From e151f010deab7417abf663fb1c8ff841539903e7 Mon Sep 17 00:00:00 2001
From: Alex Lorenz <arphaman@gmail.com>
Date: Wed, 7 Dec 2016 10:24:44 +0000
Subject: [PATCH] [ObjC++] Don't enter a C++ declarator scope when the current
 context is an Objective-C declaration

This commit ensures that Sema won't enter a C++ declarator scope when the
current context is an Objective-C declaration. This prevents an assertion
failure in EnterDeclaratorContext that's used to ensure that current context
will be restored correctly after exiting the declarator context.

rdar://20560175

Differential Revision: https://reviews.llvm.org/D26922

llvm-svn: 288893
---
 clang/lib/Parse/ParseDecl.cpp       |  8 ++++++++
 clang/lib/Sema/SemaCXXScopeSpec.cpp |  5 +++++
 clang/test/SemaObjCXX/crash.mm      | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index d15e41d..ea7ab26 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -5264,6 +5264,14 @@ void Parser::ParseDirectDeclarator(Declarator &D) {
         // Change the declaration context for name lookup, until this function
         // is exited (and the declarator has been parsed).
         DeclScopeObj.EnterDeclaratorScope();
+      else if (getObjCDeclContext()) {
+        // Ensure that we don't interpret the next token as an identifier when
+        // dealing with declarations in an Objective-C container.
+        D.SetIdentifier(nullptr, Tok.getLocation());
+        D.setInvalidType(true);
+        ConsumeToken();
+        goto PastIdentifier;
+      }
     }
 
     // C++0x [dcl.fct]p14:
diff --git a/clang/lib/Sema/SemaCXXScopeSpec.cpp b/clang/lib/Sema/SemaCXXScopeSpec.cpp
index 6c7d813..d8971c0 100644
--- a/clang/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/clang/lib/Sema/SemaCXXScopeSpec.cpp
@@ -1001,6 +1001,11 @@ void Sema::RestoreNestedNameSpecifierAnnotation(void *AnnotationPtr,
 bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) {
   assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
 
+  // Don't enter a declarator context when the current context is an Objective-C
+  // declaration.
+  if (isa<ObjCContainerDecl>(CurContext) || isa<ObjCMethodDecl>(CurContext))
+    return false;
+
   NestedNameSpecifier *Qualifier = SS.getScopeRep();
 
   // There are only two places a well-formed program may qualify a
diff --git a/clang/test/SemaObjCXX/crash.mm b/clang/test/SemaObjCXX/crash.mm
index 19cf309..a9754b7 100644
--- a/clang/test/SemaObjCXX/crash.mm
+++ b/clang/test/SemaObjCXX/crash.mm
@@ -25,3 +25,38 @@ template<typename...Ts> void f(Ts); // expected-error {{unexpanded}}
 // expected-warning@-2 {{variadic templates are a C++11 extension}}
 #endif
 @end
+
+// rdar://20560175
+
+struct OuterType {
+  typedef int InnerType;
+};
+
+namespace ns {
+  typedef int InnerType;
+};
+
+@protocol InvalidProperties
+
+@property (nonatomic) (OuterType::InnerType) invalidTypeParens;
+// expected-error@-1 {{type name requires a specifier or qualifier}}
+// expected-error@-2 {{property requires fields to be named}}
+// expected-error@-3 {{expected ';' at end of declaration list}}
+// expected-error@-4 {{C++ requires a type specifier for all declarations}}
+// expected-error@-5 {{cannot declare variable inside @interface or @protocol}}
+
+@property (nonatomic) (ns::InnerType) invalidTypeParens2;
+// expected-error@-1 {{type name requires a specifier or qualifier}}
+// expected-error@-2 {{property requires fields to be named}}
+// expected-error@-3 {{expected ';' at end of declaration list}}
+// expected-error@-4 {{C++ requires a type specifier for all declarations}}
+// expected-error@-5 {{cannot declare variable inside @interface or @protocol}}
+
+@property (nonatomic) int OuterType::InnerType; // expected-error {{property requires fields to be named}}
+
+@property (nonatomic) int OuterType::InnerType foo; // expected-error {{property requires fields to be named}}
+// expected-error@-1 {{expected ';' at end of declaration list}}
+// expected-error@-2 {{C++ requires a type specifier for all declarations}}
+// expected-error@-3 {{cannot declare variable inside @interface or @protocol}}
+
+@end
-- 
2.7.4