From 196cc96f9a643d1cb828f48ef15ec30d0de24df7 Mon Sep 17 00:00:00 2001
From: Adam Czachorowski <adamcz@google.com>
Date: Fri, 15 Jan 2021 18:37:25 +0100
Subject: [PATCH] [clang] Allow LifetimeExtendedTemporary to have no access
 specifier

The check only runs in debug mode during serialization, but
assert()-fail on:
  struct S { const int& x = 7; };
in C++ mode.

Differential Revision: https://reviews.llvm.org/D94804
---
 clang/lib/AST/DeclBase.cpp     | 16 +++++++---------
 clang/test/PCH/cxx-reference.h |  4 ++++
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 0656efa..dc59f3d 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -971,21 +971,19 @@ bool Decl::AccessDeclContextSanity() const {
   // 5. it's invalid
   // 6. it's a C++0x static_assert.
   // 7. it's a block literal declaration
-  if (isa<TranslationUnitDecl>(this) ||
-      isa<TemplateTypeParmDecl>(this) ||
-      isa<NonTypeTemplateParmDecl>(this) ||
-      !getDeclContext() ||
-      !isa<CXXRecordDecl>(getDeclContext()) ||
-      isInvalidDecl() ||
-      isa<StaticAssertDecl>(this) ||
-      isa<BlockDecl>(this) ||
+  // 8. it's a temporary with lifetime extended due to being default value.
+  if (isa<TranslationUnitDecl>(this) || isa<TemplateTypeParmDecl>(this) ||
+      isa<NonTypeTemplateParmDecl>(this) || !getDeclContext() ||
+      !isa<CXXRecordDecl>(getDeclContext()) || isInvalidDecl() ||
+      isa<StaticAssertDecl>(this) || isa<BlockDecl>(this) ||
       // FIXME: a ParmVarDecl can have ClassTemplateSpecialization
       // as DeclContext (?).
       isa<ParmVarDecl>(this) ||
       // FIXME: a ClassTemplateSpecialization or CXXRecordDecl can have
       // AS_none as access specifier.
       isa<CXXRecordDecl>(this) ||
-      isa<ClassScopeFunctionSpecializationDecl>(this))
+      isa<ClassScopeFunctionSpecializationDecl>(this) ||
+      isa<LifetimeExtendedTemporaryDecl>(this))
     return true;
 
   assert(Access != AS_none &&
diff --git a/clang/test/PCH/cxx-reference.h b/clang/test/PCH/cxx-reference.h
index b46a367..a65d3fe 100644
--- a/clang/test/PCH/cxx-reference.h
+++ b/clang/test/PCH/cxx-reference.h
@@ -11,3 +11,7 @@ LR &lrlr = c;
 LR &&rrlr = c;
 RR &lrrr = c;
 RR &&rrrr = 'c';
+
+struct S {
+  const int &x = 1; // LifetimeExtendedTemporary inside struct
+};
-- 
2.7.4