diff options
author | Stephan Bergmann <sbergman@redhat.com> | 2022-12-02 17:01:02 +0100 |
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committer | Stephan Bergmann <sbergman@redhat.com> | 2022-12-03 07:09:38 +0000 |
commit | 485c9d4f0e59e13e772da8f8a7975f0ddd77c33e (patch) | |
tree | 49771712d9488167ba69184e494eaafb470fad9b /codemaker/source | |
parent | 8f34b0d40e149b7274a1aa4ce0b33ddbf825ee52 (diff) |
Clarify the use of untools::WeakReference
...which had been introduced in 78040af9acea0ab681aa54ff23844b647bc9b4f3
"loplugin:refcounting in sc" as a variation on css::uno::WeakReference from
include/cppuhelper/weakref.hxx, but without giving much of a rationale.
And, at least for --with-latest-c++ builds using a capable C++20 compiler,
ensure that the given interface_type is such that the static_cast and
dynamic_cast in the implementation of unotools::WeakReference::get are actually
sound: If interface_type could be a UNO interface type, that would imply that
the xInterface obtained from the underlying WeakReferenceHelper::get() could be
a proxy from the C++ UNO bridge, which could (a) be a proxy for only a subtype
of interface_type (e.g., just for XInterface), so that the static_cast would be
broken, and (b) be a proxy for which the vtable's RTTI slot is not set up (see
e.g. the ENABLE_RUNTIME_OPTIMIZATIONS code in
bridges::cpp_uno::shared::VtableFactory::initializeBlock in
bridges/source/cpp_uno/gcc3_linux_x86-64/cpp2uno.cxx), so that the dynamic_cast
could crash. (These issues can even happen when the given interface_type is a
C++ implementation class type, but the given object has been bridged over some
C++ to C++ UNO ("purpose") bridge, but lets leave it at that...)
This required adding some cppu::detail::isUnoInterfaceType predicate to the
include files generated by cppumaker, which can be useful in other places too.
(For the call to isUnoInterfaceType in the requires-clause of
unotools::WeakReference<interface_type>::get to give the correct answer, it is
important that interface_type is a complete type---i.e., the corresponding
codemaker-generated .hpp having been included if interface_type actually were a
UNO include type. But that is already nicely required by the call to
std::is_convertible_v in the implementation of that function, anyway.)
Change-Id: Ia5efd70085d2d6d45fa0995d00dc8def564bbe5f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/143601
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Diffstat (limited to 'codemaker/source')
-rw-r--r-- | codemaker/source/cppumaker/cpputype.cxx | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/codemaker/source/cppumaker/cpputype.cxx b/codemaker/source/cppumaker/cpputype.cxx index 03fcd033beca..2c8f938e6bb1 100644 --- a/codemaker/source/cppumaker/cpputype.cxx +++ b/codemaker/source/cppumaker/cpputype.cxx @@ -1184,7 +1184,7 @@ void InterfaceType::dumpHppFile( out << "\n"; addDefaultHxxIncludes(includes); includes.dump(out, &name_, !(m_cppuTypeLeak || m_cppuTypeDynamic)); - out << "\n"; + out << "\n#if defined LIBO_INTERNAL_ONLY\n#include <type_traits>\n#endif\n\n"; dumpGetCppuType(out); out << "\n::css::uno::Type const & " << codemaker::cpp::scopedCppName(u2b(name_)) @@ -1194,7 +1194,15 @@ void InterfaceType::dumpHppFile( dumpType(out, name_, false, false, true); out << " >::get();\n"; dec(); - out << "}\n\n#endif // "<< headerDefine << "\n"; + out << "}\n\n#if defined LIBO_INTERNAL_ONLY\nnamespace cppu::detail {\n"; + if (name_ == "com.sun.star.uno.XInterface") { + out << "template<typename> struct IsUnoInterfaceType: ::std::false_type {};\n" + "template<typename T> inline constexpr auto isUnoInterfaceType =" + " IsUnoInterfaceType<T>::value;\n"; + } + out << "template<> struct IsUnoInterfaceType<"; + dumpType(out, name_, false, false, true); + out << ">: ::std::true_type {};\n}\n#endif\n\n#endif // "<< headerDefine << "\n"; } void InterfaceType::dumpAttributes(FileStream & out) const |