diff options
Diffstat (limited to 'gold/output.cc')
| -rw-r--r-- | gold/output.cc | 1670 |
1 files changed, 1670 insertions, 0 deletions
diff --git a/gold/output.cc b/gold/output.cc new file mode 100644 index 000000000000..2a7400def77c --- /dev/null +++ b/gold/output.cc @@ -0,0 +1,1670 @@ +// output.cc -- manage the output file for gold + +#include "gold.h" + +#include <cstdlib> +#include <cerrno> +#include <fcntl.h> +#include <unistd.h> +#include <sys/mman.h> +#include <algorithm> + +#include "object.h" +#include "symtab.h" +#include "reloc.h" +#include "merge.h" +#include "output.h" + +namespace gold +{ + +// Output_data variables. + +bool Output_data::sizes_are_fixed; + +// Output_data methods. + +Output_data::~Output_data() +{ +} + +// Set the address and offset. + +void +Output_data::set_address(uint64_t addr, off_t off) +{ + this->address_ = addr; + this->offset_ = off; + + // Let the child class know. + this->do_set_address(addr, off); +} + +// Return the default alignment for a size--32 or 64. + +uint64_t +Output_data::default_alignment(int size) +{ + if (size == 32) + return 4; + else if (size == 64) + return 8; + else + gold_unreachable(); +} + +// Output_section_header methods. This currently assumes that the +// segment and section lists are complete at construction time. + +Output_section_headers::Output_section_headers( + int size, + bool big_endian, + const Layout* layout, + const Layout::Segment_list* segment_list, + const Layout::Section_list* unattached_section_list, + const Stringpool* secnamepool) + : size_(size), + big_endian_(big_endian), + layout_(layout), + segment_list_(segment_list), + unattached_section_list_(unattached_section_list), + secnamepool_(secnamepool) +{ + // Count all the sections. Start with 1 for the null section. + off_t count = 1; + for (Layout::Segment_list::const_iterator p = segment_list->begin(); + p != segment_list->end(); + ++p) + if ((*p)->type() == elfcpp::PT_LOAD) + count += (*p)->output_section_count(); + count += unattached_section_list->size(); + + int shdr_size; + if (size == 32) + shdr_size = elfcpp::Elf_sizes<32>::shdr_size; + else if (size == 64) + shdr_size = elfcpp::Elf_sizes<64>::shdr_size; + else + gold_unreachable(); + + this->set_data_size(count * shdr_size); +} + +// Write out the section headers. + +void +Output_section_headers::do_write(Output_file* of) +{ + if (this->size_ == 32) + { + if (this->big_endian_) + this->do_sized_write<32, true>(of); + else + this->do_sized_write<32, false>(of); + } + else if (this->size_ == 64) + { + if (this->big_endian_) + this->do_sized_write<64, true>(of); + else + this->do_sized_write<64, false>(of); + } + else + gold_unreachable(); +} + +template<int size, bool big_endian> +void +Output_section_headers::do_sized_write(Output_file* of) +{ + off_t all_shdrs_size = this->data_size(); + unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size); + + const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; + unsigned char* v = view; + + { + typename elfcpp::Shdr_write<size, big_endian> oshdr(v); + oshdr.put_sh_name(0); + oshdr.put_sh_type(elfcpp::SHT_NULL); + oshdr.put_sh_flags(0); + oshdr.put_sh_addr(0); + oshdr.put_sh_offset(0); + oshdr.put_sh_size(0); + oshdr.put_sh_link(0); + oshdr.put_sh_info(0); + oshdr.put_sh_addralign(0); + oshdr.put_sh_entsize(0); + } + + v += shdr_size; + + unsigned shndx = 1; + for (Layout::Segment_list::const_iterator p = this->segment_list_->begin(); + p != this->segment_list_->end(); + ++p) + v = (*p)->write_section_headers SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( + this->layout_, this->secnamepool_, v, &shndx + SELECT_SIZE_ENDIAN(size, big_endian)); + for (Layout::Section_list::const_iterator p = + this->unattached_section_list_->begin(); + p != this->unattached_section_list_->end(); + ++p) + { + gold_assert(shndx == (*p)->out_shndx()); + elfcpp::Shdr_write<size, big_endian> oshdr(v); + (*p)->write_header(this->layout_, this->secnamepool_, &oshdr); + v += shdr_size; + ++shndx; + } + + of->write_output_view(this->offset(), all_shdrs_size, view); +} + +// Output_segment_header methods. + +Output_segment_headers::Output_segment_headers( + int size, + bool big_endian, + const Layout::Segment_list& segment_list) + : size_(size), big_endian_(big_endian), segment_list_(segment_list) +{ + int phdr_size; + if (size == 32) + phdr_size = elfcpp::Elf_sizes<32>::phdr_size; + else if (size == 64) + phdr_size = elfcpp::Elf_sizes<64>::phdr_size; + else + gold_unreachable(); + + this->set_data_size(segment_list.size() * phdr_size); +} + +void +Output_segment_headers::do_write(Output_file* of) +{ + if (this->size_ == 32) + { + if (this->big_endian_) + this->do_sized_write<32, true>(of); + else + this->do_sized_write<32, false>(of); + } + else if (this->size_ == 64) + { + if (this->big_endian_) + this->do_sized_write<64, true>(of); + else + this->do_sized_write<64, false>(of); + } + else + gold_unreachable(); +} + +template<int size, bool big_endian> +void +Output_segment_headers::do_sized_write(Output_file* of) +{ + const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size; + off_t all_phdrs_size = this->segment_list_.size() * phdr_size; + unsigned char* view = of->get_output_view(this->offset(), + all_phdrs_size); + unsigned char* v = view; + for (Layout::Segment_list::const_iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + { + elfcpp::Phdr_write<size, big_endian> ophdr(v); + (*p)->write_header(&ophdr); + v += phdr_size; + } + + of->write_output_view(this->offset(), all_phdrs_size, view); +} + +// Output_file_header methods. + +Output_file_header::Output_file_header(int size, + bool big_endian, + const General_options& options, + const Target* target, + const Symbol_table* symtab, + const Output_segment_headers* osh) + : size_(size), + big_endian_(big_endian), + options_(options), + target_(target), + symtab_(symtab), + segment_header_(osh), + section_header_(NULL), + shstrtab_(NULL) +{ + int ehdr_size; + if (size == 32) + ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size; + else if (size == 64) + ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size; + else + gold_unreachable(); + + this->set_data_size(ehdr_size); +} + +// Set the section table information for a file header. + +void +Output_file_header::set_section_info(const Output_section_headers* shdrs, + const Output_section* shstrtab) +{ + this->section_header_ = shdrs; + this->shstrtab_ = shstrtab; +} + +// Write out the file header. + +void +Output_file_header::do_write(Output_file* of) +{ + if (this->size_ == 32) + { + if (this->big_endian_) + this->do_sized_write<32, true>(of); + else + this->do_sized_write<32, false>(of); + } + else if (this->size_ == 64) + { + if (this->big_endian_) + this->do_sized_write<64, true>(of); + else + this->do_sized_write<64, false>(of); + } + else + gold_unreachable(); +} + +// Write out the file header with appropriate size and endianess. + +template<int size, bool big_endian> +void +Output_file_header::do_sized_write(Output_file* of) +{ + gold_assert(this->offset() == 0); + + int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size; + unsigned char* view = of->get_output_view(0, ehdr_size); + elfcpp::Ehdr_write<size, big_endian> oehdr(view); + + unsigned char e_ident[elfcpp::EI_NIDENT]; + memset(e_ident, 0, elfcpp::EI_NIDENT); + e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0; + e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1; + e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2; + e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3; + if (size == 32) + e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32; + else if (size == 64) + e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64; + else + gold_unreachable(); + e_ident[elfcpp::EI_DATA] = (big_endian + ? elfcpp::ELFDATA2MSB + : elfcpp::ELFDATA2LSB); + e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT; + // FIXME: Some targets may need to set EI_OSABI and EI_ABIVERSION. + oehdr.put_e_ident(e_ident); + + elfcpp::ET e_type; + // FIXME: ET_DYN. + if (this->options_.is_relocatable()) + e_type = elfcpp::ET_REL; + else + e_type = elfcpp::ET_EXEC; + oehdr.put_e_type(e_type); + + oehdr.put_e_machine(this->target_->machine_code()); + oehdr.put_e_version(elfcpp::EV_CURRENT); + + // FIXME: Need to support -e, and target specific entry symbol. + Symbol* sym = this->symtab_->lookup("_start"); + typename Sized_symbol<size>::Value_type v; + if (sym == NULL) + v = 0; + else + { + Sized_symbol<size>* ssym; + ssym = this->symtab_->get_sized_symbol SELECT_SIZE_NAME(size) ( + sym SELECT_SIZE(size)); + v = ssym->value(); + } + oehdr.put_e_entry(v); + + oehdr.put_e_phoff(this->segment_header_->offset()); + oehdr.put_e_shoff(this->section_header_->offset()); + + // FIXME: The target needs to set the flags. + oehdr.put_e_flags(0); + + oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size); + oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size); + oehdr.put_e_phnum(this->segment_header_->data_size() + / elfcpp::Elf_sizes<size>::phdr_size); + oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size); + oehdr.put_e_shnum(this->section_header_->data_size() + / elfcpp::Elf_sizes<size>::shdr_size); + oehdr.put_e_shstrndx(this->shstrtab_->out_shndx()); + + of->write_output_view(0, ehdr_size, view); +} + +// Output_data_const methods. + +void +Output_data_const::do_write(Output_file* of) +{ + of->write(this->offset(), this->data_.data(), this->data_.size()); +} + +// Output_data_const_buffer methods. + +void +Output_data_const_buffer::do_write(Output_file* of) +{ + of->write(this->offset(), this->p_, this->data_size()); +} + +// Output_section_data methods. + +// Record the output section, and set the entry size and such. + +void +Output_section_data::set_output_section(Output_section* os) +{ + gold_assert(this->output_section_ == NULL); + this->output_section_ = os; + this->do_adjust_output_section(os); +} + +// Return the section index of the output section. + +unsigned int +Output_section_data::do_out_shndx() const +{ + gold_assert(this->output_section_ != NULL); + return this->output_section_->out_shndx(); +} + +// Output_data_strtab methods. + +// Set the address. We don't actually care about the address, but we +// do set our final size. + +void +Output_data_strtab::do_set_address(uint64_t, off_t) +{ + this->strtab_->set_string_offsets(); + this->set_data_size(this->strtab_->get_strtab_size()); +} + +// Write out a string table. + +void +Output_data_strtab::do_write(Output_file* of) +{ + this->strtab_->write(of, this->offset()); +} + +// Output_reloc methods. + +// Get the symbol index of a relocation. + +template<bool dynamic, int size, bool big_endian> +unsigned int +Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index() + const +{ + unsigned int index; + switch (this->local_sym_index_) + { + case INVALID_CODE: + gold_unreachable(); + + case GSYM_CODE: + if (this->u1_.gsym == NULL) + index = 0; + else if (dynamic) + index = this->u1_.gsym->dynsym_index(); + else + index = this->u1_.gsym->symtab_index(); + break; + + case SECTION_CODE: + if (dynamic) + index = this->u1_.os->dynsym_index(); + else + index = this->u1_.os->symtab_index(); + break; + + default: + if (dynamic) + { + // FIXME: It seems that some targets may need to generate + // dynamic relocations against local symbols for some + // reasons. This will have to be addressed at some point. + gold_unreachable(); + } + else + index = this->u1_.relobj->symtab_index(this->local_sym_index_); + break; + } + gold_assert(index != -1U); + return index; +} + +// Write out the offset and info fields of a Rel or Rela relocation +// entry. + +template<bool dynamic, int size, bool big_endian> +template<typename Write_rel> +void +Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel( + Write_rel* wr) const +{ + Address address = this->address_; + if (this->shndx_ != INVALID_CODE) + { + off_t off; + Output_section* os = this->u2_.relobj->output_section(this->shndx_, + &off); + gold_assert(os != NULL); + address += os->address() + off; + } + else if (this->u2_.od != NULL) + address += this->u2_.od->address(); + wr->put_r_offset(address); + wr->put_r_info(elfcpp::elf_r_info<size>(this->get_symbol_index(), + this->type_)); +} + +// Write out a Rel relocation. + +template<bool dynamic, int size, bool big_endian> +void +Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write( + unsigned char* pov) const +{ + elfcpp::Rel_write<size, big_endian> orel(pov); + this->write_rel(&orel); +} + +// Write out a Rela relocation. + +template<bool dynamic, int size, bool big_endian> +void +Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write( + unsigned char* pov) const +{ + elfcpp::Rela_write<size, big_endian> orel(pov); + this->rel_.write_rel(&orel); + orel.put_r_addend(this->addend_); +} + +// Output_data_reloc_base methods. + +// Adjust the output section. + +template<int sh_type, bool dynamic, int size, bool big_endian> +void +Output_data_reloc_base<sh_type, dynamic, size, big_endian> + ::do_adjust_output_section(Output_section* os) +{ + if (sh_type == elfcpp::SHT_REL) + os->set_entsize(elfcpp::Elf_sizes<size>::rel_size); + else if (sh_type == elfcpp::SHT_RELA) + os->set_entsize(elfcpp::Elf_sizes<size>::rela_size); + else + gold_unreachable(); + if (dynamic) + os->set_should_link_to_dynsym(); + else + os->set_should_link_to_symtab(); +} + +// Write out relocation data. + +template<int sh_type, bool dynamic, int size, bool big_endian> +void +Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write( + Output_file* of) +{ + 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; + for (typename Relocs::const_iterator p = this->relocs_.begin(); + p != this->relocs_.end(); + ++p) + { + p->write(pov); + pov += reloc_size; + } + + gold_assert(pov - oview == oview_size); + + of->write_output_view(off, oview_size, oview); + + // We no longer need the relocation entries. + this->relocs_.clear(); +} + +// Output_data_got::Got_entry methods. + +// Write out the entry. + +template<int size, bool big_endian> +void +Output_data_got<size, big_endian>::Got_entry::write( + const General_options* options, + unsigned char* pov) const +{ + Valtype val = 0; + + switch (this->local_sym_index_) + { + case GSYM_CODE: + { + Symbol* gsym = this->u_.gsym; + + // If the symbol is resolved locally, we need to write out its + // value. Otherwise we just write zero. The target code is + // responsible for creating a relocation entry to fill in the + // value at runtime. + if (gsym->final_value_is_known(options)) + { + Sized_symbol<size>* sgsym; + // This cast is a bit ugly. We don't want to put a + // virtual method in Symbol, because we want Symbol to be + // as small as possible. + sgsym = static_cast<Sized_symbol<size>*>(gsym); + val = sgsym->value(); + } + } + break; + + case CONSTANT_CODE: + val = this->u_.constant; + break; + + default: + gold_unreachable(); + } + + elfcpp::Swap<size, big_endian>::writeval(pov, val); +} + +// Output_data_got methods. + +// Add an entry for a global symbol to the GOT. This returns true if +// this is a new GOT entry, false if the symbol already had a GOT +// entry. + +template<int size, bool big_endian> +bool +Output_data_got<size, big_endian>::add_global(Symbol* gsym) +{ + if (gsym->has_got_offset()) + return false; + + this->entries_.push_back(Got_entry(gsym)); + this->set_got_size(); + gsym->set_got_offset(this->last_got_offset()); + return true; +} + +// Write out the GOT. + +template<int size, bool big_endian> +void +Output_data_got<size, big_endian>::do_write(Output_file* of) +{ + const int add = size / 8; + + 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; + for (typename Got_entries::const_iterator p = this->entries_.begin(); + p != this->entries_.end(); + ++p) + { + p->write(this->options_, pov); + pov += add; + } + + gold_assert(pov - oview == oview_size); + + of->write_output_view(off, oview_size, oview); + + // We no longer need the GOT entries. + this->entries_.clear(); +} + +// Output_data_dynamic::Dynamic_entry methods. + +// Write out the entry. + +template<int size, bool big_endian> +void +Output_data_dynamic::Dynamic_entry::write( + unsigned char* pov, + const Stringpool* pool + ACCEPT_SIZE_ENDIAN) const +{ + typename elfcpp::Elf_types<size>::Elf_WXword val; + switch (this->classification_) + { + case DYNAMIC_NUMBER: + val = this->u_.val; + break; + + case DYNAMIC_SECTION_ADDRESS: + val = this->u_.od->address(); + break; + + case DYNAMIC_SECTION_SIZE: + val = this->u_.od->data_size(); + break; + + case DYNAMIC_SYMBOL: + { + const Sized_symbol<size>* s = + static_cast<const Sized_symbol<size>*>(this->u_.sym); + val = s->value(); + } + break; + + case DYNAMIC_STRING: + val = pool->get_offset(this->u_.str); + break; + + default: + gold_unreachable(); + } + + elfcpp::Dyn_write<size, big_endian> dw(pov); + dw.put_d_tag(this->tag_); + dw.put_d_val(val); +} + +// Output_data_dynamic methods. + +// Adjust the output section to set the entry size. + +void +Output_data_dynamic::do_adjust_output_section(Output_section* os) +{ + if (this->target_->get_size() == 32) + os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size); + else if (this->target_->get_size() == 64) + os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size); + else + gold_unreachable(); +} + +// Set the final data size. + +void +Output_data_dynamic::do_set_address(uint64_t, off_t) +{ + // Add the terminating entry. + this->add_constant(elfcpp::DT_NULL, 0); + + int dyn_size; + if (this->target_->get_size() == 32) + dyn_size = elfcpp::Elf_sizes<32>::dyn_size; + else if (this->target_->get_size() == 64) + dyn_size = elfcpp::Elf_sizes<64>::dyn_size; + else + gold_unreachable(); + this->set_data_size(this->entries_.size() * dyn_size); +} + +// Write out the dynamic entries. + +void +Output_data_dynamic::do_write(Output_file* of) +{ + if (this->target_->get_size() == 32) + { + if (this->target_->is_big_endian()) + this->sized_write<32, true>(of); + else + this->sized_write<32, false>(of); + } + else if (this->target_->get_size() == 64) + { + if (this->target_->is_big_endian()) + this->sized_write<64, true>(of); + else + this->sized_write<64, false>(of); + } + else + gold_unreachable(); +} + +template<int size, bool big_endian> +void +Output_data_dynamic::sized_write(Output_file* of) +{ + const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size; + + const off_t offset = this->offset(); + const off_t oview_size = this->data_size(); + unsigned char* const oview = of->get_output_view(offset, oview_size); + + unsigned char* pov = oview; + for (typename Dynamic_entries::const_iterator p = this->entries_.begin(); + p != this->entries_.end(); + ++p) + { + p->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)( + pov, this->pool_ SELECT_SIZE_ENDIAN(size, big_endian)); + pov += dyn_size; + } + + gold_assert(pov - oview == oview_size); + + of->write_output_view(offset, oview_size, oview); + + // We no longer need the dynamic entries. + this->entries_.clear(); +} + +// Output_section::Input_section methods. + +// Return the data size. For an input section we store the size here. +// For an Output_section_data, we have to ask it for the size. + +off_t +Output_section::Input_section::data_size() const +{ + if (this->is_input_section()) + return this->u1_.data_size; + else + return this->u2_.posd->data_size(); +} + +// Set the address and file offset. + +void +Output_section::Input_section::set_address(uint64_t addr, off_t off, + off_t secoff) +{ + if (this->is_input_section()) + this->u2_.object->set_section_offset(this->shndx_, off - secoff); + else + this->u2_.posd->set_address(addr, off); +} + +// Try to turn an input address into an output address. + +bool +Output_section::Input_section::output_address(const Relobj* object, + unsigned int shndx, + off_t offset, + uint64_t output_section_address, + uint64_t *poutput) const +{ + if (!this->is_input_section()) + return this->u2_.posd->output_address(object, shndx, offset, + output_section_address, poutput); + else + { + if (this->u2_.object != object) + return false; + off_t output_offset; + Output_section* os = object->output_section(shndx, &output_offset); + gold_assert(os != NULL); + *poutput = output_section_address + output_offset + offset; + return true; + } +} + +// Write out the data. We don't have to do anything for an input +// section--they are handled via Object::relocate--but this is where +// we write out the data for an Output_section_data. + +void +Output_section::Input_section::write(Output_file* of) +{ + if (!this->is_input_section()) + this->u2_.posd->write(of); +} + +// Output_section methods. + +// Construct an Output_section. NAME will point into a Stringpool. + +Output_section::Output_section(const char* name, elfcpp::Elf_Word type, + elfcpp::Elf_Xword flags) + : name_(name), + addralign_(0), + entsize_(0), + link_section_(NULL), + link_(0), + info_section_(NULL), + info_(0), + type_(type), + flags_(flags), + out_shndx_(0), + symtab_index_(0), + dynsym_index_(0), + input_sections_(), + first_input_offset_(0), + needs_symtab_index_(false), + needs_dynsym_index_(false), + should_link_to_symtab_(false), + should_link_to_dynsym_(false) +{ +} + +Output_section::~Output_section() +{ +} + +// Set the entry size. + +void +Output_section::set_entsize(uint64_t v) +{ + if (this->entsize_ == 0) + this->entsize_ = v; + else + gold_assert(this->entsize_ == v); +} + +// Add the input section SHNDX, with header SHDR, named SECNAME, in +// OBJECT, to the Output_section. Return the offset of the input +// section within the output section. We don't always keep track of +// input sections for an Output_section. Instead, each Object keeps +// track of the Output_section for each of its input sections. + +template<int size, bool big_endian> +off_t +Output_section::add_input_section(Relobj* object, unsigned int shndx, + const char* secname, + const elfcpp::Shdr<size, big_endian>& shdr) +{ + elfcpp::Elf_Xword addralign = shdr.get_sh_addralign(); + if ((addralign & (addralign - 1)) != 0) + { + fprintf(stderr, _("%s: %s: invalid alignment %lu for section \"%s\"\n"), + program_name, object->name().c_str(), + static_cast<unsigned long>(addralign), secname); + gold_exit(false); + } + + if (addralign > this->addralign_) + this->addralign_ = addralign; + + // If this is a SHF_MERGE section, we pass all the input sections to + // a Output_data_merge. + if ((shdr.get_sh_flags() & elfcpp::SHF_MERGE) != 0) + { + if (this->add_merge_input_section(object, shndx, shdr.get_sh_flags(), + shdr.get_sh_entsize(), + addralign)) + { + // Tell the relocation routines that they need to call the + // output_address method to determine the final address. + return -1; + } + } + + off_t ssize = this->data_size(); + ssize = align_address(ssize, addralign); + this->set_data_size(ssize + shdr.get_sh_size()); + + // We need to keep track of this section if we are already keeping + // track of sections, or if we are relaxing. FIXME: Add test for + // relaxing. + if (! this->input_sections_.empty()) + this->input_sections_.push_back(Input_section(object, shndx, + shdr.get_sh_size(), + addralign)); + + return ssize; +} + +// Add arbitrary data to an output section. + +void +Output_section::add_output_section_data(Output_section_data* posd) +{ + Input_section inp(posd); + this->add_output_section_data(&inp); +} + +// Add arbitrary data to an output section by Input_section. + +void +Output_section::add_output_section_data(Input_section* inp) +{ + if (this->input_sections_.empty()) + this->first_input_offset_ = this->data_size(); + + this->input_sections_.push_back(*inp); + + uint64_t addralign = inp->addralign(); + if (addralign > this->addralign_) + this->addralign_ = addralign; + + inp->set_output_section(this); +} + +// Add a merge section to an output section. + +void +Output_section::add_output_merge_section(Output_section_data* posd, + bool is_string, uint64_t entsize) +{ + Input_section inp(posd, is_string, entsize); + this->add_output_section_data(&inp); +} + +// Add an input section to a SHF_MERGE section. + +bool +Output_section::add_merge_input_section(Relobj* object, unsigned int shndx, + uint64_t flags, uint64_t entsize, + uint64_t addralign) +{ + // We only merge constants if the alignment is not more than the + // entry size. This could be handled, but it's unusual. + if (addralign > entsize) + return false; + + bool is_string = (flags & elfcpp::SHF_STRINGS) != 0; + Input_section_list::iterator p; + for (p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + if (p->is_merge_section(is_string, entsize)) + break; + + // We handle the actual constant merging in Output_merge_data or + // Output_merge_string_data. + if (p != this->input_sections_.end()) + p->add_input_section(object, shndx); + else + { + Output_section_data* posd; + if (!is_string) + posd = new Output_merge_data(entsize); + else if (entsize == 1) + posd = new Output_merge_string<char>(); + else if (entsize == 2) + posd = new Output_merge_string<uint16_t>(); + else if (entsize == 4) + posd = new Output_merge_string<uint32_t>(); + else + return false; + + this->add_output_merge_section(posd, is_string, entsize); + posd->add_input_section(object, shndx); + } + + return true; +} + +// Return the output virtual address of OFFSET relative to the start +// of input section SHNDX in object OBJECT. + +uint64_t +Output_section::output_address(const Relobj* object, unsigned int shndx, + off_t offset) const +{ + uint64_t addr = this->address() + this->first_input_offset_; + for (Input_section_list::const_iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + addr = align_address(addr, p->addralign()); + uint64_t output; + if (p->output_address(object, shndx, offset, addr, &output)) + return output; + addr += p->data_size(); + } + + // If we get here, it means that we don't know the mapping for this + // input section. This might happen in principle if + // add_input_section were called before add_output_section_data. + // But it should never actually happen. + + gold_unreachable(); +} + +// Set the address of an Output_section. This is where we handle +// setting the addresses of any Output_section_data objects. + +void +Output_section::do_set_address(uint64_t address, off_t startoff) +{ + if (this->input_sections_.empty()) + return; + + off_t off = startoff + this->first_input_offset_; + for (Input_section_list::iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + off = align_address(off, p->addralign()); + p->set_address(address + (off - startoff), off, startoff); + off += p->data_size(); + } + + this->set_data_size(off - startoff); +} + +// Write the section header to *OSHDR. + +template<int size, bool big_endian> +void +Output_section::write_header(const Layout* layout, + const Stringpool* secnamepool, + elfcpp::Shdr_write<size, big_endian>* oshdr) const +{ + oshdr->put_sh_name(secnamepool->get_offset(this->name_)); + oshdr->put_sh_type(this->type_); + oshdr->put_sh_flags(this->flags_); + oshdr->put_sh_addr(this->address()); + oshdr->put_sh_offset(this->offset()); + oshdr->put_sh_size(this->data_size()); + if (this->link_section_ != NULL) + oshdr->put_sh_link(this->link_section_->out_shndx()); + else if (this->should_link_to_symtab_) + oshdr->put_sh_link(layout->symtab_section()->out_shndx()); + else if (this->should_link_to_dynsym_) + oshdr->put_sh_link(layout->dynsym_section()->out_shndx()); + else + oshdr->put_sh_link(this->link_); + if (this->info_section_ != NULL) + oshdr->put_sh_info(this->info_section_->out_shndx()); + else + oshdr->put_sh_info(this->info_); + oshdr->put_sh_addralign(this->addralign_); + oshdr->put_sh_entsize(this->entsize_); +} + +// Write out the data. For input sections the data is written out by +// Object::relocate, but we have to handle Output_section_data objects +// here. + +void +Output_section::do_write(Output_file* of) +{ + for (Input_section_list::iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + p->write(of); +} + +// Output segment methods. + +Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags) + : output_data_(), + output_bss_(), + vaddr_(0), + paddr_(0), + memsz_(0), + align_(0), + offset_(0), + filesz_(0), + type_(type), + flags_(flags), + is_align_known_(false) +{ +} + +// Add an Output_section to an Output_segment. + +void +Output_segment::add_output_section(Output_section* os, + elfcpp::Elf_Word seg_flags, + bool front) +{ + gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0); + gold_assert(!this->is_align_known_); + + // Update the segment flags. + this->flags_ |= seg_flags; + + Output_segment::Output_data_list* pdl; + if (os->type() == elfcpp::SHT_NOBITS) + pdl = &this->output_bss_; + else + pdl = &this->output_data_; + + // So that PT_NOTE segments will work correctly, we need to ensure + // that all SHT_NOTE sections are adjacent. This will normally + // happen automatically, because all the SHT_NOTE input sections + // will wind up in the same output section. However, it is possible + // for multiple SHT_NOTE input sections to have different section + // flags, and thus be in different output sections, but for the + // different section flags to map into the same segment flags and + // thus the same output segment. + + // Note that while there may be many input sections in an output + // section, there are normally only a few output sections in an + // output segment. This loop is expected to be fast. + + if (os->type() == elfcpp::SHT_NOTE && !pdl->empty()) + { + Output_segment::Output_data_list::iterator p = pdl->end(); + do + { + --p; + if ((*p)->is_section_type(elfcpp::SHT_NOTE)) + { + // We don't worry about the FRONT parameter. + ++p; + pdl->insert(p, os); + return; + } + } + while (p != pdl->begin()); + } + + // Similarly, so that PT_TLS segments will work, we need to group + // SHF_TLS sections. An SHF_TLS/SHT_NOBITS section is a special + // case: we group the SHF_TLS/SHT_NOBITS sections right after the + // SHF_TLS/SHT_PROGBITS sections. This lets us set up PT_TLS + // correctly. + if ((os->flags() & elfcpp::SHF_TLS) != 0 && !this->output_data_.empty()) + { + pdl = &this->output_data_; + bool nobits = os->type() == elfcpp::SHT_NOBITS; + bool sawtls = false; + Output_segment::Output_data_list::iterator p = pdl->end(); + do + { + --p; + bool insert; + if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)) + { + sawtls = true; + // Put a NOBITS section after the first TLS section. + // But a PROGBITS section after the first TLS/PROGBITS + // section. + insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS); + } + else + { + // If we've gone past the TLS sections, but we've seen a + // TLS section, then we need to insert this section now. + insert = sawtls; + } + + if (insert) + { + // We don't worry about the FRONT parameter. + ++p; + pdl->insert(p, os); + return; + } + } + while (p != pdl->begin()); + + // There are no TLS sections yet; put this one at the requested + // location in the section list. + } + + if (front) + pdl->push_front(os); + else + pdl->push_back(os); +} + +// Add an Output_data (which is not an Output_section) to the start of +// a segment. + +void +Output_segment::add_initial_output_data(Output_data* od) +{ + gold_assert(!this->is_align_known_); + this->output_data_.push_front(od); +} + +// Return the maximum alignment of the Output_data in Output_segment. +// Once we compute this, we prohibit new sections from being added. + +uint64_t +Output_segment::addralign() +{ + if (!this->is_align_known_) + { + uint64_t addralign; + + addralign = Output_segment::maximum_alignment(&this->output_data_); + if (addralign > this->align_) + this->align_ = addralign; + + addralign = Output_segment::maximum_alignment(&this->output_bss_); + if (addralign > this->align_) + this->align_ = addralign; + + this->is_align_known_ = true; + } + + return this->align_; +} + +// Return the maximum alignment of a list of Output_data. + +uint64_t +Output_segment::maximum_alignment(const Output_data_list* pdl) +{ + uint64_t ret = 0; + for (Output_data_list::const_iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + uint64_t addralign = (*p)->addralign(); + if (addralign > ret) + ret = addralign; + } + return ret; +} + +// Set the section addresses for an Output_segment. ADDR is the +// address and *POFF is the file offset. Set the section indexes +// starting with *PSHNDX. Return the address of the immediately +// following segment. Update *POFF and *PSHNDX. + +uint64_t +Output_segment::set_section_addresses(uint64_t addr, off_t* poff, + unsigned int* pshndx) +{ + gold_assert(this->type_ == elfcpp::PT_LOAD); + + this->vaddr_ = addr; + this->paddr_ = addr; + + off_t orig_off = *poff; + this->offset_ = orig_off; + + *poff = align_address(*poff, this->addralign()); + + addr = this->set_section_list_addresses(&this->output_data_, addr, poff, + pshndx); + this->filesz_ = *poff - orig_off; + + off_t off = *poff; + + uint64_t ret = this->set_section_list_addresses(&this->output_bss_, addr, + poff, pshndx); + this->memsz_ = *poff - orig_off; + + // Ignore the file offset adjustments made by the BSS Output_data + // objects. + *poff = off; + + return ret; +} + +// Set the addresses and file offsets in a list of Output_data +// structures. + +uint64_t +Output_segment::set_section_list_addresses(Output_data_list* pdl, + uint64_t addr, off_t* poff, + unsigned int* pshndx) +{ + off_t startoff = *poff; + + off_t off = startoff; + for (Output_data_list::iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + off = align_address(off, (*p)->addralign()); + (*p)->set_address(addr + (off - startoff), off); + + // Unless this is a PT_TLS segment, we want to ignore the size + // of a SHF_TLS/SHT_NOBITS section. Such a section does not + // affect the size of a PT_LOAD segment. + if (this->type_ == elfcpp::PT_TLS + || !(*p)->is_section_flag_set(elfcpp::SHF_TLS) + || !(*p)->is_section_type(elfcpp::SHT_NOBITS)) + off += (*p)->data_size(); + + if ((*p)->is_section()) + { + (*p)->set_out_shndx(*pshndx); + ++*pshndx; + } + } + + *poff = off; + return addr + (off - startoff); +} + +// For a non-PT_LOAD segment, set the offset from the sections, if +// any. + +void +Output_segment::set_offset() +{ + gold_assert(this->type_ != elfcpp::PT_LOAD); + + if (this->output_data_.empty() && this->output_bss_.empty()) + { + this->vaddr_ = 0; + this->paddr_ = 0; + this->memsz_ = 0; + this->align_ = 0; + this->offset_ = 0; + this->filesz_ = 0; + return; + } + + const Output_data* first; + if (this->output_data_.empty()) + first = this->output_bss_.front(); + else + first = this->output_data_.front(); + this->vaddr_ = first->address(); + this->paddr_ = this->vaddr_; + this->offset_ = first->offset(); + + if (this->output_data_.empty()) + this->filesz_ = 0; + else + { + const Output_data* last_data = this->output_data_.back(); + this->filesz_ = (last_data->address() + + last_data->data_size() + - this->vaddr_); + } + + const Output_data* last; + if (this->output_bss_.empty()) + last = this->output_data_.back(); + else + last = this->output_bss_.back(); + this->memsz_ = (last->address() + + last->data_size() + - this->vaddr_); +} + +// Return the number of Output_sections in an Output_segment. + +unsigned int +Output_segment::output_section_count() const +{ + return (this->output_section_count_list(&this->output_data_) + + this->output_section_count_list(&this->output_bss_)); +} + +// Return the number of Output_sections in an Output_data_list. + +unsigned int +Output_segment::output_section_count_list(const Output_data_list* pdl) const +{ + unsigned int count = 0; + for (Output_data_list::const_iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + if ((*p)->is_section()) + ++count; + } + return count; +} + +// Write the segment data into *OPHDR. + +template<int size, bool big_endian> +void +Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr) +{ + ophdr->put_p_type(this->type_); + ophdr->put_p_offset(this->offset_); + ophdr->put_p_vaddr(this->vaddr_); + ophdr->put_p_paddr(this->paddr_); + ophdr->put_p_filesz(this->filesz_); + ophdr->put_p_memsz(this->memsz_); + ophdr->put_p_flags(this->flags_); + ophdr->put_p_align(this->addralign()); +} + +// Write the section headers into V. + +template<int size, bool big_endian> +unsigned char* +Output_segment::write_section_headers(const Layout* layout, + const Stringpool* secnamepool, + unsigned char* v, + unsigned int *pshndx + ACCEPT_SIZE_ENDIAN) const +{ + // Every section that is attached to a segment must be attached to a + // PT_LOAD segment, so we only write out section headers for PT_LOAD + // segments. + if (this->type_ != elfcpp::PT_LOAD) + return v; + + v = this->write_section_headers_list + SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( + layout, secnamepool, &this->output_data_, v, pshndx + SELECT_SIZE_ENDIAN(size, big_endian)); + v = this->write_section_headers_list + SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( + layout, secnamepool, &this->output_bss_, v, pshndx + SELECT_SIZE_ENDIAN(size, big_endian)); + return v; +} + +template<int size, bool big_endian> +unsigned char* +Output_segment::write_section_headers_list(const Layout* layout, + const Stringpool* secnamepool, + const Output_data_list* pdl, + unsigned char* v, + unsigned int* pshndx + ACCEPT_SIZE_ENDIAN) const +{ + const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; + for (Output_data_list::const_iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + if ((*p)->is_section()) + { + const Output_section* ps = static_cast<const Output_section*>(*p); + gold_assert(*pshndx == ps->out_shndx()); + elfcpp::Shdr_write<size, big_endian> oshdr(v); + ps->write_header(layout, secnamepool, &oshdr); + v += shdr_size; + ++*pshndx; + } + } + return v; +} + +// Output_file methods. + +Output_file::Output_file(const General_options& options) + : options_(options), + name_(options.output_file_name()), + o_(-1), + file_size_(0), + base_(NULL) +{ +} + +// Open the output file. + +void +Output_file::open(off_t file_size) +{ + this->file_size_ = file_size; + + int mode = this->options_.is_relocatable() ? 0666 : 0777; + int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode); + if (o < 0) + { + fprintf(stderr, _("%s: %s: open: %s\n"), + program_name, this->name_, strerror(errno)); + gold_exit(false); + } + this->o_ = o; + + // Write out one byte to make the file the right size. + if (::lseek(o, file_size - 1, SEEK_SET) < 0) + { + fprintf(stderr, _("%s: %s: lseek: %s\n"), + program_name, this->name_, strerror(errno)); + gold_exit(false); + } + char b = 0; + if (::write(o, &b, 1) != 1) + { + fprintf(stderr, _("%s: %s: write: %s\n"), + program_name, this->name_, strerror(errno)); + gold_exit(false); + } + + // Map the file into memory. + void* base = ::mmap(NULL, file_size, PROT_READ | PROT_WRITE, + MAP_SHARED, o, 0); + if (base == MAP_FAILED) + { + fprintf(stderr, _("%s: %s: mmap: %s\n"), + program_name, this->name_, strerror(errno)); + gold_exit(false); + } + this->base_ = static_cast<unsigned char*>(base); +} + +// Close the output file. + +void +Output_file::close() +{ + if (::munmap(this->base_, this->file_size_) < 0) + { + fprintf(stderr, _("%s: %s: munmap: %s\n"), + program_name, this->name_, strerror(errno)); + gold_exit(false); + } + this->base_ = NULL; + + if (::close(this->o_) < 0) + { + fprintf(stderr, _("%s: %s: close: %s\n"), + program_name, this->name_, strerror(errno)); + gold_exit(false); + } + this->o_ = -1; +} + +// Instantiate the templates we need. We could use the configure +// script to restrict this to only the ones for implemented targets. + +template +off_t +Output_section::add_input_section<32, false>( + Relobj* object, + unsigned int shndx, + const char* secname, + const elfcpp::Shdr<32, false>& shdr); + +template +off_t +Output_section::add_input_section<32, true>( + Relobj* object, + unsigned int shndx, + const char* secname, + const elfcpp::Shdr<32, true>& shdr); + +template +off_t +Output_section::add_input_section<64, false>( + Relobj* object, + unsigned int shndx, + const char* secname, + const elfcpp::Shdr<64, false>& shdr); + +template +off_t +Output_section::add_input_section<64, true>( + Relobj* object, + unsigned int shndx, + const char* secname, + const elfcpp::Shdr<64, true>& shdr); + +template +class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>; + +template +class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>; + +template +class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>; + +template +class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>; + +template +class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>; + +template +class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>; + +template +class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>; + +template +class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>; + +template +class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>; + +template +class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>; + +template +class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>; + +template +class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>; + +template +class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>; + +template +class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>; + +template +class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>; + +template +class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>; + +template +class Output_data_got<32, false>; + +template +class Output_data_got<32, true>; + +template +class Output_data_got<64, false>; + +template +class Output_data_got<64, true>; + +} // End namespace gold. + |