Fix constraint check when a type variable is used to instantiate a ge…

…neric argument (#22)
davidwrighton · May 13, 2021 · c9e4403 · c9e4403
1 parent 9495cbf
commit c9e4403
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Showing 3 changed files with 583 additions and 578 deletions.
diff --git a/src/coreclr/vm/typedesc.cpp b/src/coreclr/vm/typedesc.cpp
@@ -1905,7 +1905,12 @@ BOOL TypeVarTypeDesc::SatisfiesConstraints(SigTypeContext *pTypeContextOfConstra
                     {
                         // Static virtual methods need an extra check when an abstract type is used for instantiation
                         // to ensure that the implementation of the constraint is complete
-                        if (!thElem.IsTypeDesc() &&
+                        //
+                        // Do not apply this check when the generic argument is exactly a generic variable, as those
+                        // do not hold the correct detail for checking, and do not need to do so. This constraint rule 
+                        // is only applicable for generic arguments which have been specialized to some extent
+                        if (!thArg.IsGenericVariable() &&
+                            !thElem.IsTypeDesc() &&
                             thElem.AsMethodTable()->IsAbstract() &&
                             thConstraint.IsInterface() &&
                             thConstraint.AsMethodTable()->HasVirtualStaticMethods())

diff --git a/src/tests/Loader/classloader/StaticVirtualMethods/GenericContext/Generator/Program.cs b/src/tests/Loader/classloader/StaticVirtualMethods/GenericContext/Generator/Program.cs
@@ -559,7 +559,7 @@ static void Main(string[] args)
                             break;
 
                         case CallerMethodScenario.GenericOverConstrainedType:
-                            mdIndividualTestMethod.Name = $"{mdIndividualTestMethod.Name}<(class {CommonPrefix}IFaceGeneric`1<!!U>, {CommonPrefix}IFaceNonGeneric, class {CommonPrefix}IFaceCuriouslyRecurringGeneric`1<!!T>) T,U>";
+                            mdIndividualTestMethod.Name = $"{mdIndividualTestMethod.Name}<({(interfaceTypeSansImplPrefix.Contains("`") ? "class " : "")}{CommonPrefix}{interfaceTypeSansImplPrefix}) T,U>";
 
                             expectedString = expectedString.Replace("!!0", $"{constrainedTypePrefix}{constrainedType}");
                             expectedString = expectedString.Replace(ImplPrefix, "");