protected virtual MethodDesc ResolveVirtualMethod(MethodDesc declMethod, DefType implType)
{
MethodDesc impl;
if (declMethod.OwningType.IsInterface)
{
impl = implType.ResolveInterfaceMethodTarget(declMethod);
if (impl != null)
{
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(impl);
}
}
else
{
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(declMethod);
if (impl != null && (impl != declMethod))
{
MethodDesc slotDefiningMethodImpl = MetadataVirtualMethodAlgorithm.FindSlotDefiningMethodForVirtualMethod(impl);
MethodDesc slotDefiningMethodDecl = MetadataVirtualMethodAlgorithm.FindSlotDefiningMethodForVirtualMethod(declMethod);
if (slotDefiningMethodImpl != slotDefiningMethodDecl)
{
// We cannot resolve virtual method in case the impl is a different slot from the declMethod
impl = null;
}
}
}
return(impl);
}
protected virtual MethodDesc ResolveVirtualMethod(MethodDesc declMethod, DefType implType)
{
// Quick check: if decl matches impl, we're done.
if (declMethod.OwningType == implType)
{
return(declMethod);
}
MethodDesc impl;
if (declMethod.OwningType.IsInterface)
{
impl = implType.ResolveInterfaceMethodTarget(declMethod);
if (impl != null)
{
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(impl);
}
}
else
{
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(declMethod);
}
return(impl);
}
protected virtual MethodDesc ResolveVirtualMethod(MethodDesc declMethod, DefType implType)
{
MethodDesc impl;
if (declMethod.OwningType.IsInterface)
{
if (declMethod.OwningType.IsCanonicalSubtype(CanonicalFormKind.Any) || implType.IsCanonicalSubtype(CanonicalFormKind.Any))
{
DefType[] implTypeRuntimeInterfaces = implType.RuntimeInterfaces;
int canonicallyMatchingInterfacesFound = 0;
DefType canonicalInterfaceType = (DefType)declMethod.OwningType.ConvertToCanonForm(CanonicalFormKind.Specific);
for (int i = 0; i < implTypeRuntimeInterfaces.Length; i++)
{
DefType runtimeInterface = implTypeRuntimeInterfaces[i];
if (canonicalInterfaceType.HasSameTypeDefinition(runtimeInterface) &&
runtimeInterface.ConvertToCanonForm(CanonicalFormKind.Specific) == canonicalInterfaceType)
{
canonicallyMatchingInterfacesFound++;
if (canonicallyMatchingInterfacesFound > 1)
{
// We cannot resolve the interface as we don't know with exact enough detail which interface
// of multiple possible interfaces is being called.
return(null);
}
}
}
}
impl = implType.ResolveInterfaceMethodTarget(declMethod);
if (impl != null)
{
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(impl);
}
}
else
{
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(declMethod);
if (impl != null && (impl != declMethod))
{
MethodDesc slotDefiningMethodImpl = MetadataVirtualMethodAlgorithm.FindSlotDefiningMethodForVirtualMethod(impl);
MethodDesc slotDefiningMethodDecl = MetadataVirtualMethodAlgorithm.FindSlotDefiningMethodForVirtualMethod(declMethod);
if (slotDefiningMethodImpl != slotDefiningMethodDecl)
{
// We cannot resolve virtual method in case the impl is a different slot from the declMethod
impl = null;
}
}
}
return(impl);
}
public override IEnumerable <CombinedDependencyListEntry> GetConditionalStaticDependencies(NodeFactory factory)
{
Debug.Assert(EmitVirtualSlotsAndInterfaces);
DefType defType = _type.GetClosestDefType();
// If we're producing a full vtable, none of the dependencies are conditional.
if (!factory.VTable(defType).HasFixedSlots)
{
foreach (MethodDesc decl in defType.EnumAllVirtualSlots())
{
// Generic virtual methods are tracked by an orthogonal mechanism.
if (decl.HasInstantiation)
{
continue;
}
MethodDesc impl = defType.FindVirtualFunctionTargetMethodOnObjectType(decl);
if (impl.OwningType == defType && !impl.IsAbstract)
{
MethodDesc canonImpl = impl.GetCanonMethodTarget(CanonicalFormKind.Specific);
yield return(new CombinedDependencyListEntry(factory.MethodEntrypoint(canonImpl, _type.IsValueType), factory.VirtualMethodUse(decl), "Virtual method"));
}
}
Debug.Assert(
_type == defType ||
((System.Collections.IStructuralEquatable)defType.RuntimeInterfaces).Equals(_type.RuntimeInterfaces,
EqualityComparer <DefType> .Default));
// Add conditional dependencies for interface methods the type implements. For example, if the type T implements
// interface IFoo which has a method M1, add a dependency on T.M1 dependent on IFoo.M1 being called, since it's
// possible for any IFoo object to actually be an instance of T.
foreach (DefType interfaceType in defType.RuntimeInterfaces)
{
Debug.Assert(interfaceType.IsInterface);
foreach (MethodDesc interfaceMethod in interfaceType.GetAllMethods())
{
if (interfaceMethod.Signature.IsStatic)
{
continue;
}
// Generic virtual methods are tracked by an orthogonal mechanism.
if (interfaceMethod.HasInstantiation)
{
continue;
}
MethodDesc implMethod = defType.ResolveInterfaceMethodToVirtualMethodOnType(interfaceMethod);
if (implMethod != null)
{
yield return(new CombinedDependencyListEntry(factory.VirtualMethodUse(implMethod), factory.VirtualMethodUse(interfaceMethod), "Interface method"));
}
}
}
}
}
protected virtual MethodDesc ResolveVirtualMethod(MethodDesc declMethod, DefType implType)
{
MethodDesc impl;
if (declMethod.OwningType.IsInterface)
{
impl = implType.ResolveInterfaceMethodTarget(declMethod);
if (impl != null)
{
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(impl);
}
}
else
{
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(declMethod);
}
return(impl);
}
public override IEnumerable <CombinedDependencyListEntry> GetConditionalStaticDependencies(NodeFactory factory)
{
DefType defType = _type.GetClosestDefType();
foreach (MethodDesc decl in defType.EnumAllVirtualSlots())
{
MethodDesc impl = defType.FindVirtualFunctionTargetMethodOnObjectType(decl);
if (impl.OwningType == defType && !impl.IsAbstract)
{
yield return(new DependencyNodeCore <NodeFactory> .CombinedDependencyListEntry(factory.MethodEntrypoint(impl, _type.IsValueType), factory.VirtualMethodUse(decl), "Virtual method"));
}
}
Debug.Assert(
_type == defType ||
((System.Collections.IStructuralEquatable)defType.RuntimeInterfaces).Equals(_type.RuntimeInterfaces,
EqualityComparer <DefType> .Default));
// Add conditional dependencies for interface methods the type implements. For example, if the type T implements
// interface IFoo which has a method M1, add a dependency on T.M1 dependent on IFoo.M1 being called, since it's
// possible for any IFoo object to actually be an instance of T.
foreach (DefType interfaceType in defType.RuntimeInterfaces)
{
Debug.Assert(interfaceType.IsInterface);
foreach (MethodDesc interfaceMethod in interfaceType.GetAllVirtualMethods())
{
MethodDesc implMethod = defType.ResolveInterfaceMethodToVirtualMethodOnType(interfaceMethod);
if (implMethod != null)
{
yield return(new CombinedDependencyListEntry(factory.VirtualMethodUse(implMethod), factory.ReadyToRunHelper(ReadyToRunHelperId.InterfaceDispatch, interfaceMethod), "Interface method"));
yield return(new CombinedDependencyListEntry(factory.VirtualMethodUse(implMethod), factory.ReadyToRunHelper(ReadyToRunHelperId.ResolveVirtualFunction, interfaceMethod), "Interface method address"));
}
}
}
}
protected virtual MethodDesc ResolveVirtualMethod(MethodDesc declMethod, DefType implType, out CORINFO_DEVIRTUALIZATION_DETAIL devirtualizationDetail)
{
devirtualizationDetail = CORINFO_DEVIRTUALIZATION_DETAIL.CORINFO_DEVIRTUALIZATION_UNKNOWN;
MethodDesc impl;
if (declMethod.OwningType.IsInterface)
{
if (declMethod.OwningType.IsCanonicalSubtype(CanonicalFormKind.Any) || implType.IsCanonicalSubtype(CanonicalFormKind.Any))
{
DefType[] implTypeRuntimeInterfaces = implType.RuntimeInterfaces;
int canonicallyMatchingInterfacesFound = 0;
DefType canonicalInterfaceType = (DefType)declMethod.OwningType.ConvertToCanonForm(CanonicalFormKind.Specific);
for (int i = 0; i < implTypeRuntimeInterfaces.Length; i++)
{
DefType runtimeInterface = implTypeRuntimeInterfaces[i];
if (canonicalInterfaceType.HasSameTypeDefinition(runtimeInterface) &&
runtimeInterface.ConvertToCanonForm(CanonicalFormKind.Specific) == canonicalInterfaceType)
{
canonicallyMatchingInterfacesFound++;
if (canonicallyMatchingInterfacesFound > 1)
{
// We cannot resolve the interface as we don't know with exact enough detail which interface
// of multiple possible interfaces is being called.
devirtualizationDetail = CORINFO_DEVIRTUALIZATION_DETAIL.CORINFO_DEVIRTUALIZATION_MULTIPLE_IMPL;
return(null);
}
}
}
}
if (!implType.CanCastTo(declMethod.OwningType))
{
devirtualizationDetail = CORINFO_DEVIRTUALIZATION_DETAIL.CORINFO_DEVIRTUALIZATION_FAILED_CAST;
return(null);
}
impl = implType.ResolveInterfaceMethodTargetWithVariance(declMethod);
if (impl != null)
{
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(impl);
}
else
{
MethodDesc dimMethod = null;
// This isn't the correct lookup algorithm for variant default interface methods
// but as we will drop any results we find in any case, it doesn't matter much.
// Non-variant dispatch can simply use ResolveInterfaceMethodToDefaultImplementationOnType
// but that implementation currently cannot handle variance.
MethodDesc defaultInterfaceDispatchDeclMethod = null;
foreach (TypeDesc iface in implType.RuntimeInterfaces)
{
if (iface == declMethod.OwningType)
{
defaultInterfaceDispatchDeclMethod = declMethod;
break;
}
if (iface.HasSameTypeDefinition(declMethod.OwningType) && iface.CanCastTo(declMethod.OwningType))
{
defaultInterfaceDispatchDeclMethod = iface.FindMethodOnTypeWithMatchingTypicalMethod(declMethod);
// Prefer to find the exact match, so don't break immediately
}
}
if (defaultInterfaceDispatchDeclMethod != null)
{
switch (implType.ResolveInterfaceMethodToDefaultImplementationOnType(defaultInterfaceDispatchDeclMethod, out dimMethod))
{
case DefaultInterfaceMethodResolution.Diamond:
case DefaultInterfaceMethodResolution.Reabstraction:
devirtualizationDetail = CORINFO_DEVIRTUALIZATION_DETAIL.CORINFO_DEVIRTUALIZATION_FAILED_DIM;
return(null);
case DefaultInterfaceMethodResolution.DefaultImplementation:
if (dimMethod.OwningType.HasInstantiation || (declMethod != defaultInterfaceDispatchDeclMethod))
{
// If we devirtualized into a default interface method on a generic type, we should actually return an
// instantiating stub but this is not happening.
// Making this work is tracked by https://github.com/dotnet/runtime/issues/9588
// In addition, we fail here for variant default interface dispatch
devirtualizationDetail = CORINFO_DEVIRTUALIZATION_DETAIL.CORINFO_DEVIRTUALIZATION_FAILED_DIM;
return(null);
}
else
{
impl = dimMethod;
}
break;
}
}
}
}
else
{
// The derived class should be a subclass of the base class.
// this check is perfomed via typedef checking instead of casting, as we accept canon methods calling exact types
TypeDesc checkType;
for (checkType = implType; checkType != null && !checkType.HasSameTypeDefinition(declMethod.OwningType); checkType = checkType.BaseType)
{
}
if ((checkType == null) || (checkType.ConvertToCanonForm(CanonicalFormKind.Specific) != declMethod.OwningType.ConvertToCanonForm(CanonicalFormKind.Specific)))
{
// The derived class should be a subclass of the base class.
devirtualizationDetail = CORINFO_DEVIRTUALIZATION_DETAIL.CORINFO_DEVIRTUALIZATION_FAILED_SUBCLASS;
return(null);
}
else
{
// At this point, the decl method may be only canonically compatible, but not an exact match to a method in the type hierarchy
// Convert it to an exact match. (Or if it is an exact match, the FindMethodOnTypeWithMatchingTypicalMethod will be a no-op)
declMethod = checkType.FindMethodOnTypeWithMatchingTypicalMethod(declMethod);
}
impl = implType.FindVirtualFunctionTargetMethodOnObjectType(declMethod);
if (impl != null && (impl != declMethod))
{
MethodDesc slotDefiningMethodImpl = MetadataVirtualMethodAlgorithm.FindSlotDefiningMethodForVirtualMethod(impl);
MethodDesc slotDefiningMethodDecl = MetadataVirtualMethodAlgorithm.FindSlotDefiningMethodForVirtualMethod(declMethod);
if (slotDefiningMethodImpl != slotDefiningMethodDecl)
{
// If the derived method's slot does not match the vtable slot,
// bail on devirtualization, as the method was installed into
// the vtable slot via an explicit override and even if the
// method is final, the slot may not be.
//
// Note the jit could still safely devirtualize if it had an exact
// class, but such cases are likely rare.
devirtualizationDetail = CORINFO_DEVIRTUALIZATION_DETAIL.CORINFO_DEVIRTUALIZATION_FAILED_SLOT;
impl = null;
}
}
}
return(impl);
}
/// <summary>
/// Try to resolve a virtual call to targetMethod to its implementation on instanceType.
/// </summary>
/// <param name="instanceType">non-interface type</param>
/// <param name="targetMethod">non-generic virtual or interface method</param>
/// <param name="methodAddress">function pointer resolved</param>
/// <returns>true if successful</returns>
public static bool TryDispatchMethodOnTarget(TypeDesc instanceType, MethodDesc targetMethod, out IntPtr methodAddress)
{
methodAddress = IntPtr.Zero;
if (targetMethod == null)
{
return(false);
}
if (IsPregeneratedOrTemplateTypeLoaded(instanceType))
{
if (targetMethod.OwningType.IsInterface)
{
ushort interfaceSlot;
if (!TryGetInterfaceSlotNumberFromMethod(targetMethod, out interfaceSlot))
{
return(false);
}
methodAddress = RuntimeAugments.ResolveDispatchOnType(instanceType.GetRuntimeTypeHandle(),
targetMethod.OwningType.GetRuntimeTypeHandle(),
interfaceSlot);
Debug.Assert(methodAddress != IntPtr.Zero); // TODO! This should happen for ICastable dispatch...
return(true);
}
else
{
unsafe
{
int vtableSlotIndex = LazyVTableResolver.VirtualMethodToSlotIndex(targetMethod);
EEType *eeType = instanceType.GetRuntimeTypeHandle().ToEETypePtr();
IntPtr *vtableStart = (IntPtr *)(((byte *)eeType) + sizeof(EEType));
methodAddress = vtableStart[vtableSlotIndex];
return(true);
}
}
}
MethodDesc targetVirtualMethod = targetMethod;
DefType instanceDefType = instanceType.GetClosestDefType();
// For interface resolution, its a two step process, first get the virtual slot
if (targetVirtualMethod.OwningType.IsInterface)
{
TypeDesc instanceDefTypeToExamine;
MethodDesc newlyFoundVirtualMethod = ResolveInterfaceMethodToVirtualMethod(instanceType, out instanceDefTypeToExamine, targetVirtualMethod);
targetVirtualMethod = newlyFoundVirtualMethod;
// The pregenerated type must be the one that implements the interface method
// Call into Redhawk to deal with this.
if ((newlyFoundVirtualMethod == null) && (instanceDefTypeToExamine != null))
{
ushort interfaceSlot;
if (!TryGetInterfaceSlotNumberFromMethod(targetMethod, out interfaceSlot))
{
return(false);
}
methodAddress = RuntimeAugments.ResolveDispatchOnType(instanceDefTypeToExamine.GetRuntimeTypeHandle(),
targetMethod.OwningType.GetRuntimeTypeHandle(),
interfaceSlot);
Debug.Assert(methodAddress != IntPtr.Zero); // TODO! This should happen for ICastable dispatch...
return(true);
}
}
// VirtualSlot can be null if the interface method isn't really implemented. This should never happen, but since our
// type loader doesn't check all interface overloads at load time, it could happen
if (targetVirtualMethod == null)
{
return(false);
}
// Resolve virtual method to exact method
MethodDesc dispatchMethod = instanceDefType.FindVirtualFunctionTargetMethodOnObjectType(targetVirtualMethod);
return(TryGetVTableCallableAddress(dispatchMethod, out methodAddress));
}
private bool ResolveGenericVirtualMethodTarget(RuntimeTypeHandle targetTypeHandle, RuntimeTypeHandle declaringTypeHandle, RuntimeTypeHandle[] genericArguments, MethodNameAndSignature callingMethodNameAndSignature, out IntPtr methodPointer, out IntPtr dictionaryPointer)
{
if (IsPregeneratedOrTemplateRuntimeTypeHandle(targetTypeHandle))
{
// If the target type isn't dynamic, or at least is template type generated, the static lookup logic is what we want.
return(ResolveGenericVirtualMethodTarget_Static(targetTypeHandle, declaringTypeHandle, genericArguments, callingMethodNameAndSignature, out methodPointer, out dictionaryPointer));
}
else
{
#if SUPPORTS_NATIVE_METADATA_TYPE_LOADING
methodPointer = IntPtr.Zero;
dictionaryPointer = IntPtr.Zero;
TypeSystemContext context = TypeSystemContextFactory.Create();
DefType targetType = (DefType)context.ResolveRuntimeTypeHandle(targetTypeHandle);
// Method being called...
MethodDesc targetVirtualMethod = ResolveTypeHandleAndMethodNameAndSigToVirtualMethodDesc(context, declaringTypeHandle, callingMethodNameAndSignature);
if (targetVirtualMethod == null)
{
// If we can't find the method in the type system, it must only be present in the static environment. Search there instead.
TypeSystemContextFactory.Recycle(context);
return(ResolveGenericVirtualMethodTarget_Static(targetTypeHandle, declaringTypeHandle, genericArguments, callingMethodNameAndSignature, out methodPointer, out dictionaryPointer));
}
MethodDesc dispatchMethod = targetType.FindVirtualFunctionTargetMethodOnObjectType(targetVirtualMethod);
if (dispatchMethod == null)
{
return(false);
}
Instantiation targetMethodInstantiation = context.ResolveRuntimeTypeHandles(genericArguments);
MethodDesc instantiatedDispatchMethod = dispatchMethod.Context.ResolveGenericMethodInstantiation(dispatchMethod.OwningType.IsValueType /* get the unboxing stub */,
dispatchMethod.OwningType.GetClosestDefType(),
dispatchMethod.NameAndSignature,
targetMethodInstantiation, IntPtr.Zero, false);
GenericDictionaryCell cell = GenericDictionaryCell.CreateMethodCell(instantiatedDispatchMethod, false);
using (LockHolder.Hold(_typeLoaderLock))
{
// Now that we hold the lock, we may find that existing types can now find
// their associated RuntimeTypeHandle. Flush the type builder states as a way
// to force the reresolution of RuntimeTypeHandles which couldn't be found before.
context.FlushTypeBuilderStates();
TypeBuilder.ResolveSingleCell(cell, out methodPointer);
}
TypeSystemContextFactory.Recycle(context);
return(true);
#else
methodPointer = IntPtr.Zero;
dictionaryPointer = IntPtr.Zero;
Environment.FailFast("GVM Resolution for non template or pregenerated type");
return(false);
#endif
}
}
