PR ld/14265
[deliverable/binutils-gdb.git] / gold / object.cc
1 // object.cc -- support for an object file for linking in gold
2
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 // Free Software Foundation, Inc.
5 // Written by Ian Lance Taylor <iant@google.com>.
6
7 // This file is part of gold.
8
9 // This program is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 3 of the License, or
12 // (at your option) any later version.
13
14 // This program is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
18
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 // MA 02110-1301, USA.
23
24 #include "gold.h"
25
26 #include <cerrno>
27 #include <cstring>
28 #include <cstdarg>
29 #include "demangle.h"
30 #include "libiberty.h"
31
32 #include "gc.h"
33 #include "target-select.h"
34 #include "dwarf_reader.h"
35 #include "layout.h"
36 #include "output.h"
37 #include "symtab.h"
38 #include "cref.h"
39 #include "reloc.h"
40 #include "object.h"
41 #include "dynobj.h"
42 #include "plugin.h"
43 #include "compressed_output.h"
44 #include "incremental.h"
45
46 namespace gold
47 {
48
49 // Struct Read_symbols_data.
50
51 // Destroy any remaining File_view objects.
52
53 Read_symbols_data::~Read_symbols_data()
54 {
55 if (this->section_headers != NULL)
56 delete this->section_headers;
57 if (this->section_names != NULL)
58 delete this->section_names;
59 if (this->symbols != NULL)
60 delete this->symbols;
61 if (this->symbol_names != NULL)
62 delete this->symbol_names;
63 if (this->versym != NULL)
64 delete this->versym;
65 if (this->verdef != NULL)
66 delete this->verdef;
67 if (this->verneed != NULL)
68 delete this->verneed;
69 }
70
71 // Class Xindex.
72
73 // Initialize the symtab_xindex_ array. Find the SHT_SYMTAB_SHNDX
74 // section and read it in. SYMTAB_SHNDX is the index of the symbol
75 // table we care about.
76
77 template<int size, bool big_endian>
78 void
79 Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx)
80 {
81 if (!this->symtab_xindex_.empty())
82 return;
83
84 gold_assert(symtab_shndx != 0);
85
86 // Look through the sections in reverse order, on the theory that it
87 // is more likely to be near the end than the beginning.
88 unsigned int i = object->shnum();
89 while (i > 0)
90 {
91 --i;
92 if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX
93 && this->adjust_shndx(object->section_link(i)) == symtab_shndx)
94 {
95 this->read_symtab_xindex<size, big_endian>(object, i, NULL);
96 return;
97 }
98 }
99
100 object->error(_("missing SHT_SYMTAB_SHNDX section"));
101 }
102
103 // Read in the symtab_xindex_ array, given the section index of the
104 // SHT_SYMTAB_SHNDX section. If PSHDRS is not NULL, it points at the
105 // section headers.
106
107 template<int size, bool big_endian>
108 void
109 Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx,
110 const unsigned char* pshdrs)
111 {
112 section_size_type bytecount;
113 const unsigned char* contents;
114 if (pshdrs == NULL)
115 contents = object->section_contents(xindex_shndx, &bytecount, false);
116 else
117 {
118 const unsigned char* p = (pshdrs
119 + (xindex_shndx
120 * elfcpp::Elf_sizes<size>::shdr_size));
121 typename elfcpp::Shdr<size, big_endian> shdr(p);
122 bytecount = convert_to_section_size_type(shdr.get_sh_size());
123 contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false);
124 }
125
126 gold_assert(this->symtab_xindex_.empty());
127 this->symtab_xindex_.reserve(bytecount / 4);
128 for (section_size_type i = 0; i < bytecount; i += 4)
129 {
130 unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i);
131 // We preadjust the section indexes we save.
132 this->symtab_xindex_.push_back(this->adjust_shndx(shndx));
133 }
134 }
135
136 // Symbol symndx has a section of SHN_XINDEX; return the real section
137 // index.
138
139 unsigned int
140 Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx)
141 {
142 if (symndx >= this->symtab_xindex_.size())
143 {
144 object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"),
145 symndx);
146 return elfcpp::SHN_UNDEF;
147 }
148 unsigned int shndx = this->symtab_xindex_[symndx];
149 if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum())
150 {
151 object->error(_("extended index for symbol %u out of range: %u"),
152 symndx, shndx);
153 return elfcpp::SHN_UNDEF;
154 }
155 return shndx;
156 }
157
158 // Class Object.
159
160 // Report an error for this object file. This is used by the
161 // elfcpp::Elf_file interface, and also called by the Object code
162 // itself.
163
164 void
165 Object::error(const char* format, ...) const
166 {
167 va_list args;
168 va_start(args, format);
169 char* buf = NULL;
170 if (vasprintf(&buf, format, args) < 0)
171 gold_nomem();
172 va_end(args);
173 gold_error(_("%s: %s"), this->name().c_str(), buf);
174 free(buf);
175 }
176
177 // Return a view of the contents of a section.
178
179 const unsigned char*
180 Object::section_contents(unsigned int shndx, section_size_type* plen,
181 bool cache)
182 { return this->do_section_contents(shndx, plen, cache); }
183
184 // Read the section data into SD. This is code common to Sized_relobj_file
185 // and Sized_dynobj, so we put it into Object.
186
187 template<int size, bool big_endian>
188 void
189 Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
190 Read_symbols_data* sd)
191 {
192 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
193
194 // Read the section headers.
195 const off_t shoff = elf_file->shoff();
196 const unsigned int shnum = this->shnum();
197 sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size,
198 true, true);
199
200 // Read the section names.
201 const unsigned char* pshdrs = sd->section_headers->data();
202 const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
203 typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
204
205 if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
206 this->error(_("section name section has wrong type: %u"),
207 static_cast<unsigned int>(shdrnames.get_sh_type()));
208
209 sd->section_names_size =
210 convert_to_section_size_type(shdrnames.get_sh_size());
211 sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
212 sd->section_names_size, false,
213 false);
214 }
215
216 // If NAME is the name of a special .gnu.warning section, arrange for
217 // the warning to be issued. SHNDX is the section index. Return
218 // whether it is a warning section.
219
220 bool
221 Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
222 Symbol_table* symtab)
223 {
224 const char warn_prefix[] = ".gnu.warning.";
225 const int warn_prefix_len = sizeof warn_prefix - 1;
226 if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
227 {
228 // Read the section contents to get the warning text. It would
229 // be nicer if we only did this if we have to actually issue a
230 // warning. Unfortunately, warnings are issued as we relocate
231 // sections. That means that we can not lock the object then,
232 // as we might try to issue the same warning multiple times
233 // simultaneously.
234 section_size_type len;
235 const unsigned char* contents = this->section_contents(shndx, &len,
236 false);
237 if (len == 0)
238 {
239 const char* warning = name + warn_prefix_len;
240 contents = reinterpret_cast<const unsigned char*>(warning);
241 len = strlen(warning);
242 }
243 std::string warning(reinterpret_cast<const char*>(contents), len);
244 symtab->add_warning(name + warn_prefix_len, this, warning);
245 return true;
246 }
247 return false;
248 }
249
250 // If NAME is the name of the special section which indicates that
251 // this object was compiled with -fsplit-stack, mark it accordingly.
252
253 bool
254 Object::handle_split_stack_section(const char* name)
255 {
256 if (strcmp(name, ".note.GNU-split-stack") == 0)
257 {
258 this->uses_split_stack_ = true;
259 return true;
260 }
261 if (strcmp(name, ".note.GNU-no-split-stack") == 0)
262 {
263 this->has_no_split_stack_ = true;
264 return true;
265 }
266 return false;
267 }
268
269 // Class Relobj
270
271 // To copy the symbols data read from the file to a local data structure.
272 // This function is called from do_layout only while doing garbage
273 // collection.
274
275 void
276 Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
277 unsigned int section_header_size)
278 {
279 gc_sd->section_headers_data =
280 new unsigned char[(section_header_size)];
281 memcpy(gc_sd->section_headers_data, sd->section_headers->data(),
282 section_header_size);
283 gc_sd->section_names_data =
284 new unsigned char[sd->section_names_size];
285 memcpy(gc_sd->section_names_data, sd->section_names->data(),
286 sd->section_names_size);
287 gc_sd->section_names_size = sd->section_names_size;
288 if (sd->symbols != NULL)
289 {
290 gc_sd->symbols_data =
291 new unsigned char[sd->symbols_size];
292 memcpy(gc_sd->symbols_data, sd->symbols->data(),
293 sd->symbols_size);
294 }
295 else
296 {
297 gc_sd->symbols_data = NULL;
298 }
299 gc_sd->symbols_size = sd->symbols_size;
300 gc_sd->external_symbols_offset = sd->external_symbols_offset;
301 if (sd->symbol_names != NULL)
302 {
303 gc_sd->symbol_names_data =
304 new unsigned char[sd->symbol_names_size];
305 memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(),
306 sd->symbol_names_size);
307 }
308 else
309 {
310 gc_sd->symbol_names_data = NULL;
311 }
312 gc_sd->symbol_names_size = sd->symbol_names_size;
313 }
314
315 // This function determines if a particular section name must be included
316 // in the link. This is used during garbage collection to determine the
317 // roots of the worklist.
318
319 bool
320 Relobj::is_section_name_included(const char* name)
321 {
322 if (is_prefix_of(".ctors", name)
323 || is_prefix_of(".dtors", name)
324 || is_prefix_of(".note", name)
325 || is_prefix_of(".init", name)
326 || is_prefix_of(".fini", name)
327 || is_prefix_of(".gcc_except_table", name)
328 || is_prefix_of(".jcr", name)
329 || is_prefix_of(".preinit_array", name)
330 || (is_prefix_of(".text", name)
331 && strstr(name, "personality"))
332 || (is_prefix_of(".data", name)
333 && strstr(name, "personality"))
334 || (is_prefix_of(".gnu.linkonce.d", name)
335 && strstr(name, "personality")))
336 {
337 return true;
338 }
339 return false;
340 }
341
342 // Finalize the incremental relocation information. Allocates a block
343 // of relocation entries for each symbol, and sets the reloc_bases_
344 // array to point to the first entry in each block. If CLEAR_COUNTS
345 // is TRUE, also clear the per-symbol relocation counters.
346
347 void
348 Relobj::finalize_incremental_relocs(Layout* layout, bool clear_counts)
349 {
350 unsigned int nsyms = this->get_global_symbols()->size();
351 this->reloc_bases_ = new unsigned int[nsyms];
352
353 gold_assert(this->reloc_bases_ != NULL);
354 gold_assert(layout->incremental_inputs() != NULL);
355
356 unsigned int rindex = layout->incremental_inputs()->get_reloc_count();
357 for (unsigned int i = 0; i < nsyms; ++i)
358 {
359 this->reloc_bases_[i] = rindex;
360 rindex += this->reloc_counts_[i];
361 if (clear_counts)
362 this->reloc_counts_[i] = 0;
363 }
364 layout->incremental_inputs()->set_reloc_count(rindex);
365 }
366
367 // Class Sized_relobj.
368
369 // Iterate over local symbols, calling a visitor class V for each GOT offset
370 // associated with a local symbol.
371
372 template<int size, bool big_endian>
373 void
374 Sized_relobj<size, big_endian>::do_for_all_local_got_entries(
375 Got_offset_list::Visitor* v) const
376 {
377 unsigned int nsyms = this->local_symbol_count();
378 for (unsigned int i = 0; i < nsyms; i++)
379 {
380 Local_got_offsets::const_iterator p = this->local_got_offsets_.find(i);
381 if (p != this->local_got_offsets_.end())
382 {
383 const Got_offset_list* got_offsets = p->second;
384 got_offsets->for_all_got_offsets(v);
385 }
386 }
387 }
388
389 // Class Sized_relobj_file.
390
391 template<int size, bool big_endian>
392 Sized_relobj_file<size, big_endian>::Sized_relobj_file(
393 const std::string& name,
394 Input_file* input_file,
395 off_t offset,
396 const elfcpp::Ehdr<size, big_endian>& ehdr)
397 : Sized_relobj<size, big_endian>(name, input_file, offset),
398 elf_file_(this, ehdr),
399 symtab_shndx_(-1U),
400 local_symbol_count_(0),
401 output_local_symbol_count_(0),
402 output_local_dynsym_count_(0),
403 symbols_(),
404 defined_count_(0),
405 local_symbol_offset_(0),
406 local_dynsym_offset_(0),
407 local_values_(),
408 local_plt_offsets_(),
409 kept_comdat_sections_(),
410 has_eh_frame_(false),
411 discarded_eh_frame_shndx_(-1U),
412 deferred_layout_(),
413 deferred_layout_relocs_(),
414 compressed_sections_()
415 {
416 this->e_type_ = ehdr.get_e_type();
417 }
418
419 template<int size, bool big_endian>
420 Sized_relobj_file<size, big_endian>::~Sized_relobj_file()
421 {
422 }
423
424 // Set up an object file based on the file header. This sets up the
425 // section information.
426
427 template<int size, bool big_endian>
428 void
429 Sized_relobj_file<size, big_endian>::do_setup()
430 {
431 const unsigned int shnum = this->elf_file_.shnum();
432 this->set_shnum(shnum);
433 }
434
435 // Find the SHT_SYMTAB section, given the section headers. The ELF
436 // standard says that maybe in the future there can be more than one
437 // SHT_SYMTAB section. Until somebody figures out how that could
438 // work, we assume there is only one.
439
440 template<int size, bool big_endian>
441 void
442 Sized_relobj_file<size, big_endian>::find_symtab(const unsigned char* pshdrs)
443 {
444 const unsigned int shnum = this->shnum();
445 this->symtab_shndx_ = 0;
446 if (shnum > 0)
447 {
448 // Look through the sections in reverse order, since gas tends
449 // to put the symbol table at the end.
450 const unsigned char* p = pshdrs + shnum * This::shdr_size;
451 unsigned int i = shnum;
452 unsigned int xindex_shndx = 0;
453 unsigned int xindex_link = 0;
454 while (i > 0)
455 {
456 --i;
457 p -= This::shdr_size;
458 typename This::Shdr shdr(p);
459 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
460 {
461 this->symtab_shndx_ = i;
462 if (xindex_shndx > 0 && xindex_link == i)
463 {
464 Xindex* xindex =
465 new Xindex(this->elf_file_.large_shndx_offset());
466 xindex->read_symtab_xindex<size, big_endian>(this,
467 xindex_shndx,
468 pshdrs);
469 this->set_xindex(xindex);
470 }
471 break;
472 }
473
474 // Try to pick up the SHT_SYMTAB_SHNDX section, if there is
475 // one. This will work if it follows the SHT_SYMTAB
476 // section.
477 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX)
478 {
479 xindex_shndx = i;
480 xindex_link = this->adjust_shndx(shdr.get_sh_link());
481 }
482 }
483 }
484 }
485
486 // Return the Xindex structure to use for object with lots of
487 // sections.
488
489 template<int size, bool big_endian>
490 Xindex*
491 Sized_relobj_file<size, big_endian>::do_initialize_xindex()
492 {
493 gold_assert(this->symtab_shndx_ != -1U);
494 Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
495 xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_);
496 return xindex;
497 }
498
499 // Return whether SHDR has the right type and flags to be a GNU
500 // .eh_frame section.
501
502 template<int size, bool big_endian>
503 bool
504 Sized_relobj_file<size, big_endian>::check_eh_frame_flags(
505 const elfcpp::Shdr<size, big_endian>* shdr) const
506 {
507 elfcpp::Elf_Word sh_type = shdr->get_sh_type();
508 return ((sh_type == elfcpp::SHT_PROGBITS
509 || sh_type == elfcpp::SHT_X86_64_UNWIND)
510 && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
511 }
512
513 // Find the section header with the given name.
514
515 template<int size, bool big_endian>
516 const unsigned char*
517 Sized_relobj_file<size, big_endian>::find_shdr(
518 const unsigned char* pshdrs,
519 const char* name,
520 const char* names,
521 section_size_type names_size,
522 const unsigned char* hdr) const
523 {
524 const unsigned int shnum = this->shnum();
525 const unsigned char* hdr_end = pshdrs + This::shdr_size * shnum;
526 size_t sh_name = 0;
527
528 while (1)
529 {
530 if (hdr)
531 {
532 // We found HDR last time we were called, continue looking.
533 typename This::Shdr shdr(hdr);
534 sh_name = shdr.get_sh_name();
535 }
536 else
537 {
538 // Look for the next occurrence of NAME in NAMES.
539 // The fact that .shstrtab produced by current GNU tools is
540 // string merged means we shouldn't have both .not.foo and
541 // .foo in .shstrtab, and multiple .foo sections should all
542 // have the same sh_name. However, this is not guaranteed
543 // by the ELF spec and not all ELF object file producers may
544 // be so clever.
545 size_t len = strlen(name) + 1;
546 const char *p = sh_name ? names + sh_name + len : names;
547 p = reinterpret_cast<const char*>(memmem(p, names_size - (p - names),
548 name, len));
549 if (p == NULL)
550 return NULL;
551 sh_name = p - names;
552 hdr = pshdrs;
553 if (sh_name == 0)
554 return hdr;
555 }
556
557 hdr += This::shdr_size;
558 while (hdr < hdr_end)
559 {
560 typename This::Shdr shdr(hdr);
561 if (shdr.get_sh_name() == sh_name)
562 return hdr;
563 hdr += This::shdr_size;
564 }
565 hdr = NULL;
566 if (sh_name == 0)
567 return hdr;
568 }
569 }
570
571 // Return whether there is a GNU .eh_frame section, given the section
572 // headers and the section names.
573
574 template<int size, bool big_endian>
575 bool
576 Sized_relobj_file<size, big_endian>::find_eh_frame(
577 const unsigned char* pshdrs,
578 const char* names,
579 section_size_type names_size) const
580 {
581 const unsigned char* s = NULL;
582
583 while (1)
584 {
585 s = this->find_shdr(pshdrs, ".eh_frame", names, names_size, s);
586 if (s == NULL)
587 return false;
588
589 typename This::Shdr shdr(s);
590 if (this->check_eh_frame_flags(&shdr))
591 return true;
592 }
593 }
594
595 // Return TRUE if this is a section whose contents will be needed in the
596 // Add_symbols task. This function is only called for sections that have
597 // already passed the test in is_compressed_debug_section(), so we know
598 // that the section name begins with ".zdebug".
599
600 static bool
601 need_decompressed_section(const char* name)
602 {
603 // Skip over the ".zdebug" and a quick check for the "_".
604 name += 7;
605 if (*name++ != '_')
606 return false;
607
608 #ifdef ENABLE_THREADS
609 // Decompressing these sections now will help only if we're
610 // multithreaded.
611 if (parameters->options().threads())
612 {
613 // We will need .zdebug_str if this is not an incremental link
614 // (i.e., we are processing string merge sections) or if we need
615 // to build a gdb index.
616 if ((!parameters->incremental() || parameters->options().gdb_index())
617 && strcmp(name, "str") == 0)
618 return true;
619
620 // We will need these other sections when building a gdb index.
621 if (parameters->options().gdb_index()
622 && (strcmp(name, "info") == 0
623 || strcmp(name, "types") == 0
624 || strcmp(name, "pubnames") == 0
625 || strcmp(name, "pubtypes") == 0
626 || strcmp(name, "ranges") == 0
627 || strcmp(name, "abbrev") == 0))
628 return true;
629 }
630 #endif
631
632 // Even when single-threaded, we will need .zdebug_str if this is
633 // not an incremental link and we are building a gdb index.
634 // Otherwise, we would decompress the section twice: once for
635 // string merge processing, and once for building the gdb index.
636 if (!parameters->incremental()
637 && parameters->options().gdb_index()
638 && strcmp(name, "str") == 0)
639 return true;
640
641 return false;
642 }
643
644 // Build a table for any compressed debug sections, mapping each section index
645 // to the uncompressed size and (if needed) the decompressed contents.
646
647 template<int size, bool big_endian>
648 Compressed_section_map*
649 build_compressed_section_map(
650 const unsigned char* pshdrs,
651 unsigned int shnum,
652 const char* names,
653 section_size_type names_size,
654 Sized_relobj_file<size, big_endian>* obj)
655 {
656 Compressed_section_map* uncompressed_map = new Compressed_section_map();
657 const unsigned int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
658 const unsigned char* p = pshdrs + shdr_size;
659
660 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
661 {
662 typename elfcpp::Shdr<size, big_endian> shdr(p);
663 if (shdr.get_sh_type() == elfcpp::SHT_PROGBITS
664 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
665 {
666 if (shdr.get_sh_name() >= names_size)
667 {
668 obj->error(_("bad section name offset for section %u: %lu"),
669 i, static_cast<unsigned long>(shdr.get_sh_name()));
670 continue;
671 }
672
673 const char* name = names + shdr.get_sh_name();
674 if (is_compressed_debug_section(name))
675 {
676 section_size_type len;
677 const unsigned char* contents =
678 obj->section_contents(i, &len, false);
679 uint64_t uncompressed_size = get_uncompressed_size(contents, len);
680 Compressed_section_info info;
681 info.size = convert_to_section_size_type(uncompressed_size);
682 info.contents = NULL;
683 if (uncompressed_size != -1ULL)
684 {
685 unsigned char* uncompressed_data = NULL;
686 if (need_decompressed_section(name))
687 {
688 uncompressed_data = new unsigned char[uncompressed_size];
689 if (decompress_input_section(contents, len,
690 uncompressed_data,
691 uncompressed_size))
692 info.contents = uncompressed_data;
693 else
694 delete[] uncompressed_data;
695 }
696 (*uncompressed_map)[i] = info;
697 }
698 }
699 }
700 }
701 return uncompressed_map;
702 }
703
704 // Stash away info for a number of special sections.
705 // Return true if any of the sections found require local symbols to be read.
706
707 template<int size, bool big_endian>
708 bool
709 Sized_relobj_file<size, big_endian>::do_find_special_sections(
710 Read_symbols_data* sd)
711 {
712 const unsigned char* const pshdrs = sd->section_headers->data();
713 const unsigned char* namesu = sd->section_names->data();
714 const char* names = reinterpret_cast<const char*>(namesu);
715
716 if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
717 this->has_eh_frame_ = true;
718
719 if (memmem(names, sd->section_names_size, ".zdebug_", 8) != NULL)
720 this->compressed_sections_
721 = build_compressed_section_map(pshdrs, this->shnum(), names,
722 sd->section_names_size, this);
723 return (this->has_eh_frame_
724 || (!parameters->options().relocatable()
725 && parameters->options().gdb_index()
726 && (memmem(names, sd->section_names_size, "debug_info", 12) == 0
727 || memmem(names, sd->section_names_size, "debug_types",
728 13) == 0)));
729 }
730
731 // Read the sections and symbols from an object file.
732
733 template<int size, bool big_endian>
734 void
735 Sized_relobj_file<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
736 {
737 this->read_section_data(&this->elf_file_, sd);
738
739 const unsigned char* const pshdrs = sd->section_headers->data();
740
741 this->find_symtab(pshdrs);
742
743 bool need_local_symbols = this->do_find_special_sections(sd);
744
745 sd->symbols = NULL;
746 sd->symbols_size = 0;
747 sd->external_symbols_offset = 0;
748 sd->symbol_names = NULL;
749 sd->symbol_names_size = 0;
750
751 if (this->symtab_shndx_ == 0)
752 {
753 // No symbol table. Weird but legal.
754 return;
755 }
756
757 // Get the symbol table section header.
758 typename This::Shdr symtabshdr(pshdrs
759 + this->symtab_shndx_ * This::shdr_size);
760 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
761
762 // If this object has a .eh_frame section, or if building a .gdb_index
763 // section and there is debug info, we need all the symbols.
764 // Otherwise we only need the external symbols. While it would be
765 // simpler to just always read all the symbols, I've seen object
766 // files with well over 2000 local symbols, which for a 64-bit
767 // object file format is over 5 pages that we don't need to read
768 // now.
769
770 const int sym_size = This::sym_size;
771 const unsigned int loccount = symtabshdr.get_sh_info();
772 this->local_symbol_count_ = loccount;
773 this->local_values_.resize(loccount);
774 section_offset_type locsize = loccount * sym_size;
775 off_t dataoff = symtabshdr.get_sh_offset();
776 section_size_type datasize =
777 convert_to_section_size_type(symtabshdr.get_sh_size());
778 off_t extoff = dataoff + locsize;
779 section_size_type extsize = datasize - locsize;
780
781 off_t readoff = need_local_symbols ? dataoff : extoff;
782 section_size_type readsize = need_local_symbols ? datasize : extsize;
783
784 if (readsize == 0)
785 {
786 // No external symbols. Also weird but also legal.
787 return;
788 }
789
790 File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false);
791
792 // Read the section header for the symbol names.
793 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
794 if (strtab_shndx >= this->shnum())
795 {
796 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
797 return;
798 }
799 typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
800 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
801 {
802 this->error(_("symbol table name section has wrong type: %u"),
803 static_cast<unsigned int>(strtabshdr.get_sh_type()));
804 return;
805 }
806
807 // Read the symbol names.
808 File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
809 strtabshdr.get_sh_size(),
810 false, true);
811
812 sd->symbols = fvsymtab;
813 sd->symbols_size = readsize;
814 sd->external_symbols_offset = need_local_symbols ? locsize : 0;
815 sd->symbol_names = fvstrtab;
816 sd->symbol_names_size =
817 convert_to_section_size_type(strtabshdr.get_sh_size());
818 }
819
820 // Return the section index of symbol SYM. Set *VALUE to its value in
821 // the object file. Set *IS_ORDINARY if this is an ordinary section
822 // index, not a special code between SHN_LORESERVE and SHN_HIRESERVE.
823 // Note that for a symbol which is not defined in this object file,
824 // this will set *VALUE to 0 and return SHN_UNDEF; it will not return
825 // the final value of the symbol in the link.
826
827 template<int size, bool big_endian>
828 unsigned int
829 Sized_relobj_file<size, big_endian>::symbol_section_and_value(unsigned int sym,
830 Address* value,
831 bool* is_ordinary)
832 {
833 section_size_type symbols_size;
834 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
835 &symbols_size,
836 false);
837
838 const size_t count = symbols_size / This::sym_size;
839 gold_assert(sym < count);
840
841 elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
842 *value = elfsym.get_st_value();
843
844 return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary);
845 }
846
847 // Return whether to include a section group in the link. LAYOUT is
848 // used to keep track of which section groups we have already seen.
849 // INDEX is the index of the section group and SHDR is the section
850 // header. If we do not want to include this group, we set bits in
851 // OMIT for each section which should be discarded.
852
853 template<int size, bool big_endian>
854 bool
855 Sized_relobj_file<size, big_endian>::include_section_group(
856 Symbol_table* symtab,
857 Layout* layout,
858 unsigned int index,
859 const char* name,
860 const unsigned char* shdrs,
861 const char* section_names,
862 section_size_type section_names_size,
863 std::vector<bool>* omit)
864 {
865 // Read the section contents.
866 typename This::Shdr shdr(shdrs + index * This::shdr_size);
867 const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
868 shdr.get_sh_size(), true, false);
869 const elfcpp::Elf_Word* pword =
870 reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
871
872 // The first word contains flags. We only care about COMDAT section
873 // groups. Other section groups are always included in the link
874 // just like ordinary sections.
875 elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
876
877 // Look up the group signature, which is the name of a symbol. ELF
878 // uses a symbol name because some group signatures are long, and
879 // the name is generally already in the symbol table, so it makes
880 // sense to put the long string just once in .strtab rather than in
881 // both .strtab and .shstrtab.
882
883 // Get the appropriate symbol table header (this will normally be
884 // the single SHT_SYMTAB section, but in principle it need not be).
885 const unsigned int link = this->adjust_shndx(shdr.get_sh_link());
886 typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
887
888 // Read the symbol table entry.
889 unsigned int symndx = shdr.get_sh_info();
890 if (symndx >= symshdr.get_sh_size() / This::sym_size)
891 {
892 this->error(_("section group %u info %u out of range"),
893 index, symndx);
894 return false;
895 }
896 off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size;
897 const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
898 false);
899 elfcpp::Sym<size, big_endian> sym(psym);
900
901 // Read the symbol table names.
902 section_size_type symnamelen;
903 const unsigned char* psymnamesu;
904 psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()),
905 &symnamelen, true);
906 const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
907
908 // Get the section group signature.
909 if (sym.get_st_name() >= symnamelen)
910 {
911 this->error(_("symbol %u name offset %u out of range"),
912 symndx, sym.get_st_name());
913 return false;
914 }
915
916 std::string signature(psymnames + sym.get_st_name());
917
918 // It seems that some versions of gas will create a section group
919 // associated with a section symbol, and then fail to give a name to
920 // the section symbol. In such a case, use the name of the section.
921 if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
922 {
923 bool is_ordinary;
924 unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
925 sym.get_st_shndx(),
926 &is_ordinary);
927 if (!is_ordinary || sym_shndx >= this->shnum())
928 {
929 this->error(_("symbol %u invalid section index %u"),
930 symndx, sym_shndx);
931 return false;
932 }
933 typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size);
934 if (member_shdr.get_sh_name() < section_names_size)
935 signature = section_names + member_shdr.get_sh_name();
936 }
937
938 // Record this section group in the layout, and see whether we've already
939 // seen one with the same signature.
940 bool include_group;
941 bool is_comdat;
942 Kept_section* kept_section = NULL;
943
944 if ((flags & elfcpp::GRP_COMDAT) == 0)
945 {
946 include_group = true;
947 is_comdat = false;
948 }
949 else
950 {
951 include_group = layout->find_or_add_kept_section(signature,
952 this, index, true,
953 true, &kept_section);
954 is_comdat = true;
955 }
956
957 if (is_comdat && include_group)
958 {
959 Incremental_inputs* incremental_inputs = layout->incremental_inputs();
960 if (incremental_inputs != NULL)
961 incremental_inputs->report_comdat_group(this, signature.c_str());
962 }
963
964 size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
965
966 std::vector<unsigned int> shndxes;
967 bool relocate_group = include_group && parameters->options().relocatable();
968 if (relocate_group)
969 shndxes.reserve(count - 1);
970
971 for (size_t i = 1; i < count; ++i)
972 {
973 elfcpp::Elf_Word shndx =
974 this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
975
976 if (relocate_group)
977 shndxes.push_back(shndx);
978
979 if (shndx >= this->shnum())
980 {
981 this->error(_("section %u in section group %u out of range"),
982 shndx, index);
983 continue;
984 }
985
986 // Check for an earlier section number, since we're going to get
987 // it wrong--we may have already decided to include the section.
988 if (shndx < index)
989 this->error(_("invalid section group %u refers to earlier section %u"),
990 index, shndx);
991
992 // Get the name of the member section.
993 typename This::Shdr member_shdr(shdrs + shndx * This::shdr_size);
994 if (member_shdr.get_sh_name() >= section_names_size)
995 {
996 // This is an error, but it will be diagnosed eventually
997 // in do_layout, so we don't need to do anything here but
998 // ignore it.
999 continue;
1000 }
1001 std::string mname(section_names + member_shdr.get_sh_name());
1002
1003 if (include_group)
1004 {
1005 if (is_comdat)
1006 kept_section->add_comdat_section(mname, shndx,
1007 member_shdr.get_sh_size());
1008 }
1009 else
1010 {
1011 (*omit)[shndx] = true;
1012
1013 if (is_comdat)
1014 {
1015 Relobj* kept_object = kept_section->object();
1016 if (kept_section->is_comdat())
1017 {
1018 // Find the corresponding kept section, and store
1019 // that info in the discarded section table.
1020 unsigned int kept_shndx;
1021 uint64_t kept_size;
1022 if (kept_section->find_comdat_section(mname, &kept_shndx,
1023 &kept_size))
1024 {
1025 // We don't keep a mapping for this section if
1026 // it has a different size. The mapping is only
1027 // used for relocation processing, and we don't
1028 // want to treat the sections as similar if the
1029 // sizes are different. Checking the section
1030 // size is the approach used by the GNU linker.
1031 if (kept_size == member_shdr.get_sh_size())
1032 this->set_kept_comdat_section(shndx, kept_object,
1033 kept_shndx);
1034 }
1035 }
1036 else
1037 {
1038 // The existing section is a linkonce section. Add
1039 // a mapping if there is exactly one section in the
1040 // group (which is true when COUNT == 2) and if it
1041 // is the same size.
1042 if (count == 2
1043 && (kept_section->linkonce_size()
1044 == member_shdr.get_sh_size()))
1045 this->set_kept_comdat_section(shndx, kept_object,
1046 kept_section->shndx());
1047 }
1048 }
1049 }
1050 }
1051
1052 if (relocate_group)
1053 layout->layout_group(symtab, this, index, name, signature.c_str(),
1054 shdr, flags, &shndxes);
1055
1056 return include_group;
1057 }
1058
1059 // Whether to include a linkonce section in the link. NAME is the
1060 // name of the section and SHDR is the section header.
1061
1062 // Linkonce sections are a GNU extension implemented in the original
1063 // GNU linker before section groups were defined. The semantics are
1064 // that we only include one linkonce section with a given name. The
1065 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
1066 // where T is the type of section and SYMNAME is the name of a symbol.
1067 // In an attempt to make linkonce sections interact well with section
1068 // groups, we try to identify SYMNAME and use it like a section group
1069 // signature. We want to block section groups with that signature,
1070 // but not other linkonce sections with that signature. We also use
1071 // the full name of the linkonce section as a normal section group
1072 // signature.
1073
1074 template<int size, bool big_endian>
1075 bool
1076 Sized_relobj_file<size, big_endian>::include_linkonce_section(
1077 Layout* layout,
1078 unsigned int index,
1079 const char* name,
1080 const elfcpp::Shdr<size, big_endian>& shdr)
1081 {
1082 typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
1083 // In general the symbol name we want will be the string following
1084 // the last '.'. However, we have to handle the case of
1085 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
1086 // some versions of gcc. So we use a heuristic: if the name starts
1087 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
1088 // we look for the last '.'. We can't always simply skip
1089 // ".gnu.linkonce.X", because we have to deal with cases like
1090 // ".gnu.linkonce.d.rel.ro.local".
1091 const char* const linkonce_t = ".gnu.linkonce.t.";
1092 const char* symname;
1093 if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
1094 symname = name + strlen(linkonce_t);
1095 else
1096 symname = strrchr(name, '.') + 1;
1097 std::string sig1(symname);
1098 std::string sig2(name);
1099 Kept_section* kept1;
1100 Kept_section* kept2;
1101 bool include1 = layout->find_or_add_kept_section(sig1, this, index, false,
1102 false, &kept1);
1103 bool include2 = layout->find_or_add_kept_section(sig2, this, index, false,
1104 true, &kept2);
1105
1106 if (!include2)
1107 {
1108 // We are not including this section because we already saw the
1109 // name of the section as a signature. This normally implies
1110 // that the kept section is another linkonce section. If it is
1111 // the same size, record it as the section which corresponds to
1112 // this one.
1113 if (kept2->object() != NULL
1114 && !kept2->is_comdat()
1115 && kept2->linkonce_size() == sh_size)
1116 this->set_kept_comdat_section(index, kept2->object(), kept2->shndx());
1117 }
1118 else if (!include1)
1119 {
1120 // The section is being discarded on the basis of its symbol
1121 // name. This means that the corresponding kept section was
1122 // part of a comdat group, and it will be difficult to identify
1123 // the specific section within that group that corresponds to
1124 // this linkonce section. We'll handle the simple case where
1125 // the group has only one member section. Otherwise, it's not
1126 // worth the effort.
1127 unsigned int kept_shndx;
1128 uint64_t kept_size;
1129 if (kept1->object() != NULL
1130 && kept1->is_comdat()
1131 && kept1->find_single_comdat_section(&kept_shndx, &kept_size)
1132 && kept_size == sh_size)
1133 this->set_kept_comdat_section(index, kept1->object(), kept_shndx);
1134 }
1135 else
1136 {
1137 kept1->set_linkonce_size(sh_size);
1138 kept2->set_linkonce_size(sh_size);
1139 }
1140
1141 return include1 && include2;
1142 }
1143
1144 // Layout an input section.
1145
1146 template<int size, bool big_endian>
1147 inline void
1148 Sized_relobj_file<size, big_endian>::layout_section(
1149 Layout* layout,
1150 unsigned int shndx,
1151 const char* name,
1152 const typename This::Shdr& shdr,
1153 unsigned int reloc_shndx,
1154 unsigned int reloc_type)
1155 {
1156 off_t offset;
1157 Output_section* os = layout->layout(this, shndx, name, shdr,
1158 reloc_shndx, reloc_type, &offset);
1159
1160 this->output_sections()[shndx] = os;
1161 if (offset == -1)
1162 this->section_offsets()[shndx] = invalid_address;
1163 else
1164 this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
1165
1166 // If this section requires special handling, and if there are
1167 // relocs that apply to it, then we must do the special handling
1168 // before we apply the relocs.
1169 if (offset == -1 && reloc_shndx != 0)
1170 this->set_relocs_must_follow_section_writes();
1171 }
1172
1173 // Layout an input .eh_frame section.
1174
1175 template<int size, bool big_endian>
1176 void
1177 Sized_relobj_file<size, big_endian>::layout_eh_frame_section(
1178 Layout* layout,
1179 const unsigned char* symbols_data,
1180 section_size_type symbols_size,
1181 const unsigned char* symbol_names_data,
1182 section_size_type symbol_names_size,
1183 unsigned int shndx,
1184 const typename This::Shdr& shdr,
1185 unsigned int reloc_shndx,
1186 unsigned int reloc_type)
1187 {
1188 gold_assert(this->has_eh_frame_);
1189
1190 off_t offset;
1191 Output_section* os = layout->layout_eh_frame(this,
1192 symbols_data,
1193 symbols_size,
1194 symbol_names_data,
1195 symbol_names_size,
1196 shndx,
1197 shdr,
1198 reloc_shndx,
1199 reloc_type,
1200 &offset);
1201 this->output_sections()[shndx] = os;
1202 if (os == NULL || offset == -1)
1203 {
1204 // An object can contain at most one section holding exception
1205 // frame information.
1206 gold_assert(this->discarded_eh_frame_shndx_ == -1U);
1207 this->discarded_eh_frame_shndx_ = shndx;
1208 this->section_offsets()[shndx] = invalid_address;
1209 }
1210 else
1211 this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
1212
1213 // If this section requires special handling, and if there are
1214 // relocs that aply to it, then we must do the special handling
1215 // before we apply the relocs.
1216 if (os != NULL && offset == -1 && reloc_shndx != 0)
1217 this->set_relocs_must_follow_section_writes();
1218 }
1219
1220 // Lay out the input sections. We walk through the sections and check
1221 // whether they should be included in the link. If they should, we
1222 // pass them to the Layout object, which will return an output section
1223 // and an offset.
1224 // During garbage collection (--gc-sections) and identical code folding
1225 // (--icf), this function is called twice. When it is called the first
1226 // time, it is for setting up some sections as roots to a work-list for
1227 // --gc-sections and to do comdat processing. Actual layout happens the
1228 // second time around after all the relevant sections have been determined.
1229 // The first time, is_worklist_ready or is_icf_ready is false. It is then
1230 // set to true after the garbage collection worklist or identical code
1231 // folding is processed and the relevant sections to be kept are
1232 // determined. Then, this function is called again to layout the sections.
1233
1234 template<int size, bool big_endian>
1235 void
1236 Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
1237 Layout* layout,
1238 Read_symbols_data* sd)
1239 {
1240 const unsigned int shnum = this->shnum();
1241 bool is_gc_pass_one = ((parameters->options().gc_sections()
1242 && !symtab->gc()->is_worklist_ready())
1243 || (parameters->options().icf_enabled()
1244 && !symtab->icf()->is_icf_ready()));
1245
1246 bool is_gc_pass_two = ((parameters->options().gc_sections()
1247 && symtab->gc()->is_worklist_ready())
1248 || (parameters->options().icf_enabled()
1249 && symtab->icf()->is_icf_ready()));
1250
1251 bool is_gc_or_icf = (parameters->options().gc_sections()
1252 || parameters->options().icf_enabled());
1253
1254 // Both is_gc_pass_one and is_gc_pass_two should not be true.
1255 gold_assert(!(is_gc_pass_one && is_gc_pass_two));
1256
1257 if (shnum == 0)
1258 return;
1259 Symbols_data* gc_sd = NULL;
1260 if (is_gc_pass_one)
1261 {
1262 // During garbage collection save the symbols data to use it when
1263 // re-entering this function.
1264 gc_sd = new Symbols_data;
1265 this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
1266 this->set_symbols_data(gc_sd);
1267 }
1268 else if (is_gc_pass_two)
1269 {
1270 gc_sd = this->get_symbols_data();
1271 }
1272
1273 const unsigned char* section_headers_data = NULL;
1274 section_size_type section_names_size;
1275 const unsigned char* symbols_data = NULL;
1276 section_size_type symbols_size;
1277 const unsigned char* symbol_names_data = NULL;
1278 section_size_type symbol_names_size;
1279
1280 if (is_gc_or_icf)
1281 {
1282 section_headers_data = gc_sd->section_headers_data;
1283 section_names_size = gc_sd->section_names_size;
1284 symbols_data = gc_sd->symbols_data;
1285 symbols_size = gc_sd->symbols_size;
1286 symbol_names_data = gc_sd->symbol_names_data;
1287 symbol_names_size = gc_sd->symbol_names_size;
1288 }
1289 else
1290 {
1291 section_headers_data = sd->section_headers->data();
1292 section_names_size = sd->section_names_size;
1293 if (sd->symbols != NULL)
1294 symbols_data = sd->symbols->data();
1295 symbols_size = sd->symbols_size;
1296 if (sd->symbol_names != NULL)
1297 symbol_names_data = sd->symbol_names->data();
1298 symbol_names_size = sd->symbol_names_size;
1299 }
1300
1301 // Get the section headers.
1302 const unsigned char* shdrs = section_headers_data;
1303 const unsigned char* pshdrs;
1304
1305 // Get the section names.
1306 const unsigned char* pnamesu = (is_gc_or_icf)
1307 ? gc_sd->section_names_data
1308 : sd->section_names->data();
1309
1310 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1311
1312 // If any input files have been claimed by plugins, we need to defer
1313 // actual layout until the replacement files have arrived.
1314 const bool should_defer_layout =
1315 (parameters->options().has_plugins()
1316 && parameters->options().plugins()->should_defer_layout());
1317 unsigned int num_sections_to_defer = 0;
1318
1319 // For each section, record the index of the reloc section if any.
1320 // Use 0 to mean that there is no reloc section, -1U to mean that
1321 // there is more than one.
1322 std::vector<unsigned int> reloc_shndx(shnum, 0);
1323 std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
1324 // Skip the first, dummy, section.
1325 pshdrs = shdrs + This::shdr_size;
1326 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1327 {
1328 typename This::Shdr shdr(pshdrs);
1329
1330 // Count the number of sections whose layout will be deferred.
1331 if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1332 ++num_sections_to_defer;
1333
1334 unsigned int sh_type = shdr.get_sh_type();
1335 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
1336 {
1337 unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info());
1338 if (target_shndx == 0 || target_shndx >= shnum)
1339 {
1340 this->error(_("relocation section %u has bad info %u"),
1341 i, target_shndx);
1342 continue;
1343 }
1344
1345 if (reloc_shndx[target_shndx] != 0)
1346 reloc_shndx[target_shndx] = -1U;
1347 else
1348 {
1349 reloc_shndx[target_shndx] = i;
1350 reloc_type[target_shndx] = sh_type;
1351 }
1352 }
1353 }
1354
1355 Output_sections& out_sections(this->output_sections());
1356 std::vector<Address>& out_section_offsets(this->section_offsets());
1357
1358 if (!is_gc_pass_two)
1359 {
1360 out_sections.resize(shnum);
1361 out_section_offsets.resize(shnum);
1362 }
1363
1364 // If we are only linking for symbols, then there is nothing else to
1365 // do here.
1366 if (this->input_file()->just_symbols())
1367 {
1368 if (!is_gc_pass_two)
1369 {
1370 delete sd->section_headers;
1371 sd->section_headers = NULL;
1372 delete sd->section_names;
1373 sd->section_names = NULL;
1374 }
1375 return;
1376 }
1377
1378 if (num_sections_to_defer > 0)
1379 {
1380 parameters->options().plugins()->add_deferred_layout_object(this);
1381 this->deferred_layout_.reserve(num_sections_to_defer);
1382 }
1383
1384 // Whether we've seen a .note.GNU-stack section.
1385 bool seen_gnu_stack = false;
1386 // The flags of a .note.GNU-stack section.
1387 uint64_t gnu_stack_flags = 0;
1388
1389 // Keep track of which sections to omit.
1390 std::vector<bool> omit(shnum, false);
1391
1392 // Keep track of reloc sections when emitting relocations.
1393 const bool relocatable = parameters->options().relocatable();
1394 const bool emit_relocs = (relocatable
1395 || parameters->options().emit_relocs());
1396 std::vector<unsigned int> reloc_sections;
1397
1398 // Keep track of .eh_frame sections.
1399 std::vector<unsigned int> eh_frame_sections;
1400
1401 // Keep track of .debug_info and .debug_types sections.
1402 std::vector<unsigned int> debug_info_sections;
1403 std::vector<unsigned int> debug_types_sections;
1404
1405 // Skip the first, dummy, section.
1406 pshdrs = shdrs + This::shdr_size;
1407 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1408 {
1409 typename This::Shdr shdr(pshdrs);
1410
1411 if (shdr.get_sh_name() >= section_names_size)
1412 {
1413 this->error(_("bad section name offset for section %u: %lu"),
1414 i, static_cast<unsigned long>(shdr.get_sh_name()));
1415 return;
1416 }
1417
1418 const char* name = pnames + shdr.get_sh_name();
1419
1420 if (!is_gc_pass_two)
1421 {
1422 if (this->handle_gnu_warning_section(name, i, symtab))
1423 {
1424 if (!relocatable && !parameters->options().shared())
1425 omit[i] = true;
1426 }
1427
1428 // The .note.GNU-stack section is special. It gives the
1429 // protection flags that this object file requires for the stack
1430 // in memory.
1431 if (strcmp(name, ".note.GNU-stack") == 0)
1432 {
1433 seen_gnu_stack = true;
1434 gnu_stack_flags |= shdr.get_sh_flags();
1435 omit[i] = true;
1436 }
1437
1438 // The .note.GNU-split-stack section is also special. It
1439 // indicates that the object was compiled with
1440 // -fsplit-stack.
1441 if (this->handle_split_stack_section(name))
1442 {
1443 if (!relocatable && !parameters->options().shared())
1444 omit[i] = true;
1445 }
1446
1447 // Skip attributes section.
1448 if (parameters->target().is_attributes_section(name))
1449 {
1450 omit[i] = true;
1451 }
1452
1453 bool discard = omit[i];
1454 if (!discard)
1455 {
1456 if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
1457 {
1458 if (!this->include_section_group(symtab, layout, i, name,
1459 shdrs, pnames,
1460 section_names_size,
1461 &omit))
1462 discard = true;
1463 }
1464 else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
1465 && Layout::is_linkonce(name))
1466 {
1467 if (!this->include_linkonce_section(layout, i, name, shdr))
1468 discard = true;
1469 }
1470 }
1471
1472 // Add the section to the incremental inputs layout.
1473 Incremental_inputs* incremental_inputs = layout->incremental_inputs();
1474 if (incremental_inputs != NULL
1475 && !discard
1476 && can_incremental_update(shdr.get_sh_type()))
1477 {
1478 off_t sh_size = shdr.get_sh_size();
1479 section_size_type uncompressed_size;
1480 if (this->section_is_compressed(i, &uncompressed_size))
1481 sh_size = uncompressed_size;
1482 incremental_inputs->report_input_section(this, i, name, sh_size);
1483 }
1484
1485 if (discard)
1486 {
1487 // Do not include this section in the link.
1488 out_sections[i] = NULL;
1489 out_section_offsets[i] = invalid_address;
1490 continue;
1491 }
1492 }
1493
1494 if (is_gc_pass_one && parameters->options().gc_sections())
1495 {
1496 if (this->is_section_name_included(name)
1497 || layout->keep_input_section (this, name)
1498 || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY
1499 || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
1500 {
1501 symtab->gc()->worklist().push(Section_id(this, i));
1502 }
1503 // If the section name XXX can be represented as a C identifier
1504 // it cannot be discarded if there are references to
1505 // __start_XXX and __stop_XXX symbols. These need to be
1506 // specially handled.
1507 if (is_cident(name))
1508 {
1509 symtab->gc()->add_cident_section(name, Section_id(this, i));
1510 }
1511 }
1512
1513 // When doing a relocatable link we are going to copy input
1514 // reloc sections into the output. We only want to copy the
1515 // ones associated with sections which are not being discarded.
1516 // However, we don't know that yet for all sections. So save
1517 // reloc sections and process them later. Garbage collection is
1518 // not triggered when relocatable code is desired.
1519 if (emit_relocs
1520 && (shdr.get_sh_type() == elfcpp::SHT_REL
1521 || shdr.get_sh_type() == elfcpp::SHT_RELA))
1522 {
1523 reloc_sections.push_back(i);
1524 continue;
1525 }
1526
1527 if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
1528 continue;
1529
1530 // The .eh_frame section is special. It holds exception frame
1531 // information that we need to read in order to generate the
1532 // exception frame header. We process these after all the other
1533 // sections so that the exception frame reader can reliably
1534 // determine which sections are being discarded, and discard the
1535 // corresponding information.
1536 if (!relocatable
1537 && strcmp(name, ".eh_frame") == 0
1538 && this->check_eh_frame_flags(&shdr))
1539 {
1540 if (is_gc_pass_one)
1541 {
1542 out_sections[i] = reinterpret_cast<Output_section*>(1);
1543 out_section_offsets[i] = invalid_address;
1544 }
1545 else if (should_defer_layout)
1546 this->deferred_layout_.push_back(Deferred_layout(i, name,
1547 pshdrs,
1548 reloc_shndx[i],
1549 reloc_type[i]));
1550 else
1551 eh_frame_sections.push_back(i);
1552 continue;
1553 }
1554
1555 if (is_gc_pass_two && parameters->options().gc_sections())
1556 {
1557 // This is executed during the second pass of garbage
1558 // collection. do_layout has been called before and some
1559 // sections have been already discarded. Simply ignore
1560 // such sections this time around.
1561 if (out_sections[i] == NULL)
1562 {
1563 gold_assert(out_section_offsets[i] == invalid_address);
1564 continue;
1565 }
1566 if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1567 && symtab->gc()->is_section_garbage(this, i))
1568 {
1569 if (parameters->options().print_gc_sections())
1570 gold_info(_("%s: removing unused section from '%s'"
1571 " in file '%s'"),
1572 program_name, this->section_name(i).c_str(),
1573 this->name().c_str());
1574 out_sections[i] = NULL;
1575 out_section_offsets[i] = invalid_address;
1576 continue;
1577 }
1578 }
1579
1580 if (is_gc_pass_two && parameters->options().icf_enabled())
1581 {
1582 if (out_sections[i] == NULL)
1583 {
1584 gold_assert(out_section_offsets[i] == invalid_address);
1585 continue;
1586 }
1587 if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1588 && symtab->icf()->is_section_folded(this, i))
1589 {
1590 if (parameters->options().print_icf_sections())
1591 {
1592 Section_id folded =
1593 symtab->icf()->get_folded_section(this, i);
1594 Relobj* folded_obj =
1595 reinterpret_cast<Relobj*>(folded.first);
1596 gold_info(_("%s: ICF folding section '%s' in file '%s'"
1597 "into '%s' in file '%s'"),
1598 program_name, this->section_name(i).c_str(),
1599 this->name().c_str(),
1600 folded_obj->section_name(folded.second).c_str(),
1601 folded_obj->name().c_str());
1602 }
1603 out_sections[i] = NULL;
1604 out_section_offsets[i] = invalid_address;
1605 continue;
1606 }
1607 }
1608
1609 // Defer layout here if input files are claimed by plugins. When gc
1610 // is turned on this function is called twice. For the second call
1611 // should_defer_layout should be false.
1612 if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1613 {
1614 gold_assert(!is_gc_pass_two);
1615 this->deferred_layout_.push_back(Deferred_layout(i, name,
1616 pshdrs,
1617 reloc_shndx[i],
1618 reloc_type[i]));
1619 // Put dummy values here; real values will be supplied by
1620 // do_layout_deferred_sections.
1621 out_sections[i] = reinterpret_cast<Output_section*>(2);
1622 out_section_offsets[i] = invalid_address;
1623 continue;
1624 }
1625
1626 // During gc_pass_two if a section that was previously deferred is
1627 // found, do not layout the section as layout_deferred_sections will
1628 // do it later from gold.cc.
1629 if (is_gc_pass_two
1630 && (out_sections[i] == reinterpret_cast<Output_section*>(2)))
1631 continue;
1632
1633 if (is_gc_pass_one)
1634 {
1635 // This is during garbage collection. The out_sections are
1636 // assigned in the second call to this function.
1637 out_sections[i] = reinterpret_cast<Output_section*>(1);
1638 out_section_offsets[i] = invalid_address;
1639 }
1640 else
1641 {
1642 // When garbage collection is switched on the actual layout
1643 // only happens in the second call.
1644 this->layout_section(layout, i, name, shdr, reloc_shndx[i],
1645 reloc_type[i]);
1646
1647 // When generating a .gdb_index section, we do additional
1648 // processing of .debug_info and .debug_types sections after all
1649 // the other sections for the same reason as above.
1650 if (!relocatable
1651 && parameters->options().gdb_index()
1652 && !(shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1653 {
1654 if (strcmp(name, ".debug_info") == 0
1655 || strcmp(name, ".zdebug_info") == 0)
1656 debug_info_sections.push_back(i);
1657 else if (strcmp(name, ".debug_types") == 0
1658 || strcmp(name, ".zdebug_types") == 0)
1659 debug_types_sections.push_back(i);
1660 }
1661 }
1662 }
1663
1664 if (!is_gc_pass_two)
1665 layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags, this);
1666
1667 // When doing a relocatable link handle the reloc sections at the
1668 // end. Garbage collection and Identical Code Folding is not
1669 // turned on for relocatable code.
1670 if (emit_relocs)
1671 this->size_relocatable_relocs();
1672
1673 gold_assert(!(is_gc_or_icf) || reloc_sections.empty());
1674
1675 for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
1676 p != reloc_sections.end();
1677 ++p)
1678 {
1679 unsigned int i = *p;
1680 const unsigned char* pshdr;
1681 pshdr = section_headers_data + i * This::shdr_size;
1682 typename This::Shdr shdr(pshdr);
1683
1684 unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1685 if (data_shndx >= shnum)
1686 {
1687 // We already warned about this above.
1688 continue;
1689 }
1690
1691 Output_section* data_section = out_sections[data_shndx];
1692 if (data_section == reinterpret_cast<Output_section*>(2))
1693 {
1694 // The layout for the data section was deferred, so we need
1695 // to defer the relocation section, too.
1696 const char* name = pnames + shdr.get_sh_name();
1697 this->deferred_layout_relocs_.push_back(
1698 Deferred_layout(i, name, pshdr, 0, elfcpp::SHT_NULL));
1699 out_sections[i] = reinterpret_cast<Output_section*>(2);
1700 out_section_offsets[i] = invalid_address;
1701 continue;
1702 }
1703 if (data_section == NULL)
1704 {
1705 out_sections[i] = NULL;
1706 out_section_offsets[i] = invalid_address;
1707 continue;
1708 }
1709
1710 Relocatable_relocs* rr = new Relocatable_relocs();
1711 this->set_relocatable_relocs(i, rr);
1712
1713 Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
1714 rr);
1715 out_sections[i] = os;
1716 out_section_offsets[i] = invalid_address;
1717 }
1718
1719 // Handle the .eh_frame sections at the end.
1720 gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
1721 for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
1722 p != eh_frame_sections.end();
1723 ++p)
1724 {
1725 unsigned int i = *p;
1726 const unsigned char* pshdr;
1727 pshdr = section_headers_data + i * This::shdr_size;
1728 typename This::Shdr shdr(pshdr);
1729
1730 this->layout_eh_frame_section(layout,
1731 symbols_data,
1732 symbols_size,
1733 symbol_names_data,
1734 symbol_names_size,
1735 i,
1736 shdr,
1737 reloc_shndx[i],
1738 reloc_type[i]);
1739 }
1740
1741 // When building a .gdb_index section, scan the .debug_info and
1742 // .debug_types sections.
1743 gold_assert(!is_gc_pass_one
1744 || (debug_info_sections.empty() && debug_types_sections.empty()));
1745 for (std::vector<unsigned int>::const_iterator p
1746 = debug_info_sections.begin();
1747 p != debug_info_sections.end();
1748 ++p)
1749 {
1750 unsigned int i = *p;
1751 layout->add_to_gdb_index(false, this, symbols_data, symbols_size,
1752 i, reloc_shndx[i], reloc_type[i]);
1753 }
1754 for (std::vector<unsigned int>::const_iterator p
1755 = debug_types_sections.begin();
1756 p != debug_types_sections.end();
1757 ++p)
1758 {
1759 unsigned int i = *p;
1760 layout->add_to_gdb_index(true, this, symbols_data, symbols_size,
1761 i, reloc_shndx[i], reloc_type[i]);
1762 }
1763
1764 if (is_gc_pass_two)
1765 {
1766 delete[] gc_sd->section_headers_data;
1767 delete[] gc_sd->section_names_data;
1768 delete[] gc_sd->symbols_data;
1769 delete[] gc_sd->symbol_names_data;
1770 this->set_symbols_data(NULL);
1771 }
1772 else
1773 {
1774 delete sd->section_headers;
1775 sd->section_headers = NULL;
1776 delete sd->section_names;
1777 sd->section_names = NULL;
1778 }
1779 }
1780
1781 // Layout sections whose layout was deferred while waiting for
1782 // input files from a plugin.
1783
1784 template<int size, bool big_endian>
1785 void
1786 Sized_relobj_file<size, big_endian>::do_layout_deferred_sections(Layout* layout)
1787 {
1788 typename std::vector<Deferred_layout>::iterator deferred;
1789
1790 for (deferred = this->deferred_layout_.begin();
1791 deferred != this->deferred_layout_.end();
1792 ++deferred)
1793 {
1794 typename This::Shdr shdr(deferred->shdr_data_);
1795 // If the section is not included, it is because the garbage collector
1796 // decided it is not needed. Avoid reverting that decision.
1797 if (!this->is_section_included(deferred->shndx_))
1798 continue;
1799
1800 if (parameters->options().relocatable()
1801 || deferred->name_ != ".eh_frame"
1802 || !this->check_eh_frame_flags(&shdr))
1803 this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
1804 shdr, deferred->reloc_shndx_,
1805 deferred->reloc_type_);
1806 else
1807 {
1808 // Reading the symbols again here may be slow.
1809 Read_symbols_data sd;
1810 this->read_symbols(&sd);
1811 this->layout_eh_frame_section(layout,
1812 sd.symbols->data(),
1813 sd.symbols_size,
1814 sd.symbol_names->data(),
1815 sd.symbol_names_size,
1816 deferred->shndx_,
1817 shdr,
1818 deferred->reloc_shndx_,
1819 deferred->reloc_type_);
1820 }
1821 }
1822
1823 this->deferred_layout_.clear();
1824
1825 // Now handle the deferred relocation sections.
1826
1827 Output_sections& out_sections(this->output_sections());
1828 std::vector<Address>& out_section_offsets(this->section_offsets());
1829
1830 for (deferred = this->deferred_layout_relocs_.begin();
1831 deferred != this->deferred_layout_relocs_.end();
1832 ++deferred)
1833 {
1834 unsigned int shndx = deferred->shndx_;
1835 typename This::Shdr shdr(deferred->shdr_data_);
1836 unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1837
1838 Output_section* data_section = out_sections[data_shndx];
1839 if (data_section == NULL)
1840 {
1841 out_sections[shndx] = NULL;
1842 out_section_offsets[shndx] = invalid_address;
1843 continue;
1844 }
1845
1846 Relocatable_relocs* rr = new Relocatable_relocs();
1847 this->set_relocatable_relocs(shndx, rr);
1848
1849 Output_section* os = layout->layout_reloc(this, shndx, shdr,
1850 data_section, rr);
1851 out_sections[shndx] = os;
1852 out_section_offsets[shndx] = invalid_address;
1853 }
1854 }
1855
1856 // Add the symbols to the symbol table.
1857
1858 template<int size, bool big_endian>
1859 void
1860 Sized_relobj_file<size, big_endian>::do_add_symbols(Symbol_table* symtab,
1861 Read_symbols_data* sd,
1862 Layout*)
1863 {
1864 if (sd->symbols == NULL)
1865 {
1866 gold_assert(sd->symbol_names == NULL);
1867 return;
1868 }
1869
1870 const int sym_size = This::sym_size;
1871 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1872 / sym_size);
1873 if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
1874 {
1875 this->error(_("size of symbols is not multiple of symbol size"));
1876 return;
1877 }
1878
1879 this->symbols_.resize(symcount);
1880
1881 const char* sym_names =
1882 reinterpret_cast<const char*>(sd->symbol_names->data());
1883 symtab->add_from_relobj(this,
1884 sd->symbols->data() + sd->external_symbols_offset,
1885 symcount, this->local_symbol_count_,
1886 sym_names, sd->symbol_names_size,
1887 &this->symbols_,
1888 &this->defined_count_);
1889
1890 delete sd->symbols;
1891 sd->symbols = NULL;
1892 delete sd->symbol_names;
1893 sd->symbol_names = NULL;
1894 }
1895
1896 // Find out if this object, that is a member of a lib group, should be included
1897 // in the link. We check every symbol defined by this object. If the symbol
1898 // table has a strong undefined reference to that symbol, we have to include
1899 // the object.
1900
1901 template<int size, bool big_endian>
1902 Archive::Should_include
1903 Sized_relobj_file<size, big_endian>::do_should_include_member(
1904 Symbol_table* symtab,
1905 Layout* layout,
1906 Read_symbols_data* sd,
1907 std::string* why)
1908 {
1909 char* tmpbuf = NULL;
1910 size_t tmpbuflen = 0;
1911 const char* sym_names =
1912 reinterpret_cast<const char*>(sd->symbol_names->data());
1913 const unsigned char* syms =
1914 sd->symbols->data() + sd->external_symbols_offset;
1915 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1916 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1917 / sym_size);
1918
1919 const unsigned char* p = syms;
1920
1921 for (size_t i = 0; i < symcount; ++i, p += sym_size)
1922 {
1923 elfcpp::Sym<size, big_endian> sym(p);
1924 unsigned int st_shndx = sym.get_st_shndx();
1925 if (st_shndx == elfcpp::SHN_UNDEF)
1926 continue;
1927
1928 unsigned int st_name = sym.get_st_name();
1929 const char* name = sym_names + st_name;
1930 Symbol* symbol;
1931 Archive::Should_include t = Archive::should_include_member(symtab,
1932 layout,
1933 name,
1934 &symbol, why,
1935 &tmpbuf,
1936 &tmpbuflen);
1937 if (t == Archive::SHOULD_INCLUDE_YES)
1938 {
1939 if (tmpbuf != NULL)
1940 free(tmpbuf);
1941 return t;
1942 }
1943 }
1944 if (tmpbuf != NULL)
1945 free(tmpbuf);
1946 return Archive::SHOULD_INCLUDE_UNKNOWN;
1947 }
1948
1949 // Iterate over global defined symbols, calling a visitor class V for each.
1950
1951 template<int size, bool big_endian>
1952 void
1953 Sized_relobj_file<size, big_endian>::do_for_all_global_symbols(
1954 Read_symbols_data* sd,
1955 Library_base::Symbol_visitor_base* v)
1956 {
1957 const char* sym_names =
1958 reinterpret_cast<const char*>(sd->symbol_names->data());
1959 const unsigned char* syms =
1960 sd->symbols->data() + sd->external_symbols_offset;
1961 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1962 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1963 / sym_size);
1964 const unsigned char* p = syms;
1965
1966 for (size_t i = 0; i < symcount; ++i, p += sym_size)
1967 {
1968 elfcpp::Sym<size, big_endian> sym(p);
1969 if (sym.get_st_shndx() != elfcpp::SHN_UNDEF)
1970 v->visit(sym_names + sym.get_st_name());
1971 }
1972 }
1973
1974 // Return whether the local symbol SYMNDX has a PLT offset.
1975
1976 template<int size, bool big_endian>
1977 bool
1978 Sized_relobj_file<size, big_endian>::local_has_plt_offset(
1979 unsigned int symndx) const
1980 {
1981 typename Local_plt_offsets::const_iterator p =
1982 this->local_plt_offsets_.find(symndx);
1983 return p != this->local_plt_offsets_.end();
1984 }
1985
1986 // Get the PLT offset of a local symbol.
1987
1988 template<int size, bool big_endian>
1989 unsigned int
1990 Sized_relobj_file<size, big_endian>::do_local_plt_offset(
1991 unsigned int symndx) const
1992 {
1993 typename Local_plt_offsets::const_iterator p =
1994 this->local_plt_offsets_.find(symndx);
1995 gold_assert(p != this->local_plt_offsets_.end());
1996 return p->second;
1997 }
1998
1999 // Set the PLT offset of a local symbol.
2000
2001 template<int size, bool big_endian>
2002 void
2003 Sized_relobj_file<size, big_endian>::set_local_plt_offset(
2004 unsigned int symndx, unsigned int plt_offset)
2005 {
2006 std::pair<typename Local_plt_offsets::iterator, bool> ins =
2007 this->local_plt_offsets_.insert(std::make_pair(symndx, plt_offset));
2008 gold_assert(ins.second);
2009 }
2010
2011 // First pass over the local symbols. Here we add their names to
2012 // *POOL and *DYNPOOL, and we store the symbol value in
2013 // THIS->LOCAL_VALUES_. This function is always called from a
2014 // singleton thread. This is followed by a call to
2015 // finalize_local_symbols.
2016
2017 template<int size, bool big_endian>
2018 void
2019 Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
2020 Stringpool* dynpool)
2021 {
2022 gold_assert(this->symtab_shndx_ != -1U);
2023 if (this->symtab_shndx_ == 0)
2024 {
2025 // This object has no symbols. Weird but legal.
2026 return;
2027 }
2028
2029 // Read the symbol table section header.
2030 const unsigned int symtab_shndx = this->symtab_shndx_;
2031 typename This::Shdr symtabshdr(this,
2032 this->elf_file_.section_header(symtab_shndx));
2033 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
2034
2035 // Read the local symbols.
2036 const int sym_size = This::sym_size;
2037 const unsigned int loccount = this->local_symbol_count_;
2038 gold_assert(loccount == symtabshdr.get_sh_info());
2039 off_t locsize = loccount * sym_size;
2040 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
2041 locsize, true, true);
2042
2043 // Read the symbol names.
2044 const unsigned int strtab_shndx =
2045 this->adjust_shndx(symtabshdr.get_sh_link());
2046 section_size_type strtab_size;
2047 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
2048 &strtab_size,
2049 true);
2050 const char* pnames = reinterpret_cast<const char*>(pnamesu);
2051
2052 // Loop over the local symbols.
2053
2054 const Output_sections& out_sections(this->output_sections());
2055 unsigned int shnum = this->shnum();
2056 unsigned int count = 0;
2057 unsigned int dyncount = 0;
2058 // Skip the first, dummy, symbol.
2059 psyms += sym_size;
2060 bool strip_all = parameters->options().strip_all();
2061 bool discard_all = parameters->options().discard_all();
2062 bool discard_locals = parameters->options().discard_locals();
2063 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
2064 {
2065 elfcpp::Sym<size, big_endian> sym(psyms);
2066
2067 Symbol_value<size>& lv(this->local_values_[i]);
2068
2069 bool is_ordinary;
2070 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
2071 &is_ordinary);
2072 lv.set_input_shndx(shndx, is_ordinary);
2073
2074 if (sym.get_st_type() == elfcpp::STT_SECTION)
2075 lv.set_is_section_symbol();
2076 else if (sym.get_st_type() == elfcpp::STT_TLS)
2077 lv.set_is_tls_symbol();
2078 else if (sym.get_st_type() == elfcpp::STT_GNU_IFUNC)
2079 lv.set_is_ifunc_symbol();
2080
2081 // Save the input symbol value for use in do_finalize_local_symbols().
2082 lv.set_input_value(sym.get_st_value());
2083
2084 // Decide whether this symbol should go into the output file.
2085
2086 if ((shndx < shnum && out_sections[shndx] == NULL)
2087 || shndx == this->discarded_eh_frame_shndx_)
2088 {
2089 lv.set_no_output_symtab_entry();
2090 gold_assert(!lv.needs_output_dynsym_entry());
2091 continue;
2092 }
2093
2094 if (sym.get_st_type() == elfcpp::STT_SECTION)
2095 {
2096 lv.set_no_output_symtab_entry();
2097 gold_assert(!lv.needs_output_dynsym_entry());
2098 continue;
2099 }
2100
2101 if (sym.get_st_name() >= strtab_size)
2102 {
2103 this->error(_("local symbol %u section name out of range: %u >= %u"),
2104 i, sym.get_st_name(),
2105 static_cast<unsigned int>(strtab_size));
2106 lv.set_no_output_symtab_entry();
2107 continue;
2108 }
2109
2110 const char* name = pnames + sym.get_st_name();
2111
2112 // If needed, add the symbol to the dynamic symbol table string pool.
2113 if (lv.needs_output_dynsym_entry())
2114 {
2115 dynpool->add(name, true, NULL);
2116 ++dyncount;
2117 }
2118
2119 if (strip_all
2120 || (discard_all && lv.may_be_discarded_from_output_symtab()))
2121 {
2122 lv.set_no_output_symtab_entry();
2123 continue;
2124 }
2125
2126 // If --discard-locals option is used, discard all temporary local
2127 // symbols. These symbols start with system-specific local label
2128 // prefixes, typically .L for ELF system. We want to be compatible
2129 // with GNU ld so here we essentially use the same check in
2130 // bfd_is_local_label(). The code is different because we already
2131 // know that:
2132 //
2133 // - the symbol is local and thus cannot have global or weak binding.
2134 // - the symbol is not a section symbol.
2135 // - the symbol has a name.
2136 //
2137 // We do not discard a symbol if it needs a dynamic symbol entry.
2138 if (discard_locals
2139 && sym.get_st_type() != elfcpp::STT_FILE
2140 && !lv.needs_output_dynsym_entry()
2141 && lv.may_be_discarded_from_output_symtab()
2142 && parameters->target().is_local_label_name(name))
2143 {
2144 lv.set_no_output_symtab_entry();
2145 continue;
2146 }
2147
2148 // Discard the local symbol if -retain_symbols_file is specified
2149 // and the local symbol is not in that file.
2150 if (!parameters->options().should_retain_symbol(name))
2151 {
2152 lv.set_no_output_symtab_entry();
2153 continue;
2154 }
2155
2156 // Add the symbol to the symbol table string pool.
2157 pool->add(name, true, NULL);
2158 ++count;
2159 }
2160
2161 this->output_local_symbol_count_ = count;
2162 this->output_local_dynsym_count_ = dyncount;
2163 }
2164
2165 // Compute the final value of a local symbol.
2166
2167 template<int size, bool big_endian>
2168 typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
2169 Sized_relobj_file<size, big_endian>::compute_final_local_value_internal(
2170 unsigned int r_sym,
2171 const Symbol_value<size>* lv_in,
2172 Symbol_value<size>* lv_out,
2173 bool relocatable,
2174 const Output_sections& out_sections,
2175 const std::vector<Address>& out_offsets,
2176 const Symbol_table* symtab)
2177 {
2178 // We are going to overwrite *LV_OUT, if it has a merged symbol value,
2179 // we may have a memory leak.
2180 gold_assert(lv_out->has_output_value());
2181
2182 bool is_ordinary;
2183 unsigned int shndx = lv_in->input_shndx(&is_ordinary);
2184
2185 // Set the output symbol value.
2186
2187 if (!is_ordinary)
2188 {
2189 if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
2190 lv_out->set_output_value(lv_in->input_value());
2191 else
2192 {
2193 this->error(_("unknown section index %u for local symbol %u"),
2194 shndx, r_sym);
2195 lv_out->set_output_value(0);
2196 return This::CFLV_ERROR;
2197 }
2198 }
2199 else
2200 {
2201 if (shndx >= this->shnum())
2202 {
2203 this->error(_("local symbol %u section index %u out of range"),
2204 r_sym, shndx);
2205 lv_out->set_output_value(0);
2206 return This::CFLV_ERROR;
2207 }
2208
2209 Output_section* os = out_sections[shndx];
2210 Address secoffset = out_offsets[shndx];
2211 if (symtab->is_section_folded(this, shndx))
2212 {
2213 gold_assert(os == NULL && secoffset == invalid_address);
2214 // Get the os of the section it is folded onto.
2215 Section_id folded = symtab->icf()->get_folded_section(this,
2216 shndx);
2217 gold_assert(folded.first != NULL);
2218 Sized_relobj_file<size, big_endian>* folded_obj = reinterpret_cast
2219 <Sized_relobj_file<size, big_endian>*>(folded.first);
2220 os = folded_obj->output_section(folded.second);
2221 gold_assert(os != NULL);
2222 secoffset = folded_obj->get_output_section_offset(folded.second);
2223
2224 // This could be a relaxed input section.
2225 if (secoffset == invalid_address)
2226 {
2227 const Output_relaxed_input_section* relaxed_section =
2228 os->find_relaxed_input_section(folded_obj, folded.second);
2229 gold_assert(relaxed_section != NULL);
2230 secoffset = relaxed_section->address() - os->address();
2231 }
2232 }
2233
2234 if (os == NULL)
2235 {
2236 // This local symbol belongs to a section we are discarding.
2237 // In some cases when applying relocations later, we will
2238 // attempt to match it to the corresponding kept section,
2239 // so we leave the input value unchanged here.
2240 return This::CFLV_DISCARDED;
2241 }
2242 else if (secoffset == invalid_address)
2243 {
2244 uint64_t start;
2245
2246 // This is a SHF_MERGE section or one which otherwise
2247 // requires special handling.
2248 if (shndx == this->discarded_eh_frame_shndx_)
2249 {
2250 // This local symbol belongs to a discarded .eh_frame
2251 // section. Just treat it like the case in which
2252 // os == NULL above.
2253 gold_assert(this->has_eh_frame_);
2254 return This::CFLV_DISCARDED;
2255 }
2256 else if (!lv_in->is_section_symbol())
2257 {
2258 // This is not a section symbol. We can determine
2259 // the final value now.
2260 lv_out->set_output_value(
2261 os->output_address(this, shndx, lv_in->input_value()));
2262 }
2263 else if (!os->find_starting_output_address(this, shndx, &start))
2264 {
2265 // This is a section symbol, but apparently not one in a
2266 // merged section. First check to see if this is a relaxed
2267 // input section. If so, use its address. Otherwise just
2268 // use the start of the output section. This happens with
2269 // relocatable links when the input object has section
2270 // symbols for arbitrary non-merge sections.
2271 const Output_section_data* posd =
2272 os->find_relaxed_input_section(this, shndx);
2273 if (posd != NULL)
2274 {
2275 Address relocatable_link_adjustment =
2276 relocatable ? os->address() : 0;
2277 lv_out->set_output_value(posd->address()
2278 - relocatable_link_adjustment);
2279 }
2280 else
2281 lv_out->set_output_value(os->address());
2282 }
2283 else
2284 {
2285 // We have to consider the addend to determine the
2286 // value to use in a relocation. START is the start
2287 // of this input section. If we are doing a relocatable
2288 // link, use offset from start output section instead of
2289 // address.
2290 Address adjusted_start =
2291 relocatable ? start - os->address() : start;
2292 Merged_symbol_value<size>* msv =
2293 new Merged_symbol_value<size>(lv_in->input_value(),
2294 adjusted_start);
2295 lv_out->set_merged_symbol_value(msv);
2296 }
2297 }
2298 else if (lv_in->is_tls_symbol())
2299 lv_out->set_output_value(os->tls_offset()
2300 + secoffset
2301 + lv_in->input_value());
2302 else
2303 lv_out->set_output_value((relocatable ? 0 : os->address())
2304 + secoffset
2305 + lv_in->input_value());
2306 }
2307 return This::CFLV_OK;
2308 }
2309
2310 // Compute final local symbol value. R_SYM is the index of a local
2311 // symbol in symbol table. LV points to a symbol value, which is
2312 // expected to hold the input value and to be over-written by the
2313 // final value. SYMTAB points to a symbol table. Some targets may want
2314 // to know would-be-finalized local symbol values in relaxation.
2315 // Hence we provide this method. Since this method updates *LV, a
2316 // callee should make a copy of the original local symbol value and
2317 // use the copy instead of modifying an object's local symbols before
2318 // everything is finalized. The caller should also free up any allocated
2319 // memory in the return value in *LV.
2320 template<int size, bool big_endian>
2321 typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
2322 Sized_relobj_file<size, big_endian>::compute_final_local_value(
2323 unsigned int r_sym,
2324 const Symbol_value<size>* lv_in,
2325 Symbol_value<size>* lv_out,
2326 const Symbol_table* symtab)
2327 {
2328 // This is just a wrapper of compute_final_local_value_internal.
2329 const bool relocatable = parameters->options().relocatable();
2330 const Output_sections& out_sections(this->output_sections());
2331 const std::vector<Address>& out_offsets(this->section_offsets());
2332 return this->compute_final_local_value_internal(r_sym, lv_in, lv_out,
2333 relocatable, out_sections,
2334 out_offsets, symtab);
2335 }
2336
2337 // Finalize the local symbols. Here we set the final value in
2338 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
2339 // This function is always called from a singleton thread. The actual
2340 // output of the local symbols will occur in a separate task.
2341
2342 template<int size, bool big_endian>
2343 unsigned int
2344 Sized_relobj_file<size, big_endian>::do_finalize_local_symbols(
2345 unsigned int index,
2346 off_t off,
2347 Symbol_table* symtab)
2348 {
2349 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
2350
2351 const unsigned int loccount = this->local_symbol_count_;
2352 this->local_symbol_offset_ = off;
2353
2354 const bool relocatable = parameters->options().relocatable();
2355 const Output_sections& out_sections(this->output_sections());
2356 const std::vector<Address>& out_offsets(this->section_offsets());
2357
2358 for (unsigned int i = 1; i < loccount; ++i)
2359 {
2360 Symbol_value<size>* lv = &this->local_values_[i];
2361
2362 Compute_final_local_value_status cflv_status =
2363 this->compute_final_local_value_internal(i, lv, lv, relocatable,
2364 out_sections, out_offsets,
2365 symtab);
2366 switch (cflv_status)
2367 {
2368 case CFLV_OK:
2369 if (!lv->is_output_symtab_index_set())
2370 {
2371 lv->set_output_symtab_index(index);
2372 ++index;
2373 }
2374 break;
2375 case CFLV_DISCARDED:
2376 case CFLV_ERROR:
2377 // Do nothing.
2378 break;
2379 default:
2380 gold_unreachable();
2381 }
2382 }
2383 return index;
2384 }
2385
2386 // Set the output dynamic symbol table indexes for the local variables.
2387
2388 template<int size, bool big_endian>
2389 unsigned int
2390 Sized_relobj_file<size, big_endian>::do_set_local_dynsym_indexes(
2391 unsigned int index)
2392 {
2393 const unsigned int loccount = this->local_symbol_count_;
2394 for (unsigned int i = 1; i < loccount; ++i)
2395 {
2396 Symbol_value<size>& lv(this->local_values_[i]);
2397 if (lv.needs_output_dynsym_entry())
2398 {
2399 lv.set_output_dynsym_index(index);
2400 ++index;
2401 }
2402 }
2403 return index;
2404 }
2405
2406 // Set the offset where local dynamic symbol information will be stored.
2407 // Returns the count of local symbols contributed to the symbol table by
2408 // this object.
2409
2410 template<int size, bool big_endian>
2411 unsigned int
2412 Sized_relobj_file<size, big_endian>::do_set_local_dynsym_offset(off_t off)
2413 {
2414 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
2415 this->local_dynsym_offset_ = off;
2416 return this->output_local_dynsym_count_;
2417 }
2418
2419 // If Symbols_data is not NULL get the section flags from here otherwise
2420 // get it from the file.
2421
2422 template<int size, bool big_endian>
2423 uint64_t
2424 Sized_relobj_file<size, big_endian>::do_section_flags(unsigned int shndx)
2425 {
2426 Symbols_data* sd = this->get_symbols_data();
2427 if (sd != NULL)
2428 {
2429 const unsigned char* pshdrs = sd->section_headers_data
2430 + This::shdr_size * shndx;
2431 typename This::Shdr shdr(pshdrs);
2432 return shdr.get_sh_flags();
2433 }
2434 // If sd is NULL, read the section header from the file.
2435 return this->elf_file_.section_flags(shndx);
2436 }
2437
2438 // Get the section's ent size from Symbols_data. Called by get_section_contents
2439 // in icf.cc
2440
2441 template<int size, bool big_endian>
2442 uint64_t
2443 Sized_relobj_file<size, big_endian>::do_section_entsize(unsigned int shndx)
2444 {
2445 Symbols_data* sd = this->get_symbols_data();
2446 gold_assert(sd != NULL);
2447
2448 const unsigned char* pshdrs = sd->section_headers_data
2449 + This::shdr_size * shndx;
2450 typename This::Shdr shdr(pshdrs);
2451 return shdr.get_sh_entsize();
2452 }
2453
2454 // Write out the local symbols.
2455
2456 template<int size, bool big_endian>
2457 void
2458 Sized_relobj_file<size, big_endian>::write_local_symbols(
2459 Output_file* of,
2460 const Stringpool* sympool,
2461 const Stringpool* dynpool,
2462 Output_symtab_xindex* symtab_xindex,
2463 Output_symtab_xindex* dynsym_xindex,
2464 off_t symtab_off)
2465 {
2466 const bool strip_all = parameters->options().strip_all();
2467 if (strip_all)
2468 {
2469 if (this->output_local_dynsym_count_ == 0)
2470 return;
2471 this->output_local_symbol_count_ = 0;
2472 }
2473
2474 gold_assert(this->symtab_shndx_ != -1U);
2475 if (this->symtab_shndx_ == 0)
2476 {
2477 // This object has no symbols. Weird but legal.
2478 return;
2479 }
2480
2481 // Read the symbol table section header.
2482 const unsigned int symtab_shndx = this->symtab_shndx_;
2483 typename This::Shdr symtabshdr(this,
2484 this->elf_file_.section_header(symtab_shndx));
2485 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
2486 const unsigned int loccount = this->local_symbol_count_;
2487 gold_assert(loccount == symtabshdr.get_sh_info());
2488
2489 // Read the local symbols.
2490 const int sym_size = This::sym_size;
2491 off_t locsize = loccount * sym_size;
2492 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
2493 locsize, true, false);
2494
2495 // Read the symbol names.
2496 const unsigned int strtab_shndx =
2497 this->adjust_shndx(symtabshdr.get_sh_link());
2498 section_size_type strtab_size;
2499 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
2500 &strtab_size,
2501 false);
2502 const char* pnames = reinterpret_cast<const char*>(pnamesu);
2503
2504 // Get views into the output file for the portions of the symbol table
2505 // and the dynamic symbol table that we will be writing.
2506 off_t output_size = this->output_local_symbol_count_ * sym_size;
2507 unsigned char* oview = NULL;
2508 if (output_size > 0)
2509 oview = of->get_output_view(symtab_off + this->local_symbol_offset_,
2510 output_size);
2511
2512 off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
2513 unsigned char* dyn_oview = NULL;
2514 if (dyn_output_size > 0)
2515 dyn_oview = of->get_output_view(this->local_dynsym_offset_,
2516 dyn_output_size);
2517
2518 const Output_sections out_sections(this->output_sections());
2519
2520 gold_assert(this->local_values_.size() == loccount);
2521
2522 unsigned char* ov = oview;
2523 unsigned char* dyn_ov = dyn_oview;
2524 psyms += sym_size;
2525 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
2526 {
2527 elfcpp::Sym<size, big_endian> isym(psyms);
2528
2529 Symbol_value<size>& lv(this->local_values_[i]);
2530
2531 bool is_ordinary;
2532 unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
2533 &is_ordinary);
2534 if (is_ordinary)
2535 {
2536 gold_assert(st_shndx < out_sections.size());
2537 if (out_sections[st_shndx] == NULL)
2538 continue;
2539 st_shndx = out_sections[st_shndx]->out_shndx();
2540 if (st_shndx >= elfcpp::SHN_LORESERVE)
2541 {
2542 if (lv.has_output_symtab_entry())
2543 symtab_xindex->add(lv.output_symtab_index(), st_shndx);
2544 if (lv.has_output_dynsym_entry())
2545 dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
2546 st_shndx = elfcpp::SHN_XINDEX;
2547 }
2548 }
2549
2550 // Write the symbol to the output symbol table.
2551 if (lv.has_output_symtab_entry())
2552 {
2553 elfcpp::Sym_write<size, big_endian> osym(ov);
2554
2555 gold_assert(isym.get_st_name() < strtab_size);
2556 const char* name = pnames + isym.get_st_name();
2557 osym.put_st_name(sympool->get_offset(name));
2558 osym.put_st_value(this->local_values_[i].value(this, 0));
2559 osym.put_st_size(isym.get_st_size());
2560 osym.put_st_info(isym.get_st_info());
2561 osym.put_st_other(isym.get_st_other());
2562 osym.put_st_shndx(st_shndx);
2563
2564 ov += sym_size;
2565 }
2566
2567 // Write the symbol to the output dynamic symbol table.
2568 if (lv.has_output_dynsym_entry())
2569 {
2570 gold_assert(dyn_ov < dyn_oview + dyn_output_size);
2571 elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
2572
2573 gold_assert(isym.get_st_name() < strtab_size);
2574 const char* name = pnames + isym.get_st_name();
2575 osym.put_st_name(dynpool->get_offset(name));
2576 osym.put_st_value(this->local_values_[i].value(this, 0));
2577 osym.put_st_size(isym.get_st_size());
2578 osym.put_st_info(isym.get_st_info());
2579 osym.put_st_other(isym.get_st_other());
2580 osym.put_st_shndx(st_shndx);
2581
2582 dyn_ov += sym_size;
2583 }
2584 }
2585
2586
2587 if (output_size > 0)
2588 {
2589 gold_assert(ov - oview == output_size);
2590 of->write_output_view(symtab_off + this->local_symbol_offset_,
2591 output_size, oview);
2592 }
2593
2594 if (dyn_output_size > 0)
2595 {
2596 gold_assert(dyn_ov - dyn_oview == dyn_output_size);
2597 of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
2598 dyn_oview);
2599 }
2600 }
2601
2602 // Set *INFO to symbolic information about the offset OFFSET in the
2603 // section SHNDX. Return true if we found something, false if we
2604 // found nothing.
2605
2606 template<int size, bool big_endian>
2607 bool
2608 Sized_relobj_file<size, big_endian>::get_symbol_location_info(
2609 unsigned int shndx,
2610 off_t offset,
2611 Symbol_location_info* info)
2612 {
2613 if (this->symtab_shndx_ == 0)
2614 return false;
2615
2616 section_size_type symbols_size;
2617 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
2618 &symbols_size,
2619 false);
2620
2621 unsigned int symbol_names_shndx =
2622 this->adjust_shndx(this->section_link(this->symtab_shndx_));
2623 section_size_type names_size;
2624 const unsigned char* symbol_names_u =
2625 this->section_contents(symbol_names_shndx, &names_size, false);
2626 const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
2627
2628 const int sym_size = This::sym_size;
2629 const size_t count = symbols_size / sym_size;
2630
2631 const unsigned char* p = symbols;
2632 for (size_t i = 0; i < count; ++i, p += sym_size)
2633 {
2634 elfcpp::Sym<size, big_endian> sym(p);
2635
2636 if (sym.get_st_type() == elfcpp::STT_FILE)
2637 {
2638 if (sym.get_st_name() >= names_size)
2639 info->source_file = "(invalid)";
2640 else
2641 info->source_file = symbol_names + sym.get_st_name();
2642 continue;
2643 }
2644
2645 bool is_ordinary;
2646 unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
2647 &is_ordinary);
2648 if (is_ordinary
2649 && st_shndx == shndx
2650 && static_cast<off_t>(sym.get_st_value()) <= offset
2651 && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
2652 > offset))
2653 {
2654 if (sym.get_st_name() > names_size)
2655 info->enclosing_symbol_name = "(invalid)";
2656 else
2657 {
2658 info->enclosing_symbol_name = symbol_names + sym.get_st_name();
2659 if (parameters->options().do_demangle())
2660 {
2661 char* demangled_name = cplus_demangle(
2662 info->enclosing_symbol_name.c_str(),
2663 DMGL_ANSI | DMGL_PARAMS);
2664 if (demangled_name != NULL)
2665 {
2666 info->enclosing_symbol_name.assign(demangled_name);
2667 free(demangled_name);
2668 }
2669 }
2670 }
2671 return true;
2672 }
2673 }
2674
2675 return false;
2676 }
2677
2678 // Look for a kept section corresponding to the given discarded section,
2679 // and return its output address. This is used only for relocations in
2680 // debugging sections. If we can't find the kept section, return 0.
2681
2682 template<int size, bool big_endian>
2683 typename Sized_relobj_file<size, big_endian>::Address
2684 Sized_relobj_file<size, big_endian>::map_to_kept_section(
2685 unsigned int shndx,
2686 bool* found) const
2687 {
2688 Relobj* kept_object;
2689 unsigned int kept_shndx;
2690 if (this->get_kept_comdat_section(shndx, &kept_object, &kept_shndx))
2691 {
2692 Sized_relobj_file<size, big_endian>* kept_relobj =
2693 static_cast<Sized_relobj_file<size, big_endian>*>(kept_object);
2694 Output_section* os = kept_relobj->output_section(kept_shndx);
2695 Address offset = kept_relobj->get_output_section_offset(kept_shndx);
2696 if (os != NULL && offset != invalid_address)
2697 {
2698 *found = true;
2699 return os->address() + offset;
2700 }
2701 }
2702 *found = false;
2703 return 0;
2704 }
2705
2706 // Get symbol counts.
2707
2708 template<int size, bool big_endian>
2709 void
2710 Sized_relobj_file<size, big_endian>::do_get_global_symbol_counts(
2711 const Symbol_table*,
2712 size_t* defined,
2713 size_t* used) const
2714 {
2715 *defined = this->defined_count_;
2716 size_t count = 0;
2717 for (typename Symbols::const_iterator p = this->symbols_.begin();
2718 p != this->symbols_.end();
2719 ++p)
2720 if (*p != NULL
2721 && (*p)->source() == Symbol::FROM_OBJECT
2722 && (*p)->object() == this
2723 && (*p)->is_defined())
2724 ++count;
2725 *used = count;
2726 }
2727
2728 // Return a view of the decompressed contents of a section. Set *PLEN
2729 // to the size. Set *IS_NEW to true if the contents need to be freed
2730 // by the caller.
2731
2732 template<int size, bool big_endian>
2733 const unsigned char*
2734 Sized_relobj_file<size, big_endian>::do_decompressed_section_contents(
2735 unsigned int shndx,
2736 section_size_type* plen,
2737 bool* is_new)
2738 {
2739 section_size_type buffer_size;
2740 const unsigned char* buffer = this->do_section_contents(shndx, &buffer_size,
2741 false);
2742
2743 if (this->compressed_sections_ == NULL)
2744 {
2745 *plen = buffer_size;
2746 *is_new = false;
2747 return buffer;
2748 }
2749
2750 Compressed_section_map::const_iterator p =
2751 this->compressed_sections_->find(shndx);
2752 if (p == this->compressed_sections_->end())
2753 {
2754 *plen = buffer_size;
2755 *is_new = false;
2756 return buffer;
2757 }
2758
2759 section_size_type uncompressed_size = p->second.size;
2760 if (p->second.contents != NULL)
2761 {
2762 *plen = uncompressed_size;
2763 *is_new = false;
2764 return p->second.contents;
2765 }
2766
2767 unsigned char* uncompressed_data = new unsigned char[uncompressed_size];
2768 if (!decompress_input_section(buffer,
2769 buffer_size,
2770 uncompressed_data,
2771 uncompressed_size))
2772 this->error(_("could not decompress section %s"),
2773 this->do_section_name(shndx).c_str());
2774
2775 // We could cache the results in p->second.contents and store
2776 // false in *IS_NEW, but build_compressed_section_map() would
2777 // have done so if it had expected it to be profitable. If
2778 // we reach this point, we expect to need the contents only
2779 // once in this pass.
2780 *plen = uncompressed_size;
2781 *is_new = true;
2782 return uncompressed_data;
2783 }
2784
2785 // Discard any buffers of uncompressed sections. This is done
2786 // at the end of the Add_symbols task.
2787
2788 template<int size, bool big_endian>
2789 void
2790 Sized_relobj_file<size, big_endian>::do_discard_decompressed_sections()
2791 {
2792 if (this->compressed_sections_ == NULL)
2793 return;
2794
2795 for (Compressed_section_map::iterator p = this->compressed_sections_->begin();
2796 p != this->compressed_sections_->end();
2797 ++p)
2798 {
2799 if (p->second.contents != NULL)
2800 {
2801 delete[] p->second.contents;
2802 p->second.contents = NULL;
2803 }
2804 }
2805 }
2806
2807 // Input_objects methods.
2808
2809 // Add a regular relocatable object to the list. Return false if this
2810 // object should be ignored.
2811
2812 bool
2813 Input_objects::add_object(Object* obj)
2814 {
2815 // Print the filename if the -t/--trace option is selected.
2816 if (parameters->options().trace())
2817 gold_info("%s", obj->name().c_str());
2818
2819 if (!obj->is_dynamic())
2820 this->relobj_list_.push_back(static_cast<Relobj*>(obj));
2821 else
2822 {
2823 // See if this is a duplicate SONAME.
2824 Dynobj* dynobj = static_cast<Dynobj*>(obj);
2825 const char* soname = dynobj->soname();
2826
2827 std::pair<Unordered_set<std::string>::iterator, bool> ins =
2828 this->sonames_.insert(soname);
2829 if (!ins.second)
2830 {
2831 // We have already seen a dynamic object with this soname.
2832 return false;
2833 }
2834
2835 this->dynobj_list_.push_back(dynobj);
2836 }
2837
2838 // Add this object to the cross-referencer if requested.
2839 if (parameters->options().user_set_print_symbol_counts()
2840 || parameters->options().cref())
2841 {
2842 if (this->cref_ == NULL)
2843 this->cref_ = new Cref();
2844 this->cref_->add_object(obj);
2845 }
2846
2847 return true;
2848 }
2849
2850 // For each dynamic object, record whether we've seen all of its
2851 // explicit dependencies.
2852
2853 void
2854 Input_objects::check_dynamic_dependencies() const
2855 {
2856 bool issued_copy_dt_needed_error = false;
2857 for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
2858 p != this->dynobj_list_.end();
2859 ++p)
2860 {
2861 const Dynobj::Needed& needed((*p)->needed());
2862 bool found_all = true;
2863 Dynobj::Needed::const_iterator pneeded;
2864 for (pneeded = needed.begin(); pneeded != needed.end(); ++pneeded)
2865 {
2866 if (this->sonames_.find(*pneeded) == this->sonames_.end())
2867 {
2868 found_all = false;
2869 break;
2870 }
2871 }
2872 (*p)->set_has_unknown_needed_entries(!found_all);
2873
2874 // --copy-dt-needed-entries aka --add-needed is a GNU ld option
2875 // that gold does not support. However, they cause no trouble
2876 // unless there is a DT_NEEDED entry that we don't know about;
2877 // warn only in that case.
2878 if (!found_all
2879 && !issued_copy_dt_needed_error
2880 && (parameters->options().copy_dt_needed_entries()
2881 || parameters->options().add_needed()))
2882 {
2883 const char* optname;
2884 if (parameters->options().copy_dt_needed_entries())
2885 optname = "--copy-dt-needed-entries";
2886 else
2887 optname = "--add-needed";
2888 gold_error(_("%s is not supported but is required for %s in %s"),
2889 optname, (*pneeded).c_str(), (*p)->name().c_str());
2890 issued_copy_dt_needed_error = true;
2891 }
2892 }
2893 }
2894
2895 // Start processing an archive.
2896
2897 void
2898 Input_objects::archive_start(Archive* archive)
2899 {
2900 if (parameters->options().user_set_print_symbol_counts()
2901 || parameters->options().cref())
2902 {
2903 if (this->cref_ == NULL)
2904 this->cref_ = new Cref();
2905 this->cref_->add_archive_start(archive);
2906 }
2907 }
2908
2909 // Stop processing an archive.
2910
2911 void
2912 Input_objects::archive_stop(Archive* archive)
2913 {
2914 if (parameters->options().user_set_print_symbol_counts()
2915 || parameters->options().cref())
2916 this->cref_->add_archive_stop(archive);
2917 }
2918
2919 // Print symbol counts
2920
2921 void
2922 Input_objects::print_symbol_counts(const Symbol_table* symtab) const
2923 {
2924 if (parameters->options().user_set_print_symbol_counts()
2925 && this->cref_ != NULL)
2926 this->cref_->print_symbol_counts(symtab);
2927 }
2928
2929 // Print a cross reference table.
2930
2931 void
2932 Input_objects::print_cref(const Symbol_table* symtab, FILE* f) const
2933 {
2934 if (parameters->options().cref() && this->cref_ != NULL)
2935 this->cref_->print_cref(symtab, f);
2936 }
2937
2938 // Relocate_info methods.
2939
2940 // Return a string describing the location of a relocation when file
2941 // and lineno information is not available. This is only used in
2942 // error messages.
2943
2944 template<int size, bool big_endian>
2945 std::string
2946 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
2947 {
2948 Sized_dwarf_line_info<size, big_endian> line_info(this->object);
2949 std::string ret = line_info.addr2line(this->data_shndx, offset, NULL);
2950 if (!ret.empty())
2951 return ret;
2952
2953 ret = this->object->name();
2954
2955 Symbol_location_info info;
2956 if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
2957 {
2958 if (!info.source_file.empty())
2959 {
2960 ret += ":";
2961 ret += info.source_file;
2962 }
2963 size_t len = info.enclosing_symbol_name.length() + 100;
2964 char* buf = new char[len];
2965 snprintf(buf, len, _(":function %s"),
2966 info.enclosing_symbol_name.c_str());
2967 ret += buf;
2968 delete[] buf;
2969 return ret;
2970 }
2971
2972 ret += "(";
2973 ret += this->object->section_name(this->data_shndx);
2974 char buf[100];
2975 snprintf(buf, sizeof buf, "+0x%lx)", static_cast<long>(offset));
2976 ret += buf;
2977 return ret;
2978 }
2979
2980 } // End namespace gold.
2981
2982 namespace
2983 {
2984
2985 using namespace gold;
2986
2987 // Read an ELF file with the header and return the appropriate
2988 // instance of Object.
2989
2990 template<int size, bool big_endian>
2991 Object*
2992 make_elf_sized_object(const std::string& name, Input_file* input_file,
2993 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr,
2994 bool* punconfigured)
2995 {
2996 Target* target = select_target(input_file, offset,
2997 ehdr.get_e_machine(), size, big_endian,
2998 ehdr.get_e_ident()[elfcpp::EI_OSABI],
2999 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
3000 if (target == NULL)
3001 gold_fatal(_("%s: unsupported ELF machine number %d"),
3002 name.c_str(), ehdr.get_e_machine());
3003
3004 if (!parameters->target_valid())
3005 set_parameters_target(target);
3006 else if (target != &parameters->target())
3007 {
3008 if (punconfigured != NULL)
3009 *punconfigured = true;
3010 else
3011 gold_error(_("%s: incompatible target"), name.c_str());
3012 return NULL;
3013 }
3014
3015 return target->make_elf_object<size, big_endian>(name, input_file, offset,
3016 ehdr);
3017 }
3018
3019 } // End anonymous namespace.
3020
3021 namespace gold
3022 {
3023
3024 // Return whether INPUT_FILE is an ELF object.
3025
3026 bool
3027 is_elf_object(Input_file* input_file, off_t offset,
3028 const unsigned char** start, int* read_size)
3029 {
3030 off_t filesize = input_file->file().filesize();
3031 int want = elfcpp::Elf_recognizer::max_header_size;
3032 if (filesize - offset < want)
3033 want = filesize - offset;
3034
3035 const unsigned char* p = input_file->file().get_view(offset, 0, want,
3036 true, false);
3037 *start = p;
3038 *read_size = want;
3039
3040 return elfcpp::Elf_recognizer::is_elf_file(p, want);
3041 }
3042
3043 // Read an ELF file and return the appropriate instance of Object.
3044
3045 Object*
3046 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
3047 const unsigned char* p, section_offset_type bytes,
3048 bool* punconfigured)
3049 {
3050 if (punconfigured != NULL)
3051 *punconfigured = false;
3052
3053 std::string error;
3054 bool big_endian = false;
3055 int size = 0;
3056 if (!elfcpp::Elf_recognizer::is_valid_header(p, bytes, &size,
3057 &big_endian, &error))
3058 {
3059 gold_error(_("%s: %s"), name.c_str(), error.c_str());
3060 return NULL;
3061 }
3062
3063 if (size == 32)
3064 {
3065 if (big_endian)
3066 {
3067 #ifdef HAVE_TARGET_32_BIG
3068 elfcpp::Ehdr<32, true> ehdr(p);
3069 return make_elf_sized_object<32, true>(name, input_file,
3070 offset, ehdr, punconfigured);
3071 #else
3072 if (punconfigured != NULL)
3073 *punconfigured = true;
3074 else
3075 gold_error(_("%s: not configured to support "
3076 "32-bit big-endian object"),
3077 name.c_str());
3078 return NULL;
3079 #endif
3080 }
3081 else
3082 {
3083 #ifdef HAVE_TARGET_32_LITTLE
3084 elfcpp::Ehdr<32, false> ehdr(p);
3085 return make_elf_sized_object<32, false>(name, input_file,
3086 offset, ehdr, punconfigured);
3087 #else
3088 if (punconfigured != NULL)
3089 *punconfigured = true;
3090 else
3091 gold_error(_("%s: not configured to support "
3092 "32-bit little-endian object"),
3093 name.c_str());
3094 return NULL;
3095 #endif
3096 }
3097 }
3098 else if (size == 64)
3099 {
3100 if (big_endian)
3101 {
3102 #ifdef HAVE_TARGET_64_BIG
3103 elfcpp::Ehdr<64, true> ehdr(p);
3104 return make_elf_sized_object<64, true>(name, input_file,
3105 offset, ehdr, punconfigured);
3106 #else
3107 if (punconfigured != NULL)
3108 *punconfigured = true;
3109 else
3110 gold_error(_("%s: not configured to support "
3111 "64-bit big-endian object"),
3112 name.c_str());
3113 return NULL;
3114 #endif
3115 }
3116 else
3117 {
3118 #ifdef HAVE_TARGET_64_LITTLE
3119 elfcpp::Ehdr<64, false> ehdr(p);
3120 return make_elf_sized_object<64, false>(name, input_file,
3121 offset, ehdr, punconfigured);
3122 #else
3123 if (punconfigured != NULL)
3124 *punconfigured = true;
3125 else
3126 gold_error(_("%s: not configured to support "
3127 "64-bit little-endian object"),
3128 name.c_str());
3129 return NULL;
3130 #endif
3131 }
3132 }
3133 else
3134 gold_unreachable();
3135 }
3136
3137 // Instantiate the templates we need.
3138
3139 #ifdef HAVE_TARGET_32_LITTLE
3140 template
3141 void
3142 Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
3143 Read_symbols_data*);
3144 #endif
3145
3146 #ifdef HAVE_TARGET_32_BIG
3147 template
3148 void
3149 Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
3150 Read_symbols_data*);
3151 #endif
3152
3153 #ifdef HAVE_TARGET_64_LITTLE
3154 template
3155 void
3156 Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
3157 Read_symbols_data*);
3158 #endif
3159
3160 #ifdef HAVE_TARGET_64_BIG
3161 template
3162 void
3163 Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
3164 Read_symbols_data*);
3165 #endif
3166
3167 #ifdef HAVE_TARGET_32_LITTLE
3168 template
3169 class Sized_relobj_file<32, false>;
3170 #endif
3171
3172 #ifdef HAVE_TARGET_32_BIG
3173 template
3174 class Sized_relobj_file<32, true>;
3175 #endif
3176
3177 #ifdef HAVE_TARGET_64_LITTLE
3178 template
3179 class Sized_relobj_file<64, false>;
3180 #endif
3181
3182 #ifdef HAVE_TARGET_64_BIG
3183 template
3184 class Sized_relobj_file<64, true>;
3185 #endif
3186
3187 #ifdef HAVE_TARGET_32_LITTLE
3188 template
3189 struct Relocate_info<32, false>;
3190 #endif
3191
3192 #ifdef HAVE_TARGET_32_BIG
3193 template
3194 struct Relocate_info<32, true>;
3195 #endif
3196
3197 #ifdef HAVE_TARGET_64_LITTLE
3198 template
3199 struct Relocate_info<64, false>;
3200 #endif
3201
3202 #ifdef HAVE_TARGET_64_BIG
3203 template
3204 struct Relocate_info<64, true>;
3205 #endif
3206
3207 #ifdef HAVE_TARGET_32_LITTLE
3208 template
3209 void
3210 Xindex::initialize_symtab_xindex<32, false>(Object*, unsigned int);
3211
3212 template
3213 void
3214 Xindex::read_symtab_xindex<32, false>(Object*, unsigned int,
3215 const unsigned char*);
3216 #endif
3217
3218 #ifdef HAVE_TARGET_32_BIG
3219 template
3220 void
3221 Xindex::initialize_symtab_xindex<32, true>(Object*, unsigned int);
3222
3223 template
3224 void
3225 Xindex::read_symtab_xindex<32, true>(Object*, unsigned int,
3226 const unsigned char*);
3227 #endif
3228
3229 #ifdef HAVE_TARGET_64_LITTLE
3230 template
3231 void
3232 Xindex::initialize_symtab_xindex<64, false>(Object*, unsigned int);
3233
3234 template
3235 void
3236 Xindex::read_symtab_xindex<64, false>(Object*, unsigned int,
3237 const unsigned char*);
3238 #endif
3239
3240 #ifdef HAVE_TARGET_64_BIG
3241 template
3242 void
3243 Xindex::initialize_symtab_xindex<64, true>(Object*, unsigned int);
3244
3245 template
3246 void
3247 Xindex::read_symtab_xindex<64, true>(Object*, unsigned int,
3248 const unsigned char*);
3249 #endif
3250
3251 } // End namespace gold.
This page took 0.101896 seconds and 5 git commands to generate.