gdb/doc
[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 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #include "gold.h"
24
25 #include <cerrno>
26 #include <cstring>
27 #include <cstdarg>
28 #include "demangle.h"
29 #include "libiberty.h"
30
31 #include "gc.h"
32 #include "target-select.h"
33 #include "dwarf_reader.h"
34 #include "layout.h"
35 #include "output.h"
36 #include "symtab.h"
37 #include "cref.h"
38 #include "reloc.h"
39 #include "object.h"
40 #include "dynobj.h"
41 #include "plugin.h"
42
43 namespace gold
44 {
45
46 // Class Xindex.
47
48 // Initialize the symtab_xindex_ array. Find the SHT_SYMTAB_SHNDX
49 // section and read it in. SYMTAB_SHNDX is the index of the symbol
50 // table we care about.
51
52 template<int size, bool big_endian>
53 void
54 Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx)
55 {
56 if (!this->symtab_xindex_.empty())
57 return;
58
59 gold_assert(symtab_shndx != 0);
60
61 // Look through the sections in reverse order, on the theory that it
62 // is more likely to be near the end than the beginning.
63 unsigned int i = object->shnum();
64 while (i > 0)
65 {
66 --i;
67 if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX
68 && this->adjust_shndx(object->section_link(i)) == symtab_shndx)
69 {
70 this->read_symtab_xindex<size, big_endian>(object, i, NULL);
71 return;
72 }
73 }
74
75 object->error(_("missing SHT_SYMTAB_SHNDX section"));
76 }
77
78 // Read in the symtab_xindex_ array, given the section index of the
79 // SHT_SYMTAB_SHNDX section. If PSHDRS is not NULL, it points at the
80 // section headers.
81
82 template<int size, bool big_endian>
83 void
84 Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx,
85 const unsigned char* pshdrs)
86 {
87 section_size_type bytecount;
88 const unsigned char* contents;
89 if (pshdrs == NULL)
90 contents = object->section_contents(xindex_shndx, &bytecount, false);
91 else
92 {
93 const unsigned char* p = (pshdrs
94 + (xindex_shndx
95 * elfcpp::Elf_sizes<size>::shdr_size));
96 typename elfcpp::Shdr<size, big_endian> shdr(p);
97 bytecount = convert_to_section_size_type(shdr.get_sh_size());
98 contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false);
99 }
100
101 gold_assert(this->symtab_xindex_.empty());
102 this->symtab_xindex_.reserve(bytecount / 4);
103 for (section_size_type i = 0; i < bytecount; i += 4)
104 {
105 unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i);
106 // We preadjust the section indexes we save.
107 this->symtab_xindex_.push_back(this->adjust_shndx(shndx));
108 }
109 }
110
111 // Symbol symndx has a section of SHN_XINDEX; return the real section
112 // index.
113
114 unsigned int
115 Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx)
116 {
117 if (symndx >= this->symtab_xindex_.size())
118 {
119 object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"),
120 symndx);
121 return elfcpp::SHN_UNDEF;
122 }
123 unsigned int shndx = this->symtab_xindex_[symndx];
124 if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum())
125 {
126 object->error(_("extended index for symbol %u out of range: %u"),
127 symndx, shndx);
128 return elfcpp::SHN_UNDEF;
129 }
130 return shndx;
131 }
132
133 // Class Object.
134
135 // Set the target based on fields in the ELF file header.
136
137 void
138 Object::set_target(int machine, int size, bool big_endian, int osabi,
139 int abiversion)
140 {
141 Target* target = select_target(machine, size, big_endian, osabi, abiversion);
142 if (target == NULL)
143 gold_fatal(_("%s: unsupported ELF machine number %d"),
144 this->name().c_str(), machine);
145 this->target_ = target;
146 }
147
148 // Report an error for this object file. This is used by the
149 // elfcpp::Elf_file interface, and also called by the Object code
150 // itself.
151
152 void
153 Object::error(const char* format, ...) const
154 {
155 va_list args;
156 va_start(args, format);
157 char* buf = NULL;
158 if (vasprintf(&buf, format, args) < 0)
159 gold_nomem();
160 va_end(args);
161 gold_error(_("%s: %s"), this->name().c_str(), buf);
162 free(buf);
163 }
164
165 // Return a view of the contents of a section.
166
167 const unsigned char*
168 Object::section_contents(unsigned int shndx, section_size_type* plen,
169 bool cache)
170 {
171 Location loc(this->do_section_contents(shndx));
172 *plen = convert_to_section_size_type(loc.data_size);
173 if (*plen == 0)
174 {
175 static const unsigned char empty[1] = { '\0' };
176 return empty;
177 }
178 return this->get_view(loc.file_offset, *plen, true, cache);
179 }
180
181 // Read the section data into SD. This is code common to Sized_relobj
182 // and Sized_dynobj, so we put it into Object.
183
184 template<int size, bool big_endian>
185 void
186 Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
187 Read_symbols_data* sd)
188 {
189 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
190
191 // Read the section headers.
192 const off_t shoff = elf_file->shoff();
193 const unsigned int shnum = this->shnum();
194 sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size,
195 true, true);
196
197 // Read the section names.
198 const unsigned char* pshdrs = sd->section_headers->data();
199 const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
200 typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
201
202 if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
203 this->error(_("section name section has wrong type: %u"),
204 static_cast<unsigned int>(shdrnames.get_sh_type()));
205
206 sd->section_names_size =
207 convert_to_section_size_type(shdrnames.get_sh_size());
208 sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
209 sd->section_names_size, false,
210 false);
211 }
212
213 // If NAME is the name of a special .gnu.warning section, arrange for
214 // the warning to be issued. SHNDX is the section index. Return
215 // whether it is a warning section.
216
217 bool
218 Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
219 Symbol_table* symtab)
220 {
221 const char warn_prefix[] = ".gnu.warning.";
222 const int warn_prefix_len = sizeof warn_prefix - 1;
223 if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
224 {
225 // Read the section contents to get the warning text. It would
226 // be nicer if we only did this if we have to actually issue a
227 // warning. Unfortunately, warnings are issued as we relocate
228 // sections. That means that we can not lock the object then,
229 // as we might try to issue the same warning multiple times
230 // simultaneously.
231 section_size_type len;
232 const unsigned char* contents = this->section_contents(shndx, &len,
233 false);
234 if (len == 0)
235 {
236 const char* warning = name + warn_prefix_len;
237 contents = reinterpret_cast<const unsigned char*>(warning);
238 len = strlen(warning);
239 }
240 std::string warning(reinterpret_cast<const char*>(contents), len);
241 symtab->add_warning(name + warn_prefix_len, this, warning);
242 return true;
243 }
244 return false;
245 }
246
247 // Class Relobj
248
249 // To copy the symbols data read from the file to a local data structure.
250 // This function is called from do_layout only while doing garbage
251 // collection.
252
253 void
254 Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
255 unsigned int section_header_size)
256 {
257 gc_sd->section_headers_data =
258 new unsigned char[(section_header_size)];
259 memcpy(gc_sd->section_headers_data, sd->section_headers->data(),
260 section_header_size);
261 gc_sd->section_names_data =
262 new unsigned char[sd->section_names_size];
263 memcpy(gc_sd->section_names_data, sd->section_names->data(),
264 sd->section_names_size);
265 gc_sd->section_names_size = sd->section_names_size;
266 if (sd->symbols != NULL)
267 {
268 gc_sd->symbols_data =
269 new unsigned char[sd->symbols_size];
270 memcpy(gc_sd->symbols_data, sd->symbols->data(),
271 sd->symbols_size);
272 }
273 else
274 {
275 gc_sd->symbols_data = NULL;
276 }
277 gc_sd->symbols_size = sd->symbols_size;
278 gc_sd->external_symbols_offset = sd->external_symbols_offset;
279 if (sd->symbol_names != NULL)
280 {
281 gc_sd->symbol_names_data =
282 new unsigned char[sd->symbol_names_size];
283 memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(),
284 sd->symbol_names_size);
285 }
286 else
287 {
288 gc_sd->symbol_names_data = NULL;
289 }
290 gc_sd->symbol_names_size = sd->symbol_names_size;
291 }
292
293 // This function determines if a particular section name must be included
294 // in the link. This is used during garbage collection to determine the
295 // roots of the worklist.
296
297 bool
298 Relobj::is_section_name_included(const char* name)
299 {
300 if (is_prefix_of(".ctors", name)
301 || is_prefix_of(".dtors", name)
302 || is_prefix_of(".note", name)
303 || is_prefix_of(".init", name)
304 || is_prefix_of(".fini", name)
305 || is_prefix_of(".gcc_except_table", name)
306 || is_prefix_of(".jcr", name)
307 || is_prefix_of(".preinit_array", name)
308 || (is_prefix_of(".text", name)
309 && strstr(name, "personality"))
310 || (is_prefix_of(".data", name)
311 && strstr(name, "personality"))
312 || (is_prefix_of(".gnu.linkonce.d", name) &&
313 strstr(name, "personality")))
314 {
315 return true;
316 }
317 return false;
318 }
319
320 // Class Sized_relobj.
321
322 template<int size, bool big_endian>
323 Sized_relobj<size, big_endian>::Sized_relobj(
324 const std::string& name,
325 Input_file* input_file,
326 off_t offset,
327 const elfcpp::Ehdr<size, big_endian>& ehdr)
328 : Relobj(name, input_file, offset),
329 elf_file_(this, ehdr),
330 symtab_shndx_(-1U),
331 local_symbol_count_(0),
332 output_local_symbol_count_(0),
333 output_local_dynsym_count_(0),
334 symbols_(),
335 defined_count_(0),
336 local_symbol_offset_(0),
337 local_dynsym_offset_(0),
338 local_values_(),
339 local_got_offsets_(),
340 kept_comdat_sections_(),
341 has_eh_frame_(false),
342 discarded_eh_frame_shndx_(-1U)
343 {
344 }
345
346 template<int size, bool big_endian>
347 Sized_relobj<size, big_endian>::~Sized_relobj()
348 {
349 }
350
351 // Set up an object file based on the file header. This sets up the
352 // target and reads the section information.
353
354 template<int size, bool big_endian>
355 void
356 Sized_relobj<size, big_endian>::setup(
357 const elfcpp::Ehdr<size, big_endian>& ehdr)
358 {
359 this->set_target(ehdr.get_e_machine(), size, big_endian,
360 ehdr.get_e_ident()[elfcpp::EI_OSABI],
361 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
362
363 const unsigned int shnum = this->elf_file_.shnum();
364 this->set_shnum(shnum);
365 }
366
367 // Find the SHT_SYMTAB section, given the section headers. The ELF
368 // standard says that maybe in the future there can be more than one
369 // SHT_SYMTAB section. Until somebody figures out how that could
370 // work, we assume there is only one.
371
372 template<int size, bool big_endian>
373 void
374 Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
375 {
376 const unsigned int shnum = this->shnum();
377 this->symtab_shndx_ = 0;
378 if (shnum > 0)
379 {
380 // Look through the sections in reverse order, since gas tends
381 // to put the symbol table at the end.
382 const unsigned char* p = pshdrs + shnum * This::shdr_size;
383 unsigned int i = shnum;
384 unsigned int xindex_shndx = 0;
385 unsigned int xindex_link = 0;
386 while (i > 0)
387 {
388 --i;
389 p -= This::shdr_size;
390 typename This::Shdr shdr(p);
391 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
392 {
393 this->symtab_shndx_ = i;
394 if (xindex_shndx > 0 && xindex_link == i)
395 {
396 Xindex* xindex =
397 new Xindex(this->elf_file_.large_shndx_offset());
398 xindex->read_symtab_xindex<size, big_endian>(this,
399 xindex_shndx,
400 pshdrs);
401 this->set_xindex(xindex);
402 }
403 break;
404 }
405
406 // Try to pick up the SHT_SYMTAB_SHNDX section, if there is
407 // one. This will work if it follows the SHT_SYMTAB
408 // section.
409 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX)
410 {
411 xindex_shndx = i;
412 xindex_link = this->adjust_shndx(shdr.get_sh_link());
413 }
414 }
415 }
416 }
417
418 // Return the Xindex structure to use for object with lots of
419 // sections.
420
421 template<int size, bool big_endian>
422 Xindex*
423 Sized_relobj<size, big_endian>::do_initialize_xindex()
424 {
425 gold_assert(this->symtab_shndx_ != -1U);
426 Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
427 xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_);
428 return xindex;
429 }
430
431 // Return whether SHDR has the right type and flags to be a GNU
432 // .eh_frame section.
433
434 template<int size, bool big_endian>
435 bool
436 Sized_relobj<size, big_endian>::check_eh_frame_flags(
437 const elfcpp::Shdr<size, big_endian>* shdr) const
438 {
439 return (shdr->get_sh_type() == elfcpp::SHT_PROGBITS
440 && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
441 }
442
443 // Return whether there is a GNU .eh_frame section, given the section
444 // headers and the section names.
445
446 template<int size, bool big_endian>
447 bool
448 Sized_relobj<size, big_endian>::find_eh_frame(
449 const unsigned char* pshdrs,
450 const char* names,
451 section_size_type names_size) const
452 {
453 const unsigned int shnum = this->shnum();
454 const unsigned char* p = pshdrs + This::shdr_size;
455 for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
456 {
457 typename This::Shdr shdr(p);
458 if (this->check_eh_frame_flags(&shdr))
459 {
460 if (shdr.get_sh_name() >= names_size)
461 {
462 this->error(_("bad section name offset for section %u: %lu"),
463 i, static_cast<unsigned long>(shdr.get_sh_name()));
464 continue;
465 }
466
467 const char* name = names + shdr.get_sh_name();
468 if (strcmp(name, ".eh_frame") == 0)
469 return true;
470 }
471 }
472 return false;
473 }
474
475 // Read the sections and symbols from an object file.
476
477 template<int size, bool big_endian>
478 void
479 Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
480 {
481 this->read_section_data(&this->elf_file_, sd);
482
483 const unsigned char* const pshdrs = sd->section_headers->data();
484
485 this->find_symtab(pshdrs);
486
487 const unsigned char* namesu = sd->section_names->data();
488 const char* names = reinterpret_cast<const char*>(namesu);
489 if (memmem(names, sd->section_names_size, ".eh_frame", 10) != NULL)
490 {
491 if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
492 this->has_eh_frame_ = true;
493 }
494
495 sd->symbols = NULL;
496 sd->symbols_size = 0;
497 sd->external_symbols_offset = 0;
498 sd->symbol_names = NULL;
499 sd->symbol_names_size = 0;
500
501 if (this->symtab_shndx_ == 0)
502 {
503 // No symbol table. Weird but legal.
504 return;
505 }
506
507 // Get the symbol table section header.
508 typename This::Shdr symtabshdr(pshdrs
509 + this->symtab_shndx_ * This::shdr_size);
510 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
511
512 // If this object has a .eh_frame section, we need all the symbols.
513 // Otherwise we only need the external symbols. While it would be
514 // simpler to just always read all the symbols, I've seen object
515 // files with well over 2000 local symbols, which for a 64-bit
516 // object file format is over 5 pages that we don't need to read
517 // now.
518
519 const int sym_size = This::sym_size;
520 const unsigned int loccount = symtabshdr.get_sh_info();
521 this->local_symbol_count_ = loccount;
522 this->local_values_.resize(loccount);
523 section_offset_type locsize = loccount * sym_size;
524 off_t dataoff = symtabshdr.get_sh_offset();
525 section_size_type datasize =
526 convert_to_section_size_type(symtabshdr.get_sh_size());
527 off_t extoff = dataoff + locsize;
528 section_size_type extsize = datasize - locsize;
529
530 off_t readoff = this->has_eh_frame_ ? dataoff : extoff;
531 section_size_type readsize = this->has_eh_frame_ ? datasize : extsize;
532
533 if (readsize == 0)
534 {
535 // No external symbols. Also weird but also legal.
536 return;
537 }
538
539 File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false);
540
541 // Read the section header for the symbol names.
542 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
543 if (strtab_shndx >= this->shnum())
544 {
545 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
546 return;
547 }
548 typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
549 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
550 {
551 this->error(_("symbol table name section has wrong type: %u"),
552 static_cast<unsigned int>(strtabshdr.get_sh_type()));
553 return;
554 }
555
556 // Read the symbol names.
557 File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
558 strtabshdr.get_sh_size(),
559 false, true);
560
561 sd->symbols = fvsymtab;
562 sd->symbols_size = readsize;
563 sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0;
564 sd->symbol_names = fvstrtab;
565 sd->symbol_names_size =
566 convert_to_section_size_type(strtabshdr.get_sh_size());
567 }
568
569 // Return the section index of symbol SYM. Set *VALUE to its value in
570 // the object file. Set *IS_ORDINARY if this is an ordinary section
571 // index. not a special cod between SHN_LORESERVE and SHN_HIRESERVE.
572 // Note that for a symbol which is not defined in this object file,
573 // this will set *VALUE to 0 and return SHN_UNDEF; it will not return
574 // the final value of the symbol in the link.
575
576 template<int size, bool big_endian>
577 unsigned int
578 Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym,
579 Address* value,
580 bool* is_ordinary)
581 {
582 section_size_type symbols_size;
583 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
584 &symbols_size,
585 false);
586
587 const size_t count = symbols_size / This::sym_size;
588 gold_assert(sym < count);
589
590 elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
591 *value = elfsym.get_st_value();
592
593 return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary);
594 }
595
596 // Return whether to include a section group in the link. LAYOUT is
597 // used to keep track of which section groups we have already seen.
598 // INDEX is the index of the section group and SHDR is the section
599 // header. If we do not want to include this group, we set bits in
600 // OMIT for each section which should be discarded.
601
602 template<int size, bool big_endian>
603 bool
604 Sized_relobj<size, big_endian>::include_section_group(
605 Symbol_table* symtab,
606 Layout* layout,
607 unsigned int index,
608 const char* name,
609 const unsigned char* shdrs,
610 const char* section_names,
611 section_size_type section_names_size,
612 std::vector<bool>* omit)
613 {
614 // Read the section contents.
615 typename This::Shdr shdr(shdrs + index * This::shdr_size);
616 const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
617 shdr.get_sh_size(), true, false);
618 const elfcpp::Elf_Word* pword =
619 reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
620
621 // The first word contains flags. We only care about COMDAT section
622 // groups. Other section groups are always included in the link
623 // just like ordinary sections.
624 elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
625
626 // Look up the group signature, which is the name of a symbol. This
627 // is a lot of effort to go to to read a string. Why didn't they
628 // just have the group signature point into the string table, rather
629 // than indirect through a symbol?
630
631 // Get the appropriate symbol table header (this will normally be
632 // the single SHT_SYMTAB section, but in principle it need not be).
633 const unsigned int link = this->adjust_shndx(shdr.get_sh_link());
634 typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
635
636 // Read the symbol table entry.
637 unsigned int symndx = shdr.get_sh_info();
638 if (symndx >= symshdr.get_sh_size() / This::sym_size)
639 {
640 this->error(_("section group %u info %u out of range"),
641 index, symndx);
642 return false;
643 }
644 off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size;
645 const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
646 false);
647 elfcpp::Sym<size, big_endian> sym(psym);
648
649 // Read the symbol table names.
650 section_size_type symnamelen;
651 const unsigned char* psymnamesu;
652 psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()),
653 &symnamelen, true);
654 const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
655
656 // Get the section group signature.
657 if (sym.get_st_name() >= symnamelen)
658 {
659 this->error(_("symbol %u name offset %u out of range"),
660 symndx, sym.get_st_name());
661 return false;
662 }
663
664 std::string signature(psymnames + sym.get_st_name());
665
666 // It seems that some versions of gas will create a section group
667 // associated with a section symbol, and then fail to give a name to
668 // the section symbol. In such a case, use the name of the section.
669 if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
670 {
671 bool is_ordinary;
672 unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
673 sym.get_st_shndx(),
674 &is_ordinary);
675 if (!is_ordinary || sym_shndx >= this->shnum())
676 {
677 this->error(_("symbol %u invalid section index %u"),
678 symndx, sym_shndx);
679 return false;
680 }
681 typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size);
682 if (member_shdr.get_sh_name() < section_names_size)
683 signature = section_names + member_shdr.get_sh_name();
684 }
685
686 // Record this section group in the layout, and see whether we've already
687 // seen one with the same signature.
688 bool include_group;
689 Sized_relobj<size, big_endian>* kept_object = NULL;
690 Kept_section::Comdat_group* kept_group = NULL;
691
692 if ((flags & elfcpp::GRP_COMDAT) == 0)
693 include_group = true;
694 else
695 {
696 Kept_section this_group(this, index, true);
697 Kept_section *kept_section_group;
698 include_group = layout->find_or_add_kept_section(signature,
699 &this_group,
700 &kept_section_group);
701 if (include_group)
702 kept_section_group->group_sections = new Kept_section::Comdat_group;
703
704 kept_group = kept_section_group->group_sections;
705 kept_object = (static_cast<Sized_relobj<size, big_endian>*>
706 (kept_section_group->object));
707 }
708
709 size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
710
711 std::vector<unsigned int> shndxes;
712 bool relocate_group = include_group && parameters->options().relocatable();
713 if (relocate_group)
714 shndxes.reserve(count - 1);
715
716 for (size_t i = 1; i < count; ++i)
717 {
718 elfcpp::Elf_Word secnum =
719 this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
720
721 if (relocate_group)
722 shndxes.push_back(secnum);
723
724 if (secnum >= this->shnum())
725 {
726 this->error(_("section %u in section group %u out of range"),
727 secnum, index);
728 continue;
729 }
730
731 // Check for an earlier section number, since we're going to get
732 // it wrong--we may have already decided to include the section.
733 if (secnum < index)
734 this->error(_("invalid section group %u refers to earlier section %u"),
735 index, secnum);
736
737 // Get the name of the member section.
738 typename This::Shdr member_shdr(shdrs + secnum * This::shdr_size);
739 if (member_shdr.get_sh_name() >= section_names_size)
740 {
741 // This is an error, but it will be diagnosed eventually
742 // in do_layout, so we don't need to do anything here but
743 // ignore it.
744 continue;
745 }
746 std::string mname(section_names + member_shdr.get_sh_name());
747
748 if (!include_group)
749 {
750 (*omit)[secnum] = true;
751 if (kept_group != NULL)
752 {
753 // Find the corresponding kept section, and store that info
754 // in the discarded section table.
755 Kept_section::Comdat_group::const_iterator p =
756 kept_group->find(mname);
757 if (p != kept_group->end())
758 {
759 Kept_comdat_section* kept =
760 new Kept_comdat_section(kept_object, p->second);
761 this->set_kept_comdat_section(secnum, kept);
762 }
763 }
764 }
765 else if (flags & elfcpp::GRP_COMDAT)
766 {
767 // Add the section to the kept group table.
768 gold_assert(kept_group != NULL);
769 kept_group->insert(std::make_pair(mname, secnum));
770 }
771 }
772
773 if (relocate_group)
774 layout->layout_group(symtab, this, index, name, signature.c_str(),
775 shdr, flags, &shndxes);
776
777 return include_group;
778 }
779
780 // Whether to include a linkonce section in the link. NAME is the
781 // name of the section and SHDR is the section header.
782
783 // Linkonce sections are a GNU extension implemented in the original
784 // GNU linker before section groups were defined. The semantics are
785 // that we only include one linkonce section with a given name. The
786 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
787 // where T is the type of section and SYMNAME is the name of a symbol.
788 // In an attempt to make linkonce sections interact well with section
789 // groups, we try to identify SYMNAME and use it like a section group
790 // signature. We want to block section groups with that signature,
791 // but not other linkonce sections with that signature. We also use
792 // the full name of the linkonce section as a normal section group
793 // signature.
794
795 template<int size, bool big_endian>
796 bool
797 Sized_relobj<size, big_endian>::include_linkonce_section(
798 Layout* layout,
799 unsigned int index,
800 const char* name,
801 const elfcpp::Shdr<size, big_endian>&)
802 {
803 // In general the symbol name we want will be the string following
804 // the last '.'. However, we have to handle the case of
805 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
806 // some versions of gcc. So we use a heuristic: if the name starts
807 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
808 // we look for the last '.'. We can't always simply skip
809 // ".gnu.linkonce.X", because we have to deal with cases like
810 // ".gnu.linkonce.d.rel.ro.local".
811 const char* const linkonce_t = ".gnu.linkonce.t.";
812 const char* symname;
813 if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
814 symname = name + strlen(linkonce_t);
815 else
816 symname = strrchr(name, '.') + 1;
817 std::string sig1(symname);
818 std::string sig2(name);
819 Kept_section candidate1(this, index, false);
820 Kept_section candidate2(this, index, true);
821 Kept_section* kept1;
822 Kept_section* kept2;
823 bool include1 = layout->find_or_add_kept_section(sig1, &candidate1, &kept1);
824 bool include2 = layout->find_or_add_kept_section(sig2, &candidate2, &kept2);
825
826 if (!include2)
827 {
828 // The section is being discarded on the basis of its section
829 // name (i.e., the kept section was also a linkonce section).
830 // In this case, the section index stored with the layout object
831 // is the linkonce section that was kept.
832 unsigned int kept_group_index = kept2->shndx;
833 Relobj* kept_relobj = kept2->object;
834 if (kept_relobj != NULL)
835 {
836 Sized_relobj<size, big_endian>* kept_object =
837 static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
838 Kept_comdat_section* kept =
839 new Kept_comdat_section(kept_object, kept_group_index);
840 this->set_kept_comdat_section(index, kept);
841 }
842 }
843 else if (!include1)
844 {
845 // The section is being discarded on the basis of its symbol
846 // name. This means that the corresponding kept section was
847 // part of a comdat group, and it will be difficult to identify
848 // the specific section within that group that corresponds to
849 // this linkonce section. We'll handle the simple case where
850 // the group has only one member section. Otherwise, it's not
851 // worth the effort.
852 Relobj* kept_relobj = kept1->object;
853 if (kept_relobj != NULL)
854 {
855 Sized_relobj<size, big_endian>* kept_object =
856 static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
857 Kept_section::Comdat_group* kept_group = kept1->group_sections;
858 if (kept_group != NULL && kept_group->size() == 1)
859 {
860 Kept_section::Comdat_group::const_iterator p =
861 kept_group->begin();
862 gold_assert(p != kept_group->end());
863 Kept_comdat_section* kept =
864 new Kept_comdat_section(kept_object, p->second);
865 this->set_kept_comdat_section(index, kept);
866 }
867 }
868 }
869
870 return include1 && include2;
871 }
872
873 // Layout an input section.
874
875 template<int size, bool big_endian>
876 inline void
877 Sized_relobj<size, big_endian>::layout_section(Layout* layout,
878 unsigned int shndx,
879 const char* name,
880 typename This::Shdr& shdr,
881 unsigned int reloc_shndx,
882 unsigned int reloc_type)
883 {
884 off_t offset;
885 Output_section* os = layout->layout(this, shndx, name, shdr,
886 reloc_shndx, reloc_type, &offset);
887
888 this->output_sections()[shndx] = os;
889 if (offset == -1)
890 this->section_offsets_[shndx] = invalid_address;
891 else
892 this->section_offsets_[shndx] = convert_types<Address, off_t>(offset);
893
894 // If this section requires special handling, and if there are
895 // relocs that apply to it, then we must do the special handling
896 // before we apply the relocs.
897 if (offset == -1 && reloc_shndx != 0)
898 this->set_relocs_must_follow_section_writes();
899 }
900
901 // Lay out the input sections. We walk through the sections and check
902 // whether they should be included in the link. If they should, we
903 // pass them to the Layout object, which will return an output section
904 // and an offset.
905 // During garbage collection (gc-sections), this function is called
906 // twice. When it is called the first time, it is for setting up some
907 // sections as roots to a work-list and to do comdat processing. Actual
908 // layout happens the second time around after all the relevant sections
909 // have been determined. The first time, is_worklist_ready is false.
910 // It is then set to true after the worklist is processed and the relevant
911 // sections are determined. Then, this function is called again to
912 // layout the sections.
913
914 template<int size, bool big_endian>
915 void
916 Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
917 Layout* layout,
918 Read_symbols_data* sd)
919 {
920 const unsigned int shnum = this->shnum();
921 bool is_gc_pass_one = (parameters->options().gc_sections()
922 && !symtab->gc()->is_worklist_ready());
923 bool is_gc_pass_two = (parameters->options().gc_sections()
924 && symtab->gc()->is_worklist_ready());
925 if (shnum == 0)
926 return;
927 Symbols_data* gc_sd = NULL;
928 if (is_gc_pass_one)
929 {
930 // During garbage collection save the symbols data to use it when
931 // re-entering this function.
932 gc_sd = new Symbols_data;
933 this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
934 this->set_symbols_data(gc_sd);
935 }
936 else if (is_gc_pass_two)
937 {
938 gc_sd = this->get_symbols_data();
939 }
940
941 const unsigned char* section_headers_data = NULL;
942 section_size_type section_names_size;
943 const unsigned char* symbols_data = NULL;
944 section_size_type symbols_size;
945 section_offset_type external_symbols_offset;
946 const unsigned char* symbol_names_data = NULL;
947 section_size_type symbol_names_size;
948
949 if (parameters->options().gc_sections())
950 {
951 section_headers_data = gc_sd->section_headers_data;
952 section_names_size = gc_sd->section_names_size;
953 symbols_data = gc_sd->symbols_data;
954 symbols_size = gc_sd->symbols_size;
955 external_symbols_offset = gc_sd->external_symbols_offset;
956 symbol_names_data = gc_sd->symbol_names_data;
957 symbol_names_size = gc_sd->symbol_names_size;
958 }
959 else
960 {
961 section_headers_data = sd->section_headers->data();
962 section_names_size = sd->section_names_size;
963 if (sd->symbols != NULL)
964 symbols_data = sd->symbols->data();
965 symbols_size = sd->symbols_size;
966 external_symbols_offset = sd->external_symbols_offset;
967 if (sd->symbol_names != NULL)
968 symbol_names_data = sd->symbol_names->data();
969 symbol_names_size = sd->symbol_names_size;
970 }
971
972 // Get the section headers.
973 const unsigned char* shdrs = section_headers_data;
974 const unsigned char* pshdrs;
975
976 // Get the section names.
977 const unsigned char* pnamesu = parameters->options().gc_sections() ?
978 gc_sd->section_names_data :
979 sd->section_names->data();
980 const char* pnames = reinterpret_cast<const char*>(pnamesu);
981
982 // If any input files have been claimed by plugins, we need to defer
983 // actual layout until the replacement files have arrived.
984 const bool should_defer_layout =
985 (parameters->options().has_plugins()
986 && parameters->options().plugins()->should_defer_layout());
987 unsigned int num_sections_to_defer = 0;
988
989 // For each section, record the index of the reloc section if any.
990 // Use 0 to mean that there is no reloc section, -1U to mean that
991 // there is more than one.
992 std::vector<unsigned int> reloc_shndx(shnum, 0);
993 std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
994 // Skip the first, dummy, section.
995 pshdrs = shdrs + This::shdr_size;
996 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
997 {
998 typename This::Shdr shdr(pshdrs);
999
1000 // Count the number of sections whose layout will be deferred.
1001 if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1002 ++num_sections_to_defer;
1003
1004 unsigned int sh_type = shdr.get_sh_type();
1005 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
1006 {
1007 unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info());
1008 if (target_shndx == 0 || target_shndx >= shnum)
1009 {
1010 this->error(_("relocation section %u has bad info %u"),
1011 i, target_shndx);
1012 continue;
1013 }
1014
1015 if (reloc_shndx[target_shndx] != 0)
1016 reloc_shndx[target_shndx] = -1U;
1017 else
1018 {
1019 reloc_shndx[target_shndx] = i;
1020 reloc_type[target_shndx] = sh_type;
1021 }
1022 }
1023 }
1024
1025 Output_sections& out_sections(this->output_sections());
1026 std::vector<Address>& out_section_offsets(this->section_offsets_);
1027
1028 if (!is_gc_pass_two)
1029 {
1030 out_sections.resize(shnum);
1031 out_section_offsets.resize(shnum);
1032 }
1033
1034 // If we are only linking for symbols, then there is nothing else to
1035 // do here.
1036 if (this->input_file()->just_symbols())
1037 {
1038 if (!is_gc_pass_two)
1039 {
1040 delete sd->section_headers;
1041 sd->section_headers = NULL;
1042 delete sd->section_names;
1043 sd->section_names = NULL;
1044 }
1045 return;
1046 }
1047
1048 if (num_sections_to_defer > 0)
1049 {
1050 parameters->options().plugins()->add_deferred_layout_object(this);
1051 this->deferred_layout_.reserve(num_sections_to_defer);
1052 }
1053
1054 // Whether we've seen a .note.GNU-stack section.
1055 bool seen_gnu_stack = false;
1056 // The flags of a .note.GNU-stack section.
1057 uint64_t gnu_stack_flags = 0;
1058
1059 // Keep track of which sections to omit.
1060 std::vector<bool> omit(shnum, false);
1061
1062 // Keep track of reloc sections when emitting relocations.
1063 const bool relocatable = parameters->options().relocatable();
1064 const bool emit_relocs = (relocatable
1065 || parameters->options().emit_relocs());
1066 std::vector<unsigned int> reloc_sections;
1067
1068 // Keep track of .eh_frame sections.
1069 std::vector<unsigned int> eh_frame_sections;
1070
1071 // Skip the first, dummy, section.
1072 pshdrs = shdrs + This::shdr_size;
1073 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1074 {
1075 typename This::Shdr shdr(pshdrs);
1076
1077 if (shdr.get_sh_name() >= section_names_size)
1078 {
1079 this->error(_("bad section name offset for section %u: %lu"),
1080 i, static_cast<unsigned long>(shdr.get_sh_name()));
1081 return;
1082 }
1083
1084 const char* name = pnames + shdr.get_sh_name();
1085
1086 if (!is_gc_pass_two)
1087 {
1088 if (this->handle_gnu_warning_section(name, i, symtab))
1089 {
1090 if (!relocatable)
1091 omit[i] = true;
1092 }
1093
1094 // The .note.GNU-stack section is special. It gives the
1095 // protection flags that this object file requires for the stack
1096 // in memory.
1097 if (strcmp(name, ".note.GNU-stack") == 0)
1098 {
1099 seen_gnu_stack = true;
1100 gnu_stack_flags |= shdr.get_sh_flags();
1101 omit[i] = true;
1102 }
1103
1104 bool discard = omit[i];
1105 if (!discard)
1106 {
1107 if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
1108 {
1109 if (!this->include_section_group(symtab, layout, i, name,
1110 shdrs, pnames,
1111 section_names_size,
1112 &omit))
1113 discard = true;
1114 }
1115 else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
1116 && Layout::is_linkonce(name))
1117 {
1118 if (!this->include_linkonce_section(layout, i, name, shdr))
1119 discard = true;
1120 }
1121 }
1122
1123 if (discard)
1124 {
1125 // Do not include this section in the link.
1126 out_sections[i] = NULL;
1127 out_section_offsets[i] = invalid_address;
1128 continue;
1129 }
1130 }
1131
1132 if (is_gc_pass_one)
1133 {
1134 if (is_section_name_included(name)
1135 || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY
1136 || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
1137 {
1138 symtab->gc()->worklist().push(Section_id(this, i));
1139 }
1140 }
1141
1142 // When doing a relocatable link we are going to copy input
1143 // reloc sections into the output. We only want to copy the
1144 // ones associated with sections which are not being discarded.
1145 // However, we don't know that yet for all sections. So save
1146 // reloc sections and process them later. Garbage collection is
1147 // not triggered when relocatable code is desired.
1148 if (emit_relocs
1149 && (shdr.get_sh_type() == elfcpp::SHT_REL
1150 || shdr.get_sh_type() == elfcpp::SHT_RELA))
1151 {
1152 reloc_sections.push_back(i);
1153 continue;
1154 }
1155
1156 if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
1157 continue;
1158
1159 // The .eh_frame section is special. It holds exception frame
1160 // information that we need to read in order to generate the
1161 // exception frame header. We process these after all the other
1162 // sections so that the exception frame reader can reliably
1163 // determine which sections are being discarded, and discard the
1164 // corresponding information.
1165 if (!relocatable
1166 && strcmp(name, ".eh_frame") == 0
1167 && this->check_eh_frame_flags(&shdr))
1168 {
1169 if (is_gc_pass_one)
1170 {
1171 out_sections[i] = reinterpret_cast<Output_section*>(1);
1172 out_section_offsets[i] = invalid_address;
1173 }
1174 else
1175 eh_frame_sections.push_back(i);
1176 continue;
1177 }
1178
1179 if (is_gc_pass_two)
1180 {
1181 // This is executed during the second pass of garbage
1182 // collection. do_layout has been called before and some
1183 // sections have been already discarded. Simply ignore
1184 // such sections this time around.
1185 if (out_sections[i] == NULL)
1186 {
1187 gold_assert(out_section_offsets[i] == invalid_address);
1188 continue;
1189 }
1190 if ((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1191 if (symtab->gc()->referenced_list().find(Section_id(this,i))
1192 == symtab->gc()->referenced_list().end())
1193 {
1194 if (parameters->options().print_gc_sections())
1195 gold_info(_("%s: removing unused section from '%s'"
1196 " in file '%s"),
1197 program_name, this->section_name(i).c_str(),
1198 this->name().c_str());
1199 out_sections[i] = NULL;
1200 out_section_offsets[i] = invalid_address;
1201 continue;
1202 }
1203 }
1204 // Defer layout here if input files are claimed by plugins. When gc
1205 // is turned on this function is called twice. For the second call
1206 // should_defer_layout should be false.
1207 if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1208 {
1209 gold_assert(!is_gc_pass_two);
1210 this->deferred_layout_.push_back(Deferred_layout(i, name,
1211 pshdrs,
1212 reloc_shndx[i],
1213 reloc_type[i]));
1214 // Put dummy values here; real values will be supplied by
1215 // do_layout_deferred_sections.
1216 out_sections[i] = reinterpret_cast<Output_section*>(2);
1217 out_section_offsets[i] = invalid_address;
1218 continue;
1219 }
1220 // During gc_pass_two if a section that was previously deferred is
1221 // found, do not layout the section as layout_deferred_sections will
1222 // do it later from gold.cc.
1223 if (is_gc_pass_two
1224 && (out_sections[i] == reinterpret_cast<Output_section*>(2)))
1225 continue;
1226
1227 if (is_gc_pass_one)
1228 {
1229 // This is during garbage collection. The out_sections are
1230 // assigned in the second call to this function.
1231 out_sections[i] = reinterpret_cast<Output_section*>(1);
1232 out_section_offsets[i] = invalid_address;
1233 }
1234 else
1235 {
1236 // When garbage collection is switched on the actual layout
1237 // only happens in the second call.
1238 this->layout_section(layout, i, name, shdr, reloc_shndx[i],
1239 reloc_type[i]);
1240 }
1241 }
1242
1243 if (!is_gc_pass_one)
1244 layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
1245
1246 // When doing a relocatable link handle the reloc sections at the
1247 // end. Garbage collection is not turned on for relocatable code.
1248 if (emit_relocs)
1249 this->size_relocatable_relocs();
1250 gold_assert(!parameters->options().gc_sections() || reloc_sections.empty());
1251 for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
1252 p != reloc_sections.end();
1253 ++p)
1254 {
1255 unsigned int i = *p;
1256 const unsigned char* pshdr;
1257 pshdr = section_headers_data + i * This::shdr_size;
1258 typename This::Shdr shdr(pshdr);
1259
1260 unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1261 if (data_shndx >= shnum)
1262 {
1263 // We already warned about this above.
1264 continue;
1265 }
1266
1267 Output_section* data_section = out_sections[data_shndx];
1268 if (data_section == NULL)
1269 {
1270 out_sections[i] = NULL;
1271 out_section_offsets[i] = invalid_address;
1272 continue;
1273 }
1274
1275 Relocatable_relocs* rr = new Relocatable_relocs();
1276 this->set_relocatable_relocs(i, rr);
1277
1278 Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
1279 rr);
1280 out_sections[i] = os;
1281 out_section_offsets[i] = invalid_address;
1282 }
1283
1284 // Handle the .eh_frame sections at the end.
1285 gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
1286 for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
1287 p != eh_frame_sections.end();
1288 ++p)
1289 {
1290 gold_assert(this->has_eh_frame_);
1291 gold_assert(external_symbols_offset != 0);
1292
1293 unsigned int i = *p;
1294 const unsigned char *pshdr;
1295 pshdr = section_headers_data + i * This::shdr_size;
1296 typename This::Shdr shdr(pshdr);
1297
1298 off_t offset;
1299 Output_section* os = layout->layout_eh_frame(this,
1300 symbols_data,
1301 symbols_size,
1302 symbol_names_data,
1303 symbol_names_size,
1304 i, shdr,
1305 reloc_shndx[i],
1306 reloc_type[i],
1307 &offset);
1308 out_sections[i] = os;
1309 if (offset == -1)
1310 {
1311 // An object can contain at most one section holding exception
1312 // frame information.
1313 gold_assert(this->discarded_eh_frame_shndx_ == -1U);
1314 this->discarded_eh_frame_shndx_ = i;
1315 out_section_offsets[i] = invalid_address;
1316 }
1317 else
1318 out_section_offsets[i] = convert_types<Address, off_t>(offset);
1319
1320 // If this section requires special handling, and if there are
1321 // relocs that apply to it, then we must do the special handling
1322 // before we apply the relocs.
1323 if (offset == -1 && reloc_shndx[i] != 0)
1324 this->set_relocs_must_follow_section_writes();
1325 }
1326
1327 if (is_gc_pass_two)
1328 {
1329 delete[] gc_sd->section_headers_data;
1330 delete[] gc_sd->section_names_data;
1331 delete[] gc_sd->symbols_data;
1332 delete[] gc_sd->symbol_names_data;
1333 }
1334 else
1335 {
1336 delete sd->section_headers;
1337 sd->section_headers = NULL;
1338 delete sd->section_names;
1339 sd->section_names = NULL;
1340 }
1341 }
1342
1343 // Layout sections whose layout was deferred while waiting for
1344 // input files from a plugin.
1345
1346 template<int size, bool big_endian>
1347 void
1348 Sized_relobj<size, big_endian>::do_layout_deferred_sections(Layout* layout)
1349 {
1350 typename std::vector<Deferred_layout>::iterator deferred;
1351
1352 for (deferred = this->deferred_layout_.begin();
1353 deferred != this->deferred_layout_.end();
1354 ++deferred)
1355 {
1356 typename This::Shdr shdr(deferred->shdr_data_);
1357 this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
1358 shdr, deferred->reloc_shndx_, deferred->reloc_type_);
1359 }
1360
1361 this->deferred_layout_.clear();
1362 }
1363
1364 // Add the symbols to the symbol table.
1365
1366 template<int size, bool big_endian>
1367 void
1368 Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
1369 Read_symbols_data* sd,
1370 Layout*)
1371 {
1372 if (sd->symbols == NULL)
1373 {
1374 gold_assert(sd->symbol_names == NULL);
1375 return;
1376 }
1377
1378 const int sym_size = This::sym_size;
1379 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1380 / sym_size);
1381 if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
1382 {
1383 this->error(_("size of symbols is not multiple of symbol size"));
1384 return;
1385 }
1386
1387 this->symbols_.resize(symcount);
1388
1389 const char* sym_names =
1390 reinterpret_cast<const char*>(sd->symbol_names->data());
1391 symtab->add_from_relobj(this,
1392 sd->symbols->data() + sd->external_symbols_offset,
1393 symcount, this->local_symbol_count_,
1394 sym_names, sd->symbol_names_size,
1395 &this->symbols_,
1396 &this->defined_count_);
1397
1398 delete sd->symbols;
1399 sd->symbols = NULL;
1400 delete sd->symbol_names;
1401 sd->symbol_names = NULL;
1402 }
1403
1404 // First pass over the local symbols. Here we add their names to
1405 // *POOL and *DYNPOOL, and we store the symbol value in
1406 // THIS->LOCAL_VALUES_. This function is always called from a
1407 // singleton thread. This is followed by a call to
1408 // finalize_local_symbols.
1409
1410 template<int size, bool big_endian>
1411 void
1412 Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
1413 Stringpool* dynpool)
1414 {
1415 gold_assert(this->symtab_shndx_ != -1U);
1416 if (this->symtab_shndx_ == 0)
1417 {
1418 // This object has no symbols. Weird but legal.
1419 return;
1420 }
1421
1422 // Read the symbol table section header.
1423 const unsigned int symtab_shndx = this->symtab_shndx_;
1424 typename This::Shdr symtabshdr(this,
1425 this->elf_file_.section_header(symtab_shndx));
1426 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1427
1428 // Read the local symbols.
1429 const int sym_size = This::sym_size;
1430 const unsigned int loccount = this->local_symbol_count_;
1431 gold_assert(loccount == symtabshdr.get_sh_info());
1432 off_t locsize = loccount * sym_size;
1433 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1434 locsize, true, true);
1435
1436 // Read the symbol names.
1437 const unsigned int strtab_shndx =
1438 this->adjust_shndx(symtabshdr.get_sh_link());
1439 section_size_type strtab_size;
1440 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1441 &strtab_size,
1442 true);
1443 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1444
1445 // Loop over the local symbols.
1446
1447 const Output_sections& out_sections(this->output_sections());
1448 unsigned int shnum = this->shnum();
1449 unsigned int count = 0;
1450 unsigned int dyncount = 0;
1451 // Skip the first, dummy, symbol.
1452 psyms += sym_size;
1453 bool discard_locals = parameters->options().discard_locals();
1454 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1455 {
1456 elfcpp::Sym<size, big_endian> sym(psyms);
1457
1458 Symbol_value<size>& lv(this->local_values_[i]);
1459
1460 bool is_ordinary;
1461 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
1462 &is_ordinary);
1463 lv.set_input_shndx(shndx, is_ordinary);
1464
1465 if (sym.get_st_type() == elfcpp::STT_SECTION)
1466 lv.set_is_section_symbol();
1467 else if (sym.get_st_type() == elfcpp::STT_TLS)
1468 lv.set_is_tls_symbol();
1469
1470 // Save the input symbol value for use in do_finalize_local_symbols().
1471 lv.set_input_value(sym.get_st_value());
1472
1473 // Decide whether this symbol should go into the output file.
1474
1475 if ((shndx < shnum && out_sections[shndx] == NULL)
1476 || (shndx == this->discarded_eh_frame_shndx_))
1477 {
1478 lv.set_no_output_symtab_entry();
1479 gold_assert(!lv.needs_output_dynsym_entry());
1480 continue;
1481 }
1482
1483 if (sym.get_st_type() == elfcpp::STT_SECTION)
1484 {
1485 lv.set_no_output_symtab_entry();
1486 gold_assert(!lv.needs_output_dynsym_entry());
1487 continue;
1488 }
1489
1490 if (sym.get_st_name() >= strtab_size)
1491 {
1492 this->error(_("local symbol %u section name out of range: %u >= %u"),
1493 i, sym.get_st_name(),
1494 static_cast<unsigned int>(strtab_size));
1495 lv.set_no_output_symtab_entry();
1496 continue;
1497 }
1498
1499 // If --discard-locals option is used, discard all temporary local
1500 // symbols. These symbols start with system-specific local label
1501 // prefixes, typically .L for ELF system. We want to be compatible
1502 // with GNU ld so here we essentially use the same check in
1503 // bfd_is_local_label(). The code is different because we already
1504 // know that:
1505 //
1506 // - the symbol is local and thus cannot have global or weak binding.
1507 // - the symbol is not a section symbol.
1508 // - the symbol has a name.
1509 //
1510 // We do not discard a symbol if it needs a dynamic symbol entry.
1511 const char* name = pnames + sym.get_st_name();
1512 if (discard_locals
1513 && sym.get_st_type() != elfcpp::STT_FILE
1514 && !lv.needs_output_dynsym_entry()
1515 && parameters->target().is_local_label_name(name))
1516 {
1517 lv.set_no_output_symtab_entry();
1518 continue;
1519 }
1520
1521 // Add the symbol to the symbol table string pool.
1522 pool->add(name, true, NULL);
1523 ++count;
1524
1525 // If needed, add the symbol to the dynamic symbol table string pool.
1526 if (lv.needs_output_dynsym_entry())
1527 {
1528 dynpool->add(name, true, NULL);
1529 ++dyncount;
1530 }
1531 }
1532
1533 this->output_local_symbol_count_ = count;
1534 this->output_local_dynsym_count_ = dyncount;
1535 }
1536
1537 // Finalize the local symbols. Here we set the final value in
1538 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
1539 // This function is always called from a singleton thread. The actual
1540 // output of the local symbols will occur in a separate task.
1541
1542 template<int size, bool big_endian>
1543 unsigned int
1544 Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
1545 off_t off)
1546 {
1547 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
1548
1549 const unsigned int loccount = this->local_symbol_count_;
1550 this->local_symbol_offset_ = off;
1551
1552 const bool relocatable = parameters->options().relocatable();
1553 const Output_sections& out_sections(this->output_sections());
1554 const std::vector<Address>& out_offsets(this->section_offsets_);
1555 unsigned int shnum = this->shnum();
1556
1557 for (unsigned int i = 1; i < loccount; ++i)
1558 {
1559 Symbol_value<size>& lv(this->local_values_[i]);
1560
1561 bool is_ordinary;
1562 unsigned int shndx = lv.input_shndx(&is_ordinary);
1563
1564 // Set the output symbol value.
1565
1566 if (!is_ordinary)
1567 {
1568 if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
1569 lv.set_output_value(lv.input_value());
1570 else
1571 {
1572 this->error(_("unknown section index %u for local symbol %u"),
1573 shndx, i);
1574 lv.set_output_value(0);
1575 }
1576 }
1577 else
1578 {
1579 if (shndx >= shnum)
1580 {
1581 this->error(_("local symbol %u section index %u out of range"),
1582 i, shndx);
1583 shndx = 0;
1584 }
1585
1586 Output_section* os = out_sections[shndx];
1587
1588 if (os == NULL)
1589 {
1590 // This local symbol belongs to a section we are discarding.
1591 // In some cases when applying relocations later, we will
1592 // attempt to match it to the corresponding kept section,
1593 // so we leave the input value unchanged here.
1594 continue;
1595 }
1596 else if (out_offsets[shndx] == invalid_address)
1597 {
1598 uint64_t start;
1599
1600 // This is a SHF_MERGE section or one which otherwise
1601 // requires special handling.
1602 if (shndx == this->discarded_eh_frame_shndx_)
1603 {
1604 // This local symbol belongs to a discarded .eh_frame
1605 // section. Just treat it like the case in which
1606 // os == NULL above.
1607 gold_assert(this->has_eh_frame_);
1608 continue;
1609 }
1610 else if (!lv.is_section_symbol())
1611 {
1612 // This is not a section symbol. We can determine
1613 // the final value now.
1614 lv.set_output_value(os->output_address(this, shndx,
1615 lv.input_value()));
1616 }
1617 else if (!os->find_starting_output_address(this, shndx, &start))
1618 {
1619 // This is a section symbol, but apparently not one
1620 // in a merged section. Just use the start of the
1621 // output section. This happens with relocatable
1622 // links when the input object has section symbols
1623 // for arbitrary non-merge sections.
1624 lv.set_output_value(os->address());
1625 }
1626 else
1627 {
1628 // We have to consider the addend to determine the
1629 // value to use in a relocation. START is the start
1630 // of this input section.
1631 Merged_symbol_value<size>* msv =
1632 new Merged_symbol_value<size>(lv.input_value(), start);
1633 lv.set_merged_symbol_value(msv);
1634 }
1635 }
1636 else if (lv.is_tls_symbol())
1637 lv.set_output_value(os->tls_offset()
1638 + out_offsets[shndx]
1639 + lv.input_value());
1640 else
1641 lv.set_output_value((relocatable ? 0 : os->address())
1642 + out_offsets[shndx]
1643 + lv.input_value());
1644 }
1645
1646 if (lv.needs_output_symtab_entry())
1647 {
1648 lv.set_output_symtab_index(index);
1649 ++index;
1650 }
1651 }
1652 return index;
1653 }
1654
1655 // Set the output dynamic symbol table indexes for the local variables.
1656
1657 template<int size, bool big_endian>
1658 unsigned int
1659 Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index)
1660 {
1661 const unsigned int loccount = this->local_symbol_count_;
1662 for (unsigned int i = 1; i < loccount; ++i)
1663 {
1664 Symbol_value<size>& lv(this->local_values_[i]);
1665 if (lv.needs_output_dynsym_entry())
1666 {
1667 lv.set_output_dynsym_index(index);
1668 ++index;
1669 }
1670 }
1671 return index;
1672 }
1673
1674 // Set the offset where local dynamic symbol information will be stored.
1675 // Returns the count of local symbols contributed to the symbol table by
1676 // this object.
1677
1678 template<int size, bool big_endian>
1679 unsigned int
1680 Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off)
1681 {
1682 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
1683 this->local_dynsym_offset_ = off;
1684 return this->output_local_dynsym_count_;
1685 }
1686
1687 // Write out the local symbols.
1688
1689 template<int size, bool big_endian>
1690 void
1691 Sized_relobj<size, big_endian>::write_local_symbols(
1692 Output_file* of,
1693 const Stringpool* sympool,
1694 const Stringpool* dynpool,
1695 Output_symtab_xindex* symtab_xindex,
1696 Output_symtab_xindex* dynsym_xindex)
1697 {
1698 const bool strip_all = parameters->options().strip_all();
1699 if (strip_all)
1700 {
1701 if (this->output_local_dynsym_count_ == 0)
1702 return;
1703 this->output_local_symbol_count_ = 0;
1704 }
1705
1706 gold_assert(this->symtab_shndx_ != -1U);
1707 if (this->symtab_shndx_ == 0)
1708 {
1709 // This object has no symbols. Weird but legal.
1710 return;
1711 }
1712
1713 // Read the symbol table section header.
1714 const unsigned int symtab_shndx = this->symtab_shndx_;
1715 typename This::Shdr symtabshdr(this,
1716 this->elf_file_.section_header(symtab_shndx));
1717 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1718 const unsigned int loccount = this->local_symbol_count_;
1719 gold_assert(loccount == symtabshdr.get_sh_info());
1720
1721 // Read the local symbols.
1722 const int sym_size = This::sym_size;
1723 off_t locsize = loccount * sym_size;
1724 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1725 locsize, true, false);
1726
1727 // Read the symbol names.
1728 const unsigned int strtab_shndx =
1729 this->adjust_shndx(symtabshdr.get_sh_link());
1730 section_size_type strtab_size;
1731 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1732 &strtab_size,
1733 false);
1734 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1735
1736 // Get views into the output file for the portions of the symbol table
1737 // and the dynamic symbol table that we will be writing.
1738 off_t output_size = this->output_local_symbol_count_ * sym_size;
1739 unsigned char* oview = NULL;
1740 if (output_size > 0)
1741 oview = of->get_output_view(this->local_symbol_offset_, output_size);
1742
1743 off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
1744 unsigned char* dyn_oview = NULL;
1745 if (dyn_output_size > 0)
1746 dyn_oview = of->get_output_view(this->local_dynsym_offset_,
1747 dyn_output_size);
1748
1749 const Output_sections out_sections(this->output_sections());
1750
1751 gold_assert(this->local_values_.size() == loccount);
1752
1753 unsigned char* ov = oview;
1754 unsigned char* dyn_ov = dyn_oview;
1755 psyms += sym_size;
1756 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1757 {
1758 elfcpp::Sym<size, big_endian> isym(psyms);
1759
1760 Symbol_value<size>& lv(this->local_values_[i]);
1761
1762 bool is_ordinary;
1763 unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1764 &is_ordinary);
1765 if (is_ordinary)
1766 {
1767 gold_assert(st_shndx < out_sections.size());
1768 if (out_sections[st_shndx] == NULL)
1769 continue;
1770 st_shndx = out_sections[st_shndx]->out_shndx();
1771 if (st_shndx >= elfcpp::SHN_LORESERVE)
1772 {
1773 if (lv.needs_output_symtab_entry() && !strip_all)
1774 symtab_xindex->add(lv.output_symtab_index(), st_shndx);
1775 if (lv.needs_output_dynsym_entry())
1776 dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
1777 st_shndx = elfcpp::SHN_XINDEX;
1778 }
1779 }
1780
1781 // Write the symbol to the output symbol table.
1782 if (!strip_all && lv.needs_output_symtab_entry())
1783 {
1784 elfcpp::Sym_write<size, big_endian> osym(ov);
1785
1786 gold_assert(isym.get_st_name() < strtab_size);
1787 const char* name = pnames + isym.get_st_name();
1788 osym.put_st_name(sympool->get_offset(name));
1789 osym.put_st_value(this->local_values_[i].value(this, 0));
1790 osym.put_st_size(isym.get_st_size());
1791 osym.put_st_info(isym.get_st_info());
1792 osym.put_st_other(isym.get_st_other());
1793 osym.put_st_shndx(st_shndx);
1794
1795 ov += sym_size;
1796 }
1797
1798 // Write the symbol to the output dynamic symbol table.
1799 if (lv.needs_output_dynsym_entry())
1800 {
1801 gold_assert(dyn_ov < dyn_oview + dyn_output_size);
1802 elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
1803
1804 gold_assert(isym.get_st_name() < strtab_size);
1805 const char* name = pnames + isym.get_st_name();
1806 osym.put_st_name(dynpool->get_offset(name));
1807 osym.put_st_value(this->local_values_[i].value(this, 0));
1808 osym.put_st_size(isym.get_st_size());
1809 osym.put_st_info(isym.get_st_info());
1810 osym.put_st_other(isym.get_st_other());
1811 osym.put_st_shndx(st_shndx);
1812
1813 dyn_ov += sym_size;
1814 }
1815 }
1816
1817
1818 if (output_size > 0)
1819 {
1820 gold_assert(ov - oview == output_size);
1821 of->write_output_view(this->local_symbol_offset_, output_size, oview);
1822 }
1823
1824 if (dyn_output_size > 0)
1825 {
1826 gold_assert(dyn_ov - dyn_oview == dyn_output_size);
1827 of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
1828 dyn_oview);
1829 }
1830 }
1831
1832 // Set *INFO to symbolic information about the offset OFFSET in the
1833 // section SHNDX. Return true if we found something, false if we
1834 // found nothing.
1835
1836 template<int size, bool big_endian>
1837 bool
1838 Sized_relobj<size, big_endian>::get_symbol_location_info(
1839 unsigned int shndx,
1840 off_t offset,
1841 Symbol_location_info* info)
1842 {
1843 if (this->symtab_shndx_ == 0)
1844 return false;
1845
1846 section_size_type symbols_size;
1847 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
1848 &symbols_size,
1849 false);
1850
1851 unsigned int symbol_names_shndx =
1852 this->adjust_shndx(this->section_link(this->symtab_shndx_));
1853 section_size_type names_size;
1854 const unsigned char* symbol_names_u =
1855 this->section_contents(symbol_names_shndx, &names_size, false);
1856 const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
1857
1858 const int sym_size = This::sym_size;
1859 const size_t count = symbols_size / sym_size;
1860
1861 const unsigned char* p = symbols;
1862 for (size_t i = 0; i < count; ++i, p += sym_size)
1863 {
1864 elfcpp::Sym<size, big_endian> sym(p);
1865
1866 if (sym.get_st_type() == elfcpp::STT_FILE)
1867 {
1868 if (sym.get_st_name() >= names_size)
1869 info->source_file = "(invalid)";
1870 else
1871 info->source_file = symbol_names + sym.get_st_name();
1872 continue;
1873 }
1874
1875 bool is_ordinary;
1876 unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
1877 &is_ordinary);
1878 if (is_ordinary
1879 && st_shndx == shndx
1880 && static_cast<off_t>(sym.get_st_value()) <= offset
1881 && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
1882 > offset))
1883 {
1884 if (sym.get_st_name() > names_size)
1885 info->enclosing_symbol_name = "(invalid)";
1886 else
1887 {
1888 info->enclosing_symbol_name = symbol_names + sym.get_st_name();
1889 if (parameters->options().do_demangle())
1890 {
1891 char* demangled_name = cplus_demangle(
1892 info->enclosing_symbol_name.c_str(),
1893 DMGL_ANSI | DMGL_PARAMS);
1894 if (demangled_name != NULL)
1895 {
1896 info->enclosing_symbol_name.assign(demangled_name);
1897 free(demangled_name);
1898 }
1899 }
1900 }
1901 return true;
1902 }
1903 }
1904
1905 return false;
1906 }
1907
1908 // Look for a kept section corresponding to the given discarded section,
1909 // and return its output address. This is used only for relocations in
1910 // debugging sections. If we can't find the kept section, return 0.
1911
1912 template<int size, bool big_endian>
1913 typename Sized_relobj<size, big_endian>::Address
1914 Sized_relobj<size, big_endian>::map_to_kept_section(
1915 unsigned int shndx,
1916 bool* found) const
1917 {
1918 Kept_comdat_section *kept = this->get_kept_comdat_section(shndx);
1919 if (kept != NULL)
1920 {
1921 gold_assert(kept->object_ != NULL);
1922 *found = true;
1923 Output_section* os = kept->object_->output_section(kept->shndx_);
1924 Address offset = kept->object_->get_output_section_offset(kept->shndx_);
1925 if (os != NULL && offset != invalid_address)
1926 return os->address() + offset;
1927 }
1928 *found = false;
1929 return 0;
1930 }
1931
1932 // Get symbol counts.
1933
1934 template<int size, bool big_endian>
1935 void
1936 Sized_relobj<size, big_endian>::do_get_global_symbol_counts(
1937 const Symbol_table*,
1938 size_t* defined,
1939 size_t* used) const
1940 {
1941 *defined = this->defined_count_;
1942 size_t count = 0;
1943 for (Symbols::const_iterator p = this->symbols_.begin();
1944 p != this->symbols_.end();
1945 ++p)
1946 if (*p != NULL
1947 && (*p)->source() == Symbol::FROM_OBJECT
1948 && (*p)->object() == this
1949 && (*p)->is_defined())
1950 ++count;
1951 *used = count;
1952 }
1953
1954 // Input_objects methods.
1955
1956 // Add a regular relocatable object to the list. Return false if this
1957 // object should be ignored.
1958
1959 bool
1960 Input_objects::add_object(Object* obj)
1961 {
1962 // Set the global target from the first object file we recognize.
1963 Target* target = obj->target();
1964 if (!parameters->target_valid())
1965 set_parameters_target(target);
1966 else if (target != &parameters->target())
1967 {
1968 obj->error(_("incompatible target"));
1969 return false;
1970 }
1971
1972 // Print the filename if the -t/--trace option is selected.
1973 if (parameters->options().trace())
1974 gold_info("%s", obj->name().c_str());
1975
1976 if (!obj->is_dynamic())
1977 this->relobj_list_.push_back(static_cast<Relobj*>(obj));
1978 else
1979 {
1980 // See if this is a duplicate SONAME.
1981 Dynobj* dynobj = static_cast<Dynobj*>(obj);
1982 const char* soname = dynobj->soname();
1983
1984 std::pair<Unordered_set<std::string>::iterator, bool> ins =
1985 this->sonames_.insert(soname);
1986 if (!ins.second)
1987 {
1988 // We have already seen a dynamic object with this soname.
1989 return false;
1990 }
1991
1992 this->dynobj_list_.push_back(dynobj);
1993 }
1994
1995 // Add this object to the cross-referencer if requested.
1996 if (parameters->options().user_set_print_symbol_counts())
1997 {
1998 if (this->cref_ == NULL)
1999 this->cref_ = new Cref();
2000 this->cref_->add_object(obj);
2001 }
2002
2003 return true;
2004 }
2005
2006 // For each dynamic object, record whether we've seen all of its
2007 // explicit dependencies.
2008
2009 void
2010 Input_objects::check_dynamic_dependencies() const
2011 {
2012 for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
2013 p != this->dynobj_list_.end();
2014 ++p)
2015 {
2016 const Dynobj::Needed& needed((*p)->needed());
2017 bool found_all = true;
2018 for (Dynobj::Needed::const_iterator pneeded = needed.begin();
2019 pneeded != needed.end();
2020 ++pneeded)
2021 {
2022 if (this->sonames_.find(*pneeded) == this->sonames_.end())
2023 {
2024 found_all = false;
2025 break;
2026 }
2027 }
2028 (*p)->set_has_unknown_needed_entries(!found_all);
2029 }
2030 }
2031
2032 // Start processing an archive.
2033
2034 void
2035 Input_objects::archive_start(Archive* archive)
2036 {
2037 if (parameters->options().user_set_print_symbol_counts())
2038 {
2039 if (this->cref_ == NULL)
2040 this->cref_ = new Cref();
2041 this->cref_->add_archive_start(archive);
2042 }
2043 }
2044
2045 // Stop processing an archive.
2046
2047 void
2048 Input_objects::archive_stop(Archive* archive)
2049 {
2050 if (parameters->options().user_set_print_symbol_counts())
2051 this->cref_->add_archive_stop(archive);
2052 }
2053
2054 // Print symbol counts
2055
2056 void
2057 Input_objects::print_symbol_counts(const Symbol_table* symtab) const
2058 {
2059 if (parameters->options().user_set_print_symbol_counts()
2060 && this->cref_ != NULL)
2061 this->cref_->print_symbol_counts(symtab);
2062 }
2063
2064 // Relocate_info methods.
2065
2066 // Return a string describing the location of a relocation. This is
2067 // only used in error messages.
2068
2069 template<int size, bool big_endian>
2070 std::string
2071 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
2072 {
2073 // See if we can get line-number information from debugging sections.
2074 std::string filename;
2075 std::string file_and_lineno; // Better than filename-only, if available.
2076
2077 Sized_dwarf_line_info<size, big_endian> line_info(this->object);
2078 // This will be "" if we failed to parse the debug info for any reason.
2079 file_and_lineno = line_info.addr2line(this->data_shndx, offset);
2080
2081 std::string ret(this->object->name());
2082 ret += ':';
2083 Symbol_location_info info;
2084 if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
2085 {
2086 ret += " in function ";
2087 ret += info.enclosing_symbol_name;
2088 ret += ":";
2089 filename = info.source_file;
2090 }
2091
2092 if (!file_and_lineno.empty())
2093 ret += file_and_lineno;
2094 else
2095 {
2096 if (!filename.empty())
2097 ret += filename;
2098 ret += "(";
2099 ret += this->object->section_name(this->data_shndx);
2100 char buf[100];
2101 // Offsets into sections have to be positive.
2102 snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset));
2103 ret += buf;
2104 ret += ")";
2105 }
2106 return ret;
2107 }
2108
2109 } // End namespace gold.
2110
2111 namespace
2112 {
2113
2114 using namespace gold;
2115
2116 // Read an ELF file with the header and return the appropriate
2117 // instance of Object.
2118
2119 template<int size, bool big_endian>
2120 Object*
2121 make_elf_sized_object(const std::string& name, Input_file* input_file,
2122 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
2123 {
2124 int et = ehdr.get_e_type();
2125 if (et == elfcpp::ET_REL)
2126 {
2127 Sized_relobj<size, big_endian>* obj =
2128 new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
2129 obj->setup(ehdr);
2130 return obj;
2131 }
2132 else if (et == elfcpp::ET_DYN)
2133 {
2134 Sized_dynobj<size, big_endian>* obj =
2135 new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
2136 obj->setup(ehdr);
2137 return obj;
2138 }
2139 else
2140 {
2141 gold_error(_("%s: unsupported ELF file type %d"),
2142 name.c_str(), et);
2143 return NULL;
2144 }
2145 }
2146
2147 } // End anonymous namespace.
2148
2149 namespace gold
2150 {
2151
2152 // Return whether INPUT_FILE is an ELF object.
2153
2154 bool
2155 is_elf_object(Input_file* input_file, off_t offset,
2156 const unsigned char** start, int *read_size)
2157 {
2158 off_t filesize = input_file->file().filesize();
2159 int want = elfcpp::Elf_sizes<64>::ehdr_size;
2160 if (filesize - offset < want)
2161 want = filesize - offset;
2162
2163 const unsigned char* p = input_file->file().get_view(offset, 0, want,
2164 true, false);
2165 *start = p;
2166 *read_size = want;
2167
2168 if (want < 4)
2169 return false;
2170
2171 static unsigned char elfmagic[4] =
2172 {
2173 elfcpp::ELFMAG0, elfcpp::ELFMAG1,
2174 elfcpp::ELFMAG2, elfcpp::ELFMAG3
2175 };
2176 return memcmp(p, elfmagic, 4) == 0;
2177 }
2178
2179 // Read an ELF file and return the appropriate instance of Object.
2180
2181 Object*
2182 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
2183 const unsigned char* p, section_offset_type bytes,
2184 bool* punconfigured)
2185 {
2186 if (punconfigured != NULL)
2187 *punconfigured = false;
2188
2189 if (bytes < elfcpp::EI_NIDENT)
2190 {
2191 gold_error(_("%s: ELF file too short"), name.c_str());
2192 return NULL;
2193 }
2194
2195 int v = p[elfcpp::EI_VERSION];
2196 if (v != elfcpp::EV_CURRENT)
2197 {
2198 if (v == elfcpp::EV_NONE)
2199 gold_error(_("%s: invalid ELF version 0"), name.c_str());
2200 else
2201 gold_error(_("%s: unsupported ELF version %d"), name.c_str(), v);
2202 return NULL;
2203 }
2204
2205 int c = p[elfcpp::EI_CLASS];
2206 if (c == elfcpp::ELFCLASSNONE)
2207 {
2208 gold_error(_("%s: invalid ELF class 0"), name.c_str());
2209 return NULL;
2210 }
2211 else if (c != elfcpp::ELFCLASS32
2212 && c != elfcpp::ELFCLASS64)
2213 {
2214 gold_error(_("%s: unsupported ELF class %d"), name.c_str(), c);
2215 return NULL;
2216 }
2217
2218 int d = p[elfcpp::EI_DATA];
2219 if (d == elfcpp::ELFDATANONE)
2220 {
2221 gold_error(_("%s: invalid ELF data encoding"), name.c_str());
2222 return NULL;
2223 }
2224 else if (d != elfcpp::ELFDATA2LSB
2225 && d != elfcpp::ELFDATA2MSB)
2226 {
2227 gold_error(_("%s: unsupported ELF data encoding %d"), name.c_str(), d);
2228 return NULL;
2229 }
2230
2231 bool big_endian = d == elfcpp::ELFDATA2MSB;
2232
2233 if (c == elfcpp::ELFCLASS32)
2234 {
2235 if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
2236 {
2237 gold_error(_("%s: ELF file too short"), name.c_str());
2238 return NULL;
2239 }
2240 if (big_endian)
2241 {
2242 #ifdef HAVE_TARGET_32_BIG
2243 elfcpp::Ehdr<32, true> ehdr(p);
2244 return make_elf_sized_object<32, true>(name, input_file,
2245 offset, ehdr);
2246 #else
2247 if (punconfigured != NULL)
2248 *punconfigured = true;
2249 else
2250 gold_error(_("%s: not configured to support "
2251 "32-bit big-endian object"),
2252 name.c_str());
2253 return NULL;
2254 #endif
2255 }
2256 else
2257 {
2258 #ifdef HAVE_TARGET_32_LITTLE
2259 elfcpp::Ehdr<32, false> ehdr(p);
2260 return make_elf_sized_object<32, false>(name, input_file,
2261 offset, ehdr);
2262 #else
2263 if (punconfigured != NULL)
2264 *punconfigured = true;
2265 else
2266 gold_error(_("%s: not configured to support "
2267 "32-bit little-endian object"),
2268 name.c_str());
2269 return NULL;
2270 #endif
2271 }
2272 }
2273 else
2274 {
2275 if (bytes < elfcpp::Elf_sizes<64>::ehdr_size)
2276 {
2277 gold_error(_("%s: ELF file too short"), name.c_str());
2278 return NULL;
2279 }
2280 if (big_endian)
2281 {
2282 #ifdef HAVE_TARGET_64_BIG
2283 elfcpp::Ehdr<64, true> ehdr(p);
2284 return make_elf_sized_object<64, true>(name, input_file,
2285 offset, ehdr);
2286 #else
2287 if (punconfigured != NULL)
2288 *punconfigured = true;
2289 else
2290 gold_error(_("%s: not configured to support "
2291 "64-bit big-endian object"),
2292 name.c_str());
2293 return NULL;
2294 #endif
2295 }
2296 else
2297 {
2298 #ifdef HAVE_TARGET_64_LITTLE
2299 elfcpp::Ehdr<64, false> ehdr(p);
2300 return make_elf_sized_object<64, false>(name, input_file,
2301 offset, ehdr);
2302 #else
2303 if (punconfigured != NULL)
2304 *punconfigured = true;
2305 else
2306 gold_error(_("%s: not configured to support "
2307 "64-bit little-endian object"),
2308 name.c_str());
2309 return NULL;
2310 #endif
2311 }
2312 }
2313 }
2314
2315 // Instantiate the templates we need.
2316
2317 #ifdef HAVE_TARGET_32_LITTLE
2318 template
2319 void
2320 Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
2321 Read_symbols_data*);
2322 #endif
2323
2324 #ifdef HAVE_TARGET_32_BIG
2325 template
2326 void
2327 Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
2328 Read_symbols_data*);
2329 #endif
2330
2331 #ifdef HAVE_TARGET_64_LITTLE
2332 template
2333 void
2334 Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
2335 Read_symbols_data*);
2336 #endif
2337
2338 #ifdef HAVE_TARGET_64_BIG
2339 template
2340 void
2341 Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
2342 Read_symbols_data*);
2343 #endif
2344
2345 #ifdef HAVE_TARGET_32_LITTLE
2346 template
2347 class Sized_relobj<32, false>;
2348 #endif
2349
2350 #ifdef HAVE_TARGET_32_BIG
2351 template
2352 class Sized_relobj<32, true>;
2353 #endif
2354
2355 #ifdef HAVE_TARGET_64_LITTLE
2356 template
2357 class Sized_relobj<64, false>;
2358 #endif
2359
2360 #ifdef HAVE_TARGET_64_BIG
2361 template
2362 class Sized_relobj<64, true>;
2363 #endif
2364
2365 #ifdef HAVE_TARGET_32_LITTLE
2366 template
2367 struct Relocate_info<32, false>;
2368 #endif
2369
2370 #ifdef HAVE_TARGET_32_BIG
2371 template
2372 struct Relocate_info<32, true>;
2373 #endif
2374
2375 #ifdef HAVE_TARGET_64_LITTLE
2376 template
2377 struct Relocate_info<64, false>;
2378 #endif
2379
2380 #ifdef HAVE_TARGET_64_BIG
2381 template
2382 struct Relocate_info<64, true>;
2383 #endif
2384
2385 } // End namespace gold.
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