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 "symtab.h"
  43 #include "layout.h"
  44
  45 using namespace gold;
  46
  47 // This function emits the commandline to a hard-coded file in temp.
  48 // This is useful for debugging since ld is typically invoked by gcc,
  49 // so its commandline is not always easy to extract.  You should be
  50 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  51 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  52 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  53 // (or whatever value the environment variable GDB is set to), for
  54 // even easier debugging.  Since this is a debugging-only tool, and
  55 // creates files, it is only turned on when the user explicitly asks
  56 // for it, by compiling with -DDEBUG.  Do not do this for release
  57 // versions of the linker!
  58
  59 #ifdef DEBUG
  60 #include <stdio.h>
  61 #include <sys/stat.h>    // for chmod()
  62
  63 static std::string
  64 collect_argv(int argc, char** argv)
  65 {
  66   // This is used by write_debug_script(), which wants the unedited argv.
  67   std::string args;
  68   for (int i = 0; i < argc; ++i)
  69     {
  70       args.append(" '");
  71       // Now append argv[i], but with all single-quotes escaped
  72       const char* argpos = argv[i];
  73       while (1)
  74         {
  75           const int len = strcspn(argpos, "'");
  76           args.append(argpos, len);
  77           if (argpos[len] == '\0')
  78             break;
  79           args.append("'\"'\"'");
  80           argpos += len + 1;
  81         }
  82       args.append("'");
  83     }
  84   return args;
  85 }
  86
  87 static void
  88 write_debug_script(std::string filename_str,
  89                    const char* argv_0, const char* args)
  90 {
  91   size_t slash = filename_str.rfind('/');
  92   if (slash != std::string::npos)
  93     filename_str = filename_str.c_str() + slash + 1;
  94   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
  95   const char* filename = filename_str.c_str();
  96   FILE* fp = fopen(filename, "w");
  97   if (fp)
  98     {
  99       fprintf(fp, "[ \"$1\" = debug ]"
 100               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
 101               " && shift\n",
 102               argv_0);
 103       fprintf(fp, "$PREFIX%s $*\n", args);
 104       fclose(fp);
 105       chmod(filename, 0755);
 106     }
 107   else
 108     filename = "[none]";
 109   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 110   fflush(stderr);
 111 }
 112
 113 #else // !defined(DEBUG)
 114
 115 static inline std::string
 116 collect_argv(int, char**)
 117 {
 118   return "";
 119 }
 120
 121 static inline void
 122 write_debug_script(std::string, const char*, const char*)
 123 {
 124 }
 125
 126 #endif // !defined(DEBUG)
 127
 128
 129 int
 130 main(int argc, char** argv)
 131 {
 132 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 133   setlocale (LC_MESSAGES, "");
 134 #endif
 135 #if defined (HAVE_SETLOCALE)
 136   setlocale (LC_CTYPE, "");
 137 #endif
 138   bindtextdomain (PACKAGE, LOCALEDIR);
 139   textdomain (PACKAGE);
 140
 141   program_name = argv[0];
 142
 143   // In libiberty; expands @filename to the args in "filename".
 144   expandargv(&argc, &argv);
 145
 146   // This is used by write_debug_script(), which wants the unedited argv.
 147   std::string args = collect_argv(argc, argv);
 148
 149   Errors errors(program_name);
 150
 151   // Initialize the global parameters, to let random code get to the
 152   // errors object.
 153   set_parameters_errors(&errors);
 154
 155   // Handle the command line options.
 156   Command_line command_line;
 157   command_line.process(argc - 1, const_cast<const char**>(argv + 1));
 158
 159   long start_time = 0;
 160   if (command_line.options().stats())
 161     start_time = get_run_time();
 162
 163   // Store some options in the globally accessible parameters.
 164   set_parameters_options(&command_line.options());
 165
 166   // Do this as early as possible (since it prints a welcome message).
 167   write_debug_script(command_line.options().output_file_name(),
 168                      program_name, args.c_str());
 169
 170   // If the user asked for a map file, open it.
 171   Mapfile* mapfile = NULL;
 172   if (command_line.options().user_set_Map())
 173     {
 174       mapfile = new Mapfile();
 175       if (!mapfile->open(command_line.options().Map()))
 176         {
 177           delete mapfile;
 178           mapfile = NULL;
 179         }
 180     }
 181
 182   // The GNU linker ignores version scripts when generating
 183   // relocatable output.  If we are not compatible, then we break the
 184   // Linux kernel build, which uses a linker script with -r which must
 185   // not force symbols to be local.  It would actually be useful to
 186   // permit symbols to be forced local with -r, though, as it would
 187   // permit some linker optimizations.  Perhaps we need yet another
 188   // option to control this.  FIXME.
 189   if (parameters->options().relocatable())
 190     command_line.script_options().version_script_info()->clear();
 191
 192   // The work queue.
 193   Workqueue workqueue(command_line.options());
 194
 195   // The list of input objects.
 196   Input_objects input_objects;
 197
 198   // The symbol table.  We're going to guess here how many symbols
 199   // we're going to see based on the number of input files.  Even when
 200   // this is off, it means at worst we don't quite optimize hashtable
 201   // resizing as well as we could have (perhap using more memory).
 202   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 203                       command_line.version_script());
 204
 205   // The layout object.
 206   Layout layout(command_line.options(), &command_line.script_options());
 207
 208   // Get the search path from the -L options.
 209   Dirsearch search_path;
 210   search_path.initialize(&workqueue, &command_line.options().library_path());
 211
 212   // Queue up the first set of tasks.
 213   queue_initial_tasks(command_line.options(), search_path,
 214                       command_line, &workqueue, &input_objects,
 215                       &symtab, &layout, mapfile);
 216
 217   // Run the main task processing loop.
 218   workqueue.process(0);
 219
 220   if (command_line.options().stats())
 221     {
 222       long run_time = get_run_time() - start_time;
 223       fprintf(stderr, _("%s: total run time: %ld.%06ld seconds\n"),
 224               program_name, run_time / 1000000, run_time % 1000000);
 225 #ifdef HAVE_MALLINFO
 226       struct mallinfo m = mallinfo();
 227       fprintf(stderr, _("%s: total space allocated by malloc: %d bytes\n"),
 228               program_name, m.arena);
 229 #endif
 230       File_read::print_stats();
 231       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 232               program_name, static_cast<long long>(layout.output_file_size()));
 233       symtab.print_stats();
 234       layout.print_stats();
 235     }
 236
 237   if (mapfile != NULL)
 238     mapfile->close();
 239
 240   // Issue defined symbol report.
 241   if (command_line.options().user_set_print_symbol_counts())
 242     input_objects.print_symbol_counts(&symtab);
 243
 244   if (parameters->options().fatal_warnings()
 245       && errors.warning_count() > 0
 246       && errors.error_count() == 0)
 247     gold_error("treating warnings as errors");
 248
 249   // If the user used --noinhibit-exec, we force the exit status to be
 250   // successful.  This is compatible with GNU ld.
 251   gold_exit(errors.error_count() == 0
 252             || parameters->options().noinhibit_exec());
 253 }