Don't reprocess non-dependent initializers of non-dependent VarDecls. Fixes PR5426.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86460 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -186,6 +186,15 @@ Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
       = SemaRef.SubstExpr(D->getInit(), TemplateArgs);
     if (Init.isInvalid())
       Var->setInvalidDecl();
+    else if (!D->getType()->isDependentType() &&
+             !D->getInit()->isTypeDependent() &&
+             !D->getInit()->isValueDependent()) {
+      // If neither the declaration's type nor its initializer are dependent,
+      // we don't want to redo all the checking, especially since the
+      // initializer might have been wrapped by a CXXConstructExpr since we did
+      // it the first time.
+      Var->setInit(SemaRef.Context, Init.takeAs<Expr>());
+    }
     else if (ParenListExpr *PLE = dyn_cast<ParenListExpr>((Expr *)Init.get())) {
       // FIXME: We're faking all of the comma locations, which is suboptimal.
       // Do we even need these comma locations?

test/SemaTemplate/instantiate-decl-init.cpp

@@ -0,0 +1,22 @@
+// RUN: clang-cc -fsyntax-only -verify %s
+
+// PR5426 - the non-dependent obj would be fully processed and wrapped in a
+// CXXConstructExpr at definition time, which would lead to a failure at
+// instantiation time.
+struct arg {
+  arg();
+};
+
+struct oldstylemove {
+  oldstylemove(oldstylemove&);
+  oldstylemove(const arg&);
+};
+
+template <typename T>
+void fn(T t, const arg& arg) {
+  oldstylemove obj(arg);
+}
+
+void test() {
+  fn(1, arg());
+}