/// <summary>
/// Resolve a MethodDesc to a callable method address and unboxing stub address by searching
/// by searching in the InvokeMaps. This function is a wrapper around TryGetMethodInvokeDataFromInvokeMap
/// that produces output in the format which matches the code table system.
/// </summary>
/// <param name="method">Native metadata method description object</param>
/// <param name="methodAddress">Resolved method address</param>
/// <param name="unboxingStubAddress">Resolved unboxing stub address</param>
/// <param name="foundAddressType">Output - The type of method address match found. A canonical address may require extra parameters to call.</param>
/// <returns>true when the resolution succeeded, false when not</returns>
private static bool TryGetMethodAddressFromTypeSystemMethodViaInvokeMap(
MethodDesc method,
out IntPtr methodAddress,
out IntPtr unboxingStubAddress,
out MethodAddressType foundAddressType)
{
methodAddress = IntPtr.Zero;
unboxingStubAddress = IntPtr.Zero;
foundAddressType = MethodAddressType.None;
#if SUPPORTS_NATIVE_METADATA_TYPE_LOADING
NativeFormatMethod nativeFormatMethod = method.GetTypicalMethodDefinition() as NativeFormatMethod;
if (nativeFormatMethod == null)
{
return(false);
}
MethodSignatureComparer methodSignatureComparer = new MethodSignatureComparer(
nativeFormatMethod.MetadataReader, nativeFormatMethod.Handle);
// Try to find a specific canonical match, or if that fails, a universal match
if (TryGetMethodInvokeDataFromInvokeMap(
nativeFormatMethod,
method,
ref methodSignatureComparer,
CanonicalFormKind.Specific,
out methodAddress,
out foundAddressType) ||
TryGetMethodInvokeDataFromInvokeMap(
nativeFormatMethod,
method,
ref methodSignatureComparer,
CanonicalFormKind.Universal,
out methodAddress,
out foundAddressType))
{
if (method.OwningType.IsValueType && !method.Signature.IsStatic)
{
// In this case the invoke map found an unboxing stub, and we should pull the method address out as well
unboxingStubAddress = methodAddress;
methodAddress = RuntimeAugments.GetCodeTarget(unboxingStubAddress);
if (!method.HasInstantiation && ((foundAddressType != MethodAddressType.Exact) || method.OwningType.IsCanonicalSubtype(CanonicalFormKind.Any)))
{
IntPtr underlyingTarget; // unboxing and instantiating stub handling
if (!TypeLoaderEnvironment.TryGetTargetOfUnboxingAndInstantiatingStub(methodAddress, out underlyingTarget))
{
Environment.FailFast("Expected this to be an unboxing and instantiating stub.");
}
methodAddress = underlyingTarget;
}
}
return(true);
}
#endif
return(false);
}
public static IntPtr ConvertUnboxingFunctionPointerToUnderlyingNonUnboxingPointer(IntPtr unboxingFunctionPointer, RuntimeTypeHandle declaringType)
{
if (FunctionPointerOps.IsGenericMethodPointer(unboxingFunctionPointer))
{
// Handle shared generic methods
unsafe
{
GenericMethodDescriptor *functionPointerDescriptor = FunctionPointerOps.ConvertToGenericDescriptor(unboxingFunctionPointer);
IntPtr nonUnboxingTarget = RuntimeAugments.GetCodeTarget(functionPointerDescriptor->MethodFunctionPointer);
Debug.Assert(nonUnboxingTarget != functionPointerDescriptor->MethodFunctionPointer);
Debug.Assert(nonUnboxingTarget == RuntimeAugments.GetCodeTarget(nonUnboxingTarget));
return(FunctionPointerOps.GetGenericMethodFunctionPointer(nonUnboxingTarget, functionPointerDescriptor->InstantiationArgument));
}
}
// GetCodeTarget will look through simple unboxing stubs (ones that consist of adjusting the this pointer and then
// jumping to the target.
IntPtr exactTarget = RuntimeAugments.GetCodeTarget(unboxingFunctionPointer);
if (RuntimeAugments.IsGenericType(declaringType))
{
IntPtr fatFunctionPointerTarget;
// This check looks for unboxing and instantiating stubs generated via the compiler backend
if (TypeLoaderEnvironment.TryGetTargetOfUnboxingAndInstantiatingStub(exactTarget, out fatFunctionPointerTarget))
{
// If this is an unboxing and instantiating stub, use separate table, find target, and create fat function pointer
exactTarget = FunctionPointerOps.GetGenericMethodFunctionPointer(fatFunctionPointerTarget,
declaringType.ToIntPtr());
}
#if FEATURE_UNIVERSAL_GENERICS
else
{
IntPtr newExactTarget;
// This check looks for unboxing and instantiating stubs generated dynamically as thunks in the calling convention converter
if (CallConverterThunk.TryGetNonUnboxingFunctionPointerFromUnboxingAndInstantiatingStub(exactTarget,
declaringType, out newExactTarget))
{
// CallingConventionConverter determined non-unboxing stub
exactTarget = newExactTarget;
}
else
{
// Target method was a method on a generic, but it wasn't a shared generic, and thus none of the above
// complex unboxing stub digging logic was necessary. Do nothing, and use exactTarget as discovered
// from GetCodeTarget
}
}
#endif
}
return(exactTarget);
}
// Resolve a constrained call in case where the call is an MDIL constrained call directly through a function pointer located in the generic dictionary
// This can only happen if there is a call from shared generic code to a structure which implements multiple of the same generic interface, and which instantiation
// is decided by the exact type of the caller. For instance
//
// interface IFunc<T>
// {
// void M();
// }
//
// struct UnusualCase : IFunc<object>, IFunc<string>
// {
// void IFunc<object>.M() { Console.WriteLine("In IFunc<object>");}
// void IFunc<string>.M() { Console.WriteLine("In IFunc<object>");}
// }
// class Caller<T,U> where T : IFunc<U>
// {
// void Call(T c)
// {
// c.M();
// }
// }
//
// If Caller is instantiated as Caller<UnusualCase,object>, or Caller<UnusualCase,string> we will generate code for Caller<UnusualCase,__Canon>.Call(UnusualCase)
// However, that code will not be able to exactly specify the target of the call. It will need to use the generic dictionary.
unsafe private static IntPtr ResolveDirectConstrainedCall(IntPtr callerTransitionBlockParam, IntPtr callDescIntPtr)
{
NonGenericConstrainedCallDesc* callDesc = (NonGenericConstrainedCallDesc*)callDescIntPtr;
Debug.Assert(RuntimeAugments.IsInterface(callDesc->_constrainedMethodType));
IntPtr targetOnTypeVtable = RuntimeAugments.ResolveDispatchOnType(callDesc->_constraintType, callDesc->_constrainedMethodType, callDesc->_constrainedMethodSlot);
IntPtr exactTarget = RuntimeAugments.GetCodeTarget(targetOnTypeVtable);
IntPtr underlyingTargetIfUnboxingAndInstantiatingStub;
if (TypeLoaderEnvironment.TryGetTargetOfUnboxingAndInstantiatingStub(exactTarget, out underlyingTargetIfUnboxingAndInstantiatingStub))
{
// If this is an unboxing and instantiating stub, get the underlying pointer. The caller of this function is required to have already setup the
// instantiation argument
exactTarget = underlyingTargetIfUnboxingAndInstantiatingStub;
}
callDesc->_exactTarget = exactTarget;
return exactTarget;
}
private unsafe static IntPtr ResolveCallOnValueType(IntPtr unused, IntPtr callDescIntPtr)
#endif
{
NonGenericConstrainedCallDesc *callDesc = (NonGenericConstrainedCallDesc *)callDescIntPtr;
IntPtr exactTarget = IntPtr.Zero;
IntPtr targetOnTypeVtable = RuntimeAugments.ResolveDispatchOnType(callDesc->_constraintType, callDesc->_constrainedMethodType, callDesc->_constrainedMethodSlot);
bool decodeUnboxing = true;
if (!RuntimeAugments.IsInterface(callDesc->_constrainedMethodType))
{
// Non-interface constrained call on a valuetype to a method that isn't GetHashCode/Equals/ToString?!?!
if (callDesc->_constrainedMethodSlot > s_MaxObjectVTableSlot)
{
throw new NotSupportedException();
}
RuntimeTypeHandle baseTypeHandle;
bool gotBaseType = RuntimeAugments.TryGetBaseType(callDesc->_constraintType, out baseTypeHandle);
Debug.Assert(gotBaseType);
if (targetOnTypeVtable == RuntimeAugments.ResolveDispatchOnType(baseTypeHandle, callDesc->_constrainedMethodType, callDesc->_constrainedMethodSlot))
{
// In this case, the valuetype does not override the base types implementation of ToString(), GetHashCode(), or Equals(object)
decodeUnboxing = false;
}
}
if (decodeUnboxing)
{
exactTarget = RuntimeAugments.GetCodeTarget(targetOnTypeVtable);
if (RuntimeAugments.IsGenericType(callDesc->_constraintType))
{
IntPtr fatFunctionPointerTarget;
if (TypeLoaderEnvironment.TryGetTargetOfUnboxingAndInstantiatingStub(exactTarget, out fatFunctionPointerTarget))
{
// If this is an unboxing and instantiating stub, use seperate table, find target, and create fat function pointer
exactTarget = FunctionPointerOps.GetGenericMethodFunctionPointer(fatFunctionPointerTarget,
callDesc->_constraintType.ToIntPtr());
}
else
{
IntPtr newExactTarget;
if (CallConverterThunk.TryGetNonUnboxingFunctionPointerFromUnboxingAndInstantiatingStub(exactTarget,
callDesc->_constraintType, out newExactTarget))
{
// CallingConventionConverter determined non-unboxing stub
exactTarget = newExactTarget;
}
else
{
// Target method was a method on a generic, but it wasn't a shared generic, and thus none of the above
// complex unboxing stub digging logic was necessary. Do nothing, and use exactTarget as discovered
// from GetCodeTarget
}
}
}
}
else
{
// Create a fat function pointer, where the instantiation argument is ConstraintType, and the target is BoxAndToString, BoxAndGetHashCode, or BoxAndEquals
IntPtr realTarget;
switch (callDesc->_constrainedMethodSlot)
{
case s_ToStringSlot:
realTarget = s_boxAndToStringFuncPtr;
break;
case s_GetHashCodeSlot:
realTarget = s_boxAndGetHashCodeFuncPtr;
break;
case s_EqualsSlot:
realTarget = s_boxAndEqualsFuncPtr;
break;
default:
throw new NotSupportedException();
}
exactTarget = FunctionPointerOps.GetGenericMethodFunctionPointer(realTarget, callDesc->_constraintType.ToIntPtr());
}
// Ensure that all threads will have their function pointers completely published before updating callDesc.
// as the ExactTarget is read from callDesc by binder generated code without a barrier, we need a barrier here
// to ensure that the new function pointer data is valid on all threads
Interlocked.MemoryBarrier();
// Its possible for multiple threads to race to set exact target. Check to see we always set the same value
if (callDesc->_exactTarget != IntPtr.Zero)
{
Debug.Assert(callDesc->_exactTarget == exactTarget);
}
callDesc->_exactTarget = exactTarget;
return(exactTarget);
}
