gcc/tlink.c

   1 /* Scan linker error messages for missing template instantiations and provide
   2    them.
   3
   4    Copyright (C) 1995, 1998, 1999, 2000, 2001 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 2, 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 COPYING.  If not, write to the Free
  21 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  22 02111-1307, USA.  */
  23
  24 #include "config.h"
  25 #include "system.h"
  26 #include "coretypes.h"
  27 #include "tm.h"
  28 #include "intl.h"
  29 #include "obstack.h"
  30 #include "hashtab.h"
  31 #include "demangle.h"
  32 #include "collect2.h"
  33
  34 #define MAX_ITERATIONS 17
  35
  36 /* Defined in the automatically-generated underscore.c.  */
  37 extern int prepends_underscore;
  38
  39 static int tlink_verbose;
  40 \f
  41 /* Hash table boilerplate for working with htab_t.  We have hash tables
  42    for symbol names, file names, and demangled symbols.  */
  43
  44 typedef struct symbol_hash_entry
  45 {
  46   const char *key;
  47   struct file_hash_entry *file;
  48   int chosen;
  49   int tweaking;
  50   int tweaked;
  51 } symbol;
  52
  53 typedef struct file_hash_entry
  54 {
  55   const char *key;
  56   const char *args;
  57   const char *dir;
  58   const char *main;
  59   int tweaking;
  60 } file;
  61
  62 typedef struct demangled_hash_entry
  63 {
  64   const char *key;
  65   const char *mangled;
  66 } demangled;
  67
  68 /* Hash and comparison functions for these hash tables.  */
  69
  70 static int hash_string_eq PARAMS ((const void *, const void *));
  71 static hashval_t hash_string_hash PARAMS ((const void *));
  72
  73 static int
  74 hash_string_eq (s1_p, s2_p)
  75      const void *s1_p;
  76      const void *s2_p;
  77 {
  78   const char *const *s1 = (const char *const *) s1_p;
  79   const char *s2 = (const char *) s2_p;
  80   return strcmp (*s1, s2) == 0;
  81 }
  82
  83 static hashval_t
  84 hash_string_hash (s_p)
  85      const void *s_p;
  86 {
  87   const char *const *s = (const char *const *) s_p;
  88   return (*htab_hash_string) (*s);
  89 }
  90
  91 static htab_t symbol_table;
  92
  93 static struct symbol_hash_entry * symbol_hash_lookup PARAMS ((const char *,
  94                                                               int));
  95 static struct file_hash_entry * file_hash_lookup PARAMS ((const char *));
  96 static struct demangled_hash_entry *
  97   demangled_hash_lookup PARAMS ((const char *, int));
  98 static void symbol_push PARAMS ((symbol *));
  99 static symbol * symbol_pop PARAMS ((void));
 100 static void file_push PARAMS ((file *));
 101 static file * file_pop PARAMS ((void));
 102 static void tlink_init PARAMS ((void));
 103 static int tlink_execute PARAMS ((const char *, char **, const char *));
 104 static char * frob_extension PARAMS ((const char *, const char *));
 105 static char * obstack_fgets PARAMS ((FILE *, struct obstack *));
 106 static char * tfgets PARAMS ((FILE *));
 107 static char * pfgets PARAMS ((FILE *));
 108 static void freadsym PARAMS ((FILE *, file *, int));
 109 static void read_repo_file PARAMS ((file *));
 110 static void maybe_tweak PARAMS ((char *, file *));
 111 static int recompile_files PARAMS ((void));
 112 static int read_repo_files PARAMS ((char **));
 113 static void demangle_new_symbols PARAMS ((void));
 114 static int scan_linker_output PARAMS ((const char *));
 115
 116 /* Look up an entry in the symbol hash table.  */
 117
 118 static struct symbol_hash_entry *
 119 symbol_hash_lookup (string, create)
 120      const char *string;
 121      int create;
 122 {
 123   PTR *e;
 124   e = htab_find_slot_with_hash (symbol_table, string,
 125                                 (*htab_hash_string) (string),
 126                                 create ? INSERT : NO_INSERT);
 127   if (e == NULL)
 128     return NULL;
 129   if (*e == NULL)
 130     {
 131       struct symbol_hash_entry *v;
 132       *e = v = xcalloc (1, sizeof (*v));
 133       v->key = xstrdup (string);
 134     }
 135   return *e;
 136 }
 137
 138 static htab_t file_table;
 139
 140 /* Look up an entry in the file hash table.  */
 141
 142 static struct file_hash_entry *
 143 file_hash_lookup (string)
 144      const char *string;
 145 {
 146   PTR *e;
 147   e = htab_find_slot_with_hash (file_table, string,
 148                                 (*htab_hash_string) (string),
 149                                 INSERT);
 150   if (*e == NULL)
 151     {
 152       struct file_hash_entry *v;
 153       *e = v = xcalloc (1, sizeof (*v));
 154       v->key = xstrdup (string);
 155     }
 156   return *e;
 157 }
 158
 159 static htab_t demangled_table;
 160
 161 /* Look up an entry in the demangled name hash table.  */
 162
 163 static struct demangled_hash_entry *
 164 demangled_hash_lookup (string, create)
 165      const char *string;
 166      int create;
 167 {
 168   PTR *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 = xcalloc (1, sizeof (*v));
 178       v->key = xstrdup (string);
 179     }
 180   return *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 (p)
 203      symbol *p;
 204 {
 205   struct symbol_stack_entry *ep = (struct symbol_stack_entry *) obstack_alloc
 206     (&symbol_stack_obstack, sizeof (struct symbol_stack_entry));
 207   ep->value = p;
 208   ep->next = symbol_stack;
 209   symbol_stack = ep;
 210 }
 211
 212 static symbol *
 213 symbol_pop ()
 214 {
 215   struct symbol_stack_entry *ep = symbol_stack;
 216   symbol *p;
 217   if (ep == NULL)
 218     return NULL;
 219   p = ep->value;
 220   symbol_stack = ep->next;
 221   obstack_free (&symbol_stack_obstack, ep);
 222   return p;
 223 }
 224
 225 static void
 226 file_push (p)
 227      file *p;
 228 {
 229   struct file_stack_entry *ep;
 230
 231   if (p->tweaking)
 232     return;
 233
 234   ep = (struct file_stack_entry *) obstack_alloc
 235     (&file_stack_obstack, sizeof (struct file_stack_entry));
 236   ep->value = p;
 237   ep->next = file_stack;
 238   file_stack = ep;
 239   p->tweaking = 1;
 240 }
 241
 242 static file *
 243 file_pop ()
 244 {
 245   struct file_stack_entry *ep = file_stack;
 246   file *p;
 247   if (ep == NULL)
 248     return NULL;
 249   p = ep->value;
 250   file_stack = ep->next;
 251   obstack_free (&file_stack_obstack, ep);
 252   p->tweaking = 0;
 253   return p;
 254 }
 255 \f
 256 /* Other machinery.  */
 257
 258 /* Initialize the tlink machinery.  Called from do_tlink.  */
 259
 260 static void
 261 tlink_init ()
 262 {
 263   const char *p;
 264
 265   symbol_table = htab_create (500, hash_string_hash, hash_string_eq,
 266                               NULL);
 267   file_table = htab_create (500, hash_string_hash, hash_string_eq,
 268                             NULL);
 269   demangled_table = htab_create (500, hash_string_hash, hash_string_eq,
 270                                  NULL);
 271
 272   obstack_begin (&symbol_stack_obstack, 0);
 273   obstack_begin (&file_stack_obstack, 0);
 274
 275   p = getenv ("TLINK_VERBOSE");
 276   if (p)
 277     tlink_verbose = atoi (p);
 278   else
 279     {
 280       tlink_verbose = 1;
 281       if (vflag)
 282         tlink_verbose = 2;
 283       if (debug)
 284         tlink_verbose = 3;
 285     }
 286 }
 287
 288 static int
 289 tlink_execute (prog, argv, redir)
 290      const char *prog;
 291      char **argv;
 292      const char *redir;
 293 {
 294   collect_execute (prog, argv, redir);
 295   return collect_wait (prog);
 296 }
 297
 298 static char *
 299 frob_extension (s, ext)
 300      const char *s;
 301      const char *ext;
 302 {
 303   const char *p = strrchr (s, '/');
 304   if (! p)
 305     p = s;
 306   p = strrchr (p, '.');
 307   if (! p)
 308     p = s + strlen (s);
 309
 310   obstack_grow (&temporary_obstack, s, p - s);
 311   return obstack_copy0 (&temporary_obstack, ext, strlen (ext));
 312 }
 313
 314 static char *
 315 obstack_fgets (stream, ob)
 316      FILE *stream;
 317      struct obstack *ob;
 318 {
 319   int c;
 320   while ((c = getc (stream)) != EOF && c != '\n')
 321     obstack_1grow (ob, c);
 322   if (obstack_object_size (ob) == 0)
 323     return NULL;
 324   obstack_1grow (ob, '\0');
 325   return obstack_finish (ob);
 326 }
 327
 328 static char *
 329 tfgets (stream)
 330      FILE *stream;
 331 {
 332   return obstack_fgets (stream, &temporary_obstack);
 333 }
 334
 335 static char *
 336 pfgets (stream)
 337      FILE *stream;
 338 {
 339   return xstrdup (tfgets (stream));
 340 }
 341 \f
 342 /* Real tlink code.  */
 343
 344 /* Subroutine of read_repo_file.  We are reading the repo file for file F,
 345    which is coming in on STREAM, and the symbol that comes next in STREAM
 346    is offered, chosen or provided if CHOSEN is 0, 1 or 2, respectively.
 347
 348    XXX "provided" is unimplemented, both here and in the compiler.  */
 349
 350 static void
 351 freadsym (stream, f, chosen)
 352      FILE *stream;
 353      file *f;
 354      int chosen;
 355 {
 356   symbol *sym;
 357
 358   {
 359     const char *name = tfgets (stream);
 360     sym = symbol_hash_lookup (name, true);
 361   }
 362
 363   if (sym->file == NULL)
 364     {
 365       /* We didn't have this symbol already, so we choose this file.  */
 366
 367       symbol_push (sym);
 368       sym->file = f;
 369       sym->chosen = chosen;
 370     }
 371   else if (chosen)
 372     {
 373       /* We want this file; cast aside any pretender.  */
 374
 375       if (sym->chosen && sym->file != f)
 376         {
 377           if (sym->chosen == 1)
 378             file_push (sym->file);
 379           else
 380             {
 381               file_push (f);
 382               f = sym->file;
 383               chosen = sym->chosen;
 384             }
 385         }
 386       sym->file = f;
 387       sym->chosen = chosen;
 388     }
 389 }
 390
 391 /* Read in the repo file denoted by F, and record all its information.  */
 392
 393 static void
 394 read_repo_file (f)
 395      file *f;
 396 {
 397   char c;
 398   FILE *stream = fopen (f->key, "r");
 399
 400   if (tlink_verbose >= 2)
 401     fprintf (stderr, _("collect: reading %s\n"), f->key);
 402
 403   while (fscanf (stream, "%c ", &c) == 1)
 404     {
 405       switch (c)
 406         {
 407         case 'A':
 408           f->args = pfgets (stream);
 409           break;
 410         case 'D':
 411           f->dir = pfgets (stream);
 412           break;
 413         case 'M':
 414           f->main = pfgets (stream);
 415           break;
 416         case 'P':
 417           freadsym (stream, f, 2);
 418           break;
 419         case 'C':
 420           freadsym (stream, f, 1);
 421           break;
 422         case 'O':
 423           freadsym (stream, f, 0);
 424           break;
 425         }
 426       obstack_free (&temporary_obstack, temporary_firstobj);
 427     }
 428   fclose (stream);
 429   if (f->args == NULL)
 430     f->args = getenv ("COLLECT_GCC_OPTIONS");
 431   if (f->dir == NULL)
 432     f->dir = ".";
 433 }
 434
 435 /* We might want to modify LINE, which is a symbol line from file F.  We do
 436    this if either we saw an error message referring to the symbol in
 437    question, or we have already allocated the symbol to another file and
 438    this one wants to emit it as well.  */
 439
 440 static void
 441 maybe_tweak (line, f)
 442      char *line;
 443      file *f;
 444 {
 445   symbol *sym = symbol_hash_lookup (line + 2, false);
 446
 447   if ((sym->file == f && sym->tweaking)
 448       || (sym->file != f && line[0] == 'C'))
 449     {
 450       sym->tweaking = 0;
 451       sym->tweaked = 1;
 452
 453       if (line[0] == 'O')
 454         line[0] = 'C';
 455       else
 456         line[0] = 'O';
 457     }
 458 }
 459
 460 /* Update the repo files for each of the object files we have adjusted and
 461    recompile.
 462
 463    XXX Should this use collect_execute instead of system?  */
 464
 465 static int
 466 recompile_files ()
 467 {
 468   file *f;
 469
 470   putenv (xstrdup ("COMPILER_PATH="));
 471   putenv (xstrdup ("LIBRARY_PATH="));
 472
 473   while ((f = file_pop ()) != NULL)
 474     {
 475       char *line, *command;
 476       FILE *stream = fopen (f->key, "r");
 477       const char *const outname = frob_extension (f->key, ".rnw");
 478       FILE *output = fopen (outname, "w");
 479
 480       while ((line = tfgets (stream)) != NULL)
 481         {
 482           switch (line[0])
 483             {
 484             case 'C':
 485             case 'O':
 486               maybe_tweak (line, f);
 487             }
 488           fprintf (output, "%s\n", line);
 489         }
 490       fclose (stream);
 491       fclose (output);
 492       rename (outname, f->key);
 493
 494       obstack_grow (&temporary_obstack, "cd ", 3);
 495       obstack_grow (&temporary_obstack, f->dir, strlen (f->dir));
 496       obstack_grow (&temporary_obstack, "; ", 2);
 497       obstack_grow (&temporary_obstack, c_file_name, strlen (c_file_name));
 498       obstack_1grow (&temporary_obstack, ' ');
 499       obstack_grow (&temporary_obstack, f->args, strlen (f->args));
 500       obstack_1grow (&temporary_obstack, ' ');
 501       command = obstack_copy0 (&temporary_obstack, f->main, strlen (f->main));
 502
 503       if (tlink_verbose)
 504         fprintf (stderr, _("collect: recompiling %s\n"), f->main);
 505       if (tlink_verbose >= 3)
 506         fprintf (stderr, "%s\n", command);
 507
 508       if (system (command) != 0)
 509         return 0;
 510
 511       read_repo_file (f);
 512
 513       obstack_free (&temporary_obstack, temporary_firstobj);
 514     }
 515   return 1;
 516 }
 517
 518 /* The first phase of processing: determine which object files have
 519    .rpo files associated with them, and read in the information.  */
 520
 521 static int
 522 read_repo_files (object_lst)
 523      char **object_lst;
 524 {
 525   char **object = object_lst;
 526
 527   for (; *object; object++)
 528     {
 529       const char *p;
 530       file *f;
 531
 532       /* Don't bother trying for ld flags.  */
 533       if (*object[0] == '-')
 534         continue;
 535
 536       p = frob_extension (*object, ".rpo");
 537
 538       if (! file_exists (p))
 539         continue;
 540
 541       f = file_hash_lookup (p);
 542
 543       read_repo_file (f);
 544     }
 545
 546   if (file_stack != NULL && ! recompile_files ())
 547     return 0;
 548
 549   return (symbol_stack != NULL);
 550 }
 551
 552 /* Add the demangled forms of any new symbols to the hash table.  */
 553
 554 static void
 555 demangle_new_symbols ()
 556 {
 557   symbol *sym;
 558
 559   while ((sym = symbol_pop ()) != NULL)
 560     {
 561       demangled *dem;
 562       const char *p = cplus_demangle (sym->key, DMGL_PARAMS | DMGL_ANSI);
 563
 564       if (! p)
 565         continue;
 566
 567       dem = demangled_hash_lookup (p, true);
 568       dem->mangled = sym->key;
 569     }
 570 }
 571
 572 /* Step through the output of the linker, in the file named FNAME, and
 573    adjust the settings for each symbol encountered.  */
 574
 575 static int
 576 scan_linker_output (fname)
 577      const char *fname;
 578 {
 579   FILE *stream = fopen (fname, "r");
 580   char *line;
 581
 582   while ((line = tfgets (stream)) != NULL)
 583     {
 584       char *p = line, *q;
 585       symbol *sym;
 586       int end;
 587
 588       while (*p && ISSPACE ((unsigned char) *p))
 589         ++p;
 590
 591       if (! *p)
 592         continue;
 593
 594       for (q = p; *q && ! ISSPACE ((unsigned char) *q); ++q)
 595         ;
 596
 597       /* Try the first word on the line.  */
 598       if (*p == '.')
 599         ++p;
 600       if (!strncmp (p, USER_LABEL_PREFIX, strlen (USER_LABEL_PREFIX)))
 601         p += strlen (USER_LABEL_PREFIX);
 602
 603       end = ! *q;
 604       *q = 0;
 605       sym = symbol_hash_lookup (p, false);
 606
 607       /* Some SVR4 linkers produce messages like
 608          ld: 0711-317 ERROR: Undefined symbol: .g__t3foo1Zi
 609          */
 610       if (! sym && ! end && strstr (q + 1, "Undefined symbol: "))
 611         {
 612           char *p = strrchr (q + 1, ' ');
 613           p++;
 614           if (*p == '.')
 615             p++;
 616           if (!strncmp (p, USER_LABEL_PREFIX, strlen (USER_LABEL_PREFIX)))
 617             p += strlen (USER_LABEL_PREFIX);
 618           sym = symbol_hash_lookup (p, false);
 619         }
 620
 621       if (! sym && ! end)
 622         /* Try a mangled name in quotes.  */
 623         {
 624           const char *oldq = q + 1;
 625           demangled *dem = 0;
 626           q = 0;
 627
 628           /* First try `GNU style'.  */
 629           p = strchr (oldq, '`');
 630           if (p)
 631             p++, q = strchr (p, '\'');
 632           /* Then try "double quotes".  */
 633           else if (p = strchr (oldq, '"'), p)
 634             p++, q = strchr (p, '"');
 635
 636           if (p)
 637             {
 638               /* Don't let the strstr's below see the demangled name; we
 639                  might get spurious matches.  */
 640               p[-1] = '\0';
 641
 642               /* powerpc64-linux references .foo when calling function foo.  */
 643               if (*p == '.')
 644                 p++;
 645             }
 646
 647           /* We need to check for certain error keywords here, or we would
 648              mistakenly use GNU ld's "In function `foo':" message.  */
 649           if (q && (strstr (oldq, "ndefined")
 650                     || strstr (oldq, "nresolved")
 651                     || strstr (oldq, "nsatisfied")
 652                     || strstr (oldq, "ultiple")))
 653             {
 654               *q = 0;
 655               dem = demangled_hash_lookup (p, false);
 656               if (dem)
 657                 sym = symbol_hash_lookup (dem->mangled, false);
 658               else
 659                 {
 660                   if (!strncmp (p, USER_LABEL_PREFIX,
 661                                 strlen (USER_LABEL_PREFIX)))
 662                     p += strlen (USER_LABEL_PREFIX);
 663                   sym = symbol_hash_lookup (p, false);
 664                 }
 665             }
 666         }
 667
 668       if (sym && sym->tweaked)
 669         {
 670           fclose (stream);
 671           return 0;
 672         }
 673       if (sym && !sym->tweaking)
 674         {
 675           if (tlink_verbose >= 2)
 676             fprintf (stderr, _("collect: tweaking %s in %s\n"),
 677                      sym->key, sym->file->key);
 678           sym->tweaking = 1;
 679           file_push (sym->file);
 680         }
 681
 682       obstack_free (&temporary_obstack, temporary_firstobj);
 683     }
 684
 685   fclose (stream);
 686   return (file_stack != NULL);
 687 }
 688
 689 /* Entry point for tlink.  Called from main in collect2.c.
 690
 691    Iteratively try to provide definitions for all the unresolved symbols
 692    mentioned in the linker error messages.
 693
 694    LD_ARGV is an array of arguments for the linker.
 695    OBJECT_LST is an array of object files that we may be able to recompile
 696      to provide missing definitions.  Currently ignored.  */
 697
 698 void
 699 do_tlink (ld_argv, object_lst)
 700      char **ld_argv, **object_lst ATTRIBUTE_UNUSED;
 701 {
 702   int exit = tlink_execute ("ld", ld_argv, ldout);
 703
 704   tlink_init ();
 705
 706   if (exit)
 707     {
 708       int i = 0;
 709
 710       /* Until collect does a better job of figuring out which are object
 711          files, assume that everything on the command line could be.  */
 712       if (read_repo_files (ld_argv))
 713         while (exit && i++ < MAX_ITERATIONS)
 714           {
 715             if (tlink_verbose >= 3)
 716               dump_file (ldout);
 717             demangle_new_symbols ();
 718             if (! scan_linker_output (ldout))
 719               break;
 720             if (! recompile_files ())
 721               break;
 722             if (tlink_verbose)
 723               fprintf (stderr, _("collect: relinking\n"));
 724             exit = tlink_execute ("ld", ld_argv, ldout);
 725           }
 726     }
 727
 728   dump_file (ldout);
 729   unlink (ldout);
 730   if (exit)
 731     {
 732       error ("ld returned %d exit status", exit);
 733       collect_exit (exit);
 734     }
 735 }