// For a class that has a vtable (and hence, also has a typeinfo symbol for // RTTI), if a user marks either: // // (a) the entire class as dllexport (dllimport), or // (b) all non-inline virtual methods of the class as dllexport (dllimport) // // then Clang must export the vtable and typeinfo symbol from the TU where they // are defined (the TU containing the definition of the Itanium C++ ABI "key // function"), and must import them in other modules where they are referenced. // // Conversely to point (b), if some (but not all) of the non-inline virtual // methods of a class are marked as dllexport (dllimport), then the vtable and // typeinfo symbols must not be exported (imported). This will result in a // link-time failure when linking the importing module. This link-time failure // is the desired behavior, because the Microsoft toolchain also gets a // link-time failure in these cases (and since __declspec(dllexport) // (__declspec(dllimport)) is a Microsoft extension, our intention is to mimic // that Microsoft behavior). // // Side note: It is within the bodies of constructors (and in some cases, // destructors) that the vtable is explicitly referenced. In case (a) above, // where the entire class is exported (imported), then all constructors (among // other things) are exported (imported). So for that situation, an importing // module for a well-formed program will not actually reference the vtable, // since constructor calls will all be to functions external to that module // (and imported into it, from the exporting module). I.e., all vtable // references will be in that module where the constructor and destructor // bodies are, therefore, there will not be a need to import the vtable in // that case. // // This test contains 6 test classes: // 2 for point (a), // 2 for point (b), // and 2 negative tests for the converse of point (b). // // The two tests for each of these points are one for importing, and one for // exporting. // RUN: %clang_cc1 -I%S -fdeclspec -triple x86_64-unknown-windows-itanium -emit-llvm -o - %s -fhalf-no-semantic-interposition | FileCheck %s -check-prefix=WI // RUN: %clang_cc1 -I%S -fdeclspec -triple x86_64-scei-windows-itanium -emit-llvm -o - %s -fhalf-no-semantic-interposition | FileCheck %s --check-prefixes=PS4,SCEI_WI // RUN: %clang_cc1 -I%S -fdeclspec -triple x86_64-scei-ps4 -emit-llvm -o - %s -fhalf-no-semantic-interposition | FileCheck %s --check-prefixes=PS4,SCEI_PS4 // RUN: %clang_cc1 -I%S -fdeclspec -triple x86_64-sie-ps5 -emit-llvm -o - %s -fhalf-no-semantic-interposition | FileCheck %s --check-prefixes=PS4,SCEI_PS4 #include // Case (a) -- Import Aspect // The entire class is imported. The typeinfo symbol must also be imported, // but the vtable will not be referenced, and so does not need to be imported // (as described in the "Side note", above). // // PS4-DAG: @_ZTI10FullImport = {{.*}}dllimport // WI-DAG: @_ZTI10FullImport = external dllimport constant ptr struct __declspec(dllimport) FullImport { virtual void getId() {} virtual void Bump(); virtual void Decrement(); }; // 'FullImport::Bump()' is the key function, so the vtable and typeinfo symbol // of 'FullImport' will be defined in the TU that contains the definition of // 'Bump()' (and they must be exported from there). void FullImportTest() { typeid(FullImport).name(); } /////////////////////////////////////////////////////////////////// // Case (a) -- Export Aspect // The entire class is exported. The vtable and typeinfo symbols must also be // exported, // // PS4-DAG: @_ZTV10FullExport ={{.*}}dllexport // WI-DAG: @_ZTV10FullExport ={{.*}}dllexport // PS4-DAG: @_ZTI10FullExport ={{.*}}dllexport // WI-DAG: @_ZTI10FullExport = dso_local dllexport constant { struct __declspec(dllexport) FullExport // Easy case: Entire class is exported. { virtual void getId() {} virtual void Bump(); virtual void Decrement(); }; // This is the key function of the class 'FullExport', so the vtable and // typeinfo symbols of 'FullExport' will be defined in this TU, and so they // must be exported from this TU. void FullExport::Bump() { typeid(FullExport).name(); } /////////////////////////////////////////////////////////////////// // Case (b) -- Import Aspect // The class as a whole is not imported, but all non-inline virtual methods of // the class are, so the vtable and typeinfo symbol must be imported. // // PS4-DAG: @_ZTV9FooImport ={{.*}}dllimport // WI-DAG: @_ZTV9FooImport = linkonce_odr dso_local unnamed_addr constant { // PS4-DAG: @_ZTI9FooImport ={{.*}}dllimport // WI-DAG: @_ZTI9FooImport = linkonce_odr dso_local constant { struct FooImport { virtual void getId() const {} __declspec(dllimport) virtual void Bump(); __declspec(dllimport) virtual void Decrement(); }; // 'FooImport::Bump()' is the key function, so the vtable and typeinfo symbol // of 'FooImport' will be defined in the TU that contains the definition of // 'Bump()' (and they must be exported from there). Here, we will reference // the vtable and typeinfo symbol, so we must also import them. void importTest() { typeid(FooImport).name(); } /////////////////////////////////////////////////////////////////// // Case (b) -- Export Aspect // The class as a whole is not exported, but all non-inline virtual methods of // the class are, so the vtable and typeinfo symbol must be exported. // // PS4-DAG: @_ZTV9FooExport ={{.*}}dllexport // WI-DAG: @_ZTV9FooExport = dso_local unnamed_addr constant { // PS4-DAG: @_ZTI9FooExport ={{.*}}dllexport // WI-DAG: @_ZTI9FooExport = dso_local constant { struct FooExport { virtual void getId() const {} __declspec(dllexport) virtual void Bump(); __declspec(dllexport) virtual void Decrement(); }; // This is the key function of the class 'FooExport', so the vtable and // typeinfo symbol of 'FooExport' will be defined in this TU, and so they must // be exported from this TU. void FooExport::Bump() { FooImport f; typeid(FooExport).name(); } /////////////////////////////////////////////////////////////////// // The tests below verify that the associated vtable and typeinfo symbols are // not imported/exported. These are the converse of case (b). // // Note that ultimately, if the module doing the importing calls a constructor // of the class with the vtable, or makes a reference to the typeinfo symbol of // the class, then this will result in an unresolved reference (to the vtable // or typeinfo symbol) when linking the importing module, and thus a link-time // failure. // // Note that with the Microsoft toolchain there will also be a link-time // failure when linking the module doing the importing. With the Microsoft // toolchain, it will be an unresolved reference to the method 'Decrement()' // of the approriate class, rather than to the vtable or typeinfo symbol of // the class, because Microsoft defines the vtable and typeinfo symbol (weakly) // everywhere they are used. // Converse of case (b) -- Import Aspect // The class as a whole is not imported, and not all non-inline virtual methods // are imported, so the vtable and typeinfo symbol are not to be imported. // // CHECK-PS4: @_ZTV11FooNoImport = external dso_local unnamed_addr constant { // CHECK-WI: @_ZTV11FooNoImport = linkonce_odr dso_local unnamed_addr constant { // CHECK-PS4: @_ZTI11FooNoImport = external dso_local constant ptr{{$}} // CHECK-WI: @_ZTI11FooNoImport = linkonce_odr dso_local constant { struct FooNoImport { virtual void getId() const {} __declspec(dllimport) virtual void Bump(); virtual void Decrement(); // Not imported. int mCounter; }; void importNegativeTest() { FooNoImport f; typeid(FooNoImport).name(); } /////////////////////////////////////////////////////////////////// // Converse of case (b) -- Export Aspect // The class as a whole is not exported, and not all non-inline virtual methods // are exported, so the vtable and typeinfo symbol are not to be exported. // // SCEI_PS4-DAG: @_ZTV11FooNoImport = external unnamed_addr constant { // SCEI_WI-DAG: @_ZTV11FooNoExport = dso_local unnamed_addr constant { // WI-DAG: @_ZTV11FooNoExport = dso_local unnamed_addr constant { // SCEI_PS4-DAG: @_ZTI11FooNoExport = constant { // SCEI_WI-DAG: @_ZTI11FooNoExport = dso_local constant { // WI-DAG: @_ZTI11FooNoExport = dso_local constant { struct FooNoExport { virtual void getId() const {} __declspec(dllexport) virtual void Bump(); virtual void Decrement(); // Not exported. int mCounter; }; void FooNoExport::Bump() { typeid(FooNoExport).name(); }