Netbeans shows error for unix system call "getcontext"

I'm currently implementing a threading lib开发者_高级运维rary in linux (my OS is ubuntu natty). I'm using netbeans to do the project. I have to include the header ucontext.h, and have to call the unix system calls getcontext(), setcontext(), makecontext() and swapcontext(). The header is included fine and I'm able to use its structures like ucontext_t. But when I make a call to getcontext() or any of those functions, netbeans highlights them showing error

 unable to resolve identifier getcontext

However I was able to build and run the project. But I want to eliminate this error that is annoying, because it would be difficult for me to debug the code later on. Is there any way to make netbeans identify these system calls? Thank you very much.

Your problem sounds similar to the problem discussed on this blog. Is Netbeans finding the include directories?