<rdar://problem/13806270> A template argument list is a constant-evaluated context.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181076 91177308-0d34-0410-b5e6-96231b3b80d8

Author: DougGregor

Diff for: lib/Parse/ParseTemplate.cpp

@@ -1149,6 +1149,9 @@ bool Parser::IsTemplateArgumentList(unsigned Skip) {
 ///         template-argument-list ',' template-argument
 bool
 Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) {
+  // Template argument lists are constant-evaluation contexts.
+  EnterExpressionEvaluationContext EvalContext(Actions,Sema::ConstantEvaluated);
+
   while (true) {
     ParsedTemplateArgument Arg = ParseTemplateArgument();
     if (Tok.is(tok::ellipsis)) {

Diff for: test/SemaTemplate/temp_arg_nontype.cpp

@@ -337,3 +337,12 @@ namespace rdar13000548 {
   }
 
 }
+
+namespace rdar13806270 {
+  template <unsigned N> class X { };
+  const unsigned value = 32;
+  struct Y {
+    X<value + 1> x;
+  };
+  void foo() {}
+}