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Editing: model.py
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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