Move ownership of p/invoke fixup cells (#4353)

The RVA static fields that represent p/invoke lazy fixup cells are
currently owned by the same type that owns the p/invoke. This means that
if the owning type has a static constructor, accessing the lazy fixup
cell with trigger it. The p/invoke should not trigger a beforefieldinit
class constructor though. I'm moving the field to be owned by the global
type in the compiler-generated pseudo assembly. It doesn't really matter
who owns it.

src/Common/src/TypeSystem/IL/Stubs/PInvokeILEmitter.cs

@@ -238,8 +238,8 @@ namespace Internal.IL.Stubs
                 _importMetadata.Module,
                 _pInvokeILEmitterConfiguration))
             {
-                MetadataType lazyHelperType = _targetMethod.Context.GetHelperType("InteropHelpers");
-                FieldDesc lazyDispatchCell = new PInvokeLazyFixupField(_targetMethod);
+                MetadataType lazyHelperType = context.GetHelperType("InteropHelpers");
+                FieldDesc lazyDispatchCell = _interopStateManager.GetPInvokeLazyFixupField(_targetMethod);
 
                 fnptrLoadStream.Emit(ILOpcode.ldsflda, emitter.NewToken(lazyDispatchCell));
                 fnptrLoadStream.Emit(ILOpcode.call, emitter.NewToken(lazyHelperType
@@ -251,7 +251,7 @@ namespace Internal.IL.Stubs
                     _targetMethod.Signature.Flags | unmanagedCallConv, 0, nativeReturnType,
                     nativeParameterTypes);
 
-                ILLocalVariable vNativeFunctionPointer = emitter.NewLocal(_targetMethod.Context
+                ILLocalVariable vNativeFunctionPointer = emitter.NewLocal(context
                     .GetWellKnownType(WellKnownType.IntPtr));
 
                 fnptrLoadStream.EmitStLoc(vNativeFunctionPointer);

src/Common/src/TypeSystem/IL/Stubs/PInvokeLazyFixupField.cs

@@ -15,14 +15,24 @@ namespace Internal.IL.Stubs
     /// </summary>
     public sealed partial class PInvokeLazyFixupField : FieldDesc
     {
-        private MethodDesc _targetMethod;
+        private readonly DefType _owningType;
+        private readonly MethodDesc _targetMethod;
 
-        public PInvokeLazyFixupField(MethodDesc targetMethod)
+        public PInvokeLazyFixupField(DefType owningType, MethodDesc targetMethod)
         {
             Debug.Assert(targetMethod.IsPInvoke);
+            _owningType = owningType;
             _targetMethod = targetMethod;
         }
 
+        public MethodDesc TargetMethod
+        {
+            get
+            {
+                return _targetMethod;
+            }
+        }
+
         public PInvokeMetadata PInvokeMetadata
         {
             get
@@ -91,7 +101,7 @@ namespace Internal.IL.Stubs
         {
             get
             {
-                return (DefType)_targetMethod.OwningType;
+                return _owningType;
             }
         }
 

src/Common/src/TypeSystem/Interop/InteropStateManager.cs

@@ -21,6 +21,7 @@ namespace Internal.TypeSystem
         private readonly ForwardDelegateCreationStubHashtable _forwardDelegateCreationStubHashtable;
         private readonly PInvokeDelegateWrapperHashtable _pInvokeDelegateWrapperHashtable;
         private readonly InlineArrayHashTable _inlineArrayHashtable;
+        private readonly PInvokeLazyFixupFieldHashtable _pInvokeLazyFixupFieldHashtable;
 
         public InteropStateManager(ModuleDesc generatedAssembly)
         {
@@ -31,6 +32,7 @@ namespace Internal.TypeSystem
             _forwardDelegateCreationStubHashtable = new ForwardDelegateCreationStubHashtable(this, _generatedAssembly.GetGlobalModuleType());
             _pInvokeDelegateWrapperHashtable = new PInvokeDelegateWrapperHashtable(this, _generatedAssembly);
             _inlineArrayHashtable = new InlineArrayHashTable(this, _generatedAssembly);
+            _pInvokeLazyFixupFieldHashtable = new PInvokeLazyFixupFieldHashtable(_generatedAssembly.GetGlobalModuleType());
         }
         //
         // Delegate Marshalling Stubs
@@ -180,6 +182,10 @@ namespace Internal.TypeSystem
             return _inlineArrayHashtable.GetOrCreateValue(candidate);
         }
 
+        public FieldDesc GetPInvokeLazyFixupField(MethodDesc method)
+        {
+            return _pInvokeLazyFixupFieldHashtable.GetOrCreateValue(method);
+        }
 
         private class NativeStructTypeHashtable : LockFreeReaderHashtable<MetadataType, NativeStructType>
         {
@@ -433,6 +439,39 @@ namespace Internal.TypeSystem
             }
         }
 
+        private class PInvokeLazyFixupFieldHashtable : LockFreeReaderHashtable<MethodDesc, PInvokeLazyFixupField>
+        {
+            protected override int GetKeyHashCode(MethodDesc key)
+            {
+                return key.GetHashCode();
+            }
 
+            protected override int GetValueHashCode(PInvokeLazyFixupField value)
+            {
+                return value.TargetMethod.GetHashCode();
+            }
+
+            protected override bool CompareKeyToValue(MethodDesc key, PInvokeLazyFixupField value)
+            {
+                return key == value.TargetMethod;
+            }
+
+            protected override bool CompareValueToValue(PInvokeLazyFixupField value1, PInvokeLazyFixupField value2)
+            {
+                return value1.TargetMethod == value2.TargetMethod;
+            }
+
+            protected override PInvokeLazyFixupField CreateValueFromKey(MethodDesc key)
+            {
+                return new PInvokeLazyFixupField(_owningType, key);
+            }
+
+            private readonly DefType _owningType;
+
+            public PInvokeLazyFixupFieldHashtable(DefType owningType)
+            {
+                _owningType = owningType;
+            }
+        }
     }
-}
+}