If a default argument is a dependent type, get the real type from the desugared

template.  Passing around dependent types can lead to integral arguments that
cannot be evaluated.

llvm-svn: 186757

1 files changed, 7 insertions, 3 deletions

diff --git a/clang/lib/AST/ASTDiagnostic.cpp b/clang/lib/AST/ASTDiagnostic.cpp
index bc707ddbc1e..eb22632c937 100644
--- a/clang/lib/AST/ASTDiagnostic.cpp
+++ b/clang/lib/AST/ASTDiagnostic.cpp
@@ -1054,10 +1054,14 @@ class TemplateDiff {
 
     if (!Iter.isEnd())
       return Iter->getAsType();
-    if (!isVariadic)
-      return DefaultTTPD->getDefaultArgument();
+    if (isVariadic)
+      return QualType();
+
+    QualType ArgType = DefaultTTPD->getDefaultArgument();
+    if (ArgType->isDependentType())
+      return Iter.getDesugar().getAsType();
 
-    return QualType();
+    return ArgType;
   }
 
   /// GetExpr - Retrieves the template expression argument, including default