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, 2003, 2004, 2005
   5    Free Software Foundation, Inc.
   6    Contributed by Jason Merrill (jason@cygnus.com).
   7
   8 This file is part of GCC.
   9
  10 GCC is free software; you can redistribute it and/or modify it under
  11 the terms of the GNU General Public License as published by the Free
  12 Software Foundation; either version 2, or (at your option) any later
  13 version.
  14
  15 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  16 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18 for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GCC; see the file COPYING.  If not, write to the Free
  22 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  23 02110-1301, USA.  */
  24
  25 #include "config.h"
  26 #include "system.h"
  27 #include "coretypes.h"
  28 #include "tm.h"
  29 #include "intl.h"
  30 #include "obstack.h"
  31 #include "hashtab.h"
  32 #include "demangle.h"
  33 #include "collect2.h"
  34
  35 #define MAX_ITERATIONS 17
  36
  37 /* Defined in the automatically-generated underscore.c.  */
  38 extern int prepends_underscore;
  39
  40 static int tlink_verbose;
  41
  42 static char initial_cwd[MAXPATHLEN + 1];
  43 \f
  44 /* Hash table boilerplate for working with htab_t.  We have hash tables
  45    for symbol names, file names, and demangled symbols.  */
  46
  47 typedef struct symbol_hash_entry
  48 {
  49   const char *key;
  50   struct file_hash_entry *file;
  51   int chosen;
  52   int tweaking;
  53   int tweaked;
  54 } symbol;
  55
  56 typedef struct file_hash_entry
  57 {
  58   const char *key;
  59   const char *args;
  60   const char *dir;
  61   const char *main;
  62   int tweaking;
  63 } file;
  64
  65 typedef struct demangled_hash_entry
  66 {
  67   const char *key;
  68   const char *mangled;
  69 } demangled;
  70
  71 /* Hash and comparison functions for these hash tables.  */
  72
  73 static int hash_string_eq (const void *, const void *);
  74 static hashval_t hash_string_hash (const void *);
  75
  76 static int
  77 hash_string_eq (const void *s1_p, const void *s2_p)
  78 {
  79   const char *const *s1 = (const char *const *) s1_p;
  80   const char *s2 = (const char *) s2_p;
  81   return strcmp (*s1, s2) == 0;
  82 }
  83
  84 static hashval_t
  85 hash_string_hash (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 (const char *, int);
  94 static struct file_hash_entry * file_hash_lookup (const char *);
  95 static struct demangled_hash_entry *demangled_hash_lookup (const char *, int);
  96 static void symbol_push (symbol *);
  97 static symbol * symbol_pop (void);
  98 static void file_push (file *);
  99 static file * file_pop (void);
 100 static void tlink_init (void);
 101 static int tlink_execute (const char *, char **, const char *, const char *);
 102 static char * frob_extension (const char *, const char *);
 103 static char * obstack_fgets (FILE *, struct obstack *);
 104 static char * tfgets (FILE *);
 105 static char * pfgets (FILE *);
 106 static void freadsym (FILE *, file *, int);
 107 static void read_repo_file (file *);
 108 static void maybe_tweak (char *, file *);
 109 static int recompile_files (void);
 110 static int read_repo_files (char **);
 111 static void demangle_new_symbols (void);
 112 static int scan_linker_output (const char *);
 113
 114 /* Look up an entry in the symbol hash table.  */
 115
 116 static struct symbol_hash_entry *
 117 symbol_hash_lookup (const char *string, int create)
 118 {
 119   void **e;
 120   e = htab_find_slot_with_hash (symbol_table, string,
 121                                 (*htab_hash_string) (string),
 122                                 create ? INSERT : NO_INSERT);
 123   if (e == NULL)
 124     return NULL;
 125   if (*e == NULL)
 126     {
 127       struct symbol_hash_entry *v;
 128       *e = v = xcalloc (1, sizeof (*v));
 129       v->key = xstrdup (string);
 130     }
 131   return *e;
 132 }
 133
 134 static htab_t file_table;
 135
 136 /* Look up an entry in the file hash table.  */
 137
 138 static struct file_hash_entry *
 139 file_hash_lookup (const char *string)
 140 {
 141   void **e;
 142   e = htab_find_slot_with_hash (file_table, string,
 143                                 (*htab_hash_string) (string),
 144                                 INSERT);
 145   if (*e == NULL)
 146     {
 147       struct file_hash_entry *v;
 148       *e = v = xcalloc (1, sizeof (*v));
 149       v->key = xstrdup (string);
 150     }
 151   return *e;
 152 }
 153
 154 static htab_t demangled_table;
 155
 156 /* Look up an entry in the demangled name hash table.  */
 157
 158 static struct demangled_hash_entry *
 159 demangled_hash_lookup (const char *string, int create)
 160 {
 161   void **e;
 162   e = htab_find_slot_with_hash (demangled_table, string,
 163                                 (*htab_hash_string) (string),
 164                                 create ? INSERT : NO_INSERT);
 165   if (e == NULL)
 166     return NULL;
 167   if (*e == NULL)
 168     {
 169       struct demangled_hash_entry *v;
 170       *e = v = xcalloc (1, sizeof (*v));
 171       v->key = xstrdup (string);
 172     }
 173   return *e;
 174 }
 175 \f
 176 /* Stack code.  */
 177
 178 struct symbol_stack_entry
 179 {
 180   symbol *value;
 181   struct symbol_stack_entry *next;
 182 };
 183 struct obstack symbol_stack_obstack;
 184 struct symbol_stack_entry *symbol_stack;
 185
 186 struct file_stack_entry
 187 {
 188   file *value;
 189   struct file_stack_entry *next;
 190 };
 191 struct obstack file_stack_obstack;
 192 struct file_stack_entry *file_stack;
 193
 194 static void
 195 symbol_push (symbol *p)
 196 {
 197   struct symbol_stack_entry *ep = obstack_alloc
 198     (&symbol_stack_obstack, sizeof (struct symbol_stack_entry));
 199   ep->value = p;
 200   ep->next = symbol_stack;
 201   symbol_stack = ep;
 202 }
 203
 204 static symbol *
 205 symbol_pop (void)
 206 {
 207   struct symbol_stack_entry *ep = symbol_stack;
 208   symbol *p;
 209   if (ep == NULL)
 210     return NULL;
 211   p = ep->value;
 212   symbol_stack = ep->next;
 213   obstack_free (&symbol_stack_obstack, ep);
 214   return p;
 215 }
 216
 217 static void
 218 file_push (file *p)
 219 {
 220   struct file_stack_entry *ep;
 221
 222   if (p->tweaking)
 223     return;
 224
 225   ep = obstack_alloc
 226     (&file_stack_obstack, sizeof (struct file_stack_entry));
 227   ep->value = p;
 228   ep->next = file_stack;
 229   file_stack = ep;
 230   p->tweaking = 1;
 231 }
 232
 233 static file *
 234 file_pop (void)
 235 {
 236   struct file_stack_entry *ep = file_stack;
 237   file *p;
 238   if (ep == NULL)
 239     return NULL;
 240   p = ep->value;
 241   file_stack = ep->next;
 242   obstack_free (&file_stack_obstack, ep);
 243   p->tweaking = 0;
 244   return p;
 245 }
 246 \f
 247 /* Other machinery.  */
 248
 249 /* Initialize the tlink machinery.  Called from do_tlink.  */
 250
 251 static void
 252 tlink_init (void)
 253 {
 254   const char *p;
 255
 256   symbol_table = htab_create (500, hash_string_hash, hash_string_eq,
 257                               NULL);
 258   file_table = htab_create (500, hash_string_hash, hash_string_eq,
 259                             NULL);
 260   demangled_table = htab_create (500, hash_string_hash, hash_string_eq,
 261                                  NULL);
 262
 263   obstack_begin (&symbol_stack_obstack, 0);
 264   obstack_begin (&file_stack_obstack, 0);
 265
 266   p = getenv ("TLINK_VERBOSE");
 267   if (p)
 268     tlink_verbose = atoi (p);
 269   else
 270     {
 271       tlink_verbose = 1;
 272       if (vflag)
 273         tlink_verbose = 2;
 274       if (debug)
 275         tlink_verbose = 3;
 276     }
 277
 278   getcwd (initial_cwd, sizeof (initial_cwd));
 279 }
 280
 281 static int
 282 tlink_execute (const char *prog, char **argv, const char *outname,
 283                const char *errname)
 284 {
 285   struct pex_obj *pex;
 286
 287   pex = collect_execute (prog, argv, outname, errname);
 288   return collect_wait (prog, pex);
 289 }
 290
 291 static char *
 292 frob_extension (const char *s, const char *ext)
 293 {
 294   const char *p = strrchr (s, '/');
 295   if (! p)
 296     p = s;
 297   p = strrchr (p, '.');
 298   if (! p)
 299     p = s + strlen (s);
 300
 301   obstack_grow (&temporary_obstack, s, p - s);
 302   return obstack_copy0 (&temporary_obstack, ext, strlen (ext));
 303 }
 304
 305 static char *
 306 obstack_fgets (FILE *stream, struct obstack *ob)
 307 {
 308   int c;
 309   while ((c = getc (stream)) != EOF && c != '\n')
 310     obstack_1grow (ob, c);
 311   if (obstack_object_size (ob) == 0)
 312     return NULL;
 313   obstack_1grow (ob, '\0');
 314   return XOBFINISH (ob, char *);
 315 }
 316
 317 static char *
 318 tfgets (FILE *stream)
 319 {
 320   return obstack_fgets (stream, &temporary_obstack);
 321 }
 322
 323 static char *
 324 pfgets (FILE *stream)
 325 {
 326   return xstrdup (tfgets (stream));
 327 }
 328 \f
 329 /* Real tlink code.  */
 330
 331 /* Subroutine of read_repo_file.  We are reading the repo file for file F,
 332    which is coming in on STREAM, and the symbol that comes next in STREAM
 333    is offered, chosen or provided if CHOSEN is 0, 1 or 2, respectively.
 334
 335    XXX "provided" is unimplemented, both here and in the compiler.  */
 336
 337 static void
 338 freadsym (FILE *stream, file *f, int chosen)
 339 {
 340   symbol *sym;
 341
 342   {
 343     const char *name = tfgets (stream);
 344     sym = symbol_hash_lookup (name, true);
 345   }
 346
 347   if (sym->file == NULL)
 348     {
 349       /* We didn't have this symbol already, so we choose this file.  */
 350
 351       symbol_push (sym);
 352       sym->file = f;
 353       sym->chosen = chosen;
 354     }
 355   else if (chosen)
 356     {
 357       /* We want this file; cast aside any pretender.  */
 358
 359       if (sym->chosen && sym->file != f)
 360         {
 361           if (sym->chosen == 1)
 362             file_push (sym->file);
 363           else
 364             {
 365               file_push (f);
 366               f = sym->file;
 367               chosen = sym->chosen;
 368             }
 369         }
 370       sym->file = f;
 371       sym->chosen = chosen;
 372     }
 373 }
 374
 375 /* Read in the repo file denoted by F, and record all its information.  */
 376
 377 static void
 378 read_repo_file (file *f)
 379 {
 380   char c;
 381   FILE *stream = fopen (f->key, "r");
 382
 383   if (tlink_verbose >= 2)
 384     fprintf (stderr, _("collect: reading %s\n"), f->key);
 385
 386   while (fscanf (stream, "%c ", &c) == 1)
 387     {
 388       switch (c)
 389         {
 390         case 'A':
 391           f->args = pfgets (stream);
 392           break;
 393         case 'D':
 394           f->dir = pfgets (stream);
 395           break;
 396         case 'M':
 397           f->main = pfgets (stream);
 398           break;
 399         case 'P':
 400           freadsym (stream, f, 2);
 401           break;
 402         case 'C':
 403           freadsym (stream, f, 1);
 404           break;
 405         case 'O':
 406           freadsym (stream, f, 0);
 407           break;
 408         }
 409       obstack_free (&temporary_obstack, temporary_firstobj);
 410     }
 411   fclose (stream);
 412   if (f->args == NULL)
 413     f->args = getenv ("COLLECT_GCC_OPTIONS");
 414   if (f->dir == NULL)
 415     f->dir = ".";
 416 }
 417
 418 /* We might want to modify LINE, which is a symbol line from file F.  We do
 419    this if either we saw an error message referring to the symbol in
 420    question, or we have already allocated the symbol to another file and
 421    this one wants to emit it as well.  */
 422
 423 static void
 424 maybe_tweak (char *line, file *f)
 425 {
 426   symbol *sym = symbol_hash_lookup (line + 2, false);
 427
 428   if ((sym->file == f && sym->tweaking)
 429       || (sym->file != f && line[0] == 'C'))
 430     {
 431       sym->tweaking = 0;
 432       sym->tweaked = 1;
 433
 434       if (line[0] == 'O')
 435         line[0] = 'C';
 436       else
 437         line[0] = 'O';
 438     }
 439 }
 440
 441 /* Update the repo files for each of the object files we have adjusted and
 442    recompile.  */
 443
 444 static int
 445 recompile_files (void)
 446 {
 447   file *f;
 448
 449   putenv (xstrdup ("COMPILER_PATH="));
 450   putenv (xstrdup ("LIBRARY_PATH="));
 451
 452   while ((f = file_pop ()) != NULL)
 453     {
 454       char *line;
 455       const char *p, *q;
 456       char **argv;
 457       struct obstack arg_stack;
 458       FILE *stream = fopen (f->key, "r");
 459       const char *const outname = frob_extension (f->key, ".rnw");
 460       FILE *output = fopen (outname, "w");
 461
 462       while ((line = tfgets (stream)) != NULL)
 463         {
 464           switch (line[0])
 465             {
 466             case 'C':
 467             case 'O':
 468               maybe_tweak (line, f);
 469             }
 470           fprintf (output, "%s\n", line);
 471         }
 472       fclose (stream);
 473       fclose (output);
 474       /* On Windows "rename" returns -1 and sets ERRNO to EACCESS if
 475          the new file name already exists.  Therefore, we explicitly
 476          remove the old file first.  */
 477       if (remove (f->key) == -1)
 478         fatal_perror ("removing .rpo file");
 479       if (rename (outname, f->key) == -1)
 480         fatal_perror ("renaming .rpo file");
 481
 482       if (!f->args)
 483         {
 484           error ("repository file '%s' does not contain command-line "
 485                  "arguments", f->key);
 486           return 0;
 487         }
 488
 489       /* Build a null-terminated argv array suitable for
 490          tlink_execute().  Manipulate arguments on the arg_stack while
 491          building argv on the temporary_obstack.  */
 492
 493       obstack_init (&arg_stack);
 494       obstack_ptr_grow (&temporary_obstack, c_file_name);
 495
 496       for (p = f->args; *p != '\0'; p = q + 1)
 497         {
 498           /* Arguments are delimited by single-quotes.  Find the
 499              opening quote.  */
 500           p = strchr (p, '\'');
 501           if (!p)
 502             goto done;
 503
 504           /* Find the closing quote.  */
 505           q = strchr (p + 1, '\'');
 506           if (!q)
 507             goto done;
 508
 509           obstack_grow (&arg_stack, p + 1, q - (p + 1));
 510
 511           /* Replace '\'' with '.  This is how set_collect_gcc_options
 512              encodes a single-quote.  */
 513           while (q[1] == '\\' && q[2] == '\'' && q[3] == '\'')
 514             {
 515               const char *r;
 516
 517               r = strchr (q + 4, '\'');
 518               if (!r)
 519                 goto done;
 520
 521               obstack_grow (&arg_stack, q + 3, r - (q + 3));
 522               q = r;
 523             }
 524
 525           obstack_1grow (&arg_stack, '\0');
 526           obstack_ptr_grow (&temporary_obstack, obstack_finish (&arg_stack));
 527         }
 528     done:
 529       obstack_ptr_grow (&temporary_obstack, f->main);
 530       obstack_ptr_grow (&temporary_obstack, NULL);
 531       argv = XOBFINISH (&temporary_obstack, char **);
 532
 533       if (tlink_verbose)
 534         fprintf (stderr, _("collect: recompiling %s\n"), f->main);
 535
 536       if (chdir (f->dir) != 0
 537           || tlink_execute (c_file_name, argv, NULL, NULL) != 0
 538           || chdir (initial_cwd) != 0)
 539         return 0;
 540
 541       read_repo_file (f);
 542
 543       obstack_free (&arg_stack, NULL);
 544       obstack_free (&temporary_obstack, temporary_firstobj);
 545     }
 546   return 1;
 547 }
 548
 549 /* The first phase of processing: determine which object files have
 550    .rpo files associated with them, and read in the information.  */
 551
 552 static int
 553 read_repo_files (char **object_lst)
 554 {
 555   char **object = object_lst;
 556
 557   for (; *object; object++)
 558     {
 559       const char *p;
 560       file *f;
 561
 562       /* Don't bother trying for ld flags.  */
 563       if (*object[0] == '-')
 564         continue;
 565
 566       p = frob_extension (*object, ".rpo");
 567
 568       if (! file_exists (p))
 569         continue;
 570
 571       f = file_hash_lookup (p);
 572
 573       read_repo_file (f);
 574     }
 575
 576   if (file_stack != NULL && ! recompile_files ())
 577     return 0;
 578
 579   return (symbol_stack != NULL);
 580 }
 581
 582 /* Add the demangled forms of any new symbols to the hash table.  */
 583
 584 static void
 585 demangle_new_symbols (void)
 586 {
 587   symbol *sym;
 588
 589   while ((sym = symbol_pop ()) != NULL)
 590     {
 591       demangled *dem;
 592       const char *p = cplus_demangle (sym->key, DMGL_PARAMS | DMGL_ANSI);
 593
 594       if (! p)
 595         continue;
 596
 597       dem = demangled_hash_lookup (p, true);
 598       dem->mangled = sym->key;
 599     }
 600 }
 601
 602 /* Step through the output of the linker, in the file named FNAME, and
 603    adjust the settings for each symbol encountered.  */
 604
 605 static int
 606 scan_linker_output (const char *fname)
 607 {
 608   FILE *stream = fopen (fname, "r");
 609   char *line;
 610
 611   while ((line = tfgets (stream)) != NULL)
 612     {
 613       char *p = line, *q;
 614       symbol *sym;
 615       int end;
 616
 617       while (*p && ISSPACE ((unsigned char) *p))
 618         ++p;
 619
 620       if (! *p)
 621         continue;
 622
 623       for (q = p; *q && ! ISSPACE ((unsigned char) *q); ++q)
 624         ;
 625
 626       /* Try the first word on the line.  */
 627       if (*p == '.')
 628         ++p;
 629       if (!strncmp (p, USER_LABEL_PREFIX, strlen (USER_LABEL_PREFIX)))
 630         p += strlen (USER_LABEL_PREFIX);
 631
 632       end = ! *q;
 633       *q = 0;
 634       sym = symbol_hash_lookup (p, false);
 635
 636       /* Some SVR4 linkers produce messages like
 637          ld: 0711-317 ERROR: Undefined symbol: .g__t3foo1Zi
 638          */
 639       if (! sym && ! end && strstr (q + 1, "Undefined symbol: "))
 640         {
 641           char *p = strrchr (q + 1, ' ');
 642           p++;
 643           if (*p == '.')
 644             p++;
 645           if (!strncmp (p, USER_LABEL_PREFIX, strlen (USER_LABEL_PREFIX)))
 646             p += strlen (USER_LABEL_PREFIX);
 647           sym = symbol_hash_lookup (p, false);
 648         }
 649
 650       if (! sym && ! end)
 651         /* Try a mangled name in quotes.  */
 652         {
 653           const char *oldq = q + 1;
 654           demangled *dem = 0;
 655           q = 0;
 656
 657           /* First try `GNU style'.  */
 658           p = strchr (oldq, '`');
 659           if (p)
 660             p++, q = strchr (p, '\'');
 661           /* Then try "double quotes".  */
 662           else if (p = strchr (oldq, '"'), p)
 663             p++, q = strchr (p, '"');
 664           else {
 665             /* Then try entire line.  */
 666             q = strchr (oldq, 0);
 667             if (q != oldq)
 668               p = (char *)oldq;
 669           }
 670
 671           if (p)
 672             {
 673               /* Don't let the strstr's below see the demangled name; we
 674                  might get spurious matches.  */
 675               p[-1] = '\0';
 676
 677               /* powerpc64-linux references .foo when calling function foo.  */
 678               if (*p == '.')
 679                 p++;
 680             }
 681
 682           /* We need to check for certain error keywords here, or we would
 683              mistakenly use GNU ld's "In function `foo':" message.  */
 684           if (q && (strstr (oldq, "ndefined")
 685                     || strstr (oldq, "nresolved")
 686                     || strstr (oldq, "nsatisfied")
 687                     || strstr (oldq, "ultiple")))
 688             {
 689               *q = 0;
 690               dem = demangled_hash_lookup (p, false);
 691               if (dem)
 692                 sym = symbol_hash_lookup (dem->mangled, false);
 693               else
 694                 {
 695                   if (!strncmp (p, USER_LABEL_PREFIX,
 696                                 strlen (USER_LABEL_PREFIX)))
 697                     p += strlen (USER_LABEL_PREFIX);
 698                   sym = symbol_hash_lookup (p, false);
 699                 }
 700             }
 701         }
 702
 703       if (sym && sym->tweaked)
 704         {
 705           error ("'%s' was assigned to '%s', but was not defined "
 706                  "during recompilation, or vice versa",
 707                  sym->key, sym->file->key);
 708           fclose (stream);
 709           return 0;
 710         }
 711       if (sym && !sym->tweaking)
 712         {
 713           if (tlink_verbose >= 2)
 714             fprintf (stderr, _("collect: tweaking %s in %s\n"),
 715                      sym->key, sym->file->key);
 716           sym->tweaking = 1;
 717           file_push (sym->file);
 718         }
 719
 720       obstack_free (&temporary_obstack, temporary_firstobj);
 721     }
 722
 723   fclose (stream);
 724   return (file_stack != NULL);
 725 }
 726
 727 /* Entry point for tlink.  Called from main in collect2.c.
 728
 729    Iteratively try to provide definitions for all the unresolved symbols
 730    mentioned in the linker error messages.
 731
 732    LD_ARGV is an array of arguments for the linker.
 733    OBJECT_LST is an array of object files that we may be able to recompile
 734      to provide missing definitions.  Currently ignored.  */
 735
 736 void
 737 do_tlink (char **ld_argv, char **object_lst ATTRIBUTE_UNUSED)
 738 {
 739   int exit = tlink_execute ("ld", ld_argv, ldout, lderrout);
 740
 741   tlink_init ();
 742
 743   if (exit)
 744     {
 745       int i = 0;
 746
 747       /* Until collect does a better job of figuring out which are object
 748          files, assume that everything on the command line could be.  */
 749       if (read_repo_files (ld_argv))
 750         while (exit && i++ < MAX_ITERATIONS)
 751           {
 752             if (tlink_verbose >= 3)
 753               {
 754                 dump_file (ldout, stdout);
 755                 dump_file (lderrout, stderr);
 756               }
 757             demangle_new_symbols ();
 758             if (! scan_linker_output (ldout)
 759                 && ! scan_linker_output (lderrout))
 760               break;
 761             if (! recompile_files ())
 762               break;
 763             if (tlink_verbose)
 764               fprintf (stderr, _("collect: relinking\n"));
 765             exit = tlink_execute ("ld", ld_argv, ldout, lderrout);
 766           }
 767     }
 768
 769   dump_file (ldout, stdout);
 770   unlink (ldout);
 771   dump_file (lderrout, stderr);
 772   unlink (lderrout);
 773   if (exit)
 774     {
 775       error ("ld returned %d exit status", exit);
 776       collect_exit (exit);
 777     }
 778 }