The final program

Here is the final program, with some extra functions for modularity:

       #include <Args.h>
       #include <string.h>
       #include <osfcn.h>
   

       int compile_only = 0;
       int optimize = 0;
       int allow_anachronisms = 1;
       int profiling = 0;
       const char* output_filename = "a.out";
       int dryrun = 0;
   

       extern void add_define(const char*, const char*);
       extern void add_includedir(const char*);
       extern void align(const char*);
       extern void compile(const char*);
   

       static void
       getdefines(const Opt* opt) {
           Suboptsiter si(*opt);
           const Subopt* subopt;
           while (si.next(subopt))
               add_define(subopt->name(), subopt->value());
       }
   

       static void
       process_letter_option(const Opt* opt) {
           switch (opt->chr()) {
           case 'I':
               add_includedir(opt->value());
               break;
           case 'D':
               getdefines(opt);
               break;
           case 'c':
               compile_only = 1;
               break;
           case 'O':
               optimize = 1;
               break;
           case 'o':
               output_filename = opt->value();
               break;
           case 'p':
               if (opt->flag() == '+')
                   allow_anachronisms = 0;
               else
                   profiling = 1;
               break;
           }
       }
   

       static void
       process_option(const Opt* opt) {
           const char* key = opt->keyword();
           if (key != 0) {
               if (strcmp(key, "align") == 0)
                   align(opt->value());
               else
                   dryrun = 1;
           }
           else
               process_letter_option(opt);
       }
   

       static void
       process_nonoption_args(const Args& args) {
           Argsiter ai(args);
           const char* filename;
           while (ai.next(filename))
               compile(filename);
       }
   

       const char* keywords[] = {
           "dryrun",
           "align:",
           0
       };
   

       main(int argc, const char*const* argv) {
           Args args(argc, argv, "co:OI:D;p",
               Args::intermix | Args::plusoptions,
               keywords);
           if (args.error())
               exit(1);
           Optsiter oi(args);
           const Opt* opt;
           while (oi.next(opt))
               process_option(opt);
           process_nonoption_args(args);
       }