private static readonly object _lock = new object(); // lock for creating dynamic module for unsafe code

private static readonly object _pointerTypeCacheKey = new object(); // key for system state for the pointer type cache

private static readonly object _conversion_mode = new object(); // key for system state current conversion mode

private static Dictionary<object, RefCountInfo> _refCountTable; // dictionary used to maintain a ref count on objects

private static ModuleBuilder _dynamicModule; // the dynamic module we generate unsafe code into

private static Dictionary<int, Type> _nativeTypes = new Dictionary<int, Type>(); // native types of the specified size for marshalling

private static StringAtDelegate _stringAt = StringAt, _wstringAt = WStringAt; // delegates for wchar/char functions we hand addresses out to (just keeping it alive)

private static CastDelegate _cast = Cast; // delegate for cast function whose address we hand out (just keeping it alive)

public const string __version__ = "1.1.0";

[UnmanagedFunctionPointer(CallingConvention.Cdecl)]

private delegate IntPtr CastDelegate(IntPtr data, IntPtr obj, IntPtr type);

[UnmanagedFunctionPointer(CallingConvention.Cdecl)]

private delegate IntPtr StringAtDelegate(IntPtr addr, int length);

[SpecialName]

public static void PerformModuleReload(PythonContext/*!*/ context, PythonDictionary/*!*/ dict) {

context.EnsureModuleException("ArgumentError", dict, "ArgumentError", "_ctypes");

// TODO: Provide an implementation which is coordinated with our _refCountTable

// context.SystemState.__dict__["getrefcount"] = null;

PythonDictionary pointerTypeCache = new PythonDictionary();

dict["_pointer_type_cache"] = pointerTypeCache;

context.SetModuleState(_pointerTypeCacheKey, pointerTypeCache);

if (Environment.OSVersion.Platform == PlatformID.Win32NT ||

Environment.OSVersion.Platform == PlatformID.Win32S ||

Environment.OSVersion.Platform == PlatformID.Win32Windows ||

Environment.OSVersion.Platform == PlatformID.WinCE) {

context.EnsureModuleException(

"COMError",

PythonExceptions.Exception,

typeof(_COMError),

dict,

"COMError",

"_ctypes",

"Raised when a COM method call failed.",

(msg, _) => new COMException(msg)

);

context.SetModuleState(_conversion_mode, PythonTuple.MakeTuple("mbcs", "ignore"));

} else {

context.SetModuleState(_conversion_mode, PythonTuple.MakeTuple("ascii", "strict"));

}

}

#region Public Functions

/// <summary>

/// Gets a function which casts the specified memory. Because this is used only

/// w/ Python API we use a delegate as the return type instead of an actual address.

/// </summary>

public static object _cast_addr {

get {

return Marshal.GetFunctionPointerForDelegate(_cast).ToPython();

}

}

/// <summary>

/// Implementation of our cast function. data is marshalled as a void*

/// so it ends up as an address. obj and type are marshalled as an object

/// so we need to unmarshal them.

/// </summary>

private static IntPtr Cast(IntPtr data, IntPtr obj, IntPtr type) {

GCHandle objHandle = GCHandle.FromIntPtr(obj);

GCHandle typeHandle = GCHandle.FromIntPtr(type);

try {

CData cdata = objHandle.Target as CData;

PythonType pt = (PythonType)typeHandle.Target;

CData res = (CData)pt.CreateInstance(pt.Context.SharedContext);

if (IsPointer(pt)) {

res._memHolder = new MemoryHolder(IntPtr.Size);

if (IsPointer(DynamicHelpers.GetPythonType(cdata))) {

res._memHolder.WriteIntPtr(0, cdata._memHolder.ReadIntPtr(0));

} else {

res._memHolder.WriteIntPtr(0, data);

}

if (cdata != null) {

res._memHolder.Objects = cdata._memHolder.Objects;

res._memHolder.AddObject(IdDispenser.GetId(cdata), cdata);

}

} else {

if (cdata != null) {

res._memHolder = new MemoryHolder(data, ((INativeType)pt).Size, cdata._memHolder);

} else {

res._memHolder = new MemoryHolder(data, ((INativeType)pt).Size);

}

}

return GCHandle.ToIntPtr(GCHandle.Alloc(res));

} finally {

typeHandle.Free();

objHandle.Free();

}

}

private static bool IsPointer(PythonType pt) {

SimpleType simpleType;

return pt is PointerType || ((simpleType = pt as SimpleType) != null && (simpleType._type == SimpleTypeKind.Pointer || simpleType._type == SimpleTypeKind.CharPointer || simpleType._type == SimpleTypeKind.WCharPointer));

}

public static object _memmove_addr {

get {

return NativeFunctions.GetMemMoveAddress().ToPython();

}

}

public static object _memset_addr {

get {

return NativeFunctions.GetMemSetAddress().ToPython();

}

}

public static object _string_at_addr {

get {

return Marshal.GetFunctionPointerForDelegate(_stringAt).ToPython();

}

}

public static object _wstring_at_addr {

get {

return Marshal.GetFunctionPointerForDelegate(_wstringAt).ToPython();

}

}

public static int CopyComPointer(object src, object dest) {

throw new NotImplementedException("CopyComPointer");

}

public static string FormatError() {

return FormatError(get_last_error());

}

public static string FormatError(int errorCode) {

return new Win32Exception(errorCode).Message;

}

[PythonHidden(PlatformsAttribute.PlatformFamily.Unix)]

public static void FreeLibrary(int handle) {

FreeLibrary(new IntPtr(handle));

}

[PythonHidden(PlatformsAttribute.PlatformFamily.Unix)]

public static void FreeLibrary(BigInteger handle) {

FreeLibrary(new IntPtr((long)handle));

}

[PythonHidden(PlatformsAttribute.PlatformFamily.Unix)]

public static void FreeLibrary(IntPtr handle) {

NativeFunctions.FreeLibrary(handle);

}

[PythonHidden(PlatformsAttribute.PlatformFamily.Unix)]

public static object LoadLibrary(string library, int mode = 0) {

IntPtr res = NativeFunctions.LoadDLL(library, mode);

if (res == IntPtr.Zero) {

throw PythonOps.OSError($"cannot load library {library}");

}

return res.ToPython();

}

// Provided for Posix compat.

public static object dlopen(string library, int mode = 0) {

return LoadLibrary(library, mode);

}

/// <summary>

/// Returns a new type which represents a pointer given the existing type.

/// </summary>

public static PythonType POINTER(CodeContext/*!*/ context, PythonType type) {

PythonContext pc = context.LanguageContext;

PythonDictionary dict = (PythonDictionary)pc.GetModuleState(_pointerTypeCacheKey);

lock (dict) {

if (!dict.TryGetValue(type, out object res)) {

string name;

if (type == null) {

name = "c_void_p";

} else {

name = "LP_" + type.Name;

}

dict[type] = res = MakePointer(context, name, PythonOps.MakeDictFromItems(new object[] { type, "_type_" }));

}

return res as PythonType;

}

}

private static PointerType MakePointer(CodeContext context, string name, PythonDictionary dict) {

return new PointerType(context,

name,

PythonTuple.MakeTuple(_Pointer),

dict

);

}

public static PythonType POINTER(CodeContext/*!*/ context, [NotNull]string name) {

PythonType res = MakePointer(context, name, new PythonDictionary());

PythonContext pc = context.LanguageContext;

PythonDictionary dict = (PythonDictionary)pc.GetModuleState(_pointerTypeCacheKey);

lock (dict) {

dict[Builtin.id(res)] = res;

}

return res;

}

/// <summary>

/// Converts an address acquired from PyObj_FromPtr or that has been

/// marshaled as type 'O' back into an object.

/// </summary>

public static object PyObj_FromPtr(IntPtr address) {

GCHandle handle = GCHandle.FromIntPtr(address);

object res = handle.Target;

handle.Free();

return res;

}

/// <summary>

/// Converts an object into an opaque address which can be handed out to

/// managed code.

/// </summary>

public static IntPtr PyObj_ToPtr(object obj) {

return GCHandle.ToIntPtr(GCHandle.Alloc(obj));

}

/// <summary>

/// Decreases the ref count on an object which has been increased with

/// Py_INCREF.

/// </summary>

public static void Py_DECREF(object key) {

EnsureRefCountTable();

lock (_refCountTable) {

if (!_refCountTable.TryGetValue(key, out RefCountInfo info)) {

// dec without an inc

throw new InvalidOperationException();

}

info.RefCount--;

if (info.RefCount == 0) {

info.Handle.Free();

_refCountTable.Remove(key);

}

}

}

/// <summary>

/// Increases the ref count on an object ensuring that it will not be collected.

/// </summary>

public static void Py_INCREF(object key) {

EnsureRefCountTable();

lock (_refCountTable) {

if (!_refCountTable.TryGetValue(key, out RefCountInfo info)) {

_refCountTable[key] = info = new RefCountInfo();

// TODO: this only works w/ blittable types, what to do for others?

info.Handle = GCHandle.Alloc(key, GCHandleType.Pinned);

}

info.RefCount++;

}

}

// for testing purposes only

public static PythonTuple _buffer_info(CData data) {

return data.GetBufferInfo();

}

public static void _check_HRESULT(int hresult) {

if (hresult < 0) {

throw PythonOps.WindowsError("ctypes function returned failed HRESULT: {0:x}", (uint)hresult);

}

}

public static void _unpickle() {

}

/// <summary>

/// returns address of C instance internal buffer.

///

/// It is the callers responsibility to ensure that the provided instance will

/// stay alive if memory in the resulting address is to be used later.

/// </summary>

public static object addressof(CData data) {

return data._memHolder.UnsafeAddress.ToPython();

}

/// <summary>

/// Gets the required alignment of the given type.

/// </summary>

public static int alignment(PythonType type) {

if (!(type is INativeType nativeType)) {

throw PythonOps.TypeError("this type has no size");

}

return nativeType.Alignment;

}

/// <summary>

/// Gets the required alignment of an object.

/// </summary>

public static int alignment(object o) {

return alignment(DynamicHelpers.GetPythonType(o));

}

public static object byref(CData instance, int offset = 0) {

if (offset != 0) {

// new in 2.6

throw new NotImplementedException("byref w/ arg");

}

return new NativeArgument(instance, "P");

}

public static object call_cdeclfunction(CodeContext context, int address, PythonTuple args) {

return call_cdeclfunction(context, new IntPtr(address), args);

}

public static object call_cdeclfunction(CodeContext context, BigInteger address, PythonTuple args) {

return call_cdeclfunction(context, new IntPtr((long)address), args);

}

public static object call_cdeclfunction(CodeContext context, IntPtr address, PythonTuple args) {

CFuncPtrType funcType = GetFunctionType(context, FUNCFLAG_CDECL);

_CFuncPtr func = (_CFuncPtr)funcType.CreateInstance(context, address);

return PythonOps.CallWithArgsTuple(func, new object[0], args);

}

public static void call_commethod() {

}

public static object call_function(CodeContext context, int address, PythonTuple args) {

return call_function(context, new IntPtr(address), args);

}

public static object call_function(CodeContext context, BigInteger address, PythonTuple args) {

return call_function(context, new IntPtr((long)address), args);

}

public static object call_function(CodeContext context, IntPtr address, PythonTuple args) {

CFuncPtrType funcType = GetFunctionType(context, FUNCFLAG_STDCALL);

_CFuncPtr func = (_CFuncPtr)funcType.CreateInstance(context, address);

return PythonOps.CallWithArgsTuple(func, new object[0], args);

}

private static CFuncPtrType GetFunctionType(CodeContext context, int flags) {

// Ideally we should cache these...

SimpleType resType = new SimpleType(

context,

"int",

PythonTuple.MakeTuple(DynamicHelpers.GetPythonTypeFromType(typeof(SimpleCData))), PythonOps.MakeHomogeneousDictFromItems(new object[] { "i", "_type_" }));

CFuncPtrType funcType = new CFuncPtrType(

context,

"func",

PythonTuple.MakeTuple(DynamicHelpers.GetPythonTypeFromType(typeof(_CFuncPtr))),

PythonOps.MakeHomogeneousDictFromItems(new object[] { FUNCFLAG_STDCALL, "_flags_", resType, "_restype_" }));

return funcType;

}

public static int get_errno() {

return 0;

}

public static int get_last_error() {

if (Environment.OSVersion.Platform == PlatformID.Win32NT) {

return NativeFunctions.GetLastError();

}

throw PythonOps.NameError("get_last_error");

}

/// <summary>

/// Returns a pointer instance for the given CData

/// </summary>

public static Pointer pointer(CodeContext/*!*/ context, CData data) {

PythonType ptrType = POINTER(context, DynamicHelpers.GetPythonType(data));

return (Pointer)ptrType.CreateInstance(context, data);

}

public static void resize(CData obj, int newSize) {

if (newSize < obj.NativeType.Size) {

throw PythonOps.ValueError("minimum size is {0}", newSize);

}

MemoryHolder newMem = new MemoryHolder(newSize);

obj._memHolder.CopyTo(newMem, 0, Math.Min(obj._memHolder.Size, newSize));

obj._memHolder = newMem;

}

public static PythonTuple/*!*/ set_conversion_mode(CodeContext/*!*/ context, string encoding, string errors) {

// TODO: Need an atomic update for module state

PythonContext pc = context.LanguageContext;

PythonTuple prev = (PythonTuple)pc.GetModuleState(_conversion_mode);

pc.SetModuleState(_conversion_mode, PythonTuple.MakeTuple(encoding, errors));

return prev;

}

public static void set_errno() {

// we can't support this without a native library

}

[PythonHidden(PlatformsAttribute.PlatformFamily.Unix)]

public static int set_last_error(int errorCode) {

int old_errno = NativeFunctions.GetLastError();

NativeFunctions.SetLastError(errorCode);

return old_errno;

}

public static int @sizeof(PythonType/*!*/ type) {

if (!(type is INativeType simpleType)) {

throw PythonOps.TypeError("this type has no size");

}

return simpleType.Size;

}

public static int @sizeof(object/*!*/ instance) {

if (instance is CData cdata && cdata._memHolder != null) {

return cdata._memHolder.Size;

}

return @sizeof(DynamicHelpers.GetPythonType(instance));

}

#endregion

#region Public Constants

public const int FUNCFLAG_STDCALL = 0;

public const int FUNCFLAG_CDECL = 1;

public const int FUNCFLAG_HRESULT = 2;

public const int FUNCFLAG_PYTHONAPI = 4;

public const int FUNCFLAG_USE_ERRNO = 8;

public const int FUNCFLAG_USE_LASTERROR = 16;

public const int RTLD_GLOBAL = 0;

public const int RTLD_LOCAL = 0;

#endregion

#region Implementation Details

/// <summary>

/// Gets the ModuleBuilder used to generate our unsafe call stubs into.

/// </summary>

private static ModuleBuilder DynamicModule {

get {

if (_dynamicModule == null) {

lock (_lock) {

if (_dynamicModule == null) {

var attributes = new[] {

new CustomAttributeBuilder(typeof(UnverifiableCodeAttribute).GetConstructor(ReflectionUtils.EmptyTypes), new object[0]),

#if !NETCOREAPP && !NETSTANDARD

//PermissionSet(SecurityAction.Demand, Unrestricted = true)

new CustomAttributeBuilder(typeof(PermissionSetAttribute).GetConstructor(new Type[] { typeof(SecurityAction) }),

new object[]{ SecurityAction.Demand },

new PropertyInfo[] { typeof(PermissionSetAttribute).GetProperty(nameof(PermissionSetAttribute.Unrestricted)) },

new object[] { true }

)

#endif

};

string name = typeof(CTypes).Namespace + ".DynamicAssembly";

var assembly = AssemblyBuilder.DefineDynamicAssembly(new AssemblyName(name), AssemblyBuilderAccess.Run, attributes);

#if !NETCOREAPP && !NETSTANDARD

assembly.DefineVersionInfoResource();

#endif

_dynamicModule = assembly.DefineDynamicModule(name);

}

}

}

return _dynamicModule;

}

}

/// <summary>

/// Given a specific size returns a .NET type of the equivalent size that

/// we can use when marshalling these values across calls.

/// </summary>

private static Type/*!*/ GetMarshalTypeFromSize(int size) {

lock (_nativeTypes) {

if (!_nativeTypes.TryGetValue(size, out Type res)) {

int sizeRemaining = size;

TypeBuilder tb = DynamicModule.DefineType("interop_type_size_" + size,

TypeAttributes.Public | TypeAttributes.SequentialLayout | TypeAttributes.Sealed | TypeAttributes.Serializable,

typeof(ValueType),

size);

while (sizeRemaining > 8) {

tb.DefineField("field" + sizeRemaining, typeof(long), FieldAttributes.Private);

sizeRemaining -= 8;

}

while (sizeRemaining > 4) {

tb.DefineField("field" + sizeRemaining, typeof(int), FieldAttributes.Private);

sizeRemaining -= 4;

}

while (sizeRemaining > 0) {

tb.DefineField("field" + sizeRemaining, typeof(byte), FieldAttributes.Private);

sizeRemaining--;

}

_nativeTypes[size] = res = tb.CreateTypeInfo();

}

return res;

}

}

/// <summary>

/// Shared helper between struct and union for getting field info and validating it.

/// </summary>

private static void GetFieldInfo(INativeType type, object o, out string fieldName, out INativeType cdata, out int? bitCount) {

PythonTuple pt = o as PythonTuple;

if (pt.Count != 2 && pt.Count != 3) {

throw PythonOps.AttributeError("'_fields_' must be a sequence of pairs");

}

fieldName = pt[0] as string;

if (fieldName == null) {

throw PythonOps.TypeError("first item in _fields_ tuple must be a string, got", PythonTypeOps.GetName(pt[0]));

}

cdata = pt[1] as INativeType;

if (cdata == null) {

throw PythonOps.TypeError("second item in _fields_ tuple must be a C type, got {0}", PythonTypeOps.GetName(pt[0]));

} else if (cdata == type) {

throw StructureCannotContainSelf();

}

if (cdata is StructType st) {

st.EnsureFinal();

}

if (pt.Count != 3) {

bitCount = null;

} else {

bitCount = CheckBits(cdata, pt);

}

}

/// <summary>

/// Verifies that the provided bit field settings are valid for this type.

/// </summary>

private static int CheckBits(INativeType cdata, PythonTuple pt) {

int bitCount = Converter.ConvertToInt32(pt[2]);

if (!(cdata is SimpleType simpType)) {

throw PythonOps.TypeError("bit fields not allowed for type {0}", ((PythonType)cdata).Name);

}

switch (simpType._type) {

case SimpleTypeKind.Object:

case SimpleTypeKind.Pointer:

case SimpleTypeKind.Single:

case SimpleTypeKind.Double:

case SimpleTypeKind.Char:

case SimpleTypeKind.CharPointer:

case SimpleTypeKind.WChar:

case SimpleTypeKind.WCharPointer:

throw PythonOps.TypeError("bit fields not allowed for type {0}", ((PythonType)cdata).Name);

}

if (bitCount <= 0 || bitCount > cdata.Size * 8) {

throw PythonOps.ValueError("number of bits invalid for bit field");

}

return bitCount;

}

/// <summary>

/// Shared helper to get the _fields_ list for struct/union and validate it.

/// </summary>

private static IList<object>/*!*/ GetFieldsList(object fields) {

if (!(fields is IList<object> list)) {

throw PythonOps.TypeError("class must be a sequence of pairs");

}

return list;

}

private static Exception StructureCannotContainSelf() {

return PythonOps.AttributeError("Structure or union cannot contain itself");

}

/// <summary>

/// Helper function for translating from memset to NT's FillMemory API.

/// </summary>

private static IntPtr StringAt(IntPtr src, int len) {

Bytes res;

if (len == -1) {

res = MemoryHolder.ReadBytes(src, 0);

} else {

res = MemoryHolder.ReadBytes(src, 0, len);

}

return GCHandle.ToIntPtr(GCHandle.Alloc(res));

}

/// <summary>

/// Helper function for translating from memset to NT's FillMemory API.

/// </summary>

private static IntPtr WStringAt(IntPtr src, int len) {

string res;

if (len == -1) {

res = Marshal.PtrToStringUni(src);

} else {

res = Marshal.PtrToStringUni(src, len);

}

return GCHandle.ToIntPtr(GCHandle.Alloc(res));

}

private static IntPtr GetHandleFromObject(object dll, string errorMsg) {

IntPtr intPtrHandle;

object dllHandle = PythonOps.GetBoundAttr(DefaultContext.Default, dll, "_handle");

if (!Converter.TryConvertToBigInteger(dllHandle, out BigInteger intHandle)) {

throw PythonOps.TypeError(errorMsg);

}

intPtrHandle = new IntPtr((long)intHandle);

return intPtrHandle;

}

private static void ValidateArraySizes(ArrayModule.array array, int offset, int size) {

ValidateArraySizes(array.__len__() * array.itemsize, offset, size);

}

private static void ValidateArraySizes(Bytes bytes, int offset, int size) {

ValidateArraySizes(bytes.Count, offset, size);

}

private static void ValidateArraySizes(string data, int offset, int size) {

ValidateArraySizes(data.Length, offset, size);

}

private static void ValidateArraySizes(int arraySize, int offset, int size) {

if (offset < 0) {

throw PythonOps.ValueError("offset cannot be negative");

} else if (arraySize < size + offset) {

throw PythonOps.ValueError($"Buffer size too small ({arraySize} instead of at least {size} bytes)");

}

}

private static void ValidateArraySizes(BigInteger arraySize, int offset, int size) {

if (offset < 0) {

throw PythonOps.ValueError("offset cannot be negative");

} else if (arraySize < size + offset) {

throw PythonOps.ValueError($"Buffer size too small ({arraySize} instead of at least {size} bytes)");

}

}

// TODO: Move these to an Ops class

public static object GetCharArrayValue(_Array arr) {

return arr.NativeType.GetValue(arr._memHolder, arr, 0, false);

}

public static void SetCharArrayValue(_Array arr, object value) {

arr.NativeType.SetValue(arr._memHolder, 0, value);

}

public static void DeleteCharArrayValue(_Array arr, object value) {

throw PythonOps.TypeError("cannot delete char array value");

}

public static object GetWCharArrayValue(_Array arr) {

return arr.NativeType.GetValue(arr._memHolder, arr, 0, false);

}

public static void SetWCharArrayValue(_Array arr, object value) {

arr.NativeType.SetValue(arr._memHolder, 0, value);

}

public static object DeleteWCharArrayValue(_Array arr) {

throw PythonOps.TypeError("cannot delete wchar array value");

}

public static object GetWCharArrayRaw(_Array arr) {

return ((ArrayType)arr.NativeType).GetRawValue(arr._memHolder, 0);

}

public static void SetWCharArrayRaw(_Array arr, object value) {

MemoryView view = value as MemoryView;

if ((object)view != null) {

string strVal = view.tobytes().MakeString();

if (strVal.Length > arr.__len__()) {

throw PythonOps.ValueError("string too long");

}

value = strVal;

}

arr.NativeType.SetValue(arr._memHolder, 0, value);

}

public static object DeleteWCharArrayRaw(_Array arr) {

throw PythonOps.TypeError("cannot delete wchar array raw");

}

private class RefCountInfo {

public int RefCount;

public GCHandle Handle;

}

/// <summary>

/// Emits the marshalling code to create a CData object for reverse marshalling.

/// </summary>

private static void EmitCDataCreation(INativeType type, ILGenerator method, List<object> constantPool, int constantPoolArgument) {

LocalBuilder locVal = method.DeclareLocal(type.GetNativeType());

method.Emit(OpCodes.Stloc, locVal);

method.Emit(OpCodes.Ldloca, locVal);

constantPool.Add(type);

method.Emit(OpCodes.Ldarg, constantPoolArgument);

method.Emit(OpCodes.Ldc_I4, constantPool.Count - 1);

method.Emit(OpCodes.Ldelem_Ref);

method.Emit(OpCodes.Call, typeof(ModuleOps).GetMethod("CreateCData"));

}

private static void EnsureRefCountTable() {

if (_refCountTable == null) {

Interlocked.CompareExchange(ref _refCountTable, new Dictionary<object, RefCountInfo>(), null);

}

}

#endregion

[PythonHidden, PythonType("COMError"), DynamicBaseType]

public class _COMError : PythonExceptions.BaseException {

public _COMError(PythonType cls) : base(cls) { }

public override void __init__(params object[] args) {

base.__init__(args);

if (args.Length < 3) {

throw PythonOps.TypeError($"COMError() takes exactly 4 arguments({args.Length} given)");

}

hresult = args[0];

text = args[1];

details = args[2];

}

public object hresult { get; set; }

public object text { get; set; }

public object details { get; set; }

}