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 <cstring>
  26
  27 #ifdef HAVE_MALLINFO
  28 #include <malloc.h>
  29 #endif
  30
  31 #include "libiberty.h"
  32
  33 #include "script.h"
  34 #include "options.h"
  35 #include "parameters.h"
  36 #include "errors.h"
  37 #include "dirsearch.h"
  38 #include "workqueue.h"
  39 #include "object.h"
  40 #include "symtab.h"
  41 #include "layout.h"
  42
  43 using namespace gold;
  44
  45 // This function emits the commandline to a hard-coded file in temp.
  46 // This is useful for debugging since ld is typically invoked by gcc,
  47 // so its commandline is not always easy to extract.  You should be
  48 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  49 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  50 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  51 // (or whatever value the environment variable GDB is set to), for
  52 // even easier debugging.  Since this is a debugging-only tool, and
  53 // creates files, it is only turned on when the user explicitly asks
  54 // for it, by compiling with -DDEBUG.  Do not do this for release
  55 // versions of the linker!
  56
  57 #ifdef DEBUG
  58 #include <stdio.h>
  59 #include <sys/stat.h>    // for chmod()
  60
  61 static std::string
  62 collect_argv(int argc, char** argv)
  63 {
  64   // This is used by write_debug_script(), which wants the unedited argv.
  65   std::string args;
  66   for (int i = 0; i < argc; ++i)
  67     {
  68       args.append(" '");
  69       // Now append argv[i], but with all single-quotes escaped
  70       const char* argpos = argv[i];
  71       while (1)
  72         {
  73           const int len = strcspn(argpos, "'");
  74           args.append(argpos, len);
  75           if (argpos[len] == '\0')
  76             break;
  77           args.append("'\"'\"'");
  78           argpos += len + 1;
  79         }
  80       args.append("'");
  81     }
  82   return args;
  83 }
  84
  85 static void
  86 write_debug_script(std::string filename_str,
  87                    const char* argv_0, const char* args)
  88 {
  89   size_t slash = filename_str.rfind('/');
  90   if (slash != std::string::npos)
  91     filename_str = filename_str.c_str() + slash + 1;
  92   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
  93   const char* filename = filename_str.c_str();
  94   FILE* fp = fopen(filename, "w");
  95   if (fp)
  96     {
  97       fprintf(fp, "[ \"$1\" = debug ]"
  98               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
  99               " && shift\n",
 100               argv_0);
 101       fprintf(fp, "$PREFIX%s $*\n", args);
 102       fclose(fp);
 103       chmod(filename, 0755);
 104     }
 105   else
 106     filename = "[none]";
 107   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 108   fflush(stderr);
 109 }
 110
 111 #else // !defined(DEBUG)
 112
 113 static inline std::string
 114 collect_argv(int, char**)
 115 {
 116   return "";
 117 }
 118
 119 static inline void
 120 write_debug_script(std::string, const char*, const char*)
 121 {
 122 }
 123
 124 #endif // !defined(DEBUG)
 125
 126
 127 int
 128 main(int argc, char** argv)
 129 {
 130 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 131   setlocale (LC_MESSAGES, "");
 132 #endif
 133 #if defined (HAVE_SETLOCALE)
 134   setlocale (LC_CTYPE, "");
 135 #endif
 136   bindtextdomain (PACKAGE, LOCALEDIR);
 137   textdomain (PACKAGE);
 138
 139   program_name = argv[0];
 140
 141   // In libiberty; expands @filename to the args in "filename".
 142   expandargv(&argc, &argv);
 143
 144   // This is used by write_debug_script(), which wants the unedited argv.
 145   std::string args = collect_argv(argc, argv);
 146
 147   Errors errors(program_name);
 148
 149   // Initialize the global parameters, to let random code get to the
 150   // errors object.
 151   set_parameters_errors(&errors);
 152
 153   // Handle the command line options.
 154   Command_line command_line;
 155   command_line.process(argc - 1, const_cast<const char**>(argv + 1));
 156
 157   long start_time = 0;
 158   if (command_line.options().stats())
 159     start_time = get_run_time();
 160
 161   // Store some options in the globally accessible parameters.
 162   set_parameters_options(&command_line.options());
 163
 164   // Do this as early as possible (since it prints a welcome message).
 165   write_debug_script(command_line.options().output_file_name(),
 166                      program_name, args.c_str());
 167
 168   // The GNU linker ignores version scripts when generating
 169   // relocatable output.  If we are not compatible, then we break the
 170   // Linux kernel build, which uses a linker script with -r which must
 171   // not force symbols to be local.  It would actually be useful to
 172   // permit symbols to be forced local with -r, though, as it would
 173   // permit some linker optimizations.  Perhaps we need yet another
 174   // option to control this.  FIXME.
 175   if (parameters->options().relocatable())
 176     command_line.script_options().version_script_info()->clear();
 177
 178   // The work queue.
 179   Workqueue workqueue(command_line.options());
 180
 181   // The list of input objects.
 182   Input_objects input_objects;
 183
 184   // The symbol table.  We're going to guess here how many symbols
 185   // we're going to see based on the number of input files.  Even when
 186   // this is off, it means at worst we don't quite optimize hashtable
 187   // resizing as well as we could have (perhap using more memory).
 188   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 189                       command_line.version_script());
 190
 191   // The layout object.
 192   Layout layout(command_line.options(), &command_line.script_options());
 193
 194   // Get the search path from the -L options.
 195   Dirsearch search_path;
 196   search_path.initialize(&workqueue, &command_line.options().library_path());
 197
 198   // Queue up the first set of tasks.
 199   queue_initial_tasks(command_line.options(), search_path,
 200                       command_line, &workqueue, &input_objects,
 201                       &symtab, &layout);
 202
 203   // Run the main task processing loop.
 204   workqueue.process(0);
 205
 206   if (command_line.options().stats())
 207     {
 208       long run_time = get_run_time() - start_time;
 209       fprintf(stderr, _("%s: total run time: %ld.%06ld seconds\n"),
 210               program_name, run_time / 1000000, run_time % 1000000);
 211 #ifdef HAVE_MALLINFO
 212       struct mallinfo m = mallinfo();
 213       fprintf(stderr, _("%s: total space allocated by malloc: %d bytes\n"),
 214               program_name, m.arena);
 215 #endif
 216       File_read::print_stats();
 217       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 218               program_name, static_cast<long long>(layout.output_file_size()));
 219       symtab.print_stats();
 220       layout.print_stats();
 221     }
 222
 223   if (parameters->options().fatal_warnings()
 224       && errors.warning_count() > 0
 225       && errors.error_count() == 0)
 226     gold_error("treating warnings as errors");
 227
 228   // If the user used --noinhibit-exec, we force the exit status to be
 229   // successful.  This is compatible with GNU ld.
 230   gold_exit(errors.error_count() == 0
 231             || parameters->options().noinhibit_exec());
 232 }