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