gold/main.cc

   1 // main.cc -- gold main function.
   2
   3 // Copyright (C) 2006-2020 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 "gdb-index.h"
  51 #include "timer.h"
  52
  53 using namespace gold;
  54
  55 // This function emits the commandline to a hard-coded file in temp.
  56 // This is useful for debugging since ld is typically invoked by gcc,
  57 // so its commandline is not always easy to extract.  You should be
  58 // able to run 'gcc -B... foo.o -o foo' to invoke this linker the
  59 // first time, and then /tmp/ld-run-foo.sh to invoke it on subsequent
  60 // runes.  "/tmp/ld-run-foo.sh debug" will run the linker inside gdb
  61 // (or whatever value the environment variable GDB is set to), for
  62 // even easier debugging.  Since this is a debugging-only tool, and
  63 // creates files, it is only turned on when the user explicitly asks
  64 // for it, by compiling with -DDEBUG.  Do not do this for release
  65 // versions of the linker!
  66
  67 #ifdef DEBUG
  68 #include <stdio.h>
  69 #include <sys/stat.h>    // for chmod()
  70
  71 static std::string
  72 collect_argv(int argc, char** argv)
  73 {
  74   // This is used by write_debug_script(), which wants the unedited argv.
  75   std::string args;
  76   for (int i = 0; i < argc; ++i)
  77     {
  78       args.append(" '");
  79       // Now append argv[i], but with all single-quotes escaped
  80       const char* argpos = argv[i];
  81       while (1)
  82         {
  83           const int len = strcspn(argpos, "'");
  84           args.append(argpos, len);
  85           if (argpos[len] == '\0')
  86             break;
  87           args.append("'\"'\"'");
  88           argpos += len + 1;
  89         }
  90       args.append("'");
  91     }
  92   return args;
  93 }
  94
  95 static void
  96 write_debug_script(std::string filename_str,
  97                    const char* argv_0, const char* args)
  98 {
  99   size_t slash = filename_str.rfind('/');
 100   if (slash != std::string::npos)
 101     filename_str = filename_str.c_str() + slash + 1;
 102   filename_str = std::string("/tmp/ld-run-") + filename_str + ".sh";
 103   const char* filename = filename_str.c_str();
 104   FILE* fp = fopen(filename, "w");
 105   if (fp)
 106     {
 107       fprintf(fp, "[ \"$1\" = debug ]"
 108               " && PREFIX=\"${GDB-gdb} --annotate=3 --fullname %s --args\""
 109               " && shift\n",
 110               argv_0);
 111       fprintf(fp, "$PREFIX%s $*\n", args);
 112       fclose(fp);
 113       chmod(filename, 0755);
 114     }
 115   else
 116     filename = "[none]";
 117   fprintf(stderr, "Welcome to gold!  Commandline written to %s.\n", filename);
 118   fflush(stderr);
 119 }
 120
 121 #else // !defined(DEBUG)
 122
 123 static inline std::string
 124 collect_argv(int, char**)
 125 {
 126   return "";
 127 }
 128
 129 static inline void
 130 write_debug_script(std::string, const char*, const char*)
 131 {
 132 }
 133
 134 #endif // !defined(DEBUG)
 135
 136
 137 int
 138 main(int argc, char** argv)
 139 {
 140 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 141   setlocale(LC_MESSAGES, "");
 142 #endif
 143 #if defined (HAVE_SETLOCALE)
 144   setlocale(LC_CTYPE, "");
 145 #endif
 146   bindtextdomain(PACKAGE, LOCALEDIR);
 147   textdomain(PACKAGE);
 148
 149   program_name = argv[0];
 150
 151   // In libiberty; expands @filename to the args in "filename".
 152   expandargv(&argc, &argv);
 153
 154   // This is used by write_debug_script(), which wants the unedited argv.
 155   std::string args = collect_argv(argc, argv);
 156
 157   Errors errors(program_name);
 158
 159   // Initialize the global parameters, to let random code get to the
 160   // errors object.
 161   set_parameters_errors(&errors);
 162
 163   // Handle the command line options.
 164   Command_line command_line;
 165   command_line.process(argc - 1, const_cast<const char**>(argv + 1));
 166
 167   Timer timer;
 168   if (command_line.options().stats())
 169     {
 170       timer.start();
 171       set_parameters_timer(&timer);
 172     }
 173
 174   // Store some options in the globally accessible parameters.
 175   set_parameters_options(&command_line.options());
 176
 177   // Do this as early as possible (since it prints a welcome message).
 178   write_debug_script(command_line.options().output_file_name(),
 179                      program_name, args.c_str());
 180
 181   // If the user asked for a map file, open it.
 182   Mapfile* mapfile = NULL;
 183   if (command_line.options().user_set_Map())
 184     {
 185       mapfile = new Mapfile();
 186       if (!mapfile->open(command_line.options().Map()))
 187         {
 188           delete mapfile;
 189           mapfile = NULL;
 190         }
 191     }
 192
 193   // The GNU linker ignores version scripts when generating
 194   // relocatable output.  If we are not compatible, then we break the
 195   // Linux kernel build, which uses a linker script with -r which must
 196   // not force symbols to be local.  It would actually be useful to
 197   // permit symbols to be forced local with -r, though, as it would
 198   // permit some linker optimizations.  Perhaps we need yet another
 199   // option to control this.  FIXME.
 200   if (parameters->options().relocatable())
 201     command_line.script_options().version_script_info()->clear();
 202
 203   // The work queue.
 204   Workqueue workqueue(command_line.options());
 205
 206   // The list of input objects.
 207   Input_objects input_objects;
 208
 209   // The Garbage Collection (GC, --gc-sections) Object.
 210   Garbage_collection gc;
 211
 212   // The Identical Code Folding (ICF, --icf) Object.
 213   Icf icf;
 214
 215   // The symbol table.  We're going to guess here how many symbols
 216   // we're going to see based on the number of input files.  Even when
 217   // this is off, it means at worst we don't quite optimize hashtable
 218   // resizing as well as we could have (perhaps using more memory).
 219   Symbol_table symtab(command_line.number_of_input_files() * 1024,
 220                       command_line.version_script());
 221
 222   if (parameters->options().gc_sections())
 223     symtab.set_gc(&gc);
 224
 225   if (parameters->options().icf_enabled())
 226     symtab.set_icf(&icf);
 227
 228   // The layout object.
 229   Layout layout(command_line.number_of_input_files(),
 230                 &command_line.script_options());
 231
 232   if (layout.incremental_inputs() != NULL)
 233     layout.incremental_inputs()->report_command_line(argc, argv);
 234
 235   if (parameters->options().section_ordering_file())
 236     layout.read_layout_from_file();
 237
 238   // Load plugin libraries.
 239   if (command_line.options().has_plugins())
 240     command_line.options().plugins()->load_plugins(&layout);
 241
 242   // Get the search path from the -L options.
 243   Dirsearch search_path;
 244   search_path.initialize(&workqueue, &command_line.options().library_path());
 245
 246   // Queue up the first set of tasks.
 247   queue_initial_tasks(command_line.options(), search_path,
 248                       command_line, &workqueue, &input_objects,
 249                       &symtab, &layout, mapfile);
 250
 251   // Run the main task processing loop.
 252   workqueue.process(0);
 253
 254   if (command_line.options().print_output_format())
 255     print_output_format();
 256
 257   if (command_line.options().stats())
 258     {
 259       timer.stamp(2);
 260       Timer::TimeStats elapsed = timer.get_pass_time(0);
 261       fprintf(stderr,
 262              _("%s: initial tasks run time: " \
 263                "(user: %ld.%06ld sys: %ld.%06ld wall: %ld.%06ld)\n"),
 264               program_name,
 265               elapsed.user / 1000, (elapsed.user % 1000) * 1000,
 266               elapsed.sys / 1000, (elapsed.sys % 1000) * 1000,
 267               elapsed.wall / 1000, (elapsed.wall % 1000) * 1000);
 268       elapsed = timer.get_pass_time(1);
 269       fprintf(stderr,
 270              _("%s: middle tasks run time: " \
 271                "(user: %ld.%06ld sys: %ld.%06ld wall: %ld.%06ld)\n"),
 272               program_name,
 273               elapsed.user / 1000, (elapsed.user % 1000) * 1000,
 274               elapsed.sys / 1000, (elapsed.sys % 1000) * 1000,
 275               elapsed.wall / 1000, (elapsed.wall % 1000) * 1000);
 276       elapsed = timer.get_pass_time(2);
 277       fprintf(stderr,
 278              _("%s: final tasks run time: " \
 279                "(user: %ld.%06ld sys: %ld.%06ld wall: %ld.%06ld)\n"),
 280               program_name,
 281               elapsed.user / 1000, (elapsed.user % 1000) * 1000,
 282               elapsed.sys / 1000, (elapsed.sys % 1000) * 1000,
 283               elapsed.wall / 1000, (elapsed.wall % 1000) * 1000);
 284       elapsed = timer.get_elapsed_time();
 285       fprintf(stderr,
 286              _("%s: total run time: " \
 287                "(user: %ld.%06ld sys: %ld.%06ld wall: %ld.%06ld)\n"),
 288               program_name,
 289               elapsed.user / 1000, (elapsed.user % 1000) * 1000,
 290               elapsed.sys / 1000, (elapsed.sys % 1000) * 1000,
 291               elapsed.wall / 1000, (elapsed.wall % 1000) * 1000);
 292
 293 #ifdef HAVE_MALLINFO
 294       struct mallinfo m = mallinfo();
 295       fprintf(stderr, _("%s: total space allocated by malloc: %lld bytes\n"),
 296               program_name, static_cast<long long>(m.arena));
 297 #endif
 298       File_read::print_stats();
 299       Archive::print_stats();
 300       Lib_group::print_stats();
 301       fprintf(stderr, _("%s: output file size: %lld bytes\n"),
 302               program_name, static_cast<long long>(layout.output_file_size()));
 303       symtab.print_stats();
 304       layout.print_stats();
 305       Gdb_index::print_stats();
 306       Free_list::print_stats();
 307     }
 308
 309   // Issue defined symbol report.
 310   if (command_line.options().user_set_print_symbol_counts())
 311     input_objects.print_symbol_counts(&symtab);
 312
 313   // Output cross reference table.
 314   if (command_line.options().cref())
 315     input_objects.print_cref(&symtab,
 316                              mapfile == NULL ? stdout : mapfile->file());
 317
 318   if (mapfile != NULL)
 319     mapfile->close();
 320
 321   if (parameters->options().fatal_warnings()
 322       && errors.warning_count() > 0
 323       && errors.error_count() == 0)
 324     gold_error("treating warnings as errors");
 325
 326   // If the user used --noinhibit-exec, we force the exit status to be
 327   // successful.  This is compatible with GNU ld.
 328   gold_exit((errors.error_count() == 0
 329              || parameters->options().noinhibit_exec())
 330             ? GOLD_OK
 331             : GOLD_ERR);
 332 }