That is not what I get. I am using CodeBlocks 12.11 on Ubuntu 13.04. If I set the parameter "-help" in the Debugger settings, I get the following result in the debugger console:
Starting debugger: /usr/bin/gdb -nx -fullname -quiet -help -args /home/dev/Linux/Debug64/tool
The parameter is passed to the debugger, not to the target.
(See the attached screen shot of the debugger settings.)