daily update
[binutils.git] / ld / plugin.c
blob91fe48b9f27135a219598343d562b39c78e60d0d
1 /* Plugin control for the GNU linker.
2 Copyright 2010, 2011 Free Software Foundation, Inc.
4 This file is part of the GNU Binutils.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
21 #include "sysdep.h"
22 #include "libiberty.h"
23 #include "bfd.h"
24 #include "bfdlink.h"
25 #include "bfdver.h"
26 #include "ld.h"
27 #include "ldmain.h"
28 #include "ldmisc.h"
29 #include "ldexp.h"
30 #include "ldlang.h"
31 #include "ldfile.h"
32 #include "plugin.h"
33 #include "plugin-api.h"
34 #include "elf-bfd.h"
35 #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)
36 #include <windows.h>
37 #endif
39 /* Report plugin symbols. */
40 bfd_boolean report_plugin_symbols;
42 /* The suffix to append to the name of the real (claimed) object file
43 when generating a dummy BFD to hold the IR symbols sent from the
44 plugin. For cosmetic use only; appears in maps, crefs etc. */
45 #define IRONLY_SUFFIX " (symbol from plugin)"
47 /* Stores a single argument passed to a plugin. */
48 typedef struct plugin_arg
50 struct plugin_arg *next;
51 const char *arg;
52 } plugin_arg_t;
54 /* Holds all details of a single plugin. */
55 typedef struct plugin
57 /* Next on the list of plugins, or NULL at end of chain. */
58 struct plugin *next;
59 /* The argument string given to --plugin. */
60 const char *name;
61 /* The shared library handle returned by dlopen. */
62 void *dlhandle;
63 /* The list of argument string given to --plugin-opt. */
64 plugin_arg_t *args;
65 /* Number of args in the list, for convenience. */
66 size_t n_args;
67 /* The plugin's event handlers. */
68 ld_plugin_claim_file_handler claim_file_handler;
69 ld_plugin_all_symbols_read_handler all_symbols_read_handler;
70 ld_plugin_cleanup_handler cleanup_handler;
71 /* TRUE if the cleanup handlers have been called. */
72 bfd_boolean cleanup_done;
73 } plugin_t;
75 /* The master list of all plugins. */
76 static plugin_t *plugins_list = NULL;
78 /* We keep a tail pointer for easy linking on the end. */
79 static plugin_t **plugins_tail_chain_ptr = &plugins_list;
81 /* The last plugin added to the list, for receiving args. */
82 static plugin_t *last_plugin = NULL;
84 /* The tail of the arg chain of the last plugin added to the list. */
85 static plugin_arg_t **last_plugin_args_tail_chain_ptr = NULL;
87 /* The plugin which is currently having a callback executed. */
88 static plugin_t *called_plugin = NULL;
90 /* Last plugin to cause an error, if any. */
91 static const char *error_plugin = NULL;
93 /* State of linker "notice" interface before we poked at it. */
94 static bfd_boolean orig_notice_all;
96 /* Original linker callbacks, and the plugin version. */
97 static const struct bfd_link_callbacks *orig_callbacks;
98 static struct bfd_link_callbacks plugin_callbacks;
100 /* Set at all symbols read time, to avoid recursively offering the plugin
101 its own newly-added input files and libs to claim. */
102 bfd_boolean no_more_claiming = FALSE;
104 /* List of tags to set in the constant leading part of the tv array. */
105 static const enum ld_plugin_tag tv_header_tags[] =
107 LDPT_MESSAGE,
108 LDPT_API_VERSION,
109 LDPT_GNU_LD_VERSION,
110 LDPT_LINKER_OUTPUT,
111 LDPT_OUTPUT_NAME,
112 LDPT_REGISTER_CLAIM_FILE_HOOK,
113 LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK,
114 LDPT_REGISTER_CLEANUP_HOOK,
115 LDPT_ADD_SYMBOLS,
116 LDPT_GET_INPUT_FILE,
117 LDPT_RELEASE_INPUT_FILE,
118 LDPT_GET_SYMBOLS,
119 LDPT_GET_SYMBOLS_V2,
120 LDPT_ADD_INPUT_FILE,
121 LDPT_ADD_INPUT_LIBRARY,
122 LDPT_SET_EXTRA_LIBRARY_PATH
125 /* How many entries in the constant leading part of the tv array. */
126 static const size_t tv_header_size = ARRAY_SIZE (tv_header_tags);
128 /* Forward references. */
129 static bfd_boolean plugin_notice (struct bfd_link_info *,
130 struct bfd_link_hash_entry *, bfd *,
131 asection *, bfd_vma, flagword, const char *);
133 #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)
135 #define RTLD_NOW 0 /* Dummy value. */
137 static void *
138 dlopen (const char *file, int mode ATTRIBUTE_UNUSED)
140 return LoadLibrary (file);
143 static void *
144 dlsym (void *handle, const char *name)
146 return GetProcAddress (handle, name);
149 static int
150 dlclose (void *handle)
152 FreeLibrary (handle);
153 return 0;
156 #endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) */
158 /* Helper function for exiting with error status. */
159 static int
160 set_plugin_error (const char *plugin)
162 error_plugin = plugin;
163 return -1;
166 /* Test if an error occurred. */
167 static bfd_boolean
168 plugin_error_p (void)
170 return error_plugin != NULL;
173 /* Return name of plugin which caused an error if any. */
174 const char *
175 plugin_error_plugin (void)
177 return error_plugin ? error_plugin : _("<no plugin>");
180 /* Handle -plugin arg: find and load plugin, or return error. */
182 plugin_opt_plugin (const char *plugin)
184 plugin_t *newplug;
186 newplug = xmalloc (sizeof *newplug);
187 memset (newplug, 0, sizeof *newplug);
188 newplug->name = plugin;
189 newplug->dlhandle = dlopen (plugin, RTLD_NOW);
190 if (!newplug->dlhandle)
191 return set_plugin_error (plugin);
193 /* Chain on end, so when we run list it is in command-line order. */
194 *plugins_tail_chain_ptr = newplug;
195 plugins_tail_chain_ptr = &newplug->next;
197 /* Record it as current plugin for receiving args. */
198 last_plugin = newplug;
199 last_plugin_args_tail_chain_ptr = &newplug->args;
200 return 0;
203 /* Accumulate option arguments for last-loaded plugin, or return
204 error if none. */
206 plugin_opt_plugin_arg (const char *arg)
208 plugin_arg_t *newarg;
210 if (!last_plugin)
211 return set_plugin_error (_("<no plugin>"));
213 newarg = xmalloc (sizeof *newarg);
214 newarg->arg = arg;
215 newarg->next = NULL;
217 /* Chain on end to preserve command-line order. */
218 *last_plugin_args_tail_chain_ptr = newarg;
219 last_plugin_args_tail_chain_ptr = &newarg->next;
220 last_plugin->n_args++;
221 return 0;
224 /* Create a dummy BFD. */
225 bfd *
226 plugin_get_ir_dummy_bfd (const char *name, bfd *srctemplate)
228 bfd *abfd;
230 bfd_use_reserved_id = 1;
231 abfd = bfd_create (concat (name, IRONLY_SUFFIX, (const char *) NULL),
232 srctemplate);
233 if (abfd != NULL)
235 abfd->flags |= BFD_LINKER_CREATED | BFD_PLUGIN;
236 bfd_set_arch_info (abfd, bfd_get_arch_info (srctemplate));
237 bfd_set_gp_size (abfd, bfd_get_gp_size (srctemplate));
238 if (bfd_make_writable (abfd)
239 && bfd_copy_private_bfd_data (srctemplate, abfd))
241 flagword flags;
243 /* Create section to own the symbols. */
244 flags = (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY
245 | SEC_ALLOC | SEC_LOAD | SEC_KEEP | SEC_EXCLUDE);
246 if (bfd_make_section_anyway_with_flags (abfd, ".text", flags))
247 return abfd;
250 einfo (_("could not create dummy IR bfd: %F%E\n"));
251 return NULL;
254 /* Check if the BFD passed in is an IR dummy object file. */
255 static bfd_boolean
256 is_ir_dummy_bfd (const bfd *abfd)
258 /* ABFD can sometimes legitimately be NULL, e.g. when called from one
259 of the linker callbacks for a symbol in the *ABS* or *UND* sections.
260 Likewise, the usrdata field may be NULL if ABFD was added by the
261 backend without a corresponding input statement, as happens e.g.
262 when processing DT_NEEDED dependencies. */
263 return (abfd
264 && abfd->usrdata
265 && ((lang_input_statement_type *)(abfd->usrdata))->claimed);
268 /* Helpers to convert between BFD and GOLD symbol formats. */
269 static enum ld_plugin_status
270 asymbol_from_plugin_symbol (bfd *abfd, asymbol *asym,
271 const struct ld_plugin_symbol *ldsym)
273 flagword flags = BSF_NO_FLAGS;
274 struct bfd_section *section;
276 asym->the_bfd = abfd;
277 asym->name = (ldsym->version
278 ? concat (ldsym->name, "@", ldsym->version, (const char *) NULL)
279 : ldsym->name);
280 asym->value = 0;
281 switch (ldsym->def)
283 case LDPK_WEAKDEF:
284 flags = BSF_WEAK;
285 /* FALLTHRU */
286 case LDPK_DEF:
287 flags |= BSF_GLOBAL;
288 if (ldsym->comdat_key)
290 char *name = concat (".gnu.linkonce.t.", ldsym->comdat_key,
291 (const char *) NULL);
292 section = bfd_get_section_by_name (abfd, name);
293 if (section != NULL)
294 free (name);
295 else
297 flagword sflags;
299 sflags = (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY
300 | SEC_ALLOC | SEC_LOAD | SEC_KEEP | SEC_EXCLUDE
301 | SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD);
302 section = bfd_make_section_anyway_with_flags (abfd, name, sflags);
303 if (section == NULL)
304 return LDPS_ERR;
307 else
308 section = bfd_get_section_by_name (abfd, ".text");
309 break;
311 case LDPK_WEAKUNDEF:
312 flags = BSF_WEAK;
313 /* FALLTHRU */
314 case LDPK_UNDEF:
315 section = bfd_und_section_ptr;
316 break;
318 case LDPK_COMMON:
319 flags = BSF_GLOBAL;
320 section = bfd_com_section_ptr;
321 asym->value = ldsym->size;
322 /* For ELF targets, set alignment of common symbol to 1. */
323 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
325 ((elf_symbol_type *) asym)->internal_elf_sym.st_shndx = SHN_COMMON;
326 ((elf_symbol_type *) asym)->internal_elf_sym.st_value = 1;
328 break;
330 default:
331 return LDPS_ERR;
333 asym->flags = flags;
334 asym->section = section;
336 /* Visibility only applies on ELF targets. */
337 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
339 elf_symbol_type *elfsym = elf_symbol_from (abfd, asym);
340 unsigned char visibility;
342 if (!elfsym)
343 einfo (_("%P%F: %s: non-ELF symbol in ELF BFD!\n"), asym->name);
344 switch (ldsym->visibility)
346 default:
347 einfo (_("%P%F: unknown ELF symbol visibility: %d!\n"),
348 ldsym->visibility);
349 case LDPV_DEFAULT:
350 visibility = STV_DEFAULT;
351 break;
352 case LDPV_PROTECTED:
353 visibility = STV_PROTECTED;
354 break;
355 case LDPV_INTERNAL:
356 visibility = STV_INTERNAL;
357 break;
358 case LDPV_HIDDEN:
359 visibility = STV_HIDDEN;
360 break;
362 elfsym->internal_elf_sym.st_other
363 = (visibility | (elfsym->internal_elf_sym.st_other
364 & ~ELF_ST_VISIBILITY (-1)));
367 return LDPS_OK;
370 /* Register a claim-file handler. */
371 static enum ld_plugin_status
372 register_claim_file (ld_plugin_claim_file_handler handler)
374 ASSERT (called_plugin);
375 called_plugin->claim_file_handler = handler;
376 return LDPS_OK;
379 /* Register an all-symbols-read handler. */
380 static enum ld_plugin_status
381 register_all_symbols_read (ld_plugin_all_symbols_read_handler handler)
383 ASSERT (called_plugin);
384 called_plugin->all_symbols_read_handler = handler;
385 return LDPS_OK;
388 /* Register a cleanup handler. */
389 static enum ld_plugin_status
390 register_cleanup (ld_plugin_cleanup_handler handler)
392 ASSERT (called_plugin);
393 called_plugin->cleanup_handler = handler;
394 return LDPS_OK;
397 /* Add symbols from a plugin-claimed input file. */
398 static enum ld_plugin_status
399 add_symbols (void *handle, int nsyms, const struct ld_plugin_symbol *syms)
401 asymbol **symptrs;
402 bfd *abfd = handle;
403 int n;
405 ASSERT (called_plugin);
406 symptrs = xmalloc (nsyms * sizeof *symptrs);
407 for (n = 0; n < nsyms; n++)
409 enum ld_plugin_status rv;
410 asymbol *bfdsym;
412 bfdsym = bfd_make_empty_symbol (abfd);
413 symptrs[n] = bfdsym;
414 rv = asymbol_from_plugin_symbol (abfd, bfdsym, syms + n);
415 if (rv != LDPS_OK)
416 return rv;
418 bfd_set_symtab (abfd, symptrs, nsyms);
419 return LDPS_OK;
422 /* Get the input file information with an open (possibly re-opened)
423 file descriptor. */
424 static enum ld_plugin_status
425 get_input_file (const void *handle, struct ld_plugin_input_file *file)
427 ASSERT (called_plugin);
428 handle = handle;
429 file = file;
430 return LDPS_ERR;
433 /* Release the input file. */
434 static enum ld_plugin_status
435 release_input_file (const void *handle)
437 ASSERT (called_plugin);
438 handle = handle;
439 return LDPS_ERR;
442 /* Return TRUE if a defined symbol might be reachable from outside the
443 universe of claimed objects. */
444 static inline bfd_boolean
445 is_visible_from_outside (struct ld_plugin_symbol *lsym,
446 struct bfd_link_hash_entry *blhe)
448 struct bfd_sym_chain *sym;
450 if (link_info.relocatable)
451 return TRUE;
452 if (link_info.export_dynamic || !link_info.executable)
454 /* Check if symbol is hidden by version script. */
455 if (bfd_hide_sym_by_version (link_info.version_info,
456 blhe->root.string))
457 return FALSE;
458 /* Only ELF symbols really have visibility. */
459 if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour)
461 struct elf_link_hash_entry *el = (struct elf_link_hash_entry *)blhe;
462 int vis = ELF_ST_VISIBILITY (el->other);
463 return vis == STV_DEFAULT || vis == STV_PROTECTED;
465 /* On non-ELF targets, we can safely make inferences by considering
466 what visibility the plugin would have liked to apply when it first
467 sent us the symbol. During ELF symbol processing, visibility only
468 ever becomes more restrictive, not less, when symbols are merged,
469 so this is a conservative estimate; it may give false positives,
470 declaring something visible from outside when it in fact would
471 not have been, but this will only lead to missed optimisation
472 opportunities during LTRANS at worst; it will not give false
473 negatives, which can lead to the disastrous conclusion that the
474 related symbol is IRONLY. (See GCC PR46319 for an example.) */
475 return (lsym->visibility == LDPV_DEFAULT
476 || lsym->visibility == LDPV_PROTECTED);
479 for (sym = &entry_symbol; sym != NULL; sym = sym->next)
480 if (sym->name
481 && strcmp (sym->name, blhe->root.string) == 0)
482 return TRUE;
484 return FALSE;
487 /* Get the symbol resolution info for a plugin-claimed input file. */
488 static enum ld_plugin_status
489 get_symbols (const void *handle, int nsyms, struct ld_plugin_symbol *syms,
490 int def_ironly_exp)
492 const bfd *abfd = handle;
493 int n;
495 ASSERT (called_plugin);
496 for (n = 0; n < nsyms; n++)
498 struct bfd_link_hash_entry *blhe;
499 asection *owner_sec;
500 int res;
502 if (syms[n].def != LDPK_UNDEF)
503 blhe = bfd_link_hash_lookup (link_info.hash, syms[n].name,
504 FALSE, FALSE, TRUE);
505 else
506 blhe = bfd_wrapped_link_hash_lookup (link_info.output_bfd, &link_info,
507 syms[n].name, FALSE, FALSE, TRUE);
508 if (!blhe)
510 res = LDPR_UNKNOWN;
511 goto report_symbol;
514 /* Determine resolution from blhe type and symbol's original type. */
515 if (blhe->type == bfd_link_hash_undefined
516 || blhe->type == bfd_link_hash_undefweak)
518 res = LDPR_UNDEF;
519 goto report_symbol;
521 if (blhe->type != bfd_link_hash_defined
522 && blhe->type != bfd_link_hash_defweak
523 && blhe->type != bfd_link_hash_common)
525 /* We should not have a new, indirect or warning symbol here. */
526 einfo ("%P%F: %s: plugin symbol table corrupt (sym type %d)\n",
527 called_plugin->name, blhe->type);
530 /* Find out which section owns the symbol. Since it's not undef,
531 it must have an owner; if it's not a common symbol, both defs
532 and weakdefs keep it in the same place. */
533 owner_sec = (blhe->type == bfd_link_hash_common
534 ? blhe->u.c.p->section
535 : blhe->u.def.section);
538 /* If it was originally undefined or common, then it has been
539 resolved; determine how. */
540 if (syms[n].def == LDPK_UNDEF
541 || syms[n].def == LDPK_WEAKUNDEF
542 || syms[n].def == LDPK_COMMON)
544 if (owner_sec->owner == link_info.output_bfd)
545 res = LDPR_RESOLVED_EXEC;
546 else if (owner_sec->owner == abfd)
547 res = LDPR_PREVAILING_DEF_IRONLY;
548 else if (is_ir_dummy_bfd (owner_sec->owner))
549 res = LDPR_RESOLVED_IR;
550 else if (owner_sec->owner != NULL
551 && (owner_sec->owner->flags & DYNAMIC) != 0)
552 res = LDPR_RESOLVED_DYN;
553 else
554 res = LDPR_RESOLVED_EXEC;
557 /* Was originally def, or weakdef. Does it prevail? If the
558 owner is the original dummy bfd that supplied it, then this
559 is the definition that has prevailed. */
560 else if (owner_sec->owner == link_info.output_bfd)
561 res = LDPR_PREEMPTED_REG;
562 else if (owner_sec->owner == abfd)
563 res = LDPR_PREVAILING_DEF_IRONLY;
565 /* Was originally def, weakdef, or common, but has been pre-empted. */
566 else if (is_ir_dummy_bfd (owner_sec->owner))
567 res = LDPR_PREEMPTED_IR;
568 else
569 res = LDPR_PREEMPTED_REG;
571 if (res == LDPR_PREVAILING_DEF_IRONLY)
573 /* We need to know if the sym is referenced from non-IR files. Or
574 even potentially-referenced, perhaps in a future final link if
575 this is a partial one, perhaps dynamically at load-time if the
576 symbol is externally visible. */
577 if (blhe->non_ir_ref)
578 res = LDPR_PREVAILING_DEF;
579 else if (is_visible_from_outside (&syms[n], blhe))
580 res = def_ironly_exp;
583 report_symbol:
584 syms[n].resolution = res;
585 if (report_plugin_symbols)
586 einfo (_("%P: %B: symbol `%s' "
587 "definition: %d, visibility: %d, resolution: %d\n"),
588 abfd, syms[n].name,
589 syms[n].def, syms[n].visibility, res);
591 return LDPS_OK;
594 static enum ld_plugin_status
595 get_symbols_v1 (const void *handle, int nsyms, struct ld_plugin_symbol *syms)
597 return get_symbols (handle, nsyms, syms, LDPR_PREVAILING_DEF);
600 static enum ld_plugin_status
601 get_symbols_v2 (const void *handle, int nsyms, struct ld_plugin_symbol *syms)
603 return get_symbols (handle, nsyms, syms, LDPR_PREVAILING_DEF_IRONLY_EXP);
606 /* Add a new (real) input file generated by a plugin. */
607 static enum ld_plugin_status
608 add_input_file (const char *pathname)
610 ASSERT (called_plugin);
611 if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_file_enum,
612 NULL))
613 return LDPS_ERR;
614 return LDPS_OK;
617 /* Add a new (real) library required by a plugin. */
618 static enum ld_plugin_status
619 add_input_library (const char *pathname)
621 ASSERT (called_plugin);
622 if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_l_enum,
623 NULL))
624 return LDPS_ERR;
625 return LDPS_OK;
628 /* Set the extra library path to be used by libraries added via
629 add_input_library. */
630 static enum ld_plugin_status
631 set_extra_library_path (const char *path)
633 ASSERT (called_plugin);
634 ldfile_add_library_path (xstrdup (path), FALSE);
635 return LDPS_OK;
638 /* Issue a diagnostic message from a plugin. */
639 static enum ld_plugin_status
640 message (int level, const char *format, ...)
642 va_list args;
643 va_start (args, format);
645 switch (level)
647 case LDPL_INFO:
648 vfinfo (stdout, format, args, FALSE);
649 putchar ('\n');
650 break;
651 case LDPL_WARNING:
652 vfinfo (stdout, format, args, TRUE);
653 putchar ('\n');
654 break;
655 case LDPL_FATAL:
656 case LDPL_ERROR:
657 default:
659 char *newfmt = ACONCAT ((level == LDPL_FATAL ? "%P%F: " : "%P%X: ",
660 format, "\n", (const char *) NULL));
661 fflush (stdout);
662 vfinfo (stderr, newfmt, args, TRUE);
663 fflush (stderr);
665 break;
668 va_end (args);
669 return LDPS_OK;
672 /* Helper to size leading part of tv array and set it up. */
673 static void
674 set_tv_header (struct ld_plugin_tv *tv)
676 size_t i;
678 /* Version info. */
679 static const unsigned int major = (unsigned)(BFD_VERSION / 100000000UL);
680 static const unsigned int minor = (unsigned)(BFD_VERSION / 1000000UL) % 100;
682 for (i = 0; i < tv_header_size; i++)
684 tv[i].tv_tag = tv_header_tags[i];
685 #define TVU(x) tv[i].tv_u.tv_ ## x
686 switch (tv[i].tv_tag)
688 case LDPT_MESSAGE:
689 TVU(message) = message;
690 break;
691 case LDPT_API_VERSION:
692 TVU(val) = LD_PLUGIN_API_VERSION;
693 break;
694 case LDPT_GNU_LD_VERSION:
695 TVU(val) = major * 100 + minor;
696 break;
697 case LDPT_LINKER_OUTPUT:
698 TVU(val) = (link_info.relocatable
699 ? LDPO_REL
700 : link_info.executable ? LDPO_EXEC : LDPO_DYN);
701 break;
702 case LDPT_OUTPUT_NAME:
703 TVU(string) = output_filename;
704 break;
705 case LDPT_REGISTER_CLAIM_FILE_HOOK:
706 TVU(register_claim_file) = register_claim_file;
707 break;
708 case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK:
709 TVU(register_all_symbols_read) = register_all_symbols_read;
710 break;
711 case LDPT_REGISTER_CLEANUP_HOOK:
712 TVU(register_cleanup) = register_cleanup;
713 break;
714 case LDPT_ADD_SYMBOLS:
715 TVU(add_symbols) = add_symbols;
716 break;
717 case LDPT_GET_INPUT_FILE:
718 TVU(get_input_file) = get_input_file;
719 break;
720 case LDPT_RELEASE_INPUT_FILE:
721 TVU(release_input_file) = release_input_file;
722 break;
723 case LDPT_GET_SYMBOLS:
724 TVU(get_symbols) = get_symbols_v1;
725 break;
726 case LDPT_GET_SYMBOLS_V2:
727 TVU(get_symbols) = get_symbols_v2;
728 break;
729 case LDPT_ADD_INPUT_FILE:
730 TVU(add_input_file) = add_input_file;
731 break;
732 case LDPT_ADD_INPUT_LIBRARY:
733 TVU(add_input_library) = add_input_library;
734 break;
735 case LDPT_SET_EXTRA_LIBRARY_PATH:
736 TVU(set_extra_library_path) = set_extra_library_path;
737 break;
738 default:
739 /* Added a new entry to the array without adding
740 a new case to set up its value is a bug. */
741 FAIL ();
743 #undef TVU
747 /* Append the per-plugin args list and trailing LDPT_NULL to tv. */
748 static void
749 set_tv_plugin_args (plugin_t *plugin, struct ld_plugin_tv *tv)
751 plugin_arg_t *arg = plugin->args;
752 while (arg)
754 tv->tv_tag = LDPT_OPTION;
755 tv->tv_u.tv_string = arg->arg;
756 arg = arg->next;
757 tv++;
759 tv->tv_tag = LDPT_NULL;
760 tv->tv_u.tv_val = 0;
763 /* Return true if any plugins are active this run. Only valid
764 after options have been processed. */
765 bfd_boolean
766 plugin_active_plugins_p (void)
768 return plugins_list != NULL;
771 /* Load up and initialise all plugins after argument parsing. */
773 plugin_load_plugins (void)
775 struct ld_plugin_tv *my_tv;
776 unsigned int max_args = 0;
777 plugin_t *curplug = plugins_list;
779 /* If there are no plugins, we need do nothing this run. */
780 if (!curplug)
781 return 0;
783 /* First pass over plugins to find max # args needed so that we
784 can size and allocate the tv array. */
785 while (curplug)
787 if (curplug->n_args > max_args)
788 max_args = curplug->n_args;
789 curplug = curplug->next;
792 /* Allocate tv array and initialise constant part. */
793 my_tv = xmalloc ((max_args + 1 + tv_header_size) * sizeof *my_tv);
794 set_tv_header (my_tv);
796 /* Pass over plugins again, activating them. */
797 curplug = plugins_list;
798 while (curplug)
800 enum ld_plugin_status rv;
801 ld_plugin_onload onloadfn = dlsym (curplug->dlhandle, "onload");
802 if (!onloadfn)
803 onloadfn = dlsym (curplug->dlhandle, "_onload");
804 if (!onloadfn)
805 return set_plugin_error (curplug->name);
806 set_tv_plugin_args (curplug, &my_tv[tv_header_size]);
807 called_plugin = curplug;
808 rv = (*onloadfn) (my_tv);
809 called_plugin = NULL;
810 if (rv != LDPS_OK)
811 return set_plugin_error (curplug->name);
812 curplug = curplug->next;
815 /* Since plugin(s) inited ok, assume they're going to want symbol
816 resolutions, which needs us to track which symbols are referenced
817 by non-IR files using the linker's notice callback. */
818 orig_notice_all = link_info.notice_all;
819 orig_callbacks = link_info.callbacks;
820 plugin_callbacks = *orig_callbacks;
821 plugin_callbacks.notice = &plugin_notice;
822 link_info.notice_all = TRUE;
823 link_info.callbacks = &plugin_callbacks;
825 return 0;
828 /* Call 'claim file' hook for all plugins. */
829 static int
830 plugin_call_claim_file (const struct ld_plugin_input_file *file, int *claimed)
832 plugin_t *curplug = plugins_list;
833 *claimed = FALSE;
834 if (no_more_claiming)
835 return 0;
836 while (curplug && !*claimed)
838 if (curplug->claim_file_handler)
840 enum ld_plugin_status rv;
841 called_plugin = curplug;
842 rv = (*curplug->claim_file_handler) (file, claimed);
843 called_plugin = NULL;
844 if (rv != LDPS_OK)
845 set_plugin_error (curplug->name);
847 curplug = curplug->next;
849 return plugin_error_p () ? -1 : 0;
852 void
853 plugin_maybe_claim (struct ld_plugin_input_file *file,
854 lang_input_statement_type *entry)
856 int claimed = 0;
858 /* We create a dummy BFD, initially empty, to house whatever symbols
859 the plugin may want to add. */
860 file->handle = plugin_get_ir_dummy_bfd (entry->the_bfd->filename,
861 entry->the_bfd);
862 if (plugin_call_claim_file (file, &claimed))
863 einfo (_("%P%F: %s: plugin reported error claiming file\n"),
864 plugin_error_plugin ());
865 /* fd belongs to us, not the plugin; but we don't need it. */
866 close (file->fd);
867 if (claimed)
869 /* Discard the real file's BFD and substitute the dummy one. */
871 /* BFD archive handling caches elements so we can't call
872 bfd_close for archives. */
873 if (entry->the_bfd->my_archive == NULL)
874 bfd_close (entry->the_bfd);
875 entry->the_bfd = file->handle;
876 entry->claimed = TRUE;
877 bfd_make_readable (entry->the_bfd);
879 else
881 /* If plugin didn't claim the file, we don't need the dummy bfd.
882 Can't avoid speculatively creating it, alas. */
883 bfd_close_all_done (file->handle);
884 entry->claimed = FALSE;
888 /* Call 'all symbols read' hook for all plugins. */
890 plugin_call_all_symbols_read (void)
892 plugin_t *curplug = plugins_list;
894 /* Disable any further file-claiming. */
895 no_more_claiming = TRUE;
897 while (curplug)
899 if (curplug->all_symbols_read_handler)
901 enum ld_plugin_status rv;
902 called_plugin = curplug;
903 rv = (*curplug->all_symbols_read_handler) ();
904 called_plugin = NULL;
905 if (rv != LDPS_OK)
906 set_plugin_error (curplug->name);
908 curplug = curplug->next;
910 return plugin_error_p () ? -1 : 0;
913 /* Call 'cleanup' hook for all plugins at exit. */
914 void
915 plugin_call_cleanup (void)
917 plugin_t *curplug = plugins_list;
918 while (curplug)
920 if (curplug->cleanup_handler && !curplug->cleanup_done)
922 enum ld_plugin_status rv;
923 curplug->cleanup_done = TRUE;
924 called_plugin = curplug;
925 rv = (*curplug->cleanup_handler) ();
926 called_plugin = NULL;
927 if (rv != LDPS_OK)
928 set_plugin_error (curplug->name);
929 dlclose (curplug->dlhandle);
931 curplug = curplug->next;
933 if (plugin_error_p ())
934 info_msg (_("%P: %s: error in plugin cleanup (ignored)\n"),
935 plugin_error_plugin ());
938 /* To determine which symbols should be resolved LDPR_PREVAILING_DEF
939 and which LDPR_PREVAILING_DEF_IRONLY, we notice all the symbols as
940 the linker adds them to the linker hash table. Mark those
941 referenced from a non-IR file with non_ir_ref. We have to
942 notice_all symbols, because we won't necessarily know until later
943 which ones will be contributed by IR files. */
944 static bfd_boolean
945 plugin_notice (struct bfd_link_info *info,
946 struct bfd_link_hash_entry *h,
947 bfd *abfd,
948 asection *section,
949 bfd_vma value,
950 flagword flags,
951 const char *string)
953 if (h != NULL)
955 bfd *sym_bfd;
957 /* No further processing if this def/ref is from an IR dummy BFD. */
958 if (is_ir_dummy_bfd (abfd))
959 return TRUE;
961 /* Making an indirect symbol counts as a reference unless this
962 is a brand new symbol. */
963 if (bfd_is_ind_section (section)
964 || (flags & BSF_INDIRECT) != 0)
966 if (h->type != bfd_link_hash_new)
968 struct bfd_link_hash_entry *inh;
970 h->non_ir_ref = TRUE;
971 inh = bfd_wrapped_link_hash_lookup (abfd, info, string, FALSE,
972 FALSE, FALSE);
973 if (inh != NULL)
974 inh->non_ir_ref = TRUE;
978 /* Nothing to do here for warning symbols. */
979 else if ((flags & BSF_WARNING) != 0)
982 /* Nothing to do here for constructor symbols. */
983 else if ((flags & BSF_CONSTRUCTOR) != 0)
986 /* If this is a ref, set non_ir_ref. */
987 else if (bfd_is_und_section (section))
988 h->non_ir_ref = TRUE;
990 /* Otherwise, it must be a new def. Ensure any symbol defined
991 in an IR dummy BFD takes on a new value from a real BFD.
992 Weak symbols are not normally overridden by a new weak
993 definition, and strong symbols will normally cause multiple
994 definition errors. Avoid this by making the symbol appear
995 to be undefined. */
996 else if (((h->type == bfd_link_hash_defweak
997 || h->type == bfd_link_hash_defined)
998 && is_ir_dummy_bfd (sym_bfd = h->u.def.section->owner))
999 || (h->type == bfd_link_hash_common
1000 && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner)))
1002 h->type = bfd_link_hash_undefweak;
1003 h->u.undef.abfd = sym_bfd;
1007 /* Continue with cref/nocrossref/trace-sym processing. */
1008 if (h == NULL
1009 || orig_notice_all
1010 || (info->notice_hash != NULL
1011 && bfd_hash_lookup (info->notice_hash, h->root.string,
1012 FALSE, FALSE) != NULL))
1013 return (*orig_callbacks->notice) (info, h,
1014 abfd, section, value, flags, string);
1015 return TRUE;
1018 /* Return true if bfd is a dynamic library that should be reloaded. */
1020 bfd_boolean
1021 plugin_should_reload (bfd *abfd)
1023 return ((abfd->flags & DYNAMIC) != 0
1024 && bfd_get_flavour (abfd) == bfd_target_elf_flavour
1025 && bfd_get_format (abfd) == bfd_object
1026 && (elf_dyn_lib_class (abfd) & DYN_AS_NEEDED) != 0);