pythonnet/src/runtime/Types/ClassObject.cs at master · luoyiminga/pythonnet · GitHub

Repository navigation

History

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

using System;

using System.Diagnostics;

using System.Linq;

using System.Reflection;

using System.Runtime.Serialization;

namespace Python.Runtime

{

/// <summary>

/// Managed class that provides the implementation for reflected types.

/// Managed classes and value types are represented in Python by actual

/// Python type objects. Each of those type objects is associated with

/// an instance of ClassObject, which provides its implementation.

/// </summary>

[Serializable]

internal class ClassObject : ClassBase

{

internal readonly int NumCtors = 0;

internal ClassObject(Type tp) : base(tp)

{

var _ctors = type.Value.GetConstructors();

NumCtors = _ctors.Length;

}

/// <summary>

/// Helper to get docstring from reflected constructor info.

/// </summary>

internal NewReference GetDocString()

{

if (!type.Valid)

{

return Exceptions.RaiseTypeError(type.DeletedMessage);

}

MethodBase[] methods = type.Value.GetConstructors();

var str = "";

foreach (MethodBase t in methods)

{

if (str.Length > 0)

{

str += Environment.NewLine;

}

str += t.ToString();

}

return Runtime.PyString_FromString(str);

}

/// <summary>

/// Implements __new__ for reflected classes and value types.

/// </summary>

static NewReference tp_new_impl(BorrowedReference tp, BorrowedReference args, BorrowedReference kw)

{

var self = GetManagedObject(tp) as ClassObject;

// Sanity check: this ensures a graceful error if someone does

// something intentially wrong like use the managed metatype for

// a class that is not really derived from a managed class.

if (self == null)

{

return Exceptions.RaiseTypeError("invalid object");

}

if (!self.type.Valid)

{

return Exceptions.RaiseTypeError(self.type.DeletedMessage);

}

Type type = self.type.Value;

// Primitive types do not have constructors, but they look like

// they do from Python. If the ClassObject represents one of the

// convertible primitive types, just convert the arg directly.

if (type.IsPrimitive || type == typeof(string))

{

if (Runtime.PyTuple_Size(args) != 1)

{

Exceptions.SetError(Exceptions.TypeError, "no constructors match given arguments");

return default;

}

BorrowedReference op = Runtime.PyTuple_GetItem(args, 0);

if (!Converter.ToManaged(op, type, out var result, true))

{

return default;

}

return CLRObject.GetReference(result!, tp);

}

if (type.IsAbstract)

{

Exceptions.SetError(Exceptions.TypeError, "cannot instantiate abstract class");

return default;

}

if (type.IsEnum)

{

return NewEnum(type, args, tp);

}

if (IsGenericNullable(type))

{

// Nullable<T> has special handling in .NET runtime.

// Invoking its constructor via reflection on an uninitialized instance

// does not actually set the object fields.

return NewNullable(type, args, kw, tp);

}

object obj = FormatterServices.GetUninitializedObject(type);

return self.NewObjectToPython(obj, tp);

}

protected virtual void SetTypeNewSlot(BorrowedReference pyType, SlotsHolder slotsHolder)

{

TypeManager.InitializeSlotIfEmpty(pyType, TypeOffset.tp_new, new Interop.BBB_N(tp_new_impl), slotsHolder);

}

public override bool HasCustomNew()

{

if (base.HasCustomNew()) return true;

Type clrType = type.Value;

return clrType.IsPrimitive

|| clrType.IsEnum

|| clrType == typeof(string)

|| IsGenericNullable(clrType);

}

static bool IsGenericNullable(Type type)

=> type.IsValueType && type.IsGenericType

&& type.GetGenericTypeDefinition() == typeof(Nullable<>);

public override void InitializeSlots(BorrowedReference pyType, SlotsHolder slotsHolder)

{

base.InitializeSlots(pyType, slotsHolder);

this.SetTypeNewSlot(pyType, slotsHolder);

}

protected virtual NewReference NewObjectToPython(object obj, BorrowedReference tp)

=> CLRObject.GetReference(obj, tp);

private static NewReference NewEnum(Type type, BorrowedReference args, BorrowedReference tp)

{

nint argCount = Runtime.PyTuple_Size(args);

bool allowUnchecked = false;

if (argCount == 2)

{

var allow = Runtime.PyTuple_GetItem(args, 1);

if (!Converter.ToManaged(allow, typeof(bool), out var allowObj, true) || allowObj is null)

{

Exceptions.RaiseTypeError("second argument to enum constructor must be a boolean");

return default;

}

allowUnchecked |= (bool)allowObj;

}

if (argCount < 1 || argCount > 2)

{

Exceptions.SetError(Exceptions.TypeError, "no constructors match given arguments");

return default;

}

var op = Runtime.PyTuple_GetItem(args, 0);

if (!Converter.ToManaged(op, type.GetEnumUnderlyingType(), out object? result, true))

{

return default;

}

if (!allowUnchecked && !Enum.IsDefined(type, result) && !type.IsFlagsEnum())

{

Exceptions.SetError(Exceptions.ValueError, "Invalid enumeration value. Pass True as the second argument if unchecked conversion is desired");

return default;

}

object enumValue = Enum.ToObject(type, result);

return CLRObject.GetReference(enumValue, tp);

}

private static NewReference NewNullable(Type type, BorrowedReference args, BorrowedReference kw, BorrowedReference tp)

{

Debug.Assert(IsGenericNullable(type));

if (kw != null)

{

return Exceptions.RaiseTypeError("System.Nullable<T> constructor does not support keyword arguments");

}

nint argsCount = Runtime.PyTuple_Size(args);

if (argsCount != 1)

{

return Exceptions.RaiseTypeError("System.Nullable<T> constructor expects 1 argument, got " + (int)argsCount);

}

var value = Runtime.PyTuple_GetItem(args, 0);

var elementType = type.GetGenericArguments()[0];

return Converter.ToManaged(value, elementType, out var result, setError: true)

? CLRObject.GetReference(result!, tp)

: default;

}

/// <summary>

/// Implementation of [] semantics for reflected types. This exists

/// both to implement the Array[int] syntax for creating arrays and

/// to support generic name overload resolution using [].

/// </summary>

public override NewReference type_subscript(BorrowedReference idx)

{

if (!type.Valid)

{

return Exceptions.RaiseTypeError(type.DeletedMessage);

}

// If this type is the Array type, the [<type>] means we need to

// construct and return an array type of the given element type.

if (type.Value == typeof(Array))

{

if (Runtime.PyTuple_Check(idx))

{

return Exceptions.RaiseTypeError("type expected");

}

var c = GetManagedObject(idx) as ClassBase;

Type? t = c != null ? c.type.Value : Converter.GetTypeByAlias(idx);

if (t == null)

{

return Exceptions.RaiseTypeError("type expected");

}

Type a = t.MakeArrayType();

PyType o = ClassManager.GetClass(a);

return new NewReference(o);

}

// If there are generics in our namespace with the same base name

// as the current type, then [<type>] means the caller wants to

// bind the generic type matching the given type parameters.

Type[]? types = Runtime.PythonArgsToTypeArray(idx);

if (types == null)

{

return Exceptions.RaiseTypeError("type(s) expected");

}

Type gtype = AssemblyManager.LookupTypes($"{type.Value.FullName}`{types.Length}").FirstOrDefault();

if (gtype != null)

{

var g = (GenericType)ClassManager.GetClassImpl(gtype);

return g.type_subscript(idx);

}

return Exceptions.RaiseTypeError("unsubscriptable object");

}

pythonnet/src/runtime/Types/ClassObject.cs at master · luoyiminga/pythonnet · GitHub

Repository navigation

Expand file tree

Breadcrumbs

ClassObject.cs

Latest commit

History

Breadcrumbs

ClassObject.cs

File metadata and controls