gcc/tlink.c

   1 /* Scan linker error messages for missing template instantiations and provide
   2    them.
   3
   4    Copyright (C) 1995-2015 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 "collect-utils.h"
  33 #include "filenames.h"
  34 #include "diagnostic-core.h"
  35 #include "vec.h"
  36
  37 /* TARGET_64BIT may be defined to use driver specific functionality. */
  38 #undef TARGET_64BIT
  39 #define TARGET_64BIT TARGET_64BIT_DEFAULT
  40
  41 #define MAX_ITERATIONS 17
  42
  43 /* Defined in the automatically-generated underscore.c.  */
  44 extern int prepends_underscore;
  45
  46 static int tlink_verbose;
  47
  48 static char *initial_cwd;
  49 \f
  50 /* Hash table boilerplate for working with htab_t.  We have hash tables
  51    for symbol names, file names, and demangled symbols.  */
  52
  53 typedef struct symbol_hash_entry
  54 {
  55   const char *key;
  56   struct file_hash_entry *file;
  57   int chosen;
  58   int tweaking;
  59   int tweaked;
  60 } symbol;
  61
  62 typedef struct file_hash_entry
  63 {
  64   const char *key;
  65   const char *args;
  66   const char *dir;
  67   const char *main;
  68   int tweaking;
  69 } file;
  70
  71 typedef const char *str;
  72
  73 typedef struct demangled_hash_entry
  74 {
  75   const char *key;
  76   vec<str> mangled;
  77 } demangled;
  78
  79 /* Hash and comparison functions for these hash tables.  */
  80
  81 static int hash_string_eq (const void *, const void *);
  82 static hashval_t hash_string_hash (const void *);
  83
  84 static int
  85 hash_string_eq (const void *s1_p, const void *s2_p)
  86 {
  87   const char *const *s1 = (const char *const *) s1_p;
  88   const char *s2 = (const char *) s2_p;
  89   return strcmp (*s1, s2) == 0;
  90 }
  91
  92 static hashval_t
  93 hash_string_hash (const void *s_p)
  94 {
  95   const char *const *s = (const char *const *) s_p;
  96   return (*htab_hash_string) (*s);
  97 }
  98
  99 static htab_t symbol_table;
 100
 101 static struct symbol_hash_entry * symbol_hash_lookup (const char *, int);
 102 static struct file_hash_entry * file_hash_lookup (const char *);
 103 static struct demangled_hash_entry *demangled_hash_lookup (const char *, int);
 104 static void symbol_push (symbol *);
 105 static symbol * symbol_pop (void);
 106 static void file_push (file *);
 107 static file * file_pop (void);
 108 static char * frob_extension (const char *, const char *);
 109 static char * obstack_fgets (FILE *, struct obstack *);
 110 static char * tfgets (FILE *);
 111 static char * pfgets (FILE *);
 112 static void freadsym (FILE *, file *, int);
 113 static void read_repo_file (file *);
 114 static void maybe_tweak (char *, file *);
 115 static int recompile_files (void);
 116 static int read_repo_files (char **);
 117 static void demangle_new_symbols (void);
 118 static int scan_linker_output (const char *);
 119
 120 /* Look up an entry in the symbol hash table.  */
 121
 122 static struct symbol_hash_entry *
 123 symbol_hash_lookup (const char *string, int create)
 124 {
 125   void **e;
 126   e = htab_find_slot_with_hash (symbol_table, string,
 127                                 (*htab_hash_string) (string),
 128                                 create ? INSERT : NO_INSERT);
 129   if (e == NULL)
 130     return NULL;
 131   if (*e == NULL)
 132     {
 133       struct symbol_hash_entry *v;
 134       *e = v = XCNEW (struct symbol_hash_entry);
 135       v->key = xstrdup (string);
 136     }
 137   return (struct symbol_hash_entry *) *e;
 138 }
 139
 140 static htab_t file_table;
 141
 142 /* Look up an entry in the file hash table.  */
 143
 144 static struct file_hash_entry *
 145 file_hash_lookup (const char *string)
 146 {
 147   void **e;
 148   e = htab_find_slot_with_hash (file_table, string,
 149                                 (*htab_hash_string) (string),
 150                                 INSERT);
 151   if (*e == NULL)
 152     {
 153       struct file_hash_entry *v;
 154       *e = v = XCNEW (struct file_hash_entry);
 155       v->key = xstrdup (string);
 156     }
 157   return (struct file_hash_entry *) *e;
 158 }
 159
 160 static htab_t demangled_table;
 161
 162 /* Look up an entry in the demangled name hash table.  */
 163
 164 static struct demangled_hash_entry *
 165 demangled_hash_lookup (const char *string, int create)
 166 {
 167   void **e;
 168   e = htab_find_slot_with_hash (demangled_table, string,
 169                                 (*htab_hash_string) (string),
 170                                 create ? INSERT : NO_INSERT);
 171   if (e == NULL)
 172     return NULL;
 173   if (*e == NULL)
 174     {
 175       struct demangled_hash_entry *v;
 176       *e = v = XCNEW (struct demangled_hash_entry);
 177       v->key = xstrdup (string);
 178     }
 179   return (struct demangled_hash_entry *) *e;
 180 }
 181 \f
 182 /* Stack code.  */
 183
 184 struct symbol_stack_entry
 185 {
 186   symbol *value;
 187   struct symbol_stack_entry *next;
 188 };
 189 struct obstack symbol_stack_obstack;
 190 struct symbol_stack_entry *symbol_stack;
 191
 192 struct file_stack_entry
 193 {
 194   file *value;
 195   struct file_stack_entry *next;
 196 };
 197 struct obstack file_stack_obstack;
 198 struct file_stack_entry *file_stack;
 199
 200 static void
 201 symbol_push (symbol *p)
 202 {
 203   struct symbol_stack_entry *ep
 204     = XOBNEW (&symbol_stack_obstack, struct symbol_stack_entry);
 205   ep->value = p;
 206   ep->next = symbol_stack;
 207   symbol_stack = ep;
 208 }
 209
 210 static symbol *
 211 symbol_pop (void)
 212 {
 213   struct symbol_stack_entry *ep = symbol_stack;
 214   symbol *p;
 215   if (ep == NULL)
 216     return NULL;
 217   p = ep->value;
 218   symbol_stack = ep->next;
 219   obstack_free (&symbol_stack_obstack, ep);
 220   return p;
 221 }
 222
 223 static void
 224 file_push (file *p)
 225 {
 226   struct file_stack_entry *ep;
 227
 228   if (p->tweaking)
 229     return;
 230
 231   ep = XOBNEW (&file_stack_obstack, struct file_stack_entry);
 232   ep->value = p;
 233   ep->next = file_stack;
 234   file_stack = ep;
 235   p->tweaking = 1;
 236 }
 237
 238 static file *
 239 file_pop (void)
 240 {
 241   struct file_stack_entry *ep = file_stack;
 242   file *p;
 243   if (ep == NULL)
 244     return NULL;
 245   p = ep->value;
 246   file_stack = ep->next;
 247   obstack_free (&file_stack_obstack, ep);
 248   p->tweaking = 0;
 249   return p;
 250 }
 251 \f
 252 /* Other machinery.  */
 253
 254 /* Initialize the tlink machinery.  Called from do_tlink.  */
 255
 256 static void
 257 tlink_init (void)
 258 {
 259   const char *p;
 260
 261   symbol_table = htab_create (500, hash_string_hash, hash_string_eq,
 262                               NULL);
 263   file_table = htab_create (500, hash_string_hash, hash_string_eq,
 264                             NULL);
 265   demangled_table = htab_create (500, hash_string_hash, hash_string_eq,
 266                                  NULL);
 267
 268   obstack_begin (&symbol_stack_obstack, 0);
 269   obstack_begin (&file_stack_obstack, 0);
 270
 271   p = getenv ("TLINK_VERBOSE");
 272   if (p)
 273     tlink_verbose = atoi (p);
 274   else
 275     {
 276       tlink_verbose = 1;
 277       if (verbose)
 278         tlink_verbose = 2;
 279       if (debug)
 280         tlink_verbose = 3;
 281     }
 282
 283   initial_cwd = getpwd ();
 284 }
 285
 286 static int
 287 tlink_execute (const char *prog, char **argv, const char *outname,
 288                const char *errname, bool use_atfile)
 289 {
 290   struct pex_obj *pex;
 291
 292   pex = collect_execute (prog, argv, outname, errname,
 293                          PEX_LAST | PEX_SEARCH, use_atfile);
 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, false) != 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                            HAVE_GNU_LD && at_file_supplied);
 822
 823   tlink_init ();
 824
 825   if (ret)
 826     {
 827       int i = 0;
 828
 829       /* Until collect does a better job of figuring out which are object
 830          files, assume that everything on the command line could be.  */
 831       if (read_repo_files (ld_argv))
 832         while (ret && i++ < MAX_ITERATIONS)
 833           {
 834             if (tlink_verbose >= 3)
 835               {
 836                 dump_ld_file (ldout, stdout);
 837                 dump_ld_file (lderrout, stderr);
 838               }
 839             demangle_new_symbols ();
 840             if (! scan_linker_output (ldout)
 841                 && ! scan_linker_output (lderrout))
 842               break;
 843             if (! recompile_files ())
 844               break;
 845             if (tlink_verbose)
 846               fprintf (stderr, _("collect: relinking\n"));
 847             ret = tlink_execute ("ld", ld_argv, ldout, lderrout,
 848                                  HAVE_GNU_LD && at_file_supplied);
 849           }
 850     }
 851
 852   dump_ld_file (ldout, stdout);
 853   unlink (ldout);
 854   dump_ld_file (lderrout, stderr);
 855   unlink (lderrout);
 856   if (ret)
 857     {
 858       error ("ld returned %d exit status", ret);
 859       exit (ret);
 860     }
 861   else
 862     {
 863       /* We have just successfully produced an output file, so assume that we
 864          may unlink it if need be for now on.  */
 865       may_unlink_output_file = true;
 866     }
 867 }