Friend declarations are only valid inside class definitions.

llvm-svn: 71489

4 files changed, 21 insertions, 0 deletions

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 577392cbd60..aaaad13b128 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -243,6 +243,9 @@ def err_static_assert_expression_is_not_constant : Error<
   "static_assert expression is not an integral constant expression">;
 def err_static_assert_failed : Error<"static_assert failed \"%0\"">;
 
+def err_friend_decl_outside_class : Error<
+  "'friend' used outside of class">;
+
 def err_abstract_type_in_decl : Error<
   "%select{return|parameter|variable|field}1 type %0 is an abstract class">;
 def err_allocation_of_abstract_type : Error<
diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index 7a25fa9668d..21aca40c7d2 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -1731,6 +1731,9 @@ public:
                                                  ExprArg AssertExpr,
                                                  ExprArg AssertMessageExpr);
   
+  virtual bool ActOnFriendDecl(Scope *S, SourceLocation FriendLoc,
+                               DeclPtrTy Dcl);
+
   QualType CheckConstructorDeclarator(Declarator &D, QualType R,
                                       FunctionDecl::StorageClass& SC);
   void CheckConstructor(CXXConstructorDecl *Constructor);
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 7e91f5beac9..726080b7ff6 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -2643,6 +2643,15 @@ Sema::DeclPtrTy Sema::ActOnStaticAssertDeclaration(SourceLocation AssertLoc,
   return DeclPtrTy::make(Decl);
 }
 
+bool Sema::ActOnFriendDecl(Scope *S, SourceLocation FriendLoc, DeclPtrTy Dcl) {
+  if (!(S->getFlags() & Scope::ClassScope)) {
+    Diag(FriendLoc, diag::err_friend_decl_outside_class);
+    return true;
+  }
+  
+  return false;
+}
+
 void Sema::SetDeclDeleted(DeclPtrTy dcl, SourceLocation DelLoc) {
   Decl *Dcl = dcl.getAs<Decl>();
   FunctionDecl *Fn = dyn_cast<FunctionDecl>(Dcl);
diff --git a/clang/test/SemaCXX/friend.cpp b/clang/test/SemaCXX/friend.cpp
new file mode 100644
index 00000000000..76e84e5fbe8
--- /dev/null
+++ b/clang/test/SemaCXX/friend.cpp
@@ -0,0 +1,6 @@
+// RUN: clang-cc -fsyntax-only -verify %s
+
+friend class A; // expected-error {{'friend' used outside of class}}
+void f() { friend class A; } // expected-error {{'friend' used outside of class}}
+class C { friend class A; };
+class D { void f() { friend class A; } }; // expected-error {{'friend' used outside of class}}