/// <summary> /// Adds method body interception to the target method. /// </summary> /// <param name="IL">The <see cref="ILProcessor" /> pointing to the target method body.</param> public void Emit(ILProcessor IL) { var method = IL.Body.Method; var returnType = method.ReturnType; var endLabel = IL.Create(OpCodes.Nop); var executeOriginalInstructions = IL.Create(OpCodes.Nop); // Execute the method body replacement if and only if // interception is enabled IL.Emit(OpCodes.Ldloc, _interceptionDisabled); IL.Emit(OpCodes.Brtrue, executeOriginalInstructions); var invokeReplacement = IL.Create(OpCodes.Nop); IL.Emit(OpCodes.Ldloc, _methodReplacementProvider); IL.Emit(OpCodes.Brtrue, invokeReplacement); IL.Emit(OpCodes.Ldloc, _classMethodReplacementProvider); IL.Emit(OpCodes.Brtrue, invokeReplacement); IL.Emit(OpCodes.Br, executeOriginalInstructions); IL.Append(invokeReplacement); // This is equivalent to the following code: // var replacement = provider.GetMethodReplacement(info); var invokeMethodReplacement = new InvokeMethodReplacement(executeOriginalInstructions, _methodReplacementProvider, _classMethodReplacementProvider, _invocationInfo); invokeMethodReplacement.Emit(IL); IL.Emit(OpCodes.Br, endLabel); IL.Append(executeOriginalInstructions); var addOriginalInstructions = new AddOriginalInstructions(_oldInstructions, endLabel); addOriginalInstructions.Emit(IL); // Mark the end of the method body IL.Append(endLabel); var saveReturnValue = new SaveReturnValue(returnType, _returnValue); saveReturnValue.Emit(IL); }
public void Emit(CilWorker IL) { var method = IL.GetMethod(); var returnType = method.ReturnType.ReturnType; var endLabel = IL.Create(OpCodes.Nop); var executeOriginalInstructions = IL.Create(OpCodes.Nop); // Execute the method body replacement if and only if // interception is enabled IL.Emit(OpCodes.Ldloc, _interceptionDisabled); IL.Emit(OpCodes.Brtrue, executeOriginalInstructions); var invokeReplacement = IL.Create(OpCodes.Nop); IL.Emit(OpCodes.Ldloc, _methodReplacementProvider); IL.Emit(OpCodes.Brtrue, invokeReplacement); IL.Emit(OpCodes.Ldloc, _classMethodReplacementProvider); IL.Emit(OpCodes.Brtrue, invokeReplacement); IL.Emit(OpCodes.Br, executeOriginalInstructions); IL.Append(invokeReplacement); // This is equivalent to the following code: // var replacement = provider.GetMethodReplacement(info); var invokeMethodReplacement = new InvokeMethodReplacement(executeOriginalInstructions, _methodReplacementProvider, _classMethodReplacementProvider, _invocationInfo); invokeMethodReplacement.Emit(IL); IL.Emit(OpCodes.Br, endLabel); #region The original instruction block IL.Append(executeOriginalInstructions); var addOriginalInstructions = new AddOriginalInstructions(_oldInstructions, endLabel); addOriginalInstructions.Emit(IL); #endregion // Mark the end of the method body IL.Append(endLabel); var saveReturnValue = new SaveReturnValue(returnType, _returnValue); saveReturnValue.Emit(IL); }