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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 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->options().relocatable())
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 relocatable = parameters->options().relocatable();
598 const bool emit_relocs = (relocatable
599 || parameters->options().emit_relocs());
600 std::vector<unsigned int> reloc_sections;
601
602 // Keep track of .eh_frame sections.
603 std::vector<unsigned int> eh_frame_sections;
604
605 // Skip the first, dummy, section.
606 pshdrs = sd->section_headers->data() + This::shdr_size;
607 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
608 {
609 typename This::Shdr shdr(pshdrs);
610
611 if (shdr.get_sh_name() >= sd->section_names_size)
612 {
613 this->error(_("bad section name offset for section %u: %lu"),
614 i, static_cast<unsigned long>(shdr.get_sh_name()));
615 return;
616 }
617
618 const char* name = pnames + shdr.get_sh_name();
619
620 if (this->handle_gnu_warning_section(name, i, symtab))
621 {
622 if (!relocatable)
623 omit[i] = true;
624 }
625
626 // The .note.GNU-stack section is special. It gives the
627 // protection flags that this object file requires for the stack
628 // in memory.
629 if (strcmp(name, ".note.GNU-stack") == 0)
630 {
631 seen_gnu_stack = true;
632 gnu_stack_flags |= shdr.get_sh_flags();
633 omit[i] = true;
634 }
635
636 bool discard = omit[i];
637 if (!discard)
638 {
639 if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
640 {
641 if (!this->include_section_group(symtab, layout, i, name, shdr,
642 &omit))
643 discard = true;
644 }
645 else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
646 && Layout::is_linkonce(name))
647 {
648 if (!this->include_linkonce_section(layout, name, shdr))
649 discard = true;
650 }
651 }
652
653 if (discard)
654 {
655 // Do not include this section in the link.
656 map_sections[i].output_section = NULL;
657 continue;
658 }
659
660 // When doing a relocatable link we are going to copy input
661 // reloc sections into the output. We only want to copy the
662 // ones associated with sections which are not being discarded.
663 // However, we don't know that yet for all sections. So save
664 // reloc sections and process them later.
665 if (emit_relocs
666 && (shdr.get_sh_type() == elfcpp::SHT_REL
667 || shdr.get_sh_type() == elfcpp::SHT_RELA))
668 {
669 reloc_sections.push_back(i);
670 continue;
671 }
672
673 if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
674 continue;
675
676 // The .eh_frame section is special. It holds exception frame
677 // information that we need to read in order to generate the
678 // exception frame header. We process these after all the other
679 // sections so that the exception frame reader can reliably
680 // determine which sections are being discarded, and discard the
681 // corresponding information.
682 if (!relocatable
683 && strcmp(name, ".eh_frame") == 0
684 && this->check_eh_frame_flags(&shdr))
685 {
686 eh_frame_sections.push_back(i);
687 continue;
688 }
689
690 off_t offset;
691 Output_section* os = layout->layout(this, i, name, shdr,
692 reloc_shndx[i], reloc_type[i],
693 &offset);
694
695 map_sections[i].output_section = os;
696 map_sections[i].offset = offset;
697
698 // If this section requires special handling, and if there are
699 // relocs that apply to it, then we must do the special handling
700 // before we apply the relocs.
701 if (offset == -1 && reloc_shndx[i] != 0)
702 this->set_relocs_must_follow_section_writes();
703 }
704
705 layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
706
707 // When doing a relocatable link handle the reloc sections at the
708 // end.
709 if (emit_relocs)
710 this->size_relocatable_relocs();
711 for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
712 p != reloc_sections.end();
713 ++p)
714 {
715 unsigned int i = *p;
716 const unsigned char* pshdr;
717 pshdr = sd->section_headers->data() + i * This::shdr_size;
718 typename This::Shdr shdr(pshdr);
719
720 unsigned int data_shndx = shdr.get_sh_info();
721 if (data_shndx >= shnum)
722 {
723 // We already warned about this above.
724 continue;
725 }
726
727 Output_section* data_section = map_sections[data_shndx].output_section;
728 if (data_section == NULL)
729 {
730 map_sections[i].output_section = NULL;
731 continue;
732 }
733
734 Relocatable_relocs* rr = new Relocatable_relocs();
735 this->set_relocatable_relocs(i, rr);
736
737 Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
738 rr);
739 map_sections[i].output_section = os;
740 map_sections[i].offset = -1;
741 }
742
743 // Handle the .eh_frame sections at the end.
744 for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
745 p != eh_frame_sections.end();
746 ++p)
747 {
748 gold_assert(this->has_eh_frame_);
749 gold_assert(sd->external_symbols_offset != 0);
750
751 unsigned int i = *p;
752 const unsigned char *pshdr;
753 pshdr = sd->section_headers->data() + i * This::shdr_size;
754 typename This::Shdr shdr(pshdr);
755
756 off_t offset;
757 Output_section* os = layout->layout_eh_frame(this,
758 sd->symbols->data(),
759 sd->symbols_size,
760 sd->symbol_names->data(),
761 sd->symbol_names_size,
762 i, shdr,
763 reloc_shndx[i],
764 reloc_type[i],
765 &offset);
766 map_sections[i].output_section = os;
767 map_sections[i].offset = offset;
768
769 // If this section requires special handling, and if there are
770 // relocs that apply to it, then we must do the special handling
771 // before we apply the relocs.
772 if (offset == -1 && reloc_shndx[i] != 0)
773 this->set_relocs_must_follow_section_writes();
774 }
775
776 delete sd->section_headers;
777 sd->section_headers = NULL;
778 delete sd->section_names;
779 sd->section_names = NULL;
780 }
781
782 // Add the symbols to the symbol table.
783
784 template<int size, bool big_endian>
785 void
786 Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
787 Read_symbols_data* sd)
788 {
789 if (sd->symbols == NULL)
790 {
791 gold_assert(sd->symbol_names == NULL);
792 return;
793 }
794
795 const int sym_size = This::sym_size;
796 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
797 / sym_size);
798 if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
799 {
800 this->error(_("size of symbols is not multiple of symbol size"));
801 return;
802 }
803
804 this->symbols_.resize(symcount);
805
806 const char* sym_names =
807 reinterpret_cast<const char*>(sd->symbol_names->data());
808 symtab->add_from_relobj(this,
809 sd->symbols->data() + sd->external_symbols_offset,
810 symcount, sym_names, sd->symbol_names_size,
811 &this->symbols_);
812
813 delete sd->symbols;
814 sd->symbols = NULL;
815 delete sd->symbol_names;
816 sd->symbol_names = NULL;
817 }
818
819 // First pass over the local symbols. Here we add their names to
820 // *POOL and *DYNPOOL, and we store the symbol value in
821 // THIS->LOCAL_VALUES_. This function is always called from a
822 // singleton thread. This is followed by a call to
823 // finalize_local_symbols.
824
825 template<int size, bool big_endian>
826 void
827 Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
828 Stringpool* dynpool)
829 {
830 gold_assert(this->symtab_shndx_ != -1U);
831 if (this->symtab_shndx_ == 0)
832 {
833 // This object has no symbols. Weird but legal.
834 return;
835 }
836
837 // Read the symbol table section header.
838 const unsigned int symtab_shndx = this->symtab_shndx_;
839 typename This::Shdr symtabshdr(this,
840 this->elf_file_.section_header(symtab_shndx));
841 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
842
843 // Read the local symbols.
844 const int sym_size = This::sym_size;
845 const unsigned int loccount = this->local_symbol_count_;
846 gold_assert(loccount == symtabshdr.get_sh_info());
847 off_t locsize = loccount * sym_size;
848 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
849 locsize, true);
850
851 // Read the symbol names.
852 const unsigned int strtab_shndx = symtabshdr.get_sh_link();
853 section_size_type strtab_size;
854 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
855 &strtab_size,
856 true);
857 const char* pnames = reinterpret_cast<const char*>(pnamesu);
858
859 // Loop over the local symbols.
860
861 const std::vector<Map_to_output>& mo(this->map_to_output());
862 unsigned int shnum = this->shnum();
863 unsigned int count = 0;
864 unsigned int dyncount = 0;
865 // Skip the first, dummy, symbol.
866 psyms += sym_size;
867 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
868 {
869 elfcpp::Sym<size, big_endian> sym(psyms);
870
871 Symbol_value<size>& lv(this->local_values_[i]);
872
873 unsigned int shndx = sym.get_st_shndx();
874 lv.set_input_shndx(shndx);
875
876 if (sym.get_st_type() == elfcpp::STT_SECTION)
877 lv.set_is_section_symbol();
878 else if (sym.get_st_type() == elfcpp::STT_TLS)
879 lv.set_is_tls_symbol();
880
881 // Save the input symbol value for use in do_finalize_local_symbols().
882 lv.set_input_value(sym.get_st_value());
883
884 // Decide whether this symbol should go into the output file.
885
886 if (shndx < shnum && mo[shndx].output_section == NULL)
887 {
888 lv.set_no_output_symtab_entry();
889 gold_assert(!lv.needs_output_dynsym_entry());
890 continue;
891 }
892
893 if (sym.get_st_type() == elfcpp::STT_SECTION)
894 {
895 lv.set_no_output_symtab_entry();
896 gold_assert(!lv.needs_output_dynsym_entry());
897 continue;
898 }
899
900 if (sym.get_st_name() >= strtab_size)
901 {
902 this->error(_("local symbol %u section name out of range: %u >= %u"),
903 i, sym.get_st_name(),
904 static_cast<unsigned int>(strtab_size));
905 lv.set_no_output_symtab_entry();
906 continue;
907 }
908
909 // Add the symbol to the symbol table string pool.
910 const char* name = pnames + sym.get_st_name();
911 pool->add(name, true, NULL);
912 ++count;
913
914 // If needed, add the symbol to the dynamic symbol table string pool.
915 if (lv.needs_output_dynsym_entry())
916 {
917 dynpool->add(name, true, NULL);
918 ++dyncount;
919 }
920 }
921
922 this->output_local_symbol_count_ = count;
923 this->output_local_dynsym_count_ = dyncount;
924 }
925
926 // Finalize the local symbols. Here we set the final value in
927 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
928 // This function is always called from a singleton thread. The actual
929 // output of the local symbols will occur in a separate task.
930
931 template<int size, bool big_endian>
932 unsigned int
933 Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
934 off_t off)
935 {
936 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
937
938 const unsigned int loccount = this->local_symbol_count_;
939 this->local_symbol_offset_ = off;
940
941 const std::vector<Map_to_output>& mo(this->map_to_output());
942 unsigned int shnum = this->shnum();
943
944 for (unsigned int i = 1; i < loccount; ++i)
945 {
946 Symbol_value<size>& lv(this->local_values_[i]);
947
948 unsigned int shndx = lv.input_shndx();
949
950 // Set the output symbol value.
951
952 if (shndx >= elfcpp::SHN_LORESERVE)
953 {
954 if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)
955 lv.set_output_value(lv.input_value());
956 else
957 {
958 // FIXME: Handle SHN_XINDEX.
959 this->error(_("unknown section index %u for local symbol %u"),
960 shndx, i);
961 lv.set_output_value(0);
962 }
963 }
964 else
965 {
966 if (shndx >= shnum)
967 {
968 this->error(_("local symbol %u section index %u out of range"),
969 i, shndx);
970 shndx = 0;
971 }
972
973 Output_section* os = mo[shndx].output_section;
974
975 if (os == NULL)
976 {
977 lv.set_output_value(0);
978 continue;
979 }
980 else if (mo[shndx].offset == -1)
981 {
982 // This is a SHF_MERGE section or one which otherwise
983 // requires special handling. We get the output address
984 // of the start of the merged section. If this is not a
985 // section symbol, we can then determine the final
986 // value. If it is a section symbol, we can not, as in
987 // that case we have to consider the addend to determine
988 // the value to use in a relocation.
989 if (!lv.is_section_symbol())
990 lv.set_output_value(os->output_address(this, shndx,
991 lv.input_value()));
992 else
993 {
994 section_offset_type start =
995 os->starting_output_address(this, shndx);
996 Merged_symbol_value<size>* msv =
997 new Merged_symbol_value<size>(lv.input_value(), start);
998 lv.set_merged_symbol_value(msv);
999 }
1000 }
1001 else if (lv.is_tls_symbol())
1002 lv.set_output_value(os->tls_offset()
1003 + mo[shndx].offset
1004 + lv.input_value());
1005 else
1006 lv.set_output_value(os->address()
1007 + mo[shndx].offset
1008 + lv.input_value());
1009 }
1010
1011 if (lv.needs_output_symtab_entry())
1012 {
1013 lv.set_output_symtab_index(index);
1014 ++index;
1015 }
1016 }
1017 return index;
1018 }
1019
1020 // Set the output dynamic symbol table indexes for the local variables.
1021
1022 template<int size, bool big_endian>
1023 unsigned int
1024 Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index)
1025 {
1026 const unsigned int loccount = this->local_symbol_count_;
1027 for (unsigned int i = 1; i < loccount; ++i)
1028 {
1029 Symbol_value<size>& lv(this->local_values_[i]);
1030 if (lv.needs_output_dynsym_entry())
1031 {
1032 lv.set_output_dynsym_index(index);
1033 ++index;
1034 }
1035 }
1036 return index;
1037 }
1038
1039 // Set the offset where local dynamic symbol information will be stored.
1040 // Returns the count of local symbols contributed to the symbol table by
1041 // this object.
1042
1043 template<int size, bool big_endian>
1044 unsigned int
1045 Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off)
1046 {
1047 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
1048 this->local_dynsym_offset_ = off;
1049 return this->output_local_dynsym_count_;
1050 }
1051
1052 // Return the value of the local symbol symndx.
1053 template<int size, bool big_endian>
1054 typename elfcpp::Elf_types<size>::Elf_Addr
1055 Sized_relobj<size, big_endian>::local_symbol_value(unsigned int symndx) const
1056 {
1057 gold_assert(symndx < this->local_symbol_count_);
1058 gold_assert(symndx < this->local_values_.size());
1059 const Symbol_value<size>& lv(this->local_values_[symndx]);
1060 return lv.value(this, 0);
1061 }
1062
1063 // Write out the local symbols.
1064
1065 template<int size, bool big_endian>
1066 void
1067 Sized_relobj<size, big_endian>::write_local_symbols(
1068 Output_file* of,
1069 const Stringpool* sympool,
1070 const Stringpool* dynpool)
1071 {
1072 if (parameters->options().strip_all()
1073 && this->output_local_dynsym_count_ == 0)
1074 return;
1075
1076 gold_assert(this->symtab_shndx_ != -1U);
1077 if (this->symtab_shndx_ == 0)
1078 {
1079 // This object has no symbols. Weird but legal.
1080 return;
1081 }
1082
1083 // Read the symbol table section header.
1084 const unsigned int symtab_shndx = this->symtab_shndx_;
1085 typename This::Shdr symtabshdr(this,
1086 this->elf_file_.section_header(symtab_shndx));
1087 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1088 const unsigned int loccount = this->local_symbol_count_;
1089 gold_assert(loccount == symtabshdr.get_sh_info());
1090
1091 // Read the local symbols.
1092 const int sym_size = This::sym_size;
1093 off_t locsize = loccount * sym_size;
1094 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1095 locsize, false);
1096
1097 // Read the symbol names.
1098 const unsigned int strtab_shndx = symtabshdr.get_sh_link();
1099 section_size_type strtab_size;
1100 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1101 &strtab_size,
1102 false);
1103 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1104
1105 // Get views into the output file for the portions of the symbol table
1106 // and the dynamic symbol table that we will be writing.
1107 off_t output_size = this->output_local_symbol_count_ * sym_size;
1108 unsigned char* oview = NULL;
1109 if (output_size > 0)
1110 oview = of->get_output_view(this->local_symbol_offset_, output_size);
1111
1112 off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
1113 unsigned char* dyn_oview = NULL;
1114 if (dyn_output_size > 0)
1115 dyn_oview = of->get_output_view(this->local_dynsym_offset_,
1116 dyn_output_size);
1117
1118 const std::vector<Map_to_output>& mo(this->map_to_output());
1119
1120 gold_assert(this->local_values_.size() == loccount);
1121
1122 unsigned char* ov = oview;
1123 unsigned char* dyn_ov = dyn_oview;
1124 psyms += sym_size;
1125 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1126 {
1127 elfcpp::Sym<size, big_endian> isym(psyms);
1128
1129 unsigned int st_shndx = isym.get_st_shndx();
1130 if (st_shndx < elfcpp::SHN_LORESERVE)
1131 {
1132 gold_assert(st_shndx < mo.size());
1133 if (mo[st_shndx].output_section == NULL)
1134 continue;
1135 st_shndx = mo[st_shndx].output_section->out_shndx();
1136 }
1137
1138 // Write the symbol to the output symbol table.
1139 if (!parameters->options().strip_all()
1140 && this->local_values_[i].needs_output_symtab_entry())
1141 {
1142 elfcpp::Sym_write<size, big_endian> osym(ov);
1143
1144 gold_assert(isym.get_st_name() < strtab_size);
1145 const char* name = pnames + isym.get_st_name();
1146 osym.put_st_name(sympool->get_offset(name));
1147 osym.put_st_value(this->local_values_[i].value(this, 0));
1148 osym.put_st_size(isym.get_st_size());
1149 osym.put_st_info(isym.get_st_info());
1150 osym.put_st_other(isym.get_st_other());
1151 osym.put_st_shndx(st_shndx);
1152
1153 ov += sym_size;
1154 }
1155
1156 // Write the symbol to the output dynamic symbol table.
1157 if (this->local_values_[i].needs_output_dynsym_entry())
1158 {
1159 gold_assert(dyn_ov < dyn_oview + dyn_output_size);
1160 elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
1161
1162 gold_assert(isym.get_st_name() < strtab_size);
1163 const char* name = pnames + isym.get_st_name();
1164 osym.put_st_name(dynpool->get_offset(name));
1165 osym.put_st_value(this->local_values_[i].value(this, 0));
1166 osym.put_st_size(isym.get_st_size());
1167 osym.put_st_info(isym.get_st_info());
1168 osym.put_st_other(isym.get_st_other());
1169 osym.put_st_shndx(st_shndx);
1170
1171 dyn_ov += sym_size;
1172 }
1173 }
1174
1175
1176 if (output_size > 0)
1177 {
1178 gold_assert(ov - oview == output_size);
1179 of->write_output_view(this->local_symbol_offset_, output_size, oview);
1180 }
1181
1182 if (dyn_output_size > 0)
1183 {
1184 gold_assert(dyn_ov - dyn_oview == dyn_output_size);
1185 of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
1186 dyn_oview);
1187 }
1188 }
1189
1190 // Set *INFO to symbolic information about the offset OFFSET in the
1191 // section SHNDX. Return true if we found something, false if we
1192 // found nothing.
1193
1194 template<int size, bool big_endian>
1195 bool
1196 Sized_relobj<size, big_endian>::get_symbol_location_info(
1197 unsigned int shndx,
1198 off_t offset,
1199 Symbol_location_info* info)
1200 {
1201 if (this->symtab_shndx_ == 0)
1202 return false;
1203
1204 section_size_type symbols_size;
1205 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
1206 &symbols_size,
1207 false);
1208
1209 unsigned int symbol_names_shndx = this->section_link(this->symtab_shndx_);
1210 section_size_type names_size;
1211 const unsigned char* symbol_names_u =
1212 this->section_contents(symbol_names_shndx, &names_size, false);
1213 const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
1214
1215 const int sym_size = This::sym_size;
1216 const size_t count = symbols_size / sym_size;
1217
1218 const unsigned char* p = symbols;
1219 for (size_t i = 0; i < count; ++i, p += sym_size)
1220 {
1221 elfcpp::Sym<size, big_endian> sym(p);
1222
1223 if (sym.get_st_type() == elfcpp::STT_FILE)
1224 {
1225 if (sym.get_st_name() >= names_size)
1226 info->source_file = "(invalid)";
1227 else
1228 info->source_file = symbol_names + sym.get_st_name();
1229 }
1230 else if (sym.get_st_shndx() == shndx
1231 && static_cast<off_t>(sym.get_st_value()) <= offset
1232 && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
1233 > offset))
1234 {
1235 if (sym.get_st_name() > names_size)
1236 info->enclosing_symbol_name = "(invalid)";
1237 else
1238 {
1239 info->enclosing_symbol_name = symbol_names + sym.get_st_name();
1240 if (parameters->options().demangle())
1241 {
1242 char* demangled_name = cplus_demangle(
1243 info->enclosing_symbol_name.c_str(),
1244 DMGL_ANSI | DMGL_PARAMS);
1245 if (demangled_name != NULL)
1246 {
1247 info->enclosing_symbol_name.assign(demangled_name);
1248 free(demangled_name);
1249 }
1250 }
1251 }
1252 return true;
1253 }
1254 }
1255
1256 return false;
1257 }
1258
1259 // Input_objects methods.
1260
1261 // Add a regular relocatable object to the list. Return false if this
1262 // object should be ignored.
1263
1264 bool
1265 Input_objects::add_object(Object* obj)
1266 {
1267 // Set the global target from the first object file we recognize.
1268 Target* target = obj->target();
1269 if (!parameters->target_valid())
1270 set_parameters_target(target);
1271 else if (target != &parameters->target())
1272 {
1273 obj->error(_("incompatible target"));
1274 return false;
1275 }
1276
1277 if (!obj->is_dynamic())
1278 this->relobj_list_.push_back(static_cast<Relobj*>(obj));
1279 else
1280 {
1281 // See if this is a duplicate SONAME.
1282 Dynobj* dynobj = static_cast<Dynobj*>(obj);
1283 const char* soname = dynobj->soname();
1284
1285 std::pair<Unordered_set<std::string>::iterator, bool> ins =
1286 this->sonames_.insert(soname);
1287 if (!ins.second)
1288 {
1289 // We have already seen a dynamic object with this soname.
1290 return false;
1291 }
1292
1293 this->dynobj_list_.push_back(dynobj);
1294
1295 // If this is -lc, remember the directory in which we found it.
1296 // We use this when issuing warnings about undefined symbols: as
1297 // a heuristic, we don't warn about system libraries found in
1298 // the same directory as -lc.
1299 if (strncmp(soname, "libc.so", 7) == 0)
1300 {
1301 const char* object_name = dynobj->name().c_str();
1302 const char* base = lbasename(object_name);
1303 if (base != object_name)
1304 this->system_library_directory_.assign(object_name,
1305 base - 1 - object_name);
1306 }
1307 }
1308
1309 return true;
1310 }
1311
1312 // Return whether an object was found in the system library directory.
1313
1314 bool
1315 Input_objects::found_in_system_library_directory(const Object* object) const
1316 {
1317 return (!this->system_library_directory_.empty()
1318 && object->name().compare(0,
1319 this->system_library_directory_.size(),
1320 this->system_library_directory_) == 0);
1321 }
1322
1323 // For each dynamic object, record whether we've seen all of its
1324 // explicit dependencies.
1325
1326 void
1327 Input_objects::check_dynamic_dependencies() const
1328 {
1329 for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
1330 p != this->dynobj_list_.end();
1331 ++p)
1332 {
1333 const Dynobj::Needed& needed((*p)->needed());
1334 bool found_all = true;
1335 for (Dynobj::Needed::const_iterator pneeded = needed.begin();
1336 pneeded != needed.end();
1337 ++pneeded)
1338 {
1339 if (this->sonames_.find(*pneeded) == this->sonames_.end())
1340 {
1341 found_all = false;
1342 break;
1343 }
1344 }
1345 (*p)->set_has_unknown_needed_entries(!found_all);
1346 }
1347 }
1348
1349 // Relocate_info methods.
1350
1351 // Return a string describing the location of a relocation. This is
1352 // only used in error messages.
1353
1354 template<int size, bool big_endian>
1355 std::string
1356 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
1357 {
1358 // See if we can get line-number information from debugging sections.
1359 std::string filename;
1360 std::string file_and_lineno; // Better than filename-only, if available.
1361
1362 Sized_dwarf_line_info<size, big_endian> line_info(this->object);
1363 // This will be "" if we failed to parse the debug info for any reason.
1364 file_and_lineno = line_info.addr2line(this->data_shndx, offset);
1365
1366 std::string ret(this->object->name());
1367 ret += ':';
1368 Symbol_location_info info;
1369 if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
1370 {
1371 ret += " in function ";
1372 ret += info.enclosing_symbol_name;
1373 ret += ":";
1374 filename = info.source_file;
1375 }
1376
1377 if (!file_and_lineno.empty())
1378 ret += file_and_lineno;
1379 else
1380 {
1381 if (!filename.empty())
1382 ret += filename;
1383 ret += "(";
1384 ret += this->object->section_name(this->data_shndx);
1385 char buf[100];
1386 // Offsets into sections have to be positive.
1387 snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset));
1388 ret += buf;
1389 ret += ")";
1390 }
1391 return ret;
1392 }
1393
1394 } // End namespace gold.
1395
1396 namespace
1397 {
1398
1399 using namespace gold;
1400
1401 // Read an ELF file with the header and return the appropriate
1402 // instance of Object.
1403
1404 template<int size, bool big_endian>
1405 Object*
1406 make_elf_sized_object(const std::string& name, Input_file* input_file,
1407 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
1408 {
1409 int et = ehdr.get_e_type();
1410 if (et == elfcpp::ET_REL)
1411 {
1412 Sized_relobj<size, big_endian>* obj =
1413 new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
1414 obj->setup(ehdr);
1415 return obj;
1416 }
1417 else if (et == elfcpp::ET_DYN)
1418 {
1419 Sized_dynobj<size, big_endian>* obj =
1420 new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
1421 obj->setup(ehdr);
1422 return obj;
1423 }
1424 else
1425 {
1426 gold_error(_("%s: unsupported ELF file type %d"),
1427 name.c_str(), et);
1428 return NULL;
1429 }
1430 }
1431
1432 } // End anonymous namespace.
1433
1434 namespace gold
1435 {
1436
1437 // Read an ELF file and return the appropriate instance of Object.
1438
1439 Object*
1440 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
1441 const unsigned char* p, section_offset_type bytes)
1442 {
1443 if (bytes < elfcpp::EI_NIDENT)
1444 {
1445 gold_error(_("%s: ELF file too short"), name.c_str());
1446 return NULL;
1447 }
1448
1449 int v = p[elfcpp::EI_VERSION];
1450 if (v != elfcpp::EV_CURRENT)
1451 {
1452 if (v == elfcpp::EV_NONE)
1453 gold_error(_("%s: invalid ELF version 0"), name.c_str());
1454 else
1455 gold_error(_("%s: unsupported ELF version %d"), name.c_str(), v);
1456 return NULL;
1457 }
1458
1459 int c = p[elfcpp::EI_CLASS];
1460 if (c == elfcpp::ELFCLASSNONE)
1461 {
1462 gold_error(_("%s: invalid ELF class 0"), name.c_str());
1463 return NULL;
1464 }
1465 else if (c != elfcpp::ELFCLASS32
1466 && c != elfcpp::ELFCLASS64)
1467 {
1468 gold_error(_("%s: unsupported ELF class %d"), name.c_str(), c);
1469 return NULL;
1470 }
1471
1472 int d = p[elfcpp::EI_DATA];
1473 if (d == elfcpp::ELFDATANONE)
1474 {
1475 gold_error(_("%s: invalid ELF data encoding"), name.c_str());
1476 return NULL;
1477 }
1478 else if (d != elfcpp::ELFDATA2LSB
1479 && d != elfcpp::ELFDATA2MSB)
1480 {
1481 gold_error(_("%s: unsupported ELF data encoding %d"), name.c_str(), d);
1482 return NULL;
1483 }
1484
1485 bool big_endian = d == elfcpp::ELFDATA2MSB;
1486
1487 if (c == elfcpp::ELFCLASS32)
1488 {
1489 if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
1490 {
1491 gold_error(_("%s: ELF file too short"), name.c_str());
1492 return NULL;
1493 }
1494 if (big_endian)
1495 {
1496 #ifdef HAVE_TARGET_32_BIG
1497 elfcpp::Ehdr<32, true> ehdr(p);
1498 return make_elf_sized_object<32, true>(name, input_file,
1499 offset, ehdr);
1500 #else
1501 gold_error(_("%s: not configured to support "
1502 "32-bit big-endian object"),
1503 name.c_str());
1504 return NULL;
1505 #endif
1506 }
1507 else
1508 {
1509 #ifdef HAVE_TARGET_32_LITTLE
1510 elfcpp::Ehdr<32, false> ehdr(p);
1511 return make_elf_sized_object<32, false>(name, input_file,
1512 offset, ehdr);
1513 #else
1514 gold_error(_("%s: not configured to support "
1515 "32-bit little-endian object"),
1516 name.c_str());
1517 return NULL;
1518 #endif
1519 }
1520 }
1521 else
1522 {
1523 if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
1524 {
1525 gold_error(_("%s: ELF file too short"), name.c_str());
1526 return NULL;
1527 }
1528 if (big_endian)
1529 {
1530 #ifdef HAVE_TARGET_64_BIG
1531 elfcpp::Ehdr<64, true> ehdr(p);
1532 return make_elf_sized_object<64, true>(name, input_file,
1533 offset, ehdr);
1534 #else
1535 gold_error(_("%s: not configured to support "
1536 "64-bit big-endian object"),
1537 name.c_str());
1538 return NULL;
1539 #endif
1540 }
1541 else
1542 {
1543 #ifdef HAVE_TARGET_64_LITTLE
1544 elfcpp::Ehdr<64, false> ehdr(p);
1545 return make_elf_sized_object<64, false>(name, input_file,
1546 offset, ehdr);
1547 #else
1548 gold_error(_("%s: not configured to support "
1549 "64-bit little-endian object"),
1550 name.c_str());
1551 return NULL;
1552 #endif
1553 }
1554 }
1555 }
1556
1557 // Instantiate the templates we need. We could use the configure
1558 // script to restrict this to only the ones for implemented targets.
1559
1560 #ifdef HAVE_TARGET_32_LITTLE
1561 template
1562 class Sized_relobj<32, false>;
1563 #endif
1564
1565 #ifdef HAVE_TARGET_32_BIG
1566 template
1567 class Sized_relobj<32, true>;
1568 #endif
1569
1570 #ifdef HAVE_TARGET_64_LITTLE
1571 template
1572 class Sized_relobj<64, false>;
1573 #endif
1574
1575 #ifdef HAVE_TARGET_64_BIG
1576 template
1577 class Sized_relobj<64, true>;
1578 #endif
1579
1580 #ifdef HAVE_TARGET_32_LITTLE
1581 template
1582 struct Relocate_info<32, false>;
1583 #endif
1584
1585 #ifdef HAVE_TARGET_32_BIG
1586 template
1587 struct Relocate_info<32, true>;
1588 #endif
1589
1590 #ifdef HAVE_TARGET_64_LITTLE
1591 template
1592 struct Relocate_info<64, false>;
1593 #endif
1594
1595 #ifdef HAVE_TARGET_64_BIG
1596 template
1597 struct Relocate_info<64, true>;
1598 #endif
1599
1600 } // End namespace gold.
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