Index: llvm/trunk/lib/IR/Verifier.cpp
===================================================================
--- llvm/trunk/lib/IR/Verifier.cpp
+++ llvm/trunk/lib/IR/Verifier.cpp
@@ -1317,6 +1317,15 @@
     Assert(Inserted,
            "module flag identifiers must be unique (or of 'require' type)", ID);
   }
+
+  if (ID->getString() == "wchar_size") {
+    ConstantInt *Value
+      = mdconst::dyn_extract_or_null<ConstantInt>(Op->getOperand(2));
+    Assert(Value, "wchar_size metadata requires constant integer argument");
+    uint64_t WCharSize = Value->getZExtValue();
+    Assert(WCharSize == 0 || WCharSize == 2 || WCharSize == 4,
+           "wchar_size should be 0, 2 or 4");
+  }
 }
 
 /// Return true if this attribute kind only applies to functions.