[cfe-commits] r159360 - /cfe/trunk/lib/CodeGen/CGExprCXX.cpp

[Rafael Espindola]

Author: rafael
Date: Thu Jun 28 12:57:36 2012
New Revision: 159360

URL: http://llvm.org/viewvc/llvm-project?rev=159360&view=rev
Log:
Compare the canonical types and document why we give up on the covariant case.

Modified:
    cfe/trunk/lib/CodeGen/CGExprCXX.cpp

Modified: cfe/trunk/lib/CodeGen/CGExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprCXX.cpp?rev=159360&r1=159359&r2=159360&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprCXX.cpp Thu Jun 28 12:57:36 2012
@@ -202,8 +202,14 @@
       // we don't have support for that yet, so do a virtual call.
       DevirtualizedMethod = NULL;
     }
-    if (DevirtualizedMethod && DevirtualizedMethod->getResultType() !=
-        MD->getResultType())
+    // If the return types are not the same, this might be a case where more
+    // code needs to run to compensate for it. For example, the derived
+    // method might return a type that inherits form from the return
+    // type of MD and has a prefix.
+    // For now we just avoid devirtualizing these covariant cases.
+    if (DevirtualizedMethod &&
+        DevirtualizedMethod->getResultType().getCanonicalType() !=
+        MD->getResultType().getCanonicalType())
       DevirtualizedMethod = NULL;
   }