| // object.cc -- support for an object file for linking in gold |
| |
| // Copyright 2006, 2007, 2008 Free Software Foundation, Inc. |
| // Written by Ian Lance Taylor <iant@google.com>. |
| |
| // This file is part of gold. |
| |
| // This program is free software; you can redistribute it and/or modify |
| // it under the terms of the GNU General Public License as published by |
| // the Free Software Foundation; either version 3 of the License, or |
| // (at your option) any later version. |
| |
| // This program is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License |
| // along with this program; if not, write to the Free Software |
| // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| // MA 02110-1301, USA. |
| |
| #include "gold.h" |
| |
| #include <cerrno> |
| #include <cstring> |
| #include <cstdarg> |
| #include "demangle.h" |
| #include "libiberty.h" |
| |
| #include "target-select.h" |
| #include "dwarf_reader.h" |
| #include "layout.h" |
| #include "output.h" |
| #include "symtab.h" |
| #include "cref.h" |
| #include "reloc.h" |
| #include "object.h" |
| #include "dynobj.h" |
| |
| namespace gold |
| { |
| |
| // Class Xindex. |
| |
| // Initialize the symtab_xindex_ array. Find the SHT_SYMTAB_SHNDX |
| // section and read it in. SYMTAB_SHNDX is the index of the symbol |
| // table we care about. |
| |
| template<int size, bool big_endian> |
| void |
| Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx) |
| { |
| if (!this->symtab_xindex_.empty()) |
| return; |
| |
| gold_assert(symtab_shndx != 0); |
| |
| // Look through the sections in reverse order, on the theory that it |
| // is more likely to be near the end than the beginning. |
| unsigned int i = object->shnum(); |
| while (i > 0) |
| { |
| --i; |
| if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX |
| && this->adjust_shndx(object->section_link(i)) == symtab_shndx) |
| { |
| this->read_symtab_xindex<size, big_endian>(object, i, NULL); |
| return; |
| } |
| } |
| |
| object->error(_("missing SHT_SYMTAB_SHNDX section")); |
| } |
| |
| // Read in the symtab_xindex_ array, given the section index of the |
| // SHT_SYMTAB_SHNDX section. If PSHDRS is not NULL, it points at the |
| // section headers. |
| |
| template<int size, bool big_endian> |
| void |
| Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx, |
| const unsigned char* pshdrs) |
| { |
| section_size_type bytecount; |
| const unsigned char* contents; |
| if (pshdrs == NULL) |
| contents = object->section_contents(xindex_shndx, &bytecount, false); |
| else |
| { |
| const unsigned char* p = (pshdrs |
| + (xindex_shndx |
| * elfcpp::Elf_sizes<size>::shdr_size)); |
| typename elfcpp::Shdr<size, big_endian> shdr(p); |
| bytecount = convert_to_section_size_type(shdr.get_sh_size()); |
| contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false); |
| } |
| |
| gold_assert(this->symtab_xindex_.empty()); |
| this->symtab_xindex_.reserve(bytecount / 4); |
| for (section_size_type i = 0; i < bytecount; i += 4) |
| { |
| unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i); |
| // We preadjust the section indexes we save. |
| this->symtab_xindex_.push_back(this->adjust_shndx(shndx)); |
| } |
| } |
| |
| // Symbol symndx has a section of SHN_XINDEX; return the real section |
| // index. |
| |
| unsigned int |
| Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx) |
| { |
| if (symndx >= this->symtab_xindex_.size()) |
| { |
| object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"), |
| symndx); |
| return elfcpp::SHN_UNDEF; |
| } |
| unsigned int shndx = this->symtab_xindex_[symndx]; |
| if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum()) |
| { |
| object->error(_("extended index for symbol %u out of range: %u"), |
| symndx, shndx); |
| return elfcpp::SHN_UNDEF; |
| } |
| return shndx; |
| } |
| |
| // Class Object. |
| |
| // Set the target based on fields in the ELF file header. |
| |
| void |
| Object::set_target(int machine, int size, bool big_endian, int osabi, |
| int abiversion) |
| { |
| Target* target = select_target(machine, size, big_endian, osabi, abiversion); |
| if (target == NULL) |
| gold_fatal(_("%s: unsupported ELF machine number %d"), |
| this->name().c_str(), machine); |
| this->target_ = target; |
| } |
| |
| // Report an error for this object file. This is used by the |
| // elfcpp::Elf_file interface, and also called by the Object code |
| // itself. |
| |
| void |
| Object::error(const char* format, ...) const |
| { |
| va_list args; |
| va_start(args, format); |
| char* buf = NULL; |
| if (vasprintf(&buf, format, args) < 0) |
| gold_nomem(); |
| va_end(args); |
| gold_error(_("%s: %s"), this->name().c_str(), buf); |
| free(buf); |
| } |
| |
| // Return a view of the contents of a section. |
| |
| const unsigned char* |
| Object::section_contents(unsigned int shndx, section_size_type* plen, |
| bool cache) |
| { |
| Location loc(this->do_section_contents(shndx)); |
| *plen = convert_to_section_size_type(loc.data_size); |
| return this->get_view(loc.file_offset, *plen, true, cache); |
| } |
| |
| // Read the section data into SD. This is code common to Sized_relobj |
| // and Sized_dynobj, so we put it into Object. |
| |
| template<int size, bool big_endian> |
| void |
| Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file, |
| Read_symbols_data* sd) |
| { |
| const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; |
| |
| // Read the section headers. |
| const off_t shoff = elf_file->shoff(); |
| const unsigned int shnum = this->shnum(); |
| sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size, |
| true, true); |
| |
| // Read the section names. |
| const unsigned char* pshdrs = sd->section_headers->data(); |
| const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size; |
| typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames); |
| |
| if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB) |
| this->error(_("section name section has wrong type: %u"), |
| static_cast<unsigned int>(shdrnames.get_sh_type())); |
| |
| sd->section_names_size = |
| convert_to_section_size_type(shdrnames.get_sh_size()); |
| sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(), |
| sd->section_names_size, false, |
| false); |
| } |
| |
| // If NAME is the name of a special .gnu.warning section, arrange for |
| // the warning to be issued. SHNDX is the section index. Return |
| // whether it is a warning section. |
| |
| bool |
| Object::handle_gnu_warning_section(const char* name, unsigned int shndx, |
| Symbol_table* symtab) |
| { |
| const char warn_prefix[] = ".gnu.warning."; |
| const int warn_prefix_len = sizeof warn_prefix - 1; |
| if (strncmp(name, warn_prefix, warn_prefix_len) == 0) |
| { |
| // Read the section contents to get the warning text. It would |
| // be nicer if we only did this if we have to actually issue a |
| // warning. Unfortunately, warnings are issued as we relocate |
| // sections. That means that we can not lock the object then, |
| // as we might try to issue the same warning multiple times |
| // simultaneously. |
| section_size_type len; |
| const unsigned char* contents = this->section_contents(shndx, &len, |
| false); |
| std::string warning(reinterpret_cast<const char*>(contents), len); |
| symtab->add_warning(name + warn_prefix_len, this, warning); |
| return true; |
| } |
| return false; |
| } |
| |
| // Class Sized_relobj. |
| |
| template<int size, bool big_endian> |
| Sized_relobj<size, big_endian>::Sized_relobj( |
| const std::string& name, |
| Input_file* input_file, |
| off_t offset, |
| const elfcpp::Ehdr<size, big_endian>& ehdr) |
| : Relobj(name, input_file, offset), |
| elf_file_(this, ehdr), |
| symtab_shndx_(-1U), |
| local_symbol_count_(0), |
| output_local_symbol_count_(0), |
| output_local_dynsym_count_(0), |
| symbols_(), |
| defined_count_(0), |
| local_symbol_offset_(0), |
| local_dynsym_offset_(0), |
| local_values_(), |
| local_got_offsets_(), |
| kept_comdat_sections_(), |
| comdat_groups_(), |
| has_eh_frame_(false) |
| { |
| } |
| |
| template<int size, bool big_endian> |
| Sized_relobj<size, big_endian>::~Sized_relobj() |
| { |
| } |
| |
| // Set up an object file based on the file header. This sets up the |
| // target and reads the section information. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_relobj<size, big_endian>::setup( |
| const elfcpp::Ehdr<size, big_endian>& ehdr) |
| { |
| this->set_target(ehdr.get_e_machine(), size, big_endian, |
| ehdr.get_e_ident()[elfcpp::EI_OSABI], |
| ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]); |
| |
| const unsigned int shnum = this->elf_file_.shnum(); |
| this->set_shnum(shnum); |
| } |
| |
| // Find the SHT_SYMTAB section, given the section headers. The ELF |
| // standard says that maybe in the future there can be more than one |
| // SHT_SYMTAB section. Until somebody figures out how that could |
| // work, we assume there is only one. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs) |
| { |
| const unsigned int shnum = this->shnum(); |
| this->symtab_shndx_ = 0; |
| if (shnum > 0) |
| { |
| // Look through the sections in reverse order, since gas tends |
| // to put the symbol table at the end. |
| const unsigned char* p = pshdrs + shnum * This::shdr_size; |
| unsigned int i = shnum; |
| unsigned int xindex_shndx = 0; |
| unsigned int xindex_link = 0; |
| while (i > 0) |
| { |
| --i; |
| p -= This::shdr_size; |
| typename This::Shdr shdr(p); |
| if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB) |
| { |
| this->symtab_shndx_ = i; |
| if (xindex_shndx > 0 && xindex_link == i) |
| { |
| Xindex* xindex = |
| new Xindex(this->elf_file_.large_shndx_offset()); |
| xindex->read_symtab_xindex<size, big_endian>(this, |
| xindex_shndx, |
| pshdrs); |
| this->set_xindex(xindex); |
| } |
| break; |
| } |
| |
| // Try to pick up the SHT_SYMTAB_SHNDX section, if there is |
| // one. This will work if it follows the SHT_SYMTAB |
| // section. |
| if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX) |
| { |
| xindex_shndx = i; |
| xindex_link = this->adjust_shndx(shdr.get_sh_link()); |
| } |
| } |
| } |
| } |
| |
| // Return the Xindex structure to use for object with lots of |
| // sections. |
| |
| template<int size, bool big_endian> |
| Xindex* |
| Sized_relobj<size, big_endian>::do_initialize_xindex() |
| { |
| gold_assert(this->symtab_shndx_ != -1U); |
| Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset()); |
| xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_); |
| return xindex; |
| } |
| |
| // Return whether SHDR has the right type and flags to be a GNU |
| // .eh_frame section. |
| |
| template<int size, bool big_endian> |
| bool |
| Sized_relobj<size, big_endian>::check_eh_frame_flags( |
| const elfcpp::Shdr<size, big_endian>* shdr) const |
| { |
| return (shdr->get_sh_type() == elfcpp::SHT_PROGBITS |
| && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0); |
| } |
| |
| // Return whether there is a GNU .eh_frame section, given the section |
| // headers and the section names. |
| |
| template<int size, bool big_endian> |
| bool |
| Sized_relobj<size, big_endian>::find_eh_frame( |
| const unsigned char* pshdrs, |
| const char* names, |
| section_size_type names_size) const |
| { |
| const unsigned int shnum = this->shnum(); |
| const unsigned char* p = pshdrs + This::shdr_size; |
| for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size) |
| { |
| typename This::Shdr shdr(p); |
| if (this->check_eh_frame_flags(&shdr)) |
| { |
| if (shdr.get_sh_name() >= names_size) |
| { |
| this->error(_("bad section name offset for section %u: %lu"), |
| i, static_cast<unsigned long>(shdr.get_sh_name())); |
| continue; |
| } |
| |
| const char* name = names + shdr.get_sh_name(); |
| if (strcmp(name, ".eh_frame") == 0) |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // Read the sections and symbols from an object file. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd) |
| { |
| this->read_section_data(&this->elf_file_, sd); |
| |
| const unsigned char* const pshdrs = sd->section_headers->data(); |
| |
| this->find_symtab(pshdrs); |
| |
| const unsigned char* namesu = sd->section_names->data(); |
| const char* names = reinterpret_cast<const char*>(namesu); |
| if (memmem(names, sd->section_names_size, ".eh_frame", 10) != NULL) |
| { |
| if (this->find_eh_frame(pshdrs, names, sd->section_names_size)) |
| this->has_eh_frame_ = true; |
| } |
| |
| sd->symbols = NULL; |
| sd->symbols_size = 0; |
| sd->external_symbols_offset = 0; |
| sd->symbol_names = NULL; |
| sd->symbol_names_size = 0; |
| |
| if (this->symtab_shndx_ == 0) |
| { |
| // No symbol table. Weird but legal. |
| return; |
| } |
| |
| // Get the symbol table section header. |
| typename This::Shdr symtabshdr(pshdrs |
| + this->symtab_shndx_ * This::shdr_size); |
| gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| |
| // If this object has a .eh_frame section, we need all the symbols. |
| // Otherwise we only need the external symbols. While it would be |
| // simpler to just always read all the symbols, I've seen object |
| // files with well over 2000 local symbols, which for a 64-bit |
| // object file format is over 5 pages that we don't need to read |
| // now. |
| |
| const int sym_size = This::sym_size; |
| const unsigned int loccount = symtabshdr.get_sh_info(); |
| this->local_symbol_count_ = loccount; |
| this->local_values_.resize(loccount); |
| section_offset_type locsize = loccount * sym_size; |
| off_t dataoff = symtabshdr.get_sh_offset(); |
| section_size_type datasize = |
| convert_to_section_size_type(symtabshdr.get_sh_size()); |
| off_t extoff = dataoff + locsize; |
| section_size_type extsize = datasize - locsize; |
| |
| off_t readoff = this->has_eh_frame_ ? dataoff : extoff; |
| section_size_type readsize = this->has_eh_frame_ ? datasize : extsize; |
| |
| if (readsize == 0) |
| { |
| // No external symbols. Also weird but also legal. |
| return; |
| } |
| |
| File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false); |
| |
| // Read the section header for the symbol names. |
| unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link()); |
| if (strtab_shndx >= this->shnum()) |
| { |
| this->error(_("invalid symbol table name index: %u"), strtab_shndx); |
| return; |
| } |
| typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size); |
| if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB) |
| { |
| this->error(_("symbol table name section has wrong type: %u"), |
| static_cast<unsigned int>(strtabshdr.get_sh_type())); |
| return; |
| } |
| |
| // Read the symbol names. |
| File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(), |
| strtabshdr.get_sh_size(), |
| false, true); |
| |
| sd->symbols = fvsymtab; |
| sd->symbols_size = readsize; |
| sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0; |
| sd->symbol_names = fvstrtab; |
| sd->symbol_names_size = |
| convert_to_section_size_type(strtabshdr.get_sh_size()); |
| } |
| |
| // Return the section index of symbol SYM. Set *VALUE to its value in |
| // the object file. Set *IS_ORDINARY if this is an ordinary section |
| // index. not a special cod between SHN_LORESERVE and SHN_HIRESERVE. |
| // Note that for a symbol which is not defined in this object file, |
| // this will set *VALUE to 0 and return SHN_UNDEF; it will not return |
| // the final value of the symbol in the link. |
| |
| template<int size, bool big_endian> |
| unsigned int |
| Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym, |
| Address* value, |
| bool* is_ordinary) |
| { |
| section_size_type symbols_size; |
| const unsigned char* symbols = this->section_contents(this->symtab_shndx_, |
| &symbols_size, |
| false); |
| |
| const size_t count = symbols_size / This::sym_size; |
| gold_assert(sym < count); |
| |
| elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size); |
| *value = elfsym.get_st_value(); |
| |
| return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary); |
| } |
| |
| // Return whether to include a section group in the link. LAYOUT is |
| // used to keep track of which section groups we have already seen. |
| // INDEX is the index of the section group and SHDR is the section |
| // header. If we do not want to include this group, we set bits in |
| // OMIT for each section which should be discarded. |
| |
| template<int size, bool big_endian> |
| bool |
| Sized_relobj<size, big_endian>::include_section_group( |
| Symbol_table* symtab, |
| Layout* layout, |
| unsigned int index, |
| const char* name, |
| const unsigned char* shdrs, |
| const char* section_names, |
| section_size_type section_names_size, |
| std::vector<bool>* omit) |
| { |
| // Read the section contents. |
| typename This::Shdr shdr(shdrs + index * This::shdr_size); |
| const unsigned char* pcon = this->get_view(shdr.get_sh_offset(), |
| shdr.get_sh_size(), true, false); |
| const elfcpp::Elf_Word* pword = |
| reinterpret_cast<const elfcpp::Elf_Word*>(pcon); |
| |
| // The first word contains flags. We only care about COMDAT section |
| // groups. Other section groups are always included in the link |
| // just like ordinary sections. |
| elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword); |
| |
| // Look up the group signature, which is the name of a symbol. This |
| // is a lot of effort to go to to read a string. Why didn't they |
| // just have the group signature point into the string table, rather |
| // than indirect through a symbol? |
| |
| // Get the appropriate symbol table header (this will normally be |
| // the single SHT_SYMTAB section, but in principle it need not be). |
| const unsigned int link = this->adjust_shndx(shdr.get_sh_link()); |
| typename This::Shdr symshdr(this, this->elf_file_.section_header(link)); |
| |
| // Read the symbol table entry. |
| unsigned int symndx = shdr.get_sh_info(); |
| if (symndx >= symshdr.get_sh_size() / This::sym_size) |
| { |
| this->error(_("section group %u info %u out of range"), |
| index, symndx); |
| return false; |
| } |
| off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size; |
| const unsigned char* psym = this->get_view(symoff, This::sym_size, true, |
| false); |
| elfcpp::Sym<size, big_endian> sym(psym); |
| |
| // Read the symbol table names. |
| section_size_type symnamelen; |
| const unsigned char* psymnamesu; |
| psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()), |
| &symnamelen, true); |
| const char* psymnames = reinterpret_cast<const char*>(psymnamesu); |
| |
| // Get the section group signature. |
| if (sym.get_st_name() >= symnamelen) |
| { |
| this->error(_("symbol %u name offset %u out of range"), |
| symndx, sym.get_st_name()); |
| return false; |
| } |
| |
| std::string signature(psymnames + sym.get_st_name()); |
| |
| // It seems that some versions of gas will create a section group |
| // associated with a section symbol, and then fail to give a name to |
| // the section symbol. In such a case, use the name of the section. |
| if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION) |
| { |
| bool is_ordinary; |
| unsigned int sym_shndx = this->adjust_sym_shndx(symndx, |
| sym.get_st_shndx(), |
| &is_ordinary); |
| if (!is_ordinary || sym_shndx >= this->shnum()) |
| { |
| this->error(_("symbol %u invalid section index %u"), |
| symndx, sym_shndx); |
| return false; |
| } |
| typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size); |
| if (member_shdr.get_sh_name() < section_names_size) |
| signature = section_names + member_shdr.get_sh_name(); |
| } |
| |
| // Record this section group in the layout, and see whether we've already |
| // seen one with the same signature. |
| bool include_group = ((flags & elfcpp::GRP_COMDAT) == 0 |
| || layout->add_comdat(this, index, signature, true)); |
| |
| Sized_relobj<size, big_endian>* kept_object = NULL; |
| Comdat_group* kept_group = NULL; |
| |
| if (!include_group) |
| { |
| // This group is being discarded. Find the object and group |
| // that was kept in its place. |
| unsigned int kept_group_index = 0; |
| Relobj* kept_relobj = layout->find_kept_object(signature, |
| &kept_group_index); |
| kept_object = static_cast<Sized_relobj<size, big_endian>*>(kept_relobj); |
| if (kept_object != NULL) |
| kept_group = kept_object->find_comdat_group(kept_group_index); |
| } |
| else if (flags & elfcpp::GRP_COMDAT) |
| { |
| // This group is being kept. Create the table to map section names |
| // to section indexes and add it to the table of groups. |
| kept_group = new Comdat_group(); |
| this->add_comdat_group(index, kept_group); |
| } |
| |
| size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word); |
| |
| std::vector<unsigned int> shndxes; |
| bool relocate_group = include_group && parameters->options().relocatable(); |
| if (relocate_group) |
| shndxes.reserve(count - 1); |
| |
| for (size_t i = 1; i < count; ++i) |
| { |
| elfcpp::Elf_Word secnum = |
| this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i)); |
| |
| if (relocate_group) |
| shndxes.push_back(secnum); |
| |
| if (secnum >= this->shnum()) |
| { |
| this->error(_("section %u in section group %u out of range"), |
| secnum, index); |
| continue; |
| } |
| |
| // Check for an earlier section number, since we're going to get |
| // it wrong--we may have already decided to include the section. |
| if (secnum < index) |
| this->error(_("invalid section group %u refers to earlier section %u"), |
| index, secnum); |
| |
| // Get the name of the member section. |
| typename This::Shdr member_shdr(shdrs + secnum * This::shdr_size); |
| if (member_shdr.get_sh_name() >= section_names_size) |
| { |
| // This is an error, but it will be diagnosed eventually |
| // in do_layout, so we don't need to do anything here but |
| // ignore it. |
| continue; |
| } |
| std::string mname(section_names + member_shdr.get_sh_name()); |
| |
| if (!include_group) |
| { |
| (*omit)[secnum] = true; |
| if (kept_group != NULL) |
| { |
| // Find the corresponding kept section, and store that info |
| // in the discarded section table. |
| Comdat_group::const_iterator p = kept_group->find(mname); |
| if (p != kept_group->end()) |
| { |
| Kept_comdat_section* kept = |
| new Kept_comdat_section(kept_object, p->second); |
| this->set_kept_comdat_section(secnum, kept); |
| } |
| } |
| } |
| else if (flags & elfcpp::GRP_COMDAT) |
| { |
| // Add the section to the kept group table. |
| gold_assert(kept_group != NULL); |
| kept_group->insert(std::make_pair(mname, secnum)); |
| } |
| } |
| |
| if (relocate_group) |
| layout->layout_group(symtab, this, index, name, signature.c_str(), |
| shdr, flags, &shndxes); |
| |
| return include_group; |
| } |
| |
| // Whether to include a linkonce section in the link. NAME is the |
| // name of the section and SHDR is the section header. |
| |
| // Linkonce sections are a GNU extension implemented in the original |
| // GNU linker before section groups were defined. The semantics are |
| // that we only include one linkonce section with a given name. The |
| // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME, |
| // where T is the type of section and SYMNAME is the name of a symbol. |
| // In an attempt to make linkonce sections interact well with section |
| // groups, we try to identify SYMNAME and use it like a section group |
| // signature. We want to block section groups with that signature, |
| // but not other linkonce sections with that signature. We also use |
| // the full name of the linkonce section as a normal section group |
| // signature. |
| |
| template<int size, bool big_endian> |
| bool |
| Sized_relobj<size, big_endian>::include_linkonce_section( |
| Layout* layout, |
| unsigned int index, |
| const char* name, |
| const elfcpp::Shdr<size, big_endian>&) |
| { |
| // In general the symbol name we want will be the string following |
| // the last '.'. However, we have to handle the case of |
| // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by |
| // some versions of gcc. So we use a heuristic: if the name starts |
| // with ".gnu.linkonce.t.", we use everything after that. Otherwise |
| // we look for the last '.'. We can't always simply skip |
| // ".gnu.linkonce.X", because we have to deal with cases like |
| // ".gnu.linkonce.d.rel.ro.local". |
| const char* const linkonce_t = ".gnu.linkonce.t."; |
| const char* symname; |
| if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0) |
| symname = name + strlen(linkonce_t); |
| else |
| symname = strrchr(name, '.') + 1; |
| std::string sig1(symname); |
| std::string sig2(name); |
| bool include1 = layout->add_comdat(this, index, sig1, false); |
| bool include2 = layout->add_comdat(this, index, sig2, true); |
| |
| if (!include2) |
| { |
| // The section is being discarded on the basis of its section |
| // name (i.e., the kept section was also a linkonce section). |
| // In this case, the section index stored with the layout object |
| // is the linkonce section that was kept. |
| unsigned int kept_group_index = 0; |
| Relobj* kept_relobj = layout->find_kept_object(sig2, &kept_group_index); |
| if (kept_relobj != NULL) |
| { |
| Sized_relobj<size, big_endian>* kept_object |
| = static_cast<Sized_relobj<size, big_endian>*>(kept_relobj); |
| Kept_comdat_section* kept = |
| new Kept_comdat_section(kept_object, kept_group_index); |
| this->set_kept_comdat_section(index, kept); |
| } |
| } |
| else if (!include1) |
| { |
| // The section is being discarded on the basis of its symbol |
| // name. This means that the corresponding kept section was |
| // part of a comdat group, and it will be difficult to identify |
| // the specific section within that group that corresponds to |
| // this linkonce section. We'll handle the simple case where |
| // the group has only one member section. Otherwise, it's not |
| // worth the effort. |
| unsigned int kept_group_index = 0; |
| Relobj* kept_relobj = layout->find_kept_object(sig1, &kept_group_index); |
| if (kept_relobj != NULL) |
| { |
| Sized_relobj<size, big_endian>* kept_object = |
| static_cast<Sized_relobj<size, big_endian>*>(kept_relobj); |
| Comdat_group* kept_group = |
| kept_object->find_comdat_group(kept_group_index); |
| if (kept_group != NULL && kept_group->size() == 1) |
| { |
| Comdat_group::const_iterator p = kept_group->begin(); |
| gold_assert(p != kept_group->end()); |
| Kept_comdat_section* kept = |
| new Kept_comdat_section(kept_object, p->second); |
| this->set_kept_comdat_section(index, kept); |
| } |
| } |
| } |
| |
| return include1 && include2; |
| } |
| |
| // Lay out the input sections. We walk through the sections and check |
| // whether they should be included in the link. If they should, we |
| // pass them to the Layout object, which will return an output section |
| // and an offset. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab, |
| Layout* layout, |
| Read_symbols_data* sd) |
| { |
| const unsigned int shnum = this->shnum(); |
| if (shnum == 0) |
| return; |
| |
| // Get the section headers. |
| const unsigned char* shdrs = sd->section_headers->data(); |
| const unsigned char* pshdrs; |
| |
| // Get the section names. |
| const unsigned char* pnamesu = sd->section_names->data(); |
| const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| |
| // For each section, record the index of the reloc section if any. |
| // Use 0 to mean that there is no reloc section, -1U to mean that |
| // there is more than one. |
| std::vector<unsigned int> reloc_shndx(shnum, 0); |
| std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL); |
| // Skip the first, dummy, section. |
| pshdrs = shdrs + This::shdr_size; |
| for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size) |
| { |
| typename This::Shdr shdr(pshdrs); |
| |
| unsigned int sh_type = shdr.get_sh_type(); |
| if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA) |
| { |
| unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info()); |
| if (target_shndx == 0 || target_shndx >= shnum) |
| { |
| this->error(_("relocation section %u has bad info %u"), |
| i, target_shndx); |
| continue; |
| } |
| |
| if (reloc_shndx[target_shndx] != 0) |
| reloc_shndx[target_shndx] = -1U; |
| else |
| { |
| reloc_shndx[target_shndx] = i; |
| reloc_type[target_shndx] = sh_type; |
| } |
| } |
| } |
| |
| Output_sections& out_sections(this->output_sections()); |
| std::vector<Address>& out_section_offsets(this->section_offsets_); |
| |
| out_sections.resize(shnum); |
| out_section_offsets.resize(shnum); |
| |
| // If we are only linking for symbols, then there is nothing else to |
| // do here. |
| if (this->input_file()->just_symbols()) |
| { |
| delete sd->section_headers; |
| sd->section_headers = NULL; |
| delete sd->section_names; |
| sd->section_names = NULL; |
| return; |
| } |
| |
| // Whether we've seen a .note.GNU-stack section. |
| bool seen_gnu_stack = false; |
| // The flags of a .note.GNU-stack section. |
| uint64_t gnu_stack_flags = 0; |
| |
| // Keep track of which sections to omit. |
| std::vector<bool> omit(shnum, false); |
| |
| // Keep track of reloc sections when emitting relocations. |
| const bool relocatable = parameters->options().relocatable(); |
| const bool emit_relocs = (relocatable |
| || parameters->options().emit_relocs()); |
| std::vector<unsigned int> reloc_sections; |
| |
| // Keep track of .eh_frame sections. |
| std::vector<unsigned int> eh_frame_sections; |
| |
| // Skip the first, dummy, section. |
| pshdrs = shdrs + This::shdr_size; |
| for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size) |
| { |
| typename This::Shdr shdr(pshdrs); |
| |
| if (shdr.get_sh_name() >= sd->section_names_size) |
| { |
| this->error(_("bad section name offset for section %u: %lu"), |
| i, static_cast<unsigned long>(shdr.get_sh_name())); |
| return; |
| } |
| |
| const char* name = pnames + shdr.get_sh_name(); |
| |
| if (this->handle_gnu_warning_section(name, i, symtab)) |
| { |
| if (!relocatable) |
| omit[i] = true; |
| } |
| |
| // The .note.GNU-stack section is special. It gives the |
| // protection flags that this object file requires for the stack |
| // in memory. |
| if (strcmp(name, ".note.GNU-stack") == 0) |
| { |
| seen_gnu_stack = true; |
| gnu_stack_flags |= shdr.get_sh_flags(); |
| omit[i] = true; |
| } |
| |
| bool discard = omit[i]; |
| if (!discard) |
| { |
| if (shdr.get_sh_type() == elfcpp::SHT_GROUP) |
| { |
| if (!this->include_section_group(symtab, layout, i, name, shdrs, |
| pnames, sd->section_names_size, |
| &omit)) |
| discard = true; |
| } |
| else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0 |
| && Layout::is_linkonce(name)) |
| { |
| if (!this->include_linkonce_section(layout, i, name, shdr)) |
| discard = true; |
| } |
| } |
| |
| if (discard) |
| { |
| // Do not include this section in the link. |
| out_sections[i] = NULL; |
| out_section_offsets[i] = invalid_address; |
| continue; |
| } |
| |
| // When doing a relocatable link we are going to copy input |
| // reloc sections into the output. We only want to copy the |
| // ones associated with sections which are not being discarded. |
| // However, we don't know that yet for all sections. So save |
| // reloc sections and process them later. |
| if (emit_relocs |
| && (shdr.get_sh_type() == elfcpp::SHT_REL |
| || shdr.get_sh_type() == elfcpp::SHT_RELA)) |
| { |
| reloc_sections.push_back(i); |
| continue; |
| } |
| |
| if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP) |
| continue; |
| |
| // The .eh_frame section is special. It holds exception frame |
| // information that we need to read in order to generate the |
| // exception frame header. We process these after all the other |
| // sections so that the exception frame reader can reliably |
| // determine which sections are being discarded, and discard the |
| // corresponding information. |
| if (!relocatable |
| && strcmp(name, ".eh_frame") == 0 |
| && this->check_eh_frame_flags(&shdr)) |
| { |
| eh_frame_sections.push_back(i); |
| continue; |
| } |
| |
| off_t offset; |
| Output_section* os = layout->layout(this, i, name, shdr, |
| reloc_shndx[i], reloc_type[i], |
| &offset); |
| |
| out_sections[i] = os; |
| if (offset == -1) |
| out_section_offsets[i] = invalid_address; |
| else |
| out_section_offsets[i] = convert_types<Address, off_t>(offset); |
| |
| // If this section requires special handling, and if there are |
| // relocs that apply to it, then we must do the special handling |
| // before we apply the relocs. |
| if (offset == -1 && reloc_shndx[i] != 0) |
| this->set_relocs_must_follow_section_writes(); |
| } |
| |
| layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags); |
| |
| // When doing a relocatable link handle the reloc sections at the |
| // end. |
| if (emit_relocs) |
| this->size_relocatable_relocs(); |
| for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin(); |
| p != reloc_sections.end(); |
| ++p) |
| { |
| unsigned int i = *p; |
| const unsigned char* pshdr; |
| pshdr = sd->section_headers->data() + i * This::shdr_size; |
| typename This::Shdr shdr(pshdr); |
| |
| unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info()); |
| if (data_shndx >= shnum) |
| { |
| // We already warned about this above. |
| continue; |
| } |
| |
| Output_section* data_section = out_sections[data_shndx]; |
| if (data_section == NULL) |
| { |
| out_sections[i] = NULL; |
| out_section_offsets[i] = invalid_address; |
| continue; |
| } |
| |
| Relocatable_relocs* rr = new Relocatable_relocs(); |
| this->set_relocatable_relocs(i, rr); |
| |
| Output_section* os = layout->layout_reloc(this, i, shdr, data_section, |
| rr); |
| out_sections[i] = os; |
| out_section_offsets[i] = invalid_address; |
| } |
| |
| // Handle the .eh_frame sections at the end. |
| for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin(); |
| p != eh_frame_sections.end(); |
| ++p) |
| { |
| gold_assert(this->has_eh_frame_); |
| gold_assert(sd->external_symbols_offset != 0); |
| |
| unsigned int i = *p; |
| const unsigned char *pshdr; |
| pshdr = sd->section_headers->data() + i * This::shdr_size; |
| typename This::Shdr shdr(pshdr); |
| |
| off_t offset; |
| Output_section* os = layout->layout_eh_frame(this, |
| sd->symbols->data(), |
| sd->symbols_size, |
| sd->symbol_names->data(), |
| sd->symbol_names_size, |
| i, shdr, |
| reloc_shndx[i], |
| reloc_type[i], |
| &offset); |
| out_sections[i] = os; |
| if (offset == -1) |
| out_section_offsets[i] = invalid_address; |
| else |
| out_section_offsets[i] = convert_types<Address, off_t>(offset); |
| |
| // If this section requires special handling, and if there are |
| // relocs that apply to it, then we must do the special handling |
| // before we apply the relocs. |
| if (offset == -1 && reloc_shndx[i] != 0) |
| this->set_relocs_must_follow_section_writes(); |
| } |
| |
| delete sd->section_headers; |
| sd->section_headers = NULL; |
| delete sd->section_names; |
| sd->section_names = NULL; |
| } |
| |
| // Add the symbols to the symbol table. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab, |
| Read_symbols_data* sd) |
| { |
| if (sd->symbols == NULL) |
| { |
| gold_assert(sd->symbol_names == NULL); |
| return; |
| } |
| |
| const int sym_size = This::sym_size; |
| size_t symcount = ((sd->symbols_size - sd->external_symbols_offset) |
| / sym_size); |
| if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset) |
| { |
| this->error(_("size of symbols is not multiple of symbol size")); |
| return; |
| } |
| |
| this->symbols_.resize(symcount); |
| |
| const char* sym_names = |
| reinterpret_cast<const char*>(sd->symbol_names->data()); |
| symtab->add_from_relobj(this, |
| sd->symbols->data() + sd->external_symbols_offset, |
| symcount, this->local_symbol_count_, |
| sym_names, sd->symbol_names_size, |
| &this->symbols_, |
| &this->defined_count_); |
| |
| delete sd->symbols; |
| sd->symbols = NULL; |
| delete sd->symbol_names; |
| sd->symbol_names = NULL; |
| } |
| |
| // First pass over the local symbols. Here we add their names to |
| // *POOL and *DYNPOOL, and we store the symbol value in |
| // THIS->LOCAL_VALUES_. This function is always called from a |
| // singleton thread. This is followed by a call to |
| // finalize_local_symbols. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool, |
| Stringpool* dynpool) |
| { |
| gold_assert(this->symtab_shndx_ != -1U); |
| if (this->symtab_shndx_ == 0) |
| { |
| // This object has no symbols. Weird but legal. |
| return; |
| } |
| |
| // Read the symbol table section header. |
| const unsigned int symtab_shndx = this->symtab_shndx_; |
| typename This::Shdr symtabshdr(this, |
| this->elf_file_.section_header(symtab_shndx)); |
| gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| |
| // Read the local symbols. |
| const int sym_size = This::sym_size; |
| const unsigned int loccount = this->local_symbol_count_; |
| gold_assert(loccount == symtabshdr.get_sh_info()); |
| off_t locsize = loccount * sym_size; |
| const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
| locsize, true, true); |
| |
| // Read the symbol names. |
| const unsigned int strtab_shndx = |
| this->adjust_shndx(symtabshdr.get_sh_link()); |
| section_size_type strtab_size; |
| const unsigned char* pnamesu = this->section_contents(strtab_shndx, |
| &strtab_size, |
| true); |
| const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| |
| // Loop over the local symbols. |
| |
| const Output_sections& out_sections(this->output_sections()); |
| unsigned int shnum = this->shnum(); |
| unsigned int count = 0; |
| unsigned int dyncount = 0; |
| // Skip the first, dummy, symbol. |
| psyms += sym_size; |
| for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size) |
| { |
| elfcpp::Sym<size, big_endian> sym(psyms); |
| |
| Symbol_value<size>& lv(this->local_values_[i]); |
| |
| bool is_ordinary; |
| unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(), |
| &is_ordinary); |
| lv.set_input_shndx(shndx, is_ordinary); |
| |
| if (sym.get_st_type() == elfcpp::STT_SECTION) |
| lv.set_is_section_symbol(); |
| else if (sym.get_st_type() == elfcpp::STT_TLS) |
| lv.set_is_tls_symbol(); |
| |
| // Save the input symbol value for use in do_finalize_local_symbols(). |
| lv.set_input_value(sym.get_st_value()); |
| |
| // Decide whether this symbol should go into the output file. |
| |
| if (shndx < shnum && out_sections[shndx] == NULL) |
| { |
| lv.set_no_output_symtab_entry(); |
| gold_assert(!lv.needs_output_dynsym_entry()); |
| continue; |
| } |
| |
| if (sym.get_st_type() == elfcpp::STT_SECTION) |
| { |
| lv.set_no_output_symtab_entry(); |
| gold_assert(!lv.needs_output_dynsym_entry()); |
| continue; |
| } |
| |
| if (sym.get_st_name() >= strtab_size) |
| { |
| this->error(_("local symbol %u section name out of range: %u >= %u"), |
| i, sym.get_st_name(), |
| static_cast<unsigned int>(strtab_size)); |
| lv.set_no_output_symtab_entry(); |
| continue; |
| } |
| |
| // Add the symbol to the symbol table string pool. |
| const char* name = pnames + sym.get_st_name(); |
| pool->add(name, true, NULL); |
| ++count; |
| |
| // If needed, add the symbol to the dynamic symbol table string pool. |
| if (lv.needs_output_dynsym_entry()) |
| { |
| dynpool->add(name, true, NULL); |
| ++dyncount; |
| } |
| } |
| |
| this->output_local_symbol_count_ = count; |
| this->output_local_dynsym_count_ = dyncount; |
| } |
| |
| // Finalize the local symbols. Here we set the final value in |
| // THIS->LOCAL_VALUES_ and set their output symbol table indexes. |
| // This function is always called from a singleton thread. The actual |
| // output of the local symbols will occur in a separate task. |
| |
| template<int size, bool big_endian> |
| unsigned int |
| Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index, |
| off_t off) |
| { |
| gold_assert(off == static_cast<off_t>(align_address(off, size >> 3))); |
| |
| const unsigned int loccount = this->local_symbol_count_; |
| this->local_symbol_offset_ = off; |
| |
| const Output_sections& out_sections(this->output_sections()); |
| const std::vector<Address>& out_offsets(this->section_offsets_); |
| unsigned int shnum = this->shnum(); |
| |
| for (unsigned int i = 1; i < loccount; ++i) |
| { |
| Symbol_value<size>& lv(this->local_values_[i]); |
| |
| bool is_ordinary; |
| unsigned int shndx = lv.input_shndx(&is_ordinary); |
| |
| // Set the output symbol value. |
| |
| if (!is_ordinary) |
| { |
| if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON) |
| lv.set_output_value(lv.input_value()); |
| else |
| { |
| this->error(_("unknown section index %u for local symbol %u"), |
| shndx, i); |
| lv.set_output_value(0); |
| } |
| } |
| else |
| { |
| if (shndx >= shnum) |
| { |
| this->error(_("local symbol %u section index %u out of range"), |
| i, shndx); |
| shndx = 0; |
| } |
| |
| Output_section* os = out_sections[shndx]; |
| |
| if (os == NULL) |
| { |
| // This local symbol belongs to a section we are discarding. |
| // In some cases when applying relocations later, we will |
| // attempt to match it to the corresponding kept section, |
| // so we leave the input value unchanged here. |
| continue; |
| } |
| else if (out_offsets[shndx] == invalid_address) |
| { |
| // This is a SHF_MERGE section or one which otherwise |
| // requires special handling. We get the output address |
| // of the start of the merged section. If this is not a |
| // section symbol, we can then determine the final |
| // value. If it is a section symbol, we can not, as in |
| // that case we have to consider the addend to determine |
| // the value to use in a relocation. |
| if (!lv.is_section_symbol()) |
| lv.set_output_value(os->output_address(this, shndx, |
| lv.input_value())); |
| else |
| { |
| section_offset_type start = |
| os->starting_output_address(this, shndx); |
| Merged_symbol_value<size>* msv = |
| new Merged_symbol_value<size>(lv.input_value(), start); |
| lv.set_merged_symbol_value(msv); |
| } |
| } |
| else if (lv.is_tls_symbol()) |
| lv.set_output_value(os->tls_offset() |
| + out_offsets[shndx] |
| + lv.input_value()); |
| else |
| lv.set_output_value(os->address() |
| + out_offsets[shndx] |
| + lv.input_value()); |
| } |
| |
| if (lv.needs_output_symtab_entry()) |
| { |
| lv.set_output_symtab_index(index); |
| ++index; |
| } |
| } |
| return index; |
| } |
| |
| // Set the output dynamic symbol table indexes for the local variables. |
| |
| template<int size, bool big_endian> |
| unsigned int |
| Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index) |
| { |
| const unsigned int loccount = this->local_symbol_count_; |
| for (unsigned int i = 1; i < loccount; ++i) |
| { |
| Symbol_value<size>& lv(this->local_values_[i]); |
| if (lv.needs_output_dynsym_entry()) |
| { |
| lv.set_output_dynsym_index(index); |
| ++index; |
| } |
| } |
| return index; |
| } |
| |
| // Set the offset where local dynamic symbol information will be stored. |
| // Returns the count of local symbols contributed to the symbol table by |
| // this object. |
| |
| template<int size, bool big_endian> |
| unsigned int |
| Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off) |
| { |
| gold_assert(off == static_cast<off_t>(align_address(off, size >> 3))); |
| this->local_dynsym_offset_ = off; |
| return this->output_local_dynsym_count_; |
| } |
| |
| // Write out the local symbols. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_relobj<size, big_endian>::write_local_symbols( |
| Output_file* of, |
| const Stringpool* sympool, |
| const Stringpool* dynpool, |
| Output_symtab_xindex* symtab_xindex, |
| Output_symtab_xindex* dynsym_xindex) |
| { |
| if (parameters->options().strip_all() |
| && this->output_local_dynsym_count_ == 0) |
| return; |
| |
| gold_assert(this->symtab_shndx_ != -1U); |
| if (this->symtab_shndx_ == 0) |
| { |
| // This object has no symbols. Weird but legal. |
| return; |
| } |
| |
| // Read the symbol table section header. |
| const unsigned int symtab_shndx = this->symtab_shndx_; |
| typename This::Shdr symtabshdr(this, |
| this->elf_file_.section_header(symtab_shndx)); |
| gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| const unsigned int loccount = this->local_symbol_count_; |
| gold_assert(loccount == symtabshdr.get_sh_info()); |
| |
| // Read the local symbols. |
| const int sym_size = This::sym_size; |
| off_t locsize = loccount * sym_size; |
| const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
| locsize, true, false); |
| |
| // Read the symbol names. |
| const unsigned int strtab_shndx = |
| this->adjust_shndx(symtabshdr.get_sh_link()); |
| section_size_type strtab_size; |
| const unsigned char* pnamesu = this->section_contents(strtab_shndx, |
| &strtab_size, |
| false); |
| const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| |
| // Get views into the output file for the portions of the symbol table |
| // and the dynamic symbol table that we will be writing. |
| off_t output_size = this->output_local_symbol_count_ * sym_size; |
| unsigned char* oview = NULL; |
| if (output_size > 0) |
| oview = of->get_output_view(this->local_symbol_offset_, output_size); |
| |
| off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size; |
| unsigned char* dyn_oview = NULL; |
| if (dyn_output_size > 0) |
| dyn_oview = of->get_output_view(this->local_dynsym_offset_, |
| dyn_output_size); |
| |
| const Output_sections out_sections(this->output_sections()); |
| |
| gold_assert(this->local_values_.size() == loccount); |
| |
| unsigned char* ov = oview; |
| unsigned char* dyn_ov = dyn_oview; |
| psyms += sym_size; |
| for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size) |
| { |
| elfcpp::Sym<size, big_endian> isym(psyms); |
| |
| Symbol_value<size>& lv(this->local_values_[i]); |
| |
| bool is_ordinary; |
| unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(), |
| &is_ordinary); |
| if (is_ordinary) |
| { |
| gold_assert(st_shndx < out_sections.size()); |
| if (out_sections[st_shndx] == NULL) |
| continue; |
| st_shndx = out_sections[st_shndx]->out_shndx(); |
| if (st_shndx >= elfcpp::SHN_LORESERVE) |
| { |
| if (lv.needs_output_symtab_entry()) |
| symtab_xindex->add(lv.output_symtab_index(), st_shndx); |
| if (lv.needs_output_dynsym_entry()) |
| dynsym_xindex->add(lv.output_dynsym_index(), st_shndx); |
| st_shndx = elfcpp::SHN_XINDEX; |
| } |
| } |
| |
| // Write the symbol to the output symbol table. |
| if (!parameters->options().strip_all() |
| && lv.needs_output_symtab_entry()) |
| { |
| elfcpp::Sym_write<size, big_endian> osym(ov); |
| |
| gold_assert(isym.get_st_name() < strtab_size); |
| const char* name = pnames + isym.get_st_name(); |
| osym.put_st_name(sympool->get_offset(name)); |
| osym.put_st_value(this->local_values_[i].value(this, 0)); |
| osym.put_st_size(isym.get_st_size()); |
| osym.put_st_info(isym.get_st_info()); |
| osym.put_st_other(isym.get_st_other()); |
| osym.put_st_shndx(st_shndx); |
| |
| ov += sym_size; |
| } |
| |
| // Write the symbol to the output dynamic symbol table. |
| if (lv.needs_output_dynsym_entry()) |
| { |
| gold_assert(dyn_ov < dyn_oview + dyn_output_size); |
| elfcpp::Sym_write<size, big_endian> osym(dyn_ov); |
| |
| gold_assert(isym.get_st_name() < strtab_size); |
| const char* name = pnames + isym.get_st_name(); |
| osym.put_st_name(dynpool->get_offset(name)); |
| osym.put_st_value(this->local_values_[i].value(this, 0)); |
| osym.put_st_size(isym.get_st_size()); |
| osym.put_st_info(isym.get_st_info()); |
| osym.put_st_other(isym.get_st_other()); |
| osym.put_st_shndx(st_shndx); |
| |
| dyn_ov += sym_size; |
| } |
| } |
| |
| |
| if (output_size > 0) |
| { |
| gold_assert(ov - oview == output_size); |
| of->write_output_view(this->local_symbol_offset_, output_size, oview); |
| } |
| |
| if (dyn_output_size > 0) |
| { |
| gold_assert(dyn_ov - dyn_oview == dyn_output_size); |
| of->write_output_view(this->local_dynsym_offset_, dyn_output_size, |
| dyn_oview); |
| } |
| } |
| |
| // Set *INFO to symbolic information about the offset OFFSET in the |
| // section SHNDX. Return true if we found something, false if we |
| // found nothing. |
| |
| template<int size, bool big_endian> |
| bool |
| Sized_relobj<size, big_endian>::get_symbol_location_info( |
| unsigned int shndx, |
| off_t offset, |
| Symbol_location_info* info) |
| { |
| if (this->symtab_shndx_ == 0) |
| return false; |
| |
| section_size_type symbols_size; |
| const unsigned char* symbols = this->section_contents(this->symtab_shndx_, |
| &symbols_size, |
| false); |
| |
| unsigned int symbol_names_shndx = |
| this->adjust_shndx(this->section_link(this->symtab_shndx_)); |
| section_size_type names_size; |
| const unsigned char* symbol_names_u = |
| this->section_contents(symbol_names_shndx, &names_size, false); |
| const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u); |
| |
| const int sym_size = This::sym_size; |
| const size_t count = symbols_size / sym_size; |
| |
| const unsigned char* p = symbols; |
| for (size_t i = 0; i < count; ++i, p += sym_size) |
| { |
| elfcpp::Sym<size, big_endian> sym(p); |
| |
| if (sym.get_st_type() == elfcpp::STT_FILE) |
| { |
| if (sym.get_st_name() >= names_size) |
| info->source_file = "(invalid)"; |
| else |
| info->source_file = symbol_names + sym.get_st_name(); |
| continue; |
| } |
| |
| bool is_ordinary; |
| unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(), |
| &is_ordinary); |
| if (is_ordinary |
| && st_shndx == shndx |
| && static_cast<off_t>(sym.get_st_value()) <= offset |
| && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size()) |
| > offset)) |
| { |
| if (sym.get_st_name() > names_size) |
| info->enclosing_symbol_name = "(invalid)"; |
| else |
| { |
| info->enclosing_symbol_name = symbol_names + sym.get_st_name(); |
| if (parameters->options().do_demangle()) |
| { |
| char* demangled_name = cplus_demangle( |
| info->enclosing_symbol_name.c_str(), |
| DMGL_ANSI | DMGL_PARAMS); |
| if (demangled_name != NULL) |
| { |
| info->enclosing_symbol_name.assign(demangled_name); |
| free(demangled_name); |
| } |
| } |
| } |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| // Look for a kept section corresponding to the given discarded section, |
| // and return its output address. This is used only for relocations in |
| // debugging sections. If we can't find the kept section, return 0. |
| |
| template<int size, bool big_endian> |
| typename Sized_relobj<size, big_endian>::Address |
| Sized_relobj<size, big_endian>::map_to_kept_section( |
| unsigned int shndx, |
| bool* found) const |
| { |
| Kept_comdat_section *kept = this->get_kept_comdat_section(shndx); |
| if (kept != NULL) |
| { |
| gold_assert(kept->object_ != NULL); |
| *found = true; |
| Output_section* os = kept->object_->output_section(kept->shndx_); |
| Address offset = kept->object_->get_output_section_offset(kept->shndx_); |
| gold_assert(os != NULL && offset != invalid_address); |
| return os->address() + offset; |
| } |
| *found = false; |
| return 0; |
| } |
| |
| // Get symbol counts. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_relobj<size, big_endian>::do_get_global_symbol_counts( |
| const Symbol_table*, |
| size_t* defined, |
| size_t* used) const |
| { |
| *defined = this->defined_count_; |
| size_t count = 0; |
| for (Symbols::const_iterator p = this->symbols_.begin(); |
| p != this->symbols_.end(); |
| ++p) |
| if (*p != NULL |
| && (*p)->source() == Symbol::FROM_OBJECT |
| && (*p)->object() == this |
| && (*p)->is_defined()) |
| ++count; |
| *used = count; |
| } |
| |
| // Input_objects methods. |
| |
| // Add a regular relocatable object to the list. Return false if this |
| // object should be ignored. |
| |
| bool |
| Input_objects::add_object(Object* obj) |
| { |
| // Set the global target from the first object file we recognize. |
| Target* target = obj->target(); |
| if (!parameters->target_valid()) |
| set_parameters_target(target); |
| else if (target != ¶meters->target()) |
| { |
| obj->error(_("incompatible target")); |
| return false; |
| } |
| |
| // Print the filename if the -t/--trace option is selected. |
| if (parameters->options().trace()) |
| gold_info("%s", obj->name().c_str()); |
| |
| if (!obj->is_dynamic()) |
| this->relobj_list_.push_back(static_cast<Relobj*>(obj)); |
| else |
| { |
| // See if this is a duplicate SONAME. |
| Dynobj* dynobj = static_cast<Dynobj*>(obj); |
| const char* soname = dynobj->soname(); |
| |
| std::pair<Unordered_set<std::string>::iterator, bool> ins = |
| this->sonames_.insert(soname); |
| if (!ins.second) |
| { |
| // We have already seen a dynamic object with this soname. |
| return false; |
| } |
| |
| this->dynobj_list_.push_back(dynobj); |
| |
| // If this is -lc, remember the directory in which we found it. |
| // We use this when issuing warnings about undefined symbols: as |
| // a heuristic, we don't warn about system libraries found in |
| // the same directory as -lc. |
| if (strncmp(soname, "libc.so", 7) == 0) |
| { |
| const char* object_name = dynobj->name().c_str(); |
| const char* base = lbasename(object_name); |
| if (base != object_name) |
| this->system_library_directory_.assign(object_name, |
| base - 1 - object_name); |
| } |
| } |
| |
| // Add this object to the cross-referencer if requested. |
| if (parameters->options().user_set_print_symbol_counts()) |
| { |
| if (this->cref_ == NULL) |
| this->cref_ = new Cref(); |
| this->cref_->add_object(obj); |
| } |
| |
| return true; |
| } |
| |
| // Return whether an object was found in the system library directory. |
| |
| bool |
| Input_objects::found_in_system_library_directory(const Object* object) const |
| { |
| return (!this->system_library_directory_.empty() |
| && object->name().compare(0, |
| this->system_library_directory_.size(), |
| this->system_library_directory_) == 0); |
| } |
| |
| // For each dynamic object, record whether we've seen all of its |
| // explicit dependencies. |
| |
| void |
| Input_objects::check_dynamic_dependencies() const |
| { |
| for (Dynobj_list::const_iterator p = this->dynobj_list_.begin(); |
| p != this->dynobj_list_.end(); |
| ++p) |
| { |
| const Dynobj::Needed& needed((*p)->needed()); |
| bool found_all = true; |
| for (Dynobj::Needed::const_iterator pneeded = needed.begin(); |
| pneeded != needed.end(); |
| ++pneeded) |
| { |
| if (this->sonames_.find(*pneeded) == this->sonames_.end()) |
| { |
| found_all = false; |
| break; |
| } |
| } |
| (*p)->set_has_unknown_needed_entries(!found_all); |
| } |
| } |
| |
| // Start processing an archive. |
| |
| void |
| Input_objects::archive_start(Archive* archive) |
| { |
| if (parameters->options().user_set_print_symbol_counts()) |
| { |
| if (this->cref_ == NULL) |
| this->cref_ = new Cref(); |
| this->cref_->add_archive_start(archive); |
| } |
| } |
| |
| // Stop processing an archive. |
| |
| void |
| Input_objects::archive_stop(Archive* archive) |
| { |
| if (parameters->options().user_set_print_symbol_counts()) |
| this->cref_->add_archive_stop(archive); |
| } |
| |
| // Print symbol counts |
| |
| void |
| Input_objects::print_symbol_counts(const Symbol_table* symtab) const |
| { |
| if (parameters->options().user_set_print_symbol_counts() |
| && this->cref_ != NULL) |
| this->cref_->print_symbol_counts(symtab); |
| } |
| |
| // Relocate_info methods. |
| |
| // Return a string describing the location of a relocation. This is |
| // only used in error messages. |
| |
| template<int size, bool big_endian> |
| std::string |
| Relocate_info<size, big_endian>::location(size_t, off_t offset) const |
| { |
| // See if we can get line-number information from debugging sections. |
| std::string filename; |
| std::string file_and_lineno; // Better than filename-only, if available. |
| |
| Sized_dwarf_line_info<size, big_endian> line_info(this->object); |
| // This will be "" if we failed to parse the debug info for any reason. |
| file_and_lineno = line_info.addr2line(this->data_shndx, offset); |
| |
| std::string ret(this->object->name()); |
| ret += ':'; |
| Symbol_location_info info; |
| if (this->object->get_symbol_location_info(this->data_shndx, offset, &info)) |
| { |
| ret += " in function "; |
| ret += info.enclosing_symbol_name; |
| ret += ":"; |
| filename = info.source_file; |
| } |
| |
| if (!file_and_lineno.empty()) |
| ret += file_and_lineno; |
| else |
| { |
| if (!filename.empty()) |
| ret += filename; |
| ret += "("; |
| ret += this->object->section_name(this->data_shndx); |
| char buf[100]; |
| // Offsets into sections have to be positive. |
| snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset)); |
| ret += buf; |
| ret += ")"; |
| } |
| return ret; |
| } |
| |
| } // End namespace gold. |
| |
| namespace |
| { |
| |
| using namespace gold; |
| |
| // Read an ELF file with the header and return the appropriate |
| // instance of Object. |
| |
| template<int size, bool big_endian> |
| Object* |
| make_elf_sized_object(const std::string& name, Input_file* input_file, |
| off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr) |
| { |
| int et = ehdr.get_e_type(); |
| if (et == elfcpp::ET_REL) |
| { |
| Sized_relobj<size, big_endian>* obj = |
| new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr); |
| obj->setup(ehdr); |
| return obj; |
| } |
| else if (et == elfcpp::ET_DYN) |
| { |
| Sized_dynobj<size, big_endian>* obj = |
| new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr); |
| obj->setup(ehdr); |
| return obj; |
| } |
| else |
| { |
| gold_error(_("%s: unsupported ELF file type %d"), |
| name.c_str(), et); |
| return NULL; |
| } |
| } |
| |
| } // End anonymous namespace. |
| |
| namespace gold |
| { |
| |
| // Read an ELF file and return the appropriate instance of Object. |
| |
| Object* |
| make_elf_object(const std::string& name, Input_file* input_file, off_t offset, |
| const unsigned char* p, section_offset_type bytes) |
| { |
| if (bytes < elfcpp::EI_NIDENT) |
| { |
| gold_error(_("%s: ELF file too short"), name.c_str()); |
| return NULL; |
| } |
| |
| int v = p[elfcpp::EI_VERSION]; |
| if (v != elfcpp::EV_CURRENT) |
| { |
| if (v == elfcpp::EV_NONE) |
| gold_error(_("%s: invalid ELF version 0"), name.c_str()); |
| else |
| gold_error(_("%s: unsupported ELF version %d"), name.c_str(), v); |
| return NULL; |
| } |
| |
| int c = p[elfcpp::EI_CLASS]; |
| if (c == elfcpp::ELFCLASSNONE) |
| { |
| gold_error(_("%s: invalid ELF class 0"), name.c_str()); |
| return NULL; |
| } |
| else if (c != elfcpp::ELFCLASS32 |
| && c != elfcpp::ELFCLASS64) |
| { |
| gold_error(_("%s: unsupported ELF class %d"), name.c_str(), c); |
| return NULL; |
| } |
| |
| int d = p[elfcpp::EI_DATA]; |
| if (d == elfcpp::ELFDATANONE) |
| { |
| gold_error(_("%s: invalid ELF data encoding"), name.c_str()); |
| return NULL; |
| } |
| else if (d != elfcpp::ELFDATA2LSB |
| && d != elfcpp::ELFDATA2MSB) |
| { |
| gold_error(_("%s: unsupported ELF data encoding %d"), name.c_str(), d); |
| return NULL; |
| } |
| |
| bool big_endian = d == elfcpp::ELFDATA2MSB; |
| |
| if (c == elfcpp::ELFCLASS32) |
| { |
| if (bytes < elfcpp::Elf_sizes<32>::ehdr_size) |
| { |
| gold_error(_("%s: ELF file too short"), name.c_str()); |
| return NULL; |
| } |
| if (big_endian) |
| { |
| #ifdef HAVE_TARGET_32_BIG |
| elfcpp::Ehdr<32, true> ehdr(p); |
| return make_elf_sized_object<32, true>(name, input_file, |
| offset, ehdr); |
| #else |
| gold_error(_("%s: not configured to support " |
| "32-bit big-endian object"), |
| name.c_str()); |
| return NULL; |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_32_LITTLE |
| elfcpp::Ehdr<32, false> ehdr(p); |
| return make_elf_sized_object<32, false>(name, input_file, |
| offset, ehdr); |
| #else |
| gold_error(_("%s: not configured to support " |
| "32-bit little-endian object"), |
| name.c_str()); |
| return NULL; |
| #endif |
| } |
| } |
| else |
| { |
| if (bytes < elfcpp::Elf_sizes<64>::ehdr_size) |
| { |
| gold_error(_("%s: ELF file too short"), name.c_str()); |
| return NULL; |
| } |
| if (big_endian) |
| { |
| #ifdef HAVE_TARGET_64_BIG |
| elfcpp::Ehdr<64, true> ehdr(p); |
| return make_elf_sized_object<64, true>(name, input_file, |
| offset, ehdr); |
| #else |
| gold_error(_("%s: not configured to support " |
| "64-bit big-endian object"), |
| name.c_str()); |
| return NULL; |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_64_LITTLE |
| elfcpp::Ehdr<64, false> ehdr(p); |
| return make_elf_sized_object<64, false>(name, input_file, |
| offset, ehdr); |
| #else |
| gold_error(_("%s: not configured to support " |
| "64-bit little-endian object"), |
| name.c_str()); |
| return NULL; |
| #endif |
| } |
| } |
| } |
| |
| // Instantiate the templates we need. |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| void |
| Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*, |
| Read_symbols_data*); |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| void |
| Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*, |
| Read_symbols_data*); |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| void |
| Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*, |
| Read_symbols_data*); |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| void |
| Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*, |
| Read_symbols_data*); |
| #endif |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| class Sized_relobj<32, false>; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| class Sized_relobj<32, true>; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| class Sized_relobj<64, false>; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| class Sized_relobj<64, true>; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| struct Relocate_info<32, false>; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| struct Relocate_info<32, true>; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| struct Relocate_info<64, false>; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| struct Relocate_info<64, true>; |
| #endif |
| |
| } // End namespace gold. |