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 "archive.h"
  43 #include "symtab.h"
  44 #include "layout.h"
  45
  46 using namespace gold;
  47
  48 // This function emits the commandline to a hard-coded file in temp.
  49 // This is useful for debugging since ld is typically invoked by gcc,
  50 // so its commandline is not always easy to extract.  You should be
  51 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  52 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  53 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  54 // (or whatever value the environment variable GDB is set to), for
  55 // even easier debugging.  Since this is a debugging-only tool, and
  56 // creates files, it is only turned on when the user explicitly asks
  57 // for it, by compiling with -DDEBUG.  Do not do this for release
  58 // versions of the linker!
  59
  60 #ifdef DEBUG
  61 #include <stdio.h>
  62 #include <sys/stat.h>    // for chmod()
  63
  64 static std::string
  65 collect_argv(int argc, char** argv)
  66 {
  67   // This is used by write_debug_script(), which wants the unedited argv.
  68   std::string args;
  69   for (int i = 0; i < argc; ++i)
  70     {
  71       args.append(" '");
  72       // Now append argv[i], but with all single-quotes escaped
  73       const char* argpos = argv[i];
  74       while (1)
  75         {
  76           const int len = strcspn(argpos, "'");
  77           args.append(argpos, len);
  78           if (argpos[len] == '\0')
  79             break;
  80           args.append("'\"'\"'");
  81           argpos += len + 1;
  82         }
  83       args.append("'");
  84     }
  85   return args;
  86 }
  87
  88 static void
  89 write_debug_script(std::string filename_str,
  90                    const char* argv_0, const char* args)
  91 {
  92   size_t slash = filename_str.rfind('/');
  93   if (slash != std::string::npos)
  94     filename_str = filename_str.c_str() + slash + 1;
  95   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
  96   const char* filename = filename_str.c_str();
  97   FILE* fp = fopen(filename, "w");
  98   if (fp)
  99     {
 100       fprintf(fp, "[ \"$1\" = debug ]"
 101               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
 102               " && shift\n",
 103               argv_0);
 104       fprintf(fp, "$PREFIX%s $*\n", args);
 105       fclose(fp);
 106       chmod(filename, 0755);
 107     }
 108   else
 109     filename = "[none]";
 110   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 111   fflush(stderr);
 112 }
 113
 114 #else // !defined(DEBUG)
 115
 116 static inline std::string
 117 collect_argv(int, char**)
 118 {
 119   return "";
 120 }
 121
 122 static inline void
 123 write_debug_script(std::string, const char*, const char*)
 124 {
 125 }
 126
 127 #endif // !defined(DEBUG)
 128
 129
 130 int
 131 main(int argc, char** argv)
 132 {
 133 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 134   setlocale (LC_MESSAGES, "");
 135 #endif
 136 #if defined (HAVE_SETLOCALE)
 137   setlocale (LC_CTYPE, "");
 138 #endif
 139   bindtextdomain (PACKAGE, LOCALEDIR);
 140   textdomain (PACKAGE);
 141
 142   program_name = argv[0];
 143
 144   // In libiberty; expands @filename to the args in "filename".
 145   expandargv(&argc, &argv);
 146
 147   // This is used by write_debug_script(), which wants the unedited argv.
 148   std::string args = collect_argv(argc, argv);
 149
 150   Errors errors(program_name);
 151
 152   // Initialize the global parameters, to let random code get to the
 153   // errors object.
 154   set_parameters_errors(&errors);
 155
 156   // Handle the command line options.
 157   Command_line command_line;
 158   command_line.process(argc - 1, const_cast<const char**>(argv + 1));
 159
 160   long start_time = 0;
 161   if (command_line.options().stats())
 162     start_time = get_run_time();
 163
 164   // Store some options in the globally accessible parameters.
 165   set_parameters_options(&command_line.options());
 166
 167   // Do this as early as possible (since it prints a welcome message).
 168   write_debug_script(command_line.options().output_file_name(),
 169                      program_name, args.c_str());
 170
 171   // If the user asked for a map file, open it.
 172   Mapfile* mapfile = NULL;
 173   if (command_line.options().user_set_Map())
 174     {
 175       mapfile = new Mapfile();
 176       if (!mapfile->open(command_line.options().Map()))
 177         {
 178           delete mapfile;
 179           mapfile = NULL;
 180         }
 181     }
 182
 183   // The GNU linker ignores version scripts when generating
 184   // relocatable output.  If we are not compatible, then we break the
 185   // Linux kernel build, which uses a linker script with -r which must
 186   // not force symbols to be local.  It would actually be useful to
 187   // permit symbols to be forced local with -r, though, as it would
 188   // permit some linker optimizations.  Perhaps we need yet another
 189   // option to control this.  FIXME.
 190   if (parameters->options().relocatable())
 191     command_line.script_options().version_script_info()->clear();
 192
 193   // The work queue.
 194   Workqueue workqueue(command_line.options());
 195
 196   // The list of input objects.
 197   Input_objects input_objects;
 198
 199   // The symbol table.  We're going to guess here how many symbols
 200   // we're going to see based on the number of input files.  Even when
 201   // this is off, it means at worst we don't quite optimize hashtable
 202   // resizing as well as we could have (perhap using more memory).
 203   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 204                       command_line.version_script());
 205
 206   // The layout object.
 207   Layout layout(command_line.options(), &command_line.script_options());
 208
 209   // Get the search path from the -L options.
 210   Dirsearch search_path;
 211   search_path.initialize(&workqueue, &command_line.options().library_path());
 212
 213   // Queue up the first set of tasks.
 214   queue_initial_tasks(command_line.options(), search_path,
 215                       command_line, &workqueue, &input_objects,
 216                       &symtab, &layout, mapfile);
 217
 218   // Run the main task processing loop.
 219   workqueue.process(0);
 220
 221   if (command_line.options().stats())
 222     {
 223       long run_time = get_run_time() - start_time;
 224       fprintf(stderr, _("%s: total run time: %ld.%06ld seconds\n"),
 225               program_name, run_time / 1000000, run_time % 1000000);
 226 #ifdef HAVE_MALLINFO
 227       struct mallinfo m = mallinfo();
 228       fprintf(stderr, _("%s: total space allocated by malloc: %d bytes\n"),
 229               program_name, m.arena);
 230 #endif
 231       File_read::print_stats();
 232       Archive::print_stats();
 233       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 234               program_name, static_cast<long long>(layout.output_file_size()));
 235       symtab.print_stats();
 236       layout.print_stats();
 237     }
 238
 239   if (mapfile != NULL)
 240     mapfile->close();
 241
 242   // Issue defined symbol report.
 243   if (command_line.options().user_set_print_symbol_counts())
 244     input_objects.print_symbol_counts(&symtab);
 245
 246   if (parameters->options().fatal_warnings()
 247       && errors.warning_count() > 0
 248       && errors.error_count() == 0)
 249     gold_error("treating warnings as errors");
 250
 251   // If the user used --noinhibit-exec, we force the exit status to be
 252   // successful.  This is compatible with GNU ld.
 253   gold_exit(errors.error_count() == 0
 254             || parameters->options().noinhibit_exec());
 255 }