v in self.values]
def c_null(self):
return c_enum_const(self.name, (self.member_names() + ['_MAX'])[0],
self.prefix)
def json_type(self):
return 'string'
def visit(self, visitor):
visitor.visit_enum_type(self.name, self.info,
self.member_names(), self.prefix)
class QAPISchemaArrayType(QAPISchemaType):
def __init__(self, name, info, element_type):
QAPISchemaType.__init__(self, name, info)
assert isinstance(element_type, str)
self._element_type_name = element_type
self.element_type = None
def check(self, schema):
self.element_type = schema.lookup_type(self._element_type_name)
assert self.element_type
def is_implicit(self):
return True
def json_type(self):
return 'array'
def visit(self, visitor):
visitor.visit_array_type(self.name, self.info, self.element_type)
class QAPISchemaObjectType(QAPISchemaType):
def __init__(self, name, info, base, local_members, variants):
# struct has local_members, optional base, and no variants
# flat union has base, variants, and no local_members
# simple union has local_members, variants, and no base
QAPISchemaType.__init__(self, name, info)
assert base is None or isinstance(base, str)
for m in local_members:
assert isinstance(m, QAPISchemaObjectTypeMember)
m.set_owner(name)
if variants is not None:
assert isinstance(variants, QAPISchemaObjectTypeVariants)
variants.set_owner(name)
self._base_name = base
self.base = None
self.local_members = local_members
self.variants = variants
self.members = None
def check(self, schema):
if self.members is False: # check for cycles
raise QAPIExprError(self.info,
"Object %s contains itself" % self.name)
if self.members:
return
self.members = False # mark as being checked
seen = OrderedDict()
if self._base_name:
self.base = schema.lookup_type(self._base_name)
assert isinstance(self.base, QAPISchemaObjectType)
self.base.check(schema)
self.base.check_clash(schema, self.info, seen)
for m in self.local_members:
m.check(schema)
m.check_clash(self.info, seen)
self.members = seen.values()
if self.variants:
self.variants.check(schema, seen)
assert self.variants.tag_member in self.members
self.variants.check_clash(schema, self.info, seen)
# Check that the members of this type do not cause duplicate JSON fields,
# and update seen to track the members seen so far. Report any errors
# on behalf of info, which is not necessarily self.info
def check_clash(self, schema, info, seen):
assert not self.variants # not implemented
for m in self.members:
m.check_clash(info, seen)
def is_implicit(self):
# See QAPISchema._make_implicit_object_type()
return self.name[0] == ':'
def c_name(self):
assert not self.is_implicit()
return QAPISchemaType.c_name(self)
def c_type(self, is_param=False):
assert not self.is_implicit()
return QAPISchemaType.c_type(self)
def json_type(self):
return 'object'
def visit(self, visitor):
visitor.visit_object_type(self.name, self.info,
self.base, self.local_members, self.variants)
visitor.visit_object_type_flat(self.name, self.info,
self.members, self.variants)
class QAPISchemaMember(object):
role = 'member'
def __init__(self, name):
assert isinstance(name, str)
self.name = name
self.owner = None
def set_owner(self, name):
assert not self.owner
self.owner = name
def check_clash(self, info, seen):
cname = c_name(self.name)
if cname.lower() != cname and self.owner not in case_whitelist:
raise QAPIExprError(info,
"%s should not use uppercase" % self.describe())
if cname in seen:
raise QAPIExprError(info,
"%s collides with %s"
% (self.describe(), seen[cname].describe()))
seen[cname] = self
def _pretty_owner(self):
owner = self.owner
if owner.startswith(':obj-'):
# See QAPISchema._make_implicit_object_type() - reverse the
# mapping there to create a nice human-readable description
owner = owner[5:]
if owner.endswith('-arg'):
return '(parameter of %s)' % owner[:-4]
else:
assert owner.endswith('-wrapper')
# Unreachable and not implemented
assert False
if owner.endswith('Kind'):
# See QAPISchema._make_implicit_enum_type()
return '(branch of %s)' % owner[:-4]
return '(%s of %s)' % (self.role, owner)
def describe(self):
return "'%s' %s" % (self.name, self._pretty_owner())
class QAPISchemaObjectTypeMember(QAPISchemaMember):
def __init__(self, name, typ, optional):
QAPISchemaMember.__init__(self, name)
assert isinstance(typ, str)
assert isinstance(optional, bool)
self._type_name = typ
self.type = None
self.optional = optional
def check(self, schema):
assert self.owner
self.type = schema.lookup_type(self._type_name)
assert self.type
class QAPISchemaObjectTypeVariants(object):
def __init__(self, tag_name, tag_member, variants):
# Flat unions pass tag_name but not tag_member.
# Simple unions and alternates pass tag_member but not tag_name.
# After check(), tag_member is always set, and tag_name remains
# a reliable witness of being used by a flat union.
assert bool(tag_member) != bool(tag_name)
assert (isinstance(tag_name, str) or
isinstance(tag_member, QAPISchemaObjectTypeMember))
for v in variants:
assert isinstance(v, QAPISchemaObjectTypeVariant)
self.tag_name = tag_name
self.tag_member = tag_member
self.variants = variants
def set_owner(self, name):
for v in self.variants:
v.set_owner(name)
def check(self, schema, seen):
if not self.tag_member: # flat union
self.tag_member = seen[c_name(self.tag_name)]
assert self.tag_name == self.tag_member.name
assert isinstance(self.tag_member.type, QAPISchemaEnumType)
for v in self.variants:
v.check(schema)
# Union names must match enum values; alternate names are
# checked separately. Use 'seen' to tell the two apart.
if seen:
assert v.name in self.tag_member.type.member_names()
assert isinstance(v.type, QAPISchemaObjectType)
v.type.check(schema)
def check_clash(self, schema, info, seen):
for v in self.variants:
# Reset seen map for each variant, since qapi names from one
# branch do not affect another branch
assert isinstance(v.type, QAPISchemaObjectType)
v.type.check_clash(schema, info, dict(seen))
class QAPISchemaObjectTypeVariant(QAPISchemaObjectTypeMember):
role = 'branch'
def __init__(self, name, typ):
QAPISchemaObjectTypeMember.__init__(self, name, typ, False)
# This function exists to support ugly simple union special cases
# TODO get rid of them, and drop the function
def simple_union_type(self):
if (self.type.is_implicit() and
isinstance(self.type, QAPISchemaObjectType)):
assert len(self.type.members) == 1
assert not self.type.variants
return self.type.members[0].type
return None
class QAPISchemaAlternateType(QAPISchemaType):
def __init__(self, name, info, variants):
QAPISchemaType.__init__(self, name, info)
assert isinstance(variants, QAPISchemaObjectTypeVariants)
assert not variants.tag_name
variants.set_owner(name)
variants.tag_member.set_owner(self.name)
self.variants = variants
def check(self, schema):
self.variants.tag_member.check(schema)
# Not calling self.variants.check_clash(), because there's nothing
# to clash with
self.variants.check(schema, {})
# Alternate branch names have no relation to the tag enum values;
# so we have to check for potential name collisions ourselves.
seen = {}
for v in self.variants.variants:
v.check_clash(self.info, seen)
def json_type(self):
return 'value'
def visit(self, visitor):
visitor.visit_alternate_type(self.name, self.info, self.variants)
class QAPISchemaCommand(QAPISchemaEntity):
def __init__(self, name, info, arg_type, ret_type, gen, success_response):
QAPISchemaEntity.__init__(self, name, info)
assert not arg_type or isinstance(arg_type, str)
assert not ret_type or isinstance(ret_type, str)
self._arg_type_name = arg_type
self.arg_type = None
self._ret_type_name = ret_type
self.ret_type = None
self.gen = gen
self.success_response = success_response
def check(self, schema):
if self._arg_type_name:
self.arg_type = schema.lookup_type(self._arg_type_name)
assert isinstance(self.arg_type, QAPISchemaObjectType)
assert not self.arg_type.variants # not implemented
if self._ret_type_name:
self.ret_type = schema.lookup_type(self._ret_type_name)
assert isinstance(self.ret_type, QAPISchemaType)
def visit(self, visitor):
visitor.visit_command(self.name, self.info,
self.arg_type, self.ret_type,
self.gen, self.success_response)
class QAPISchemaEvent(QAPISchemaEntity):
def __init__(self, name, info, arg_type):
QAPISchemaEntity.__init__(self, name, info)
assert not arg_type or isinstance(arg_type, str)
self._arg_type_name = arg_type
self.arg_type = None
def check(self, schema):
if self._arg_type_name:
self.arg_type = schema.lookup_type(self._arg_type_name)
assert isinstance(self.arg_type, QAPISchemaObjectType)
assert not self.arg_type.variants # not implemented
def visit(self, visitor):
visitor.visit_event(self.name, self.info, self.arg_type)
class QAPISchema(object):
def __init__(self, fname):
try:
self.exprs = check_exprs(QAPISchemaParser(open(fname, "r")).exprs)
self._entity_dict = {}
self._predefining = True
self._def_predefineds()
self._predefining = False
self._def_exprs()
self.check()
except (QAPISchemaError, QAPIExprError), err:
print >>sys.stderr, err
exit(1)
def _def_entity(self, ent):
# Only the predefined types are allowed to not have info
assert ent.info or self._predefining
assert ent.name not in self._entity_dict
self._entity_dict[ent.name] = ent
def lookup_entity(self, name, typ=None):
ent = self._entity_dict.get(name)
if typ and not isinstance(ent, typ):
return None
return ent
def lookup_type(self, name):
return self.lookup_entity(name, QAPISchemaType)
def _def_builtin_type(self, name, json_type, c_type, c_null):
self._def_entity(QAPISchemaBuiltinType(name, json_type,
c_type, c_null))
# TODO As long as we have QAPI_TYPES_BUILTIN to share multiple
# qapi-types.h from a single .c, all arrays of builtins must be
# declared in the first file whether or not they are used. Nicer
# would be to use lazy instantiation, while figuring out how to
# avoid compilation issues with multiple qapi-types.h.
self._make_array_type(name, None)
def _def_predefineds(self):
for t in [('str', 'string', 'char' + pointer_suffix, 'NULL'),
('number', 'number', 'double', '0'),
('int', 'int', 'int64_t', '0'),
('int8', 'int', 'int8_t', '0'),
('int16', 'int', 'int16_t', '0'),
('int32', 'int', 'int32_t', '0'),
('int64', 'int', 'int64_t', '0'),
('uint8', 'int', 'uint8_t', '0'),
('uint16', 'int', 'uint16_t', '0'),
('uint32', 'int', 'uint32_t', '0'),
('uint64', 'int', 'uint64_t', '0'),
('size', 'int', 'uint64_t', '0'),
('bool', 'boolean', 'bool', 'false'),
('any', 'value', 'QObject' + pointer_suffix, 'NULL')]:
self._def_builtin_type(*t)
self.the_empty_object_type = QAPISchemaObjectType(':empty', None, None,
[], None)
self._def_entity(self.the_empty_object_type)
qtype_values = self._make_enum_members(['none', 'qnull', 'qint',
'qstring', 'qdict', 'qlist',
'qfloat', 'qbool'])
self._def_entity(QAPISchemaEnumType('QType', None, qtype_values,
'QTYPE'))
def _make_enum_members(self, values):
return [QAPISchemaMember(v) for v in values]
def _make_implicit_enum_type(self, name, info, values):
# See also QAPISchemaObjectTypeMember._pretty_owner()
name = name + 'Kind' # Use namespace reserved by add_name()
self._def_entity(QAPISchemaEnumType(
name, info, self._make_enum_members(values), None))
return name
def _make_array_type(self, element_type, info):
name = element_type + 'List' # Use namespace reserved by add_name()
if not self.lookup_type(name):
self._def_entity(QAPISchemaArrayType(name, info, element_type))
return name
def _make_implicit_object_type(self, name, info, role, members):
if not members:
return None
# See also QAPISchemaObjectTypeMember._pretty_owner()
name = ':obj-%s-%s' % (name, role)
if not self.lookup_entity(name, QAPISchemaObjectType):
self._def_entity(QAPISchemaObjectType(name, info, None,
members, None))
return name
def _def_enum_type(self, expr, info):
name = expr['enum']
data = expr['data']
prefix = expr.get('prefix')
self._def_entity(QAPISchemaEnumType(
name, info, self._make_enum_members(data), prefix))
def _make_member(self, name, typ, info):
optional = False
if name.startswith('*'):
name = name[1:]
optional = True
if isinstance(typ, list):
assert len(typ) == 1
typ = self._make_array_type(typ[0], info)
return QAPISchemaObjectTypeMember(name, typ, optional)
def _make_members(self, data, info):
return [self._make_member(key, value, info)
for (key, value) in data.iteritems()]
def _def_struct_type(self, expr, info):
name = expr['struct']
base = expr.get('base')
data = expr['data']
self._def_entity(QAPISchemaObjectType(name, info, base,
self._make_members(data, info),
None))
def _make_variant(self, case, typ):
return QAPISchemaObjectTypeVariant(case, typ)
def _make_simple_variant(self, case, typ, info):
if isinstance(typ, list):
assert len(typ) == 1
typ = self._make_array_type(typ[0], info)
typ = self._make_implicit_object_type(
typ, info, 'wrapper', [self._make_member('data', typ, info)])
return QAPISchemaObjectTypeVariant(case, typ)
def _def_union_type(self, expr, info):
name = expr['union']
data = expr['data']
base = expr.get('base')
tag_name = expr.get('discriminator')
tag_member = None
if tag_name:
variants = [self._make_variant(key, value)
for (key, value) in data.iteritems()]
members = []
else:
variants = [self._make_simple_variant(key, value, info)
for (key, value) in data.iteritems()]
typ = self._make_implicit_enum_type(name, info,
[v.name for v in variants])
tag_member = QAPISchemaObjectTypeMember('type', typ, False)
members = [tag_member]
self._def_entity(
QAPISchemaObjectType(name, info, base, members,
QAPISchemaObjectTypeVariants(tag_name,
tag_member,
variants)))
def _def_alternate_type(self, expr, info):
name = expr['alternate']
data = expr['data']
variants = [self._make_variant(key, value)
for (key, value) in data.iteritems()]
tag_member = QAPISchemaObjectTypeMember('type', 'QType', False)
self._def_entity(
QAPISchemaAlternateType(name, info,
QAPISchemaObjectTypeVariants(None,
tag_member,
variants)))
def _def_command(self, expr, info):
name = expr['command']
data = expr.get('data')
rets = expr.get('returns')
gen = expr.get('gen', True)
success_response = expr.get('success-response', True)
if isinstance(data, OrderedDict):
data = self._make_implicit_object_type(
name, info, 'arg', self._make_members(data, info))
if isinstance(rets, list):
assert len(rets) == 1
rets = self._make_array_type(rets[0], info)
self._def_entity(QAPISchemaCommand(name, info, data, rets, gen,
success_response))
def _def_event(self, expr, info):
name = expr['event']
data = expr.get('data')
if isinstance(data, OrderedDict):
data = self._make_implicit_object_type(
name, info, 'arg', self._make_members(data, info))
self._def_entity(QAPISchemaEvent(name, info, data))
def _def_exprs(self):
for expr_elem in self.exprs:
expr = expr_elem['expr']
info = expr_elem['info']
if 'enum' in expr:
self._def_enum_type(expr, info)
elif 'struct' in expr:
self._def_struct_type(expr, info)
elif 'union' in expr:
self._def_union_type(expr, info)
elif 'alternate' in expr:
self._def_alternate_type(expr, info)
elif 'command' in expr:
self._def_command(expr, info)
elif 'event' in expr:
self._def_event(expr, info)
else:
assert False
def check(self):
for ent in self._entity_dict.values():
ent.check(self)
def visit(self, visitor):
visitor.visit_begin(self)
for (name, entity) in sorted(self._entity_dict.items()):
if visitor.visit_needed(entity):
entity.visit(visitor)
visitor.visit_end()
#
# Code generation helpers
#
def camel_case(name):
new_name = ''
first = True
for ch in name:
if ch in ['_', '-']:
first = True
elif first:
new_name += ch.upper()
first = False
else:
new_name += ch.lower()
return new_name
# ENUMName -> ENUM_NAME, EnumName1 -> ENUM_NAME1
# ENUM_NAME -> ENUM_NAME, ENUM_NAME1 -> ENUM_NAME1, ENUM_Name2 -> ENUM_NAME2
# ENUM24_Name -> ENUM24_NAME
def camel_to_upper(value):
c_fun_str = c_name(value, False)
if value.isupper():
return c_fun_str
new_name = ''
l = len(c_fun_str)
for i in range(l):
c = c_fun_str[i]
# When c is upper and no "_" appears before, do more checks
if c.isupper() and (i > 0) and c_fun_str[i - 1] != "_":
if i < l - 1 and c_fun_str[i + 1].islower():
new_name += '_'
elif c_fun_str[i - 1].isdigit():
new_name += '_'
new_name += c
return new_name.lstrip('_').upper()
def c_enum_const(type_name, const_name, prefix=None):
if prefix is not None:
type_name = prefix
return camel_to_upper(type_name) + '_' + c_name(const_name, False).upper()
c_name_trans = string.maketrans('.-', '__')
# Map @name to a valid C identifier.
# If @protect, avoid returning certain ticklish identifiers (like
# C keywords) by prepending "q_".
#
# Used for converting 'name' from a 'name':'type' qapi definition
# into a generated struct member, as well as converting type names
# into substrings of a generated C function name.
# '__a.b_c' -> '__a_b_c', 'x-foo' -> 'x_foo'
# protect=True: 'int' -> 'q_int'; protect=False: 'int' -> 'int'
def c_name(name, protect=True):
# ANSI X3J11/88-090, 3.1.1
c89_words = set(['auto', 'break', 'case', 'char', 'const', 'continue',
'default', 'do', 'double', 'else', 'enum', 'extern',
'float', 'for', 'goto', 'if', 'int', 'long', 'register',
'return', 'short', 'signed', 'sizeof', 'static',
'struct', 'switch', 'typedef', 'union', 'unsigned',
'void', 'volatile', 'while'])
# ISO/IEC 9899:1999, 6.4.1
c99_words = set(['inline', 'restrict', '_Bool', '_Complex', '_Imaginary'])
# ISO/IEC 9899:2011, 6.4.1
c11_words = set(['_Alignas', '_Alignof', '_Atomic', '_Generic',
'_Noreturn', '_Static_assert', '_Thread_local'])
# GCC http://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/C-Extensions.html
# excluding _.*
gcc_words = set(['asm', 'typeof'])
# C++ ISO/IEC 14882:2003 2.11
cpp_words = set(['bool', 'catch', 'class', 'const_cast', 'delete',
'dynamic_cast', 'explicit', 'false', 'friend', 'mutable',
'namespace', 'new', 'operator', 'private', 'protected',
'public', 'reinterpret_cast', 'static_cast', 'template',
'this', 'throw', 'true', 'try', 'typeid', 'typename',
'using', 'virtual', 'wchar_t',
# alternative representations
'and', 'and_eq', 'bitand', 'bitor', 'compl', 'not',
'not_eq', 'or', 'or_eq', 'xor', 'xor_eq'])
# namespace pollution:
polluted_words = set(['unix', 'errno'])
name = name.translate(c_name_trans)
if protect and (name in c89_words | c99_words | c11_words | gcc_words
| cpp_words | polluted_words):
return "q_" + name
return name
eatspace = '\033EATSPACE.'
pointer_suffix = ' *' + eatspace
def genindent(count):
ret = ""
for _ in range(count):
ret += " "
return ret
indent_level = 0
def push_indent(indent_amount=4):
global indent_level
indent_level += indent_amount
def pop_indent(indent_amount=4):
global indent_level
indent_level -= indent_amount
# Generate @code with @kwds interpolated.
# Obey indent_level, and strip eatspace.
def cgen(code, **kwds):
raw = code % kwds
if indent_level:
indent = genindent(indent_level)
# re.subn() lacks flags support before Python 2.7, use re.compile()
raw = re.subn(re.compile("^.", re.MULTILINE),
indent + r'\g<0>', raw)
raw = raw[0]
return re.sub(re.escape(eatspace) + ' *', '', raw)
def mcgen(code, **kwds):
if code[0] == '\n':
code = code[1:]
return cgen(code, **kwds)
def guardname(filename):
return c_name(filename, protect=False).upper()
def guardstart(name):
return mcgen('''
#ifndef %(name)s
#define %(name)s
''',
name=guardname(name))
def guardend(name):
return mcgen('''
#endif /* %(name)s */
''',
name=guardname(name))
def gen_enum_lookup(name, values, prefix=None):
ret = mcgen('''
const char *const %(c_name)s_lookup[] = {
''',
c_name=c_name(name))
for value in values:
index = c_enum_const(name, value, prefix)
ret += mcgen('''
[%(index)s] = "%(value)s",
''',
index=index, value=value)
max_index = c_enum_const(name, '_MAX', prefix)
ret += mcgen('''
[%(max_index)s] = NULL,
};
''',
max_index=max_index)
return ret
def gen_enum(name, values, prefix=None):
# append automatically generated _MAX value
enum_values = values + ['_MAX']
ret = mcgen('''
typedef enum %(c_name)s {
''',
c_name=c_name(name))
i = 0
for value in enum_values:
ret += mcgen('''
%(c_enum)s = %(i)d,
''',
c_enum=c_enum_const(name, value, prefix),
i=i)
i += 1
ret += mcgen('''
} %(c_name)s;
''',
c_name=c_name(name))
ret += mcgen('''
extern const char *const %(c_name)s_lookup[];
''',
c_name=c_name(name))
return ret
def gen_params(arg_type, extra):
if not arg_type:
return extra
assert not arg_type.variants
ret = ''
sep = ''
for memb in arg_type.members:
ret += sep
sep = ', '
if memb.optional:
ret += 'bool has_%s, ' % c_name(memb.name)
ret += '%s %s' % (memb.type.c_type(is_param=True), c_name(memb.name))
if extra:
ret += sep + extra
return ret
def gen_err_check(label='out', skiperr=False):
if skiperr:
return ''
return mcgen('''
if (err) {
goto %(label)s;
}
''',
label=label)
def gen_visit_fields(members, prefix='', need_cast=False, skiperr=False):
ret = ''
if skiperr:
errparg = 'NULL'
else:
errparg = '&err'
for memb in members:
if memb.optional:
ret += mcgen('''
if (visit_optional(v, &%(prefix)shas_%(c_name)s, "%(name)s")) {
''',
prefix=prefix, c_name=c_name(memb.name),
name=memb.name, errp=errparg)
push_indent()
# Ugly: sometimes we need to cast away const
if need_cast and memb.type.name == 'str':
cast = '(char **)'
else:
cast = ''
ret += mcgen('''
visit_type_%(c_type)s(v, %(cast)s&%(prefix)s%(c_name)s, "%(name)s", %(errp)s);
''',
c_type=memb.type.c_name(), prefix=prefix, cast=cast,
c_name=c_name(memb.name), name=memb.name,
errp=errparg)
ret += gen_err_check(skiperr=skiperr)
if memb.optional:
pop_indent()
ret += mcgen('''
}
''')
return ret
#
# Common command line parsing
#
def parse_command_line(extra_options="", extra_long_options=[]):
try:
opts, args = getopt.gnu_getopt(sys.argv[1:],
"chp:o:" + extra_options,
["source", "header", "prefix=",
"output-dir="] + extra_long_options)
except getopt.GetoptError, err:
print >>sys.stderr, "%s: %s" % (sys.argv[0], str(err))
sys.exit(1)
output_dir = ""
prefix = ""
do_c = False
do_h = False
extra_opts = []
for oa in opts:
o, a = oa
if o in ("-p", "--prefix"):
match = re.match('([A-Za-z_.-][A-Za-z0-9_.-]*)?', a)
if match.end() != len(a):
print >>sys.stderr, \
"%s: 'funny character '%s' in argument of --prefix" \
% (sys.argv[0], a[match.end()])
sys.exit(1)
prefix = a
elif o in ("-o", "--output-dir"):
output_dir = a + "/"
elif o in ("-c", "--source"):
do_c = True
elif o in ("-h", "--header"):
do_h = True
else:
extra_opts.append(oa)
if not do_c and not do_h:
do_c = True
do_h = True
if len(args) != 1:
print >>sys.stderr, "%s: need exactly one argument" % sys.argv[0]
sys.exit(1)
fname = args[0]
return (fname, output_dir, do_c, do_h, prefix, extra_opts)
#
# Generate output files with boilerplate
#
def open_output(output_dir, do_c, do_h, prefix, c_file, h_file,
c_comment, h_comment):
guard = guardname(prefix + h_file)
c_file = output_dir + prefix + c_file
h_file = output_dir + prefix + h_file
if output_dir:
try:
os.makedirs(output_dir)
except os.error, e:
if e.errno != errno.EEXIST:
raise
def maybe_open(really, name, opt):
if really:
return open(name, opt)
else:
import StringIO
return StringIO.StringIO()
fdef = maybe_open(do_c, c_file, 'w')
fdecl = maybe_open(do_h, h_file, 'w')
fdef.write(mcgen('''
/* AUTOMATICALLY GENERATED, DO NOT MODIFY */
%(comment)s
''',
comment=c_comment))
fdecl.write(mcgen('''
/* AUTOMATICALLY GENERATED, DO NOT MODIFY */
%(comment)s
#ifndef %(guard)s
#define %(guard)s
''',
comment=h_comment, guard=guard))
return (fdef, fdecl)
def close_output(fdef, fdecl):
fdecl.write('''
#endif
''')
fdecl.close()
fdef.close()