Fix gcc 2.95.3 Type Info Functions

[bonefish]

Currently the type info functions for __si_type_info and __class_type_info generated by gcc 2.95.3 are calling the base class(es) type info function(s), but instead of using the return value, refer to the base class type info(s) separately. This can cause problems with shared objects generated by older compilers (e.g. the BDirectWindow type info in libgame.so), since they can contain a type info without a type info function and a type info function of a library loaded later could therefore use the uninitialized one from the old library.

A fact contributing to the problem is that everything is linked with -Bsymbolic (thus disabling symbol preemption), which makes a type info function always initialize and return the type info defined in the same shared library instead of one defined in a library loaded earlier.

The place where to fix the bug is gcc/cp/rtti.c. expand_si_desc() is responsible for creating __si_type_info and expand_class_desc() for __class_type_info type info functions.

The naive approach to move the "get_typeid_1(type)" into the "elems" initialization in expand_si_desc() doesn't work, BTW.

[scottmc]

Was this worked on in the recent gcc update?

[bonefish]

Replying to scottmc:

Was this worked on in the recent gcc update?

Nope.

[bonefish]

#6963 is another instance of this problem.