Move TLS check from LValueExprEvaluator::VisitVarDecl to
CheckLValueConstantExpression.

Richard pointed out that using the address of a TLS variable is ok in a
core C++11 constant expression, as long as it isn't part of the eventual
result of constant expression evaluation. Having the check in
CheckLValueConstantExpression accomplishes this.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162850 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index ac21b46..fb0c4d2 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -987,6 +987,14 @@
           LVal.getLValueCallIndex() == 0) &&
          "have call index for global lvalue");
 
+  // Check if this is a thread-local variable.
+  if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
+    if (const VarDecl *Var = dyn_cast<const VarDecl>(VD)) {
+      if (Var->isThreadSpecified())
+        return false;
+    }
+  }
+
   // Allow address constant expressions to be past-the-end pointers. This is
   // an extension: the standard requires them to point to an object.
   if (!IsReferenceType)
@@ -2832,8 +2840,6 @@
 }
 
 bool LValueExprEvaluator::VisitVarDecl(const Expr *E, const VarDecl *VD) {
-  if (VD->isThreadSpecified())
-    return Error(E);
   if (!VD->getType()->isReferenceType()) {
     if (isa<ParmVarDecl>(VD)) {
       Result.set(VD, Info.CurrentCall->Index);