X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Foutput.cc;h=61e5c8750498a20185d075e10d5b381ff0903eb9;hb=1ae4d23b731a2a5fa5d688bc255d52e7f1eb9232;hp=f0d7985732db40a8c58ae87354f576ff74091958;hpb=16649710df23ad9038e0057035882a92e783f7e6;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/output.cc b/gold/output.cc index f0d7985732..61e5c87504 100644 --- a/gold/output.cc +++ b/gold/output.cc @@ -1,25 +1,68 @@ // output.cc -- manage the output file for gold +// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Written by Ian Lance Taylor . + +// 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 +#include #include #include #include #include +#include #include +#include "libiberty.h" +#include "parameters.h" #include "object.h" #include "symtab.h" #include "reloc.h" +#include "merge.h" +#include "descriptors.h" #include "output.h" +// Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS +#ifndef MAP_ANONYMOUS +# define MAP_ANONYMOUS MAP_ANON +#endif + +#ifndef HAVE_POSIX_FALLOCATE +// A dummy, non general, version of posix_fallocate. Here we just set +// the file size and hope that there is enough disk space. FIXME: We +// could allocate disk space by walking block by block and writing a +// zero byte into each block. +static int +posix_fallocate(int o, off_t offset, off_t len) +{ + return ftruncate(o, offset + len); +} +#endif // !defined(HAVE_POSIX_FALLOCATE) + namespace gold { // Output_data variables. -bool Output_data::sizes_are_fixed; +bool Output_data::allocated_sizes_are_fixed; // Output_data methods. @@ -27,22 +70,19 @@ Output_data::~Output_data() { } -// Set the address and offset. +// Return the default alignment for the target size. -void -Output_data::set_address(uint64_t addr, off_t off) +uint64_t +Output_data::default_alignment() { - this->address_ = addr; - this->offset_ = off; - - // Let the child class know. - this->do_set_address(addr, off); + return Output_data::default_alignment_for_size( + parameters->target().get_size()); } // Return the default alignment for a size--32 or 64. uint64_t -Output_data::default_alignment(int size) +Output_data::default_alignment_for_size(int size) { if (size == 32) return 4; @@ -56,28 +96,49 @@ Output_data::default_alignment(int size) // 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* section_list, const Layout::Section_list* unattached_section_list, - const Stringpool* secnamepool) - : size_(size), - big_endian_(big_endian), - layout_(layout), + const Stringpool* secnamepool, + const Output_section* shstrtab_section) + : layout_(layout), segment_list_(segment_list), + section_list_(section_list), unattached_section_list_(unattached_section_list), - secnamepool_(secnamepool) + secnamepool_(secnamepool), + shstrtab_section_(shstrtab_section) +{ +} + +// Compute the current data size. + +off_t +Output_section_headers::do_size() const { // 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(); + if (!parameters->options().relocatable()) + { + for (Layout::Segment_list::const_iterator p = + this->segment_list_->begin(); + p != this->segment_list_->end(); + ++p) + if ((*p)->type() == elfcpp::PT_LOAD) + count += (*p)->output_section_count(); + } + else + { + for (Layout::Section_list::const_iterator p = + this->section_list_->begin(); + p != this->section_list_->end(); + ++p) + if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0) + ++count; + } + count += this->unattached_section_list_->size(); + const int size = parameters->target().get_size(); int shdr_size; if (size == 32) shdr_size = elfcpp::Elf_sizes<32>::shdr_size; @@ -86,7 +147,7 @@ Output_section_headers::Output_section_headers( else gold_unreachable(); - this->set_data_size(count * shdr_size); + return count * shdr_size; } // Write out the section headers. @@ -94,22 +155,31 @@ Output_section_headers::Output_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) + switch (parameters->size_and_endianness()) { - if (this->big_endian_) - this->do_sized_write<64, true>(of); - else - this->do_sized_write<64, false>(of); +#ifdef HAVE_TARGET_32_LITTLE + case Parameters::TARGET_32_LITTLE: + this->do_sized_write<32, false>(of); + break; +#endif +#ifdef HAVE_TARGET_32_BIG + case Parameters::TARGET_32_BIG: + this->do_sized_write<32, true>(of); + break; +#endif +#ifdef HAVE_TARGET_64_LITTLE + case Parameters::TARGET_64_LITTLE: + this->do_sized_write<64, false>(of); + break; +#endif +#ifdef HAVE_TARGET_64_BIG + case Parameters::TARGET_64_BIG: + this->do_sized_write<64, true>(of); + break; +#endif + default: + gold_unreachable(); } - else - gold_unreachable(); } template @@ -129,8 +199,20 @@ Output_section_headers::do_sized_write(Output_file* of) 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); + + size_t section_count = (this->data_size() + / elfcpp::Elf_sizes::shdr_size); + if (section_count < elfcpp::SHN_LORESERVE) + oshdr.put_sh_size(0); + else + oshdr.put_sh_size(section_count); + + unsigned int shstrndx = this->shstrtab_section_->out_shndx(); + if (shstrndx < elfcpp::SHN_LORESERVE) + oshdr.put_sh_link(0); + else + oshdr.put_sh_link(shstrndx); + oshdr.put_sh_info(0); oshdr.put_sh_addralign(0); oshdr.put_sh_entsize(0); @@ -138,18 +220,48 @@ Output_section_headers::do_sized_write(Output_file* of) 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)); + unsigned int shndx = 1; + if (!parameters->options().relocatable()) + { + for (Layout::Segment_list::const_iterator p = + this->segment_list_->begin(); + p != this->segment_list_->end(); + ++p) + v = (*p)->write_section_headers(this->layout_, + this->secnamepool_, + v, + &shndx); + } + else + { + for (Layout::Section_list::const_iterator p = + this->section_list_->begin(); + p != this->section_list_->end(); + ++p) + { + // We do unallocated sections below, except that group + // sections have to come first. + if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0 + && (*p)->type() != elfcpp::SHT_GROUP) + continue; + gold_assert(shndx == (*p)->out_shndx()); + elfcpp::Shdr_write oshdr(v); + (*p)->write_header(this->layout_, this->secnamepool_, &oshdr); + v += shdr_size; + ++shndx; + } + } + for (Layout::Section_list::const_iterator p = this->unattached_section_list_->begin(); p != this->unattached_section_list_->end(); ++p) { + // For a relocatable link, we did unallocated group sections + // above, since they have to come first. + if ((*p)->type() == elfcpp::SHT_GROUP + && parameters->options().relocatable()) + continue; gold_assert(shndx == (*p)->out_shndx()); elfcpp::Shdr_write oshdr(v); (*p)->write_header(this->layout_, this->secnamepool_, &oshdr); @@ -163,41 +275,39 @@ Output_section_headers::do_sized_write(Output_file* of) // 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) + : 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) + switch (parameters->size_and_endianness()) { - 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); +#ifdef HAVE_TARGET_32_LITTLE + case Parameters::TARGET_32_LITTLE: + this->do_sized_write<32, false>(of); + break; +#endif +#ifdef HAVE_TARGET_32_BIG + case Parameters::TARGET_32_BIG: + this->do_sized_write<32, true>(of); + break; +#endif +#ifdef HAVE_TARGET_64_LITTLE + case Parameters::TARGET_64_LITTLE: + this->do_sized_write<64, false>(of); + break; +#endif +#ifdef HAVE_TARGET_64_BIG + case Parameters::TARGET_64_BIG: + this->do_sized_write<64, true>(of); + break; +#endif + default: + gold_unreachable(); } - else - gold_unreachable(); } template @@ -206,6 +316,7 @@ Output_segment_headers::do_sized_write(Output_file* of) { const int phdr_size = elfcpp::Elf_sizes::phdr_size; off_t all_phdrs_size = this->segment_list_.size() * phdr_size; + gold_assert(all_phdrs_size == this->data_size()); unsigned char* view = of->get_output_view(this->offset(), all_phdrs_size); unsigned char* v = view; @@ -218,35 +329,40 @@ Output_segment_headers::do_sized_write(Output_file* of) v += phdr_size; } + gold_assert(v - view == all_phdrs_size); + of->write_output_view(this->offset(), all_phdrs_size, view); } +off_t +Output_segment_headers::do_size() const +{ + const int size = parameters->target().get_size(); + 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(); + + return this->segment_list_.size() * phdr_size; +} + // Output_file_header methods. -Output_file_header::Output_file_header(int size, - bool big_endian, - const General_options& options, - const Target* target, +Output_file_header::Output_file_header(const Target* target, const Symbol_table* symtab, - const Output_segment_headers* osh) - : size_(size), - big_endian_(big_endian), - options_(options), - target_(target), + const Output_segment_headers* osh, + const char* entry) + : target_(target), symtab_(symtab), segment_header_(osh), section_header_(NULL), - shstrtab_(NULL) + shstrtab_(NULL), + entry_(entry) { - 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); + this->set_data_size(this->do_size()); } // Set the section table information for a file header. @@ -264,22 +380,33 @@ Output_file_header::set_section_info(const Output_section_headers* shdrs, 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) + gold_assert(this->offset() == 0); + + switch (parameters->size_and_endianness()) { - if (this->big_endian_) - this->do_sized_write<64, true>(of); - else - this->do_sized_write<64, false>(of); +#ifdef HAVE_TARGET_32_LITTLE + case Parameters::TARGET_32_LITTLE: + this->do_sized_write<32, false>(of); + break; +#endif +#ifdef HAVE_TARGET_32_BIG + case Parameters::TARGET_32_BIG: + this->do_sized_write<32, true>(of); + break; +#endif +#ifdef HAVE_TARGET_64_LITTLE + case Parameters::TARGET_64_LITTLE: + this->do_sized_write<64, false>(of); + break; +#endif +#ifdef HAVE_TARGET_64_BIG + case Parameters::TARGET_64_BIG: + this->do_sized_write<64, true>(of); + break; +#endif + default: + gold_unreachable(); } - else - gold_unreachable(); } // Write out the file header with appropriate size and endianess. @@ -310,13 +437,13 @@ Output_file_header::do_sized_write(Output_file* of) ? 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()) + if (parameters->options().relocatable()) e_type = elfcpp::ET_REL; + else if (parameters->options().output_is_position_independent()) + e_type = elfcpp::ET_DYN; else e_type = elfcpp::ET_EXEC; oehdr.put_e_type(e_type); @@ -324,38 +451,110 @@ Output_file_header::do_sized_write(Output_file* of) 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::Value_type v; - if (sym == NULL) - v = 0; + oehdr.put_e_entry(this->entry()); + + if (this->segment_header_ == NULL) + oehdr.put_e_phoff(0); else - { - Sized_symbol* 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_phoff(this->segment_header_->offset()); oehdr.put_e_shoff(this->section_header_->offset()); + oehdr.put_e_flags(this->target_->processor_specific_flags()); + oehdr.put_e_ehsize(elfcpp::Elf_sizes::ehdr_size); - // FIXME: The target needs to set the flags. - oehdr.put_e_flags(0); + if (this->segment_header_ == NULL) + { + oehdr.put_e_phentsize(0); + oehdr.put_e_phnum(0); + } + else + { + oehdr.put_e_phentsize(elfcpp::Elf_sizes::phdr_size); + oehdr.put_e_phnum(this->segment_header_->data_size() + / elfcpp::Elf_sizes::phdr_size); + } - oehdr.put_e_ehsize(elfcpp::Elf_sizes::ehdr_size); - oehdr.put_e_phentsize(elfcpp::Elf_sizes::phdr_size); - oehdr.put_e_phnum(this->segment_header_->data_size() - / elfcpp::Elf_sizes::phdr_size); oehdr.put_e_shentsize(elfcpp::Elf_sizes::shdr_size); - oehdr.put_e_shnum(this->section_header_->data_size() - / elfcpp::Elf_sizes::shdr_size); - oehdr.put_e_shstrndx(this->shstrtab_->out_shndx()); + size_t section_count = (this->section_header_->data_size() + / elfcpp::Elf_sizes::shdr_size); + + if (section_count < elfcpp::SHN_LORESERVE) + oehdr.put_e_shnum(this->section_header_->data_size() + / elfcpp::Elf_sizes::shdr_size); + else + oehdr.put_e_shnum(0); + + unsigned int shstrndx = this->shstrtab_->out_shndx(); + if (shstrndx < elfcpp::SHN_LORESERVE) + oehdr.put_e_shstrndx(this->shstrtab_->out_shndx()); + else + oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX); + + // Let the target adjust the ELF header, e.g., to set EI_OSABI in + // the e_ident field. + parameters->target().adjust_elf_header(view, ehdr_size); of->write_output_view(0, ehdr_size, view); } +// Return the value to use for the entry address. THIS->ENTRY_ is the +// symbol specified on the command line, if any. + +template +typename elfcpp::Elf_types::Elf_Addr +Output_file_header::entry() +{ + const bool should_issue_warning = (this->entry_ != NULL + && !parameters->options().relocatable() + && !parameters->options().shared()); + + // FIXME: Need to support target specific entry symbol. + const char* entry = this->entry_; + if (entry == NULL) + entry = "_start"; + + Symbol* sym = this->symtab_->lookup(entry); + + typename Sized_symbol::Value_type v; + if (sym != NULL) + { + Sized_symbol* ssym; + ssym = this->symtab_->get_sized_symbol(sym); + if (!ssym->is_defined() && should_issue_warning) + gold_warning("entry symbol '%s' exists but is not defined", entry); + v = ssym->value(); + } + else + { + // We couldn't find the entry symbol. See if we can parse it as + // a number. This supports, e.g., -e 0x1000. + char* endptr; + v = strtoull(entry, &endptr, 0); + if (*endptr != '\0') + { + if (should_issue_warning) + gold_warning("cannot find entry symbol '%s'", entry); + v = 0; + } + } + + return v; +} + +// Compute the current data size. + +off_t +Output_file_header::do_size() const +{ + const int size = parameters->target().get_size(); + if (size == 32) + return elfcpp::Elf_sizes<32>::ehdr_size; + else if (size == 64) + return elfcpp::Elf_sizes<64>::ehdr_size; + else + gold_unreachable(); +} + // Output_data_const methods. void @@ -393,13 +592,24 @@ Output_section_data::do_out_shndx() const return this->output_section_->out_shndx(); } +// Set the alignment, which means we may need to update the alignment +// of the output section. + +void +Output_section_data::set_addralign(uint64_t addralign) +{ + this->addralign_ = addralign; + if (this->output_section_ != NULL + && this->output_section_->addralign() < addralign) + this->output_section_->set_addralign(addralign); +} + // Output_data_strtab methods. -// Set the address. We don't actually care about the address, but we -// do set our final size. +// Set the final data size. void -Output_data_strtab::do_set_address(uint64_t, off_t) +Output_data_strtab::set_final_data_size() { this->strtab_->set_string_offsets(); this->set_data_size(this->strtab_->get_strtab_size()); @@ -415,6 +625,174 @@ Output_data_strtab::do_write(Output_file* of) // Output_reloc methods. +// A reloc against a global symbol. + +template +Output_reloc::Output_reloc( + Symbol* gsym, + unsigned int type, + Output_data* od, + Address address, + bool is_relative) + : address_(address), local_sym_index_(GSYM_CODE), type_(type), + is_relative_(is_relative), is_section_symbol_(false), shndx_(INVALID_CODE) +{ + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.gsym = gsym; + this->u2_.od = od; + if (dynamic) + this->set_needs_dynsym_index(); +} + +template +Output_reloc::Output_reloc( + Symbol* gsym, + unsigned int type, + Sized_relobj* relobj, + unsigned int shndx, + Address address, + bool is_relative) + : address_(address), local_sym_index_(GSYM_CODE), type_(type), + is_relative_(is_relative), is_section_symbol_(false), shndx_(shndx) +{ + gold_assert(shndx != INVALID_CODE); + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.gsym = gsym; + this->u2_.relobj = relobj; + if (dynamic) + this->set_needs_dynsym_index(); +} + +// A reloc against a local symbol. + +template +Output_reloc::Output_reloc( + Sized_relobj* relobj, + unsigned int local_sym_index, + unsigned int type, + Output_data* od, + Address address, + bool is_relative, + bool is_section_symbol) + : address_(address), local_sym_index_(local_sym_index), type_(type), + is_relative_(is_relative), is_section_symbol_(is_section_symbol), + shndx_(INVALID_CODE) +{ + gold_assert(local_sym_index != GSYM_CODE + && local_sym_index != INVALID_CODE); + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.relobj = relobj; + this->u2_.od = od; + if (dynamic) + this->set_needs_dynsym_index(); +} + +template +Output_reloc::Output_reloc( + Sized_relobj* relobj, + unsigned int local_sym_index, + unsigned int type, + unsigned int shndx, + Address address, + bool is_relative, + bool is_section_symbol) + : address_(address), local_sym_index_(local_sym_index), type_(type), + is_relative_(is_relative), is_section_symbol_(is_section_symbol), + shndx_(shndx) +{ + gold_assert(local_sym_index != GSYM_CODE + && local_sym_index != INVALID_CODE); + gold_assert(shndx != INVALID_CODE); + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.relobj = relobj; + this->u2_.relobj = relobj; + if (dynamic) + this->set_needs_dynsym_index(); +} + +// A reloc against the STT_SECTION symbol of an output section. + +template +Output_reloc::Output_reloc( + Output_section* os, + unsigned int type, + Output_data* od, + Address address) + : address_(address), local_sym_index_(SECTION_CODE), type_(type), + is_relative_(false), is_section_symbol_(true), shndx_(INVALID_CODE) +{ + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.os = os; + this->u2_.od = od; + if (dynamic) + this->set_needs_dynsym_index(); + else + os->set_needs_symtab_index(); +} + +template +Output_reloc::Output_reloc( + Output_section* os, + unsigned int type, + Sized_relobj* relobj, + unsigned int shndx, + Address address) + : address_(address), local_sym_index_(SECTION_CODE), type_(type), + is_relative_(false), is_section_symbol_(true), shndx_(shndx) +{ + gold_assert(shndx != INVALID_CODE); + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.os = os; + this->u2_.relobj = relobj; + if (dynamic) + this->set_needs_dynsym_index(); + else + os->set_needs_symtab_index(); +} + +// Record that we need a dynamic symbol index for this relocation. + +template +void +Output_reloc:: +set_needs_dynsym_index() +{ + if (this->is_relative_) + return; + switch (this->local_sym_index_) + { + case INVALID_CODE: + gold_unreachable(); + + case GSYM_CODE: + this->u1_.gsym->set_needs_dynsym_entry(); + break; + + case SECTION_CODE: + this->u1_.os->set_needs_dynsym_index(); + break; + + case 0: + break; + + default: + { + const unsigned int lsi = this->local_sym_index_; + if (!this->is_section_symbol_) + this->u1_.relobj->set_needs_output_dynsym_entry(lsi); + else + this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index(); + } + break; + } +} + // Get the symbol index of a relocation. template @@ -444,45 +822,99 @@ Output_reloc::get_symbol_index() index = this->u1_.os->symtab_index(); break; + case 0: + // Relocations without symbols use a symbol index of 0. + index = 0; + 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_); + { + const unsigned int lsi = this->local_sym_index_; + if (!this->is_section_symbol_) + { + if (dynamic) + index = this->u1_.relobj->dynsym_index(lsi); + else + index = this->u1_.relobj->symtab_index(lsi); + } + else + { + Output_section* os = this->u1_.relobj->output_section(lsi); + gold_assert(os != NULL); + if (dynamic) + index = os->dynsym_index(); + else + index = os->symtab_index(); + } + } break; } gold_assert(index != -1U); return index; } -// Write out the offset and info fields of a Rel or Rela relocation -// entry. +// For a local section symbol, get the address of the offset ADDEND +// within the input section. template -template -void -Output_reloc::write_rel( - Write_rel* wr) const +typename elfcpp::Elf_types::Elf_Addr +Output_reloc:: + local_section_offset(Addend addend) const +{ + gold_assert(this->local_sym_index_ != GSYM_CODE + && this->local_sym_index_ != SECTION_CODE + && this->local_sym_index_ != INVALID_CODE + && this->is_section_symbol_); + const unsigned int lsi = this->local_sym_index_; + Output_section* os = this->u1_.relobj->output_section(lsi); + gold_assert(os != NULL); + Address offset = this->u1_.relobj->get_output_section_offset(lsi); + if (offset != invalid_address) + return offset + addend; + // This is a merge section. + offset = os->output_address(this->u1_.relobj, lsi, addend); + gold_assert(offset != invalid_address); + return offset; +} + +// Get the output address of a relocation. + +template +typename elfcpp::Elf_types::Elf_Addr +Output_reloc::get_address() const { Address address = this->address_; if (this->shndx_ != INVALID_CODE) { - off_t off; - Output_section* os = this->u2_.relobj->output_section(this->shndx_, - &off); + Output_section* os = this->u2_.relobj->output_section(this->shndx_); gold_assert(os != NULL); - address += os->address() + off; + Address off = this->u2_.relobj->get_output_section_offset(this->shndx_); + if (off != invalid_address) + address += os->address() + off; + else + { + address = os->output_address(this->u2_.relobj, this->shndx_, + address); + gold_assert(address != invalid_address); + } } else if (this->u2_.od != NULL) address += this->u2_.od->address(); - wr->put_r_offset(address); - wr->put_r_info(elfcpp::elf_r_info(this->get_symbol_index(), - this->type_)); + return address; +} + +// Write out the offset and info fields of a Rel or Rela relocation +// entry. + +template +template +void +Output_reloc::write_rel( + Write_rel* wr) const +{ + wr->put_r_offset(this->get_address()); + unsigned int sym_index = this->is_relative_ ? 0 : this->get_symbol_index(); + wr->put_r_info(elfcpp::elf_r_info(sym_index, this->type_)); } // Write out a Rel relocation. @@ -496,16 +928,93 @@ Output_reloc::write( this->write_rel(&orel); } -// Write out a Rela relocation. +// Get the value of the symbol referred to by a Rel relocation. template -void -Output_reloc::write( - unsigned char* pov) const +typename elfcpp::Elf_types::Elf_Addr +Output_reloc::symbol_value( + Addend addend) const { - elfcpp::Rela_write orel(pov); - this->rel_.write_rel(&orel); - orel.put_r_addend(this->addend_); + if (this->local_sym_index_ == GSYM_CODE) + { + const Sized_symbol* sym; + sym = static_cast*>(this->u1_.gsym); + return sym->value() + addend; + } + gold_assert(this->local_sym_index_ != SECTION_CODE + && this->local_sym_index_ != INVALID_CODE + && !this->is_section_symbol_); + const unsigned int lsi = this->local_sym_index_; + const Symbol_value* symval = this->u1_.relobj->local_symbol(lsi); + return symval->value(this->u1_.relobj, addend); +} + +// Reloc comparison. This function sorts the dynamic relocs for the +// benefit of the dynamic linker. First we sort all relative relocs +// to the front. Among relative relocs, we sort by output address. +// Among non-relative relocs, we sort by symbol index, then by output +// address. + +template +int +Output_reloc:: + compare(const Output_reloc& r2) + const +{ + if (this->is_relative_) + { + if (!r2.is_relative_) + return -1; + // Otherwise sort by reloc address below. + } + else if (r2.is_relative_) + return 1; + else + { + unsigned int sym1 = this->get_symbol_index(); + unsigned int sym2 = r2.get_symbol_index(); + if (sym1 < sym2) + return -1; + else if (sym1 > sym2) + return 1; + // Otherwise sort by reloc address. + } + + section_offset_type addr1 = this->get_address(); + section_offset_type addr2 = r2.get_address(); + if (addr1 < addr2) + return -1; + else if (addr1 > addr2) + return 1; + + // Final tie breaker, in order to generate the same output on any + // host: reloc type. + unsigned int type1 = this->type_; + unsigned int type2 = r2.type_; + if (type1 < type2) + return -1; + else if (type1 > type2) + return 1; + + // These relocs appear to be exactly the same. + return 0; +} + +// Write out a Rela relocation. + +template +void +Output_reloc::write( + unsigned char* pov) const +{ + elfcpp::Rela_write orel(pov); + this->rel_.write_rel(&orel); + Addend addend = this->addend_; + if (this->rel_.is_relative()) + addend = this->rel_.symbol_value(addend); + else if (this->rel_.is_local_section_symbol()) + addend = this->rel_.local_section_offset(addend); + orel.put_r_addend(addend); } // Output_data_reloc_base methods. @@ -540,6 +1049,13 @@ Output_data_reloc_base::do_write( const off_t oview_size = this->data_size(); unsigned char* const oview = of->get_output_view(off, oview_size); + if (this->sort_relocs_) + { + gold_assert(dynamic); + std::sort(this->relocs_.begin(), this->relocs_.end(), + Sort_relocs_comparison()); + } + unsigned char* pov = oview; for (typename Relocs::const_iterator p = this->relocs_.begin(); p != this->relocs_.end(); @@ -557,15 +1073,83 @@ Output_data_reloc_base::do_write( this->relocs_.clear(); } +// Class Output_relocatable_relocs. + +template +void +Output_relocatable_relocs::set_final_data_size() +{ + this->set_data_size(this->rr_->output_reloc_count() + * Reloc_types::reloc_size); +} + +// class Output_data_group. + +template +Output_data_group::Output_data_group( + Sized_relobj* relobj, + section_size_type entry_count, + elfcpp::Elf_Word flags, + std::vector* input_shndxes) + : Output_section_data(entry_count * 4, 4, false), + relobj_(relobj), + flags_(flags) +{ + this->input_shndxes_.swap(*input_shndxes); +} + +// Write out the section group, which means translating the section +// indexes to apply to the output file. + +template +void +Output_data_group::do_write(Output_file* of) +{ + const off_t off = this->offset(); + const section_size_type oview_size = + convert_to_section_size_type(this->data_size()); + unsigned char* const oview = of->get_output_view(off, oview_size); + + elfcpp::Elf_Word* contents = reinterpret_cast(oview); + elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_); + ++contents; + + for (std::vector::const_iterator p = + this->input_shndxes_.begin(); + p != this->input_shndxes_.end(); + ++p, ++contents) + { + Output_section* os = this->relobj_->output_section(*p); + + unsigned int output_shndx; + if (os != NULL) + output_shndx = os->out_shndx(); + else + { + this->relobj_->error(_("section group retained but " + "group element discarded")); + output_shndx = 0; + } + + elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx); + } + + size_t wrote = reinterpret_cast(contents) - oview; + gold_assert(wrote == oview_size); + + of->write_output_view(off, oview_size, oview); + + // We no longer need this information. + this->input_shndxes_.clear(); +} + // Output_data_got::Got_entry methods. // Write out the entry. template void -Output_data_got::Got_entry::write( - const General_options* options, - unsigned char* pov) const +Output_data_got::Got_entry::write(unsigned char* pov) const { Valtype val = 0; @@ -573,21 +1157,16 @@ Output_data_got::Got_entry::write( { case GSYM_CODE: { + // If the symbol is resolved locally, we need to write out the + // link-time value, which will be relocated dynamically by a + // RELATIVE relocation. 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* 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*>(gsym); - val = sgsym->value(); - } + Sized_symbol* 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*>(gsym); + val = sgsym->value(); } break; @@ -596,7 +1175,12 @@ Output_data_got::Got_entry::write( break; default: - gold_unreachable(); + { + const unsigned int lsi = this->local_sym_index_; + const Symbol_value* symval = this->u_.object->local_symbol(lsi); + val = symval->value(this->u_.object, 0); + } + break; } elfcpp::Swap::writeval(pov, val); @@ -610,17 +1194,237 @@ Output_data_got::Got_entry::write( template bool -Output_data_got::add_global(Symbol* gsym) +Output_data_got::add_global( + Symbol* gsym, + unsigned int got_type) { - if (gsym->has_got_offset()) + if (gsym->has_got_offset(got_type)) return false; this->entries_.push_back(Got_entry(gsym)); this->set_got_size(); - gsym->set_got_offset(this->last_got_offset()); + gsym->set_got_offset(got_type, this->last_got_offset()); return true; } +// Add an entry for a global symbol to the GOT, and add a dynamic +// relocation of type R_TYPE for the GOT entry. +template +void +Output_data_got::add_global_with_rel( + Symbol* gsym, + unsigned int got_type, + Rel_dyn* rel_dyn, + unsigned int r_type) +{ + if (gsym->has_got_offset(got_type)) + return; + + this->entries_.push_back(Got_entry()); + this->set_got_size(); + unsigned int got_offset = this->last_got_offset(); + gsym->set_got_offset(got_type, got_offset); + rel_dyn->add_global(gsym, r_type, this, got_offset); +} + +template +void +Output_data_got::add_global_with_rela( + Symbol* gsym, + unsigned int got_type, + Rela_dyn* rela_dyn, + unsigned int r_type) +{ + if (gsym->has_got_offset(got_type)) + return; + + this->entries_.push_back(Got_entry()); + this->set_got_size(); + unsigned int got_offset = this->last_got_offset(); + gsym->set_got_offset(got_type, got_offset); + rela_dyn->add_global(gsym, r_type, this, got_offset, 0); +} + +// Add a pair of entries for a global symbol to the GOT, and add +// dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively. +// If R_TYPE_2 == 0, add the second entry with no relocation. +template +void +Output_data_got::add_global_pair_with_rel( + Symbol* gsym, + unsigned int got_type, + Rel_dyn* rel_dyn, + unsigned int r_type_1, + unsigned int r_type_2) +{ + if (gsym->has_got_offset(got_type)) + return; + + this->entries_.push_back(Got_entry()); + unsigned int got_offset = this->last_got_offset(); + gsym->set_got_offset(got_type, got_offset); + rel_dyn->add_global(gsym, r_type_1, this, got_offset); + + this->entries_.push_back(Got_entry()); + if (r_type_2 != 0) + { + got_offset = this->last_got_offset(); + rel_dyn->add_global(gsym, r_type_2, this, got_offset); + } + + this->set_got_size(); +} + +template +void +Output_data_got::add_global_pair_with_rela( + Symbol* gsym, + unsigned int got_type, + Rela_dyn* rela_dyn, + unsigned int r_type_1, + unsigned int r_type_2) +{ + if (gsym->has_got_offset(got_type)) + return; + + this->entries_.push_back(Got_entry()); + unsigned int got_offset = this->last_got_offset(); + gsym->set_got_offset(got_type, got_offset); + rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0); + + this->entries_.push_back(Got_entry()); + if (r_type_2 != 0) + { + got_offset = this->last_got_offset(); + rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0); + } + + this->set_got_size(); +} + +// Add an entry for a local symbol to the GOT. This returns true if +// this is a new GOT entry, false if the symbol already has a GOT +// entry. + +template +bool +Output_data_got::add_local( + Sized_relobj* object, + unsigned int symndx, + unsigned int got_type) +{ + if (object->local_has_got_offset(symndx, got_type)) + return false; + + this->entries_.push_back(Got_entry(object, symndx)); + this->set_got_size(); + object->set_local_got_offset(symndx, got_type, this->last_got_offset()); + return true; +} + +// Add an entry for a local symbol to the GOT, and add a dynamic +// relocation of type R_TYPE for the GOT entry. +template +void +Output_data_got::add_local_with_rel( + Sized_relobj* object, + unsigned int symndx, + unsigned int got_type, + Rel_dyn* rel_dyn, + unsigned int r_type) +{ + if (object->local_has_got_offset(symndx, got_type)) + return; + + this->entries_.push_back(Got_entry()); + this->set_got_size(); + unsigned int got_offset = this->last_got_offset(); + object->set_local_got_offset(symndx, got_type, got_offset); + rel_dyn->add_local(object, symndx, r_type, this, got_offset); +} + +template +void +Output_data_got::add_local_with_rela( + Sized_relobj* object, + unsigned int symndx, + unsigned int got_type, + Rela_dyn* rela_dyn, + unsigned int r_type) +{ + if (object->local_has_got_offset(symndx, got_type)) + return; + + this->entries_.push_back(Got_entry()); + this->set_got_size(); + unsigned int got_offset = this->last_got_offset(); + object->set_local_got_offset(symndx, got_type, got_offset); + rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0); +} + +// Add a pair of entries for a local symbol to the GOT, and add +// dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively. +// If R_TYPE_2 == 0, add the second entry with no relocation. +template +void +Output_data_got::add_local_pair_with_rel( + Sized_relobj* object, + unsigned int symndx, + unsigned int shndx, + unsigned int got_type, + Rel_dyn* rel_dyn, + unsigned int r_type_1, + unsigned int r_type_2) +{ + if (object->local_has_got_offset(symndx, got_type)) + return; + + this->entries_.push_back(Got_entry()); + unsigned int got_offset = this->last_got_offset(); + object->set_local_got_offset(symndx, got_type, got_offset); + Output_section* os = object->output_section(shndx); + rel_dyn->add_output_section(os, r_type_1, this, got_offset); + + this->entries_.push_back(Got_entry(object, symndx)); + if (r_type_2 != 0) + { + got_offset = this->last_got_offset(); + rel_dyn->add_output_section(os, r_type_2, this, got_offset); + } + + this->set_got_size(); +} + +template +void +Output_data_got::add_local_pair_with_rela( + Sized_relobj* object, + unsigned int symndx, + unsigned int shndx, + unsigned int got_type, + Rela_dyn* rela_dyn, + unsigned int r_type_1, + unsigned int r_type_2) +{ + if (object->local_has_got_offset(symndx, got_type)) + return; + + this->entries_.push_back(Got_entry()); + unsigned int got_offset = this->last_got_offset(); + object->set_local_got_offset(symndx, got_type, got_offset); + Output_section* os = object->output_section(shndx); + rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0); + + this->entries_.push_back(Got_entry(object, symndx)); + if (r_type_2 != 0) + { + got_offset = this->last_got_offset(); + rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0); + } + + this->set_got_size(); +} + // Write out the GOT. template @@ -638,7 +1442,7 @@ Output_data_got::do_write(Output_file* of) p != this->entries_.end(); ++p) { - p->write(this->options_, pov); + p->write(pov); pov += add; } @@ -658,20 +1462,15 @@ template void Output_data_dynamic::Dynamic_entry::write( unsigned char* pov, - const Stringpool* pool - ACCEPT_SIZE_ENDIAN) const + const Stringpool* pool) const { typename elfcpp::Elf_types::Elf_WXword val; - switch (this->classification_) + switch (this->offset_) { 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; @@ -689,7 +1488,8 @@ Output_data_dynamic::Dynamic_entry::write( break; default: - gold_unreachable(); + val = this->u_.od->address() + this->offset_; + break; } elfcpp::Dyn_write dw(pov); @@ -704,9 +1504,9 @@ Output_data_dynamic::Dynamic_entry::write( void Output_data_dynamic::do_adjust_output_section(Output_section* os) { - if (this->target_->get_size() == 32) + if (parameters->target().get_size() == 32) os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size); - else if (this->target_->get_size() == 64) + else if (parameters->target().get_size() == 64) os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size); else gold_unreachable(); @@ -715,15 +1515,18 @@ Output_data_dynamic::do_adjust_output_section(Output_section* os) // Set the final data size. void -Output_data_dynamic::do_set_address(uint64_t, off_t) +Output_data_dynamic::set_final_data_size() { - // Add the terminating entry. - this->add_constant(elfcpp::DT_NULL, 0); + // Add the terminating entry if it hasn't been added. + // Because of relaxation, we can run this multiple times. + if (this->entries_.empty() + || this->entries_.rbegin()->tag() != elfcpp::DT_NULL) + this->add_constant(elfcpp::DT_NULL, 0); int dyn_size; - if (this->target_->get_size() == 32) + if (parameters->target().get_size() == 32) dyn_size = elfcpp::Elf_sizes<32>::dyn_size; - else if (this->target_->get_size() == 64) + else if (parameters->target().get_size() == 64) dyn_size = elfcpp::Elf_sizes<64>::dyn_size; else gold_unreachable(); @@ -735,22 +1538,31 @@ Output_data_dynamic::do_set_address(uint64_t, off_t) 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) + switch (parameters->size_and_endianness()) { - if (this->target_->is_big_endian()) - this->sized_write<64, true>(of); - else - this->sized_write<64, false>(of); +#ifdef HAVE_TARGET_32_LITTLE + case Parameters::TARGET_32_LITTLE: + this->sized_write<32, false>(of); + break; +#endif +#ifdef HAVE_TARGET_32_BIG + case Parameters::TARGET_32_BIG: + this->sized_write<32, true>(of); + break; +#endif +#ifdef HAVE_TARGET_64_LITTLE + case Parameters::TARGET_64_LITTLE: + this->sized_write<64, false>(of); + break; +#endif +#ifdef HAVE_TARGET_64_BIG + case Parameters::TARGET_64_BIG: + this->sized_write<64, true>(of); + break; +#endif + default: + gold_unreachable(); } - else - gold_unreachable(); } template @@ -768,8 +1580,7 @@ Output_data_dynamic::sized_write(Output_file* of) p != this->entries_.end(); ++p) { - p->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)( - pov, this->pool_ SELECT_SIZE_ENDIAN(size, big_endian)); + p->write(pov, this->pool_); pov += dyn_size; } @@ -781,6 +1592,42 @@ Output_data_dynamic::sized_write(Output_file* of) this->entries_.clear(); } +// Class Output_symtab_xindex. + +void +Output_symtab_xindex::do_write(Output_file* of) +{ + 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); + + memset(oview, 0, oview_size); + + if (parameters->target().is_big_endian()) + this->endian_do_write(oview); + else + this->endian_do_write(oview); + + of->write_output_view(offset, oview_size, oview); + + // We no longer need the data. + this->entries_.clear(); +} + +template +void +Output_symtab_xindex::endian_do_write(unsigned char* const oview) +{ + for (Xindex_entries::const_iterator p = this->entries_.begin(); + p != this->entries_.end(); + ++p) + { + unsigned int symndx = p->first; + gold_assert(symndx * 4 < this->data_size()); + elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second); + } +} + // Output_section::Input_section methods. // Return the data size. For an input section we store the size here. @@ -790,21 +1637,76 @@ off_t Output_section::Input_section::data_size() const { if (this->is_input_section()) - return this->data_size_; + return this->u1_.data_size; else - return this->u_.posd->data_size(); + 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) +Output_section::Input_section::set_address_and_file_offset( + uint64_t address, + off_t file_offset, + off_t section_file_offset) { if (this->is_input_section()) - this->u_.object->set_section_offset(this->shndx_, off - secoff); + this->u2_.object->set_section_offset(this->shndx_, + file_offset - section_file_offset); + else + this->u2_.posd->set_address_and_file_offset(address, file_offset); +} + +// Reset the address and file offset. + +void +Output_section::Input_section::reset_address_and_file_offset() +{ + if (!this->is_input_section()) + this->u2_.posd->reset_address_and_file_offset(); +} + +// Finalize the data size. + +void +Output_section::Input_section::finalize_data_size() +{ + if (!this->is_input_section()) + this->u2_.posd->finalize_data_size(); +} + +// Try to turn an input offset into an output offset. We want to +// return the output offset relative to the start of this +// Input_section in the output section. + +inline bool +Output_section::Input_section::output_offset( + const Relobj* object, + unsigned int shndx, + section_offset_type offset, + section_offset_type *poutput) const +{ + if (!this->is_input_section()) + return this->u2_.posd->output_offset(object, shndx, offset, poutput); else - this->u_.posd->set_address(addr, off); + { + if (this->shndx_ != shndx || this->u2_.object != object) + return false; + *poutput = offset; + return true; + } +} + +// Return whether this is the merge section for the input section +// SHNDX in OBJECT. + +inline bool +Output_section::Input_section::is_merge_section_for(const Relobj* object, + unsigned int shndx) const +{ + if (this->is_input_section()) + return false; + return this->u2_.posd->is_merge_section_for(object, shndx); } // Write out the data. We don't have to do anything for an input @@ -815,7 +1717,44 @@ void Output_section::Input_section::write(Output_file* of) { if (!this->is_input_section()) - this->u_.posd->write(of); + this->u2_.posd->write(of); +} + +// Write the data to a buffer. As for write(), we don't have to do +// anything for an input section. + +void +Output_section::Input_section::write_to_buffer(unsigned char* buffer) +{ + if (!this->is_input_section()) + this->u2_.posd->write_to_buffer(buffer); +} + +// Print to a map file. + +void +Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const +{ + switch (this->shndx_) + { + case OUTPUT_SECTION_CODE: + case MERGE_DATA_SECTION_CODE: + case MERGE_STRING_SECTION_CODE: + this->u2_.posd->print_to_mapfile(mapfile); + break; + + case RELAXED_INPUT_SECTION_CODE: + { + Output_relaxed_input_section* relaxed_section = + this->relaxed_input_section(); + mapfile->print_input_section(relaxed_section->relobj(), + relaxed_section->shndx()); + } + break; + default: + mapfile->print_input_section(this->u2_.object, this->shndx_); + break; + } } // Output_section methods. @@ -823,31 +1762,59 @@ Output_section::Input_section::write(Output_file* of) // 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, bool may_add_data) + elfcpp::Elf_Xword flags) : name_(name), addralign_(0), entsize_(0), + load_address_(0), link_section_(NULL), link_(0), info_section_(NULL), + info_symndx_(NULL), info_(0), type_(type), flags_(flags), - out_shndx_(0), + out_shndx_(-1U), symtab_index_(0), dynsym_index_(0), input_sections_(), first_input_offset_(0), - may_add_data_(may_add_data), + fills_(), + postprocessing_buffer_(NULL), needs_symtab_index_(false), needs_dynsym_index_(false), should_link_to_symtab_(false), - should_link_to_dynsym_(false) + should_link_to_dynsym_(false), + after_input_sections_(false), + requires_postprocessing_(false), + found_in_sections_clause_(false), + has_load_address_(false), + info_uses_section_index_(false), + may_sort_attached_input_sections_(false), + must_sort_attached_input_sections_(false), + attached_input_sections_are_sorted_(false), + is_relro_(false), + is_relro_local_(false), + is_small_section_(false), + is_large_section_(false), + tls_offset_(0), + checkpoint_(NULL), + merge_section_map_(), + merge_section_by_properties_map_(), + relaxed_input_section_map_(), + is_relaxed_input_section_map_valid_(true), + generate_code_fills_at_write_(false) { + // An unallocated section has no address. Forcing this means that + // we don't need special treatment for symbols defined in debug + // sections. + if ((flags & elfcpp::SHF_ALLOC) == 0) + this->set_address(0); } Output_section::~Output_section() { + delete this->checkpoint_; } // Set the entry size. @@ -862,87 +1829,870 @@ Output_section::set_entsize(uint64_t 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. +// OBJECT, to the Output_section. RELOC_SHNDX is the index of a +// relocation section which applies to this section, or 0 if none, or +// -1U if more than one. Return the offset of the input section +// within the output section. Return -1 if the input section will +// receive special handling. In the normal case 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. However, if HAVE_SECTIONS_SCRIPT is true, we do keep +// track of input sections here; this is used when SECTIONS appears in +// a linker script. template off_t -Output_section::add_input_section(Relobj* object, unsigned int shndx, +Output_section::add_input_section(Sized_relobj* object, + unsigned int shndx, const char* secname, - const elfcpp::Shdr& shdr) + const elfcpp::Shdr& shdr, + unsigned int reloc_shndx, + bool have_sections_script) { - gold_assert(this->may_add_data_); - 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(addralign), secname); - gold_exit(false); + object->error(_("invalid alignment %lu for section \"%s\""), + static_cast(addralign), secname); + addralign = 1; } if (addralign > this->addralign_) this->addralign_ = addralign; - 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)); + typename elfcpp::Elf_types::Elf_WXword sh_flags = shdr.get_sh_flags(); + this->update_flags_for_input_section(sh_flags); - return ssize; -} + uint64_t entsize = shdr.get_sh_entsize(); -// Add arbitrary data to an output section. + // .debug_str is a mergeable string section, but is not always so + // marked by compilers. Mark manually here so we can optimize. + if (strcmp(secname, ".debug_str") == 0) + { + sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS); + entsize = 1; + } -void -Output_section::add_output_section_data(Output_section_data* posd) + // If this is a SHF_MERGE section, we pass all the input sections to + // a Output_data_merge. We don't try to handle relocations for such + // a section. We don't try to handle empty merge sections--they + // mess up the mappings, and are useless anyhow. + if ((sh_flags & elfcpp::SHF_MERGE) != 0 + && reloc_shndx == 0 + && shdr.get_sh_size() > 0) + { + if (this->add_merge_input_section(object, shndx, sh_flags, + entsize, addralign)) + { + // Tell the relocation routines that they need to call the + // output_offset method to determine the final address. + return -1; + } + } + + off_t offset_in_section = this->current_data_size_for_child(); + off_t aligned_offset_in_section = align_address(offset_in_section, + addralign); + + // Determine if we want to delay code-fill generation until the output + // section is written. When the target is relaxing, we want to delay fill + // generating to avoid adjusting them during relaxation. + if (!this->generate_code_fills_at_write_ + && !have_sections_script + && (sh_flags & elfcpp::SHF_EXECINSTR) != 0 + && parameters->target().has_code_fill() + && parameters->target().may_relax()) + { + gold_assert(this->fills_.empty()); + this->generate_code_fills_at_write_ = true; + } + + if (aligned_offset_in_section > offset_in_section + && !this->generate_code_fills_at_write_ + && !have_sections_script + && (sh_flags & elfcpp::SHF_EXECINSTR) != 0 + && parameters->target().has_code_fill()) + { + // We need to add some fill data. Using fill_list_ when + // possible is an optimization, since we will often have fill + // sections without input sections. + off_t fill_len = aligned_offset_in_section - offset_in_section; + if (this->input_sections_.empty()) + this->fills_.push_back(Fill(offset_in_section, fill_len)); + else + { + std::string fill_data(parameters->target().code_fill(fill_len)); + Output_data_const* odc = new Output_data_const(fill_data, 1); + this->input_sections_.push_back(Input_section(odc)); + } + } + + this->set_current_data_size_for_child(aligned_offset_in_section + + 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. Also, if this is a + // section which requires sorting, or which may require sorting in + // the future, we keep track of the sections. + if (have_sections_script + || !this->input_sections_.empty() + || this->may_sort_attached_input_sections() + || this->must_sort_attached_input_sections() + || parameters->options().user_set_Map() + || parameters->target().may_relax()) + this->input_sections_.push_back(Input_section(object, shndx, + shdr.get_sh_size(), + addralign)); + + return aligned_offset_in_section; +} + +// Add arbitrary data to an output section. + +void +Output_section::add_output_section_data(Output_section_data* posd) { - gold_assert(this->may_add_data_); + Input_section inp(posd); + this->add_output_section_data(&inp); + if (posd->is_data_size_valid()) + { + off_t offset_in_section = this->current_data_size_for_child(); + off_t aligned_offset_in_section = align_address(offset_in_section, + posd->addralign()); + this->set_current_data_size_for_child(aligned_offset_in_section + + posd->data_size()); + } +} + +// Add a relaxed input section. + +void +Output_section::add_relaxed_input_section(Output_relaxed_input_section* poris) +{ + Input_section inp(poris); + this->add_output_section_data(&inp); + if (this->is_relaxed_input_section_map_valid_) + { + Input_section_specifier iss(poris->relobj(), poris->shndx()); + this->relaxed_input_section_map_[iss] = poris; + } + + // For a relaxed section, we use the current data size. Linker scripts + // get all the input sections, including relaxed one from an output + // section and add them back to them same output section to compute the + // output section size. If we do not account for sizes of relaxed input + // sections, an output section would be incorrectly sized. + off_t offset_in_section = this->current_data_size_for_child(); + off_t aligned_offset_in_section = align_address(offset_in_section, + poris->addralign()); + this->set_current_data_size_for_child(aligned_offset_in_section + + poris->current_data_size()); +} + +// 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->first_input_offset_ = this->current_data_size_for_child(); - this->input_sections_.push_back(Input_section(posd)); + this->input_sections_.push_back(*inp); - uint64_t addralign = posd->addralign(); + uint64_t addralign = inp->addralign(); if (addralign > this->addralign_) this->addralign_ = addralign; - posd->set_output_section(this); + inp->set_output_section(this); } -// Set the address of an Output_section. This is where we handle +// 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) +{ + bool is_string = (flags & elfcpp::SHF_STRINGS) != 0; + + // We only merge strings if the alignment is not more than the + // character size. This could be handled, but it's unusual. + if (is_string && addralign > entsize) + return false; + + // We cannot restore merged input section states. + gold_assert(this->checkpoint_ == NULL); + + // Look up merge sections by required properties. + Merge_section_properties msp(is_string, entsize, addralign); + Merge_section_by_properties_map::const_iterator p = + this->merge_section_by_properties_map_.find(msp); + if (p != this->merge_section_by_properties_map_.end()) + { + Output_merge_base* merge_section = p->second; + merge_section->add_input_section(object, shndx); + gold_assert(merge_section->is_string() == is_string + && merge_section->entsize() == entsize + && merge_section->addralign() == addralign); + + // Link input section to found merge section. + Input_section_specifier iss(object, shndx); + this->merge_section_map_[iss] = merge_section; + return true; + } + + // We handle the actual constant merging in Output_merge_data or + // Output_merge_string_data. + Output_merge_base* pomb; + if (!is_string) + pomb = new Output_merge_data(entsize, addralign); + else + { + switch (entsize) + { + case 1: + pomb = new Output_merge_string(addralign); + break; + case 2: + pomb = new Output_merge_string(addralign); + break; + case 4: + pomb = new Output_merge_string(addralign); + break; + default: + return false; + } + } + + // Add new merge section to this output section and link merge section + // properties to new merge section in map. + this->add_output_merge_section(pomb, is_string, entsize); + this->merge_section_by_properties_map_[msp] = pomb; + + // Add input section to new merge section and link input section to new + // merge section in map. + pomb->add_input_section(object, shndx); + Input_section_specifier iss(object, shndx); + this->merge_section_map_[iss] = pomb; + + return true; +} + +// Build a relaxation map to speed up relaxation of existing input sections. +// Look up to the first LIMIT elements in INPUT_SECTIONS. + +void +Output_section::build_relaxation_map( + const Input_section_list& input_sections, + size_t limit, + Relaxation_map* relaxation_map) const +{ + for (size_t i = 0; i < limit; ++i) + { + const Input_section& is(input_sections[i]); + if (is.is_input_section() || is.is_relaxed_input_section()) + { + Input_section_specifier iss(is.relobj(), is.shndx()); + (*relaxation_map)[iss] = i; + } + } +} + +// Convert regular input sections in INPUT_SECTIONS into relaxed input +// sections in RELAXED_SECTIONS. MAP is a prebuilt map from input section +// specifier to indices of INPUT_SECTIONS. + +void +Output_section::convert_input_sections_in_list_to_relaxed_sections( + const std::vector& relaxed_sections, + const Relaxation_map& map, + Input_section_list* input_sections) +{ + for (size_t i = 0; i < relaxed_sections.size(); ++i) + { + Output_relaxed_input_section* poris = relaxed_sections[i]; + Input_section_specifier iss(poris->relobj(), poris->shndx()); + Relaxation_map::const_iterator p = map.find(iss); + gold_assert(p != map.end()); + gold_assert((*input_sections)[p->second].is_input_section()); + (*input_sections)[p->second] = Input_section(poris); + } +} + +// Convert regular input sections into relaxed input sections. RELAXED_SECTIONS +// is a vector of pointers to Output_relaxed_input_section or its derived +// classes. The relaxed sections must correspond to existing input sections. + +void +Output_section::convert_input_sections_to_relaxed_sections( + const std::vector& relaxed_sections) +{ + gold_assert(parameters->target().may_relax()); + + // We want to make sure that restore_states does not undo the effect of + // this. If there is no checkpoint active, just search the current + // input section list and replace the sections there. If there is + // a checkpoint, also replace the sections there. + + // By default, we look at the whole list. + size_t limit = this->input_sections_.size(); + + if (this->checkpoint_ != NULL) + { + // Replace input sections with relaxed input section in the saved + // copy of the input section list. + if (this->checkpoint_->input_sections_saved()) + { + Relaxation_map map; + this->build_relaxation_map( + *(this->checkpoint_->input_sections()), + this->checkpoint_->input_sections()->size(), + &map); + this->convert_input_sections_in_list_to_relaxed_sections( + relaxed_sections, + map, + this->checkpoint_->input_sections()); + } + else + { + // We have not copied the input section list yet. Instead, just + // look at the portion that would be saved. + limit = this->checkpoint_->input_sections_size(); + } + } + + // Convert input sections in input_section_list. + Relaxation_map map; + this->build_relaxation_map(this->input_sections_, limit, &map); + this->convert_input_sections_in_list_to_relaxed_sections( + relaxed_sections, + map, + &this->input_sections_); +} + +// Update the output section flags based on input section flags. + +void +Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags) +{ + // If we created the section with SHF_ALLOC clear, we set the + // address. If we are now setting the SHF_ALLOC flag, we need to + // undo that. + if ((this->flags_ & elfcpp::SHF_ALLOC) == 0 + && (flags & elfcpp::SHF_ALLOC) != 0) + this->mark_address_invalid(); + + this->flags_ |= (flags + & (elfcpp::SHF_WRITE + | elfcpp::SHF_ALLOC + | elfcpp::SHF_EXECINSTR)); +} + +// Find the merge section into which an input section with index SHNDX in +// OBJECT has been added. Return NULL if none found. + +Output_section_data* +Output_section::find_merge_section(const Relobj* object, + unsigned int shndx) const +{ + Input_section_specifier iss(object, shndx); + Output_section_data_by_input_section_map::const_iterator p = + this->merge_section_map_.find(iss); + if (p != this->merge_section_map_.end()) + { + Output_section_data* posd = p->second; + gold_assert(posd->is_merge_section_for(object, shndx)); + return posd; + } + else + return NULL; +} + +// Find an relaxed input section corresponding to an input section +// in OBJECT with index SHNDX. + +const Output_section_data* +Output_section::find_relaxed_input_section(const Relobj* object, + unsigned int shndx) const +{ + // Be careful that the map may not be valid due to input section export + // to scripts or a check-point restore. + if (!this->is_relaxed_input_section_map_valid_) + { + // Rebuild the map as needed. + this->relaxed_input_section_map_.clear(); + for (Input_section_list::const_iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + if (p->is_relaxed_input_section()) + { + Input_section_specifier iss(p->relobj(), p->shndx()); + this->relaxed_input_section_map_[iss] = + p->relaxed_input_section(); + } + this->is_relaxed_input_section_map_valid_ = true; + } + + Input_section_specifier iss(object, shndx); + Output_section_data_by_input_section_map::const_iterator p = + this->relaxed_input_section_map_.find(iss); + if (p != this->relaxed_input_section_map_.end()) + return p->second; + else + return NULL; +} + +// Given an address OFFSET relative to the start of input section +// SHNDX in OBJECT, return whether this address is being included in +// the final link. This should only be called if SHNDX in OBJECT has +// a special mapping. + +bool +Output_section::is_input_address_mapped(const Relobj* object, + unsigned int shndx, + off_t offset) const +{ + // Look at the Output_section_data_maps first. + const Output_section_data* posd = this->find_merge_section(object, shndx); + if (posd == NULL) + posd = this->find_relaxed_input_section(object, shndx); + + if (posd != NULL) + { + section_offset_type output_offset; + bool found = posd->output_offset(object, shndx, offset, &output_offset); + gold_assert(found); + return output_offset != -1; + } + + // Fall back to the slow look-up. + for (Input_section_list::const_iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + section_offset_type output_offset; + if (p->output_offset(object, shndx, offset, &output_offset)) + return output_offset != -1; + } + + // By default we assume that the address is mapped. This should + // only be called after we have passed all sections to Layout. At + // that point we should know what we are discarding. + return true; +} + +// Given an address OFFSET relative to the start of input section +// SHNDX in object OBJECT, return the output offset relative to the +// start of the input section in the output section. This should only +// be called if SHNDX in OBJECT has a special mapping. + +section_offset_type +Output_section::output_offset(const Relobj* object, unsigned int shndx, + section_offset_type offset) const +{ + // This can only be called meaningfully when we know the data size + // of this. + gold_assert(this->is_data_size_valid()); + + // Look at the Output_section_data_maps first. + const Output_section_data* posd = this->find_merge_section(object, shndx); + if (posd == NULL) + posd = this->find_relaxed_input_section(object, shndx); + if (posd != NULL) + { + section_offset_type output_offset; + bool found = posd->output_offset(object, shndx, offset, &output_offset); + gold_assert(found); + return output_offset; + } + + // Fall back to the slow look-up. + for (Input_section_list::const_iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + section_offset_type output_offset; + if (p->output_offset(object, shndx, offset, &output_offset)) + return output_offset; + } + gold_unreachable(); +} + +// 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_; + + // Look at the Output_section_data_maps first. + const Output_section_data* posd = this->find_merge_section(object, shndx); + if (posd == NULL) + posd = this->find_relaxed_input_section(object, shndx); + if (posd != NULL && posd->is_address_valid()) + { + section_offset_type output_offset; + bool found = posd->output_offset(object, shndx, offset, &output_offset); + gold_assert(found); + return posd->address() + output_offset; + } + + // Fall back to the slow look-up. + for (Input_section_list::const_iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + addr = align_address(addr, p->addralign()); + section_offset_type output_offset; + if (p->output_offset(object, shndx, offset, &output_offset)) + { + if (output_offset == -1) + return -1ULL; + return addr + output_offset; + } + 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(); +} + +// Find the output address of the start of the merged section for +// input section SHNDX in object OBJECT. + +bool +Output_section::find_starting_output_address(const Relobj* object, + unsigned int shndx, + uint64_t* paddr) const +{ + // FIXME: This becomes a bottle-neck if we have many relaxed sections. + // Looking up the merge section map does not always work as we sometimes + // find a merge section without its address set. + 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()); + + // It would be nice if we could use the existing output_offset + // method to get the output offset of input offset 0. + // Unfortunately we don't know for sure that input offset 0 is + // mapped at all. + if (p->is_merge_section_for(object, shndx)) + { + *paddr = addr; + return true; + } + + addr += p->data_size(); + } + + // We couldn't find a merge output section for this input section. + return false; +} + +// Set the data size 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) +Output_section::set_final_data_size() { if (this->input_sections_.empty()) - return; + { + this->set_data_size(this->current_data_size_for_child()); + return; + } + if (this->must_sort_attached_input_sections()) + this->sort_attached_input_sections(); + + uint64_t address = this->address(); + off_t startoff = this->offset(); 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); + p->set_address_and_file_offset(address + (off - startoff), off, + startoff); off += p->data_size(); } this->set_data_size(off - startoff); } +// Reset the address and file offset. + +void +Output_section::do_reset_address_and_file_offset() +{ + // An unallocated section has no address. Forcing this means that + // we don't need special treatment for symbols defined in debug + // sections. We do the same in the constructor. + if ((this->flags_ & elfcpp::SHF_ALLOC) == 0) + this->set_address(0); + + for (Input_section_list::iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + p->reset_address_and_file_offset(); +} + +// Return true if address and file offset have the values after reset. + +bool +Output_section::do_address_and_file_offset_have_reset_values() const +{ + if (this->is_offset_valid()) + return false; + + // An unallocated section has address 0 after its construction or a reset. + if ((this->flags_ & elfcpp::SHF_ALLOC) == 0) + return this->is_address_valid() && this->address() == 0; + else + return !this->is_address_valid(); +} + +// Set the TLS offset. Called only for SHT_TLS sections. + +void +Output_section::do_set_tls_offset(uint64_t tls_base) +{ + this->tls_offset_ = this->address() - tls_base; +} + +// In a few cases we need to sort the input sections attached to an +// output section. This is used to implement the type of constructor +// priority ordering implemented by the GNU linker, in which the +// priority becomes part of the section name and the sections are +// sorted by name. We only do this for an output section if we see an +// attached input section matching ".ctor.*", ".dtor.*", +// ".init_array.*" or ".fini_array.*". + +class Output_section::Input_section_sort_entry +{ + public: + Input_section_sort_entry() + : input_section_(), index_(-1U), section_has_name_(false), + section_name_() + { } + + Input_section_sort_entry(const Input_section& input_section, + unsigned int index) + : input_section_(input_section), index_(index), + section_has_name_(input_section.is_input_section() + || input_section.is_relaxed_input_section()) + { + if (this->section_has_name_) + { + // This is only called single-threaded from Layout::finalize, + // so it is OK to lock. Unfortunately we have no way to pass + // in a Task token. + const Task* dummy_task = reinterpret_cast(-1); + Object* obj = (input_section.is_input_section() + ? input_section.relobj() + : input_section.relaxed_input_section()->relobj()); + Task_lock_obj tl(dummy_task, obj); + + // This is a slow operation, which should be cached in + // Layout::layout if this becomes a speed problem. + this->section_name_ = obj->section_name(input_section.shndx()); + } + } + + // Return the Input_section. + const Input_section& + input_section() const + { + gold_assert(this->index_ != -1U); + return this->input_section_; + } + + // The index of this entry in the original list. This is used to + // make the sort stable. + unsigned int + index() const + { + gold_assert(this->index_ != -1U); + return this->index_; + } + + // Whether there is a section name. + bool + section_has_name() const + { return this->section_has_name_; } + + // The section name. + const std::string& + section_name() const + { + gold_assert(this->section_has_name_); + return this->section_name_; + } + + // Return true if the section name has a priority. This is assumed + // to be true if it has a dot after the initial dot. + bool + has_priority() const + { + gold_assert(this->section_has_name_); + return this->section_name_.find('.', 1); + } + + // Return true if this an input file whose base name matches + // FILE_NAME. The base name must have an extension of ".o", and + // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o". + // This is to match crtbegin.o as well as crtbeginS.o without + // getting confused by other possibilities. Overall matching the + // file name this way is a dreadful hack, but the GNU linker does it + // in order to better support gcc, and we need to be compatible. + bool + match_file_name(const char* match_file_name) const + { + const std::string& file_name(this->input_section_.relobj()->name()); + const char* base_name = lbasename(file_name.c_str()); + size_t match_len = strlen(match_file_name); + if (strncmp(base_name, match_file_name, match_len) != 0) + return false; + size_t base_len = strlen(base_name); + if (base_len != match_len + 2 && base_len != match_len + 3) + return false; + return memcmp(base_name + base_len - 2, ".o", 2) == 0; + } + + private: + // The Input_section we are sorting. + Input_section input_section_; + // The index of this Input_section in the original list. + unsigned int index_; + // Whether this Input_section has a section name--it won't if this + // is some random Output_section_data. + bool section_has_name_; + // The section name if there is one. + std::string section_name_; +}; + +// Return true if S1 should come before S2 in the output section. + +bool +Output_section::Input_section_sort_compare::operator()( + const Output_section::Input_section_sort_entry& s1, + const Output_section::Input_section_sort_entry& s2) const +{ + // crtbegin.o must come first. + bool s1_begin = s1.match_file_name("crtbegin"); + bool s2_begin = s2.match_file_name("crtbegin"); + if (s1_begin || s2_begin) + { + if (!s1_begin) + return false; + if (!s2_begin) + return true; + return s1.index() < s2.index(); + } + + // crtend.o must come last. + bool s1_end = s1.match_file_name("crtend"); + bool s2_end = s2.match_file_name("crtend"); + if (s1_end || s2_end) + { + if (!s1_end) + return true; + if (!s2_end) + return false; + return s1.index() < s2.index(); + } + + // We sort all the sections with no names to the end. + if (!s1.section_has_name() || !s2.section_has_name()) + { + if (s1.section_has_name()) + return true; + if (s2.section_has_name()) + return false; + return s1.index() < s2.index(); + } + + // A section with a priority follows a section without a priority. + // The GNU linker does this for all but .init_array sections; until + // further notice we'll assume that that is an mistake. + bool s1_has_priority = s1.has_priority(); + bool s2_has_priority = s2.has_priority(); + if (s1_has_priority && !s2_has_priority) + return false; + if (!s1_has_priority && s2_has_priority) + return true; + + // Otherwise we sort by name. + int compare = s1.section_name().compare(s2.section_name()); + if (compare != 0) + return compare < 0; + + // Otherwise we keep the input order. + return s1.index() < s2.index(); +} + +// Sort the input sections attached to an output section. + +void +Output_section::sort_attached_input_sections() +{ + if (this->attached_input_sections_are_sorted_) + return; + + if (this->checkpoint_ != NULL + && !this->checkpoint_->input_sections_saved()) + this->checkpoint_->save_input_sections(); + + // The only thing we know about an input section is the object and + // the section index. We need the section name. Recomputing this + // is slow but this is an unusual case. If this becomes a speed + // problem we can cache the names as required in Layout::layout. + + // We start by building a larger vector holding a copy of each + // Input_section, plus its current index in the list and its name. + std::vector sort_list; + + unsigned int i = 0; + for (Input_section_list::iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p, ++i) + sort_list.push_back(Input_section_sort_entry(*p, i)); + + // Sort the input sections. + std::sort(sort_list.begin(), sort_list.end(), Input_section_sort_compare()); + + // Copy the sorted input sections back to our list. + this->input_sections_.clear(); + for (std::vector::iterator p = sort_list.begin(); + p != sort_list.end(); + ++p) + this->input_sections_.push_back(p->input_section()); + + // Remember that we sorted the input sections, since we might get + // called again. + this->attached_input_sections_are_sorted_ = true; +} + // Write the section header to *OSHDR. template @@ -953,7 +2703,12 @@ Output_section::write_header(const Layout* layout, { oshdr->put_sh_name(secnamepool->get_offset(this->name_)); oshdr->put_sh_type(this->type_); - oshdr->put_sh_flags(this->flags_); + + elfcpp::Elf_Xword flags = this->flags_; + if (this->info_section_ != NULL && this->info_uses_section_index_) + flags |= elfcpp::SHF_INFO_LINK; + oshdr->put_sh_flags(flags); + oshdr->put_sh_addr(this->address()); oshdr->put_sh_offset(this->offset()); oshdr->put_sh_size(this->data_size()); @@ -965,10 +2720,21 @@ Output_section::write_header(const Layout* layout, oshdr->put_sh_link(layout->dynsym_section()->out_shndx()); else oshdr->put_sh_link(this->link_); + + elfcpp::Elf_Word info; if (this->info_section_ != NULL) - oshdr->put_sh_info(this->info_section_->out_shndx()); + { + if (this->info_uses_section_index_) + info = this->info_section_->out_shndx(); + else + info = this->info_section_->symtab_index(); + } + else if (this->info_symndx_ != NULL) + info = this->info_symndx_->symtab_index(); else - oshdr->put_sh_info(this->info_); + info = this->info_; + oshdr->put_sh_info(info); + oshdr->put_sh_addralign(this->addralign_); oshdr->put_sh_entsize(this->entsize_); } @@ -980,10 +2746,276 @@ Output_section::write_header(const Layout* layout, void Output_section::do_write(Output_file* of) { + gold_assert(!this->requires_postprocessing()); + + // If the target performs relaxation, we delay filler generation until now. + gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty()); + + off_t output_section_file_offset = this->offset(); + for (Fill_list::iterator p = this->fills_.begin(); + p != this->fills_.end(); + ++p) + { + std::string fill_data(parameters->target().code_fill(p->length())); + of->write(output_section_file_offset + p->section_offset(), + fill_data.data(), fill_data.size()); + } + + off_t off = this->offset() + this->first_input_offset_; + for (Input_section_list::iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + off_t aligned_off = align_address(off, p->addralign()); + if (this->generate_code_fills_at_write_ && (off != aligned_off)) + { + size_t fill_len = aligned_off - off; + std::string fill_data(parameters->target().code_fill(fill_len)); + of->write(off, fill_data.data(), fill_data.size()); + } + + p->write(of); + off = aligned_off + p->data_size(); + } +} + +// If a section requires postprocessing, create the buffer to use. + +void +Output_section::create_postprocessing_buffer() +{ + gold_assert(this->requires_postprocessing()); + + if (this->postprocessing_buffer_ != NULL) + return; + + if (!this->input_sections_.empty()) + { + off_t off = 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->finalize_data_size(); + off += p->data_size(); + } + this->set_current_data_size_for_child(off); + } + + off_t buffer_size = this->current_data_size_for_child(); + this->postprocessing_buffer_ = new unsigned char[buffer_size]; +} + +// Write all the data of an Output_section into the postprocessing +// buffer. This is used for sections which require postprocessing, +// such as compression. Input sections are handled by +// Object::Relocate. + +void +Output_section::write_to_postprocessing_buffer() +{ + gold_assert(this->requires_postprocessing()); + + // If the target performs relaxation, we delay filler generation until now. + gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty()); + + unsigned char* buffer = this->postprocessing_buffer(); + for (Fill_list::iterator p = this->fills_.begin(); + p != this->fills_.end(); + ++p) + { + std::string fill_data(parameters->target().code_fill(p->length())); + memcpy(buffer + p->section_offset(), fill_data.data(), + fill_data.size()); + } + + off_t off = this->first_input_offset_; + for (Input_section_list::iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + off_t aligned_off = align_address(off, p->addralign()); + if (this->generate_code_fills_at_write_ && (off != aligned_off)) + { + size_t fill_len = aligned_off - off; + std::string fill_data(parameters->target().code_fill(fill_len)); + memcpy(buffer + off, fill_data.data(), fill_data.size()); + } + + p->write_to_buffer(buffer + aligned_off); + off = aligned_off + p->data_size(); + } +} + +// Get the input sections for linker script processing. We leave +// behind the Output_section_data entries. Note that this may be +// slightly incorrect for merge sections. We will leave them behind, +// but it is possible that the script says that they should follow +// some other input sections, as in: +// .rodata { *(.rodata) *(.rodata.cst*) } +// For that matter, we don't handle this correctly: +// .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) } +// With luck this will never matter. + +uint64_t +Output_section::get_input_sections( + uint64_t address, + const std::string& fill, + std::list* input_sections) +{ + if (this->checkpoint_ != NULL + && !this->checkpoint_->input_sections_saved()) + this->checkpoint_->save_input_sections(); + + // Invalidate the relaxed input section map. + this->is_relaxed_input_section_map_valid_ = false; + + uint64_t orig_address = address; + + address = align_address(address, this->addralign()); + + Input_section_list remaining; for (Input_section_list::iterator p = this->input_sections_.begin(); p != this->input_sections_.end(); ++p) - p->write(of); + { + if (p->is_input_section()) + input_sections->push_back(Simple_input_section(p->relobj(), + p->shndx())); + else if (p->is_relaxed_input_section()) + input_sections->push_back( + Simple_input_section(p->relaxed_input_section())); + else + { + uint64_t aligned_address = align_address(address, p->addralign()); + if (aligned_address != address && !fill.empty()) + { + section_size_type length = + convert_to_section_size_type(aligned_address - address); + std::string this_fill; + this_fill.reserve(length); + while (this_fill.length() + fill.length() <= length) + this_fill += fill; + if (this_fill.length() < length) + this_fill.append(fill, 0, length - this_fill.length()); + + Output_section_data* posd = new Output_data_const(this_fill, 0); + remaining.push_back(Input_section(posd)); + } + address = aligned_address; + + remaining.push_back(*p); + + p->finalize_data_size(); + address += p->data_size(); + } + } + + this->input_sections_.swap(remaining); + this->first_input_offset_ = 0; + + uint64_t data_size = address - orig_address; + this->set_current_data_size_for_child(data_size); + return data_size; +} + +// Add an input section from a script. + +void +Output_section::add_input_section_for_script(const Simple_input_section& sis, + off_t data_size, + uint64_t addralign) +{ + if (addralign > this->addralign_) + this->addralign_ = addralign; + + off_t offset_in_section = this->current_data_size_for_child(); + off_t aligned_offset_in_section = align_address(offset_in_section, + addralign); + + this->set_current_data_size_for_child(aligned_offset_in_section + + data_size); + + Input_section is = + (sis.is_relaxed_input_section() + ? Input_section(sis.relaxed_input_section()) + : Input_section(sis.relobj(), sis.shndx(), data_size, addralign)); + this->input_sections_.push_back(is); +} + +// + +void +Output_section::save_states() +{ + gold_assert(this->checkpoint_ == NULL); + Checkpoint_output_section* checkpoint = + new Checkpoint_output_section(this->addralign_, this->flags_, + this->input_sections_, + this->first_input_offset_, + this->attached_input_sections_are_sorted_); + this->checkpoint_ = checkpoint; + gold_assert(this->fills_.empty()); +} + +void +Output_section::restore_states() +{ + gold_assert(this->checkpoint_ != NULL); + Checkpoint_output_section* checkpoint = this->checkpoint_; + + this->addralign_ = checkpoint->addralign(); + this->flags_ = checkpoint->flags(); + this->first_input_offset_ = checkpoint->first_input_offset(); + + if (!checkpoint->input_sections_saved()) + { + // If we have not copied the input sections, just resize it. + size_t old_size = checkpoint->input_sections_size(); + gold_assert(this->input_sections_.size() >= old_size); + this->input_sections_.resize(old_size); + } + else + { + // We need to copy the whole list. This is not efficient for + // extremely large output with hundreads of thousands of input + // objects. We may need to re-think how we should pass sections + // to scripts. + this->input_sections_ = *checkpoint->input_sections(); + } + + this->attached_input_sections_are_sorted_ = + checkpoint->attached_input_sections_are_sorted(); + + // Simply invalidate the relaxed input section map since we do not keep + // track of it. + this->is_relaxed_input_section_map_valid_ = false; +} + +// Print to the map file. + +void +Output_section::do_print_to_mapfile(Mapfile* mapfile) const +{ + mapfile->print_output_section(this); + + for (Input_section_list::const_iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + p->print_to_mapfile(mapfile); +} + +// Print stats for merge sections to stderr. + +void +Output_section::print_merge_stats() +{ + Input_section_list::iterator p; + for (p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + p->print_merge_stats(this->name_); } // Output segment methods. @@ -994,12 +3026,15 @@ Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags) vaddr_(0), paddr_(0), memsz_(0), - align_(0), + max_align_(0), + min_p_align_(0), offset_(0), filesz_(0), type_(type), flags_(flags), - is_align_known_(false) + is_max_align_known_(false), + are_addresses_set_(false), + is_large_data_segment_(false) { } @@ -1007,11 +3042,11 @@ Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags) void Output_segment::add_output_section(Output_section* os, - elfcpp::Elf_Word seg_flags, - bool front) + elfcpp::Elf_Word seg_flags) { gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0); - gold_assert(!this->is_align_known_); + gold_assert(!this->is_max_align_known_); + gold_assert(os->is_large_data_section() == this->is_large_data_segment()); // Update the segment flags. this->flags_ |= seg_flags; @@ -1043,7 +3078,6 @@ Output_segment::add_output_section(Output_section* os, --p; if ((*p)->is_section_type(elfcpp::SHT_NOTE)) { - // We don't worry about the FRONT parameter. ++p; pdl->insert(p, os); return; @@ -1056,50 +3090,160 @@ Output_segment::add_output_section(Output_section* os, // 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()) + // correctly. SHF_TLS sections get added to both a PT_LOAD segment + // and the PT_TLS segment -- we do this grouping only for the + // PT_LOAD segment. + if (this->type_ != elfcpp::PT_TLS + && (os->flags() & elfcpp::SHF_TLS) != 0) { pdl = &this->output_data_; - bool nobits = os->type() == elfcpp::SHT_NOBITS; - bool sawtls = false; - Output_segment::Output_data_list::iterator p = pdl->end(); - do + if (!pdl->empty()) { - --p; - bool insert; - if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)) + bool nobits = os->type() == elfcpp::SHT_NOBITS; + bool sawtls = false; + Output_segment::Output_data_list::iterator p = pdl->end(); + gold_assert(p != pdl->begin()); + do { - 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); + --p; + bool insert; + if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)) + { + sawtls = true; + // Put a NOBITS section after the first TLS section. + // Put 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) + { + ++p; + pdl->insert(p, os); + return; + } } - else + while (p != pdl->begin()); + } + + // There are no TLS sections yet; put this one at the requested + // location in the section list. + } + + // For the PT_GNU_RELRO segment, we need to group relro sections, + // and we need to put them before any non-relro sections. Also, + // relro local sections go before relro non-local sections. + if (parameters->options().relro() && os->is_relro()) + { + gold_assert(pdl == &this->output_data_); + Output_segment::Output_data_list::iterator p; + for (p = pdl->begin(); p != pdl->end(); ++p) + { + if (!(*p)->is_section()) + break; + + Output_section* pos = (*p)->output_section(); + if (!pos->is_relro() + || (os->is_relro_local() && !pos->is_relro_local())) + break; + } + + pdl->insert(p, os); + return; + } + + // Small data sections go at the end of the list of data sections. + // If OS is not small, and there are small sections, we have to + // insert it before the first small section. + if (os->type() != elfcpp::SHT_NOBITS + && !os->is_small_section() + && !pdl->empty() + && pdl->back()->is_section() + && pdl->back()->output_section()->is_small_section()) + { + for (Output_segment::Output_data_list::iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + if ((*p)->is_section() + && (*p)->output_section()->is_small_section()) + { + pdl->insert(p, os); + return; + } + } + gold_unreachable(); + } + + // A small BSS section goes at the start of the BSS sections, after + // other small BSS sections. + if (os->type() == elfcpp::SHT_NOBITS && os->is_small_section()) + { + for (Output_segment::Output_data_list::iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + if (!(*p)->is_section() + || !(*p)->output_section()->is_small_section()) { - // 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; + pdl->insert(p, os); + return; } + } + } - if (insert) + // A large BSS section goes at the end of the BSS sections, which + // means that one that is not large must come before the first large + // one. + if (os->type() == elfcpp::SHT_NOBITS + && !os->is_large_section() + && !pdl->empty() + && pdl->back()->is_section() + && pdl->back()->output_section()->is_large_section()) + { + for (Output_segment::Output_data_list::iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + if ((*p)->is_section() + && (*p)->output_section()->is_large_section()) { - // 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. + gold_unreachable(); } - if (front) - pdl->push_front(os); - else - pdl->push_back(os); + pdl->push_back(os); +} + +// Remove an Output_section from this segment. It is an error if it +// is not present. + +void +Output_segment::remove_output_section(Output_section* os) +{ + // We only need this for SHT_PROGBITS. + gold_assert(os->type() == elfcpp::SHT_PROGBITS); + for (Output_data_list::iterator p = this->output_data_.begin(); + p != this->output_data_.end(); + ++p) + { + if (*p == os) + { + this->output_data_.erase(p); + return; + } + } + gold_unreachable(); } // Add an Output_data (which is not an Output_section) to the start of @@ -1108,38 +3252,60 @@ Output_segment::add_output_section(Output_section* os, void Output_segment::add_initial_output_data(Output_data* od) { - gold_assert(!this->is_align_known_); + gold_assert(!this->is_max_align_known_); this->output_data_.push_front(od); } +// Return whether the first data section is a relro section. + +bool +Output_segment::is_first_section_relro() const +{ + return (!this->output_data_.empty() + && this->output_data_.front()->is_section() + && this->output_data_.front()->output_section()->is_relro()); +} + // 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() +Output_segment::maximum_alignment() { - if (!this->is_align_known_) + if (!this->is_max_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; + addralign = Output_segment::maximum_alignment_list(&this->output_data_); + if (addralign > this->max_align_) + this->max_align_ = addralign; + + addralign = Output_segment::maximum_alignment_list(&this->output_bss_); + if (addralign > this->max_align_) + this->max_align_ = addralign; + + // If -z relro is in effect, and the first section in this + // segment is a relro section, then the segment must be aligned + // to at least the common page size. This ensures that the + // PT_GNU_RELRO segment will start at a page boundary. + if (this->type_ == elfcpp::PT_LOAD + && parameters->options().relro() + && this->is_first_section_relro()) + { + addralign = parameters->target().common_pagesize(); + if (addralign > this->max_align_) + this->max_align_ = addralign; + } - this->is_align_known_ = true; + this->is_max_align_known_ = true; } - return this->align_; + return this->max_align_; } // Return the maximum alignment of a list of Output_data. uint64_t -Output_segment::maximum_alignment(const Output_data_list* pdl) +Output_segment::maximum_alignment_list(const Output_data_list* pdl) { uint64_t ret = 0; for (Output_data_list::const_iterator p = pdl->begin(); @@ -1153,33 +3319,90 @@ Output_segment::maximum_alignment(const Output_data_list* pdl) 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. +// Return the number of dynamic relocs applied to this segment. + +unsigned int +Output_segment::dynamic_reloc_count() const +{ + return (this->dynamic_reloc_count_list(&this->output_data_) + + this->dynamic_reloc_count_list(&this->output_bss_)); +} + +// Return the number of dynamic relocs applied to an Output_data_list. + +unsigned int +Output_segment::dynamic_reloc_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) + count += (*p)->dynamic_reloc_count(); + return count; +} + +// Set the section addresses for an Output_segment. If RESET is true, +// reset the addresses first. 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, +Output_segment::set_section_addresses(const Layout* layout, bool reset, + uint64_t addr, off_t* poff, unsigned int* pshndx) { gold_assert(this->type_ == elfcpp::PT_LOAD); - this->vaddr_ = addr; - this->paddr_ = addr; + if (!reset && this->are_addresses_set_) + { + gold_assert(this->paddr_ == addr); + addr = this->vaddr_; + } + else + { + this->vaddr_ = addr; + this->paddr_ = addr; + this->are_addresses_set_ = true; + } + + bool in_tls = false; + + bool in_relro = (parameters->options().relro() + && this->is_first_section_relro()); 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); + addr = this->set_section_list_addresses(layout, reset, &this->output_data_, + addr, poff, pshndx, &in_tls, + &in_relro); this->filesz_ = *poff - orig_off; off_t off = *poff; - uint64_t ret = this->set_section_list_addresses(&this->output_bss_, addr, - poff, pshndx); + uint64_t ret = this->set_section_list_addresses(layout, reset, + &this->output_bss_, + addr, poff, pshndx, + &in_tls, &in_relro); + + // If the last section was a TLS section, align upward to the + // alignment of the TLS segment, so that the overall size of the TLS + // segment is aligned. + if (in_tls) + { + uint64_t segment_align = layout->tls_segment()->maximum_alignment(); + *poff = align_address(*poff, segment_align); + } + + // If all the sections were relro sections, align upward to the + // common page size. + if (in_relro) + { + uint64_t page_align = parameters->target().common_pagesize(); + *poff = align_address(*poff, page_align); + } + this->memsz_ = *poff - orig_off; // Ignore the file offset adjustments made by the BSS Output_data @@ -1189,12 +3412,15 @@ Output_segment::set_section_addresses(uint64_t addr, off_t* poff, return ret; } -// Set the addresses in a list of Output_data structures. +// 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, +Output_segment::set_section_list_addresses(const Layout* layout, bool reset, + Output_data_list* pdl, uint64_t addr, off_t* poff, - unsigned int* pshndx) + unsigned int* pshndx, + bool* in_tls, bool* in_relro) { off_t startoff = *poff; @@ -1203,14 +3429,101 @@ Output_segment::set_section_list_addresses(Output_data_list* pdl, p != pdl->end(); ++p) { - off = align_address(off, (*p)->addralign()); - (*p)->set_address(addr + (off - startoff), off); + if (reset) + (*p)->reset_address_and_file_offset(); + + // When using a linker script the section will most likely + // already have an address. + if (!(*p)->is_address_valid()) + { + uint64_t align = (*p)->addralign(); + + if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)) + { + // Give the first TLS section the alignment of the + // entire TLS segment. Otherwise the TLS segment as a + // whole may be misaligned. + if (!*in_tls) + { + Output_segment* tls_segment = layout->tls_segment(); + gold_assert(tls_segment != NULL); + uint64_t segment_align = tls_segment->maximum_alignment(); + gold_assert(segment_align >= align); + align = segment_align; + + *in_tls = true; + } + } + else + { + // If this is the first section after the TLS segment, + // align it to at least the alignment of the TLS + // segment, so that the size of the overall TLS segment + // is aligned. + if (*in_tls) + { + uint64_t segment_align = + layout->tls_segment()->maximum_alignment(); + if (segment_align > align) + align = segment_align; + + *in_tls = false; + } + } + + // If this is a non-relro section after a relro section, + // align it to a common page boundary so that the dynamic + // linker has a page to mark as read-only. + if (*in_relro + && (!(*p)->is_section() + || !(*p)->output_section()->is_relro())) + { + uint64_t page_align = parameters->target().common_pagesize(); + if (page_align > align) + align = page_align; + *in_relro = false; + } + + off = align_address(off, align); + (*p)->set_address_and_file_offset(addr + (off - startoff), off); + } + else + { + // The script may have inserted a skip forward, but it + // better not have moved backward. + if ((*p)->address() >= addr + (off - startoff)) + off += (*p)->address() - (addr + (off - startoff)); + else + { + if (!layout->script_options()->saw_sections_clause()) + gold_unreachable(); + else + { + Output_section* os = (*p)->output_section(); + + // Cast to unsigned long long to avoid format warnings. + unsigned long long previous_dot = + static_cast(addr + (off - startoff)); + unsigned long long dot = + static_cast((*p)->address()); + + if (os == NULL) + gold_error(_("dot moves backward in linker script " + "from 0x%llx to 0x%llx"), previous_dot, dot); + else + gold_error(_("address of section '%s' moves backward " + "from 0x%llx to 0x%llx"), + os->name(), previous_dot, dot); + } + } + (*p)->set_file_offset(off); + (*p)->finalize_data_size(); + } - // 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) + // We want to ignore the size of a SHF_TLS or SHT_NOBITS + // section. Such a section does not affect the size of a + // PT_LOAD segment. + if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS) || !(*p)->is_section_type(elfcpp::SHT_NOBITS)) off += (*p)->data_size(); @@ -1233,12 +3546,15 @@ Output_segment::set_offset() { gold_assert(this->type_ != elfcpp::PT_LOAD); + gold_assert(!this->are_addresses_set_); + if (this->output_data_.empty() && this->output_bss_.empty()) { this->vaddr_ = 0; this->paddr_ = 0; + this->are_addresses_set_ = true; this->memsz_ = 0; - this->align_ = 0; + this->min_p_align_ = 0; this->offset_ = 0; this->filesz_ = 0; return; @@ -1250,7 +3566,10 @@ Output_segment::set_offset() else first = this->output_data_.front(); this->vaddr_ = first->address(); - this->paddr_ = this->vaddr_; + this->paddr_ = (first->has_load_address() + ? first->load_address() + : this->vaddr_); + this->are_addresses_set_ = true; this->offset_ = first->offset(); if (this->output_data_.empty()) @@ -1271,6 +3590,64 @@ Output_segment::set_offset() this->memsz_ = (last->address() + last->data_size() - this->vaddr_); + + // If this is a TLS segment, align the memory size. The code in + // set_section_list ensures that the section after the TLS segment + // is aligned to give us room. + if (this->type_ == elfcpp::PT_TLS) + { + uint64_t segment_align = this->maximum_alignment(); + gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align)); + this->memsz_ = align_address(this->memsz_, segment_align); + } + + // If this is a RELRO segment, align the memory size. The code in + // set_section_list ensures that the section after the RELRO segment + // is aligned to give us room. + if (this->type_ == elfcpp::PT_GNU_RELRO) + { + uint64_t page_align = parameters->target().common_pagesize(); + gold_assert(this->vaddr_ == align_address(this->vaddr_, page_align)); + this->memsz_ = align_address(this->memsz_, page_align); + } +} + +// Set the TLS offsets of the sections in the PT_TLS segment. + +void +Output_segment::set_tls_offsets() +{ + gold_assert(this->type_ == elfcpp::PT_TLS); + + for (Output_data_list::iterator p = this->output_data_.begin(); + p != this->output_data_.end(); + ++p) + (*p)->set_tls_offset(this->vaddr_); + + for (Output_data_list::iterator p = this->output_bss_.begin(); + p != this->output_bss_.end(); + ++p) + (*p)->set_tls_offset(this->vaddr_); +} + +// Return the address of the first section. + +uint64_t +Output_segment::first_section_load_address() const +{ + for (Output_data_list::const_iterator p = this->output_data_.begin(); + p != this->output_data_.end(); + ++p) + if ((*p)->is_section()) + return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address(); + + for (Output_data_list::const_iterator p = this->output_bss_.begin(); + p != this->output_bss_.end(); + ++p) + if ((*p)->is_section()) + return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address(); + + gold_unreachable(); } // Return the number of Output_sections in an Output_segment. @@ -1298,6 +3675,55 @@ Output_segment::output_section_count_list(const Output_data_list* pdl) const return count; } +// Return the section attached to the list segment with the lowest +// load address. This is used when handling a PHDRS clause in a +// linker script. + +Output_section* +Output_segment::section_with_lowest_load_address() const +{ + Output_section* found = NULL; + uint64_t found_lma = 0; + this->lowest_load_address_in_list(&this->output_data_, &found, &found_lma); + + Output_section* found_data = found; + this->lowest_load_address_in_list(&this->output_bss_, &found, &found_lma); + if (found != found_data && found_data != NULL) + { + gold_error(_("nobits section %s may not precede progbits section %s " + "in same segment"), + found->name(), found_data->name()); + return NULL; + } + + return found; +} + +// Look through a list for a section with a lower load address. + +void +Output_segment::lowest_load_address_in_list(const Output_data_list* pdl, + Output_section** found, + uint64_t* found_lma) const +{ + for (Output_data_list::const_iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + if (!(*p)->is_section()) + continue; + Output_section* os = static_cast(*p); + uint64_t lma = (os->has_load_address() + ? os->load_address() + : os->address()); + if (*found == NULL || lma < *found_lma) + { + *found = os; + *found_lma = lma; + } + } +} + // Write the segment data into *OPHDR. template @@ -1311,7 +3737,7 @@ Output_segment::write_header(elfcpp::Phdr_write* ophdr) ophdr->put_p_filesz(this->filesz_); ophdr->put_p_memsz(this->memsz_); ophdr->put_p_flags(this->flags_); - ophdr->put_p_align(this->addralign()); + ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment())); } // Write the section headers into V. @@ -1321,8 +3747,7 @@ unsigned char* Output_segment::write_section_headers(const Layout* layout, const Stringpool* secnamepool, unsigned char* v, - unsigned int *pshndx - ACCEPT_SIZE_ENDIAN) const + unsigned int *pshndx) 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 @@ -1330,14 +3755,12 @@ Output_segment::write_section_headers(const Layout* layout, 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)); + v = this->write_section_headers_list(layout, secnamepool, + &this->output_data_, + v, pshndx); + v = this->write_section_headers_list(layout, secnamepool, + &this->output_bss_, + v, pshndx); return v; } @@ -1347,8 +3770,7 @@ 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 + unsigned int* pshndx) const { const int shdr_size = elfcpp::Elf_sizes::shdr_size; for (Output_data_list::const_iterator p = pdl->begin(); @@ -1368,15 +3790,75 @@ Output_segment::write_section_headers_list(const Layout* layout, return v; } +// Print the output sections to the map file. + +void +Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const +{ + if (this->type() != elfcpp::PT_LOAD) + return; + this->print_section_list_to_mapfile(mapfile, &this->output_data_); + this->print_section_list_to_mapfile(mapfile, &this->output_bss_); +} + +// Print an output section list to the map file. + +void +Output_segment::print_section_list_to_mapfile(Mapfile* mapfile, + const Output_data_list* pdl) const +{ + for (Output_data_list::const_iterator p = pdl->begin(); + p != pdl->end(); + ++p) + (*p)->print_to_mapfile(mapfile); +} + // Output_file methods. -Output_file::Output_file(const General_options& options) - : options_(options), - name_(options.output_file_name()), +Output_file::Output_file(const char* name) + : name_(name), o_(-1), file_size_(0), - base_(NULL) + base_(NULL), + map_is_anonymous_(false), + is_temporary_(false) +{ +} + +// Try to open an existing file. Returns false if the file doesn't +// exist, has a size of 0 or can't be mmapped. + +bool +Output_file::open_for_modification() { + // The name "-" means "stdout". + if (strcmp(this->name_, "-") == 0) + return false; + + // Don't bother opening files with a size of zero. + struct stat s; + if (::stat(this->name_, &s) != 0 || s.st_size == 0) + return false; + + int o = open_descriptor(-1, this->name_, O_RDWR, 0); + if (o < 0) + gold_fatal(_("%s: open: %s"), this->name_, strerror(errno)); + this->o_ = o; + this->file_size_ = s.st_size; + + // If the file can't be mmapped, copying the content to an anonymous + // map will probably negate the performance benefits of incremental + // linking. This could be helped by using views and loading only + // the necessary parts, but this is not supported as of now. + if (!this->map_no_anonymous()) + { + release_descriptor(o, true); + this->o_ = -1; + this->file_size_ = 0; + return false; + } + + return true; } // Open the output file. @@ -1386,158 +3868,498 @@ 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) + // Unlink the file first; otherwise the open() may fail if the file + // is busy (e.g. it's an executable that's currently being executed). + // + // However, the linker may be part of a system where a zero-length + // file is created for it to write to, with tight permissions (gcc + // 2.95 did something like this). Unlinking the file would work + // around those permission controls, so we only unlink if the file + // has a non-zero size. We also unlink only regular files to avoid + // trouble with directories/etc. + // + // If we fail, continue; this command is merely a best-effort attempt + // to improve the odds for open(). + + // We let the name "-" mean "stdout" + if (!this->is_temporary_) { - fprintf(stderr, _("%s: %s: open: %s\n"), - program_name, this->name_, strerror(errno)); - gold_exit(false); + if (strcmp(this->name_, "-") == 0) + this->o_ = STDOUT_FILENO; + else + { + struct stat s; + if (::stat(this->name_, &s) == 0 + && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode))) + { + if (s.st_size != 0) + ::unlink(this->name_); + else if (!parameters->options().relocatable()) + { + // If we don't unlink the existing file, add execute + // permission where read permissions already exist + // and where the umask permits. + int mask = ::umask(0); + ::umask(mask); + s.st_mode |= (s.st_mode & 0444) >> 2; + ::chmod(this->name_, s.st_mode & ~mask); + } + } + + int mode = parameters->options().relocatable() ? 0666 : 0777; + int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC, + mode); + if (o < 0) + gold_fatal(_("%s: open: %s"), this->name_, strerror(errno)); + this->o_ = o; + } } - this->o_ = o; - // Write out one byte to make the file the right size. - if (::lseek(o, file_size - 1, SEEK_SET) < 0) + this->map(); +} + +// Resize the output file. + +void +Output_file::resize(off_t file_size) +{ + // If the mmap is mapping an anonymous memory buffer, this is easy: + // just mremap to the new size. If it's mapping to a file, we want + // to unmap to flush to the file, then remap after growing the file. + if (this->map_is_anonymous_) { - fprintf(stderr, _("%s: %s: lseek: %s\n"), - program_name, this->name_, strerror(errno)); - gold_exit(false); + void* base = ::mremap(this->base_, this->file_size_, file_size, + MREMAP_MAYMOVE); + if (base == MAP_FAILED) + gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno)); + this->base_ = static_cast(base); + this->file_size_ = file_size; } - char b = 0; - if (::write(o, &b, 1) != 1) + else { - fprintf(stderr, _("%s: %s: write: %s\n"), - program_name, this->name_, strerror(errno)); - gold_exit(false); + this->unmap(); + this->file_size_ = file_size; + if (!this->map_no_anonymous()) + gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno)); } +} - // Map the file into memory. - void* base = ::mmap(NULL, file_size, PROT_READ | PROT_WRITE, - MAP_SHARED, o, 0); - if (base == MAP_FAILED) +// Map an anonymous block of memory which will later be written to the +// file. Return whether the map succeeded. + +bool +Output_file::map_anonymous() +{ + void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (base != MAP_FAILED) { - fprintf(stderr, _("%s: %s: mmap: %s\n"), - program_name, this->name_, strerror(errno)); - gold_exit(false); + this->map_is_anonymous_ = true; + this->base_ = static_cast(base); + return true; } + return false; +} + +// Map the file into memory. Return whether the mapping succeeded. + +bool +Output_file::map_no_anonymous() +{ + const int o = this->o_; + + // If the output file is not a regular file, don't try to mmap it; + // instead, we'll mmap a block of memory (an anonymous buffer), and + // then later write the buffer to the file. + void* base; + struct stat statbuf; + if (o == STDOUT_FILENO || o == STDERR_FILENO + || ::fstat(o, &statbuf) != 0 + || !S_ISREG(statbuf.st_mode) + || this->is_temporary_) + return false; + + // Ensure that we have disk space available for the file. If we + // don't do this, it is possible that we will call munmap, close, + // and exit with dirty buffers still in the cache with no assigned + // disk blocks. If the disk is out of space at that point, the + // output file will wind up incomplete, but we will have already + // exited. The alternative to fallocate would be to use fdatasync, + // but that would be a more significant performance hit. + if (::posix_fallocate(o, 0, this->file_size_) < 0) + gold_fatal(_("%s: %s"), this->name_, strerror(errno)); + + // Map the file into memory. + base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE, + MAP_SHARED, o, 0); + + // The mmap call might fail because of file system issues: the file + // system might not support mmap at all, or it might not support + // mmap with PROT_WRITE. + if (base == MAP_FAILED) + return false; + + this->map_is_anonymous_ = false; this->base_ = static_cast(base); + return true; } -// Close the output file. +// Map the file into memory. void -Output_file::close() +Output_file::map() +{ + if (this->map_no_anonymous()) + return; + + // The mmap call might fail because of file system issues: the file + // system might not support mmap at all, or it might not support + // mmap with PROT_WRITE. I'm not sure which errno values we will + // see in all cases, so if the mmap fails for any reason and we + // don't care about file contents, try for an anonymous map. + if (this->map_anonymous()) + return; + + gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"), + this->name_, static_cast(this->file_size_), + strerror(errno)); +} + +// Unmap the file from memory. + +void +Output_file::unmap() { if (::munmap(this->base_, this->file_size_) < 0) - { - fprintf(stderr, _("%s: %s: munmap: %s\n"), - program_name, this->name_, strerror(errno)); - gold_exit(false); - } + gold_error(_("%s: munmap: %s"), this->name_, strerror(errno)); this->base_ = NULL; +} + +// Close the output file. - if (::close(this->o_) < 0) +void +Output_file::close() +{ + // If the map isn't file-backed, we need to write it now. + if (this->map_is_anonymous_ && !this->is_temporary_) { - fprintf(stderr, _("%s: %s: close: %s\n"), - program_name, this->name_, strerror(errno)); - gold_exit(false); + size_t bytes_to_write = this->file_size_; + size_t offset = 0; + while (bytes_to_write > 0) + { + ssize_t bytes_written = ::write(this->o_, this->base_ + offset, + bytes_to_write); + if (bytes_written == 0) + gold_error(_("%s: write: unexpected 0 return-value"), this->name_); + else if (bytes_written < 0) + gold_error(_("%s: write: %s"), this->name_, strerror(errno)); + else + { + bytes_to_write -= bytes_written; + offset += bytes_written; + } + } } + this->unmap(); + + // We don't close stdout or stderr + if (this->o_ != STDOUT_FILENO + && this->o_ != STDERR_FILENO + && !this->is_temporary_) + if (::close(this->o_) < 0) + gold_error(_("%s: close: %s"), this->name_, strerror(errno)); this->o_ = -1; } // Instantiate the templates we need. We could use the configure // script to restrict this to only the ones for implemented targets. +#ifdef HAVE_TARGET_32_LITTLE template off_t Output_section::add_input_section<32, false>( - Relobj* object, + Sized_relobj<32, false>* object, unsigned int shndx, const char* secname, - const elfcpp::Shdr<32, false>& shdr); + const elfcpp::Shdr<32, false>& shdr, + unsigned int reloc_shndx, + bool have_sections_script); +#endif +#ifdef HAVE_TARGET_32_BIG template off_t Output_section::add_input_section<32, true>( - Relobj* object, + Sized_relobj<32, true>* object, unsigned int shndx, const char* secname, - const elfcpp::Shdr<32, true>& shdr); + const elfcpp::Shdr<32, true>& shdr, + unsigned int reloc_shndx, + bool have_sections_script); +#endif +#ifdef HAVE_TARGET_64_LITTLE template off_t Output_section::add_input_section<64, false>( - Relobj* object, + Sized_relobj<64, false>* object, unsigned int shndx, const char* secname, - const elfcpp::Shdr<64, false>& shdr); + const elfcpp::Shdr<64, false>& shdr, + unsigned int reloc_shndx, + bool have_sections_script); +#endif +#ifdef HAVE_TARGET_64_BIG template off_t Output_section::add_input_section<64, true>( - Relobj* object, + Sized_relobj<64, true>* object, unsigned int shndx, const char* secname, - const elfcpp::Shdr<64, true>& shdr); + const elfcpp::Shdr<64, true>& shdr, + unsigned int reloc_shndx, + bool have_sections_script); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_32_BIG +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_64_BIG +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_32_BIG +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_64_BIG +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_32_BIG +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_64_BIG +template +class Output_reloc; +#endif +#ifdef HAVE_TARGET_32_LITTLE +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_32_BIG +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_64_BIG +template +class Output_reloc; +#endif + +#ifdef HAVE_TARGET_32_LITTLE template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_32_BIG template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_64_LITTLE template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_64_BIG template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_32_LITTLE template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_32_BIG template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_64_LITTLE template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_64_BIG template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_32_LITTLE template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_32_BIG template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_64_LITTLE template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_64_BIG template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_32_LITTLE template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_32_BIG template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_64_LITTLE template class Output_data_reloc; +#endif +#ifdef HAVE_TARGET_64_BIG template class Output_data_reloc; +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +class Output_relocatable_relocs; +#endif + +#ifdef HAVE_TARGET_32_BIG +template +class Output_relocatable_relocs; +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +class Output_relocatable_relocs; +#endif + +#ifdef HAVE_TARGET_64_BIG +template +class Output_relocatable_relocs; +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +class Output_relocatable_relocs; +#endif + +#ifdef HAVE_TARGET_32_BIG +template +class Output_relocatable_relocs; +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +class Output_relocatable_relocs; +#endif + +#ifdef HAVE_TARGET_64_BIG +template +class Output_relocatable_relocs; +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +class Output_data_group<32, false>; +#endif + +#ifdef HAVE_TARGET_32_BIG +template +class Output_data_group<32, true>; +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +class Output_data_group<64, false>; +#endif + +#ifdef HAVE_TARGET_64_BIG +template +class Output_data_group<64, true>; +#endif +#ifdef HAVE_TARGET_32_LITTLE template class Output_data_got<32, false>; +#endif +#ifdef HAVE_TARGET_32_BIG template class Output_data_got<32, true>; +#endif +#ifdef HAVE_TARGET_64_LITTLE template class Output_data_got<64, false>; +#endif +#ifdef HAVE_TARGET_64_BIG template class Output_data_got<64, true>; +#endif } // End namespace gold.