gold/main.cc

   1 // main.cc -- gold main function.
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010 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 "icf.h"
  48 #include "incremental.h"
  49 #include "timer.h"
  50
  51 using namespace gold;
  52
  53 // This function emits the commandline to a hard-coded file in temp.
  54 // This is useful for debugging since ld is typically invoked by gcc,
  55 // so its commandline is not always easy to extract.  You should be
  56 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  57 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  58 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  59 // (or whatever value the environment variable GDB is set to), for
  60 // even easier debugging.  Since this is a debugging-only tool, and
  61 // creates files, it is only turned on when the user explicitly asks
  62 // for it, by compiling with -DDEBUG.  Do not do this for release
  63 // versions of the linker!
  64
  65 #ifdef DEBUG
  66 #include <stdio.h>
  67 #include <sys/stat.h>    // for chmod()
  68
  69 static std::string
  70 collect_argv(int argc, char** argv)
  71 {
  72   // This is used by write_debug_script(), which wants the unedited argv.
  73   std::string args;
  74   for (int i = 0; i < argc; ++i)
  75     {
  76       args.append(" '");
  77       // Now append argv[i], but with all single-quotes escaped
  78       const char* argpos = argv[i];
  79       while (1)
  80         {
  81           const int len = strcspn(argpos, "'");
  82           args.append(argpos, len);
  83           if (argpos[len] == '\0')
  84             break;
  85           args.append("'\"'\"'");
  86           argpos += len + 1;
  87         }
  88       args.append("'");
  89     }
  90   return args;
  91 }
  92
  93 static void
  94 write_debug_script(std::string filename_str,
  95                    const char* argv_0, const char* args)
  96 {
  97   size_t slash = filename_str.rfind('/');
  98   if (slash != std::string::npos)
  99     filename_str = filename_str.c_str() + slash + 1;
 100   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
 101   const char* filename = filename_str.c_str();
 102   FILE* fp = fopen(filename, "w");
 103   if (fp)
 104     {
 105       fprintf(fp, "[ \"$1\" = debug ]"
 106               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
 107               " && shift\n",
 108               argv_0);
 109       fprintf(fp, "$PREFIX%s $*\n", args);
 110       fclose(fp);
 111       chmod(filename, 0755);
 112     }
 113   else
 114     filename = "[none]";
 115   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 116   fflush(stderr);
 117 }
 118
 119 #else // !defined(DEBUG)
 120
 121 static inline std::string
 122 collect_argv(int, char**)
 123 {
 124   return "";
 125 }
 126
 127 static inline void
 128 write_debug_script(std::string, const char*, const char*)
 129 {
 130 }
 131
 132 #endif // !defined(DEBUG)
 133
 134
 135 int
 136 main(int argc, char** argv)
 137 {
 138 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 139   setlocale (LC_MESSAGES, "");
 140 #endif
 141 #if defined (HAVE_SETLOCALE)
 142   setlocale (LC_CTYPE, "");
 143 #endif
 144   bindtextdomain (PACKAGE, LOCALEDIR);
 145   textdomain (PACKAGE);
 146
 147   program_name = argv[0];
 148
 149   // In libiberty; expands @filename to the args in "filename".
 150   expandargv(&argc, &argv);
 151
 152   // This is used by write_debug_script(), which wants the unedited argv.
 153   std::string args = collect_argv(argc, argv);
 154
 155   Errors errors(program_name);
 156
 157   // Initialize the global parameters, to let random code get to the
 158   // errors object.
 159   set_parameters_errors(&errors);
 160
 161   // Handle the command line options.
 162   Command_line command_line;
 163   command_line.process(argc - 1, const_cast<const char**>(argv + 1));
 164
 165   Timer timer;
 166   if (command_line.options().stats())
 167     timer.start();
 168
 169   // Store some options in the globally accessible parameters.
 170   set_parameters_options(&command_line.options());
 171
 172   // Do this as early as possible (since it prints a welcome message).
 173   write_debug_script(command_line.options().output_file_name(),
 174                      program_name, args.c_str());
 175
 176   // If the user asked for a map file, open it.
 177   Mapfile* mapfile = NULL;
 178   if (command_line.options().user_set_Map())
 179     {
 180       mapfile = new Mapfile();
 181       if (!mapfile->open(command_line.options().Map()))
 182         {
 183           delete mapfile;
 184           mapfile = NULL;
 185         }
 186     }
 187
 188   // The GNU linker ignores version scripts when generating
 189   // relocatable output.  If we are not compatible, then we break the
 190   // Linux kernel build, which uses a linker script with -r which must
 191   // not force symbols to be local.  It would actually be useful to
 192   // permit symbols to be forced local with -r, though, as it would
 193   // permit some linker optimizations.  Perhaps we need yet another
 194   // option to control this.  FIXME.
 195   if (parameters->options().relocatable())
 196     command_line.script_options().version_script_info()->clear();
 197
 198   // Load plugin libraries.
 199   if (command_line.options().has_plugins())
 200     command_line.options().plugins()->load_plugins();
 201
 202   // The work queue.
 203   Workqueue workqueue(command_line.options());
 204
 205   // The list of input objects.
 206   Input_objects input_objects;
 207
 208   // The Garbage Collection (GC, --gc-sections) Object.
 209   Garbage_collection gc;
 210
 211   // The Identical Code Folding (ICF, --icf) Object.
 212   Icf icf;
 213
 214   // The symbol table.  We're going to guess here how many symbols
 215   // we're going to see based on the number of input files.  Even when
 216   // this is off, it means at worst we don't quite optimize hashtable
 217   // resizing as well as we could have (perhap using more memory).
 218   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 219                       command_line.version_script());
 220
 221   if (parameters->options().gc_sections())
 222     symtab.set_gc(&gc);
 223
 224   if (parameters->options().icf_enabled())
 225     symtab.set_icf(&icf);
 226
 227   // The layout object.
 228   Layout layout(command_line.number_of_input_files(),
 229                 &command_line.script_options());
 230
 231   if (layout.incremental_inputs() != NULL)
 232     {
 233       layout.incremental_inputs()->report_command_line(argc, argv);
 234       layout.incremental_inputs()->report_inputs(command_line.inputs());
 235     }
 236
 237   if (parameters->options().section_ordering_file())
 238     layout.read_layout_from_file();
 239
 240   // Get the search path from the -L options.
 241   Dirsearch search_path;
 242   search_path.initialize(&workqueue, &command_line.options().library_path());
 243
 244   // Queue up the first set of tasks.
 245   queue_initial_tasks(command_line.options(), search_path,
 246                       command_line, &workqueue, &input_objects,
 247                       &symtab, &layout, mapfile);
 248
 249   // Run the main task processing loop.
 250   workqueue.process(0);
 251
 252   if (command_line.options().stats())
 253     {
 254       Timer::TimeStats elapsed = timer.get_elapsed_time();
 255       fprintf(stderr,
 256              _("%s: total run time: " \
 257                "(user: %ld.%06ld sys: %ld.%06ld wall: %ld.%06ld)\n"),
 258               program_name,
 259               elapsed.user / 1000, (elapsed.user % 1000) * 1000,
 260               elapsed.sys / 1000, (elapsed.sys % 1000) * 1000,
 261               elapsed.wall / 1000, (elapsed.wall % 1000) * 1000);
 262
 263 #ifdef HAVE_MALLINFO
 264       struct mallinfo m = mallinfo();
 265       fprintf(stderr, _("%s: total space allocated by malloc: %d bytes\n"),
 266               program_name, m.arena);
 267 #endif
 268       File_read::print_stats();
 269       Archive::print_stats();
 270       Lib_group::print_stats();
 271       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 272               program_name, static_cast<long long>(layout.output_file_size()));
 273       symtab.print_stats();
 274       layout.print_stats();
 275     }
 276
 277   // Issue defined symbol report.
 278   if (command_line.options().user_set_print_symbol_counts())
 279     input_objects.print_symbol_counts(&symtab);
 280
 281   // Output cross reference table.
 282   if (command_line.options().cref())
 283     input_objects.print_cref(&symtab,
 284                              mapfile == NULL ? stdout : mapfile->file());
 285
 286   if (mapfile != NULL)
 287     mapfile->close();
 288
 289   if (parameters->options().fatal_warnings()
 290       && errors.warning_count() > 0
 291       && errors.error_count() == 0)
 292     gold_error("treating warnings as errors");
 293
 294   // If the user used --noinhibit-exec, we force the exit status to be
 295   // successful.  This is compatible with GNU ld.
 296   gold_exit(errors.error_count() == 0
 297             || parameters->options().noinhibit_exec());
 298 }