Implement -q/--emit-relocs.
[binutils-gdb.git] / gold / object.cc
1 // object.cc -- support for an object file for linking in gold
2
3 // Copyright 2006, 2007 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, 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, true);
100
101 // Read the section names.
102 const unsigned char* pshdrs = sd->section_headers->data();
103 const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
104 typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
105
106 if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
107 this->error(_("section name section has wrong type: %u"),
108 static_cast<unsigned int>(shdrnames.get_sh_type()));
109
110 sd->section_names_size =
111 convert_to_section_size_type(shdrnames.get_sh_size());
112 sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
113 sd->section_names_size, false);
114 }
115
116 // If NAME is the name of a special .gnu.warning section, arrange for
117 // the warning to be issued. SHNDX is the section index. Return
118 // whether it is a warning section.
119
120 bool
121 Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
122 Symbol_table* symtab)
123 {
124 const char warn_prefix[] = ".gnu.warning.";
125 const int warn_prefix_len = sizeof warn_prefix - 1;
126 if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
127 {
128 // Read the section contents to get the warning text. It would
129 // be nicer if we only did this if we have to actually issue a
130 // warning. Unfortunately, warnings are issued as we relocate
131 // sections. That means that we can not lock the object then,
132 // as we might try to issue the same warning multiple times
133 // simultaneously.
134 section_size_type len;
135 const unsigned char* contents = this->section_contents(shndx, &len,
136 false);
137 std::string warning(reinterpret_cast<const char*>(contents), len);
138 symtab->add_warning(name + warn_prefix_len, this, warning);
139 return true;
140 }
141 return false;
142 }
143
144 // Class Sized_relobj.
145
146 template<int size, bool big_endian>
147 Sized_relobj<size, big_endian>::Sized_relobj(
148 const std::string& name,
149 Input_file* input_file,
150 off_t offset,
151 const elfcpp::Ehdr<size, big_endian>& ehdr)
152 : Relobj(name, input_file, offset),
153 elf_file_(this, ehdr),
154 symtab_shndx_(-1U),
155 local_symbol_count_(0),
156 output_local_symbol_count_(0),
157 output_local_dynsym_count_(0),
158 symbols_(),
159 local_symbol_offset_(0),
160 local_dynsym_offset_(0),
161 local_values_(),
162 local_got_offsets_(),
163 has_eh_frame_(false)
164 {
165 }
166
167 template<int size, bool big_endian>
168 Sized_relobj<size, big_endian>::~Sized_relobj()
169 {
170 }
171
172 // Set up an object file based on the file header. This sets up the
173 // target and reads the section information.
174
175 template<int size, bool big_endian>
176 void
177 Sized_relobj<size, big_endian>::setup(
178 const elfcpp::Ehdr<size, big_endian>& ehdr)
179 {
180 this->set_target(ehdr.get_e_machine(), size, big_endian,
181 ehdr.get_e_ident()[elfcpp::EI_OSABI],
182 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
183
184 const unsigned int shnum = this->elf_file_.shnum();
185 this->set_shnum(shnum);
186 }
187
188 // Find the SHT_SYMTAB section, given the section headers. The ELF
189 // standard says that maybe in the future there can be more than one
190 // SHT_SYMTAB section. Until somebody figures out how that could
191 // work, we assume there is only one.
192
193 template<int size, bool big_endian>
194 void
195 Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
196 {
197 const unsigned int shnum = this->shnum();
198 this->symtab_shndx_ = 0;
199 if (shnum > 0)
200 {
201 // Look through the sections in reverse order, since gas tends
202 // to put the symbol table at the end.
203 const unsigned char* p = pshdrs + shnum * This::shdr_size;
204 unsigned int i = shnum;
205 while (i > 0)
206 {
207 --i;
208 p -= This::shdr_size;
209 typename This::Shdr shdr(p);
210 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
211 {
212 this->symtab_shndx_ = i;
213 break;
214 }
215 }
216 }
217 }
218
219 // Return whether SHDR has the right type and flags to be a GNU
220 // .eh_frame section.
221
222 template<int size, bool big_endian>
223 bool
224 Sized_relobj<size, big_endian>::check_eh_frame_flags(
225 const elfcpp::Shdr<size, big_endian>* shdr) const
226 {
227 return (shdr->get_sh_size() > 0
228 && shdr->get_sh_type() == elfcpp::SHT_PROGBITS
229 && shdr->get_sh_flags() == elfcpp::SHF_ALLOC);
230 }
231
232 // Return whether there is a GNU .eh_frame section, given the section
233 // headers and the section names.
234
235 template<int size, bool big_endian>
236 bool
237 Sized_relobj<size, big_endian>::find_eh_frame(
238 const unsigned char* pshdrs,
239 const char* names,
240 section_size_type names_size) const
241 {
242 const unsigned int shnum = this->shnum();
243 const unsigned char* p = pshdrs + This::shdr_size;
244 for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
245 {
246 typename This::Shdr shdr(p);
247 if (this->check_eh_frame_flags(&shdr))
248 {
249 if (shdr.get_sh_name() >= names_size)
250 {
251 this->error(_("bad section name offset for section %u: %lu"),
252 i, static_cast<unsigned long>(shdr.get_sh_name()));
253 continue;
254 }
255
256 const char* name = names + shdr.get_sh_name();
257 if (strcmp(name, ".eh_frame") == 0)
258 return true;
259 }
260 }
261 return false;
262 }
263
264 // Read the sections and symbols from an object file.
265
266 template<int size, bool big_endian>
267 void
268 Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
269 {
270 this->read_section_data(&this->elf_file_, sd);
271
272 const unsigned char* const pshdrs = sd->section_headers->data();
273
274 this->find_symtab(pshdrs);
275
276 const unsigned char* namesu = sd->section_names->data();
277 const char* names = reinterpret_cast<const char*>(namesu);
278 if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
279 this->has_eh_frame_ = true;
280
281 sd->symbols = NULL;
282 sd->symbols_size = 0;
283 sd->external_symbols_offset = 0;
284 sd->symbol_names = NULL;
285 sd->symbol_names_size = 0;
286
287 if (this->symtab_shndx_ == 0)
288 {
289 // No symbol table. Weird but legal.
290 return;
291 }
292
293 // Get the symbol table section header.
294 typename This::Shdr symtabshdr(pshdrs
295 + this->symtab_shndx_ * This::shdr_size);
296 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
297
298 // If this object has a .eh_frame section, we need all the symbols.
299 // Otherwise we only need the external symbols. While it would be
300 // simpler to just always read all the symbols, I've seen object
301 // files with well over 2000 local symbols, which for a 64-bit
302 // object file format is over 5 pages that we don't need to read
303 // now.
304
305 const int sym_size = This::sym_size;
306 const unsigned int loccount = symtabshdr.get_sh_info();
307 this->local_symbol_count_ = loccount;
308 this->local_values_.resize(loccount);
309 section_offset_type locsize = loccount * sym_size;
310 off_t dataoff = symtabshdr.get_sh_offset();
311 section_size_type datasize =
312 convert_to_section_size_type(symtabshdr.get_sh_size());
313 off_t extoff = dataoff + locsize;
314 section_size_type extsize = datasize - locsize;
315
316 off_t readoff = this->has_eh_frame_ ? dataoff : extoff;
317 section_size_type readsize = this->has_eh_frame_ ? datasize : extsize;
318
319 File_view* fvsymtab = this->get_lasting_view(readoff, readsize, false);
320
321 // Read the section header for the symbol names.
322 unsigned int strtab_shndx = symtabshdr.get_sh_link();
323 if (strtab_shndx >= this->shnum())
324 {
325 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
326 return;
327 }
328 typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
329 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
330 {
331 this->error(_("symbol table name section has wrong type: %u"),
332 static_cast<unsigned int>(strtabshdr.get_sh_type()));
333 return;
334 }
335
336 // Read the symbol names.
337 File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
338 strtabshdr.get_sh_size(), true);
339
340 sd->symbols = fvsymtab;
341 sd->symbols_size = readsize;
342 sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0;
343 sd->symbol_names = fvstrtab;
344 sd->symbol_names_size =
345 convert_to_section_size_type(strtabshdr.get_sh_size());
346 }
347
348 // Return the section index of symbol SYM. Set *VALUE to its value in
349 // the object file. Note that for a symbol which is not defined in
350 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
351 // it will not return the final value of the symbol in the link.
352
353 template<int size, bool big_endian>
354 unsigned int
355 Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym,
356 Address* value)
357 {
358 section_size_type symbols_size;
359 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
360 &symbols_size,
361 false);
362
363 const size_t count = symbols_size / This::sym_size;
364 gold_assert(sym < count);
365
366 elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
367 *value = elfsym.get_st_value();
368 // FIXME: Handle SHN_XINDEX.
369 return elfsym.get_st_shndx();
370 }
371
372 // Return whether to include a section group in the link. LAYOUT is
373 // used to keep track of which section groups we have already seen.
374 // INDEX is the index of the section group and SHDR is the section
375 // header. If we do not want to include this group, we set bits in
376 // OMIT for each section which should be discarded.
377
378 template<int size, bool big_endian>
379 bool
380 Sized_relobj<size, big_endian>::include_section_group(
381 Symbol_table* symtab,
382 Layout* layout,
383 unsigned int index,
384 const char* name,
385 const elfcpp::Shdr<size, big_endian>& shdr,
386 std::vector<bool>* omit)
387 {
388 // Read the section contents.
389 const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
390 shdr.get_sh_size(), false);
391 const elfcpp::Elf_Word* pword =
392 reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
393
394 // The first word contains flags. We only care about COMDAT section
395 // groups. Other section groups are always included in the link
396 // just like ordinary sections.
397 elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
398
399 // Look up the group signature, which is the name of a symbol. This
400 // is a lot of effort to go to to read a string. Why didn't they
401 // just have the group signature point into the string table, rather
402 // than indirect through a symbol?
403
404 // Get the appropriate symbol table header (this will normally be
405 // the single SHT_SYMTAB section, but in principle it need not be).
406 const unsigned int link = shdr.get_sh_link();
407 typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
408
409 // Read the symbol table entry.
410 if (shdr.get_sh_info() >= symshdr.get_sh_size() / This::sym_size)
411 {
412 this->error(_("section group %u info %u out of range"),
413 index, shdr.get_sh_info());
414 return false;
415 }
416 off_t symoff = symshdr.get_sh_offset() + shdr.get_sh_info() * This::sym_size;
417 const unsigned char* psym = this->get_view(symoff, This::sym_size, false);
418 elfcpp::Sym<size, big_endian> sym(psym);
419
420 // Read the symbol table names.
421 section_size_type symnamelen;
422 const unsigned char* psymnamesu;
423 psymnamesu = this->section_contents(symshdr.get_sh_link(), &symnamelen,
424 true);
425 const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
426
427 // Get the section group signature.
428 if (sym.get_st_name() >= symnamelen)
429 {
430 this->error(_("symbol %u name offset %u out of range"),
431 shdr.get_sh_info(), sym.get_st_name());
432 return false;
433 }
434
435 const char* signature = psymnames + sym.get_st_name();
436
437 // It seems that some versions of gas will create a section group
438 // associated with a section symbol, and then fail to give a name to
439 // the section symbol. In such a case, use the name of the section.
440 // FIXME.
441 std::string secname;
442 if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
443 {
444 secname = this->section_name(sym.get_st_shndx());
445 signature = secname.c_str();
446 }
447
448 // Record this section group, and see whether we've already seen one
449 // with the same signature.
450
451 if ((flags & elfcpp::GRP_COMDAT) == 0
452 || layout->add_comdat(signature, true))
453 {
454 if (parameters->output_is_object())
455 layout->layout_group(symtab, this, index, name, signature, shdr,
456 pword);
457 return true;
458 }
459
460 // This is a duplicate. We want to discard the sections in this
461 // group.
462 size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
463 for (size_t i = 1; i < count; ++i)
464 {
465 elfcpp::Elf_Word secnum =
466 elfcpp::Swap<32, big_endian>::readval(pword + i);
467 if (secnum >= this->shnum())
468 {
469 this->error(_("section %u in section group %u out of range"),
470 secnum, index);
471 continue;
472 }
473 (*omit)[secnum] = true;
474 }
475
476 return false;
477 }
478
479 // Whether to include a linkonce section in the link. NAME is the
480 // name of the section and SHDR is the section header.
481
482 // Linkonce sections are a GNU extension implemented in the original
483 // GNU linker before section groups were defined. The semantics are
484 // that we only include one linkonce section with a given name. The
485 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
486 // where T is the type of section and SYMNAME is the name of a symbol.
487 // In an attempt to make linkonce sections interact well with section
488 // groups, we try to identify SYMNAME and use it like a section group
489 // signature. We want to block section groups with that signature,
490 // but not other linkonce sections with that signature. We also use
491 // the full name of the linkonce section as a normal section group
492 // signature.
493
494 template<int size, bool big_endian>
495 bool
496 Sized_relobj<size, big_endian>::include_linkonce_section(
497 Layout* layout,
498 const char* name,
499 const elfcpp::Shdr<size, big_endian>&)
500 {
501 // In general the symbol name we want will be the string following
502 // the last '.'. However, we have to handle the case of
503 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
504 // some versions of gcc. So we use a heuristic: if the name starts
505 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
506 // we look for the last '.'. We can't always simply skip
507 // ".gnu.linkonce.X", because we have to deal with cases like
508 // ".gnu.linkonce.d.rel.ro.local".
509 const char* const linkonce_t = ".gnu.linkonce.t.";
510 const char* symname;
511 if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
512 symname = name + strlen(linkonce_t);
513 else
514 symname = strrchr(name, '.') + 1;
515 bool include1 = layout->add_comdat(symname, false);
516 bool include2 = layout->add_comdat(name, true);
517 return include1 && include2;
518 }
519
520 // Lay out the input sections. We walk through the sections and check
521 // whether they should be included in the link. If they should, we
522 // pass them to the Layout object, which will return an output section
523 // and an offset.
524
525 template<int size, bool big_endian>
526 void
527 Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
528 Layout* layout,
529 Read_symbols_data* sd)
530 {
531 const unsigned int shnum = this->shnum();
532 if (shnum == 0)
533 return;
534
535 // Get the section headers.
536 const unsigned char* pshdrs = sd->section_headers->data();
537
538 // Get the section names.
539 const unsigned char* pnamesu = sd->section_names->data();
540 const char* pnames = reinterpret_cast<const char*>(pnamesu);
541
542 // For each section, record the index of the reloc section if any.
543 // Use 0 to mean that there is no reloc section, -1U to mean that
544 // there is more than one.
545 std::vector<unsigned int> reloc_shndx(shnum, 0);
546 std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
547 // Skip the first, dummy, section.
548 pshdrs += This::shdr_size;
549 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
550 {
551 typename This::Shdr shdr(pshdrs);
552
553 unsigned int sh_type = shdr.get_sh_type();
554 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
555 {
556 unsigned int target_shndx = shdr.get_sh_info();
557 if (target_shndx == 0 || target_shndx >= shnum)
558 {
559 this->error(_("relocation section %u has bad info %u"),
560 i, target_shndx);
561 continue;
562 }
563
564 if (reloc_shndx[target_shndx] != 0)
565 reloc_shndx[target_shndx] = -1U;
566 else
567 {
568 reloc_shndx[target_shndx] = i;
569 reloc_type[target_shndx] = sh_type;
570 }
571 }
572 }
573
574 std::vector<Map_to_output>& map_sections(this->map_to_output());
575 map_sections.resize(shnum);
576
577 // If we are only linking for symbols, then there is nothing else to
578 // do here.
579 if (this->input_file()->just_symbols())
580 {
581 delete sd->section_headers;
582 sd->section_headers = NULL;
583 delete sd->section_names;
584 sd->section_names = NULL;
585 return;
586 }
587
588 // Whether we've seen a .note.GNU-stack section.
589 bool seen_gnu_stack = false;
590 // The flags of a .note.GNU-stack section.
591 uint64_t gnu_stack_flags = 0;
592
593 // Keep track of which sections to omit.
594 std::vector<bool> omit(shnum, false);
595
596 // Keep track of reloc sections when emitting relocations.
597 const bool output_is_object = parameters->output_is_object();
598 const bool emit_relocs = output_is_object || parameters->emit_relocs();
599 std::vector<unsigned int> reloc_sections;
600
601 // Keep track of .eh_frame sections.
602 std::vector<unsigned int> eh_frame_sections;
603
604 // Skip the first, dummy, section.
605 pshdrs = sd->section_headers->data() + This::shdr_size;
606 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
607 {
608 typename This::Shdr shdr(pshdrs);
609
610 if (shdr.get_sh_name() >= sd->section_names_size)
611 {
612 this->error(_("bad section name offset for section %u: %lu"),
613 i, static_cast<unsigned long>(shdr.get_sh_name()));
614 return;
615 }
616
617 const char* name = pnames + shdr.get_sh_name();
618
619 if (this->handle_gnu_warning_section(name, i, symtab))
620 {
621 if (!output_is_object)
622 omit[i] = true;
623 }
624
625 // The .note.GNU-stack section is special. It gives the
626 // protection flags that this object file requires for the stack
627 // in memory.
628 if (strcmp(name, ".note.GNU-stack") == 0)
629 {
630 seen_gnu_stack = true;
631 gnu_stack_flags |= shdr.get_sh_flags();
632 omit[i] = true;
633 }
634
635 bool discard = omit[i];
636 if (!discard)
637 {
638 if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
639 {
640 if (!this->include_section_group(symtab, layout, i, name, shdr,
641 &omit))
642 discard = true;
643 }
644 else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
645 && Layout::is_linkonce(name))
646 {
647 if (!this->include_linkonce_section(layout, name, shdr))
648 discard = true;
649 }
650 }
651
652 if (discard)
653 {
654 // Do not include this section in the link.
655 map_sections[i].output_section = NULL;
656 continue;
657 }
658
659 // When doing a relocatable link we are going to copy input
660 // reloc sections into the output. We only want to copy the
661 // ones associated with sections which are not being discarded.
662 // However, we don't know that yet for all sections. So save
663 // reloc sections and process them later.
664 if (emit_relocs
665 && (shdr.get_sh_type() == elfcpp::SHT_REL
666 || shdr.get_sh_type() == elfcpp::SHT_RELA))
667 {
668 reloc_sections.push_back(i);
669 continue;
670 }
671
672 if (output_is_object && shdr.get_sh_type() == elfcpp::SHT_GROUP)
673 continue;
674
675 // The .eh_frame section is special. It holds exception frame
676 // information that we need to read in order to generate the
677 // exception frame header. We process these after all the other
678 // sections so that the exception frame reader can reliably
679 // determine which sections are being discarded, and discard the
680 // corresponding information.
681 if (!output_is_object
682 && strcmp(name, ".eh_frame") == 0
683 && this->check_eh_frame_flags(&shdr))
684 {
685 eh_frame_sections.push_back(i);
686 continue;
687 }
688
689 off_t offset;
690 Output_section* os = layout->layout(this, i, name, shdr,
691 reloc_shndx[i], reloc_type[i],
692 &offset);
693
694 map_sections[i].output_section = os;
695 map_sections[i].offset = offset;
696
697 // If this section requires special handling, and if there are
698 // relocs that apply to it, then we must do the special handling
699 // before we apply the relocs.
700 if (offset == -1 && reloc_shndx[i] != 0)
701 this->set_relocs_must_follow_section_writes();
702 }
703
704 layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
705
706 // When doing a relocatable link handle the reloc sections at the
707 // end.
708 if (emit_relocs)
709 this->size_relocatable_relocs();
710 for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
711 p != reloc_sections.end();
712 ++p)
713 {
714 unsigned int i = *p;
715 const unsigned char* pshdr;
716 pshdr = sd->section_headers->data() + i * This::shdr_size;
717 typename This::Shdr shdr(pshdr);
718
719 unsigned int data_shndx = shdr.get_sh_info();
720 if (data_shndx >= shnum)
721 {
722 // We already warned about this above.
723 continue;
724 }
725
726 Output_section* data_section = map_sections[data_shndx].output_section;
727 if (data_section == NULL)
728 {
729 map_sections[i].output_section = NULL;
730 continue;
731 }
732
733 Relocatable_relocs* rr = new Relocatable_relocs();
734 this->set_relocatable_relocs(i, rr);
735
736 Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
737 rr);
738 map_sections[i].output_section = os;
739 map_sections[i].offset = -1;
740 }
741
742 // Handle the .eh_frame sections at the end.
743 for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
744 p != eh_frame_sections.end();
745 ++p)
746 {
747 gold_assert(this->has_eh_frame_);
748 gold_assert(sd->external_symbols_offset != 0);
749
750 unsigned int i = *p;
751 const unsigned char *pshdr;
752 pshdr = sd->section_headers->data() + i * This::shdr_size;
753 typename This::Shdr shdr(pshdr);
754
755 off_t offset;
756 Output_section* os = layout->layout_eh_frame(this,
757 sd->symbols->data(),
758 sd->symbols_size,
759 sd->symbol_names->data(),
760 sd->symbol_names_size,
761 i, shdr,
762 reloc_shndx[i],
763 reloc_type[i],
764 &offset);
765 map_sections[i].output_section = os;
766 map_sections[i].offset = offset;
767
768 // If this section requires special handling, and if there are
769 // relocs that apply to it, then we must do the special handling
770 // before we apply the relocs.
771 if (offset == -1 && reloc_shndx[i] != 0)
772 this->set_relocs_must_follow_section_writes();
773 }
774
775 delete sd->section_headers;
776 sd->section_headers = NULL;
777 delete sd->section_names;
778 sd->section_names = NULL;
779 }
780
781 // Add the symbols to the symbol table.
782
783 template<int size, bool big_endian>
784 void
785 Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
786 Read_symbols_data* sd)
787 {
788 if (sd->symbols == NULL)
789 {
790 gold_assert(sd->symbol_names == NULL);
791 return;
792 }
793
794 const int sym_size = This::sym_size;
795 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
796 / sym_size);
797 if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
798 {
799 this->error(_("size of symbols is not multiple of symbol size"));
800 return;
801 }
802
803 this->symbols_.resize(symcount);
804
805 const char* sym_names =
806 reinterpret_cast<const char*>(sd->symbol_names->data());
807 symtab->add_from_relobj(this,
808 sd->symbols->data() + sd->external_symbols_offset,
809 symcount, sym_names, sd->symbol_names_size,
810 &this->symbols_);
811
812 delete sd->symbols;
813 sd->symbols = NULL;
814 delete sd->symbol_names;
815 sd->symbol_names = NULL;
816 }
817
818 // First pass over the local symbols. Here we add their names to
819 // *POOL and *DYNPOOL, and we store the symbol value in
820 // THIS->LOCAL_VALUES_. This function is always called from a
821 // singleton thread. This is followed by a call to
822 // finalize_local_symbols.
823
824 template<int size, bool big_endian>
825 void
826 Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
827 Stringpool* dynpool)
828 {
829 gold_assert(this->symtab_shndx_ != -1U);
830 if (this->symtab_shndx_ == 0)
831 {
832 // This object has no symbols. Weird but legal.
833 return;
834 }
835
836 // Read the symbol table section header.
837 const unsigned int symtab_shndx = this->symtab_shndx_;
838 typename This::Shdr symtabshdr(this,
839 this->elf_file_.section_header(symtab_shndx));
840 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
841
842 // Read the local symbols.
843 const int sym_size = This::sym_size;
844 const unsigned int loccount = this->local_symbol_count_;
845 gold_assert(loccount == symtabshdr.get_sh_info());
846 off_t locsize = loccount * sym_size;
847 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
848 locsize, true);
849
850 // Read the symbol names.
851 const unsigned int strtab_shndx = symtabshdr.get_sh_link();
852 section_size_type strtab_size;
853 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
854 &strtab_size,
855 true);
856 const char* pnames = reinterpret_cast<const char*>(pnamesu);
857
858 // Loop over the local symbols.
859
860 const std::vector<Map_to_output>& mo(this->map_to_output());
861 unsigned int shnum = this->shnum();
862 unsigned int count = 0;
863 unsigned int dyncount = 0;
864 // Skip the first, dummy, symbol.
865 psyms += sym_size;
866 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
867 {
868 elfcpp::Sym<size, big_endian> sym(psyms);
869
870 Symbol_value<size>& lv(this->local_values_[i]);
871
872 unsigned int shndx = sym.get_st_shndx();
873 lv.set_input_shndx(shndx);
874
875 if (sym.get_st_type() == elfcpp::STT_SECTION)
876 lv.set_is_section_symbol();
877 else if (sym.get_st_type() == elfcpp::STT_TLS)
878 lv.set_is_tls_symbol();
879
880 // Save the input symbol value for use in do_finalize_local_symbols().
881 lv.set_input_value(sym.get_st_value());
882
883 // Decide whether this symbol should go into the output file.
884
885 if (shndx < shnum && mo[shndx].output_section == NULL)
886 {
887 lv.set_no_output_symtab_entry();
888 gold_assert(!lv.needs_output_dynsym_entry());
889 continue;
890 }
891
892 if (sym.get_st_type() == elfcpp::STT_SECTION)
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_name() >= strtab_size)
900 {
901 this->error(_("local symbol %u section name out of range: %u >= %u"),
902 i, sym.get_st_name(),
903 static_cast<unsigned int>(strtab_size));
904 lv.set_no_output_symtab_entry();
905 continue;
906 }
907
908 // Add the symbol to the symbol table string pool.
909 const char* name = pnames + sym.get_st_name();
910 pool->add(name, true, NULL);
911 ++count;
912
913 // If needed, add the symbol to the dynamic symbol table string pool.
914 if (lv.needs_output_dynsym_entry())
915 {
916 dynpool->add(name, true, NULL);
917 ++dyncount;
918 }
919 }
920
921 this->output_local_symbol_count_ = count;
922 this->output_local_dynsym_count_ = dyncount;
923 }
924
925 // Finalize the local symbols. Here we set the final value in
926 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
927 // This function is always called from a singleton thread. The actual
928 // output of the local symbols will occur in a separate task.
929
930 template<int size, bool big_endian>
931 unsigned int
932 Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
933 off_t off)
934 {
935 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
936
937 const unsigned int loccount = this->local_symbol_count_;
938 this->local_symbol_offset_ = off;
939
940 const std::vector<Map_to_output>& mo(this->map_to_output());
941 unsigned int shnum = this->shnum();
942
943 for (unsigned int i = 1; i < loccount; ++i)
944 {
945 Symbol_value<size>& lv(this->local_values_[i]);
946
947 unsigned int shndx = lv.input_shndx();
948
949 // Set the output symbol value.
950
951 if (shndx >= elfcpp::SHN_LORESERVE)
952 {
953 if (shndx == elfcpp::SHN_ABS)
954 lv.set_output_value(lv.input_value());
955 else
956 {
957 // FIXME: Handle SHN_XINDEX.
958 this->error(_("unknown section index %u for local symbol %u"),
959 shndx, i);
960 lv.set_output_value(0);
961 }
962 }
963 else
964 {
965 if (shndx >= shnum)
966 {
967 this->error(_("local symbol %u section index %u out of range"),
968 i, shndx);
969 shndx = 0;
970 }
971
972 Output_section* os = mo[shndx].output_section;
973
974 if (os == NULL)
975 {
976 lv.set_output_value(0);
977 continue;
978 }
979 else if (mo[shndx].offset == -1)
980 {
981 // This is a SHF_MERGE section or one which otherwise
982 // requires special handling. We get the output address
983 // of the start of the merged section. If this is not a
984 // section symbol, we can then determine the final
985 // value. If it is a section symbol, we can not, as in
986 // that case we have to consider the addend to determine
987 // the value to use in a relocation.
988 if (!lv.is_section_symbol())
989 lv.set_output_value(os->output_address(this, shndx,
990 lv.input_value()));
991 else
992 {
993 section_offset_type start =
994 os->starting_output_address(this, shndx);
995 Merged_symbol_value<size>* msv =
996 new Merged_symbol_value<size>(lv.input_value(), start);
997 lv.set_merged_symbol_value(msv);
998 }
999 }
1000 else if (lv.is_tls_symbol())
1001 lv.set_output_value(os->tls_offset()
1002 + mo[shndx].offset
1003 + lv.input_value());
1004 else
1005 lv.set_output_value(os->address()
1006 + mo[shndx].offset
1007 + lv.input_value());
1008 }
1009
1010 if (lv.needs_output_symtab_entry())
1011 {
1012 lv.set_output_symtab_index(index);
1013 ++index;
1014 }
1015 }
1016 return index;
1017 }
1018
1019 // Set the output dynamic symbol table indexes for the local variables.
1020
1021 template<int size, bool big_endian>
1022 unsigned int
1023 Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index)
1024 {
1025 const unsigned int loccount = this->local_symbol_count_;
1026 for (unsigned int i = 1; i < loccount; ++i)
1027 {
1028 Symbol_value<size>& lv(this->local_values_[i]);
1029 if (lv.needs_output_dynsym_entry())
1030 {
1031 lv.set_output_dynsym_index(index);
1032 ++index;
1033 }
1034 }
1035 return index;
1036 }
1037
1038 // Set the offset where local dynamic symbol information will be stored.
1039 // Returns the count of local symbols contributed to the symbol table by
1040 // this object.
1041
1042 template<int size, bool big_endian>
1043 unsigned int
1044 Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off)
1045 {
1046 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
1047 this->local_dynsym_offset_ = off;
1048 return this->output_local_dynsym_count_;
1049 }
1050
1051 // Return the value of the local symbol symndx.
1052 template<int size, bool big_endian>
1053 typename elfcpp::Elf_types<size>::Elf_Addr
1054 Sized_relobj<size, big_endian>::local_symbol_value(unsigned int symndx) const
1055 {
1056 gold_assert(symndx < this->local_symbol_count_);
1057 gold_assert(symndx < this->local_values_.size());
1058 const Symbol_value<size>& lv(this->local_values_[symndx]);
1059 return lv.value(this, 0);
1060 }
1061
1062 // Write out the local symbols.
1063
1064 template<int size, bool big_endian>
1065 void
1066 Sized_relobj<size, big_endian>::write_local_symbols(
1067 Output_file* of,
1068 const Stringpool* sympool,
1069 const Stringpool* dynpool)
1070 {
1071 if (parameters->strip_all() && this->output_local_dynsym_count_ == 0)
1072 return;
1073
1074 gold_assert(this->symtab_shndx_ != -1U);
1075 if (this->symtab_shndx_ == 0)
1076 {
1077 // This object has no symbols. Weird but legal.
1078 return;
1079 }
1080
1081 // Read the symbol table section header.
1082 const unsigned int symtab_shndx = this->symtab_shndx_;
1083 typename This::Shdr symtabshdr(this,
1084 this->elf_file_.section_header(symtab_shndx));
1085 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1086 const unsigned int loccount = this->local_symbol_count_;
1087 gold_assert(loccount == symtabshdr.get_sh_info());
1088
1089 // Read the local symbols.
1090 const int sym_size = This::sym_size;
1091 off_t locsize = loccount * sym_size;
1092 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1093 locsize, false);
1094
1095 // Read the symbol names.
1096 const unsigned int strtab_shndx = symtabshdr.get_sh_link();
1097 section_size_type strtab_size;
1098 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1099 &strtab_size,
1100 false);
1101 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1102
1103 // Get views into the output file for the portions of the symbol table
1104 // and the dynamic symbol table that we will be writing.
1105 off_t output_size = this->output_local_symbol_count_ * sym_size;
1106 unsigned char* oview = NULL;
1107 if (output_size > 0)
1108 oview = of->get_output_view(this->local_symbol_offset_, output_size);
1109
1110 off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
1111 unsigned char* dyn_oview = NULL;
1112 if (dyn_output_size > 0)
1113 dyn_oview = of->get_output_view(this->local_dynsym_offset_,
1114 dyn_output_size);
1115
1116 const std::vector<Map_to_output>& mo(this->map_to_output());
1117
1118 gold_assert(this->local_values_.size() == loccount);
1119
1120 unsigned char* ov = oview;
1121 unsigned char* dyn_ov = dyn_oview;
1122 psyms += sym_size;
1123 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1124 {
1125 elfcpp::Sym<size, big_endian> isym(psyms);
1126
1127 unsigned int st_shndx = isym.get_st_shndx();
1128 if (st_shndx < elfcpp::SHN_LORESERVE)
1129 {
1130 gold_assert(st_shndx < mo.size());
1131 if (mo[st_shndx].output_section == NULL)
1132 continue;
1133 st_shndx = mo[st_shndx].output_section->out_shndx();
1134 }
1135
1136 // Write the symbol to the output symbol table.
1137 if (!parameters->strip_all()
1138 && this->local_values_[i].needs_output_symtab_entry())
1139 {
1140 elfcpp::Sym_write<size, big_endian> osym(ov);
1141
1142 gold_assert(isym.get_st_name() < strtab_size);
1143 const char* name = pnames + isym.get_st_name();
1144 osym.put_st_name(sympool->get_offset(name));
1145 osym.put_st_value(this->local_values_[i].value(this, 0));
1146 osym.put_st_size(isym.get_st_size());
1147 osym.put_st_info(isym.get_st_info());
1148 osym.put_st_other(isym.get_st_other());
1149 osym.put_st_shndx(st_shndx);
1150
1151 ov += sym_size;
1152 }
1153
1154 // Write the symbol to the output dynamic symbol table.
1155 if (this->local_values_[i].needs_output_dynsym_entry())
1156 {
1157 gold_assert(dyn_ov < dyn_oview + dyn_output_size);
1158 elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
1159
1160 gold_assert(isym.get_st_name() < strtab_size);
1161 const char* name = pnames + isym.get_st_name();
1162 osym.put_st_name(dynpool->get_offset(name));
1163 osym.put_st_value(this->local_values_[i].value(this, 0));
1164 osym.put_st_size(isym.get_st_size());
1165 osym.put_st_info(isym.get_st_info());
1166 osym.put_st_other(isym.get_st_other());
1167 osym.put_st_shndx(st_shndx);
1168
1169 dyn_ov += sym_size;
1170 }
1171 }
1172
1173
1174 if (output_size > 0)
1175 {
1176 gold_assert(ov - oview == output_size);
1177 of->write_output_view(this->local_symbol_offset_, output_size, oview);
1178 }
1179
1180 if (dyn_output_size > 0)
1181 {
1182 gold_assert(dyn_ov - dyn_oview == dyn_output_size);
1183 of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
1184 dyn_oview);
1185 }
1186 }
1187
1188 // Set *INFO to symbolic information about the offset OFFSET in the
1189 // section SHNDX. Return true if we found something, false if we
1190 // found nothing.
1191
1192 template<int size, bool big_endian>
1193 bool
1194 Sized_relobj<size, big_endian>::get_symbol_location_info(
1195 unsigned int shndx,
1196 off_t offset,
1197 Symbol_location_info* info)
1198 {
1199 if (this->symtab_shndx_ == 0)
1200 return false;
1201
1202 section_size_type symbols_size;
1203 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
1204 &symbols_size,
1205 false);
1206
1207 unsigned int symbol_names_shndx = this->section_link(this->symtab_shndx_);
1208 section_size_type names_size;
1209 const unsigned char* symbol_names_u =
1210 this->section_contents(symbol_names_shndx, &names_size, false);
1211 const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
1212
1213 const int sym_size = This::sym_size;
1214 const size_t count = symbols_size / sym_size;
1215
1216 const unsigned char* p = symbols;
1217 for (size_t i = 0; i < count; ++i, p += sym_size)
1218 {
1219 elfcpp::Sym<size, big_endian> sym(p);
1220
1221 if (sym.get_st_type() == elfcpp::STT_FILE)
1222 {
1223 if (sym.get_st_name() >= names_size)
1224 info->source_file = "(invalid)";
1225 else
1226 info->source_file = symbol_names + sym.get_st_name();
1227 }
1228 else if (sym.get_st_shndx() == shndx
1229 && static_cast<off_t>(sym.get_st_value()) <= offset
1230 && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
1231 > offset))
1232 {
1233 if (sym.get_st_name() > names_size)
1234 info->enclosing_symbol_name = "(invalid)";
1235 else
1236 {
1237 info->enclosing_symbol_name = symbol_names + sym.get_st_name();
1238 if (parameters->demangle())
1239 {
1240 char* demangled_name = cplus_demangle(
1241 info->enclosing_symbol_name.c_str(),
1242 DMGL_ANSI | DMGL_PARAMS);
1243 if (demangled_name != NULL)
1244 {
1245 info->enclosing_symbol_name.assign(demangled_name);
1246 free(demangled_name);
1247 }
1248 }
1249 }
1250 return true;
1251 }
1252 }
1253
1254 return false;
1255 }
1256
1257 // Input_objects methods.
1258
1259 // Add a regular relocatable object to the list. Return false if this
1260 // object should be ignored.
1261
1262 bool
1263 Input_objects::add_object(Object* obj)
1264 {
1265 // Set the global target from the first object file we recognize.
1266 Target* target = obj->target();
1267 if (!parameters->is_target_valid())
1268 set_parameters_target(target);
1269 else if (target != parameters->target())
1270 {
1271 obj->error(_("incompatible target"));
1272 return false;
1273 }
1274
1275 if (!obj->is_dynamic())
1276 this->relobj_list_.push_back(static_cast<Relobj*>(obj));
1277 else
1278 {
1279 // See if this is a duplicate SONAME.
1280 Dynobj* dynobj = static_cast<Dynobj*>(obj);
1281 const char* soname = dynobj->soname();
1282
1283 std::pair<Unordered_set<std::string>::iterator, bool> ins =
1284 this->sonames_.insert(soname);
1285 if (!ins.second)
1286 {
1287 // We have already seen a dynamic object with this soname.
1288 return false;
1289 }
1290
1291 this->dynobj_list_.push_back(dynobj);
1292
1293 // If this is -lc, remember the directory in which we found it.
1294 // We use this when issuing warnings about undefined symbols: as
1295 // a heuristic, we don't warn about system libraries found in
1296 // the same directory as -lc.
1297 if (strncmp(soname, "libc.so", 7) == 0)
1298 {
1299 const char* object_name = dynobj->name().c_str();
1300 const char* base = lbasename(object_name);
1301 if (base != object_name)
1302 this->system_library_directory_.assign(object_name,
1303 base - 1 - object_name);
1304 }
1305 }
1306
1307 return true;
1308 }
1309
1310 // Return whether an object was found in the system library directory.
1311
1312 bool
1313 Input_objects::found_in_system_library_directory(const Object* object) const
1314 {
1315 return (!this->system_library_directory_.empty()
1316 && object->name().compare(0,
1317 this->system_library_directory_.size(),
1318 this->system_library_directory_) == 0);
1319 }
1320
1321 // For each dynamic object, record whether we've seen all of its
1322 // explicit dependencies.
1323
1324 void
1325 Input_objects::check_dynamic_dependencies() const
1326 {
1327 for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
1328 p != this->dynobj_list_.end();
1329 ++p)
1330 {
1331 const Dynobj::Needed& needed((*p)->needed());
1332 bool found_all = true;
1333 for (Dynobj::Needed::const_iterator pneeded = needed.begin();
1334 pneeded != needed.end();
1335 ++pneeded)
1336 {
1337 if (this->sonames_.find(*pneeded) == this->sonames_.end())
1338 {
1339 found_all = false;
1340 break;
1341 }
1342 }
1343 (*p)->set_has_unknown_needed_entries(!found_all);
1344 }
1345 }
1346
1347 // Relocate_info methods.
1348
1349 // Return a string describing the location of a relocation. This is
1350 // only used in error messages.
1351
1352 template<int size, bool big_endian>
1353 std::string
1354 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
1355 {
1356 // See if we can get line-number information from debugging sections.
1357 std::string filename;
1358 std::string file_and_lineno; // Better than filename-only, if available.
1359
1360 Sized_dwarf_line_info<size, big_endian> line_info(this->object);
1361 // This will be "" if we failed to parse the debug info for any reason.
1362 file_and_lineno = line_info.addr2line(this->data_shndx, offset);
1363
1364 std::string ret(this->object->name());
1365 ret += ':';
1366 Symbol_location_info info;
1367 if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
1368 {
1369 ret += " in function ";
1370 ret += info.enclosing_symbol_name;
1371 ret += ":";
1372 filename = info.source_file;
1373 }
1374
1375 if (!file_and_lineno.empty())
1376 ret += file_and_lineno;
1377 else
1378 {
1379 if (!filename.empty())
1380 ret += filename;
1381 ret += "(";
1382 ret += this->object->section_name(this->data_shndx);
1383 char buf[100];
1384 // Offsets into sections have to be positive.
1385 snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset));
1386 ret += buf;
1387 ret += ")";
1388 }
1389 return ret;
1390 }
1391
1392 } // End namespace gold.
1393
1394 namespace
1395 {
1396
1397 using namespace gold;
1398
1399 // Read an ELF file with the header and return the appropriate
1400 // instance of Object.
1401
1402 template<int size, bool big_endian>
1403 Object*
1404 make_elf_sized_object(const std::string& name, Input_file* input_file,
1405 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
1406 {
1407 int et = ehdr.get_e_type();
1408 if (et == elfcpp::ET_REL)
1409 {
1410 Sized_relobj<size, big_endian>* obj =
1411 new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
1412 obj->setup(ehdr);
1413 return obj;
1414 }
1415 else if (et == elfcpp::ET_DYN)
1416 {
1417 Sized_dynobj<size, big_endian>* obj =
1418 new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
1419 obj->setup(ehdr);
1420 return obj;
1421 }
1422 else
1423 {
1424 gold_error(_("%s: unsupported ELF file type %d"),
1425 name.c_str(), et);
1426 return NULL;
1427 }
1428 }
1429
1430 } // End anonymous namespace.
1431
1432 namespace gold
1433 {
1434
1435 // Read an ELF file and return the appropriate instance of Object.
1436
1437 Object*
1438 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
1439 const unsigned char* p, section_offset_type bytes)
1440 {
1441 if (bytes < elfcpp::EI_NIDENT)
1442 {
1443 gold_error(_("%s: ELF file too short"), name.c_str());
1444 return NULL;
1445 }
1446
1447 int v = p[elfcpp::EI_VERSION];
1448 if (v != elfcpp::EV_CURRENT)
1449 {
1450 if (v == elfcpp::EV_NONE)
1451 gold_error(_("%s: invalid ELF version 0"), name.c_str());
1452 else
1453 gold_error(_("%s: unsupported ELF version %d"), name.c_str(), v);
1454 return NULL;
1455 }
1456
1457 int c = p[elfcpp::EI_CLASS];
1458 if (c == elfcpp::ELFCLASSNONE)
1459 {
1460 gold_error(_("%s: invalid ELF class 0"), name.c_str());
1461 return NULL;
1462 }
1463 else if (c != elfcpp::ELFCLASS32
1464 && c != elfcpp::ELFCLASS64)
1465 {
1466 gold_error(_("%s: unsupported ELF class %d"), name.c_str(), c);
1467 return NULL;
1468 }
1469
1470 int d = p[elfcpp::EI_DATA];
1471 if (d == elfcpp::ELFDATANONE)
1472 {
1473 gold_error(_("%s: invalid ELF data encoding"), name.c_str());
1474 return NULL;
1475 }
1476 else if (d != elfcpp::ELFDATA2LSB
1477 && d != elfcpp::ELFDATA2MSB)
1478 {
1479 gold_error(_("%s: unsupported ELF data encoding %d"), name.c_str(), d);
1480 return NULL;
1481 }
1482
1483 bool big_endian = d == elfcpp::ELFDATA2MSB;
1484
1485 if (c == elfcpp::ELFCLASS32)
1486 {
1487 if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
1488 {
1489 gold_error(_("%s: ELF file too short"), name.c_str());
1490 return NULL;
1491 }
1492 if (big_endian)
1493 {
1494 #ifdef HAVE_TARGET_32_BIG
1495 elfcpp::Ehdr<32, true> ehdr(p);
1496 return make_elf_sized_object<32, true>(name, input_file,
1497 offset, ehdr);
1498 #else
1499 gold_error(_("%s: not configured to support "
1500 "32-bit big-endian object"),
1501 name.c_str());
1502 return NULL;
1503 #endif
1504 }
1505 else
1506 {
1507 #ifdef HAVE_TARGET_32_LITTLE
1508 elfcpp::Ehdr<32, false> ehdr(p);
1509 return make_elf_sized_object<32, false>(name, input_file,
1510 offset, ehdr);
1511 #else
1512 gold_error(_("%s: not configured to support "
1513 "32-bit little-endian object"),
1514 name.c_str());
1515 return NULL;
1516 #endif
1517 }
1518 }
1519 else
1520 {
1521 if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
1522 {
1523 gold_error(_("%s: ELF file too short"), name.c_str());
1524 return NULL;
1525 }
1526 if (big_endian)
1527 {
1528 #ifdef HAVE_TARGET_64_BIG
1529 elfcpp::Ehdr<64, true> ehdr(p);
1530 return make_elf_sized_object<64, true>(name, input_file,
1531 offset, ehdr);
1532 #else
1533 gold_error(_("%s: not configured to support "
1534 "64-bit big-endian object"),
1535 name.c_str());
1536 return NULL;
1537 #endif
1538 }
1539 else
1540 {
1541 #ifdef HAVE_TARGET_64_LITTLE
1542 elfcpp::Ehdr<64, false> ehdr(p);
1543 return make_elf_sized_object<64, false>(name, input_file,
1544 offset, ehdr);
1545 #else
1546 gold_error(_("%s: not configured to support "
1547 "64-bit little-endian object"),
1548 name.c_str());
1549 return NULL;
1550 #endif
1551 }
1552 }
1553 }
1554
1555 // Instantiate the templates we need. We could use the configure
1556 // script to restrict this to only the ones for implemented targets.
1557
1558 #ifdef HAVE_TARGET_32_LITTLE
1559 template
1560 class Sized_relobj<32, false>;
1561 #endif
1562
1563 #ifdef HAVE_TARGET_32_BIG
1564 template
1565 class Sized_relobj<32, true>;
1566 #endif
1567
1568 #ifdef HAVE_TARGET_64_LITTLE
1569 template
1570 class Sized_relobj<64, false>;
1571 #endif
1572
1573 #ifdef HAVE_TARGET_64_BIG
1574 template
1575 class Sized_relobj<64, true>;
1576 #endif
1577
1578 #ifdef HAVE_TARGET_32_LITTLE
1579 template
1580 struct Relocate_info<32, false>;
1581 #endif
1582
1583 #ifdef HAVE_TARGET_32_BIG
1584 template
1585 struct Relocate_info<32, true>;
1586 #endif
1587
1588 #ifdef HAVE_TARGET_64_LITTLE
1589 template
1590 struct Relocate_info<64, false>;
1591 #endif
1592
1593 #ifdef HAVE_TARGET_64_BIG
1594 template
1595 struct Relocate_info<64, true>;
1596 #endif
1597
1598 } // End namespace gold.