ok
Mini Shell
import types
import weakref
from .lock import allocate_lock
from .error import CDefError, VerificationError, VerificationMissing
# type qualifiers
Q_CONST = 0x01
Q_RESTRICT = 0x02
Q_VOLATILE = 0x04
def qualify(quals, replace_with):
if quals & Q_CONST:
replace_with = ' const ' + replace_with.lstrip()
if quals & Q_VOLATILE:
replace_with = ' volatile ' + replace_with.lstrip()
if quals & Q_RESTRICT:
# It seems that __restrict is supported by gcc and msvc.
# If you hit some different compiler, add a #define in
# _cffi_include.h for it (and in its copies, documented there)
replace_with = ' __restrict ' + replace_with.lstrip()
return replace_with
class BaseTypeByIdentity(object):
is_array_type = False
is_raw_function = False
def get_c_name(self, replace_with='', context='a C file', quals=0):
result = self.c_name_with_marker
assert result.count('&') == 1
# some logic duplication with ffi.getctype()... :-(
replace_with = replace_with.strip()
if replace_with:
if replace_with.startswith('*') and '&[' in result:
replace_with = '(%s)' % replace_with
elif not replace_with[0] in '[(':
replace_with = ' ' + replace_with
replace_with = qualify(quals, replace_with)
result = result.replace('&', replace_with)
if '$' in result:
raise VerificationError(
"cannot generate '%s' in %s: unknown type name"
% (self._get_c_name(), context))
return result
def _get_c_name(self):
return self.c_name_with_marker.replace('&', '')
def has_c_name(self):
return '$' not in self._get_c_name()
def is_integer_type(self):
return False
def get_cached_btype(self, ffi, finishlist, can_delay=False):
try:
BType = ffi._cached_btypes[self]
except KeyError:
BType = self.build_backend_type(ffi, finishlist)
BType2 = ffi._cached_btypes.setdefault(self, BType)
assert BType2 is BType
return BType
def __repr__(self):
return '<%s>' % (self._get_c_name(),)
def _get_items(self):
return [(name, getattr(self, name)) for name in self._attrs_]
class BaseType(BaseTypeByIdentity):
def __eq__(self, other):
return (self.__class__ == other.__class__ and
self._get_items() == other._get_items())
def __ne__(self, other):
return not self == other
def __hash__(self):
return hash((self.__class__, tuple(self._get_items())))
class VoidType(BaseType):
_attrs_ = ()
def __init__(self):
self.c_name_with_marker = 'void&'
def build_backend_type(self, ffi, finishlist):
return global_cache(self, ffi, 'new_void_type')
void_type = VoidType()
class BasePrimitiveType(BaseType):
def is_complex_type(self):
return False
class PrimitiveType(BasePrimitiveType):
_attrs_ = ('name',)
ALL_PRIMITIVE_TYPES = {
'char': 'c',
'short': 'i',
'int': 'i',
'long': 'i',
'long long': 'i',
'signed char': 'i',
'unsigned char': 'i',
'unsigned short': 'i',
'unsigned int': 'i',
'unsigned long': 'i',
'unsigned long long': 'i',
'float': 'f',
'double': 'f',
'long double': 'f',
'float _Complex': 'j',
'double _Complex': 'j',
'_Bool': 'i',
# the following types are not primitive in the C sense
'wchar_t': 'c',
'char16_t': 'c',
'char32_t': 'c',
'int8_t': 'i',
'uint8_t': 'i',
'int16_t': 'i',
'uint16_t': 'i',
'int32_t': 'i',
'uint32_t': 'i',
'int64_t': 'i',
'uint64_t': 'i',
'int_least8_t': 'i',
'uint_least8_t': 'i',
'int_least16_t': 'i',
'uint_least16_t': 'i',
'int_least32_t': 'i',
'uint_least32_t': 'i',
'int_least64_t': 'i',
'uint_least64_t': 'i',
'int_fast8_t': 'i',
'uint_fast8_t': 'i',
'int_fast16_t': 'i',
'uint_fast16_t': 'i',
'int_fast32_t': 'i',
'uint_fast32_t': 'i',
'int_fast64_t': 'i',
'uint_fast64_t': 'i',
'intptr_t': 'i',
'uintptr_t': 'i',
'intmax_t': 'i',
'uintmax_t': 'i',
'ptrdiff_t': 'i',
'size_t': 'i',
'ssize_t': 'i',
}
def __init__(self, name):
assert name in self.ALL_PRIMITIVE_TYPES
self.name = name
self.c_name_with_marker = name + '&'
def is_char_type(self):
return self.ALL_PRIMITIVE_TYPES[self.name] == 'c'
def is_integer_type(self):
return self.ALL_PRIMITIVE_TYPES[self.name] == 'i'
def is_float_type(self):
return self.ALL_PRIMITIVE_TYPES[self.name] == 'f'
def is_complex_type(self):
return self.ALL_PRIMITIVE_TYPES[self.name] == 'j'
def build_backend_type(self, ffi, finishlist):
return global_cache(self, ffi, 'new_primitive_type', self.name)
class UnknownIntegerType(BasePrimitiveType):
_attrs_ = ('name',)
def __init__(self, name):
self.name = name
self.c_name_with_marker = name + '&'
def is_integer_type(self):
return True
def build_backend_type(self, ffi, finishlist):
raise NotImplementedError("integer type '%s' can only be used after "
"compilation" % self.name)
class UnknownFloatType(BasePrimitiveType):
_attrs_ = ('name', )
def __init__(self, name):
self.name = name
self.c_name_with_marker = name + '&'
def build_backend_type(self, ffi, finishlist):
raise NotImplementedError("float type '%s' can only be used after "
"compilation" % self.name)
class BaseFunctionType(BaseType):
_attrs_ = ('args', 'result', 'ellipsis', 'abi')
def __init__(self, args, result, ellipsis, abi=None):
self.args = args
self.result = result
self.ellipsis = ellipsis
self.abi = abi
#
reprargs = [arg._get_c_name() for arg in self.args]
if self.ellipsis:
reprargs.append('...')
reprargs = reprargs or ['void']
replace_with = self._base_pattern % (', '.join(reprargs),)
if abi is not None:
replace_with = replace_with[:1] + abi + ' ' + replace_with[1:]
self.c_name_with_marker = (
self.result.c_name_with_marker.replace('&', replace_with))
class RawFunctionType(BaseFunctionType):
# Corresponds to a C type like 'int(int)', which is the C type of
# a function, but not a pointer-to-function. The backend has no
# notion of such a type; it's used temporarily by parsing.
_base_pattern = '(&)(%s)'
is_raw_function = True
def build_backend_type(self, ffi, finishlist):
raise CDefError("cannot render the type %r: it is a function "
"type, not a pointer-to-function type" % (self,))
def as_function_pointer(self):
return FunctionPtrType(self.args, self.result, self.ellipsis, self.abi)
class FunctionPtrType(BaseFunctionType):
_base_pattern = '(*&)(%s)'
def build_backend_type(self, ffi, finishlist):
result = self.result.get_cached_btype(ffi, finishlist)
args = []
for tp in self.args:
args.append(tp.get_cached_btype(ffi, finishlist))
abi_args = ()
if self.abi == "__stdcall":
if not self.ellipsis: # __stdcall ignored for variadic funcs
try:
abi_args = (ffi._backend.FFI_STDCALL,)
except AttributeError:
pass
return global_cache(self, ffi, 'new_function_type',
tuple(args), result, self.ellipsis, *abi_args)
def as_raw_function(self):
return RawFunctionType(self.args, self.result, self.ellipsis, self.abi)
class PointerType(BaseType):
_attrs_ = ('totype', 'quals')
def __init__(self, totype, quals=0):
self.totype = totype
self.quals = quals
extra = qualify(quals, " *&")
if totype.is_array_type:
extra = "(%s)" % (extra.lstrip(),)
self.c_name_with_marker = totype.c_name_with_marker.replace('&', extra)
def build_backend_type(self, ffi, finishlist):
BItem = self.totype.get_cached_btype(ffi, finishlist, can_delay=True)
return global_cache(self, ffi, 'new_pointer_type', BItem)
voidp_type = PointerType(void_type)
def ConstPointerType(totype):
return PointerType(totype, Q_CONST)
const_voidp_type = ConstPointerType(void_type)
class NamedPointerType(PointerType):
_attrs_ = ('totype', 'name')
def __init__(self, totype, name, quals=0):
PointerType.__init__(self, totype, quals)
self.name = name
self.c_name_with_marker = name + '&'
class ArrayType(BaseType):
_attrs_ = ('item', 'length')
is_array_type = True
def __init__(self, item, length):
self.item = item
self.length = length
#
if length is None:
brackets = '&[]'
elif length == '...':
brackets = '&[/*...*/]'
else:
brackets = '&[%s]' % length
self.c_name_with_marker = (
self.item.c_name_with_marker.replace('&', brackets))
def length_is_unknown(self):
return isinstance(self.length, str)
def resolve_length(self, newlength):
return ArrayType(self.item, newlength)
def build_backend_type(self, ffi, finishlist):
if self.length_is_unknown():
raise CDefError("cannot render the type %r: unknown length" %
(self,))
self.item.get_cached_btype(ffi, finishlist) # force the item BType
BPtrItem = PointerType(self.item).get_cached_btype(ffi, finishlist)
return global_cache(self, ffi, 'new_array_type', BPtrItem, self.length)
char_array_type = ArrayType(PrimitiveType('char'), None)
class StructOrUnionOrEnum(BaseTypeByIdentity):
_attrs_ = ('name',)
forcename = None
def build_c_name_with_marker(self):
name = self.forcename or '%s %s' % (self.kind, self.name)
self.c_name_with_marker = name + '&'
def force_the_name(self, forcename):
self.forcename = forcename
self.build_c_name_with_marker()
def get_official_name(self):
assert self.c_name_with_marker.endswith('&')
return self.c_name_with_marker[:-1]
class StructOrUnion(StructOrUnionOrEnum):
fixedlayout = None
completed = 0
partial = False
packed = 0
def __init__(self, name, fldnames, fldtypes, fldbitsize, fldquals=None):
self.name = name
self.fldnames = fldnames
self.fldtypes = fldtypes
self.fldbitsize = fldbitsize
self.fldquals = fldquals
self.build_c_name_with_marker()
def anonymous_struct_fields(self):
if self.fldtypes is not None:
for name, type in zip(self.fldnames, self.fldtypes):
if name == '' and isinstance(type, StructOrUnion):
yield type
def enumfields(self, expand_anonymous_struct_union=True):
fldquals = self.fldquals
if fldquals is None:
fldquals = (0,) * len(self.fldnames)
for name, type, bitsize, quals in zip(self.fldnames, self.fldtypes,
self.fldbitsize, fldquals):
if (name == '' and isinstance(type, StructOrUnion)
and expand_anonymous_struct_union):
# nested anonymous struct/union
for result in type.enumfields():
yield result
else:
yield (name, type, bitsize, quals)
def force_flatten(self):
# force the struct or union to have a declaration that lists
# directly all fields returned by enumfields(), flattening
# nested anonymous structs/unions.
names = []
types = []
bitsizes = []
fldquals = []
for name, type, bitsize, quals in self.enumfields():
names.append(name)
types.append(type)
bitsizes.append(bitsize)
fldquals.append(quals)
self.fldnames = tuple(names)
self.fldtypes = tuple(types)
self.fldbitsize = tuple(bitsizes)
self.fldquals = tuple(fldquals)
def get_cached_btype(self, ffi, finishlist, can_delay=False):
BType = StructOrUnionOrEnum.get_cached_btype(self, ffi, finishlist,
can_delay)
if not can_delay:
self.finish_backend_type(ffi, finishlist)
return BType
def finish_backend_type(self, ffi, finishlist):
if self.completed:
if self.completed != 2:
raise NotImplementedError("recursive structure declaration "
"for '%s'" % (self.name,))
return
BType = ffi._cached_btypes[self]
#
self.completed = 1
#
if self.fldtypes is None:
pass # not completing it: it's an opaque struct
#
elif self.fixedlayout is None:
fldtypes = [tp.get_cached_btype(ffi, finishlist)
for tp in self.fldtypes]
lst = list(zip(self.fldnames, fldtypes, self.fldbitsize))
extra_flags = ()
if self.packed:
if self.packed == 1:
extra_flags = (8,) # SF_PACKED
else:
extra_flags = (0, self.packed)
ffi._backend.complete_struct_or_union(BType, lst, self,
-1, -1, *extra_flags)
#
else:
fldtypes = []
fieldofs, fieldsize, totalsize, totalalignment = self.fixedlayout
for i in range(len(self.fldnames)):
fsize = fieldsize[i]
ftype = self.fldtypes[i]
#
if isinstance(ftype, ArrayType) and ftype.length_is_unknown():
# fix the length to match the total size
BItemType = ftype.item.get_cached_btype(ffi, finishlist)
nlen, nrest = divmod(fsize, ffi.sizeof(BItemType))
if nrest != 0:
self._verification_error(
"field '%s.%s' has a bogus size?" % (
self.name, self.fldnames[i] or '{}'))
ftype = ftype.resolve_length(nlen)
self.fldtypes = (self.fldtypes[:i] + (ftype,) +
self.fldtypes[i+1:])
#
BFieldType = ftype.get_cached_btype(ffi, finishlist)
if isinstance(ftype, ArrayType) and ftype.length is None:
assert fsize == 0
else:
bitemsize = ffi.sizeof(BFieldType)
if bitemsize != fsize:
self._verification_error(
"field '%s.%s' is declared as %d bytes, but is "
"really %d bytes" % (self.name,
self.fldnames[i] or '{}',
bitemsize, fsize))
fldtypes.append(BFieldType)
#
lst = list(zip(self.fldnames, fldtypes, self.fldbitsize, fieldofs))
ffi._backend.complete_struct_or_union(BType, lst, self,
totalsize, totalalignment)
self.completed = 2
def _verification_error(self, msg):
raise VerificationError(msg)
def check_not_partial(self):
if self.partial and self.fixedlayout is None:
raise VerificationMissing(self._get_c_name())
def build_backend_type(self, ffi, finishlist):
self.check_not_partial()
finishlist.append(self)
#
return global_cache(self, ffi, 'new_%s_type' % self.kind,
self.get_official_name(), key=self)
class StructType(StructOrUnion):
kind = 'struct'
class UnionType(StructOrUnion):
kind = 'union'
class EnumType(StructOrUnionOrEnum):
kind = 'enum'
partial = False
partial_resolved = False
def __init__(self, name, enumerators, enumvalues, baseinttype=None):
self.name = name
self.enumerators = enumerators
self.enumvalues = enumvalues
self.baseinttype = baseinttype
self.build_c_name_with_marker()
def force_the_name(self, forcename):
StructOrUnionOrEnum.force_the_name(self, forcename)
if self.forcename is None:
name = self.get_official_name()
self.forcename = '$' + name.replace(' ', '_')
def check_not_partial(self):
if self.partial and not self.partial_resolved:
raise VerificationMissing(self._get_c_name())
def build_backend_type(self, ffi, finishlist):
self.check_not_partial()
base_btype = self.build_baseinttype(ffi, finishlist)
return global_cache(self, ffi, 'new_enum_type',
self.get_official_name(),
self.enumerators, self.enumvalues,
base_btype, key=self)
def build_baseinttype(self, ffi, finishlist):
if self.baseinttype is not None:
return self.baseinttype.get_cached_btype(ffi, finishlist)
#
if self.enumvalues:
smallest_value = min(self.enumvalues)
largest_value = max(self.enumvalues)
else:
import warnings
try:
# XXX! The goal is to ensure that the warnings.warn()
# will not suppress the warning. We want to get it
# several times if we reach this point several times.
__warningregistry__.clear()
except NameError:
pass
warnings.warn("%r has no values explicitly defined; "
"guessing that it is equivalent to 'unsigned int'"
% self._get_c_name())
smallest_value = largest_value = 0
if smallest_value < 0: # needs a signed type
sign = 1
candidate1 = PrimitiveType("int")
candidate2 = PrimitiveType("long")
else:
sign = 0
candidate1 = PrimitiveType("unsigned int")
candidate2 = PrimitiveType("unsigned long")
btype1 = candidate1.get_cached_btype(ffi, finishlist)
btype2 = candidate2.get_cached_btype(ffi, finishlist)
size1 = ffi.sizeof(btype1)
size2 = ffi.sizeof(btype2)
if (smallest_value >= ((-1) << (8*size1-1)) and
largest_value < (1 << (8*size1-sign))):
return btype1
if (smallest_value >= ((-1) << (8*size2-1)) and
largest_value < (1 << (8*size2-sign))):
return btype2
raise CDefError("%s values don't all fit into either 'long' "
"or 'unsigned long'" % self._get_c_name())
def unknown_type(name, structname=None):
if structname is None:
structname = '$%s' % name
tp = StructType(structname, None, None, None)
tp.force_the_name(name)
tp.origin = "unknown_type"
return tp
def unknown_ptr_type(name, structname=None):
if structname is None:
structname = '$$%s' % name
tp = StructType(structname, None, None, None)
return NamedPointerType(tp, name)
global_lock = allocate_lock()
_typecache_cffi_backend = weakref.WeakValueDictionary()
def get_typecache(backend):
# returns _typecache_cffi_backend if backend is the _cffi_backend
# module, or type(backend).__typecache if backend is an instance of
# CTypesBackend (or some FakeBackend class during tests)
if isinstance(backend, types.ModuleType):
return _typecache_cffi_backend
with global_lock:
if not hasattr(type(backend), '__typecache'):
type(backend).__typecache = weakref.WeakValueDictionary()
return type(backend).__typecache
def global_cache(srctype, ffi, funcname, *args, **kwds):
key = kwds.pop('key', (funcname, args))
assert not kwds
try:
return ffi._typecache[key]
except KeyError:
pass
try:
res = getattr(ffi._backend, funcname)(*args)
except NotImplementedError as e:
raise NotImplementedError("%s: %r: %s" % (funcname, srctype, e))
# note that setdefault() on WeakValueDictionary is not atomic
# and contains a rare bug (http://bugs.python.org/issue19542);
# we have to use a lock and do it ourselves
cache = ffi._typecache
with global_lock:
res1 = cache.get(key)
if res1 is None:
cache[key] = res
return res
else:
return res1
def pointer_cache(ffi, BType):
return global_cache('?', ffi, 'new_pointer_type', BType)
def attach_exception_info(e, name):
if e.args and type(e.args[0]) is str:
e.args = ('%s: %s' % (name, e.args[0]),) + e.args[1:]
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