gcc/config/i386/intelmic-mkoffload.c

   1 /* Offload image generation tool for Intel MIC devices.
   2
   3    Copyright (C) 2014-2015 Free Software Foundation, Inc.
   4
   5    Contributed by Ilya Verbin <ilya.verbin@intel.com>.
   6
   7    This file is part of GCC.
   8
   9    GCC is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3, or (at your option)
  12    any later version.
  13
  14    GCC is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with GCC; see the file COPYING3.  If not see
  21    <http://www.gnu.org/licenses/>.  */
  22
  23 #include "config.h"
  24 #include <libgen.h>
  25 #include "system.h"
  26 #include "coretypes.h"
  27 #include "obstack.h"
  28 #include "intl.h"
  29 #include "diagnostic.h"
  30 #include "collect-utils.h"
  31 #include <libgomp_target.h>
  32
  33 const char tool_name[] = "intelmic mkoffload";
  34
  35 const char image_section_name[] = ".gnu.offload_images";
  36 const char *symbols[3] = { "__offload_image_intelmic_start",
  37                            "__offload_image_intelmic_end",
  38                            "__offload_image_intelmic_size" };
  39 const char *out_obj_filename = NULL;
  40
  41 int num_temps = 0;
  42 const int MAX_NUM_TEMPS = 10;
  43 const char *temp_files[MAX_NUM_TEMPS];
  44
  45 /* Shows if we should compile binaries for i386 instead of x86-64.  */
  46 bool target_ilp32 = false;
  47
  48 /* Delete tempfiles and exit function.  */
  49 void
  50 tool_cleanup (bool from_signal ATTRIBUTE_UNUSED)
  51 {
  52   for (int i = 0; i < num_temps; i++)
  53     maybe_unlink (temp_files[i]);
  54 }
  55
  56 static void
  57 mkoffload_atexit (void)
  58 {
  59   tool_cleanup (false);
  60 }
  61
  62 /* Unlink FILE unless we are debugging.  */
  63 void
  64 maybe_unlink (const char *file)
  65 {
  66   if (debug)
  67     notice ("[Leaving %s]\n", file);
  68   else
  69     unlink_if_ordinary (file);
  70 }
  71
  72 /* Add or change the value of an environment variable, outputting the
  73    change to standard error if in verbose mode.  */
  74 static void
  75 xputenv (const char *string)
  76 {
  77   if (verbose)
  78     fprintf (stderr, "%s\n", string);
  79   putenv (CONST_CAST (char *, string));
  80 }
  81
  82 /* Parse STR, saving found tokens into PVALUES and return their number.
  83    Tokens are assumed to be delimited by ':'.  */
  84 static unsigned
  85 parse_env_var (const char *str, char ***pvalues)
  86 {
  87   const char *curval, *nextval;
  88   char **values;
  89   unsigned num = 1, i;
  90
  91   curval = strchr (str, ':');
  92   while (curval)
  93     {
  94       num++;
  95       curval = strchr (curval + 1, ':');
  96     }
  97
  98   values = (char **) xmalloc (num * sizeof (char *));
  99   curval = str;
 100   nextval = strchr (curval, ':');
 101   if (nextval == NULL)
 102     nextval = strchr (curval, '\0');
 103
 104   for (i = 0; i < num; i++)
 105     {
 106       int l = nextval - curval;
 107       values[i] = (char *) xmalloc (l + 1);
 108       memcpy (values[i], curval, l);
 109       values[i][l] = 0;
 110       curval = nextval + 1;
 111       nextval = strchr (curval, ':');
 112       if (nextval == NULL)
 113         nextval = strchr (curval, '\0');
 114     }
 115   *pvalues = values;
 116   return num;
 117 }
 118
 119 /* Auxiliary function that frees elements of PTR and PTR itself.
 120    N is number of elements to be freed.  If PTR is NULL, nothing is freed.
 121    If an element is NULL, subsequent elements are not freed.  */
 122 static void
 123 free_array_of_ptrs (void **ptr, unsigned n)
 124 {
 125   unsigned i;
 126   if (!ptr)
 127     return;
 128   for (i = 0; i < n; i++)
 129     {
 130       if (!ptr[i])
 131         break;
 132       free (ptr[i]);
 133     }
 134   free (ptr);
 135   return;
 136 }
 137
 138 /* Check whether NAME can be accessed in MODE.  This is like access,
 139    except that it never considers directories to be executable.  */
 140 static int
 141 access_check (const char *name, int mode)
 142 {
 143   if (mode == X_OK)
 144     {
 145       struct stat st;
 146
 147       if (stat (name, &st) < 0 || S_ISDIR (st.st_mode))
 148         return -1;
 149     }
 150
 151   return access (name, mode);
 152 }
 153
 154 /* Find target compiler using a path from COLLECT_GCC or COMPILER_PATH.  */
 155 static char *
 156 find_target_compiler (const char *name)
 157 {
 158   bool found = false;
 159   char **paths = NULL;
 160   unsigned n_paths, i;
 161   const char *collect_path = dirname (ASTRDUP (getenv ("COLLECT_GCC")));
 162   size_t len = strlen (collect_path) + 1 + strlen (name) + 1;
 163   char *target_compiler = XNEWVEC (char, len);
 164   sprintf (target_compiler, "%s/%s", collect_path, name);
 165   if (access_check (target_compiler, X_OK) == 0)
 166     {
 167       found = true;
 168       goto out;
 169     }
 170
 171   n_paths = parse_env_var (getenv ("COMPILER_PATH"), &paths);
 172   for (i = 0; i < n_paths; i++)
 173     {
 174       len = strlen (paths[i]) + 1 + strlen (name) + 1;
 175       target_compiler = XRESIZEVEC (char, target_compiler, len);
 176       sprintf (target_compiler, "%s/%s", paths[i], name);
 177       if (access_check (target_compiler, X_OK) == 0)
 178         {
 179           found = true;
 180           break;
 181         }
 182     }
 183
 184 out:
 185   free_array_of_ptrs ((void **) paths, n_paths);
 186   return found ? target_compiler : NULL;
 187 }
 188
 189 static void
 190 compile_for_target (struct obstack *argv_obstack)
 191 {
 192   if (target_ilp32)
 193     obstack_ptr_grow (argv_obstack, "-m32");
 194   else
 195     obstack_ptr_grow (argv_obstack, "-m64");
 196   obstack_ptr_grow (argv_obstack, NULL);
 197   char **argv = XOBFINISH (argv_obstack, char **);
 198
 199   /* Save environment variables.  */
 200   const char *epath = getenv ("GCC_EXEC_PREFIX");
 201   const char *cpath = getenv ("COMPILER_PATH");
 202   const char *lpath = getenv ("LIBRARY_PATH");
 203   const char *rpath = getenv ("LD_RUN_PATH");
 204   unsetenv ("GCC_EXEC_PREFIX");
 205   unsetenv ("COMPILER_PATH");
 206   unsetenv ("LIBRARY_PATH");
 207   unsetenv ("LD_RUN_PATH");
 208
 209   fork_execute (argv[0], argv, false);
 210   obstack_free (argv_obstack, NULL);
 211
 212   /* Restore environment variables.  */
 213   xputenv (concat ("GCC_EXEC_PREFIX=", epath, NULL));
 214   xputenv (concat ("COMPILER_PATH=", cpath, NULL));
 215   xputenv (concat ("LIBRARY_PATH=", lpath, NULL));
 216   xputenv (concat ("LD_RUN_PATH=", rpath, NULL));
 217 }
 218
 219 /* Generates object file with the descriptor for the target library.  */
 220 static const char *
 221 generate_target_descr_file (const char *target_compiler)
 222 {
 223   const char *src_filename = make_temp_file ("_target_descr.c");
 224   const char *obj_filename = make_temp_file ("_target_descr.o");
 225   temp_files[num_temps++] = src_filename;
 226   temp_files[num_temps++] = obj_filename;
 227   FILE *src_file = fopen (src_filename, "w");
 228
 229   if (!src_file)
 230     fatal_error ("cannot open '%s'", src_filename);
 231
 232   fprintf (src_file,
 233            "extern void *__offload_funcs_end[];\n"
 234            "extern void *__offload_vars_end[];\n\n"
 235
 236            "void *__offload_func_table[0]\n"
 237            "__attribute__ ((__used__, visibility (\"hidden\"),\n"
 238            "section (\".gnu.offload_funcs\"))) = { };\n\n"
 239
 240            "void *__offload_var_table[0]\n"
 241            "__attribute__ ((__used__, visibility (\"hidden\"),\n"
 242            "section (\".gnu.offload_vars\"))) = { };\n\n"
 243
 244            "void *__OFFLOAD_TARGET_TABLE__[]\n"
 245            "__attribute__ ((__used__, visibility (\"hidden\"))) = {\n"
 246            "  &__offload_func_table, &__offload_funcs_end,\n"
 247            "  &__offload_var_table, &__offload_vars_end\n"
 248            "};\n\n");
 249
 250   fprintf (src_file,
 251            "#ifdef __cplusplus\n"
 252            "extern \"C\"\n"
 253            "#endif\n"
 254            "void target_register_lib (const void *);\n\n"
 255
 256            "__attribute__((constructor))\n"
 257            "static void\n"
 258            "init (void)\n"
 259            "{\n"
 260            "  target_register_lib (__OFFLOAD_TARGET_TABLE__);\n"
 261            "}\n");
 262   fclose (src_file);
 263
 264   struct obstack argv_obstack;
 265   obstack_init (&argv_obstack);
 266   obstack_ptr_grow (&argv_obstack, target_compiler);
 267   obstack_ptr_grow (&argv_obstack, "-c");
 268   obstack_ptr_grow (&argv_obstack, "-shared");
 269   obstack_ptr_grow (&argv_obstack, "-fPIC");
 270   obstack_ptr_grow (&argv_obstack, src_filename);
 271   obstack_ptr_grow (&argv_obstack, "-o");
 272   obstack_ptr_grow (&argv_obstack, obj_filename);
 273   compile_for_target (&argv_obstack);
 274
 275   return obj_filename;
 276 }
 277
 278 /* Generates object file with __offload_*_end symbols for the target
 279    library.  */
 280 static const char *
 281 generate_target_offloadend_file (const char *target_compiler)
 282 {
 283   const char *src_filename = make_temp_file ("_target_offloadend.c");
 284   const char *obj_filename = make_temp_file ("_target_offloadend.o");
 285   temp_files[num_temps++] = src_filename;
 286   temp_files[num_temps++] = obj_filename;
 287   FILE *src_file = fopen (src_filename, "w");
 288
 289   if (!src_file)
 290     fatal_error ("cannot open '%s'", src_filename);
 291
 292   fprintf (src_file,
 293            "void *__offload_funcs_end[0]\n"
 294            "__attribute__ ((__used__, visibility (\"hidden\"),\n"
 295            "section (\".gnu.offload_funcs\"))) = { };\n\n"
 296
 297            "void *__offload_vars_end[0]\n"
 298            "__attribute__ ((__used__, visibility (\"hidden\"),\n"
 299            "section (\".gnu.offload_vars\"))) = { };\n");
 300   fclose (src_file);
 301
 302   struct obstack argv_obstack;
 303   obstack_init (&argv_obstack);
 304   obstack_ptr_grow (&argv_obstack, target_compiler);
 305   obstack_ptr_grow (&argv_obstack, "-c");
 306   obstack_ptr_grow (&argv_obstack, "-shared");
 307   obstack_ptr_grow (&argv_obstack, "-fPIC");
 308   obstack_ptr_grow (&argv_obstack, src_filename);
 309   obstack_ptr_grow (&argv_obstack, "-o");
 310   obstack_ptr_grow (&argv_obstack, obj_filename);
 311   compile_for_target (&argv_obstack);
 312
 313   return obj_filename;
 314 }
 315
 316 /* Generates object file with the host side descriptor.  */
 317 static const char *
 318 generate_host_descr_file (const char *host_compiler)
 319 {
 320   const char *src_filename = make_temp_file ("_host_descr.c");
 321   const char *obj_filename = make_temp_file ("_host_descr.o");
 322   temp_files[num_temps++] = src_filename;
 323   temp_files[num_temps++] = obj_filename;
 324   FILE *src_file = fopen (src_filename, "w");
 325
 326   if (!src_file)
 327     fatal_error ("cannot open '%s'", src_filename);
 328
 329   fprintf (src_file,
 330            "extern void *__OFFLOAD_TABLE__;\n"
 331            "extern void *__offload_image_intelmic_start;\n"
 332            "extern void *__offload_image_intelmic_end;\n\n"
 333
 334            "static const void *__offload_target_data[] = {\n"
 335            "  &__offload_image_intelmic_start, &__offload_image_intelmic_end\n"
 336            "};\n\n");
 337
 338   fprintf (src_file,
 339            "#ifdef __cplusplus\n"
 340            "extern \"C\"\n"
 341            "#endif\n"
 342            "void GOMP_offload_register (void *, int, void *);\n\n"
 343
 344            "__attribute__((constructor))\n"
 345            "static void\n"
 346            "init (void)\n"
 347            "{\n"
 348            "  GOMP_offload_register (&__OFFLOAD_TABLE__, %d, __offload_target_data);\n"
 349            "}\n", OFFLOAD_TARGET_TYPE_INTEL_MIC);
 350   fclose (src_file);
 351
 352   unsigned new_argc = 0;
 353   const char *new_argv[9];
 354   new_argv[new_argc++] = host_compiler;
 355   new_argv[new_argc++] = "-c";
 356   new_argv[new_argc++] = "-fPIC";
 357   new_argv[new_argc++] = "-shared";
 358   if (target_ilp32)
 359     new_argv[new_argc++] = "-m32";
 360   else
 361     new_argv[new_argc++] = "-m64";
 362   new_argv[new_argc++] = src_filename;
 363   new_argv[new_argc++] = "-o";
 364   new_argv[new_argc++] = obj_filename;
 365   new_argv[new_argc++] = NULL;
 366
 367   fork_execute (new_argv[0], CONST_CAST (char **, new_argv), false);
 368
 369   return obj_filename;
 370 }
 371
 372 static const char *
 373 prepare_target_image (const char *target_compiler, int argc, char **argv)
 374 {
 375   const char *target_descr_filename
 376     = generate_target_descr_file (target_compiler);
 377   const char *target_offloadend_filename
 378     = generate_target_offloadend_file (target_compiler);
 379
 380   char *opt1
 381     = XALLOCAVEC (char, sizeof ("-Wl,") + strlen (target_descr_filename));
 382   char *opt2
 383     = XALLOCAVEC (char, sizeof ("-Wl,") + strlen (target_offloadend_filename));
 384   sprintf (opt1, "-Wl,%s", target_descr_filename);
 385   sprintf (opt2, "-Wl,%s", target_offloadend_filename);
 386
 387   const char *target_so_filename = make_temp_file ("_offload_intelmic.so");
 388   temp_files[num_temps++] = target_so_filename;
 389   struct obstack argv_obstack;
 390   obstack_init (&argv_obstack);
 391   obstack_ptr_grow (&argv_obstack, target_compiler);
 392   obstack_ptr_grow (&argv_obstack, "-xlto");
 393   obstack_ptr_grow (&argv_obstack, "-fopenmp");
 394   obstack_ptr_grow (&argv_obstack, "-shared");
 395   obstack_ptr_grow (&argv_obstack, "-fPIC");
 396   obstack_ptr_grow (&argv_obstack, opt1);
 397   for (int i = 1; i < argc; i++)
 398     {
 399       if (!strcmp (argv[i], "-o") && i + 1 != argc)
 400         out_obj_filename = argv[++i];
 401       else
 402         obstack_ptr_grow (&argv_obstack, argv[i]);
 403     }
 404   if (!out_obj_filename)
 405     fatal_error ("output file not specified");
 406   obstack_ptr_grow (&argv_obstack, opt2);
 407   obstack_ptr_grow (&argv_obstack, "-o");
 408   obstack_ptr_grow (&argv_obstack, target_so_filename);
 409   compile_for_target (&argv_obstack);
 410
 411   /* Run objcopy.  */
 412   char *rename_section_opt
 413     = XALLOCAVEC (char, sizeof (".data=") + strlen (image_section_name));
 414   sprintf (rename_section_opt, ".data=%s", image_section_name);
 415   const char *objcopy_argv[11];
 416   objcopy_argv[0] = "objcopy";
 417   objcopy_argv[1] = "-B";
 418   objcopy_argv[2] = "i386";
 419   objcopy_argv[3] = "-I";
 420   objcopy_argv[4] = "binary";
 421   objcopy_argv[5] = "-O";
 422   if (target_ilp32)
 423     objcopy_argv[6] = "elf32-i386";
 424   else
 425     objcopy_argv[6] = "elf64-x86-64";
 426   objcopy_argv[7] = target_so_filename;
 427   objcopy_argv[8] = "--rename-section";
 428   objcopy_argv[9] = rename_section_opt;
 429   objcopy_argv[10] = NULL;
 430   fork_execute (objcopy_argv[0], CONST_CAST (char **, objcopy_argv), false);
 431
 432   /* Objcopy has created symbols, containing the input file name with
 433      special characters replaced with '_'.  We are going to rename these
 434      new symbols.  */
 435   size_t symbol_name_len = strlen (target_so_filename);
 436   char *symbol_name = XALLOCAVEC (char, symbol_name_len + 1);
 437   for (size_t i = 0; i <= symbol_name_len; i++)
 438     {
 439       char c = target_so_filename[i];
 440       if ((c == '/') || (c == '.'))
 441         c = '_';
 442       symbol_name[i] = c;
 443     }
 444
 445   char *opt_for_objcopy[3];
 446   opt_for_objcopy[0] = XALLOCAVEC (char, sizeof ("_binary__start=")
 447                                          + symbol_name_len
 448                                          + strlen (symbols[0]));
 449   opt_for_objcopy[1] = XALLOCAVEC (char, sizeof ("_binary__end=")
 450                                          + symbol_name_len
 451                                          + strlen (symbols[1]));
 452   opt_for_objcopy[2] = XALLOCAVEC (char, sizeof ("_binary__size=")
 453                                          + symbol_name_len
 454                                          + strlen (symbols[2]));
 455   sprintf (opt_for_objcopy[0], "_binary_%s_start=%s", symbol_name, symbols[0]);
 456   sprintf (opt_for_objcopy[1], "_binary_%s_end=%s", symbol_name, symbols[1]);
 457   sprintf (opt_for_objcopy[2], "_binary_%s_size=%s", symbol_name, symbols[2]);
 458
 459   objcopy_argv[0] = "objcopy";
 460   objcopy_argv[1] = target_so_filename;
 461   objcopy_argv[2] = "--redefine-sym";
 462   objcopy_argv[3] = opt_for_objcopy[0];
 463   objcopy_argv[4] = "--redefine-sym";
 464   objcopy_argv[5] = opt_for_objcopy[1];
 465   objcopy_argv[6] = "--redefine-sym";
 466   objcopy_argv[7] = opt_for_objcopy[2];
 467   objcopy_argv[8] = NULL;
 468   fork_execute (objcopy_argv[0], CONST_CAST (char **, objcopy_argv), false);
 469
 470   return target_so_filename;
 471 }
 472
 473 int
 474 main (int argc, char **argv)
 475 {
 476   progname = "mkoffload-intelmic";
 477   gcc_init_libintl ();
 478   diagnostic_initialize (global_dc, 0);
 479
 480   if (atexit (mkoffload_atexit) != 0)
 481     fatal_error ("atexit failed");
 482
 483   const char *host_compiler = getenv ("COLLECT_GCC");
 484   if (!host_compiler)
 485     fatal_error ("COLLECT_GCC must be set");
 486
 487   const char *target_driver_name
 488     = DEFAULT_REAL_TARGET_MACHINE "-accel-" DEFAULT_TARGET_MACHINE "-gcc";
 489   char *target_compiler = find_target_compiler (target_driver_name);
 490   if (target_compiler == NULL)
 491     fatal_error ("offload compiler %s not found", target_driver_name);
 492
 493   /* We may be called with all the arguments stored in some file and
 494      passed with @file.  Expand them into argv before processing.  */
 495   expandargv (&argc, &argv);
 496
 497   /* Find out whether we should compile binaries for i386 or x86-64.  */
 498   for (int i = argc - 1; i > 0; i--)
 499     if (strncmp (argv[i], "-foffload-abi=", sizeof ("-foffload-abi=") - 1) == 0)
 500       {
 501         if (strstr (argv[i], "ilp32"))
 502           target_ilp32 = true;
 503         else if (!strstr (argv[i], "lp64"))
 504           fatal_error ("unrecognizable argument of option -foffload-abi");
 505         break;
 506       }
 507
 508   const char *target_so_filename
 509     = prepare_target_image (target_compiler, argc, argv);
 510
 511   const char *host_descr_filename = generate_host_descr_file (host_compiler);
 512
 513   /* Perform partial linking for the target image and host side descriptor.
 514      As a result we'll get a finalized object file with all offload data.  */
 515   unsigned new_argc = 0;
 516   const char *new_argv[9];
 517   new_argv[new_argc++] = "ld";
 518   new_argv[new_argc++] = "-m";
 519   if (target_ilp32)
 520     new_argv[new_argc++] = "elf_i386";
 521   else
 522     new_argv[new_argc++] = "elf_x86_64";
 523   new_argv[new_argc++] = "--relocatable";
 524   new_argv[new_argc++] = host_descr_filename;
 525   new_argv[new_argc++] = target_so_filename;
 526   new_argv[new_argc++] = "-o";
 527   new_argv[new_argc++] = out_obj_filename;
 528   new_argv[new_argc++] = NULL;
 529   fork_execute (new_argv[0], CONST_CAST (char **, new_argv), false);
 530
 531   /* Run objcopy on the resultant object file to localize generated symbols
 532      to avoid conflicting between different DSO and an executable.  */
 533   new_argv[0] = "objcopy";
 534   new_argv[1] = "-L";
 535   new_argv[2] = symbols[0];
 536   new_argv[3] = "-L";
 537   new_argv[4] = symbols[1];
 538   new_argv[5] = "-L";
 539   new_argv[6] = symbols[2];
 540   new_argv[7] = out_obj_filename;
 541   new_argv[8] = NULL;
 542   fork_execute (new_argv[0], CONST_CAST (char **, new_argv), false);
 543
 544   return 0;
 545 }