gold/main.cc

   1 // main.cc -- gold main function.
   2
   3 // Copyright 2006, 2007, 2008, 2009 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 #include "gc.h"
  47 #include "incremental.h"
  48
  49 using namespace gold;
  50
  51 // This function emits the commandline to a hard-coded file in temp.
  52 // This is useful for debugging since ld is typically invoked by gcc,
  53 // so its commandline is not always easy to extract.  You should be
  54 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  55 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  56 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  57 // (or whatever value the environment variable GDB is set to), for
  58 // even easier debugging.  Since this is a debugging-only tool, and
  59 // creates files, it is only turned on when the user explicitly asks
  60 // for it, by compiling with -DDEBUG.  Do not do this for release
  61 // versions of the linker!
  62
  63 #ifdef DEBUG
  64 #include <stdio.h>
  65 #include <sys/stat.h>    // for chmod()
  66
  67 static std::string
  68 collect_argv(int argc, char** argv)
  69 {
  70   // This is used by write_debug_script(), which wants the unedited argv.
  71   std::string args;
  72   for (int i = 0; i < argc; ++i)
  73     {
  74       args.append(" '");
  75       // Now append argv[i], but with all single-quotes escaped
  76       const char* argpos = argv[i];
  77       while (1)
  78         {
  79           const int len = strcspn(argpos, "'");
  80           args.append(argpos, len);
  81           if (argpos[len] == '\0')
  82             break;
  83           args.append("'\"'\"'");
  84           argpos += len + 1;
  85         }
  86       args.append("'");
  87     }
  88   return args;
  89 }
  90
  91 static void
  92 write_debug_script(std::string filename_str,
  93                    const char* argv_0, const char* args)
  94 {
  95   size_t slash = filename_str.rfind('/');
  96   if (slash != std::string::npos)
  97     filename_str = filename_str.c_str() + slash + 1;
  98   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
  99   const char* filename = filename_str.c_str();
 100   FILE* fp = fopen(filename, "w");
 101   if (fp)
 102     {
 103       fprintf(fp, "[ \"$1\" = debug ]"
 104               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
 105               " && shift\n",
 106               argv_0);
 107       fprintf(fp, "$PREFIX%s $*\n", args);
 108       fclose(fp);
 109       chmod(filename, 0755);
 110     }
 111   else
 112     filename = "[none]";
 113   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 114   fflush(stderr);
 115 }
 116
 117 #else // !defined(DEBUG)
 118
 119 static inline std::string
 120 collect_argv(int, char**)
 121 {
 122   return "";
 123 }
 124
 125 static inline void
 126 write_debug_script(std::string, const char*, const char*)
 127 {
 128 }
 129
 130 #endif // !defined(DEBUG)
 131
 132
 133 int
 134 main(int argc, char** argv)
 135 {
 136 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 137   setlocale (LC_MESSAGES, "");
 138 #endif
 139 #if defined (HAVE_SETLOCALE)
 140   setlocale (LC_CTYPE, "");
 141 #endif
 142   bindtextdomain (PACKAGE, LOCALEDIR);
 143   textdomain (PACKAGE);
 144
 145   program_name = argv[0];
 146
 147   // In libiberty; expands @filename to the args in "filename".
 148   expandargv(&argc, &argv);
 149
 150   // This is used by write_debug_script(), which wants the unedited argv.
 151   std::string args = collect_argv(argc, argv);
 152
 153   Errors errors(program_name);
 154
 155   // Initialize the global parameters, to let random code get to the
 156   // errors object.
 157   set_parameters_errors(&errors);
 158
 159   // Handle the command line options.
 160   Command_line command_line;
 161   command_line.process(argc - 1, const_cast<const char**>(argv + 1));
 162
 163   long start_time = 0;
 164   if (command_line.options().stats())
 165     start_time = get_run_time();
 166
 167   // Store some options in the globally accessible parameters.
 168   set_parameters_options(&command_line.options());
 169
 170   // Do this as early as possible (since it prints a welcome message).
 171   write_debug_script(command_line.options().output_file_name(),
 172                      program_name, args.c_str());
 173
 174   // If the user asked for a map file, open it.
 175   Mapfile* mapfile = NULL;
 176   if (command_line.options().user_set_Map())
 177     {
 178       mapfile = new Mapfile();
 179       if (!mapfile->open(command_line.options().Map()))
 180         {
 181           delete mapfile;
 182           mapfile = NULL;
 183         }
 184     }
 185
 186   // The GNU linker ignores version scripts when generating
 187   // relocatable output.  If we are not compatible, then we break the
 188   // Linux kernel build, which uses a linker script with -r which must
 189   // not force symbols to be local.  It would actually be useful to
 190   // permit symbols to be forced local with -r, though, as it would
 191   // permit some linker optimizations.  Perhaps we need yet another
 192   // option to control this.  FIXME.
 193   if (parameters->options().relocatable())
 194     command_line.script_options().version_script_info()->clear();
 195
 196   // Load plugin libraries.
 197   if (command_line.options().has_plugins())
 198     command_line.options().plugins()->load_plugins();
 199
 200   // The work queue.
 201   Workqueue workqueue(command_line.options());
 202
 203   // The list of input objects.
 204   Input_objects input_objects;
 205
 206   // The Garbage Collection Object.
 207   Garbage_collection gc;
 208
 209   // The symbol table.  We're going to guess here how many symbols
 210   // we're going to see based on the number of input files.  Even when
 211   // this is off, it means at worst we don't quite optimize hashtable
 212   // resizing as well as we could have (perhap using more memory).
 213   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 214                       command_line.version_script());
 215
 216   if (parameters->options().gc_sections())
 217     symtab.set_gc(&gc);
 218
 219   // The layout object.
 220   Layout layout(command_line.number_of_input_files(),
 221                 &command_line.script_options());
 222
 223   if (layout.incremental_inputs() != NULL)
 224     layout.incremental_inputs()->report_command_line(argc, argv);
 225
 226   // Get the search path from the -L options.
 227   Dirsearch search_path;
 228   search_path.initialize(&workqueue, &command_line.options().library_path());
 229
 230   // Queue up the first set of tasks.
 231   queue_initial_tasks(command_line.options(), search_path,
 232                       command_line, &workqueue, &input_objects,
 233                       &symtab, &layout, mapfile);
 234
 235   // Run the main task processing loop.
 236   workqueue.process(0);
 237
 238   if (command_line.options().stats())
 239     {
 240       long run_time = get_run_time() - start_time;
 241       fprintf(stderr, _("%s: total run time: %ld.%06ld seconds\n"),
 242               program_name, run_time / 1000000, run_time % 1000000);
 243 #ifdef HAVE_MALLINFO
 244       struct mallinfo m = mallinfo();
 245       fprintf(stderr, _("%s: total space allocated by malloc: %d bytes\n"),
 246               program_name, m.arena);
 247 #endif
 248       File_read::print_stats();
 249       Archive::print_stats();
 250       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 251               program_name, static_cast<long long>(layout.output_file_size()));
 252       symtab.print_stats();
 253       layout.print_stats();
 254     }
 255
 256   if (mapfile != NULL)
 257     mapfile->close();
 258
 259   // Issue defined symbol report.
 260   if (command_line.options().user_set_print_symbol_counts())
 261     input_objects.print_symbol_counts(&symtab);
 262
 263   if (parameters->options().fatal_warnings()
 264       && errors.warning_count() > 0
 265       && errors.error_count() == 0)
 266     gold_error("treating warnings as errors");
 267
 268   // If the user used --noinhibit-exec, we force the exit status to be
 269   // successful.  This is compatible with GNU ld.
 270   gold_exit(errors.error_count() == 0
 271             || parameters->options().noinhibit_exec());
 272 }