Fix r162835 as per Richard's comments.

VisitVarDecl should return Error(E), and we should test that the address
of a TLS var can't be used as a constexpr.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162837 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 8 insertions, 1 deletions

diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 6b88246f82..ac21b46941 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -2833,7 +2833,7 @@ bool LValueExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
 
 bool LValueExprEvaluator::VisitVarDecl(const Expr *E, const VarDecl *VD) {
   if (VD->isThreadSpecified())
-    return false;
+    return Error(E);
   if (!VD->getType()->isReferenceType()) {
     if (isa<ParmVarDecl>(VD)) {
       Result.set(VD, Info.CurrentCall->Index);
diff --git a/test/SemaCXX/constant-expression-cxx11.cpp b/test/SemaCXX/constant-expression-cxx11.cpp
index a3ead79a84..984ee1b08b 100644
--- a/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/test/SemaCXX/constant-expression-cxx11.cpp
@@ -1374,3 +1374,10 @@ namespace ConditionalLValToRVal {
   constexpr A a(4);
   static_assert(f(a).v == 4, "");
 }
+
+namespace TLS {
+  __thread int n;
+  constexpr int &f() { // expected-error {{constexpr function never produces a constant expression}}
+    return n; // expected-note {{subexpression not valid in a constant expression}}
+  }
+}