Add generic detection of Stream.{Begin|End}{Read|Write} overrides

1 files changed, 54 insertions, 0 deletions

diff --git a/src/vm/comutilnative.cpp b/src/vm/comutilnative.cpp
index 9664bf9325..1b21f12cda 100644
--- a/src/vm/comutilnative.cpp
+++ b/src/vm/comutilnative.cpp
@@ -3159,3 +3159,57 @@ INT32 QCALLTYPE CoreFxGlobalization::HashSortKey(PCBYTE pSortKey, INT32 cbSortKe
     return retVal;
 }
 #endif //FEATURE_COREFX_GLOBALIZATION
+
+static MethodTable * g_pStreamMT;
+static WORD g_slotBeginRead, g_slotEndRead;
+static WORD g_slotBeginWrite, g_slotEndWrite;
+
+FCIMPL1(FC_BOOL_RET, StreamNative::HasOverridenBeginEndRead, Object *stream)
+{
+    FCALL_CONTRACT;
+
+    if (stream == NULL)
+        FC_RETURN_BOOL(TRUE);
+
+    if (g_pStreamMT == NULL || g_slotBeginRead == 0 || g_slotEndRead == 0)
+    {
+        HELPER_METHOD_FRAME_BEGIN_RET_1(stream);
+        g_pStreamMT = MscorlibBinder::GetClass(CLASS__STREAM);
+        g_slotBeginRead = MscorlibBinder::GetMethod(METHOD__STREAM__BEGIN_READ)->GetSlot();
+        g_slotEndRead = MscorlibBinder::GetMethod(METHOD__STREAM__END_READ)->GetSlot();
+        HELPER_METHOD_FRAME_END();
+    }
+
+    MethodTable * pMT = stream->GetMethodTable();
+
+    FC_RETURN_BOOL(
+        pMT->GetRestoredSlot(g_slotBeginRead) != g_pStreamMT->GetRestoredSlot(g_slotBeginRead) ||
+        pMT->GetRestoredSlot(g_slotEndRead) != g_pStreamMT->GetRestoredSlot(g_slotEndRead)
+    );
+}
+FCIMPLEND
+
+FCIMPL1(FC_BOOL_RET, StreamNative::HasOverridenBeginEndWrite, Object *stream)
+{
+    FCALL_CONTRACT;
+
+    if (stream == NULL) 
+        FC_RETURN_BOOL(TRUE);
+
+    if (g_pStreamMT == NULL || g_slotBeginWrite == 0 || g_slotEndWrite == 0)
+    {
+        HELPER_METHOD_FRAME_BEGIN_RET_1(stream);
+        g_pStreamMT = MscorlibBinder::GetClass(CLASS__STREAM);
+        g_slotBeginWrite = MscorlibBinder::GetMethod(METHOD__STREAM__BEGIN_WRITE)->GetSlot();
+        g_slotEndWrite = MscorlibBinder::GetMethod(METHOD__STREAM__END_WRITE)->GetSlot();
+        HELPER_METHOD_FRAME_END();
+    }
+
+    MethodTable * pMT = stream->GetMethodTable();
+
+    FC_RETURN_BOOL(
+        pMT->GetRestoredSlot(g_slotBeginWrite) != g_pStreamMT->GetRestoredSlot(g_slotBeginWrite) ||
+        pMT->GetRestoredSlot(g_slotEndWrite) != g_pStreamMT->GetRestoredSlot(g_slotEndWrite)
+    );
+}
+FCIMPLEND