From fb9b689230eed1d9c1b7cecc80e4545d233b3b91 Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Sat, 22 Feb 2014 00:17:46 +0000
Subject: [PATCH] Sema: Don't crash when trying to instantiate a local class
 with an invalid base specifier

It was previously thought that Sema::InstantiateClass could not fail
from within this point in instantiate.

However, it can happen if the class is invalid some way (i.e. invalid
base specifier).

This fixes PR18907.

Differential Revision: http://llvm-reviews.chandlerc.com/D2850


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@201913 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaTemplateInstantiateDecl.cpp      | 13 +++++--------
 test/SemaTemplate/instantiate-local-class.cpp | 15 ++++++++++++++-
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 7b84a06eaa..6439b9208c 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1187,14 +1187,11 @@ Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
   // DR1484 clarifies that the members of a local class are instantiated as part
   // of the instantiation of their enclosing entity.
   if (D->isCompleteDefinition() && D->isLocalClass()) {
-    if (SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
-                                 TSK_ImplicitInstantiation,
-                                 /*Complain=*/true)) {
-      llvm_unreachable("InstantiateClass shouldn't fail here!");
-    } else {
-      SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
-                                      TSK_ImplicitInstantiation);
-    }
+    SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
+                             TSK_ImplicitInstantiation,
+                             /*Complain=*/true);
+    SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
+                                    TSK_ImplicitInstantiation);
   }
   return Record;
 }
diff --git a/test/SemaTemplate/instantiate-local-class.cpp b/test/SemaTemplate/instantiate-local-class.cpp
index 2bf24c2188..c9897b9c61 100644
--- a/test/SemaTemplate/instantiate-local-class.cpp
+++ b/test/SemaTemplate/instantiate-local-class.cpp
@@ -1,5 +1,4 @@
 // RUN: %clang_cc1 -verify -std=c++11 %s
-// expected-no-diagnostics
 template<typename T>
 void f0() {
   struct X;
@@ -181,3 +180,17 @@ namespace PR14373 {
     return 0;
   }
 }
+
+namespace PR18907 {
+template <typename>
+class C : public C<int> {}; // expected-error{{within its own definition}}
+
+template <typename X>
+void F() {
+  struct A : C<X> {};
+}
+
+struct B {
+  void f() { F<int>(); }
+};
+}
-- 
2.40.0