1 files changed, 70 insertions, 9 deletions
diff --git a/bridges/source/cpp_uno/msvc_win32_intel/cpp2uno.cxx b/bridges/source/cpp_uno/msvc_win32_intel/cpp2uno.cxx
index 0908c7666b50..577c318c5767 100644
--- a/bridges/source/cpp_uno/msvc_win32_intel/cpp2uno.cxx
+++ b/bridges/source/cpp_uno/msvc_win32_intel/cpp2uno.cxx
@@ -18,6 +18,10 @@
  */
 
 
+#include <sal/config.h>
+
+#include <typeinfo>
+
 #include <malloc.h>
 
 #include <com/sun/star/uno/genfunc.hxx>
@@ -124,23 +128,80 @@ std::size_t bridges::cpp_uno::shared::VtableFactory::getBlockSize(
     return (slotCount + 1) * sizeof (Slot) + slotCount * codeSnippetSize;
 }
 
+namespace {
+
+// Some dummy type whose RTTI is used in the synthesized proxy vtables to make uses of dynamic_cast
+// on such proxy objects not crash:
+struct ProxyRtti {};
+
+// The following vtable RTTI data is based on how the code at
+// <https://github.com/llvm/llvm-project/blob/main/clang/lib/CodeGen/MicrosoftCXXABI.cpp> computes
+// such data:
+
+struct RttiClassHierarchyDescriptor;
+
+#pragma warning (push)
+#pragma warning (disable: 4324) // "structure was padded due to alignment specifier"
+
+struct alignas(16) RttiBaseClassDescriptor {
+    sal_uInt32 n0 = reinterpret_cast<sal_uInt32>(&typeid(ProxyRtti));
+    sal_uInt32 n1 = 0;
+    sal_uInt32 n2 = 0;
+    sal_uInt32 n3 = 0xFFFFFFFF;
+    sal_uInt32 n4 = 0;
+    sal_uInt32 n5 = 0x40;
+    sal_uInt32 n6;
+    RttiBaseClassDescriptor(RttiClassHierarchyDescriptor const * chd):
+        n6(reinterpret_cast<sal_uInt32>(chd)) {}
+};
+
+struct alignas(4) RttiBaseClassArray {
+    sal_uInt32 n0;
+    sal_uInt32 n1 = 0;
+    RttiBaseClassArray(RttiBaseClassDescriptor const * bcd): n0(reinterpret_cast<sal_uInt32>(bcd))
+    {}
+};
+
+struct alignas(4) RttiClassHierarchyDescriptor {
+    sal_uInt32 n0 = 0;
+    sal_uInt32 n1 = 0;
+    sal_uInt32 n2 = 1;
+    sal_uInt32 n3;
+    RttiClassHierarchyDescriptor(RttiBaseClassArray const * bca):
+        n3(reinterpret_cast<sal_uInt32>(bca)) {}
+};
+
+struct alignas(16) RttiCompleteObjectLocator {
+    sal_uInt32 n0 = 0;
+    sal_uInt32 n1 = 0;
+    sal_uInt32 n2 = 0;
+    sal_uInt32 n3 = reinterpret_cast<sal_uInt32>(&typeid(ProxyRtti));
+    sal_uInt32 n4;
+    RttiCompleteObjectLocator(RttiClassHierarchyDescriptor const * chd):
+        n4(reinterpret_cast<sal_uInt32>(chd)) {}
+};
+
+struct Rtti {
+    RttiBaseClassDescriptor bcd;
+    RttiBaseClassArray bca;
+    RttiClassHierarchyDescriptor chd;
+    RttiCompleteObjectLocator col;
+    Rtti(): bcd(&chd), bca(&bcd), chd(&bca), col(&chd) {}
+};
+
+#pragma warning (pop)
+
+}
+
 bridges::cpp_uno::shared::VtableFactory::Slot *
 bridges::cpp_uno::shared::VtableFactory::initializeBlock(
     void * block, sal_Int32 slotCount, sal_Int32,
     typelib_InterfaceTypeDescription *)
 {
-    struct Rtti {
-        sal_Int32 n0, n1, n2;
-        type_info * rtti;
-        Rtti():
-            n0(0), n1(0), n2(0),
-            rtti(RTTInfos::get("com.sun.star.uno.XInterface"))
-        {}
-    };
     static Rtti rtti;
 
     Slot * slots = mapBlockToVtable(block);
-    slots[-1].fn = &rtti;
+    slots[-1].fn = &rtti.col;
     return slots + slotCount;
 }