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[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 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 "target-select.h"
32 #include "dwarf_reader.h"
33 #include "layout.h"
34 #include "output.h"
35 #include "symtab.h"
36 #include "reloc.h"
37 #include "object.h"
38 #include "dynobj.h"
39
40 namespace gold
41 {
42
43 // Class Object.
44
45 // Set the target based on fields in the ELF file header.
46
47 void
48 Object::set_target(int machine, int size, bool big_endian, int osabi,
49 int abiversion)
50 {
51 Target* target = select_target(machine, size, big_endian, osabi, abiversion);
52 if (target == NULL)
53 gold_fatal(_("%s: unsupported ELF machine number %d"),
54 this->name().c_str(), machine);
55 this->target_ = target;
56 }
57
58 // Report an error for this object file. This is used by the
59 // elfcpp::Elf_file interface, and also called by the Object code
60 // itself.
61
62 void
63 Object::error(const char* format, ...) const
64 {
65 va_list args;
66 va_start(args, format);
67 char* buf = NULL;
68 if (vasprintf(&buf, format, args) < 0)
69 gold_nomem();
70 va_end(args);
71 gold_error(_("%s: %s"), this->name().c_str(), buf);
72 free(buf);
73 }
74
75 // Return a view of the contents of a section.
76
77 const unsigned char*
78 Object::section_contents(unsigned int shndx, section_size_type* plen,
79 bool cache)
80 {
81 Location loc(this->do_section_contents(shndx));
82 *plen = convert_to_section_size_type(loc.data_size);
83 return this->get_view(loc.file_offset, *plen, true, cache);
84 }
85
86 // Read the section data into SD. This is code common to Sized_relobj
87 // and Sized_dynobj, so we put it into Object.
88
89 template<int size, bool big_endian>
90 void
91 Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
92 Read_symbols_data* sd)
93 {
94 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
95
96 // Read the section headers.
97 const off_t shoff = elf_file->shoff();
98 const unsigned int shnum = this->shnum();
99 sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size,
100 true, true);
101
102 // Read the section names.
103 const unsigned char* pshdrs = sd->section_headers->data();
104 const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
105 typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
106
107 if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
108 this->error(_("section name section has wrong type: %u"),
109 static_cast<unsigned int>(shdrnames.get_sh_type()));
110
111 sd->section_names_size =
112 convert_to_section_size_type(shdrnames.get_sh_size());
113 sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
114 sd->section_names_size, false,
115 false);
116 }
117
118 // If NAME is the name of a special .gnu.warning section, arrange for
119 // the warning to be issued. SHNDX is the section index. Return
120 // whether it is a warning section.
121
122 bool
123 Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
124 Symbol_table* symtab)
125 {
126 const char warn_prefix[] = ".gnu.warning.";
127 const int warn_prefix_len = sizeof warn_prefix - 1;
128 if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
129 {
130 // Read the section contents to get the warning text. It would
131 // be nicer if we only did this if we have to actually issue a
132 // warning. Unfortunately, warnings are issued as we relocate
133 // sections. That means that we can not lock the object then,
134 // as we might try to issue the same warning multiple times
135 // simultaneously.
136 section_size_type len;
137 const unsigned char* contents = this->section_contents(shndx, &len,
138 false);
139 std::string warning(reinterpret_cast<const char*>(contents), len);
140 symtab->add_warning(name + warn_prefix_len, this, warning);
141 return true;
142 }
143 return false;
144 }
145
146 // Class Sized_relobj.
147
148 template<int size, bool big_endian>
149 Sized_relobj<size, big_endian>::Sized_relobj(
150 const std::string& name,
151 Input_file* input_file,
152 off_t offset,
153 const elfcpp::Ehdr<size, big_endian>& ehdr)
154 : Relobj(name, input_file, offset),
155 elf_file_(this, ehdr),
156 symtab_shndx_(-1U),
157 local_symbol_count_(0),
158 output_local_symbol_count_(0),
159 output_local_dynsym_count_(0),
160 symbols_(),
161 local_symbol_offset_(0),
162 local_dynsym_offset_(0),
163 local_values_(),
164 local_got_offsets_(),
165 has_eh_frame_(false)
166 {
167 }
168
169 template<int size, bool big_endian>
170 Sized_relobj<size, big_endian>::~Sized_relobj()
171 {
172 }
173
174 // Set up an object file based on the file header. This sets up the
175 // target and reads the section information.
176
177 template<int size, bool big_endian>
178 void
179 Sized_relobj<size, big_endian>::setup(
180 const elfcpp::Ehdr<size, big_endian>& ehdr)
181 {
182 this->set_target(ehdr.get_e_machine(), size, big_endian,
183 ehdr.get_e_ident()[elfcpp::EI_OSABI],
184 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
185
186 const unsigned int shnum = this->elf_file_.shnum();
187 this->set_shnum(shnum);
188 }
189
190 // Find the SHT_SYMTAB section, given the section headers. The ELF
191 // standard says that maybe in the future there can be more than one
192 // SHT_SYMTAB section. Until somebody figures out how that could
193 // work, we assume there is only one.
194
195 template<int size, bool big_endian>
196 void
197 Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
198 {
199 const unsigned int shnum = this->shnum();
200 this->symtab_shndx_ = 0;
201 if (shnum > 0)
202 {
203 // Look through the sections in reverse order, since gas tends
204 // to put the symbol table at the end.
205 const unsigned char* p = pshdrs + shnum * This::shdr_size;
206 unsigned int i = shnum;
207 while (i > 0)
208 {
209 --i;
210 p -= This::shdr_size;
211 typename This::Shdr shdr(p);
212 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
213 {
214 this->symtab_shndx_ = i;
215 break;
216 }
217 }
218 }
219 }
220
221 // Return whether SHDR has the right type and flags to be a GNU
222 // .eh_frame section.
223
224 template<int size, bool big_endian>
225 bool
226 Sized_relobj<size, big_endian>::check_eh_frame_flags(
227 const elfcpp::Shdr<size, big_endian>* shdr) const
228 {
229 return (shdr->get_sh_type() == elfcpp::SHT_PROGBITS
230 && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
231 }
232
233 // Return whether there is a GNU .eh_frame section, given the section
234 // headers and the section names.
235
236 template<int size, bool big_endian>
237 bool
238 Sized_relobj<size, big_endian>::find_eh_frame(
239 const unsigned char* pshdrs,
240 const char* names,
241 section_size_type names_size) const
242 {
243 const unsigned int shnum = this->shnum();
244 const unsigned char* p = pshdrs + This::shdr_size;
245 for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
246 {
247 typename This::Shdr shdr(p);
248 if (this->check_eh_frame_flags(&shdr))
249 {
250 if (shdr.get_sh_name() >= names_size)
251 {
252 this->error(_("bad section name offset for section %u: %lu"),
253 i, static_cast<unsigned long>(shdr.get_sh_name()));
254 continue;
255 }
256
257 const char* name = names + shdr.get_sh_name();
258 if (strcmp(name, ".eh_frame") == 0)
259 return true;
260 }
261 }
262 return false;
263 }
264
265 // Read the sections and symbols from an object file.
266
267 template<int size, bool big_endian>
268 void
269 Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
270 {
271 this->read_section_data(&this->elf_file_, sd);
272
273 const unsigned char* const pshdrs = sd->section_headers->data();
274
275 this->find_symtab(pshdrs);
276
277 const unsigned char* namesu = sd->section_names->data();
278 const char* names = reinterpret_cast<const char*>(namesu);
279 if (memmem(names, sd->section_names_size, ".eh_frame", 10) != NULL)
280 {
281 if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
282 this->has_eh_frame_ = true;
283 }
284
285 sd->symbols = NULL;
286 sd->symbols_size = 0;
287 sd->external_symbols_offset = 0;
288 sd->symbol_names = NULL;
289 sd->symbol_names_size = 0;
290
291 if (this->symtab_shndx_ == 0)
292 {
293 // No symbol table. Weird but legal.
294 return;
295 }
296
297 // Get the symbol table section header.
298 typename This::Shdr symtabshdr(pshdrs
299 + this->symtab_shndx_ * This::shdr_size);
300 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
301
302 // If this object has a .eh_frame section, we need all the symbols.
303 // Otherwise we only need the external symbols. While it would be
304 // simpler to just always read all the symbols, I've seen object
305 // files with well over 2000 local symbols, which for a 64-bit
306 // object file format is over 5 pages that we don't need to read
307 // now.
308
309 const int sym_size = This::sym_size;
310 const unsigned int loccount = symtabshdr.get_sh_info();
311 this->local_symbol_count_ = loccount;
312 this->local_values_.resize(loccount);
313 section_offset_type locsize = loccount * sym_size;
314 off_t dataoff = symtabshdr.get_sh_offset();
315 section_size_type datasize =
316 convert_to_section_size_type(symtabshdr.get_sh_size());
317 off_t extoff = dataoff + locsize;
318 section_size_type extsize = datasize - locsize;
319
320 off_t readoff = this->has_eh_frame_ ? dataoff : extoff;
321 section_size_type readsize = this->has_eh_frame_ ? datasize : extsize;
322
323 File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false);
324
325 // Read the section header for the symbol names.
326 unsigned int strtab_shndx = symtabshdr.get_sh_link();
327 if (strtab_shndx >= this->shnum())
328 {
329 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
330 return;
331 }
332 typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
333 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
334 {
335 this->error(_("symbol table name section has wrong type: %u"),
336 static_cast<unsigned int>(strtabshdr.get_sh_type()));
337 return;
338 }
339
340 // Read the symbol names.
341 File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
342 strtabshdr.get_sh_size(),
343 false, true);
344
345 sd->symbols = fvsymtab;
346 sd->symbols_size = readsize;
347 sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0;
348 sd->symbol_names = fvstrtab;
349 sd->symbol_names_size =
350 convert_to_section_size_type(strtabshdr.get_sh_size());
351 }
352
353 // Return the section index of symbol SYM. Set *VALUE to its value in
354 // the object file. Note that for a symbol which is not defined in
355 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
356 // it will not return the final value of the symbol in the link.
357
358 template<int size, bool big_endian>
359 unsigned int
360 Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym,
361 Address* value)
362 {
363 section_size_type symbols_size;
364 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
365 &symbols_size,
366 false);
367
368 const size_t count = symbols_size / This::sym_size;
369 gold_assert(sym < count);
370
371 elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
372 *value = elfsym.get_st_value();
373 // FIXME: Handle SHN_XINDEX.
374 return elfsym.get_st_shndx();
375 }
376
377 // Return whether to include a section group in the link. LAYOUT is
378 // used to keep track of which section groups we have already seen.
379 // INDEX is the index of the section group and SHDR is the section
380 // header. If we do not want to include this group, we set bits in
381 // OMIT for each section which should be discarded.
382
383 template<int size, bool big_endian>
384 bool
385 Sized_relobj<size, big_endian>::include_section_group(
386 Symbol_table* symtab,
387 Layout* layout,
388 unsigned int index,
389 const char* name,
390 const elfcpp::Shdr<size, big_endian>& shdr,
391 std::vector<bool>* omit)
392 {
393 // Read the section contents.
394 const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
395 shdr.get_sh_size(), true, false);
396 const elfcpp::Elf_Word* pword =
397 reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
398
399 // The first word contains flags. We only care about COMDAT section
400 // groups. Other section groups are always included in the link
401 // just like ordinary sections.
402 elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
403
404 // Look up the group signature, which is the name of a symbol. This
405 // is a lot of effort to go to to read a string. Why didn't they
406 // just have the group signature point into the string table, rather
407 // than indirect through a symbol?
408
409 // Get the appropriate symbol table header (this will normally be
410 // the single SHT_SYMTAB section, but in principle it need not be).
411 const unsigned int link = shdr.get_sh_link();
412 typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
413
414 // Read the symbol table entry.
415 if (shdr.get_sh_info() >= symshdr.get_sh_size() / This::sym_size)
416 {
417 this->error(_("section group %u info %u out of range"),
418 index, shdr.get_sh_info());
419 return false;
420 }
421 off_t symoff = symshdr.get_sh_offset() + shdr.get_sh_info() * This::sym_size;
422 const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
423 false);
424 elfcpp::Sym<size, big_endian> sym(psym);
425
426 // Read the symbol table names.
427 section_size_type symnamelen;
428 const unsigned char* psymnamesu;
429 psymnamesu = this->section_contents(symshdr.get_sh_link(), &symnamelen,
430 true);
431 const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
432
433 // Get the section group signature.
434 if (sym.get_st_name() >= symnamelen)
435 {
436 this->error(_("symbol %u name offset %u out of range"),
437 shdr.get_sh_info(), sym.get_st_name());
438 return false;
439 }
440
441 const char* signature = psymnames + sym.get_st_name();
442
443 // It seems that some versions of gas will create a section group
444 // associated with a section symbol, and then fail to give a name to
445 // the section symbol. In such a case, use the name of the section.
446 // FIXME.
447 std::string secname;
448 if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
449 {
450 secname = this->section_name(sym.get_st_shndx());
451 signature = secname.c_str();
452 }
453
454 // Record this section group, and see whether we've already seen one
455 // with the same signature.
456
457 if ((flags & elfcpp::GRP_COMDAT) == 0
458 || layout->add_comdat(signature, true))
459 {
460 if (parameters->options().relocatable())
461 layout->layout_group(symtab, this, index, name, signature, shdr,
462 pword);
463 return true;
464 }
465
466 // This is a duplicate. We want to discard the sections in this
467 // group.
468 size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
469 for (size_t i = 1; i < count; ++i)
470 {
471 elfcpp::Elf_Word secnum =
472 elfcpp::Swap<32, big_endian>::readval(pword + i);
473 if (secnum >= this->shnum())
474 {
475 this->error(_("section %u in section group %u out of range"),
476 secnum, index);
477 continue;
478 }
479 (*omit)[secnum] = true;
480 }
481
482 return false;
483 }
484
485 // Whether to include a linkonce section in the link. NAME is the
486 // name of the section and SHDR is the section header.
487
488 // Linkonce sections are a GNU extension implemented in the original
489 // GNU linker before section groups were defined. The semantics are
490 // that we only include one linkonce section with a given name. The
491 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
492 // where T is the type of section and SYMNAME is the name of a symbol.
493 // In an attempt to make linkonce sections interact well with section
494 // groups, we try to identify SYMNAME and use it like a section group
495 // signature. We want to block section groups with that signature,
496 // but not other linkonce sections with that signature. We also use
497 // the full name of the linkonce section as a normal section group
498 // signature.
499
500 template<int size, bool big_endian>
501 bool
502 Sized_relobj<size, big_endian>::include_linkonce_section(
503 Layout* layout,
504 const char* name,
505 const elfcpp::Shdr<size, big_endian>&)
506 {
507 // In general the symbol name we want will be the string following
508 // the last '.'. However, we have to handle the case of
509 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
510 // some versions of gcc. So we use a heuristic: if the name starts
511 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
512 // we look for the last '.'. We can't always simply skip
513 // ".gnu.linkonce.X", because we have to deal with cases like
514 // ".gnu.linkonce.d.rel.ro.local".
515 const char* const linkonce_t = ".gnu.linkonce.t.";
516 const char* symname;
517 if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
518 symname = name + strlen(linkonce_t);
519 else
520 symname = strrchr(name, '.') + 1;
521 bool include1 = layout->add_comdat(symname, false);
522 bool include2 = layout->add_comdat(name, true);
523 return include1 && include2;
524 }
525
526 // Lay out the input sections. We walk through the sections and check
527 // whether they should be included in the link. If they should, we
528 // pass them to the Layout object, which will return an output section
529 // and an offset.
530
531 template<int size, bool big_endian>
532 void
533 Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
534 Layout* layout,
535 Read_symbols_data* sd)
536 {
537 const unsigned int shnum = this->shnum();
538 if (shnum == 0)
539 return;
540
541 // Get the section headers.
542 const unsigned char* pshdrs = sd->section_headers->data();
543
544 // Get the section names.
545 const unsigned char* pnamesu = sd->section_names->data();
546 const char* pnames = reinterpret_cast<const char*>(pnamesu);
547
548 // For each section, record the index of the reloc section if any.
549 // Use 0 to mean that there is no reloc section, -1U to mean that
550 // there is more than one.
551 std::vector<unsigned int> reloc_shndx(shnum, 0);
552 std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
553 // Skip the first, dummy, section.
554 pshdrs += This::shdr_size;
555 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
556 {
557 typename This::Shdr shdr(pshdrs);
558
559 unsigned int sh_type = shdr.get_sh_type();
560 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
561 {
562 unsigned int target_shndx = shdr.get_sh_info();
563 if (target_shndx == 0 || target_shndx >= shnum)
564 {
565 this->error(_("relocation section %u has bad info %u"),
566 i, target_shndx);
567 continue;
568 }
569
570 if (reloc_shndx[target_shndx] != 0)
571 reloc_shndx[target_shndx] = -1U;
572 else
573 {
574 reloc_shndx[target_shndx] = i;
575 reloc_type[target_shndx] = sh_type;
576 }
577 }
578 }
579
580 std::vector<Map_to_output>& map_sections(this->map_to_output());
581 map_sections.resize(shnum);
582
583 // If we are only linking for symbols, then there is nothing else to
584 // do here.
585 if (this->input_file()->just_symbols())
586 {
587 delete sd->section_headers;
588 sd->section_headers = NULL;
589 delete sd->section_names;
590 sd->section_names = NULL;
591 return;
592 }
593
594 // Whether we've seen a .note.GNU-stack section.
595 bool seen_gnu_stack = false;
596 // The flags of a .note.GNU-stack section.
597 uint64_t gnu_stack_flags = 0;
598
599 // Keep track of which sections to omit.
600 std::vector<bool> omit(shnum, false);
601
602 // Keep track of reloc sections when emitting relocations.
603 const bool relocatable = parameters->options().relocatable();
604 const bool emit_relocs = (relocatable
605 || parameters->options().emit_relocs());
606 std::vector<unsigned int> reloc_sections;
607
608 // Keep track of .eh_frame sections.
609 std::vector<unsigned int> eh_frame_sections;
610
611 // Skip the first, dummy, section.
612 pshdrs = sd->section_headers->data() + This::shdr_size;
613 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
614 {
615 typename This::Shdr shdr(pshdrs);
616
617 if (shdr.get_sh_name() >= sd->section_names_size)
618 {
619 this->error(_("bad section name offset for section %u: %lu"),
620 i, static_cast<unsigned long>(shdr.get_sh_name()));
621 return;
622 }
623
624 const char* name = pnames + shdr.get_sh_name();
625
626 if (this->handle_gnu_warning_section(name, i, symtab))
627 {
628 if (!relocatable)
629 omit[i] = true;
630 }
631
632 // The .note.GNU-stack section is special. It gives the
633 // protection flags that this object file requires for the stack
634 // in memory.
635 if (strcmp(name, ".note.GNU-stack") == 0)
636 {
637 seen_gnu_stack = true;
638 gnu_stack_flags |= shdr.get_sh_flags();
639 omit[i] = true;
640 }
641
642 bool discard = omit[i];
643 if (!discard)
644 {
645 if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
646 {
647 if (!this->include_section_group(symtab, layout, i, name, shdr,
648 &omit))
649 discard = true;
650 }
651 else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
652 && Layout::is_linkonce(name))
653 {
654 if (!this->include_linkonce_section(layout, name, shdr))
655 discard = true;
656 }
657 }
658
659 if (discard)
660 {
661 // Do not include this section in the link.
662 map_sections[i].output_section = NULL;
663 continue;
664 }
665
666 // When doing a relocatable link we are going to copy input
667 // reloc sections into the output. We only want to copy the
668 // ones associated with sections which are not being discarded.
669 // However, we don't know that yet for all sections. So save
670 // reloc sections and process them later.
671 if (emit_relocs
672 && (shdr.get_sh_type() == elfcpp::SHT_REL
673 || shdr.get_sh_type() == elfcpp::SHT_RELA))
674 {
675 reloc_sections.push_back(i);
676 continue;
677 }
678
679 if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
680 continue;
681
682 // The .eh_frame section is special. It holds exception frame
683 // information that we need to read in order to generate the
684 // exception frame header. We process these after all the other
685 // sections so that the exception frame reader can reliably
686 // determine which sections are being discarded, and discard the
687 // corresponding information.
688 if (!relocatable
689 && strcmp(name, ".eh_frame") == 0
690 && this->check_eh_frame_flags(&shdr))
691 {
692 eh_frame_sections.push_back(i);
693 continue;
694 }
695
696 off_t offset;
697 Output_section* os = layout->layout(this, i, name, shdr,
698 reloc_shndx[i], reloc_type[i],
699 &offset);
700
701 map_sections[i].output_section = os;
702 map_sections[i].offset = offset;
703
704 // If this section requires special handling, and if there are
705 // relocs that apply to it, then we must do the special handling
706 // before we apply the relocs.
707 if (offset == -1 && reloc_shndx[i] != 0)
708 this->set_relocs_must_follow_section_writes();
709 }
710
711 layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
712
713 // When doing a relocatable link handle the reloc sections at the
714 // end.
715 if (emit_relocs)
716 this->size_relocatable_relocs();
717 for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
718 p != reloc_sections.end();
719 ++p)
720 {
721 unsigned int i = *p;
722 const unsigned char* pshdr;
723 pshdr = sd->section_headers->data() + i * This::shdr_size;
724 typename This::Shdr shdr(pshdr);
725
726 unsigned int data_shndx = shdr.get_sh_info();
727 if (data_shndx >= shnum)
728 {
729 // We already warned about this above.
730 continue;
731 }
732
733 Output_section* data_section = map_sections[data_shndx].output_section;
734 if (data_section == NULL)
735 {
736 map_sections[i].output_section = NULL;
737 continue;
738 }
739
740 Relocatable_relocs* rr = new Relocatable_relocs();
741 this->set_relocatable_relocs(i, rr);
742
743 Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
744 rr);
745 map_sections[i].output_section = os;
746 map_sections[i].offset = -1;
747 }
748
749 // Handle the .eh_frame sections at the end.
750 for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
751 p != eh_frame_sections.end();
752 ++p)
753 {
754 gold_assert(this->has_eh_frame_);
755 gold_assert(sd->external_symbols_offset != 0);
756
757 unsigned int i = *p;
758 const unsigned char *pshdr;
759 pshdr = sd->section_headers->data() + i * This::shdr_size;
760 typename This::Shdr shdr(pshdr);
761
762 off_t offset;
763 Output_section* os = layout->layout_eh_frame(this,
764 sd->symbols->data(),
765 sd->symbols_size,
766 sd->symbol_names->data(),
767 sd->symbol_names_size,
768 i, shdr,
769 reloc_shndx[i],
770 reloc_type[i],
771 &offset);
772 map_sections[i].output_section = os;
773 map_sections[i].offset = offset;
774
775 // If this section requires special handling, and if there are
776 // relocs that apply to it, then we must do the special handling
777 // before we apply the relocs.
778 if (offset == -1 && reloc_shndx[i] != 0)
779 this->set_relocs_must_follow_section_writes();
780 }
781
782 delete sd->section_headers;
783 sd->section_headers = NULL;
784 delete sd->section_names;
785 sd->section_names = NULL;
786 }
787
788 // Add the symbols to the symbol table.
789
790 template<int size, bool big_endian>
791 void
792 Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
793 Read_symbols_data* sd)
794 {
795 if (sd->symbols == NULL)
796 {
797 gold_assert(sd->symbol_names == NULL);
798 return;
799 }
800
801 const int sym_size = This::sym_size;
802 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
803 / sym_size);
804 if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
805 {
806 this->error(_("size of symbols is not multiple of symbol size"));
807 return;
808 }
809
810 this->symbols_.resize(symcount);
811
812 const char* sym_names =
813 reinterpret_cast<const char*>(sd->symbol_names->data());
814 symtab->add_from_relobj(this,
815 sd->symbols->data() + sd->external_symbols_offset,
816 symcount, sym_names, sd->symbol_names_size,
817 &this->symbols_);
818
819 delete sd->symbols;
820 sd->symbols = NULL;
821 delete sd->symbol_names;
822 sd->symbol_names = NULL;
823 }
824
825 // First pass over the local symbols. Here we add their names to
826 // *POOL and *DYNPOOL, and we store the symbol value in
827 // THIS->LOCAL_VALUES_. This function is always called from a
828 // singleton thread. This is followed by a call to
829 // finalize_local_symbols.
830
831 template<int size, bool big_endian>
832 void
833 Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
834 Stringpool* dynpool)
835 {
836 gold_assert(this->symtab_shndx_ != -1U);
837 if (this->symtab_shndx_ == 0)
838 {
839 // This object has no symbols. Weird but legal.
840 return;
841 }
842
843 // Read the symbol table section header.
844 const unsigned int symtab_shndx = this->symtab_shndx_;
845 typename This::Shdr symtabshdr(this,
846 this->elf_file_.section_header(symtab_shndx));
847 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
848
849 // Read the local symbols.
850 const int sym_size = This::sym_size;
851 const unsigned int loccount = this->local_symbol_count_;
852 gold_assert(loccount == symtabshdr.get_sh_info());
853 off_t locsize = loccount * sym_size;
854 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
855 locsize, true, true);
856
857 // Read the symbol names.
858 const unsigned int strtab_shndx = symtabshdr.get_sh_link();
859 section_size_type strtab_size;
860 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
861 &strtab_size,
862 true);
863 const char* pnames = reinterpret_cast<const char*>(pnamesu);
864
865 // Loop over the local symbols.
866
867 const std::vector<Map_to_output>& mo(this->map_to_output());
868 unsigned int shnum = this->shnum();
869 unsigned int count = 0;
870 unsigned int dyncount = 0;
871 // Skip the first, dummy, symbol.
872 psyms += sym_size;
873 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
874 {
875 elfcpp::Sym<size, big_endian> sym(psyms);
876
877 Symbol_value<size>& lv(this->local_values_[i]);
878
879 unsigned int shndx = sym.get_st_shndx();
880 lv.set_input_shndx(shndx);
881
882 if (sym.get_st_type() == elfcpp::STT_SECTION)
883 lv.set_is_section_symbol();
884 else if (sym.get_st_type() == elfcpp::STT_TLS)
885 lv.set_is_tls_symbol();
886
887 // Save the input symbol value for use in do_finalize_local_symbols().
888 lv.set_input_value(sym.get_st_value());
889
890 // Decide whether this symbol should go into the output file.
891
892 if (shndx < shnum && mo[shndx].output_section == NULL)
893 {
894 lv.set_no_output_symtab_entry();
895 gold_assert(!lv.needs_output_dynsym_entry());
896 continue;
897 }
898
899 if (sym.get_st_type() == elfcpp::STT_SECTION)
900 {
901 lv.set_no_output_symtab_entry();
902 gold_assert(!lv.needs_output_dynsym_entry());
903 continue;
904 }
905
906 if (sym.get_st_name() >= strtab_size)
907 {
908 this->error(_("local symbol %u section name out of range: %u >= %u"),
909 i, sym.get_st_name(),
910 static_cast<unsigned int>(strtab_size));
911 lv.set_no_output_symtab_entry();
912 continue;
913 }
914
915 // Add the symbol to the symbol table string pool.
916 const char* name = pnames + sym.get_st_name();
917 pool->add(name, true, NULL);
918 ++count;
919
920 // If needed, add the symbol to the dynamic symbol table string pool.
921 if (lv.needs_output_dynsym_entry())
922 {
923 dynpool->add(name, true, NULL);
924 ++dyncount;
925 }
926 }
927
928 this->output_local_symbol_count_ = count;
929 this->output_local_dynsym_count_ = dyncount;
930 }
931
932 // Finalize the local symbols. Here we set the final value in
933 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
934 // This function is always called from a singleton thread. The actual
935 // output of the local symbols will occur in a separate task.
936
937 template<int size, bool big_endian>
938 unsigned int
939 Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
940 off_t off)
941 {
942 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
943
944 const unsigned int loccount = this->local_symbol_count_;
945 this->local_symbol_offset_ = off;
946
947 const std::vector<Map_to_output>& mo(this->map_to_output());
948 unsigned int shnum = this->shnum();
949
950 for (unsigned int i = 1; i < loccount; ++i)
951 {
952 Symbol_value<size>& lv(this->local_values_[i]);
953
954 unsigned int shndx = lv.input_shndx();
955
956 // Set the output symbol value.
957
958 if (shndx >= elfcpp::SHN_LORESERVE)
959 {
960 if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)
961 lv.set_output_value(lv.input_value());
962 else
963 {
964 // FIXME: Handle SHN_XINDEX.
965 this->error(_("unknown section index %u for local symbol %u"),
966 shndx, i);
967 lv.set_output_value(0);
968 }
969 }
970 else
971 {
972 if (shndx >= shnum)
973 {
974 this->error(_("local symbol %u section index %u out of range"),
975 i, shndx);
976 shndx = 0;
977 }
978
979 Output_section* os = mo[shndx].output_section;
980
981 if (os == NULL)
982 {
983 lv.set_output_value(0);
984 continue;
985 }
986 else if (mo[shndx].offset == -1)
987 {
988 // This is a SHF_MERGE section or one which otherwise
989 // requires special handling. We get the output address
990 // of the start of the merged section. If this is not a
991 // section symbol, we can then determine the final
992 // value. If it is a section symbol, we can not, as in
993 // that case we have to consider the addend to determine
994 // the value to use in a relocation.
995 if (!lv.is_section_symbol())
996 lv.set_output_value(os->output_address(this, shndx,
997 lv.input_value()));
998 else
999 {
1000 section_offset_type start =
1001 os->starting_output_address(this, shndx);
1002 Merged_symbol_value<size>* msv =
1003 new Merged_symbol_value<size>(lv.input_value(), start);
1004 lv.set_merged_symbol_value(msv);
1005 }
1006 }
1007 else if (lv.is_tls_symbol())
1008 lv.set_output_value(os->tls_offset()
1009 + mo[shndx].offset
1010 + lv.input_value());
1011 else
1012 lv.set_output_value(os->address()
1013 + mo[shndx].offset
1014 + lv.input_value());
1015 }
1016
1017 if (lv.needs_output_symtab_entry())
1018 {
1019 lv.set_output_symtab_index(index);
1020 ++index;
1021 }
1022 }
1023 return index;
1024 }
1025
1026 // Set the output dynamic symbol table indexes for the local variables.
1027
1028 template<int size, bool big_endian>
1029 unsigned int
1030 Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index)
1031 {
1032 const unsigned int loccount = this->local_symbol_count_;
1033 for (unsigned int i = 1; i < loccount; ++i)
1034 {
1035 Symbol_value<size>& lv(this->local_values_[i]);
1036 if (lv.needs_output_dynsym_entry())
1037 {
1038 lv.set_output_dynsym_index(index);
1039 ++index;
1040 }
1041 }
1042 return index;
1043 }
1044
1045 // Set the offset where local dynamic symbol information will be stored.
1046 // Returns the count of local symbols contributed to the symbol table by
1047 // this object.
1048
1049 template<int size, bool big_endian>
1050 unsigned int
1051 Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off)
1052 {
1053 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
1054 this->local_dynsym_offset_ = off;
1055 return this->output_local_dynsym_count_;
1056 }
1057
1058 // Write out the local symbols.
1059
1060 template<int size, bool big_endian>
1061 void
1062 Sized_relobj<size, big_endian>::write_local_symbols(
1063 Output_file* of,
1064 const Stringpool* sympool,
1065 const Stringpool* dynpool)
1066 {
1067 if (parameters->options().strip_all()
1068 && this->output_local_dynsym_count_ == 0)
1069 return;
1070
1071 gold_assert(this->symtab_shndx_ != -1U);
1072 if (this->symtab_shndx_ == 0)
1073 {
1074 // This object has no symbols. Weird but legal.
1075 return;
1076 }
1077
1078 // Read the symbol table section header.
1079 const unsigned int symtab_shndx = this->symtab_shndx_;
1080 typename This::Shdr symtabshdr(this,
1081 this->elf_file_.section_header(symtab_shndx));
1082 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1083 const unsigned int loccount = this->local_symbol_count_;
1084 gold_assert(loccount == symtabshdr.get_sh_info());
1085
1086 // Read the local symbols.
1087 const int sym_size = This::sym_size;
1088 off_t locsize = loccount * sym_size;
1089 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1090 locsize, true, false);
1091
1092 // Read the symbol names.
1093 const unsigned int strtab_shndx = symtabshdr.get_sh_link();
1094 section_size_type strtab_size;
1095 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1096 &strtab_size,
1097 false);
1098 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1099
1100 // Get views into the output file for the portions of the symbol table
1101 // and the dynamic symbol table that we will be writing.
1102 off_t output_size = this->output_local_symbol_count_ * sym_size;
1103 unsigned char* oview = NULL;
1104 if (output_size > 0)
1105 oview = of->get_output_view(this->local_symbol_offset_, output_size);
1106
1107 off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
1108 unsigned char* dyn_oview = NULL;
1109 if (dyn_output_size > 0)
1110 dyn_oview = of->get_output_view(this->local_dynsym_offset_,
1111 dyn_output_size);
1112
1113 const std::vector<Map_to_output>& mo(this->map_to_output());
1114
1115 gold_assert(this->local_values_.size() == loccount);
1116
1117 unsigned char* ov = oview;
1118 unsigned char* dyn_ov = dyn_oview;
1119 psyms += sym_size;
1120 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1121 {
1122 elfcpp::Sym<size, big_endian> isym(psyms);
1123
1124 unsigned int st_shndx = isym.get_st_shndx();
1125 if (st_shndx < elfcpp::SHN_LORESERVE)
1126 {
1127 gold_assert(st_shndx < mo.size());
1128 if (mo[st_shndx].output_section == NULL)
1129 continue;
1130 st_shndx = mo[st_shndx].output_section->out_shndx();
1131 }
1132
1133 // Write the symbol to the output symbol table.
1134 if (!parameters->options().strip_all()
1135 && this->local_values_[i].needs_output_symtab_entry())
1136 {
1137 elfcpp::Sym_write<size, big_endian> osym(ov);
1138
1139 gold_assert(isym.get_st_name() < strtab_size);
1140 const char* name = pnames + isym.get_st_name();
1141 osym.put_st_name(sympool->get_offset(name));
1142 osym.put_st_value(this->local_values_[i].value(this, 0));
1143 osym.put_st_size(isym.get_st_size());
1144 osym.put_st_info(isym.get_st_info());
1145 osym.put_st_other(isym.get_st_other());
1146 osym.put_st_shndx(st_shndx);
1147
1148 ov += sym_size;
1149 }
1150
1151 // Write the symbol to the output dynamic symbol table.
1152 if (this->local_values_[i].needs_output_dynsym_entry())
1153 {
1154 gold_assert(dyn_ov < dyn_oview + dyn_output_size);
1155 elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
1156
1157 gold_assert(isym.get_st_name() < strtab_size);
1158 const char* name = pnames + isym.get_st_name();
1159 osym.put_st_name(dynpool->get_offset(name));
1160 osym.put_st_value(this->local_values_[i].value(this, 0));
1161 osym.put_st_size(isym.get_st_size());
1162 osym.put_st_info(isym.get_st_info());
1163 osym.put_st_other(isym.get_st_other());
1164 osym.put_st_shndx(st_shndx);
1165
1166 dyn_ov += sym_size;
1167 }
1168 }
1169
1170
1171 if (output_size > 0)
1172 {
1173 gold_assert(ov - oview == output_size);
1174 of->write_output_view(this->local_symbol_offset_, output_size, oview);
1175 }
1176
1177 if (dyn_output_size > 0)
1178 {
1179 gold_assert(dyn_ov - dyn_oview == dyn_output_size);
1180 of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
1181 dyn_oview);
1182 }
1183 }
1184
1185 // Set *INFO to symbolic information about the offset OFFSET in the
1186 // section SHNDX. Return true if we found something, false if we
1187 // found nothing.
1188
1189 template<int size, bool big_endian>
1190 bool
1191 Sized_relobj<size, big_endian>::get_symbol_location_info(
1192 unsigned int shndx,
1193 off_t offset,
1194 Symbol_location_info* info)
1195 {
1196 if (this->symtab_shndx_ == 0)
1197 return false;
1198
1199 section_size_type symbols_size;
1200 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
1201 &symbols_size,
1202 false);
1203
1204 unsigned int symbol_names_shndx = this->section_link(this->symtab_shndx_);
1205 section_size_type names_size;
1206 const unsigned char* symbol_names_u =
1207 this->section_contents(symbol_names_shndx, &names_size, false);
1208 const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
1209
1210 const int sym_size = This::sym_size;
1211 const size_t count = symbols_size / sym_size;
1212
1213 const unsigned char* p = symbols;
1214 for (size_t i = 0; i < count; ++i, p += sym_size)
1215 {
1216 elfcpp::Sym<size, big_endian> sym(p);
1217
1218 if (sym.get_st_type() == elfcpp::STT_FILE)
1219 {
1220 if (sym.get_st_name() >= names_size)
1221 info->source_file = "(invalid)";
1222 else
1223 info->source_file = symbol_names + sym.get_st_name();
1224 }
1225 else if (sym.get_st_shndx() == shndx
1226 && static_cast<off_t>(sym.get_st_value()) <= offset
1227 && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
1228 > offset))
1229 {
1230 if (sym.get_st_name() > names_size)
1231 info->enclosing_symbol_name = "(invalid)";
1232 else
1233 {
1234 info->enclosing_symbol_name = symbol_names + sym.get_st_name();
1235 if (parameters->options().do_demangle())
1236 {
1237 char* demangled_name = cplus_demangle(
1238 info->enclosing_symbol_name.c_str(),
1239 DMGL_ANSI | DMGL_PARAMS);
1240 if (demangled_name != NULL)
1241 {
1242 info->enclosing_symbol_name.assign(demangled_name);
1243 free(demangled_name);
1244 }
1245 }
1246 }
1247 return true;
1248 }
1249 }
1250
1251 return false;
1252 }
1253
1254 // Input_objects methods.
1255
1256 // Add a regular relocatable object to the list. Return false if this
1257 // object should be ignored.
1258
1259 bool
1260 Input_objects::add_object(Object* obj)
1261 {
1262 // Set the global target from the first object file we recognize.
1263 Target* target = obj->target();
1264 if (!parameters->target_valid())
1265 set_parameters_target(target);
1266 else if (target != &parameters->target())
1267 {
1268 obj->error(_("incompatible target"));
1269 return false;
1270 }
1271
1272 if (!obj->is_dynamic())
1273 this->relobj_list_.push_back(static_cast<Relobj*>(obj));
1274 else
1275 {
1276 // See if this is a duplicate SONAME.
1277 Dynobj* dynobj = static_cast<Dynobj*>(obj);
1278 const char* soname = dynobj->soname();
1279
1280 std::pair<Unordered_set<std::string>::iterator, bool> ins =
1281 this->sonames_.insert(soname);
1282 if (!ins.second)
1283 {
1284 // We have already seen a dynamic object with this soname.
1285 return false;
1286 }
1287
1288 this->dynobj_list_.push_back(dynobj);
1289
1290 // If this is -lc, remember the directory in which we found it.
1291 // We use this when issuing warnings about undefined symbols: as
1292 // a heuristic, we don't warn about system libraries found in
1293 // the same directory as -lc.
1294 if (strncmp(soname, "libc.so", 7) == 0)
1295 {
1296 const char* object_name = dynobj->name().c_str();
1297 const char* base = lbasename(object_name);
1298 if (base != object_name)
1299 this->system_library_directory_.assign(object_name,
1300 base - 1 - object_name);
1301 }
1302 }
1303
1304 return true;
1305 }
1306
1307 // Return whether an object was found in the system library directory.
1308
1309 bool
1310 Input_objects::found_in_system_library_directory(const Object* object) const
1311 {
1312 return (!this->system_library_directory_.empty()
1313 && object->name().compare(0,
1314 this->system_library_directory_.size(),
1315 this->system_library_directory_) == 0);
1316 }
1317
1318 // For each dynamic object, record whether we've seen all of its
1319 // explicit dependencies.
1320
1321 void
1322 Input_objects::check_dynamic_dependencies() const
1323 {
1324 for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
1325 p != this->dynobj_list_.end();
1326 ++p)
1327 {
1328 const Dynobj::Needed& needed((*p)->needed());
1329 bool found_all = true;
1330 for (Dynobj::Needed::const_iterator pneeded = needed.begin();
1331 pneeded != needed.end();
1332 ++pneeded)
1333 {
1334 if (this->sonames_.find(*pneeded) == this->sonames_.end())
1335 {
1336 found_all = false;
1337 break;
1338 }
1339 }
1340 (*p)->set_has_unknown_needed_entries(!found_all);
1341 }
1342 }
1343
1344 // Relocate_info methods.
1345
1346 // Return a string describing the location of a relocation. This is
1347 // only used in error messages.
1348
1349 template<int size, bool big_endian>
1350 std::string
1351 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
1352 {
1353 // See if we can get line-number information from debugging sections.
1354 std::string filename;
1355 std::string file_and_lineno; // Better than filename-only, if available.
1356
1357 Sized_dwarf_line_info<size, big_endian> line_info(this->object);
1358 // This will be "" if we failed to parse the debug info for any reason.
1359 file_and_lineno = line_info.addr2line(this->data_shndx, offset);
1360
1361 std::string ret(this->object->name());
1362 ret += ':';
1363 Symbol_location_info info;
1364 if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
1365 {
1366 ret += " in function ";
1367 ret += info.enclosing_symbol_name;
1368 ret += ":";
1369 filename = info.source_file;
1370 }
1371
1372 if (!file_and_lineno.empty())
1373 ret += file_and_lineno;
1374 else
1375 {
1376 if (!filename.empty())
1377 ret += filename;
1378 ret += "(";
1379 ret += this->object->section_name(this->data_shndx);
1380 char buf[100];
1381 // Offsets into sections have to be positive.
1382 snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset));
1383 ret += buf;
1384 ret += ")";
1385 }
1386 return ret;
1387 }
1388
1389 } // End namespace gold.
1390
1391 namespace
1392 {
1393
1394 using namespace gold;
1395
1396 // Read an ELF file with the header and return the appropriate
1397 // instance of Object.
1398
1399 template<int size, bool big_endian>
1400 Object*
1401 make_elf_sized_object(const std::string& name, Input_file* input_file,
1402 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
1403 {
1404 int et = ehdr.get_e_type();
1405 if (et == elfcpp::ET_REL)
1406 {
1407 Sized_relobj<size, big_endian>* obj =
1408 new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
1409 obj->setup(ehdr);
1410 return obj;
1411 }
1412 else if (et == elfcpp::ET_DYN)
1413 {
1414 Sized_dynobj<size, big_endian>* obj =
1415 new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
1416 obj->setup(ehdr);
1417 return obj;
1418 }
1419 else
1420 {
1421 gold_error(_("%s: unsupported ELF file type %d"),
1422 name.c_str(), et);
1423 return NULL;
1424 }
1425 }
1426
1427 } // End anonymous namespace.
1428
1429 namespace gold
1430 {
1431
1432 // Read an ELF file and return the appropriate instance of Object.
1433
1434 Object*
1435 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
1436 const unsigned char* p, section_offset_type bytes)
1437 {
1438 if (bytes < elfcpp::EI_NIDENT)
1439 {
1440 gold_error(_("%s: ELF file too short"), name.c_str());
1441 return NULL;
1442 }
1443
1444 int v = p[elfcpp::EI_VERSION];
1445 if (v != elfcpp::EV_CURRENT)
1446 {
1447 if (v == elfcpp::EV_NONE)
1448 gold_error(_("%s: invalid ELF version 0"), name.c_str());
1449 else
1450 gold_error(_("%s: unsupported ELF version %d"), name.c_str(), v);
1451 return NULL;
1452 }
1453
1454 int c = p[elfcpp::EI_CLASS];
1455 if (c == elfcpp::ELFCLASSNONE)
1456 {
1457 gold_error(_("%s: invalid ELF class 0"), name.c_str());
1458 return NULL;
1459 }
1460 else if (c != elfcpp::ELFCLASS32
1461 && c != elfcpp::ELFCLASS64)
1462 {
1463 gold_error(_("%s: unsupported ELF class %d"), name.c_str(), c);
1464 return NULL;
1465 }
1466
1467 int d = p[elfcpp::EI_DATA];
1468 if (d == elfcpp::ELFDATANONE)
1469 {
1470 gold_error(_("%s: invalid ELF data encoding"), name.c_str());
1471 return NULL;
1472 }
1473 else if (d != elfcpp::ELFDATA2LSB
1474 && d != elfcpp::ELFDATA2MSB)
1475 {
1476 gold_error(_("%s: unsupported ELF data encoding %d"), name.c_str(), d);
1477 return NULL;
1478 }
1479
1480 bool big_endian = d == elfcpp::ELFDATA2MSB;
1481
1482 if (c == elfcpp::ELFCLASS32)
1483 {
1484 if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
1485 {
1486 gold_error(_("%s: ELF file too short"), name.c_str());
1487 return NULL;
1488 }
1489 if (big_endian)
1490 {
1491 #ifdef HAVE_TARGET_32_BIG
1492 elfcpp::Ehdr<32, true> ehdr(p);
1493 return make_elf_sized_object<32, true>(name, input_file,
1494 offset, ehdr);
1495 #else
1496 gold_error(_("%s: not configured to support "
1497 "32-bit big-endian object"),
1498 name.c_str());
1499 return NULL;
1500 #endif
1501 }
1502 else
1503 {
1504 #ifdef HAVE_TARGET_32_LITTLE
1505 elfcpp::Ehdr<32, false> ehdr(p);
1506 return make_elf_sized_object<32, false>(name, input_file,
1507 offset, ehdr);
1508 #else
1509 gold_error(_("%s: not configured to support "
1510 "32-bit little-endian object"),
1511 name.c_str());
1512 return NULL;
1513 #endif
1514 }
1515 }
1516 else
1517 {
1518 if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
1519 {
1520 gold_error(_("%s: ELF file too short"), name.c_str());
1521 return NULL;
1522 }
1523 if (big_endian)
1524 {
1525 #ifdef HAVE_TARGET_64_BIG
1526 elfcpp::Ehdr<64, true> ehdr(p);
1527 return make_elf_sized_object<64, true>(name, input_file,
1528 offset, ehdr);
1529 #else
1530 gold_error(_("%s: not configured to support "
1531 "64-bit big-endian object"),
1532 name.c_str());
1533 return NULL;
1534 #endif
1535 }
1536 else
1537 {
1538 #ifdef HAVE_TARGET_64_LITTLE
1539 elfcpp::Ehdr<64, false> ehdr(p);
1540 return make_elf_sized_object<64, false>(name, input_file,
1541 offset, ehdr);
1542 #else
1543 gold_error(_("%s: not configured to support "
1544 "64-bit little-endian object"),
1545 name.c_str());
1546 return NULL;
1547 #endif
1548 }
1549 }
1550 }
1551
1552 // Instantiate the templates we need.
1553
1554 #ifdef HAVE_TARGET_32_LITTLE
1555 template
1556 void
1557 Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
1558 Read_symbols_data*);
1559 #endif
1560
1561 #ifdef HAVE_TARGET_32_BIG
1562 template
1563 void
1564 Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
1565 Read_symbols_data*);
1566 #endif
1567
1568 #ifdef HAVE_TARGET_64_LITTLE
1569 template
1570 void
1571 Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
1572 Read_symbols_data*);
1573 #endif
1574
1575 #ifdef HAVE_TARGET_64_BIG
1576 template
1577 void
1578 Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
1579 Read_symbols_data*);
1580 #endif
1581
1582 #ifdef HAVE_TARGET_32_LITTLE
1583 template
1584 class Sized_relobj<32, false>;
1585 #endif
1586
1587 #ifdef HAVE_TARGET_32_BIG
1588 template
1589 class Sized_relobj<32, true>;
1590 #endif
1591
1592 #ifdef HAVE_TARGET_64_LITTLE
1593 template
1594 class Sized_relobj<64, false>;
1595 #endif
1596
1597 #ifdef HAVE_TARGET_64_BIG
1598 template
1599 class Sized_relobj<64, true>;
1600 #endif
1601
1602 #ifdef HAVE_TARGET_32_LITTLE
1603 template
1604 struct Relocate_info<32, false>;
1605 #endif
1606
1607 #ifdef HAVE_TARGET_32_BIG
1608 template
1609 struct Relocate_info<32, true>;
1610 #endif
1611
1612 #ifdef HAVE_TARGET_64_LITTLE
1613 template
1614 struct Relocate_info<64, false>;
1615 #endif
1616
1617 #ifdef HAVE_TARGET_64_BIG
1618 template
1619 struct Relocate_info<64, true>;
1620 #endif
1621
1622 } // End namespace gold.
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