optimization - How can I force GCC to compile functions that are not used?

Question

I am splitting off some of the code in my project into a separate library to be reused in another application. This new library has various functions defined but not implemented, and both my current project and the other application will implement their own versions of these functions.

I implemented these functions in my original project, but they are not called anywhere inside it. They are only called by this new library. As a result, the compiler optimizes them away, and I get linking failures. When I add a dummy call to these functions, the linking failures disappear.

Is there any way to tell GCC to compile these functions even if they're not being called?

I am compiling with gcc 4.2.2 using -O2 on SuSE linux (x86-64_linux_2.6.5_ImageSLES9SP3-3).

Answer 1

You could try __attribute__ ((used)) - see Declaring Attributes of Functions in the gcc manual.