ef53355355
<https://gerrit.libreoffice.org/c/core/+/144139> "New loplugin:unocast" had argued that uses of dynamic_cast from a UNO interface type are broken in general (because if the source object is a proxy from the C*+ UNO bridge, its vtable's RTTI slot will normally not be set up, which can cause a crash), and should be replaced with uses of XUnoTunnel. Which the various recent "loplugin:unocast (...)" commits started to do. However, it became clear that that is not the most ideal way forward: For one, getting more and more implementations of XUnoTunnel::getSomething into existing class hierarchies is error prone, as each such implementation must manually delegate to all its base class implementations. For another, uses of comphelper::getFromUnoTunnel (which often needs to do a queryInterface to XUnoTunnel first) are easily more expensive than uses of dynamic_cast. Thanks to Noel, the insight here is that for the use case of a dynamic_cast from a UNO interface type to a local C++ class type, and if the source object is a proxy, it is sufficient that the dynamic_cast will not crash. It will necessarily always return null (as the proxy will never be the implementation of a local C++ class type), so it is sufficient to fill the RTTI slots of the proxies' vtables with dummy values. That avoids having to set up proper RTTI for those potentially multiple-inheritance proxy types. (And with this in place, all those recent "loplugin:unocast (...)" commits can be reverted again in a next step.) I verified the changes for the gcc3_linux_aarch64 (on macOS), gcc3_linux_intel, gcc3_linux_x86-64, gcc3_macosx_x86-64, msvc_win32_intel, and msvc_win32_x86-64 bridges. The changes for all the other bridges were done blindly. (For gcc3_linux_x86-64, which already conditionally supported proper RTTI for UBSan, setting the offset-to-top slot to non-zero had to be made conditional too, as the dummy ProxyRtti will always pretend to be a full class rather than a potential base class that could have a non-zero offset-to-top value. For msvc_win32_*, it turned out that the existing code to set up dummy XInterface RTTI (which was there for reasons lost to history) was broken.) Change-Id: Iec4b8067d26b14b6fb02c2fdd15e1eee20919590 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/145038 Tested-by: Jenkins Reviewed-by: Stephan Bergmann <sbergman@redhat.com> |
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| .. | ||
| inc | ||
| source | ||
| CustomTarget_gcc3_linux_arm.mk | ||
| Jar_java_uno.mk | ||
| Library_cpp_uno.mk | ||
| Library_java_uno.mk | ||
| Makefile | ||
| Module_bridges.mk | ||
| Package_jnilib_java_uno.mk | ||
| README.md | ||
UNO Bridges
Bridges from various C++ ABIs, Java JNI, MS .NET to UNO and back. A bridge for .NET is in
cli_ure.
Also implementation of the UNO Remote Protocol.