quote: When gcc 3.x compiles a C++ constructor or C++ destructor, it generates 2 or 3 different versions of the object code. These versions have unique mangled names (they have to, in order for linking to work), but they have identical source code names, which leads to a great deal of confusion. Specifically, if you set a breakpoint in a constructor or a destructor, gdb will put a breakpoint in one of the versions, but your program may execute the other version. This makes it impossible to set breakpoints reliably in constructors or destructors. gcc 3.x generates these multiple object code functions in order to implement virtual base classes. gcc 2.x generated just one object code function with a hidden parameter, but gcc 3.x conforms to a multi-vendor ABI for C++ which requires multiple object code functions.