Throw an exception when passing strings by-value as out parameters. (#21513)

* Throw an exception when passing strings by-value as out parameters.

* Fix encoding

* Don't use override in this PR.

* Clean up Marshal_In

Marshal_In was copied back into existence from Marshal_InOut. Clean it up a bit.

* Remove extraneous whitespace.

* Fix failing test.

* Remove out attribute in COM string tests.

* Add back attribute and check for exception thow in COM tests.

* Add block comment to explain the implementation of Reverse_LPWStr_OutAttr in the NETServer.

* Only throw in a CLR->Native marshalling situation.

* Fix asserts from changed code-paths used in ILWSTRMarshaler.

* Add comment and explicitly load in a null value (instead of leaving it uninitialized).

* Apply suggestions from code review

Co-Authored-By: jkoritzinsky <jkoritzinsky@gmail.com>


Co-authored-by: Jan Vorlicek <janvorli@microsoft.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/src/vm/ilmarshalers.h b/src/vm/ilmarshalers.h
index 1c58c0c2a7..3f2c16b4d5 100644
--- a/src/vm/ilmarshalers.h
+++ b/src/vm/ilmarshalers.h
@@ -1946,7 +1946,7 @@ class ILWSTRMarshaler : public ILMarshaler
 public:
     enum
     {
-        c_fInOnly               = TRUE,
+        c_fInOnly               = FALSE,
         c_nativeSize            = sizeof(void *),
         c_CLRSize               = sizeof(OBJECTREF),
     };
@@ -1961,6 +1961,18 @@ public:
     }
 #endif // _DEBUG
 
+    
+    virtual bool SupportsArgumentMarshal(DWORD dwMarshalFlags, UINT* pErrorResID)
+    {
+        if (IsOut(dwMarshalFlags) && !IsByref(dwMarshalFlags) && IsCLRToNative(dwMarshalFlags))
+        {
+            *pErrorResID = IDS_EE_BADMARSHAL_STRING_OUT;
+            return false;
+        }
+
+        return true;
+    }
+
 protected:
     virtual LocalDesc GetNativeType();
     virtual LocalDesc GetManagedType();
@@ -1972,7 +1984,6 @@ protected:
 
     virtual void EmitConvertSpaceNativeToCLR(ILCodeStream* pslILEmit);
     virtual void EmitConvertContentsNativeToCLR(ILCodeStream* pslILEmit);
-    virtual void EmitConvertSpaceAndContentsNativeToCLR(ILCodeStream* pslILEmit);
 
     virtual bool NeedsClearNative();
     virtual void EmitClearNative(ILCodeStream* pslILEmit);