On 14/12/2022 13:19, Stephan Bergmann wrote:
On 02/03/2012 15:45, Stephan Bergmann wrote:
I've never given much thought to dynamic_cast vs. XUnoTunnel (at least
I don't remember right now I ever did; searching old mail archives
would probably prove me wrong) -- to me XUnoTunnel was always that
rarely needed hack where the notational overhead doesn't really hurt.
But sure, for the UNO wrappers in the application layers things look
different. Anyway, thinking about it now, I see no reason one could
not use dynamic_cast instead of XUnoTunnel in the scenario outlined
above.
Took me ten years to find the reason again why XUnoTunnel cannot be
replaced with dynamic_cast, in general. :) See
<https://gerrit.libreoffice.org/c/core/+/144139> "New loplugin:unocast":
"Find uses of dynamic_cast that cast from a UNO interface type. Unless
it is known that the dynamic_cast must succeed, it can cause a crash:
If the source object is a proxy from the C++ UNO bridge, its vtable's
RTTI slot will normally not be 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)."
...but
<https://git.libreoffice.org/core/+/ef533553559fe09b4afab651fc692885d1acf4ed%5E%21>
"Rudimentary support for dynamic_cast on UNO proxy objects" to the rescue :)
