// inremental.cc -- incremental linking support for gold // Copyright (C) 2009-2019 Free Software Foundation, Inc. // Written by Mikolaj Zalewski <mikolajz@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 <set> #include <cstdarg> #include "libiberty.h" #include "elfcpp.h" #include "options.h" #include "output.h" #include "symtab.h" #include "incremental.h" #include "archive.h" #include "object.h" #include "target-select.h" #include "target.h" #include "fileread.h" #include "script.h" namespace gold { // Version number for the .gnu_incremental_inputs section. // Version 1 was the initial checkin. // Version 2 adds some padding to ensure 8-byte alignment where necessary. const unsigned int INCREMENTAL_LINK_VERSION = 2; // This class manages the .gnu_incremental_inputs section, which holds // the header information, a directory of input files, and separate // entries for each input file. template<int size, bool big_endian> class Output_section_incremental_inputs : public Output_section_data { public: Output_section_incremental_inputs(const Incremental_inputs* inputs, const Symbol_table* symtab) : Output_section_data(size / 8), inputs_(inputs), symtab_(symtab) { } protected: // This is called to update the section size prior to assigning // the address and file offset. void update_data_size() { this->set_final_data_size(); } // Set the final data size. void set_final_data_size(); // Write the data to the file. void do_write(Output_file*); // Write to a map file. void do_print_to_mapfile(Mapfile* mapfile) const { mapfile->print_output_data(this, _("** incremental_inputs")); } private: // Write the section header. unsigned char* write_header(unsigned char* pov, unsigned int input_file_count, section_offset_type command_line_offset); // Write the input file entries. unsigned char* write_input_files(unsigned char* oview, unsigned char* pov, Stringpool* strtab); // Write the supplemental information blocks. unsigned char* write_info_blocks(unsigned char* oview, unsigned char* pov, Stringpool* strtab, unsigned int* global_syms, unsigned int global_sym_count); // Write the contents of the .gnu_incremental_symtab section. void write_symtab(unsigned char* pov, unsigned int* global_syms, unsigned int global_sym_count); // Write the contents of the .gnu_incremental_got_plt section. void write_got_plt(unsigned char* pov, off_t view_size); // Typedefs for writing the data to the output sections. typedef elfcpp::Swap<size, big_endian> Swap; typedef elfcpp::Swap<16, big_endian> Swap16; typedef elfcpp::Swap<32, big_endian> Swap32; typedef elfcpp::Swap<64, big_endian> Swap64; // Sizes of various structures. static const int sizeof_addr = size / 8; static const int header_size = Incremental_inputs_reader<size, big_endian>::header_size; static const int input_entry_size = Incremental_inputs_reader<size, big_endian>::input_entry_size; static const unsigned int object_info_size = Incremental_inputs_reader<size, big_endian>::object_info_size; static const unsigned int input_section_entry_size = Incremental_inputs_reader<size, big_endian>::input_section_entry_size; static const unsigned int global_sym_entry_size = Incremental_inputs_reader<size, big_endian>::global_sym_entry_size; static const unsigned int incr_reloc_size = Incremental_relocs_reader<size, big_endian>::reloc_size; // The Incremental_inputs object. const Incremental_inputs* inputs_; // The symbol table. const Symbol_table* symtab_; }; // Inform the user why we don't do an incremental link. Not called in // the obvious case of missing output file. TODO: Is this helpful? void vexplain_no_incremental(const char* format, va_list args) { char* buf = NULL; if (vasprintf(&buf, format, args) < 0) gold_nomem(); gold_info(_("the link might take longer: " "cannot perform incremental link: %s"), buf); free(buf); } void explain_no_incremental(const char* format, ...) { va_list args; va_start(args, format); vexplain_no_incremental(format, args); va_end(args); } // Report an error. void Incremental_binary::error(const char* format, ...) const { va_list args; va_start(args, format); // Current code only checks if the file can be used for incremental linking, // so errors shouldn't fail the build, but only result in a fallback to a // full build. // TODO: when we implement incremental editing of the file, we may need a // flag that will cause errors to be treated seriously. vexplain_no_incremental(format, args); va_end(args); } // Return TRUE if a section of type SH_TYPE can be updated in place // during an incremental update. We can update sections of type PROGBITS, // NOBITS, INIT_ARRAY, FINI_ARRAY, PREINIT_ARRAY, NOTE, and // (processor-specific) unwind sections. All others will be regenerated. bool can_incremental_update(unsigned int sh_type) { return (sh_type == elfcpp::SHT_PROGBITS || sh_type == elfcpp::SHT_NOBITS || sh_type == elfcpp::SHT_INIT_ARRAY || sh_type == elfcpp::SHT_FINI_ARRAY || sh_type == elfcpp::SHT_PREINIT_ARRAY || sh_type == elfcpp::SHT_NOTE || sh_type == parameters->target().unwind_section_type()); } // Find the .gnu_incremental_inputs section and related sections. template<int size, bool big_endian> bool Sized_incremental_binary<size, big_endian>::find_incremental_inputs_sections( unsigned int* p_inputs_shndx, unsigned int* p_symtab_shndx, unsigned int* p_relocs_shndx, unsigned int* p_got_plt_shndx, unsigned int* p_strtab_shndx) { unsigned int inputs_shndx = this->elf_file_.find_section_by_type(elfcpp::SHT_GNU_INCREMENTAL_INPUTS); if (inputs_shndx == elfcpp::SHN_UNDEF) // Not found. return false; unsigned int symtab_shndx = this->elf_file_.find_section_by_type(elfcpp::SHT_GNU_INCREMENTAL_SYMTAB); if (symtab_shndx == elfcpp::SHN_UNDEF) // Not found. return false; if (this->elf_file_.section_link(symtab_shndx) != inputs_shndx) return false; unsigned int relocs_shndx = this->elf_file_.find_section_by_type(elfcpp::SHT_GNU_INCREMENTAL_RELOCS); if (relocs_shndx == elfcpp::SHN_UNDEF) // Not found. return false; if (this->elf_file_.section_link(relocs_shndx) != inputs_shndx) return false; unsigned int got_plt_shndx = this->elf_file_.find_section_by_type(elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT); if (got_plt_shndx == elfcpp::SHN_UNDEF) // Not found. return false; if (this->elf_file_.section_link(got_plt_shndx) != inputs_shndx) return false; unsigned int strtab_shndx = this->elf_file_.section_link(inputs_shndx); if (strtab_shndx == elfcpp::SHN_UNDEF || strtab_shndx > this->elf_file_.shnum() || this->elf_file_.section_type(strtab_shndx) != elfcpp::SHT_STRTAB) return false; if (p_inputs_shndx != NULL) *p_inputs_shndx = inputs_shndx; if (p_symtab_shndx != NULL) *p_symtab_shndx = symtab_shndx; if (p_relocs_shndx != NULL) *p_relocs_shndx = relocs_shndx; if (p_got_plt_shndx != NULL) *p_got_plt_shndx = got_plt_shndx; if (p_strtab_shndx != NULL) *p_strtab_shndx = strtab_shndx; return true; } // Set up the readers into the incremental info sections. template<int size, bool big_endian> void Sized_incremental_binary<size, big_endian>::setup_readers() { unsigned int inputs_shndx; unsigned int symtab_shndx; unsigned int relocs_shndx; unsigned int got_plt_shndx; unsigned int strtab_shndx; if (!this->find_incremental_inputs_sections(&inputs_shndx, &symtab_shndx, &relocs_shndx, &got_plt_shndx, &strtab_shndx)) return; Location inputs_location(this->elf_file_.section_contents(inputs_shndx)); Location symtab_location(this->elf_file_.section_contents(symtab_shndx)); Location relocs_location(this->elf_file_.section_contents(relocs_shndx)); Location got_plt_location(this->elf_file_.section_contents(got_plt_shndx)); Location strtab_location(this->elf_file_.section_contents(strtab_shndx)); View inputs_view = this->view(inputs_location); View symtab_view = this->view(symtab_location); View relocs_view = this->view(relocs_location); View got_plt_view = this->view(got_plt_location); View strtab_view = this->view(strtab_location); elfcpp::Elf_strtab strtab(strtab_view.data(), strtab_location.data_size); this->inputs_reader_ = Incremental_inputs_reader<size, big_endian>(inputs_view.data(), strtab); this->symtab_reader_ = Incremental_symtab_reader<big_endian>(symtab_view.data(), symtab_location.data_size); this->relocs_reader_ = Incremental_relocs_reader<size, big_endian>(relocs_view.data(), relocs_location.data_size); this->got_plt_reader_ = Incremental_got_plt_reader<big_endian>(got_plt_view.data()); // Find the main symbol table. unsigned int main_symtab_shndx = this->elf_file_.find_section_by_type(elfcpp::SHT_SYMTAB); gold_assert(main_symtab_shndx != elfcpp::SHN_UNDEF); this->main_symtab_loc_ = this->elf_file_.section_contents(main_symtab_shndx); // Find the main symbol string table. unsigned int main_strtab_shndx = this->elf_file_.section_link(main_symtab_shndx); gold_assert(main_strtab_shndx != elfcpp::SHN_UNDEF && main_strtab_shndx < this->elf_file_.shnum()); this->main_strtab_loc_ = this->elf_file_.section_contents(main_strtab_shndx); // Walk the list of input files (a) to setup an Input_reader for each // input file, and (b) to record maps of files added from archive // libraries and scripts. Incremental_inputs_reader<size, big_endian>& inputs = this->inputs_reader_; unsigned int count = inputs.input_file_count(); this->input_objects_.resize(count); this->input_entry_readers_.reserve(count); this->library_map_.resize(count); this->script_map_.resize(count); for (unsigned int i = 0; i < count; i++) { Input_entry_reader input_file = inputs.input_file(i); #if __cplusplus >= 2001103L this->input_entry_readers_.emplace_back(input_file); #else this->input_entry_readers_.push_back(Sized_input_reader(input_file)); #endif switch (input_file.type()) { case INCREMENTAL_INPUT_OBJECT: case INCREMENTAL_INPUT_ARCHIVE_MEMBER: case INCREMENTAL_INPUT_SHARED_LIBRARY: // No special treatment necessary. break; case INCREMENTAL_INPUT_ARCHIVE: { Incremental_library* lib = new Incremental_library(input_file.filename(), i, &this->input_entry_readers_[i]); this->library_map_[i] = lib; unsigned int member_count = input_file.get_member_count(); for (unsigned int j = 0; j < member_count; j++) { int member_offset = input_file.get_member_offset(j); int member_index = inputs.input_file_index(member_offset); this->library_map_[member_index] = lib; } } break; case INCREMENTAL_INPUT_SCRIPT: { Script_info* script = new Script_info(input_file.filename(), i); this->script_map_[i] = script; unsigned int object_count = input_file.get_object_count(); for (unsigned int j = 0; j < object_count; j++) { int object_offset = input_file.get_object_offset(j); int object_index = inputs.input_file_index(object_offset); this->script_map_[object_index] = script; } } break; default: gold_unreachable(); } } // Initialize the map of global symbols. unsigned int nglobals = this->symtab_reader_.symbol_count(); this->symbol_map_.resize(nglobals); this->has_incremental_info_ = true; } // Walk the list of input files given on the command line, and build // a direct map of file index to the corresponding input argument. void check_input_args(std::vector<const Input_argument*>& input_args_map, Input_arguments::const_iterator begin, Input_arguments::const_iterator end) { for (Input_arguments::const_iterator p = begin; p != end; ++p) { if (p->is_group()) { const Input_file_group* group = p->group(); check_input_args(input_args_map, group->begin(), group->end()); } else if (p->is_lib()) { const Input_file_lib* lib = p->lib(); check_input_args(input_args_map, lib->begin(), lib->end()); } else { gold_assert(p->is_file()); unsigned int arg_serial = p->file().arg_serial(); if (arg_serial > 0) { gold_assert(arg_serial <= input_args_map.size()); gold_assert(input_args_map[arg_serial - 1] == 0); input_args_map[arg_serial - 1] = &*p; } } } } // Determine whether an incremental link based on the existing output file // can be done. template<int size, bool big_endian> bool Sized_incremental_binary<size, big_endian>::do_check_inputs( const Command_line& cmdline, Incremental_inputs* incremental_inputs) { Incremental_inputs_reader<size, big_endian>& inputs = this->inputs_reader_; if (!this->has_incremental_info_) { explain_no_incremental(_("no incremental data from previous build")); return false; } if (inputs.version() != INCREMENTAL_LINK_VERSION) { explain_no_incremental(_("different version of incremental build data")); return false; } if (incremental_inputs->command_line() != inputs.command_line()) { gold_debug(DEBUG_INCREMENTAL, "old command line: %s", inputs.command_line()); gold_debug(DEBUG_INCREMENTAL, "new command line: %s", incremental_inputs->command_line().c_str()); explain_no_incremental(_("command line changed")); return false; } // Walk the list of input files given on the command line, and build // a direct map of argument serial numbers to the corresponding input // arguments. this->input_args_map_.resize(cmdline.number_of_input_files()); check_input_args(this->input_args_map_, cmdline.begin(), cmdline.end()); // Walk the list of input files to check for conditions that prevent // an incremental update link. unsigned int count = inputs.input_file_count(); for (unsigned int i = 0; i < count; i++) { Input_entry_reader input_file = inputs.input_file(i); switch (input_file.type()) { case INCREMENTAL_INPUT_OBJECT: case INCREMENTAL_INPUT_ARCHIVE_MEMBER: case INCREMENTAL_INPUT_SHARED_LIBRARY: case INCREMENTAL_INPUT_ARCHIVE: // No special treatment necessary. break; case INCREMENTAL_INPUT_SCRIPT: if (this->do_file_has_changed(i)) { explain_no_incremental(_("%s: script file changed"), input_file.filename()); return false; } break; default: gold_unreachable(); } } return true; } // Return TRUE if input file N has changed since the last incremental link. template<int size, bool big_endian> bool Sized_incremental_binary<size, big_endian>::do_file_has_changed( unsigned int n) const { Input_entry_reader input_file = this->inputs_reader_.input_file(n); Incremental_disposition disp = INCREMENTAL_CHECK; // For files named in scripts, find the file that was actually named // on the command line, so that we can get the incremental disposition // flag. Script_info* script = this->get_script_info(n); if (script != NULL) n = script->input_file_index(); const Input_argument* input_argument = this->get_input_argument(n); if (input_argument != NULL) disp = input_argument->file().options().incremental_disposition(); // For files at the beginning of the command line (i.e., those added // implicitly by gcc), check whether the --incremental-startup-unchanged // option was used. if (disp == INCREMENTAL_STARTUP) disp = parameters->options().incremental_startup_disposition(); if (disp != INCREMENTAL_CHECK) return disp == INCREMENTAL_CHANGED; const char* filename = input_file.filename(); Timespec old_mtime = input_file.get_mtime(); Timespec new_mtime; if (!get_mtime(filename, &new_mtime)) { // If we can't open get the current modification time, assume it has // changed. If the file doesn't exist, we'll issue an error when we // try to open it later. return true; } if (new_mtime.seconds > old_mtime.seconds) return true; if (new_mtime.seconds == old_mtime.seconds && new_mtime.nanoseconds > old_mtime.nanoseconds) return true; return false; } // Initialize the layout of the output file based on the existing // output file. template<int size, bool big_endian> void Sized_incremental_binary<size, big_endian>::do_init_layout(Layout* layout) { typedef elfcpp::Shdr<size, big_endian> Shdr; const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; // Get views of the section headers and the section string table. const off_t shoff = this->elf_file_.shoff(); const unsigned int shnum = this->elf_file_.shnum(); const unsigned int shstrndx = this->elf_file_.shstrndx(); Location shdrs_location(shoff, shnum * shdr_size); Location shstrndx_location(this->elf_file_.section_contents(shstrndx)); View shdrs_view = this->view(shdrs_location); View shstrndx_view = this->view(shstrndx_location); elfcpp::Elf_strtab shstrtab(shstrndx_view.data(), shstrndx_location.data_size); layout->set_incremental_base(this); // Initialize the layout. this->section_map_.resize(shnum); const unsigned char* pshdr = shdrs_view.data() + shdr_size; for (unsigned int i = 1; i < shnum; i++) { Shdr shdr(pshdr); const char* name; if (!shstrtab.get_c_string(shdr.get_sh_name(), &name)) name = NULL; gold_debug(DEBUG_INCREMENTAL, "Output section: %2d %08lx %08lx %08lx %3d %s", i, static_cast<long>(shdr.get_sh_addr()), static_cast<long>(shdr.get_sh_offset()), static_cast<long>(shdr.get_sh_size()), shdr.get_sh_type(), name ? name : "<null>"); this->section_map_[i] = layout->init_fixed_output_section(name, shdr); pshdr += shdr_size; } } // Mark regions of the input file that must be kept unchanged. template<int size, bool big_endian> void Sized_incremental_binary<size, big_endian>::do_reserve_layout( unsigned int input_file_index) { const int sym_size = elfcpp::Elf_sizes<size>::sym_size; Input_entry_reader input_file = this->inputs_reader_.input_file(input_file_index); if (input_file.type() == INCREMENTAL_INPUT_SHARED_LIBRARY) { // Reserve the BSS space used for COPY relocations. unsigned int nsyms = input_file.get_global_symbol_count(); Incremental_binary::View symtab_view(NULL); unsigned int symtab_count; elfcpp::Elf_strtab strtab(NULL, 0); this->get_symtab_view(&symtab_view, &symtab_count, &strtab); for (unsigned int i = 0; i < nsyms; ++i) { bool is_def; bool is_copy; unsigned int output_symndx = input_file.get_output_symbol_index(i, &is_def, &is_copy); if (is_copy) { const unsigned char* sym_p = (symtab_view.data() + output_symndx * sym_size); elfcpp::Sym<size, big_endian> gsym(sym_p); unsigned int shndx = gsym.get_st_shndx(); if (shndx < 1 || shndx >= this->section_map_.size()) continue; Output_section* os = this->section_map_[shndx]; off_t offset = gsym.get_st_value() - os->address(); os->reserve(offset, gsym.get_st_size()); gold_debug(DEBUG_INCREMENTAL, "Reserve for COPY reloc: %s, off %d, size %d", os->name(), static_cast<int>(offset), static_cast<int>(gsym.get_st_size())); } } return; } unsigned int shnum = input_file.get_input_section_count(); for (unsigned int i = 0; i < shnum; i++) { typename Input_entry_reader::Input_section_info sect = input_file.get_input_section(i); if (sect.output_shndx == 0 || sect.sh_offset == -1) continue; Output_section* os = this->section_map_[sect.output_shndx]; gold_assert(os != NULL); os->reserve(sect.sh_offset, sect.sh_size); } } // Process the GOT and PLT entries from the existing output file. template<int size, bool big_endian> void Sized_incremental_binary<size, big_endian>::do_process_got_plt( Symbol_table* symtab, Layout* layout) { Incremental_got_plt_reader<big_endian> got_plt_reader(this->got_plt_reader()); Sized_target<size, big_endian>* target = parameters->sized_target<size, big_endian>(); // Get the number of symbols in the main symbol table and in the // incremental symbol table. The difference between the two counts // is the index of the first forced-local or global symbol in the // main symbol table. unsigned int symtab_count = this->main_symtab_loc_.data_size / elfcpp::Elf_sizes<size>::sym_size; unsigned int isym_count = this->symtab_reader_.symbol_count(); unsigned int first_global = symtab_count - isym_count; // Tell the target how big the GOT and PLT sections are. unsigned int got_count = got_plt_reader.get_got_entry_count(); unsigned int plt_count = got_plt_reader.get_plt_entry_count(); Output_data_got_base* got = target->init_got_plt_for_update(symtab, layout, got_count, plt_count); // Read the GOT entries from the base file and build the outgoing GOT. for (unsigned int i = 0; i < got_count; ++i) { unsigned int got_type = got_plt_reader.get_got_type(i); if ((got_type & 0x7f) == 0x7f) { // This is the second entry of a pair. got->reserve_slot(i); continue; } unsigned int symndx = got_plt_reader.get_got_symndx(i); if (got_type & 0x80) { // This is an entry for a local symbol. Ignore this entry if // the object file was replaced. unsigned int input_index = got_plt_reader.get_got_input_index(i); gold_debug(DEBUG_INCREMENTAL, "GOT entry %d, type %02x: (local symbol)", i, got_type & 0x7f); Sized_relobj_incr<size, big_endian>* obj = this->input_object(input_index); if (obj != NULL) target->reserve_local_got_entry(i, obj, symndx, got_type & 0x7f); } else { // This is an entry for a global symbol. GOT_DESC is the symbol // table index. // FIXME: This should really be a fatal error (corrupt input). gold_assert(symndx >= first_global && symndx < symtab_count); Symbol* sym = this->global_symbol(symndx - first_global); // Add the GOT entry only if the symbol is still referenced. if (sym != NULL && sym->in_reg()) { gold_debug(DEBUG_INCREMENTAL, "GOT entry %d, type %02x: %s", i, got_type, sym->name()); target->reserve_global_got_entry(i, sym, got_type); } } } // Read the PLT entries from the base file and pass each to the target. for (unsigned int i = 0; i < plt_count; ++i) { unsigned int plt_desc = got_plt_reader.get_plt_desc(i); // FIXME: This should really be a fatal error (corrupt input). gold_assert(plt_desc >= first_global && plt_desc < symtab_count); Symbol* sym = this->global_symbol(plt_desc - first_global); // Add the PLT entry only if the symbol is still referenced. if (sym != NULL && sym->in_reg()) { gold_debug(DEBUG_INCREMENTAL, "PLT entry %d: %s", i, sym->name()); target->register_global_plt_entry(symtab, layout, i, sym); } } } // Emit COPY relocations from the existing output file. template<int size, bool big_endian> void Sized_incremental_binary<size, big_endian>::do_emit_copy_relocs( Symbol_table* symtab) { Sized_target<size, big_endian>* target = parameters->sized_target<size, big_endian>(); for (typename Copy_relocs::iterator p = this->copy_relocs_.begin(); p != this->copy_relocs_.end(); ++p) { if (!(*p).symbol->is_copied_from_dynobj()) target->emit_copy_reloc(symtab, (*p).symbol, (*p).output_section, (*p).offset); } } // Apply incremental relocations for symbols whose values have changed. template<int size, bool big_endian> void Sized_incremental_binary<size, big_endian>::do_apply_incremental_relocs( const Symbol_table* symtab, Layout* layout, Output_file* of) { typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; typedef typename elfcpp::Elf_types<size>::Elf_Swxword Addend; Incremental_symtab_reader<big_endian> isymtab(this->symtab_reader()); Incremental_relocs_reader<size, big_endian> irelocs(this->relocs_reader()); unsigned int nglobals = isymtab.symbol_count(); const unsigned int incr_reloc_size = irelocs.reloc_size; Relocate_info<size, big_endian> relinfo; relinfo.symtab = symtab; relinfo.layout = layout; relinfo.object = NULL; relinfo.reloc_shndx = 0; relinfo.reloc_shdr = NULL; relinfo.data_shndx = 0; relinfo.data_shdr = NULL; Sized_target<size, big_endian>* target = parameters->sized_target<size, big_endian>(); for (unsigned int i = 0; i < nglobals; i++) { const Symbol* gsym = this->global_symbol(i); // If the symbol is not referenced from any unchanged input files, // we do not need to reapply any of its relocations. if (gsym == NULL) continue; // If the symbol is defined in an unchanged file, we do not need to // reapply any of its relocations. if (gsym->source() == Symbol::FROM_OBJECT && gsym->object()->is_incremental()) continue; gold_debug(DEBUG_INCREMENTAL, "Applying incremental relocations for global symbol %s [%d]", gsym->name(), i); // Follow the linked list of input symbol table entries for this symbol. // We don't bother to figure out whether the symbol table entry belongs // to a changed or unchanged file because it's easier just to apply all // the relocations -- although we might scribble over an area that has // been reallocated, we do this before copying any new data into the // output file. unsigned int offset = isymtab.get_list_head(i); while (offset > 0) { Incremental_global_symbol_reader<big_endian> sym_info = this->inputs_reader().global_symbol_reader_at_offset(offset); unsigned int r_base = sym_info.reloc_offset(); unsigned int r_count = sym_info.reloc_count(); // Apply each relocation for this symbol table entry. for (unsigned int j = 0; j < r_count; ++j, r_base += incr_reloc_size) { unsigned int r_type = irelocs.get_r_type(r_base); unsigned int r_shndx = irelocs.get_r_shndx(r_base); Address r_offset = irelocs.get_r_offset(r_base); Addend r_addend = irelocs.get_r_addend(r_base); Output_section* os = this->output_section(r_shndx); Address address = os->address(); off_t section_offset = os->offset(); size_t view_size = os->data_size(); unsigned char* const view = of->get_output_view(section_offset, view_size); gold_debug(DEBUG_INCREMENTAL, " %08lx: %s + %d: type %d addend %ld", (long)(section_offset + r_offset), os->name(), (int)r_offset, r_type, (long)r_addend); target->apply_relocation(&relinfo, r_offset, r_type, r_addend, gsym, view, address, view_size); // FIXME: Do something more efficient if write_output_view // ever becomes more than a no-op. of->write_output_view(section_offset, view_size, view); } offset = sym_info.next_offset(); } } } // Get a view of the main symbol table and the symbol string table. template<int size, bool big_endian> void Sized_incremental_binary<size, big_endian>::get_symtab_view( View* symtab_view, unsigned int* nsyms, elfcpp::Elf_strtab* strtab) { *symtab_view = this->view(this->main_symtab_loc_); *nsyms = this->main_symtab_loc_.data_size / elfcpp::Elf_sizes<size>::sym_size; View strtab_view(this->view(this->main_strtab_loc_)); *strtab = elfcpp::Elf_strtab(strtab_view.data(), this->main_strtab_loc_.data_size); } namespace { // Create a Sized_incremental_binary object of the specified size and // endianness. Fails if the target architecture is not supported. template<int size, bool big_endian> Incremental_binary* make_sized_incremental_binary(Output_file* file, const elfcpp::Ehdr<size, big_endian>& ehdr) { Target* target = select_target(NULL, 0, // XXX ehdr.get_e_machine(), size, big_endian, ehdr.get_e_ident()[elfcpp::EI_OSABI], ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]); if (target == NULL) { explain_no_incremental(_("unsupported ELF machine number %d"), ehdr.get_e_machine()); return NULL; } if (!parameters->target_valid()) set_parameters_target(target); else if (target != ¶meters->target()) gold_error(_("%s: incompatible target"), file->filename()); return new Sized_incremental_binary<size, big_endian>(file, ehdr, target); } } // End of anonymous namespace. // Create an Incremental_binary object for FILE. Returns NULL is this is not // possible, e.g. FILE is not an ELF file or has an unsupported target. FILE // should be opened. Incremental_binary* open_incremental_binary(Output_file* file) { off_t filesize = file->filesize(); int want = elfcpp::Elf_recognizer::max_header_size; if (filesize < want) want = filesize; const unsigned char* p = file->get_input_view(0, want); if (!elfcpp::Elf_recognizer::is_elf_file(p, want)) { explain_no_incremental(_("output is not an ELF file.")); return NULL; } int size = 0; bool big_endian = false; std::string error; if (!elfcpp::Elf_recognizer::is_valid_header(p, want, &size, &big_endian, &error)) { explain_no_incremental(error.c_str()); return NULL; } Incremental_binary* result = NULL; if (size == 32) { if (big_endian) { #ifdef HAVE_TARGET_32_BIG result = make_sized_incremental_binary<32, true>( file, elfcpp::Ehdr<32, true>(p)); #else explain_no_incremental(_("unsupported file: 32-bit, big-endian")); #endif } else { #ifdef HAVE_TARGET_32_LITTLE result = make_sized_incremental_binary<32, false>( file, elfcpp::Ehdr<32, false>(p)); #else explain_no_incremental(_("unsupported file: 32-bit, little-endian")); #endif } } else if (size == 64) { if (big_endian) { #ifdef HAVE_TARGET_64_BIG result = make_sized_incremental_binary<64, true>( file, elfcpp::Ehdr<64, true>(p)); #else explain_no_incremental(_("unsupported file: 64-bit, big-endian")); #endif } else { #ifdef HAVE_TARGET_64_LITTLE result = make_sized_incremental_binary<64, false>( file, elfcpp::Ehdr<64, false>(p)); #else explain_no_incremental(_("unsupported file: 64-bit, little-endian")); #endif } } else gold_unreachable(); return result; } // Class Incremental_inputs. // Add the command line to the string table, setting // command_line_key_. In incremental builds, the command line is // stored in .gnu_incremental_inputs so that the next linker run can // check if the command line options didn't change. void Incremental_inputs::report_command_line(int argc, const char* const* argv) { // Always store 'gold' as argv[0] to avoid a full relink if the user used a // different path to the linker. std::string args("gold"); // Copied from collect_argv in main.cc. for (int i = 1; i < argc; ++i) { // Adding/removing these options should not result in a full relink. if (strcmp(argv[i], "--incremental") == 0 || strcmp(argv[i], "--incremental-full") == 0 || strcmp(argv[i], "--incremental-update") == 0 || strcmp(argv[i], "--incremental-changed") == 0 || strcmp(argv[i], "--incremental-unchanged") == 0 || strcmp(argv[i], "--incremental-unknown") == 0 || strcmp(argv[i], "--incremental-startup-unchanged") == 0 || is_prefix_of("--incremental-base=", argv[i]) || is_prefix_of("--incremental-patch=", argv[i]) || is_prefix_of("--debug=", argv[i])) continue; if (strcmp(argv[i], "--incremental-base") == 0 || strcmp(argv[i], "--incremental-patch") == 0 || strcmp(argv[i], "--debug") == 0) { // When these options are used without the '=', skip the // following parameter as well. ++i; continue; } args.append(" '"); // Now append argv[i], but with all single-quotes escaped const char* argpos = argv[i]; while (1) { const int len = strcspn(argpos, "'"); args.append(argpos, len); if (argpos[len] == '\0') break; args.append("'\"'\"'"); argpos += len + 1; } args.append("'"); } this->command_line_ = args; this->strtab_->add(this->command_line_.c_str(), false, &this->command_line_key_); } // Record the input archive file ARCHIVE. This is called by the // Add_archive_symbols task before determining which archive members // to include. We create the Incremental_archive_entry here and // attach it to the Archive, but we do not add it to the list of // input objects until report_archive_end is called. void Incremental_inputs::report_archive_begin(Library_base* arch, unsigned int arg_serial, Script_info* script_info) { Stringpool::Key filename_key; Timespec mtime = arch->get_mtime(); // For a file loaded from a script, don't record its argument serial number. if (script_info != NULL) arg_serial = 0; this->strtab_->add(arch->filename().c_str(), false, &filename_key); Incremental_archive_entry* entry = new Incremental_archive_entry(filename_key, arg_serial, mtime); arch->set_incremental_info(entry); if (script_info != NULL) { Incremental_script_entry* script_entry = script_info->incremental_info(); gold_assert(script_entry != NULL); script_entry->add_object(entry); } } // Visitor class for processing the unused global symbols in a library. // An instance of this class is passed to the library's // for_all_unused_symbols() iterator, which will call the visit() // function for each global symbol defined in each unused library // member. We add those symbol names to the incremental info for the // library. class Unused_symbol_visitor : public Library_base::Symbol_visitor_base { public: Unused_symbol_visitor(Incremental_archive_entry* entry, Stringpool* strtab) : entry_(entry), strtab_(strtab) { } void visit(const char* sym) { Stringpool::Key symbol_key; this->strtab_->add(sym, true, &symbol_key); this->entry_->add_unused_global_symbol(symbol_key); } private: Incremental_archive_entry* entry_; Stringpool* strtab_; }; // Finish recording the input archive file ARCHIVE. This is called by the // Add_archive_symbols task after determining which archive members // to include. void Incremental_inputs::report_archive_end(Library_base* arch) { Incremental_archive_entry* entry = arch->incremental_info(); gold_assert(entry != NULL); this->inputs_.push_back(entry); // Collect unused global symbols. Unused_symbol_visitor v(entry, this->strtab_); arch->for_all_unused_symbols(&v); } // Record the input object file OBJ. If ARCH is not NULL, attach // the object file to the archive. This is called by the // Add_symbols task after finding out the type of the file. void Incremental_inputs::report_object(Object* obj, unsigned int arg_serial, Library_base* arch, Script_info* script_info) { Stringpool::Key filename_key; Timespec mtime = obj->get_mtime(); // For a file loaded from a script, don't record its argument serial number. if (script_info != NULL) arg_serial = 0; this->strtab_->add(obj->name().c_str(), false, &filename_key); Incremental_input_entry* input_entry; this->current_object_ = obj; if (!obj->is_dynamic()) { this->current_object_entry_ = new Incremental_object_entry(filename_key, obj, arg_serial, mtime); input_entry = this->current_object_entry_; if (arch != NULL) { Incremental_archive_entry* arch_entry = arch->incremental_info(); gold_assert(arch_entry != NULL); arch_entry->add_object(this->current_object_entry_); } } else { this->current_object_entry_ = NULL; Stringpool::Key soname_key; Dynobj* dynobj = obj->dynobj(); gold_assert(dynobj != NULL); this->strtab_->add(dynobj->soname(), false, &soname_key); input_entry = new Incremental_dynobj_entry(filename_key, soname_key, obj, arg_serial, mtime); } if (obj->is_in_system_directory()) input_entry->set_is_in_system_directory(); if (obj->as_needed()) input_entry->set_as_needed(); this->inputs_.push_back(input_entry); if (script_info != NULL) { Incremental_script_entry* script_entry = script_info->incremental_info(); gold_assert(script_entry != NULL); script_entry->add_object(input_entry); } } // Record an input section SHNDX from object file OBJ. void Incremental_inputs::report_input_section(Object* obj, unsigned int shndx, const char* name, off_t sh_size) { Stringpool::Key key = 0; if (name != NULL) this->strtab_->add(name, true, &key); gold_assert(obj == this->current_object_); gold_assert(this->current_object_entry_ != NULL); this->current_object_entry_->add_input_section(shndx, key, sh_size); } // Record a kept COMDAT group belonging to object file OBJ. void Incremental_inputs::report_comdat_group(Object* obj, const char* name) { Stringpool::Key key = 0; if (name != NULL) this->strtab_->add(name, true, &key); gold_assert(obj == this->current_object_); gold_assert(this->current_object_entry_ != NULL); this->current_object_entry_->add_comdat_group(key); } // Record that the input argument INPUT is a script SCRIPT. This is // called by read_script after parsing the script and reading the list // of inputs added by this script. void Incremental_inputs::report_script(Script_info* script, unsigned int arg_serial, Timespec mtime) { Stringpool::Key filename_key; this->strtab_->add(script->filename().c_str(), false, &filename_key); Incremental_script_entry* entry = new Incremental_script_entry(filename_key, arg_serial, script, mtime); this->inputs_.push_back(entry); script->set_incremental_info(entry); } // Finalize the incremental link information. Called from // Layout::finalize. void Incremental_inputs::finalize() { // Finalize the string table. this->strtab_->set_string_offsets(); } // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections. void Incremental_inputs::create_data_sections(Symbol_table* symtab) { int reloc_align = 4; switch (parameters->size_and_endianness()) { #ifdef HAVE_TARGET_32_LITTLE case Parameters::TARGET_32_LITTLE: this->inputs_section_ = new Output_section_incremental_inputs<32, false>(this, symtab); reloc_align = 4; break; #endif #ifdef HAVE_TARGET_32_BIG case Parameters::TARGET_32_BIG: this->inputs_section_ = new Output_section_incremental_inputs<32, true>(this, symtab); reloc_align = 4; break; #endif #ifdef HAVE_TARGET_64_LITTLE case Parameters::TARGET_64_LITTLE: this->inputs_section_ = new Output_section_incremental_inputs<64, false>(this, symtab); reloc_align = 8; break; #endif #ifdef HAVE_TARGET_64_BIG case Parameters::TARGET_64_BIG: this->inputs_section_ = new Output_section_incremental_inputs<64, true>(this, symtab); reloc_align = 8; break; #endif default: gold_unreachable(); } this->symtab_section_ = new Output_data_space(4, "** incremental_symtab"); this->relocs_section_ = new Output_data_space(reloc_align, "** incremental_relocs"); this->got_plt_section_ = new Output_data_space(4, "** incremental_got_plt"); } // Return the sh_entsize value for the .gnu_incremental_relocs section. unsigned int Incremental_inputs::relocs_entsize() const { return 8 + 2 * parameters->target().get_size() / 8; } // Class Output_section_incremental_inputs. // Finalize the offsets for each input section and supplemental info block, // and set the final data size of the incremental output sections. template<int size, bool big_endian> void Output_section_incremental_inputs<size, big_endian>::set_final_data_size() { const Incremental_inputs* inputs = this->inputs_; // Offset of each input entry. unsigned int input_offset = this->header_size; // Offset of each supplemental info block. unsigned int file_index = 0; unsigned int info_offset = this->header_size; info_offset += this->input_entry_size * inputs->input_file_count(); // Count each input file and its supplemental information block. for (Incremental_inputs::Input_list::const_iterator p = inputs->input_files().begin(); p != inputs->input_files().end(); ++p) { // Set the index and offset of the input file entry. (*p)->set_offset(file_index, input_offset); ++file_index; input_offset += this->input_entry_size; // Set the offset of the supplemental info block. switch ((*p)->type()) { case INCREMENTAL_INPUT_SCRIPT: { Incremental_script_entry *entry = (*p)->script_entry(); gold_assert(entry != NULL); (*p)->set_info_offset(info_offset); // Object count. info_offset += 4; // Each member. info_offset += (entry->get_object_count() * 4); } break; case INCREMENTAL_INPUT_OBJECT: case INCREMENTAL_INPUT_ARCHIVE_MEMBER: { Incremental_object_entry* entry = (*p)->object_entry(); gold_assert(entry != NULL); (*p)->set_info_offset(info_offset); // Input section count, global symbol count, local symbol offset, // local symbol count, first dynamic reloc, dynamic reloc count, // comdat group count. info_offset += this->object_info_size; // Each input section. info_offset += (entry->get_input_section_count() * this->input_section_entry_size); // Each global symbol. const Object::Symbols* syms = entry->object()->get_global_symbols(); info_offset += syms->size() * this->global_sym_entry_size; // Each comdat group. info_offset += entry->get_comdat_group_count() * 4; } break; case INCREMENTAL_INPUT_SHARED_LIBRARY: { Incremental_dynobj_entry* entry = (*p)->dynobj_entry(); gold_assert(entry != NULL); (*p)->set_info_offset(info_offset); // Global symbol count, soname index. info_offset += 8; // Each global symbol. const Object::Symbols* syms = entry->object()->get_global_symbols(); gold_assert(syms != NULL); unsigned int nsyms = syms->size(); unsigned int nsyms_out = 0; for (unsigned int i = 0; i < nsyms; ++i) { const Symbol* sym = (*syms)[i]; if (sym == NULL) continue; if (sym->is_forwarder()) sym = this->symtab_->resolve_forwards(sym); if (sym->symtab_index() != -1U) ++nsyms_out; } info_offset += nsyms_out * 4; } break; case INCREMENTAL_INPUT_ARCHIVE: { Incremental_archive_entry* entry = (*p)->archive_entry(); gold_assert(entry != NULL); (*p)->set_info_offset(info_offset); // Member count + unused global symbol count. info_offset += 8; // Each member. info_offset += (entry->get_member_count() * 4); // Each global symbol. info_offset += (entry->get_unused_global_symbol_count() * 4); } break; default: gold_unreachable(); } // Pad so each supplemental info block begins at an 8-byte boundary. if (info_offset & 4) info_offset += 4; } this->set_data_size(info_offset); // Set the size of the .gnu_incremental_symtab section. inputs->symtab_section()->set_current_data_size(this->symtab_->output_count() * sizeof(unsigned int)); // Set the size of the .gnu_incremental_relocs section. inputs->relocs_section()->set_current_data_size(inputs->get_reloc_count() * this->incr_reloc_size); // Set the size of the .gnu_incremental_got_plt section. Sized_target<size, big_endian>* target = parameters->sized_target<size, big_endian>(); unsigned int got_count = target->got_entry_count(); unsigned int plt_count = target->plt_entry_count(); unsigned int got_plt_size = 8; // GOT entry count, PLT entry count. got_plt_size = (got_plt_size + got_count + 3) & ~3; // GOT type array. got_plt_size += got_count * 8 + plt_count * 4; // GOT array, PLT array. inputs->got_plt_section()->set_current_data_size(got_plt_size); } // Write the contents of the .gnu_incremental_inputs and // .gnu_incremental_symtab sections. template<int size, bool big_endian> void Output_section_incremental_inputs<size, big_endian>::do_write(Output_file* of) { const Incremental_inputs* inputs = this->inputs_; Stringpool* strtab = inputs->get_stringpool(); // Get a view into the .gnu_incremental_inputs section. const off_t off = this->offset(); const off_t oview_size = this->data_size(); unsigned char* const oview = of->get_output_view(off, oview_size); unsigned char* pov = oview; // Get a view into the .gnu_incremental_symtab section. const off_t symtab_off = inputs->symtab_section()->offset(); const off_t symtab_size = inputs->symtab_section()->data_size(); unsigned char* const symtab_view = of->get_output_view(symtab_off, symtab_size); // Allocate an array of linked list heads for the .gnu_incremental_symtab // section. Each element corresponds to a global symbol in the output // symbol table, and points to the head of the linked list that threads // through the object file input entries. The value of each element // is the section-relative offset to a global symbol entry in a // supplemental information block. unsigned int global_sym_count = this->symtab_->output_count(); unsigned int* global_syms = new unsigned int[global_sym_count]; memset(global_syms, 0, global_sym_count * sizeof(unsigned int)); // Write the section header. Stringpool::Key command_line_key = inputs->command_line_key(); pov = this->write_header(pov, inputs->input_file_count(), strtab->get_offset_from_key(command_line_key)); // Write the list of input files. pov = this->write_input_files(oview, pov, strtab); // Write the supplemental information blocks for each input file. pov = this->write_info_blocks(oview, pov, strtab, global_syms, global_sym_count); gold_assert(pov - oview == oview_size); // Write the .gnu_incremental_symtab section. gold_assert(static_cast<off_t>(global_sym_count) * 4 == symtab_size); this->write_symtab(symtab_view, global_syms, global_sym_count); delete[] global_syms; // Write the .gnu_incremental_got_plt section. const off_t got_plt_off = inputs->got_plt_section()->offset(); const off_t got_plt_size = inputs->got_plt_section()->data_size(); unsigned char* const got_plt_view = of->get_output_view(got_plt_off, got_plt_size); this->write_got_plt(got_plt_view, got_plt_size); of->write_output_view(off, oview_size, oview); of->write_output_view(symtab_off, symtab_size, symtab_view); of->write_output_view(got_plt_off, got_plt_size, got_plt_view); } // Write the section header: version, input file count, offset of command line // in the string table, and 4 bytes of padding. template<int size, bool big_endian> unsigned char* Output_section_incremental_inputs<size, big_endian>::write_header( unsigned char* pov, unsigned int input_file_count, section_offset_type command_line_offset) { Swap32::writeval(pov, INCREMENTAL_LINK_VERSION); Swap32::writeval(pov + 4, input_file_count); Swap32::writeval(pov + 8, command_line_offset); Swap32::writeval(pov + 12, 0); gold_assert(this->header_size == 16); return pov + this->header_size; } // Write the input file entries. template<int size, bool big_endian> unsigned char* Output_section_incremental_inputs<size, big_endian>::write_input_files( unsigned char* oview, unsigned char* pov, Stringpool* strtab) { const Incremental_inputs* inputs = this->inputs_; for (Incremental_inputs::Input_list::const_iterator p = inputs->input_files().begin(); p != inputs->input_files().end(); ++p) { gold_assert(static_cast<unsigned int>(pov - oview) == (*p)->get_offset()); section_offset_type filename_offset = strtab->get_offset_from_key((*p)->get_filename_key()); const Timespec& mtime = (*p)->get_mtime(); unsigned int flags = (*p)->type(); if ((*p)->is_in_system_directory()) flags |= INCREMENTAL_INPUT_IN_SYSTEM_DIR; if ((*p)->as_needed()) flags |= INCREMENTAL_INPUT_AS_NEEDED; Swap32::writeval(pov, filename_offset); Swap32::writeval(pov + 4, (*p)->get_info_offset()); Swap64::writeval(pov + 8, mtime.seconds); Swap32::writeval(pov + 16, mtime.nanoseconds); Swap16::writeval(pov + 20, flags); Swap16::writeval(pov + 22, (*p)->arg_serial()); gold_assert(this->input_entry_size == 24); pov += this->input_entry_size; } return pov; } // Write the supplemental information blocks. template<int size, bool big_endian> unsigned char* Output_section_incremental_inputs<size, big_endian>::write_info_blocks( unsigned char* oview, unsigned char* pov, Stringpool* strtab, unsigned int* global_syms, unsigned int global_sym_count) { const Incremental_inputs* inputs = this->inputs_; unsigned int first_global_index = this->symtab_->first_global_index(); for (Incremental_inputs::Input_list::const_iterator p = inputs->input_files().begin(); p != inputs->input_files().end(); ++p) { switch ((*p)->type()) { case INCREMENTAL_INPUT_SCRIPT: { gold_assert(static_cast<unsigned int>(pov - oview) == (*p)->get_info_offset()); Incremental_script_entry* entry = (*p)->script_entry(); gold_assert(entry != NULL); // Write the object count. unsigned int nobjects = entry->get_object_count(); Swap32::writeval(pov, nobjects); pov += 4; // For each object, write the offset to its input file entry. for (unsigned int i = 0; i < nobjects; ++i) { Incremental_input_entry* obj = entry->get_object(i); Swap32::writeval(pov, obj->get_offset()); pov += 4; } } break; case INCREMENTAL_INPUT_OBJECT: case INCREMENTAL_INPUT_ARCHIVE_MEMBER: { gold_assert(static_cast<unsigned int>(pov - oview) == (*p)->get_info_offset()); Incremental_object_entry* entry = (*p)->object_entry(); gold_assert(entry != NULL); const Object* obj = entry->object(); const Relobj* relobj = static_cast<const Relobj*>(obj); const Object::Symbols* syms = obj->get_global_symbols(); // Write the input section count and global symbol count. unsigned int nsections = entry->get_input_section_count(); unsigned int nsyms = syms->size(); off_t locals_offset = relobj->local_symbol_offset(); unsigned int nlocals = relobj->output_local_symbol_count(); unsigned int first_dynrel = relobj->first_dyn_reloc(); unsigned int ndynrel = relobj->dyn_reloc_count(); unsigned int ncomdat = entry->get_comdat_group_count(); Swap32::writeval(pov, nsections); Swap32::writeval(pov + 4, nsyms); Swap32::writeval(pov + 8, static_cast<unsigned int>(locals_offset)); Swap32::writeval(pov + 12, nlocals); Swap32::writeval(pov + 16, first_dynrel); Swap32::writeval(pov + 20, ndynrel); Swap32::writeval(pov + 24, ncomdat); Swap32::writeval(pov + 28, 0); gold_assert(this->object_info_size == 32); pov += this->object_info_size; // Build a temporary array to map input section indexes // from the original object file index to the index in the // incremental info table. unsigned int* index_map = new unsigned int[obj->shnum()]; memset(index_map, 0, obj->shnum() * sizeof(unsigned int)); // For each input section, write the name, output section index, // offset within output section, and input section size. for (unsigned int i = 0; i < nsections; i++) { unsigned int shndx = entry->get_input_section_index(i); index_map[shndx] = i + 1; Stringpool::Key key = entry->get_input_section_name_key(i); off_t name_offset = 0; if (key != 0) name_offset = strtab->get_offset_from_key(key); int out_shndx = 0; off_t out_offset = 0; off_t sh_size = 0; Output_section* os = obj->output_section(shndx); if (os != NULL) { out_shndx = os->out_shndx(); out_offset = obj->output_section_offset(shndx); sh_size = entry->get_input_section_size(i); } Swap32::writeval(pov, name_offset); Swap32::writeval(pov + 4, out_shndx); Swap::writeval(pov + 8, out_offset); Swap::writeval(pov + 8 + sizeof_addr, sh_size); gold_assert(this->input_section_entry_size == 8 + 2 * sizeof_addr); pov += this->input_section_entry_size; } // For each global symbol, write its associated relocations, // add it to the linked list of globals, then write the // supplemental information: global symbol table index, // input section index, linked list chain pointer, relocation // count, and offset to the relocations. for (unsigned int i = 0; i < nsyms; i++) { const Symbol* sym = (*syms)[i]; if (sym->is_forwarder()) sym = this->symtab_->resolve_forwards(sym); unsigned int shndx = 0; if (sym->source() != Symbol::FROM_OBJECT) { // The symbol was defined by the linker (e.g., common). // We mark these symbols with a special SHNDX of -1, // but exclude linker-predefined symbols and symbols // copied from shared objects. if (!sym->is_predefined() && !sym->is_copied_from_dynobj()) shndx = -1U; } else if (sym->object() == obj && sym->is_defined()) { bool is_ordinary; unsigned int orig_shndx = sym->shndx(&is_ordinary); if (is_ordinary) shndx = index_map[orig_shndx]; else shndx = 1; } unsigned int symtab_index = sym->symtab_index(); unsigned int chain = 0; unsigned int first_reloc = 0; unsigned int nrelocs = obj->get_incremental_reloc_count(i); if (nrelocs > 0) { gold_assert(symtab_index != -1U && (symtab_index - first_global_index < global_sym_count)); first_reloc = obj->get_incremental_reloc_base(i); chain = global_syms[symtab_index - first_global_index]; global_syms[symtab_index - first_global_index] = pov - oview; } Swap32::writeval(pov, symtab_index); Swap32::writeval(pov + 4, shndx); Swap32::writeval(pov + 8, chain); Swap32::writeval(pov + 12, nrelocs); Swap32::writeval(pov + 16, first_reloc * (8 + 2 * sizeof_addr)); gold_assert(this->global_sym_entry_size == 20); pov += this->global_sym_entry_size; } // For each kept COMDAT group, write the group signature. for (unsigned int i = 0; i < ncomdat; i++) { Stringpool::Key key = entry->get_comdat_signature_key(i); off_t name_offset = 0; if (key != 0) name_offset = strtab->get_offset_from_key(key); Swap32::writeval(pov, name_offset); pov += 4; } delete[] index_map; } break; case INCREMENTAL_INPUT_SHARED_LIBRARY: { gold_assert(static_cast<unsigned int>(pov - oview) == (*p)->get_info_offset()); Incremental_dynobj_entry* entry = (*p)->dynobj_entry(); gold_assert(entry != NULL); Object* obj = entry->object(); Dynobj* dynobj = obj->dynobj(); gold_assert(dynobj != NULL); const Object::Symbols* syms = obj->get_global_symbols(); // Write the soname string table index. section_offset_type soname_offset = strtab->get_offset_from_key(entry->get_soname_key()); Swap32::writeval(pov, soname_offset); pov += 4; // Skip the global symbol count for now. unsigned char* orig_pov = pov; pov += 4; // For each global symbol, write the global symbol table index. unsigned int nsyms = syms->size(); unsigned int nsyms_out = 0; for (unsigned int i = 0; i < nsyms; i++) { const Symbol* sym = (*syms)[i]; if (sym == NULL) continue; if (sym->is_forwarder()) sym = this->symtab_->resolve_forwards(sym); if (sym->symtab_index() == -1U) continue; unsigned int flags = 0; // If the symbol has hidden or internal visibility, we // mark it as defined in the shared object so we don't // try to resolve it during an incremental update. if (sym->visibility() == elfcpp::STV_HIDDEN || sym->visibility() == elfcpp::STV_INTERNAL) flags = INCREMENTAL_SHLIB_SYM_DEF; else if (sym->source() == Symbol::FROM_OBJECT && sym->object() == obj && sym->is_defined()) flags = INCREMENTAL_SHLIB_SYM_DEF; else if (sym->is_copied_from_dynobj() && this->symtab_->get_copy_source(sym) == dynobj) flags = INCREMENTAL_SHLIB_SYM_COPY; flags <<= INCREMENTAL_SHLIB_SYM_FLAGS_SHIFT; Swap32::writeval(pov, sym->symtab_index() | flags); pov += 4; ++nsyms_out; } // Now write the global symbol count. Swap32::writeval(orig_pov, nsyms_out); } break; case INCREMENTAL_INPUT_ARCHIVE: { gold_assert(static_cast<unsigned int>(pov - oview) == (*p)->get_info_offset()); Incremental_archive_entry* entry = (*p)->archive_entry(); gold_assert(entry != NULL); // Write the member count and unused global symbol count. unsigned int nmembers = entry->get_member_count(); unsigned int nsyms = entry->get_unused_global_symbol_count(); Swap32::writeval(pov, nmembers); Swap32::writeval(pov + 4, nsyms); pov += 8; // For each member, write the offset to its input file entry. for (unsigned int i = 0; i < nmembers; ++i) { Incremental_object_entry* member = entry->get_member(i); Swap32::writeval(pov, member->get_offset()); pov += 4; } // For each global symbol, write the name offset. for (unsigned int i = 0; i < nsyms; ++i) { Stringpool::Key key = entry->get_unused_global_symbol(i); Swap32::writeval(pov, strtab->get_offset_from_key(key)); pov += 4; } } break; default: gold_unreachable(); } // Pad the info block to a multiple of 8 bytes. if (static_cast<unsigned int>(pov - oview) & 4) { Swap32::writeval(pov, 0); pov += 4; } } return pov; } // Write the contents of the .gnu_incremental_symtab section. template<int size, bool big_endian> void Output_section_incremental_inputs<size, big_endian>::write_symtab( unsigned char* pov, unsigned int* global_syms, unsigned int global_sym_count) { for (unsigned int i = 0; i < global_sym_count; ++i) { Swap32::writeval(pov, global_syms[i]); pov += 4; } } // This struct holds the view information needed to write the // .gnu_incremental_got_plt section. struct Got_plt_view_info { // Start of the GOT type array in the output view. unsigned char* got_type_p; // Start of the GOT descriptor array in the output view. unsigned char* got_desc_p; // Start of the PLT descriptor array in the output view. unsigned char* plt_desc_p; // Number of GOT entries. unsigned int got_count; // Number of PLT entries. unsigned int plt_count; // Offset of the first non-reserved PLT entry (this is a target-dependent value). unsigned int first_plt_entry_offset; // Size of a PLT entry (this is a target-dependent value). unsigned int plt_entry_size; // Size of a GOT entry (this is a target-dependent value). unsigned int got_entry_size; // Symbol index to write in the GOT descriptor array. For global symbols, // this is the global symbol table index; for local symbols, it is the // local symbol table index. unsigned int sym_index; // Input file index to write in the GOT descriptor array. For global // symbols, this is 0; for local symbols, it is the index of the input // file entry in the .gnu_incremental_inputs section. unsigned int input_index; }; // Functor class for processing a GOT offset list for local symbols. // Writes the GOT type and symbol index into the GOT type and descriptor // arrays in the output section. template<int size, bool big_endian> class Local_got_offset_visitor : public Got_offset_list::Visitor { public: Local_got_offset_visitor(struct Got_plt_view_info& info) : info_(info) { } void visit(unsigned int got_type, unsigned int got_offset) { unsigned int got_index = got_offset / this->info_.got_entry_size; gold_assert(got_index < this->info_.got_count); // We can only handle GOT entry types in the range 0..0x7e // because we use a byte array to store them, and we use the // high bit to flag a local symbol. gold_assert(got_type < 0x7f); this->info_.got_type_p[got_index] = got_type | 0x80; unsigned char* pov = this->info_.got_desc_p + got_index * 8; elfcpp::Swap<32, big_endian>::writeval(pov, this->info_.sym_index); elfcpp::Swap<32, big_endian>::writeval(pov + 4, this->info_.input_index); } private: struct Got_plt_view_info& info_; }; // Functor class for processing a GOT offset list. Writes the GOT type // and symbol index into the GOT type and descriptor arrays in the output // section. template<int size, bool big_endian> class Global_got_offset_visitor : public Got_offset_list::Visitor { public: Global_got_offset_visitor(struct Got_plt_view_info& info) : info_(info) { } void visit(unsigned int got_type, unsigned int got_offset) { unsigned int got_index = got_offset / this->info_.got_entry_size; gold_assert(got_index < this->info_.got_count); // We can only handle GOT entry types in the range 0..0x7e // because we use a byte array to store them, and we use the // high bit to flag a local symbol. gold_assert(got_type < 0x7f); this->info_.got_type_p[got_index] = got_type; unsigned char* pov = this->info_.got_desc_p + got_index * 8; elfcpp::Swap<32, big_endian>::writeval(pov, this->info_.sym_index); elfcpp::Swap<32, big_endian>::writeval(pov + 4, 0); } private: struct Got_plt_view_info& info_; }; // Functor class for processing the global symbol table. Processes the // GOT offset list for the symbol, and writes the symbol table index // into the PLT descriptor array in the output section. template<int size, bool big_endian> class Global_symbol_visitor_got_plt { public: Global_symbol_visitor_got_plt(struct Got_plt_view_info& info) : info_(info) { } void operator()(const Sized_symbol<size>* sym) { typedef Global_got_offset_visitor<size, big_endian> Got_visitor; const Got_offset_list* got_offsets = sym->got_offset_list(); if (got_offsets != NULL) { this->info_.sym_index = sym->symtab_index(); this->info_.input_index = 0; Got_visitor v(this->info_); got_offsets->for_all_got_offsets(&v); } if (sym->has_plt_offset()) { unsigned int plt_index = ((sym->plt_offset() - this->info_.first_plt_entry_offset) / this->info_.plt_entry_size); gold_assert(plt_index < this->info_.plt_count); unsigned char* pov = this->info_.plt_desc_p + plt_index * 4; elfcpp::Swap<32, big_endian>::writeval(pov, sym->symtab_index()); } } private: struct Got_plt_view_info& info_; }; // Write the contents of the .gnu_incremental_got_plt section. template<int size, bool big_endian> void Output_section_incremental_inputs<size, big_endian>::write_got_plt( unsigned char* pov, off_t view_size) { Sized_target<size, big_endian>* target = parameters->sized_target<size, big_endian>(); // Set up the view information for the functors. struct Got_plt_view_info view_info; view_info.got_count = target->got_entry_count(); view_info.plt_count = target->plt_entry_count(); view_info.first_plt_entry_offset = target->first_plt_entry_offset(); view_info.plt_entry_size = target->plt_entry_size(); view_info.got_entry_size = target->got_entry_size(); view_info.got_type_p = pov + 8; view_info.got_desc_p = (view_info.got_type_p + ((view_info.got_count + 3) & ~3)); view_info.plt_desc_p = view_info.got_desc_p + view_info.got_count * 8; gold_assert(pov + view_size == view_info.plt_desc_p + view_info.plt_count * 4); // Write the section header. Swap32::writeval(pov, view_info.got_count); Swap32::writeval(pov + 4, view_info.plt_count); // Initialize the GOT type array to 0xff (reserved). memset(view_info.got_type_p, 0xff, view_info.got_count); // Write the incremental GOT descriptors for local symbols. typedef Local_got_offset_visitor<size, big_endian> Got_visitor; for (Incremental_inputs::Input_list::const_iterator p = this->inputs_->input_files().begin(); p != this->inputs_->input_files().end(); ++p) { if ((*p)->type() != INCREMENTAL_INPUT_OBJECT && (*p)->type() != INCREMENTAL_INPUT_ARCHIVE_MEMBER) continue; Incremental_object_entry* entry = (*p)->object_entry(); gold_assert(entry != NULL); const Object* obj = entry->object(); gold_assert(obj != NULL); view_info.input_index = (*p)->get_file_index(); Got_visitor v(view_info); obj->for_all_local_got_entries(&v); } // Write the incremental GOT and PLT descriptors for global symbols. typedef Global_symbol_visitor_got_plt<size, big_endian> Symbol_visitor; symtab_->for_all_symbols<size, Symbol_visitor>(Symbol_visitor(view_info)); } // Class Sized_relobj_incr. Most of these methods are not used for // Incremental objects, but are required to be implemented by the // base class Object. template<int size, bool big_endian> Sized_relobj_incr<size, big_endian>::Sized_relobj_incr( const std::string& name, Sized_incremental_binary<size, big_endian>* ibase, unsigned int input_file_index) : Sized_relobj<size, big_endian>(name, NULL), ibase_(ibase), input_file_index_(input_file_index), input_reader_(ibase->inputs_reader().input_file(input_file_index)), local_symbol_count_(0), output_local_dynsym_count_(0), local_symbol_index_(0), local_symbol_offset_(0), local_dynsym_offset_(0), symbols_(), defined_count_(0), incr_reloc_offset_(-1U), incr_reloc_count_(0), incr_reloc_output_index_(0), incr_relocs_(NULL), local_symbols_() { if (this->input_reader_.is_in_system_directory()) this->set_is_in_system_directory(); const unsigned int shnum = this->input_reader_.get_input_section_count() + 1; this->set_shnum(shnum); ibase->set_input_object(input_file_index, this); } // Read the symbols. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_read_symbols(Read_symbols_data*) { gold_unreachable(); } // Lay out the input sections. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_layout( Symbol_table*, Layout* layout, Read_symbols_data*) { const unsigned int shnum = this->shnum(); Incremental_inputs* incremental_inputs = layout->incremental_inputs(); gold_assert(incremental_inputs != NULL); Output_sections& out_sections(this->output_sections()); out_sections.resize(shnum); this->section_offsets().resize(shnum); // Keep track of .debug_info and .debug_types sections. std::vector<unsigned int> debug_info_sections; std::vector<unsigned int> debug_types_sections; for (unsigned int i = 1; i < shnum; i++) { typename Input_entry_reader::Input_section_info sect = this->input_reader_.get_input_section(i - 1); // Add the section to the incremental inputs layout. incremental_inputs->report_input_section(this, i, sect.name, sect.sh_size); if (sect.output_shndx == 0 || sect.sh_offset == -1) continue; Output_section* os = this->ibase_->output_section(sect.output_shndx); gold_assert(os != NULL); out_sections[i] = os; this->section_offsets()[i] = static_cast<Address>(sect.sh_offset); // When generating a .gdb_index section, we do additional // processing of .debug_info and .debug_types sections after all // the other sections. if (parameters->options().gdb_index()) { const char* name = os->name(); if (strcmp(name, ".debug_info") == 0) debug_info_sections.push_back(i); else if (strcmp(name, ".debug_types") == 0) debug_types_sections.push_back(i); } } // Process the COMDAT groups. unsigned int ncomdat = this->input_reader_.get_comdat_group_count(); for (unsigned int i = 0; i < ncomdat; i++) { const char* signature = this->input_reader_.get_comdat_group_signature(i); if (signature == NULL || signature[0] == '\0') this->error(_("COMDAT group has no signature")); bool keep = layout->find_or_add_kept_section(signature, this, i, true, true, NULL); if (keep) incremental_inputs->report_comdat_group(this, signature); else this->error(_("COMDAT group %s included twice in incremental link"), signature); } // When building a .gdb_index section, scan the .debug_info and // .debug_types sections. for (std::vector<unsigned int>::const_iterator p = debug_info_sections.begin(); p != debug_info_sections.end(); ++p) { unsigned int i = *p; layout->add_to_gdb_index(false, this, NULL, 0, i, 0, 0); } for (std::vector<unsigned int>::const_iterator p = debug_types_sections.begin(); p != debug_types_sections.end(); ++p) { unsigned int i = *p; layout->add_to_gdb_index(true, this, 0, 0, i, 0, 0); } } // Layout sections whose layout was deferred while waiting for // input files from a plugin. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_layout_deferred_sections(Layout*) { } // Add the symbols to the symbol table. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_add_symbols( Symbol_table* symtab, Read_symbols_data*, Layout*) { const int sym_size = elfcpp::Elf_sizes<size>::sym_size; unsigned char symbuf[sym_size]; elfcpp::Sym<size, big_endian> sym(symbuf); elfcpp::Sym_write<size, big_endian> osym(symbuf); typedef typename elfcpp::Elf_types<size>::Elf_WXword Elf_size_type; unsigned int nsyms = this->input_reader_.get_global_symbol_count(); this->symbols_.resize(nsyms); Incremental_binary::View symtab_view(NULL); unsigned int symtab_count; elfcpp::Elf_strtab strtab(NULL, 0); this->ibase_->get_symtab_view(&symtab_view, &symtab_count, &strtab); Incremental_symtab_reader<big_endian> isymtab(this->ibase_->symtab_reader()); unsigned int isym_count = isymtab.symbol_count(); unsigned int first_global = symtab_count - isym_count; const unsigned char* sym_p; for (unsigned int i = 0; i < nsyms; ++i) { Incremental_global_symbol_reader<big_endian> info = this->input_reader_.get_global_symbol_reader(i); unsigned int output_symndx = info.output_symndx(); sym_p = symtab_view.data() + output_symndx * sym_size; elfcpp::Sym<size, big_endian> gsym(sym_p); const char* name; if (!strtab.get_c_string(gsym.get_st_name(), &name)) name = ""; typename elfcpp::Elf_types<size>::Elf_Addr v = gsym.get_st_value(); unsigned int shndx = gsym.get_st_shndx(); elfcpp::STB st_bind = gsym.get_st_bind(); elfcpp::STT st_type = gsym.get_st_type(); // Local hidden symbols start out as globals, but get converted to // to local during output. if (st_bind == elfcpp::STB_LOCAL) st_bind = elfcpp::STB_GLOBAL; unsigned int input_shndx = info.shndx(); if (input_shndx == 0 || input_shndx == -1U) { shndx = elfcpp::SHN_UNDEF; v = 0; } else if (shndx != elfcpp::SHN_ABS) { // Find the input section and calculate the section-relative value. gold_assert(shndx != elfcpp::SHN_UNDEF); Output_section* os = this->ibase_->output_section(shndx); gold_assert(os != NULL && os->has_fixed_layout()); typename Input_entry_reader::Input_section_info sect = this->input_reader_.get_input_section(input_shndx - 1); gold_assert(sect.output_shndx == shndx); if (st_type != elfcpp::STT_TLS) v -= os->address(); v -= sect.sh_offset; shndx = input_shndx; } osym.put_st_name(0); osym.put_st_value(v); osym.put_st_size(gsym.get_st_size()); osym.put_st_info(st_bind, st_type); osym.put_st_other(gsym.get_st_other()); osym.put_st_shndx(shndx); Symbol* res = symtab->add_from_incrobj(this, name, NULL, &sym); if (shndx != elfcpp::SHN_UNDEF) ++this->defined_count_; // If this is a linker-defined symbol that hasn't yet been defined, // define it now. if (input_shndx == -1U && !res->is_defined()) { shndx = gsym.get_st_shndx(); v = gsym.get_st_value(); Elf_size_type symsize = gsym.get_st_size(); if (shndx == elfcpp::SHN_ABS) { symtab->define_as_constant(name, NULL, Symbol_table::INCREMENTAL_BASE, v, symsize, st_type, st_bind, gsym.get_st_visibility(), 0, false, false); } else { Output_section* os = this->ibase_->output_section(shndx); gold_assert(os != NULL && os->has_fixed_layout()); v -= os->address(); if (symsize > 0) os->reserve(v, symsize); symtab->define_in_output_data(name, NULL, Symbol_table::INCREMENTAL_BASE, os, v, symsize, st_type, st_bind, gsym.get_st_visibility(), 0, false, false); } } this->symbols_[i] = res; this->ibase_->add_global_symbol(output_symndx - first_global, res); } } // Return TRUE if we should include this object from an archive library. template<int size, bool big_endian> Archive::Should_include Sized_relobj_incr<size, big_endian>::do_should_include_member( Symbol_table*, Layout*, Read_symbols_data*, std::string*) { gold_unreachable(); } // Iterate over global symbols, calling a visitor class V for each. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_for_all_global_symbols( Read_symbols_data*, Library_base::Symbol_visitor_base*) { // This routine is not used for incremental objects. } // Get the size of a section. template<int size, bool big_endian> uint64_t Sized_relobj_incr<size, big_endian>::do_section_size(unsigned int) { gold_unreachable(); } // Get the name of a section. This returns the name of the output // section, because we don't usually track the names of the input // sections. template<int size, bool big_endian> std::string Sized_relobj_incr<size, big_endian>::do_section_name(unsigned int shndx) const { const Output_sections& out_sections(this->output_sections()); const Output_section* os = out_sections[shndx]; if (os == NULL) return NULL; return os->name(); } // Return a view of the contents of a section. template<int size, bool big_endian> const unsigned char* Sized_relobj_incr<size, big_endian>::do_section_contents( unsigned int shndx, section_size_type* plen, bool) { Output_sections& out_sections(this->output_sections()); Output_section* os = out_sections[shndx]; gold_assert(os != NULL); off_t section_offset = os->offset(); typename Input_entry_reader::Input_section_info sect = this->input_reader_.get_input_section(shndx - 1); section_offset += sect.sh_offset; *plen = sect.sh_size; return this->ibase_->view(section_offset, sect.sh_size).data(); } // Return section flags. template<int size, bool big_endian> uint64_t Sized_relobj_incr<size, big_endian>::do_section_flags(unsigned int) { gold_unreachable(); } // Return section entsize. template<int size, bool big_endian> uint64_t Sized_relobj_incr<size, big_endian>::do_section_entsize(unsigned int) { gold_unreachable(); } // Return section address. template<int size, bool big_endian> uint64_t Sized_relobj_incr<size, big_endian>::do_section_address(unsigned int) { gold_unreachable(); } // Return section type. template<int size, bool big_endian> unsigned int Sized_relobj_incr<size, big_endian>::do_section_type(unsigned int) { gold_unreachable(); } // Return the section link field. template<int size, bool big_endian> unsigned int Sized_relobj_incr<size, big_endian>::do_section_link(unsigned int) { gold_unreachable(); } // Return the section link field. template<int size, bool big_endian> unsigned int Sized_relobj_incr<size, big_endian>::do_section_info(unsigned int) { gold_unreachable(); } // Return the section alignment. template<int size, bool big_endian> uint64_t Sized_relobj_incr<size, big_endian>::do_section_addralign(unsigned int) { gold_unreachable(); } // Return the Xindex structure to use. template<int size, bool big_endian> Xindex* Sized_relobj_incr<size, big_endian>::do_initialize_xindex() { gold_unreachable(); } // Get symbol counts. template<int size, bool big_endian> void Sized_relobj_incr<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 (typename 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; } // Read the relocs. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_read_relocs(Read_relocs_data*) { } // Process the relocs to find list of referenced sections. Used only // during garbage collection. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*) { gold_unreachable(); } // Scan the relocs and adjust the symbol table. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_scan_relocs(Symbol_table*, Layout* layout, Read_relocs_data*) { // Count the incremental relocations for this object. unsigned int nsyms = this->input_reader_.get_global_symbol_count(); this->allocate_incremental_reloc_counts(); for (unsigned int i = 0; i < nsyms; i++) { Incremental_global_symbol_reader<big_endian> sym = this->input_reader_.get_global_symbol_reader(i); unsigned int reloc_count = sym.reloc_count(); if (reloc_count > 0 && this->incr_reloc_offset_ == -1U) this->incr_reloc_offset_ = sym.reloc_offset(); this->incr_reloc_count_ += reloc_count; for (unsigned int j = 0; j < reloc_count; j++) this->count_incremental_reloc(i); } this->incr_reloc_output_index_ = layout->incremental_inputs()->get_reloc_count(); this->finalize_incremental_relocs(layout, false); // The incoming incremental relocations may not end up in the same // location after the incremental update, because the incremental info // is regenerated in each link. Because the new location may overlap // with other data in the updated output file, we need to copy the // relocations into a buffer so that we can still read them safely // after we start writing updates to the output file. if (this->incr_reloc_count_ > 0) { const Incremental_relocs_reader<size, big_endian>& relocs_reader = this->ibase_->relocs_reader(); const unsigned int incr_reloc_size = relocs_reader.reloc_size; unsigned int len = this->incr_reloc_count_ * incr_reloc_size; this->incr_relocs_ = new unsigned char[len]; memcpy(this->incr_relocs_, relocs_reader.data(this->incr_reloc_offset_), len); } } // Count the local symbols. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_count_local_symbols( Stringpool_template<char>* pool, Stringpool_template<char>*) { const int sym_size = elfcpp::Elf_sizes<size>::sym_size; // Set the count of local symbols based on the incremental info. unsigned int nlocals = this->input_reader_.get_local_symbol_count(); this->local_symbol_count_ = nlocals; this->local_symbols_.reserve(nlocals); // Get views of the base file's symbol table and string table. Incremental_binary::View symtab_view(NULL); unsigned int symtab_count; elfcpp::Elf_strtab strtab(NULL, 0); this->ibase_->get_symtab_view(&symtab_view, &symtab_count, &strtab); // Read the local symbols from the base file's symbol table. off_t off = this->input_reader_.get_local_symbol_offset(); const unsigned char* symp = symtab_view.data() + off; for (unsigned int i = 0; i < nlocals; ++i, symp += sym_size) { elfcpp::Sym<size, big_endian> sym(symp); const char* name; if (!strtab.get_c_string(sym.get_st_name(), &name)) name = ""; gold_debug(DEBUG_INCREMENTAL, "Local symbol %d: %s", i, name); name = pool->add(name, true, NULL); this->local_symbols_.push_back(Local_symbol(name, sym.get_st_value(), sym.get_st_size(), sym.get_st_shndx(), sym.get_st_type(), false)); } } // Finalize the local symbols. template<int size, bool big_endian> unsigned int Sized_relobj_incr<size, big_endian>::do_finalize_local_symbols( unsigned int index, off_t off, Symbol_table*) { this->local_symbol_index_ = index; this->local_symbol_offset_ = off; return index + this->local_symbol_count_; } // Set the offset where local dynamic symbol information will be stored. template<int size, bool big_endian> unsigned int Sized_relobj_incr<size, big_endian>::do_set_local_dynsym_indexes( unsigned int index) { // FIXME: set local dynsym indexes. return index; } // Set the offset where local dynamic symbol information will be stored. template<int size, bool big_endian> unsigned int Sized_relobj_incr<size, big_endian>::do_set_local_dynsym_offset(off_t) { return 0; } // Relocate the input sections and write out the local symbols. // We don't actually do any relocation here. For unchanged input files, // we reapply relocations only for symbols that have changed; that happens // in Layout_task_runner::run(). We do need to rewrite the incremental // relocations for this object. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_relocate(const Symbol_table*, const Layout* layout, Output_file* of) { if (this->incr_reloc_count_ == 0) return; const unsigned int incr_reloc_size = Incremental_relocs_reader<size, big_endian>::reloc_size; // Get a view for the .gnu_incremental_relocs section. Incremental_inputs* inputs = layout->incremental_inputs(); gold_assert(inputs != NULL); const off_t relocs_off = inputs->relocs_section()->offset(); const off_t relocs_size = inputs->relocs_section()->data_size(); unsigned char* const view = of->get_output_view(relocs_off, relocs_size); // Copy the relocations from the buffer. off_t off = this->incr_reloc_output_index_ * incr_reloc_size; unsigned int len = this->incr_reloc_count_ * incr_reloc_size; memcpy(view + off, this->incr_relocs_, len); // The output section table may have changed, so we need to map // the old section index to the new section index for each relocation. for (unsigned int i = 0; i < this->incr_reloc_count_; ++i) { unsigned char* pov = view + off + i * incr_reloc_size; unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(pov + 4); Output_section* os = this->ibase_->output_section(shndx); gold_assert(os != NULL); shndx = os->out_shndx(); elfcpp::Swap<32, big_endian>::writeval(pov + 4, shndx); } of->write_output_view(off, len, view); // 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 symtab_off = layout->symtab_section()->offset(); off_t output_size = this->local_symbol_count_ * This::sym_size; unsigned char* oview = NULL; if (output_size > 0) oview = of->get_output_view(symtab_off + 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); // Write the local symbols. unsigned char* ov = oview; unsigned char* dyn_ov = dyn_oview; const Stringpool* sympool = layout->sympool(); const Stringpool* dynpool = layout->dynpool(); Output_symtab_xindex* symtab_xindex = layout->symtab_xindex(); Output_symtab_xindex* dynsym_xindex = layout->dynsym_xindex(); for (unsigned int i = 0; i < this->local_symbol_count_; ++i) { Local_symbol& lsym(this->local_symbols_[i]); bool is_ordinary; unsigned int st_shndx = this->adjust_sym_shndx(i, lsym.st_shndx, &is_ordinary); if (is_ordinary) { Output_section* os = this->ibase_->output_section(st_shndx); st_shndx = os->out_shndx(); if (st_shndx >= elfcpp::SHN_LORESERVE) { symtab_xindex->add(this->local_symbol_index_ + i, st_shndx); if (lsym.needs_dynsym_entry) dynsym_xindex->add(lsym.output_dynsym_index, st_shndx); st_shndx = elfcpp::SHN_XINDEX; } } // Write the symbol to the output symbol table. { elfcpp::Sym_write<size, big_endian> osym(ov); osym.put_st_name(sympool->get_offset(lsym.name)); osym.put_st_value(lsym.st_value); osym.put_st_size(lsym.st_size); osym.put_st_info(elfcpp::STB_LOCAL, static_cast<elfcpp::STT>(lsym.st_type)); osym.put_st_other(0); osym.put_st_shndx(st_shndx); ov += sym_size; } // Write the symbol to the output dynamic symbol table. if (lsym.needs_dynsym_entry) { gold_assert(dyn_ov < dyn_oview + dyn_output_size); elfcpp::Sym_write<size, big_endian> osym(dyn_ov); osym.put_st_name(dynpool->get_offset(lsym.name)); osym.put_st_value(lsym.st_value); osym.put_st_size(lsym.st_size); osym.put_st_info(elfcpp::STB_LOCAL, static_cast<elfcpp::STT>(lsym.st_type)); osym.put_st_other(0); osym.put_st_shndx(st_shndx); dyn_ov += sym_size; } } if (output_size > 0) { gold_assert(ov - oview == output_size); of->write_output_view(symtab_off + 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 the offset of a section. template<int size, bool big_endian> void Sized_relobj_incr<size, big_endian>::do_set_section_offset(unsigned int, uint64_t) { } // Class Sized_incr_dynobj. Most of these methods are not used for // Incremental objects, but are required to be implemented by the // base class Object. template<int size, bool big_endian> Sized_incr_dynobj<size, big_endian>::Sized_incr_dynobj( const std::string& name, Sized_incremental_binary<size, big_endian>* ibase, unsigned int input_file_index) : Dynobj(name, NULL), ibase_(ibase), input_file_index_(input_file_index), input_reader_(ibase->inputs_reader().input_file(input_file_index)), symbols_(), defined_count_(0) { if (this->input_reader_.is_in_system_directory()) this->set_is_in_system_directory(); if (this->input_reader_.as_needed()) this->set_as_needed(); this->set_soname_string(this->input_reader_.get_soname()); this->set_shnum(0); } // Read the symbols. template<int size, bool big_endian> void Sized_incr_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data*) { gold_unreachable(); } // Lay out the input sections. template<int size, bool big_endian> void Sized_incr_dynobj<size, big_endian>::do_layout( Symbol_table*, Layout*, Read_symbols_data*) { } // Add the symbols to the symbol table. template<int size, bool big_endian> void Sized_incr_dynobj<size, big_endian>::do_add_symbols( Symbol_table* symtab, Read_symbols_data*, Layout*) { const int sym_size = elfcpp::Elf_sizes<size>::sym_size; unsigned char symbuf[sym_size]; elfcpp::Sym<size, big_endian> sym(symbuf); elfcpp::Sym_write<size, big_endian> osym(symbuf); unsigned int nsyms = this->input_reader_.get_global_symbol_count(); this->symbols_.resize(nsyms); Incremental_binary::View symtab_view(NULL); unsigned int symtab_count; elfcpp::Elf_strtab strtab(NULL, 0); this->ibase_->get_symtab_view(&symtab_view, &symtab_count, &strtab); Incremental_symtab_reader<big_endian> isymtab(this->ibase_->symtab_reader()); unsigned int isym_count = isymtab.symbol_count(); unsigned int first_global = symtab_count - isym_count; // We keep a set of symbols that we have generated COPY relocations // for, indexed by the symbol value. We do not need more than one // COPY relocation per address. typedef typename std::set<Address> Copied_symbols; Copied_symbols copied_symbols; const unsigned char* sym_p; for (unsigned int i = 0; i < nsyms; ++i) { bool is_def; bool is_copy; unsigned int output_symndx = this->input_reader_.get_output_symbol_index(i, &is_def, &is_copy); sym_p = symtab_view.data() + output_symndx * sym_size; elfcpp::Sym<size, big_endian> gsym(sym_p); const char* name; if (!strtab.get_c_string(gsym.get_st_name(), &name)) name = ""; Address v; unsigned int shndx; elfcpp::STB st_bind = gsym.get_st_bind(); elfcpp::STT st_type = gsym.get_st_type(); // Local hidden symbols start out as globals, but get converted to // to local during output. if (st_bind == elfcpp::STB_LOCAL) st_bind = elfcpp::STB_GLOBAL; if (!is_def) { shndx = elfcpp::SHN_UNDEF; v = 0; } else { // For a symbol defined in a shared object, the section index // is meaningless, as long as it's not SHN_UNDEF. shndx = 1; v = gsym.get_st_value(); ++this->defined_count_; } osym.put_st_name(0); osym.put_st_value(v); osym.put_st_size(gsym.get_st_size()); osym.put_st_info(st_bind, st_type); osym.put_st_other(gsym.get_st_other()); osym.put_st_shndx(shndx); Sized_symbol<size>* res = symtab->add_from_incrobj<size, big_endian>(this, name, NULL, &sym); this->symbols_[i] = res; this->ibase_->add_global_symbol(output_symndx - first_global, this->symbols_[i]); if (is_copy) { std::pair<typename Copied_symbols::iterator, bool> ins = copied_symbols.insert(v); if (ins.second) { unsigned int shndx = gsym.get_st_shndx(); Output_section* os = this->ibase_->output_section(shndx); off_t offset = v - os->address(); this->ibase_->add_copy_reloc(this->symbols_[i], os, offset); } } } } // Return TRUE if we should include this object from an archive library. template<int size, bool big_endian> Archive::Should_include Sized_incr_dynobj<size, big_endian>::do_should_include_member( Symbol_table*, Layout*, Read_symbols_data*, std::string*) { gold_unreachable(); } // Iterate over global symbols, calling a visitor class V for each. template<int size, bool big_endian> void Sized_incr_dynobj<size, big_endian>::do_for_all_global_symbols( Read_symbols_data*, Library_base::Symbol_visitor_base*) { // This routine is not used for dynamic libraries. } // Iterate over local symbols, calling a visitor class V for each GOT offset // associated with a local symbol. template<int size, bool big_endian> void Sized_incr_dynobj<size, big_endian>::do_for_all_local_got_entries( Got_offset_list::Visitor*) const { } // Get the size of a section. template<int size, bool big_endian> uint64_t Sized_incr_dynobj<size, big_endian>::do_section_size(unsigned int) { gold_unreachable(); } // Get the name of a section. template<int size, bool big_endian> std::string Sized_incr_dynobj<size, big_endian>::do_section_name(unsigned int) const { gold_unreachable(); } // Return a view of the contents of a section. template<int size, bool big_endian> const unsigned char* Sized_incr_dynobj<size, big_endian>::do_section_contents( unsigned int, section_size_type*, bool) { gold_unreachable(); } // Return section flags. template<int size, bool big_endian> uint64_t Sized_incr_dynobj<size, big_endian>::do_section_flags(unsigned int) { gold_unreachable(); } // Return section entsize. template<int size, bool big_endian> uint64_t Sized_incr_dynobj<size, big_endian>::do_section_entsize(unsigned int) { gold_unreachable(); } // Return section address. template<int size, bool big_endian> uint64_t Sized_incr_dynobj<size, big_endian>::do_section_address(unsigned int) { gold_unreachable(); } // Return section type. template<int size, bool big_endian> unsigned int Sized_incr_dynobj<size, big_endian>::do_section_type(unsigned int) { gold_unreachable(); } // Return the section link field. template<int size, bool big_endian> unsigned int Sized_incr_dynobj<size, big_endian>::do_section_link(unsigned int) { gold_unreachable(); } // Return the section link field. template<int size, bool big_endian> unsigned int Sized_incr_dynobj<size, big_endian>::do_section_info(unsigned int) { gold_unreachable(); } // Return the section alignment. template<int size, bool big_endian> uint64_t Sized_incr_dynobj<size, big_endian>::do_section_addralign(unsigned int) { gold_unreachable(); } // Return the Xindex structure to use. template<int size, bool big_endian> Xindex* Sized_incr_dynobj<size, big_endian>::do_initialize_xindex() { gold_unreachable(); } // Get symbol counts. template<int size, bool big_endian> void Sized_incr_dynobj<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 (typename 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() && (*p)->dynsym_index() != -1U) ++count; *used = count; } // Allocate an incremental object of the appropriate size and endianness. Object* make_sized_incremental_object( Incremental_binary* ibase, unsigned int input_file_index, Incremental_input_type input_type, const Incremental_binary::Input_reader* input_reader) { Object* obj = NULL; std::string name(input_reader->filename()); switch (parameters->size_and_endianness()) { #ifdef HAVE_TARGET_32_LITTLE case Parameters::TARGET_32_LITTLE: { Sized_incremental_binary<32, false>* sized_ibase = static_cast<Sized_incremental_binary<32, false>*>(ibase); if (input_type == INCREMENTAL_INPUT_SHARED_LIBRARY) obj = new Sized_incr_dynobj<32, false>(name, sized_ibase, input_file_index); else obj = new Sized_relobj_incr<32, false>(name, sized_ibase, input_file_index); } break; #endif #ifdef HAVE_TARGET_32_BIG case Parameters::TARGET_32_BIG: { Sized_incremental_binary<32, true>* sized_ibase = static_cast<Sized_incremental_binary<32, true>*>(ibase); if (input_type == INCREMENTAL_INPUT_SHARED_LIBRARY) obj = new Sized_incr_dynobj<32, true>(name, sized_ibase, input_file_index); else obj = new Sized_relobj_incr<32, true>(name, sized_ibase, input_file_index); } break; #endif #ifdef HAVE_TARGET_64_LITTLE case Parameters::TARGET_64_LITTLE: { Sized_incremental_binary<64, false>* sized_ibase = static_cast<Sized_incremental_binary<64, false>*>(ibase); if (input_type == INCREMENTAL_INPUT_SHARED_LIBRARY) obj = new Sized_incr_dynobj<64, false>(name, sized_ibase, input_file_index); else obj = new Sized_relobj_incr<64, false>(name, sized_ibase, input_file_index); } break; #endif #ifdef HAVE_TARGET_64_BIG case Parameters::TARGET_64_BIG: { Sized_incremental_binary<64, true>* sized_ibase = static_cast<Sized_incremental_binary<64, true>*>(ibase); if (input_type == INCREMENTAL_INPUT_SHARED_LIBRARY) obj = new Sized_incr_dynobj<64, true>(name, sized_ibase, input_file_index); else obj = new Sized_relobj_incr<64, true>(name, sized_ibase, input_file_index); } break; #endif default: gold_unreachable(); } gold_assert(obj != NULL); return obj; } // Copy the unused symbols from the incremental input info. // We need to do this because we may be overwriting the incremental // input info in the base file before we write the new incremental // info. void Incremental_library::copy_unused_symbols() { unsigned int symcount = this->input_reader_->get_unused_symbol_count(); this->unused_symbols_.reserve(symcount); for (unsigned int i = 0; i < symcount; ++i) { std::string name(this->input_reader_->get_unused_symbol(i)); this->unused_symbols_.push_back(name); } } // Iterator for unused global symbols in the library. void Incremental_library::do_for_all_unused_symbols(Symbol_visitor_base* v) const { for (Symbol_list::const_iterator p = this->unused_symbols_.begin(); p != this->unused_symbols_.end(); ++p) v->visit(p->c_str()); } // Instantiate the templates we need. #ifdef HAVE_TARGET_32_LITTLE template class Sized_incremental_binary<32, false>; template class Sized_relobj_incr<32, false>; template class Sized_incr_dynobj<32, false>; #endif #ifdef HAVE_TARGET_32_BIG template class Sized_incremental_binary<32, true>; template class Sized_relobj_incr<32, true>; template class Sized_incr_dynobj<32, true>; #endif #ifdef HAVE_TARGET_64_LITTLE template class Sized_incremental_binary<64, false>; template class Sized_relobj_incr<64, false>; template class Sized_incr_dynobj<64, false>; #endif #ifdef HAVE_TARGET_64_BIG template class Sized_incremental_binary<64, true>; template class Sized_relobj_incr<64, true>; template class Sized_incr_dynobj<64, true>; #endif } // End namespace gold.