real.cpp

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// Copyright Vladimir Prus 2002-2004.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)


#include <boost/program_options.hpp>
using namespace boost::program_options;

#include <iostream>
using namespace std;

/* Auxiliary functions for checking input for validity. */

/* Function used to check that 'opt1' and 'opt2' are not specified
   at the same time. */
void conflicting_options(const variables_map& vm, 
                         const char* opt1, const char* opt2)
{
    if (vm.count(opt1) && !vm[opt1].defaulted() 
        && vm.count(opt2) && !vm[opt2].defaulted())
        throw logic_error(string("Conflicting options '") 
                          + opt1 + "' and '" + opt2 + "'.");
}

/* Function used to check that of 'for_what' is specified, then
   'required_option' is specified too. */
void option_dependency(const variables_map& vm,
                        const char* for_what, const char* required_option)
{
    if (vm.count(for_what) && !vm[for_what].defaulted())
        if (vm.count(required_option) == 0 || vm[required_option].defaulted())
            throw logic_error(string("Option '") + for_what 
                              + "' requires option '" + required_option + "'.");
}

int main(int argc, char* argv[])
{
    try {
        string ofile;
        string macrofile, libmakfile;
        bool t_given = false;
        bool b_given = false;
        string mainpackage;
        string depends = "deps_file";
        string sources = "src_file";
        string root = ".";

        options_description desc("Allowed options");
        desc.add_options()
        // First parameter describes option name/short name
        // The second is parameter to option
        // The third is description
        ("help,h", "print usage message")
        ("output,o", value(&ofile), "pathname for output")
        ("macrofile,m", value(&macrofile), "full pathname of macro.h")
        ("two,t", bool_switch(&t_given), "preprocess both header and body")
        ("body,b", bool_switch(&b_given), "preprocess body in the header context")
        ("libmakfile,l", value(&libmakfile), 
             "write include makefile for library")
        ("mainpackage,p", value(&mainpackage), 
             "output dependency information")
        ("depends,d", value(&depends), 
         "write dependencies to <pathname>")
        ("sources,s", value(&sources), "write source package list to <pathname>")
        ("root,r", value(&root), "treat <dirname> as project root directory")
        ;
    
        variables_map vm;
        store(parse_command_line(argc, argv, desc), vm);

        if (vm.count("help")) {  
            cout << desc << "\n";
            return 0;
        }

        conflicting_options(vm, "output", "two");
        conflicting_options(vm, "output", "body");
        conflicting_options(vm, "output", "mainpackage");
        conflicting_options(vm, "two", "mainpackage");
        conflicting_options(vm, "body", "mainpackage");

        conflicting_options(vm, "two", "body");
        conflicting_options(vm, "libmakfile", "mainpackage");
        conflicting_options(vm, "libmakfile", "mainpackage");

        option_dependency(vm, "depends", "mainpackage");
        option_dependency(vm, "sources", "mainpackage");
        option_dependency(vm, "root", "mainpackage");

        cout << "two = " << vm["two"].as<bool>() << "\n";
    }
    catch(exception& e) {
        cerr << e.what() << "\n";
    }
}