X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Foutput.cc;h=75d2fc354a55fbec400ba6a654901cb6b9df7cf5;hb=21af24c8371a3e040f6f548ddfafb20114442c28;hp=f2ec6ee906ede77e1ddd37cc908ba093aaba087e;hpb=e29e076ab80ed58ab0343c9910e02df7220233f8;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/output.cc b/gold/output.cc index f2ec6ee906..75d2fc354a 100644 --- a/gold/output.cc +++ b/gold/output.cc @@ -1,6 +1,6 @@ // output.cc -- manage the output file for gold -// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Copyright (C) 2006-2020 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -27,27 +27,131 @@ #include #include #include -#include #include #include -#include "libiberty.h" // for unlink_if_ordinary() +#ifdef HAVE_SYS_MMAN_H +#include +#endif + +#include "libiberty.h" + +#include "dwarf.h" #include "parameters.h" #include "object.h" #include "symtab.h" #include "reloc.h" #include "merge.h" #include "descriptors.h" +#include "layout.h" #include "output.h" +// For systems without mmap support. +#ifndef HAVE_MMAP +# define mmap gold_mmap +# define munmap gold_munmap +# define mremap gold_mremap +# ifndef MAP_FAILED +# define MAP_FAILED (reinterpret_cast(-1)) +# endif +# ifndef PROT_READ +# define PROT_READ 0 +# endif +# ifndef PROT_WRITE +# define PROT_WRITE 0 +# endif +# ifndef MAP_PRIVATE +# define MAP_PRIVATE 0 +# endif +# ifndef MAP_ANONYMOUS +# define MAP_ANONYMOUS 0 +# endif +# ifndef MAP_SHARED +# define MAP_SHARED 0 +# endif + +# ifndef ENOSYS +# define ENOSYS EINVAL +# endif + +static void * +gold_mmap(void *, size_t, int, int, int, off_t) +{ + errno = ENOSYS; + return MAP_FAILED; +} + +static int +gold_munmap(void *, size_t) +{ + errno = ENOSYS; + return -1; +} + +static void * +gold_mremap(void *, size_t, size_t, int) +{ + errno = ENOSYS; + return MAP_FAILED; +} + +#endif + +#if defined(HAVE_MMAP) && !defined(HAVE_MREMAP) +# define mremap gold_mremap +extern "C" void *gold_mremap(void *, size_t, size_t, int); +#endif + // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS #ifndef MAP_ANONYMOUS # define MAP_ANONYMOUS MAP_ANON #endif +#ifndef MREMAP_MAYMOVE +# define MREMAP_MAYMOVE 1 +#endif + +// Mingw does not have S_ISLNK. +#ifndef S_ISLNK +# define S_ISLNK(mode) 0 +#endif + namespace gold { +// A wrapper around posix_fallocate. If we don't have posix_fallocate, +// or the --no-posix-fallocate option is set, we try the fallocate +// system call directly. If that fails, we use ftruncate to set +// the file size and hope that there is enough disk space. + +static int +gold_fallocate(int o, off_t offset, off_t len) +{ + if (len <= 0) + return 0; + +#ifdef HAVE_POSIX_FALLOCATE + if (parameters->options().posix_fallocate()) + { + int err = ::posix_fallocate(o, offset, len); + if (err != EINVAL && err != ENOSYS && err != EOPNOTSUPP) + return err; + } +#endif // defined(HAVE_POSIX_FALLOCATE) + +#ifdef HAVE_FALLOCATE + { + int err = ::fallocate(o, 0, offset, len); + if (err != EINVAL && err != ENOSYS && err != EOPNOTSUPP) + return err; + } +#endif // defined(HAVE_FALLOCATE) + + if (::ftruncate(o, offset + len) < 0) + return errno; + return 0; +} + // Output_data variables. bool Output_data::allocated_sizes_are_fixed; @@ -96,26 +200,35 @@ Output_section_headers::Output_section_headers( unattached_section_list_(unattached_section_list), 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; if (!parameters->options().relocatable()) { - for (Layout::Segment_list::const_iterator p = segment_list->begin(); - p != segment_list->end(); + 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 = section_list->begin(); - p != section_list->end(); + 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 += unattached_section_list->size(); + count += this->unattached_section_list_->size(); const int size = parameters->target().get_size(); int shdr_size; @@ -126,7 +239,7 @@ 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. @@ -192,7 +305,9 @@ Output_section_headers::do_sized_write(Output_file* of) else oshdr.put_sh_link(shstrndx); - oshdr.put_sh_info(0); + size_t segment_count = this->segment_list_->size(); + oshdr.put_sh_info(segment_count >= elfcpp::PN_XNUM ? segment_count : 0); + oshdr.put_sh_addralign(0); oshdr.put_sh_entsize(0); } @@ -257,16 +372,7 @@ Output_segment_headers::Output_segment_headers( const Layout::Segment_list& segment_list) : segment_list_(segment_list) { - 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(); - - this->set_data_size(segment_list.size() * phdr_size); + this->set_current_data_size_for_child(this->do_size()); } void @@ -323,29 +429,33 @@ Output_segment_headers::do_sized_write(Output_file* of) 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(const Target* target, +Output_file_header::Output_file_header(Target* target, const Symbol_table* symtab, - const Output_segment_headers* osh, - const char* entry) + const Output_segment_headers* osh) : target_(target), symtab_(symtab), segment_header_(osh), section_header_(NULL), - shstrtab_(NULL), - entry_(entry) + shstrtab_(NULL) { - const int size = parameters->target().get_size(); - 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. @@ -392,7 +502,7 @@ Output_file_header::do_write(Output_file* of) } } -// Write out the file header with appropriate size and endianess. +// Write out the file header with appropriate size and endianness. template void @@ -420,13 +530,12 @@ 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; if (parameters->options().relocatable()) e_type = elfcpp::ET_REL; - else if (parameters->options().shared()) + else if (parameters->options().output_is_position_independent()) e_type = elfcpp::ET_DYN; else e_type = elfcpp::ET_EXEC; @@ -443,10 +552,7 @@ Output_file_header::do_sized_write(Output_file* of) oehdr.put_e_phoff(this->segment_header_->offset()); oehdr.put_e_shoff(this->section_header_->offset()); - - // FIXME: The target needs to set the flags. - oehdr.put_e_flags(0); - + oehdr.put_e_flags(this->target_->processor_specific_flags()); oehdr.put_e_ehsize(elfcpp::Elf_sizes::ehdr_size); if (this->segment_header_ == NULL) @@ -457,8 +563,11 @@ Output_file_header::do_sized_write(Output_file* of) else { oehdr.put_e_phentsize(elfcpp::Elf_sizes::phdr_size); - oehdr.put_e_phnum(this->segment_header_->data_size() - / elfcpp::Elf_sizes::phdr_size); + size_t phnum = (this->segment_header_->data_size() + / elfcpp::Elf_sizes::phdr_size); + if (phnum > elfcpp::PN_XNUM) + phnum = elfcpp::PN_XNUM; + oehdr.put_e_phnum(phnum); } oehdr.put_e_shentsize(elfcpp::Elf_sizes::shdr_size); @@ -477,25 +586,23 @@ Output_file_header::do_sized_write(Output_file* of) 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. + this->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. +// Return the value to use for the entry address. template typename elfcpp::Elf_types::Elf_Addr Output_file_header::entry() { - const bool should_issue_warning = (this->entry_ != NULL + const bool should_issue_warning = (parameters->options().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"; - + && !parameters->options().shared()); + const char* entry = parameters->entry(); Symbol* sym = this->symtab_->lookup(entry); typename Sized_symbol::Value_type v; @@ -524,6 +631,20 @@ Output_file_header::entry() 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 @@ -602,9 +723,12 @@ Output_reloc::Output_reloc( unsigned int type, Output_data* od, Address address, - bool is_relative) + bool is_relative, + bool is_symbolless, + bool use_plt_offset) : address_(address), local_sym_index_(GSYM_CODE), type_(type), - is_relative_(is_relative), is_section_symbol_(false), shndx_(INVALID_CODE) + is_relative_(is_relative), is_symbolless_(is_symbolless), + is_section_symbol_(false), use_plt_offset_(use_plt_offset), shndx_(INVALID_CODE) { // this->type_ is a bitfield; make sure TYPE fits. gold_assert(this->type_ == type); @@ -621,9 +745,12 @@ Output_reloc::Output_reloc( Sized_relobj* relobj, unsigned int shndx, Address address, - bool is_relative) + bool is_relative, + bool is_symbolless, + bool use_plt_offset) : address_(address), local_sym_index_(GSYM_CODE), type_(type), - is_relative_(is_relative), is_section_symbol_(false), shndx_(shndx) + is_relative_(is_relative), is_symbolless_(is_symbolless), + is_section_symbol_(false), use_plt_offset_(use_plt_offset), shndx_(shndx) { gold_assert(shndx != INVALID_CODE); // this->type_ is a bitfield; make sure TYPE fits. @@ -644,13 +771,16 @@ Output_reloc::Output_reloc( Output_data* od, Address address, bool is_relative, - bool is_section_symbol) + bool is_symbolless, + bool is_section_symbol, + bool use_plt_offset) : address_(address), local_sym_index_(local_sym_index), type_(type), - is_relative_(is_relative), is_section_symbol_(is_section_symbol), + is_relative_(is_relative), is_symbolless_(is_symbolless), + is_section_symbol_(is_section_symbol), use_plt_offset_(use_plt_offset), shndx_(INVALID_CODE) { gold_assert(local_sym_index != GSYM_CODE - && local_sym_index != INVALID_CODE); + && local_sym_index != INVALID_CODE); // this->type_ is a bitfield; make sure TYPE fits. gold_assert(this->type_ == type); this->u1_.relobj = relobj; @@ -667,13 +797,16 @@ Output_reloc::Output_reloc( unsigned int shndx, Address address, bool is_relative, - bool is_section_symbol) + bool is_symbolless, + bool is_section_symbol, + bool use_plt_offset) : address_(address), local_sym_index_(local_sym_index), type_(type), - is_relative_(is_relative), is_section_symbol_(is_section_symbol), + is_relative_(is_relative), is_symbolless_(is_symbolless), + is_section_symbol_(is_section_symbol), use_plt_offset_(use_plt_offset), shndx_(shndx) { gold_assert(local_sym_index != GSYM_CODE - && local_sym_index != INVALID_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); @@ -690,9 +823,11 @@ Output_reloc::Output_reloc( Output_section* os, unsigned int type, Output_data* od, - Address address) + Address address, + bool is_relative) : address_(address), local_sym_index_(SECTION_CODE), type_(type), - is_relative_(false), is_section_symbol_(true), shndx_(INVALID_CODE) + is_relative_(is_relative), is_symbolless_(is_relative), + is_section_symbol_(true), use_plt_offset_(false), shndx_(INVALID_CODE) { // this->type_ is a bitfield; make sure TYPE fits. gold_assert(this->type_ == type); @@ -710,9 +845,11 @@ Output_reloc::Output_reloc( unsigned int type, Sized_relobj* relobj, unsigned int shndx, - Address address) + Address address, + bool is_relative) : address_(address), local_sym_index_(SECTION_CODE), type_(type), - is_relative_(false), is_section_symbol_(true), shndx_(shndx) + is_relative_(is_relative), is_symbolless_(is_relative), + is_section_symbol_(true), use_plt_offset_(false), shndx_(shndx) { gold_assert(shndx != INVALID_CODE); // this->type_ is a bitfield; make sure TYPE fits. @@ -725,6 +862,78 @@ Output_reloc::Output_reloc( os->set_needs_symtab_index(); } +// An absolute or relative relocation. + +template +Output_reloc::Output_reloc( + unsigned int type, + Output_data* od, + Address address, + bool is_relative) + : address_(address), local_sym_index_(0), type_(type), + is_relative_(is_relative), is_symbolless_(false), + is_section_symbol_(false), use_plt_offset_(false), shndx_(INVALID_CODE) +{ + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.relobj = NULL; + this->u2_.od = od; +} + +template +Output_reloc::Output_reloc( + unsigned int type, + Sized_relobj* relobj, + unsigned int shndx, + Address address, + bool is_relative) + : address_(address), local_sym_index_(0), type_(type), + is_relative_(is_relative), is_symbolless_(false), + is_section_symbol_(false), use_plt_offset_(false), shndx_(shndx) +{ + gold_assert(shndx != INVALID_CODE); + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.relobj = NULL; + this->u2_.relobj = relobj; +} + +// A target specific relocation. + +template +Output_reloc::Output_reloc( + unsigned int type, + void* arg, + Output_data* od, + Address address) + : address_(address), local_sym_index_(TARGET_CODE), type_(type), + is_relative_(false), is_symbolless_(false), + is_section_symbol_(false), use_plt_offset_(false), shndx_(INVALID_CODE) +{ + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.arg = arg; + this->u2_.od = od; +} + +template +Output_reloc::Output_reloc( + unsigned int type, + void* arg, + Sized_relobj* relobj, + unsigned int shndx, + Address address) + : address_(address), local_sym_index_(TARGET_CODE), type_(type), + is_relative_(false), is_symbolless_(false), + is_section_symbol_(false), use_plt_offset_(false), shndx_(shndx) +{ + gold_assert(shndx != INVALID_CODE); + // this->type_ is a bitfield; make sure TYPE fits. + gold_assert(this->type_ == type); + this->u1_.arg = arg; + this->u2_.relobj = relobj; +} + // Record that we need a dynamic symbol index for this relocation. template @@ -732,7 +941,7 @@ void Output_reloc:: set_needs_dynsym_index() { - if (this->is_relative_) + if (this->is_symbolless_) return; switch (this->local_sym_index_) { @@ -747,16 +956,23 @@ set_needs_dynsym_index() this->u1_.os->set_needs_dynsym_index(); break; + case TARGET_CODE: + // The target must take care of this if necessary. + 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(); + const unsigned int lsi = this->local_sym_index_; + Sized_relobj_file* relobj = + this->u1_.relobj->sized_relobj(); + gold_assert(relobj != NULL); + if (!this->is_section_symbol_) + relobj->set_needs_output_dynsym_entry(lsi); + else + relobj->output_section(lsi)->set_needs_dynsym_index(); } break; } @@ -770,6 +986,8 @@ Output_reloc::get_symbol_index() const { unsigned int index; + if (this->is_symbolless_) + return 0; switch (this->local_sym_index_) { case INVALID_CODE: @@ -791,6 +1009,11 @@ Output_reloc::get_symbol_index() index = this->u1_.os->symtab_index(); break; + case TARGET_CODE: + index = parameters->target().reloc_symbol_index(this->u1_.arg, + this->type_); + break; + case 0: // Relocations without symbols use a symbol index of 0. index = 0; @@ -798,23 +1021,26 @@ Output_reloc::get_symbol_index() default: { - 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(); - } + const unsigned int lsi = this->local_sym_index_; + Sized_relobj_file* relobj = + this->u1_.relobj->sized_relobj(); + gold_assert(relobj != NULL); + if (!this->is_section_symbol_) + { + if (dynamic) + index = relobj->dynsym_index(lsi); + else + index = relobj->symtab_index(lsi); + } + else + { + Output_section* os = relobj->output_section(lsi); + gold_assert(os != NULL); + if (dynamic) + index = os->dynsym_index(); + else + index = os->symtab_index(); + } } break; } @@ -831,9 +1057,11 @@ 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_); + && this->local_sym_index_ != SECTION_CODE + && this->local_sym_index_ != TARGET_CODE + && this->local_sym_index_ != INVALID_CODE + && this->local_sym_index_ != 0 + && 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); @@ -841,7 +1069,10 @@ Output_reloc:: if (offset != invalid_address) return offset + addend; // This is a merge section. - offset = os->output_address(this->u1_.relobj, lsi, addend); + Sized_relobj_file* relobj = + this->u1_.relobj->sized_relobj(); + gold_assert(relobj != NULL); + offset = os->output_address(relobj, lsi, addend); gold_assert(offset != invalid_address); return offset; } @@ -862,8 +1093,10 @@ Output_reloc::get_address() const address += os->address() + off; else { - address = os->output_address(this->u2_.relobj, this->shndx_, - address); + Sized_relobj_file* relobj = + this->u2_.relobj->sized_relobj(); + gold_assert(relobj != NULL); + address = os->output_address(relobj, this->shndx_, address); gold_assert(address != invalid_address); } } @@ -882,7 +1115,7 @@ 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(); + unsigned int sym_index = this->get_symbol_index(); wr->put_r_info(elfcpp::elf_r_info(sym_index, this->type_)); } @@ -908,14 +1141,28 @@ Output_reloc::symbol_value( { const Sized_symbol* sym; sym = static_cast*>(this->u1_.gsym); - return sym->value() + addend; + if (this->use_plt_offset_ && sym->has_plt_offset()) + return parameters->target().plt_address_for_global(sym); + else + return sym->value() + addend; + } + if (this->local_sym_index_ == SECTION_CODE) + { + gold_assert(!this->use_plt_offset_); + return this->u1_.os->address() + addend; } - gold_assert(this->local_sym_index_ != SECTION_CODE - && this->local_sym_index_ != INVALID_CODE - && !this->is_section_symbol_); + gold_assert(this->local_sym_index_ != TARGET_CODE + && this->local_sym_index_ != INVALID_CODE + && this->local_sym_index_ != 0 + && !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); + Sized_relobj_file* relobj = + this->u1_.relobj->sized_relobj(); + gold_assert(relobj != NULL); + if (this->use_plt_offset_) + return parameters->target().plt_address_for_local(relobj, lsi); + const Symbol_value* symval = relobj->local_symbol(lsi); + return symval->value(relobj, addend); } // Reloc comparison. This function sorts the dynamic relocs for the @@ -979,7 +1226,10 @@ Output_reloc::write( elfcpp::Rela_write orel(pov); this->rel_.write_rel(&orel); Addend addend = this->addend_; - if (this->rel_.is_relative()) + if (this->rel_.is_target_specific()) + addend = parameters->target().reloc_addend(this->rel_.target_arg(), + this->rel_.type(), addend); + else if (this->rel_.is_symbolless()) addend = this->rel_.symbol_value(addend); else if (this->rel_.is_local_section_symbol()) addend = this->rel_.local_section_offset(addend); @@ -1001,12 +1251,32 @@ Output_data_reloc_base os->set_entsize(elfcpp::Elf_sizes::rela_size); else gold_unreachable(); - if (dynamic) - os->set_should_link_to_dynsym(); - else + + // A STT_GNU_IFUNC symbol may require a IRELATIVE reloc when doing a + // static link. The backends will generate a dynamic reloc section + // to hold this. In that case we don't want to link to the dynsym + // section, because there isn't one. + if (!dynamic) os->set_should_link_to_symtab(); + else if (parameters->doing_static_link()) + ; + else + os->set_should_link_to_dynsym(); } +// Standard relocation writer, which just calls Output_reloc::write(). + +template +struct Output_reloc_writer +{ + typedef Output_reloc Output_reloc_type; + typedef std::vector Relocs; + + static void + write(typename Relocs::const_iterator p, unsigned char* pov) + { p->write(pov); } +}; + // Write out relocation data. template @@ -1014,32 +1284,8 @@ void Output_data_reloc_base::do_write( Output_file* of) { - const off_t off = this->offset(); - const off_t oview_size = this->data_size(); - unsigned char* const oview = of->get_output_view(off, oview_size); - - 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(); - ++p) - { - p->write(pov); - pov += reloc_size; - } - - gold_assert(pov - oview == oview_size); - - of->write_output_view(off, oview_size, oview); - - // We no longer need the relocation entries. - this->relocs_.clear(); + typedef Output_reloc_writer Writer; + this->do_write_generic(of); } // Class Output_relocatable_relocs. @@ -1056,11 +1302,11 @@ Output_relocatable_relocs::set_final_data_size() template Output_data_group::Output_data_group( - Sized_relobj* relobj, + Sized_relobj_file* relobj, section_size_type entry_count, elfcpp::Elf_Word flags, std::vector* input_shndxes) - : Output_section_data(entry_count * 4, 4), + : Output_section_data(entry_count * 4, 4, false), relobj_(relobj), flags_(flags) { @@ -1116,9 +1362,11 @@ Output_data_group::do_write(Output_file* of) // Write out the entry. -template +template void -Output_data_got::Got_entry::write(unsigned char* pov) const +Output_data_got::Got_entry::write( + unsigned int got_indx, + unsigned char* pov) const { Valtype val = 0; @@ -1130,12 +1378,43 @@ Output_data_got::Got_entry::write(unsigned char* pov) const // link-time value, which will be relocated dynamically by a // RELATIVE relocation. Symbol* gsym = this->u_.gsym; - 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(); + if (this->use_plt_or_tls_offset_ && gsym->has_plt_offset()) + val = parameters->target().plt_address_for_global(gsym); + else + { + switch (parameters->size_and_endianness()) + { +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) + case Parameters::TARGET_32_LITTLE: + case Parameters::TARGET_32_BIG: + { + // This cast is ugly. We don't want to put a + // virtual method in Symbol, because we want Symbol + // to be as small as possible. + Sized_symbol<32>::Value_type v; + v = static_cast*>(gsym)->value(); + val = convert_types::Value_type>(v); + } + break; +#endif +#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) + case Parameters::TARGET_64_LITTLE: + case Parameters::TARGET_64_BIG: + { + Sized_symbol<64>::Value_type v; + v = static_cast*>(gsym)->value(); + val = convert_types::Value_type>(v); + } + break; +#endif + default: + gold_unreachable(); + } + if (this->use_plt_or_tls_offset_ + && gsym->type() == elfcpp::STT_TLS) + val += parameters->target().tls_offset_for_global(gsym, + got_indx); + } } break; @@ -1143,16 +1422,33 @@ Output_data_got::Got_entry::write(unsigned char* pov) const val = this->u_.constant; break; + case RESERVED_CODE: + // If we're doing an incremental update, don't touch this GOT entry. + if (parameters->incremental_update()) + return; + val = this->u_.constant; + break; + default: { - 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); + const Relobj* object = this->u_.object; + const unsigned int lsi = this->local_sym_index_; + bool is_tls = object->local_is_tls(lsi); + if (this->use_plt_or_tls_offset_ && !is_tls) + val = parameters->target().plt_address_for_local(object, lsi); + else + { + uint64_t lval = object->local_symbol_value(lsi, this->addend_); + val = convert_types(lval); + if (this->use_plt_or_tls_offset_ && is_tls) + val += parameters->target().tls_offset_for_local(object, lsi, + got_indx); + } } break; } - elfcpp::Swap::writeval(pov, val); + elfcpp::Swap::writeval(pov, val); } // Output_data_got methods. @@ -1161,257 +1457,296 @@ Output_data_got::Got_entry::write(unsigned char* pov) const // this is a new GOT entry, false if the symbol already had a GOT // entry. -template +template bool -Output_data_got::add_global( +Output_data_got::add_global( Symbol* gsym, unsigned int got_type) { if (gsym->has_got_offset(got_type)) return false; - this->entries_.push_back(Got_entry(gsym)); - this->set_got_size(); - gsym->set_got_offset(got_type, this->last_got_offset()); + unsigned int got_offset = this->add_got_entry(Got_entry(gsym, false)); + gsym->set_got_offset(got_type, 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) +// Like add_global, but use the PLT offset. + +template +bool +Output_data_got::add_global_plt(Symbol* gsym, + unsigned int got_type) { if (gsym->has_got_offset(got_type)) - return; + return false; - this->entries_.push_back(Got_entry()); - this->set_got_size(); - unsigned int got_offset = this->last_got_offset(); + unsigned int got_offset = this->add_got_entry(Got_entry(gsym, true)); gsym->set_got_offset(got_type, got_offset); - rel_dyn->add_global(gsym, r_type, this, got_offset); + return true; } -template +// 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_rela( +Output_data_got::add_global_with_rel( Symbol* gsym, unsigned int got_type, - Rela_dyn* rela_dyn, + Output_data_reloc_generic* 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(); + unsigned int got_offset = this->add_got_entry(Got_entry()); gsym->set_got_offset(got_type, got_offset); - rela_dyn->add_global(gsym, r_type, this, got_offset, 0); + rel_dyn->add_global_generic(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 +template void -Output_data_got::add_global_pair_with_rela( +Output_data_got::add_global_pair_with_rel( Symbol* gsym, unsigned int got_type, - Rela_dyn* rela_dyn, + Output_data_reloc_generic* 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(); + unsigned int got_offset = this->add_got_entry_pair(Got_entry(), Got_entry()); gsym->set_got_offset(got_type, got_offset); - rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0); + rel_dyn->add_global_generic(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(); + rel_dyn->add_global_generic(gsym, r_type_2, this, + got_offset + got_size / 8, 0); } // 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 +template bool -Output_data_got::add_local( - Sized_relobj* object, +Output_data_got::add_local( + 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()); + unsigned int got_offset = this->add_got_entry(Got_entry(object, symndx, + false)); + object->set_local_got_offset(symndx, got_type, 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, +// Add an entry for a local symbol plus ADDEND 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( + Relobj* object, unsigned int symndx, unsigned int got_type, - Rel_dyn* rel_dyn, - unsigned int r_type) + uint64_t addend) { - if (object->local_has_got_offset(symndx, got_type)) - return; + if (object->local_has_got_offset(symndx, got_type, addend)) + return false; - 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); + unsigned int got_offset = this->add_got_entry(Got_entry(object, symndx, + false, addend)); + object->set_local_got_offset(symndx, got_type, got_offset, addend); + return true; } -template -void -Output_data_got::add_local_with_rela( - Sized_relobj* object, +// Like add_local, but use the PLT offset. + +template +bool +Output_data_got::add_local_plt( + Relobj* object, + unsigned int symndx, + unsigned int got_type) +{ + if (object->local_has_got_offset(symndx, got_type)) + return false; + + unsigned int got_offset = this->add_got_entry(Got_entry(object, symndx, + true)); + object->set_local_got_offset(symndx, got_type, 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( + Relobj* object, unsigned int symndx, unsigned int got_type, - Rela_dyn* rela_dyn, + Output_data_reloc_generic* 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(); + unsigned int got_offset = this->add_got_entry(Got_entry()); object->set_local_got_offset(symndx, got_type, got_offset); - rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0); + rel_dyn->add_local_generic(object, symndx, r_type, this, got_offset, 0); +} + +// Add an entry for a local symbol plus ADDEND 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( + Relobj* object, + unsigned int symndx, + unsigned int got_type, + Output_data_reloc_generic* rel_dyn, + unsigned int r_type, uint64_t addend) +{ + if (object->local_has_got_offset(symndx, got_type, addend)) + return; + + unsigned int got_offset = this->add_got_entry(Got_entry()); + object->set_local_got_offset(symndx, got_type, got_offset, addend); + rel_dyn->add_local_generic(object, symndx, r_type, this, got_offset, + addend); } // 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 +// a dynamic relocation of type R_TYPE using the section symbol of +// the output section to which input section SHNDX maps, on the first. +// The first got entry will have a value of zero, the second the +// value of the local symbol. +template void -Output_data_got::add_local_pair_with_rel( - Sized_relobj* object, +Output_data_got::add_local_pair_with_rel( + 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) + Output_data_reloc_generic* rel_dyn, + unsigned int r_type) { if (object->local_has_got_offset(symndx, got_type)) return; - this->entries_.push_back(Got_entry()); - unsigned int got_offset = this->last_got_offset(); + unsigned int got_offset = + this->add_got_entry_pair(Got_entry(), + Got_entry(object, symndx, false)); 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); + rel_dyn->add_output_section_generic(os, r_type, this, got_offset, 0); +} - 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); - } +// Add a pair of entries for a local symbol plus ADDEND to the GOT, and add +// a dynamic relocation of type R_TYPE using the section symbol of +// the output section to which input section SHNDX maps, on the first. +// The first got entry will have a value of zero, the second the +// value of the local symbol. +template +void +Output_data_got::add_local_pair_with_rel( + Relobj* object, + unsigned int symndx, + unsigned int shndx, + unsigned int got_type, + Output_data_reloc_generic* rel_dyn, + unsigned int r_type, uint64_t addend) +{ + if (object->local_has_got_offset(symndx, got_type, addend)) + return; - this->set_got_size(); + unsigned int got_offset = + this->add_got_entry_pair(Got_entry(), + Got_entry(object, symndx, false, addend)); + object->set_local_got_offset(symndx, got_type, got_offset, addend); + Output_section* os = object->output_section(shndx); + rel_dyn->add_output_section_generic(os, r_type, this, got_offset, addend); } -template +// Add a pair of entries for a local symbol to the GOT, and add +// a dynamic relocation of type R_TYPE using STN_UNDEF on the first. +// The first got entry will have a value of zero, the second the +// value of the local symbol offset by Target::tls_offset_for_local. +template void -Output_data_got::add_local_pair_with_rela( - Sized_relobj* object, +Output_data_got::add_local_tls_pair( + 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) + Output_data_reloc_generic* rel_dyn, + unsigned int r_type) { if (object->local_has_got_offset(symndx, got_type)) return; - this->entries_.push_back(Got_entry()); - unsigned int got_offset = this->last_got_offset(); + unsigned int got_offset + = this->add_got_entry_pair(Got_entry(), + Got_entry(object, symndx, true)); 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); + rel_dyn->add_local_generic(object, 0, r_type, 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); - } +// Reserve a slot in the GOT for a local symbol or the second slot of a pair. + +template +void +Output_data_got::reserve_local( + unsigned int i, + Relobj* object, + unsigned int sym_index, + unsigned int got_type) +{ + this->do_reserve_slot(i); + object->set_local_got_offset(sym_index, got_type, this->got_offset(i)); +} + +// Reserve a slot in the GOT for a global symbol. - this->set_got_size(); +template +void +Output_data_got::reserve_global( + unsigned int i, + Symbol* gsym, + unsigned int got_type) +{ + this->do_reserve_slot(i); + gsym->set_got_offset(got_type, this->got_offset(i)); } // Write out the GOT. -template +template void -Output_data_got::do_write(Output_file* of) +Output_data_got::do_write(Output_file* of) { - const int add = size / 8; + const int add = got_size / 8; const off_t off = this->offset(); const off_t oview_size = this->data_size(); unsigned char* const oview = of->get_output_view(off, oview_size); unsigned char* pov = oview; - for (typename Got_entries::const_iterator p = this->entries_.begin(); - p != this->entries_.end(); - ++p) + for (unsigned int i = 0; i < this->entries_.size(); ++i) { - p->write(pov); + this->entries_[i].write(i, pov); pov += add; } @@ -1423,6 +1758,78 @@ Output_data_got::do_write(Output_file* of) this->entries_.clear(); } +// Create a new GOT entry and return its offset. + +template +unsigned int +Output_data_got::add_got_entry(Got_entry got_entry) +{ + if (!this->is_data_size_valid()) + { + this->entries_.push_back(got_entry); + this->set_got_size(); + return this->last_got_offset(); + } + else + { + // For an incremental update, find an available slot. + off_t got_offset = this->free_list_.allocate(got_size / 8, + got_size / 8, 0); + if (got_offset == -1) + gold_fallback(_("out of patch space (GOT);" + " relink with --incremental-full")); + unsigned int got_index = got_offset / (got_size / 8); + gold_assert(got_index < this->entries_.size()); + this->entries_[got_index] = got_entry; + return static_cast(got_offset); + } +} + +// Create a pair of new GOT entries and return the offset of the first. + +template +unsigned int +Output_data_got::add_got_entry_pair( + Got_entry got_entry_1, + Got_entry got_entry_2) +{ + if (!this->is_data_size_valid()) + { + unsigned int got_offset; + this->entries_.push_back(got_entry_1); + got_offset = this->last_got_offset(); + this->entries_.push_back(got_entry_2); + this->set_got_size(); + return got_offset; + } + else + { + // For an incremental update, find an available pair of slots. + off_t got_offset = this->free_list_.allocate(2 * got_size / 8, + got_size / 8, 0); + if (got_offset == -1) + gold_fallback(_("out of patch space (GOT);" + " relink with --incremental-full")); + unsigned int got_index = got_offset / (got_size / 8); + gold_assert(got_index < this->entries_.size()); + this->entries_[got_index] = got_entry_1; + this->entries_[got_index + 1] = got_entry_2; + return static_cast(got_offset); + } +} + +// Replace GOT entry I with a new value. + +template +void +Output_data_got::replace_got_entry( + unsigned int i, + Got_entry got_entry) +{ + gold_assert(i < this->entries_.size()); + this->entries_[i] = got_entry; +} + // Output_data_dynamic::Dynamic_entry methods. // Write out the entry. @@ -1442,6 +1849,8 @@ Output_data_dynamic::Dynamic_entry::write( case DYNAMIC_SECTION_SIZE: val = this->u_.od->data_size(); + if (this->od2 != NULL) + val += this->od2->data_size(); break; case DYNAMIC_SYMBOL: @@ -1456,6 +1865,10 @@ Output_data_dynamic::Dynamic_entry::write( val = pool->get_offset(this->u_.str); break; + case DYNAMIC_CUSTOM: + val = parameters->target().dynamic_tag_custom_value(this->tag_); + break; + default: val = this->u_.od->address() + this->offset_; break; @@ -1481,13 +1894,41 @@ Output_data_dynamic::do_adjust_output_section(Output_section* os) gold_unreachable(); } +// Get a dynamic entry offset. + +unsigned int +Output_data_dynamic::get_entry_offset(elfcpp::DT tag) const +{ + int dyn_size; + + if (parameters->target().get_size() == 32) + dyn_size = elfcpp::Elf_sizes<32>::dyn_size; + else if (parameters->target().get_size() == 64) + dyn_size = elfcpp::Elf_sizes<64>::dyn_size; + else + gold_unreachable(); + + for (size_t i = 0; i < entries_.size(); ++i) + if (entries_[i].tag() == tag) + return i * dyn_size; + + return -1U; +} + // Set the final data size. void 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_.back().tag() != elfcpp::DT_NULL) + { + int extra = parameters->options().spare_dynamic_tags(); + for (int i = 0; i < extra; ++i) + this->add_constant(elfcpp::DT_NULL, 0); + this->add_constant(elfcpp::DT_NULL, 0); + } int dyn_size; if (parameters->target().get_size() == 32) @@ -1587,11 +2028,166 @@ Output_symtab_xindex::endian_do_write(unsigned char* const oview) for (Xindex_entries::const_iterator p = this->entries_.begin(); p != this->entries_.end(); ++p) - elfcpp::Swap<32, big_endian>::writeval(oview + p->first * 4, p->second); + { + unsigned int symndx = p->first; + gold_assert(static_cast(symndx) * 4 < this->data_size()); + elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second); + } +} + +// Output_fill_debug_info methods. + +// Return the minimum size needed for a dummy compilation unit header. + +size_t +Output_fill_debug_info::do_minimum_hole_size() const +{ + // Compile unit header fields: unit_length, version, debug_abbrev_offset, + // address_size. + const size_t len = 4 + 2 + 4 + 1; + // For type units, add type_signature, type_offset. + if (this->is_debug_types_) + return len + 8 + 4; + return len; +} + +// Write a dummy compilation unit header to fill a hole in the +// .debug_info or .debug_types section. + +void +Output_fill_debug_info::do_write(Output_file* of, off_t off, size_t len) const +{ + gold_debug(DEBUG_INCREMENTAL, "fill_debug_info(%08lx, %08lx)", + static_cast(off), static_cast(len)); + + gold_assert(len >= this->do_minimum_hole_size()); + + unsigned char* const oview = of->get_output_view(off, len); + unsigned char* pov = oview; + + // Write header fields: unit_length, version, debug_abbrev_offset, + // address_size. + if (this->is_big_endian()) + { + elfcpp::Swap_unaligned<32, true>::writeval(pov, len - 4); + elfcpp::Swap_unaligned<16, true>::writeval(pov + 4, this->version); + elfcpp::Swap_unaligned<32, true>::writeval(pov + 6, 0); + } + else + { + elfcpp::Swap_unaligned<32, false>::writeval(pov, len - 4); + elfcpp::Swap_unaligned<16, false>::writeval(pov + 4, this->version); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 6, 0); + } + pov += 4 + 2 + 4; + *pov++ = 4; + + // For type units, the additional header fields -- type_signature, + // type_offset -- can be filled with zeroes. + + // Fill the remainder of the free space with zeroes. The first + // zero should tell the consumer there are no DIEs to read in this + // compilation unit. + if (pov < oview + len) + memset(pov, 0, oview + len - pov); + + of->write_output_view(off, len, oview); +} + +// Output_fill_debug_line methods. + +// Return the minimum size needed for a dummy line number program header. + +size_t +Output_fill_debug_line::do_minimum_hole_size() const +{ + // Line number program header fields: unit_length, version, header_length, + // minimum_instruction_length, default_is_stmt, line_base, line_range, + // opcode_base, standard_opcode_lengths[], include_directories, filenames. + const size_t len = 4 + 2 + 4 + this->header_length; + return len; +} + +// Write a dummy line number program header to fill a hole in the +// .debug_line section. + +void +Output_fill_debug_line::do_write(Output_file* of, off_t off, size_t len) const +{ + gold_debug(DEBUG_INCREMENTAL, "fill_debug_line(%08lx, %08lx)", + static_cast(off), static_cast(len)); + + gold_assert(len >= this->do_minimum_hole_size()); + + unsigned char* const oview = of->get_output_view(off, len); + unsigned char* pov = oview; + + // Write header fields: unit_length, version, header_length, + // minimum_instruction_length, default_is_stmt, line_base, line_range, + // opcode_base, standard_opcode_lengths[], include_directories, filenames. + // We set the header_length field to cover the entire hole, so the + // line number program is empty. + if (this->is_big_endian()) + { + elfcpp::Swap_unaligned<32, true>::writeval(pov, len - 4); + elfcpp::Swap_unaligned<16, true>::writeval(pov + 4, this->version); + elfcpp::Swap_unaligned<32, true>::writeval(pov + 6, len - (4 + 2 + 4)); + } + else + { + elfcpp::Swap_unaligned<32, false>::writeval(pov, len - 4); + elfcpp::Swap_unaligned<16, false>::writeval(pov + 4, this->version); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 6, len - (4 + 2 + 4)); + } + pov += 4 + 2 + 4; + *pov++ = 1; // minimum_instruction_length + *pov++ = 0; // default_is_stmt + *pov++ = 0; // line_base + *pov++ = 5; // line_range + *pov++ = 13; // opcode_base + *pov++ = 0; // standard_opcode_lengths[1] + *pov++ = 1; // standard_opcode_lengths[2] + *pov++ = 1; // standard_opcode_lengths[3] + *pov++ = 1; // standard_opcode_lengths[4] + *pov++ = 1; // standard_opcode_lengths[5] + *pov++ = 0; // standard_opcode_lengths[6] + *pov++ = 0; // standard_opcode_lengths[7] + *pov++ = 0; // standard_opcode_lengths[8] + *pov++ = 1; // standard_opcode_lengths[9] + *pov++ = 0; // standard_opcode_lengths[10] + *pov++ = 0; // standard_opcode_lengths[11] + *pov++ = 1; // standard_opcode_lengths[12] + *pov++ = 0; // include_directories (empty) + *pov++ = 0; // filenames (empty) + + // Some consumers don't check the header_length field, and simply + // start reading the line number program immediately following the + // header. For those consumers, we fill the remainder of the free + // space with DW_LNS_set_basic_block opcodes. These are effectively + // no-ops: the resulting line table program will not create any rows. + if (pov < oview + len) + memset(pov, elfcpp::DW_LNS_set_basic_block, oview + len - pov); + + of->write_output_view(off, len, oview); } // Output_section::Input_section methods. +// Return the current data size. For an input section we store the size here. +// For an Output_section_data, we have to ask it for the size. + +off_t +Output_section::Input_section::current_data_size() const +{ + if (this->is_input_section()) + return this->u1_.data_size; + else + { + this->u2_.posd->pre_finalize_data_size(); + return this->u2_.posd->current_data_size(); + } +} + // Return the data size. For an input section we store the size here. // For an Output_section_data, we have to ask it for the size. @@ -1604,6 +2200,42 @@ Output_section::Input_section::data_size() const return this->u2_.posd->data_size(); } +// Return the object for an input section. + +Relobj* +Output_section::Input_section::relobj() const +{ + if (this->is_input_section()) + return this->u2_.object; + else if (this->is_merge_section()) + { + gold_assert(this->u2_.pomb->first_relobj() != NULL); + return this->u2_.pomb->first_relobj(); + } + else if (this->is_relaxed_input_section()) + return this->u2_.poris->relobj(); + else + gold_unreachable(); +} + +// Return the input section index for an input section. + +unsigned int +Output_section::Input_section::shndx() const +{ + if (this->is_input_section()) + return this->shndx_; + else if (this->is_merge_section()) + { + gold_assert(this->u2_.pomb->first_relobj() != NULL); + return this->u2_.pomb->first_shndx(); + } + else if (this->is_relaxed_input_section()) + return this->u2_.poris->shndx(); + else + gold_unreachable(); +} + // Set the address and file offset. void @@ -1646,7 +2278,7 @@ Output_section::Input_section::output_offset( const Relobj* object, unsigned int shndx, section_offset_type offset, - section_offset_type *poutput) const + section_offset_type* poutput) const { if (!this->is_input_section()) return this->u2_.posd->output_offset(object, shndx, offset, poutput); @@ -1659,18 +2291,6 @@ Output_section::Input_section::output_offset( } } -// 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 // section--they are handled via Object::relocate--but this is where // we write out the data for an Output_section_data. @@ -1705,6 +2325,14 @@ Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const 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; @@ -1728,6 +2356,7 @@ Output_section::Output_section(const char* name, elfcpp::Elf_Word type, info_(0), type_(type), flags_(flags), + order_(ORDER_INVALID), out_shndx_(-1U), symtab_index_(0), dynsym_index_(0), @@ -1744,12 +2373,30 @@ Output_section::Output_section(const char* name, elfcpp::Elf_Word type, found_in_sections_clause_(false), has_load_address_(false), info_uses_section_index_(false), + input_section_order_specified_(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), - tls_offset_(0) + is_small_section_(false), + is_large_section_(false), + generate_code_fills_at_write_(false), + is_entsize_zero_(false), + section_offsets_need_adjustment_(false), + is_noload_(false), + always_keeps_input_sections_(false), + has_fixed_layout_(false), + is_patch_space_allowed_(false), + is_unique_segment_(false), + tls_offset_(0), + extra_segment_flags_(0), + segment_alignment_(0), + checkpoint_(NULL), + lookup_maps_(new Output_section_lookup_maps), + free_list_(), + free_space_fill_(NULL), + patch_space_(0), + reloc_section_(NULL) { // An unallocated section has no address. Forcing this means that // we don't need special treatment for symbols defined in debug @@ -1760,6 +2407,7 @@ Output_section::Output_section(const char* name, elfcpp::Elf_Word type, Output_section::~Output_section() { + delete this->checkpoint_; } // Set the entry size. @@ -1767,10 +2415,15 @@ Output_section::~Output_section() void Output_section::set_entsize(uint64_t v) { - if (this->entsize_ == 0) + if (this->is_entsize_zero_) + ; + else if (this->entsize_ == 0) this->entsize_ = v; - else - gold_assert(this->entsize_ == v); + else if (this->entsize_ != v) + { + this->entsize_ = 0; + this->is_entsize_zero_ = 1; + } } // Add the input section SHNDX, with header SHDR, named SECNAME, in @@ -1787,14 +2440,21 @@ Output_section::set_entsize(uint64_t v) template off_t -Output_section::add_input_section(Sized_relobj* object, +Output_section::add_input_section(Layout* layout, + Sized_relobj_file* object, unsigned int shndx, const char* secname, const elfcpp::Shdr& shdr, unsigned int reloc_shndx, bool have_sections_script) { + section_size_type input_section_size = shdr.get_sh_size(); + section_size_type uncompressed_size; elfcpp::Elf_Xword addralign = shdr.get_sh_addralign(); + if (object->section_is_compressed(shndx, &uncompressed_size, + &addralign)) + input_section_size = uncompressed_size; + if ((addralign & (addralign - 1)) != 0) { object->error(_("invalid alignment %lu for section \"%s\""), @@ -1806,8 +2466,6 @@ Output_section::add_input_section(Sized_relobj* object, this->addralign_ = addralign; typename elfcpp::Elf_types::Elf_WXword sh_flags = shdr.get_sh_flags(); - this->update_flags_for_input_section(sh_flags); - uint64_t entsize = shdr.get_sh_entsize(); // .debug_str is a mergeable string section, but is not always so @@ -1818,16 +2476,27 @@ Output_section::add_input_section(Sized_relobj* object, entsize = 1; } + this->update_flags_for_input_section(sh_flags); + this->set_entsize(entsize); + // 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. + // FIXME: Need to handle merge sections during incremental update. if ((sh_flags & elfcpp::SHF_MERGE) != 0 && reloc_shndx == 0 - && shdr.get_sh_size() > 0) + && shdr.get_sh_size() > 0 + && !parameters->incremental()) { - if (this->add_merge_input_section(object, shndx, sh_flags, - entsize, addralign)) + // Keep information about merged input sections for rebuilding fast + // lookup maps if we have sections-script or we do relaxation. + bool keeps_input_sections = (this->always_keeps_input_sections_ + || have_sections_script + || parameters->target().may_relax()); + + if (this->add_merge_input_section(object, shndx, sh_flags, entsize, + addralign, keeps_input_sections)) { // Tell the relocation routines that they need to call the // output_offset method to determine the final address. @@ -1835,47 +2504,92 @@ Output_section::add_input_section(Sized_relobj* object, } } - off_t offset_in_section = this->current_data_size_for_child(); + off_t offset_in_section; + + if (this->has_fixed_layout()) + { + // For incremental updates, find a chunk of unused space in the section. + offset_in_section = this->free_list_.allocate(input_section_size, + addralign, 0); + if (offset_in_section == -1) + gold_fallback(_("out of patch space in section %s; " + "relink with --incremental-full"), + this->name()); + return offset_in_section; + } + + offset_in_section = this->current_data_size_for_child(); off_t aligned_offset_in_section = align_address(offset_in_section, - addralign); + addralign); + this->set_current_data_size_for_child(aligned_offset_in_section + + input_section_size); + + // 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. Also, if we are + // sorting input sections we must delay fill generation. + 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() + || layout->is_section_ordering_specified())) + { + 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 - && object->target()->has_code_fill()) + && 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)); + this->fills_.push_back(Fill(offset_in_section, fill_len)); else - { - // FIXME: When relaxing, the size needs to adjust to - // maintain a constant alignment. - std::string fill_data(object->target()->code_fill(fill_len)); - Output_data_const* odc = new Output_data_const(fill_data, 1); - this->input_sections_.push_back(Input_section(odc)); - } + { + 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. FIXME: Add test for - // relaxing. - if (have_sections_script + // the future, we keep track of the sections. If the + // --section-ordering-file option is used to specify the order of + // sections, we need to keep track of sections. + if (this->always_keeps_input_sections_ + || have_sections_script || !this->input_sections_.empty() || this->may_sort_attached_input_sections() || this->must_sort_attached_input_sections() - || parameters->options().user_set_Map()) - this->input_sections_.push_back(Input_section(object, shndx, - shdr.get_sh_size(), - addralign)); + || parameters->options().user_set_Map() + || parameters->target().may_relax() + || layout->is_section_ordering_specified()) + { + Input_section isecn(object, shndx, input_section_size, addralign); + /* If section ordering is requested by specifying a ordering file, + using --section-ordering-file, match the section name with + a pattern. */ + if (parameters->options().section_ordering_file()) + { + unsigned int section_order_index = + layout->find_section_order_index(std::string(secname)); + if (section_order_index != 0) + { + isecn.set_section_order_index(section_order_index); + this->set_input_section_order_specified(); + } + } + this->input_sections_.push_back(isecn); + } return aligned_offset_in_section; } @@ -1890,12 +2604,81 @@ Output_section::add_output_section_data(Output_section_data* posd) 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()); + off_t offset_in_section; + if (this->has_fixed_layout()) + { + // For incremental updates, find a chunk of unused space. + offset_in_section = this->free_list_.allocate(posd->data_size(), + posd->addralign(), 0); + if (offset_in_section == -1) + gold_fallback(_("out of patch space in section %s; " + "relink with --incremental-full"), + this->name()); + // Finalize the address and offset now. + uint64_t addr = this->address(); + off_t offset = this->offset(); + posd->set_address_and_file_offset(addr + offset_in_section, + offset + offset_in_section); + } + else + { + 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()); + } + } + else if (this->has_fixed_layout()) + { + // For incremental updates, arrange for the data to have a fixed layout. + // This will mean that additions to the data must be allocated from + // free space within the containing output section. + uint64_t addr = this->address(); + posd->set_address(addr); + posd->set_file_offset(0); + // FIXME: This should eventually be unreachable. + // gold_unreachable(); + } +} + +// Add a relaxed input section. + +void +Output_section::add_relaxed_input_section(Layout* layout, + Output_relaxed_input_section* poris, + const std::string& name) +{ + Input_section inp(poris); + + // If the --section-ordering-file option is used to specify the order of + // sections, we need to keep track of sections. + if (layout->is_section_ordering_specified()) + { + unsigned int section_order_index = + layout->find_section_order_index(name); + if (section_order_index != 0) + { + inp.set_section_order_index(section_order_index); + this->set_input_section_order_specified(); + } } + + this->add_output_section_data(&inp); + if (this->lookup_maps_->is_valid()) + this->lookup_maps_->add_relaxed_input_section(poris->relobj(), + poris->shndx(), 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 the 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. @@ -1930,52 +2713,265 @@ Output_section::add_output_merge_section(Output_section_data* posd, bool Output_section::add_merge_input_section(Relobj* object, unsigned int shndx, uint64_t flags, uint64_t entsize, - uint64_t addralign) + uint64_t addralign, + bool keeps_input_sections) { - 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) + // We cannot merge sections with entsize == 0. + if (entsize == 0) return false; - Input_section_list::iterator p; - for (p = this->input_sections_.begin(); - p != this->input_sections_.end(); - ++p) - if (p->is_merge_section(is_string, entsize, addralign)) - { - p->add_input_section(object, shndx); - return true; - } + bool is_string = (flags & elfcpp::SHF_STRINGS) != 0; - // We handle the actual constant merging in Output_merge_data or - // Output_merge_string_data. - Output_section_data* posd; - if (!is_string) - posd = new Output_merge_data(entsize, addralign); + // We cannot restore merged input section states. + gold_assert(this->checkpoint_ == NULL); + + // Look up merge sections by required properties. + // Currently, we only invalidate the lookup maps in script processing + // and relaxation. We should not have done either when we reach here. + // So we assume that the lookup maps are valid to simply code. + gold_assert(this->lookup_maps_->is_valid()); + Merge_section_properties msp(is_string, entsize, addralign); + Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp); + bool is_new = false; + if (pomb != NULL) + { + gold_assert(pomb->is_string() == is_string + && pomb->entsize() == entsize + && pomb->addralign() == addralign); + } else { - switch (entsize) + // Create a new Output_merge_data or Output_merge_string_data. + if (!is_string) + pomb = new Output_merge_data(entsize, addralign); + else { - case 1: - posd = new Output_merge_string(addralign); - break; - case 2: - posd = new Output_merge_string(addralign); - break; - case 4: - posd = new Output_merge_string(addralign); - break; - default: - return false; + 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; + } } + // If we need to do script processing or relaxation, we need to keep + // the original input sections to rebuild the fast lookup maps. + if (keeps_input_sections) + pomb->set_keeps_input_sections(); + is_new = true; } - this->add_output_merge_section(posd, is_string, entsize); - posd->add_input_section(object, shndx); + if (pomb->add_input_section(object, shndx)) + { + // Add new merge section to this output section and link merge + // section properties to new merge section in map. + if (is_new) + { + this->add_output_merge_section(pomb, is_string, entsize); + this->lookup_maps_->add_merge_section(msp, pomb); + } - return true; + return true; + } + else + { + // If add_input_section failed, delete new merge section to avoid + // exporting empty merge sections in Output_section::get_input_section. + if (is_new) + delete pomb; + return false; + } +} + +// 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()) + { + Section_id sid(is.relobj(), is.shndx()); + (*relaxation_map)[sid] = i; + } + } +} + +// Convert regular input sections in INPUT_SECTIONS into relaxed input +// sections in RELAXED_SECTIONS. MAP is a prebuilt map from section id +// 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]; + Section_id sid(poris->relobj(), poris->shndx()); + Relaxation_map::const_iterator p = map.find(sid); + gold_assert(p != map.end()); + gold_assert((*input_sections)[p->second].is_input_section()); + + // Remember section order index of original input section + // if it is set. Copy it to the relaxed input section. + unsigned int soi = + (*input_sections)[p->second].section_order_index(); + (*input_sections)[p->second] = Input_section(poris); + (*input_sections)[p->second].set_section_order_index(soi); + } +} + +// 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 fast look-up map. + if (this->lookup_maps_->is_valid()) + for (size_t i = 0; i < relaxed_sections.size(); ++i) + { + Output_relaxed_input_section* poris = relaxed_sections[i]; + this->lookup_maps_->add_relaxed_input_section(poris->relobj(), + poris->shndx(), poris); + } +} + +// 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)); + + if ((flags & elfcpp::SHF_MERGE) == 0) + this->flags_ &=~ elfcpp::SHF_MERGE; + else + { + if (this->current_data_size_for_child() == 0) + this->flags_ |= elfcpp::SHF_MERGE; + } + + if ((flags & elfcpp::SHF_STRINGS) == 0) + this->flags_ &=~ elfcpp::SHF_STRINGS; + else + { + if (this->current_data_size_for_child() == 0) + this->flags_ |= elfcpp::SHF_STRINGS; + } +} + +// Find the merge section into which an input section with index SHNDX in +// OBJECT has been added. Return NULL if none found. + +const Output_section_data* +Output_section::find_merge_section(const Relobj* object, + unsigned int shndx) const +{ + return object->find_merge_section(shndx); +} + +// Build the lookup maps for relaxed sections. This needs +// to be declared as a const method so that it is callable with a const +// Output_section pointer. The method only updates states of the maps. + +void +Output_section::build_lookup_maps() const +{ + this->lookup_maps_->clear(); + for (Input_section_list::const_iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + if (p->is_relaxed_input_section()) + { + Output_relaxed_input_section* poris = p->relaxed_input_section(); + this->lookup_maps_->add_relaxed_input_section(poris->relobj(), + poris->shndx(), poris); + } + } +} + +// Find an relaxed input section corresponding to an input section +// in OBJECT with index SHNDX. + +const Output_relaxed_input_section* +Output_section::find_relaxed_input_section(const Relobj* object, + unsigned int shndx) const +{ + if (!this->lookup_maps_->is_valid()) + this->build_lookup_maps(); + return this->lookup_maps_->find_relaxed_input_section(object, shndx); } // Given an address OFFSET relative to the start of input section @@ -1988,6 +2984,23 @@ 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); + // By default we assume that the address is mapped. See comment at the + // end. + if (!found) + return true; + 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) @@ -2012,9 +3025,23 @@ 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 layout is complete. - gold_assert(Output_data::is_layout_complete()); + // 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) @@ -2034,6 +3061,20 @@ 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) @@ -2065,6 +3106,13 @@ Output_section::find_starting_output_address(const Relobj* object, unsigned int shndx, uint64_t* paddr) const { + const Output_section_data* data = this->find_merge_section(object, shndx); + if (data == NULL) + return false; + + // 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(); @@ -2076,7 +3124,7 @@ Output_section::find_starting_output_address(const Relobj* object, // 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)) + if (!p->is_input_section() && p->output_section_data() == data) { *paddr = addr; return true; @@ -2089,35 +3137,81 @@ Output_section::find_starting_output_address(const Relobj* object, return false; } -// Set the data size of an Output_section. This is where we handle -// setting the addresses of any Output_section_data objects. +// Update the data size of an Output_section. void -Output_section::set_final_data_size() +Output_section::update_data_size() { if (this->input_sections_.empty()) - { - this->set_data_size(this->current_data_size_for_child()); return; - } - if (this->must_sort_attached_input_sections()) + if (this->must_sort_attached_input_sections() + || this->input_section_order_specified()) this->sort_attached_input_sections(); - uint64_t address = this->address(); - off_t startoff = this->offset(); - off_t off = startoff + this->first_input_offset_; + 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->set_address_and_file_offset(address + (off - startoff), off, - startoff); - off += p->data_size(); + off += p->current_data_size(); + } + + this->set_current_data_size_for_child(off); +} + +// 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::set_final_data_size() +{ + off_t data_size; + + if (this->input_sections_.empty()) + data_size = this->current_data_size_for_child(); + else + { + if (this->must_sort_attached_input_sections() + || this->input_section_order_specified()) + this->sort_attached_input_sections(); + + uint64_t address = this->address(); + off_t startoff = this->offset(); + 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->set_address_and_file_offset(address + off, startoff + off, + startoff); + off += p->data_size(); + } + data_size = off; + } + + // For full incremental links, we want to allocate some patch space + // in most sections for subsequent incremental updates. + if (this->is_patch_space_allowed_ && parameters->incremental_full()) + { + double pct = parameters->options().incremental_patch(); + size_t extra = static_cast(data_size * pct); + if (this->free_space_fill_ != NULL + && this->free_space_fill_->minimum_hole_size() > extra) + extra = this->free_space_fill_->minimum_hole_size(); + off_t new_size = align_address(data_size + extra, this->addralign()); + this->patch_space_ = new_size - data_size; + gold_debug(DEBUG_INCREMENTAL, + "set_final_data_size: %08lx + %08lx: section %s", + static_cast(data_size), + static_cast(this->patch_space_), + this->name()); + data_size = new_size; } - this->set_data_size(off - startoff); + this->set_data_size(data_size); } // Reset the address and file offset. @@ -2125,10 +3219,40 @@ Output_section::set_final_data_size() 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. This does not + // apply to NOLOAD sections though. + if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_) + 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(); + + // Remove any patch space that was added in set_final_data_size. + if (this->patch_space_ > 0) + { + this->set_current_data_size_for_child(this->current_data_size_for_child() + - this->patch_space_); + this->patch_space_ = 0; + } +} + +// 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. @@ -2144,35 +3268,45 @@ Output_section::do_set_tls_offset(uint64_t tls_base) // 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.*", +// attached input section matching ".ctors.*", ".dtors.*", // ".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_(), index_(-1U), 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()) + unsigned int index, + bool must_sort_attached_input_sections, + const char* output_section_name) + : input_section_(input_section), index_(index), section_name_() { - if (this->section_has_name_) + if ((input_section.is_input_section() + || input_section.is_relaxed_input_section()) + && must_sort_attached_input_sections) { // 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.relobj(); + 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()); } + else if (input_section.is_output_section_data() + && must_sort_attached_input_sections) + { + // For linker-generated sections, use the output section name. + this->section_name_.assign(output_section_name); + } } // Return the Input_section. @@ -2192,16 +3326,10 @@ class Output_section::Input_section_sort_entry 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_; } @@ -2210,8 +3338,34 @@ class Output_section::Input_section_sort_entry bool has_priority() const { - gold_assert(this->section_has_name_); - return this->section_name_.find('.', 1); + return this->section_name_.find('.', 1) != std::string::npos; + } + + // Return the priority. Believe it or not, gcc encodes the priority + // differently for .ctors/.dtors and .init_array/.fini_array + // sections. + unsigned int + get_priority() const + { + bool is_ctors; + if (is_prefix_of(".ctors.", this->section_name_.c_str()) + || is_prefix_of(".dtors.", this->section_name_.c_str())) + is_ctors = true; + else if (is_prefix_of(".init_array.", this->section_name_.c_str()) + || is_prefix_of(".fini_array.", this->section_name_.c_str())) + is_ctors = false; + else + return 0; + char* end; + unsigned long prio = strtoul((this->section_name_.c_str() + + (is_ctors ? 7 : 12)), + &end, 10); + if (*end != '\0') + return 0; + else if (is_ctors) + return 65535 - prio; + else + return prio; } // Return true if this an input file whose base name matches @@ -2222,17 +3376,28 @@ class Output_section::Input_section_sort_entry // 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 + match_file_name(const char* 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) + if (this->input_section_.is_output_section_data()) return false; - return memcmp(base_name + base_len - 2, ".o", 2) == 0; + return Layout::match_file_name(this->input_section_.relobj(), file_name); + } + + // Returns 1 if THIS should appear before S in section order, -1 if S + // appears before THIS and 0 if they are not comparable. + int + compare_section_ordering(const Input_section_sort_entry& s) const + { + unsigned int this_secn_index = this->input_section_.section_order_index(); + unsigned int s_secn_index = s.input_section().section_order_index(); + if (this_secn_index > 0 && s_secn_index > 0) + { + if (this_secn_index < s_secn_index) + return 1; + else if (this_secn_index > s_secn_index) + return -1; + } + return 0; } private: @@ -2240,9 +3405,6 @@ class Output_section::Input_section_sort_entry 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_; }; @@ -2278,19 +3440,7 @@ Output_section::Input_section_sort_compare::operator()( 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) @@ -2298,6 +3448,66 @@ Output_section::Input_section_sort_compare::operator()( if (!s1_has_priority && s2_has_priority) return true; + // Check if a section order exists for these sections through a section + // ordering file. If sequence_num is 0, an order does not exist. + int sequence_num = s1.compare_section_ordering(s2); + if (sequence_num != 0) + return sequence_num == 1; + + // 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(); +} + +// Return true if S1 should come before S2 in an .init_array or .fini_array +// output section. + +bool +Output_section::Input_section_sort_init_fini_compare::operator()( + const Output_section::Input_section_sort_entry& s1, + const Output_section::Input_section_sort_entry& s2) const +{ + // A section without a priority follows a section with a priority. + // This is the reverse of .ctors and .dtors sections. + bool s1_has_priority = s1.has_priority(); + bool s2_has_priority = s2.has_priority(); + if (s1_has_priority && !s2_has_priority) + return true; + if (!s1_has_priority && s2_has_priority) + return false; + + // .ctors and .dtors sections without priority come after + // .init_array and .fini_array sections without priority. + if (!s1_has_priority + && (s1.section_name() == ".ctors" || s1.section_name() == ".dtors") + && s1.section_name() != s2.section_name()) + return false; + if (!s2_has_priority + && (s2.section_name() == ".ctors" || s2.section_name() == ".dtors") + && s2.section_name() != s1.section_name()) + return true; + + // Sort by priority if we can. + if (s1_has_priority) + { + unsigned int s1_prio = s1.get_priority(); + unsigned int s2_prio = s2.get_priority(); + if (s1_prio < s2_prio) + return true; + else if (s1_prio > s2_prio) + return false; + } + + // Check if a section order exists for these sections through a section + // ordering file. If sequence_num is 0, an order does not exist. + int sequence_num = s1.compare_section_ordering(s2); + if (sequence_num != 0) + return sequence_num == 1; + // Otherwise we sort by name. int compare = s1.section_name().compare(s2.section_name()); if (compare != 0) @@ -2307,6 +3517,106 @@ Output_section::Input_section_sort_compare::operator()( return s1.index() < s2.index(); } +// Return true if S1 should come before S2. Sections that do not match +// any pattern in the section ordering file are placed ahead of the sections +// that match some pattern. + +bool +Output_section::Input_section_sort_section_order_index_compare::operator()( + const Output_section::Input_section_sort_entry& s1, + const Output_section::Input_section_sort_entry& s2) const +{ + unsigned int s1_secn_index = s1.input_section().section_order_index(); + unsigned int s2_secn_index = s2.input_section().section_order_index(); + + // Keep input order if section ordering cannot determine order. + if (s1_secn_index == s2_secn_index) + return s1.index() < s2.index(); + + return s1_secn_index < s2_secn_index; +} + +// Return true if S1 should come before S2. This is the sort comparison +// function for .text to sort sections with prefixes +// .text.{unlikely,exit,startup,hot} before other sections. + +bool +Output_section::Input_section_sort_section_prefix_special_ordering_compare + ::operator()( + const Output_section::Input_section_sort_entry& s1, + const Output_section::Input_section_sort_entry& s2) const +{ + // Some input section names have special ordering requirements. + const char *s1_section_name = s1.section_name().c_str(); + const char *s2_section_name = s2.section_name().c_str(); + int o1 = Layout::special_ordering_of_input_section(s1_section_name); + int o2 = Layout::special_ordering_of_input_section(s2_section_name); + if (o1 != o2) + { + if (o1 < 0) + return false; + else if (o2 < 0) + return true; + else + return o1 < o2; + } + else if (is_prefix_of(".text.sorted", s1_section_name)) + return strcmp(s1_section_name, s2_section_name) <= 0; + + // Keep input order otherwise. + return s1.index() < s2.index(); +} + +// Return true if S1 should come before S2. This is the sort comparison +// function for sections to sort them by name. + +bool +Output_section::Input_section_sort_section_name_compare + ::operator()( + const Output_section::Input_section_sort_entry& s1, + const Output_section::Input_section_sort_entry& s2) const +{ + // We sort by name. + int compare = s1.section_name().compare(s2.section_name()); + if (compare != 0) + return compare < 0; + + // Keep input order otherwise. + return s1.index() < s2.index(); +} + +// This updates the section order index of input sections according to the +// the order specified in the mapping from Section id to order index. + +void +Output_section::update_section_layout( + const Section_layout_order* order_map) +{ + for (Input_section_list::iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + if (p->is_input_section() + || p->is_relaxed_input_section()) + { + Relobj* obj = (p->is_input_section() + ? p->relobj() + : p->relaxed_input_section()->relobj()); + unsigned int shndx = p->shndx(); + Section_layout_order::const_iterator it + = order_map->find(Section_id(obj, shndx)); + if (it == order_map->end()) + continue; + unsigned int section_order_index = it->second; + if (section_order_index != 0) + { + p->set_section_order_index(section_order_index); + this->set_input_section_order_specified(); + } + } + } +} + // Sort the input sections attached to an output section. void @@ -2315,6 +3625,10 @@ 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 @@ -2328,10 +3642,34 @@ Output_section::sort_attached_input_sections() 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_list.push_back(Input_section_sort_entry(*p, i, + this->must_sort_attached_input_sections(), + this->name())); // Sort the input sections. - std::sort(sort_list.begin(), sort_list.end(), Input_section_sort_compare()); + if (this->must_sort_attached_input_sections()) + { + if (this->type() == elfcpp::SHT_PREINIT_ARRAY + || this->type() == elfcpp::SHT_INIT_ARRAY + || this->type() == elfcpp::SHT_FINI_ARRAY) + std::sort(sort_list.begin(), sort_list.end(), + Input_section_sort_init_fini_compare()); + else if (strcmp(parameters->options().sort_section(), "name") == 0) + std::sort(sort_list.begin(), sort_list.end(), + Input_section_sort_section_name_compare()); + else if (strcmp(this->name(), ".text") == 0) + std::sort(sort_list.begin(), sort_list.end(), + Input_section_sort_section_prefix_special_ordering_compare()); + else + std::sort(sort_list.begin(), sort_list.end(), + Input_section_sort_compare()); + } + else + { + gold_assert(this->input_section_order_specified()); + std::sort(sort_list.begin(), sort_list.end(), + Input_section_sort_section_order_index_compare()); + } // Copy the sorted input sections back to our list. this->input_sections_.clear(); @@ -2339,6 +3677,7 @@ Output_section::sort_attached_input_sections() p != sort_list.end(); ++p) this->input_sections_.push_back(p->input_section()); + sort_list.clear(); // Remember that we sorted the input sections, since we might get // called again. @@ -2367,7 +3706,7 @@ Output_section::write_header(const Layout* layout, if (this->link_section_ != NULL) oshdr->put_sh_link(this->link_section_->out_shndx()); else if (this->should_link_to_symtab_) - oshdr->put_sh_link(layout->symtab_section()->out_shndx()); + oshdr->put_sh_link(layout->symtab_section_shndx()); else if (this->should_link_to_dynsym_) oshdr->put_sh_link(layout->dynsym_section()->out_shndx()); else @@ -2400,6 +3739,9 @@ 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(); @@ -2410,10 +3752,42 @@ Output_section::do_write(Output_file* of) 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) - p->write(of); + { + 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(); + } + + // For incremental links, fill in unused chunks in debug sections + // with dummy compilation unit headers. + if (this->free_space_fill_ != NULL) + { + for (Free_list::Const_iterator p = this->free_list_.begin(); + p != this->free_list_.end(); + ++p) + { + off_t off = p->start_; + size_t len = p->end_ - off; + this->free_space_fill_->write(of, this->offset() + off, len); + } + if (this->patch_space_ > 0) + { + off_t off = this->current_data_size_for_child() - this->patch_space_; + this->free_space_fill_->write(of, this->offset() + off, + this->patch_space_); + } + } } // If a section requires postprocessing, create the buffer to use. @@ -2454,6 +3828,9 @@ 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(); @@ -2469,9 +3846,16 @@ Output_section::write_to_postprocessing_buffer() p != this->input_sections_.end(); ++p) { - off = align_address(off, p->addralign()); - p->write_to_buffer(buffer + off); - off += p->data_size(); + 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(); } } @@ -2489,8 +3873,15 @@ uint64_t Output_section::get_input_sections( uint64_t address, const std::string& fill, - std::list >* input_sections) + std::list* input_sections) { + if (this->checkpoint_ != NULL + && !this->checkpoint_->input_sections_saved()) + this->checkpoint_->save_input_sections(); + + // Invalidate fast look-up maps. + this->lookup_maps_->invalidate(); + uint64_t orig_address = address; address = align_address(address, this->addralign()); @@ -2500,8 +3891,10 @@ Output_section::get_input_sections( p != this->input_sections_.end(); ++p) { - if (p->is_input_section()) - input_sections->push_back(std::make_pair(p->relobj(), p->shndx())); + if (p->is_input_section() + || p->is_relaxed_input_section() + || p->is_merge_section()) + input_sections->push_back(*p); else { uint64_t aligned_address = align_address(address, p->addralign()); @@ -2536,14 +3929,16 @@ Output_section::get_input_sections( return data_size; } -// Add an input section from a script. +// Add a script input section. SIS is an Output_section::Input_section, +// which can be either a plain input section or a special input section like +// a relaxed input section. For a special input section, its size must be +// finalized. void -Output_section::add_input_section_for_script(Relobj* object, - unsigned int shndx, - off_t data_size, - uint64_t addralign) +Output_section::add_script_input_section(const Input_section& sis) { + uint64_t data_size = sis.data_size(); + uint64_t addralign = sis.addralign(); if (addralign > this->addralign_) this->addralign_ = addralign; @@ -2554,8 +3949,103 @@ Output_section::add_input_section_for_script(Relobj* object, this->set_current_data_size_for_child(aligned_offset_in_section + data_size); - this->input_sections_.push_back(Input_section(object, shndx, - data_size, addralign)); + this->input_sections_.push_back(sis); + + // Update fast lookup maps if necessary. + if (this->lookup_maps_->is_valid()) + { + if (sis.is_relaxed_input_section()) + { + Output_relaxed_input_section* poris = sis.relaxed_input_section(); + this->lookup_maps_->add_relaxed_input_section(poris->relobj(), + poris->shndx(), poris); + } + } +} + +// Save states for relaxation. + +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::discard_states() +{ + gold_assert(this->checkpoint_ != NULL); + delete this->checkpoint_; + this->checkpoint_ = NULL; + gold_assert(this->fills_.empty()); + + // Simply invalidate the fast lookup maps since we do not keep + // track of them. + this->lookup_maps_->invalidate(); +} + +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 fast lookup maps since we do not keep + // track of them. + this->lookup_maps_->invalidate(); +} + +// Update the section offsets of input sections in this. This is required if +// relaxation causes some input sections to change sizes. + +void +Output_section::adjust_section_offsets() +{ + if (!this->section_offsets_need_adjustment_) + return; + + off_t off = 0; + for (Input_section_list::iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + off = align_address(off, p->addralign()); + if (p->is_input_section()) + p->relobj()->set_section_offset(p->shndx(), off); + off += p->data_size(); + } + + this->section_offsets_need_adjustment_ = false; } // Print to the map file. @@ -2583,12 +4073,44 @@ Output_section::print_merge_stats() p->print_merge_stats(this->name_); } +// Set a fixed layout for the section. Used for incremental update links. + +void +Output_section::set_fixed_layout(uint64_t sh_addr, off_t sh_offset, + off_t sh_size, uint64_t sh_addralign) +{ + this->addralign_ = sh_addralign; + this->set_current_data_size(sh_size); + if ((this->flags_ & elfcpp::SHF_ALLOC) != 0) + this->set_address(sh_addr); + this->set_file_offset(sh_offset); + this->finalize_data_size(); + this->free_list_.init(sh_size, false); + this->has_fixed_layout_ = true; +} + +// Reserve space within the fixed layout for the section. Used for +// incremental update links. + +void +Output_section::reserve(uint64_t sh_offset, uint64_t sh_size) +{ + this->free_list_.remove(sh_offset, sh_offset + sh_size); +} + +// Allocate space from the free list for the section. Used for +// incremental update links. + +off_t +Output_section::allocate(off_t len, uint64_t addralign) +{ + return this->free_list_.allocate(len, addralign, 0); +} + // Output segment methods. Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags) - : output_data_(), - output_bss_(), - vaddr_(0), + : vaddr_(0), paddr_(0), memsz_(0), max_align_(0), @@ -2598,126 +4120,54 @@ Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags) type_(type), flags_(flags), is_max_align_known_(false), - are_addresses_set_(false) + are_addresses_set_(false), + is_large_data_segment_(false), + is_unique_segment_(false) { + // The ELF ABI specifies that a PT_TLS segment always has PF_R as + // the flags. + if (type == elfcpp::PT_TLS) + this->flags_ = elfcpp::PF_R; } -// Add an Output_section to an Output_segment. +// Add an Output_section to a PT_LOAD Output_segment. void -Output_segment::add_output_section(Output_section* os, - elfcpp::Elf_Word seg_flags) +Output_segment::add_output_section_to_load(Layout* layout, + Output_section* os, + elfcpp::Elf_Word seg_flags) { + gold_assert(this->type() == elfcpp::PT_LOAD); gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0); 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; + this->update_flags_for_output_section(seg_flags); - Output_segment::Output_data_list* pdl; - if (os->type() == elfcpp::SHT_NOBITS) - pdl = &this->output_bss_; + // We don't want to change the ordering if we have a linker script + // with a SECTIONS clause. + Output_section_order order = os->order(); + if (layout->script_options()->saw_sections_clause()) + order = static_cast(0); else - pdl = &this->output_data_; - - // So that PT_NOTE segments will work correctly, we need to ensure - // that all SHT_NOTE sections are adjacent. This will normally - // happen automatically, because all the SHT_NOTE input sections - // will wind up in the same output section. However, it is possible - // for multiple SHT_NOTE input sections to have different section - // flags, and thus be in different output sections, but for the - // different section flags to map into the same segment flags and - // thus the same output segment. - - // Note that while there may be many input sections in an output - // section, there are normally only a few output sections in an - // output segment. This loop is expected to be fast. - - if (os->type() == elfcpp::SHT_NOTE && !pdl->empty()) - { - Output_segment::Output_data_list::iterator p = pdl->end(); - do - { - --p; - if ((*p)->is_section_type(elfcpp::SHT_NOTE)) - { - ++p; - pdl->insert(p, os); - return; - } - } - while (p != pdl->begin()); - } - - // Similarly, so that PT_TLS segments will work, we need to group - // SHF_TLS sections. An SHF_TLS/SHT_NOBITS section is a special - // case: we group the SHF_TLS/SHT_NOBITS sections right after the - // SHF_TLS/SHT_PROGBITS sections. This lets us set up PT_TLS - // correctly. 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 - { - --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; - } - } - 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; + gold_assert(order != ORDER_INVALID); - Output_section* pos = (*p)->output_section(); - if (!pos->is_relro() - || (os->is_relro_local() && !pos->is_relro_local())) - break; - } + this->output_lists_[order].push_back(os); +} - pdl->insert(p, os); - return; - } +// Add an Output_section to a non-PT_LOAD Output_segment. + +void +Output_segment::add_output_section_to_nonload(Output_section* os, + elfcpp::Elf_Word seg_flags) +{ + gold_assert(this->type() != elfcpp::PT_LOAD); + gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0); + gold_assert(!this->is_max_align_known_); - pdl->push_back(os); + this->update_flags_for_output_section(seg_flags); + + this->output_lists_[0].push_back(os); } // Remove an Output_section from this segment. It is an error if it @@ -2726,39 +4176,72 @@ Output_segment::add_output_section(Output_section* os, 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; - } - } + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + { + Output_data_list* pdl = &this->output_lists_[i]; + for (Output_data_list::iterator p = pdl->begin(); p != pdl->end(); ++p) + { + if (*p == os) + { + pdl->erase(p); + return; + } + } + } gold_unreachable(); } -// Add an Output_data (which is not an Output_section) to the start of -// a segment. +// Add an Output_data (which need not be an Output_section) to the +// start of a segment. void Output_segment::add_initial_output_data(Output_data* od) { gold_assert(!this->is_max_align_known_); - this->output_data_.push_front(od); + Output_data_list::iterator p = this->output_lists_[0].begin(); + this->output_lists_[0].insert(p, od); +} + +// Return true if this segment has any sections which hold actual +// data, rather than being a BSS section. + +bool +Output_segment::has_any_data_sections() const +{ + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + { + const Output_data_list* pdl = &this->output_lists_[i]; + for (Output_data_list::const_iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + if (!(*p)->is_section()) + return true; + if ((*p)->output_section()->type() != elfcpp::SHT_NOBITS) + return true; + } + } + return false; } -// Return whether the first data section is a relro section. +// Return whether the first data section (not counting TLS sections) +// 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()); + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + { + if (i == static_cast(ORDER_TLS_BSS)) + continue; + const Output_data_list* pdl = &this->output_lists_[i]; + if (!pdl->empty()) + { + Output_data* p = pdl->front(); + return p->is_section() && p->output_section()->is_relro(); + } + } + return false; } // Return the maximum alignment of the Output_data in Output_segment. @@ -2768,29 +4251,13 @@ Output_segment::maximum_alignment() { if (!this->is_max_align_known_) { - uint64_t 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()) + for (int i = 0; i < static_cast(ORDER_MAX); ++i) { - addralign = parameters->target().common_pagesize(); + const Output_data_list* pdl = &this->output_lists_[i]; + uint64_t addralign = Output_segment::maximum_alignment_list(pdl); if (addralign > this->max_align_) this->max_align_ = addralign; } - this->is_max_align_known_ = true; } @@ -2814,41 +4281,124 @@ Output_segment::maximum_alignment_list(const Output_data_list* pdl) return ret; } -// Return the number of dynamic relocs applied to this segment. +// Return whether this segment has any dynamic relocs. -unsigned int -Output_segment::dynamic_reloc_count() const +bool +Output_segment::has_dynamic_reloc() const { - return (this->dynamic_reloc_count_list(&this->output_data_) - + this->dynamic_reloc_count_list(&this->output_bss_)); + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + if (this->has_dynamic_reloc_list(&this->output_lists_[i])) + return true; + return false; } -// Return the number of dynamic relocs applied to an Output_data_list. +// Return whether this Output_data_list has any dynamic relocs. -unsigned int -Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const +bool +Output_segment::has_dynamic_reloc_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; + if ((*p)->has_dynamic_reloc()) + return true; + return false; } // 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. +// INCREASE_RELRO is the size of the portion of the first non-relro +// section that should be included in the PT_GNU_RELRO segment. +// If this segment has relro sections, and has been aligned for +// that purpose, set *HAS_RELRO to TRUE. Return the address of +// the immediately following segment. Update *HAS_RELRO, *POFF, +// and *PSHNDX. uint64_t -Output_segment::set_section_addresses(const Layout* layout, bool reset, - uint64_t addr, off_t* poff, +Output_segment::set_section_addresses(const Target* target, + Layout* layout, bool reset, + uint64_t addr, + unsigned int* increase_relro, + bool* has_relro, + off_t* poff, unsigned int* pshndx) { gold_assert(this->type_ == elfcpp::PT_LOAD); + uint64_t last_relro_pad = 0; + off_t orig_off = *poff; + + bool in_tls = false; + + // If we have relro sections, we need to pad forward now so that the + // relro sections plus INCREASE_RELRO end on an abi page boundary. + if (parameters->options().relro() + && this->is_first_section_relro() + && (!this->are_addresses_set_ || reset)) + { + uint64_t relro_size = 0; + off_t off = *poff; + uint64_t max_align = 0; + for (int i = 0; i <= static_cast(ORDER_RELRO_LAST); ++i) + { + Output_data_list* pdl = &this->output_lists_[i]; + Output_data_list::iterator p; + for (p = pdl->begin(); p != pdl->end(); ++p) + { + if (!(*p)->is_section()) + break; + uint64_t align = (*p)->addralign(); + if (align > max_align) + max_align = align; + if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)) + in_tls = true; + else if (in_tls) + { + // Align the first non-TLS section to the alignment + // of the TLS segment. + align = max_align; + in_tls = false; + } + // Ignore the size of the .tbss section. + if ((*p)->is_section_flag_set(elfcpp::SHF_TLS) + && (*p)->is_section_type(elfcpp::SHT_NOBITS)) + continue; + relro_size = align_address(relro_size, align); + if ((*p)->is_address_valid()) + relro_size += (*p)->data_size(); + else + { + // FIXME: This could be faster. + (*p)->set_address_and_file_offset(relro_size, + relro_size); + relro_size += (*p)->data_size(); + (*p)->reset_address_and_file_offset(); + } + } + if (p != pdl->end()) + break; + } + relro_size += *increase_relro; + // Pad the total relro size to a multiple of the maximum + // section alignment seen. + uint64_t aligned_size = align_address(relro_size, max_align); + // Note the amount of padding added after the last relro section. + last_relro_pad = aligned_size - relro_size; + *has_relro = true; + + uint64_t page_align = parameters->target().abi_pagesize(); + + // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0. + uint64_t desired_align = page_align - (aligned_size % page_align); + if (desired_align < off % page_align) + off += page_align; + off += desired_align - off % page_align; + addr += off - orig_off; + orig_off = off; + *poff = off; + } + if (!reset && this->are_addresses_set_) { gold_assert(this->paddr_ == addr); @@ -2861,25 +4411,47 @@ Output_segment::set_section_addresses(const Layout* layout, bool reset, this->are_addresses_set_ = true; } - bool in_tls = false; - - bool in_relro = (parameters->options().relro() - && this->is_first_section_relro()); + in_tls = false; - off_t orig_off = *poff; this->offset_ = orig_off; - 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(layout, reset, - &this->output_bss_, - addr, poff, pshndx, - &in_tls, &in_relro); + off_t off = 0; + off_t foff = *poff; + uint64_t ret = 0; + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + { + if (i == static_cast(ORDER_RELRO_LAST)) + { + *poff += last_relro_pad; + foff += last_relro_pad; + addr += last_relro_pad; + if (this->output_lists_[i].empty()) + { + // If there is nothing in the ORDER_RELRO_LAST list, + // the padding will occur at the end of the relro + // segment, and we need to add it to *INCREASE_RELRO. + *increase_relro += last_relro_pad; + } + } + addr = this->set_section_list_addresses(layout, reset, + &this->output_lists_[i], + addr, poff, &foff, pshndx, + &in_tls); + + // FOFF tracks the last offset used for the file image, + // and *POFF tracks the last offset used for the memory image. + // When not using a linker script, bss sections should all + // be processed in the ORDER_SMALL_BSS and later buckets. + gold_assert(*poff == foff + || i == static_cast(ORDER_TLS_BSS) + || i >= static_cast(ORDER_SMALL_BSS) + || layout->script_options()->saw_sections_clause()); + + this->filesz_ = foff - orig_off; + off = foff; + + ret = addr; + } // 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 @@ -2890,20 +4462,47 @@ Output_segment::set_section_addresses(const Layout* layout, bool reset, *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 // objects. *poff = off; + // If code segments must contain only code, and this code segment is + // page-aligned in the file, then fill it out to a whole page with + // code fill (the tail of the segment will not be within any section). + // Thus the entire code segment can be mapped from the file as whole + // pages and that mapping will contain only valid instructions. + if (target->isolate_execinstr() && (this->flags() & elfcpp::PF_X) != 0) + { + uint64_t abi_pagesize = target->abi_pagesize(); + if (orig_off % abi_pagesize == 0 && off % abi_pagesize != 0) + { + size_t fill_size = abi_pagesize - (off % abi_pagesize); + + std::string fill_data; + if (target->has_code_fill()) + fill_data = target->code_fill(fill_size); + else + fill_data.resize(fill_size); // Zero fill. + + Output_data_const* fill = new Output_data_const(fill_data, 0); + fill->set_address(this->vaddr_ + this->memsz_); + fill->set_file_offset(off); + layout->add_relax_output(fill); + + off += fill_size; + gold_assert(off % abi_pagesize == 0); + ret += fill_size; + gold_assert(ret % abi_pagesize == 0); + + gold_assert((uint64_t) this->filesz_ == this->memsz_); + this->memsz_ = this->filesz_ += fill_size; + + *poff = off; + } + } + return ret; } @@ -2911,94 +4510,171 @@ Output_segment::set_section_addresses(const Layout* layout, bool reset, // structures. uint64_t -Output_segment::set_section_list_addresses(const Layout* layout, bool reset, - Output_data_list* pdl, +Output_segment::set_section_list_addresses(Layout* layout, bool reset, + Output_data_list* pdl, uint64_t addr, off_t* poff, + off_t* pfoff, unsigned int* pshndx, - bool* in_tls, bool* in_relro) + bool* in_tls) { off_t startoff = *poff; + // For incremental updates, we may allocate non-fixed sections from + // free space in the file. This keeps track of the high-water mark. + off_t maxoff = startoff; off_t off = startoff; + off_t foff = *pfoff; for (Output_data_list::iterator p = pdl->begin(); p != pdl->end(); ++p) { + bool is_bss = (*p)->is_section_type(elfcpp::SHT_NOBITS); + bool is_tls = (*p)->is_section_flag_set(elfcpp::SHF_TLS); + if (reset) (*p)->reset_address_and_file_offset(); - // When using a linker script the section will most likely - // already have an address. + // When doing an incremental update or 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 align = (*p)->addralign(); + + if (is_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 { - uint64_t page_align = parameters->target().common_pagesize(); - if (page_align > align) - align = page_align; - *in_relro = false; + // 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; + } } - off = align_address(off, align); - (*p)->set_address_and_file_offset(addr + (off - startoff), off); + if (!parameters->incremental_update()) + { + gold_assert(off == foff || is_bss); + off = align_address(off, align); + if (is_tls || !is_bss) + foff = off; + (*p)->set_address_and_file_offset(addr + (off - startoff), foff); + } + else + { + // Incremental update: allocate file space from free list. + (*p)->pre_finalize_data_size(); + off_t current_size = (*p)->current_data_size(); + off = layout->allocate(current_size, align, startoff); + foff = off; + if (off == -1) + { + gold_assert((*p)->output_section() != NULL); + gold_fallback(_("out of patch space for section %s; " + "relink with --incremental-full"), + (*p)->output_section()->name()); + } + (*p)->set_address_and_file_offset(addr + (off - startoff), foff); + if ((*p)->data_size() > current_size) + { + gold_assert((*p)->output_section() != NULL); + gold_fallback(_("%s: section changed size; " + "relink with --incremental-full"), + (*p)->output_section()->name()); + } + } + } + else if (parameters->incremental_update()) + { + // For incremental updates, use the fixed offset for the + // high-water mark computation. + off = (*p)->offset(); + foff = off; } else { // The script may have inserted a skip forward, but it // better not have moved backward. - gold_assert((*p)->address() >= addr + (off - startoff)); - off += (*p)->address() - (addr + (off - startoff)); - (*p)->set_file_offset(off); + if ((*p)->address() >= addr + (off - startoff)) + { + if (!is_bss && off > foff) + gold_warning(_("script places BSS section in the middle " + "of a LOAD segment; space will be allocated " + "in the file")); + off += (*p)->address() - (addr + (off - startoff)); + if (is_tls || !is_bss) + foff = off; + } + 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(foff); (*p)->finalize_data_size(); } - // We want to ignore the size of a SHF_TLS or SHT_NOBITS + if (parameters->incremental_update()) + gold_debug(DEBUG_INCREMENTAL, + "set_section_list_addresses: %08lx %08lx %s", + static_cast(off), + static_cast((*p)->data_size()), + ((*p)->output_section() != NULL + ? (*p)->output_section()->name() : "(special)")); + + // 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 (!(*p)->is_section_flag_set(elfcpp::SHF_TLS) - || !(*p)->is_section_type(elfcpp::SHT_NOBITS)) + if (!is_tls || !is_bss) off += (*p)->data_size(); + // We don't allocate space in the file for SHT_NOBITS sections, + // unless a script has force-placed one in the middle of a segment. + if (!is_bss) + foff = off; + + if (off > maxoff) + maxoff = off; + if ((*p)->is_section()) { (*p)->set_out_shndx(*pshndx); @@ -3006,22 +4682,28 @@ Output_segment::set_section_list_addresses(const Layout* layout, bool reset, } } - *poff = off; - return addr + (off - startoff); + *poff = maxoff; + *pfoff = foff; + return addr + (maxoff - startoff); } // For a non-PT_LOAD segment, set the offset from the sections, if -// any. +// any. Add INCREASE to the file size and the memory size. void -Output_segment::set_offset() +Output_segment::set_offset(unsigned int increase) { gold_assert(this->type_ != elfcpp::PT_LOAD); gold_assert(!this->are_addresses_set_); - if (this->output_data_.empty() && this->output_bss_.empty()) + // A non-load section only uses output_lists_[0]. + + Output_data_list* pdl = &this->output_lists_[0]; + + if (pdl->empty()) { + gold_assert(increase == 0); this->vaddr_ = 0; this->paddr_ = 0; this->are_addresses_set_ = true; @@ -3032,11 +4714,32 @@ Output_segment::set_offset() return; } - const Output_data* first; - if (this->output_data_.empty()) - first = this->output_bss_.front(); - else - first = this->output_data_.front(); + // Find the first and last section by address. + const Output_data* first = NULL; + const Output_data* last_data = NULL; + const Output_data* last_bss = NULL; + for (Output_data_list::const_iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + if (first == NULL + || (*p)->address() < first->address() + || ((*p)->address() == first->address() + && (*p)->data_size() < first->data_size())) + first = *p; + const Output_data** plast; + if ((*p)->is_section() + && (*p)->output_section()->type() == elfcpp::SHT_NOBITS) + plast = &last_bss; + else + plast = &last_data; + if (*plast == NULL + || (*p)->address() > (*plast)->address() + || ((*p)->address() == (*plast)->address() + && (*p)->data_size() > (*plast)->data_size())) + *plast = *p; + } + this->vaddr_ = first->address(); this->paddr_ = (first->has_load_address() ? first->load_address() @@ -3044,25 +4747,38 @@ Output_segment::set_offset() this->are_addresses_set_ = true; this->offset_ = first->offset(); - if (this->output_data_.empty()) + if (last_data == NULL) this->filesz_ = 0; else - { - const Output_data* last_data = this->output_data_.back(); - this->filesz_ = (last_data->address() - + last_data->data_size() - - this->vaddr_); - } + this->filesz_ = (last_data->address() + + last_data->data_size() + - this->vaddr_); - const Output_data* last; - if (this->output_bss_.empty()) - last = this->output_data_.back(); - else - last = this->output_bss_.back(); + const Output_data* last = last_bss != NULL ? last_bss : last_data; this->memsz_ = (last->address() + last->data_size() - this->vaddr_); + this->filesz_ += increase; + this->memsz_ += increase; + + // If this is a RELRO segment, verify that the segment ends at a + // page boundary. + if (this->type_ == elfcpp::PT_GNU_RELRO) + { + uint64_t page_align = parameters->target().abi_pagesize(); + uint64_t segment_end = this->vaddr_ + this->memsz_; + if (parameters->incremental_update()) + { + // The INCREASE_RELRO calculation is bypassed for an incremental + // update, so we need to adjust the segment size manually here. + segment_end = align_address(segment_end, page_align); + this->memsz_ = segment_end - this->vaddr_; + } + else + gold_assert(segment_end == align_address(segment_end, page_align)); + } + // 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. @@ -3072,16 +4788,6 @@ Output_segment::set_offset() 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. @@ -3091,35 +4797,29 @@ 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(); + for (Output_data_list::iterator p = this->output_lists_[0].begin(); + p != this->output_lists_[0].end(); ++p) (*p)->set_tls_offset(this->vaddr_); } -// Return the address of the first section. +// Return the first section. -uint64_t -Output_segment::first_section_load_address() const +Output_section* +Output_segment::first_section() 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(); + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + { + const Output_data_list* pdl = &this->output_lists_[i]; + for (Output_data_list::const_iterator p = pdl->begin(); + p != pdl->end(); + ++p) + { + if ((*p)->is_section()) + return (*p)->output_section(); + } + } + return NULL; } // Return the number of Output_sections in an Output_segment. @@ -3127,8 +4827,10 @@ Output_segment::first_section_load_address() const unsigned int Output_segment::output_section_count() const { - return (this->output_section_count_list(&this->output_data_) - + this->output_section_count_list(&this->output_bss_)); + unsigned int ret = 0; + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + ret += this->output_section_count_list(&this->output_lists_[i]); + return ret; } // Return the number of Output_sections in an Output_data_list. @@ -3156,18 +4858,9 @@ 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; - } - + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + this->lowest_load_address_in_list(&this->output_lists_[i], &found, + &found_lma); return found; } @@ -3219,7 +4912,7 @@ unsigned char* Output_segment::write_section_headers(const Layout* layout, const Stringpool* secnamepool, unsigned char* v, - unsigned int *pshndx) 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 @@ -3227,12 +4920,15 @@ Output_segment::write_section_headers(const Layout* layout, if (this->type_ != elfcpp::PT_LOAD) return v; - 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); + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + { + const Output_data_list* pdl = &this->output_lists_[i]; + v = this->write_section_headers_list(layout, + secnamepool, + pdl, + v, pshndx); + } + return v; } @@ -3269,8 +4965,8 @@ 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_); + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + this->print_section_list_to_mapfile(mapfile, &this->output_lists_[i]); } // Print an output section list to the map file. @@ -3293,10 +4989,103 @@ Output_file::Output_file(const char* name) file_size_(0), base_(NULL), map_is_anonymous_(false), + map_is_allocated_(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. If BASE_NAME is not +// NULL, open that file as the base for incremental linking, and +// copy its contents to the new output file. This routine can +// be called for incremental updates, in which case WRITABLE should +// be true, or by the incremental-dump utility, in which case +// WRITABLE should be false. + +bool +Output_file::open_base_file(const char* base_name, bool writable) +{ + // The name "-" means "stdout". + if (strcmp(this->name_, "-") == 0) + return false; + + bool use_base_file = base_name != NULL; + if (!use_base_file) + base_name = this->name_; + else if (strcmp(base_name, this->name_) == 0) + gold_fatal(_("%s: incremental base and output file name are the same"), + base_name); + + // Don't bother opening files with a size of zero. + struct stat s; + if (::stat(base_name, &s) != 0) + { + gold_info(_("%s: stat: %s"), base_name, strerror(errno)); + return false; + } + if (s.st_size == 0) + { + gold_info(_("%s: incremental base file is empty"), base_name); + return false; + } + + // If we're using a base file, we want to open it read-only. + if (use_base_file) + writable = false; + + int oflags = writable ? O_RDWR : O_RDONLY; + int o = open_descriptor(-1, base_name, oflags, 0); + if (o < 0) + { + gold_info(_("%s: open: %s"), base_name, strerror(errno)); + return false; + } + + // If the base file and the output file are different, open a + // new output file and read the contents from the base file into + // the newly-mapped region. + if (use_base_file) + { + this->open(s.st_size); + ssize_t bytes_to_read = s.st_size; + unsigned char* p = this->base_; + while (bytes_to_read > 0) + { + ssize_t len = ::read(o, p, bytes_to_read); + if (len < 0) + { + gold_info(_("%s: read failed: %s"), base_name, strerror(errno)); + return false; + } + if (len == 0) + { + gold_info(_("%s: file too short: read only %lld of %lld bytes"), + base_name, + static_cast(s.st_size - bytes_to_read), + static_cast(s.st_size)); + return false; + } + p += len; + bytes_to_read -= len; + } + ::close(o); + return true; + } + + this->o_ = o; + this->file_size_ = s.st_size; + + if (!this->map_no_anonymous(writable)) + { + release_descriptor(o, true); + this->o_ = -1; + this->file_size_ = 0; + return false; + } + + return true; +} + // Open the output file. void @@ -3325,8 +5114,22 @@ Output_file::open(off_t file_size) else { struct stat s; - if (::stat(this->name_, &s) == 0 && s.st_size != 0) - unlink_if_ordinary(this->name_); + 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, @@ -3350,10 +5153,23 @@ Output_file::resize(off_t file_size) // to unmap to flush to the file, then remap after growing the file. if (this->map_is_anonymous_) { - 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)); + void* base; + if (!this->map_is_allocated_) + { + base = ::mremap(this->base_, this->file_size_, file_size, + MREMAP_MAYMOVE); + if (base == MAP_FAILED) + gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno)); + } + else + { + base = realloc(this->base_, file_size); + if (base == NULL) + gold_nomem(); + if (file_size > this->file_size_) + memset(static_cast(base) + this->file_size_, 0, + file_size - this->file_size_); + } this->base_ = static_cast(base); this->file_size_ = file_size; } @@ -3361,14 +5177,37 @@ Output_file::resize(off_t file_size) { this->unmap(); this->file_size_ = file_size; - this->map(); + if (!this->map_no_anonymous(true)) + gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno)); } } -// Map the file into memory. +// Map an anonymous block of memory which will later be written to the +// file. Return whether the map succeeded. -void -Output_file::map() +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) + { + base = malloc(this->file_size_); + if (base == NULL) + return false; + memset(base, 0, this->file_size_); + this->map_is_allocated_ = true; + } + this->base_ = static_cast(base); + this->map_is_anonymous_ = true; + return true; +} + +// Map the file into memory. Return whether the mapping succeeded. +// If WRITABLE is true, map with write access. + +bool +Output_file::map_no_anonymous(bool writable) { const int o = this->o_; @@ -3381,28 +5220,59 @@ Output_file::map() || ::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 (writable) { - this->map_is_anonymous_ = true; - base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + int err = gold_fallocate(o, 0, this->file_size_); + if (err != 0) + gold_fatal(_("%s: %s"), this->name_, strerror(err)); } - else - { - // Write out one byte to make the file the right size. - if (::lseek(o, this->file_size_ - 1, SEEK_SET) < 0) - gold_fatal(_("%s: lseek: %s"), this->name_, strerror(errno)); - char b = 0; - if (::write(o, &b, 1) != 1) - gold_fatal(_("%s: write: %s"), this->name_, strerror(errno)); - // Map the file into memory. - this->map_is_anonymous_ = false; - base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE, - MAP_SHARED, o, 0); - } + // Map the file into memory. + int prot = PROT_READ; + if (writable) + prot |= PROT_WRITE; + base = ::mmap(NULL, this->file_size_, prot, 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) - gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno)); + return false; + + this->map_is_anonymous_ = false; this->base_ = static_cast(base); + return true; +} + +// Map the file into memory. + +void +Output_file::map() +{ + if (parameters->options().mmap_output_file() + && this->map_no_anonymous(true)) + 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. @@ -3410,8 +5280,16 @@ Output_file::map() void Output_file::unmap() { - if (::munmap(this->base_, this->file_size_) < 0) - gold_error(_("%s: munmap: %s"), this->name_, strerror(errno)); + if (this->map_is_anonymous_) + { + // We've already written out the data, so there is no reason to + // waste time unmapping or freeing the memory. + } + else + { + if (::munmap(this->base_, this->file_size_) < 0) + gold_error(_("%s: munmap: %s"), this->name_, strerror(errno)); + } this->base_ = NULL; } @@ -3424,16 +5302,21 @@ Output_file::close() if (this->map_is_anonymous_ && !this->is_temporary_) { 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_, 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; - } + { + 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(); @@ -3453,7 +5336,8 @@ Output_file::close() template off_t Output_section::add_input_section<32, false>( - Sized_relobj<32, false>* object, + Layout* layout, + Sized_relobj_file<32, false>* object, unsigned int shndx, const char* secname, const elfcpp::Shdr<32, false>& shdr, @@ -3465,7 +5349,8 @@ Output_section::add_input_section<32, false>( template off_t Output_section::add_input_section<32, true>( - Sized_relobj<32, true>* object, + Layout* layout, + Sized_relobj_file<32, true>* object, unsigned int shndx, const char* secname, const elfcpp::Shdr<32, true>& shdr, @@ -3477,7 +5362,8 @@ Output_section::add_input_section<32, true>( template off_t Output_section::add_input_section<64, false>( - Sized_relobj<64, false>* object, + Layout* layout, + Sized_relobj_file<64, false>* object, unsigned int shndx, const char* secname, const elfcpp::Shdr<64, false>& shdr, @@ -3489,7 +5375,8 @@ Output_section::add_input_section<64, false>( template off_t Output_section::add_input_section<64, true>( - Sized_relobj<64, true>* object, + Layout* layout, + Sized_relobj_file<64, true>* object, unsigned int shndx, const char* secname, const elfcpp::Shdr<64, true>& shdr, @@ -3717,24 +5604,16 @@ 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.