Index: include/clang/Basic/DiagnosticSemaKinds.td =================================================================== --- include/clang/Basic/DiagnosticSemaKinds.td (revision 184825) +++ include/clang/Basic/DiagnosticSemaKinds.td (working copy) @@ -4267,6 +4267,10 @@ "out-of-line definition of %0 from class %1 without definition">; def err_member_def_does_not_match : Error< "out-of-line definition of %0 does not match any declaration in %1">; +def err_friend_decl_with_def_arg_must_be_def : Error< + "friend declaration specifying a default argument must be a definition">; +def err_friend_decl_with_def_arg_redeclared : Error< + "friend declaration specifying a default argument must be the only declaration">; def err_friend_decl_does_not_match : Error< "friend declaration of %0 does not match any declaration in %1">; def err_member_def_does_not_match_suggest : Error< Index: lib/Sema/SemaDeclCXX.cpp =================================================================== --- lib/Sema/SemaDeclCXX.cpp (revision 184825) +++ lib/Sema/SemaDeclCXX.cpp (working copy) @@ -404,6 +404,15 @@ } } +static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) { + for (unsigned NumParams = FD->getNumParams(); NumParams > 0; --NumParams) { + const ParmVarDecl *PVD = FD->getParamDecl(NumParams-1); + if (PVD->hasDefaultArg() && !PVD->hasInheritedDefaultArg()) + return true; + } + return false; +} + /// MergeCXXFunctionDecl - Merge two declarations of the same C++ /// function, once we already know that they have the same /// type. Subroutine of MergeFunctionDecl. Returns true if there was an @@ -578,6 +587,18 @@ Invalid = true; } + // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default + // argument expression, that declaration shall be a deļ¬nition and shall be + // the only declaration of the function or function template in the + // translation unit. + if (!isa(Old) && + Old->getFriendObjectKind() == Decl::FOK_Undeclared && + functionDeclHasDefaultArgument(Old)) { + Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared); + Diag(Old->getLocation(), diag::note_previous_declaration); + Invalid = true; + } + if (CheckEquivalentExceptionSpec(Old, New)) Invalid = true; @@ -11377,6 +11398,18 @@ else FD = cast(ND); + // C++11 [dcl.fct.default]p4: If a friend declaration specifies a + // default argument expression, that declaration shall be a definition + // and shall be the only declaration of the function or function + // template in the translation unit. + if (!isa(FD) && functionDeclHasDefaultArgument(FD)) { + if (FunctionDecl *OldFD = FD->getPreviousDecl()) { + Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared); + Diag(OldFD->getLocation(), diag::note_previous_declaration); + } else if (!D.isFunctionDefinition()) + Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def); + } + // Mark templated-scope function declarations as unsupported. if (FD->getNumTemplateParameterLists()) FrD->setUnsupportedFriend(true); Index: test/CodeGenCXX/2004-11-27-FriendDefaultArgCrash.cpp =================================================================== --- test/CodeGenCXX/2004-11-27-FriendDefaultArgCrash.cpp (revision 184825) +++ test/CodeGenCXX/2004-11-27-FriendDefaultArgCrash.cpp (working copy) @@ -4,6 +4,6 @@ namespace nm { struct str { - friend int foo(int arg = 0); + friend void foo(int arg = 0) {}; }; } Index: test/CXX/drs/dr1xx.cpp =================================================================== --- test/CXX/drs/dr1xx.cpp (revision 184825) +++ test/CXX/drs/dr1xx.cpp (working copy) @@ -357,25 +357,33 @@ }; } -namespace dr136 { // dr136: no - void f(int, int, int = 0); - void g(int, int, int); +namespace dr136 { // dr136: yes + void f(int, int, int = 0); // expected-note {{previous declaration is here}} + void g(int, int, int); // expected-note {{previous declaration is here}} struct A { - // FIXME: These declarations of f, g, and h are invalid. - friend void f(int, int = 0, int); - friend void g(int, int, int = 0); - friend void h(int, int, int = 0); - friend void i(int, int, int = 0) {} + friend void f(int, int = 0, int); // expected-error {{friend declaration specifying a default argument must be the only declaration}} + friend void g(int, int, int = 0); // expected-error {{friend declaration specifying a default argument must be the only declaration}} + friend void h(int, int, int = 0); // expected-error {{friend declaration specifying a default argument must be a definition}} + friend void i(int, int, int = 0) {} // expected-note {{previous declaration is here}} friend void j(int, int, int = 0) {} operator int(); }; - // FIXME: This declaration of i is invalid. - void i(int, int, int); + void i(int, int, int); // expected-error {{friend declaration specifying a default argument must be the only declaration}} void q() { j(A(), A()); // ok, has default argument } - // FIXME: Also test extern "C" friends and default arguments from other - // namespaces? + extern "C" void k(int, int, int, int); // expected-note {{previous declaration is here}} + namespace NSA { + struct A { + friend void dr136::k(int, int, int, int = 0); // expected-error {{friend declaration specifying a default argument must be the only declaration}} \ + // expected-note {{previous declaration is here}} + }; + } + namespace NSB { + struct A { + friend void dr136::k(int, int, int = 0, int); // expected-error {{friend declaration specifying a default argument must be the only declaration}} + }; + } } namespace dr137 { // dr137: yes Index: test/SemaCXX/friend.cpp =================================================================== --- test/SemaCXX/friend.cpp (revision 184825) +++ test/SemaCXX/friend.cpp (working copy) @@ -44,7 +44,7 @@ // PR5134 namespace test3 { class Foo { - friend const int getInt(int inInt = 0); + friend const int getInt(int inInt = 0) {} }; }