gcc/lto-wrapper.c

   1 /* Wrapper to call lto.  Used by collect2 and the linker plugin.
   2    Copyright (C) 2009 Free Software Foundation, Inc.
   3
   4    Factored out of collect2 by Rafael Espindola <espindola@google.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22
  23 /* This program is passed a gcc, a list of gcc arguments and a list of
  24    object files containing IL. It scans the argument list to check if
  25    we are in whopr mode or not modifies the arguments and needed and
  26    prints a list of output files on stdout.
  27
  28    Example:
  29
  30    $ lto-wrapper gcc/xgcc -B gcc a.o b.o -o test -flto
  31
  32    The above will print something like
  33    /tmp/ccwbQ8B2.lto.o
  34
  35    If -fwhopr is used instead, more than one file might be produced
  36    ./ccXj2DTk.lto.ltrans.o
  37    ./ccCJuXGv.lto.ltrans.o
  38 */
  39
  40 #include "config.h"
  41 #include "system.h"
  42 #include "coretypes.h"
  43 #include "tm.h"
  44 #include "intl.h"
  45 #include "libiberty.h"
  46
  47 int debug;                              /* true if -debug */
  48
  49 enum lto_mode_d {
  50   LTO_MODE_NONE,                        /* Not doing LTO. */
  51   LTO_MODE_LTO,                         /* Normal LTO. */
  52   LTO_MODE_WHOPR                        /* WHOPR. */
  53 };
  54
  55 /* Current LTO mode.  */
  56 static enum lto_mode_d lto_mode = LTO_MODE_NONE;
  57
  58 static char *ltrans_output_file;
  59 static char *flto_out;
  60 static char *args_name;
  61
  62 static void maybe_unlink_file (const char *);
  63
  64 /* Delete tempfiles and exit function.  */
  65
  66 static void
  67 lto_wrapper_exit (int status)
  68 {
  69   if (ltrans_output_file)
  70     maybe_unlink_file (ltrans_output_file);
  71   if (flto_out)
  72     maybe_unlink_file (flto_out);
  73   if (args_name)
  74     maybe_unlink_file (args_name);
  75   exit (status);
  76 }
  77
  78 /* Just die. CMSGID is the error message. */
  79
  80 static void __attribute__ ((format (printf, 1, 2)))
  81 fatal (const char * cmsgid, ...)
  82 {
  83   va_list ap;
  84
  85   va_start (ap, cmsgid);
  86   fprintf (stderr, "lto-wrapper: ");
  87   vfprintf (stderr, _(cmsgid), ap);
  88   fprintf (stderr, "\n");
  89   va_end (ap);
  90
  91   lto_wrapper_exit (FATAL_EXIT_CODE);
  92 }
  93
  94
  95 /* Die when sys call fails. CMSGID is the error message.  */
  96
  97 static void __attribute__ ((format (printf, 1, 2)))
  98 fatal_perror (const char *cmsgid, ...)
  99 {
 100   int e = errno;
 101   va_list ap;
 102
 103   va_start (ap, cmsgid);
 104   fprintf (stderr, "lto-wrapper: ");
 105   vfprintf (stderr, _(cmsgid), ap);
 106   fprintf (stderr, ": %s\n", xstrerror (e));
 107   va_end (ap);
 108
 109   lto_wrapper_exit (FATAL_EXIT_CODE);
 110 }
 111
 112
 113 /* Execute a program, and wait for the reply. ARGV are the arguments. The
 114    last one must be NULL. */
 115
 116 static struct pex_obj *
 117 collect_execute (char **argv)
 118 {
 119   struct pex_obj *pex;
 120   const char *errmsg;
 121   int err;
 122
 123   if (debug)
 124     {
 125       char **p_argv;
 126       const char *str;
 127
 128       for (p_argv = argv; (str = *p_argv) != (char *) 0; p_argv++)
 129         fprintf (stderr, " %s", str);
 130
 131       fprintf (stderr, "\n");
 132     }
 133
 134   fflush (stdout);
 135   fflush (stderr);
 136
 137   pex = pex_init (0, "lto-wrapper", NULL);
 138   if (pex == NULL)
 139     fatal_perror ("pex_init failed");
 140
 141   errmsg = pex_run (pex, PEX_LAST | PEX_SEARCH, argv[0], argv, NULL,
 142                     NULL, &err);
 143   if (errmsg != NULL)
 144     {
 145       if (err != 0)
 146         {
 147           errno = err;
 148           fatal_perror (errmsg);
 149         }
 150       else
 151         fatal (errmsg);
 152     }
 153
 154   return pex;
 155 }
 156
 157
 158 /* Wait for a process to finish, and exit if a nonzero status is found.
 159    PROG is the program name. PEX is the process we should wait for. */
 160
 161 static int
 162 collect_wait (const char *prog, struct pex_obj *pex)
 163 {
 164   int status;
 165
 166   if (!pex_get_status (pex, 1, &status))
 167     fatal_perror ("can't get program status");
 168   pex_free (pex);
 169
 170   if (status)
 171     {
 172       if (WIFSIGNALED (status))
 173         {
 174           int sig = WTERMSIG (status);
 175           if (WCOREDUMP (status))
 176             fatal ("%s terminated with signal %d [%s], core dumped",
 177                    prog, sig, strsignal (sig));
 178           else
 179             fatal ("%s terminated with signal %d [%s]",
 180                    prog, sig, strsignal (sig));
 181         }
 182
 183       if (WIFEXITED (status))
 184         fatal ("%s returned %d exit status", prog, WEXITSTATUS (status));
 185     }
 186
 187   return 0;
 188 }
 189
 190
 191 /* Unlink a temporary LTRANS file unless requested otherwise.  */
 192
 193 static void
 194 maybe_unlink_file (const char *file)
 195 {
 196   if (! debug)
 197     {
 198       if (unlink_if_ordinary (file))
 199         fatal_perror ("deleting LTRANS file %s", file);
 200     }
 201   else
 202     fprintf (stderr, "[Leaving LTRANS %s]\n", file);
 203 }
 204
 205
 206 /* Execute program ARGV[0] with arguments ARGV. Wait for it to finish.  */
 207
 208 static void
 209 fork_execute (char **argv)
 210 {
 211   struct pex_obj *pex;
 212   char *new_argv[3];
 213   char *at_args;
 214   FILE *args;
 215   int status;
 216
 217   args_name = make_temp_file (".args");
 218   at_args = concat ("@", args_name, NULL);
 219   args = fopen (args_name, "w");
 220   if (args == NULL)
 221     fatal ("failed to open %s", args_name);
 222
 223   status = writeargv (&argv[1], args);
 224
 225   if (status)
 226     fatal ("could not write to temporary file %s",  args_name);
 227
 228   fclose (args);
 229
 230   new_argv[0] = argv[0];
 231   new_argv[1] = at_args;
 232   new_argv[2] = NULL;
 233
 234   pex = collect_execute (new_argv);
 235   collect_wait (new_argv[0], pex);
 236
 237   maybe_unlink_file (args_name);
 238   free (at_args);
 239 }
 240
 241
 242 /* Execute gcc. ARGC is the number of arguments. ARGV contains the arguments. */
 243
 244 static void
 245 run_gcc (unsigned argc, char *argv[])
 246 {
 247   unsigned i;
 248   unsigned new_argc = argc;
 249   const char **new_argv;
 250   const char **argv_ptr;
 251   char *list_option_full = NULL;
 252
 253   new_argc += 8;
 254   new_argv = (const char **) xcalloc (sizeof (char *), new_argc);
 255
 256   argv_ptr = new_argv;
 257
 258   *argv_ptr++ = argv[0];
 259   *argv_ptr++ = "-combine";
 260   *argv_ptr++ = "-x";
 261   *argv_ptr++ = "lto";
 262   *argv_ptr++ = "-c";
 263   if (lto_mode == LTO_MODE_LTO)
 264     {
 265       flto_out = make_temp_file (".lto.o");
 266       *argv_ptr++ = "-o";
 267       *argv_ptr++ = flto_out;
 268     }
 269   else if (lto_mode == LTO_MODE_WHOPR)
 270     {
 271       const char *list_option = "-fltrans-output-list=";
 272       size_t list_option_len = strlen (list_option);
 273       char *tmp;
 274
 275       ltrans_output_file = make_temp_file (".ltrans.out");
 276       list_option_full = (char *) xmalloc (sizeof (char) *
 277                          (strlen (ltrans_output_file) + list_option_len + 1));
 278       tmp = list_option_full;
 279
 280       *argv_ptr++ = tmp;
 281       strcpy (tmp, list_option);
 282       tmp += list_option_len;
 283       strcpy (tmp, ltrans_output_file);
 284
 285       *argv_ptr++ = "-fwpa";
 286     }
 287   else
 288     fatal ("invalid LTO mode");
 289
 290   /* Add inherited GCC options to the LTO back end command line.
 291      Filter out some obviously inappropriate options that will
 292      conflict with  the options that we force above.  We pass
 293      all of the remaining options on to LTO, and let it complain
 294      about any it doesn't like. Note that we invoke LTO via the
 295      `gcc' driver, so the usual option processing takes place.
 296      Except for `-flto' and `-fwhopr', we should only filter options that
 297      are meaningful to `ld', lest an option go silently unclaimed.  */
 298   for (i = 1; i < argc; i++)
 299     {
 300       const char *s = argv[i];
 301
 302       if (strcmp (s, "-flto") == 0 || strcmp (s, "-fwhopr") == 0)
 303         /* We've handled this LTO option, don't pass it on.  */
 304         ;
 305       else if (*s == '-' && s[1] == 'o')
 306         {
 307           /* Drop `-o' and its filename argument.  We will use a
 308              temporary file for the LTO output.  The `-o' option
 309              will be interpreted by the linker.  */
 310           if (s[2] == '\0')
 311             i++;
 312         }
 313       else
 314         /* Pass the option or argument to LTO.  */
 315         *argv_ptr++ = s;
 316     }
 317
 318   *argv_ptr = NULL;
 319
 320   fork_execute (CONST_CAST (char **, new_argv));
 321   free (new_argv);
 322   new_argv = NULL;
 323
 324   if (lto_mode == LTO_MODE_LTO)
 325     {
 326       printf("%s\n", flto_out);
 327       free (flto_out);
 328       flto_out = NULL;
 329     }
 330   else if (lto_mode == LTO_MODE_WHOPR)
 331     {
 332       FILE *stream = fopen (ltrans_output_file, "r");
 333       int c;
 334
 335       if (!stream)
 336         fatal_perror ("fopen: %s", ltrans_output_file);
 337
 338       while ((c = getc (stream)) != EOF)
 339         putc (c, stdout);
 340       fclose (stream);
 341       maybe_unlink_file (ltrans_output_file);
 342       free (list_option_full);
 343     }
 344   else
 345     fatal ("invalid LTO mode");
 346 }
 347
 348
 349 /* Parse the command line. Copy any unused argument to GCC_ARGV. ARGC is the
 350    number of arguments. ARGV contains the arguments. */
 351
 352 static int
 353 process_args (int argc, char *argv[], char *gcc_argv[])
 354 {
 355   int i;
 356   int j = 0;
 357
 358   for (i = 1; i < argc; i ++)
 359     {
 360       if (! strcmp (argv[i], "-debug"))
 361         debug = 1;
 362       else if (! strcmp (argv[i], "-flto"))
 363         lto_mode = LTO_MODE_LTO;
 364       else if (! strcmp (argv[i], "-fwhopr"))
 365         lto_mode = LTO_MODE_WHOPR;
 366       else
 367         {
 368           gcc_argv[j] = argv[i];
 369           j++;
 370         }
 371     }
 372
 373   return j;
 374 }
 375
 376
 377 /* Entry point.  */
 378
 379 int
 380 main (int argc, char *argv[])
 381 {
 382   char **gcc_argv;
 383   int gcc_argc;
 384
 385   gcc_init_libintl ();
 386
 387   /* We may be called with all the arguments stored in some file and
 388      passed with @file.  Expand them into argv before processing.  */
 389   expandargv (&argc, &argv);
 390   gcc_argv = (char **) xcalloc (sizeof (char *), argc);
 391   gcc_argc = process_args (argc, argv, gcc_argv);
 392   run_gcc (gcc_argc, gcc_argv);
 393   free (gcc_argv);
 394
 395   return 0;
 396 }