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