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