gcc/tlink.c

   1 /* Scan linker error messages for missing template instantiations and provide
   2    them.
   3
   4    Copyright (C) 1995-2014 Free Software Foundation, Inc.
   5    Contributed by Jason Merrill (jason@cygnus.com).
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify it under
  10 the terms of the GNU General Public License as published by the Free
  11 Software Foundation; either version 3, or (at your option) any later
  12 version.
  13
  14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17 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 "system.h"
  25 #include "coretypes.h"
  26 #include "tm.h"
  27 #include "intl.h"
  28 #include "obstack.h"
  29 #include "hashtab.h"
  30 #include "demangle.h"
  31 #include "collect2.h"
  32 #include "filenames.h"
  33 #include "diagnostic-core.h"
  34 #include "vec.h"
  35
  36 /* TARGET_64BIT may be defined to use driver specific functionality. */
  37 #undef TARGET_64BIT
  38 #define TARGET_64BIT TARGET_64BIT_DEFAULT
  39
  40 #define MAX_ITERATIONS 17
  41
  42 /* Defined in the automatically-generated underscore.c.  */
  43 extern int prepends_underscore;
  44
  45 static int tlink_verbose;
  46
  47 static char *initial_cwd;
  48 \f
  49 /* Hash table boilerplate for working with htab_t.  We have hash tables
  50    for symbol names, file names, and demangled symbols.  */
  51
  52 typedef struct symbol_hash_entry
  53 {
  54   const char *key;
  55   struct file_hash_entry *file;
  56   int chosen;
  57   int tweaking;
  58   int tweaked;
  59 } symbol;
  60
  61 typedef struct file_hash_entry
  62 {
  63   const char *key;
  64   const char *args;
  65   const char *dir;
  66   const char *main;
  67   int tweaking;
  68 } file;
  69
  70 typedef const char *str;
  71
  72 typedef struct demangled_hash_entry
  73 {
  74   const char *key;
  75   vec<str> mangled;
  76 } demangled;
  77
  78 /* Hash and comparison functions for these hash tables.  */
  79
  80 static int hash_string_eq (const void *, const void *);
  81 static hashval_t hash_string_hash (const void *);
  82
  83 static int
  84 hash_string_eq (const void *s1_p, const void *s2_p)
  85 {
  86   const char *const *s1 = (const char *const *) s1_p;
  87   const char *s2 = (const char *) s2_p;
  88   return strcmp (*s1, s2) == 0;
  89 }
  90
  91 static hashval_t
  92 hash_string_hash (const void *s_p)
  93 {
  94   const char *const *s = (const char *const *) s_p;
  95   return (*htab_hash_string) (*s);
  96 }
  97
  98 static htab_t symbol_table;
  99
 100 static struct symbol_hash_entry * symbol_hash_lookup (const char *, int);
 101 static struct file_hash_entry * file_hash_lookup (const char *);
 102 static struct demangled_hash_entry *demangled_hash_lookup (const char *, int);
 103 static void symbol_push (symbol *);
 104 static symbol * symbol_pop (void);
 105 static void file_push (file *);
 106 static file * file_pop (void);
 107 static void tlink_init (void);
 108 static int tlink_execute (const char *, char **, const char *, const char *);
 109 static char * frob_extension (const char *, const char *);
 110 static char * obstack_fgets (FILE *, struct obstack *);
 111 static char * tfgets (FILE *);
 112 static char * pfgets (FILE *);
 113 static void freadsym (FILE *, file *, int);
 114 static void read_repo_file (file *);
 115 static void maybe_tweak (char *, file *);
 116 static int recompile_files (void);
 117 static int read_repo_files (char **);
 118 static void demangle_new_symbols (void);
 119 static int scan_linker_output (const char *);
 120
 121 /* Look up an entry in the symbol hash table.  */
 122
 123 static struct symbol_hash_entry *
 124 symbol_hash_lookup (const char *string, int create)
 125 {
 126   void **e;
 127   e = htab_find_slot_with_hash (symbol_table, string,
 128                                 (*htab_hash_string) (string),
 129                                 create ? INSERT : NO_INSERT);
 130   if (e == NULL)
 131     return NULL;
 132   if (*e == NULL)
 133     {
 134       struct symbol_hash_entry *v;
 135       *e = v = XCNEW (struct symbol_hash_entry);
 136       v->key = xstrdup (string);
 137     }
 138   return (struct symbol_hash_entry *) *e;
 139 }
 140
 141 static htab_t file_table;
 142
 143 /* Look up an entry in the file hash table.  */
 144
 145 static struct file_hash_entry *
 146 file_hash_lookup (const char *string)
 147 {
 148   void **e;
 149   e = htab_find_slot_with_hash (file_table, string,
 150                                 (*htab_hash_string) (string),
 151                                 INSERT);
 152   if (*e == NULL)
 153     {
 154       struct file_hash_entry *v;
 155       *e = v = XCNEW (struct file_hash_entry);
 156       v->key = xstrdup (string);
 157     }
 158   return (struct file_hash_entry *) *e;
 159 }
 160
 161 static htab_t demangled_table;
 162
 163 /* Look up an entry in the demangled name hash table.  */
 164
 165 static struct demangled_hash_entry *
 166 demangled_hash_lookup (const char *string, int create)
 167 {
 168   void **e;
 169   e = htab_find_slot_with_hash (demangled_table, string,
 170                                 (*htab_hash_string) (string),
 171                                 create ? INSERT : NO_INSERT);
 172   if (e == NULL)
 173     return NULL;
 174   if (*e == NULL)
 175     {
 176       struct demangled_hash_entry *v;
 177       *e = v = XCNEW (struct demangled_hash_entry);
 178       v->key = xstrdup (string);
 179     }
 180   return (struct demangled_hash_entry *) *e;
 181 }
 182 \f
 183 /* Stack code.  */
 184
 185 struct symbol_stack_entry
 186 {
 187   symbol *value;
 188   struct symbol_stack_entry *next;
 189 };
 190 struct obstack symbol_stack_obstack;
 191 struct symbol_stack_entry *symbol_stack;
 192
 193 struct file_stack_entry
 194 {
 195   file *value;
 196   struct file_stack_entry *next;
 197 };
 198 struct obstack file_stack_obstack;
 199 struct file_stack_entry *file_stack;
 200
 201 static void
 202 symbol_push (symbol *p)
 203 {
 204   struct symbol_stack_entry *ep
 205     = XOBNEW (&symbol_stack_obstack, struct symbol_stack_entry);
 206   ep->value = p;
 207   ep->next = symbol_stack;
 208   symbol_stack = ep;
 209 }
 210
 211 static symbol *
 212 symbol_pop (void)
 213 {
 214   struct symbol_stack_entry *ep = symbol_stack;
 215   symbol *p;
 216   if (ep == NULL)
 217     return NULL;
 218   p = ep->value;
 219   symbol_stack = ep->next;
 220   obstack_free (&symbol_stack_obstack, ep);
 221   return p;
 222 }
 223
 224 static void
 225 file_push (file *p)
 226 {
 227   struct file_stack_entry *ep;
 228
 229   if (p->tweaking)
 230     return;
 231
 232   ep = XOBNEW (&file_stack_obstack, struct file_stack_entry);
 233   ep->value = p;
 234   ep->next = file_stack;
 235   file_stack = ep;
 236   p->tweaking = 1;
 237 }
 238
 239 static file *
 240 file_pop (void)
 241 {
 242   struct file_stack_entry *ep = file_stack;
 243   file *p;
 244   if (ep == NULL)
 245     return NULL;
 246   p = ep->value;
 247   file_stack = ep->next;
 248   obstack_free (&file_stack_obstack, ep);
 249   p->tweaking = 0;
 250   return p;
 251 }
 252 \f
 253 /* Other machinery.  */
 254
 255 /* Initialize the tlink machinery.  Called from do_tlink.  */
 256
 257 static void
 258 tlink_init (void)
 259 {
 260   const char *p;
 261
 262   symbol_table = htab_create (500, hash_string_hash, hash_string_eq,
 263                               NULL);
 264   file_table = htab_create (500, hash_string_hash, hash_string_eq,
 265                             NULL);
 266   demangled_table = htab_create (500, hash_string_hash, hash_string_eq,
 267                                  NULL);
 268
 269   obstack_begin (&symbol_stack_obstack, 0);
 270   obstack_begin (&file_stack_obstack, 0);
 271
 272   p = getenv ("TLINK_VERBOSE");
 273   if (p)
 274     tlink_verbose = atoi (p);
 275   else
 276     {
 277       tlink_verbose = 1;
 278       if (vflag)
 279         tlink_verbose = 2;
 280       if (debug)
 281         tlink_verbose = 3;
 282     }
 283
 284   initial_cwd = getpwd ();
 285 }
 286
 287 static int
 288 tlink_execute (const char *prog, char **argv, const char *outname,
 289                const char *errname)
 290 {
 291   struct pex_obj *pex;
 292
 293   pex = collect_execute (prog, argv, outname, errname, PEX_LAST | PEX_SEARCH);
 294   return collect_wait (prog, pex);
 295 }
 296
 297 static char *
 298 frob_extension (const char *s, const char *ext)
 299 {
 300   const char *p;
 301
 302   p = strrchr (lbasename (s), '.');
 303   if (! p)
 304     p = s + strlen (s);
 305
 306   obstack_grow (&temporary_obstack, s, p - s);
 307   return (char *) obstack_copy0 (&temporary_obstack, ext, strlen (ext));
 308 }
 309
 310 static char *
 311 obstack_fgets (FILE *stream, struct obstack *ob)
 312 {
 313   int c;
 314   while ((c = getc (stream)) != EOF && c != '\n')
 315     obstack_1grow (ob, c);
 316   if (obstack_object_size (ob) == 0)
 317     return NULL;
 318   obstack_1grow (ob, '\0');
 319   return XOBFINISH (ob, char *);
 320 }
 321
 322 static char *
 323 tfgets (FILE *stream)
 324 {
 325   return obstack_fgets (stream, &temporary_obstack);
 326 }
 327
 328 static char *
 329 pfgets (FILE *stream)
 330 {
 331   return xstrdup (tfgets (stream));
 332 }
 333 \f
 334 /* Real tlink code.  */
 335
 336 /* Subroutine of read_repo_file.  We are reading the repo file for file F,
 337    which is coming in on STREAM, and the symbol that comes next in STREAM
 338    is offered, chosen or provided if CHOSEN is 0, 1 or 2, respectively.
 339
 340    XXX "provided" is unimplemented, both here and in the compiler.  */
 341
 342 static void
 343 freadsym (FILE *stream, file *f, int chosen)
 344 {
 345   symbol *sym;
 346
 347   {
 348     const char *name = tfgets (stream);
 349     sym = symbol_hash_lookup (name, true);
 350   }
 351
 352   if (sym->file == NULL)
 353     {
 354       /* We didn't have this symbol already, so we choose this file.  */
 355
 356       symbol_push (sym);
 357       sym->file = f;
 358       sym->chosen = chosen;
 359     }
 360   else if (chosen)
 361     {
 362       /* We want this file; cast aside any pretender.  */
 363
 364       if (sym->chosen && sym->file != f)
 365         {
 366           if (sym->chosen == 1)
 367             file_push (sym->file);
 368           else
 369             {
 370               file_push (f);
 371               f = sym->file;
 372               chosen = sym->chosen;
 373             }
 374         }
 375       sym->file = f;
 376       sym->chosen = chosen;
 377     }
 378 }
 379
 380 /* Read in the repo file denoted by F, and record all its information.  */
 381
 382 static void
 383 read_repo_file (file *f)
 384 {
 385   char c;
 386   FILE *stream = fopen (f->key, "r");
 387
 388   if (tlink_verbose >= 2)
 389     fprintf (stderr, _("collect: reading %s\n"), f->key);
 390
 391   while (fscanf (stream, "%c ", &c) == 1)
 392     {
 393       switch (c)
 394         {
 395         case 'A':
 396           f->args = pfgets (stream);
 397           break;
 398         case 'D':
 399           f->dir = pfgets (stream);
 400           break;
 401         case 'M':
 402           f->main = pfgets (stream);
 403           break;
 404         case 'P':
 405           freadsym (stream, f, 2);
 406           break;
 407         case 'C':
 408           freadsym (stream, f, 1);
 409           break;
 410         case 'O':
 411           freadsym (stream, f, 0);
 412           break;
 413         }
 414       obstack_free (&temporary_obstack, temporary_firstobj);
 415     }
 416   fclose (stream);
 417   if (f->args == NULL)
 418     f->args = getenv ("COLLECT_GCC_OPTIONS");
 419   if (f->dir == NULL)
 420     f->dir = ".";
 421 }
 422
 423 /* We might want to modify LINE, which is a symbol line from file F.  We do
 424    this if either we saw an error message referring to the symbol in
 425    question, or we have already allocated the symbol to another file and
 426    this one wants to emit it as well.  */
 427
 428 static void
 429 maybe_tweak (char *line, file *f)
 430 {
 431   symbol *sym = symbol_hash_lookup (line + 2, false);
 432
 433   if ((sym->file == f && sym->tweaking)
 434       || (sym->file != f && line[0] == 'C'))
 435     {
 436       sym->tweaking = 0;
 437       sym->tweaked = 1;
 438
 439       if (line[0] == 'O')
 440         {
 441           line[0] = 'C';
 442           sym->chosen = 1;
 443         }
 444       else
 445         {
 446           line[0] = 'O';
 447           sym->chosen = 0;
 448         }
 449     }
 450 }
 451
 452 /* Update the repo files for each of the object files we have adjusted and
 453    recompile.  */
 454
 455 static int
 456 recompile_files (void)
 457 {
 458   file *f;
 459
 460   putenv (xstrdup ("COMPILER_PATH="));
 461   putenv (xstrdup ("LIBRARY_PATH="));
 462
 463   while ((f = file_pop ()) != NULL)
 464     {
 465       char *line;
 466       const char *p, *q;
 467       char **argv;
 468       struct obstack arg_stack;
 469       FILE *stream = fopen (f->key, "r");
 470       const char *const outname = frob_extension (f->key, ".rnw");
 471       FILE *output = fopen (outname, "w");
 472
 473       while ((line = tfgets (stream)) != NULL)
 474         {
 475           switch (line[0])
 476             {
 477             case 'C':
 478             case 'O':
 479               maybe_tweak (line, f);
 480             }
 481           fprintf (output, "%s\n", line);
 482         }
 483       fclose (stream);
 484       fclose (output);
 485       /* On Windows "rename" returns -1 and sets ERRNO to EACCESS if
 486          the new file name already exists.  Therefore, we explicitly
 487          remove the old file first.  */
 488       if (remove (f->key) == -1)
 489         fatal_error ("removing .rpo file: %m");
 490       if (rename (outname, f->key) == -1)
 491         fatal_error ("renaming .rpo file: %m");
 492
 493       if (!f->args)
 494         {
 495           error ("repository file '%s' does not contain command-line "
 496                  "arguments", f->key);
 497           return 0;
 498         }
 499
 500       /* Build a null-terminated argv array suitable for
 501          tlink_execute().  Manipulate arguments on the arg_stack while
 502          building argv on the temporary_obstack.  */
 503
 504       obstack_init (&arg_stack);
 505       obstack_ptr_grow (&temporary_obstack, c_file_name);
 506
 507       for (p = f->args; *p != '\0'; p = q + 1)
 508         {
 509           /* Arguments are delimited by single-quotes.  Find the
 510              opening quote.  */
 511           p = strchr (p, '\'');
 512           if (!p)
 513             goto done;
 514
 515           /* Find the closing quote.  */
 516           q = strchr (p + 1, '\'');
 517           if (!q)
 518             goto done;
 519
 520           obstack_grow (&arg_stack, p + 1, q - (p + 1));
 521
 522           /* Replace '\'' with '.  This is how set_collect_gcc_options
 523              encodes a single-quote.  */
 524           while (q[1] == '\\' && q[2] == '\'' && q[3] == '\'')
 525             {
 526               const char *r;
 527
 528               r = strchr (q + 4, '\'');
 529               if (!r)
 530                 goto done;
 531
 532               obstack_grow (&arg_stack, q + 3, r - (q + 3));
 533               q = r;
 534             }
 535
 536           obstack_1grow (&arg_stack, '\0');
 537           obstack_ptr_grow (&temporary_obstack, obstack_finish (&arg_stack));
 538         }
 539     done:
 540       obstack_ptr_grow (&temporary_obstack, f->main);
 541       obstack_ptr_grow (&temporary_obstack, NULL);
 542       argv = XOBFINISH (&temporary_obstack, char **);
 543
 544       if (tlink_verbose)
 545         fprintf (stderr, _("collect: recompiling %s\n"), f->main);
 546
 547       if (chdir (f->dir) != 0
 548           || tlink_execute (c_file_name, argv, NULL, NULL) != 0
 549           || chdir (initial_cwd) != 0)
 550         return 0;
 551
 552       read_repo_file (f);
 553
 554       obstack_free (&arg_stack, NULL);
 555       obstack_free (&temporary_obstack, temporary_firstobj);
 556     }
 557   return 1;
 558 }
 559
 560 /* The first phase of processing: determine which object files have
 561    .rpo files associated with them, and read in the information.  */
 562
 563 static int
 564 read_repo_files (char **object_lst)
 565 {
 566   char **object = object_lst;
 567
 568   for (; *object; object++)
 569     {
 570       const char *p;
 571       file *f;
 572
 573       /* Don't bother trying for ld flags.  */
 574       if (*object[0] == '-')
 575         continue;
 576
 577       p = frob_extension (*object, ".rpo");
 578
 579       if (! file_exists (p))
 580         continue;
 581
 582       f = file_hash_lookup (p);
 583
 584       read_repo_file (f);
 585     }
 586
 587   if (file_stack != NULL && ! recompile_files ())
 588     return 0;
 589
 590   return (symbol_stack != NULL);
 591 }
 592
 593 /* Add the demangled forms of any new symbols to the hash table.  */
 594
 595 static void
 596 demangle_new_symbols (void)
 597 {
 598   symbol *sym;
 599
 600   while ((sym = symbol_pop ()) != NULL)
 601     {
 602       demangled *dem;
 603       const char *p = cplus_demangle (sym->key, DMGL_PARAMS | DMGL_ANSI);
 604
 605       if (! p)
 606         continue;
 607
 608       dem = demangled_hash_lookup (p, true);
 609       dem->mangled.safe_push (sym->key);
 610     }
 611 }
 612
 613 /* We want to tweak symbol SYM.  Return true if all is well, false on
 614    error.  */
 615
 616 static bool
 617 start_tweaking (symbol *sym)
 618 {
 619   if (sym && sym->tweaked)
 620     {
 621       error ("'%s' was assigned to '%s', but was not defined "
 622              "during recompilation, or vice versa",
 623              sym->key, sym->file->key);
 624       return 0;
 625     }
 626   if (sym && !sym->tweaking)
 627     {
 628       if (tlink_verbose >= 2)
 629         fprintf (stderr, _("collect: tweaking %s in %s\n"),
 630                  sym->key, sym->file->key);
 631       sym->tweaking = 1;
 632       file_push (sym->file);
 633     }
 634   return true;
 635 }
 636
 637 /* Step through the output of the linker, in the file named FNAME, and
 638    adjust the settings for each symbol encountered.  */
 639
 640 static int
 641 scan_linker_output (const char *fname)
 642 {
 643   FILE *stream = fopen (fname, "r");
 644   char *line;
 645   int skip_next_in_line = 0;
 646
 647   while ((line = tfgets (stream)) != NULL)
 648     {
 649       char *p = line, *q;
 650       symbol *sym;
 651       demangled *dem = 0;
 652       int end;
 653       int ok = 0;
 654       unsigned ix;
 655       str s;
 656
 657       /* On darwin9, we might have to skip " in " lines as well.  */
 658       if (skip_next_in_line
 659           && strstr (p, " in "))
 660           continue;
 661       skip_next_in_line = 0;
 662
 663       while (*p && ISSPACE ((unsigned char) *p))
 664         ++p;
 665
 666       if (! *p)
 667         continue;
 668
 669       for (q = p; *q && ! ISSPACE ((unsigned char) *q); ++q)
 670         ;
 671
 672       /* Try the first word on the line.  */
 673       if (*p == '.')
 674         ++p;
 675       if (!strncmp (p, USER_LABEL_PREFIX, strlen (USER_LABEL_PREFIX)))
 676         p += strlen (USER_LABEL_PREFIX);
 677
 678       end = ! *q;
 679       *q = 0;
 680       sym = symbol_hash_lookup (p, false);
 681
 682       /* Some SVR4 linkers produce messages like
 683          ld: 0711-317 ERROR: Undefined symbol: .g__t3foo1Zi
 684          */
 685       if (! sym && ! end && strstr (q + 1, "Undefined symbol: "))
 686         {
 687           char *p = strrchr (q + 1, ' ');
 688           p++;
 689           if (*p == '.')
 690             p++;
 691           if (!strncmp (p, USER_LABEL_PREFIX, strlen (USER_LABEL_PREFIX)))
 692             p += strlen (USER_LABEL_PREFIX);
 693           sym = symbol_hash_lookup (p, false);
 694         }
 695
 696       if (! sym && ! end)
 697         /* Try a mangled name in quotes.  */
 698         {
 699           char *oldq = q + 1;
 700           q = 0;
 701
 702           /* On darwin9, we look for "foo" referenced from:\n\(.* in .*\n\)*  */
 703           if (strcmp (oldq, "referenced from:") == 0)
 704             {
 705               /* We have to remember that we found a symbol to tweak.  */
 706               ok = 1;
 707
 708               /* We actually want to start from the first word on the
 709                  line.  */
 710               oldq = p;
 711
 712               /* Since the format is multiline, we have to skip
 713                  following lines with " in ".  */
 714               skip_next_in_line = 1;
 715             }
 716
 717           /* First try `GNU style'.  */
 718           p = strchr (oldq, '`');
 719           if (p)
 720             p++, q = strchr (p, '\'');
 721           /* Then try "double quotes".  */
 722           else if (p = strchr (oldq, '"'), p)
 723             p++, q = strchr (p, '"');
 724           /* Then try 'single quotes'.  */
 725           else if (p = strchr (oldq, '\''), p)
 726             p++, q = strchr (p, '\'');
 727           else {
 728             /* Then try entire line.  */
 729             q = strchr (oldq, 0);
 730             if (q != oldq)
 731               p = (char *)oldq;
 732           }
 733
 734           if (p)
 735             {
 736               /* Don't let the strstr's below see the demangled name; we
 737                  might get spurious matches.  */
 738               p[-1] = '\0';
 739
 740               /* powerpc64-linux references .foo when calling function foo.  */
 741               if (*p == '.')
 742                 p++;
 743             }
 744
 745           /* We need to check for certain error keywords here, or we would
 746              mistakenly use GNU ld's "In function `foo':" message.  */
 747           if (q && (ok
 748                     || strstr (oldq, "ndefined")
 749                     || strstr (oldq, "nresolved")
 750                     || strstr (oldq, "nsatisfied")
 751                     || strstr (oldq, "ultiple")))
 752             {
 753               *q = 0;
 754               dem = demangled_hash_lookup (p, false);
 755               if (!dem)
 756                 {
 757                   if (!strncmp (p, USER_LABEL_PREFIX,
 758                                 strlen (USER_LABEL_PREFIX)))
 759                     p += strlen (USER_LABEL_PREFIX);
 760                   sym = symbol_hash_lookup (p, false);
 761                 }
 762             }
 763         }
 764
 765       if (dem)
 766         {
 767           /* We found a demangled name.  If this is the name of a
 768              constructor or destructor, there can be several mangled names
 769              that match it, so choose or unchoose all of them.  If some are
 770              chosen and some not, leave the later ones that don't match
 771              alone for now; either this will cause the link to succeed, or
 772              on the next attempt we will switch all of them the other way
 773              and that will cause it to succeed.  */
 774           int chosen = 0;
 775           int len = dem->mangled.length ();
 776           ok = true;
 777           FOR_EACH_VEC_ELT (dem->mangled, ix, s)
 778             {
 779               sym = symbol_hash_lookup (s, false);
 780               if (ix == 0)
 781                 chosen = sym->chosen;
 782               else if (sym->chosen != chosen)
 783                 /* Mismatch.  */
 784                 continue;
 785               /* Avoid an error about re-tweaking when we guess wrong in
 786                  the case of mismatch.  */
 787               if (len > 1)
 788                 sym->tweaked = false;
 789               ok = start_tweaking (sym);
 790             }
 791         }
 792       else
 793         ok = start_tweaking (sym);
 794
 795       obstack_free (&temporary_obstack, temporary_firstobj);
 796
 797       if (!ok)
 798         {
 799           fclose (stream);
 800           return 0;
 801         }
 802     }
 803
 804   fclose (stream);
 805   return (file_stack != NULL);
 806 }
 807
 808 /* Entry point for tlink.  Called from main in collect2.c.
 809
 810    Iteratively try to provide definitions for all the unresolved symbols
 811    mentioned in the linker error messages.
 812
 813    LD_ARGV is an array of arguments for the linker.
 814    OBJECT_LST is an array of object files that we may be able to recompile
 815      to provide missing definitions.  Currently ignored.  */
 816
 817 void
 818 do_tlink (char **ld_argv, char **object_lst ATTRIBUTE_UNUSED)
 819 {
 820   int ret = tlink_execute ("ld", ld_argv, ldout, lderrout);
 821
 822   tlink_init ();
 823
 824   if (ret)
 825     {
 826       int i = 0;
 827
 828       /* Until collect does a better job of figuring out which are object
 829          files, assume that everything on the command line could be.  */
 830       if (read_repo_files (ld_argv))
 831         while (ret && i++ < MAX_ITERATIONS)
 832           {
 833             if (tlink_verbose >= 3)
 834               {
 835                 dump_ld_file (ldout, stdout);
 836                 dump_ld_file (lderrout, stderr);
 837               }
 838             demangle_new_symbols ();
 839             if (! scan_linker_output (ldout)
 840                 && ! scan_linker_output (lderrout))
 841               break;
 842             if (! recompile_files ())
 843               break;
 844             if (tlink_verbose)
 845               fprintf (stderr, _("collect: relinking\n"));
 846             ret = tlink_execute ("ld", ld_argv, ldout, lderrout);
 847           }
 848     }
 849
 850   dump_ld_file (ldout, stdout);
 851   unlink (ldout);
 852   dump_ld_file (lderrout, stderr);
 853   unlink (lderrout);
 854   if (ret)
 855     {
 856       error ("ld returned %d exit status", ret);
 857       exit (ret);
 858     }
 859   else
 860     {
 861       /* We have just successfully produced an output file, so assume that we
 862          may unlink it if need be for now on.  */
 863       may_unlink_output_file = true;
 864     }
 865 }