diff options
Diffstat (limited to 'binutils-2.25/gold/layout.cc')
| -rw-r--r-- | binutils-2.25/gold/layout.cc | 5909 |
1 files changed, 5909 insertions, 0 deletions
diff --git a/binutils-2.25/gold/layout.cc b/binutils-2.25/gold/layout.cc new file mode 100644 index 00000000..38fd272b --- /dev/null +++ b/binutils-2.25/gold/layout.cc @@ -0,0 +1,5909 @@ +// layout.cc -- lay out output file sections for gold + +// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 +// Free Software Foundation, Inc. +// Written by Ian Lance Taylor <iant@google.com>. + +// This file is part of gold. + +// This program is free software; you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation; either version 3 of the License, or +// (at your option) any later version. + +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License +// along with this program; if not, write to the Free Software +// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, +// MA 02110-1301, USA. + +#include "gold.h" + +#include <cerrno> +#include <cstring> +#include <algorithm> +#include <iostream> +#include <fstream> +#include <utility> +#include <fcntl.h> +#include <fnmatch.h> +#include <unistd.h> +#include "libiberty.h" +#include "md5.h" +#include "sha1.h" + +#include "parameters.h" +#include "options.h" +#include "mapfile.h" +#include "script.h" +#include "script-sections.h" +#include "output.h" +#include "symtab.h" +#include "dynobj.h" +#include "ehframe.h" +#include "gdb-index.h" +#include "compressed_output.h" +#include "reduced_debug_output.h" +#include "object.h" +#include "reloc.h" +#include "descriptors.h" +#include "plugin.h" +#include "incremental.h" +#include "layout.h" + +namespace gold +{ + +// Class Free_list. + +// The total number of free lists used. +unsigned int Free_list::num_lists = 0; +// The total number of free list nodes used. +unsigned int Free_list::num_nodes = 0; +// The total number of calls to Free_list::remove. +unsigned int Free_list::num_removes = 0; +// The total number of nodes visited during calls to Free_list::remove. +unsigned int Free_list::num_remove_visits = 0; +// The total number of calls to Free_list::allocate. +unsigned int Free_list::num_allocates = 0; +// The total number of nodes visited during calls to Free_list::allocate. +unsigned int Free_list::num_allocate_visits = 0; + +// Initialize the free list. Creates a single free list node that +// describes the entire region of length LEN. If EXTEND is true, +// allocate() is allowed to extend the region beyond its initial +// length. + +void +Free_list::init(off_t len, bool extend) +{ + this->list_.push_front(Free_list_node(0, len)); + this->last_remove_ = this->list_.begin(); + this->extend_ = extend; + this->length_ = len; + ++Free_list::num_lists; + ++Free_list::num_nodes; +} + +// Remove a chunk from the free list. Because we start with a single +// node that covers the entire section, and remove chunks from it one +// at a time, we do not need to coalesce chunks or handle cases that +// span more than one free node. We expect to remove chunks from the +// free list in order, and we expect to have only a few chunks of free +// space left (corresponding to files that have changed since the last +// incremental link), so a simple linear list should provide sufficient +// performance. + +void +Free_list::remove(off_t start, off_t end) +{ + if (start == end) + return; + gold_assert(start < end); + + ++Free_list::num_removes; + + Iterator p = this->last_remove_; + if (p->start_ > start) + p = this->list_.begin(); + + for (; p != this->list_.end(); ++p) + { + ++Free_list::num_remove_visits; + // Find a node that wholly contains the indicated region. + if (p->start_ <= start && p->end_ >= end) + { + // Case 1: the indicated region spans the whole node. + // Add some fuzz to avoid creating tiny free chunks. + if (p->start_ + 3 >= start && p->end_ <= end + 3) + p = this->list_.erase(p); + // Case 2: remove a chunk from the start of the node. + else if (p->start_ + 3 >= start) + p->start_ = end; + // Case 3: remove a chunk from the end of the node. + else if (p->end_ <= end + 3) + p->end_ = start; + // Case 4: remove a chunk from the middle, and split + // the node into two. + else + { + Free_list_node newnode(p->start_, start); + p->start_ = end; + this->list_.insert(p, newnode); + ++Free_list::num_nodes; + } + this->last_remove_ = p; + return; + } + } + + // Did not find a node containing the given chunk. This could happen + // because a small chunk was already removed due to the fuzz. + gold_debug(DEBUG_INCREMENTAL, + "Free_list::remove(%d,%d) not found", + static_cast<int>(start), static_cast<int>(end)); +} + +// Allocate a chunk of size LEN from the free list. Returns -1ULL +// if a sufficiently large chunk of free space is not found. +// We use a simple first-fit algorithm. + +off_t +Free_list::allocate(off_t len, uint64_t align, off_t minoff) +{ + gold_debug(DEBUG_INCREMENTAL, + "Free_list::allocate(%08lx, %d, %08lx)", + static_cast<long>(len), static_cast<int>(align), + static_cast<long>(minoff)); + if (len == 0) + return align_address(minoff, align); + + ++Free_list::num_allocates; + + // We usually want to drop free chunks smaller than 4 bytes. + // If we need to guarantee a minimum hole size, though, we need + // to keep track of all free chunks. + const int fuzz = this->min_hole_ > 0 ? 0 : 3; + + for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p) + { + ++Free_list::num_allocate_visits; + off_t start = p->start_ > minoff ? p->start_ : minoff; + start = align_address(start, align); + off_t end = start + len; + if (end > p->end_ && p->end_ == this->length_ && this->extend_) + { + this->length_ = end; + p->end_ = end; + } + if (end == p->end_ || (end <= p->end_ - this->min_hole_)) + { + if (p->start_ + fuzz >= start && p->end_ <= end + fuzz) + this->list_.erase(p); + else if (p->start_ + fuzz >= start) + p->start_ = end; + else if (p->end_ <= end + fuzz) + p->end_ = start; + else + { + Free_list_node newnode(p->start_, start); + p->start_ = end; + this->list_.insert(p, newnode); + ++Free_list::num_nodes; + } + return start; + } + } + if (this->extend_) + { + off_t start = align_address(this->length_, align); + this->length_ = start + len; + return start; + } + return -1; +} + +// Dump the free list (for debugging). +void +Free_list::dump() +{ + gold_info("Free list:\n start end length\n"); + for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p) + gold_info(" %08lx %08lx %08lx", static_cast<long>(p->start_), + static_cast<long>(p->end_), + static_cast<long>(p->end_ - p->start_)); +} + +// Print the statistics for the free lists. +void +Free_list::print_stats() +{ + fprintf(stderr, _("%s: total free lists: %u\n"), + program_name, Free_list::num_lists); + fprintf(stderr, _("%s: total free list nodes: %u\n"), + program_name, Free_list::num_nodes); + fprintf(stderr, _("%s: calls to Free_list::remove: %u\n"), + program_name, Free_list::num_removes); + fprintf(stderr, _("%s: nodes visited: %u\n"), + program_name, Free_list::num_remove_visits); + fprintf(stderr, _("%s: calls to Free_list::allocate: %u\n"), + program_name, Free_list::num_allocates); + fprintf(stderr, _("%s: nodes visited: %u\n"), + program_name, Free_list::num_allocate_visits); +} + +// A Hash_task computes the MD5 checksum of an array of char. +// It has a blocker on either side (i.e., the task cannot run until +// the first is unblocked, and it unblocks the second after running). + +class Hash_task : public Task +{ + public: + Hash_task(const unsigned char* src, + size_t size, + unsigned char* dst, + Task_token* build_id_blocker, + Task_token* final_blocker) + : src_(src), size_(size), dst_(dst), build_id_blocker_(build_id_blocker), + final_blocker_(final_blocker) + { } + + void + run(Workqueue*) + { md5_buffer(reinterpret_cast<const char*>(src_), size_, dst_); } + + Task_token* + is_runnable(); + + // Unblock FINAL_BLOCKER_ when done. + void + locks(Task_locker* tl) + { tl->add(this, this->final_blocker_); } + + std::string + get_name() const + { return "Hash_task"; } + + private: + const unsigned char* const src_; + const size_t size_; + unsigned char* const dst_; + Task_token* const build_id_blocker_; + Task_token* const final_blocker_; +}; + +Task_token* +Hash_task::is_runnable() +{ + if (this->build_id_blocker_->is_blocked()) + return this->build_id_blocker_; + return NULL; +} + +// Layout::Relaxation_debug_check methods. + +// Check that sections and special data are in reset states. +// We do not save states for Output_sections and special Output_data. +// So we check that they have not assigned any addresses or offsets. +// clean_up_after_relaxation simply resets their addresses and offsets. +void +Layout::Relaxation_debug_check::check_output_data_for_reset_values( + const Layout::Section_list& sections, + const Layout::Data_list& special_outputs, + const Layout::Data_list& relax_outputs) +{ + for(Layout::Section_list::const_iterator p = sections.begin(); + p != sections.end(); + ++p) + gold_assert((*p)->address_and_file_offset_have_reset_values()); + + for(Layout::Data_list::const_iterator p = special_outputs.begin(); + p != special_outputs.end(); + ++p) + gold_assert((*p)->address_and_file_offset_have_reset_values()); + + gold_assert(relax_outputs.empty()); +} + +// Save information of SECTIONS for checking later. + +void +Layout::Relaxation_debug_check::read_sections( + const Layout::Section_list& sections) +{ + for(Layout::Section_list::const_iterator p = sections.begin(); + p != sections.end(); + ++p) + { + Output_section* os = *p; + Section_info info; + info.output_section = os; + info.address = os->is_address_valid() ? os->address() : 0; + info.data_size = os->is_data_size_valid() ? os->data_size() : -1; + info.offset = os->is_offset_valid()? os->offset() : -1 ; + this->section_infos_.push_back(info); + } +} + +// Verify SECTIONS using previously recorded information. + +void +Layout::Relaxation_debug_check::verify_sections( + const Layout::Section_list& sections) +{ + size_t i = 0; + for(Layout::Section_list::const_iterator p = sections.begin(); + p != sections.end(); + ++p, ++i) + { + Output_section* os = *p; + uint64_t address = os->is_address_valid() ? os->address() : 0; + off_t data_size = os->is_data_size_valid() ? os->data_size() : -1; + off_t offset = os->is_offset_valid()? os->offset() : -1 ; + + if (i >= this->section_infos_.size()) + { + gold_fatal("Section_info of %s missing.\n", os->name()); + } + const Section_info& info = this->section_infos_[i]; + if (os != info.output_section) + gold_fatal("Section order changed. Expecting %s but see %s\n", + info.output_section->name(), os->name()); + if (address != info.address + || data_size != info.data_size + || offset != info.offset) + gold_fatal("Section %s changed.\n", os->name()); + } +} + +// Layout_task_runner methods. + +// Lay out the sections. This is called after all the input objects +// have been read. + +void +Layout_task_runner::run(Workqueue* workqueue, const Task* task) +{ + // See if any of the input definitions violate the One Definition Rule. + // TODO: if this is too slow, do this as a task, rather than inline. + this->symtab_->detect_odr_violations(task, this->options_.output_file_name()); + + Layout* layout = this->layout_; + off_t file_size = layout->finalize(this->input_objects_, + this->symtab_, + this->target_, + task); + + // Now we know the final size of the output file and we know where + // each piece of information goes. + + if (this->mapfile_ != NULL) + { + this->mapfile_->print_discarded_sections(this->input_objects_); + layout->print_to_mapfile(this->mapfile_); + } + + Output_file* of; + if (layout->incremental_base() == NULL) + { + of = new Output_file(parameters->options().output_file_name()); + if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF) + of->set_is_temporary(); + of->open(file_size); + } + else + { + of = layout->incremental_base()->output_file(); + + // Apply the incremental relocations for symbols whose values + // have changed. We do this before we resize the file and start + // writing anything else to it, so that we can read the old + // incremental information from the file before (possibly) + // overwriting it. + if (parameters->incremental_update()) + layout->incremental_base()->apply_incremental_relocs(this->symtab_, + this->layout_, + of); + + of->resize(file_size); + } + + // Queue up the final set of tasks. + gold::queue_final_tasks(this->options_, this->input_objects_, + this->symtab_, layout, workqueue, of); +} + +// Layout methods. + +Layout::Layout(int number_of_input_files, Script_options* script_options) + : number_of_input_files_(number_of_input_files), + script_options_(script_options), + namepool_(), + sympool_(), + dynpool_(), + signatures_(), + section_name_map_(), + segment_list_(), + section_list_(), + unattached_section_list_(), + special_output_list_(), + relax_output_list_(), + section_headers_(NULL), + tls_segment_(NULL), + relro_segment_(NULL), + interp_segment_(NULL), + increase_relro_(0), + symtab_section_(NULL), + symtab_xindex_(NULL), + dynsym_section_(NULL), + dynsym_xindex_(NULL), + dynamic_section_(NULL), + dynamic_symbol_(NULL), + dynamic_data_(NULL), + eh_frame_section_(NULL), + eh_frame_data_(NULL), + added_eh_frame_data_(false), + eh_frame_hdr_section_(NULL), + gdb_index_data_(NULL), + build_id_note_(NULL), + array_of_hashes_(NULL), + size_of_array_of_hashes_(0), + input_view_(NULL), + debug_abbrev_(NULL), + debug_info_(NULL), + group_signatures_(), + output_file_size_(-1), + have_added_input_section_(false), + sections_are_attached_(false), + input_requires_executable_stack_(false), + input_with_gnu_stack_note_(false), + input_without_gnu_stack_note_(false), + has_static_tls_(false), + any_postprocessing_sections_(false), + resized_signatures_(false), + have_stabstr_section_(false), + section_ordering_specified_(false), + unique_segment_for_sections_specified_(false), + incremental_inputs_(NULL), + record_output_section_data_from_script_(false), + script_output_section_data_list_(), + segment_states_(NULL), + relaxation_debug_check_(NULL), + section_order_map_(), + section_segment_map_(), + input_section_position_(), + input_section_glob_(), + incremental_base_(NULL), + free_list_() +{ + // Make space for more than enough segments for a typical file. + // This is just for efficiency--it's OK if we wind up needing more. + this->segment_list_.reserve(12); + + // We expect two unattached Output_data objects: the file header and + // the segment headers. + this->special_output_list_.reserve(2); + + // Initialize structure needed for an incremental build. + if (parameters->incremental()) + this->incremental_inputs_ = new Incremental_inputs; + + // The section name pool is worth optimizing in all cases, because + // it is small, but there are often overlaps due to .rel sections. + this->namepool_.set_optimize(); +} + +// For incremental links, record the base file to be modified. + +void +Layout::set_incremental_base(Incremental_binary* base) +{ + this->incremental_base_ = base; + this->free_list_.init(base->output_file()->filesize(), true); +} + +// Hash a key we use to look up an output section mapping. + +size_t +Layout::Hash_key::operator()(const Layout::Key& k) const +{ + return k.first + k.second.first + k.second.second; +} + +// These are the debug sections that are actually used by gdb. +// Currently, we've checked versions of gdb up to and including 7.4. +// We only check the part of the name that follows ".debug_" or +// ".zdebug_". + +static const char* gdb_sections[] = +{ + "abbrev", + "addr", // Fission extension + // "aranges", // not used by gdb as of 7.4 + "frame", + "info", + "types", + "line", + "loc", + "macinfo", + "macro", + // "pubnames", // not used by gdb as of 7.4 + // "pubtypes", // not used by gdb as of 7.4 + "ranges", + "str", +}; + +// This is the minimum set of sections needed for line numbers. + +static const char* lines_only_debug_sections[] = +{ + "abbrev", + // "addr", // Fission extension + // "aranges", // not used by gdb as of 7.4 + // "frame", + "info", + // "types", + "line", + // "loc", + // "macinfo", + // "macro", + // "pubnames", // not used by gdb as of 7.4 + // "pubtypes", // not used by gdb as of 7.4 + // "ranges", + "str", +}; + +// These sections are the DWARF fast-lookup tables, and are not needed +// when building a .gdb_index section. + +static const char* gdb_fast_lookup_sections[] = +{ + "aranges", + "pubnames", + "pubtypes", +}; + +// Returns whether the given debug section is in the list of +// debug-sections-used-by-some-version-of-gdb. SUFFIX is the +// portion of the name following ".debug_" or ".zdebug_". + +static inline bool +is_gdb_debug_section(const char* suffix) +{ + // We can do this faster: binary search or a hashtable. But why bother? + for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i) + if (strcmp(suffix, gdb_sections[i]) == 0) + return true; + return false; +} + +// Returns whether the given section is needed for lines-only debugging. + +static inline bool +is_lines_only_debug_section(const char* suffix) +{ + // We can do this faster: binary search or a hashtable. But why bother? + for (size_t i = 0; + i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections); + ++i) + if (strcmp(suffix, lines_only_debug_sections[i]) == 0) + return true; + return false; +} + +// Returns whether the given section is a fast-lookup section that +// will not be needed when building a .gdb_index section. + +static inline bool +is_gdb_fast_lookup_section(const char* suffix) +{ + // We can do this faster: binary search or a hashtable. But why bother? + for (size_t i = 0; + i < sizeof(gdb_fast_lookup_sections)/sizeof(*gdb_fast_lookup_sections); + ++i) + if (strcmp(suffix, gdb_fast_lookup_sections[i]) == 0) + return true; + return false; +} + +// Sometimes we compress sections. This is typically done for +// sections that are not part of normal program execution (such as +// .debug_* sections), and where the readers of these sections know +// how to deal with compressed sections. This routine doesn't say for +// certain whether we'll compress -- it depends on commandline options +// as well -- just whether this section is a candidate for compression. +// (The Output_compressed_section class decides whether to compress +// a given section, and picks the name of the compressed section.) + +static bool +is_compressible_debug_section(const char* secname) +{ + return (is_prefix_of(".debug", secname)); +} + +// We may see compressed debug sections in input files. Return TRUE +// if this is the name of a compressed debug section. + +bool +is_compressed_debug_section(const char* secname) +{ + return (is_prefix_of(".zdebug", secname)); +} + +// Whether to include this section in the link. + +template<int size, bool big_endian> +bool +Layout::include_section(Sized_relobj_file<size, big_endian>*, const char* name, + const elfcpp::Shdr<size, big_endian>& shdr) +{ + if (!parameters->options().relocatable() + && (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)) + return false; + + switch (shdr.get_sh_type()) + { + case elfcpp::SHT_NULL: + case elfcpp::SHT_SYMTAB: + case elfcpp::SHT_DYNSYM: + case elfcpp::SHT_HASH: + case elfcpp::SHT_DYNAMIC: + case elfcpp::SHT_SYMTAB_SHNDX: + return false; + + case elfcpp::SHT_STRTAB: + // Discard the sections which have special meanings in the ELF + // ABI. Keep others (e.g., .stabstr). We could also do this by + // checking the sh_link fields of the appropriate sections. + return (strcmp(name, ".dynstr") != 0 + && strcmp(name, ".strtab") != 0 + && strcmp(name, ".shstrtab") != 0); + + case elfcpp::SHT_RELA: + case elfcpp::SHT_REL: + case elfcpp::SHT_GROUP: + // If we are emitting relocations these should be handled + // elsewhere. + gold_assert(!parameters->options().relocatable()); + return false; + + case elfcpp::SHT_PROGBITS: + if (parameters->options().strip_debug() + && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0) + { + if (is_debug_info_section(name)) + return false; + } + if (parameters->options().strip_debug_non_line() + && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0) + { + // Debugging sections can only be recognized by name. + if (is_prefix_of(".debug_", name) + && !is_lines_only_debug_section(name + 7)) + return false; + if (is_prefix_of(".zdebug_", name) + && !is_lines_only_debug_section(name + 8)) + return false; + } + if (parameters->options().strip_debug_gdb() + && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0) + { + // Debugging sections can only be recognized by name. + if (is_prefix_of(".debug_", name) + && !is_gdb_debug_section(name + 7)) + return false; + if (is_prefix_of(".zdebug_", name) + && !is_gdb_debug_section(name + 8)) + return false; + } + if (parameters->options().gdb_index() + && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0) + { + // When building .gdb_index, we can strip .debug_pubnames, + // .debug_pubtypes, and .debug_aranges sections. + if (is_prefix_of(".debug_", name) + && is_gdb_fast_lookup_section(name + 7)) + return false; + if (is_prefix_of(".zdebug_", name) + && is_gdb_fast_lookup_section(name + 8)) + return false; + } + if (parameters->options().strip_lto_sections() + && !parameters->options().relocatable() + && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0) + { + // Ignore LTO sections containing intermediate code. + if (is_prefix_of(".gnu.lto_", name)) + return false; + } + // The GNU linker strips .gnu_debuglink sections, so we do too. + // This is a feature used to keep debugging information in + // separate files. + if (strcmp(name, ".gnu_debuglink") == 0) + return false; + return true; + + default: + return true; + } +} + +// Return an output section named NAME, or NULL if there is none. + +Output_section* +Layout::find_output_section(const char* name) const +{ + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + if (strcmp((*p)->name(), name) == 0) + return *p; + return NULL; +} + +// Return an output segment of type TYPE, with segment flags SET set +// and segment flags CLEAR clear. Return NULL if there is none. + +Output_segment* +Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set, + elfcpp::Elf_Word clear) const +{ + for (Segment_list::const_iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + if (static_cast<elfcpp::PT>((*p)->type()) == type + && ((*p)->flags() & set) == set + && ((*p)->flags() & clear) == 0) + return *p; + return NULL; +} + +// When we put a .ctors or .dtors section with more than one word into +// a .init_array or .fini_array section, we need to reverse the words +// in the .ctors/.dtors section. This is because .init_array executes +// constructors front to back, where .ctors executes them back to +// front, and vice-versa for .fini_array/.dtors. Although we do want +// to remap .ctors/.dtors into .init_array/.fini_array because it can +// be more efficient, we don't want to change the order in which +// constructors/destructors are run. This set just keeps track of +// these sections which need to be reversed. It is only changed by +// Layout::layout. It should be a private member of Layout, but that +// would require layout.h to #include object.h to get the definition +// of Section_id. +static Unordered_set<Section_id, Section_id_hash> ctors_sections_in_init_array; + +// Return whether OBJECT/SHNDX is a .ctors/.dtors section mapped to a +// .init_array/.fini_array section. + +bool +Layout::is_ctors_in_init_array(Relobj* relobj, unsigned int shndx) const +{ + return (ctors_sections_in_init_array.find(Section_id(relobj, shndx)) + != ctors_sections_in_init_array.end()); +} + +// Return the output section to use for section NAME with type TYPE +// and section flags FLAGS. NAME must be canonicalized in the string +// pool, and NAME_KEY is the key. ORDER is where this should appear +// in the output sections. IS_RELRO is true for a relro section. + +Output_section* +Layout::get_output_section(const char* name, Stringpool::Key name_key, + elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, + Output_section_order order, bool is_relro) +{ + elfcpp::Elf_Word lookup_type = type; + + // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and + // PREINIT_ARRAY like PROGBITS. This ensures that we combine + // .init_array, .fini_array, and .preinit_array sections by name + // whatever their type in the input file. We do this because the + // types are not always right in the input files. + if (lookup_type == elfcpp::SHT_INIT_ARRAY + || lookup_type == elfcpp::SHT_FINI_ARRAY + || lookup_type == elfcpp::SHT_PREINIT_ARRAY) + lookup_type = elfcpp::SHT_PROGBITS; + + elfcpp::Elf_Xword lookup_flags = flags; + + // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine + // read-write with read-only sections. Some other ELF linkers do + // not do this. FIXME: Perhaps there should be an option + // controlling this. + lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR); + + const Key key(name_key, std::make_pair(lookup_type, lookup_flags)); + const std::pair<Key, Output_section*> v(key, NULL); + std::pair<Section_name_map::iterator, bool> ins( + this->section_name_map_.insert(v)); + + if (!ins.second) + return ins.first->second; + else + { + // This is the first time we've seen this name/type/flags + // combination. For compatibility with the GNU linker, we + // combine sections with contents and zero flags with sections + // with non-zero flags. This is a workaround for cases where + // assembler code forgets to set section flags. FIXME: Perhaps + // there should be an option to control this. + Output_section* os = NULL; + + if (lookup_type == elfcpp::SHT_PROGBITS) + { + if (flags == 0) + { + Output_section* same_name = this->find_output_section(name); + if (same_name != NULL + && (same_name->type() == elfcpp::SHT_PROGBITS + || same_name->type() == elfcpp::SHT_INIT_ARRAY + || same_name->type() == elfcpp::SHT_FINI_ARRAY + || same_name->type() == elfcpp::SHT_PREINIT_ARRAY) + && (same_name->flags() & elfcpp::SHF_TLS) == 0) + os = same_name; + } + else if ((flags & elfcpp::SHF_TLS) == 0) + { + elfcpp::Elf_Xword zero_flags = 0; + const Key zero_key(name_key, std::make_pair(lookup_type, + zero_flags)); + Section_name_map::iterator p = + this->section_name_map_.find(zero_key); + if (p != this->section_name_map_.end()) + os = p->second; + } + } + + if (os == NULL) + os = this->make_output_section(name, type, flags, order, is_relro); + + ins.first->second = os; + return os; + } +} + +// Returns TRUE iff NAME (an input section from RELOBJ) will +// be mapped to an output section that should be KEPT. + +bool +Layout::keep_input_section(const Relobj* relobj, const char* name) +{ + if (! this->script_options_->saw_sections_clause()) + return false; + + Script_sections* ss = this->script_options_->script_sections(); + const char* file_name = relobj == NULL ? NULL : relobj->name().c_str(); + Output_section** output_section_slot; + Script_sections::Section_type script_section_type; + bool keep; + + name = ss->output_section_name(file_name, name, &output_section_slot, + &script_section_type, &keep); + return name != NULL && keep; +} + +// Clear the input section flags that should not be copied to the +// output section. + +elfcpp::Elf_Xword +Layout::get_output_section_flags(elfcpp::Elf_Xword input_section_flags) +{ + // Some flags in the input section should not be automatically + // copied to the output section. + input_section_flags &= ~ (elfcpp::SHF_INFO_LINK + | elfcpp::SHF_GROUP + | elfcpp::SHF_MERGE + | elfcpp::SHF_STRINGS); + + // We only clear the SHF_LINK_ORDER flag in for + // a non-relocatable link. + if (!parameters->options().relocatable()) + input_section_flags &= ~elfcpp::SHF_LINK_ORDER; + + return input_section_flags; +} + +// Pick the output section to use for section NAME, in input file +// RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a +// linker created section. IS_INPUT_SECTION is true if we are +// choosing an output section for an input section found in a input +// file. ORDER is where this section should appear in the output +// sections. IS_RELRO is true for a relro section. This will return +// NULL if the input section should be discarded. + +Output_section* +Layout::choose_output_section(const Relobj* relobj, const char* name, + elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, + bool is_input_section, Output_section_order order, + bool is_relro) +{ + // We should not see any input sections after we have attached + // sections to segments. + gold_assert(!is_input_section || !this->sections_are_attached_); + + flags = this->get_output_section_flags(flags); + + if (this->script_options_->saw_sections_clause()) + { + // We are using a SECTIONS clause, so the output section is + // chosen based only on the name. + + Script_sections* ss = this->script_options_->script_sections(); + const char* file_name = relobj == NULL ? NULL : relobj->name().c_str(); + Output_section** output_section_slot; + Script_sections::Section_type script_section_type; + const char* orig_name = name; + bool keep; + name = ss->output_section_name(file_name, name, &output_section_slot, + &script_section_type, &keep); + + if (name == NULL) + { + gold_debug(DEBUG_SCRIPT, _("Unable to create output section '%s' " + "because it is not allowed by the " + "SECTIONS clause of the linker script"), + orig_name); + // The SECTIONS clause says to discard this input section. + return NULL; + } + + // We can only handle script section types ST_NONE and ST_NOLOAD. + switch (script_section_type) + { + case Script_sections::ST_NONE: + break; + case Script_sections::ST_NOLOAD: + flags &= elfcpp::SHF_ALLOC; + break; + default: + gold_unreachable(); + } + + // If this is an orphan section--one not mentioned in the linker + // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the + // default processing below. + + if (output_section_slot != NULL) + { + if (*output_section_slot != NULL) + { + (*output_section_slot)->update_flags_for_input_section(flags); + return *output_section_slot; + } + + // We don't put sections found in the linker script into + // SECTION_NAME_MAP_. That keeps us from getting confused + // if an orphan section is mapped to a section with the same + // name as one in the linker script. + + name = this->namepool_.add(name, false, NULL); + + Output_section* os = this->make_output_section(name, type, flags, + order, is_relro); + + os->set_found_in_sections_clause(); + + // Special handling for NOLOAD sections. + if (script_section_type == Script_sections::ST_NOLOAD) + { + os->set_is_noload(); + + // The constructor of Output_section sets addresses of non-ALLOC + // sections to 0 by default. We don't want that for NOLOAD + // sections even if they have no SHF_ALLOC flag. + if ((os->flags() & elfcpp::SHF_ALLOC) == 0 + && os->is_address_valid()) + { + gold_assert(os->address() == 0 + && !os->is_offset_valid() + && !os->is_data_size_valid()); + os->reset_address_and_file_offset(); + } + } + + *output_section_slot = os; + return os; + } + } + + // FIXME: Handle SHF_OS_NONCONFORMING somewhere. + + size_t len = strlen(name); + char* uncompressed_name = NULL; + + // Compressed debug sections should be mapped to the corresponding + // uncompressed section. + if (is_compressed_debug_section(name)) + { + uncompressed_name = new char[len]; + uncompressed_name[0] = '.'; + gold_assert(name[0] == '.' && name[1] == 'z'); + strncpy(&uncompressed_name[1], &name[2], len - 2); + uncompressed_name[len - 1] = '\0'; + len -= 1; + name = uncompressed_name; + } + + // Turn NAME from the name of the input section into the name of the + // output section. + if (is_input_section + && !this->script_options_->saw_sections_clause() + && !parameters->options().relocatable()) + { + const char *orig_name = name; + name = parameters->target().output_section_name(relobj, name, &len); + if (name == NULL) + name = Layout::output_section_name(relobj, orig_name, &len); + } + + Stringpool::Key name_key; + name = this->namepool_.add_with_length(name, len, true, &name_key); + + if (uncompressed_name != NULL) + delete[] uncompressed_name; + + // Find or make the output section. The output section is selected + // based on the section name, type, and flags. + return this->get_output_section(name, name_key, type, flags, order, is_relro); +} + +// For incremental links, record the initial fixed layout of a section +// from the base file, and return a pointer to the Output_section. + +template<int size, bool big_endian> +Output_section* +Layout::init_fixed_output_section(const char* name, + elfcpp::Shdr<size, big_endian>& shdr) +{ + unsigned int sh_type = shdr.get_sh_type(); + + // We preserve the layout of PROGBITS, NOBITS, INIT_ARRAY, FINI_ARRAY, + // PRE_INIT_ARRAY, and NOTE sections. + // All others will be created from scratch and reallocated. + if (!can_incremental_update(sh_type)) + return NULL; + + // If we're generating a .gdb_index section, we need to regenerate + // it from scratch. + if (parameters->options().gdb_index() + && sh_type == elfcpp::SHT_PROGBITS + && strcmp(name, ".gdb_index") == 0) + return NULL; + + typename elfcpp::Elf_types<size>::Elf_Addr sh_addr = shdr.get_sh_addr(); + typename elfcpp::Elf_types<size>::Elf_Off sh_offset = shdr.get_sh_offset(); + typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size(); + typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags(); + typename elfcpp::Elf_types<size>::Elf_WXword sh_addralign = + shdr.get_sh_addralign(); + + // Make the output section. + Stringpool::Key name_key; + name = this->namepool_.add(name, true, &name_key); + Output_section* os = this->get_output_section(name, name_key, sh_type, + sh_flags, ORDER_INVALID, false); + os->set_fixed_layout(sh_addr, sh_offset, sh_size, sh_addralign); + if (sh_type != elfcpp::SHT_NOBITS) + this->free_list_.remove(sh_offset, sh_offset + sh_size); + return os; +} + +// Return the index by which an input section should be ordered. This +// is used to sort some .text sections, for compatibility with GNU ld. + +int +Layout::special_ordering_of_input_section(const char* name) +{ + // The GNU linker has some special handling for some sections that + // wind up in the .text section. Sections that start with these + // prefixes must appear first, and must appear in the order listed + // here. + static const char* const text_section_sort[] = + { + ".text.unlikely", + ".text.exit", + ".text.startup", + ".text.hot" + }; + + for (size_t i = 0; + i < sizeof(text_section_sort) / sizeof(text_section_sort[0]); + i++) + if (is_prefix_of(text_section_sort[i], name)) + return i; + + return -1; +} + +// Return the output section to use for input section SHNDX, with name +// NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the +// index of a relocation section which applies to this section, or 0 +// if none, or -1U if more than one. RELOC_TYPE is the type of the +// relocation section if there is one. Set *OFF to the offset of this +// input section without the output section. Return NULL if the +// section should be discarded. Set *OFF to -1 if the section +// contents should not be written directly to the output file, but +// will instead receive special handling. + +template<int size, bool big_endian> +Output_section* +Layout::layout(Sized_relobj_file<size, big_endian>* object, unsigned int shndx, + const char* name, const elfcpp::Shdr<size, big_endian>& shdr, + unsigned int reloc_shndx, unsigned int, off_t* off) +{ + *off = 0; + + if (!this->include_section(object, name, shdr)) + return NULL; + + elfcpp::Elf_Word sh_type = shdr.get_sh_type(); + + // In a relocatable link a grouped section must not be combined with + // any other sections. + Output_section* os; + if (parameters->options().relocatable() + && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0) + { + name = this->namepool_.add(name, true, NULL); + os = this->make_output_section(name, sh_type, shdr.get_sh_flags(), + ORDER_INVALID, false); + } + else + { + // Plugins can choose to place one or more subsets of sections in + // unique segments and this is done by mapping these section subsets + // to unique output sections. Check if this section needs to be + // remapped to a unique output section. + Section_segment_map::iterator it + = this->section_segment_map_.find(Const_section_id(object, shndx)); + if (it == this->section_segment_map_.end()) + { + os = this->choose_output_section(object, name, sh_type, + shdr.get_sh_flags(), true, + ORDER_INVALID, false); + } + else + { + // We know the name of the output section, directly call + // get_output_section here by-passing choose_output_section. + elfcpp::Elf_Xword flags + = this->get_output_section_flags(shdr.get_sh_flags()); + + const char* os_name = it->second->name; + Stringpool::Key name_key; + os_name = this->namepool_.add(os_name, true, &name_key); + os = this->get_output_section(os_name, name_key, sh_type, flags, + ORDER_INVALID, false); + if (!os->is_unique_segment()) + { + os->set_is_unique_segment(); + os->set_extra_segment_flags(it->second->flags); + os->set_segment_alignment(it->second->align); + } + } + if (os == NULL) + return NULL; + } + + // By default the GNU linker sorts input sections whose names match + // .ctors.*, .dtors.*, .init_array.*, or .fini_array.*. The + // sections are sorted by name. This is used to implement + // constructor priority ordering. We are compatible. When we put + // .ctor sections in .init_array and .dtor sections in .fini_array, + // we must also sort plain .ctor and .dtor sections. + if (!this->script_options_->saw_sections_clause() + && !parameters->options().relocatable() + && (is_prefix_of(".ctors.", name) + || is_prefix_of(".dtors.", name) + || is_prefix_of(".init_array.", name) + || is_prefix_of(".fini_array.", name) + || (parameters->options().ctors_in_init_array() + && (strcmp(name, ".ctors") == 0 + || strcmp(name, ".dtors") == 0)))) + os->set_must_sort_attached_input_sections(); + + // By default the GNU linker sorts some special text sections ahead + // of others. We are compatible. + if (parameters->options().text_reorder() + && !this->script_options_->saw_sections_clause() + && !this->is_section_ordering_specified() + && !parameters->options().relocatable() + && Layout::special_ordering_of_input_section(name) >= 0) + os->set_must_sort_attached_input_sections(); + + // If this is a .ctors or .ctors.* section being mapped to a + // .init_array section, or a .dtors or .dtors.* section being mapped + // to a .fini_array section, we will need to reverse the words if + // there is more than one. Record this section for later. See + // ctors_sections_in_init_array above. + if (!this->script_options_->saw_sections_clause() + && !parameters->options().relocatable() + && shdr.get_sh_size() > size / 8 + && (((strcmp(name, ".ctors") == 0 + || is_prefix_of(".ctors.", name)) + && strcmp(os->name(), ".init_array") == 0) + || ((strcmp(name, ".dtors") == 0 + || is_prefix_of(".dtors.", name)) + && strcmp(os->name(), ".fini_array") == 0))) + ctors_sections_in_init_array.insert(Section_id(object, shndx)); + + // FIXME: Handle SHF_LINK_ORDER somewhere. + + elfcpp::Elf_Xword orig_flags = os->flags(); + + *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx, + this->script_options_->saw_sections_clause()); + + // If the flags changed, we may have to change the order. + if ((orig_flags & elfcpp::SHF_ALLOC) != 0) + { + orig_flags &= (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR); + elfcpp::Elf_Xword new_flags = + os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR); + if (orig_flags != new_flags) + os->set_order(this->default_section_order(os, false)); + } + + this->have_added_input_section_ = true; + + return os; +} + +// Maps section SECN to SEGMENT s. +void +Layout::insert_section_segment_map(Const_section_id secn, + Unique_segment_info *s) +{ + gold_assert(this->unique_segment_for_sections_specified_); + this->section_segment_map_[secn] = s; +} + +// Handle a relocation section when doing a relocatable link. + +template<int size, bool big_endian> +Output_section* +Layout::layout_reloc(Sized_relobj_file<size, big_endian>* object, + unsigned int, + const elfcpp::Shdr<size, big_endian>& shdr, + Output_section* data_section, + Relocatable_relocs* rr) +{ + gold_assert(parameters->options().relocatable() + || parameters->options().emit_relocs()); + + int sh_type = shdr.get_sh_type(); + + std::string name; + if (sh_type == elfcpp::SHT_REL) + name = ".rel"; + else if (sh_type == elfcpp::SHT_RELA) + name = ".rela"; + else + gold_unreachable(); + name += data_section->name(); + + // In a relocatable link relocs for a grouped section must not be + // combined with other reloc sections. + Output_section* os; + if (!parameters->options().relocatable() + || (data_section->flags() & elfcpp::SHF_GROUP) == 0) + os = this->choose_output_section(object, name.c_str(), sh_type, + shdr.get_sh_flags(), false, + ORDER_INVALID, false); + else + { + const char* n = this->namepool_.add(name.c_str(), true, NULL); + os = this->make_output_section(n, sh_type, shdr.get_sh_flags(), + ORDER_INVALID, false); + } + + os->set_should_link_to_symtab(); + os->set_info_section(data_section); + + Output_section_data* posd; + if (sh_type == elfcpp::SHT_REL) + { + os->set_entsize(elfcpp::Elf_sizes<size>::rel_size); + posd = new Output_relocatable_relocs<elfcpp::SHT_REL, + size, + big_endian>(rr); + } + else if (sh_type == elfcpp::SHT_RELA) + { + os->set_entsize(elfcpp::Elf_sizes<size>::rela_size); + posd = new Output_relocatable_relocs<elfcpp::SHT_RELA, + size, + big_endian>(rr); + } + else + gold_unreachable(); + + os->add_output_section_data(posd); + rr->set_output_data(posd); + + return os; +} + +// Handle a group section when doing a relocatable link. + +template<int size, bool big_endian> +void +Layout::layout_group(Symbol_table* symtab, + Sized_relobj_file<size, big_endian>* object, + unsigned int, + const char* group_section_name, + const char* signature, + const elfcpp::Shdr<size, big_endian>& shdr, + elfcpp::Elf_Word flags, + std::vector<unsigned int>* shndxes) +{ + gold_assert(parameters->options().relocatable()); + gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP); + group_section_name = this->namepool_.add(group_section_name, true, NULL); + Output_section* os = this->make_output_section(group_section_name, + elfcpp::SHT_GROUP, + shdr.get_sh_flags(), + ORDER_INVALID, false); + + // We need to find a symbol with the signature in the symbol table. + // If we don't find one now, we need to look again later. + Symbol* sym = symtab->lookup(signature, NULL); + if (sym != NULL) + os->set_info_symndx(sym); + else + { + // Reserve some space to minimize reallocations. + if (this->group_signatures_.empty()) + this->group_signatures_.reserve(this->number_of_input_files_ * 16); + + // We will wind up using a symbol whose name is the signature. + // So just put the signature in the symbol name pool to save it. + signature = symtab->canonicalize_name(signature); + this->group_signatures_.push_back(Group_signature(os, signature)); + } + + os->set_should_link_to_symtab(); + os->set_entsize(4); + + section_size_type entry_count = + convert_to_section_size_type(shdr.get_sh_size() / 4); + Output_section_data* posd = + new Output_data_group<size, big_endian>(object, entry_count, flags, + shndxes); + os->add_output_section_data(posd); +} + +// Special GNU handling of sections name .eh_frame. They will +// normally hold exception frame data as defined by the C++ ABI +// (http://codesourcery.com/cxx-abi/). + +template<int size, bool big_endian> +Output_section* +Layout::layout_eh_frame(Sized_relobj_file<size, big_endian>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + const elfcpp::Shdr<size, big_endian>& shdr, + unsigned int reloc_shndx, unsigned int reloc_type, + off_t* off) +{ + gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS + || shdr.get_sh_type() == elfcpp::SHT_X86_64_UNWIND); + gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0); + + Output_section* os = this->make_eh_frame_section(object); + if (os == NULL) + return NULL; + + gold_assert(this->eh_frame_section_ == os); + + elfcpp::Elf_Xword orig_flags = os->flags(); + + if (!parameters->incremental() + && this->eh_frame_data_->add_ehframe_input_section(object, + symbols, + symbols_size, + symbol_names, + symbol_names_size, + shndx, + reloc_shndx, + reloc_type)) + { + os->update_flags_for_input_section(shdr.get_sh_flags()); + + // A writable .eh_frame section is a RELRO section. + if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)) + != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))) + { + os->set_is_relro(); + os->set_order(ORDER_RELRO); + } + + // We found a .eh_frame section we are going to optimize, so now + // we can add the set of optimized sections to the output + // section. We need to postpone adding this until we've found a + // section we can optimize so that the .eh_frame section in + // crtbegin.o winds up at the start of the output section. + if (!this->added_eh_frame_data_) + { + os->add_output_section_data(this->eh_frame_data_); + this->added_eh_frame_data_ = true; + } + *off = -1; + } + else + { + // We couldn't handle this .eh_frame section for some reason. + // Add it as a normal section. + bool saw_sections_clause = this->script_options_->saw_sections_clause(); + *off = os->add_input_section(this, object, shndx, ".eh_frame", shdr, + reloc_shndx, saw_sections_clause); + this->have_added_input_section_ = true; + + if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)) + != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))) + os->set_order(this->default_section_order(os, false)); + } + + return os; +} + +// Create and return the magic .eh_frame section. Create +// .eh_frame_hdr also if appropriate. OBJECT is the object with the +// input .eh_frame section; it may be NULL. + +Output_section* +Layout::make_eh_frame_section(const Relobj* object) +{ + // FIXME: On x86_64, this could use SHT_X86_64_UNWIND rather than + // SHT_PROGBITS. + Output_section* os = this->choose_output_section(object, ".eh_frame", + elfcpp::SHT_PROGBITS, + elfcpp::SHF_ALLOC, false, + ORDER_EHFRAME, false); + if (os == NULL) + return NULL; + + if (this->eh_frame_section_ == NULL) + { + this->eh_frame_section_ = os; + this->eh_frame_data_ = new Eh_frame(); + + // For incremental linking, we do not optimize .eh_frame sections + // or create a .eh_frame_hdr section. + if (parameters->options().eh_frame_hdr() && !parameters->incremental()) + { + Output_section* hdr_os = + this->choose_output_section(NULL, ".eh_frame_hdr", + elfcpp::SHT_PROGBITS, + elfcpp::SHF_ALLOC, false, + ORDER_EHFRAME, false); + + if (hdr_os != NULL) + { + Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os, + this->eh_frame_data_); + hdr_os->add_output_section_data(hdr_posd); + + hdr_os->set_after_input_sections(); + + if (!this->script_options_->saw_phdrs_clause()) + { + Output_segment* hdr_oseg; + hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME, + elfcpp::PF_R); + hdr_oseg->add_output_section_to_nonload(hdr_os, + elfcpp::PF_R); + } + + this->eh_frame_data_->set_eh_frame_hdr(hdr_posd); + } + } + } + + return os; +} + +// Add an exception frame for a PLT. This is called from target code. + +void +Layout::add_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data, + size_t cie_length, const unsigned char* fde_data, + size_t fde_length) +{ + if (parameters->incremental()) + { + // FIXME: Maybe this could work some day.... + return; + } + Output_section* os = this->make_eh_frame_section(NULL); + if (os == NULL) + return; + this->eh_frame_data_->add_ehframe_for_plt(plt, cie_data, cie_length, + fde_data, fde_length); + if (!this->added_eh_frame_data_) + { + os->add_output_section_data(this->eh_frame_data_); + this->added_eh_frame_data_ = true; + } +} + +// Scan a .debug_info or .debug_types section, and add summary +// information to the .gdb_index section. + +template<int size, bool big_endian> +void +Layout::add_to_gdb_index(bool is_type_unit, + Sized_relobj<size, big_endian>* object, + const unsigned char* symbols, + off_t symbols_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type) +{ + if (this->gdb_index_data_ == NULL) + { + Output_section* os = this->choose_output_section(NULL, ".gdb_index", + elfcpp::SHT_PROGBITS, 0, + false, ORDER_INVALID, + false); + if (os == NULL) + return; + + this->gdb_index_data_ = new Gdb_index(os); + os->add_output_section_data(this->gdb_index_data_); + os->set_after_input_sections(); + } + + this->gdb_index_data_->scan_debug_info(is_type_unit, object, symbols, + symbols_size, shndx, reloc_shndx, + reloc_type); +} + +// Add POSD to an output section using NAME, TYPE, and FLAGS. Return +// the output section. + +Output_section* +Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type, + elfcpp::Elf_Xword flags, + Output_section_data* posd, + Output_section_order order, bool is_relro) +{ + Output_section* os = this->choose_output_section(NULL, name, type, flags, + false, order, is_relro); + if (os != NULL) + os->add_output_section_data(posd); + return os; +} + +// Map section flags to segment flags. + +elfcpp::Elf_Word +Layout::section_flags_to_segment(elfcpp::Elf_Xword flags) +{ + elfcpp::Elf_Word ret = elfcpp::PF_R; + if ((flags & elfcpp::SHF_WRITE) != 0) + ret |= elfcpp::PF_W; + if ((flags & elfcpp::SHF_EXECINSTR) != 0) + ret |= elfcpp::PF_X; + return ret; +} + +// Make a new Output_section, and attach it to segments as +// appropriate. ORDER is the order in which this section should +// appear in the output segment. IS_RELRO is true if this is a relro +// (read-only after relocations) section. + +Output_section* +Layout::make_output_section(const char* name, elfcpp::Elf_Word type, + elfcpp::Elf_Xword flags, + Output_section_order order, bool is_relro) +{ + Output_section* os; + if ((flags & elfcpp::SHF_ALLOC) == 0 + && strcmp(parameters->options().compress_debug_sections(), "none") != 0 + && is_compressible_debug_section(name)) + os = new Output_compressed_section(¶meters->options(), name, type, + flags); + else if ((flags & elfcpp::SHF_ALLOC) == 0 + && parameters->options().strip_debug_non_line() + && strcmp(".debug_abbrev", name) == 0) + { + os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section( + name, type, flags); + if (this->debug_info_) + this->debug_info_->set_abbreviations(this->debug_abbrev_); + } + else if ((flags & elfcpp::SHF_ALLOC) == 0 + && parameters->options().strip_debug_non_line() + && strcmp(".debug_info", name) == 0) + { + os = this->debug_info_ = new Output_reduced_debug_info_section( + name, type, flags); + if (this->debug_abbrev_) + this->debug_info_->set_abbreviations(this->debug_abbrev_); + } + else + { + // Sometimes .init_array*, .preinit_array* and .fini_array* do + // not have correct section types. Force them here. + if (type == elfcpp::SHT_PROGBITS) + { + if (is_prefix_of(".init_array", name)) + type = elfcpp::SHT_INIT_ARRAY; + else if (is_prefix_of(".preinit_array", name)) + type = elfcpp::SHT_PREINIT_ARRAY; + else if (is_prefix_of(".fini_array", name)) + type = elfcpp::SHT_FINI_ARRAY; + } + + // FIXME: const_cast is ugly. + Target* target = const_cast<Target*>(¶meters->target()); + os = target->make_output_section(name, type, flags); + } + + // With -z relro, we have to recognize the special sections by name. + // There is no other way. + bool is_relro_local = false; + if (!this->script_options_->saw_sections_clause() + && parameters->options().relro() + && (flags & elfcpp::SHF_ALLOC) != 0 + && (flags & elfcpp::SHF_WRITE) != 0) + { + if (type == elfcpp::SHT_PROGBITS) + { + if ((flags & elfcpp::SHF_TLS) != 0) + is_relro = true; + else if (strcmp(name, ".data.rel.ro") == 0) + is_relro = true; + else if (strcmp(name, ".data.rel.ro.local") == 0) + { + is_relro = true; + is_relro_local = true; + } + else if (strcmp(name, ".ctors") == 0 + || strcmp(name, ".dtors") == 0 + || strcmp(name, ".jcr") == 0) + is_relro = true; + } + else if (type == elfcpp::SHT_INIT_ARRAY + || type == elfcpp::SHT_FINI_ARRAY + || type == elfcpp::SHT_PREINIT_ARRAY) + is_relro = true; + } + + if (is_relro) + os->set_is_relro(); + + if (order == ORDER_INVALID && (flags & elfcpp::SHF_ALLOC) != 0) + order = this->default_section_order(os, is_relro_local); + + os->set_order(order); + + parameters->target().new_output_section(os); + + this->section_list_.push_back(os); + + // The GNU linker by default sorts some sections by priority, so we + // do the same. We need to know that this might happen before we + // attach any input sections. + if (!this->script_options_->saw_sections_clause() + && !parameters->options().relocatable() + && (strcmp(name, ".init_array") == 0 + || strcmp(name, ".fini_array") == 0 + || (!parameters->options().ctors_in_init_array() + && (strcmp(name, ".ctors") == 0 + || strcmp(name, ".dtors") == 0)))) + os->set_may_sort_attached_input_sections(); + + // The GNU linker by default sorts .text.{unlikely,exit,startup,hot} + // sections before other .text sections. We are compatible. We + // need to know that this might happen before we attach any input + // sections. + if (parameters->options().text_reorder() + && !this->script_options_->saw_sections_clause() + && !this->is_section_ordering_specified() + && !parameters->options().relocatable() + && strcmp(name, ".text") == 0) + os->set_may_sort_attached_input_sections(); + + // GNU linker sorts section by name with --sort-section=name. + if (strcmp(parameters->options().sort_section(), "name") == 0) + os->set_must_sort_attached_input_sections(); + + // Check for .stab*str sections, as .stab* sections need to link to + // them. + if (type == elfcpp::SHT_STRTAB + && !this->have_stabstr_section_ + && strncmp(name, ".stab", 5) == 0 + && strcmp(name + strlen(name) - 3, "str") == 0) + this->have_stabstr_section_ = true; + + // During a full incremental link, we add patch space to most + // PROGBITS and NOBITS sections. Flag those that may be + // arbitrarily padded. + if ((type == elfcpp::SHT_PROGBITS || type == elfcpp::SHT_NOBITS) + && order != ORDER_INTERP + && order != ORDER_INIT + && order != ORDER_PLT + && order != ORDER_FINI + && order != ORDER_RELRO_LAST + && order != ORDER_NON_RELRO_FIRST + && strcmp(name, ".eh_frame") != 0 + && strcmp(name, ".ctors") != 0 + && strcmp(name, ".dtors") != 0 + && strcmp(name, ".jcr") != 0) + { + os->set_is_patch_space_allowed(); + + // Certain sections require "holes" to be filled with + // specific fill patterns. These fill patterns may have + // a minimum size, so we must prevent allocations from the + // free list that leave a hole smaller than the minimum. + if (strcmp(name, ".debug_info") == 0) + os->set_free_space_fill(new Output_fill_debug_info(false)); + else if (strcmp(name, ".debug_types") == 0) + os->set_free_space_fill(new Output_fill_debug_info(true)); + else if (strcmp(name, ".debug_line") == 0) + os->set_free_space_fill(new Output_fill_debug_line()); + } + + // If we have already attached the sections to segments, then we + // need to attach this one now. This happens for sections created + // directly by the linker. + if (this->sections_are_attached_) + this->attach_section_to_segment(¶meters->target(), os); + + return os; +} + +// Return the default order in which a section should be placed in an +// output segment. This function captures a lot of the ideas in +// ld/scripttempl/elf.sc in the GNU linker. Note that the order of a +// linker created section is normally set when the section is created; +// this function is used for input sections. + +Output_section_order +Layout::default_section_order(Output_section* os, bool is_relro_local) +{ + gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0); + bool is_write = (os->flags() & elfcpp::SHF_WRITE) != 0; + bool is_execinstr = (os->flags() & elfcpp::SHF_EXECINSTR) != 0; + bool is_bss = false; + + switch (os->type()) + { + default: + case elfcpp::SHT_PROGBITS: + break; + case elfcpp::SHT_NOBITS: + is_bss = true; + break; + case elfcpp::SHT_RELA: + case elfcpp::SHT_REL: + if (!is_write) + return ORDER_DYNAMIC_RELOCS; + break; + case elfcpp::SHT_HASH: + case elfcpp::SHT_DYNAMIC: + case elfcpp::SHT_SHLIB: + case elfcpp::SHT_DYNSYM: + case elfcpp::SHT_GNU_HASH: + case elfcpp::SHT_GNU_verdef: + case elfcpp::SHT_GNU_verneed: + case elfcpp::SHT_GNU_versym: + if (!is_write) + return ORDER_DYNAMIC_LINKER; + break; + case elfcpp::SHT_NOTE: + return is_write ? ORDER_RW_NOTE : ORDER_RO_NOTE; + } + + if ((os->flags() & elfcpp::SHF_TLS) != 0) + return is_bss ? ORDER_TLS_BSS : ORDER_TLS_DATA; + + if (!is_bss && !is_write) + { + if (is_execinstr) + { + if (strcmp(os->name(), ".init") == 0) + return ORDER_INIT; + else if (strcmp(os->name(), ".fini") == 0) + return ORDER_FINI; + } + return is_execinstr ? ORDER_TEXT : ORDER_READONLY; + } + + if (os->is_relro()) + return is_relro_local ? ORDER_RELRO_LOCAL : ORDER_RELRO; + + if (os->is_small_section()) + return is_bss ? ORDER_SMALL_BSS : ORDER_SMALL_DATA; + if (os->is_large_section()) + return is_bss ? ORDER_LARGE_BSS : ORDER_LARGE_DATA; + + return is_bss ? ORDER_BSS : ORDER_DATA; +} + +// Attach output sections to segments. This is called after we have +// seen all the input sections. + +void +Layout::attach_sections_to_segments(const Target* target) +{ + for (Section_list::iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + this->attach_section_to_segment(target, *p); + + this->sections_are_attached_ = true; +} + +// Attach an output section to a segment. + +void +Layout::attach_section_to_segment(const Target* target, Output_section* os) +{ + if ((os->flags() & elfcpp::SHF_ALLOC) == 0) + this->unattached_section_list_.push_back(os); + else + this->attach_allocated_section_to_segment(target, os); +} + +// Attach an allocated output section to a segment. + +void +Layout::attach_allocated_section_to_segment(const Target* target, + Output_section* os) +{ + elfcpp::Elf_Xword flags = os->flags(); + gold_assert((flags & elfcpp::SHF_ALLOC) != 0); + + if (parameters->options().relocatable()) + return; + + // If we have a SECTIONS clause, we can't handle the attachment to + // segments until after we've seen all the sections. + if (this->script_options_->saw_sections_clause()) + return; + + gold_assert(!this->script_options_->saw_phdrs_clause()); + + // This output section goes into a PT_LOAD segment. + + elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags); + + // If this output section's segment has extra flags that need to be set, + // coming from a linker plugin, do that. + seg_flags |= os->extra_segment_flags(); + + // Check for --section-start. + uint64_t addr; + bool is_address_set = parameters->options().section_start(os->name(), &addr); + + // In general the only thing we really care about for PT_LOAD + // segments is whether or not they are writable or executable, + // so that is how we search for them. + // Large data sections also go into their own PT_LOAD segment. + // People who need segments sorted on some other basis will + // have to use a linker script. + + Segment_list::const_iterator p; + if (!os->is_unique_segment()) + { + for (p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + { + if ((*p)->type() != elfcpp::PT_LOAD) + continue; + if ((*p)->is_unique_segment()) + continue; + if (!parameters->options().omagic() + && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W)) + continue; + if ((target->isolate_execinstr() || parameters->options().rosegment()) + && ((*p)->flags() & elfcpp::PF_X) != (seg_flags & elfcpp::PF_X)) + continue; + // If -Tbss was specified, we need to separate the data and BSS + // segments. + if (parameters->options().user_set_Tbss()) + { + if ((os->type() == elfcpp::SHT_NOBITS) + == (*p)->has_any_data_sections()) + continue; + } + if (os->is_large_data_section() && !(*p)->is_large_data_segment()) + continue; + + if (is_address_set) + { + if ((*p)->are_addresses_set()) + continue; + + (*p)->add_initial_output_data(os); + (*p)->update_flags_for_output_section(seg_flags); + (*p)->set_addresses(addr, addr); + break; + } + + (*p)->add_output_section_to_load(this, os, seg_flags); + break; + } + } + + if (p == this->segment_list_.end() + || os->is_unique_segment()) + { + Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD, + seg_flags); + if (os->is_large_data_section()) + oseg->set_is_large_data_segment(); + oseg->add_output_section_to_load(this, os, seg_flags); + if (is_address_set) + oseg->set_addresses(addr, addr); + // Check if segment should be marked unique. For segments marked + // unique by linker plugins, set the new alignment if specified. + if (os->is_unique_segment()) + { + oseg->set_is_unique_segment(); + if (os->segment_alignment() != 0) + oseg->set_minimum_p_align(os->segment_alignment()); + } + } + + // If we see a loadable SHT_NOTE section, we create a PT_NOTE + // segment. + if (os->type() == elfcpp::SHT_NOTE) + { + // See if we already have an equivalent PT_NOTE segment. + for (p = this->segment_list_.begin(); + p != segment_list_.end(); + ++p) + { + if ((*p)->type() == elfcpp::PT_NOTE + && (((*p)->flags() & elfcpp::PF_W) + == (seg_flags & elfcpp::PF_W))) + { + (*p)->add_output_section_to_nonload(os, seg_flags); + break; + } + } + + if (p == this->segment_list_.end()) + { + Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE, + seg_flags); + oseg->add_output_section_to_nonload(os, seg_flags); + } + } + + // If we see a loadable SHF_TLS section, we create a PT_TLS + // segment. There can only be one such segment. + if ((flags & elfcpp::SHF_TLS) != 0) + { + if (this->tls_segment_ == NULL) + this->make_output_segment(elfcpp::PT_TLS, seg_flags); + this->tls_segment_->add_output_section_to_nonload(os, seg_flags); + } + + // If -z relro is in effect, and we see a relro section, we create a + // PT_GNU_RELRO segment. There can only be one such segment. + if (os->is_relro() && parameters->options().relro()) + { + gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W)); + if (this->relro_segment_ == NULL) + this->make_output_segment(elfcpp::PT_GNU_RELRO, seg_flags); + this->relro_segment_->add_output_section_to_nonload(os, seg_flags); + } + + // If we see a section named .interp, put it into a PT_INTERP + // segment. This seems broken to me, but this is what GNU ld does, + // and glibc expects it. + if (strcmp(os->name(), ".interp") == 0 + && !this->script_options_->saw_phdrs_clause()) + { + if (this->interp_segment_ == NULL) + this->make_output_segment(elfcpp::PT_INTERP, seg_flags); + else + gold_warning(_("multiple '.interp' sections in input files " + "may cause confusing PT_INTERP segment")); + this->interp_segment_->add_output_section_to_nonload(os, seg_flags); + } +} + +// Make an output section for a script. + +Output_section* +Layout::make_output_section_for_script( + const char* name, + Script_sections::Section_type section_type) +{ + name = this->namepool_.add(name, false, NULL); + elfcpp::Elf_Xword sh_flags = elfcpp::SHF_ALLOC; + if (section_type == Script_sections::ST_NOLOAD) + sh_flags = 0; + Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS, + sh_flags, ORDER_INVALID, + false); + os->set_found_in_sections_clause(); + if (section_type == Script_sections::ST_NOLOAD) + os->set_is_noload(); + return os; +} + +// Return the number of segments we expect to see. + +size_t +Layout::expected_segment_count() const +{ + size_t ret = this->segment_list_.size(); + + // If we didn't see a SECTIONS clause in a linker script, we should + // already have the complete list of segments. Otherwise we ask the + // SECTIONS clause how many segments it expects, and add in the ones + // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.) + + if (!this->script_options_->saw_sections_clause()) + return ret; + else + { + const Script_sections* ss = this->script_options_->script_sections(); + return ret + ss->expected_segment_count(this); + } +} + +// Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK +// is whether we saw a .note.GNU-stack section in the object file. +// GNU_STACK_FLAGS is the section flags. The flags give the +// protection required for stack memory. We record this in an +// executable as a PT_GNU_STACK segment. If an object file does not +// have a .note.GNU-stack segment, we must assume that it is an old +// object. On some targets that will force an executable stack. + +void +Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags, + const Object* obj) +{ + if (!seen_gnu_stack) + { + this->input_without_gnu_stack_note_ = true; + if (parameters->options().warn_execstack() + && parameters->target().is_default_stack_executable()) + gold_warning(_("%s: missing .note.GNU-stack section" + " implies executable stack"), + obj->name().c_str()); + } + else + { + this->input_with_gnu_stack_note_ = true; + if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0) + { + this->input_requires_executable_stack_ = true; + if (parameters->options().warn_execstack() + || parameters->options().is_stack_executable()) + gold_warning(_("%s: requires executable stack"), + obj->name().c_str()); + } + } +} + +// Create automatic note sections. + +void +Layout::create_notes() +{ + this->create_gold_note(); + this->create_executable_stack_info(); + this->create_build_id(); +} + +// Create the dynamic sections which are needed before we read the +// relocs. + +void +Layout::create_initial_dynamic_sections(Symbol_table* symtab) +{ + if (parameters->doing_static_link()) + return; + + this->dynamic_section_ = this->choose_output_section(NULL, ".dynamic", + elfcpp::SHT_DYNAMIC, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + false, ORDER_RELRO, + true); + + // A linker script may discard .dynamic, so check for NULL. + if (this->dynamic_section_ != NULL) + { + this->dynamic_symbol_ = + symtab->define_in_output_data("_DYNAMIC", NULL, + Symbol_table::PREDEFINED, + this->dynamic_section_, 0, 0, + elfcpp::STT_OBJECT, elfcpp::STB_LOCAL, + elfcpp::STV_HIDDEN, 0, false, false); + + this->dynamic_data_ = new Output_data_dynamic(&this->dynpool_); + + this->dynamic_section_->add_output_section_data(this->dynamic_data_); + } +} + +// For each output section whose name can be represented as C symbol, +// define __start and __stop symbols for the section. This is a GNU +// extension. + +void +Layout::define_section_symbols(Symbol_table* symtab) +{ + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + const char* const name = (*p)->name(); + if (is_cident(name)) + { + const std::string name_string(name); + const std::string start_name(cident_section_start_prefix + + name_string); + const std::string stop_name(cident_section_stop_prefix + + name_string); + + symtab->define_in_output_data(start_name.c_str(), + NULL, // version + Symbol_table::PREDEFINED, + *p, + 0, // value + 0, // symsize + elfcpp::STT_NOTYPE, + elfcpp::STB_GLOBAL, + elfcpp::STV_DEFAULT, + 0, // nonvis + false, // offset_is_from_end + true); // only_if_ref + + symtab->define_in_output_data(stop_name.c_str(), + NULL, // version + Symbol_table::PREDEFINED, + *p, + 0, // value + 0, // symsize + elfcpp::STT_NOTYPE, + elfcpp::STB_GLOBAL, + elfcpp::STV_DEFAULT, + 0, // nonvis + true, // offset_is_from_end + true); // only_if_ref + } + } +} + +// Define symbols for group signatures. + +void +Layout::define_group_signatures(Symbol_table* symtab) +{ + for (Group_signatures::iterator p = this->group_signatures_.begin(); + p != this->group_signatures_.end(); + ++p) + { + Symbol* sym = symtab->lookup(p->signature, NULL); + if (sym != NULL) + p->section->set_info_symndx(sym); + else + { + // Force the name of the group section to the group + // signature, and use the group's section symbol as the + // signature symbol. + if (strcmp(p->section->name(), p->signature) != 0) + { + const char* name = this->namepool_.add(p->signature, + true, NULL); + p->section->set_name(name); + } + p->section->set_needs_symtab_index(); + p->section->set_info_section_symndx(p->section); + } + } + + this->group_signatures_.clear(); +} + +// Find the first read-only PT_LOAD segment, creating one if +// necessary. + +Output_segment* +Layout::find_first_load_seg(const Target* target) +{ + Output_segment* best = NULL; + for (Segment_list::const_iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + { + if ((*p)->type() == elfcpp::PT_LOAD + && ((*p)->flags() & elfcpp::PF_R) != 0 + && (parameters->options().omagic() + || ((*p)->flags() & elfcpp::PF_W) == 0) + && (!target->isolate_execinstr() + || ((*p)->flags() & elfcpp::PF_X) == 0)) + { + if (best == NULL || this->segment_precedes(*p, best)) + best = *p; + } + } + if (best != NULL) + return best; + + gold_assert(!this->script_options_->saw_phdrs_clause()); + + Output_segment* load_seg = this->make_output_segment(elfcpp::PT_LOAD, + elfcpp::PF_R); + return load_seg; +} + +// Save states of all current output segments. Store saved states +// in SEGMENT_STATES. + +void +Layout::save_segments(Segment_states* segment_states) +{ + for (Segment_list::const_iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + { + Output_segment* segment = *p; + // Shallow copy. + Output_segment* copy = new Output_segment(*segment); + (*segment_states)[segment] = copy; + } +} + +// Restore states of output segments and delete any segment not found in +// SEGMENT_STATES. + +void +Layout::restore_segments(const Segment_states* segment_states) +{ + // Go through the segment list and remove any segment added in the + // relaxation loop. + this->tls_segment_ = NULL; + this->relro_segment_ = NULL; + Segment_list::iterator list_iter = this->segment_list_.begin(); + while (list_iter != this->segment_list_.end()) + { + Output_segment* segment = *list_iter; + Segment_states::const_iterator states_iter = + segment_states->find(segment); + if (states_iter != segment_states->end()) + { + const Output_segment* copy = states_iter->second; + // Shallow copy to restore states. + *segment = *copy; + + // Also fix up TLS and RELRO segment pointers as appropriate. + if (segment->type() == elfcpp::PT_TLS) + this->tls_segment_ = segment; + else if (segment->type() == elfcpp::PT_GNU_RELRO) + this->relro_segment_ = segment; + + ++list_iter; + } + else + { + list_iter = this->segment_list_.erase(list_iter); + // This is a segment created during section layout. It should be + // safe to remove it since we should have removed all pointers to it. + delete segment; + } + } +} + +// Clean up after relaxation so that sections can be laid out again. + +void +Layout::clean_up_after_relaxation() +{ + // Restore the segments to point state just prior to the relaxation loop. + Script_sections* script_section = this->script_options_->script_sections(); + script_section->release_segments(); + this->restore_segments(this->segment_states_); + + // Reset section addresses and file offsets + for (Section_list::iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + (*p)->restore_states(); + + // If an input section changes size because of relaxation, + // we need to adjust the section offsets of all input sections. + // after such a section. + if ((*p)->section_offsets_need_adjustment()) + (*p)->adjust_section_offsets(); + + (*p)->reset_address_and_file_offset(); + } + + // Reset special output object address and file offsets. + for (Data_list::iterator p = this->special_output_list_.begin(); + p != this->special_output_list_.end(); + ++p) + (*p)->reset_address_and_file_offset(); + + // A linker script may have created some output section data objects. + // They are useless now. + for (Output_section_data_list::const_iterator p = + this->script_output_section_data_list_.begin(); + p != this->script_output_section_data_list_.end(); + ++p) + delete *p; + this->script_output_section_data_list_.clear(); + + // Special-case fill output objects are recreated each time through + // the relaxation loop. + this->reset_relax_output(); +} + +void +Layout::reset_relax_output() +{ + for (Data_list::const_iterator p = this->relax_output_list_.begin(); + p != this->relax_output_list_.end(); + ++p) + delete *p; + this->relax_output_list_.clear(); +} + +// Prepare for relaxation. + +void +Layout::prepare_for_relaxation() +{ + // Create an relaxation debug check if in debugging mode. + if (is_debugging_enabled(DEBUG_RELAXATION)) + this->relaxation_debug_check_ = new Relaxation_debug_check(); + + // Save segment states. + this->segment_states_ = new Segment_states(); + this->save_segments(this->segment_states_); + + for(Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + (*p)->save_states(); + + if (is_debugging_enabled(DEBUG_RELAXATION)) + this->relaxation_debug_check_->check_output_data_for_reset_values( + this->section_list_, this->special_output_list_, + this->relax_output_list_); + + // Also enable recording of output section data from scripts. + this->record_output_section_data_from_script_ = true; +} + +// If the user set the address of the text segment, that may not be +// compatible with putting the segment headers and file headers into +// that segment. For isolate_execinstr() targets, it's the rodata +// segment rather than text where we might put the headers. +static inline bool +load_seg_unusable_for_headers(const Target* target) +{ + const General_options& options = parameters->options(); + if (target->isolate_execinstr()) + return (options.user_set_Trodata_segment() + && options.Trodata_segment() % target->abi_pagesize() != 0); + else + return (options.user_set_Ttext() + && options.Ttext() % target->abi_pagesize() != 0); +} + +// Relaxation loop body: If target has no relaxation, this runs only once +// Otherwise, the target relaxation hook is called at the end of +// each iteration. If the hook returns true, it means re-layout of +// section is required. +// +// The number of segments created by a linking script without a PHDRS +// clause may be affected by section sizes and alignments. There is +// a remote chance that relaxation causes different number of PT_LOAD +// segments are created and sections are attached to different segments. +// Therefore, we always throw away all segments created during section +// layout. In order to be able to restart the section layout, we keep +// a copy of the segment list right before the relaxation loop and use +// that to restore the segments. +// +// PASS is the current relaxation pass number. +// SYMTAB is a symbol table. +// PLOAD_SEG is the address of a pointer for the load segment. +// PHDR_SEG is a pointer to the PHDR segment. +// SEGMENT_HEADERS points to the output segment header. +// FILE_HEADER points to the output file header. +// PSHNDX is the address to store the output section index. + +off_t inline +Layout::relaxation_loop_body( + int pass, + Target* target, + Symbol_table* symtab, + Output_segment** pload_seg, + Output_segment* phdr_seg, + Output_segment_headers* segment_headers, + Output_file_header* file_header, + unsigned int* pshndx) +{ + // If this is not the first iteration, we need to clean up after + // relaxation so that we can lay out the sections again. + if (pass != 0) + this->clean_up_after_relaxation(); + + // If there is a SECTIONS clause, put all the input sections into + // the required order. + Output_segment* load_seg; + if (this->script_options_->saw_sections_clause()) + load_seg = this->set_section_addresses_from_script(symtab); + else if (parameters->options().relocatable()) + load_seg = NULL; + else + load_seg = this->find_first_load_seg(target); + + if (parameters->options().oformat_enum() + != General_options::OBJECT_FORMAT_ELF) + load_seg = NULL; + + if (load_seg_unusable_for_headers(target)) + { + load_seg = NULL; + phdr_seg = NULL; + } + + gold_assert(phdr_seg == NULL + || load_seg != NULL + || this->script_options_->saw_sections_clause()); + + // If the address of the load segment we found has been set by + // --section-start rather than by a script, then adjust the VMA and + // LMA downward if possible to include the file and section headers. + uint64_t header_gap = 0; + if (load_seg != NULL + && load_seg->are_addresses_set() + && !this->script_options_->saw_sections_clause() + && !parameters->options().relocatable()) + { + file_header->finalize_data_size(); + segment_headers->finalize_data_size(); + size_t sizeof_headers = (file_header->data_size() + + segment_headers->data_size()); + const uint64_t abi_pagesize = target->abi_pagesize(); + uint64_t hdr_paddr = load_seg->paddr() - sizeof_headers; + hdr_paddr &= ~(abi_pagesize - 1); + uint64_t subtract = load_seg->paddr() - hdr_paddr; + if (load_seg->paddr() < subtract || load_seg->vaddr() < subtract) + load_seg = NULL; + else + { + load_seg->set_addresses(load_seg->vaddr() - subtract, + load_seg->paddr() - subtract); + header_gap = subtract - sizeof_headers; + } + } + + // Lay out the segment headers. + if (!parameters->options().relocatable()) + { + gold_assert(segment_headers != NULL); + if (header_gap != 0 && load_seg != NULL) + { + Output_data_zero_fill* z = new Output_data_zero_fill(header_gap, 1); + load_seg->add_initial_output_data(z); + } + if (load_seg != NULL) + load_seg->add_initial_output_data(segment_headers); + if (phdr_seg != NULL) + phdr_seg->add_initial_output_data(segment_headers); + } + + // Lay out the file header. + if (load_seg != NULL) + load_seg->add_initial_output_data(file_header); + + if (this->script_options_->saw_phdrs_clause() + && !parameters->options().relocatable()) + { + // Support use of FILEHDRS and PHDRS attachments in a PHDRS + // clause in a linker script. + Script_sections* ss = this->script_options_->script_sections(); + ss->put_headers_in_phdrs(file_header, segment_headers); + } + + // We set the output section indexes in set_segment_offsets and + // set_section_indexes. + *pshndx = 1; + + // Set the file offsets of all the segments, and all the sections + // they contain. + off_t off; + if (!parameters->options().relocatable()) + off = this->set_segment_offsets(target, load_seg, pshndx); + else + off = this->set_relocatable_section_offsets(file_header, pshndx); + + // Verify that the dummy relaxation does not change anything. + if (is_debugging_enabled(DEBUG_RELAXATION)) + { + if (pass == 0) + this->relaxation_debug_check_->read_sections(this->section_list_); + else + this->relaxation_debug_check_->verify_sections(this->section_list_); + } + + *pload_seg = load_seg; + return off; +} + +// Search the list of patterns and find the postion of the given section +// name in the output section. If the section name matches a glob +// pattern and a non-glob name, then the non-glob position takes +// precedence. Return 0 if no match is found. + +unsigned int +Layout::find_section_order_index(const std::string& section_name) +{ + Unordered_map<std::string, unsigned int>::iterator map_it; + map_it = this->input_section_position_.find(section_name); + if (map_it != this->input_section_position_.end()) + return map_it->second; + + // Absolute match failed. Linear search the glob patterns. + std::vector<std::string>::iterator it; + for (it = this->input_section_glob_.begin(); + it != this->input_section_glob_.end(); + ++it) + { + if (fnmatch((*it).c_str(), section_name.c_str(), FNM_NOESCAPE) == 0) + { + map_it = this->input_section_position_.find(*it); + gold_assert(map_it != this->input_section_position_.end()); + return map_it->second; + } + } + return 0; +} + +// Read the sequence of input sections from the file specified with +// option --section-ordering-file. + +void +Layout::read_layout_from_file() +{ + const char* filename = parameters->options().section_ordering_file(); + std::ifstream in; + std::string line; + + in.open(filename); + if (!in) + gold_fatal(_("unable to open --section-ordering-file file %s: %s"), + filename, strerror(errno)); + + std::getline(in, line); // this chops off the trailing \n, if any + unsigned int position = 1; + this->set_section_ordering_specified(); + + while (in) + { + if (!line.empty() && line[line.length() - 1] == '\r') // Windows + line.resize(line.length() - 1); + // Ignore comments, beginning with '#' + if (line[0] == '#') + { + std::getline(in, line); + continue; + } + this->input_section_position_[line] = position; + // Store all glob patterns in a vector. + if (is_wildcard_string(line.c_str())) + this->input_section_glob_.push_back(line); + position++; + std::getline(in, line); + } +} + +// Finalize the layout. When this is called, we have created all the +// output sections and all the output segments which are based on +// input sections. We have several things to do, and we have to do +// them in the right order, so that we get the right results correctly +// and efficiently. + +// 1) Finalize the list of output segments and create the segment +// table header. + +// 2) Finalize the dynamic symbol table and associated sections. + +// 3) Determine the final file offset of all the output segments. + +// 4) Determine the final file offset of all the SHF_ALLOC output +// sections. + +// 5) Create the symbol table sections and the section name table +// section. + +// 6) Finalize the symbol table: set symbol values to their final +// value and make a final determination of which symbols are going +// into the output symbol table. + +// 7) Create the section table header. + +// 8) Determine the final file offset of all the output sections which +// are not SHF_ALLOC, including the section table header. + +// 9) Finalize the ELF file header. + +// This function returns the size of the output file. + +off_t +Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab, + Target* target, const Task* task) +{ + target->finalize_sections(this, input_objects, symtab); + + this->count_local_symbols(task, input_objects); + + this->link_stabs_sections(); + + Output_segment* phdr_seg = NULL; + if (!parameters->options().relocatable() && !parameters->doing_static_link()) + { + // There was a dynamic object in the link. We need to create + // some information for the dynamic linker. + + // Create the PT_PHDR segment which will hold the program + // headers. + if (!this->script_options_->saw_phdrs_clause()) + phdr_seg = this->make_output_segment(elfcpp::PT_PHDR, elfcpp::PF_R); + + // Create the dynamic symbol table, including the hash table. + Output_section* dynstr; + std::vector<Symbol*> dynamic_symbols; + unsigned int local_dynamic_count; + Versions versions(*this->script_options()->version_script_info(), + &this->dynpool_); + this->create_dynamic_symtab(input_objects, symtab, &dynstr, + &local_dynamic_count, &dynamic_symbols, + &versions); + + // Create the .interp section to hold the name of the + // interpreter, and put it in a PT_INTERP segment. Don't do it + // if we saw a .interp section in an input file. + if ((!parameters->options().shared() + || parameters->options().dynamic_linker() != NULL) + && this->interp_segment_ == NULL) + this->create_interp(target); + + // Finish the .dynamic section to hold the dynamic data, and put + // it in a PT_DYNAMIC segment. + this->finish_dynamic_section(input_objects, symtab); + + // We should have added everything we need to the dynamic string + // table. + this->dynpool_.set_string_offsets(); + + // Create the version sections. We can't do this until the + // dynamic string table is complete. + this->create_version_sections(&versions, symtab, local_dynamic_count, + dynamic_symbols, dynstr); + + // Set the size of the _DYNAMIC symbol. We can't do this until + // after we call create_version_sections. + this->set_dynamic_symbol_size(symtab); + } + + // Create segment headers. + Output_segment_headers* segment_headers = + (parameters->options().relocatable() + ? NULL + : new Output_segment_headers(this->segment_list_)); + + // Lay out the file header. + Output_file_header* file_header = new Output_file_header(target, symtab, + segment_headers); + + this->special_output_list_.push_back(file_header); + if (segment_headers != NULL) + this->special_output_list_.push_back(segment_headers); + + // Find approriate places for orphan output sections if we are using + // a linker script. + if (this->script_options_->saw_sections_clause()) + this->place_orphan_sections_in_script(); + + Output_segment* load_seg; + off_t off; + unsigned int shndx; + int pass = 0; + + // Take a snapshot of the section layout as needed. + if (target->may_relax()) + this->prepare_for_relaxation(); + + // Run the relaxation loop to lay out sections. + do + { + off = this->relaxation_loop_body(pass, target, symtab, &load_seg, + phdr_seg, segment_headers, file_header, + &shndx); + pass++; + } + while (target->may_relax() + && target->relax(pass, input_objects, symtab, this, task)); + + // If there is a load segment that contains the file and program headers, + // provide a symbol __ehdr_start pointing there. + // A program can use this to examine itself robustly. + if (load_seg != NULL) + symtab->define_in_output_segment("__ehdr_start", NULL, + Symbol_table::PREDEFINED, load_seg, 0, 0, + elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, + elfcpp::STV_HIDDEN, 0, + Symbol::SEGMENT_START, true); + + // Set the file offsets of all the non-data sections we've seen so + // far which don't have to wait for the input sections. We need + // this in order to finalize local symbols in non-allocated + // sections. + off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS); + + // Set the section indexes of all unallocated sections seen so far, + // in case any of them are somehow referenced by a symbol. + shndx = this->set_section_indexes(shndx); + + // Create the symbol table sections. + this->create_symtab_sections(input_objects, symtab, shndx, &off); + if (!parameters->doing_static_link()) + this->assign_local_dynsym_offsets(input_objects); + + // Process any symbol assignments from a linker script. This must + // be called after the symbol table has been finalized. + this->script_options_->finalize_symbols(symtab, this); + + // Create the incremental inputs sections. + if (this->incremental_inputs_) + { + this->incremental_inputs_->finalize(); + this->create_incremental_info_sections(symtab); + } + + // Create the .shstrtab section. + Output_section* shstrtab_section = this->create_shstrtab(); + + // Set the file offsets of the rest of the non-data sections which + // don't have to wait for the input sections. + off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS); + + // Now that all sections have been created, set the section indexes + // for any sections which haven't been done yet. + shndx = this->set_section_indexes(shndx); + + // Create the section table header. + this->create_shdrs(shstrtab_section, &off); + + // If there are no sections which require postprocessing, we can + // handle the section names now, and avoid a resize later. + if (!this->any_postprocessing_sections_) + { + off = this->set_section_offsets(off, + POSTPROCESSING_SECTIONS_PASS); + off = + this->set_section_offsets(off, + STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS); + } + + file_header->set_section_info(this->section_headers_, shstrtab_section); + + // Now we know exactly where everything goes in the output file + // (except for non-allocated sections which require postprocessing). + Output_data::layout_complete(); + + this->output_file_size_ = off; + + return off; +} + +// Create a note header following the format defined in the ELF ABI. +// NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name +// of the section to create, DESCSZ is the size of the descriptor. +// ALLOCATE is true if the section should be allocated in memory. +// This returns the new note section. It sets *TRAILING_PADDING to +// the number of trailing zero bytes required. + +Output_section* +Layout::create_note(const char* name, int note_type, + const char* section_name, size_t descsz, + bool allocate, size_t* trailing_padding) +{ + // Authorities all agree that the values in a .note field should + // be aligned on 4-byte boundaries for 32-bit binaries. However, + // they differ on what the alignment is for 64-bit binaries. + // The GABI says unambiguously they take 8-byte alignment: + // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section + // Other documentation says alignment should always be 4 bytes: + // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format + // GNU ld and GNU readelf both support the latter (at least as of + // version 2.16.91), and glibc always generates the latter for + // .note.ABI-tag (as of version 1.6), so that's the one we go with + // here. +#ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default. + const int size = parameters->target().get_size(); +#else + const int size = 32; +#endif + + // The contents of the .note section. + size_t namesz = strlen(name) + 1; + size_t aligned_namesz = align_address(namesz, size / 8); + size_t aligned_descsz = align_address(descsz, size / 8); + + size_t notehdrsz = 3 * (size / 8) + aligned_namesz; + + unsigned char* buffer = new unsigned char[notehdrsz]; + memset(buffer, 0, notehdrsz); + + bool is_big_endian = parameters->target().is_big_endian(); + + if (size == 32) + { + if (!is_big_endian) + { + elfcpp::Swap<32, false>::writeval(buffer, namesz); + elfcpp::Swap<32, false>::writeval(buffer + 4, descsz); + elfcpp::Swap<32, false>::writeval(buffer + 8, note_type); + } + else + { + elfcpp::Swap<32, true>::writeval(buffer, namesz); + elfcpp::Swap<32, true>::writeval(buffer + 4, descsz); + elfcpp::Swap<32, true>::writeval(buffer + 8, note_type); + } + } + else if (size == 64) + { + if (!is_big_endian) + { + elfcpp::Swap<64, false>::writeval(buffer, namesz); + elfcpp::Swap<64, false>::writeval(buffer + 8, descsz); + elfcpp::Swap<64, false>::writeval(buffer + 16, note_type); + } + else + { + elfcpp::Swap<64, true>::writeval(buffer, namesz); + elfcpp::Swap<64, true>::writeval(buffer + 8, descsz); + elfcpp::Swap<64, true>::writeval(buffer + 16, note_type); + } + } + else + gold_unreachable(); + + memcpy(buffer + 3 * (size / 8), name, namesz); + + elfcpp::Elf_Xword flags = 0; + Output_section_order order = ORDER_INVALID; + if (allocate) + { + flags = elfcpp::SHF_ALLOC; + order = ORDER_RO_NOTE; + } + Output_section* os = this->choose_output_section(NULL, section_name, + elfcpp::SHT_NOTE, + flags, false, order, false); + if (os == NULL) + return NULL; + + Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz, + size / 8, + "** note header"); + os->add_output_section_data(posd); + + *trailing_padding = aligned_descsz - descsz; + + return os; +} + +// For an executable or shared library, create a note to record the +// version of gold used to create the binary. + +void +Layout::create_gold_note() +{ + if (parameters->options().relocatable() + || parameters->incremental_update()) + return; + + std::string desc = std::string("gold ") + gold::get_version_string(); + + size_t trailing_padding; + Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION, + ".note.gnu.gold-version", desc.size(), + false, &trailing_padding); + if (os == NULL) + return; + + Output_section_data* posd = new Output_data_const(desc, 4); + os->add_output_section_data(posd); + + if (trailing_padding > 0) + { + posd = new Output_data_zero_fill(trailing_padding, 0); + os->add_output_section_data(posd); + } +} + +// Record whether the stack should be executable. This can be set +// from the command line using the -z execstack or -z noexecstack +// options. Otherwise, if any input file has a .note.GNU-stack +// section with the SHF_EXECINSTR flag set, the stack should be +// executable. Otherwise, if at least one input file a +// .note.GNU-stack section, and some input file has no .note.GNU-stack +// section, we use the target default for whether the stack should be +// executable. Otherwise, we don't generate a stack note. When +// generating a object file, we create a .note.GNU-stack section with +// the appropriate marking. When generating an executable or shared +// library, we create a PT_GNU_STACK segment. + +void +Layout::create_executable_stack_info() +{ + bool is_stack_executable; + if (parameters->options().is_execstack_set()) + is_stack_executable = parameters->options().is_stack_executable(); + else if (!this->input_with_gnu_stack_note_) + return; + else + { + if (this->input_requires_executable_stack_) + is_stack_executable = true; + else if (this->input_without_gnu_stack_note_) + is_stack_executable = + parameters->target().is_default_stack_executable(); + else + is_stack_executable = false; + } + + if (parameters->options().relocatable()) + { + const char* name = this->namepool_.add(".note.GNU-stack", false, NULL); + elfcpp::Elf_Xword flags = 0; + if (is_stack_executable) + flags |= elfcpp::SHF_EXECINSTR; + this->make_output_section(name, elfcpp::SHT_PROGBITS, flags, + ORDER_INVALID, false); + } + else + { + if (this->script_options_->saw_phdrs_clause()) + return; + int flags = elfcpp::PF_R | elfcpp::PF_W; + if (is_stack_executable) + flags |= elfcpp::PF_X; + this->make_output_segment(elfcpp::PT_GNU_STACK, flags); + } +} + +// If --build-id was used, set up the build ID note. + +void +Layout::create_build_id() +{ + if (!parameters->options().user_set_build_id()) + return; + + const char* style = parameters->options().build_id(); + if (strcmp(style, "none") == 0) + return; + + // Set DESCSZ to the size of the note descriptor. When possible, + // set DESC to the note descriptor contents. + size_t descsz; + std::string desc; + if (strcmp(style, "md5") == 0) + descsz = 128 / 8; + else if ((strcmp(style, "sha1") == 0) || (strcmp(style, "tree") == 0)) + descsz = 160 / 8; + else if (strcmp(style, "uuid") == 0) + { + const size_t uuidsz = 128 / 8; + + char buffer[uuidsz]; + memset(buffer, 0, uuidsz); + + int descriptor = open_descriptor(-1, "/dev/urandom", O_RDONLY); + if (descriptor < 0) + gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"), + strerror(errno)); + else + { + ssize_t got = ::read(descriptor, buffer, uuidsz); + release_descriptor(descriptor, true); + if (got < 0) + gold_error(_("/dev/urandom: read failed: %s"), strerror(errno)); + else if (static_cast<size_t>(got) != uuidsz) + gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"), + uuidsz, got); + } + + desc.assign(buffer, uuidsz); + descsz = uuidsz; + } + else if (strncmp(style, "0x", 2) == 0) + { + hex_init(); + const char* p = style + 2; + while (*p != '\0') + { + if (hex_p(p[0]) && hex_p(p[1])) + { + char c = (hex_value(p[0]) << 4) | hex_value(p[1]); + desc += c; + p += 2; + } + else if (*p == '-' || *p == ':') + ++p; + else + gold_fatal(_("--build-id argument '%s' not a valid hex number"), + style); + } + descsz = desc.size(); + } + else + gold_fatal(_("unrecognized --build-id argument '%s'"), style); + + // Create the note. + size_t trailing_padding; + Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID, + ".note.gnu.build-id", descsz, true, + &trailing_padding); + if (os == NULL) + return; + + if (!desc.empty()) + { + // We know the value already, so we fill it in now. + gold_assert(desc.size() == descsz); + + Output_section_data* posd = new Output_data_const(desc, 4); + os->add_output_section_data(posd); + + if (trailing_padding != 0) + { + posd = new Output_data_zero_fill(trailing_padding, 0); + os->add_output_section_data(posd); + } + } + else + { + // We need to compute a checksum after we have completed the + // link. + gold_assert(trailing_padding == 0); + this->build_id_note_ = new Output_data_zero_fill(descsz, 4); + os->add_output_section_data(this->build_id_note_); + } +} + +// If we have both .stabXX and .stabXXstr sections, then the sh_link +// field of the former should point to the latter. I'm not sure who +// started this, but the GNU linker does it, and some tools depend +// upon it. + +void +Layout::link_stabs_sections() +{ + if (!this->have_stabstr_section_) + return; + + for (Section_list::iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + if ((*p)->type() != elfcpp::SHT_STRTAB) + continue; + + const char* name = (*p)->name(); + if (strncmp(name, ".stab", 5) != 0) + continue; + + size_t len = strlen(name); + if (strcmp(name + len - 3, "str") != 0) + continue; + + std::string stab_name(name, len - 3); + Output_section* stab_sec; + stab_sec = this->find_output_section(stab_name.c_str()); + if (stab_sec != NULL) + stab_sec->set_link_section(*p); + } +} + +// Create .gnu_incremental_inputs and related sections needed +// for the next run of incremental linking to check what has changed. + +void +Layout::create_incremental_info_sections(Symbol_table* symtab) +{ + Incremental_inputs* incr = this->incremental_inputs_; + + gold_assert(incr != NULL); + + // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections. + incr->create_data_sections(symtab); + + // Add the .gnu_incremental_inputs section. + const char* incremental_inputs_name = + this->namepool_.add(".gnu_incremental_inputs", false, NULL); + Output_section* incremental_inputs_os = + this->make_output_section(incremental_inputs_name, + elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0, + ORDER_INVALID, false); + incremental_inputs_os->add_output_section_data(incr->inputs_section()); + + // Add the .gnu_incremental_symtab section. + const char* incremental_symtab_name = + this->namepool_.add(".gnu_incremental_symtab", false, NULL); + Output_section* incremental_symtab_os = + this->make_output_section(incremental_symtab_name, + elfcpp::SHT_GNU_INCREMENTAL_SYMTAB, 0, + ORDER_INVALID, false); + incremental_symtab_os->add_output_section_data(incr->symtab_section()); + incremental_symtab_os->set_entsize(4); + + // Add the .gnu_incremental_relocs section. + const char* incremental_relocs_name = + this->namepool_.add(".gnu_incremental_relocs", false, NULL); + Output_section* incremental_relocs_os = + this->make_output_section(incremental_relocs_name, + elfcpp::SHT_GNU_INCREMENTAL_RELOCS, 0, + ORDER_INVALID, false); + incremental_relocs_os->add_output_section_data(incr->relocs_section()); + incremental_relocs_os->set_entsize(incr->relocs_entsize()); + + // Add the .gnu_incremental_got_plt section. + const char* incremental_got_plt_name = + this->namepool_.add(".gnu_incremental_got_plt", false, NULL); + Output_section* incremental_got_plt_os = + this->make_output_section(incremental_got_plt_name, + elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT, 0, + ORDER_INVALID, false); + incremental_got_plt_os->add_output_section_data(incr->got_plt_section()); + + // Add the .gnu_incremental_strtab section. + const char* incremental_strtab_name = + this->namepool_.add(".gnu_incremental_strtab", false, NULL); + Output_section* incremental_strtab_os = this->make_output_section(incremental_strtab_name, + elfcpp::SHT_STRTAB, 0, + ORDER_INVALID, false); + Output_data_strtab* strtab_data = + new Output_data_strtab(incr->get_stringpool()); + incremental_strtab_os->add_output_section_data(strtab_data); + + incremental_inputs_os->set_after_input_sections(); + incremental_symtab_os->set_after_input_sections(); + incremental_relocs_os->set_after_input_sections(); + incremental_got_plt_os->set_after_input_sections(); + + incremental_inputs_os->set_link_section(incremental_strtab_os); + incremental_symtab_os->set_link_section(incremental_inputs_os); + incremental_relocs_os->set_link_section(incremental_inputs_os); + incremental_got_plt_os->set_link_section(incremental_inputs_os); +} + +// Return whether SEG1 should be before SEG2 in the output file. This +// is based entirely on the segment type and flags. When this is +// called the segment addresses have normally not yet been set. + +bool +Layout::segment_precedes(const Output_segment* seg1, + const Output_segment* seg2) +{ + elfcpp::Elf_Word type1 = seg1->type(); + elfcpp::Elf_Word type2 = seg2->type(); + + // The single PT_PHDR segment is required to precede any loadable + // segment. We simply make it always first. + if (type1 == elfcpp::PT_PHDR) + { + gold_assert(type2 != elfcpp::PT_PHDR); + return true; + } + if (type2 == elfcpp::PT_PHDR) + return false; + + // The single PT_INTERP segment is required to precede any loadable + // segment. We simply make it always second. + if (type1 == elfcpp::PT_INTERP) + { + gold_assert(type2 != elfcpp::PT_INTERP); + return true; + } + if (type2 == elfcpp::PT_INTERP) + return false; + + // We then put PT_LOAD segments before any other segments. + if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD) + return true; + if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD) + return false; + + // We put the PT_TLS segment last except for the PT_GNU_RELRO + // segment, because that is where the dynamic linker expects to find + // it (this is just for efficiency; other positions would also work + // correctly). + if (type1 == elfcpp::PT_TLS + && type2 != elfcpp::PT_TLS + && type2 != elfcpp::PT_GNU_RELRO) + return false; + if (type2 == elfcpp::PT_TLS + && type1 != elfcpp::PT_TLS + && type1 != elfcpp::PT_GNU_RELRO) + return true; + + // We put the PT_GNU_RELRO segment last, because that is where the + // dynamic linker expects to find it (as with PT_TLS, this is just + // for efficiency). + if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO) + return false; + if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO) + return true; + + const elfcpp::Elf_Word flags1 = seg1->flags(); + const elfcpp::Elf_Word flags2 = seg2->flags(); + + // The order of non-PT_LOAD segments is unimportant. We simply sort + // by the numeric segment type and flags values. There should not + // be more than one segment with the same type and flags, except + // when a linker script specifies such. + if (type1 != elfcpp::PT_LOAD) + { + if (type1 != type2) + return type1 < type2; + gold_assert(flags1 != flags2 + || this->script_options_->saw_phdrs_clause()); + return flags1 < flags2; + } + + // If the addresses are set already, sort by load address. + if (seg1->are_addresses_set()) + { + if (!seg2->are_addresses_set()) + return true; + + unsigned int section_count1 = seg1->output_section_count(); + unsigned int section_count2 = seg2->output_section_count(); + if (section_count1 == 0 && section_count2 > 0) + return true; + if (section_count1 > 0 && section_count2 == 0) + return false; + + uint64_t paddr1 = (seg1->are_addresses_set() + ? seg1->paddr() + : seg1->first_section_load_address()); + uint64_t paddr2 = (seg2->are_addresses_set() + ? seg2->paddr() + : seg2->first_section_load_address()); + + if (paddr1 != paddr2) + return paddr1 < paddr2; + } + else if (seg2->are_addresses_set()) + return false; + + // A segment which holds large data comes after a segment which does + // not hold large data. + if (seg1->is_large_data_segment()) + { + if (!seg2->is_large_data_segment()) + return false; + } + else if (seg2->is_large_data_segment()) + return true; + + // Otherwise, we sort PT_LOAD segments based on the flags. Readonly + // segments come before writable segments. Then writable segments + // with data come before writable segments without data. Then + // executable segments come before non-executable segments. Then + // the unlikely case of a non-readable segment comes before the + // normal case of a readable segment. If there are multiple + // segments with the same type and flags, we require that the + // address be set, and we sort by virtual address and then physical + // address. + if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W)) + return (flags1 & elfcpp::PF_W) == 0; + if ((flags1 & elfcpp::PF_W) != 0 + && seg1->has_any_data_sections() != seg2->has_any_data_sections()) + return seg1->has_any_data_sections(); + if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X)) + return (flags1 & elfcpp::PF_X) != 0; + if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R)) + return (flags1 & elfcpp::PF_R) == 0; + + // We shouldn't get here--we shouldn't create segments which we + // can't distinguish. Unless of course we are using a weird linker + // script or overlapping --section-start options. We could also get + // here if plugins want unique segments for subsets of sections. + gold_assert(this->script_options_->saw_phdrs_clause() + || parameters->options().any_section_start() + || this->is_unique_segment_for_sections_specified()); + return false; +} + +// Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE. + +static off_t +align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize) +{ + uint64_t unsigned_off = off; + uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1)) + | (addr & (abi_pagesize - 1))); + if (aligned_off < unsigned_off) + aligned_off += abi_pagesize; + return aligned_off; +} + +// On targets where the text segment contains only executable code, +// a non-executable segment is never the text segment. + +static inline bool +is_text_segment(const Target* target, const Output_segment* seg) +{ + elfcpp::Elf_Xword flags = seg->flags(); + if ((flags & elfcpp::PF_W) != 0) + return false; + if ((flags & elfcpp::PF_X) == 0) + return !target->isolate_execinstr(); + return true; +} + +// Set the file offsets of all the segments, and all the sections they +// contain. They have all been created. LOAD_SEG must be be laid out +// first. Return the offset of the data to follow. + +off_t +Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, + unsigned int* pshndx) +{ + // Sort them into the final order. We use a stable sort so that we + // don't randomize the order of indistinguishable segments created + // by linker scripts. + std::stable_sort(this->segment_list_.begin(), this->segment_list_.end(), + Layout::Compare_segments(this)); + + // Find the PT_LOAD segments, and set their addresses and offsets + // and their section's addresses and offsets. + uint64_t start_addr; + if (parameters->options().user_set_Ttext()) + start_addr = parameters->options().Ttext(); + else if (parameters->options().output_is_position_independent()) + start_addr = 0; + else + start_addr = target->default_text_segment_address(); + + uint64_t addr = start_addr; + off_t off = 0; + + // If LOAD_SEG is NULL, then the file header and segment headers + // will not be loadable. But they still need to be at offset 0 in + // the file. Set their offsets now. + if (load_seg == NULL) + { + for (Data_list::iterator p = this->special_output_list_.begin(); + p != this->special_output_list_.end(); + ++p) + { + off = align_address(off, (*p)->addralign()); + (*p)->set_address_and_file_offset(0, off); + off += (*p)->data_size(); + } + } + + unsigned int increase_relro = this->increase_relro_; + if (this->script_options_->saw_sections_clause()) + increase_relro = 0; + + const bool check_sections = parameters->options().check_sections(); + Output_segment* last_load_segment = NULL; + + unsigned int shndx_begin = *pshndx; + unsigned int shndx_load_seg = *pshndx; + + for (Segment_list::iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + { + if ((*p)->type() == elfcpp::PT_LOAD) + { + if (target->isolate_execinstr()) + { + // When we hit the segment that should contain the + // file headers, reset the file offset so we place + // it and subsequent segments appropriately. + // We'll fix up the preceding segments below. + if (load_seg == *p) + { + if (off == 0) + load_seg = NULL; + else + { + off = 0; + shndx_load_seg = *pshndx; + } + } + } + else + { + // Verify that the file headers fall into the first segment. + if (load_seg != NULL && load_seg != *p) + gold_unreachable(); + load_seg = NULL; + } + + bool are_addresses_set = (*p)->are_addresses_set(); + if (are_addresses_set) + { + // When it comes to setting file offsets, we care about + // the physical address. + addr = (*p)->paddr(); + } + else if (parameters->options().user_set_Ttext() + && (parameters->options().omagic() + || is_text_segment(target, *p))) + { + are_addresses_set = true; + } + else if (parameters->options().user_set_Trodata_segment() + && ((*p)->flags() & (elfcpp::PF_W | elfcpp::PF_X)) == 0) + { + addr = parameters->options().Trodata_segment(); + are_addresses_set = true; + } + else if (parameters->options().user_set_Tdata() + && ((*p)->flags() & elfcpp::PF_W) != 0 + && (!parameters->options().user_set_Tbss() + || (*p)->has_any_data_sections())) + { + addr = parameters->options().Tdata(); + are_addresses_set = true; + } + else if (parameters->options().user_set_Tbss() + && ((*p)->flags() & elfcpp::PF_W) != 0 + && !(*p)->has_any_data_sections()) + { + addr = parameters->options().Tbss(); + are_addresses_set = true; + } + + uint64_t orig_addr = addr; + uint64_t orig_off = off; + + uint64_t aligned_addr = 0; + uint64_t abi_pagesize = target->abi_pagesize(); + uint64_t common_pagesize = target->common_pagesize(); + + if (!parameters->options().nmagic() + && !parameters->options().omagic()) + (*p)->set_minimum_p_align(abi_pagesize); + + if (!are_addresses_set) + { + // Skip the address forward one page, maintaining the same + // position within the page. This lets us store both segments + // overlapping on a single page in the file, but the loader will + // put them on different pages in memory. We will revisit this + // decision once we know the size of the segment. + + addr = align_address(addr, (*p)->maximum_alignment()); + aligned_addr = addr; + + if (load_seg == *p) + { + // This is the segment that will contain the file + // headers, so its offset will have to be exactly zero. + gold_assert(orig_off == 0); + + // If the target wants a fixed minimum distance from the + // text segment to the read-only segment, move up now. + uint64_t min_addr = + start_addr + (parameters->options().user_set_rosegment_gap() + ? parameters->options().rosegment_gap() + : target->rosegment_gap()); + if (addr < min_addr) + addr = min_addr; + + // But this is not the first segment! To make its + // address congruent with its offset, that address better + // be aligned to the ABI-mandated page size. + addr = align_address(addr, abi_pagesize); + aligned_addr = addr; + } + else + { + if ((addr & (abi_pagesize - 1)) != 0) + addr = addr + abi_pagesize; + + off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1)); + } + } + + if (!parameters->options().nmagic() + && !parameters->options().omagic()) + { + // Here we are also taking care of the case when + // the maximum segment alignment is larger than the page size. + off = align_file_offset(off, addr, + std::max(abi_pagesize, + (*p)->maximum_alignment())); + } + else + { + // This is -N or -n with a section script which prevents + // us from using a load segment. We need to ensure that + // the file offset is aligned to the alignment of the + // segment. This is because the linker script + // implicitly assumed a zero offset. If we don't align + // here, then the alignment of the sections in the + // linker script may not match the alignment of the + // sections in the set_section_addresses call below, + // causing an error about dot moving backward. + off = align_address(off, (*p)->maximum_alignment()); + } + + unsigned int shndx_hold = *pshndx; + bool has_relro = false; + uint64_t new_addr = (*p)->set_section_addresses(target, this, + false, addr, + &increase_relro, + &has_relro, + &off, pshndx); + + // Now that we know the size of this segment, we may be able + // to save a page in memory, at the cost of wasting some + // file space, by instead aligning to the start of a new + // page. Here we use the real machine page size rather than + // the ABI mandated page size. If the segment has been + // aligned so that the relro data ends at a page boundary, + // we do not try to realign it. + + if (!are_addresses_set + && !has_relro + && aligned_addr != addr + && !parameters->incremental()) + { + uint64_t first_off = (common_pagesize + - (aligned_addr + & (common_pagesize - 1))); + uint64_t last_off = new_addr & (common_pagesize - 1); + if (first_off > 0 + && last_off > 0 + && ((aligned_addr & ~ (common_pagesize - 1)) + != (new_addr & ~ (common_pagesize - 1))) + && first_off + last_off <= common_pagesize) + { + *pshndx = shndx_hold; + addr = align_address(aligned_addr, common_pagesize); + addr = align_address(addr, (*p)->maximum_alignment()); + if ((addr & (abi_pagesize - 1)) != 0) + addr = addr + abi_pagesize; + off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1)); + off = align_file_offset(off, addr, abi_pagesize); + + increase_relro = this->increase_relro_; + if (this->script_options_->saw_sections_clause()) + increase_relro = 0; + has_relro = false; + + new_addr = (*p)->set_section_addresses(target, this, + true, addr, + &increase_relro, + &has_relro, + &off, pshndx); + } + } + + addr = new_addr; + + // Implement --check-sections. We know that the segments + // are sorted by LMA. + if (check_sections && last_load_segment != NULL) + { + gold_assert(last_load_segment->paddr() <= (*p)->paddr()); + if (last_load_segment->paddr() + last_load_segment->memsz() + > (*p)->paddr()) + { + unsigned long long lb1 = last_load_segment->paddr(); + unsigned long long le1 = lb1 + last_load_segment->memsz(); + unsigned long long lb2 = (*p)->paddr(); + unsigned long long le2 = lb2 + (*p)->memsz(); + gold_error(_("load segment overlap [0x%llx -> 0x%llx] and " + "[0x%llx -> 0x%llx]"), + lb1, le1, lb2, le2); + } + } + last_load_segment = *p; + } + } + + if (load_seg != NULL && target->isolate_execinstr()) + { + // Process the early segments again, setting their file offsets + // so they land after the segments starting at LOAD_SEG. + off = align_file_offset(off, 0, target->abi_pagesize()); + + this->reset_relax_output(); + + for (Segment_list::iterator p = this->segment_list_.begin(); + *p != load_seg; + ++p) + { + if ((*p)->type() == elfcpp::PT_LOAD) + { + // We repeat the whole job of assigning addresses and + // offsets, but we really only want to change the offsets and + // must ensure that the addresses all come out the same as + // they did the first time through. + bool has_relro = false; + const uint64_t old_addr = (*p)->vaddr(); + const uint64_t old_end = old_addr + (*p)->memsz(); + uint64_t new_addr = (*p)->set_section_addresses(target, this, + true, old_addr, + &increase_relro, + &has_relro, + &off, + &shndx_begin); + gold_assert(new_addr == old_end); + } + } + + gold_assert(shndx_begin == shndx_load_seg); + } + + // Handle the non-PT_LOAD segments, setting their offsets from their + // section's offsets. + for (Segment_list::iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + { + if ((*p)->type() != elfcpp::PT_LOAD) + (*p)->set_offset((*p)->type() == elfcpp::PT_GNU_RELRO + ? increase_relro + : 0); + } + + // Set the TLS offsets for each section in the PT_TLS segment. + if (this->tls_segment_ != NULL) + this->tls_segment_->set_tls_offsets(); + + return off; +} + +// Set the offsets of all the allocated sections when doing a +// relocatable link. This does the same jobs as set_segment_offsets, +// only for a relocatable link. + +off_t +Layout::set_relocatable_section_offsets(Output_data* file_header, + unsigned int* pshndx) +{ + off_t off = 0; + + file_header->set_address_and_file_offset(0, 0); + off += file_header->data_size(); + + for (Section_list::iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + // We skip unallocated sections here, except that group sections + // have to come first. + if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0 + && (*p)->type() != elfcpp::SHT_GROUP) + continue; + + off = align_address(off, (*p)->addralign()); + + // The linker script might have set the address. + if (!(*p)->is_address_valid()) + (*p)->set_address(0); + (*p)->set_file_offset(off); + (*p)->finalize_data_size(); + if ((*p)->type() != elfcpp::SHT_NOBITS) + off += (*p)->data_size(); + + (*p)->set_out_shndx(*pshndx); + ++*pshndx; + } + + return off; +} + +// Set the file offset of all the sections not associated with a +// segment. + +off_t +Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass) +{ + off_t startoff = off; + off_t maxoff = off; + + for (Section_list::iterator p = this->unattached_section_list_.begin(); + p != this->unattached_section_list_.end(); + ++p) + { + // The symtab section is handled in create_symtab_sections. + if (*p == this->symtab_section_) + continue; + + // If we've already set the data size, don't set it again. + if ((*p)->is_offset_valid() && (*p)->is_data_size_valid()) + continue; + + if (pass == BEFORE_INPUT_SECTIONS_PASS + && (*p)->requires_postprocessing()) + { + (*p)->create_postprocessing_buffer(); + this->any_postprocessing_sections_ = true; + } + + if (pass == BEFORE_INPUT_SECTIONS_PASS + && (*p)->after_input_sections()) + continue; + else if (pass == POSTPROCESSING_SECTIONS_PASS + && (!(*p)->after_input_sections() + || (*p)->type() == elfcpp::SHT_STRTAB)) + continue; + else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS + && (!(*p)->after_input_sections() + || (*p)->type() != elfcpp::SHT_STRTAB)) + continue; + + if (!parameters->incremental_update()) + { + off = align_address(off, (*p)->addralign()); + (*p)->set_file_offset(off); + (*p)->finalize_data_size(); + } + else + { + // Incremental update: allocate file space from free list. + (*p)->pre_finalize_data_size(); + off_t current_size = (*p)->current_data_size(); + off = this->allocate(current_size, (*p)->addralign(), startoff); + if (off == -1) + { + if (is_debugging_enabled(DEBUG_INCREMENTAL)) + this->free_list_.dump(); + 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_file_offset(off); + (*p)->finalize_data_size(); + 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()); + } + gold_debug(DEBUG_INCREMENTAL, + "set_section_offsets: %08lx %08lx %s", + static_cast<long>(off), + static_cast<long>((*p)->data_size()), + ((*p)->output_section() != NULL + ? (*p)->output_section()->name() : "(special)")); + } + + off += (*p)->data_size(); + if (off > maxoff) + maxoff = off; + + // At this point the name must be set. + if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS) + this->namepool_.add((*p)->name(), false, NULL); + } + return maxoff; +} + +// Set the section indexes of all the sections not associated with a +// segment. + +unsigned int +Layout::set_section_indexes(unsigned int shndx) +{ + for (Section_list::iterator p = this->unattached_section_list_.begin(); + p != this->unattached_section_list_.end(); + ++p) + { + if (!(*p)->has_out_shndx()) + { + (*p)->set_out_shndx(shndx); + ++shndx; + } + } + return shndx; +} + +// Set the section addresses according to the linker script. This is +// only called when we see a SECTIONS clause. This returns the +// program segment which should hold the file header and segment +// headers, if any. It will return NULL if they should not be in a +// segment. + +Output_segment* +Layout::set_section_addresses_from_script(Symbol_table* symtab) +{ + Script_sections* ss = this->script_options_->script_sections(); + gold_assert(ss->saw_sections_clause()); + return this->script_options_->set_section_addresses(symtab, this); +} + +// Place the orphan sections in the linker script. + +void +Layout::place_orphan_sections_in_script() +{ + Script_sections* ss = this->script_options_->script_sections(); + gold_assert(ss->saw_sections_clause()); + + // Place each orphaned output section in the script. + for (Section_list::iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + if (!(*p)->found_in_sections_clause()) + ss->place_orphan(*p); + } +} + +// Count the local symbols in the regular symbol table and the dynamic +// symbol table, and build the respective string pools. + +void +Layout::count_local_symbols(const Task* task, + const Input_objects* input_objects) +{ + // First, figure out an upper bound on the number of symbols we'll + // be inserting into each pool. This helps us create the pools with + // the right size, to avoid unnecessary hashtable resizing. + unsigned int symbol_count = 0; + for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); + p != input_objects->relobj_end(); + ++p) + symbol_count += (*p)->local_symbol_count(); + + // Go from "upper bound" to "estimate." We overcount for two + // reasons: we double-count symbols that occur in more than one + // object file, and we count symbols that are dropped from the + // output. Add it all together and assume we overcount by 100%. + symbol_count /= 2; + + // We assume all symbols will go into both the sympool and dynpool. + this->sympool_.reserve(symbol_count); + this->dynpool_.reserve(symbol_count); + + for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); + p != input_objects->relobj_end(); + ++p) + { + Task_lock_obj<Object> tlo(task, *p); + (*p)->count_local_symbols(&this->sympool_, &this->dynpool_); + } +} + +// Create the symbol table sections. Here we also set the final +// values of the symbols. At this point all the loadable sections are +// fully laid out. SHNUM is the number of sections so far. + +void +Layout::create_symtab_sections(const Input_objects* input_objects, + Symbol_table* symtab, + unsigned int shnum, + off_t* poff) +{ + int symsize; + unsigned int align; + if (parameters->target().get_size() == 32) + { + symsize = elfcpp::Elf_sizes<32>::sym_size; + align = 4; + } + else if (parameters->target().get_size() == 64) + { + symsize = elfcpp::Elf_sizes<64>::sym_size; + align = 8; + } + else + gold_unreachable(); + + // Compute file offsets relative to the start of the symtab section. + off_t off = 0; + + // Save space for the dummy symbol at the start of the section. We + // never bother to write this out--it will just be left as zero. + off += symsize; + unsigned int local_symbol_index = 1; + + // Add STT_SECTION symbols for each Output section which needs one. + for (Section_list::iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + if (!(*p)->needs_symtab_index()) + (*p)->set_symtab_index(-1U); + else + { + (*p)->set_symtab_index(local_symbol_index); + ++local_symbol_index; + off += symsize; + } + } + + for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); + p != input_objects->relobj_end(); + ++p) + { + unsigned int index = (*p)->finalize_local_symbols(local_symbol_index, + off, symtab); + off += (index - local_symbol_index) * symsize; + local_symbol_index = index; + } + + unsigned int local_symcount = local_symbol_index; + gold_assert(static_cast<off_t>(local_symcount * symsize) == off); + + off_t dynoff; + size_t dyn_global_index; + size_t dyncount; + if (this->dynsym_section_ == NULL) + { + dynoff = 0; + dyn_global_index = 0; + dyncount = 0; + } + else + { + dyn_global_index = this->dynsym_section_->info(); + off_t locsize = dyn_global_index * this->dynsym_section_->entsize(); + dynoff = this->dynsym_section_->offset() + locsize; + dyncount = (this->dynsym_section_->data_size() - locsize) / symsize; + gold_assert(static_cast<off_t>(dyncount * symsize) + == this->dynsym_section_->data_size() - locsize); + } + + off_t global_off = off; + off = symtab->finalize(off, dynoff, dyn_global_index, dyncount, + &this->sympool_, &local_symcount); + + if (!parameters->options().strip_all()) + { + this->sympool_.set_string_offsets(); + + const char* symtab_name = this->namepool_.add(".symtab", false, NULL); + Output_section* osymtab = this->make_output_section(symtab_name, + elfcpp::SHT_SYMTAB, + 0, ORDER_INVALID, + false); + this->symtab_section_ = osymtab; + + Output_section_data* pos = new Output_data_fixed_space(off, align, + "** symtab"); + osymtab->add_output_section_data(pos); + + // We generate a .symtab_shndx section if we have more than + // SHN_LORESERVE sections. Technically it is possible that we + // don't need one, because it is possible that there are no + // symbols in any of sections with indexes larger than + // SHN_LORESERVE. That is probably unusual, though, and it is + // easier to always create one than to compute section indexes + // twice (once here, once when writing out the symbols). + if (shnum >= elfcpp::SHN_LORESERVE) + { + const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx", + false, NULL); + Output_section* osymtab_xindex = + this->make_output_section(symtab_xindex_name, + elfcpp::SHT_SYMTAB_SHNDX, 0, + ORDER_INVALID, false); + + size_t symcount = off / symsize; + this->symtab_xindex_ = new Output_symtab_xindex(symcount); + + osymtab_xindex->add_output_section_data(this->symtab_xindex_); + + osymtab_xindex->set_link_section(osymtab); + osymtab_xindex->set_addralign(4); + osymtab_xindex->set_entsize(4); + + osymtab_xindex->set_after_input_sections(); + + // This tells the driver code to wait until the symbol table + // has written out before writing out the postprocessing + // sections, including the .symtab_shndx section. + this->any_postprocessing_sections_ = true; + } + + const char* strtab_name = this->namepool_.add(".strtab", false, NULL); + Output_section* ostrtab = this->make_output_section(strtab_name, + elfcpp::SHT_STRTAB, + 0, ORDER_INVALID, + false); + + Output_section_data* pstr = new Output_data_strtab(&this->sympool_); + ostrtab->add_output_section_data(pstr); + + off_t symtab_off; + if (!parameters->incremental_update()) + symtab_off = align_address(*poff, align); + else + { + symtab_off = this->allocate(off, align, *poff); + if (off == -1) + gold_fallback(_("out of patch space for symbol table; " + "relink with --incremental-full")); + gold_debug(DEBUG_INCREMENTAL, + "create_symtab_sections: %08lx %08lx .symtab", + static_cast<long>(symtab_off), + static_cast<long>(off)); + } + + symtab->set_file_offset(symtab_off + global_off); + osymtab->set_file_offset(symtab_off); + osymtab->finalize_data_size(); + osymtab->set_link_section(ostrtab); + osymtab->set_info(local_symcount); + osymtab->set_entsize(symsize); + + if (symtab_off + off > *poff) + *poff = symtab_off + off; + } +} + +// Create the .shstrtab section, which holds the names of the +// sections. At the time this is called, we have created all the +// output sections except .shstrtab itself. + +Output_section* +Layout::create_shstrtab() +{ + // FIXME: We don't need to create a .shstrtab section if we are + // stripping everything. + + const char* name = this->namepool_.add(".shstrtab", false, NULL); + + Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0, + ORDER_INVALID, false); + + if (strcmp(parameters->options().compress_debug_sections(), "none") != 0) + { + // We can't write out this section until we've set all the + // section names, and we don't set the names of compressed + // output sections until relocations are complete. FIXME: With + // the current names we use, this is unnecessary. + os->set_after_input_sections(); + } + + Output_section_data* posd = new Output_data_strtab(&this->namepool_); + os->add_output_section_data(posd); + + return os; +} + +// Create the section headers. SIZE is 32 or 64. OFF is the file +// offset. + +void +Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff) +{ + Output_section_headers* oshdrs; + oshdrs = new Output_section_headers(this, + &this->segment_list_, + &this->section_list_, + &this->unattached_section_list_, + &this->namepool_, + shstrtab_section); + off_t off; + if (!parameters->incremental_update()) + off = align_address(*poff, oshdrs->addralign()); + else + { + oshdrs->pre_finalize_data_size(); + off = this->allocate(oshdrs->data_size(), oshdrs->addralign(), *poff); + if (off == -1) + gold_fallback(_("out of patch space for section header table; " + "relink with --incremental-full")); + gold_debug(DEBUG_INCREMENTAL, + "create_shdrs: %08lx %08lx (section header table)", + static_cast<long>(off), + static_cast<long>(off + oshdrs->data_size())); + } + oshdrs->set_address_and_file_offset(0, off); + off += oshdrs->data_size(); + if (off > *poff) + *poff = off; + this->section_headers_ = oshdrs; +} + +// Count the allocated sections. + +size_t +Layout::allocated_output_section_count() const +{ + size_t section_count = 0; + for (Segment_list::const_iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + section_count += (*p)->output_section_count(); + return section_count; +} + +// Create the dynamic symbol table. + +void +Layout::create_dynamic_symtab(const Input_objects* input_objects, + Symbol_table* symtab, + Output_section** pdynstr, + unsigned int* plocal_dynamic_count, + std::vector<Symbol*>* pdynamic_symbols, + Versions* pversions) +{ + // Count all the symbols in the dynamic symbol table, and set the + // dynamic symbol indexes. + + // Skip symbol 0, which is always all zeroes. + unsigned int index = 1; + + // Add STT_SECTION symbols for each Output section which needs one. + for (Section_list::iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + if (!(*p)->needs_dynsym_index()) + (*p)->set_dynsym_index(-1U); + else + { + (*p)->set_dynsym_index(index); + ++index; + } + } + + // Count the local symbols that need to go in the dynamic symbol table, + // and set the dynamic symbol indexes. + for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); + p != input_objects->relobj_end(); + ++p) + { + unsigned int new_index = (*p)->set_local_dynsym_indexes(index); + index = new_index; + } + + unsigned int local_symcount = index; + *plocal_dynamic_count = local_symcount; + + index = symtab->set_dynsym_indexes(index, pdynamic_symbols, + &this->dynpool_, pversions); + + int symsize; + unsigned int align; + const int size = parameters->target().get_size(); + if (size == 32) + { + symsize = elfcpp::Elf_sizes<32>::sym_size; + align = 4; + } + else if (size == 64) + { + symsize = elfcpp::Elf_sizes<64>::sym_size; + align = 8; + } + else + gold_unreachable(); + + // Create the dynamic symbol table section. + + Output_section* dynsym = this->choose_output_section(NULL, ".dynsym", + elfcpp::SHT_DYNSYM, + elfcpp::SHF_ALLOC, + false, + ORDER_DYNAMIC_LINKER, + false); + + // Check for NULL as a linker script may discard .dynsym. + if (dynsym != NULL) + { + Output_section_data* odata = new Output_data_fixed_space(index * symsize, + align, + "** dynsym"); + dynsym->add_output_section_data(odata); + + dynsym->set_info(local_symcount); + dynsym->set_entsize(symsize); + dynsym->set_addralign(align); + + this->dynsym_section_ = dynsym; + } + + Output_data_dynamic* const odyn = this->dynamic_data_; + if (odyn != NULL) + { + odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym); + odyn->add_constant(elfcpp::DT_SYMENT, symsize); + } + + // If there are more than SHN_LORESERVE allocated sections, we + // create a .dynsym_shndx section. It is possible that we don't + // need one, because it is possible that there are no dynamic + // symbols in any of the sections with indexes larger than + // SHN_LORESERVE. This is probably unusual, though, and at this + // time we don't know the actual section indexes so it is + // inconvenient to check. + if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE) + { + Output_section* dynsym_xindex = + this->choose_output_section(NULL, ".dynsym_shndx", + elfcpp::SHT_SYMTAB_SHNDX, + elfcpp::SHF_ALLOC, + false, ORDER_DYNAMIC_LINKER, false); + + if (dynsym_xindex != NULL) + { + this->dynsym_xindex_ = new Output_symtab_xindex(index); + + dynsym_xindex->add_output_section_data(this->dynsym_xindex_); + + dynsym_xindex->set_link_section(dynsym); + dynsym_xindex->set_addralign(4); + dynsym_xindex->set_entsize(4); + + dynsym_xindex->set_after_input_sections(); + + // This tells the driver code to wait until the symbol table + // has written out before writing out the postprocessing + // sections, including the .dynsym_shndx section. + this->any_postprocessing_sections_ = true; + } + } + + // Create the dynamic string table section. + + Output_section* dynstr = this->choose_output_section(NULL, ".dynstr", + elfcpp::SHT_STRTAB, + elfcpp::SHF_ALLOC, + false, + ORDER_DYNAMIC_LINKER, + false); + *pdynstr = dynstr; + if (dynstr != NULL) + { + Output_section_data* strdata = new Output_data_strtab(&this->dynpool_); + dynstr->add_output_section_data(strdata); + + if (dynsym != NULL) + dynsym->set_link_section(dynstr); + if (this->dynamic_section_ != NULL) + this->dynamic_section_->set_link_section(dynstr); + + if (odyn != NULL) + { + odyn->add_section_address(elfcpp::DT_STRTAB, dynstr); + odyn->add_section_size(elfcpp::DT_STRSZ, dynstr); + } + } + + // Create the hash tables. + + if (strcmp(parameters->options().hash_style(), "sysv") == 0 + || strcmp(parameters->options().hash_style(), "both") == 0) + { + unsigned char* phash; + unsigned int hashlen; + Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount, + &phash, &hashlen); + + Output_section* hashsec = + this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH, + elfcpp::SHF_ALLOC, false, + ORDER_DYNAMIC_LINKER, false); + + Output_section_data* hashdata = new Output_data_const_buffer(phash, + hashlen, + align, + "** hash"); + if (hashsec != NULL && hashdata != NULL) + hashsec->add_output_section_data(hashdata); + + if (hashsec != NULL) + { + if (dynsym != NULL) + hashsec->set_link_section(dynsym); + hashsec->set_entsize(4); + } + + if (odyn != NULL) + odyn->add_section_address(elfcpp::DT_HASH, hashsec); + } + + if (strcmp(parameters->options().hash_style(), "gnu") == 0 + || strcmp(parameters->options().hash_style(), "both") == 0) + { + unsigned char* phash; + unsigned int hashlen; + Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount, + &phash, &hashlen); + + Output_section* hashsec = + this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH, + elfcpp::SHF_ALLOC, false, + ORDER_DYNAMIC_LINKER, false); + + Output_section_data* hashdata = new Output_data_const_buffer(phash, + hashlen, + align, + "** hash"); + if (hashsec != NULL && hashdata != NULL) + hashsec->add_output_section_data(hashdata); + + if (hashsec != NULL) + { + if (dynsym != NULL) + hashsec->set_link_section(dynsym); + + // For a 64-bit target, the entries in .gnu.hash do not have + // a uniform size, so we only set the entry size for a + // 32-bit target. + if (parameters->target().get_size() == 32) + hashsec->set_entsize(4); + + if (odyn != NULL) + odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec); + } + } +} + +// Assign offsets to each local portion of the dynamic symbol table. + +void +Layout::assign_local_dynsym_offsets(const Input_objects* input_objects) +{ + Output_section* dynsym = this->dynsym_section_; + if (dynsym == NULL) + return; + + off_t off = dynsym->offset(); + + // Skip the dummy symbol at the start of the section. + off += dynsym->entsize(); + + for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); + p != input_objects->relobj_end(); + ++p) + { + unsigned int count = (*p)->set_local_dynsym_offset(off); + off += count * dynsym->entsize(); + } +} + +// Create the version sections. + +void +Layout::create_version_sections(const Versions* versions, + const Symbol_table* symtab, + unsigned int local_symcount, + const std::vector<Symbol*>& dynamic_symbols, + const Output_section* dynstr) +{ + if (!versions->any_defs() && !versions->any_needs()) + return; + + switch (parameters->size_and_endianness()) + { +#ifdef HAVE_TARGET_32_LITTLE + case Parameters::TARGET_32_LITTLE: + this->sized_create_version_sections<32, false>(versions, symtab, + local_symcount, + dynamic_symbols, dynstr); + break; +#endif +#ifdef HAVE_TARGET_32_BIG + case Parameters::TARGET_32_BIG: + this->sized_create_version_sections<32, true>(versions, symtab, + local_symcount, + dynamic_symbols, dynstr); + break; +#endif +#ifdef HAVE_TARGET_64_LITTLE + case Parameters::TARGET_64_LITTLE: + this->sized_create_version_sections<64, false>(versions, symtab, + local_symcount, + dynamic_symbols, dynstr); + break; +#endif +#ifdef HAVE_TARGET_64_BIG + case Parameters::TARGET_64_BIG: + this->sized_create_version_sections<64, true>(versions, symtab, + local_symcount, + dynamic_symbols, dynstr); + break; +#endif + default: + gold_unreachable(); + } +} + +// Create the version sections, sized version. + +template<int size, bool big_endian> +void +Layout::sized_create_version_sections( + const Versions* versions, + const Symbol_table* symtab, + unsigned int local_symcount, + const std::vector<Symbol*>& dynamic_symbols, + const Output_section* dynstr) +{ + Output_section* vsec = this->choose_output_section(NULL, ".gnu.version", + elfcpp::SHT_GNU_versym, + elfcpp::SHF_ALLOC, + false, + ORDER_DYNAMIC_LINKER, + false); + + // Check for NULL since a linker script may discard this section. + if (vsec != NULL) + { + unsigned char* vbuf; + unsigned int vsize; + versions->symbol_section_contents<size, big_endian>(symtab, + &this->dynpool_, + local_symcount, + dynamic_symbols, + &vbuf, &vsize); + + Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2, + "** versions"); + + vsec->add_output_section_data(vdata); + vsec->set_entsize(2); + vsec->set_link_section(this->dynsym_section_); + } + + Output_data_dynamic* const odyn = this->dynamic_data_; + if (odyn != NULL && vsec != NULL) + odyn->add_section_address(elfcpp::DT_VERSYM, vsec); + + if (versions->any_defs()) + { + Output_section* vdsec; + vdsec = this->choose_output_section(NULL, ".gnu.version_d", + elfcpp::SHT_GNU_verdef, + elfcpp::SHF_ALLOC, + false, ORDER_DYNAMIC_LINKER, false); + + if (vdsec != NULL) + { + unsigned char* vdbuf; + unsigned int vdsize; + unsigned int vdentries; + versions->def_section_contents<size, big_endian>(&this->dynpool_, + &vdbuf, &vdsize, + &vdentries); + + Output_section_data* vddata = + new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs"); + + vdsec->add_output_section_data(vddata); + vdsec->set_link_section(dynstr); + vdsec->set_info(vdentries); + + if (odyn != NULL) + { + odyn->add_section_address(elfcpp::DT_VERDEF, vdsec); + odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries); + } + } + } + + if (versions->any_needs()) + { + Output_section* vnsec; + vnsec = this->choose_output_section(NULL, ".gnu.version_r", + elfcpp::SHT_GNU_verneed, + elfcpp::SHF_ALLOC, + false, ORDER_DYNAMIC_LINKER, false); + + if (vnsec != NULL) + { + unsigned char* vnbuf; + unsigned int vnsize; + unsigned int vnentries; + versions->need_section_contents<size, big_endian>(&this->dynpool_, + &vnbuf, &vnsize, + &vnentries); + + Output_section_data* vndata = + new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs"); + + vnsec->add_output_section_data(vndata); + vnsec->set_link_section(dynstr); + vnsec->set_info(vnentries); + + if (odyn != NULL) + { + odyn->add_section_address(elfcpp::DT_VERNEED, vnsec); + odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries); + } + } + } +} + +// Create the .interp section and PT_INTERP segment. + +void +Layout::create_interp(const Target* target) +{ + gold_assert(this->interp_segment_ == NULL); + + const char* interp = parameters->options().dynamic_linker(); + if (interp == NULL) + { + interp = target->dynamic_linker(); + gold_assert(interp != NULL); + } + + size_t len = strlen(interp) + 1; + + Output_section_data* odata = new Output_data_const(interp, len, 1); + + Output_section* osec = this->choose_output_section(NULL, ".interp", + elfcpp::SHT_PROGBITS, + elfcpp::SHF_ALLOC, + false, ORDER_INTERP, + false); + if (osec != NULL) + osec->add_output_section_data(odata); +} + +// Add dynamic tags for the PLT and the dynamic relocs. This is +// called by the target-specific code. This does nothing if not doing +// a dynamic link. + +// USE_REL is true for REL relocs rather than RELA relocs. + +// If PLT_GOT is not NULL, then DT_PLTGOT points to it. + +// If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL, +// and we also set DT_PLTREL. We use PLT_REL's output section, since +// some targets have multiple reloc sections in PLT_REL. + +// If DYN_REL is not NULL, it is used for DT_REL/DT_RELA, +// DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT. Again we use the output +// section. + +// If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an +// executable. + +void +Layout::add_target_dynamic_tags(bool use_rel, const Output_data* plt_got, + const Output_data* plt_rel, + const Output_data_reloc_generic* dyn_rel, + bool add_debug, bool dynrel_includes_plt) +{ + Output_data_dynamic* odyn = this->dynamic_data_; + if (odyn == NULL) + return; + + if (plt_got != NULL && plt_got->output_section() != NULL) + odyn->add_section_address(elfcpp::DT_PLTGOT, plt_got); + + if (plt_rel != NULL && plt_rel->output_section() != NULL) + { + odyn->add_section_size(elfcpp::DT_PLTRELSZ, plt_rel->output_section()); + odyn->add_section_address(elfcpp::DT_JMPREL, plt_rel->output_section()); + odyn->add_constant(elfcpp::DT_PLTREL, + use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA); + } + + if ((dyn_rel != NULL && dyn_rel->output_section() != NULL) + || (dynrel_includes_plt + && plt_rel != NULL + && plt_rel->output_section() != NULL)) + { + bool have_dyn_rel = dyn_rel != NULL && dyn_rel->output_section() != NULL; + bool have_plt_rel = plt_rel != NULL && plt_rel->output_section() != NULL; + odyn->add_section_address(use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA, + (have_dyn_rel + ? dyn_rel->output_section() + : plt_rel->output_section())); + elfcpp::DT size_tag = use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ; + if (have_dyn_rel && have_plt_rel && dynrel_includes_plt) + odyn->add_section_size(size_tag, + dyn_rel->output_section(), + plt_rel->output_section()); + else if (have_dyn_rel) + odyn->add_section_size(size_tag, dyn_rel->output_section()); + else + odyn->add_section_size(size_tag, plt_rel->output_section()); + const int size = parameters->target().get_size(); + elfcpp::DT rel_tag; + int rel_size; + if (use_rel) + { + rel_tag = elfcpp::DT_RELENT; + if (size == 32) + rel_size = Reloc_types<elfcpp::SHT_REL, 32, false>::reloc_size; + else if (size == 64) + rel_size = Reloc_types<elfcpp::SHT_REL, 64, false>::reloc_size; + else + gold_unreachable(); + } + else + { + rel_tag = elfcpp::DT_RELAENT; + if (size == 32) + rel_size = Reloc_types<elfcpp::SHT_RELA, 32, false>::reloc_size; + else if (size == 64) + rel_size = Reloc_types<elfcpp::SHT_RELA, 64, false>::reloc_size; + else + gold_unreachable(); + } + odyn->add_constant(rel_tag, rel_size); + + if (parameters->options().combreloc() && have_dyn_rel) + { + size_t c = dyn_rel->relative_reloc_count(); + if (c > 0) + odyn->add_constant((use_rel + ? elfcpp::DT_RELCOUNT + : elfcpp::DT_RELACOUNT), + c); + } + } + + if (add_debug && !parameters->options().shared()) + { + // The value of the DT_DEBUG tag is filled in by the dynamic + // linker at run time, and used by the debugger. + odyn->add_constant(elfcpp::DT_DEBUG, 0); + } +} + +// Finish the .dynamic section and PT_DYNAMIC segment. + +void +Layout::finish_dynamic_section(const Input_objects* input_objects, + const Symbol_table* symtab) +{ + if (!this->script_options_->saw_phdrs_clause() + && this->dynamic_section_ != NULL) + { + Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC, + (elfcpp::PF_R + | elfcpp::PF_W)); + oseg->add_output_section_to_nonload(this->dynamic_section_, + elfcpp::PF_R | elfcpp::PF_W); + } + + Output_data_dynamic* const odyn = this->dynamic_data_; + if (odyn == NULL) + return; + + for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin(); + p != input_objects->dynobj_end(); + ++p) + { + if (!(*p)->is_needed() && (*p)->as_needed()) + { + // This dynamic object was linked with --as-needed, but it + // is not needed. + continue; + } + + odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname()); + } + + if (parameters->options().shared()) + { + const char* soname = parameters->options().soname(); + if (soname != NULL) + odyn->add_string(elfcpp::DT_SONAME, soname); + } + + Symbol* sym = symtab->lookup(parameters->options().init()); + if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj()) + odyn->add_symbol(elfcpp::DT_INIT, sym); + + sym = symtab->lookup(parameters->options().fini()); + if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj()) + odyn->add_symbol(elfcpp::DT_FINI, sym); + + // Look for .init_array, .preinit_array and .fini_array by checking + // section types. + for(Layout::Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + switch((*p)->type()) + { + case elfcpp::SHT_FINI_ARRAY: + odyn->add_section_address(elfcpp::DT_FINI_ARRAY, *p); + odyn->add_section_size(elfcpp::DT_FINI_ARRAYSZ, *p); + break; + case elfcpp::SHT_INIT_ARRAY: + odyn->add_section_address(elfcpp::DT_INIT_ARRAY, *p); + odyn->add_section_size(elfcpp::DT_INIT_ARRAYSZ, *p); + break; + case elfcpp::SHT_PREINIT_ARRAY: + odyn->add_section_address(elfcpp::DT_PREINIT_ARRAY, *p); + odyn->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ, *p); + break; + default: + break; + } + + // Add a DT_RPATH entry if needed. + const General_options::Dir_list& rpath(parameters->options().rpath()); + if (!rpath.empty()) + { + std::string rpath_val; + for (General_options::Dir_list::const_iterator p = rpath.begin(); + p != rpath.end(); + ++p) + { + if (rpath_val.empty()) + rpath_val = p->name(); + else + { + // Eliminate duplicates. + General_options::Dir_list::const_iterator q; + for (q = rpath.begin(); q != p; ++q) + if (q->name() == p->name()) + break; + if (q == p) + { + rpath_val += ':'; + rpath_val += p->name(); + } + } + } + + if (!parameters->options().enable_new_dtags()) + odyn->add_string(elfcpp::DT_RPATH, rpath_val); + else + odyn->add_string(elfcpp::DT_RUNPATH, rpath_val); + } + + // Look for text segments that have dynamic relocations. + bool have_textrel = false; + if (!this->script_options_->saw_sections_clause()) + { + for (Segment_list::const_iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + { + if ((*p)->type() == elfcpp::PT_LOAD + && ((*p)->flags() & elfcpp::PF_W) == 0 + && (*p)->has_dynamic_reloc()) + { + have_textrel = true; + break; + } + } + } + else + { + // We don't know the section -> segment mapping, so we are + // conservative and just look for readonly sections with + // relocations. If those sections wind up in writable segments, + // then we have created an unnecessary DT_TEXTREL entry. + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0 + && ((*p)->flags() & elfcpp::SHF_WRITE) == 0 + && (*p)->has_dynamic_reloc()) + { + have_textrel = true; + break; + } + } + } + + if (parameters->options().filter() != NULL) + odyn->add_string(elfcpp::DT_FILTER, parameters->options().filter()); + if (parameters->options().any_auxiliary()) + { + for (options::String_set::const_iterator p = + parameters->options().auxiliary_begin(); + p != parameters->options().auxiliary_end(); + ++p) + odyn->add_string(elfcpp::DT_AUXILIARY, *p); + } + + // Add a DT_FLAGS entry if necessary. + unsigned int flags = 0; + if (have_textrel) + { + // Add a DT_TEXTREL for compatibility with older loaders. + odyn->add_constant(elfcpp::DT_TEXTREL, 0); + flags |= elfcpp::DF_TEXTREL; + + if (parameters->options().text()) + gold_error(_("read-only segment has dynamic relocations")); + else if (parameters->options().warn_shared_textrel() + && parameters->options().shared()) + gold_warning(_("shared library text segment is not shareable")); + } + if (parameters->options().shared() && this->has_static_tls()) + flags |= elfcpp::DF_STATIC_TLS; + if (parameters->options().origin()) + flags |= elfcpp::DF_ORIGIN; + if (parameters->options().Bsymbolic()) + { + flags |= elfcpp::DF_SYMBOLIC; + // Add DT_SYMBOLIC for compatibility with older loaders. + odyn->add_constant(elfcpp::DT_SYMBOLIC, 0); + } + if (parameters->options().now()) + flags |= elfcpp::DF_BIND_NOW; + if (flags != 0) + odyn->add_constant(elfcpp::DT_FLAGS, flags); + + flags = 0; + if (parameters->options().initfirst()) + flags |= elfcpp::DF_1_INITFIRST; + if (parameters->options().interpose()) + flags |= elfcpp::DF_1_INTERPOSE; + if (parameters->options().loadfltr()) + flags |= elfcpp::DF_1_LOADFLTR; + if (parameters->options().nodefaultlib()) + flags |= elfcpp::DF_1_NODEFLIB; + if (parameters->options().nodelete()) + flags |= elfcpp::DF_1_NODELETE; + if (parameters->options().nodlopen()) + flags |= elfcpp::DF_1_NOOPEN; + if (parameters->options().nodump()) + flags |= elfcpp::DF_1_NODUMP; + if (!parameters->options().shared()) + flags &= ~(elfcpp::DF_1_INITFIRST + | elfcpp::DF_1_NODELETE + | elfcpp::DF_1_NOOPEN); + if (parameters->options().origin()) + flags |= elfcpp::DF_1_ORIGIN; + if (parameters->options().now()) + flags |= elfcpp::DF_1_NOW; + if (parameters->options().Bgroup()) + flags |= elfcpp::DF_1_GROUP; + if (flags != 0) + odyn->add_constant(elfcpp::DT_FLAGS_1, flags); +} + +// Set the size of the _DYNAMIC symbol table to be the size of the +// dynamic data. + +void +Layout::set_dynamic_symbol_size(const Symbol_table* symtab) +{ + Output_data_dynamic* const odyn = this->dynamic_data_; + if (odyn == NULL) + return; + odyn->finalize_data_size(); + if (this->dynamic_symbol_ == NULL) + return; + off_t data_size = odyn->data_size(); + const int size = parameters->target().get_size(); + if (size == 32) + symtab->get_sized_symbol<32>(this->dynamic_symbol_)->set_symsize(data_size); + else if (size == 64) + symtab->get_sized_symbol<64>(this->dynamic_symbol_)->set_symsize(data_size); + else + gold_unreachable(); +} + +// The mapping of input section name prefixes to output section names. +// In some cases one prefix is itself a prefix of another prefix; in +// such a case the longer prefix must come first. These prefixes are +// based on the GNU linker default ELF linker script. + +#define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 } +#define MAPPING_INIT_EXACT(f, t) { f, 0, t, sizeof(t) - 1 } +const Layout::Section_name_mapping Layout::section_name_mapping[] = +{ + MAPPING_INIT(".text.", ".text"), + MAPPING_INIT(".rodata.", ".rodata"), + MAPPING_INIT(".data.rel.ro.local.", ".data.rel.ro.local"), + MAPPING_INIT_EXACT(".data.rel.ro.local", ".data.rel.ro.local"), + MAPPING_INIT(".data.rel.ro.", ".data.rel.ro"), + MAPPING_INIT_EXACT(".data.rel.ro", ".data.rel.ro"), + MAPPING_INIT(".data.", ".data"), + MAPPING_INIT(".bss.", ".bss"), + MAPPING_INIT(".tdata.", ".tdata"), + MAPPING_INIT(".tbss.", ".tbss"), + MAPPING_INIT(".init_array.", ".init_array"), + MAPPING_INIT(".fini_array.", ".fini_array"), + MAPPING_INIT(".sdata.", ".sdata"), + MAPPING_INIT(".sbss.", ".sbss"), + // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled + // differently depending on whether it is creating a shared library. + MAPPING_INIT(".sdata2.", ".sdata"), + MAPPING_INIT(".sbss2.", ".sbss"), + MAPPING_INIT(".lrodata.", ".lrodata"), + MAPPING_INIT(".ldata.", ".ldata"), + MAPPING_INIT(".lbss.", ".lbss"), + MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"), + MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"), + MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"), + MAPPING_INIT(".gnu.linkonce.t.", ".text"), + MAPPING_INIT(".gnu.linkonce.r.", ".rodata"), + MAPPING_INIT(".gnu.linkonce.d.", ".data"), + MAPPING_INIT(".gnu.linkonce.b.", ".bss"), + MAPPING_INIT(".gnu.linkonce.s.", ".sdata"), + MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"), + MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"), + MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"), + MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"), + MAPPING_INIT(".gnu.linkonce.td.", ".tdata"), + MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"), + MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"), + MAPPING_INIT(".gnu.linkonce.l.", ".ldata"), + MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"), + MAPPING_INIT(".ARM.extab", ".ARM.extab"), + MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"), + MAPPING_INIT(".ARM.exidx", ".ARM.exidx"), + MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"), +}; +#undef MAPPING_INIT +#undef MAPPING_INIT_EXACT + +const int Layout::section_name_mapping_count = + (sizeof(Layout::section_name_mapping) + / sizeof(Layout::section_name_mapping[0])); + +// Choose the output section name to use given an input section name. +// Set *PLEN to the length of the name. *PLEN is initialized to the +// length of NAME. + +const char* +Layout::output_section_name(const Relobj* relobj, const char* name, + size_t* plen) +{ + // gcc 4.3 generates the following sorts of section names when it + // needs a section name specific to a function: + // .text.FN + // .rodata.FN + // .sdata2.FN + // .data.FN + // .data.rel.FN + // .data.rel.local.FN + // .data.rel.ro.FN + // .data.rel.ro.local.FN + // .sdata.FN + // .bss.FN + // .sbss.FN + // .tdata.FN + // .tbss.FN + + // The GNU linker maps all of those to the part before the .FN, + // except that .data.rel.local.FN is mapped to .data, and + // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections + // beginning with .data.rel.ro.local are grouped together. + + // For an anonymous namespace, the string FN can contain a '.'. + + // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the + // GNU linker maps to .rodata. + + // The .data.rel.ro sections are used with -z relro. The sections + // are recognized by name. We use the same names that the GNU + // linker does for these sections. + + // It is hard to handle this in a principled way, so we don't even + // try. We use a table of mappings. If the input section name is + // not found in the table, we simply use it as the output section + // name. + + const Section_name_mapping* psnm = section_name_mapping; + for (int i = 0; i < section_name_mapping_count; ++i, ++psnm) + { + if (psnm->fromlen > 0) + { + if (strncmp(name, psnm->from, psnm->fromlen) == 0) + { + *plen = psnm->tolen; + return psnm->to; + } + } + else + { + if (strcmp(name, psnm->from) == 0) + { + *plen = psnm->tolen; + return psnm->to; + } + } + } + + // As an additional complication, .ctors sections are output in + // either .ctors or .init_array sections, and .dtors sections are + // output in either .dtors or .fini_array sections. + if (is_prefix_of(".ctors.", name) || is_prefix_of(".dtors.", name)) + { + if (parameters->options().ctors_in_init_array()) + { + *plen = 11; + return name[1] == 'c' ? ".init_array" : ".fini_array"; + } + else + { + *plen = 6; + return name[1] == 'c' ? ".ctors" : ".dtors"; + } + } + if (parameters->options().ctors_in_init_array() + && (strcmp(name, ".ctors") == 0 || strcmp(name, ".dtors") == 0)) + { + // To make .init_array/.fini_array work with gcc we must exclude + // .ctors and .dtors sections from the crtbegin and crtend + // files. + if (relobj == NULL + || (!Layout::match_file_name(relobj, "crtbegin") + && !Layout::match_file_name(relobj, "crtend"))) + { + *plen = 11; + return name[1] == 'c' ? ".init_array" : ".fini_array"; + } + } + + return name; +} + +// Return true if RELOBJ is an input file whose base name matches +// FILE_NAME. The base name must have an extension of ".o", and must +// be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is +// to match crtbegin.o as well as crtbeginS.o without getting confused +// by other possibilities. Overall matching the file name this way is +// a dreadful hack, but the GNU linker does it in order to better +// support gcc, and we need to be compatible. + +bool +Layout::match_file_name(const Relobj* relobj, const char* match) +{ + const std::string& file_name(relobj->name()); + const char* base_name = lbasename(file_name.c_str()); + size_t match_len = strlen(match); + if (strncmp(base_name, match, 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; +} + +// Check if a comdat group or .gnu.linkonce section with the given +// NAME is selected for the link. If there is already a section, +// *KEPT_SECTION is set to point to the existing section and the +// function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and +// IS_GROUP_NAME are recorded for this NAME in the layout object, +// *KEPT_SECTION is set to the internal copy and the function returns +// true. + +bool +Layout::find_or_add_kept_section(const std::string& name, + Relobj* object, + unsigned int shndx, + bool is_comdat, + bool is_group_name, + Kept_section** kept_section) +{ + // It's normal to see a couple of entries here, for the x86 thunk + // sections. If we see more than a few, we're linking a C++ + // program, and we resize to get more space to minimize rehashing. + if (this->signatures_.size() > 4 + && !this->resized_signatures_) + { + reserve_unordered_map(&this->signatures_, + this->number_of_input_files_ * 64); + this->resized_signatures_ = true; + } + + Kept_section candidate; + std::pair<Signatures::iterator, bool> ins = + this->signatures_.insert(std::make_pair(name, candidate)); + + if (kept_section != NULL) + *kept_section = &ins.first->second; + if (ins.second) + { + // This is the first time we've seen this signature. + ins.first->second.set_object(object); + ins.first->second.set_shndx(shndx); + if (is_comdat) + ins.first->second.set_is_comdat(); + if (is_group_name) + ins.first->second.set_is_group_name(); + return true; + } + + // We have already seen this signature. + + if (ins.first->second.is_group_name()) + { + // We've already seen a real section group with this signature. + // If the kept group is from a plugin object, and we're in the + // replacement phase, accept the new one as a replacement. + if (ins.first->second.object() == NULL + && parameters->options().plugins()->in_replacement_phase()) + { + ins.first->second.set_object(object); + ins.first->second.set_shndx(shndx); + return true; + } + return false; + } + else if (is_group_name) + { + // This is a real section group, and we've already seen a + // linkonce section with this signature. Record that we've seen + // a section group, and don't include this section group. + ins.first->second.set_is_group_name(); + return false; + } + else + { + // We've already seen a linkonce section and this is a linkonce + // section. These don't block each other--this may be the same + // symbol name with different section types. + return true; + } +} + +// Store the allocated sections into the section list. + +void +Layout::get_allocated_sections(Section_list* section_list) const +{ + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0) + section_list->push_back(*p); +} + +// Store the executable sections into the section list. + +void +Layout::get_executable_sections(Section_list* section_list) const +{ + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + if (((*p)->flags() & (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR)) + == (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR)) + section_list->push_back(*p); +} + +// Create an output segment. + +Output_segment* +Layout::make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags) +{ + gold_assert(!parameters->options().relocatable()); + Output_segment* oseg = new Output_segment(type, flags); + this->segment_list_.push_back(oseg); + + if (type == elfcpp::PT_TLS) + this->tls_segment_ = oseg; + else if (type == elfcpp::PT_GNU_RELRO) + this->relro_segment_ = oseg; + else if (type == elfcpp::PT_INTERP) + this->interp_segment_ = oseg; + + return oseg; +} + +// Return the file offset of the normal symbol table. + +off_t +Layout::symtab_section_offset() const +{ + if (this->symtab_section_ != NULL) + return this->symtab_section_->offset(); + return 0; +} + +// Return the section index of the normal symbol table. It may have +// been stripped by the -s/--strip-all option. + +unsigned int +Layout::symtab_section_shndx() const +{ + if (this->symtab_section_ != NULL) + return this->symtab_section_->out_shndx(); + return 0; +} + +// Write out the Output_sections. Most won't have anything to write, +// since most of the data will come from input sections which are +// handled elsewhere. But some Output_sections do have Output_data. + +void +Layout::write_output_sections(Output_file* of) const +{ + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + if (!(*p)->after_input_sections()) + (*p)->write(of); + } +} + +// Write out data not associated with a section or the symbol table. + +void +Layout::write_data(const Symbol_table* symtab, Output_file* of) const +{ + if (!parameters->options().strip_all()) + { + const Output_section* symtab_section = this->symtab_section_; + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + if ((*p)->needs_symtab_index()) + { + gold_assert(symtab_section != NULL); + unsigned int index = (*p)->symtab_index(); + gold_assert(index > 0 && index != -1U); + off_t off = (symtab_section->offset() + + index * symtab_section->entsize()); + symtab->write_section_symbol(*p, this->symtab_xindex_, of, off); + } + } + } + + const Output_section* dynsym_section = this->dynsym_section_; + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + if ((*p)->needs_dynsym_index()) + { + gold_assert(dynsym_section != NULL); + unsigned int index = (*p)->dynsym_index(); + gold_assert(index > 0 && index != -1U); + off_t off = (dynsym_section->offset() + + index * dynsym_section->entsize()); + symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off); + } + } + + // Write out the Output_data which are not in an Output_section. + for (Data_list::const_iterator p = this->special_output_list_.begin(); + p != this->special_output_list_.end(); + ++p) + (*p)->write(of); + + // Write out the Output_data which are not in an Output_section + // and are regenerated in each iteration of relaxation. + for (Data_list::const_iterator p = this->relax_output_list_.begin(); + p != this->relax_output_list_.end(); + ++p) + (*p)->write(of); +} + +// Write out the Output_sections which can only be written after the +// input sections are complete. + +void +Layout::write_sections_after_input_sections(Output_file* of) +{ + // Determine the final section offsets, and thus the final output + // file size. Note we finalize the .shstrab last, to allow the + // after_input_section sections to modify their section-names before + // writing. + if (this->any_postprocessing_sections_) + { + off_t off = this->output_file_size_; + off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS); + + // Now that we've finalized the names, we can finalize the shstrab. + off = + this->set_section_offsets(off, + STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS); + + if (off > this->output_file_size_) + { + of->resize(off); + this->output_file_size_ = off; + } + } + + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + { + if ((*p)->after_input_sections()) + (*p)->write(of); + } + + this->section_headers_->write(of); +} + +// Build IDs can be computed as a "flat" sha1 or md5 of a string of bytes, +// or as a "tree" where each chunk of the string is hashed and then those +// hashes are put into a (much smaller) string which is hashed with sha1. +// We compute a checksum over the entire file because that is simplest. + +Task_token* +Layout::queue_build_id_tasks(Workqueue* workqueue, Task_token* build_id_blocker, + Output_file* of) +{ + const size_t filesize = (this->output_file_size() <= 0 ? 0 + : static_cast<size_t>(this->output_file_size())); + if (this->build_id_note_ != NULL + && strcmp(parameters->options().build_id(), "tree") == 0 + && parameters->options().build_id_chunk_size_for_treehash() > 0 + && filesize > 0 + && (filesize >= + parameters->options().build_id_min_file_size_for_treehash())) + { + static const size_t MD5_OUTPUT_SIZE_IN_BYTES = 16; + const size_t chunk_size = + parameters->options().build_id_chunk_size_for_treehash(); + const size_t num_hashes = ((filesize - 1) / chunk_size) + 1; + Task_token* post_hash_tasks_blocker = new Task_token(true); + post_hash_tasks_blocker->add_blockers(num_hashes); + this->size_of_array_of_hashes_ = num_hashes * MD5_OUTPUT_SIZE_IN_BYTES; + const unsigned char* src = of->get_input_view(0, filesize); + this->input_view_ = src; + unsigned char *dst = new unsigned char[this->size_of_array_of_hashes_]; + this->array_of_hashes_ = dst; + for (size_t i = 0, src_offset = 0; i < num_hashes; + i++, dst += MD5_OUTPUT_SIZE_IN_BYTES, src_offset += chunk_size) + { + size_t size = std::min(chunk_size, filesize - src_offset); + workqueue->queue(new Hash_task(src + src_offset, + size, + dst, + build_id_blocker, + post_hash_tasks_blocker)); + } + return post_hash_tasks_blocker; + } + return build_id_blocker; +} + +// If a tree-style build ID was requested, the parallel part of that computation +// is already done, and the final hash-of-hashes is computed here. For other +// types of build IDs, all the work is done here. + +void +Layout::write_build_id(Output_file* of) const +{ + if (this->build_id_note_ == NULL) + return; + + unsigned char* ov = of->get_output_view(this->build_id_note_->offset(), + this->build_id_note_->data_size()); + + if (this->array_of_hashes_ == NULL) + { + const size_t output_file_size = this->output_file_size(); + const unsigned char* iv = of->get_input_view(0, output_file_size); + const char* style = parameters->options().build_id(); + + // If we get here with style == "tree" then the output must be + // too small for chunking, and we use SHA-1 in that case. + if ((strcmp(style, "sha1") == 0) || (strcmp(style, "tree") == 0)) + sha1_buffer(reinterpret_cast<const char*>(iv), output_file_size, ov); + else if (strcmp(style, "md5") == 0) + md5_buffer(reinterpret_cast<const char*>(iv), output_file_size, ov); + else + gold_unreachable(); + + of->free_input_view(0, output_file_size, iv); + } + else + { + // Non-overlapping substrings of the output file have been hashed. + // Compute SHA-1 hash of the hashes. + sha1_buffer(reinterpret_cast<const char*>(this->array_of_hashes_), + this->size_of_array_of_hashes_, ov); + delete[] this->array_of_hashes_; + of->free_input_view(0, this->output_file_size(), this->input_view_); + } + + of->write_output_view(this->build_id_note_->offset(), + this->build_id_note_->data_size(), + ov); +} + +// Write out a binary file. This is called after the link is +// complete. IN is the temporary output file we used to generate the +// ELF code. We simply walk through the segments, read them from +// their file offset in IN, and write them to their load address in +// the output file. FIXME: with a bit more work, we could support +// S-records and/or Intel hex format here. + +void +Layout::write_binary(Output_file* in) const +{ + gold_assert(parameters->options().oformat_enum() + == General_options::OBJECT_FORMAT_BINARY); + + // Get the size of the binary file. + uint64_t max_load_address = 0; + for (Segment_list::const_iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + { + if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0) + { + uint64_t max_paddr = (*p)->paddr() + (*p)->filesz(); + if (max_paddr > max_load_address) + max_load_address = max_paddr; + } + } + + Output_file out(parameters->options().output_file_name()); + out.open(max_load_address); + + for (Segment_list::const_iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + { + if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0) + { + const unsigned char* vin = in->get_input_view((*p)->offset(), + (*p)->filesz()); + unsigned char* vout = out.get_output_view((*p)->paddr(), + (*p)->filesz()); + memcpy(vout, vin, (*p)->filesz()); + out.write_output_view((*p)->paddr(), (*p)->filesz(), vout); + in->free_input_view((*p)->offset(), (*p)->filesz(), vin); + } + } + + out.close(); +} + +// Print the output sections to the map file. + +void +Layout::print_to_mapfile(Mapfile* mapfile) const +{ + for (Segment_list::const_iterator p = this->segment_list_.begin(); + p != this->segment_list_.end(); + ++p) + (*p)->print_sections_to_mapfile(mapfile); +} + +// Print statistical information to stderr. This is used for --stats. + +void +Layout::print_stats() const +{ + this->namepool_.print_stats("section name pool"); + this->sympool_.print_stats("output symbol name pool"); + this->dynpool_.print_stats("dynamic name pool"); + + for (Section_list::const_iterator p = this->section_list_.begin(); + p != this->section_list_.end(); + ++p) + (*p)->print_merge_stats(); +} + +// Write_sections_task methods. + +// We can always run this task. + +Task_token* +Write_sections_task::is_runnable() +{ + return NULL; +} + +// We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER +// when finished. + +void +Write_sections_task::locks(Task_locker* tl) +{ + tl->add(this, this->output_sections_blocker_); + tl->add(this, this->final_blocker_); +} + +// Run the task--write out the data. + +void +Write_sections_task::run(Workqueue*) +{ + this->layout_->write_output_sections(this->of_); +} + +// Write_data_task methods. + +// We can always run this task. + +Task_token* +Write_data_task::is_runnable() +{ + return NULL; +} + +// We need to unlock FINAL_BLOCKER when finished. + +void +Write_data_task::locks(Task_locker* tl) +{ + tl->add(this, this->final_blocker_); +} + +// Run the task--write out the data. + +void +Write_data_task::run(Workqueue*) +{ + this->layout_->write_data(this->symtab_, this->of_); +} + +// Write_symbols_task methods. + +// We can always run this task. + +Task_token* +Write_symbols_task::is_runnable() +{ + return NULL; +} + +// We need to unlock FINAL_BLOCKER when finished. + +void +Write_symbols_task::locks(Task_locker* tl) +{ + tl->add(this, this->final_blocker_); +} + +// Run the task--write out the symbols. + +void +Write_symbols_task::run(Workqueue*) +{ + this->symtab_->write_globals(this->sympool_, this->dynpool_, + this->layout_->symtab_xindex(), + this->layout_->dynsym_xindex(), this->of_); +} + +// Write_after_input_sections_task methods. + +// We can only run this task after the input sections have completed. + +Task_token* +Write_after_input_sections_task::is_runnable() +{ + if (this->input_sections_blocker_->is_blocked()) + return this->input_sections_blocker_; + return NULL; +} + +// We need to unlock FINAL_BLOCKER when finished. + +void +Write_after_input_sections_task::locks(Task_locker* tl) +{ + tl->add(this, this->final_blocker_); +} + +// Run the task. + +void +Write_after_input_sections_task::run(Workqueue*) +{ + this->layout_->write_sections_after_input_sections(this->of_); +} + +// Close_task_runner methods. + +// Finish up the build ID computation, if necessary, and write a binary file, +// if necessary. Then close the output file. + +void +Close_task_runner::run(Workqueue*, const Task*) +{ + // At this point the multi-threaded part of the build ID computation, + // if any, is done. See queue_build_id_tasks(). + this->layout_->write_build_id(this->of_); + + // If we've been asked to create a binary file, we do so here. + if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF) + this->layout_->write_binary(this->of_); + + this->of_->close(); +} + +// Instantiate the templates we need. We could use the configure +// script to restrict this to only the ones for implemented targets. + +#ifdef HAVE_TARGET_32_LITTLE +template +Output_section* +Layout::init_fixed_output_section<32, false>( + const char* name, + elfcpp::Shdr<32, false>& shdr); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +Output_section* +Layout::init_fixed_output_section<32, true>( + const char* name, + elfcpp::Shdr<32, true>& shdr); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +Output_section* +Layout::init_fixed_output_section<64, false>( + const char* name, + elfcpp::Shdr<64, false>& shdr); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +Output_section* +Layout::init_fixed_output_section<64, true>( + const char* name, + elfcpp::Shdr<64, true>& shdr); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +Output_section* +Layout::layout<32, false>(Sized_relobj_file<32, false>* object, + unsigned int shndx, + const char* name, + const elfcpp::Shdr<32, false>& shdr, + unsigned int, unsigned int, off_t*); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +Output_section* +Layout::layout<32, true>(Sized_relobj_file<32, true>* object, + unsigned int shndx, + const char* name, + const elfcpp::Shdr<32, true>& shdr, + unsigned int, unsigned int, off_t*); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +Output_section* +Layout::layout<64, false>(Sized_relobj_file<64, false>* object, + unsigned int shndx, + const char* name, + const elfcpp::Shdr<64, false>& shdr, + unsigned int, unsigned int, off_t*); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +Output_section* +Layout::layout<64, true>(Sized_relobj_file<64, true>* object, + unsigned int shndx, + const char* name, + const elfcpp::Shdr<64, true>& shdr, + unsigned int, unsigned int, off_t*); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +Output_section* +Layout::layout_reloc<32, false>(Sized_relobj_file<32, false>* object, + unsigned int reloc_shndx, + const elfcpp::Shdr<32, false>& shdr, + Output_section* data_section, + Relocatable_relocs* rr); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +Output_section* +Layout::layout_reloc<32, true>(Sized_relobj_file<32, true>* object, + unsigned int reloc_shndx, + const elfcpp::Shdr<32, true>& shdr, + Output_section* data_section, + Relocatable_relocs* rr); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +Output_section* +Layout::layout_reloc<64, false>(Sized_relobj_file<64, false>* object, + unsigned int reloc_shndx, + const elfcpp::Shdr<64, false>& shdr, + Output_section* data_section, + Relocatable_relocs* rr); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +Output_section* +Layout::layout_reloc<64, true>(Sized_relobj_file<64, true>* object, + unsigned int reloc_shndx, + const elfcpp::Shdr<64, true>& shdr, + Output_section* data_section, + Relocatable_relocs* rr); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +void +Layout::layout_group<32, false>(Symbol_table* symtab, + Sized_relobj_file<32, false>* object, + unsigned int, + const char* group_section_name, + const char* signature, + const elfcpp::Shdr<32, false>& shdr, + elfcpp::Elf_Word flags, + std::vector<unsigned int>* shndxes); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +void +Layout::layout_group<32, true>(Symbol_table* symtab, + Sized_relobj_file<32, true>* object, + unsigned int, + const char* group_section_name, + const char* signature, + const elfcpp::Shdr<32, true>& shdr, + elfcpp::Elf_Word flags, + std::vector<unsigned int>* shndxes); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +void +Layout::layout_group<64, false>(Symbol_table* symtab, + Sized_relobj_file<64, false>* object, + unsigned int, + const char* group_section_name, + const char* signature, + const elfcpp::Shdr<64, false>& shdr, + elfcpp::Elf_Word flags, + std::vector<unsigned int>* shndxes); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +void +Layout::layout_group<64, true>(Symbol_table* symtab, + Sized_relobj_file<64, true>* object, + unsigned int, + const char* group_section_name, + const char* signature, + const elfcpp::Shdr<64, true>& shdr, + elfcpp::Elf_Word flags, + std::vector<unsigned int>* shndxes); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +Output_section* +Layout::layout_eh_frame<32, false>(Sized_relobj_file<32, false>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + const elfcpp::Shdr<32, false>& shdr, + unsigned int reloc_shndx, + unsigned int reloc_type, + off_t* off); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +Output_section* +Layout::layout_eh_frame<32, true>(Sized_relobj_file<32, true>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + const elfcpp::Shdr<32, true>& shdr, + unsigned int reloc_shndx, + unsigned int reloc_type, + off_t* off); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +Output_section* +Layout::layout_eh_frame<64, false>(Sized_relobj_file<64, false>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + const elfcpp::Shdr<64, false>& shdr, + unsigned int reloc_shndx, + unsigned int reloc_type, + off_t* off); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +Output_section* +Layout::layout_eh_frame<64, true>(Sized_relobj_file<64, true>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + const elfcpp::Shdr<64, true>& shdr, + unsigned int reloc_shndx, + unsigned int reloc_type, + off_t* off); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +void +Layout::add_to_gdb_index(bool is_type_unit, + Sized_relobj<32, false>* object, + const unsigned char* symbols, + off_t symbols_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +void +Layout::add_to_gdb_index(bool is_type_unit, + Sized_relobj<32, true>* object, + const unsigned char* symbols, + off_t symbols_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +void +Layout::add_to_gdb_index(bool is_type_unit, + Sized_relobj<64, false>* object, + const unsigned char* symbols, + off_t symbols_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +void +Layout::add_to_gdb_index(bool is_type_unit, + Sized_relobj<64, true>* object, + const unsigned char* symbols, + off_t symbols_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type); +#endif + +} // End namespace gold. |