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 #ifdef HAVE_MALLINFO
  26 #include <malloc.h>
  27 #endif
  28 #include "libiberty.h"
  29
  30 #include "script.h"
  31 #include "options.h"
  32 #include "parameters.h"
  33 #include "errors.h"
  34 #include "dirsearch.h"
  35 #include "workqueue.h"
  36 #include "object.h"
  37 #include "symtab.h"
  38 #include "layout.h"
  39
  40 using namespace gold;
  41
  42 // This function emits the commandline to a hard-coded file in temp.
  43 // This is useful for debugging since ld is typically invoked by gcc,
  44 // so its commandline is not always easy to extract.  You should be
  45 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  46 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  47 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  48 // (or whatever value the environment variable GDB is set to), for
  49 // even easier debugging.  Since this is a debugging-only tool, and
  50 // creates files, it is only turned on when the user explicitly asks
  51 // for it, by compiling with -DDEBUG.  Do not do this for release
  52 // versions of the linker!
  53
  54 #ifdef DEBUG
  55 #include <stdio.h>
  56 #include <sys/stat.h>    // for chmod()
  57
  58 static std::string
  59 collect_argv(int argc, char** argv)
  60 {
  61   // This is used by write_debug_script(), which wants the unedited argv.
  62   std::string args;
  63   for (int i = 0; i < argc; ++i)
  64     {
  65       args.append(" '");
  66       // Now append argv[i], but with all single-quotes escaped
  67       const char* argpos = argv[i];
  68       while (1)
  69         {
  70           const int len = strcspn(argpos, "'");
  71           args.append(argpos, len);
  72           if (argpos[len] == '\0')
  73             break;
  74           args.append("'\"'\"'");
  75           argpos += len + 1;
  76         }
  77       args.append("'");
  78     }
  79   return args;
  80 }
  81
  82 static void
  83 write_debug_script(std::string filename_str,
  84                    const char* argv_0, const char* args)
  85 {
  86   size_t slash = filename_str.rfind('/');
  87   if (slash != std::string::npos)
  88     filename_str = filename_str.c_str() + slash + 1;
  89   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
  90   const char* filename = filename_str.c_str();
  91   FILE* fp = fopen(filename, "w");
  92   if (fp)
  93     {
  94       fprintf(fp, "[ \"$1\" = debug ]"
  95               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
  96               " && shift\n",
  97               argv_0);
  98       fprintf(fp, "$PREFIX%s $*\n", args);
  99       fclose(fp);
 100       chmod(filename, 0755);
 101     }
 102   else
 103     filename = "[none]";
 104   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 105   fflush(stderr);
 106 }
 107
 108 #else // !defined(DEBUG)
 109
 110 static inline std::string
 111 collect_argv(int, char**)
 112 {
 113   return "";
 114 }
 115
 116 static inline void
 117 write_debug_script(std::string, const char*, const char*)
 118 {
 119 }
 120
 121 #endif // !defined(DEBUG)
 122
 123
 124 int
 125 main(int argc, char** argv)
 126 {
 127 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 128   setlocale (LC_MESSAGES, "");
 129 #endif
 130 #if defined (HAVE_SETLOCALE)
 131   setlocale (LC_CTYPE, "");
 132 #endif
 133   bindtextdomain (PACKAGE, LOCALEDIR);
 134   textdomain (PACKAGE);
 135
 136   program_name = argv[0];
 137
 138   // In libiberty; expands @filename to the args in "filename".
 139   expandargv(&argc, &argv);
 140
 141   // This is used by write_debug_script(), which wants the unedited argv.
 142   std::string args = collect_argv(argc, argv);
 143
 144   Errors errors(program_name);
 145
 146   // Initialize the global parameters, to let random code get to the
 147   // errors object.
 148   initialize_parameters(&errors);
 149
 150   // Options which may be set by the command line or by linker
 151   // scripts.
 152   Script_options script_options;
 153
 154   // Handle the command line options.
 155   Command_line command_line(&script_options);
 156   command_line.process(argc - 1, argv + 1);
 157
 158   long start_time = 0;
 159   if (command_line.options().print_stats())
 160     start_time = get_run_time();
 161
 162   // Store some options in the globally accessible parameters.
 163   set_parameters_from_options(&command_line.options());
 164
 165   // Do this as early as possible (since it prints a welcome message).
 166   write_debug_script(command_line.options().output_file_name(),
 167                      program_name, args.c_str());
 168
 169   // The GNU linker ignores version scripts when generating
 170   // relocatable output.  If we are not compatible, then we break the
 171   // Linux kernel build, which uses a linker script with -r which must
 172   // not force symbols to be local.  It would actually be useful to
 173   // permit symbols to be forced local with -r, though, as it would
 174   // permit some linker optimizations.  Perhaps we need yet another
 175   // option to control this.  FIXME.
 176   if (parameters->output_is_object())
 177     command_line.script_options()->version_script_info()->clear();
 178
 179   // The work queue.
 180   Workqueue workqueue(command_line.options());
 181
 182   // The list of input objects.
 183   Input_objects input_objects;
 184
 185   // The symbol table.  We're going to guess here how many symbols
 186   // we're going to see based on the number of input files.  Even when
 187   // this is off, it means at worst we don't quite optimize hashtable
 188   // resizing as well as we could have (perhap using more memory).
 189   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 190                       command_line.options().version_script());
 191
 192   // The layout object.
 193   Layout layout(command_line.options(), &script_options);
 194
 195   // Get the search path from the -L options.
 196   Dirsearch search_path;
 197   search_path.initialize(&workqueue, &command_line.options().search_path());
 198
 199   // Queue up the first set of tasks.
 200   queue_initial_tasks(command_line.options(), search_path,
 201                       command_line, &workqueue, &input_objects,
 202                       &symtab, &layout);
 203
 204   // Run the main task processing loop.
 205   workqueue.process(0);
 206
 207   if (command_line.options().print_stats())
 208     {
 209       long run_time = get_run_time() - start_time;
 210       fprintf(stderr, _("%s: total run time: %ld.%06ld seconds\n"),
 211               program_name, run_time / 1000000, run_time % 1000000);
 212 #ifdef HAVE_MALLINFO
 213       struct mallinfo m = mallinfo();
 214       fprintf(stderr, _("%s: total space allocated by malloc: %d bytes\n"),
 215               program_name, m.arena);
 216 #endif
 217       File_read::print_stats();
 218       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 219               program_name, static_cast<long long>(layout.output_file_size()));
 220       symtab.print_stats();
 221       layout.print_stats();
 222     }
 223
 224   gold_exit(errors.error_count() == 0);
 225 }