“Unresolved inclusion” error with Eclipse CDT for C standard library headers

Question

I set up CDT for eclipse and wrote a simple hello world C program:

#include 

int main(void){
    puts(\"Hello, world.\");
    return 0;
}
         


        

Answer 1

Normally, Eclipse should be able to automatically resolve the standard include files. It does this by calling gcc and asking its configuration. Most likely Eclipse is not finding your gcc (or at least not the version you use for compiling).

Instead of specifying all the standard include paths in project settings, you probably want to make sure Eclipse finds gcc. Add the directory where gcc is found to PATH environment variable before starting Eclipse.

If you want different projects to use different compilers, then you might want to tweak the discovery options. These are hidden by default, so first enable them from Window > Preferences > C/C++ > Property Pages Settings > Display "Discovery Options" page. Then you can find them under C/C++ Build > Discovery Options in project properties.