gold/main.cc

   1 // main.cc -- gold main function.
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 "target-select.h"
  37 #include "parameters.h"
  38 #include "errors.h"
  39 #include "mapfile.h"
  40 #include "dirsearch.h"
  41 #include "workqueue.h"
  42 #include "object.h"
  43 #include "archive.h"
  44 #include "symtab.h"
  45 #include "layout.h"
  46 #include "plugin.h"
  47 #include "gc.h"
  48 #include "icf.h"
  49 #include "incremental.h"
  50 #include "timer.h"
  51
  52 using namespace gold;
  53
  54 // This function emits the commandline to a hard-coded file in temp.
  55 // This is useful for debugging since ld is typically invoked by gcc,
  56 // so its commandline is not always easy to extract.  You should be
  57 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  58 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  59 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  60 // (or whatever value the environment variable GDB is set to), for
  61 // even easier debugging.  Since this is a debugging-only tool, and
  62 // creates files, it is only turned on when the user explicitly asks
  63 // for it, by compiling with -DDEBUG.  Do not do this for release
  64 // versions of the linker!
  65
  66 #ifdef DEBUG
  67 #include <stdio.h>
  68 #include <sys/stat.h>    // for chmod()
  69
  70 static std::string
  71 collect_argv(int argc, char** argv)
  72 {
  73   // This is used by write_debug_script(), which wants the unedited argv.
  74   std::string args;
  75   for (int i = 0; i < argc; ++i)
  76     {
  77       args.append(" '");
  78       // Now append argv[i], but with all single-quotes escaped
  79       const char* argpos = argv[i];
  80       while (1)
  81         {
  82           const int len = strcspn(argpos, "'");
  83           args.append(argpos, len);
  84           if (argpos[len] == '\0')
  85             break;
  86           args.append("'\"'\"'");
  87           argpos += len + 1;
  88         }
  89       args.append("'");
  90     }
  91   return args;
  92 }
  93
  94 static void
  95 write_debug_script(std::string filename_str,
  96                    const char* argv_0, const char* args)
  97 {
  98   size_t slash = filename_str.rfind('/');
  99   if (slash != std::string::npos)
 100     filename_str = filename_str.c_str() + slash + 1;
 101   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
 102   const char* filename = filename_str.c_str();
 103   FILE* fp = fopen(filename, "w");
 104   if (fp)
 105     {
 106       fprintf(fp, "[ \"$1\" = debug ]"
 107               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
 108               " && shift\n",
 109               argv_0);
 110       fprintf(fp, "$PREFIX%s $*\n", args);
 111       fclose(fp);
 112       chmod(filename, 0755);
 113     }
 114   else
 115     filename = "[none]";
 116   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 117   fflush(stderr);
 118 }
 119
 120 #else // !defined(DEBUG)
 121
 122 static inline std::string
 123 collect_argv(int, char**)
 124 {
 125   return "";
 126 }
 127
 128 static inline void
 129 write_debug_script(std::string, const char*, const char*)
 130 {
 131 }
 132
 133 #endif // !defined(DEBUG)
 134
 135
 136 int
 137 main(int argc, char** argv)
 138 {
 139 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 140   setlocale(LC_MESSAGES, "");
 141 #endif
 142 #if defined (HAVE_SETLOCALE)
 143   setlocale(LC_CTYPE, "");
 144 #endif
 145   bindtextdomain(PACKAGE, LOCALEDIR);
 146   textdomain(PACKAGE);
 147
 148   program_name = argv[0];
 149
 150   // In libiberty; expands @filename to the args in "filename".
 151   expandargv(&argc, &argv);
 152
 153   // This is used by write_debug_script(), which wants the unedited argv.
 154   std::string args = collect_argv(argc, argv);
 155
 156   Errors errors(program_name);
 157
 158   // Initialize the global parameters, to let random code get to the
 159   // errors object.
 160   set_parameters_errors(&errors);
 161
 162   // Handle the command line options.
 163   Command_line command_line;
 164   command_line.process(argc - 1, const_cast<const char**>(argv + 1));
 165
 166   Timer timer;
 167   if (command_line.options().stats())
 168     timer.start();
 169
 170   // Store some options in the globally accessible parameters.
 171   set_parameters_options(&command_line.options());
 172
 173   // Do this as early as possible (since it prints a welcome message).
 174   write_debug_script(command_line.options().output_file_name(),
 175                      program_name, args.c_str());
 176
 177   // If the user asked for a map file, open it.
 178   Mapfile* mapfile = NULL;
 179   if (command_line.options().user_set_Map())
 180     {
 181       mapfile = new Mapfile();
 182       if (!mapfile->open(command_line.options().Map()))
 183         {
 184           delete mapfile;
 185           mapfile = NULL;
 186         }
 187     }
 188
 189   // The GNU linker ignores version scripts when generating
 190   // relocatable output.  If we are not compatible, then we break the
 191   // Linux kernel build, which uses a linker script with -r which must
 192   // not force symbols to be local.  It would actually be useful to
 193   // permit symbols to be forced local with -r, though, as it would
 194   // permit some linker optimizations.  Perhaps we need yet another
 195   // option to control this.  FIXME.
 196   if (parameters->options().relocatable())
 197     command_line.script_options().version_script_info()->clear();
 198
 199   // The work queue.
 200   Workqueue workqueue(command_line.options());
 201
 202   // The list of input objects.
 203   Input_objects input_objects;
 204
 205   // The Garbage Collection (GC, --gc-sections) Object.
 206   Garbage_collection gc;
 207
 208   // The Identical Code Folding (ICF, --icf) Object.
 209   Icf icf;
 210
 211   // The symbol table.  We're going to guess here how many symbols
 212   // we're going to see based on the number of input files.  Even when
 213   // this is off, it means at worst we don't quite optimize hashtable
 214   // resizing as well as we could have (perhaps using more memory).
 215   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 216                       command_line.version_script());
 217
 218   if (parameters->options().gc_sections())
 219     symtab.set_gc(&gc);
 220
 221   if (parameters->options().icf_enabled())
 222     symtab.set_icf(&icf);
 223
 224   // The layout object.
 225   Layout layout(command_line.number_of_input_files(),
 226                 &command_line.script_options());
 227
 228   if (layout.incremental_inputs() != NULL)
 229     layout.incremental_inputs()->report_command_line(argc, argv);
 230
 231   if (parameters->options().section_ordering_file())
 232     layout.read_layout_from_file();
 233
 234   // Load plugin libraries.
 235   if (command_line.options().has_plugins())
 236     command_line.options().plugins()->load_plugins(&layout);
 237
 238   // Get the search path from the -L options.
 239   Dirsearch search_path;
 240   search_path.initialize(&workqueue, &command_line.options().library_path());
 241
 242   // Queue up the first set of tasks.
 243   queue_initial_tasks(command_line.options(), search_path,
 244                       command_line, &workqueue, &input_objects,
 245                       &symtab, &layout, mapfile);
 246
 247   // Run the main task processing loop.
 248   workqueue.process(0);
 249
 250   if (command_line.options().print_output_format())
 251     print_output_format();
 252
 253   if (command_line.options().stats())
 254     {
 255       Timer::TimeStats elapsed = timer.get_elapsed_time();
 256       fprintf(stderr,
 257              _("%s: total run time: " \
 258                "(user: %ld.%06ld sys: %ld.%06ld wall: %ld.%06ld)\n"),
 259               program_name,
 260               elapsed.user / 1000, (elapsed.user % 1000) * 1000,
 261               elapsed.sys / 1000, (elapsed.sys % 1000) * 1000,
 262               elapsed.wall / 1000, (elapsed.wall % 1000) * 1000);
 263
 264 #ifdef HAVE_MALLINFO
 265       struct mallinfo m = mallinfo();
 266       fprintf(stderr, _("%s: total space allocated by malloc: %d bytes\n"),
 267               program_name, m.arena);
 268 #endif
 269       File_read::print_stats();
 270       Archive::print_stats();
 271       Lib_group::print_stats();
 272       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 273               program_name, static_cast<long long>(layout.output_file_size()));
 274       symtab.print_stats();
 275       layout.print_stats();
 276       Free_list::print_stats();
 277     }
 278
 279   // Issue defined symbol report.
 280   if (command_line.options().user_set_print_symbol_counts())
 281     input_objects.print_symbol_counts(&symtab);
 282
 283   // Output cross reference table.
 284   if (command_line.options().cref())
 285     input_objects.print_cref(&symtab,
 286                              mapfile == NULL ? stdout : mapfile->file());
 287
 288   if (mapfile != NULL)
 289     mapfile->close();
 290
 291   if (parameters->options().fatal_warnings()
 292       && errors.warning_count() > 0
 293       && errors.error_count() == 0)
 294     gold_error("treating warnings as errors");
 295
 296   // If the user used --noinhibit-exec, we force the exit status to be
 297   // successful.  This is compatible with GNU ld.
 298   gold_exit((errors.error_count() == 0
 299              || parameters->options().noinhibit_exec())
 300             ? GOLD_OK
 301             : GOLD_ERR);
 302 }