gold/main.cc

   1 // main.cc -- gold main function.
   2
   3 // Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstdio>
  26 #include <cstring>
  27
  28 #ifdef HAVE_MALLINFO
  29 #include <malloc.h>
  30 #endif
  31
  32 #include "libiberty.h"
  33
  34 #include "script.h"
  35 #include "options.h"
  36 #include "parameters.h"
  37 #include "errors.h"
  38 #include "mapfile.h"
  39 #include "dirsearch.h"
  40 #include "workqueue.h"
  41 #include "object.h"
  42 #include "archive.h"
  43 #include "symtab.h"
  44 #include "layout.h"
  45 #include "plugin.h"
  46
  47 using namespace gold;
  48
  49 // This function emits the commandline to a hard-coded file in temp.
  50 // This is useful for debugging since ld is typically invoked by gcc,
  51 // so its commandline is not always easy to extract.  You should be
  52 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  53 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  54 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  55 // (or whatever value the environment variable GDB is set to), for
  56 // even easier debugging.  Since this is a debugging-only tool, and
  57 // creates files, it is only turned on when the user explicitly asks
  58 // for it, by compiling with -DDEBUG.  Do not do this for release
  59 // versions of the linker!
  60
  61 #ifdef DEBUG
  62 #include <stdio.h>
  63 #include <sys/stat.h>    // for chmod()
  64
  65 static std::string
  66 collect_argv(int argc, char** argv)
  67 {
  68   // This is used by write_debug_script(), which wants the unedited argv.
  69   std::string args;
  70   for (int i = 0; i < argc; ++i)
  71     {
  72       args.append(" '");
  73       // Now append argv[i], but with all single-quotes escaped
  74       const char* argpos = argv[i];
  75       while (1)
  76         {
  77           const int len = strcspn(argpos, "'");
  78           args.append(argpos, len);
  79           if (argpos[len] == '\0')
  80             break;
  81           args.append("'\"'\"'");
  82           argpos += len + 1;
  83         }
  84       args.append("'");
  85     }
  86   return args;
  87 }
  88
  89 static void
  90 write_debug_script(std::string filename_str,
  91                    const char* argv_0, const char* args)
  92 {
  93   size_t slash = filename_str.rfind('/');
  94   if (slash != std::string::npos)
  95     filename_str = filename_str.c_str() + slash + 1;
  96   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
  97   const char* filename = filename_str.c_str();
  98   FILE* fp = fopen(filename, "w");
  99   if (fp)
 100     {
 101       fprintf(fp, "[ \"$1\" = debug ]"
 102               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
 103               " && shift\n",
 104               argv_0);
 105       fprintf(fp, "$PREFIX%s $*\n", args);
 106       fclose(fp);
 107       chmod(filename, 0755);
 108     }
 109   else
 110     filename = "[none]";
 111   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 112   fflush(stderr);
 113 }
 114
 115 #else // !defined(DEBUG)
 116
 117 static inline std::string
 118 collect_argv(int, char**)
 119 {
 120   return "";
 121 }
 122
 123 static inline void
 124 write_debug_script(std::string, const char*, const char*)
 125 {
 126 }
 127
 128 #endif // !defined(DEBUG)
 129
 130
 131 int
 132 main(int argc, char** argv)
 133 {
 134 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 135   setlocale (LC_MESSAGES, "");
 136 #endif
 137 #if defined (HAVE_SETLOCALE)
 138   setlocale (LC_CTYPE, "");
 139 #endif
 140   bindtextdomain (PACKAGE, LOCALEDIR);
 141   textdomain (PACKAGE);
 142
 143   program_name = argv[0];
 144
 145   // In libiberty; expands @filename to the args in "filename".
 146   expandargv(&argc, &argv);
 147
 148   // This is used by write_debug_script(), which wants the unedited argv.
 149   std::string args = collect_argv(argc, argv);
 150
 151   Errors errors(program_name);
 152
 153   // Initialize the global parameters, to let random code get to the
 154   // errors object.
 155   set_parameters_errors(&errors);
 156
 157   // Handle the command line options.
 158   Command_line command_line;
 159   command_line.process(argc - 1, const_cast<const char**>(argv + 1));
 160
 161   long start_time = 0;
 162   if (command_line.options().stats())
 163     start_time = get_run_time();
 164
 165   // Store some options in the globally accessible parameters.
 166   set_parameters_options(&command_line.options());
 167
 168   // Do this as early as possible (since it prints a welcome message).
 169   write_debug_script(command_line.options().output_file_name(),
 170                      program_name, args.c_str());
 171
 172   // If the user asked for a map file, open it.
 173   Mapfile* mapfile = NULL;
 174   if (command_line.options().user_set_Map())
 175     {
 176       mapfile = new Mapfile();
 177       if (!mapfile->open(command_line.options().Map()))
 178         {
 179           delete mapfile;
 180           mapfile = NULL;
 181         }
 182     }
 183
 184   // The GNU linker ignores version scripts when generating
 185   // relocatable output.  If we are not compatible, then we break the
 186   // Linux kernel build, which uses a linker script with -r which must
 187   // not force symbols to be local.  It would actually be useful to
 188   // permit symbols to be forced local with -r, though, as it would
 189   // permit some linker optimizations.  Perhaps we need yet another
 190   // option to control this.  FIXME.
 191   if (parameters->options().relocatable())
 192     command_line.script_options().version_script_info()->clear();
 193
 194   // Load plugin libraries.
 195   if (command_line.options().has_plugins())
 196     command_line.options().plugins()->load_plugins();
 197
 198   // The work queue.
 199   Workqueue workqueue(command_line.options());
 200
 201   // The list of input objects.
 202   Input_objects input_objects;
 203
 204   // The symbol table.  We're going to guess here how many symbols
 205   // we're going to see based on the number of input files.  Even when
 206   // this is off, it means at worst we don't quite optimize hashtable
 207   // resizing as well as we could have (perhap using more memory).
 208   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 209                       command_line.version_script());
 210
 211   // The layout object.
 212   Layout layout(command_line.options(), &command_line.script_options());
 213
 214   // Get the search path from the -L options.
 215   Dirsearch search_path;
 216   search_path.initialize(&workqueue, &command_line.options().library_path());
 217
 218   // Queue up the first set of tasks.
 219   queue_initial_tasks(command_line.options(), search_path,
 220                       command_line, &workqueue, &input_objects,
 221                       &symtab, &layout, mapfile);
 222
 223   // Run the main task processing loop.
 224   workqueue.process(0);
 225
 226   if (command_line.options().stats())
 227     {
 228       long run_time = get_run_time() - start_time;
 229       fprintf(stderr, _("%s: total run time: %ld.%06ld seconds\n"),
 230               program_name, run_time / 1000000, run_time % 1000000);
 231 #ifdef HAVE_MALLINFO
 232       struct mallinfo m = mallinfo();
 233       fprintf(stderr, _("%s: total space allocated by malloc: %d bytes\n"),
 234               program_name, m.arena);
 235 #endif
 236       File_read::print_stats();
 237       Archive::print_stats();
 238       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 239               program_name, static_cast<long long>(layout.output_file_size()));
 240       symtab.print_stats();
 241       layout.print_stats();
 242     }
 243
 244   if (mapfile != NULL)
 245     mapfile->close();
 246
 247   // Issue defined symbol report.
 248   if (command_line.options().user_set_print_symbol_counts())
 249     input_objects.print_symbol_counts(&symtab);
 250
 251   if (parameters->options().fatal_warnings()
 252       && errors.warning_count() > 0
 253       && errors.error_count() == 0)
 254     gold_error("treating warnings as errors");
 255
 256   // If the user used --noinhibit-exec, we force the exit status to be
 257   // successful.  This is compatible with GNU ld.
 258   gold_exit(errors.error_count() == 0
 259             || parameters->options().noinhibit_exec());
 260 }