/// <summary>
/// Rewrites the instructions in the target method body.
/// </summary>
/// <param name="method">The target method.</param>
/// <param name="IL">The <see cref="CilWorker"/> instance that represents the method body.</param>
/// <param name="oldInstructions">The IL instructions of the original method body.</param>
protected override void RewriteMethodBody(MethodDefinition method, CilWorker IL,
IEnumerable <Instruction> oldInstructions)
{
if (IsExcluded(method))
{
AddOriginalInstructions(IL, oldInstructions);
return;
}
VariableDefinition interceptionDisabled = method.AddLocal <bool>();
VariableDefinition invocationInfo = method.AddLocal <IInvocationInfo>();
VariableDefinition aroundInvokeProvider = method.AddLocal <IAroundInvokeProvider>();
VariableDefinition methodReplacementProvider = method.AddLocal <IMethodReplacementProvider>();
VariableDefinition returnValue = method.AddLocal <object>();
VariableDefinition classMethodReplacementProvider = method.AddLocal <IMethodReplacementProvider>();
Func <ModuleDefinition, MethodReference> getInstanceMethodReplacementProviderMethod =
module => module.Import(typeof(IMethodReplacementHost).GetMethod("get_MethodBodyReplacementProvider"));
var parameters = new MethodBodyRewriterParameters(IL,
oldInstructions,
interceptionDisabled,
invocationInfo, returnValue,
methodReplacementProvider,
aroundInvokeProvider,
classMethodReplacementProvider,
getInstanceMethodReplacementProviderMethod,
typeof(AroundMethodBodyRegistry));
var emitter = new InvocationInfoEmitter(true);
IInstructionEmitter getMethodReplacementProvider =
new GetMethodReplacementProvider(methodReplacementProvider, method,
getInstanceMethodReplacementProviderMethod);
IInstructionEmitter getInterceptionDisabled = new GetInterceptionDisabled(parameters);
ISurroundMethodBody surroundMethodBody = new SurroundMethodBody(parameters, "AroundMethodBodyProvider");
IInstructionEmitter getClassMethodReplacementProvider = new GetClassMethodReplacementProvider(parameters,
module =>
module.Import(
typeof(
MethodBodyReplacementProviderRegistry
).
GetMethod
("GetProvider")));
IInstructionEmitter addMethodReplacement = new AddMethodReplacementImplementation(parameters);
var rewriter = new InterceptAndSurroundMethodBody(emitter, getInterceptionDisabled, surroundMethodBody,
getMethodReplacementProvider,
getClassMethodReplacementProvider, addMethodReplacement,
parameters);
// Determine whether or not the method should be intercepted
rewriter.Rewrite(method, IL, oldInstructions);
}
/// <summary>
/// Rewrites the instructions in the target method body.
/// </summary>
/// <param name="method">The target method.</param>
/// <param name="IL">The <see cref="CilWorker"/> instance that represents the method body.</param>
/// <param name="oldInstructions">The IL instructions of the original method body.</param>
protected override void RewriteMethodBody(MethodDefinition method, CilWorker IL,
IEnumerable<Instruction> oldInstructions)
{
if (IsExcluded(method))
{
AddOriginalInstructions(IL, oldInstructions);
return;
}
VariableDefinition interceptionDisabled = method.AddLocal<bool>();
VariableDefinition invocationInfo = method.AddLocal<IInvocationInfo>();
VariableDefinition aroundInvokeProvider = method.AddLocal<IAroundInvokeProvider>();
VariableDefinition methodReplacementProvider = method.AddLocal<IMethodReplacementProvider>();
VariableDefinition returnValue = method.AddLocal<object>();
VariableDefinition classMethodReplacementProvider = method.AddLocal<IMethodReplacementProvider>();
Func<ModuleDefinition, MethodReference> getInstanceMethodReplacementProviderMethod =
module => module.Import(typeof (IMethodReplacementHost).GetMethod("get_MethodBodyReplacementProvider"));
var parameters = new MethodBodyRewriterParameters(IL,
oldInstructions,
interceptionDisabled,
invocationInfo, returnValue,
aroundInvokeProvider,
methodReplacementProvider,
classMethodReplacementProvider,
getInstanceMethodReplacementProviderMethod,
typeof (AroundMethodBodyRegistry));
var emitter = new InvocationInfoEmitter(true);
IInstructionEmitter getMethodReplacementProvider =
new GetMethodReplacementProvider(methodReplacementProvider, method,
getInstanceMethodReplacementProviderMethod);
IInstructionEmitter getInterceptionDisabled = new GetInterceptionDisabled(parameters);
ISurroundMethodBody surroundMethodBody = new SurroundMethodBody(parameters, "AroundMethodBodyProvider");
IInstructionEmitter getClassMethodReplacementProvider = new GetClassMethodReplacementProvider(parameters,
module =>
module.Import(
typeof (
MethodBodyReplacementProviderRegistry
).
GetMethod
("GetProvider")));
IInstructionEmitter addMethodReplacement = new AddMethodReplacementImplementation(parameters);
var rewriter = new InterceptAndSurroundMethodBody(emitter, getInterceptionDisabled, surroundMethodBody,
getMethodReplacementProvider,
getClassMethodReplacementProvider, addMethodReplacement,
parameters);
// Determine whether or not the method should be intercepted
rewriter.Rewrite(method, IL, oldInstructions);
}
/// <summary>
/// Rewrites the instructions in the target method body to support dynamic exception handling.
/// </summary>
/// <param name="targetMethod">The target method.</param>
/// <param name="IL">The <see cref="CilWorker"/> instance that represents the method body.</param>
/// <param name="oldInstructions">The IL instructions of the original method body.</param>
protected override void RewriteMethodBody(MethodDefinition targetMethod, CilWorker IL,
IEnumerable <Instruction> oldInstructions)
{
var endOfOriginalInstructionBlock = IL.Create(OpCodes.Nop);
var addOriginalInstructions = new AddOriginalInstructions(oldInstructions, endOfOriginalInstructionBlock);
var endLabel = IL.Create(OpCodes.Nop);
var tryStart = IL.Emit(OpCodes.Nop);
var tryEnd = IL.Emit(OpCodes.Nop);
var catchStart = IL.Emit(OpCodes.Nop);
var catchEnd = IL.Emit(OpCodes.Nop);
var module = IL.GetModule();
var handler = new ExceptionHandler(ExceptionHandlerType.Catch);
var body = targetMethod.Body;
body.ExceptionHandlers.Add(handler);
handler.CatchType = module.ImportType <Exception>();
handler.TryStart = tryStart;
handler.TryEnd = tryEnd;
handler.HandlerStart = catchStart;
handler.HandlerEnd = catchEnd;
var emitter = new InvocationInfoEmitter(true);
var returnType = targetMethod.ReturnType.ReturnType;
// try {
IL.Append(tryStart);
addOriginalInstructions.Emit(IL);
IL.Append(endOfOriginalInstructionBlock);
if (returnType != _voidType && _returnValue != null)
{
IL.Emit(OpCodes.Stloc, _returnValue);
}
IL.Emit(OpCodes.Leave, endLabel);
// }
IL.Append(tryEnd);
// catch (Exception ex) {
IL.Append(catchStart);
IL.Emit(OpCodes.Stloc, _exception);
SaveExceptionInfo(targetMethod, emitter);
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
var getHandlerMethodInfo = typeof(ExceptionHandlerRegistry).GetMethod("GetHandler");
var getHandlerMethod = module.Import(getHandlerMethodInfo);
IL.Emit(OpCodes.Call, getHandlerMethod);
IL.Emit(OpCodes.Stloc, _exceptionHandler);
// if (exceptionHandler == null)
// throw;
var doRethrow = IL.Create(OpCodes.Nop);
IL.Emit(OpCodes.Ldloc, _exceptionHandler);
IL.Emit(OpCodes.Brfalse, doRethrow);
// if (handler.CanCatch(exceptionInfo)) {
var leaveBlock = IL.Create(OpCodes.Nop);
var canCatch = module.ImportMethod <IExceptionHandler>("CanCatch");
IL.Emit(OpCodes.Ldloc, _exceptionHandler);
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Callvirt, canCatch);
IL.Emit(OpCodes.Brfalse, doRethrow);
var catchMethod = module.ImportMethod <IExceptionHandler>("Catch");
IL.Emit(OpCodes.Ldloc, _exceptionHandler);
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Callvirt, catchMethod);
// }
var getShouldSkipRethrow = module.ImportMethod <IExceptionHandlerInfo>("get_ShouldSkipRethrow");
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Callvirt, getShouldSkipRethrow);
IL.Emit(OpCodes.Brfalse, doRethrow);
IL.Emit(OpCodes.Br, leaveBlock);
IL.Append(doRethrow);
IL.Emit(OpCodes.Rethrow);
IL.Append(leaveBlock);
IL.Emit(OpCodes.Leave, endLabel);
IL.Append(catchEnd);
// }
IL.Append(endLabel);
if (returnType != _voidType && _returnValue != null)
{
var returnOriginalValue = IL.Create(OpCodes.Nop);
var getReturnValue = module.ImportMethod <IExceptionHandlerInfo>("get_ReturnValue");
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Brfalse, returnOriginalValue);
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Callvirt, getReturnValue);
IL.Emit(OpCodes.Stloc, _returnValue);
IL.Append(returnOriginalValue);
IL.Emit(OpCodes.Ldloc, _returnValue);
}
IL.Emit(OpCodes.Ret);
}
/// <summary>
/// Rewrites the instructions in the target method body to support dynamic exception handling.
/// </summary>
/// <param name="targetMethod">The target method.</param>
/// <param name="IL">The <see cref="CilWorker"/> instance that represents the method body.</param>
/// <param name="oldInstructions">The IL instructions of the original method body.</param>
protected override void RewriteMethodBody(MethodDefinition targetMethod, CilWorker IL,
IEnumerable<Instruction> oldInstructions)
{
var endOfOriginalInstructionBlock = IL.Create(OpCodes.Nop);
var addOriginalInstructions = new AddOriginalInstructions(oldInstructions, endOfOriginalInstructionBlock);
var endLabel = IL.Create(OpCodes.Nop);
var tryStart = IL.Emit(OpCodes.Nop);
var tryEnd = IL.Emit(OpCodes.Nop);
var catchStart = IL.Emit(OpCodes.Nop);
var catchEnd = IL.Emit(OpCodes.Nop);
var module = IL.GetModule();
var handler = new ExceptionHandler(ExceptionHandlerType.Catch);
var body = targetMethod.Body;
body.ExceptionHandlers.Add(handler);
handler.CatchType = module.ImportType<Exception>();
handler.TryStart = tryStart;
handler.TryEnd = tryEnd;
handler.HandlerStart = catchStart;
handler.HandlerEnd = catchEnd;
var emitter = new InvocationInfoEmitter(true);
var returnType = targetMethod.ReturnType.ReturnType;
// try {
IL.Append(tryStart);
addOriginalInstructions.Emit(IL);
IL.Append(endOfOriginalInstructionBlock);
if (returnType != _voidType && _returnValue != null)
{
IL.Emit(OpCodes.Stloc, _returnValue);
}
IL.Emit(OpCodes.Leave, endLabel);
// }
IL.Append(tryEnd);
// catch (Exception ex) {
IL.Append(catchStart);
IL.Emit(OpCodes.Stloc, _exception);
SaveExceptionInfo(targetMethod, emitter);
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
var getHandlerMethodInfo = typeof (ExceptionHandlerRegistry).GetMethod("GetHandler");
var getHandlerMethod = module.Import(getHandlerMethodInfo);
IL.Emit(OpCodes.Call, getHandlerMethod);
IL.Emit(OpCodes.Stloc, _exceptionHandler);
// if (exceptionHandler == null)
// throw;
var doRethrow = IL.Create(OpCodes.Nop);
IL.Emit(OpCodes.Ldloc, _exceptionHandler);
IL.Emit(OpCodes.Brfalse, doRethrow);
// if (handler.CanCatch(exceptionInfo)) {
var leaveBlock = IL.Create(OpCodes.Nop);
var canCatch = module.ImportMethod<IExceptionHandler>("CanCatch");
IL.Emit(OpCodes.Ldloc, _exceptionHandler);
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Callvirt, canCatch);
IL.Emit(OpCodes.Brfalse, doRethrow);
var catchMethod = module.ImportMethod<IExceptionHandler>("Catch");
IL.Emit(OpCodes.Ldloc, _exceptionHandler);
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Callvirt, catchMethod);
// }
var getShouldSkipRethrow = module.ImportMethod<IExceptionHandlerInfo>("get_ShouldSkipRethrow");
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Callvirt, getShouldSkipRethrow);
IL.Emit(OpCodes.Brfalse, doRethrow);
IL.Emit(OpCodes.Br, leaveBlock);
IL.Append(doRethrow);
IL.Emit(OpCodes.Rethrow);
IL.Append(leaveBlock);
IL.Emit(OpCodes.Leave, endLabel);
IL.Append(catchEnd);
// }
IL.Append(endLabel);
if (returnType != _voidType && _returnValue != null)
{
var returnOriginalValue = IL.Create(OpCodes.Nop);
var getReturnValue = module.ImportMethod<IExceptionHandlerInfo>("get_ReturnValue");
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Brfalse, returnOriginalValue);
IL.Emit(OpCodes.Ldloc, _exceptionInfo);
IL.Emit(OpCodes.Callvirt, getReturnValue);
IL.Emit(OpCodes.Stloc, _returnValue);
IL.Append(returnOriginalValue);
IL.Emit(OpCodes.Ldloc, _returnValue);
}
IL.Emit(OpCodes.Ret);
}
/// <summary>
/// Initializes the class with the default values.
/// </summary>
public MethodBodyEmitter()
{
InvocationInfoEmitter = new InvocationInfoEmitter();
}