...which had been introduced in 78040af9ac
"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>
Stephan Bergmann
485c9d4f0e