1/* Scan linker error messages for missing template instantiations and provide
2 them.
3
4 Copyright (C) 1995-2017 Free Software Foundation, Inc.
5 Contributed by Jason Merrill (jason@cygnus.com).
6
7This file is part of GCC.
8
9GCC is free software; you can redistribute it and/or modify it under
10the terms of the GNU General Public License as published by the Free
11Software Foundation; either version 3, or (at your option) any later
12version.
13
14GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15WARRANTY; without even the implied warranty of MERCHANTABILITY or
16FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17for more details.
18
19You should have received a copy of the GNU General Public License
20along 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 "demangle.h"
30#include "collect2.h"
31#include "collect-utils.h"
32#include "filenames.h"
33#include "diagnostic-core.h"
34
35/* TARGET_64BIT may be defined to use driver specific functionality. */
36#undef TARGET_64BIT
37#define TARGET_64BIT TARGET_64BIT_DEFAULT
38
39#define MAX_ITERATIONS 17
40
41/* Defined in the automatically-generated underscore.c. */
42extern int prepends_underscore;
43
44static int tlink_verbose;
45
46static char *initial_cwd;
47
48/* Hash table boilerplate for working with htab_t. We have hash tables
49 for symbol names, file names, and demangled symbols. */
50
51typedef struct symbol_hash_entry
52{
53 const char *key;
54 struct file_hash_entry *file;
55 int chosen;
56 int tweaking;
57 int tweaked;
58} symbol;
59
60typedef struct file_hash_entry
61{
62 const char *key;
63 const char *args;
64 const char *dir;
65 const char *main;
66 int tweaking;
67} file;
68
69typedef const char *str;
70
71typedef struct demangled_hash_entry
72{
73 const char *key;
74 vec<str> mangled;
75} demangled;
76
77/* Hash and comparison functions for these hash tables. */
78
79static int hash_string_eq (const void *, const void *);
80static hashval_t hash_string_hash (const void *);
81
82static int
83hash_string_eq (const void *s1_p, const void *s2_p)
84{
85 const char *const *s1 = (const char *const *) s1_p;
86 const char *s2 = (const char *) s2_p;
87 return strcmp (*s1, s2) == 0;
88}
89
90static hashval_t
91hash_string_hash (const void *s_p)
92{
93 const char *const *s = (const char *const *) s_p;
94 return (*htab_hash_string) (*s);
95}
96
97static htab_t symbol_table;
98
99static struct symbol_hash_entry * symbol_hash_lookup (const char *, int);
100static struct file_hash_entry * file_hash_lookup (const char *);
101static struct demangled_hash_entry *demangled_hash_lookup (const char *, int);
102static void symbol_push (symbol *);
103static symbol * symbol_pop (void);
104static void file_push (file *);
105static file * file_pop (void);
106static char * frob_extension (const char *, const char *);
107static char * obstack_fgets (FILE *, struct obstack *);
108static char * tfgets (FILE *);
109static char * pfgets (FILE *);
110static void freadsym (FILE *, file *, int);
111static void read_repo_file (file *);
112static void maybe_tweak (char *, file *);
113static int recompile_files (void);
114static int read_repo_files (char **);
115static void demangle_new_symbols (void);
116static int scan_linker_output (const char *);
117
118/* Look up an entry in the symbol hash table. */
119
120static struct symbol_hash_entry *
121symbol_hash_lookup (const char *string, int create)
122{
123 void **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 = XCNEW (struct symbol_hash_entry);
133 v->key = xstrdup (string);
134 }
135 return (struct symbol_hash_entry *) *e;
136}
137
138static htab_t file_table;
139
140/* Look up an entry in the file hash table. */
141
142static struct file_hash_entry *
143file_hash_lookup (const char *string)
144{
145 void **e;
146 e = htab_find_slot_with_hash (file_table, string,
147 (*htab_hash_string) (string),
148 INSERT);
149 if (*e == NULL)
150 {
151 struct file_hash_entry *v;
152 *e = v = XCNEW (struct file_hash_entry);
153 v->key = xstrdup (string);
154 }
155 return (struct file_hash_entry *) *e;
156}
157
158static htab_t demangled_table;
159
160/* Look up an entry in the demangled name hash table. */
161
162static struct demangled_hash_entry *
163demangled_hash_lookup (const char *string, int create)
164{
165 void **e;
166 e = htab_find_slot_with_hash (demangled_table, string,
167 (*htab_hash_string) (string),
168 create ? INSERT : NO_INSERT);
169 if (e == NULL)
170 return NULL;
171 if (*e == NULL)
172 {
173 struct demangled_hash_entry *v;
174 *e = v = XCNEW (struct demangled_hash_entry);
175 v->key = xstrdup (string);
176 }
177 return (struct demangled_hash_entry *) *e;
178}
179
180/* Stack code. */
181
182struct symbol_stack_entry
183{
184 symbol *value;
185 struct symbol_stack_entry *next;
186};
187struct obstack symbol_stack_obstack;
188struct symbol_stack_entry *symbol_stack;
189
190struct file_stack_entry
191{
192 file *value;
193 struct file_stack_entry *next;
194};
195struct obstack file_stack_obstack;
196struct file_stack_entry *file_stack;
197
198static void
199symbol_push (symbol *p)
200{
201 struct symbol_stack_entry *ep
202 = XOBNEW (&symbol_stack_obstack, struct symbol_stack_entry);
203 ep->value = p;
204 ep->next = symbol_stack;
205 symbol_stack = ep;
206}
207
208static symbol *
209symbol_pop (void)
210{
211 struct symbol_stack_entry *ep = symbol_stack;
212 symbol *p;
213 if (ep == NULL)
214 return NULL;
215 p = ep->value;
216 symbol_stack = ep->next;
217 obstack_free (&symbol_stack_obstack, ep);
218 return p;
219}
220
221static void
222file_push (file *p)
223{
224 struct file_stack_entry *ep;
225
226 if (p->tweaking)
227 return;
228
229 ep = XOBNEW (&file_stack_obstack, struct file_stack_entry);
230 ep->value = p;
231 ep->next = file_stack;
232 file_stack = ep;
233 p->tweaking = 1;
234}
235
236static file *
237file_pop (void)
238{
239 struct file_stack_entry *ep = file_stack;
240 file *p;
241 if (ep == NULL)
242 return NULL;
243 p = ep->value;
244 file_stack = ep->next;
245 obstack_free (&file_stack_obstack, ep);
246 p->tweaking = 0;
247 return p;
248}
249
250/* Other machinery. */
251
252/* Initialize the tlink machinery. Called from do_tlink. */
253
254static void
255tlink_init (void)
256{
257 const char *p;
258
259 symbol_table = htab_create (500, hash_string_hash, hash_string_eq,
260 NULL);
261 file_table = htab_create (500, hash_string_hash, hash_string_eq,
262 NULL);
263 demangled_table = htab_create (500, hash_string_hash, hash_string_eq,
264 NULL);
265
266 obstack_begin (&symbol_stack_obstack, 0);
267 obstack_begin (&file_stack_obstack, 0);
268
269 p = getenv ("TLINK_VERBOSE");
270 if (p)
271 tlink_verbose = atoi (p);
272 else
273 {
274 tlink_verbose = 1;
275 if (verbose)
276 tlink_verbose = 2;
277 if (debug)
278 tlink_verbose = 3;
279 }
280
281 initial_cwd = getpwd ();
282}
283
284static int
285tlink_execute (const char *prog, char **argv, const char *outname,
286 const char *errname, bool use_atfile)
287{
288 struct pex_obj *pex;
289
290 pex = collect_execute (prog, argv, outname, errname,
291 PEX_LAST | PEX_SEARCH, use_atfile);
292 return collect_wait (prog, pex);
293}
294
295static char *
296frob_extension (const char *s, const char *ext)
297{
298 const char *p;
299
300 p = strrchr (lbasename (s), '.');
301 if (! p)
302 p = s + strlen (s);
303
304 obstack_grow (&temporary_obstack, s, p - s);
305 return (char *) obstack_copy0 (&temporary_obstack, ext, strlen (ext));
306}
307
308static char *
309obstack_fgets (FILE *stream, struct obstack *ob)
310{
311 int c;
312 while ((c = getc (stream)) != EOF && c != '\n')
313 obstack_1grow (ob, c);
314 if (obstack_object_size (ob) == 0)
315 return NULL;
316 obstack_1grow (ob, '\0');
317 return XOBFINISH (ob, char *);
318}
319
320static char *
321tfgets (FILE *stream)
322{
323 return obstack_fgets (stream, &temporary_obstack);
324}
325
326static char *
327pfgets (FILE *stream)
328{
329 return xstrdup (tfgets (stream));
330}
331
332/* Real tlink code. */
333
334/* Subroutine of read_repo_file. We are reading the repo file for file F,
335 which is coming in on STREAM, and the symbol that comes next in STREAM
336 is offered, chosen or provided if CHOSEN is 0, 1 or 2, respectively.
337
338 XXX "provided" is unimplemented, both here and in the compiler. */
339
340static void
341freadsym (FILE *stream, file *f, int chosen)
342{
343 symbol *sym;
344
345 {
346 const char *name = tfgets (stream);
347 sym = symbol_hash_lookup (name, true);
348 }
349
350 if (sym->file == NULL)
351 {
352 /* We didn't have this symbol already, so we choose this file. */
353
354 symbol_push (sym);
355 sym->file = f;
356 sym->chosen = chosen;
357 }
358 else if (chosen)
359 {
360 /* We want this file; cast aside any pretender. */
361
362 if (sym->chosen && sym->file != f)
363 {
364 if (sym->chosen == 1)
365 file_push (sym->file);
366 else
367 {
368 file_push (f);
369 f = sym->file;
370 chosen = sym->chosen;
371 }
372 }
373 sym->file = f;
374 sym->chosen = chosen;
375 }
376}
377
378/* Read in the repo file denoted by F, and record all its information. */
379
380static void
381read_repo_file (file *f)
382{
383 char c;
384 FILE *stream = fopen (f->key, "r");
385
386 if (tlink_verbose >= 2)
387 fprintf (stderr, _("collect: reading %s\n"), f->key);
388
389 while (fscanf (stream, "%c ", &c) == 1)
390 {
391 switch (c)
392 {
393 case 'A':
394 f->args = pfgets (stream);
395 break;
396 case 'D':
397 f->dir = pfgets (stream);
398 break;
399 case 'M':
400 f->main = pfgets (stream);
401 break;
402 case 'P':
403 freadsym (stream, f, 2);
404 break;
405 case 'C':
406 freadsym (stream, f, 1);
407 break;
408 case 'O':
409 freadsym (stream, f, 0);
410 break;
411 }
412 obstack_free (&temporary_obstack, temporary_firstobj);
413 }
414 fclose (stream);
415 if (f->args == NULL)
416 f->args = getenv ("COLLECT_GCC_OPTIONS");
417 if (f->dir == NULL)
418 f->dir = ".";
419}
420
421/* We might want to modify LINE, which is a symbol line from file F. We do
422 this if either we saw an error message referring to the symbol in
423 question, or we have already allocated the symbol to another file and
424 this one wants to emit it as well. */
425
426static void
427maybe_tweak (char *line, file *f)
428{
429 symbol *sym = symbol_hash_lookup (line + 2, false);
430
431 if ((sym->file == f && sym->tweaking)
432 || (sym->file != f && line[0] == 'C'))
433 {
434 sym->tweaking = 0;
435 sym->tweaked = 1;
436
437 if (line[0] == 'O')
438 {
439 line[0] = 'C';
440 sym->chosen = 1;
441 }
442 else
443 {
444 line[0] = 'O';
445 sym->chosen = 0;
446 }
447 }
448}
449
450/* Update the repo files for each of the object files we have adjusted and
451 recompile. */
452
453static int
454recompile_files (void)
455{
456 file *f;
457
458 putenv (xstrdup ("COMPILER_PATH="));
459 putenv (xstrdup ("LIBRARY_PATH="));
460
461 while ((f = file_pop ()) != NULL)
462 {
463 char *line;
464 const char *p, *q;
465 char **argv;
466 struct obstack arg_stack;
467 FILE *stream = fopen (f->key, "r");
468 const char *const outname = frob_extension (f->key, ".rnw");
469 FILE *output = fopen (outname, "w");
470
471 while ((line = tfgets (stream)) != NULL)
472 {
473 switch (line[0])
474 {
475 case 'C':
476 case 'O':
477 maybe_tweak (line, f);
478 }
479 fprintf (output, "%s\n", line);
480 }
481 fclose (stream);
482 fclose (output);
483 /* On Windows "rename" returns -1 and sets ERRNO to EACCESS if
484 the new file name already exists. Therefore, we explicitly
485 remove the old file first. */
486 if (remove (f->key) == -1)
487 fatal_error (input_location, "removing .rpo file: %m");
488 if (rename (outname, f->key) == -1)
489 fatal_error (input_location, "renaming .rpo file: %m");
490
491 if (!f->args)
492 {
493 error ("repository file '%s' does not contain command-line "
494 "arguments", f->key);
495 return 0;
496 }
497
498 /* Build a null-terminated argv array suitable for
499 tlink_execute(). Manipulate arguments on the arg_stack while
500 building argv on the temporary_obstack. */
501
502 obstack_init (&arg_stack);
503 obstack_ptr_grow (&temporary_obstack, c_file_name);
504
505 for (p = f->args; *p != '\0'; p = q + 1)
506 {
507 /* Arguments are delimited by single-quotes. Find the
508 opening quote. */
509 p = strchr (p, '\'');
510 if (!p)
511 goto done;
512
513 /* Find the closing quote. */
514 q = strchr (p + 1, '\'');
515 if (!q)
516 goto done;
517
518 obstack_grow (&arg_stack, p + 1, q - (p + 1));
519
520 /* Replace '\'' with '. This is how set_collect_gcc_options
521 encodes a single-quote. */
522 while (q[1] == '\\' && q[2] == '\'' && q[3] == '\'')
523 {
524 const char *r;
525
526 r = strchr (q + 4, '\'');
527 if (!r)
528 goto done;
529
530 obstack_grow (&arg_stack, q + 3, r - (q + 3));
531 q = r;
532 }
533
534 obstack_1grow (&arg_stack, '\0');
535 obstack_ptr_grow (&temporary_obstack, obstack_finish (&arg_stack));
536 }
537 done:
538 obstack_ptr_grow (&temporary_obstack, f->main);
539 obstack_ptr_grow (&temporary_obstack, NULL);
540 argv = XOBFINISH (&temporary_obstack, char **);
541
542 if (tlink_verbose)
543 fprintf (stderr, _("collect: recompiling %s\n"), f->main);
544
545 if (chdir (f->dir) != 0
546 || tlink_execute (c_file_name, argv, NULL, NULL, false) != 0
547 || chdir (initial_cwd) != 0)
548 return 0;
549
550 read_repo_file (f);
551
552 obstack_free (&arg_stack, NULL);
553 obstack_free (&temporary_obstack, temporary_firstobj);
554 }
555 return 1;
556}
557
558/* The first phase of processing: determine which object files have
559 .rpo files associated with them, and read in the information. */
560
561static int
562read_repo_files (char **object_lst)
563{
564 char **object = object_lst;
565
566 for (; *object; object++)
567 {
568 const char *p;
569 file *f;
570
571 /* Don't bother trying for ld flags. */
572 if (*object[0] == '-')
573 continue;
574
575 p = frob_extension (*object, ".rpo");
576
577 if (! file_exists (p))
578 continue;
579
580 f = file_hash_lookup (p);
581
582 read_repo_file (f);
583 }
584
585 if (file_stack != NULL && ! recompile_files ())
586 return 0;
587
588 return (symbol_stack != NULL);
589}
590
591/* Add the demangled forms of any new symbols to the hash table. */
592
593static void
594demangle_new_symbols (void)
595{
596 symbol *sym;
597
598 while ((sym = symbol_pop ()) != NULL)
599 {
600 demangled *dem;
601 const char *p = cplus_demangle (sym->key, DMGL_PARAMS | DMGL_ANSI);
602
603 if (! p)
604 continue;
605
606 dem = demangled_hash_lookup (p, true);
607 dem->mangled.safe_push (sym->key);
608 }
609}
610
611/* We want to tweak symbol SYM. Return true if all is well, false on
612 error. */
613
614static bool
615start_tweaking (symbol *sym)
616{
617 if (sym && sym->tweaked)
618 {
619 error ("'%s' was assigned to '%s', but was not defined "
620 "during recompilation, or vice versa",
621 sym->key, sym->file->key);
622 return 0;
623 }
624 if (sym && !sym->tweaking)
625 {
626 if (tlink_verbose >= 2)
627 fprintf (stderr, _("collect: tweaking %s in %s\n"),
628 sym->key, sym->file->key);
629 sym->tweaking = 1;
630 file_push (sym->file);
631 }
632 return true;
633}
634
635/* Step through the output of the linker, in the file named FNAME, and
636 adjust the settings for each symbol encountered. */
637
638static int
639scan_linker_output (const char *fname)
640{
641 FILE *stream = fopen (fname, "r");
642 char *line;
643 int skip_next_in_line = 0;
644
645 while ((line = tfgets (stream)) != NULL)
646 {
647 char *p = line, *q;
648 symbol *sym;
649 demangled *dem = 0;
650 int end;
651 int ok = 0;
652 unsigned ix;
653 str s;
654
655 /* On darwin9, we might have to skip " in " lines as well. */
656 if (skip_next_in_line
657 && strstr (p, " in "))
658 continue;
659 skip_next_in_line = 0;
660
661 while (*p && ISSPACE ((unsigned char) *p))
662 ++p;
663
664 if (! *p)
665 continue;
666
667 for (q = p; *q && ! ISSPACE ((unsigned char) *q); ++q)
668 ;
669
670 /* Try the first word on the line. */
671 if (*p == '.')
672 ++p;
673 if (!strncmp (p, USER_LABEL_PREFIX, strlen (USER_LABEL_PREFIX)))
674 p += strlen (USER_LABEL_PREFIX);
675
676 end = ! *q;
677 *q = 0;
678 sym = symbol_hash_lookup (p, false);
679
680 /* Some SVR4 linkers produce messages like
681 ld: 0711-317 ERROR: Undefined symbol: .g__t3foo1Zi
682 */
683 if (! sym && ! end && strstr (q + 1, "Undefined symbol: "))
684 {
685 char *p = strrchr (q + 1, ' ');
686 p++;
687 if (*p == '.')
688 p++;
689 if (!strncmp (p, USER_LABEL_PREFIX, strlen (USER_LABEL_PREFIX)))
690 p += strlen (USER_LABEL_PREFIX);
691 sym = symbol_hash_lookup (p, false);
692 }
693
694 if (! sym && ! end)
695 /* Try a mangled name in quotes. */
696 {
697 char *oldq = q + 1;
698 q = 0;
699
700 /* On darwin9, we look for "foo" referenced from:\n\(.* in .*\n\)* */
701 if (strcmp (oldq, "referenced from:") == 0)
702 {
703 /* We have to remember that we found a symbol to tweak. */
704 ok = 1;
705
706 /* We actually want to start from the first word on the
707 line. */
708 oldq = p;
709
710 /* Since the format is multiline, we have to skip
711 following lines with " in ". */
712 skip_next_in_line = 1;
713 }
714
715 /* First try `GNU style'. */
716 p = strchr (oldq, '`');
717 if (p)
718 p++, q = strchr (p, '\'');
719 /* Then try "double quotes". */
720 else if (p = strchr (oldq, '"'), p)
721 p++, q = strchr (p, '"');
722 /* Then try 'single quotes'. */
723 else if (p = strchr (oldq, '\''), p)
724 p++, q = strchr (p, '\'');
725 else {
726 /* Then try entire line. */
727 q = strchr (oldq, 0);
728 if (q != oldq)
729 p = (char *)oldq;
730 }
731
732 if (p)
733 {
734 /* Don't let the strstr's below see the demangled name; we
735 might get spurious matches. */
736 p[-1] = '\0';
737
738 /* powerpc64-linux references .foo when calling function foo. */
739 if (*p == '.')
740 p++;
741 }
742
743 /* We need to check for certain error keywords here, or we would
744 mistakenly use GNU ld's "In function `foo':" message. */
745 if (q && (ok
746 || strstr (oldq, "ndefined")
747 || strstr (oldq, "nresolved")
748 || strstr (oldq, "nsatisfied")
749 || strstr (oldq, "ultiple")))
750 {
751 *q = 0;
752 dem = demangled_hash_lookup (p, false);
753 if (!dem)
754 {
755 if (!strncmp (p, USER_LABEL_PREFIX,
756 strlen (USER_LABEL_PREFIX)))
757 p += strlen (USER_LABEL_PREFIX);
758 sym = symbol_hash_lookup (p, false);
759 }
760 }
761 }
762
763 if (dem)
764 {
765 /* We found a demangled name. If this is the name of a
766 constructor or destructor, there can be several mangled names
767 that match it, so choose or unchoose all of them. If some are
768 chosen and some not, leave the later ones that don't match
769 alone for now; either this will cause the link to succeed, or
770 on the next attempt we will switch all of them the other way
771 and that will cause it to succeed. */
772 int chosen = 0;
773 int len = dem->mangled.length ();
774 ok = true;
775 FOR_EACH_VEC_ELT (dem->mangled, ix, s)
776 {
777 sym = symbol_hash_lookup (s, false);
778 if (ix == 0)
779 chosen = sym->chosen;
780 else if (sym->chosen != chosen)
781 /* Mismatch. */
782 continue;
783 /* Avoid an error about re-tweaking when we guess wrong in
784 the case of mismatch. */
785 if (len > 1)
786 sym->tweaked = false;
787 ok = start_tweaking (sym);
788 }
789 }
790 else
791 ok = start_tweaking (sym);
792
793 obstack_free (&temporary_obstack, temporary_firstobj);
794
795 if (!ok)
796 {
797 fclose (stream);
798 return 0;
799 }
800 }
801
802 fclose (stream);
803 return (file_stack != NULL);
804}
805
806/* Entry point for tlink. Called from main in collect2.c.
807
808 Iteratively try to provide definitions for all the unresolved symbols
809 mentioned in the linker error messages.
810
811 LD_ARGV is an array of arguments for the linker.
812 OBJECT_LST is an array of object files that we may be able to recompile
813 to provide missing definitions. Currently ignored. */
814
815void
816do_tlink (char **ld_argv, char **object_lst ATTRIBUTE_UNUSED)
817{
818 int ret = tlink_execute ("ld", ld_argv, ldout, lderrout,
819 HAVE_GNU_LD && at_file_supplied);
820
821 tlink_init ();
822
823 if (ret)
824 {
825 int i = 0;
826
827 /* Until collect does a better job of figuring out which are object
828 files, assume that everything on the command line could be. */
829 if (read_repo_files (ld_argv))
830 while (ret && i++ < MAX_ITERATIONS)
831 {
832 if (tlink_verbose >= 3)
833 {
834 dump_ld_file (ldout, stdout);
835 dump_ld_file (lderrout, stderr);
836 }
837 demangle_new_symbols ();
838 if (! scan_linker_output (ldout)
839 && ! scan_linker_output (lderrout))
840 break;
841 if (! recompile_files ())
842 break;
843 if (tlink_verbose)
844 fprintf (stderr, _("collect: relinking\n"));
845 ret = tlink_execute ("ld", ld_argv, ldout, lderrout,
846 HAVE_GNU_LD && at_file_supplied);
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}
866