Merge pull request #2500 from dotnet-bot/from-tfs

Merge changes from TFS

5 files changed, 34 insertions, 21 deletions

diff --git a/src/System.Private.Reflection.Execution/src/Internal/Reflection/Execution/ExecutionEnvironmentImplementation.MappingTables.cs b/src/System.Private.Reflection.Execution/src/Internal/Reflection/Execution/ExecutionEnvironmentImplementation.MappingTables.cs
index 3d2fe2832..35e6a3e64 100644
--- a/src/System.Private.Reflection.Execution/src/Internal/Reflection/Execution/ExecutionEnvironmentImplementation.MappingTables.cs
+++ b/src/System.Private.Reflection.Execution/src/Internal/Reflection/Execution/ExecutionEnvironmentImplementation.MappingTables.cs
@@ -1075,7 +1075,7 @@ namespace Internal.Reflection.Execution
             }
             else
             {
-                uint nameAndSigOffset = externalReferences.GetNativeLayoutOffsetFromIndex(entryMethodHandleOrNameAndSigRaw);
+                uint nameAndSigOffset = externalReferences.GetExternalNativeLayoutOffset(entryMethodHandleOrNameAndSigRaw);
                 MethodNameAndSignature nameAndSig;
                 if (!TypeLoaderEnvironment.Instance.TryGetMethodNameAndSignatureFromNativeLayoutOffset(mappingTableModule, nameAndSigOffset, out nameAndSig))
                 {
diff --git a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/ExternalReferencesTable.cs b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/ExternalReferencesTable.cs
index 644eac90e..99f151906 100644
--- a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/ExternalReferencesTable.cs
+++ b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/ExternalReferencesTable.cs
@@ -137,16 +137,29 @@ namespace Internal.Runtime.TypeLoader
         {
             return RuntimeAugments.CreateRuntimeTypeHandle(GetIntPtrFromIndex(index));
         }
+    }
 
-        unsafe public uint GetNativeLayoutOffsetFromIndex(uint index)
+    public static class ExternalReferencesTableExtentions
+    {
+        public static uint GetExternalNativeLayoutOffset(this ExternalReferencesTable extRefs, uint index)
         {
-            if (index >= _elementsCount)
-                throw new BadImageFormatException();
-
+            // CoreRT is a bit more optimized than ProjectN. In ProjectN, some tables that reference data
+            // in the native layout are constructed at NUTC compilation time, but the native layout is only 
+            // generated at binder time, so we use the external references table to link the nutc-built
+            // tables with their native layout dependencies.
+            // 
+            // In ProjectN, the nutc-built tables will be emitted with indices into the external references 
+            // table, and the entries in the external references table will contain the offsets into the
+            // native layout blob.
+            //
+            // In CoreRT, since all tables and native layout blob are built together at the same time, we can
+            // optimize by writing the native layout offsets directly into the table, without requiring the extra
+            // lookup in the external references table.
+            //
 #if CORERT
-            return *(uint*)(((IntPtr*)_elements)[index]);
+            return index;
 #else
-            return ((TableElement*)_elements)[index];
+            return extRefs.GetRvaFromIndex(index);
 #endif
         }
     }
diff --git a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TemplateLocator.cs b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TemplateLocator.cs
index ec5656cdc..7726b09d6 100644
--- a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TemplateLocator.cs
+++ b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TemplateLocator.cs
@@ -92,7 +92,7 @@ namespace Internal.Runtime.TypeLoader
                     if (typeDesc == canonForm)
                     {
                         TypeLoaderLogger.WriteLine("Found metadata template for type " + concreteType.ToString() + ": " + typeDesc.ToString());
-                        nativeLayoutInfoToken = (uint)externalFixupsTable.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                        nativeLayoutInfoToken = (uint)externalFixupsTable.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                         if (nativeLayoutInfoToken == BadTokenFixupValue)
                         {
                             throw new BadImageFormatException();
@@ -150,7 +150,7 @@ namespace Internal.Runtime.TypeLoader
                     if (methodDesc == canonForm)
                     {
                         TypeLoaderLogger.WriteLine("Found metadata template for method " + concreteMethod.ToString() + ": " + methodDesc.ToString());
-                        nativeLayoutInfoToken = (uint)externalFixupsTable.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                        nativeLayoutInfoToken = (uint)externalFixupsTable.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                         if (nativeLayoutInfoToken == BadTokenFixupValue)
                         {
                             throw new BadImageFormatException();
@@ -197,7 +197,7 @@ namespace Internal.Runtime.TypeLoader
                     if (canonForm == candidateTemplate.ConvertToCanonForm(kind))
                     {
                         TypeLoaderLogger.WriteLine("Found template for type " + concreteType.ToString() + ": " + candidateTemplate.ToString());
-                        nativeLayoutInfoToken = (uint)externalFixupsTable.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                        nativeLayoutInfoToken = (uint)externalFixupsTable.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                         if (nativeLayoutInfoToken == BadTokenFixupValue)
                         {
                             // TODO: once multifile gets fixed up, make this throw a BadImageFormatException
@@ -269,7 +269,7 @@ namespace Internal.Runtime.TypeLoader
                 NativeParser entryParser;
                 while (!(entryParser = enumerator.GetNext()).IsNull)
                 {
-                    var methodSignatureParser = new NativeParser(nativeLayoutReader, externalFixupsTable.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned()));
+                    var methodSignatureParser = new NativeParser(nativeLayoutReader, externalFixupsTable.GetExternalNativeLayoutOffset(entryParser.GetUnsigned()));
 
                     // Get the unified generic method holder and convert it to its canonical form
                     var candidateTemplate = (InstantiatedMethod)context.GetMethod(ref methodSignatureParser);
@@ -279,7 +279,7 @@ namespace Internal.Runtime.TypeLoader
                     {
                         TypeLoaderLogger.WriteLine("Found template for generic method " + concreteMethod.ToString() + ": " + candidateTemplate.ToString());
                         nativeLayoutInfoModule = moduleHandle;
-                        nativeLayoutInfoToken = (uint)externalFixupsTable.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                        nativeLayoutInfoToken = (uint)externalFixupsTable.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                         if (nativeLayoutInfoToken == BadTokenFixupValue)
                         {
                             // TODO: once multifile gets fixed up, make this throw a BadImageFormatException
diff --git a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.GVMResolution.cs b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.GVMResolution.cs
index c701c13a6..dd7403ba5 100644
--- a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.GVMResolution.cs
+++ b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.GVMResolution.cs
@@ -85,7 +85,7 @@ namespace Internal.Runtime.TypeLoader
 
             for (uint j = 0; j < numTargetImplementations; j++)
             {
-                uint nameAndSigToken = extRefs.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                uint nameAndSigToken = extRefs.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                 MethodNameAndSignature targetMethodNameAndSignature = GetMethodNameAndSignatureFromNativeReader(nativeLayoutReader, moduleHandle, nameAndSigToken);
                 RuntimeTypeHandle targetTypeHandle = extRefs.GetRuntimeTypeHandleFromIndex(entryParser.GetUnsigned());
 
@@ -114,7 +114,7 @@ namespace Internal.Runtime.TypeLoader
                     {
                         RuntimeTypeHandle currentIfaceTypeHandle = default(RuntimeTypeHandle);
 
-                        NativeParser ifaceSigParser = new NativeParser(nativeLayoutReader, extRefs.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned()));
+                        NativeParser ifaceSigParser = new NativeParser(nativeLayoutReader, extRefs.GetExternalNativeLayoutOffset(entryParser.GetUnsigned()));
 
                         if (TypeLoaderEnvironment.Instance.GetTypeFromSignatureAndContext(ref ifaceSigParser, moduleHandle, targetTypeInstantiation, null, out currentIfaceTypeHandle))
                         {
@@ -226,7 +226,7 @@ namespace Internal.Runtime.TypeLoader
                     if (!openCallingTypeHandle.Equals(interfaceTypeHandle))
                         continue;
 
-                    uint nameAndSigToken = extRefs.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                    uint nameAndSigToken = extRefs.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                     MethodNameAndSignature interfaceMethodNameAndSignature = GetMethodNameAndSignatureFromNativeReader(nativeLayoutReader, moduleHandle, nameAndSigToken);
 
                     if (!interfaceMethodNameAndSignature.Equals(methodNameAndSignature))
@@ -459,13 +459,13 @@ namespace Internal.Runtime.TypeLoader
                     if (!parsedTargetTypeHandle.Equals(openTargetTypeHandle))
                         continue;
 
-                    uint parsedCallingNameAndSigToken = extRefs.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                    uint parsedCallingNameAndSigToken = extRefs.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                     MethodNameAndSignature parsedCallingNameAndSignature = GetMethodNameAndSignatureFromNativeReader(nativeLayoutReader, moduleHandle, parsedCallingNameAndSigToken);
 
                     if (!parsedCallingNameAndSignature.Equals(callingMethodNameAndSignature))
                         continue;
 
-                    uint parsedTargetMethodNameAndSigToken = extRefs.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                    uint parsedTargetMethodNameAndSigToken = extRefs.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                     MethodNameAndSignature targetMethodNameAndSignature = GetMethodNameAndSignatureFromNativeReader(nativeLayoutReader, moduleHandle, parsedTargetMethodNameAndSigToken);
 
                     Debug.Assert(targetMethodNameAndSignature != null);
diff --git a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.Metadata.cs b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.Metadata.cs
index c52479aad..22d2c7d56 100644
--- a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.Metadata.cs
+++ b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.Metadata.cs
@@ -852,7 +852,7 @@ namespace Internal.Runtime.TypeLoader
                 if (!entryType.Equals(definitionType))
                     continue;
 
-                uint nameAndSigPointerToken = externalReferences.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                uint nameAndSigPointerToken = externalReferences.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
 
                 MethodNameAndSignature nameAndSig;
                 if (!TypeLoaderEnvironment.Instance.TryGetMethodNameAndSignatureFromNativeLayoutOffset(moduleHandle, nameAndSigPointerToken, out nameAndSig))
@@ -995,7 +995,7 @@ namespace Internal.Runtime.TypeLoader
                 if (!entryType.Equals(definitionType))
                     continue;
 
-                uint nameAndSigPointerToken = externalReferences.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                uint nameAndSigPointerToken = externalReferences.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
 
                 uint parentHierarchyAndFlag = entryParser.GetUnsigned();
                 bool isGenericVirtualMethod = ((parentHierarchyAndFlag & VirtualInvokeTableEntry.FlagsMask) == VirtualInvokeTableEntry.GenericVirtualMethod);
@@ -1576,7 +1576,7 @@ namespace Internal.Runtime.TypeLoader
                 }
                 else
                 {
-                    uint nameAndSigToken = extRefTable.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                    uint nameAndSigToken = extRefTable.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                     MethodNameAndSignature nameAndSig;
                     if (!TypeLoaderEnvironment.Instance.TryGetMethodNameAndSignatureFromNativeLayoutOffset(_moduleHandle, nameAndSigToken, out nameAndSig))
                     {
@@ -1608,7 +1608,7 @@ namespace Internal.Runtime.TypeLoader
                 {
                     Debug.Assert((_hasEntryPoint || ((_flags & InvokeTableFlags.HasVirtualInvoke) != 0)) && ((_flags & InvokeTableFlags.RequiresInstArg) != 0));
 
-                    uint nameAndSigPointerToken = extRefTable.GetNativeLayoutOffsetFromIndex(entryParser.GetUnsigned());
+                    uint nameAndSigPointerToken = extRefTable.GetExternalNativeLayoutOffset(entryParser.GetUnsigned());
                     if (!TypeLoaderEnvironment.Instance.TryGetMethodNameAndSignatureFromNativeLayoutOffset(_moduleHandle, nameAndSigPointerToken, out _nameAndSignature))
                     {
                         Debug.Assert(false);    //Error