Default Interface Method Prototype (#10505)

* allow non-zero RVA on abstract interface method in ilasm

* Revert "allow non-zero RVA on abstract interface method in ilasm"

This reverts commit eecb8024e58f14a20e5e49359f38019f5768ac41.

* add a test case and allow virtual non-abstract method in ilasm

* allow non-abstract methods in the loader

* fixup dispatch map

* support for simple default interface method scenario

* fix a bug with incorrect usage of MethodIterator skpping the first method. add a test case for overriding but it may not be what we want

* add another simple test case for base class

* allow private/internal methods in ilasm and add a explict impl test

* update reference to mscorlib in il test

* add shared generics and variance case

* allow interface dispatch to return instantiating stubs with the right PARAM_TYPE calling conv

* simple factoring and add a valuetype test case

* add a test case for generic virtual methods

* a bit more refactoring by moving the CALLCONV_PARAMTYPE logic inside getMethodSigInternal

* support explicit methodimpl and remove implicit methodimpl test case

* update test cases to give more clear output

* Fix a bug where GetMethodDescForSlot chokes on interface MethodDesc without precode. This is accdentally discovered by methodimpl test case when iterating methods on a default interface method that has already been JITted

* cleanup code after review and add a bit more comments

* update comments

* only use custom ILAsm for default interface methods tests - some tests are choking on CoreCLR ilasm for security related stuff

* address comments and allow instance methods, and add a constraint value type call test scenario

* disable the failing protected method scenario

1 files changed, 7 insertions, 24 deletions

diff --git a/src/vm/classcompat.cpp b/src/vm/classcompat.cpp
index 91004cdbc7..031604bc8e 100644
--- a/src/vm/classcompat.cpp
+++ b/src/vm/classcompat.cpp
@@ -2619,26 +2619,6 @@ VOID    MethodTableBuilder::EnumerateClassMethods()
             }
         }
 
-        // Some interface checks.
-        if (IsInterface())
-        {
-            if (IsMdVirtual(dwMemberAttrs))
-            {
-                if (!IsMdAbstract(dwMemberAttrs))
-                {
-                    BuildMethodTableThrowException(BFA_VIRTUAL_NONAB_INT_METHOD);
-                }
-            }
-            else
-            {
-                // Instance field/method
-                if (!IsMdStatic(dwMemberAttrs))
-                {
-                    BuildMethodTableThrowException(BFA_NONVIRT_INST_INT_METHOD);
-                }
-            }
-        }
-
         // No synchronized methods in ValueTypes
         if(fIsClassValueType && IsMiSynchronized(dwImplFlags))
         {
@@ -2804,17 +2784,20 @@ VOID    MethodTableBuilder::EnumerateClassMethods()
                 // If the interface is a standard managed interface then allocate space for an FCall method desc.
                 Classification = mcFCall;
             }
-            else
+            else if (IsMdAbstract(dwMemberAttrs))
             {
                 // If COM interop is supported then all other interface MDs may be
                 // accessed via COM interop <TODO> mcComInterop MDs are BIG -
                 // this is very often a waste of space </TODO>
+                // @DIM_TODO - What if default interface method is called through COM interop?
                 Classification = mcComInterop;
             }
-#else // !FEATURE_COMINTEROP
-            // This codepath is used by remoting
-            Classification = mcIL;
+            else
 #endif // !FEATURE_COMINTEROP
+            {
+                // This codepath is used by remoting and default interface methods
+                Classification = mcIL;
+            }
         }
         else
         {