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 "icf.h"
  48 #include "incremental.h"
  49
  50 using namespace gold;
  51
  52 // This function emits the commandline to a hard-coded file in temp.
  53 // This is useful for debugging since ld is typically invoked by gcc,
  54 // so its commandline is not always easy to extract.  You should be
  55 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  56 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  57 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  58 // (or whatever value the environment variable GDB is set to), for
  59 // even easier debugging.  Since this is a debugging-only tool, and
  60 // creates files, it is only turned on when the user explicitly asks
  61 // for it, by compiling with -DDEBUG.  Do not do this for release
  62 // versions of the linker!
  63
  64 #ifdef DEBUG
  65 #include <stdio.h>
  66 #include <sys/stat.h>    // for chmod()
  67
  68 static std::string
  69 collect_argv(int argc, char** argv)
  70 {
  71   // This is used by write_debug_script(), which wants the unedited argv.
  72   std::string args;
  73   for (int i = 0; i < argc; ++i)
  74     {
  75       args.append(" '");
  76       // Now append argv[i], but with all single-quotes escaped
  77       const char* argpos = argv[i];
  78       while (1)
  79         {
  80           const int len = strcspn(argpos, "'");
  81           args.append(argpos, len);
  82           if (argpos[len] == '\0')
  83             break;
  84           args.append("'\"'\"'");
  85           argpos += len + 1;
  86         }
  87       args.append("'");
  88     }
  89   return args;
  90 }
  91
  92 static void
  93 write_debug_script(std::string filename_str,
  94                    const char* argv_0, const char* args)
  95 {
  96   size_t slash = filename_str.rfind('/');
  97   if (slash != std::string::npos)
  98     filename_str = filename_str.c_str() + slash + 1;
  99   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
 100   const char* filename = filename_str.c_str();
 101   FILE* fp = fopen(filename, "w");
 102   if (fp)
 103     {
 104       fprintf(fp, "[ \"$1\" = debug ]"
 105               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
 106               " && shift\n",
 107               argv_0);
 108       fprintf(fp, "$PREFIX%s $*\n", args);
 109       fclose(fp);
 110       chmod(filename, 0755);
 111     }
 112   else
 113     filename = "[none]";
 114   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 115   fflush(stderr);
 116 }
 117
 118 #else // !defined(DEBUG)
 119
 120 static inline std::string
 121 collect_argv(int, char**)
 122 {
 123   return "";
 124 }
 125
 126 static inline void
 127 write_debug_script(std::string, const char*, const char*)
 128 {
 129 }
 130
 131 #endif // !defined(DEBUG)
 132
 133
 134 int
 135 main(int argc, char** argv)
 136 {
 137 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 138   setlocale (LC_MESSAGES, "");
 139 #endif
 140 #if defined (HAVE_SETLOCALE)
 141   setlocale (LC_CTYPE, "");
 142 #endif
 143   bindtextdomain (PACKAGE, LOCALEDIR);
 144   textdomain (PACKAGE);
 145
 146   program_name = argv[0];
 147
 148   // In libiberty; expands @filename to the args in "filename".
 149   expandargv(&argc, &argv);
 150
 151   // This is used by write_debug_script(), which wants the unedited argv.
 152   std::string args = collect_argv(argc, argv);
 153
 154   Errors errors(program_name);
 155
 156   // Initialize the global parameters, to let random code get to the
 157   // errors object.
 158   set_parameters_errors(&errors);
 159
 160   // Handle the command line options.
 161   Command_line command_line;
 162   command_line.process(argc - 1, const_cast<const char**>(argv + 1));
 163
 164   long start_time = 0;
 165   if (command_line.options().stats())
 166     start_time = get_run_time();
 167
 168   // Store some options in the globally accessible parameters.
 169   set_parameters_options(&command_line.options());
 170
 171   // Do this as early as possible (since it prints a welcome message).
 172   write_debug_script(command_line.options().output_file_name(),
 173                      program_name, args.c_str());
 174
 175   // If the user asked for a map file, open it.
 176   Mapfile* mapfile = NULL;
 177   if (command_line.options().user_set_Map())
 178     {
 179       mapfile = new Mapfile();
 180       if (!mapfile->open(command_line.options().Map()))
 181         {
 182           delete mapfile;
 183           mapfile = NULL;
 184         }
 185     }
 186
 187   // The GNU linker ignores version scripts when generating
 188   // relocatable output.  If we are not compatible, then we break the
 189   // Linux kernel build, which uses a linker script with -r which must
 190   // not force symbols to be local.  It would actually be useful to
 191   // permit symbols to be forced local with -r, though, as it would
 192   // permit some linker optimizations.  Perhaps we need yet another
 193   // option to control this.  FIXME.
 194   if (parameters->options().relocatable())
 195     command_line.script_options().version_script_info()->clear();
 196
 197   // Load plugin libraries.
 198   if (command_line.options().has_plugins())
 199     command_line.options().plugins()->load_plugins();
 200
 201   // The work queue.
 202   Workqueue workqueue(command_line.options());
 203
 204   // The list of input objects.
 205   Input_objects input_objects;
 206
 207   // The Garbage Collection (GC, --gc-sections) Object.
 208   Garbage_collection gc;
 209
 210   // The Identical Code Folding (ICF, --icf) Object.
 211   Icf icf;
 212
 213   // The symbol table.  We're going to guess here how many symbols
 214   // we're going to see based on the number of input files.  Even when
 215   // this is off, it means at worst we don't quite optimize hashtable
 216   // resizing as well as we could have (perhap using more memory).
 217   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 218                       command_line.version_script());
 219
 220   if (parameters->options().gc_sections())
 221     symtab.set_gc(&gc);
 222
 223   if (parameters->options().icf())
 224     symtab.set_icf(&icf);
 225
 226   // The layout object.
 227   Layout layout(command_line.number_of_input_files(),
 228                 &command_line.script_options());
 229
 230   if (layout.incremental_inputs() != NULL)
 231     {
 232       layout.incremental_inputs()->report_command_line(argc, argv);
 233       layout.incremental_inputs()->report_inputs(command_line.inputs());
 234     }
 235
 236   // Get the search path from the -L options.
 237   Dirsearch search_path;
 238   search_path.initialize(&workqueue, &command_line.options().library_path());
 239
 240   // Queue up the first set of tasks.
 241   queue_initial_tasks(command_line.options(), search_path,
 242                       command_line, &workqueue, &input_objects,
 243                       &symtab, &layout, mapfile);
 244
 245   // Run the main task processing loop.
 246   workqueue.process(0);
 247
 248   if (command_line.options().stats())
 249     {
 250       long run_time = get_run_time() - start_time;
 251       fprintf(stderr, _("%s: total run time: %ld.%06ld seconds\n"),
 252               program_name, run_time / 1000000, run_time % 1000000);
 253 #ifdef HAVE_MALLINFO
 254       struct mallinfo m = mallinfo();
 255       fprintf(stderr, _("%s: total space allocated by malloc: %d bytes\n"),
 256               program_name, m.arena);
 257 #endif
 258       File_read::print_stats();
 259       Archive::print_stats();
 260       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 261               program_name, static_cast<long long>(layout.output_file_size()));
 262       symtab.print_stats();
 263       layout.print_stats();
 264     }
 265
 266   if (mapfile != NULL)
 267     mapfile->close();
 268
 269   // Issue defined symbol report.
 270   if (command_line.options().user_set_print_symbol_counts())
 271     input_objects.print_symbol_counts(&symtab);
 272
 273   if (parameters->options().fatal_warnings()
 274       && errors.warning_count() > 0
 275       && errors.error_count() == 0)
 276     gold_error("treating warnings as errors");
 277
 278   // If the user used --noinhibit-exec, we force the exit status to be
 279   // successful.  This is compatible with GNU ld.
 280   gold_exit(errors.error_count() == 0
 281             || parameters->options().noinhibit_exec());
 282 }