If a variable template is inside a context with template arguments that is being instantiated, and that instantiation fails, fail our instantiation instead of crashing. Errors have already been emitted.

llvm-svn: 244515

2 files changed, 12 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 4fa54257ee4..c8a067658bf 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1143,6 +1143,7 @@ Decl *TemplateDeclInstantiator::VisitVarTemplateDecl(VarTemplateDecl *D) {
   VarDecl *VarInst =
       cast_or_null<VarDecl>(VisitVarDecl(Pattern,
                                          /*InstantiatingVarTemplate=*/true));
+  if (!VarInst) return nullptr;
 
   DeclContext *DC = Owner;
 
diff --git a/clang/test/SemaCXX/cxx1y-variable-templates_in_class.cpp b/clang/test/SemaCXX/cxx1y-variable-templates_in_class.cpp
index 123fcfff7f7..65e2d6b608c 100644
--- a/clang/test/SemaCXX/cxx1y-variable-templates_in_class.cpp
+++ b/clang/test/SemaCXX/cxx1y-variable-templates_in_class.cpp
@@ -327,3 +327,14 @@ struct S {
   static int f : I; // expected-error {{static member 'f' cannot be a bit-field}}
 };
 }
+
+namespace b20896909 {
+  // This used to crash.
+  template<typename T> struct helper {};
+  template<typename T> class A {
+    template <typename> static helper<typename T::error> x;  // expected-error {{type 'int' cannot be used prior to '::' because it has no members}}
+  };
+  void test() {
+    A<int> ai;  // expected-note {{in instantiation of}}
+  }
+}