-qrtti, -fno-rtti (-qnortti) (C++ only)

Purpose

Generates runtime type identification (RTTI) information for exception handling and for use by the typeid and dynamic_cast operators.


        .-rtti---.   
>>- -q--+-nortti-+---------------------------------------------><


>>- -f--no-rtti------------------------------------------------><

-qrtti

For improved runtime performance, suppress RTTI information generation with the -fno-rtti (-qnortti) setting.

You should be aware of the following effects when specifying the -qrtti compiler option:

Contents of the virtual function table will be different when -qrtti is specified.
When linking objects together, all corresponding source files must be compiled with the correct -qrtti option specified.
If you compile a library with mixed objects (-qrtti specified for some objects, -fno-rtti (-qnortti) specified for others), you may get an undefined symbol error.

__GXX_RTTI is predefined to a value of 1 when -qrtti is in effect; otherwise, it is undefined.
__NO_RTTI__ is defined to 1 when -fno-rtti (-qnortti) is in effect; otherwise, it is undefined.
__RTTI_ALL__ is defined to 1 when -qrtti is in effect; otherwise, it is undefined.
__RTTI_DYNAMIC_CAST__ is predefined to a value of 1 when -qrtti is in effect; otherwise, it is undefined.
__RTTI_TYPE_INFO__ is predefined to a value of 1 when -qrtti is in effect; otherwise, it is undefined.