1 // layout.cc -- lay out output file sections for gold
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 // Free Software Foundation, Inc.
5 // Written by Ian Lance Taylor <iant@google.com>.
7 // This file is part of gold.
9 // This program is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 3 of the License, or
12 // (at your option) any later version.
14 // This program is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 // MA 02110-1301, USA.
35 #include "libiberty.h"
39 #include "parameters.h"
43 #include "script-sections.h"
48 #include "gdb-index.h"
49 #include "compressed_output.h"
50 #include "reduced_debug_output.h"
53 #include "descriptors.h"
55 #include "incremental.h"
63 // The total number of free lists used.
64 unsigned int Free_list::num_lists = 0;
65 // The total number of free list nodes used.
66 unsigned int Free_list::num_nodes = 0;
67 // The total number of calls to Free_list::remove.
68 unsigned int Free_list::num_removes = 0;
69 // The total number of nodes visited during calls to Free_list::remove.
70 unsigned int Free_list::num_remove_visits = 0;
71 // The total number of calls to Free_list::allocate.
72 unsigned int Free_list::num_allocates = 0;
73 // The total number of nodes visited during calls to Free_list::allocate.
74 unsigned int Free_list::num_allocate_visits = 0;
76 // Initialize the free list. Creates a single free list node that
77 // describes the entire region of length LEN. If EXTEND is true,
78 // allocate() is allowed to extend the region beyond its initial
82 Free_list::init(off_t len, bool extend)
84 this->list_.push_front(Free_list_node(0, len));
85 this->last_remove_ = this->list_.begin();
86 this->extend_ = extend;
88 ++Free_list::num_lists;
89 ++Free_list::num_nodes;
92 // Remove a chunk from the free list. Because we start with a single
93 // node that covers the entire section, and remove chunks from it one
94 // at a time, we do not need to coalesce chunks or handle cases that
95 // span more than one free node. We expect to remove chunks from the
96 // free list in order, and we expect to have only a few chunks of free
97 // space left (corresponding to files that have changed since the last
98 // incremental link), so a simple linear list should provide sufficient
102 Free_list::remove(off_t start, off_t end)
106 gold_assert(start < end);
108 ++Free_list::num_removes;
110 Iterator p = this->last_remove_;
111 if (p->start_ > start)
112 p = this->list_.begin();
114 for (; p != this->list_.end(); ++p)
116 ++Free_list::num_remove_visits;
117 // Find a node that wholly contains the indicated region.
118 if (p->start_ <= start && p->end_ >= end)
120 // Case 1: the indicated region spans the whole node.
121 // Add some fuzz to avoid creating tiny free chunks.
122 if (p->start_ + 3 >= start && p->end_ <= end + 3)
123 p = this->list_.erase(p);
124 // Case 2: remove a chunk from the start of the node.
125 else if (p->start_ + 3 >= start)
127 // Case 3: remove a chunk from the end of the node.
128 else if (p->end_ <= end + 3)
130 // Case 4: remove a chunk from the middle, and split
131 // the node into two.
134 Free_list_node newnode(p->start_, start);
136 this->list_.insert(p, newnode);
137 ++Free_list::num_nodes;
139 this->last_remove_ = p;
144 // Did not find a node containing the given chunk. This could happen
145 // because a small chunk was already removed due to the fuzz.
146 gold_debug(DEBUG_INCREMENTAL,
147 "Free_list::remove(%d,%d) not found",
148 static_cast<int>(start), static_cast<int>(end));
151 // Allocate a chunk of size LEN from the free list. Returns -1ULL
152 // if a sufficiently large chunk of free space is not found.
153 // We use a simple first-fit algorithm.
156 Free_list::allocate(off_t len, uint64_t align, off_t minoff)
158 gold_debug(DEBUG_INCREMENTAL,
159 "Free_list::allocate(%08lx, %d, %08lx)",
160 static_cast<long>(len), static_cast<int>(align),
161 static_cast<long>(minoff));
163 return align_address(minoff, align);
165 ++Free_list::num_allocates;
167 // We usually want to drop free chunks smaller than 4 bytes.
168 // If we need to guarantee a minimum hole size, though, we need
169 // to keep track of all free chunks.
170 const int fuzz = this->min_hole_ > 0 ? 0 : 3;
172 for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
174 ++Free_list::num_allocate_visits;
175 off_t start = p->start_ > minoff ? p->start_ : minoff;
176 start = align_address(start, align);
177 off_t end = start + len;
178 if (end > p->end_ && p->end_ == this->length_ && this->extend_)
183 if (end == p->end_ || (end <= p->end_ - this->min_hole_))
185 if (p->start_ + fuzz >= start && p->end_ <= end + fuzz)
186 this->list_.erase(p);
187 else if (p->start_ + fuzz >= start)
189 else if (p->end_ <= end + fuzz)
193 Free_list_node newnode(p->start_, start);
195 this->list_.insert(p, newnode);
196 ++Free_list::num_nodes;
203 off_t start = align_address(this->length_, align);
204 this->length_ = start + len;
210 // Dump the free list (for debugging).
214 gold_info("Free list:\n start end length\n");
215 for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
216 gold_info(" %08lx %08lx %08lx", static_cast<long>(p->start_),
217 static_cast<long>(p->end_),
218 static_cast<long>(p->end_ - p->start_));
221 // Print the statistics for the free lists.
223 Free_list::print_stats()
225 fprintf(stderr, _("%s: total free lists: %u\n"),
226 program_name, Free_list::num_lists);
227 fprintf(stderr, _("%s: total free list nodes: %u\n"),
228 program_name, Free_list::num_nodes);
229 fprintf(stderr, _("%s: calls to Free_list::remove: %u\n"),
230 program_name, Free_list::num_removes);
231 fprintf(stderr, _("%s: nodes visited: %u\n"),
232 program_name, Free_list::num_remove_visits);
233 fprintf(stderr, _("%s: calls to Free_list::allocate: %u\n"),
234 program_name, Free_list::num_allocates);
235 fprintf(stderr, _("%s: nodes visited: %u\n"),
236 program_name, Free_list::num_allocate_visits);
239 // Layout::Relaxation_debug_check methods.
241 // Check that sections and special data are in reset states.
242 // We do not save states for Output_sections and special Output_data.
243 // So we check that they have not assigned any addresses or offsets.
244 // clean_up_after_relaxation simply resets their addresses and offsets.
246 Layout::Relaxation_debug_check::check_output_data_for_reset_values(
247 const Layout::Section_list& sections,
248 const Layout::Data_list& special_outputs)
250 for(Layout::Section_list::const_iterator p = sections.begin();
253 gold_assert((*p)->address_and_file_offset_have_reset_values());
255 for(Layout::Data_list::const_iterator p = special_outputs.begin();
256 p != special_outputs.end();
258 gold_assert((*p)->address_and_file_offset_have_reset_values());
261 // Save information of SECTIONS for checking later.
264 Layout::Relaxation_debug_check::read_sections(
265 const Layout::Section_list& sections)
267 for(Layout::Section_list::const_iterator p = sections.begin();
271 Output_section* os = *p;
273 info.output_section = os;
274 info.address = os->is_address_valid() ? os->address() : 0;
275 info.data_size = os->is_data_size_valid() ? os->data_size() : -1;
276 info.offset = os->is_offset_valid()? os->offset() : -1 ;
277 this->section_infos_.push_back(info);
281 // Verify SECTIONS using previously recorded information.
284 Layout::Relaxation_debug_check::verify_sections(
285 const Layout::Section_list& sections)
288 for(Layout::Section_list::const_iterator p = sections.begin();
292 Output_section* os = *p;
293 uint64_t address = os->is_address_valid() ? os->address() : 0;
294 off_t data_size = os->is_data_size_valid() ? os->data_size() : -1;
295 off_t offset = os->is_offset_valid()? os->offset() : -1 ;
297 if (i >= this->section_infos_.size())
299 gold_fatal("Section_info of %s missing.\n", os->name());
301 const Section_info& info = this->section_infos_[i];
302 if (os != info.output_section)
303 gold_fatal("Section order changed. Expecting %s but see %s\n",
304 info.output_section->name(), os->name());
305 if (address != info.address
306 || data_size != info.data_size
307 || offset != info.offset)
308 gold_fatal("Section %s changed.\n", os->name());
312 // Layout_task_runner methods.
314 // Lay out the sections. This is called after all the input objects
318 Layout_task_runner::run(Workqueue* workqueue, const Task* task)
320 Layout* layout = this->layout_;
321 off_t file_size = layout->finalize(this->input_objects_,
326 // Now we know the final size of the output file and we know where
327 // each piece of information goes.
329 if (this->mapfile_ != NULL)
331 this->mapfile_->print_discarded_sections(this->input_objects_);
332 layout->print_to_mapfile(this->mapfile_);
336 if (layout->incremental_base() == NULL)
338 of = new Output_file(parameters->options().output_file_name());
339 if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
340 of->set_is_temporary();
345 of = layout->incremental_base()->output_file();
347 // Apply the incremental relocations for symbols whose values
348 // have changed. We do this before we resize the file and start
349 // writing anything else to it, so that we can read the old
350 // incremental information from the file before (possibly)
352 if (parameters->incremental_update())
353 layout->incremental_base()->apply_incremental_relocs(this->symtab_,
357 of->resize(file_size);
360 // Queue up the final set of tasks.
361 gold::queue_final_tasks(this->options_, this->input_objects_,
362 this->symtab_, layout, workqueue, of);
367 Layout::Layout(int number_of_input_files, Script_options* script_options)
368 : number_of_input_files_(number_of_input_files),
369 script_options_(script_options),
377 unattached_section_list_(),
378 special_output_list_(),
379 section_headers_(NULL),
381 relro_segment_(NULL),
382 interp_segment_(NULL),
384 symtab_section_(NULL),
385 symtab_xindex_(NULL),
386 dynsym_section_(NULL),
387 dynsym_xindex_(NULL),
388 dynamic_section_(NULL),
389 dynamic_symbol_(NULL),
391 eh_frame_section_(NULL),
392 eh_frame_data_(NULL),
393 added_eh_frame_data_(false),
394 eh_frame_hdr_section_(NULL),
395 gdb_index_data_(NULL),
396 build_id_note_(NULL),
400 output_file_size_(-1),
401 have_added_input_section_(false),
402 sections_are_attached_(false),
403 input_requires_executable_stack_(false),
404 input_with_gnu_stack_note_(false),
405 input_without_gnu_stack_note_(false),
406 has_static_tls_(false),
407 any_postprocessing_sections_(false),
408 resized_signatures_(false),
409 have_stabstr_section_(false),
410 section_ordering_specified_(false),
411 unique_segment_for_sections_specified_(false),
412 incremental_inputs_(NULL),
413 record_output_section_data_from_script_(false),
414 script_output_section_data_list_(),
415 segment_states_(NULL),
416 relaxation_debug_check_(NULL),
417 section_order_map_(),
418 section_segment_map_(),
419 input_section_position_(),
420 input_section_glob_(),
421 incremental_base_(NULL),
424 // Make space for more than enough segments for a typical file.
425 // This is just for efficiency--it's OK if we wind up needing more.
426 this->segment_list_.reserve(12);
428 // We expect two unattached Output_data objects: the file header and
429 // the segment headers.
430 this->special_output_list_.reserve(2);
432 // Initialize structure needed for an incremental build.
433 if (parameters->incremental())
434 this->incremental_inputs_ = new Incremental_inputs;
436 // The section name pool is worth optimizing in all cases, because
437 // it is small, but there are often overlaps due to .rel sections.
438 this->namepool_.set_optimize();
441 // For incremental links, record the base file to be modified.
444 Layout::set_incremental_base(Incremental_binary* base)
446 this->incremental_base_ = base;
447 this->free_list_.init(base->output_file()->filesize(), true);
450 // Hash a key we use to look up an output section mapping.
453 Layout::Hash_key::operator()(const Layout::Key& k) const
455 return k.first + k.second.first + k.second.second;
458 // These are the debug sections that are actually used by gdb.
459 // Currently, we've checked versions of gdb up to and including 7.4.
460 // We only check the part of the name that follows ".debug_" or
463 static const char* gdb_sections[] =
466 "addr", // Fission extension
467 // "aranges", // not used by gdb as of 7.4
475 // "pubnames", // not used by gdb as of 7.4
476 // "pubtypes", // not used by gdb as of 7.4
481 // This is the minimum set of sections needed for line numbers.
483 static const char* lines_only_debug_sections[] =
486 // "addr", // Fission extension
487 // "aranges", // not used by gdb as of 7.4
495 // "pubnames", // not used by gdb as of 7.4
496 // "pubtypes", // not used by gdb as of 7.4
501 // These sections are the DWARF fast-lookup tables, and are not needed
502 // when building a .gdb_index section.
504 static const char* gdb_fast_lookup_sections[] =
511 // Returns whether the given debug section is in the list of
512 // debug-sections-used-by-some-version-of-gdb. SUFFIX is the
513 // portion of the name following ".debug_" or ".zdebug_".
516 is_gdb_debug_section(const char* suffix)
518 // We can do this faster: binary search or a hashtable. But why bother?
519 for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
520 if (strcmp(suffix, gdb_sections[i]) == 0)
525 // Returns whether the given section is needed for lines-only debugging.
528 is_lines_only_debug_section(const char* suffix)
530 // We can do this faster: binary search or a hashtable. But why bother?
532 i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections);
534 if (strcmp(suffix, lines_only_debug_sections[i]) == 0)
539 // Returns whether the given section is a fast-lookup section that
540 // will not be needed when building a .gdb_index section.
543 is_gdb_fast_lookup_section(const char* suffix)
545 // We can do this faster: binary search or a hashtable. But why bother?
547 i < sizeof(gdb_fast_lookup_sections)/sizeof(*gdb_fast_lookup_sections);
549 if (strcmp(suffix, gdb_fast_lookup_sections[i]) == 0)
554 // Sometimes we compress sections. This is typically done for
555 // sections that are not part of normal program execution (such as
556 // .debug_* sections), and where the readers of these sections know
557 // how to deal with compressed sections. This routine doesn't say for
558 // certain whether we'll compress -- it depends on commandline options
559 // as well -- just whether this section is a candidate for compression.
560 // (The Output_compressed_section class decides whether to compress
561 // a given section, and picks the name of the compressed section.)
564 is_compressible_debug_section(const char* secname)
566 return (is_prefix_of(".debug", secname));
569 // We may see compressed debug sections in input files. Return TRUE
570 // if this is the name of a compressed debug section.
573 is_compressed_debug_section(const char* secname)
575 return (is_prefix_of(".zdebug", secname));
578 // Whether to include this section in the link.
580 template<int size, bool big_endian>
582 Layout::include_section(Sized_relobj_file<size, big_endian>*, const char* name,
583 const elfcpp::Shdr<size, big_endian>& shdr)
585 if (!parameters->options().relocatable()
586 && (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE))
589 switch (shdr.get_sh_type())
591 case elfcpp::SHT_NULL:
592 case elfcpp::SHT_SYMTAB:
593 case elfcpp::SHT_DYNSYM:
594 case elfcpp::SHT_HASH:
595 case elfcpp::SHT_DYNAMIC:
596 case elfcpp::SHT_SYMTAB_SHNDX:
599 case elfcpp::SHT_STRTAB:
600 // Discard the sections which have special meanings in the ELF
601 // ABI. Keep others (e.g., .stabstr). We could also do this by
602 // checking the sh_link fields of the appropriate sections.
603 return (strcmp(name, ".dynstr") != 0
604 && strcmp(name, ".strtab") != 0
605 && strcmp(name, ".shstrtab") != 0);
607 case elfcpp::SHT_RELA:
608 case elfcpp::SHT_REL:
609 case elfcpp::SHT_GROUP:
610 // If we are emitting relocations these should be handled
612 gold_assert(!parameters->options().relocatable());
615 case elfcpp::SHT_PROGBITS:
616 if (parameters->options().strip_debug()
617 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
619 if (is_debug_info_section(name))
622 if (parameters->options().strip_debug_non_line()
623 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
625 // Debugging sections can only be recognized by name.
626 if (is_prefix_of(".debug_", name)
627 && !is_lines_only_debug_section(name + 7))
629 if (is_prefix_of(".zdebug_", name)
630 && !is_lines_only_debug_section(name + 8))
633 if (parameters->options().strip_debug_gdb()
634 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
636 // Debugging sections can only be recognized by name.
637 if (is_prefix_of(".debug_", name)
638 && !is_gdb_debug_section(name + 7))
640 if (is_prefix_of(".zdebug_", name)
641 && !is_gdb_debug_section(name + 8))
644 if (parameters->options().gdb_index()
645 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
647 // When building .gdb_index, we can strip .debug_pubnames,
648 // .debug_pubtypes, and .debug_aranges sections.
649 if (is_prefix_of(".debug_", name)
650 && is_gdb_fast_lookup_section(name + 7))
652 if (is_prefix_of(".zdebug_", name)
653 && is_gdb_fast_lookup_section(name + 8))
656 if (parameters->options().strip_lto_sections()
657 && !parameters->options().relocatable()
658 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
660 // Ignore LTO sections containing intermediate code.
661 if (is_prefix_of(".gnu.lto_", name))
664 // The GNU linker strips .gnu_debuglink sections, so we do too.
665 // This is a feature used to keep debugging information in
667 if (strcmp(name, ".gnu_debuglink") == 0)
676 // Return an output section named NAME, or NULL if there is none.
679 Layout::find_output_section(const char* name) const
681 for (Section_list::const_iterator p = this->section_list_.begin();
682 p != this->section_list_.end();
684 if (strcmp((*p)->name(), name) == 0)
689 // Return an output segment of type TYPE, with segment flags SET set
690 // and segment flags CLEAR clear. Return NULL if there is none.
693 Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
694 elfcpp::Elf_Word clear) const
696 for (Segment_list::const_iterator p = this->segment_list_.begin();
697 p != this->segment_list_.end();
699 if (static_cast<elfcpp::PT>((*p)->type()) == type
700 && ((*p)->flags() & set) == set
701 && ((*p)->flags() & clear) == 0)
706 // When we put a .ctors or .dtors section with more than one word into
707 // a .init_array or .fini_array section, we need to reverse the words
708 // in the .ctors/.dtors section. This is because .init_array executes
709 // constructors front to back, where .ctors executes them back to
710 // front, and vice-versa for .fini_array/.dtors. Although we do want
711 // to remap .ctors/.dtors into .init_array/.fini_array because it can
712 // be more efficient, we don't want to change the order in which
713 // constructors/destructors are run. This set just keeps track of
714 // these sections which need to be reversed. It is only changed by
715 // Layout::layout. It should be a private member of Layout, but that
716 // would require layout.h to #include object.h to get the definition
718 static Unordered_set<Section_id, Section_id_hash> ctors_sections_in_init_array;
720 // Return whether OBJECT/SHNDX is a .ctors/.dtors section mapped to a
721 // .init_array/.fini_array section.
724 Layout::is_ctors_in_init_array(Relobj* relobj, unsigned int shndx) const
726 return (ctors_sections_in_init_array.find(Section_id(relobj, shndx))
727 != ctors_sections_in_init_array.end());
730 // Return the output section to use for section NAME with type TYPE
731 // and section flags FLAGS. NAME must be canonicalized in the string
732 // pool, and NAME_KEY is the key. ORDER is where this should appear
733 // in the output sections. IS_RELRO is true for a relro section.
736 Layout::get_output_section(const char* name, Stringpool::Key name_key,
737 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
738 Output_section_order order, bool is_relro)
740 elfcpp::Elf_Word lookup_type = type;
742 // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and
743 // PREINIT_ARRAY like PROGBITS. This ensures that we combine
744 // .init_array, .fini_array, and .preinit_array sections by name
745 // whatever their type in the input file. We do this because the
746 // types are not always right in the input files.
747 if (lookup_type == elfcpp::SHT_INIT_ARRAY
748 || lookup_type == elfcpp::SHT_FINI_ARRAY
749 || lookup_type == elfcpp::SHT_PREINIT_ARRAY)
750 lookup_type = elfcpp::SHT_PROGBITS;
752 elfcpp::Elf_Xword lookup_flags = flags;
754 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
755 // read-write with read-only sections. Some other ELF linkers do
756 // not do this. FIXME: Perhaps there should be an option
758 lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
760 const Key key(name_key, std::make_pair(lookup_type, lookup_flags));
761 const std::pair<Key, Output_section*> v(key, NULL);
762 std::pair<Section_name_map::iterator, bool> ins(
763 this->section_name_map_.insert(v));
766 return ins.first->second;
769 // This is the first time we've seen this name/type/flags
770 // combination. For compatibility with the GNU linker, we
771 // combine sections with contents and zero flags with sections
772 // with non-zero flags. This is a workaround for cases where
773 // assembler code forgets to set section flags. FIXME: Perhaps
774 // there should be an option to control this.
775 Output_section* os = NULL;
777 if (lookup_type == elfcpp::SHT_PROGBITS)
781 Output_section* same_name = this->find_output_section(name);
782 if (same_name != NULL
783 && (same_name->type() == elfcpp::SHT_PROGBITS
784 || same_name->type() == elfcpp::SHT_INIT_ARRAY
785 || same_name->type() == elfcpp::SHT_FINI_ARRAY
786 || same_name->type() == elfcpp::SHT_PREINIT_ARRAY)
787 && (same_name->flags() & elfcpp::SHF_TLS) == 0)
790 else if ((flags & elfcpp::SHF_TLS) == 0)
792 elfcpp::Elf_Xword zero_flags = 0;
793 const Key zero_key(name_key, std::make_pair(lookup_type,
795 Section_name_map::iterator p =
796 this->section_name_map_.find(zero_key);
797 if (p != this->section_name_map_.end())
803 os = this->make_output_section(name, type, flags, order, is_relro);
805 ins.first->second = os;
810 // Returns TRUE iff NAME (an input section from RELOBJ) will
811 // be mapped to an output section that should be KEPT.
814 Layout::keep_input_section(const Relobj* relobj, const char* name)
816 if (! this->script_options_->saw_sections_clause())
819 Script_sections* ss = this->script_options_->script_sections();
820 const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
821 Output_section** output_section_slot;
822 Script_sections::Section_type script_section_type;
825 name = ss->output_section_name(file_name, name, &output_section_slot,
826 &script_section_type, &keep);
827 return name != NULL && keep;
830 // Clear the input section flags that should not be copied to the
834 Layout::get_output_section_flags(elfcpp::Elf_Xword input_section_flags)
836 // Some flags in the input section should not be automatically
837 // copied to the output section.
838 input_section_flags &= ~ (elfcpp::SHF_INFO_LINK
841 | elfcpp::SHF_STRINGS);
843 // We only clear the SHF_LINK_ORDER flag in for
844 // a non-relocatable link.
845 if (!parameters->options().relocatable())
846 input_section_flags &= ~elfcpp::SHF_LINK_ORDER;
848 return input_section_flags;
851 // Pick the output section to use for section NAME, in input file
852 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
853 // linker created section. IS_INPUT_SECTION is true if we are
854 // choosing an output section for an input section found in a input
855 // file. ORDER is where this section should appear in the output
856 // sections. IS_RELRO is true for a relro section. This will return
857 // NULL if the input section should be discarded.
860 Layout::choose_output_section(const Relobj* relobj, const char* name,
861 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
862 bool is_input_section, Output_section_order order,
865 // We should not see any input sections after we have attached
866 // sections to segments.
867 gold_assert(!is_input_section || !this->sections_are_attached_);
869 flags = this->get_output_section_flags(flags);
871 if (this->script_options_->saw_sections_clause())
873 // We are using a SECTIONS clause, so the output section is
874 // chosen based only on the name.
876 Script_sections* ss = this->script_options_->script_sections();
877 const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
878 Output_section** output_section_slot;
879 Script_sections::Section_type script_section_type;
880 const char* orig_name = name;
882 name = ss->output_section_name(file_name, name, &output_section_slot,
883 &script_section_type, &keep);
887 gold_debug(DEBUG_SCRIPT, _("Unable to create output section '%s' "
888 "because it is not allowed by the "
889 "SECTIONS clause of the linker script"),
891 // The SECTIONS clause says to discard this input section.
895 // We can only handle script section types ST_NONE and ST_NOLOAD.
896 switch (script_section_type)
898 case Script_sections::ST_NONE:
900 case Script_sections::ST_NOLOAD:
901 flags &= elfcpp::SHF_ALLOC;
907 // If this is an orphan section--one not mentioned in the linker
908 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
909 // default processing below.
911 if (output_section_slot != NULL)
913 if (*output_section_slot != NULL)
915 (*output_section_slot)->update_flags_for_input_section(flags);
916 return *output_section_slot;
919 // We don't put sections found in the linker script into
920 // SECTION_NAME_MAP_. That keeps us from getting confused
921 // if an orphan section is mapped to a section with the same
922 // name as one in the linker script.
924 name = this->namepool_.add(name, false, NULL);
926 Output_section* os = this->make_output_section(name, type, flags,
929 os->set_found_in_sections_clause();
931 // Special handling for NOLOAD sections.
932 if (script_section_type == Script_sections::ST_NOLOAD)
936 // The constructor of Output_section sets addresses of non-ALLOC
937 // sections to 0 by default. We don't want that for NOLOAD
938 // sections even if they have no SHF_ALLOC flag.
939 if ((os->flags() & elfcpp::SHF_ALLOC) == 0
940 && os->is_address_valid())
942 gold_assert(os->address() == 0
943 && !os->is_offset_valid()
944 && !os->is_data_size_valid());
945 os->reset_address_and_file_offset();
949 *output_section_slot = os;
954 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
956 size_t len = strlen(name);
957 char* uncompressed_name = NULL;
959 // Compressed debug sections should be mapped to the corresponding
960 // uncompressed section.
961 if (is_compressed_debug_section(name))
963 uncompressed_name = new char[len];
964 uncompressed_name[0] = '.';
965 gold_assert(name[0] == '.' && name[1] == 'z');
966 strncpy(&uncompressed_name[1], &name[2], len - 2);
967 uncompressed_name[len - 1] = '\0';
969 name = uncompressed_name;
972 // Turn NAME from the name of the input section into the name of the
975 && !this->script_options_->saw_sections_clause()
976 && !parameters->options().relocatable())
978 const char *orig_name = name;
979 name = parameters->target().output_section_name(relobj, name, &len);
981 name = Layout::output_section_name(relobj, orig_name, &len);
984 Stringpool::Key name_key;
985 name = this->namepool_.add_with_length(name, len, true, &name_key);
987 if (uncompressed_name != NULL)
988 delete[] uncompressed_name;
990 // Find or make the output section. The output section is selected
991 // based on the section name, type, and flags.
992 return this->get_output_section(name, name_key, type, flags, order, is_relro);
995 // For incremental links, record the initial fixed layout of a section
996 // from the base file, and return a pointer to the Output_section.
998 template<int size, bool big_endian>
1000 Layout::init_fixed_output_section(const char* name,
1001 elfcpp::Shdr<size, big_endian>& shdr)
1003 unsigned int sh_type = shdr.get_sh_type();
1005 // We preserve the layout of PROGBITS, NOBITS, INIT_ARRAY, FINI_ARRAY,
1006 // PRE_INIT_ARRAY, and NOTE sections.
1007 // All others will be created from scratch and reallocated.
1008 if (!can_incremental_update(sh_type))
1011 // If we're generating a .gdb_index section, we need to regenerate
1013 if (parameters->options().gdb_index()
1014 && sh_type == elfcpp::SHT_PROGBITS
1015 && strcmp(name, ".gdb_index") == 0)
1018 typename elfcpp::Elf_types<size>::Elf_Addr sh_addr = shdr.get_sh_addr();
1019 typename elfcpp::Elf_types<size>::Elf_Off sh_offset = shdr.get_sh_offset();
1020 typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
1021 typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
1022 typename elfcpp::Elf_types<size>::Elf_WXword sh_addralign =
1023 shdr.get_sh_addralign();
1025 // Make the output section.
1026 Stringpool::Key name_key;
1027 name = this->namepool_.add(name, true, &name_key);
1028 Output_section* os = this->get_output_section(name, name_key, sh_type,
1029 sh_flags, ORDER_INVALID, false);
1030 os->set_fixed_layout(sh_addr, sh_offset, sh_size, sh_addralign);
1031 if (sh_type != elfcpp::SHT_NOBITS)
1032 this->free_list_.remove(sh_offset, sh_offset + sh_size);
1036 // Return the output section to use for input section SHNDX, with name
1037 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
1038 // index of a relocation section which applies to this section, or 0
1039 // if none, or -1U if more than one. RELOC_TYPE is the type of the
1040 // relocation section if there is one. Set *OFF to the offset of this
1041 // input section without the output section. Return NULL if the
1042 // section should be discarded. Set *OFF to -1 if the section
1043 // contents should not be written directly to the output file, but
1044 // will instead receive special handling.
1046 template<int size, bool big_endian>
1048 Layout::layout(Sized_relobj_file<size, big_endian>* object, unsigned int shndx,
1049 const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
1050 unsigned int reloc_shndx, unsigned int, off_t* off)
1054 if (!this->include_section(object, name, shdr))
1057 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
1059 // In a relocatable link a grouped section must not be combined with
1060 // any other sections.
1062 if (parameters->options().relocatable()
1063 && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
1065 name = this->namepool_.add(name, true, NULL);
1066 os = this->make_output_section(name, sh_type, shdr.get_sh_flags(),
1067 ORDER_INVALID, false);
1071 // Plugins can choose to place one or more subsets of sections in
1072 // unique segments and this is done by mapping these section subsets
1073 // to unique output sections. Check if this section needs to be
1074 // remapped to a unique output section.
1075 Section_segment_map::iterator it
1076 = this->section_segment_map_.find(Const_section_id(object, shndx));
1077 if (it == this->section_segment_map_.end())
1079 os = this->choose_output_section(object, name, sh_type,
1080 shdr.get_sh_flags(), true,
1081 ORDER_INVALID, false);
1085 // We know the name of the output section, directly call
1086 // get_output_section here by-passing choose_output_section.
1087 elfcpp::Elf_Xword flags
1088 = this->get_output_section_flags(shdr.get_sh_flags());
1090 const char* os_name = it->second->name;
1091 Stringpool::Key name_key;
1092 os_name = this->namepool_.add(os_name, true, &name_key);
1093 os = this->get_output_section(os_name, name_key, sh_type, flags,
1094 ORDER_INVALID, false);
1095 if (!os->is_unique_segment())
1097 os->set_is_unique_segment();
1098 os->set_extra_segment_flags(it->second->flags);
1099 os->set_segment_alignment(it->second->align);
1106 // By default the GNU linker sorts input sections whose names match
1107 // .ctors.*, .dtors.*, .init_array.*, or .fini_array.*. The
1108 // sections are sorted by name. This is used to implement
1109 // constructor priority ordering. We are compatible. When we put
1110 // .ctor sections in .init_array and .dtor sections in .fini_array,
1111 // we must also sort plain .ctor and .dtor sections.
1112 if (!this->script_options_->saw_sections_clause()
1113 && !parameters->options().relocatable()
1114 && (is_prefix_of(".ctors.", name)
1115 || is_prefix_of(".dtors.", name)
1116 || is_prefix_of(".init_array.", name)
1117 || is_prefix_of(".fini_array.", name)
1118 || (parameters->options().ctors_in_init_array()
1119 && (strcmp(name, ".ctors") == 0
1120 || strcmp(name, ".dtors") == 0))))
1121 os->set_must_sort_attached_input_sections();
1123 // If this is a .ctors or .ctors.* section being mapped to a
1124 // .init_array section, or a .dtors or .dtors.* section being mapped
1125 // to a .fini_array section, we will need to reverse the words if
1126 // there is more than one. Record this section for later. See
1127 // ctors_sections_in_init_array above.
1128 if (!this->script_options_->saw_sections_clause()
1129 && !parameters->options().relocatable()
1130 && shdr.get_sh_size() > size / 8
1131 && (((strcmp(name, ".ctors") == 0
1132 || is_prefix_of(".ctors.", name))
1133 && strcmp(os->name(), ".init_array") == 0)
1134 || ((strcmp(name, ".dtors") == 0
1135 || is_prefix_of(".dtors.", name))
1136 && strcmp(os->name(), ".fini_array") == 0)))
1137 ctors_sections_in_init_array.insert(Section_id(object, shndx));
1139 // FIXME: Handle SHF_LINK_ORDER somewhere.
1141 elfcpp::Elf_Xword orig_flags = os->flags();
1143 *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
1144 this->script_options_->saw_sections_clause());
1146 // If the flags changed, we may have to change the order.
1147 if ((orig_flags & elfcpp::SHF_ALLOC) != 0)
1149 orig_flags &= (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
1150 elfcpp::Elf_Xword new_flags =
1151 os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
1152 if (orig_flags != new_flags)
1153 os->set_order(this->default_section_order(os, false));
1156 this->have_added_input_section_ = true;
1161 // Maps section SECN to SEGMENT s.
1163 Layout::insert_section_segment_map(Const_section_id secn,
1164 Unique_segment_info *s)
1166 gold_assert(this->unique_segment_for_sections_specified_);
1167 this->section_segment_map_[secn] = s;
1170 // Handle a relocation section when doing a relocatable link.
1172 template<int size, bool big_endian>
1174 Layout::layout_reloc(Sized_relobj_file<size, big_endian>* object,
1176 const elfcpp::Shdr<size, big_endian>& shdr,
1177 Output_section* data_section,
1178 Relocatable_relocs* rr)
1180 gold_assert(parameters->options().relocatable()
1181 || parameters->options().emit_relocs());
1183 int sh_type = shdr.get_sh_type();
1186 if (sh_type == elfcpp::SHT_REL)
1188 else if (sh_type == elfcpp::SHT_RELA)
1192 name += data_section->name();
1194 // In a relocatable link relocs for a grouped section must not be
1195 // combined with other reloc sections.
1197 if (!parameters->options().relocatable()
1198 || (data_section->flags() & elfcpp::SHF_GROUP) == 0)
1199 os = this->choose_output_section(object, name.c_str(), sh_type,
1200 shdr.get_sh_flags(), false,
1201 ORDER_INVALID, false);
1204 const char* n = this->namepool_.add(name.c_str(), true, NULL);
1205 os = this->make_output_section(n, sh_type, shdr.get_sh_flags(),
1206 ORDER_INVALID, false);
1209 os->set_should_link_to_symtab();
1210 os->set_info_section(data_section);
1212 Output_section_data* posd;
1213 if (sh_type == elfcpp::SHT_REL)
1215 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1216 posd = new Output_relocatable_relocs<elfcpp::SHT_REL,
1220 else if (sh_type == elfcpp::SHT_RELA)
1222 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1223 posd = new Output_relocatable_relocs<elfcpp::SHT_RELA,
1230 os->add_output_section_data(posd);
1231 rr->set_output_data(posd);
1236 // Handle a group section when doing a relocatable link.
1238 template<int size, bool big_endian>
1240 Layout::layout_group(Symbol_table* symtab,
1241 Sized_relobj_file<size, big_endian>* object,
1243 const char* group_section_name,
1244 const char* signature,
1245 const elfcpp::Shdr<size, big_endian>& shdr,
1246 elfcpp::Elf_Word flags,
1247 std::vector<unsigned int>* shndxes)
1249 gold_assert(parameters->options().relocatable());
1250 gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
1251 group_section_name = this->namepool_.add(group_section_name, true, NULL);
1252 Output_section* os = this->make_output_section(group_section_name,
1254 shdr.get_sh_flags(),
1255 ORDER_INVALID, false);
1257 // We need to find a symbol with the signature in the symbol table.
1258 // If we don't find one now, we need to look again later.
1259 Symbol* sym = symtab->lookup(signature, NULL);
1261 os->set_info_symndx(sym);
1264 // Reserve some space to minimize reallocations.
1265 if (this->group_signatures_.empty())
1266 this->group_signatures_.reserve(this->number_of_input_files_ * 16);
1268 // We will wind up using a symbol whose name is the signature.
1269 // So just put the signature in the symbol name pool to save it.
1270 signature = symtab->canonicalize_name(signature);
1271 this->group_signatures_.push_back(Group_signature(os, signature));
1274 os->set_should_link_to_symtab();
1277 section_size_type entry_count =
1278 convert_to_section_size_type(shdr.get_sh_size() / 4);
1279 Output_section_data* posd =
1280 new Output_data_group<size, big_endian>(object, entry_count, flags,
1282 os->add_output_section_data(posd);
1285 // Special GNU handling of sections name .eh_frame. They will
1286 // normally hold exception frame data as defined by the C++ ABI
1287 // (http://codesourcery.com/cxx-abi/).
1289 template<int size, bool big_endian>
1291 Layout::layout_eh_frame(Sized_relobj_file<size, big_endian>* object,
1292 const unsigned char* symbols,
1294 const unsigned char* symbol_names,
1295 off_t symbol_names_size,
1297 const elfcpp::Shdr<size, big_endian>& shdr,
1298 unsigned int reloc_shndx, unsigned int reloc_type,
1301 gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS
1302 || shdr.get_sh_type() == elfcpp::SHT_X86_64_UNWIND);
1303 gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
1305 Output_section* os = this->make_eh_frame_section(object);
1309 gold_assert(this->eh_frame_section_ == os);
1311 elfcpp::Elf_Xword orig_flags = os->flags();
1313 if (!parameters->incremental()
1314 && this->eh_frame_data_->add_ehframe_input_section(object,
1323 os->update_flags_for_input_section(shdr.get_sh_flags());
1325 // A writable .eh_frame section is a RELRO section.
1326 if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))
1327 != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)))
1330 os->set_order(ORDER_RELRO);
1333 // We found a .eh_frame section we are going to optimize, so now
1334 // we can add the set of optimized sections to the output
1335 // section. We need to postpone adding this until we've found a
1336 // section we can optimize so that the .eh_frame section in
1337 // crtbegin.o winds up at the start of the output section.
1338 if (!this->added_eh_frame_data_)
1340 os->add_output_section_data(this->eh_frame_data_);
1341 this->added_eh_frame_data_ = true;
1347 // We couldn't handle this .eh_frame section for some reason.
1348 // Add it as a normal section.
1349 bool saw_sections_clause = this->script_options_->saw_sections_clause();
1350 *off = os->add_input_section(this, object, shndx, ".eh_frame", shdr,
1351 reloc_shndx, saw_sections_clause);
1352 this->have_added_input_section_ = true;
1354 if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))
1355 != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)))
1356 os->set_order(this->default_section_order(os, false));
1362 // Create and return the magic .eh_frame section. Create
1363 // .eh_frame_hdr also if appropriate. OBJECT is the object with the
1364 // input .eh_frame section; it may be NULL.
1367 Layout::make_eh_frame_section(const Relobj* object)
1369 // FIXME: On x86_64, this could use SHT_X86_64_UNWIND rather than
1371 Output_section* os = this->choose_output_section(object, ".eh_frame",
1372 elfcpp::SHT_PROGBITS,
1373 elfcpp::SHF_ALLOC, false,
1374 ORDER_EHFRAME, false);
1378 if (this->eh_frame_section_ == NULL)
1380 this->eh_frame_section_ = os;
1381 this->eh_frame_data_ = new Eh_frame();
1383 // For incremental linking, we do not optimize .eh_frame sections
1384 // or create a .eh_frame_hdr section.
1385 if (parameters->options().eh_frame_hdr() && !parameters->incremental())
1387 Output_section* hdr_os =
1388 this->choose_output_section(NULL, ".eh_frame_hdr",
1389 elfcpp::SHT_PROGBITS,
1390 elfcpp::SHF_ALLOC, false,
1391 ORDER_EHFRAME, false);
1395 Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os,
1396 this->eh_frame_data_);
1397 hdr_os->add_output_section_data(hdr_posd);
1399 hdr_os->set_after_input_sections();
1401 if (!this->script_options_->saw_phdrs_clause())
1403 Output_segment* hdr_oseg;
1404 hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
1406 hdr_oseg->add_output_section_to_nonload(hdr_os,
1410 this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
1418 // Add an exception frame for a PLT. This is called from target code.
1421 Layout::add_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data,
1422 size_t cie_length, const unsigned char* fde_data,
1425 if (parameters->incremental())
1427 // FIXME: Maybe this could work some day....
1430 Output_section* os = this->make_eh_frame_section(NULL);
1433 this->eh_frame_data_->add_ehframe_for_plt(plt, cie_data, cie_length,
1434 fde_data, fde_length);
1435 if (!this->added_eh_frame_data_)
1437 os->add_output_section_data(this->eh_frame_data_);
1438 this->added_eh_frame_data_ = true;
1442 // Scan a .debug_info or .debug_types section, and add summary
1443 // information to the .gdb_index section.
1445 template<int size, bool big_endian>
1447 Layout::add_to_gdb_index(bool is_type_unit,
1448 Sized_relobj<size, big_endian>* object,
1449 const unsigned char* symbols,
1452 unsigned int reloc_shndx,
1453 unsigned int reloc_type)
1455 if (this->gdb_index_data_ == NULL)
1457 Output_section* os = this->choose_output_section(NULL, ".gdb_index",
1458 elfcpp::SHT_PROGBITS, 0,
1459 false, ORDER_INVALID,
1464 this->gdb_index_data_ = new Gdb_index(os);
1465 os->add_output_section_data(this->gdb_index_data_);
1466 os->set_after_input_sections();
1469 this->gdb_index_data_->scan_debug_info(is_type_unit, object, symbols,
1470 symbols_size, shndx, reloc_shndx,
1474 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
1475 // the output section.
1478 Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
1479 elfcpp::Elf_Xword flags,
1480 Output_section_data* posd,
1481 Output_section_order order, bool is_relro)
1483 Output_section* os = this->choose_output_section(NULL, name, type, flags,
1484 false, order, is_relro);
1486 os->add_output_section_data(posd);
1490 // Map section flags to segment flags.
1493 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
1495 elfcpp::Elf_Word ret = elfcpp::PF_R;
1496 if ((flags & elfcpp::SHF_WRITE) != 0)
1497 ret |= elfcpp::PF_W;
1498 if ((flags & elfcpp::SHF_EXECINSTR) != 0)
1499 ret |= elfcpp::PF_X;
1503 // Make a new Output_section, and attach it to segments as
1504 // appropriate. ORDER is the order in which this section should
1505 // appear in the output segment. IS_RELRO is true if this is a relro
1506 // (read-only after relocations) section.
1509 Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
1510 elfcpp::Elf_Xword flags,
1511 Output_section_order order, bool is_relro)
1514 if ((flags & elfcpp::SHF_ALLOC) == 0
1515 && strcmp(parameters->options().compress_debug_sections(), "none") != 0
1516 && is_compressible_debug_section(name))
1517 os = new Output_compressed_section(¶meters->options(), name, type,
1519 else if ((flags & elfcpp::SHF_ALLOC) == 0
1520 && parameters->options().strip_debug_non_line()
1521 && strcmp(".debug_abbrev", name) == 0)
1523 os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
1525 if (this->debug_info_)
1526 this->debug_info_->set_abbreviations(this->debug_abbrev_);
1528 else if ((flags & elfcpp::SHF_ALLOC) == 0
1529 && parameters->options().strip_debug_non_line()
1530 && strcmp(".debug_info", name) == 0)
1532 os = this->debug_info_ = new Output_reduced_debug_info_section(
1534 if (this->debug_abbrev_)
1535 this->debug_info_->set_abbreviations(this->debug_abbrev_);
1539 // Sometimes .init_array*, .preinit_array* and .fini_array* do
1540 // not have correct section types. Force them here.
1541 if (type == elfcpp::SHT_PROGBITS)
1543 if (is_prefix_of(".init_array", name))
1544 type = elfcpp::SHT_INIT_ARRAY;
1545 else if (is_prefix_of(".preinit_array", name))
1546 type = elfcpp::SHT_PREINIT_ARRAY;
1547 else if (is_prefix_of(".fini_array", name))
1548 type = elfcpp::SHT_FINI_ARRAY;
1551 // FIXME: const_cast is ugly.
1552 Target* target = const_cast<Target*>(¶meters->target());
1553 os = target->make_output_section(name, type, flags);
1556 // With -z relro, we have to recognize the special sections by name.
1557 // There is no other way.
1558 bool is_relro_local = false;
1559 if (!this->script_options_->saw_sections_clause()
1560 && parameters->options().relro()
1561 && (flags & elfcpp::SHF_ALLOC) != 0
1562 && (flags & elfcpp::SHF_WRITE) != 0)
1564 if (type == elfcpp::SHT_PROGBITS)
1566 if ((flags & elfcpp::SHF_TLS) != 0)
1568 else if (strcmp(name, ".data.rel.ro") == 0)
1570 else if (strcmp(name, ".data.rel.ro.local") == 0)
1573 is_relro_local = true;
1575 else if (strcmp(name, ".ctors") == 0
1576 || strcmp(name, ".dtors") == 0
1577 || strcmp(name, ".jcr") == 0)
1580 else if (type == elfcpp::SHT_INIT_ARRAY
1581 || type == elfcpp::SHT_FINI_ARRAY
1582 || type == elfcpp::SHT_PREINIT_ARRAY)
1589 if (order == ORDER_INVALID && (flags & elfcpp::SHF_ALLOC) != 0)
1590 order = this->default_section_order(os, is_relro_local);
1592 os->set_order(order);
1594 parameters->target().new_output_section(os);
1596 this->section_list_.push_back(os);
1598 // The GNU linker by default sorts some sections by priority, so we
1599 // do the same. We need to know that this might happen before we
1600 // attach any input sections.
1601 if (!this->script_options_->saw_sections_clause()
1602 && !parameters->options().relocatable()
1603 && (strcmp(name, ".init_array") == 0
1604 || strcmp(name, ".fini_array") == 0
1605 || (!parameters->options().ctors_in_init_array()
1606 && (strcmp(name, ".ctors") == 0
1607 || strcmp(name, ".dtors") == 0))))
1608 os->set_may_sort_attached_input_sections();
1610 // Check for .stab*str sections, as .stab* sections need to link to
1612 if (type == elfcpp::SHT_STRTAB
1613 && !this->have_stabstr_section_
1614 && strncmp(name, ".stab", 5) == 0
1615 && strcmp(name + strlen(name) - 3, "str") == 0)
1616 this->have_stabstr_section_ = true;
1618 // During a full incremental link, we add patch space to most
1619 // PROGBITS and NOBITS sections. Flag those that may be
1620 // arbitrarily padded.
1621 if ((type == elfcpp::SHT_PROGBITS || type == elfcpp::SHT_NOBITS)
1622 && order != ORDER_INTERP
1623 && order != ORDER_INIT
1624 && order != ORDER_PLT
1625 && order != ORDER_FINI
1626 && order != ORDER_RELRO_LAST
1627 && order != ORDER_NON_RELRO_FIRST
1628 && strcmp(name, ".eh_frame") != 0
1629 && strcmp(name, ".ctors") != 0
1630 && strcmp(name, ".dtors") != 0
1631 && strcmp(name, ".jcr") != 0)
1633 os->set_is_patch_space_allowed();
1635 // Certain sections require "holes" to be filled with
1636 // specific fill patterns. These fill patterns may have
1637 // a minimum size, so we must prevent allocations from the
1638 // free list that leave a hole smaller than the minimum.
1639 if (strcmp(name, ".debug_info") == 0)
1640 os->set_free_space_fill(new Output_fill_debug_info(false));
1641 else if (strcmp(name, ".debug_types") == 0)
1642 os->set_free_space_fill(new Output_fill_debug_info(true));
1643 else if (strcmp(name, ".debug_line") == 0)
1644 os->set_free_space_fill(new Output_fill_debug_line());
1647 // If we have already attached the sections to segments, then we
1648 // need to attach this one now. This happens for sections created
1649 // directly by the linker.
1650 if (this->sections_are_attached_)
1651 this->attach_section_to_segment(¶meters->target(), os);
1656 // Return the default order in which a section should be placed in an
1657 // output segment. This function captures a lot of the ideas in
1658 // ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
1659 // linker created section is normally set when the section is created;
1660 // this function is used for input sections.
1662 Output_section_order
1663 Layout::default_section_order(Output_section* os, bool is_relro_local)
1665 gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1666 bool is_write = (os->flags() & elfcpp::SHF_WRITE) != 0;
1667 bool is_execinstr = (os->flags() & elfcpp::SHF_EXECINSTR) != 0;
1668 bool is_bss = false;
1673 case elfcpp::SHT_PROGBITS:
1675 case elfcpp::SHT_NOBITS:
1678 case elfcpp::SHT_RELA:
1679 case elfcpp::SHT_REL:
1681 return ORDER_DYNAMIC_RELOCS;
1683 case elfcpp::SHT_HASH:
1684 case elfcpp::SHT_DYNAMIC:
1685 case elfcpp::SHT_SHLIB:
1686 case elfcpp::SHT_DYNSYM:
1687 case elfcpp::SHT_GNU_HASH:
1688 case elfcpp::SHT_GNU_verdef:
1689 case elfcpp::SHT_GNU_verneed:
1690 case elfcpp::SHT_GNU_versym:
1692 return ORDER_DYNAMIC_LINKER;
1694 case elfcpp::SHT_NOTE:
1695 return is_write ? ORDER_RW_NOTE : ORDER_RO_NOTE;
1698 if ((os->flags() & elfcpp::SHF_TLS) != 0)
1699 return is_bss ? ORDER_TLS_BSS : ORDER_TLS_DATA;
1701 if (!is_bss && !is_write)
1705 if (strcmp(os->name(), ".init") == 0)
1707 else if (strcmp(os->name(), ".fini") == 0)
1710 return is_execinstr ? ORDER_TEXT : ORDER_READONLY;
1714 return is_relro_local ? ORDER_RELRO_LOCAL : ORDER_RELRO;
1716 if (os->is_small_section())
1717 return is_bss ? ORDER_SMALL_BSS : ORDER_SMALL_DATA;
1718 if (os->is_large_section())
1719 return is_bss ? ORDER_LARGE_BSS : ORDER_LARGE_DATA;
1721 return is_bss ? ORDER_BSS : ORDER_DATA;
1724 // Attach output sections to segments. This is called after we have
1725 // seen all the input sections.
1728 Layout::attach_sections_to_segments(const Target* target)
1730 for (Section_list::iterator p = this->section_list_.begin();
1731 p != this->section_list_.end();
1733 this->attach_section_to_segment(target, *p);
1735 this->sections_are_attached_ = true;
1738 // Attach an output section to a segment.
1741 Layout::attach_section_to_segment(const Target* target, Output_section* os)
1743 if ((os->flags() & elfcpp::SHF_ALLOC) == 0)
1744 this->unattached_section_list_.push_back(os);
1746 this->attach_allocated_section_to_segment(target, os);
1749 // Attach an allocated output section to a segment.
1752 Layout::attach_allocated_section_to_segment(const Target* target,
1755 elfcpp::Elf_Xword flags = os->flags();
1756 gold_assert((flags & elfcpp::SHF_ALLOC) != 0);
1758 if (parameters->options().relocatable())
1761 // If we have a SECTIONS clause, we can't handle the attachment to
1762 // segments until after we've seen all the sections.
1763 if (this->script_options_->saw_sections_clause())
1766 gold_assert(!this->script_options_->saw_phdrs_clause());
1768 // This output section goes into a PT_LOAD segment.
1770 elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
1772 // If this output section's segment has extra flags that need to be set,
1773 // coming from a linker plugin, do that.
1774 seg_flags |= os->extra_segment_flags();
1776 // Check for --section-start.
1778 bool is_address_set = parameters->options().section_start(os->name(), &addr);
1780 // In general the only thing we really care about for PT_LOAD
1781 // segments is whether or not they are writable or executable,
1782 // so that is how we search for them.
1783 // Large data sections also go into their own PT_LOAD segment.
1784 // People who need segments sorted on some other basis will
1785 // have to use a linker script.
1787 Segment_list::const_iterator p;
1788 if (!os->is_unique_segment())
1790 for (p = this->segment_list_.begin();
1791 p != this->segment_list_.end();
1794 if ((*p)->type() != elfcpp::PT_LOAD)
1796 if ((*p)->is_unique_segment())
1798 if (!parameters->options().omagic()
1799 && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
1801 if ((target->isolate_execinstr() || parameters->options().rosegment())
1802 && ((*p)->flags() & elfcpp::PF_X) != (seg_flags & elfcpp::PF_X))
1804 // If -Tbss was specified, we need to separate the data and BSS
1806 if (parameters->options().user_set_Tbss())
1808 if ((os->type() == elfcpp::SHT_NOBITS)
1809 == (*p)->has_any_data_sections())
1812 if (os->is_large_data_section() && !(*p)->is_large_data_segment())
1817 if ((*p)->are_addresses_set())
1820 (*p)->add_initial_output_data(os);
1821 (*p)->update_flags_for_output_section(seg_flags);
1822 (*p)->set_addresses(addr, addr);
1826 (*p)->add_output_section_to_load(this, os, seg_flags);
1831 if (p == this->segment_list_.end()
1832 || os->is_unique_segment())
1834 Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
1836 if (os->is_large_data_section())
1837 oseg->set_is_large_data_segment();
1838 oseg->add_output_section_to_load(this, os, seg_flags);
1840 oseg->set_addresses(addr, addr);
1841 // Check if segment should be marked unique. For segments marked
1842 // unique by linker plugins, set the new alignment if specified.
1843 if (os->is_unique_segment())
1845 oseg->set_is_unique_segment();
1846 if (os->segment_alignment() != 0)
1847 oseg->set_minimum_p_align(os->segment_alignment());
1851 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1853 if (os->type() == elfcpp::SHT_NOTE)
1855 // See if we already have an equivalent PT_NOTE segment.
1856 for (p = this->segment_list_.begin();
1857 p != segment_list_.end();
1860 if ((*p)->type() == elfcpp::PT_NOTE
1861 && (((*p)->flags() & elfcpp::PF_W)
1862 == (seg_flags & elfcpp::PF_W)))
1864 (*p)->add_output_section_to_nonload(os, seg_flags);
1869 if (p == this->segment_list_.end())
1871 Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
1873 oseg->add_output_section_to_nonload(os, seg_flags);
1877 // If we see a loadable SHF_TLS section, we create a PT_TLS
1878 // segment. There can only be one such segment.
1879 if ((flags & elfcpp::SHF_TLS) != 0)
1881 if (this->tls_segment_ == NULL)
1882 this->make_output_segment(elfcpp::PT_TLS, seg_flags);
1883 this->tls_segment_->add_output_section_to_nonload(os, seg_flags);
1886 // If -z relro is in effect, and we see a relro section, we create a
1887 // PT_GNU_RELRO segment. There can only be one such segment.
1888 if (os->is_relro() && parameters->options().relro())
1890 gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
1891 if (this->relro_segment_ == NULL)
1892 this->make_output_segment(elfcpp::PT_GNU_RELRO, seg_flags);
1893 this->relro_segment_->add_output_section_to_nonload(os, seg_flags);
1896 // If we see a section named .interp, put it into a PT_INTERP
1897 // segment. This seems broken to me, but this is what GNU ld does,
1898 // and glibc expects it.
1899 if (strcmp(os->name(), ".interp") == 0
1900 && !this->script_options_->saw_phdrs_clause())
1902 if (this->interp_segment_ == NULL)
1903 this->make_output_segment(elfcpp::PT_INTERP, seg_flags);
1905 gold_warning(_("multiple '.interp' sections in input files "
1906 "may cause confusing PT_INTERP segment"));
1907 this->interp_segment_->add_output_section_to_nonload(os, seg_flags);
1911 // Make an output section for a script.
1914 Layout::make_output_section_for_script(
1916 Script_sections::Section_type section_type)
1918 name = this->namepool_.add(name, false, NULL);
1919 elfcpp::Elf_Xword sh_flags = elfcpp::SHF_ALLOC;
1920 if (section_type == Script_sections::ST_NOLOAD)
1922 Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
1923 sh_flags, ORDER_INVALID,
1925 os->set_found_in_sections_clause();
1926 if (section_type == Script_sections::ST_NOLOAD)
1927 os->set_is_noload();
1931 // Return the number of segments we expect to see.
1934 Layout::expected_segment_count() const
1936 size_t ret = this->segment_list_.size();
1938 // If we didn't see a SECTIONS clause in a linker script, we should
1939 // already have the complete list of segments. Otherwise we ask the
1940 // SECTIONS clause how many segments it expects, and add in the ones
1941 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1943 if (!this->script_options_->saw_sections_clause())
1947 const Script_sections* ss = this->script_options_->script_sections();
1948 return ret + ss->expected_segment_count(this);
1952 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
1953 // is whether we saw a .note.GNU-stack section in the object file.
1954 // GNU_STACK_FLAGS is the section flags. The flags give the
1955 // protection required for stack memory. We record this in an
1956 // executable as a PT_GNU_STACK segment. If an object file does not
1957 // have a .note.GNU-stack segment, we must assume that it is an old
1958 // object. On some targets that will force an executable stack.
1961 Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags,
1964 if (!seen_gnu_stack)
1966 this->input_without_gnu_stack_note_ = true;
1967 if (parameters->options().warn_execstack()
1968 && parameters->target().is_default_stack_executable())
1969 gold_warning(_("%s: missing .note.GNU-stack section"
1970 " implies executable stack"),
1971 obj->name().c_str());
1975 this->input_with_gnu_stack_note_ = true;
1976 if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
1978 this->input_requires_executable_stack_ = true;
1979 if (parameters->options().warn_execstack()
1980 || parameters->options().is_stack_executable())
1981 gold_warning(_("%s: requires executable stack"),
1982 obj->name().c_str());
1987 // Create automatic note sections.
1990 Layout::create_notes()
1992 this->create_gold_note();
1993 this->create_executable_stack_info();
1994 this->create_build_id();
1997 // Create the dynamic sections which are needed before we read the
2001 Layout::create_initial_dynamic_sections(Symbol_table* symtab)
2003 if (parameters->doing_static_link())
2006 this->dynamic_section_ = this->choose_output_section(NULL, ".dynamic",
2007 elfcpp::SHT_DYNAMIC,
2009 | elfcpp::SHF_WRITE),
2013 // A linker script may discard .dynamic, so check for NULL.
2014 if (this->dynamic_section_ != NULL)
2016 this->dynamic_symbol_ =
2017 symtab->define_in_output_data("_DYNAMIC", NULL,
2018 Symbol_table::PREDEFINED,
2019 this->dynamic_section_, 0, 0,
2020 elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
2021 elfcpp::STV_HIDDEN, 0, false, false);
2023 this->dynamic_data_ = new Output_data_dynamic(&this->dynpool_);
2025 this->dynamic_section_->add_output_section_data(this->dynamic_data_);
2029 // For each output section whose name can be represented as C symbol,
2030 // define __start and __stop symbols for the section. This is a GNU
2034 Layout::define_section_symbols(Symbol_table* symtab)
2036 for (Section_list::const_iterator p = this->section_list_.begin();
2037 p != this->section_list_.end();
2040 const char* const name = (*p)->name();
2041 if (is_cident(name))
2043 const std::string name_string(name);
2044 const std::string start_name(cident_section_start_prefix
2046 const std::string stop_name(cident_section_stop_prefix
2049 symtab->define_in_output_data(start_name.c_str(),
2051 Symbol_table::PREDEFINED,
2057 elfcpp::STV_DEFAULT,
2059 false, // offset_is_from_end
2060 true); // only_if_ref
2062 symtab->define_in_output_data(stop_name.c_str(),
2064 Symbol_table::PREDEFINED,
2070 elfcpp::STV_DEFAULT,
2072 true, // offset_is_from_end
2073 true); // only_if_ref
2078 // Define symbols for group signatures.
2081 Layout::define_group_signatures(Symbol_table* symtab)
2083 for (Group_signatures::iterator p = this->group_signatures_.begin();
2084 p != this->group_signatures_.end();
2087 Symbol* sym = symtab->lookup(p->signature, NULL);
2089 p->section->set_info_symndx(sym);
2092 // Force the name of the group section to the group
2093 // signature, and use the group's section symbol as the
2094 // signature symbol.
2095 if (strcmp(p->section->name(), p->signature) != 0)
2097 const char* name = this->namepool_.add(p->signature,
2099 p->section->set_name(name);
2101 p->section->set_needs_symtab_index();
2102 p->section->set_info_section_symndx(p->section);
2106 this->group_signatures_.clear();
2109 // Find the first read-only PT_LOAD segment, creating one if
2113 Layout::find_first_load_seg(const Target* target)
2115 Output_segment* best = NULL;
2116 for (Segment_list::const_iterator p = this->segment_list_.begin();
2117 p != this->segment_list_.end();
2120 if ((*p)->type() == elfcpp::PT_LOAD
2121 && ((*p)->flags() & elfcpp::PF_R) != 0
2122 && (parameters->options().omagic()
2123 || ((*p)->flags() & elfcpp::PF_W) == 0)
2124 && (!target->isolate_execinstr()
2125 || ((*p)->flags() & elfcpp::PF_X) == 0))
2127 if (best == NULL || this->segment_precedes(*p, best))
2134 gold_assert(!this->script_options_->saw_phdrs_clause());
2136 Output_segment* load_seg = this->make_output_segment(elfcpp::PT_LOAD,
2141 // Save states of all current output segments. Store saved states
2142 // in SEGMENT_STATES.
2145 Layout::save_segments(Segment_states* segment_states)
2147 for (Segment_list::const_iterator p = this->segment_list_.begin();
2148 p != this->segment_list_.end();
2151 Output_segment* segment = *p;
2153 Output_segment* copy = new Output_segment(*segment);
2154 (*segment_states)[segment] = copy;
2158 // Restore states of output segments and delete any segment not found in
2162 Layout::restore_segments(const Segment_states* segment_states)
2164 // Go through the segment list and remove any segment added in the
2166 this->tls_segment_ = NULL;
2167 this->relro_segment_ = NULL;
2168 Segment_list::iterator list_iter = this->segment_list_.begin();
2169 while (list_iter != this->segment_list_.end())
2171 Output_segment* segment = *list_iter;
2172 Segment_states::const_iterator states_iter =
2173 segment_states->find(segment);
2174 if (states_iter != segment_states->end())
2176 const Output_segment* copy = states_iter->second;
2177 // Shallow copy to restore states.
2180 // Also fix up TLS and RELRO segment pointers as appropriate.
2181 if (segment->type() == elfcpp::PT_TLS)
2182 this->tls_segment_ = segment;
2183 else if (segment->type() == elfcpp::PT_GNU_RELRO)
2184 this->relro_segment_ = segment;
2190 list_iter = this->segment_list_.erase(list_iter);
2191 // This is a segment created during section layout. It should be
2192 // safe to remove it since we should have removed all pointers to it.
2198 // Clean up after relaxation so that sections can be laid out again.
2201 Layout::clean_up_after_relaxation()
2203 // Restore the segments to point state just prior to the relaxation loop.
2204 Script_sections* script_section = this->script_options_->script_sections();
2205 script_section->release_segments();
2206 this->restore_segments(this->segment_states_);
2208 // Reset section addresses and file offsets
2209 for (Section_list::iterator p = this->section_list_.begin();
2210 p != this->section_list_.end();
2213 (*p)->restore_states();
2215 // If an input section changes size because of relaxation,
2216 // we need to adjust the section offsets of all input sections.
2217 // after such a section.
2218 if ((*p)->section_offsets_need_adjustment())
2219 (*p)->adjust_section_offsets();
2221 (*p)->reset_address_and_file_offset();
2224 // Reset special output object address and file offsets.
2225 for (Data_list::iterator p = this->special_output_list_.begin();
2226 p != this->special_output_list_.end();
2228 (*p)->reset_address_and_file_offset();
2230 // A linker script may have created some output section data objects.
2231 // They are useless now.
2232 for (Output_section_data_list::const_iterator p =
2233 this->script_output_section_data_list_.begin();
2234 p != this->script_output_section_data_list_.end();
2237 this->script_output_section_data_list_.clear();
2240 // Prepare for relaxation.
2243 Layout::prepare_for_relaxation()
2245 // Create an relaxation debug check if in debugging mode.
2246 if (is_debugging_enabled(DEBUG_RELAXATION))
2247 this->relaxation_debug_check_ = new Relaxation_debug_check();
2249 // Save segment states.
2250 this->segment_states_ = new Segment_states();
2251 this->save_segments(this->segment_states_);
2253 for(Section_list::const_iterator p = this->section_list_.begin();
2254 p != this->section_list_.end();
2256 (*p)->save_states();
2258 if (is_debugging_enabled(DEBUG_RELAXATION))
2259 this->relaxation_debug_check_->check_output_data_for_reset_values(
2260 this->section_list_, this->special_output_list_);
2262 // Also enable recording of output section data from scripts.
2263 this->record_output_section_data_from_script_ = true;
2266 // Relaxation loop body: If target has no relaxation, this runs only once
2267 // Otherwise, the target relaxation hook is called at the end of
2268 // each iteration. If the hook returns true, it means re-layout of
2269 // section is required.
2271 // The number of segments created by a linking script without a PHDRS
2272 // clause may be affected by section sizes and alignments. There is
2273 // a remote chance that relaxation causes different number of PT_LOAD
2274 // segments are created and sections are attached to different segments.
2275 // Therefore, we always throw away all segments created during section
2276 // layout. In order to be able to restart the section layout, we keep
2277 // a copy of the segment list right before the relaxation loop and use
2278 // that to restore the segments.
2280 // PASS is the current relaxation pass number.
2281 // SYMTAB is a symbol table.
2282 // PLOAD_SEG is the address of a pointer for the load segment.
2283 // PHDR_SEG is a pointer to the PHDR segment.
2284 // SEGMENT_HEADERS points to the output segment header.
2285 // FILE_HEADER points to the output file header.
2286 // PSHNDX is the address to store the output section index.
2289 Layout::relaxation_loop_body(
2292 Symbol_table* symtab,
2293 Output_segment** pload_seg,
2294 Output_segment* phdr_seg,
2295 Output_segment_headers* segment_headers,
2296 Output_file_header* file_header,
2297 unsigned int* pshndx)
2299 // If this is not the first iteration, we need to clean up after
2300 // relaxation so that we can lay out the sections again.
2302 this->clean_up_after_relaxation();
2304 // If there is a SECTIONS clause, put all the input sections into
2305 // the required order.
2306 Output_segment* load_seg;
2307 if (this->script_options_->saw_sections_clause())
2308 load_seg = this->set_section_addresses_from_script(symtab);
2309 else if (parameters->options().relocatable())
2312 load_seg = this->find_first_load_seg(target);
2314 if (parameters->options().oformat_enum()
2315 != General_options::OBJECT_FORMAT_ELF)
2318 // If the user set the address of the text segment, that may not be
2319 // compatible with putting the segment headers and file headers into
2321 if (parameters->options().user_set_Ttext()
2322 && parameters->options().Ttext() % target->abi_pagesize() != 0)
2328 gold_assert(phdr_seg == NULL
2330 || this->script_options_->saw_sections_clause());
2332 // If the address of the load segment we found has been set by
2333 // --section-start rather than by a script, then adjust the VMA and
2334 // LMA downward if possible to include the file and section headers.
2335 uint64_t header_gap = 0;
2336 if (load_seg != NULL
2337 && load_seg->are_addresses_set()
2338 && !this->script_options_->saw_sections_clause()
2339 && !parameters->options().relocatable())
2341 file_header->finalize_data_size();
2342 segment_headers->finalize_data_size();
2343 size_t sizeof_headers = (file_header->data_size()
2344 + segment_headers->data_size());
2345 const uint64_t abi_pagesize = target->abi_pagesize();
2346 uint64_t hdr_paddr = load_seg->paddr() - sizeof_headers;
2347 hdr_paddr &= ~(abi_pagesize - 1);
2348 uint64_t subtract = load_seg->paddr() - hdr_paddr;
2349 if (load_seg->paddr() < subtract || load_seg->vaddr() < subtract)
2353 load_seg->set_addresses(load_seg->vaddr() - subtract,
2354 load_seg->paddr() - subtract);
2355 header_gap = subtract - sizeof_headers;
2359 // Lay out the segment headers.
2360 if (!parameters->options().relocatable())
2362 gold_assert(segment_headers != NULL);
2363 if (header_gap != 0 && load_seg != NULL)
2365 Output_data_zero_fill* z = new Output_data_zero_fill(header_gap, 1);
2366 load_seg->add_initial_output_data(z);
2368 if (load_seg != NULL)
2369 load_seg->add_initial_output_data(segment_headers);
2370 if (phdr_seg != NULL)
2371 phdr_seg->add_initial_output_data(segment_headers);
2374 // Lay out the file header.
2375 if (load_seg != NULL)
2376 load_seg->add_initial_output_data(file_header);
2378 if (this->script_options_->saw_phdrs_clause()
2379 && !parameters->options().relocatable())
2381 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2382 // clause in a linker script.
2383 Script_sections* ss = this->script_options_->script_sections();
2384 ss->put_headers_in_phdrs(file_header, segment_headers);
2387 // We set the output section indexes in set_segment_offsets and
2388 // set_section_indexes.
2391 // Set the file offsets of all the segments, and all the sections
2394 if (!parameters->options().relocatable())
2395 off = this->set_segment_offsets(target, load_seg, pshndx);
2397 off = this->set_relocatable_section_offsets(file_header, pshndx);
2399 // Verify that the dummy relaxation does not change anything.
2400 if (is_debugging_enabled(DEBUG_RELAXATION))
2403 this->relaxation_debug_check_->read_sections(this->section_list_);
2405 this->relaxation_debug_check_->verify_sections(this->section_list_);
2408 *pload_seg = load_seg;
2412 // By default, gold groups input sections with certain prefixes. This
2413 // function returns true if this section name NAME contains such a prefix.
2416 Layout::is_section_name_prefix_grouped(const char *name)
2418 if (is_prefix_of(".text.unlikely", name)
2419 || is_prefix_of(".text.startup", name)
2420 || is_prefix_of(".text.hot", name))
2426 // Search the list of patterns and find the postion of the given section
2427 // name in the output section. If the section name matches a glob
2428 // pattern and a non-glob name, then the non-glob position takes
2429 // precedence. Return 0 if no match is found.
2432 Layout::find_section_order_index(const std::string& section_name)
2434 Unordered_map<std::string, unsigned int>::iterator map_it;
2435 map_it = this->input_section_position_.find(section_name);
2436 if (map_it != this->input_section_position_.end())
2437 return map_it->second;
2439 // Absolute match failed. Linear search the glob patterns.
2440 std::vector<std::string>::iterator it;
2441 for (it = this->input_section_glob_.begin();
2442 it != this->input_section_glob_.end();
2445 if (fnmatch((*it).c_str(), section_name.c_str(), FNM_NOESCAPE) == 0)
2447 map_it = this->input_section_position_.find(*it);
2448 gold_assert(map_it != this->input_section_position_.end());
2449 return map_it->second;
2455 // Read the sequence of input sections from the file specified with
2456 // option --section-ordering-file.
2459 Layout::read_layout_from_file()
2461 const char* filename = parameters->options().section_ordering_file();
2467 gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2468 filename, strerror(errno));
2470 std::getline(in, line); // this chops off the trailing \n, if any
2471 unsigned int position = 1;
2472 this->set_section_ordering_specified();
2476 if (!line.empty() && line[line.length() - 1] == '\r') // Windows
2477 line.resize(line.length() - 1);
2478 // Ignore comments, beginning with '#'
2481 std::getline(in, line);
2484 this->input_section_position_[line] = position;
2485 // Store all glob patterns in a vector.
2486 if (is_wildcard_string(line.c_str()))
2487 this->input_section_glob_.push_back(line);
2489 std::getline(in, line);
2493 // Finalize the layout. When this is called, we have created all the
2494 // output sections and all the output segments which are based on
2495 // input sections. We have several things to do, and we have to do
2496 // them in the right order, so that we get the right results correctly
2499 // 1) Finalize the list of output segments and create the segment
2502 // 2) Finalize the dynamic symbol table and associated sections.
2504 // 3) Determine the final file offset of all the output segments.
2506 // 4) Determine the final file offset of all the SHF_ALLOC output
2509 // 5) Create the symbol table sections and the section name table
2512 // 6) Finalize the symbol table: set symbol values to their final
2513 // value and make a final determination of which symbols are going
2514 // into the output symbol table.
2516 // 7) Create the section table header.
2518 // 8) Determine the final file offset of all the output sections which
2519 // are not SHF_ALLOC, including the section table header.
2521 // 9) Finalize the ELF file header.
2523 // This function returns the size of the output file.
2526 Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
2527 Target* target, const Task* task)
2529 target->finalize_sections(this, input_objects, symtab);
2531 this->count_local_symbols(task, input_objects);
2533 this->link_stabs_sections();
2535 Output_segment* phdr_seg = NULL;
2536 if (!parameters->options().relocatable() && !parameters->doing_static_link())
2538 // There was a dynamic object in the link. We need to create
2539 // some information for the dynamic linker.
2541 // Create the PT_PHDR segment which will hold the program
2543 if (!this->script_options_->saw_phdrs_clause())
2544 phdr_seg = this->make_output_segment(elfcpp::PT_PHDR, elfcpp::PF_R);
2546 // Create the dynamic symbol table, including the hash table.
2547 Output_section* dynstr;
2548 std::vector<Symbol*> dynamic_symbols;
2549 unsigned int local_dynamic_count;
2550 Versions versions(*this->script_options()->version_script_info(),
2552 this->create_dynamic_symtab(input_objects, symtab, &dynstr,
2553 &local_dynamic_count, &dynamic_symbols,
2556 // Create the .interp section to hold the name of the
2557 // interpreter, and put it in a PT_INTERP segment. Don't do it
2558 // if we saw a .interp section in an input file.
2559 if ((!parameters->options().shared()
2560 || parameters->options().dynamic_linker() != NULL)
2561 && this->interp_segment_ == NULL)
2562 this->create_interp(target);
2564 // Finish the .dynamic section to hold the dynamic data, and put
2565 // it in a PT_DYNAMIC segment.
2566 this->finish_dynamic_section(input_objects, symtab);
2568 // We should have added everything we need to the dynamic string
2570 this->dynpool_.set_string_offsets();
2572 // Create the version sections. We can't do this until the
2573 // dynamic string table is complete.
2574 this->create_version_sections(&versions, symtab, local_dynamic_count,
2575 dynamic_symbols, dynstr);
2577 // Set the size of the _DYNAMIC symbol. We can't do this until
2578 // after we call create_version_sections.
2579 this->set_dynamic_symbol_size(symtab);
2582 // Create segment headers.
2583 Output_segment_headers* segment_headers =
2584 (parameters->options().relocatable()
2586 : new Output_segment_headers(this->segment_list_));
2588 // Lay out the file header.
2589 Output_file_header* file_header = new Output_file_header(target, symtab,
2592 this->special_output_list_.push_back(file_header);
2593 if (segment_headers != NULL)
2594 this->special_output_list_.push_back(segment_headers);
2596 // Find approriate places for orphan output sections if we are using
2598 if (this->script_options_->saw_sections_clause())
2599 this->place_orphan_sections_in_script();
2601 Output_segment* load_seg;
2606 // Take a snapshot of the section layout as needed.
2607 if (target->may_relax())
2608 this->prepare_for_relaxation();
2610 // Run the relaxation loop to lay out sections.
2613 off = this->relaxation_loop_body(pass, target, symtab, &load_seg,
2614 phdr_seg, segment_headers, file_header,
2618 while (target->may_relax()
2619 && target->relax(pass, input_objects, symtab, this, task));
2621 // If there is a load segment that contains the file and program headers,
2622 // provide a symbol __ehdr_start pointing there.
2623 // A program can use this to examine itself robustly.
2624 if (load_seg != NULL)
2625 symtab->define_in_output_segment("__ehdr_start", NULL,
2626 Symbol_table::PREDEFINED, load_seg, 0, 0,
2627 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2628 elfcpp::STV_DEFAULT, 0,
2629 Symbol::SEGMENT_START, true);
2631 // Set the file offsets of all the non-data sections we've seen so
2632 // far which don't have to wait for the input sections. We need
2633 // this in order to finalize local symbols in non-allocated
2635 off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
2637 // Set the section indexes of all unallocated sections seen so far,
2638 // in case any of them are somehow referenced by a symbol.
2639 shndx = this->set_section_indexes(shndx);
2641 // Create the symbol table sections.
2642 this->create_symtab_sections(input_objects, symtab, shndx, &off);
2643 if (!parameters->doing_static_link())
2644 this->assign_local_dynsym_offsets(input_objects);
2646 // Process any symbol assignments from a linker script. This must
2647 // be called after the symbol table has been finalized.
2648 this->script_options_->finalize_symbols(symtab, this);
2650 // Create the incremental inputs sections.
2651 if (this->incremental_inputs_)
2653 this->incremental_inputs_->finalize();
2654 this->create_incremental_info_sections(symtab);
2657 // Create the .shstrtab section.
2658 Output_section* shstrtab_section = this->create_shstrtab();
2660 // Set the file offsets of the rest of the non-data sections which
2661 // don't have to wait for the input sections.
2662 off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
2664 // Now that all sections have been created, set the section indexes
2665 // for any sections which haven't been done yet.
2666 shndx = this->set_section_indexes(shndx);
2668 // Create the section table header.
2669 this->create_shdrs(shstrtab_section, &off);
2671 // If there are no sections which require postprocessing, we can
2672 // handle the section names now, and avoid a resize later.
2673 if (!this->any_postprocessing_sections_)
2675 off = this->set_section_offsets(off,
2676 POSTPROCESSING_SECTIONS_PASS);
2678 this->set_section_offsets(off,
2679 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
2682 file_header->set_section_info(this->section_headers_, shstrtab_section);
2684 // Now we know exactly where everything goes in the output file
2685 // (except for non-allocated sections which require postprocessing).
2686 Output_data::layout_complete();
2688 this->output_file_size_ = off;
2693 // Create a note header following the format defined in the ELF ABI.
2694 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
2695 // of the section to create, DESCSZ is the size of the descriptor.
2696 // ALLOCATE is true if the section should be allocated in memory.
2697 // This returns the new note section. It sets *TRAILING_PADDING to
2698 // the number of trailing zero bytes required.
2701 Layout::create_note(const char* name, int note_type,
2702 const char* section_name, size_t descsz,
2703 bool allocate, size_t* trailing_padding)
2705 // Authorities all agree that the values in a .note field should
2706 // be aligned on 4-byte boundaries for 32-bit binaries. However,
2707 // they differ on what the alignment is for 64-bit binaries.
2708 // The GABI says unambiguously they take 8-byte alignment:
2709 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2710 // Other documentation says alignment should always be 4 bytes:
2711 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2712 // GNU ld and GNU readelf both support the latter (at least as of
2713 // version 2.16.91), and glibc always generates the latter for
2714 // .note.ABI-tag (as of version 1.6), so that's the one we go with
2716 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
2717 const int size = parameters->target().get_size();
2719 const int size = 32;
2722 // The contents of the .note section.
2723 size_t namesz = strlen(name) + 1;
2724 size_t aligned_namesz = align_address(namesz, size / 8);
2725 size_t aligned_descsz = align_address(descsz, size / 8);
2727 size_t notehdrsz = 3 * (size / 8) + aligned_namesz;
2729 unsigned char* buffer = new unsigned char[notehdrsz];
2730 memset(buffer, 0, notehdrsz);
2732 bool is_big_endian = parameters->target().is_big_endian();
2738 elfcpp::Swap<32, false>::writeval(buffer, namesz);
2739 elfcpp::Swap<32, false>::writeval(buffer + 4, descsz);
2740 elfcpp::Swap<32, false>::writeval(buffer + 8, note_type);
2744 elfcpp::Swap<32, true>::writeval(buffer, namesz);
2745 elfcpp::Swap<32, true>::writeval(buffer + 4, descsz);
2746 elfcpp::Swap<32, true>::writeval(buffer + 8, note_type);
2749 else if (size == 64)
2753 elfcpp::Swap<64, false>::writeval(buffer, namesz);
2754 elfcpp::Swap<64, false>::writeval(buffer + 8, descsz);
2755 elfcpp::Swap<64, false>::writeval(buffer + 16, note_type);
2759 elfcpp::Swap<64, true>::writeval(buffer, namesz);
2760 elfcpp::Swap<64, true>::writeval(buffer + 8, descsz);
2761 elfcpp::Swap<64, true>::writeval(buffer + 16, note_type);
2767 memcpy(buffer + 3 * (size / 8), name, namesz);
2769 elfcpp::Elf_Xword flags = 0;
2770 Output_section_order order = ORDER_INVALID;
2773 flags = elfcpp::SHF_ALLOC;
2774 order = ORDER_RO_NOTE;
2776 Output_section* os = this->choose_output_section(NULL, section_name,
2778 flags, false, order, false);
2782 Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
2785 os->add_output_section_data(posd);
2787 *trailing_padding = aligned_descsz - descsz;
2792 // For an executable or shared library, create a note to record the
2793 // version of gold used to create the binary.
2796 Layout::create_gold_note()
2798 if (parameters->options().relocatable()
2799 || parameters->incremental_update())
2802 std::string desc = std::string("gold ") + gold::get_version_string();
2804 size_t trailing_padding;
2805 Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
2806 ".note.gnu.gold-version", desc.size(),
2807 false, &trailing_padding);
2811 Output_section_data* posd = new Output_data_const(desc, 4);
2812 os->add_output_section_data(posd);
2814 if (trailing_padding > 0)
2816 posd = new Output_data_zero_fill(trailing_padding, 0);
2817 os->add_output_section_data(posd);
2821 // Record whether the stack should be executable. This can be set
2822 // from the command line using the -z execstack or -z noexecstack
2823 // options. Otherwise, if any input file has a .note.GNU-stack
2824 // section with the SHF_EXECINSTR flag set, the stack should be
2825 // executable. Otherwise, if at least one input file a
2826 // .note.GNU-stack section, and some input file has no .note.GNU-stack
2827 // section, we use the target default for whether the stack should be
2828 // executable. Otherwise, we don't generate a stack note. When
2829 // generating a object file, we create a .note.GNU-stack section with
2830 // the appropriate marking. When generating an executable or shared
2831 // library, we create a PT_GNU_STACK segment.
2834 Layout::create_executable_stack_info()
2836 bool is_stack_executable;
2837 if (parameters->options().is_execstack_set())
2838 is_stack_executable = parameters->options().is_stack_executable();
2839 else if (!this->input_with_gnu_stack_note_)
2843 if (this->input_requires_executable_stack_)
2844 is_stack_executable = true;
2845 else if (this->input_without_gnu_stack_note_)
2846 is_stack_executable =
2847 parameters->target().is_default_stack_executable();
2849 is_stack_executable = false;
2852 if (parameters->options().relocatable())
2854 const char* name = this->namepool_.add(".note.GNU-stack", false, NULL);
2855 elfcpp::Elf_Xword flags = 0;
2856 if (is_stack_executable)
2857 flags |= elfcpp::SHF_EXECINSTR;
2858 this->make_output_section(name, elfcpp::SHT_PROGBITS, flags,
2859 ORDER_INVALID, false);
2863 if (this->script_options_->saw_phdrs_clause())
2865 int flags = elfcpp::PF_R | elfcpp::PF_W;
2866 if (is_stack_executable)
2867 flags |= elfcpp::PF_X;
2868 this->make_output_segment(elfcpp::PT_GNU_STACK, flags);
2872 // If --build-id was used, set up the build ID note.
2875 Layout::create_build_id()
2877 if (!parameters->options().user_set_build_id())
2880 const char* style = parameters->options().build_id();
2881 if (strcmp(style, "none") == 0)
2884 // Set DESCSZ to the size of the note descriptor. When possible,
2885 // set DESC to the note descriptor contents.
2888 if (strcmp(style, "md5") == 0)
2890 else if (strcmp(style, "sha1") == 0)
2892 else if (strcmp(style, "uuid") == 0)
2894 const size_t uuidsz = 128 / 8;
2896 char buffer[uuidsz];
2897 memset(buffer, 0, uuidsz);
2899 int descriptor = open_descriptor(-1, "/dev/urandom", O_RDONLY);
2901 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
2905 ssize_t got = ::read(descriptor, buffer, uuidsz);
2906 release_descriptor(descriptor, true);
2908 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
2909 else if (static_cast<size_t>(got) != uuidsz)
2910 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
2914 desc.assign(buffer, uuidsz);
2917 else if (strncmp(style, "0x", 2) == 0)
2920 const char* p = style + 2;
2923 if (hex_p(p[0]) && hex_p(p[1]))
2925 char c = (hex_value(p[0]) << 4) | hex_value(p[1]);
2929 else if (*p == '-' || *p == ':')
2932 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
2935 descsz = desc.size();
2938 gold_fatal(_("unrecognized --build-id argument '%s'"), style);
2941 size_t trailing_padding;
2942 Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID,
2943 ".note.gnu.build-id", descsz, true,
2950 // We know the value already, so we fill it in now.
2951 gold_assert(desc.size() == descsz);
2953 Output_section_data* posd = new Output_data_const(desc, 4);
2954 os->add_output_section_data(posd);
2956 if (trailing_padding != 0)
2958 posd = new Output_data_zero_fill(trailing_padding, 0);
2959 os->add_output_section_data(posd);
2964 // We need to compute a checksum after we have completed the
2966 gold_assert(trailing_padding == 0);
2967 this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
2968 os->add_output_section_data(this->build_id_note_);
2972 // If we have both .stabXX and .stabXXstr sections, then the sh_link
2973 // field of the former should point to the latter. I'm not sure who
2974 // started this, but the GNU linker does it, and some tools depend
2978 Layout::link_stabs_sections()
2980 if (!this->have_stabstr_section_)
2983 for (Section_list::iterator p = this->section_list_.begin();
2984 p != this->section_list_.end();
2987 if ((*p)->type() != elfcpp::SHT_STRTAB)
2990 const char* name = (*p)->name();
2991 if (strncmp(name, ".stab", 5) != 0)
2994 size_t len = strlen(name);
2995 if (strcmp(name + len - 3, "str") != 0)
2998 std::string stab_name(name, len - 3);
2999 Output_section* stab_sec;
3000 stab_sec = this->find_output_section(stab_name.c_str());
3001 if (stab_sec != NULL)
3002 stab_sec->set_link_section(*p);
3006 // Create .gnu_incremental_inputs and related sections needed
3007 // for the next run of incremental linking to check what has changed.
3010 Layout::create_incremental_info_sections(Symbol_table* symtab)
3012 Incremental_inputs* incr = this->incremental_inputs_;
3014 gold_assert(incr != NULL);
3016 // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
3017 incr->create_data_sections(symtab);
3019 // Add the .gnu_incremental_inputs section.
3020 const char* incremental_inputs_name =
3021 this->namepool_.add(".gnu_incremental_inputs", false, NULL);
3022 Output_section* incremental_inputs_os =
3023 this->make_output_section(incremental_inputs_name,
3024 elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0,
3025 ORDER_INVALID, false);
3026 incremental_inputs_os->add_output_section_data(incr->inputs_section());
3028 // Add the .gnu_incremental_symtab section.
3029 const char* incremental_symtab_name =
3030 this->namepool_.add(".gnu_incremental_symtab", false, NULL);
3031 Output_section* incremental_symtab_os =
3032 this->make_output_section(incremental_symtab_name,
3033 elfcpp::SHT_GNU_INCREMENTAL_SYMTAB, 0,
3034 ORDER_INVALID, false);
3035 incremental_symtab_os->add_output_section_data(incr->symtab_section());
3036 incremental_symtab_os->set_entsize(4);
3038 // Add the .gnu_incremental_relocs section.
3039 const char* incremental_relocs_name =
3040 this->namepool_.add(".gnu_incremental_relocs", false, NULL);
3041 Output_section* incremental_relocs_os =
3042 this->make_output_section(incremental_relocs_name,
3043 elfcpp::SHT_GNU_INCREMENTAL_RELOCS, 0,
3044 ORDER_INVALID, false);
3045 incremental_relocs_os->add_output_section_data(incr->relocs_section());
3046 incremental_relocs_os->set_entsize(incr->relocs_entsize());
3048 // Add the .gnu_incremental_got_plt section.
3049 const char* incremental_got_plt_name =
3050 this->namepool_.add(".gnu_incremental_got_plt", false, NULL);
3051 Output_section* incremental_got_plt_os =
3052 this->make_output_section(incremental_got_plt_name,
3053 elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT, 0,
3054 ORDER_INVALID, false);
3055 incremental_got_plt_os->add_output_section_data(incr->got_plt_section());
3057 // Add the .gnu_incremental_strtab section.
3058 const char* incremental_strtab_name =
3059 this->namepool_.add(".gnu_incremental_strtab", false, NULL);
3060 Output_section* incremental_strtab_os = this->make_output_section(incremental_strtab_name,
3061 elfcpp::SHT_STRTAB, 0,
3062 ORDER_INVALID, false);
3063 Output_data_strtab* strtab_data =
3064 new Output_data_strtab(incr->get_stringpool());
3065 incremental_strtab_os->add_output_section_data(strtab_data);
3067 incremental_inputs_os->set_after_input_sections();
3068 incremental_symtab_os->set_after_input_sections();
3069 incremental_relocs_os->set_after_input_sections();
3070 incremental_got_plt_os->set_after_input_sections();
3072 incremental_inputs_os->set_link_section(incremental_strtab_os);
3073 incremental_symtab_os->set_link_section(incremental_inputs_os);
3074 incremental_relocs_os->set_link_section(incremental_inputs_os);
3075 incremental_got_plt_os->set_link_section(incremental_inputs_os);
3078 // Return whether SEG1 should be before SEG2 in the output file. This
3079 // is based entirely on the segment type and flags. When this is
3080 // called the segment addresses have normally not yet been set.
3083 Layout::segment_precedes(const Output_segment* seg1,
3084 const Output_segment* seg2)
3086 elfcpp::Elf_Word type1 = seg1->type();
3087 elfcpp::Elf_Word type2 = seg2->type();
3089 // The single PT_PHDR segment is required to precede any loadable
3090 // segment. We simply make it always first.
3091 if (type1 == elfcpp::PT_PHDR)
3093 gold_assert(type2 != elfcpp::PT_PHDR);
3096 if (type2 == elfcpp::PT_PHDR)
3099 // The single PT_INTERP segment is required to precede any loadable
3100 // segment. We simply make it always second.
3101 if (type1 == elfcpp::PT_INTERP)
3103 gold_assert(type2 != elfcpp::PT_INTERP);
3106 if (type2 == elfcpp::PT_INTERP)
3109 // We then put PT_LOAD segments before any other segments.
3110 if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD)
3112 if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
3115 // We put the PT_TLS segment last except for the PT_GNU_RELRO
3116 // segment, because that is where the dynamic linker expects to find
3117 // it (this is just for efficiency; other positions would also work
3119 if (type1 == elfcpp::PT_TLS
3120 && type2 != elfcpp::PT_TLS
3121 && type2 != elfcpp::PT_GNU_RELRO)
3123 if (type2 == elfcpp::PT_TLS
3124 && type1 != elfcpp::PT_TLS
3125 && type1 != elfcpp::PT_GNU_RELRO)
3128 // We put the PT_GNU_RELRO segment last, because that is where the
3129 // dynamic linker expects to find it (as with PT_TLS, this is just
3131 if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
3133 if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
3136 const elfcpp::Elf_Word flags1 = seg1->flags();
3137 const elfcpp::Elf_Word flags2 = seg2->flags();
3139 // The order of non-PT_LOAD segments is unimportant. We simply sort
3140 // by the numeric segment type and flags values. There should not
3141 // be more than one segment with the same type and flags.
3142 if (type1 != elfcpp::PT_LOAD)
3145 return type1 < type2;
3146 gold_assert(flags1 != flags2);
3147 return flags1 < flags2;
3150 // If the addresses are set already, sort by load address.
3151 if (seg1->are_addresses_set())
3153 if (!seg2->are_addresses_set())
3156 unsigned int section_count1 = seg1->output_section_count();
3157 unsigned int section_count2 = seg2->output_section_count();
3158 if (section_count1 == 0 && section_count2 > 0)
3160 if (section_count1 > 0 && section_count2 == 0)
3163 uint64_t paddr1 = (seg1->are_addresses_set()
3165 : seg1->first_section_load_address());
3166 uint64_t paddr2 = (seg2->are_addresses_set()
3168 : seg2->first_section_load_address());
3170 if (paddr1 != paddr2)
3171 return paddr1 < paddr2;
3173 else if (seg2->are_addresses_set())
3176 // A segment which holds large data comes after a segment which does
3177 // not hold large data.
3178 if (seg1->is_large_data_segment())
3180 if (!seg2->is_large_data_segment())
3183 else if (seg2->is_large_data_segment())
3186 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
3187 // segments come before writable segments. Then writable segments
3188 // with data come before writable segments without data. Then
3189 // executable segments come before non-executable segments. Then
3190 // the unlikely case of a non-readable segment comes before the
3191 // normal case of a readable segment. If there are multiple
3192 // segments with the same type and flags, we require that the
3193 // address be set, and we sort by virtual address and then physical
3195 if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
3196 return (flags1 & elfcpp::PF_W) == 0;
3197 if ((flags1 & elfcpp::PF_W) != 0
3198 && seg1->has_any_data_sections() != seg2->has_any_data_sections())
3199 return seg1->has_any_data_sections();
3200 if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X))
3201 return (flags1 & elfcpp::PF_X) != 0;
3202 if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R))
3203 return (flags1 & elfcpp::PF_R) == 0;
3205 // We shouldn't get here--we shouldn't create segments which we
3206 // can't distinguish. Unless of course we are using a weird linker
3207 // script or overlapping --section-start options. We could also get
3208 // here if plugins want unique segments for subsets of sections.
3209 gold_assert(this->script_options_->saw_phdrs_clause()
3210 || parameters->options().any_section_start()
3211 || this->is_unique_segment_for_sections_specified());
3215 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
3218 align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize)
3220 uint64_t unsigned_off = off;
3221 uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
3222 | (addr & (abi_pagesize - 1)));
3223 if (aligned_off < unsigned_off)
3224 aligned_off += abi_pagesize;
3228 // Set the file offsets of all the segments, and all the sections they
3229 // contain. They have all been created. LOAD_SEG must be be laid out
3230 // first. Return the offset of the data to follow.
3233 Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
3234 unsigned int* pshndx)
3236 // Sort them into the final order. We use a stable sort so that we
3237 // don't randomize the order of indistinguishable segments created
3238 // by linker scripts.
3239 std::stable_sort(this->segment_list_.begin(), this->segment_list_.end(),
3240 Layout::Compare_segments(this));
3242 // Find the PT_LOAD segments, and set their addresses and offsets
3243 // and their section's addresses and offsets.
3244 uint64_t start_addr;
3245 if (parameters->options().user_set_Ttext())
3246 start_addr = parameters->options().Ttext();
3247 else if (parameters->options().output_is_position_independent())
3250 start_addr = target->default_text_segment_address();
3252 uint64_t addr = start_addr;
3255 // If LOAD_SEG is NULL, then the file header and segment headers
3256 // will not be loadable. But they still need to be at offset 0 in
3257 // the file. Set their offsets now.
3258 if (load_seg == NULL)
3260 for (Data_list::iterator p = this->special_output_list_.begin();
3261 p != this->special_output_list_.end();
3264 off = align_address(off, (*p)->addralign());
3265 (*p)->set_address_and_file_offset(0, off);
3266 off += (*p)->data_size();
3270 unsigned int increase_relro = this->increase_relro_;
3271 if (this->script_options_->saw_sections_clause())
3274 const bool check_sections = parameters->options().check_sections();
3275 Output_segment* last_load_segment = NULL;
3277 unsigned int shndx_begin = *pshndx;
3278 unsigned int shndx_load_seg = *pshndx;
3280 for (Segment_list::iterator p = this->segment_list_.begin();
3281 p != this->segment_list_.end();
3284 if ((*p)->type() == elfcpp::PT_LOAD)
3286 if (target->isolate_execinstr())
3288 // When we hit the segment that should contain the
3289 // file headers, reset the file offset so we place
3290 // it and subsequent segments appropriately.
3291 // We'll fix up the preceding segments below.
3299 shndx_load_seg = *pshndx;
3305 // Verify that the file headers fall into the first segment.
3306 if (load_seg != NULL && load_seg != *p)
3311 bool are_addresses_set = (*p)->are_addresses_set();
3312 if (are_addresses_set)
3314 // When it comes to setting file offsets, we care about
3315 // the physical address.
3316 addr = (*p)->paddr();
3318 else if (parameters->options().user_set_Ttext()
3319 && ((*p)->flags() & elfcpp::PF_W) == 0)
3321 are_addresses_set = true;
3323 else if (parameters->options().user_set_Tdata()
3324 && ((*p)->flags() & elfcpp::PF_W) != 0
3325 && (!parameters->options().user_set_Tbss()
3326 || (*p)->has_any_data_sections()))
3328 addr = parameters->options().Tdata();
3329 are_addresses_set = true;
3331 else if (parameters->options().user_set_Tbss()
3332 && ((*p)->flags() & elfcpp::PF_W) != 0
3333 && !(*p)->has_any_data_sections())
3335 addr = parameters->options().Tbss();
3336 are_addresses_set = true;
3339 uint64_t orig_addr = addr;
3340 uint64_t orig_off = off;
3342 uint64_t aligned_addr = 0;
3343 uint64_t abi_pagesize = target->abi_pagesize();
3344 uint64_t common_pagesize = target->common_pagesize();
3346 if (!parameters->options().nmagic()
3347 && !parameters->options().omagic())
3348 (*p)->set_minimum_p_align(abi_pagesize);
3350 if (!are_addresses_set)
3352 // Skip the address forward one page, maintaining the same
3353 // position within the page. This lets us store both segments
3354 // overlapping on a single page in the file, but the loader will
3355 // put them on different pages in memory. We will revisit this
3356 // decision once we know the size of the segment.
3358 addr = align_address(addr, (*p)->maximum_alignment());
3359 aligned_addr = addr;
3363 // This is the segment that will contain the file
3364 // headers, so its offset will have to be exactly zero.
3365 gold_assert(orig_off == 0);
3367 // If the target wants a fixed minimum distance from the
3368 // text segment to the read-only segment, move up now.
3369 uint64_t min_addr = start_addr + target->rosegment_gap();
3370 if (addr < min_addr)
3373 // But this is not the first segment! To make its
3374 // address congruent with its offset, that address better
3375 // be aligned to the ABI-mandated page size.
3376 addr = align_address(addr, abi_pagesize);
3377 aligned_addr = addr;
3381 if ((addr & (abi_pagesize - 1)) != 0)
3382 addr = addr + abi_pagesize;
3384 off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
3388 if (!parameters->options().nmagic()
3389 && !parameters->options().omagic())
3390 off = align_file_offset(off, addr, abi_pagesize);
3393 // This is -N or -n with a section script which prevents
3394 // us from using a load segment. We need to ensure that
3395 // the file offset is aligned to the alignment of the
3396 // segment. This is because the linker script
3397 // implicitly assumed a zero offset. If we don't align
3398 // here, then the alignment of the sections in the
3399 // linker script may not match the alignment of the
3400 // sections in the set_section_addresses call below,
3401 // causing an error about dot moving backward.
3402 off = align_address(off, (*p)->maximum_alignment());
3405 unsigned int shndx_hold = *pshndx;
3406 bool has_relro = false;
3407 uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
3412 // Now that we know the size of this segment, we may be able
3413 // to save a page in memory, at the cost of wasting some
3414 // file space, by instead aligning to the start of a new
3415 // page. Here we use the real machine page size rather than
3416 // the ABI mandated page size. If the segment has been
3417 // aligned so that the relro data ends at a page boundary,
3418 // we do not try to realign it.
3420 if (!are_addresses_set
3422 && aligned_addr != addr
3423 && !parameters->incremental())
3425 uint64_t first_off = (common_pagesize
3427 & (common_pagesize - 1)));
3428 uint64_t last_off = new_addr & (common_pagesize - 1);
3431 && ((aligned_addr & ~ (common_pagesize - 1))
3432 != (new_addr & ~ (common_pagesize - 1)))
3433 && first_off + last_off <= common_pagesize)
3435 *pshndx = shndx_hold;
3436 addr = align_address(aligned_addr, common_pagesize);
3437 addr = align_address(addr, (*p)->maximum_alignment());
3438 if ((addr & (abi_pagesize - 1)) != 0)
3439 addr = addr + abi_pagesize;
3440 off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
3441 off = align_file_offset(off, addr, abi_pagesize);
3443 increase_relro = this->increase_relro_;
3444 if (this->script_options_->saw_sections_clause())
3448 new_addr = (*p)->set_section_addresses(this, true, addr,
3457 // Implement --check-sections. We know that the segments
3458 // are sorted by LMA.
3459 if (check_sections && last_load_segment != NULL)
3461 gold_assert(last_load_segment->paddr() <= (*p)->paddr());
3462 if (last_load_segment->paddr() + last_load_segment->memsz()
3465 unsigned long long lb1 = last_load_segment->paddr();
3466 unsigned long long le1 = lb1 + last_load_segment->memsz();
3467 unsigned long long lb2 = (*p)->paddr();
3468 unsigned long long le2 = lb2 + (*p)->memsz();
3469 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3470 "[0x%llx -> 0x%llx]"),
3471 lb1, le1, lb2, le2);
3474 last_load_segment = *p;
3478 if (load_seg != NULL && target->isolate_execinstr())
3480 // Process the early segments again, setting their file offsets
3481 // so they land after the segments starting at LOAD_SEG.
3482 off = align_file_offset(off, 0, target->abi_pagesize());
3484 for (Segment_list::iterator p = this->segment_list_.begin();
3488 if ((*p)->type() == elfcpp::PT_LOAD)
3490 // We repeat the whole job of assigning addresses and
3491 // offsets, but we really only want to change the offsets and
3492 // must ensure that the addresses all come out the same as
3493 // they did the first time through.
3494 bool has_relro = false;
3495 const uint64_t old_addr = (*p)->vaddr();
3496 const uint64_t old_end = old_addr + (*p)->memsz();
3497 uint64_t new_addr = (*p)->set_section_addresses(this, true,
3503 gold_assert(new_addr == old_end);
3507 gold_assert(shndx_begin == shndx_load_seg);
3510 // Handle the non-PT_LOAD segments, setting their offsets from their
3511 // section's offsets.
3512 for (Segment_list::iterator p = this->segment_list_.begin();
3513 p != this->segment_list_.end();
3516 if ((*p)->type() != elfcpp::PT_LOAD)
3517 (*p)->set_offset((*p)->type() == elfcpp::PT_GNU_RELRO
3522 // Set the TLS offsets for each section in the PT_TLS segment.
3523 if (this->tls_segment_ != NULL)
3524 this->tls_segment_->set_tls_offsets();
3529 // Set the offsets of all the allocated sections when doing a
3530 // relocatable link. This does the same jobs as set_segment_offsets,
3531 // only for a relocatable link.
3534 Layout::set_relocatable_section_offsets(Output_data* file_header,
3535 unsigned int* pshndx)
3539 file_header->set_address_and_file_offset(0, 0);
3540 off += file_header->data_size();
3542 for (Section_list::iterator p = this->section_list_.begin();
3543 p != this->section_list_.end();
3546 // We skip unallocated sections here, except that group sections
3547 // have to come first.
3548 if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
3549 && (*p)->type() != elfcpp::SHT_GROUP)
3552 off = align_address(off, (*p)->addralign());
3554 // The linker script might have set the address.
3555 if (!(*p)->is_address_valid())
3556 (*p)->set_address(0);
3557 (*p)->set_file_offset(off);
3558 (*p)->finalize_data_size();
3559 off += (*p)->data_size();
3561 (*p)->set_out_shndx(*pshndx);
3568 // Set the file offset of all the sections not associated with a
3572 Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
3574 off_t startoff = off;
3577 for (Section_list::iterator p = this->unattached_section_list_.begin();
3578 p != this->unattached_section_list_.end();
3581 // The symtab section is handled in create_symtab_sections.
3582 if (*p == this->symtab_section_)
3585 // If we've already set the data size, don't set it again.
3586 if ((*p)->is_offset_valid() && (*p)->is_data_size_valid())
3589 if (pass == BEFORE_INPUT_SECTIONS_PASS
3590 && (*p)->requires_postprocessing())
3592 (*p)->create_postprocessing_buffer();
3593 this->any_postprocessing_sections_ = true;
3596 if (pass == BEFORE_INPUT_SECTIONS_PASS
3597 && (*p)->after_input_sections())
3599 else if (pass == POSTPROCESSING_SECTIONS_PASS
3600 && (!(*p)->after_input_sections()
3601 || (*p)->type() == elfcpp::SHT_STRTAB))
3603 else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
3604 && (!(*p)->after_input_sections()
3605 || (*p)->type() != elfcpp::SHT_STRTAB))
3608 if (!parameters->incremental_update())
3610 off = align_address(off, (*p)->addralign());
3611 (*p)->set_file_offset(off);
3612 (*p)->finalize_data_size();
3616 // Incremental update: allocate file space from free list.
3617 (*p)->pre_finalize_data_size();
3618 off_t current_size = (*p)->current_data_size();
3619 off = this->allocate(current_size, (*p)->addralign(), startoff);
3622 if (is_debugging_enabled(DEBUG_INCREMENTAL))
3623 this->free_list_.dump();
3624 gold_assert((*p)->output_section() != NULL);
3625 gold_fallback(_("out of patch space for section %s; "
3626 "relink with --incremental-full"),
3627 (*p)->output_section()->name());
3629 (*p)->set_file_offset(off);
3630 (*p)->finalize_data_size();
3631 if ((*p)->data_size() > current_size)
3633 gold_assert((*p)->output_section() != NULL);
3634 gold_fallback(_("%s: section changed size; "
3635 "relink with --incremental-full"),
3636 (*p)->output_section()->name());
3638 gold_debug(DEBUG_INCREMENTAL,
3639 "set_section_offsets: %08lx %08lx %s",
3640 static_cast<long>(off),
3641 static_cast<long>((*p)->data_size()),
3642 ((*p)->output_section() != NULL
3643 ? (*p)->output_section()->name() : "(special)"));
3646 off += (*p)->data_size();
3650 // At this point the name must be set.
3651 if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
3652 this->namepool_.add((*p)->name(), false, NULL);
3657 // Set the section indexes of all the sections not associated with a
3661 Layout::set_section_indexes(unsigned int shndx)
3663 for (Section_list::iterator p = this->unattached_section_list_.begin();
3664 p != this->unattached_section_list_.end();
3667 if (!(*p)->has_out_shndx())
3669 (*p)->set_out_shndx(shndx);
3676 // Set the section addresses according to the linker script. This is
3677 // only called when we see a SECTIONS clause. This returns the
3678 // program segment which should hold the file header and segment
3679 // headers, if any. It will return NULL if they should not be in a
3683 Layout::set_section_addresses_from_script(Symbol_table* symtab)
3685 Script_sections* ss = this->script_options_->script_sections();
3686 gold_assert(ss->saw_sections_clause());
3687 return this->script_options_->set_section_addresses(symtab, this);
3690 // Place the orphan sections in the linker script.
3693 Layout::place_orphan_sections_in_script()
3695 Script_sections* ss = this->script_options_->script_sections();
3696 gold_assert(ss->saw_sections_clause());
3698 // Place each orphaned output section in the script.
3699 for (Section_list::iterator p = this->section_list_.begin();
3700 p != this->section_list_.end();
3703 if (!(*p)->found_in_sections_clause())
3704 ss->place_orphan(*p);
3708 // Count the local symbols in the regular symbol table and the dynamic
3709 // symbol table, and build the respective string pools.
3712 Layout::count_local_symbols(const Task* task,
3713 const Input_objects* input_objects)
3715 // First, figure out an upper bound on the number of symbols we'll
3716 // be inserting into each pool. This helps us create the pools with
3717 // the right size, to avoid unnecessary hashtable resizing.
3718 unsigned int symbol_count = 0;
3719 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3720 p != input_objects->relobj_end();
3722 symbol_count += (*p)->local_symbol_count();
3724 // Go from "upper bound" to "estimate." We overcount for two
3725 // reasons: we double-count symbols that occur in more than one
3726 // object file, and we count symbols that are dropped from the
3727 // output. Add it all together and assume we overcount by 100%.
3730 // We assume all symbols will go into both the sympool and dynpool.
3731 this->sympool_.reserve(symbol_count);
3732 this->dynpool_.reserve(symbol_count);
3734 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3735 p != input_objects->relobj_end();
3738 Task_lock_obj<Object> tlo(task, *p);
3739 (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
3743 // Create the symbol table sections. Here we also set the final
3744 // values of the symbols. At this point all the loadable sections are
3745 // fully laid out. SHNUM is the number of sections so far.
3748 Layout::create_symtab_sections(const Input_objects* input_objects,
3749 Symbol_table* symtab,
3755 if (parameters->target().get_size() == 32)
3757 symsize = elfcpp::Elf_sizes<32>::sym_size;
3760 else if (parameters->target().get_size() == 64)
3762 symsize = elfcpp::Elf_sizes<64>::sym_size;
3768 // Compute file offsets relative to the start of the symtab section.
3771 // Save space for the dummy symbol at the start of the section. We
3772 // never bother to write this out--it will just be left as zero.
3774 unsigned int local_symbol_index = 1;
3776 // Add STT_SECTION symbols for each Output section which needs one.
3777 for (Section_list::iterator p = this->section_list_.begin();
3778 p != this->section_list_.end();
3781 if (!(*p)->needs_symtab_index())
3782 (*p)->set_symtab_index(-1U);
3785 (*p)->set_symtab_index(local_symbol_index);
3786 ++local_symbol_index;
3791 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3792 p != input_objects->relobj_end();
3795 unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
3797 off += (index - local_symbol_index) * symsize;
3798 local_symbol_index = index;
3801 unsigned int local_symcount = local_symbol_index;
3802 gold_assert(static_cast<off_t>(local_symcount * symsize) == off);
3805 size_t dyn_global_index;
3807 if (this->dynsym_section_ == NULL)
3810 dyn_global_index = 0;
3815 dyn_global_index = this->dynsym_section_->info();
3816 off_t locsize = dyn_global_index * this->dynsym_section_->entsize();
3817 dynoff = this->dynsym_section_->offset() + locsize;
3818 dyncount = (this->dynsym_section_->data_size() - locsize) / symsize;
3819 gold_assert(static_cast<off_t>(dyncount * symsize)
3820 == this->dynsym_section_->data_size() - locsize);
3823 off_t global_off = off;
3824 off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
3825 &this->sympool_, &local_symcount);
3827 if (!parameters->options().strip_all())
3829 this->sympool_.set_string_offsets();
3831 const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
3832 Output_section* osymtab = this->make_output_section(symtab_name,
3836 this->symtab_section_ = osymtab;
3838 Output_section_data* pos = new Output_data_fixed_space(off, align,
3840 osymtab->add_output_section_data(pos);
3842 // We generate a .symtab_shndx section if we have more than
3843 // SHN_LORESERVE sections. Technically it is possible that we
3844 // don't need one, because it is possible that there are no
3845 // symbols in any of sections with indexes larger than
3846 // SHN_LORESERVE. That is probably unusual, though, and it is
3847 // easier to always create one than to compute section indexes
3848 // twice (once here, once when writing out the symbols).
3849 if (shnum >= elfcpp::SHN_LORESERVE)
3851 const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx",
3853 Output_section* osymtab_xindex =
3854 this->make_output_section(symtab_xindex_name,
3855 elfcpp::SHT_SYMTAB_SHNDX, 0,
3856 ORDER_INVALID, false);
3858 size_t symcount = off / symsize;
3859 this->symtab_xindex_ = new Output_symtab_xindex(symcount);
3861 osymtab_xindex->add_output_section_data(this->symtab_xindex_);
3863 osymtab_xindex->set_link_section(osymtab);
3864 osymtab_xindex->set_addralign(4);
3865 osymtab_xindex->set_entsize(4);
3867 osymtab_xindex->set_after_input_sections();
3869 // This tells the driver code to wait until the symbol table
3870 // has written out before writing out the postprocessing
3871 // sections, including the .symtab_shndx section.
3872 this->any_postprocessing_sections_ = true;
3875 const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
3876 Output_section* ostrtab = this->make_output_section(strtab_name,
3881 Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
3882 ostrtab->add_output_section_data(pstr);
3885 if (!parameters->incremental_update())
3886 symtab_off = align_address(*poff, align);
3889 symtab_off = this->allocate(off, align, *poff);
3891 gold_fallback(_("out of patch space for symbol table; "
3892 "relink with --incremental-full"));
3893 gold_debug(DEBUG_INCREMENTAL,
3894 "create_symtab_sections: %08lx %08lx .symtab",
3895 static_cast<long>(symtab_off),
3896 static_cast<long>(off));
3899 symtab->set_file_offset(symtab_off + global_off);
3900 osymtab->set_file_offset(symtab_off);
3901 osymtab->finalize_data_size();
3902 osymtab->set_link_section(ostrtab);
3903 osymtab->set_info(local_symcount);
3904 osymtab->set_entsize(symsize);
3906 if (symtab_off + off > *poff)
3907 *poff = symtab_off + off;
3911 // Create the .shstrtab section, which holds the names of the
3912 // sections. At the time this is called, we have created all the
3913 // output sections except .shstrtab itself.
3916 Layout::create_shstrtab()
3918 // FIXME: We don't need to create a .shstrtab section if we are
3919 // stripping everything.
3921 const char* name = this->namepool_.add(".shstrtab", false, NULL);
3923 Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0,
3924 ORDER_INVALID, false);
3926 if (strcmp(parameters->options().compress_debug_sections(), "none") != 0)
3928 // We can't write out this section until we've set all the
3929 // section names, and we don't set the names of compressed
3930 // output sections until relocations are complete. FIXME: With
3931 // the current names we use, this is unnecessary.
3932 os->set_after_input_sections();
3935 Output_section_data* posd = new Output_data_strtab(&this->namepool_);
3936 os->add_output_section_data(posd);
3941 // Create the section headers. SIZE is 32 or 64. OFF is the file
3945 Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff)
3947 Output_section_headers* oshdrs;
3948 oshdrs = new Output_section_headers(this,
3949 &this->segment_list_,
3950 &this->section_list_,
3951 &this->unattached_section_list_,
3955 if (!parameters->incremental_update())
3956 off = align_address(*poff, oshdrs->addralign());
3959 oshdrs->pre_finalize_data_size();
3960 off = this->allocate(oshdrs->data_size(), oshdrs->addralign(), *poff);
3962 gold_fallback(_("out of patch space for section header table; "
3963 "relink with --incremental-full"));
3964 gold_debug(DEBUG_INCREMENTAL,
3965 "create_shdrs: %08lx %08lx (section header table)",
3966 static_cast<long>(off),
3967 static_cast<long>(off + oshdrs->data_size()));
3969 oshdrs->set_address_and_file_offset(0, off);
3970 off += oshdrs->data_size();
3973 this->section_headers_ = oshdrs;
3976 // Count the allocated sections.
3979 Layout::allocated_output_section_count() const
3981 size_t section_count = 0;
3982 for (Segment_list::const_iterator p = this->segment_list_.begin();
3983 p != this->segment_list_.end();
3985 section_count += (*p)->output_section_count();
3986 return section_count;
3989 // Create the dynamic symbol table.
3992 Layout::create_dynamic_symtab(const Input_objects* input_objects,
3993 Symbol_table* symtab,
3994 Output_section** pdynstr,
3995 unsigned int* plocal_dynamic_count,
3996 std::vector<Symbol*>* pdynamic_symbols,
3997 Versions* pversions)
3999 // Count all the symbols in the dynamic symbol table, and set the
4000 // dynamic symbol indexes.
4002 // Skip symbol 0, which is always all zeroes.
4003 unsigned int index = 1;
4005 // Add STT_SECTION symbols for each Output section which needs one.
4006 for (Section_list::iterator p = this->section_list_.begin();
4007 p != this->section_list_.end();
4010 if (!(*p)->needs_dynsym_index())
4011 (*p)->set_dynsym_index(-1U);
4014 (*p)->set_dynsym_index(index);
4019 // Count the local symbols that need to go in the dynamic symbol table,
4020 // and set the dynamic symbol indexes.
4021 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
4022 p != input_objects->relobj_end();
4025 unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
4029 unsigned int local_symcount = index;
4030 *plocal_dynamic_count = local_symcount;
4032 index = symtab->set_dynsym_indexes(index, pdynamic_symbols,
4033 &this->dynpool_, pversions);
4037 const int size = parameters->target().get_size();
4040 symsize = elfcpp::Elf_sizes<32>::sym_size;
4043 else if (size == 64)
4045 symsize = elfcpp::Elf_sizes<64>::sym_size;
4051 // Create the dynamic symbol table section.
4053 Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
4057 ORDER_DYNAMIC_LINKER,
4060 // Check for NULL as a linker script may discard .dynsym.
4063 Output_section_data* odata = new Output_data_fixed_space(index * symsize,
4066 dynsym->add_output_section_data(odata);
4068 dynsym->set_info(local_symcount);
4069 dynsym->set_entsize(symsize);
4070 dynsym->set_addralign(align);
4072 this->dynsym_section_ = dynsym;
4075 Output_data_dynamic* const odyn = this->dynamic_data_;
4078 odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
4079 odyn->add_constant(elfcpp::DT_SYMENT, symsize);
4082 // If there are more than SHN_LORESERVE allocated sections, we
4083 // create a .dynsym_shndx section. It is possible that we don't
4084 // need one, because it is possible that there are no dynamic
4085 // symbols in any of the sections with indexes larger than
4086 // SHN_LORESERVE. This is probably unusual, though, and at this
4087 // time we don't know the actual section indexes so it is
4088 // inconvenient to check.
4089 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE)
4091 Output_section* dynsym_xindex =
4092 this->choose_output_section(NULL, ".dynsym_shndx",
4093 elfcpp::SHT_SYMTAB_SHNDX,
4095 false, ORDER_DYNAMIC_LINKER, false);
4097 if (dynsym_xindex != NULL)
4099 this->dynsym_xindex_ = new Output_symtab_xindex(index);
4101 dynsym_xindex->add_output_section_data(this->dynsym_xindex_);
4103 dynsym_xindex->set_link_section(dynsym);
4104 dynsym_xindex->set_addralign(4);
4105 dynsym_xindex->set_entsize(4);
4107 dynsym_xindex->set_after_input_sections();
4109 // This tells the driver code to wait until the symbol table
4110 // has written out before writing out the postprocessing
4111 // sections, including the .dynsym_shndx section.
4112 this->any_postprocessing_sections_ = true;
4116 // Create the dynamic string table section.
4118 Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
4122 ORDER_DYNAMIC_LINKER,
4127 Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
4128 dynstr->add_output_section_data(strdata);
4131 dynsym->set_link_section(dynstr);
4132 if (this->dynamic_section_ != NULL)
4133 this->dynamic_section_->set_link_section(dynstr);
4137 odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
4138 odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
4144 // Create the hash tables.
4146 if (strcmp(parameters->options().hash_style(), "sysv") == 0
4147 || strcmp(parameters->options().hash_style(), "both") == 0)
4149 unsigned char* phash;
4150 unsigned int hashlen;
4151 Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
4154 Output_section* hashsec =
4155 this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH,
4156 elfcpp::SHF_ALLOC, false,
4157 ORDER_DYNAMIC_LINKER, false);
4159 Output_section_data* hashdata = new Output_data_const_buffer(phash,
4163 if (hashsec != NULL && hashdata != NULL)
4164 hashsec->add_output_section_data(hashdata);
4166 if (hashsec != NULL)
4169 hashsec->set_link_section(dynsym);
4170 hashsec->set_entsize(4);
4174 odyn->add_section_address(elfcpp::DT_HASH, hashsec);
4177 if (strcmp(parameters->options().hash_style(), "gnu") == 0
4178 || strcmp(parameters->options().hash_style(), "both") == 0)
4180 unsigned char* phash;
4181 unsigned int hashlen;
4182 Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
4185 Output_section* hashsec =
4186 this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH,
4187 elfcpp::SHF_ALLOC, false,
4188 ORDER_DYNAMIC_LINKER, false);
4190 Output_section_data* hashdata = new Output_data_const_buffer(phash,
4194 if (hashsec != NULL && hashdata != NULL)
4195 hashsec->add_output_section_data(hashdata);
4197 if (hashsec != NULL)
4200 hashsec->set_link_section(dynsym);
4202 // For a 64-bit target, the entries in .gnu.hash do not have
4203 // a uniform size, so we only set the entry size for a
4205 if (parameters->target().get_size() == 32)
4206 hashsec->set_entsize(4);
4209 odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
4214 // Assign offsets to each local portion of the dynamic symbol table.
4217 Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
4219 Output_section* dynsym = this->dynsym_section_;
4223 off_t off = dynsym->offset();
4225 // Skip the dummy symbol at the start of the section.
4226 off += dynsym->entsize();
4228 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
4229 p != input_objects->relobj_end();
4232 unsigned int count = (*p)->set_local_dynsym_offset(off);
4233 off += count * dynsym->entsize();
4237 // Create the version sections.
4240 Layout::create_version_sections(const Versions* versions,
4241 const Symbol_table* symtab,
4242 unsigned int local_symcount,
4243 const std::vector<Symbol*>& dynamic_symbols,
4244 const Output_section* dynstr)
4246 if (!versions->any_defs() && !versions->any_needs())
4249 switch (parameters->size_and_endianness())
4251 #ifdef HAVE_TARGET_32_LITTLE
4252 case Parameters::TARGET_32_LITTLE:
4253 this->sized_create_version_sections<32, false>(versions, symtab,
4255 dynamic_symbols, dynstr);
4258 #ifdef HAVE_TARGET_32_BIG
4259 case Parameters::TARGET_32_BIG:
4260 this->sized_create_version_sections<32, true>(versions, symtab,
4262 dynamic_symbols, dynstr);
4265 #ifdef HAVE_TARGET_64_LITTLE
4266 case Parameters::TARGET_64_LITTLE:
4267 this->sized_create_version_sections<64, false>(versions, symtab,
4269 dynamic_symbols, dynstr);
4272 #ifdef HAVE_TARGET_64_BIG
4273 case Parameters::TARGET_64_BIG:
4274 this->sized_create_version_sections<64, true>(versions, symtab,
4276 dynamic_symbols, dynstr);
4284 // Create the version sections, sized version.
4286 template<int size, bool big_endian>
4288 Layout::sized_create_version_sections(
4289 const Versions* versions,
4290 const Symbol_table* symtab,
4291 unsigned int local_symcount,
4292 const std::vector<Symbol*>& dynamic_symbols,
4293 const Output_section* dynstr)
4295 Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
4296 elfcpp::SHT_GNU_versym,
4299 ORDER_DYNAMIC_LINKER,
4302 // Check for NULL since a linker script may discard this section.
4305 unsigned char* vbuf;
4307 versions->symbol_section_contents<size, big_endian>(symtab,
4313 Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
4316 vsec->add_output_section_data(vdata);
4317 vsec->set_entsize(2);
4318 vsec->set_link_section(this->dynsym_section_);
4321 Output_data_dynamic* const odyn = this->dynamic_data_;
4322 if (odyn != NULL && vsec != NULL)
4323 odyn->add_section_address(elfcpp::DT_VERSYM, vsec);
4325 if (versions->any_defs())
4327 Output_section* vdsec;
4328 vdsec = this->choose_output_section(NULL, ".gnu.version_d",
4329 elfcpp::SHT_GNU_verdef,
4331 false, ORDER_DYNAMIC_LINKER, false);
4335 unsigned char* vdbuf;
4336 unsigned int vdsize;
4337 unsigned int vdentries;
4338 versions->def_section_contents<size, big_endian>(&this->dynpool_,
4342 Output_section_data* vddata =
4343 new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
4345 vdsec->add_output_section_data(vddata);
4346 vdsec->set_link_section(dynstr);
4347 vdsec->set_info(vdentries);
4351 odyn->add_section_address(elfcpp::DT_VERDEF, vdsec);
4352 odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries);
4357 if (versions->any_needs())
4359 Output_section* vnsec;
4360 vnsec = this->choose_output_section(NULL, ".gnu.version_r",
4361 elfcpp::SHT_GNU_verneed,
4363 false, ORDER_DYNAMIC_LINKER, false);
4367 unsigned char* vnbuf;
4368 unsigned int vnsize;
4369 unsigned int vnentries;
4370 versions->need_section_contents<size, big_endian>(&this->dynpool_,
4374 Output_section_data* vndata =
4375 new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
4377 vnsec->add_output_section_data(vndata);
4378 vnsec->set_link_section(dynstr);
4379 vnsec->set_info(vnentries);
4383 odyn->add_section_address(elfcpp::DT_VERNEED, vnsec);
4384 odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries);
4390 // Create the .interp section and PT_INTERP segment.
4393 Layout::create_interp(const Target* target)
4395 gold_assert(this->interp_segment_ == NULL);
4397 const char* interp = parameters->options().dynamic_linker();
4400 interp = target->dynamic_linker();
4401 gold_assert(interp != NULL);
4404 size_t len = strlen(interp) + 1;
4406 Output_section_data* odata = new Output_data_const(interp, len, 1);
4408 Output_section* osec = this->choose_output_section(NULL, ".interp",
4409 elfcpp::SHT_PROGBITS,
4411 false, ORDER_INTERP,
4414 osec->add_output_section_data(odata);
4417 // Add dynamic tags for the PLT and the dynamic relocs. This is
4418 // called by the target-specific code. This does nothing if not doing
4421 // USE_REL is true for REL relocs rather than RELA relocs.
4423 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
4425 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
4426 // and we also set DT_PLTREL. We use PLT_REL's output section, since
4427 // some targets have multiple reloc sections in PLT_REL.
4429 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
4430 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT. Again we use the output
4433 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
4437 Layout::add_target_dynamic_tags(bool use_rel, const Output_data* plt_got,
4438 const Output_data* plt_rel,
4439 const Output_data_reloc_generic* dyn_rel,
4440 bool add_debug, bool dynrel_includes_plt)
4442 Output_data_dynamic* odyn = this->dynamic_data_;
4446 if (plt_got != NULL && plt_got->output_section() != NULL)
4447 odyn->add_section_address(elfcpp::DT_PLTGOT, plt_got);
4449 if (plt_rel != NULL && plt_rel->output_section() != NULL)
4451 odyn->add_section_size(elfcpp::DT_PLTRELSZ, plt_rel->output_section());
4452 odyn->add_section_address(elfcpp::DT_JMPREL, plt_rel->output_section());
4453 odyn->add_constant(elfcpp::DT_PLTREL,
4454 use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA);
4457 if ((dyn_rel != NULL && dyn_rel->output_section() != NULL)
4458 || (dynrel_includes_plt
4460 && plt_rel->output_section() != NULL))
4462 bool have_dyn_rel = dyn_rel != NULL && dyn_rel->output_section() != NULL;
4463 bool have_plt_rel = plt_rel != NULL && plt_rel->output_section() != NULL;
4464 odyn->add_section_address(use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA,
4466 ? dyn_rel->output_section()
4467 : plt_rel->output_section()));
4468 elfcpp::DT size_tag = use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ;
4469 if (have_dyn_rel && have_plt_rel && dynrel_includes_plt)
4470 odyn->add_section_size(size_tag,
4471 dyn_rel->output_section(),
4472 plt_rel->output_section());
4473 else if (have_dyn_rel)
4474 odyn->add_section_size(size_tag, dyn_rel->output_section());
4476 odyn->add_section_size(size_tag, plt_rel->output_section());
4477 const int size = parameters->target().get_size();
4482 rel_tag = elfcpp::DT_RELENT;
4484 rel_size = Reloc_types<elfcpp::SHT_REL, 32, false>::reloc_size;
4485 else if (size == 64)
4486 rel_size = Reloc_types<elfcpp::SHT_REL, 64, false>::reloc_size;
4492 rel_tag = elfcpp::DT_RELAENT;
4494 rel_size = Reloc_types<elfcpp::SHT_RELA, 32, false>::reloc_size;
4495 else if (size == 64)
4496 rel_size = Reloc_types<elfcpp::SHT_RELA, 64, false>::reloc_size;
4500 odyn->add_constant(rel_tag, rel_size);
4502 if (parameters->options().combreloc() && have_dyn_rel)
4504 size_t c = dyn_rel->relative_reloc_count();
4506 odyn->add_constant((use_rel
4507 ? elfcpp::DT_RELCOUNT
4508 : elfcpp::DT_RELACOUNT),
4513 if (add_debug && !parameters->options().shared())
4515 // The value of the DT_DEBUG tag is filled in by the dynamic
4516 // linker at run time, and used by the debugger.
4517 odyn->add_constant(elfcpp::DT_DEBUG, 0);
4521 // Finish the .dynamic section and PT_DYNAMIC segment.
4524 Layout::finish_dynamic_section(const Input_objects* input_objects,
4525 const Symbol_table* symtab)
4527 if (!this->script_options_->saw_phdrs_clause()
4528 && this->dynamic_section_ != NULL)
4530 Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
4533 oseg->add_output_section_to_nonload(this->dynamic_section_,
4534 elfcpp::PF_R | elfcpp::PF_W);
4537 Output_data_dynamic* const odyn = this->dynamic_data_;
4541 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
4542 p != input_objects->dynobj_end();
4545 if (!(*p)->is_needed() && (*p)->as_needed())
4547 // This dynamic object was linked with --as-needed, but it
4552 odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
4555 if (parameters->options().shared())
4557 const char* soname = parameters->options().soname();
4559 odyn->add_string(elfcpp::DT_SONAME, soname);
4562 Symbol* sym = symtab->lookup(parameters->options().init());
4563 if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
4564 odyn->add_symbol(elfcpp::DT_INIT, sym);
4566 sym = symtab->lookup(parameters->options().fini());
4567 if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
4568 odyn->add_symbol(elfcpp::DT_FINI, sym);
4570 // Look for .init_array, .preinit_array and .fini_array by checking
4572 for(Layout::Section_list::const_iterator p = this->section_list_.begin();
4573 p != this->section_list_.end();
4575 switch((*p)->type())
4577 case elfcpp::SHT_FINI_ARRAY:
4578 odyn->add_section_address(elfcpp::DT_FINI_ARRAY, *p);
4579 odyn->add_section_size(elfcpp::DT_FINI_ARRAYSZ, *p);
4581 case elfcpp::SHT_INIT_ARRAY:
4582 odyn->add_section_address(elfcpp::DT_INIT_ARRAY, *p);
4583 odyn->add_section_size(elfcpp::DT_INIT_ARRAYSZ, *p);
4585 case elfcpp::SHT_PREINIT_ARRAY:
4586 odyn->add_section_address(elfcpp::DT_PREINIT_ARRAY, *p);
4587 odyn->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ, *p);
4593 // Add a DT_RPATH entry if needed.
4594 const General_options::Dir_list& rpath(parameters->options().rpath());
4597 std::string rpath_val;
4598 for (General_options::Dir_list::const_iterator p = rpath.begin();
4602 if (rpath_val.empty())
4603 rpath_val = p->name();
4606 // Eliminate duplicates.
4607 General_options::Dir_list::const_iterator q;
4608 for (q = rpath.begin(); q != p; ++q)
4609 if (q->name() == p->name())
4614 rpath_val += p->name();
4619 odyn->add_string(elfcpp::DT_RPATH, rpath_val);
4620 if (parameters->options().enable_new_dtags())
4621 odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
4624 // Look for text segments that have dynamic relocations.
4625 bool have_textrel = false;
4626 if (!this->script_options_->saw_sections_clause())
4628 for (Segment_list::const_iterator p = this->segment_list_.begin();
4629 p != this->segment_list_.end();
4632 if ((*p)->type() == elfcpp::PT_LOAD
4633 && ((*p)->flags() & elfcpp::PF_W) == 0
4634 && (*p)->has_dynamic_reloc())
4636 have_textrel = true;
4643 // We don't know the section -> segment mapping, so we are
4644 // conservative and just look for readonly sections with
4645 // relocations. If those sections wind up in writable segments,
4646 // then we have created an unnecessary DT_TEXTREL entry.
4647 for (Section_list::const_iterator p = this->section_list_.begin();
4648 p != this->section_list_.end();
4651 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
4652 && ((*p)->flags() & elfcpp::SHF_WRITE) == 0
4653 && (*p)->has_dynamic_reloc())
4655 have_textrel = true;
4661 if (parameters->options().filter() != NULL)
4662 odyn->add_string(elfcpp::DT_FILTER, parameters->options().filter());
4663 if (parameters->options().any_auxiliary())
4665 for (options::String_set::const_iterator p =
4666 parameters->options().auxiliary_begin();
4667 p != parameters->options().auxiliary_end();
4669 odyn->add_string(elfcpp::DT_AUXILIARY, *p);
4672 // Add a DT_FLAGS entry if necessary.
4673 unsigned int flags = 0;
4676 // Add a DT_TEXTREL for compatibility with older loaders.
4677 odyn->add_constant(elfcpp::DT_TEXTREL, 0);
4678 flags |= elfcpp::DF_TEXTREL;
4680 if (parameters->options().text())
4681 gold_error(_("read-only segment has dynamic relocations"));
4682 else if (parameters->options().warn_shared_textrel()
4683 && parameters->options().shared())
4684 gold_warning(_("shared library text segment is not shareable"));
4686 if (parameters->options().shared() && this->has_static_tls())
4687 flags |= elfcpp::DF_STATIC_TLS;
4688 if (parameters->options().origin())
4689 flags |= elfcpp::DF_ORIGIN;
4690 if (parameters->options().Bsymbolic())
4692 flags |= elfcpp::DF_SYMBOLIC;
4693 // Add DT_SYMBOLIC for compatibility with older loaders.
4694 odyn->add_constant(elfcpp::DT_SYMBOLIC, 0);
4696 if (parameters->options().now())
4697 flags |= elfcpp::DF_BIND_NOW;
4699 odyn->add_constant(elfcpp::DT_FLAGS, flags);
4702 if (parameters->options().initfirst())
4703 flags |= elfcpp::DF_1_INITFIRST;
4704 if (parameters->options().interpose())
4705 flags |= elfcpp::DF_1_INTERPOSE;
4706 if (parameters->options().loadfltr())
4707 flags |= elfcpp::DF_1_LOADFLTR;
4708 if (parameters->options().nodefaultlib())
4709 flags |= elfcpp::DF_1_NODEFLIB;
4710 if (parameters->options().nodelete())
4711 flags |= elfcpp::DF_1_NODELETE;
4712 if (parameters->options().nodlopen())
4713 flags |= elfcpp::DF_1_NOOPEN;
4714 if (parameters->options().nodump())
4715 flags |= elfcpp::DF_1_NODUMP;
4716 if (!parameters->options().shared())
4717 flags &= ~(elfcpp::DF_1_INITFIRST
4718 | elfcpp::DF_1_NODELETE
4719 | elfcpp::DF_1_NOOPEN);
4720 if (parameters->options().origin())
4721 flags |= elfcpp::DF_1_ORIGIN;
4722 if (parameters->options().now())
4723 flags |= elfcpp::DF_1_NOW;
4724 if (parameters->options().Bgroup())
4725 flags |= elfcpp::DF_1_GROUP;
4727 odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
4730 // Set the size of the _DYNAMIC symbol table to be the size of the
4734 Layout::set_dynamic_symbol_size(const Symbol_table* symtab)
4736 Output_data_dynamic* const odyn = this->dynamic_data_;
4739 odyn->finalize_data_size();
4740 if (this->dynamic_symbol_ == NULL)
4742 off_t data_size = odyn->data_size();
4743 const int size = parameters->target().get_size();
4745 symtab->get_sized_symbol<32>(this->dynamic_symbol_)->set_symsize(data_size);
4746 else if (size == 64)
4747 symtab->get_sized_symbol<64>(this->dynamic_symbol_)->set_symsize(data_size);
4752 // The mapping of input section name prefixes to output section names.
4753 // In some cases one prefix is itself a prefix of another prefix; in
4754 // such a case the longer prefix must come first. These prefixes are
4755 // based on the GNU linker default ELF linker script.
4757 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
4758 #define MAPPING_INIT_EXACT(f, t) { f, 0, t, sizeof(t) - 1 }
4759 const Layout::Section_name_mapping Layout::section_name_mapping[] =
4761 MAPPING_INIT(".text.", ".text"),
4762 MAPPING_INIT(".rodata.", ".rodata"),
4763 MAPPING_INIT(".data.rel.ro.local.", ".data.rel.ro.local"),
4764 MAPPING_INIT_EXACT(".data.rel.ro.local", ".data.rel.ro.local"),
4765 MAPPING_INIT(".data.rel.ro.", ".data.rel.ro"),
4766 MAPPING_INIT_EXACT(".data.rel.ro", ".data.rel.ro"),
4767 MAPPING_INIT(".data.", ".data"),
4768 MAPPING_INIT(".bss.", ".bss"),
4769 MAPPING_INIT(".tdata.", ".tdata"),
4770 MAPPING_INIT(".tbss.", ".tbss"),
4771 MAPPING_INIT(".init_array.", ".init_array"),
4772 MAPPING_INIT(".fini_array.", ".fini_array"),
4773 MAPPING_INIT(".sdata.", ".sdata"),
4774 MAPPING_INIT(".sbss.", ".sbss"),
4775 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
4776 // differently depending on whether it is creating a shared library.
4777 MAPPING_INIT(".sdata2.", ".sdata"),
4778 MAPPING_INIT(".sbss2.", ".sbss"),
4779 MAPPING_INIT(".lrodata.", ".lrodata"),
4780 MAPPING_INIT(".ldata.", ".ldata"),
4781 MAPPING_INIT(".lbss.", ".lbss"),
4782 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
4783 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
4784 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
4785 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
4786 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
4787 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
4788 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
4789 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
4790 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
4791 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
4792 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
4793 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
4794 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
4795 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
4796 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
4797 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
4798 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
4799 MAPPING_INIT(".ARM.extab", ".ARM.extab"),
4800 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
4801 MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
4802 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
4805 #undef MAPPING_INIT_EXACT
4807 const int Layout::section_name_mapping_count =
4808 (sizeof(Layout::section_name_mapping)
4809 / sizeof(Layout::section_name_mapping[0]));
4811 // Choose the output section name to use given an input section name.
4812 // Set *PLEN to the length of the name. *PLEN is initialized to the
4816 Layout::output_section_name(const Relobj* relobj, const char* name,
4819 // gcc 4.3 generates the following sorts of section names when it
4820 // needs a section name specific to a function:
4826 // .data.rel.local.FN
4828 // .data.rel.ro.local.FN
4835 // The GNU linker maps all of those to the part before the .FN,
4836 // except that .data.rel.local.FN is mapped to .data, and
4837 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
4838 // beginning with .data.rel.ro.local are grouped together.
4840 // For an anonymous namespace, the string FN can contain a '.'.
4842 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
4843 // GNU linker maps to .rodata.
4845 // The .data.rel.ro sections are used with -z relro. The sections
4846 // are recognized by name. We use the same names that the GNU
4847 // linker does for these sections.
4849 // It is hard to handle this in a principled way, so we don't even
4850 // try. We use a table of mappings. If the input section name is
4851 // not found in the table, we simply use it as the output section
4854 const Section_name_mapping* psnm = section_name_mapping;
4855 for (int i = 0; i < section_name_mapping_count; ++i, ++psnm)
4857 if (psnm->fromlen > 0)
4859 if (strncmp(name, psnm->from, psnm->fromlen) == 0)
4861 *plen = psnm->tolen;
4867 if (strcmp(name, psnm->from) == 0)
4869 *plen = psnm->tolen;
4875 // As an additional complication, .ctors sections are output in
4876 // either .ctors or .init_array sections, and .dtors sections are
4877 // output in either .dtors or .fini_array sections.
4878 if (is_prefix_of(".ctors.", name) || is_prefix_of(".dtors.", name))
4880 if (parameters->options().ctors_in_init_array())
4883 return name[1] == 'c' ? ".init_array" : ".fini_array";
4888 return name[1] == 'c' ? ".ctors" : ".dtors";
4891 if (parameters->options().ctors_in_init_array()
4892 && (strcmp(name, ".ctors") == 0 || strcmp(name, ".dtors") == 0))
4894 // To make .init_array/.fini_array work with gcc we must exclude
4895 // .ctors and .dtors sections from the crtbegin and crtend
4898 || (!Layout::match_file_name(relobj, "crtbegin")
4899 && !Layout::match_file_name(relobj, "crtend")))
4902 return name[1] == 'c' ? ".init_array" : ".fini_array";
4909 // Return true if RELOBJ is an input file whose base name matches
4910 // FILE_NAME. The base name must have an extension of ".o", and must
4911 // be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is
4912 // to match crtbegin.o as well as crtbeginS.o without getting confused
4913 // by other possibilities. Overall matching the file name this way is
4914 // a dreadful hack, but the GNU linker does it in order to better
4915 // support gcc, and we need to be compatible.
4918 Layout::match_file_name(const Relobj* relobj, const char* match)
4920 const std::string& file_name(relobj->name());
4921 const char* base_name = lbasename(file_name.c_str());
4922 size_t match_len = strlen(match);
4923 if (strncmp(base_name, match, match_len) != 0)
4925 size_t base_len = strlen(base_name);
4926 if (base_len != match_len + 2 && base_len != match_len + 3)
4928 return memcmp(base_name + base_len - 2, ".o", 2) == 0;
4931 // Check if a comdat group or .gnu.linkonce section with the given
4932 // NAME is selected for the link. If there is already a section,
4933 // *KEPT_SECTION is set to point to the existing section and the
4934 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
4935 // IS_GROUP_NAME are recorded for this NAME in the layout object,
4936 // *KEPT_SECTION is set to the internal copy and the function returns
4940 Layout::find_or_add_kept_section(const std::string& name,
4945 Kept_section** kept_section)
4947 // It's normal to see a couple of entries here, for the x86 thunk
4948 // sections. If we see more than a few, we're linking a C++
4949 // program, and we resize to get more space to minimize rehashing.
4950 if (this->signatures_.size() > 4
4951 && !this->resized_signatures_)
4953 reserve_unordered_map(&this->signatures_,
4954 this->number_of_input_files_ * 64);
4955 this->resized_signatures_ = true;
4958 Kept_section candidate;
4959 std::pair<Signatures::iterator, bool> ins =
4960 this->signatures_.insert(std::make_pair(name, candidate));
4962 if (kept_section != NULL)
4963 *kept_section = &ins.first->second;
4966 // This is the first time we've seen this signature.
4967 ins.first->second.set_object(object);
4968 ins.first->second.set_shndx(shndx);
4970 ins.first->second.set_is_comdat();
4972 ins.first->second.set_is_group_name();
4976 // We have already seen this signature.
4978 if (ins.first->second.is_group_name())
4980 // We've already seen a real section group with this signature.
4981 // If the kept group is from a plugin object, and we're in the
4982 // replacement phase, accept the new one as a replacement.
4983 if (ins.first->second.object() == NULL
4984 && parameters->options().plugins()->in_replacement_phase())
4986 ins.first->second.set_object(object);
4987 ins.first->second.set_shndx(shndx);
4992 else if (is_group_name)
4994 // This is a real section group, and we've already seen a
4995 // linkonce section with this signature. Record that we've seen
4996 // a section group, and don't include this section group.
4997 ins.first->second.set_is_group_name();
5002 // We've already seen a linkonce section and this is a linkonce
5003 // section. These don't block each other--this may be the same
5004 // symbol name with different section types.
5009 // Store the allocated sections into the section list.
5012 Layout::get_allocated_sections(Section_list* section_list) const
5014 for (Section_list::const_iterator p = this->section_list_.begin();
5015 p != this->section_list_.end();
5017 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
5018 section_list->push_back(*p);
5021 // Store the executable sections into the section list.
5024 Layout::get_executable_sections(Section_list* section_list) const
5026 for (Section_list::const_iterator p = this->section_list_.begin();
5027 p != this->section_list_.end();
5029 if (((*p)->flags() & (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR))
5030 == (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR))
5031 section_list->push_back(*p);
5034 // Create an output segment.
5037 Layout::make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
5039 gold_assert(!parameters->options().relocatable());
5040 Output_segment* oseg = new Output_segment(type, flags);
5041 this->segment_list_.push_back(oseg);
5043 if (type == elfcpp::PT_TLS)
5044 this->tls_segment_ = oseg;
5045 else if (type == elfcpp::PT_GNU_RELRO)
5046 this->relro_segment_ = oseg;
5047 else if (type == elfcpp::PT_INTERP)
5048 this->interp_segment_ = oseg;
5053 // Return the file offset of the normal symbol table.
5056 Layout::symtab_section_offset() const
5058 if (this->symtab_section_ != NULL)
5059 return this->symtab_section_->offset();
5063 // Return the section index of the normal symbol table. It may have
5064 // been stripped by the -s/--strip-all option.
5067 Layout::symtab_section_shndx() const
5069 if (this->symtab_section_ != NULL)
5070 return this->symtab_section_->out_shndx();
5074 // Write out the Output_sections. Most won't have anything to write,
5075 // since most of the data will come from input sections which are
5076 // handled elsewhere. But some Output_sections do have Output_data.
5079 Layout::write_output_sections(Output_file* of) const
5081 for (Section_list::const_iterator p = this->section_list_.begin();
5082 p != this->section_list_.end();
5085 if (!(*p)->after_input_sections())
5090 // Write out data not associated with a section or the symbol table.
5093 Layout::write_data(const Symbol_table* symtab, Output_file* of) const
5095 if (!parameters->options().strip_all())
5097 const Output_section* symtab_section = this->symtab_section_;
5098 for (Section_list::const_iterator p = this->section_list_.begin();
5099 p != this->section_list_.end();
5102 if ((*p)->needs_symtab_index())
5104 gold_assert(symtab_section != NULL);
5105 unsigned int index = (*p)->symtab_index();
5106 gold_assert(index > 0 && index != -1U);
5107 off_t off = (symtab_section->offset()
5108 + index * symtab_section->entsize());
5109 symtab->write_section_symbol(*p, this->symtab_xindex_, of, off);
5114 const Output_section* dynsym_section = this->dynsym_section_;
5115 for (Section_list::const_iterator p = this->section_list_.begin();
5116 p != this->section_list_.end();
5119 if ((*p)->needs_dynsym_index())
5121 gold_assert(dynsym_section != NULL);
5122 unsigned int index = (*p)->dynsym_index();
5123 gold_assert(index > 0 && index != -1U);
5124 off_t off = (dynsym_section->offset()
5125 + index * dynsym_section->entsize());
5126 symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off);
5130 // Write out the Output_data which are not in an Output_section.
5131 for (Data_list::const_iterator p = this->special_output_list_.begin();
5132 p != this->special_output_list_.end();
5137 // Write out the Output_sections which can only be written after the
5138 // input sections are complete.
5141 Layout::write_sections_after_input_sections(Output_file* of)
5143 // Determine the final section offsets, and thus the final output
5144 // file size. Note we finalize the .shstrab last, to allow the
5145 // after_input_section sections to modify their section-names before
5147 if (this->any_postprocessing_sections_)
5149 off_t off = this->output_file_size_;
5150 off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
5152 // Now that we've finalized the names, we can finalize the shstrab.
5154 this->set_section_offsets(off,
5155 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
5157 if (off > this->output_file_size_)
5160 this->output_file_size_ = off;
5164 for (Section_list::const_iterator p = this->section_list_.begin();
5165 p != this->section_list_.end();
5168 if ((*p)->after_input_sections())
5172 this->section_headers_->write(of);
5175 // If the build ID requires computing a checksum, do so here, and
5176 // write it out. We compute a checksum over the entire file because
5177 // that is simplest.
5180 Layout::write_build_id(Output_file* of) const
5182 if (this->build_id_note_ == NULL)
5185 const unsigned char* iv = of->get_input_view(0, this->output_file_size_);
5187 unsigned char* ov = of->get_output_view(this->build_id_note_->offset(),
5188 this->build_id_note_->data_size());
5190 const char* style = parameters->options().build_id();
5191 if (strcmp(style, "sha1") == 0)
5194 sha1_init_ctx(&ctx);
5195 sha1_process_bytes(iv, this->output_file_size_, &ctx);
5196 sha1_finish_ctx(&ctx, ov);
5198 else if (strcmp(style, "md5") == 0)
5202 md5_process_bytes(iv, this->output_file_size_, &ctx);
5203 md5_finish_ctx(&ctx, ov);
5208 of->write_output_view(this->build_id_note_->offset(),
5209 this->build_id_note_->data_size(),
5212 of->free_input_view(0, this->output_file_size_, iv);
5215 // Write out a binary file. This is called after the link is
5216 // complete. IN is the temporary output file we used to generate the
5217 // ELF code. We simply walk through the segments, read them from
5218 // their file offset in IN, and write them to their load address in
5219 // the output file. FIXME: with a bit more work, we could support
5220 // S-records and/or Intel hex format here.
5223 Layout::write_binary(Output_file* in) const
5225 gold_assert(parameters->options().oformat_enum()
5226 == General_options::OBJECT_FORMAT_BINARY);
5228 // Get the size of the binary file.
5229 uint64_t max_load_address = 0;
5230 for (Segment_list::const_iterator p = this->segment_list_.begin();
5231 p != this->segment_list_.end();
5234 if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
5236 uint64_t max_paddr = (*p)->paddr() + (*p)->filesz();
5237 if (max_paddr > max_load_address)
5238 max_load_address = max_paddr;
5242 Output_file out(parameters->options().output_file_name());
5243 out.open(max_load_address);
5245 for (Segment_list::const_iterator p = this->segment_list_.begin();
5246 p != this->segment_list_.end();
5249 if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
5251 const unsigned char* vin = in->get_input_view((*p)->offset(),
5253 unsigned char* vout = out.get_output_view((*p)->paddr(),
5255 memcpy(vout, vin, (*p)->filesz());
5256 out.write_output_view((*p)->paddr(), (*p)->filesz(), vout);
5257 in->free_input_view((*p)->offset(), (*p)->filesz(), vin);
5264 // Print the output sections to the map file.
5267 Layout::print_to_mapfile(Mapfile* mapfile) const
5269 for (Segment_list::const_iterator p = this->segment_list_.begin();
5270 p != this->segment_list_.end();
5272 (*p)->print_sections_to_mapfile(mapfile);
5275 // Print statistical information to stderr. This is used for --stats.
5278 Layout::print_stats() const
5280 this->namepool_.print_stats("section name pool");
5281 this->sympool_.print_stats("output symbol name pool");
5282 this->dynpool_.print_stats("dynamic name pool");
5284 for (Section_list::const_iterator p = this->section_list_.begin();
5285 p != this->section_list_.end();
5287 (*p)->print_merge_stats();
5290 // Write_sections_task methods.
5292 // We can always run this task.
5295 Write_sections_task::is_runnable()
5300 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
5304 Write_sections_task::locks(Task_locker* tl)
5306 tl->add(this, this->output_sections_blocker_);
5307 tl->add(this, this->final_blocker_);
5310 // Run the task--write out the data.
5313 Write_sections_task::run(Workqueue*)
5315 this->layout_->write_output_sections(this->of_);
5318 // Write_data_task methods.
5320 // We can always run this task.
5323 Write_data_task::is_runnable()
5328 // We need to unlock FINAL_BLOCKER when finished.
5331 Write_data_task::locks(Task_locker* tl)
5333 tl->add(this, this->final_blocker_);
5336 // Run the task--write out the data.
5339 Write_data_task::run(Workqueue*)
5341 this->layout_->write_data(this->symtab_, this->of_);
5344 // Write_symbols_task methods.
5346 // We can always run this task.
5349 Write_symbols_task::is_runnable()
5354 // We need to unlock FINAL_BLOCKER when finished.
5357 Write_symbols_task::locks(Task_locker* tl)
5359 tl->add(this, this->final_blocker_);
5362 // Run the task--write out the symbols.
5365 Write_symbols_task::run(Workqueue*)
5367 this->symtab_->write_globals(this->sympool_, this->dynpool_,
5368 this->layout_->symtab_xindex(),
5369 this->layout_->dynsym_xindex(), this->of_);
5372 // Write_after_input_sections_task methods.
5374 // We can only run this task after the input sections have completed.
5377 Write_after_input_sections_task::is_runnable()
5379 if (this->input_sections_blocker_->is_blocked())
5380 return this->input_sections_blocker_;
5384 // We need to unlock FINAL_BLOCKER when finished.
5387 Write_after_input_sections_task::locks(Task_locker* tl)
5389 tl->add(this, this->final_blocker_);
5395 Write_after_input_sections_task::run(Workqueue*)
5397 this->layout_->write_sections_after_input_sections(this->of_);
5400 // Close_task_runner methods.
5402 // Run the task--close the file.
5405 Close_task_runner::run(Workqueue*, const Task*)
5407 // If we need to compute a checksum for the BUILD if, we do so here.
5408 this->layout_->write_build_id(this->of_);
5410 // If we've been asked to create a binary file, we do so here.
5411 if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF)
5412 this->layout_->write_binary(this->of_);
5417 // Instantiate the templates we need. We could use the configure
5418 // script to restrict this to only the ones for implemented targets.
5420 #ifdef HAVE_TARGET_32_LITTLE
5423 Layout::init_fixed_output_section<32, false>(
5425 elfcpp::Shdr<32, false>& shdr);
5428 #ifdef HAVE_TARGET_32_BIG
5431 Layout::init_fixed_output_section<32, true>(
5433 elfcpp::Shdr<32, true>& shdr);
5436 #ifdef HAVE_TARGET_64_LITTLE
5439 Layout::init_fixed_output_section<64, false>(
5441 elfcpp::Shdr<64, false>& shdr);
5444 #ifdef HAVE_TARGET_64_BIG
5447 Layout::init_fixed_output_section<64, true>(
5449 elfcpp::Shdr<64, true>& shdr);
5452 #ifdef HAVE_TARGET_32_LITTLE
5455 Layout::layout<32, false>(Sized_relobj_file<32, false>* object,
5458 const elfcpp::Shdr<32, false>& shdr,
5459 unsigned int, unsigned int, off_t*);
5462 #ifdef HAVE_TARGET_32_BIG
5465 Layout::layout<32, true>(Sized_relobj_file<32, true>* object,
5468 const elfcpp::Shdr<32, true>& shdr,
5469 unsigned int, unsigned int, off_t*);
5472 #ifdef HAVE_TARGET_64_LITTLE
5475 Layout::layout<64, false>(Sized_relobj_file<64, false>* object,
5478 const elfcpp::Shdr<64, false>& shdr,
5479 unsigned int, unsigned int, off_t*);
5482 #ifdef HAVE_TARGET_64_BIG
5485 Layout::layout<64, true>(Sized_relobj_file<64, true>* object,
5488 const elfcpp::Shdr<64, true>& shdr,
5489 unsigned int, unsigned int, off_t*);
5492 #ifdef HAVE_TARGET_32_LITTLE
5495 Layout::layout_reloc<32, false>(Sized_relobj_file<32, false>* object,
5496 unsigned int reloc_shndx,
5497 const elfcpp::Shdr<32, false>& shdr,
5498 Output_section* data_section,
5499 Relocatable_relocs* rr);
5502 #ifdef HAVE_TARGET_32_BIG
5505 Layout::layout_reloc<32, true>(Sized_relobj_file<32, true>* object,
5506 unsigned int reloc_shndx,
5507 const elfcpp::Shdr<32, true>& shdr,
5508 Output_section* data_section,
5509 Relocatable_relocs* rr);
5512 #ifdef HAVE_TARGET_64_LITTLE
5515 Layout::layout_reloc<64, false>(Sized_relobj_file<64, false>* object,
5516 unsigned int reloc_shndx,
5517 const elfcpp::Shdr<64, false>& shdr,
5518 Output_section* data_section,
5519 Relocatable_relocs* rr);
5522 #ifdef HAVE_TARGET_64_BIG
5525 Layout::layout_reloc<64, true>(Sized_relobj_file<64, true>* object,
5526 unsigned int reloc_shndx,
5527 const elfcpp::Shdr<64, true>& shdr,
5528 Output_section* data_section,
5529 Relocatable_relocs* rr);
5532 #ifdef HAVE_TARGET_32_LITTLE
5535 Layout::layout_group<32, false>(Symbol_table* symtab,
5536 Sized_relobj_file<32, false>* object,
5538 const char* group_section_name,
5539 const char* signature,
5540 const elfcpp::Shdr<32, false>& shdr,
5541 elfcpp::Elf_Word flags,
5542 std::vector<unsigned int>* shndxes);
5545 #ifdef HAVE_TARGET_32_BIG
5548 Layout::layout_group<32, true>(Symbol_table* symtab,
5549 Sized_relobj_file<32, true>* object,
5551 const char* group_section_name,
5552 const char* signature,
5553 const elfcpp::Shdr<32, true>& shdr,
5554 elfcpp::Elf_Word flags,
5555 std::vector<unsigned int>* shndxes);
5558 #ifdef HAVE_TARGET_64_LITTLE
5561 Layout::layout_group<64, false>(Symbol_table* symtab,
5562 Sized_relobj_file<64, false>* object,
5564 const char* group_section_name,
5565 const char* signature,
5566 const elfcpp::Shdr<64, false>& shdr,
5567 elfcpp::Elf_Word flags,
5568 std::vector<unsigned int>* shndxes);
5571 #ifdef HAVE_TARGET_64_BIG
5574 Layout::layout_group<64, true>(Symbol_table* symtab,
5575 Sized_relobj_file<64, true>* object,
5577 const char* group_section_name,
5578 const char* signature,
5579 const elfcpp::Shdr<64, true>& shdr,
5580 elfcpp::Elf_Word flags,
5581 std::vector<unsigned int>* shndxes);
5584 #ifdef HAVE_TARGET_32_LITTLE
5587 Layout::layout_eh_frame<32, false>(Sized_relobj_file<32, false>* object,
5588 const unsigned char* symbols,
5590 const unsigned char* symbol_names,
5591 off_t symbol_names_size,
5593 const elfcpp::Shdr<32, false>& shdr,
5594 unsigned int reloc_shndx,
5595 unsigned int reloc_type,
5599 #ifdef HAVE_TARGET_32_BIG
5602 Layout::layout_eh_frame<32, true>(Sized_relobj_file<32, true>* object,
5603 const unsigned char* symbols,
5605 const unsigned char* symbol_names,
5606 off_t symbol_names_size,
5608 const elfcpp::Shdr<32, true>& shdr,
5609 unsigned int reloc_shndx,
5610 unsigned int reloc_type,
5614 #ifdef HAVE_TARGET_64_LITTLE
5617 Layout::layout_eh_frame<64, false>(Sized_relobj_file<64, false>* object,
5618 const unsigned char* symbols,
5620 const unsigned char* symbol_names,
5621 off_t symbol_names_size,
5623 const elfcpp::Shdr<64, false>& shdr,
5624 unsigned int reloc_shndx,
5625 unsigned int reloc_type,
5629 #ifdef HAVE_TARGET_64_BIG
5632 Layout::layout_eh_frame<64, true>(Sized_relobj_file<64, true>* object,
5633 const unsigned char* symbols,
5635 const unsigned char* symbol_names,
5636 off_t symbol_names_size,
5638 const elfcpp::Shdr<64, true>& shdr,
5639 unsigned int reloc_shndx,
5640 unsigned int reloc_type,
5644 #ifdef HAVE_TARGET_32_LITTLE
5647 Layout::add_to_gdb_index(bool is_type_unit,
5648 Sized_relobj<32, false>* object,
5649 const unsigned char* symbols,
5652 unsigned int reloc_shndx,
5653 unsigned int reloc_type);
5656 #ifdef HAVE_TARGET_32_BIG
5659 Layout::add_to_gdb_index(bool is_type_unit,
5660 Sized_relobj<32, true>* object,
5661 const unsigned char* symbols,
5664 unsigned int reloc_shndx,
5665 unsigned int reloc_type);
5668 #ifdef HAVE_TARGET_64_LITTLE
5671 Layout::add_to_gdb_index(bool is_type_unit,
5672 Sized_relobj<64, false>* object,
5673 const unsigned char* symbols,
5676 unsigned int reloc_shndx,
5677 unsigned int reloc_type);
5680 #ifdef HAVE_TARGET_64_BIG
5683 Layout::add_to_gdb_index(bool is_type_unit,
5684 Sized_relobj<64, true>* object,
5685 const unsigned char* symbols,
5688 unsigned int reloc_shndx,
5689 unsigned int reloc_type);
5692 } // End namespace gold.