/*
 * Copyright (c) 2011, Chris Johns <chrisj@rtems.org> 
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
/**
 * @file
 *
 * @ingroup rtems_rld
 *
 * @brief RTEMS Linker Main manages opions, sequence of operations and exceptions.
 *
 */

#if HAVE_CONFIG_H
#include "config.h"
#endif

#include <iostream>

#include <cxxabi.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <getopt.h>

#include <rld.h>
#include <rld-gcc.h>
#include <rld-outputter.h>
#include <rld-process.h>
#include <rld-resolver.h>

#ifndef HAVE_KILL
#define kill(p,s) raise(s)
#endif

/**
 * RTEMS Linker options. This needs to be rewritten to be like gcc where only a
 * single '-' and long options is present.
 */
static struct option rld_opts[] = {
  { "help",        no_argument,            NULL,           'h' },
  { "version",     no_argument,            NULL,           'V' },
  { "verbose",     no_argument,            NULL,           'v' },
  { "warn",        no_argument,            NULL,           'w' },
  { "map",         no_argument,            NULL,           'M' },
  { "output",      required_argument,      NULL,           'o' },
  { "lib-path",    required_argument,      NULL,           'L' },
  { "lib",         required_argument,      NULL,           'l' },
  { "no-stdlibs",  no_argument,            NULL,           'n' },
  { "exec-prefix", required_argument,      NULL,           'E' },
  { "march",       required_argument,      NULL,           'a' },
  { "mcpu",        required_argument,      NULL,           'c' },
  { "entry",       required_argument,      NULL,           'e' },
  { "define",      required_argument,      NULL,           'd' },
  { "undefined",   required_argument,      NULL,           'u' },
  { "base",        required_argument,      NULL,           'b' },
  { "script",      no_argument,            NULL,           'S' },
  { NULL,          0,                      NULL,            0 }
};

#if TO_BE_USED_FOR_THE_UNDEFINES
void
split_on_equals (const std::string& opt, std::string& left, std::string& right)
{
  std::string::size_type eq = opt.find_first_of('=');
}
#endif

void
usage (int exit_code)
{
  std::cerr << "rtems-ld [-hvVdMwnS] [-e exec-prefix] [-a arch] [-c cpu] [-e entry] "
            << "[-d define] [-u undefined] [-L path] [-l libraries] [-o output] [-b base] objects"
            << std::endl;
  ::exit (exit_code);
}

static void
fatal_signal (int signum)
{
  signal (signum, SIG_DFL);

  rld::process::temporaries.clean_up ();

  /* 
   * Get the same signal again, this time not handled, so its normal effect
   * occurs.  
   */
  kill (getpid (), signum);
}

static void
setup_signals (void)
{
  if (signal (SIGINT, SIG_IGN) != SIG_IGN)
    signal (SIGINT, fatal_signal);
#ifdef SIGHUP
  if (signal (SIGHUP, SIG_IGN) != SIG_IGN)
    signal (SIGHUP, fatal_signal);
#endif
  if (signal (SIGTERM, SIG_IGN) != SIG_IGN)
    signal (SIGTERM, fatal_signal);
#ifdef SIGPIPE
  if (signal (SIGPIPE, SIG_IGN) != SIG_IGN)
    signal (SIGPIPE, fatal_signal);
#endif
#ifdef SIGCHLD
  signal (SIGCHLD, SIG_DFL);
#endif
}

int
main (int argc, char* argv[])
{
  int ec = 0;

  setup_signals ();

  try
  {
    rld::files::cache   cache;
    rld::files::cache   base;
    rld::files::paths   libpaths;
    rld::files::paths   libs;
    rld::files::paths   objects;
    rld::files::paths   libraries;
    rld::symbols::table base_symbols;
    rld::symbols::table symbols;
    rld::symbols::table undefined;
    std::string         entry;
    std::string         output = "a.out";
    std::string         base_name;
    bool                script = false;
    bool                standard_libs = true;
    bool                exec_prefix_set = false;
    bool                map = false;
    bool                warnings = false;

    libpaths.push_back (".");

    while (true)
    {
      int opt = ::getopt_long (argc, argv, "hvwVMnSb:E:o:L:l:a:c:e:d:u:", rld_opts, NULL);
      if (opt < 0)
        break;
    
      switch (opt)
      {
        case 'V':
          std::cout << "rtems-ld (RTEMS Linker) " << rld::version () 
                    << std::endl;
          ::exit (0);
          break;
        
        case 'v':
          rld::verbose_inc ();
          break;
        
        case 'M':
          map = true;
          break;

        case 'w':
          warnings = true;
          break;

        case 'o':
          if (output.size () != 0)
            std::cerr << "error: output already set" << std::endl;
          output = optarg;
          break;

        case 'S':
          script = true;
          break;

        case 'l':
          /*
           * The order is important. It is the search order.
           */
          libs.push_back (optarg);
          break;

        case 'L':
          if ((optarg[::strlen (optarg) - 1] == '/') ||
              (optarg[::strlen (optarg) - 1] == '\\'))
            optarg[::strlen (optarg) - 1] = '\0';
          libpaths.push_back (optarg);
          break;

        case 'n':
          standard_libs = false;
          break;

        case 'E':
          exec_prefix_set = true;
          rld::gcc::exec_prefix = optarg;
          break;

        case 'a':
          rld::gcc::march = optarg;
          break;

        case 'c':
          rld::gcc::mcpu = optarg;
          break;

        case 'e':
          entry = optarg;
          break;

        case 'd':
          symbols[optarg] = rld::symbols::symbol (optarg);
          break;

        case 'u':
          undefined[optarg] = rld::symbols::symbol (optarg);
          break;

        case 'b':
          base_name = optarg;
          break;

        case '?':
          usage (3);
          break;

        case 'h':
          usage (0);
          break;
      }
    }

    argc -= optind;
    argv += optind;

    if (rld::verbose () || map)
      std::cout << "RTEMS Linker " << rld::version () << std::endl;

    /*
     * If there are no object files there is nothing to link.
     */
    if ((argc == 0) && !map)
      throw rld::error ("no object files", "options");

    /*
     * Load the remaining command line arguments into the cache as object
     * files.
     */
    while (argc--)
      objects.push_back (*argv++);
    
    /*
     * Add the object files to the cache.
     */
    cache.add (objects);

    /*
     * Open the cache.
     */
    cache.open ();

    /*
     * If the exec-prefix is not set by the command line see if it can be
     * detected from the object file types. This must be after we have added
     * the object files.
     */
    if (!exec_prefix_set)
      rld::gcc::exec_prefix = rld::elf::machine_type ();

    /*
     * If we have a base image add it.
     */
    if (base_name.length ())
    {
      base.open ();
      base.add (base_name);
      base.load_symbols (base_symbols, true);
    }

    /*
     * Get the standard library paths
     */
    rld::gcc::get_standard_libpaths (libpaths);

    /*
     * Get the command line libraries.
     */
    rld::files::find_libraries (libraries, libpaths, libs);

    /*
     * Are we to load standard libraries ?
     */
    if (standard_libs)
      rld::gcc::get_standard_libs (libraries, libpaths);

    /*
     * Load the library to the cache.
     */
    cache.add_libraries (libraries);

    /*
     * Load the symbol table.
     */
    cache.load_symbols (symbols);

    /*
     * Map ?
     */
    if (map)
    {
      if (base_name.length ())
        rld::map (base, base_symbols);
      rld::map (cache, symbols);
    }

    if (cache.path_count ())
    {
      /*
       * This structure allows us to add different operations with the same
       * structure.
       */
      rld::files::object_list dependents;
      rld::resolver::resolve (dependents, cache, base_symbols, symbols, undefined);

      /**
       * Output the file.
       */
      if (script)
        rld::outputter::script (output, dependents, cache);
      else
        rld::outputter::archive (output, dependents, cache);

      /**
       * Check for warnings.
       */
      if (warnings)
      {
        rld::warn_unused_externals (dependents);
      }
    }
  }
  catch (rld::error re)
  {
    std::cerr << "error: "
              << re.where << ": " << re.what
              << std::endl;
    ec = 10;
  }
  catch (std::exception e)
  { 
    int   status;
    char* realname;
    realname = abi::__cxa_demangle (e.what(), 0, 0, &status);
    std::cerr << "error: std::exception: " << realname << " [";
    ::free (realname);
    const std::type_info &ti = typeid (e);
    realname = abi::__cxa_demangle (ti.name(), 0, 0, &status);
    std::cerr << realname << "] " << e.what () << std::endl;
    ::free (realname);
    ec = 11;
  }
  catch (...)
  { 
    /*
     * Helps to know if this happens.
     */
    std::cout << "error: unhandled exception" << std::endl;
    ec = 12;
  }

  return ec;
}