X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Foutput.cc;h=9bf6a42122b0e153d7817c407099156133d20258;hb=8f00849d119b05066ce3f5ea1f1c72f05a76ea01;hp=d49f08b605c715a10dde25d9703aee206f869c5b;hpb=2a0ff005c89d674c7e233c7fa612aa2434bcd8df;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/output.cc b/gold/output.cc index d49f08b605..9bf6a42122 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 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -27,24 +27,90 @@ #include #include #include -#include #include #include + +#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 + #ifndef HAVE_POSIX_FALLOCATE // A dummy, non general, version of posix_fallocate. Here we just set // the file size and hope that there is enough disk space. FIXME: We @@ -57,6 +123,11 @@ posix_fallocate(int o, off_t offset, off_t len) } #endif // !defined(HAVE_POSIX_FALLOCATE) +// Mingw does not have S_ISLNK. +#ifndef S_ISLNK +# define S_ISLNK(mode) 0 +#endif + namespace gold { @@ -280,6 +351,7 @@ Output_segment_headers::Output_segment_headers( const Layout::Segment_list& segment_list) : segment_list_(segment_list) { + this->set_current_data_size_for_child(this->do_size()); } void @@ -355,14 +427,12 @@ Output_segment_headers::do_size() const Output_file_header::Output_file_header(const 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) { this->set_data_size(this->do_size()); } @@ -411,7 +481,7 @@ 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 @@ -502,22 +572,16 @@ Output_file_header::do_sized_write(Output_file* of) 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"; - + const char* entry = parameters->entry(); Symbol* sym = this->symtab_->lookup(entry); typename Sized_symbol::Value_type v; @@ -871,10 +935,13 @@ set_needs_dynsym_index() default: { 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_) - this->u1_.relobj->set_needs_output_dynsym_entry(lsi); + relobj->set_needs_output_dynsym_entry(lsi); else - this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index(); + relobj->output_section(lsi)->set_needs_dynsym_index(); } break; } @@ -924,16 +991,19 @@ Output_reloc::get_symbol_index() default: { 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 = this->u1_.relobj->dynsym_index(lsi); + index = relobj->dynsym_index(lsi); else - index = this->u1_.relobj->symtab_index(lsi); + index = relobj->symtab_index(lsi); } else { - Output_section* os = this->u1_.relobj->output_section(lsi); + Output_section* os = relobj->output_section(lsi); gold_assert(os != NULL); if (dynamic) index = os->dynsym_index(); @@ -968,7 +1038,10 @@ 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; } @@ -989,8 +1062,10 @@ 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); } } @@ -1043,8 +1118,11 @@ Output_reloc::symbol_value( && 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); + const Symbol_value* symval = relobj->local_symbol(lsi); + return symval->value(relobj, addend); } // Reloc comparison. This function sorts the dynamic relocs for the @@ -1133,10 +1211,17 @@ 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(); } // Write out relocation data. @@ -1188,7 +1273,7 @@ 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) @@ -1262,12 +1347,18 @@ 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_offset_ && gsym->has_plt_offset()) + val = (parameters->target().plt_address_for_global(gsym) + + gsym->plt_offset()); + else + { + Sized_symbol* sgsym; + // This cast is a bit ugly. We don't want to put a + // virtual method in Symbol, because we want Symbol to be + // as small as possible. + sgsym = static_cast*>(gsym); + val = sgsym->value(); + } } break; @@ -1275,11 +1366,26 @@ 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 Sized_relobj_file* object = this->u_.object; 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 Symbol_value* symval = object->local_symbol(lsi); + if (!this->use_plt_offset_) + val = symval->value(this->u_.object, 0); + else + { + uint64_t plt_address = + parameters->target().plt_address_for_local(object, lsi); + val = plt_address + object->local_plt_offset(lsi); + } } break; } @@ -1302,14 +1408,29 @@ Output_data_got::add_global( 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; +} + +// 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 false; + + unsigned int got_offset = this->add_got_entry(Got_entry(gsym, true)); + 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( @@ -1321,9 +1442,7 @@ Output_data_got::add_global_with_rel( 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); rel_dyn->add_global(gsym, r_type, this, got_offset); } @@ -1339,9 +1458,7 @@ Output_data_got::add_global_with_rela( 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); } @@ -1361,19 +1478,12 @@ Output_data_got::add_global_pair_with_rel( 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); 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(); + rel_dyn->add_global(gsym, r_type_2, this, got_offset + size / 8); } template @@ -1388,19 +1498,12 @@ Output_data_got::add_global_pair_with_rela( 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); - 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(); + rela_dyn->add_global(gsym, r_type_2, this, got_offset + size / 8, 0); } // Add an entry for a local symbol to the GOT. This returns true if @@ -1410,25 +1513,44 @@ Output_data_got::add_global_pair_with_rela( template bool Output_data_got::add_local( - Sized_relobj* object, + Sized_relobj_file* 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, + false)); + object->set_local_got_offset(symndx, got_type, got_offset); + return true; +} + +// Like add_local, but use the PLT offset. + +template +bool +Output_data_got::add_local_plt( + Sized_relobj_file* 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, + 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( - Sized_relobj* object, + Sized_relobj_file* object, unsigned int symndx, unsigned int got_type, Rel_dyn* rel_dyn, @@ -1437,9 +1559,7 @@ Output_data_got::add_local_with_rel( 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); rel_dyn->add_local(object, symndx, r_type, this, got_offset); } @@ -1447,7 +1567,7 @@ Output_data_got::add_local_with_rel( template void Output_data_got::add_local_with_rela( - Sized_relobj* object, + Sized_relobj_file* object, unsigned int symndx, unsigned int got_type, Rela_dyn* rela_dyn, @@ -1456,9 +1576,7 @@ Output_data_got::add_local_with_rela( 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); } @@ -1469,7 +1587,7 @@ Output_data_got::add_local_with_rela( template void Output_data_got::add_local_pair_with_rel( - Sized_relobj* object, + Sized_relobj_file* object, unsigned int symndx, unsigned int shndx, unsigned int got_type, @@ -1480,26 +1598,21 @@ Output_data_got::add_local_pair_with_rel( 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); - this->entries_.push_back(Got_entry(object, symndx)); if (r_type_2 != 0) - { - got_offset = this->last_got_offset(); - rel_dyn->add_output_section(os, r_type_2, this, got_offset); - } - - this->set_got_size(); + rel_dyn->add_output_section(os, r_type_2, this, got_offset + size / 8); } template void Output_data_got::add_local_pair_with_rela( - Sized_relobj* object, + Sized_relobj_file* object, unsigned int symndx, unsigned int shndx, unsigned int got_type, @@ -1510,20 +1623,42 @@ Output_data_got::add_local_pair_with_rela( 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); rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0); - this->entries_.push_back(Got_entry(object, symndx)); if (r_type_2 != 0) - { - got_offset = this->last_got_offset(); - rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0); - } + rela_dyn->add_output_section(os, r_type_2, this, got_offset + size / 8, 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, + Sized_relobj* object, + unsigned int sym_index, + unsigned int got_type) +{ + this->reserve_slot(i); + object->set_local_got_offset(sym_index, got_type, this->got_offset(i)); +} - this->set_got_size(); +// Reserve a slot in the GOT for a global symbol. + +template +void +Output_data_got::reserve_global( + unsigned int i, + Symbol* gsym, + unsigned int got_type) +{ + this->reserve_slot(i); + gsym->set_got_offset(got_type, this->got_offset(i)); } // Write out the GOT. @@ -1555,6 +1690,63 @@ 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(size / 8, size / 8, 0); + if (got_offset == -1) + gold_fallback(_("out of patch space (GOT);" + " relink with --incremental-full")); + unsigned int got_index = got_offset / (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 * size / 8, size / 8, 0); + if (got_offset == -1) + gold_fallback(_("out of patch space (GOT);" + " relink with --incremental-full")); + unsigned int got_index = got_offset / (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); + } +} + // Output_data_dynamic::Dynamic_entry methods. // Write out the entry. @@ -1622,9 +1814,13 @@ Output_data_dynamic::set_final_data_size() { // Add the terminating entry if it hasn't been added. // Because of relaxation, we can run this multiple times. - if (this->entries_.empty() - || this->entries_.rbegin()->tag() != elfcpp::DT_NULL) - this->add_constant(elfcpp::DT_NULL, 0); + 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) @@ -1731,8 +1927,159 @@ Output_symtab_xindex::endian_do_write(unsigned char* const oview) } } +// 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<32, true>::writeval(pov, len - 4); + elfcpp::Swap<16, true>::writeval(pov + 4, this->version); + elfcpp::Swap<32, true>::writeval(pov + 6, 0); + } + else + { + elfcpp::Swap<32, false>::writeval(pov, len - 4); + elfcpp::Swap<16, false>::writeval(pov + 4, this->version); + elfcpp::Swap<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<32, true>::writeval(pov, len - 4); + elfcpp::Swap<16, true>::writeval(pov + 4, this->version); + elfcpp::Swap<32, true>::writeval(pov + 6, len - (4 + 2 + 4)); + } + else + { + elfcpp::Swap<32, false>::writeval(pov, len - 4); + elfcpp::Swap<16, false>::writeval(pov + 4, this->version); + elfcpp::Swap<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. @@ -1745,6 +2092,42 @@ 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 @@ -1787,7 +2170,7 @@ 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); @@ -1877,6 +2260,7 @@ 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), @@ -1893,26 +2277,26 @@ 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), - is_last_relro_(false), - is_first_non_relro_(false), is_small_section_(false), is_large_section_(false), - is_interp_(false), - is_dynamic_linker_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), tls_offset_(0), checkpoint_(NULL), - merge_section_map_(), - merge_section_by_properties_map_(), - relaxed_input_section_map_(), - is_relaxed_input_section_map_valid_(true) + lookup_maps_(new Output_section_lookup_maps), + free_list_(), + free_space_fill_(NULL), + patch_space_(0) { // An unallocated section has no address. Forcing this means that // we don't need special treatment for symbols defined in debug @@ -1956,7 +2340,8 @@ 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, @@ -1992,12 +2377,20 @@ Output_section::add_input_section(Sized_relobj* object, // 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. @@ -2005,18 +2398,43 @@ Output_section::add_input_section(Sized_relobj* object, } } - off_t offset_in_section = this->current_data_size_for_child(); - off_t aligned_offset_in_section = align_address(offset_in_section, - addralign); + section_size_type input_section_size = shdr.get_sh_size(); + section_size_type uncompressed_size; + if (object->section_is_compressed(shndx, &uncompressed_size)) + input_section_size = uncompressed_size; + + off_t offset_in_section; + off_t aligned_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()); + aligned_offset_in_section = offset_in_section; + } + else + { + offset_in_section = this->current_data_size_for_child(); + aligned_offset_in_section = align_address(offset_in_section, + 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. + // 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()) + && (parameters->target().may_relax() + || layout->is_section_ordering_specified())) { gold_assert(this->fills_.empty()); this->generate_code_fills_at_write_ = true; @@ -2042,22 +2460,42 @@ Output_section::add_input_section(Sized_relobj* object, } } - this->set_current_data_size_for_child(aligned_offset_in_section - + shdr.get_sh_size()); - // We need to keep track of this section if we are already keeping // track of sections, or if we are relaxing. Also, if this is a // section which requires sorting, or which may require sorting in - // the future, we keep track of the sections. - if (have_sections_script + // 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() - || parameters->target().may_relax()) - this->input_sections_.push_back(Input_section(object, shndx, - shdr.get_sh_size(), - addralign)); + || parameters->target().may_relax() + || layout->is_section_ordering_specified()) + { + Input_section isecn(object, shndx, input_section_size, addralign); + if (layout->is_section_ordering_specified()) + { + 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(); + } + } + if (this->has_fixed_layout()) + { + // For incremental updates, finalize the address and offset now. + uint64_t addr = this->address(); + isecn.set_address_and_file_offset(addr + aligned_offset_in_section, + aligned_offset_in_section, + this->offset()); + } + this->input_sections_.push_back(isecn); + } return aligned_offset_in_section; } @@ -2072,27 +2510,71 @@ 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(Output_relaxed_input_section* poris) +Output_section::add_relaxed_input_section(Layout* layout, + Output_relaxed_input_section* poris, + const std::string& name) { Input_section inp(poris); - this->add_output_section_data(&inp); - if (this->is_relaxed_input_section_map_valid_) + + // 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()) { - Const_section_id csid(poris->relobj(), poris->shndx()); - this->relaxed_input_section_map_[csid] = poris; + 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 them same output section to compute the @@ -2137,7 +2619,8 @@ 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; @@ -2150,58 +2633,71 @@ Output_section::add_merge_input_section(Relobj* object, unsigned int shndx, 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); - Merge_section_by_properties_map::const_iterator p = - this->merge_section_by_properties_map_.find(msp); - if (p != this->merge_section_by_properties_map_.end()) + Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp); + bool is_new = false; + if (pomb != NULL) { - Output_merge_base* merge_section = p->second; - merge_section->add_input_section(object, shndx); - gold_assert(merge_section->is_string() == is_string - && merge_section->entsize() == entsize - && merge_section->addralign() == addralign); - - // Link input section to found merge section. - Const_section_id csid(object, shndx); - this->merge_section_map_[csid] = merge_section; - return true; + gold_assert(pomb->is_string() == is_string + && pomb->entsize() == entsize + && pomb->addralign() == addralign); } - - // We handle the actual constant merging in Output_merge_data or - // Output_merge_string_data. - Output_merge_base* pomb; - if (!is_string) - pomb = new Output_merge_data(entsize, addralign); else { - switch (entsize) + // Create a new Output_merge_data or Output_merge_string_data. + if (!is_string) + pomb = new Output_merge_data(entsize, addralign); + else { - 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; + 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; } - // Add new merge section to this output section and link merge section - // properties to new merge section in map. - this->add_output_merge_section(pomb, is_string, entsize); - this->merge_section_by_properties_map_[msp] = pomb; - - // Add input section to new merge section and link input section to new - // merge section in map. - pomb->add_input_section(object, shndx); - Const_section_id csid(object, shndx); - this->merge_section_map_[csid] = pomb; + 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; + // Add input section to new merge section and link input section to new + // merge section in map. + this->lookup_maps_->add_merge_input_section(object, shndx, pomb); + 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. @@ -2241,7 +2737,13 @@ Output_section::convert_input_sections_in_list_to_relaxed_sections( 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); } } @@ -2296,12 +2798,12 @@ Output_section::convert_input_sections_to_relaxed_sections( &this->input_sections_); // Update fast look-up map. - if (this->is_relaxed_input_section_map_valid_) + if (this->lookup_maps_->is_valid()) for (size_t i = 0; i < relaxed_sections.size(); ++i) { Output_relaxed_input_section* poris = relaxed_sections[i]; - Const_section_id csid(poris->relobj(), poris->shndx()); - this->relaxed_input_section_map_[csid] = poris; + this->lookup_maps_->add_relaxed_input_section(poris->relobj(), + poris->shndx(), poris); } } @@ -2346,51 +2848,59 @@ Output_section_data* Output_section::find_merge_section(const Relobj* object, unsigned int shndx) const { - Const_section_id csid(object, shndx); - Output_section_data_by_input_section_map::const_iterator p = - this->merge_section_map_.find(csid); - if (p != this->merge_section_map_.end()) - { - Output_section_data* posd = p->second; - gold_assert(posd->is_merge_section_for(object, shndx)); - return posd; - } - else - return NULL; + if (!this->lookup_maps_->is_valid()) + this->build_lookup_maps(); + return this->lookup_maps_->find_merge_section(object, shndx); } -// Find an relaxed input section corresponding to an input section -// in OBJECT with index SHNDX. +// Build the lookup maps for merge and relaxed sections. This is needs +// to be declared as a const methods so that it is callable with a const +// Output_section pointer. The method only updates states of the maps. -const Output_relaxed_input_section* -Output_section::find_relaxed_input_section(const Relobj* object, - unsigned int shndx) const +void +Output_section::build_lookup_maps() const { - // Be careful that the map may not be valid due to input section export - // to scripts or a check-point restore. - if (!this->is_relaxed_input_section_map_valid_) + this->lookup_maps_->clear(); + for (Input_section_list::const_iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) { - // Rebuild the map as needed. - this->relaxed_input_section_map_.clear(); - for (Input_section_list::const_iterator p = this->input_sections_.begin(); - p != this->input_sections_.end(); - ++p) - if (p->is_relaxed_input_section()) - { - Const_section_id csid(p->relobj(), p->shndx()); - this->relaxed_input_section_map_[csid] = - p->relaxed_input_section(); - } - this->is_relaxed_input_section_map_valid_ = true; + if (p->is_merge_section()) + { + Output_merge_base* pomb = p->output_merge_base(); + Merge_section_properties msp(pomb->is_string(), pomb->entsize(), + pomb->addralign()); + this->lookup_maps_->add_merge_section(msp, pomb); + for (Output_merge_base::Input_sections::const_iterator is = + pomb->input_sections_begin(); + is != pomb->input_sections_end(); + ++is) + { + const Const_section_id& csid = *is; + this->lookup_maps_->add_merge_input_section(csid.first, + csid.second, pomb); + } + + } + else 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); + } } +} - Const_section_id csid(object, shndx); - Output_relaxed_input_section_by_input_section_map::const_iterator p = - this->relaxed_input_section_map_.find(csid); - if (p != this->relaxed_input_section_map_.end()) - return p->second; - else - return NULL; +// 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 @@ -2549,35 +3059,81 @@ 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_data_size(off - startoff); + 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 = startoff + this->first_input_offset_; + for (Input_section_list::iterator p = this->input_sections_.begin(); + p != this->input_sections_.end(); + ++p) + { + off = align_address(off, p->addralign()); + p->set_address_and_file_offset(address + (off - startoff), off, + startoff); + off += p->data_size(); + } + data_size = off - startoff; + } + + // 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(data_size); } // Reset the address and file offset. @@ -2587,16 +3143,25 @@ Output_section::do_reset_address_and_file_offset() { // An unallocated section has no address. Forcing this means that // we don't need special treatment for symbols defined in debug - // sections. We do the same in the constructor. - if ((this->flags_ & elfcpp::SHF_ALLOC) == 0) + // 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 @@ -2625,7 +3190,7 @@ 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 @@ -2637,12 +3202,14 @@ class Output_section::Input_section_sort_entry { } Input_section_sort_entry(const Input_section& input_section, - unsigned int index) + unsigned int index, + bool must_sort_attached_input_sections) : input_section_(input_section), index_(index), section_has_name_(input_section.is_input_section() || input_section.is_relaxed_input_section()) { - if (this->section_has_name_) + if (this->section_has_name_ + && 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 @@ -2698,6 +3265,34 @@ class Output_section::Input_section_sort_entry 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 + { + gold_assert(this->section_has_name_); + 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 // FILE_NAME. The base name must have an extension of ".o", and // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o". @@ -2706,17 +3301,24 @@ 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 + { 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 { - const std::string& file_name(this->input_section_.relobj()->name()); - const char* base_name = lbasename(file_name.c_str()); - size_t match_len = strlen(match_file_name); - if (strncmp(base_name, match_file_name, match_len) != 0) - return false; - size_t base_len = strlen(base_name); - if (base_len != match_len + 2 && base_len != match_len + 3) - return false; - return memcmp(base_name + base_len - 2, ".o", 2) == 0; + 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: @@ -2780,6 +3382,12 @@ 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) @@ -2816,6 +3424,34 @@ Output_section::Input_section_sort_init_fini_compare::operator()( 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) @@ -2825,6 +3461,57 @@ Output_section::Input_section_sort_init_fini_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; +} + +// 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()) + { + Object* 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 @@ -2850,17 +3537,27 @@ 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())); // Sort the 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()); + 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 + std::sort(sort_list.begin(), sort_list.end(), + Input_section_sort_compare()); + } else - std::sort(sort_list.begin(), sort_list.end(), - Input_section_sort_compare()); + { + 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(); @@ -2868,6 +3565,7 @@ 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. @@ -2896,7 +3594,7 @@ 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 @@ -2958,6 +3656,26 @@ Output_section::do_write(Output_file* of) 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. @@ -3043,14 +3761,14 @@ 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 the relaxed input section map. - this->is_relaxed_input_section_map_valid_ = false; + // Invalidate fast look-up maps. + this->lookup_maps_->invalidate(); uint64_t orig_address = address; @@ -3061,12 +3779,10 @@ Output_section::get_input_sections( p != this->input_sections_.end(); ++p) { - if (p->is_input_section()) - input_sections->push_back(Simple_input_section(p->relobj(), - p->shndx())); - else if (p->is_relaxed_input_section()) - input_sections->push_back( - Simple_input_section(p->relaxed_input_section())); + 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()); @@ -3101,13 +3817,16 @@ Output_section::get_input_sections( return data_size; } -// Add an simple input section. +// 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_simple_input_section(const Simple_input_section& sis, - 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; @@ -3118,11 +3837,31 @@ Output_section::add_simple_input_section(const Simple_input_section& sis, this->set_current_data_size_for_child(aligned_offset_in_section + data_size); - Input_section is = - (sis.is_relaxed_input_section() - ? Input_section(sis.relaxed_input_section()) - : Input_section(sis.relobj(), sis.shndx(), data_size, addralign)); - this->input_sections_.push_back(is); + this->input_sections_.push_back(sis); + + // Update fast lookup maps if necessary. + if (this->lookup_maps_->is_valid()) + { + if (sis.is_merge_section()) + { + Output_merge_base* pomb = sis.output_merge_base(); + Merge_section_properties msp(pomb->is_string(), pomb->entsize(), + pomb->addralign()); + this->lookup_maps_->add_merge_section(msp, pomb); + for (Output_merge_base::Input_sections::const_iterator p = + pomb->input_sections_begin(); + p != pomb->input_sections_end(); + ++p) + this->lookup_maps_->add_merge_input_section(p->first, p->second, + pomb); + } + else 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. @@ -3148,9 +3887,9 @@ Output_section::discard_states() this->checkpoint_ = NULL; gold_assert(this->fills_.empty()); - // Simply invalidate the relaxed input section map since we do not keep - // track of it. - this->is_relaxed_input_section_map_valid_ = false; + // Simply invalidate the fast lookup maps since we do not keep + // track of them. + this->lookup_maps_->invalidate(); } void @@ -3182,9 +3921,9 @@ Output_section::restore_states() this->attached_input_sections_are_sorted_ = checkpoint->attached_input_sections_are_sorted(); - // Simply invalidate the relaxed input section map since we do not keep - // track of it. - this->is_relaxed_input_section_map_valid_ = false; + // 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 @@ -3235,12 +3974,44 @@ 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), @@ -3259,293 +4030,64 @@ Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags) 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, - bool do_sort) +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()); - gold_assert(this->type() == elfcpp::PT_LOAD || !do_sort); 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_; - - // 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. The loops below are expected to be fast. + gold_assert(order != ORDER_INVALID); - // So that PT_NOTE segments will work correctly, we need to ensure - // that all SHT_NOTE sections are adjacent. - 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_; - if (!pdl->empty()) - { - bool nobits = os->type() == elfcpp::SHT_NOBITS; - bool sawtls = false; - Output_segment::Output_data_list::iterator p = pdl->end(); - gold_assert(p != pdl->begin()); - do - { - --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. - } - - if (do_sort) - { - // For the PT_GNU_RELRO segment, we need to group relro - // sections, and we need to put them before any non-relro - // sections. Any relro local sections go before relro non-local - // sections. One section may be marked as the last relro - // section. - if (os->is_relro()) - { - gold_assert(pdl == &this->output_data_); - Output_segment::Output_data_list::iterator p; - for (p = pdl->begin(); p != pdl->end(); ++p) - { - if (!(*p)->is_section()) - break; - - Output_section* pos = (*p)->output_section(); - if (!pos->is_relro() - || (os->is_relro_local() && !pos->is_relro_local()) - || (!os->is_last_relro() && pos->is_last_relro())) - break; - } - - pdl->insert(p, os); - return; - } + this->output_lists_[order].push_back(os); +} - // One section may be marked as the first section which follows - // the relro sections. - if (os->is_first_non_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; +// Add an Output_section to a non-PT_LOAD Output_segment. - Output_section* pos = (*p)->output_section(); - if (!pos->is_relro()) - break; - } +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->insert(p, os); - return; - } - } + this->update_flags_for_output_section(seg_flags); - // Small data sections go at the end of the list of data sections. - // If OS is not small, and there are small sections, we have to - // insert it before the first small section. - if (os->type() != elfcpp::SHT_NOBITS - && !os->is_small_section() - && !pdl->empty() - && pdl->back()->is_section() - && pdl->back()->output_section()->is_small_section()) - { - for (Output_segment::Output_data_list::iterator p = pdl->begin(); - p != pdl->end(); - ++p) - { - if ((*p)->is_section() - && (*p)->output_section()->is_small_section()) - { - pdl->insert(p, os); - return; - } - } - gold_unreachable(); - } + this->output_lists_[0].push_back(os); +} - // A small BSS section goes at the start of the BSS sections, after - // other small BSS sections. - if (os->type() == elfcpp::SHT_NOBITS && os->is_small_section()) - { - for (Output_segment::Output_data_list::iterator p = pdl->begin(); - p != pdl->end(); - ++p) - { - if (!(*p)->is_section() - || !(*p)->output_section()->is_small_section()) - { - pdl->insert(p, os); - return; - } - } - } +// Remove an Output_section from this segment. It is an error if it +// is not present. - // A large BSS section goes at the end of the BSS sections, which - // means that one that is not large must come before the first large - // one. - if (os->type() == elfcpp::SHT_NOBITS - && !os->is_large_section() - && !pdl->empty() - && pdl->back()->is_section() - && pdl->back()->output_section()->is_large_section()) +void +Output_segment::remove_output_section(Output_section* os) +{ + for (int i = 0; i < static_cast(ORDER_MAX); ++i) { - for (Output_segment::Output_data_list::iterator p = pdl->begin(); - p != pdl->end(); - ++p) + Output_data_list* pdl = &this->output_lists_[i]; + for (Output_data_list::iterator p = pdl->begin(); p != pdl->end(); ++p) { - if ((*p)->is_section() - && (*p)->output_section()->is_large_section()) + if (*p == os) { - pdl->insert(p, os); + pdl->erase(p); return; } } - gold_unreachable(); - } - - // We do some further output section sorting in order to make the - // generated program run more efficiently. We should only do this - // when not using a linker script, so it is controled by the DO_SORT - // parameter. - if (do_sort) - { - // FreeBSD requires the .interp section to be in the first page - // of the executable. That is a more efficient location anyhow - // for any OS, since it means that the kernel will have the data - // handy after it reads the program headers. - if (os->is_interp() && !pdl->empty()) - { - pdl->insert(pdl->begin(), os); - return; - } - - // Put loadable non-writable notes immediately after the .interp - // sections, so that the PT_NOTE segment is on the first page of - // the executable. - if (os->type() == elfcpp::SHT_NOTE - && (os->flags() & elfcpp::SHF_WRITE) == 0 - && !pdl->empty()) - { - Output_segment::Output_data_list::iterator p = pdl->begin(); - if ((*p)->is_section() && (*p)->output_section()->is_interp()) - ++p; - pdl->insert(p, os); - return; - } - - // If this section is used by the dynamic linker, and it is not - // writable, then put it first, after the .interp section and - // any loadable notes. This makes it more likely that the - // dynamic linker will have to read less data from the disk. - if (os->is_dynamic_linker_section() - && !pdl->empty() - && (os->flags() & elfcpp::SHF_WRITE) == 0) - { - bool is_reloc = (os->type() == elfcpp::SHT_REL - || os->type() == elfcpp::SHT_RELA); - Output_segment::Output_data_list::iterator p = pdl->begin(); - while (p != pdl->end() - && (*p)->is_section() - && ((*p)->output_section()->is_dynamic_linker_section() - || (*p)->output_section()->type() == elfcpp::SHT_NOTE)) - { - // Put reloc sections after the other ones. Putting the - // dynamic reloc sections first confuses BFD, notably - // objcopy and strip. - if (!is_reloc - && ((*p)->output_section()->type() == elfcpp::SHT_REL - || (*p)->output_section()->type() == elfcpp::SHT_RELA)) - break; - ++p; - } - pdl->insert(p, os); - return; - } } - - // If there were no constraints on the output section, just add it - // to the end of the list. - pdl->push_back(os); -} - -// Remove an Output_section from this segment. It is an error if it -// is not present. - -void -Output_segment::remove_output_section(Output_section* os) -{ - // We only need this for SHT_PROGBITS. - gold_assert(os->type() == elfcpp::SHT_PROGBITS); - for (Output_data_list::iterator p = this->output_data_.begin(); - p != this->output_data_.end(); - ++p) - { - if (*p == os) - { - this->output_data_.erase(p); - return; - } - } gold_unreachable(); } @@ -3556,17 +4098,51 @@ 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 whether the first data section is a relro section. +// 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 (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_DATA) + || 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. @@ -3576,16 +4152,13 @@ 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; - + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + { + 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; } @@ -3609,45 +4182,55 @@ 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, +Output_segment::set_section_addresses(Layout* layout, bool reset, uint64_t addr, - unsigned int increase_relro, + 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 a common page boundary. if (parameters->options().relro() @@ -3656,33 +4239,58 @@ Output_segment::set_section_addresses(const Layout* layout, bool reset, { uint64_t relro_size = 0; off_t off = *poff; - for (Output_data_list::iterator p = this->output_data_.begin(); - p != this->output_data_.end(); - ++p) + uint64_t max_align = 0; + for (int i = 0; i <= static_cast(ORDER_RELRO_LAST); ++i) { - if (!(*p)->is_section()) - break; - Output_section* pos = (*p)->output_section(); - if (!pos->is_relro()) - break; - gold_assert(!(*p)->is_section_flag_set(elfcpp::SHF_TLS)); - if ((*p)->is_address_valid()) - relro_size += (*p)->data_size(); - else + Output_data_list* pdl = &this->output_lists_[i]; + Output_data_list::iterator p; + for (p = pdl->begin(); p != pdl->end(); ++p) { - // FIXME: This could be faster. - (*p)->set_address_and_file_offset(addr + relro_size, - off + relro_size); - relro_size += (*p)->data_size(); - (*p)->reset_address_and_file_offset(); + 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; + } + relro_size = align_address(relro_size, align); + // Ignore the size of the .tbss section. + if ((*p)->is_section_flag_set(elfcpp::SHF_TLS) + && (*p)->is_section_type(elfcpp::SHT_NOBITS)) + continue; + if ((*p)->is_address_valid()) + relro_size += (*p)->data_size(); + else + { + // FIXME: This could be faster. + (*p)->set_address_and_file_offset(addr + relro_size, + off + relro_size); + relro_size += (*p)->data_size(); + (*p)->reset_address_and_file_offset(); + } } + if (p != pdl->end()) + break; } - relro_size += increase_relro; + 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().common_pagesize(); // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0. - uint64_t desired_align = page_align - (relro_size % page_align); + uint64_t desired_align = page_align - (aligned_size % page_align); if (desired_align < *poff % page_align) *poff += page_align - *poff % page_align; *poff += desired_align - *poff % page_align; @@ -3702,20 +4310,37 @@ Output_segment::set_section_addresses(const Layout* layout, bool reset, this->are_addresses_set_ = true; } - bool in_tls = false; + in_tls = false; this->offset_ = orig_off; - addr = this->set_section_list_addresses(layout, reset, &this->output_data_, - addr, poff, pshndx, &in_tls); - this->filesz_ = *poff - orig_off; - - off_t off = *poff; + off_t off = 0; + uint64_t ret; + for (int i = 0; i < static_cast(ORDER_MAX); ++i) + { + if (i == static_cast(ORDER_RELRO_LAST)) + { + *poff += 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, pshndx, &in_tls); + if (i < static_cast(ORDER_SMALL_BSS)) + { + this->filesz_ = *poff - orig_off; + off = *poff; + } - uint64_t ret = this->set_section_list_addresses(layout, reset, - &this->output_bss_, - addr, poff, pshndx, - &in_tls); + 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 @@ -3739,13 +4364,16 @@ 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_segment::set_section_list_addresses(Layout* layout, bool reset, Output_data_list* pdl, uint64_t addr, off_t* poff, unsigned int* pshndx, 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; for (Output_data_list::iterator p = pdl->begin(); @@ -3755,8 +4383,8 @@ Output_segment::set_section_list_addresses(const Layout* layout, bool reset, 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(); @@ -3794,9 +4422,40 @@ Output_segment::set_section_list_addresses(const Layout* layout, bool reset, } } - off = align_address(off, align); - (*p)->set_address_and_file_offset(addr + (off - startoff), off); + if (!parameters->incremental_update()) + { + off = align_address(off, align); + (*p)->set_address_and_file_offset(addr + (off - startoff), off); + } + 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); + 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), off); + 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(); + } else { // The script may have inserted a skip forward, but it @@ -3830,13 +4489,24 @@ Output_segment::set_section_list_addresses(const Layout* layout, bool reset, (*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)) off += (*p)->data_size(); + if (off > maxoff) + maxoff = off; + if ((*p)->is_section()) { (*p)->set_out_shndx(*pshndx); @@ -3844,8 +4514,8 @@ Output_segment::set_section_list_addresses(const Layout* layout, bool reset, } } - *poff = off; - return addr + (off - startoff); + *poff = maxoff; + return addr + (maxoff - startoff); } // For a non-PT_LOAD segment, set the offset from the sections, if @@ -3858,7 +4528,11 @@ Output_segment::set_offset(unsigned int increase) 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; @@ -3871,11 +4545,32 @@ Output_segment::set_offset(unsigned int increase) 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() @@ -3883,21 +4578,14 @@ Output_segment::set_offset(unsigned int increase) 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_); @@ -3905,6 +4593,23 @@ Output_segment::set_offset(unsigned int increase) 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().common_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. @@ -3923,34 +4628,30 @@ 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 load address of the first section. uint64_t Output_segment::first_section_load_address() const { - for (Output_data_list::const_iterator p = this->output_data_.begin(); - p != this->output_data_.end(); - ++p) - if ((*p)->is_section()) - return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address(); - - for (Output_data_list::const_iterator p = this->output_bss_.begin(); - p != this->output_bss_.end(); - ++p) - if ((*p)->is_section()) - return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address(); - + 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)->has_load_address() + ? (*p)->load_address() + : (*p)->address()); + } + } gold_unreachable(); } @@ -3959,8 +4660,10 @@ 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. @@ -3988,18 +4691,9 @@ 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; } @@ -4051,7 +4745,7 @@ 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 @@ -4059,12 +4753,15 @@ 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; } @@ -4101,8 +4798,8 @@ 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. @@ -4125,36 +4822,83 @@ 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. +// 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_for_modification() +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(this->name_, &s) != 0 || s.st_size == 0) - return false; + 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 o = open_descriptor(-1, this->name_, O_RDWR, 0); + int oflags = writable ? O_RDWR : O_RDONLY; + int o = open_descriptor(-1, base_name, oflags, 0); if (o < 0) - gold_fatal(_("%s: open: %s"), this->name_, strerror(errno)); + { + 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 len = ::read(o, this->base_, s.st_size); + if (len < 0) + { + gold_info(_("%s: read failed: %s"), base_name, strerror(errno)); + return false; + } + if (len < s.st_size) + { + gold_info(_("%s: file too short"), base_name); + return false; + } + ::close(o); + return true; + } + this->o_ = o; this->file_size_ = s.st_size; - // If the file can't be mmapped, copying the content to an anonymous - // map will probably negate the performance benefits of incremental - // linking. This could be helped by using views and loading only - // the necessary parts, but this is not supported as of now. - if (!this->map_no_anonymous()) + if (!this->map_no_anonymous(writable)) { release_descriptor(o, true); this->o_ = -1; @@ -4232,10 +4976,23 @@ 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; } @@ -4243,7 +5000,7 @@ Output_file::resize(off_t file_size) { this->unmap(); this->file_size_ = file_size; - if (!this->map_no_anonymous()) + if (!this->map_no_anonymous(true)) gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno)); } } @@ -4256,19 +5013,24 @@ 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) + if (base == MAP_FAILED) { - this->map_is_anonymous_ = true; - this->base_ = static_cast(base); - return true; + base = malloc(this->file_size_); + if (base == NULL) + return false; + memset(base, 0, this->file_size_); + this->map_is_allocated_ = true; } - return false; + 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() +Output_file::map_no_anonymous(bool writable) { const int o = this->o_; @@ -4290,12 +5052,14 @@ Output_file::map_no_anonymous() // output file will wind up incomplete, but we will have already // exited. The alternative to fallocate would be to use fdatasync, // but that would be a more significant performance hit. - if (::posix_fallocate(o, 0, this->file_size_) < 0) + if (writable && ::posix_fallocate(o, 0, this->file_size_) < 0) gold_fatal(_("%s: %s"), this->name_, strerror(errno)); // Map the file into memory. - base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE, - MAP_SHARED, o, 0); + 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 @@ -4313,7 +5077,7 @@ Output_file::map_no_anonymous() void Output_file::map() { - if (this->map_no_anonymous()) + if (this->map_no_anonymous(true)) return; // The mmap call might fail because of file system issues: the file @@ -4334,8 +5098,16 @@ 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; } @@ -4382,7 +5154,8 @@ 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, @@ -4394,7 +5167,8 @@ 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, @@ -4406,7 +5180,8 @@ 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, @@ -4418,7 +5193,8 @@ 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,