UTF8 Marshaling support(UnmanagedType.LPUTF8Str)

Usage: [MarshalAs(UnmanagedType.LPUTF8Str)] applied to string
and stringbuilder.

Implementation mostly use Encoding.UTF8 API to do the byte buffer
to string roundtripping. Introducing two new marshalers,
UTF8StringMarshaler and UTF8BufferMarshaler which handle string
and StringBuilder respectively. [Out] StringBuilder marshaling use
builder capacity as the buffer size ie (builder. Capacity + 1) *3
which is enough for any UTF8 char in BMP plane, infact Encoding.UTF8
mscorlib APIs use the same length.All marshaling flags(ThrowOnUnmapable,
defaultchar) are ignored since they do not make sense in UTF16 to UTD8
context.

The public contracts are not yet updated, the public contracts and
public marshaling API (Marshal.PtrToStringUtf8 and StringToHGlobalUtf8)
will be added once the implementation is in. The marshal api are anyway
going to be a wrapper around Encoding.GetBytes and GetChars.

1 files changed, 108 insertions, 0 deletions

diff --git a/src/vm/fieldmarshaler.cpp b/src/vm/fieldmarshaler.cpp
index 37ad39eb4f..39465c269d 100644
--- a/src/vm/fieldmarshaler.cpp
+++ b/src/vm/fieldmarshaler.cpp
@@ -770,6 +770,10 @@ do                                                      \
                         case NATIVE_TYPE_LPWSTR:
                             INITFIELDMARSHALER(NFT_STRINGUNI, FieldMarshaler_StringUni, ());
                             break;
+                        
+                        case NATIVE_TYPE_LPUTF8STR:
+							INITFIELDMARSHALER(NFT_STRINGUTF8, FieldMarshaler_StringUtf8, ());
+							break;
 
                         case NATIVE_TYPE_LPTSTR:
                             // We no longer support Win9x so LPTSTR always maps to a Unicode string.
@@ -3158,7 +3162,109 @@ VOID FieldMarshaler_StringAnsi::DestroyNativeImpl(LPVOID pNativeValue) const
         CoTaskMemFree(sz);
 }
 
+//=======================================================================
+// CoTask Utf8 <--> System.String
+// See FieldMarshaler for details.
+//=======================================================================
+VOID FieldMarshaler_StringUtf8::UpdateNativeImpl(OBJECTREF* pCLRValue, LPVOID pNativeValue, OBJECTREF *ppCleanupWorkListOnStack) const
+{
+    CONTRACTL
+    {
+        THROWS;
+        GC_TRIGGERS;
+        MODE_COOPERATIVE;
+        INJECT_FAULT(COMPlusThrowOM());
+        PRECONDITION(CheckPointer(pNativeValue));
+    }
+    CONTRACTL_END;
+
+    STRINGREF pString = (STRINGREF)(*pCLRValue);
+    if (pString == NULL)
+    {
+        MAYBE_UNALIGNED_WRITE(pNativeValue, _PTR, NULL);
+    }
+    else
+    {
+        DWORD nc = pString->GetStringLength();
+        if (nc > MAX_SIZE_FOR_INTEROP)
+            COMPlusThrow(kMarshalDirectiveException, IDS_EE_STRING_TOOLONG);
+
+        // Characters would be # of characters + 1 in case left over high surrogate is ?
+        // Max 3 bytes per char for basic multi-lingual plane.          
+        nc = (nc + 1) * 3;
+        // +1 for '\0'
+        LPUTF8  lpBuffer = (LPUTF8)CoTaskMemAlloc(nc + 1);
+        if (!lpBuffer)
+            COMPlusThrowOM();
+
+        // UTF8Marshaler.ConvertToNative
+        MethodDescCallSite convertToNative(METHOD__CUTF8MARSHALER__CONVERT_TO_NATIVE);
+        
+        ARG_SLOT args[] =
+        {
+            ((ARG_SLOT)(CLR_I4)0),
+            ObjToArgSlot(*pCLRValue),
+            PtrToArgSlot(lpBuffer)
+        };
+        convertToNative.Call(args);
+        MAYBE_UNALIGNED_WRITE(pNativeValue, _PTR, lpBuffer);
+    }
+}
+
+
+//=======================================================================
+// CoTask Utf8 <--> System.String
+// See FieldMarshaler for details.
+//=======================================================================
+VOID FieldMarshaler_StringUtf8::UpdateCLRImpl(const VOID *pNativeValue, OBJECTREF *ppProtectedCLRValue, OBJECTREF *ppProtectedOldCLRValue) const
+{
+    CONTRACTL
+    {
+        THROWS;
+    GC_TRIGGERS;
+    MODE_COOPERATIVE;
+    INJECT_FAULT(COMPlusThrowOM());
+    PRECONDITION(CheckPointer(pNativeValue));
+    PRECONDITION(CheckPointer(ppProtectedCLRValue));
+    }
+    CONTRACTL_END;
+
+    STRINGREF pString = NULL;
+    LPCUTF8  sz = (LPCUTF8)MAYBE_UNALIGNED_READ(pNativeValue, _PTR);
+    if (!sz)
+        pString = NULL;
+    else
+    {
+        MethodDescCallSite convertToManaged(METHOD__CUTF8MARSHALER__CONVERT_TO_MANAGED);
+        ARG_SLOT args[] =
+        {
+            PtrToArgSlot(pNativeValue),
+        };
+        pString = convertToManaged.Call_RetSTRINGREF(args);
+    }
+    *((STRINGREF*)ppProtectedCLRValue) = pString;
+}
+
+//=======================================================================
+// CoTask Utf8 <--> System.String
+// See FieldMarshaler for details.
+//=======================================================================
+VOID FieldMarshaler_StringUtf8::DestroyNativeImpl(LPVOID pNativeValue) const
+{
+    CONTRACTL
+    {
+        NOTHROW;
+        GC_NOTRIGGER;
+        MODE_ANY;
+        PRECONDITION(CheckPointer(pNativeValue));
+    }
+    CONTRACTL_END;
 
+    LPSTR lpBuffer = (LPSTR)MAYBE_UNALIGNED_READ(pNativeValue, _PTR);
+    MAYBE_UNALIGNED_WRITE(pNativeValue, _PTR, NULL);
+    if (lpBuffer)
+        CoTaskMemFree(lpBuffer);
+}
 
 //=======================================================================
 // FixedString <--> System.String
@@ -4607,6 +4713,7 @@ VOID NStructFieldTypeToString(FieldMarshaler* pFM, SString& strNStructFieldType)
         switch (GetNStructFieldType()) { \
         case NFT_STRINGUNI: rettype ((FieldMarshaler_StringUni*)this)->name##Impl args; break; \
         case NFT_STRINGANSI: rettype ((FieldMarshaler_StringAnsi*)this)->name##Impl args; break; \
+        case NFT_STRINGUTF8: rettype ((FieldMarshaler_StringUtf8*)this)->name##Impl args; break; \
         case NFT_FIXEDSTRINGUNI: rettype ((FieldMarshaler_FixedStringUni*)this)->name##Impl args; break; \
         case NFT_FIXEDSTRINGANSI: rettype ((FieldMarshaler_FixedStringAnsi*)this)->name##Impl args; break; \
         case NFT_FIXEDCHARARRAYANSI: rettype ((FieldMarshaler_FixedCharArrayAnsi*)this)->name##Impl args; break; \
@@ -4649,6 +4756,7 @@ VOID NStructFieldTypeToString(FieldMarshaler* pFM, SString& strNStructFieldType)
         switch (GetNStructFieldType()) { \
         case NFT_STRINGUNI: rettype ((FieldMarshaler_StringUni*)this)->name##Impl args; break; \
         case NFT_STRINGANSI: rettype ((FieldMarshaler_StringAnsi*)this)->name##Impl args; break; \
+        case NFT_STRINGUTF8: rettype ((FieldMarshaler_StringUtf8*)this)->name##Impl args; break; \
         case NFT_FIXEDSTRINGUNI: rettype ((FieldMarshaler_FixedStringUni*)this)->name##Impl args; break; \
         case NFT_FIXEDSTRINGANSI: rettype ((FieldMarshaler_FixedStringAnsi*)this)->name##Impl args; break; \
         case NFT_FIXEDCHARARRAYANSI: rettype ((FieldMarshaler_FixedCharArrayAnsi*)this)->name##Impl args; break; \