void setGcompiler()
{
    // try a C++ compiler; if not found: try a C compiler; if not found
    // try COMPILER. 
    // Same for matching options.

#ifdef CXX
    g_compiler = setOpt(CXX, "CXX") + " " + setOpt(CXXFLAGS, "CXXFLAGS");
#else
    #ifdef CC
        g_compiler = setOpt(CC, "CC") + " " + setOpt(CFLAGS, "CFLAGS");
    #else
        #ifdef COMPILER

            #ifdef COMPILER_OPTIONS
                g_compiler = COMPILER + " " + COMPILER_OPTIONS;
            #endif

        #endif // COMPILER
    #endif // CC
#endif // CXX
}
