pythonnet/src/runtime/PythonException.cs at master · ZeroMSN/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

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

using System;

using System.Diagnostics;

using System.Linq;

using System.Runtime.CompilerServices;

using System.Runtime.ExceptionServices;

using System.Runtime.Serialization;

using System.Security.Permissions;

using System.Text;

using Python.Runtime.Native;

namespace Python.Runtime

{

/// <summary>

/// Provides a managed interface to exceptions thrown by the Python

/// runtime.

/// </summary>

[Serializable]

public class PythonException : System.Exception

{

public PythonException(PyType type, PyObject? value, PyObject? traceback,

string message, Exception? innerException)

: base(message, innerException)

{

Type = type ?? throw new ArgumentNullException(nameof(type));

Value = value;

Traceback = traceback;

}

public PythonException(PyType type, PyObject? value, PyObject? traceback,

Exception? innerException)

: this(type, value, traceback, GetMessage(value, type), innerException) { }

public PythonException(PyType type, PyObject? value, PyObject? traceback)

: this(type, value, traceback, innerException: null) { }

/// <summary>

/// Rethrows the last Python exception as corresponding CLR exception.

/// It is recommended to call this as <code>throw ThrowLastAsClrException()</code>

/// to assist control flow checks.

/// </summary>

[DebuggerHidden]

internal static Exception ThrowLastAsClrException()

{

// prevent potential interop errors in this method

// from crashing process with undebuggable StackOverflowException

RuntimeHelpers.EnsureSufficientExecutionStack();

var exception = FetchCurrentOrNull(out ExceptionDispatchInfo? dispatchInfo)

?? throw new InvalidOperationException("No exception is set");

dispatchInfo?.Throw();

// when dispatchInfo is not null, this line will not be reached

throw exception;

}

internal static PythonException? FetchCurrentOrNullRaw()

{

using var _ = new Py.GILState();

Runtime.PyErr_Fetch(type: out var type, val: out var value, tb: out var traceback);

if (type.IsNull())

{

Debug.Assert(value.IsNull());

Debug.Assert(traceback.IsNull());

return null;

}

return new PythonException(

type: new PyType(type.Steal()),

value: value.MoveToPyObjectOrNull(),

traceback: traceback.MoveToPyObjectOrNull());

}

internal static PythonException FetchCurrentRaw()

=> FetchCurrentOrNullRaw()

?? throw new InvalidOperationException("No exception is set");

internal static Exception? PeekCurrentOrNull(out ExceptionDispatchInfo? dispatchInfo)

{

using var _ = new Py.GILState();

Runtime.PyErr_Fetch(out var type, out var value, out var traceback);

Runtime.PyErr_Restore(

new NewReference(type, canBeNull: true).StealNullable(),

new NewReference(value, canBeNull: true).StealNullable(),

new NewReference(traceback, canBeNull: true).StealNullable());

var err = FetchCurrentOrNull(out dispatchInfo);

Runtime.PyErr_Restore(type.StealNullable(), value.StealNullable(), traceback.StealNullable());

return err;

}

internal static Exception? FetchCurrentOrNull(out ExceptionDispatchInfo? dispatchInfo)

{

dispatchInfo = null;

// prevent potential interop errors in this method

// from crashing process with undebuggable StackOverflowException

RuntimeHelpers.EnsureSufficientExecutionStack();

using var _ = new Py.GILState();

Runtime.PyErr_Fetch(out var type, out var value, out var traceback);

if (type.IsNull())

{

Debug.Assert(value.IsNull());

Debug.Assert(traceback.IsNull());

return null;

}

try

{

if (TryDecodePyErr(type.Borrow(), value.BorrowNullable(), traceback.BorrowNullable()) is { } pyErr)

{

type.Dispose();

value.Dispose();

traceback.Dispose();

return pyErr;

}

catch

{

type.Dispose();

value.Dispose();

traceback.Dispose();

throw;

}

Runtime.PyErr_NormalizeException(type: ref type, val: ref value, tb: ref traceback);

try

{

return FromPyErr(typeRef: type.Borrow(), valRef: value.Borrow(), tbRef: traceback.BorrowNullable(), out dispatchInfo);

}

finally

{

type.Dispose();

value.Dispose();

traceback.Dispose();

}

internal static Exception FetchCurrent()

=> FetchCurrentOrNull(out _)

?? throw new InvalidOperationException("No exception is set");

private static ExceptionDispatchInfo? TryGetDispatchInfo(BorrowedReference exception)

{

if (exception.IsNull) return null;

using var pyInfo = Runtime.PyObject_GetAttrString(exception, Exceptions.DispatchInfoAttribute);

if (pyInfo.IsNull())

{

if (Exceptions.ExceptionMatches(Exceptions.AttributeError))

{

Exceptions.Clear();

}

return null;

}

if (Converter.ToManagedValue(pyInfo.Borrow(), typeof(ExceptionDispatchInfo), out object? result, setError: false))

{

return (ExceptionDispatchInfo)result!;

}

return null;

}

/// <summary>

/// Requires lock to be acquired elsewhere

/// </summary>

private static Exception FromPyErr(BorrowedReference typeRef, BorrowedReference valRef, BorrowedReference tbRef,

out ExceptionDispatchInfo? exceptionDispatchInfo)

{

if (valRef == null) throw new ArgumentNullException(nameof(valRef));

var type = PyType.FromReference(typeRef);

var value = new PyObject(valRef);

var traceback = PyObject.FromNullableReference(tbRef);

exceptionDispatchInfo = TryGetDispatchInfo(valRef);

if (exceptionDispatchInfo != null)

{

return exceptionDispatchInfo.SourceException;

}

if (ManagedType.GetManagedObject(valRef) is CLRObject { inst: Exception e })

{

return e;

}

if (TryDecodePyErr(typeRef, valRef, tbRef) is { } pyErr)

{

return pyErr;

}

if (PyObjectConversions.TryDecode(valRef, typeRef, typeof(Exception), out object? decoded)

&& decoded is Exception decodedException)

{

return decodedException;

}

using var cause = Runtime.PyException_GetCause(valRef);

Exception? inner = FromCause(cause.BorrowNullable());

return new PythonException(type, value, traceback, inner);

}

private static PyDict ToPyErrArgs(BorrowedReference typeRef, BorrowedReference valRef, BorrowedReference tbRef)

{

using var type = PyType.FromReference(typeRef);

using var value = PyObject.FromNullableReference(valRef);

using var traceback = PyObject.FromNullableReference(tbRef);

var errorDict = new PyDict();

errorDict["type"] = type;

if (value is not null) errorDict["value"] = value;

if (traceback is not null) errorDict["traceback"] = traceback;

return errorDict;

}

private static Exception? TryDecodePyErr(BorrowedReference typeRef, BorrowedReference valRef, BorrowedReference tbRef)

{

using var pyErrType = Runtime.InteropModule.GetAttr("PyErr");

using var errorDict = ToPyErrArgs(typeRef, valRef, tbRef);

using var pyErrInfo = pyErrType.Invoke(new PyTuple(), errorDict);

if (PyObjectConversions.TryDecode(pyErrInfo.Reference, pyErrType.Reference,

typeof(Exception), out object? decoded) && decoded is Exception decodedPyErrInfo)

{

return decodedPyErrInfo;

}

return null;

}

private static Exception? FromCause(BorrowedReference cause)

{

if (cause == null || cause.IsNone()) return null;

Debug.Assert(Runtime.PyObject_TypeCheck(cause, Exceptions.BaseException));

using var innerTraceback = Runtime.PyException_GetTraceback(cause);

return FromPyErr(

typeRef: Runtime.PyObject_TYPE(cause),

valRef: cause,

tbRef: innerTraceback.BorrowNullable(),

out _);

}

private static string GetMessage(PyObject? value, PyType type)

{

if (type is null) throw new ArgumentNullException(nameof(type));

if (value != null && !value.IsNone())

{

return value.ToString() ?? "no message";

}

return type.Name;

}

private static string TracebackToString(PyObject traceback)

{

if (traceback is null)

{

throw new ArgumentNullException(nameof(traceback));

}

using var tracebackModule = PyModule.Import("traceback");

using var stackLines = new PyList(tracebackModule.InvokeMethod("format_tb", traceback));

stackLines.Reverse();

var result = new StringBuilder();

foreach (PyObject stackLine in stackLines)

{

result.Append(stackLine);

stackLine.Dispose();

}

return result.ToString();

}

/// <summary>Restores python error.</summary>

internal void Restore()

{

NewReference type = Type.NewReferenceOrNull();

NewReference value = Value.NewReferenceOrNull();

NewReference traceback = Traceback.NewReferenceOrNull();

Runtime.PyErr_Restore(

type: type.Steal(),

val: value.StealNullable(),

tb: traceback.StealNullable());

}

/// <summary>

/// Returns the exception type as a Python object.

/// </summary>

public PyType Type { get; private set; }

/// <summary>

/// Returns the exception value as a Python object.

/// </summary>

/// <seealso cref="Normalize"/>

public PyObject? Value { get; private set; }

/// <remarks>

/// Returns the TraceBack as a Python object.

/// </remarks>

public PyObject? Traceback { get; }

/// <summary>

/// StackTrace Property

/// </summary>

/// <remarks>

/// A string representing the python exception stack trace.

/// </remarks>

public override string StackTrace

{

get

{

if (Traceback is null) return base.StackTrace;

if (!PythonEngine.IsInitialized && Runtime.Py_IsInitialized() == 0)

return "Python stack unavailable as runtime was shut down\n" + base.StackTrace;

using var _ = new Py.GILState();

return TracebackToString(Traceback) + base.StackTrace;

}

public bool IsNormalized

{

get

{

if (Value is null) return false;

CheckRuntimeIsRunning();

using var _ = new Py.GILState();

return Runtime.PyObject_TypeCheck(Value.Reference, Type.Reference);

}

/// <summary>

/// Replaces Value with an instance of Type, if Value is not already an instance of Type.

/// </summary>

public void Normalize()

{

CheckRuntimeIsRunning();

PyGILState gs = PythonEngine.AcquireLock();

try

{

if (Exceptions.ErrorOccurred()) throw new InvalidOperationException("Cannot normalize when an error is set");

// If an error is set and this PythonException is unnormalized, the error will be cleared and the PythonException will be replaced by a different error.

NewReference value = Value.NewReferenceOrNull();

NewReference type = Type.NewReferenceOrNull();

NewReference tb = Traceback.NewReferenceOrNull();

Runtime.PyErr_NormalizeException(type: ref type, val: ref value, tb: ref tb);

Value = value.MoveToPyObject();

Type = new PyType(type.Steal());

try

{

Debug.Assert(Traceback is null == tb.IsNull());

if (!tb.IsNull())

{

Debug.Assert(Traceback!.Reference == tb.Borrow());

int r = Runtime.PyException_SetTraceback(Value.Reference, tb.Borrow());

ThrowIfIsNotZero(r);

}

finally

{

tb.Dispose();

}

finally

{

PythonEngine.ReleaseLock(gs);

}

/// <summary>

/// Formats this PythonException object into a message as would be printed

/// out via the Python console. See traceback.format_exception

/// </summary>

public string Format()

{

CheckRuntimeIsRunning();

using var _ = new Py.GILState();

var copy = Clone();

copy.Normalize();

if (copy.Traceback is null || copy.Value is null)

return StackTrace;

using var traceback = PyModule.Import("traceback");

var buffer = new StringBuilder();

using var values = traceback.InvokeMethod("format_exception", copy.Type, copy.Value, copy.Traceback);

foreach (PyObject val in PyIter.GetIter(values))

{

buffer.Append(val);

val.Dispose();

}

return buffer.ToString();

}

public PythonException Clone()

=> new(

type: Type,

value: Value,

traceback: Traceback,

Message,

InnerException

);

#region Serializable

[SecurityPermission(SecurityAction.Demand, SerializationFormatter = true)]

protected PythonException(SerializationInfo info, StreamingContext context)

: base(info, context)

{

Type = (PyType)info.GetValue(nameof(Type), typeof(PyType));

Value = (PyObject)info.GetValue(nameof(Value), typeof(PyObject));

Traceback = (PyObject)info.GetValue(nameof(Traceback), typeof(PyObject));

}

[SecurityPermission(SecurityAction.Demand, SerializationFormatter = true)]

public override void GetObjectData(SerializationInfo info, StreamingContext context)

{

if (info == null)

{

throw new ArgumentNullException(nameof(info));

}

base.GetObjectData(info, context);

info.AddValue(nameof(Type), Type);

info.AddValue(nameof(Value), Value);

info.AddValue(nameof(Traceback), Traceback);

}

#endregion

internal bool Is(BorrowedReference type)

{

return Runtime.PyErr_GivenExceptionMatches(

given: (Value ?? Type).Reference,

typeOrTypes: type) != 0;

}

private static void CheckRuntimeIsRunning()

{

if (!PythonEngine.IsInitialized && Runtime.Py_IsInitialized() == 0)

throw new InvalidOperationException("Python runtime must be running");

}

/// <summary>

/// Returns <c>true</c> if the current Python exception

/// matches the given exception type.

/// </summary>

internal static bool CurrentMatches(BorrowedReference ob)

{

return Runtime.PyErr_ExceptionMatches(ob) != 0;

}

[DebuggerHidden]

internal static void ThrowIfIsNull(in NewReference ob)

{

if (ob.BorrowNullable() == null)

{

throw ThrowLastAsClrException();

}

internal static BorrowedReference ThrowIfIsNull(BorrowedReference ob)

=> Exceptions.ErrorCheck(ob);

[DebuggerHidden]

internal static void ThrowIfIsNotZero(int value)

{

if (value != 0)

{

throw ThrowLastAsClrException();

}

pythonnet/src/runtime/PythonException.cs at master · ZeroMSN/pythonnet · GitHub

Repository navigation

Expand file tree

Breadcrumbs

PythonException.cs

Latest commit

History

Breadcrumbs

PythonException.cs

File metadata and controls