1 // layout.cc -- lay out output file sections for gold
3 // Copyright (C) 2006-2018 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
34 #include "libiberty.h"
42 #include "parameters.h"
46 #include "script-sections.h"
51 #include "gdb-index.h"
52 #include "compressed_output.h"
53 #include "reduced_debug_output.h"
56 #include "descriptors.h"
58 #include "incremental.h"
66 // The total number of free lists used.
67 unsigned int Free_list::num_lists
= 0;
68 // The total number of free list nodes used.
69 unsigned int Free_list::num_nodes
= 0;
70 // The total number of calls to Free_list::remove.
71 unsigned int Free_list::num_removes
= 0;
72 // The total number of nodes visited during calls to Free_list::remove.
73 unsigned int Free_list::num_remove_visits
= 0;
74 // The total number of calls to Free_list::allocate.
75 unsigned int Free_list::num_allocates
= 0;
76 // The total number of nodes visited during calls to Free_list::allocate.
77 unsigned int Free_list::num_allocate_visits
= 0;
79 // Initialize the free list. Creates a single free list node that
80 // describes the entire region of length LEN. If EXTEND is true,
81 // allocate() is allowed to extend the region beyond its initial
85 Free_list::init(off_t len
, bool extend
)
87 this->list_
.push_front(Free_list_node(0, len
));
88 this->last_remove_
= this->list_
.begin();
89 this->extend_
= extend
;
91 ++Free_list::num_lists
;
92 ++Free_list::num_nodes
;
95 // Remove a chunk from the free list. Because we start with a single
96 // node that covers the entire section, and remove chunks from it one
97 // at a time, we do not need to coalesce chunks or handle cases that
98 // span more than one free node. We expect to remove chunks from the
99 // free list in order, and we expect to have only a few chunks of free
100 // space left (corresponding to files that have changed since the last
101 // incremental link), so a simple linear list should provide sufficient
105 Free_list::remove(off_t start
, off_t end
)
109 gold_assert(start
< end
);
111 ++Free_list::num_removes
;
113 Iterator p
= this->last_remove_
;
114 if (p
->start_
> start
)
115 p
= this->list_
.begin();
117 for (; p
!= this->list_
.end(); ++p
)
119 ++Free_list::num_remove_visits
;
120 // Find a node that wholly contains the indicated region.
121 if (p
->start_
<= start
&& p
->end_
>= end
)
123 // Case 1: the indicated region spans the whole node.
124 // Add some fuzz to avoid creating tiny free chunks.
125 if (p
->start_
+ 3 >= start
&& p
->end_
<= end
+ 3)
126 p
= this->list_
.erase(p
);
127 // Case 2: remove a chunk from the start of the node.
128 else if (p
->start_
+ 3 >= start
)
130 // Case 3: remove a chunk from the end of the node.
131 else if (p
->end_
<= end
+ 3)
133 // Case 4: remove a chunk from the middle, and split
134 // the node into two.
137 Free_list_node
newnode(p
->start_
, start
);
139 this->list_
.insert(p
, newnode
);
140 ++Free_list::num_nodes
;
142 this->last_remove_
= p
;
147 // Did not find a node containing the given chunk. This could happen
148 // because a small chunk was already removed due to the fuzz.
149 gold_debug(DEBUG_INCREMENTAL
,
150 "Free_list::remove(%d,%d) not found",
151 static_cast<int>(start
), static_cast<int>(end
));
154 // Allocate a chunk of size LEN from the free list. Returns -1ULL
155 // if a sufficiently large chunk of free space is not found.
156 // We use a simple first-fit algorithm.
159 Free_list::allocate(off_t len
, uint64_t align
, off_t minoff
)
161 gold_debug(DEBUG_INCREMENTAL
,
162 "Free_list::allocate(%08lx, %d, %08lx)",
163 static_cast<long>(len
), static_cast<int>(align
),
164 static_cast<long>(minoff
));
166 return align_address(minoff
, align
);
168 ++Free_list::num_allocates
;
170 // We usually want to drop free chunks smaller than 4 bytes.
171 // If we need to guarantee a minimum hole size, though, we need
172 // to keep track of all free chunks.
173 const int fuzz
= this->min_hole_
> 0 ? 0 : 3;
175 for (Iterator p
= this->list_
.begin(); p
!= this->list_
.end(); ++p
)
177 ++Free_list::num_allocate_visits
;
178 off_t start
= p
->start_
> minoff
? p
->start_
: minoff
;
179 start
= align_address(start
, align
);
180 off_t end
= start
+ len
;
181 if (end
> p
->end_
&& p
->end_
== this->length_
&& this->extend_
)
186 if (end
== p
->end_
|| (end
<= p
->end_
- this->min_hole_
))
188 if (p
->start_
+ fuzz
>= start
&& p
->end_
<= end
+ fuzz
)
189 this->list_
.erase(p
);
190 else if (p
->start_
+ fuzz
>= start
)
192 else if (p
->end_
<= end
+ fuzz
)
196 Free_list_node
newnode(p
->start_
, start
);
198 this->list_
.insert(p
, newnode
);
199 ++Free_list::num_nodes
;
206 off_t start
= align_address(this->length_
, align
);
207 this->length_
= start
+ len
;
213 // Dump the free list (for debugging).
217 gold_info("Free list:\n start end length\n");
218 for (Iterator p
= this->list_
.begin(); p
!= this->list_
.end(); ++p
)
219 gold_info(" %08lx %08lx %08lx", static_cast<long>(p
->start_
),
220 static_cast<long>(p
->end_
),
221 static_cast<long>(p
->end_
- p
->start_
));
224 // Print the statistics for the free lists.
226 Free_list::print_stats()
228 fprintf(stderr
, _("%s: total free lists: %u\n"),
229 program_name
, Free_list::num_lists
);
230 fprintf(stderr
, _("%s: total free list nodes: %u\n"),
231 program_name
, Free_list::num_nodes
);
232 fprintf(stderr
, _("%s: calls to Free_list::remove: %u\n"),
233 program_name
, Free_list::num_removes
);
234 fprintf(stderr
, _("%s: nodes visited: %u\n"),
235 program_name
, Free_list::num_remove_visits
);
236 fprintf(stderr
, _("%s: calls to Free_list::allocate: %u\n"),
237 program_name
, Free_list::num_allocates
);
238 fprintf(stderr
, _("%s: nodes visited: %u\n"),
239 program_name
, Free_list::num_allocate_visits
);
242 // A Hash_task computes the MD5 checksum of an array of char.
244 class Hash_task
: public Task
247 Hash_task(Output_file
* of
,
251 Task_token
* final_blocker
)
252 : of_(of
), offset_(offset
), size_(size
), dst_(dst
),
253 final_blocker_(final_blocker
)
259 const unsigned char* iv
=
260 this->of_
->get_input_view(this->offset_
, this->size_
);
261 md5_buffer(reinterpret_cast<const char*>(iv
), this->size_
, this->dst_
);
262 this->of_
->free_input_view(this->offset_
, this->size_
, iv
);
269 // Unblock FINAL_BLOCKER_ when done.
271 locks(Task_locker
* tl
)
272 { tl
->add(this, this->final_blocker_
); }
276 { return "Hash_task"; }
280 const size_t offset_
;
282 unsigned char* const dst_
;
283 Task_token
* const final_blocker_
;
286 // Layout::Relaxation_debug_check methods.
288 // Check that sections and special data are in reset states.
289 // We do not save states for Output_sections and special Output_data.
290 // So we check that they have not assigned any addresses or offsets.
291 // clean_up_after_relaxation simply resets their addresses and offsets.
293 Layout::Relaxation_debug_check::check_output_data_for_reset_values(
294 const Layout::Section_list
& sections
,
295 const Layout::Data_list
& special_outputs
,
296 const Layout::Data_list
& relax_outputs
)
298 for(Layout::Section_list::const_iterator p
= sections
.begin();
301 gold_assert((*p
)->address_and_file_offset_have_reset_values());
303 for(Layout::Data_list::const_iterator p
= special_outputs
.begin();
304 p
!= special_outputs
.end();
306 gold_assert((*p
)->address_and_file_offset_have_reset_values());
308 gold_assert(relax_outputs
.empty());
311 // Save information of SECTIONS for checking later.
314 Layout::Relaxation_debug_check::read_sections(
315 const Layout::Section_list
& sections
)
317 for(Layout::Section_list::const_iterator p
= sections
.begin();
321 Output_section
* os
= *p
;
323 info
.output_section
= os
;
324 info
.address
= os
->is_address_valid() ? os
->address() : 0;
325 info
.data_size
= os
->is_data_size_valid() ? os
->data_size() : -1;
326 info
.offset
= os
->is_offset_valid()? os
->offset() : -1 ;
327 this->section_infos_
.push_back(info
);
331 // Verify SECTIONS using previously recorded information.
334 Layout::Relaxation_debug_check::verify_sections(
335 const Layout::Section_list
& sections
)
338 for(Layout::Section_list::const_iterator p
= sections
.begin();
342 Output_section
* os
= *p
;
343 uint64_t address
= os
->is_address_valid() ? os
->address() : 0;
344 off_t data_size
= os
->is_data_size_valid() ? os
->data_size() : -1;
345 off_t offset
= os
->is_offset_valid()? os
->offset() : -1 ;
347 if (i
>= this->section_infos_
.size())
349 gold_fatal("Section_info of %s missing.\n", os
->name());
351 const Section_info
& info
= this->section_infos_
[i
];
352 if (os
!= info
.output_section
)
353 gold_fatal("Section order changed. Expecting %s but see %s\n",
354 info
.output_section
->name(), os
->name());
355 if (address
!= info
.address
356 || data_size
!= info
.data_size
357 || offset
!= info
.offset
)
358 gold_fatal("Section %s changed.\n", os
->name());
362 // Layout_task_runner methods.
364 // Lay out the sections. This is called after all the input objects
368 Layout_task_runner::run(Workqueue
* workqueue
, const Task
* task
)
370 // See if any of the input definitions violate the One Definition Rule.
371 // TODO: if this is too slow, do this as a task, rather than inline.
372 this->symtab_
->detect_odr_violations(task
, this->options_
.output_file_name());
374 Layout
* layout
= this->layout_
;
375 off_t file_size
= layout
->finalize(this->input_objects_
,
380 // Now we know the final size of the output file and we know where
381 // each piece of information goes.
383 if (this->mapfile_
!= NULL
)
385 this->mapfile_
->print_discarded_sections(this->input_objects_
);
386 layout
->print_to_mapfile(this->mapfile_
);
390 if (layout
->incremental_base() == NULL
)
392 of
= new Output_file(parameters
->options().output_file_name());
393 if (this->options_
.oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
394 of
->set_is_temporary();
399 of
= layout
->incremental_base()->output_file();
401 // Apply the incremental relocations for symbols whose values
402 // have changed. We do this before we resize the file and start
403 // writing anything else to it, so that we can read the old
404 // incremental information from the file before (possibly)
406 if (parameters
->incremental_update())
407 layout
->incremental_base()->apply_incremental_relocs(this->symtab_
,
411 of
->resize(file_size
);
414 // Queue up the final set of tasks.
415 gold::queue_final_tasks(this->options_
, this->input_objects_
,
416 this->symtab_
, layout
, workqueue
, of
);
421 Layout::Layout(int number_of_input_files
, Script_options
* script_options
)
422 : number_of_input_files_(number_of_input_files
),
423 script_options_(script_options
),
431 unattached_section_list_(),
432 special_output_list_(),
433 relax_output_list_(),
434 section_headers_(NULL
),
436 relro_segment_(NULL
),
437 interp_segment_(NULL
),
439 symtab_section_(NULL
),
440 symtab_xindex_(NULL
),
441 dynsym_section_(NULL
),
442 dynsym_xindex_(NULL
),
443 dynamic_section_(NULL
),
444 dynamic_symbol_(NULL
),
446 eh_frame_section_(NULL
),
447 eh_frame_data_(NULL
),
448 added_eh_frame_data_(false),
449 eh_frame_hdr_section_(NULL
),
450 gdb_index_data_(NULL
),
451 build_id_note_(NULL
),
455 output_file_size_(-1),
456 have_added_input_section_(false),
457 sections_are_attached_(false),
458 input_requires_executable_stack_(false),
459 input_with_gnu_stack_note_(false),
460 input_without_gnu_stack_note_(false),
461 has_static_tls_(false),
462 any_postprocessing_sections_(false),
463 resized_signatures_(false),
464 have_stabstr_section_(false),
465 section_ordering_specified_(false),
466 unique_segment_for_sections_specified_(false),
467 incremental_inputs_(NULL
),
468 record_output_section_data_from_script_(false),
469 script_output_section_data_list_(),
470 segment_states_(NULL
),
471 relaxation_debug_check_(NULL
),
472 section_order_map_(),
473 section_segment_map_(),
474 input_section_position_(),
475 input_section_glob_(),
476 incremental_base_(NULL
),
480 // Make space for more than enough segments for a typical file.
481 // This is just for efficiency--it's OK if we wind up needing more.
482 this->segment_list_
.reserve(12);
484 // We expect two unattached Output_data objects: the file header and
485 // the segment headers.
486 this->special_output_list_
.reserve(2);
488 // Initialize structure needed for an incremental build.
489 if (parameters
->incremental())
490 this->incremental_inputs_
= new Incremental_inputs
;
492 // The section name pool is worth optimizing in all cases, because
493 // it is small, but there are often overlaps due to .rel sections.
494 this->namepool_
.set_optimize();
497 // For incremental links, record the base file to be modified.
500 Layout::set_incremental_base(Incremental_binary
* base
)
502 this->incremental_base_
= base
;
503 this->free_list_
.init(base
->output_file()->filesize(), true);
506 // Hash a key we use to look up an output section mapping.
509 Layout::Hash_key::operator()(const Layout::Key
& k
) const
511 return k
.first
+ k
.second
.first
+ k
.second
.second
;
514 // These are the debug sections that are actually used by gdb.
515 // Currently, we've checked versions of gdb up to and including 7.4.
516 // We only check the part of the name that follows ".debug_" or
519 static const char* gdb_sections
[] =
522 "addr", // Fission extension
523 // "aranges", // not used by gdb as of 7.4
532 // "pubnames", // not used by gdb as of 7.4
533 // "pubtypes", // not used by gdb as of 7.4
534 // "gnu_pubnames", // Fission extension
535 // "gnu_pubtypes", // Fission extension
541 // This is the minimum set of sections needed for line numbers.
543 static const char* lines_only_debug_sections
[] =
546 // "addr", // Fission extension
547 // "aranges", // not used by gdb as of 7.4
556 // "pubnames", // not used by gdb as of 7.4
557 // "pubtypes", // not used by gdb as of 7.4
558 // "gnu_pubnames", // Fission extension
559 // "gnu_pubtypes", // Fission extension
562 "str_offsets", // Fission extension
565 // These sections are the DWARF fast-lookup tables, and are not needed
566 // when building a .gdb_index section.
568 static const char* gdb_fast_lookup_sections
[] =
577 // Returns whether the given debug section is in the list of
578 // debug-sections-used-by-some-version-of-gdb. SUFFIX is the
579 // portion of the name following ".debug_" or ".zdebug_".
582 is_gdb_debug_section(const char* suffix
)
584 // We can do this faster: binary search or a hashtable. But why bother?
585 for (size_t i
= 0; i
< sizeof(gdb_sections
)/sizeof(*gdb_sections
); ++i
)
586 if (strcmp(suffix
, gdb_sections
[i
]) == 0)
591 // Returns whether the given section is needed for lines-only debugging.
594 is_lines_only_debug_section(const char* suffix
)
596 // We can do this faster: binary search or a hashtable. But why bother?
598 i
< sizeof(lines_only_debug_sections
)/sizeof(*lines_only_debug_sections
);
600 if (strcmp(suffix
, lines_only_debug_sections
[i
]) == 0)
605 // Returns whether the given section is a fast-lookup section that
606 // will not be needed when building a .gdb_index section.
609 is_gdb_fast_lookup_section(const char* suffix
)
611 // We can do this faster: binary search or a hashtable. But why bother?
613 i
< sizeof(gdb_fast_lookup_sections
)/sizeof(*gdb_fast_lookup_sections
);
615 if (strcmp(suffix
, gdb_fast_lookup_sections
[i
]) == 0)
620 // Sometimes we compress sections. This is typically done for
621 // sections that are not part of normal program execution (such as
622 // .debug_* sections), and where the readers of these sections know
623 // how to deal with compressed sections. This routine doesn't say for
624 // certain whether we'll compress -- it depends on commandline options
625 // as well -- just whether this section is a candidate for compression.
626 // (The Output_compressed_section class decides whether to compress
627 // a given section, and picks the name of the compressed section.)
630 is_compressible_debug_section(const char* secname
)
632 return (is_prefix_of(".debug", secname
));
635 // We may see compressed debug sections in input files. Return TRUE
636 // if this is the name of a compressed debug section.
639 is_compressed_debug_section(const char* secname
)
641 return (is_prefix_of(".zdebug", secname
));
645 corresponding_uncompressed_section_name(std::string secname
)
647 gold_assert(secname
[0] == '.' && secname
[1] == 'z');
648 std::string
ret(".");
649 ret
.append(secname
, 2, std::string::npos
);
653 // Whether to include this section in the link.
655 template<int size
, bool big_endian
>
657 Layout::include_section(Sized_relobj_file
<size
, big_endian
>*, const char* name
,
658 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
660 if (!parameters
->options().relocatable()
661 && (shdr
.get_sh_flags() & elfcpp::SHF_EXCLUDE
))
664 elfcpp::Elf_Word sh_type
= shdr
.get_sh_type();
666 if ((sh_type
>= elfcpp::SHT_LOOS
&& sh_type
<= elfcpp::SHT_HIOS
)
667 || (sh_type
>= elfcpp::SHT_LOPROC
&& sh_type
<= elfcpp::SHT_HIPROC
))
668 return parameters
->target().should_include_section(sh_type
);
672 case elfcpp::SHT_NULL
:
673 case elfcpp::SHT_SYMTAB
:
674 case elfcpp::SHT_DYNSYM
:
675 case elfcpp::SHT_HASH
:
676 case elfcpp::SHT_DYNAMIC
:
677 case elfcpp::SHT_SYMTAB_SHNDX
:
680 case elfcpp::SHT_STRTAB
:
681 // Discard the sections which have special meanings in the ELF
682 // ABI. Keep others (e.g., .stabstr). We could also do this by
683 // checking the sh_link fields of the appropriate sections.
684 return (strcmp(name
, ".dynstr") != 0
685 && strcmp(name
, ".strtab") != 0
686 && strcmp(name
, ".shstrtab") != 0);
688 case elfcpp::SHT_RELA
:
689 case elfcpp::SHT_REL
:
690 case elfcpp::SHT_GROUP
:
691 // If we are emitting relocations these should be handled
693 gold_assert(!parameters
->options().relocatable());
696 case elfcpp::SHT_PROGBITS
:
697 if (parameters
->options().strip_debug()
698 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
700 if (is_debug_info_section(name
))
703 if (parameters
->options().strip_debug_non_line()
704 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
706 // Debugging sections can only be recognized by name.
707 if (is_prefix_of(".debug_", name
)
708 && !is_lines_only_debug_section(name
+ 7))
710 if (is_prefix_of(".zdebug_", name
)
711 && !is_lines_only_debug_section(name
+ 8))
714 if (parameters
->options().strip_debug_gdb()
715 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
717 // Debugging sections can only be recognized by name.
718 if (is_prefix_of(".debug_", name
)
719 && !is_gdb_debug_section(name
+ 7))
721 if (is_prefix_of(".zdebug_", name
)
722 && !is_gdb_debug_section(name
+ 8))
725 if (parameters
->options().gdb_index()
726 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
728 // When building .gdb_index, we can strip .debug_pubnames,
729 // .debug_pubtypes, and .debug_aranges sections.
730 if (is_prefix_of(".debug_", name
)
731 && is_gdb_fast_lookup_section(name
+ 7))
733 if (is_prefix_of(".zdebug_", name
)
734 && is_gdb_fast_lookup_section(name
+ 8))
737 if (parameters
->options().strip_lto_sections()
738 && !parameters
->options().relocatable()
739 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
741 // Ignore LTO sections containing intermediate code.
742 if (is_prefix_of(".gnu.lto_", name
))
745 // The GNU linker strips .gnu_debuglink sections, so we do too.
746 // This is a feature used to keep debugging information in
748 if (strcmp(name
, ".gnu_debuglink") == 0)
757 // Return an output section named NAME, or NULL if there is none.
760 Layout::find_output_section(const char* name
) const
762 for (Section_list::const_iterator p
= this->section_list_
.begin();
763 p
!= this->section_list_
.end();
765 if (strcmp((*p
)->name(), name
) == 0)
770 // Return an output segment of type TYPE, with segment flags SET set
771 // and segment flags CLEAR clear. Return NULL if there is none.
774 Layout::find_output_segment(elfcpp::PT type
, elfcpp::Elf_Word set
,
775 elfcpp::Elf_Word clear
) const
777 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
778 p
!= this->segment_list_
.end();
780 if (static_cast<elfcpp::PT
>((*p
)->type()) == type
781 && ((*p
)->flags() & set
) == set
782 && ((*p
)->flags() & clear
) == 0)
787 // When we put a .ctors or .dtors section with more than one word into
788 // a .init_array or .fini_array section, we need to reverse the words
789 // in the .ctors/.dtors section. This is because .init_array executes
790 // constructors front to back, where .ctors executes them back to
791 // front, and vice-versa for .fini_array/.dtors. Although we do want
792 // to remap .ctors/.dtors into .init_array/.fini_array because it can
793 // be more efficient, we don't want to change the order in which
794 // constructors/destructors are run. This set just keeps track of
795 // these sections which need to be reversed. It is only changed by
796 // Layout::layout. It should be a private member of Layout, but that
797 // would require layout.h to #include object.h to get the definition
799 static Unordered_set
<Section_id
, Section_id_hash
> ctors_sections_in_init_array
;
801 // Return whether OBJECT/SHNDX is a .ctors/.dtors section mapped to a
802 // .init_array/.fini_array section.
805 Layout::is_ctors_in_init_array(Relobj
* relobj
, unsigned int shndx
) const
807 return (ctors_sections_in_init_array
.find(Section_id(relobj
, shndx
))
808 != ctors_sections_in_init_array
.end());
811 // Return the output section to use for section NAME with type TYPE
812 // and section flags FLAGS. NAME must be canonicalized in the string
813 // pool, and NAME_KEY is the key. ORDER is where this should appear
814 // in the output sections. IS_RELRO is true for a relro section.
817 Layout::get_output_section(const char* name
, Stringpool::Key name_key
,
818 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
819 Output_section_order order
, bool is_relro
)
821 elfcpp::Elf_Word lookup_type
= type
;
823 // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and
824 // PREINIT_ARRAY like PROGBITS. This ensures that we combine
825 // .init_array, .fini_array, and .preinit_array sections by name
826 // whatever their type in the input file. We do this because the
827 // types are not always right in the input files.
828 if (lookup_type
== elfcpp::SHT_INIT_ARRAY
829 || lookup_type
== elfcpp::SHT_FINI_ARRAY
830 || lookup_type
== elfcpp::SHT_PREINIT_ARRAY
)
831 lookup_type
= elfcpp::SHT_PROGBITS
;
833 elfcpp::Elf_Xword lookup_flags
= flags
;
835 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
836 // read-write with read-only sections. Some other ELF linkers do
837 // not do this. FIXME: Perhaps there should be an option
839 lookup_flags
&= ~(elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
841 const Key
key(name_key
, std::make_pair(lookup_type
, lookup_flags
));
842 const std::pair
<Key
, Output_section
*> v(key
, NULL
);
843 std::pair
<Section_name_map::iterator
, bool> ins(
844 this->section_name_map_
.insert(v
));
847 return ins
.first
->second
;
850 // This is the first time we've seen this name/type/flags
851 // combination. For compatibility with the GNU linker, we
852 // combine sections with contents and zero flags with sections
853 // with non-zero flags. This is a workaround for cases where
854 // assembler code forgets to set section flags. FIXME: Perhaps
855 // there should be an option to control this.
856 Output_section
* os
= NULL
;
858 if (lookup_type
== elfcpp::SHT_PROGBITS
)
862 Output_section
* same_name
= this->find_output_section(name
);
863 if (same_name
!= NULL
864 && (same_name
->type() == elfcpp::SHT_PROGBITS
865 || same_name
->type() == elfcpp::SHT_INIT_ARRAY
866 || same_name
->type() == elfcpp::SHT_FINI_ARRAY
867 || same_name
->type() == elfcpp::SHT_PREINIT_ARRAY
)
868 && (same_name
->flags() & elfcpp::SHF_TLS
) == 0)
871 else if ((flags
& elfcpp::SHF_TLS
) == 0)
873 elfcpp::Elf_Xword zero_flags
= 0;
874 const Key
zero_key(name_key
, std::make_pair(lookup_type
,
876 Section_name_map::iterator p
=
877 this->section_name_map_
.find(zero_key
);
878 if (p
!= this->section_name_map_
.end())
884 os
= this->make_output_section(name
, type
, flags
, order
, is_relro
);
886 ins
.first
->second
= os
;
891 // Returns TRUE iff NAME (an input section from RELOBJ) will
892 // be mapped to an output section that should be KEPT.
895 Layout::keep_input_section(const Relobj
* relobj
, const char* name
)
897 if (! this->script_options_
->saw_sections_clause())
900 Script_sections
* ss
= this->script_options_
->script_sections();
901 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
902 Output_section
** output_section_slot
;
903 Script_sections::Section_type script_section_type
;
906 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
907 &script_section_type
, &keep
, true);
908 return name
!= NULL
&& keep
;
911 // Clear the input section flags that should not be copied to the
915 Layout::get_output_section_flags(elfcpp::Elf_Xword input_section_flags
)
917 // Some flags in the input section should not be automatically
918 // copied to the output section.
919 input_section_flags
&= ~ (elfcpp::SHF_INFO_LINK
921 | elfcpp::SHF_COMPRESSED
923 | elfcpp::SHF_STRINGS
);
925 // We only clear the SHF_LINK_ORDER flag in for
926 // a non-relocatable link.
927 if (!parameters
->options().relocatable())
928 input_section_flags
&= ~elfcpp::SHF_LINK_ORDER
;
930 return input_section_flags
;
933 // Pick the output section to use for section NAME, in input file
934 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
935 // linker created section. IS_INPUT_SECTION is true if we are
936 // choosing an output section for an input section found in a input
937 // file. ORDER is where this section should appear in the output
938 // sections. IS_RELRO is true for a relro section. This will return
939 // NULL if the input section should be discarded. MATCH_INPUT_SPEC
940 // is true if the section name should be matched against input specs
941 // in a linker script.
944 Layout::choose_output_section(const Relobj
* relobj
, const char* name
,
945 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
946 bool is_input_section
, Output_section_order order
,
947 bool is_relro
, bool is_reloc
,
948 bool match_input_spec
)
950 // We should not see any input sections after we have attached
951 // sections to segments.
952 gold_assert(!is_input_section
|| !this->sections_are_attached_
);
954 flags
= this->get_output_section_flags(flags
);
956 if (this->script_options_
->saw_sections_clause() && !is_reloc
)
958 // We are using a SECTIONS clause, so the output section is
959 // chosen based only on the name.
961 Script_sections
* ss
= this->script_options_
->script_sections();
962 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
963 Output_section
** output_section_slot
;
964 Script_sections::Section_type script_section_type
;
965 const char* orig_name
= name
;
967 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
968 &script_section_type
, &keep
,
973 gold_debug(DEBUG_SCRIPT
, _("Unable to create output section '%s' "
974 "because it is not allowed by the "
975 "SECTIONS clause of the linker script"),
977 // The SECTIONS clause says to discard this input section.
981 // We can only handle script section types ST_NONE and ST_NOLOAD.
982 switch (script_section_type
)
984 case Script_sections::ST_NONE
:
986 case Script_sections::ST_NOLOAD
:
987 flags
&= elfcpp::SHF_ALLOC
;
993 // If this is an orphan section--one not mentioned in the linker
994 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
995 // default processing below.
997 if (output_section_slot
!= NULL
)
999 if (*output_section_slot
!= NULL
)
1001 (*output_section_slot
)->update_flags_for_input_section(flags
);
1002 return *output_section_slot
;
1005 // We don't put sections found in the linker script into
1006 // SECTION_NAME_MAP_. That keeps us from getting confused
1007 // if an orphan section is mapped to a section with the same
1008 // name as one in the linker script.
1010 name
= this->namepool_
.add(name
, false, NULL
);
1012 Output_section
* os
= this->make_output_section(name
, type
, flags
,
1015 os
->set_found_in_sections_clause();
1017 // Special handling for NOLOAD sections.
1018 if (script_section_type
== Script_sections::ST_NOLOAD
)
1020 os
->set_is_noload();
1022 // The constructor of Output_section sets addresses of non-ALLOC
1023 // sections to 0 by default. We don't want that for NOLOAD
1024 // sections even if they have no SHF_ALLOC flag.
1025 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0
1026 && os
->is_address_valid())
1028 gold_assert(os
->address() == 0
1029 && !os
->is_offset_valid()
1030 && !os
->is_data_size_valid());
1031 os
->reset_address_and_file_offset();
1035 *output_section_slot
= os
;
1040 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
1042 size_t len
= strlen(name
);
1043 std::string uncompressed_name
;
1045 // Compressed debug sections should be mapped to the corresponding
1046 // uncompressed section.
1047 if (is_compressed_debug_section(name
))
1050 corresponding_uncompressed_section_name(std::string(name
, len
));
1051 name
= uncompressed_name
.c_str();
1052 len
= uncompressed_name
.length();
1055 // Turn NAME from the name of the input section into the name of the
1057 if (is_input_section
1058 && !this->script_options_
->saw_sections_clause()
1059 && !parameters
->options().relocatable())
1061 const char *orig_name
= name
;
1062 name
= parameters
->target().output_section_name(relobj
, name
, &len
);
1064 name
= Layout::output_section_name(relobj
, orig_name
, &len
);
1067 Stringpool::Key name_key
;
1068 name
= this->namepool_
.add_with_length(name
, len
, true, &name_key
);
1070 // Find or make the output section. The output section is selected
1071 // based on the section name, type, and flags.
1072 return this->get_output_section(name
, name_key
, type
, flags
, order
, is_relro
);
1075 // For incremental links, record the initial fixed layout of a section
1076 // from the base file, and return a pointer to the Output_section.
1078 template<int size
, bool big_endian
>
1080 Layout::init_fixed_output_section(const char* name
,
1081 elfcpp::Shdr
<size
, big_endian
>& shdr
)
1083 unsigned int sh_type
= shdr
.get_sh_type();
1085 // We preserve the layout of PROGBITS, NOBITS, INIT_ARRAY, FINI_ARRAY,
1086 // PRE_INIT_ARRAY, and NOTE sections.
1087 // All others will be created from scratch and reallocated.
1088 if (!can_incremental_update(sh_type
))
1091 // If we're generating a .gdb_index section, we need to regenerate
1093 if (parameters
->options().gdb_index()
1094 && sh_type
== elfcpp::SHT_PROGBITS
1095 && strcmp(name
, ".gdb_index") == 0)
1098 typename
elfcpp::Elf_types
<size
>::Elf_Addr sh_addr
= shdr
.get_sh_addr();
1099 typename
elfcpp::Elf_types
<size
>::Elf_Off sh_offset
= shdr
.get_sh_offset();
1100 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
1101 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_flags
= shdr
.get_sh_flags();
1102 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_addralign
=
1103 shdr
.get_sh_addralign();
1105 // Make the output section.
1106 Stringpool::Key name_key
;
1107 name
= this->namepool_
.add(name
, true, &name_key
);
1108 Output_section
* os
= this->get_output_section(name
, name_key
, sh_type
,
1109 sh_flags
, ORDER_INVALID
, false);
1110 os
->set_fixed_layout(sh_addr
, sh_offset
, sh_size
, sh_addralign
);
1111 if (sh_type
!= elfcpp::SHT_NOBITS
)
1112 this->free_list_
.remove(sh_offset
, sh_offset
+ sh_size
);
1116 // Return the index by which an input section should be ordered. This
1117 // is used to sort some .text sections, for compatibility with GNU ld.
1120 Layout::special_ordering_of_input_section(const char* name
)
1122 // The GNU linker has some special handling for some sections that
1123 // wind up in the .text section. Sections that start with these
1124 // prefixes must appear first, and must appear in the order listed
1126 static const char* const text_section_sort
[] =
1135 i
< sizeof(text_section_sort
) / sizeof(text_section_sort
[0]);
1137 if (is_prefix_of(text_section_sort
[i
], name
))
1143 // Return the output section to use for input section SHNDX, with name
1144 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
1145 // index of a relocation section which applies to this section, or 0
1146 // if none, or -1U if more than one. RELOC_TYPE is the type of the
1147 // relocation section if there is one. Set *OFF to the offset of this
1148 // input section without the output section. Return NULL if the
1149 // section should be discarded. Set *OFF to -1 if the section
1150 // contents should not be written directly to the output file, but
1151 // will instead receive special handling.
1153 template<int size
, bool big_endian
>
1155 Layout::layout(Sized_relobj_file
<size
, big_endian
>* object
, unsigned int shndx
,
1156 const char* name
, const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1157 unsigned int sh_type
, unsigned int reloc_shndx
,
1158 unsigned int, off_t
* off
)
1162 if (!this->include_section(object
, name
, shdr
))
1165 // In a relocatable link a grouped section must not be combined with
1166 // any other sections.
1168 if (parameters
->options().relocatable()
1169 && (shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) != 0)
1171 // Some flags in the input section should not be automatically
1172 // copied to the output section.
1173 elfcpp::Elf_Xword flags
= (shdr
.get_sh_flags()
1174 & ~ elfcpp::SHF_COMPRESSED
);
1175 name
= this->namepool_
.add(name
, true, NULL
);
1176 os
= this->make_output_section(name
, sh_type
, flags
,
1177 ORDER_INVALID
, false);
1181 // All ".text.unlikely.*" sections can be moved to a unique
1182 // segment with --text-unlikely-segment option.
1183 bool text_unlikely_segment
1184 = (parameters
->options().text_unlikely_segment()
1185 && is_prefix_of(".text.unlikely",
1186 object
->section_name(shndx
).c_str()));
1187 if (text_unlikely_segment
)
1189 elfcpp::Elf_Xword flags
1190 = this->get_output_section_flags(shdr
.get_sh_flags());
1192 Stringpool::Key name_key
;
1193 const char* os_name
= this->namepool_
.add(".text.unlikely", true,
1195 os
= this->get_output_section(os_name
, name_key
, sh_type
, flags
,
1196 ORDER_INVALID
, false);
1197 // Map this output section to a unique segment. This is done to
1198 // separate "text" that is not likely to be executed from "text"
1199 // that is likely executed.
1200 os
->set_is_unique_segment();
1204 // Plugins can choose to place one or more subsets of sections in
1205 // unique segments and this is done by mapping these section subsets
1206 // to unique output sections. Check if this section needs to be
1207 // remapped to a unique output section.
1208 Section_segment_map::iterator it
1209 = this->section_segment_map_
.find(Const_section_id(object
, shndx
));
1210 if (it
== this->section_segment_map_
.end())
1212 os
= this->choose_output_section(object
, name
, sh_type
,
1213 shdr
.get_sh_flags(), true,
1214 ORDER_INVALID
, false, false,
1219 // We know the name of the output section, directly call
1220 // get_output_section here by-passing choose_output_section.
1221 elfcpp::Elf_Xword flags
1222 = this->get_output_section_flags(shdr
.get_sh_flags());
1224 const char* os_name
= it
->second
->name
;
1225 Stringpool::Key name_key
;
1226 os_name
= this->namepool_
.add(os_name
, true, &name_key
);
1227 os
= this->get_output_section(os_name
, name_key
, sh_type
, flags
,
1228 ORDER_INVALID
, false);
1229 if (!os
->is_unique_segment())
1231 os
->set_is_unique_segment();
1232 os
->set_extra_segment_flags(it
->second
->flags
);
1233 os
->set_segment_alignment(it
->second
->align
);
1241 // By default the GNU linker sorts input sections whose names match
1242 // .ctors.*, .dtors.*, .init_array.*, or .fini_array.*. The
1243 // sections are sorted by name. This is used to implement
1244 // constructor priority ordering. We are compatible. When we put
1245 // .ctor sections in .init_array and .dtor sections in .fini_array,
1246 // we must also sort plain .ctor and .dtor sections.
1247 if (!this->script_options_
->saw_sections_clause()
1248 && !parameters
->options().relocatable()
1249 && (is_prefix_of(".ctors.", name
)
1250 || is_prefix_of(".dtors.", name
)
1251 || is_prefix_of(".init_array.", name
)
1252 || is_prefix_of(".fini_array.", name
)
1253 || (parameters
->options().ctors_in_init_array()
1254 && (strcmp(name
, ".ctors") == 0
1255 || strcmp(name
, ".dtors") == 0))))
1256 os
->set_must_sort_attached_input_sections();
1258 // By default the GNU linker sorts some special text sections ahead
1259 // of others. We are compatible.
1260 if (parameters
->options().text_reorder()
1261 && !this->script_options_
->saw_sections_clause()
1262 && !this->is_section_ordering_specified()
1263 && !parameters
->options().relocatable()
1264 && Layout::special_ordering_of_input_section(name
) >= 0)
1265 os
->set_must_sort_attached_input_sections();
1267 // If this is a .ctors or .ctors.* section being mapped to a
1268 // .init_array section, or a .dtors or .dtors.* section being mapped
1269 // to a .fini_array section, we will need to reverse the words if
1270 // there is more than one. Record this section for later. See
1271 // ctors_sections_in_init_array above.
1272 if (!this->script_options_
->saw_sections_clause()
1273 && !parameters
->options().relocatable()
1274 && shdr
.get_sh_size() > size
/ 8
1275 && (((strcmp(name
, ".ctors") == 0
1276 || is_prefix_of(".ctors.", name
))
1277 && strcmp(os
->name(), ".init_array") == 0)
1278 || ((strcmp(name
, ".dtors") == 0
1279 || is_prefix_of(".dtors.", name
))
1280 && strcmp(os
->name(), ".fini_array") == 0)))
1281 ctors_sections_in_init_array
.insert(Section_id(object
, shndx
));
1283 // FIXME: Handle SHF_LINK_ORDER somewhere.
1285 elfcpp::Elf_Xword orig_flags
= os
->flags();
1287 *off
= os
->add_input_section(this, object
, shndx
, name
, shdr
, reloc_shndx
,
1288 this->script_options_
->saw_sections_clause());
1290 // If the flags changed, we may have to change the order.
1291 if ((orig_flags
& elfcpp::SHF_ALLOC
) != 0)
1293 orig_flags
&= (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1294 elfcpp::Elf_Xword new_flags
=
1295 os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1296 if (orig_flags
!= new_flags
)
1297 os
->set_order(this->default_section_order(os
, false));
1300 this->have_added_input_section_
= true;
1305 // Maps section SECN to SEGMENT s.
1307 Layout::insert_section_segment_map(Const_section_id secn
,
1308 Unique_segment_info
*s
)
1310 gold_assert(this->unique_segment_for_sections_specified_
);
1311 this->section_segment_map_
[secn
] = s
;
1314 // Handle a relocation section when doing a relocatable link.
1316 template<int size
, bool big_endian
>
1318 Layout::layout_reloc(Sized_relobj_file
<size
, big_endian
>*,
1320 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1321 Output_section
* data_section
,
1322 Relocatable_relocs
* rr
)
1324 gold_assert(parameters
->options().relocatable()
1325 || parameters
->options().emit_relocs());
1327 int sh_type
= shdr
.get_sh_type();
1330 if (sh_type
== elfcpp::SHT_REL
)
1332 else if (sh_type
== elfcpp::SHT_RELA
)
1336 name
+= data_section
->name();
1338 // If the output data section already has a reloc section, use that;
1339 // otherwise, make a new one.
1340 Output_section
* os
= data_section
->reloc_section();
1343 const char* n
= this->namepool_
.add(name
.c_str(), true, NULL
);
1344 os
= this->make_output_section(n
, sh_type
, shdr
.get_sh_flags(),
1345 ORDER_INVALID
, false);
1346 os
->set_should_link_to_symtab();
1347 os
->set_info_section(data_section
);
1348 data_section
->set_reloc_section(os
);
1351 Output_section_data
* posd
;
1352 if (sh_type
== elfcpp::SHT_REL
)
1354 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rel_size
);
1355 posd
= new Output_relocatable_relocs
<elfcpp::SHT_REL
,
1359 else if (sh_type
== elfcpp::SHT_RELA
)
1361 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rela_size
);
1362 posd
= new Output_relocatable_relocs
<elfcpp::SHT_RELA
,
1369 os
->add_output_section_data(posd
);
1370 rr
->set_output_data(posd
);
1375 // Handle a group section when doing a relocatable link.
1377 template<int size
, bool big_endian
>
1379 Layout::layout_group(Symbol_table
* symtab
,
1380 Sized_relobj_file
<size
, big_endian
>* object
,
1382 const char* group_section_name
,
1383 const char* signature
,
1384 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1385 elfcpp::Elf_Word flags
,
1386 std::vector
<unsigned int>* shndxes
)
1388 gold_assert(parameters
->options().relocatable());
1389 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_GROUP
);
1390 group_section_name
= this->namepool_
.add(group_section_name
, true, NULL
);
1391 Output_section
* os
= this->make_output_section(group_section_name
,
1393 shdr
.get_sh_flags(),
1394 ORDER_INVALID
, false);
1396 // We need to find a symbol with the signature in the symbol table.
1397 // If we don't find one now, we need to look again later.
1398 Symbol
* sym
= symtab
->lookup(signature
, NULL
);
1400 os
->set_info_symndx(sym
);
1403 // Reserve some space to minimize reallocations.
1404 if (this->group_signatures_
.empty())
1405 this->group_signatures_
.reserve(this->number_of_input_files_
* 16);
1407 // We will wind up using a symbol whose name is the signature.
1408 // So just put the signature in the symbol name pool to save it.
1409 signature
= symtab
->canonicalize_name(signature
);
1410 this->group_signatures_
.push_back(Group_signature(os
, signature
));
1413 os
->set_should_link_to_symtab();
1416 section_size_type entry_count
=
1417 convert_to_section_size_type(shdr
.get_sh_size() / 4);
1418 Output_section_data
* posd
=
1419 new Output_data_group
<size
, big_endian
>(object
, entry_count
, flags
,
1421 os
->add_output_section_data(posd
);
1424 // Special GNU handling of sections name .eh_frame. They will
1425 // normally hold exception frame data as defined by the C++ ABI
1426 // (http://codesourcery.com/cxx-abi/).
1428 template<int size
, bool big_endian
>
1430 Layout::layout_eh_frame(Sized_relobj_file
<size
, big_endian
>* object
,
1431 const unsigned char* symbols
,
1433 const unsigned char* symbol_names
,
1434 off_t symbol_names_size
,
1436 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1437 unsigned int reloc_shndx
, unsigned int reloc_type
,
1440 const unsigned int unwind_section_type
=
1441 parameters
->target().unwind_section_type();
1443 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
1444 || shdr
.get_sh_type() == unwind_section_type
);
1445 gold_assert((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
1447 Output_section
* os
= this->make_eh_frame_section(object
);
1451 gold_assert(this->eh_frame_section_
== os
);
1453 elfcpp::Elf_Xword orig_flags
= os
->flags();
1455 Eh_frame::Eh_frame_section_disposition disp
=
1456 Eh_frame::EH_UNRECOGNIZED_SECTION
;
1457 if (!parameters
->incremental())
1459 disp
= this->eh_frame_data_
->add_ehframe_input_section(object
,
1469 if (disp
== Eh_frame::EH_OPTIMIZABLE_SECTION
)
1471 os
->update_flags_for_input_section(shdr
.get_sh_flags());
1473 // A writable .eh_frame section is a RELRO section.
1474 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1475 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1478 os
->set_order(ORDER_RELRO
);
1485 if (disp
== Eh_frame::EH_END_MARKER_SECTION
&& !this->added_eh_frame_data_
)
1487 // We found the end marker section, so now we can add the set of
1488 // optimized sections to the output section. We need to postpone
1489 // adding this until we've found a section we can optimize so that
1490 // the .eh_frame section in crtbeginT.o winds up at the start of
1491 // the output section.
1492 os
->add_output_section_data(this->eh_frame_data_
);
1493 this->added_eh_frame_data_
= true;
1496 // We couldn't handle this .eh_frame section for some reason.
1497 // Add it as a normal section.
1498 bool saw_sections_clause
= this->script_options_
->saw_sections_clause();
1499 *off
= os
->add_input_section(this, object
, shndx
, ".eh_frame", shdr
,
1500 reloc_shndx
, saw_sections_clause
);
1501 this->have_added_input_section_
= true;
1503 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1504 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1505 os
->set_order(this->default_section_order(os
, false));
1511 Layout::finalize_eh_frame_section()
1513 // If we never found an end marker section, we need to add the
1514 // optimized eh sections to the output section now.
1515 if (!parameters
->incremental()
1516 && this->eh_frame_section_
!= NULL
1517 && !this->added_eh_frame_data_
)
1519 this->eh_frame_section_
->add_output_section_data(this->eh_frame_data_
);
1520 this->added_eh_frame_data_
= true;
1524 // Create and return the magic .eh_frame section. Create
1525 // .eh_frame_hdr also if appropriate. OBJECT is the object with the
1526 // input .eh_frame section; it may be NULL.
1529 Layout::make_eh_frame_section(const Relobj
* object
)
1531 const unsigned int unwind_section_type
=
1532 parameters
->target().unwind_section_type();
1534 Output_section
* os
= this->choose_output_section(object
, ".eh_frame",
1535 unwind_section_type
,
1536 elfcpp::SHF_ALLOC
, false,
1537 ORDER_EHFRAME
, false, false,
1542 if (this->eh_frame_section_
== NULL
)
1544 this->eh_frame_section_
= os
;
1545 this->eh_frame_data_
= new Eh_frame();
1547 // For incremental linking, we do not optimize .eh_frame sections
1548 // or create a .eh_frame_hdr section.
1549 if (parameters
->options().eh_frame_hdr() && !parameters
->incremental())
1551 Output_section
* hdr_os
=
1552 this->choose_output_section(NULL
, ".eh_frame_hdr",
1553 unwind_section_type
,
1554 elfcpp::SHF_ALLOC
, false,
1555 ORDER_EHFRAME
, false, false,
1560 Eh_frame_hdr
* hdr_posd
= new Eh_frame_hdr(os
,
1561 this->eh_frame_data_
);
1562 hdr_os
->add_output_section_data(hdr_posd
);
1564 hdr_os
->set_after_input_sections();
1566 if (!this->script_options_
->saw_phdrs_clause())
1568 Output_segment
* hdr_oseg
;
1569 hdr_oseg
= this->make_output_segment(elfcpp::PT_GNU_EH_FRAME
,
1571 hdr_oseg
->add_output_section_to_nonload(hdr_os
,
1575 this->eh_frame_data_
->set_eh_frame_hdr(hdr_posd
);
1583 // Add an exception frame for a PLT. This is called from target code.
1586 Layout::add_eh_frame_for_plt(Output_data
* plt
, const unsigned char* cie_data
,
1587 size_t cie_length
, const unsigned char* fde_data
,
1590 if (parameters
->incremental())
1592 // FIXME: Maybe this could work some day....
1595 Output_section
* os
= this->make_eh_frame_section(NULL
);
1598 this->eh_frame_data_
->add_ehframe_for_plt(plt
, cie_data
, cie_length
,
1599 fde_data
, fde_length
);
1600 if (!this->added_eh_frame_data_
)
1602 os
->add_output_section_data(this->eh_frame_data_
);
1603 this->added_eh_frame_data_
= true;
1607 // Remove .eh_frame information for a PLT. FDEs using the CIE must
1608 // be removed in reverse order to the order they were added.
1611 Layout::remove_eh_frame_for_plt(Output_data
* plt
, const unsigned char* cie_data
,
1612 size_t cie_length
, const unsigned char* fde_data
,
1615 if (parameters
->incremental())
1617 // FIXME: Maybe this could work some day....
1620 this->eh_frame_data_
->remove_ehframe_for_plt(plt
, cie_data
, cie_length
,
1621 fde_data
, fde_length
);
1624 // Scan a .debug_info or .debug_types section, and add summary
1625 // information to the .gdb_index section.
1627 template<int size
, bool big_endian
>
1629 Layout::add_to_gdb_index(bool is_type_unit
,
1630 Sized_relobj
<size
, big_endian
>* object
,
1631 const unsigned char* symbols
,
1634 unsigned int reloc_shndx
,
1635 unsigned int reloc_type
)
1637 if (this->gdb_index_data_
== NULL
)
1639 Output_section
* os
= this->choose_output_section(NULL
, ".gdb_index",
1640 elfcpp::SHT_PROGBITS
, 0,
1641 false, ORDER_INVALID
,
1642 false, false, false);
1646 this->gdb_index_data_
= new Gdb_index(os
);
1647 os
->add_output_section_data(this->gdb_index_data_
);
1648 os
->set_after_input_sections();
1651 this->gdb_index_data_
->scan_debug_info(is_type_unit
, object
, symbols
,
1652 symbols_size
, shndx
, reloc_shndx
,
1656 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
1657 // the output section.
1660 Layout::add_output_section_data(const char* name
, elfcpp::Elf_Word type
,
1661 elfcpp::Elf_Xword flags
,
1662 Output_section_data
* posd
,
1663 Output_section_order order
, bool is_relro
)
1665 Output_section
* os
= this->choose_output_section(NULL
, name
, type
, flags
,
1666 false, order
, is_relro
,
1669 os
->add_output_section_data(posd
);
1673 // Map section flags to segment flags.
1676 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags
)
1678 elfcpp::Elf_Word ret
= elfcpp::PF_R
;
1679 if ((flags
& elfcpp::SHF_WRITE
) != 0)
1680 ret
|= elfcpp::PF_W
;
1681 if ((flags
& elfcpp::SHF_EXECINSTR
) != 0)
1682 ret
|= elfcpp::PF_X
;
1686 // Make a new Output_section, and attach it to segments as
1687 // appropriate. ORDER is the order in which this section should
1688 // appear in the output segment. IS_RELRO is true if this is a relro
1689 // (read-only after relocations) section.
1692 Layout::make_output_section(const char* name
, elfcpp::Elf_Word type
,
1693 elfcpp::Elf_Xword flags
,
1694 Output_section_order order
, bool is_relro
)
1697 if ((flags
& elfcpp::SHF_ALLOC
) == 0
1698 && strcmp(parameters
->options().compress_debug_sections(), "none") != 0
1699 && is_compressible_debug_section(name
))
1700 os
= new Output_compressed_section(¶meters
->options(), name
, type
,
1702 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1703 && parameters
->options().strip_debug_non_line()
1704 && strcmp(".debug_abbrev", name
) == 0)
1706 os
= this->debug_abbrev_
= new Output_reduced_debug_abbrev_section(
1708 if (this->debug_info_
)
1709 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1711 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1712 && parameters
->options().strip_debug_non_line()
1713 && strcmp(".debug_info", name
) == 0)
1715 os
= this->debug_info_
= new Output_reduced_debug_info_section(
1717 if (this->debug_abbrev_
)
1718 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1722 // Sometimes .init_array*, .preinit_array* and .fini_array* do
1723 // not have correct section types. Force them here.
1724 if (type
== elfcpp::SHT_PROGBITS
)
1726 if (is_prefix_of(".init_array", name
))
1727 type
= elfcpp::SHT_INIT_ARRAY
;
1728 else if (is_prefix_of(".preinit_array", name
))
1729 type
= elfcpp::SHT_PREINIT_ARRAY
;
1730 else if (is_prefix_of(".fini_array", name
))
1731 type
= elfcpp::SHT_FINI_ARRAY
;
1734 // FIXME: const_cast is ugly.
1735 Target
* target
= const_cast<Target
*>(¶meters
->target());
1736 os
= target
->make_output_section(name
, type
, flags
);
1739 // With -z relro, we have to recognize the special sections by name.
1740 // There is no other way.
1741 bool is_relro_local
= false;
1742 if (!this->script_options_
->saw_sections_clause()
1743 && parameters
->options().relro()
1744 && (flags
& elfcpp::SHF_ALLOC
) != 0
1745 && (flags
& elfcpp::SHF_WRITE
) != 0)
1747 if (type
== elfcpp::SHT_PROGBITS
)
1749 if ((flags
& elfcpp::SHF_TLS
) != 0)
1751 else if (strcmp(name
, ".data.rel.ro") == 0)
1753 else if (strcmp(name
, ".data.rel.ro.local") == 0)
1756 is_relro_local
= true;
1758 else if (strcmp(name
, ".ctors") == 0
1759 || strcmp(name
, ".dtors") == 0
1760 || strcmp(name
, ".jcr") == 0)
1763 else if (type
== elfcpp::SHT_INIT_ARRAY
1764 || type
== elfcpp::SHT_FINI_ARRAY
1765 || type
== elfcpp::SHT_PREINIT_ARRAY
)
1772 if (order
== ORDER_INVALID
&& (flags
& elfcpp::SHF_ALLOC
) != 0)
1773 order
= this->default_section_order(os
, is_relro_local
);
1775 os
->set_order(order
);
1777 parameters
->target().new_output_section(os
);
1779 this->section_list_
.push_back(os
);
1781 // The GNU linker by default sorts some sections by priority, so we
1782 // do the same. We need to know that this might happen before we
1783 // attach any input sections.
1784 if (!this->script_options_
->saw_sections_clause()
1785 && !parameters
->options().relocatable()
1786 && (strcmp(name
, ".init_array") == 0
1787 || strcmp(name
, ".fini_array") == 0
1788 || (!parameters
->options().ctors_in_init_array()
1789 && (strcmp(name
, ".ctors") == 0
1790 || strcmp(name
, ".dtors") == 0))))
1791 os
->set_may_sort_attached_input_sections();
1793 // The GNU linker by default sorts .text.{unlikely,exit,startup,hot}
1794 // sections before other .text sections. We are compatible. We
1795 // need to know that this might happen before we attach any input
1797 if (parameters
->options().text_reorder()
1798 && !this->script_options_
->saw_sections_clause()
1799 && !this->is_section_ordering_specified()
1800 && !parameters
->options().relocatable()
1801 && strcmp(name
, ".text") == 0)
1802 os
->set_may_sort_attached_input_sections();
1804 // GNU linker sorts section by name with --sort-section=name.
1805 if (strcmp(parameters
->options().sort_section(), "name") == 0)
1806 os
->set_must_sort_attached_input_sections();
1808 // Check for .stab*str sections, as .stab* sections need to link to
1810 if (type
== elfcpp::SHT_STRTAB
1811 && !this->have_stabstr_section_
1812 && strncmp(name
, ".stab", 5) == 0
1813 && strcmp(name
+ strlen(name
) - 3, "str") == 0)
1814 this->have_stabstr_section_
= true;
1816 // During a full incremental link, we add patch space to most
1817 // PROGBITS and NOBITS sections. Flag those that may be
1818 // arbitrarily padded.
1819 if ((type
== elfcpp::SHT_PROGBITS
|| type
== elfcpp::SHT_NOBITS
)
1820 && order
!= ORDER_INTERP
1821 && order
!= ORDER_INIT
1822 && order
!= ORDER_PLT
1823 && order
!= ORDER_FINI
1824 && order
!= ORDER_RELRO_LAST
1825 && order
!= ORDER_NON_RELRO_FIRST
1826 && strcmp(name
, ".eh_frame") != 0
1827 && strcmp(name
, ".ctors") != 0
1828 && strcmp(name
, ".dtors") != 0
1829 && strcmp(name
, ".jcr") != 0)
1831 os
->set_is_patch_space_allowed();
1833 // Certain sections require "holes" to be filled with
1834 // specific fill patterns. These fill patterns may have
1835 // a minimum size, so we must prevent allocations from the
1836 // free list that leave a hole smaller than the minimum.
1837 if (strcmp(name
, ".debug_info") == 0)
1838 os
->set_free_space_fill(new Output_fill_debug_info(false));
1839 else if (strcmp(name
, ".debug_types") == 0)
1840 os
->set_free_space_fill(new Output_fill_debug_info(true));
1841 else if (strcmp(name
, ".debug_line") == 0)
1842 os
->set_free_space_fill(new Output_fill_debug_line());
1845 // If we have already attached the sections to segments, then we
1846 // need to attach this one now. This happens for sections created
1847 // directly by the linker.
1848 if (this->sections_are_attached_
)
1849 this->attach_section_to_segment(¶meters
->target(), os
);
1854 // Return the default order in which a section should be placed in an
1855 // output segment. This function captures a lot of the ideas in
1856 // ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
1857 // linker created section is normally set when the section is created;
1858 // this function is used for input sections.
1860 Output_section_order
1861 Layout::default_section_order(Output_section
* os
, bool is_relro_local
)
1863 gold_assert((os
->flags() & elfcpp::SHF_ALLOC
) != 0);
1864 bool is_write
= (os
->flags() & elfcpp::SHF_WRITE
) != 0;
1865 bool is_execinstr
= (os
->flags() & elfcpp::SHF_EXECINSTR
) != 0;
1866 bool is_bss
= false;
1871 case elfcpp::SHT_PROGBITS
:
1873 case elfcpp::SHT_NOBITS
:
1876 case elfcpp::SHT_RELA
:
1877 case elfcpp::SHT_REL
:
1879 return ORDER_DYNAMIC_RELOCS
;
1881 case elfcpp::SHT_HASH
:
1882 case elfcpp::SHT_DYNAMIC
:
1883 case elfcpp::SHT_SHLIB
:
1884 case elfcpp::SHT_DYNSYM
:
1885 case elfcpp::SHT_GNU_HASH
:
1886 case elfcpp::SHT_GNU_verdef
:
1887 case elfcpp::SHT_GNU_verneed
:
1888 case elfcpp::SHT_GNU_versym
:
1890 return ORDER_DYNAMIC_LINKER
;
1892 case elfcpp::SHT_NOTE
:
1893 return is_write
? ORDER_RW_NOTE
: ORDER_RO_NOTE
;
1896 if ((os
->flags() & elfcpp::SHF_TLS
) != 0)
1897 return is_bss
? ORDER_TLS_BSS
: ORDER_TLS_DATA
;
1899 if (!is_bss
&& !is_write
)
1903 if (strcmp(os
->name(), ".init") == 0)
1905 else if (strcmp(os
->name(), ".fini") == 0)
1907 else if (parameters
->options().keep_text_section_prefix())
1909 // -z,keep-text-section-prefix introduces additional
1911 if (strcmp(os
->name(), ".text.hot") == 0)
1912 return ORDER_TEXT_HOT
;
1913 else if (strcmp(os
->name(), ".text.startup") == 0)
1914 return ORDER_TEXT_STARTUP
;
1915 else if (strcmp(os
->name(), ".text.exit") == 0)
1916 return ORDER_TEXT_EXIT
;
1917 else if (strcmp(os
->name(), ".text.unlikely") == 0)
1918 return ORDER_TEXT_UNLIKELY
;
1921 return is_execinstr
? ORDER_TEXT
: ORDER_READONLY
;
1925 return is_relro_local
? ORDER_RELRO_LOCAL
: ORDER_RELRO
;
1927 if (os
->is_small_section())
1928 return is_bss
? ORDER_SMALL_BSS
: ORDER_SMALL_DATA
;
1929 if (os
->is_large_section())
1930 return is_bss
? ORDER_LARGE_BSS
: ORDER_LARGE_DATA
;
1932 return is_bss
? ORDER_BSS
: ORDER_DATA
;
1935 // Attach output sections to segments. This is called after we have
1936 // seen all the input sections.
1939 Layout::attach_sections_to_segments(const Target
* target
)
1941 for (Section_list::iterator p
= this->section_list_
.begin();
1942 p
!= this->section_list_
.end();
1944 this->attach_section_to_segment(target
, *p
);
1946 this->sections_are_attached_
= true;
1949 // Attach an output section to a segment.
1952 Layout::attach_section_to_segment(const Target
* target
, Output_section
* os
)
1954 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0)
1955 this->unattached_section_list_
.push_back(os
);
1957 this->attach_allocated_section_to_segment(target
, os
);
1960 // Attach an allocated output section to a segment.
1963 Layout::attach_allocated_section_to_segment(const Target
* target
,
1966 elfcpp::Elf_Xword flags
= os
->flags();
1967 gold_assert((flags
& elfcpp::SHF_ALLOC
) != 0);
1969 if (parameters
->options().relocatable())
1972 // If we have a SECTIONS clause, we can't handle the attachment to
1973 // segments until after we've seen all the sections.
1974 if (this->script_options_
->saw_sections_clause())
1977 gold_assert(!this->script_options_
->saw_phdrs_clause());
1979 // This output section goes into a PT_LOAD segment.
1981 elfcpp::Elf_Word seg_flags
= Layout::section_flags_to_segment(flags
);
1983 // If this output section's segment has extra flags that need to be set,
1984 // coming from a linker plugin, do that.
1985 seg_flags
|= os
->extra_segment_flags();
1987 // Check for --section-start.
1989 bool is_address_set
= parameters
->options().section_start(os
->name(), &addr
);
1991 // In general the only thing we really care about for PT_LOAD
1992 // segments is whether or not they are writable or executable,
1993 // so that is how we search for them.
1994 // Large data sections also go into their own PT_LOAD segment.
1995 // People who need segments sorted on some other basis will
1996 // have to use a linker script.
1998 Segment_list::const_iterator p
;
1999 if (!os
->is_unique_segment())
2001 for (p
= this->segment_list_
.begin();
2002 p
!= this->segment_list_
.end();
2005 if ((*p
)->type() != elfcpp::PT_LOAD
)
2007 if ((*p
)->is_unique_segment())
2009 if (!parameters
->options().omagic()
2010 && ((*p
)->flags() & elfcpp::PF_W
) != (seg_flags
& elfcpp::PF_W
))
2012 if ((target
->isolate_execinstr() || parameters
->options().rosegment())
2013 && ((*p
)->flags() & elfcpp::PF_X
) != (seg_flags
& elfcpp::PF_X
))
2015 // If -Tbss was specified, we need to separate the data and BSS
2017 if (parameters
->options().user_set_Tbss())
2019 if ((os
->type() == elfcpp::SHT_NOBITS
)
2020 == (*p
)->has_any_data_sections())
2023 if (os
->is_large_data_section() && !(*p
)->is_large_data_segment())
2028 if ((*p
)->are_addresses_set())
2031 (*p
)->add_initial_output_data(os
);
2032 (*p
)->update_flags_for_output_section(seg_flags
);
2033 (*p
)->set_addresses(addr
, addr
);
2037 (*p
)->add_output_section_to_load(this, os
, seg_flags
);
2042 if (p
== this->segment_list_
.end()
2043 || os
->is_unique_segment())
2045 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_LOAD
,
2047 if (os
->is_large_data_section())
2048 oseg
->set_is_large_data_segment();
2049 oseg
->add_output_section_to_load(this, os
, seg_flags
);
2051 oseg
->set_addresses(addr
, addr
);
2052 // Check if segment should be marked unique. For segments marked
2053 // unique by linker plugins, set the new alignment if specified.
2054 if (os
->is_unique_segment())
2056 oseg
->set_is_unique_segment();
2057 if (os
->segment_alignment() != 0)
2058 oseg
->set_minimum_p_align(os
->segment_alignment());
2062 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
2064 if (os
->type() == elfcpp::SHT_NOTE
)
2066 // See if we already have an equivalent PT_NOTE segment.
2067 for (p
= this->segment_list_
.begin();
2068 p
!= segment_list_
.end();
2071 if ((*p
)->type() == elfcpp::PT_NOTE
2072 && (((*p
)->flags() & elfcpp::PF_W
)
2073 == (seg_flags
& elfcpp::PF_W
)))
2075 (*p
)->add_output_section_to_nonload(os
, seg_flags
);
2080 if (p
== this->segment_list_
.end())
2082 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_NOTE
,
2084 oseg
->add_output_section_to_nonload(os
, seg_flags
);
2088 // If we see a loadable SHF_TLS section, we create a PT_TLS
2089 // segment. There can only be one such segment.
2090 if ((flags
& elfcpp::SHF_TLS
) != 0)
2092 if (this->tls_segment_
== NULL
)
2093 this->make_output_segment(elfcpp::PT_TLS
, seg_flags
);
2094 this->tls_segment_
->add_output_section_to_nonload(os
, seg_flags
);
2097 // If -z relro is in effect, and we see a relro section, we create a
2098 // PT_GNU_RELRO segment. There can only be one such segment.
2099 if (os
->is_relro() && parameters
->options().relro())
2101 gold_assert(seg_flags
== (elfcpp::PF_R
| elfcpp::PF_W
));
2102 if (this->relro_segment_
== NULL
)
2103 this->make_output_segment(elfcpp::PT_GNU_RELRO
, seg_flags
);
2104 this->relro_segment_
->add_output_section_to_nonload(os
, seg_flags
);
2107 // If we see a section named .interp, put it into a PT_INTERP
2108 // segment. This seems broken to me, but this is what GNU ld does,
2109 // and glibc expects it.
2110 if (strcmp(os
->name(), ".interp") == 0
2111 && !this->script_options_
->saw_phdrs_clause())
2113 if (this->interp_segment_
== NULL
)
2114 this->make_output_segment(elfcpp::PT_INTERP
, seg_flags
);
2116 gold_warning(_("multiple '.interp' sections in input files "
2117 "may cause confusing PT_INTERP segment"));
2118 this->interp_segment_
->add_output_section_to_nonload(os
, seg_flags
);
2122 // Make an output section for a script.
2125 Layout::make_output_section_for_script(
2127 Script_sections::Section_type section_type
)
2129 name
= this->namepool_
.add(name
, false, NULL
);
2130 elfcpp::Elf_Xword sh_flags
= elfcpp::SHF_ALLOC
;
2131 if (section_type
== Script_sections::ST_NOLOAD
)
2133 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_PROGBITS
,
2134 sh_flags
, ORDER_INVALID
,
2136 os
->set_found_in_sections_clause();
2137 if (section_type
== Script_sections::ST_NOLOAD
)
2138 os
->set_is_noload();
2142 // Return the number of segments we expect to see.
2145 Layout::expected_segment_count() const
2147 size_t ret
= this->segment_list_
.size();
2149 // If we didn't see a SECTIONS clause in a linker script, we should
2150 // already have the complete list of segments. Otherwise we ask the
2151 // SECTIONS clause how many segments it expects, and add in the ones
2152 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
2154 if (!this->script_options_
->saw_sections_clause())
2158 const Script_sections
* ss
= this->script_options_
->script_sections();
2159 return ret
+ ss
->expected_segment_count(this);
2163 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
2164 // is whether we saw a .note.GNU-stack section in the object file.
2165 // GNU_STACK_FLAGS is the section flags. The flags give the
2166 // protection required for stack memory. We record this in an
2167 // executable as a PT_GNU_STACK segment. If an object file does not
2168 // have a .note.GNU-stack segment, we must assume that it is an old
2169 // object. On some targets that will force an executable stack.
2172 Layout::layout_gnu_stack(bool seen_gnu_stack
, uint64_t gnu_stack_flags
,
2175 if (!seen_gnu_stack
)
2177 this->input_without_gnu_stack_note_
= true;
2178 if (parameters
->options().warn_execstack()
2179 && parameters
->target().is_default_stack_executable())
2180 gold_warning(_("%s: missing .note.GNU-stack section"
2181 " implies executable stack"),
2182 obj
->name().c_str());
2186 this->input_with_gnu_stack_note_
= true;
2187 if ((gnu_stack_flags
& elfcpp::SHF_EXECINSTR
) != 0)
2189 this->input_requires_executable_stack_
= true;
2190 if (parameters
->options().warn_execstack())
2191 gold_warning(_("%s: requires executable stack"),
2192 obj
->name().c_str());
2197 // Read a value with given size and endianness.
2199 static inline uint64_t
2200 read_sized_value(size_t size
, const unsigned char* buf
, bool is_big_endian
,
2201 const Object
* object
)
2207 val
= elfcpp::Swap
<32, true>::readval(buf
);
2209 val
= elfcpp::Swap
<32, false>::readval(buf
);
2214 val
= elfcpp::Swap
<64, true>::readval(buf
);
2216 val
= elfcpp::Swap
<64, false>::readval(buf
);
2220 gold_warning(_("%s: in .note.gnu.properties section, "
2221 "pr_datasz must be 4 or 8"),
2222 object
->name().c_str());
2227 // Write a value with given size and endianness.
2230 write_sized_value(uint64_t value
, size_t size
, unsigned char* buf
,
2236 elfcpp::Swap
<32, true>::writeval(buf
, static_cast<uint32_t>(value
));
2238 elfcpp::Swap
<32, false>::writeval(buf
, static_cast<uint32_t>(value
));
2243 elfcpp::Swap
<64, true>::writeval(buf
, value
);
2245 elfcpp::Swap
<64, false>::writeval(buf
, value
);
2249 // We will have already complained about this.
2253 // Handle the .note.gnu.property section at layout time.
2256 Layout::layout_gnu_property(unsigned int note_type
,
2257 unsigned int pr_type
,
2259 const unsigned char* pr_data
,
2260 const Object
* object
)
2262 // We currently support only the one note type.
2263 gold_assert(note_type
== elfcpp::NT_GNU_PROPERTY_TYPE_0
);
2265 Gnu_properties::iterator pprop
= this->gnu_properties_
.find(pr_type
);
2266 if (pprop
== this->gnu_properties_
.end())
2269 prop
.pr_datasz
= pr_datasz
;
2270 prop
.pr_data
= new unsigned char[pr_datasz
];
2271 memcpy(prop
.pr_data
, pr_data
, pr_datasz
);
2272 this->gnu_properties_
[pr_type
] = prop
;
2276 if (pr_type
>= elfcpp::GNU_PROPERTY_LOPROC
2277 && pr_type
< elfcpp::GNU_PROPERTY_HIPROC
)
2279 // Target-dependent property value; call the target to merge.
2280 parameters
->target().merge_gnu_property(note_type
,
2284 pprop
->second
.pr_datasz
,
2285 pprop
->second
.pr_data
,
2290 const bool is_big_endian
= parameters
->target().is_big_endian();
2293 case elfcpp::GNU_PROPERTY_STACK_SIZE
:
2294 // Record the maximum value seen.
2296 uint64_t val1
= read_sized_value(pprop
->second
.pr_datasz
,
2297 pprop
->second
.pr_data
,
2298 is_big_endian
, object
);
2299 uint64_t val2
= read_sized_value(pr_datasz
, pr_data
,
2300 is_big_endian
, object
);
2302 write_sized_value(val2
, pprop
->second
.pr_datasz
,
2303 pprop
->second
.pr_data
, is_big_endian
);
2306 case elfcpp::GNU_PROPERTY_NO_COPY_ON_PROTECTED
:
2307 // No data to merge.
2310 gold_warning(_("%s: unknown program property type %d "
2311 "in .note.gnu.properties section"),
2312 object
->name().c_str(), pr_type
);
2318 // Create automatic note sections.
2321 Layout::create_notes()
2323 this->create_gnu_properties_note();
2324 this->create_gold_note();
2325 this->create_stack_segment();
2326 this->create_build_id();
2329 // Create the dynamic sections which are needed before we read the
2333 Layout::create_initial_dynamic_sections(Symbol_table
* symtab
)
2335 if (parameters
->doing_static_link())
2338 this->dynamic_section_
= this->choose_output_section(NULL
, ".dynamic",
2339 elfcpp::SHT_DYNAMIC
,
2341 | elfcpp::SHF_WRITE
),
2343 true, false, false);
2345 // A linker script may discard .dynamic, so check for NULL.
2346 if (this->dynamic_section_
!= NULL
)
2348 this->dynamic_symbol_
=
2349 symtab
->define_in_output_data("_DYNAMIC", NULL
,
2350 Symbol_table::PREDEFINED
,
2351 this->dynamic_section_
, 0, 0,
2352 elfcpp::STT_OBJECT
, elfcpp::STB_LOCAL
,
2353 elfcpp::STV_HIDDEN
, 0, false, false);
2355 this->dynamic_data_
= new Output_data_dynamic(&this->dynpool_
);
2357 this->dynamic_section_
->add_output_section_data(this->dynamic_data_
);
2361 // For each output section whose name can be represented as C symbol,
2362 // define __start and __stop symbols for the section. This is a GNU
2366 Layout::define_section_symbols(Symbol_table
* symtab
)
2368 for (Section_list::const_iterator p
= this->section_list_
.begin();
2369 p
!= this->section_list_
.end();
2372 const char* const name
= (*p
)->name();
2373 if (is_cident(name
))
2375 const std::string
name_string(name
);
2376 const std::string
start_name(cident_section_start_prefix
2378 const std::string
stop_name(cident_section_stop_prefix
2381 symtab
->define_in_output_data(start_name
.c_str(),
2383 Symbol_table::PREDEFINED
,
2389 elfcpp::STV_PROTECTED
,
2391 false, // offset_is_from_end
2392 true); // only_if_ref
2394 symtab
->define_in_output_data(stop_name
.c_str(),
2396 Symbol_table::PREDEFINED
,
2402 elfcpp::STV_PROTECTED
,
2404 true, // offset_is_from_end
2405 true); // only_if_ref
2410 // Define symbols for group signatures.
2413 Layout::define_group_signatures(Symbol_table
* symtab
)
2415 for (Group_signatures::iterator p
= this->group_signatures_
.begin();
2416 p
!= this->group_signatures_
.end();
2419 Symbol
* sym
= symtab
->lookup(p
->signature
, NULL
);
2421 p
->section
->set_info_symndx(sym
);
2424 // Force the name of the group section to the group
2425 // signature, and use the group's section symbol as the
2426 // signature symbol.
2427 if (strcmp(p
->section
->name(), p
->signature
) != 0)
2429 const char* name
= this->namepool_
.add(p
->signature
,
2431 p
->section
->set_name(name
);
2433 p
->section
->set_needs_symtab_index();
2434 p
->section
->set_info_section_symndx(p
->section
);
2438 this->group_signatures_
.clear();
2441 // Find the first read-only PT_LOAD segment, creating one if
2445 Layout::find_first_load_seg(const Target
* target
)
2447 Output_segment
* best
= NULL
;
2448 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2449 p
!= this->segment_list_
.end();
2452 if ((*p
)->type() == elfcpp::PT_LOAD
2453 && ((*p
)->flags() & elfcpp::PF_R
) != 0
2454 && (parameters
->options().omagic()
2455 || ((*p
)->flags() & elfcpp::PF_W
) == 0)
2456 && (!target
->isolate_execinstr()
2457 || ((*p
)->flags() & elfcpp::PF_X
) == 0))
2459 if (best
== NULL
|| this->segment_precedes(*p
, best
))
2466 gold_assert(!this->script_options_
->saw_phdrs_clause());
2468 Output_segment
* load_seg
= this->make_output_segment(elfcpp::PT_LOAD
,
2473 // Save states of all current output segments. Store saved states
2474 // in SEGMENT_STATES.
2477 Layout::save_segments(Segment_states
* segment_states
)
2479 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2480 p
!= this->segment_list_
.end();
2483 Output_segment
* segment
= *p
;
2485 Output_segment
* copy
= new Output_segment(*segment
);
2486 (*segment_states
)[segment
] = copy
;
2490 // Restore states of output segments and delete any segment not found in
2494 Layout::restore_segments(const Segment_states
* segment_states
)
2496 // Go through the segment list and remove any segment added in the
2498 this->tls_segment_
= NULL
;
2499 this->relro_segment_
= NULL
;
2500 Segment_list::iterator list_iter
= this->segment_list_
.begin();
2501 while (list_iter
!= this->segment_list_
.end())
2503 Output_segment
* segment
= *list_iter
;
2504 Segment_states::const_iterator states_iter
=
2505 segment_states
->find(segment
);
2506 if (states_iter
!= segment_states
->end())
2508 const Output_segment
* copy
= states_iter
->second
;
2509 // Shallow copy to restore states.
2512 // Also fix up TLS and RELRO segment pointers as appropriate.
2513 if (segment
->type() == elfcpp::PT_TLS
)
2514 this->tls_segment_
= segment
;
2515 else if (segment
->type() == elfcpp::PT_GNU_RELRO
)
2516 this->relro_segment_
= segment
;
2522 list_iter
= this->segment_list_
.erase(list_iter
);
2523 // This is a segment created during section layout. It should be
2524 // safe to remove it since we should have removed all pointers to it.
2530 // Clean up after relaxation so that sections can be laid out again.
2533 Layout::clean_up_after_relaxation()
2535 // Restore the segments to point state just prior to the relaxation loop.
2536 Script_sections
* script_section
= this->script_options_
->script_sections();
2537 script_section
->release_segments();
2538 this->restore_segments(this->segment_states_
);
2540 // Reset section addresses and file offsets
2541 for (Section_list::iterator p
= this->section_list_
.begin();
2542 p
!= this->section_list_
.end();
2545 (*p
)->restore_states();
2547 // If an input section changes size because of relaxation,
2548 // we need to adjust the section offsets of all input sections.
2549 // after such a section.
2550 if ((*p
)->section_offsets_need_adjustment())
2551 (*p
)->adjust_section_offsets();
2553 (*p
)->reset_address_and_file_offset();
2556 // Reset special output object address and file offsets.
2557 for (Data_list::iterator p
= this->special_output_list_
.begin();
2558 p
!= this->special_output_list_
.end();
2560 (*p
)->reset_address_and_file_offset();
2562 // A linker script may have created some output section data objects.
2563 // They are useless now.
2564 for (Output_section_data_list::const_iterator p
=
2565 this->script_output_section_data_list_
.begin();
2566 p
!= this->script_output_section_data_list_
.end();
2569 this->script_output_section_data_list_
.clear();
2571 // Special-case fill output objects are recreated each time through
2572 // the relaxation loop.
2573 this->reset_relax_output();
2577 Layout::reset_relax_output()
2579 for (Data_list::const_iterator p
= this->relax_output_list_
.begin();
2580 p
!= this->relax_output_list_
.end();
2583 this->relax_output_list_
.clear();
2586 // Prepare for relaxation.
2589 Layout::prepare_for_relaxation()
2591 // Create an relaxation debug check if in debugging mode.
2592 if (is_debugging_enabled(DEBUG_RELAXATION
))
2593 this->relaxation_debug_check_
= new Relaxation_debug_check();
2595 // Save segment states.
2596 this->segment_states_
= new Segment_states();
2597 this->save_segments(this->segment_states_
);
2599 for(Section_list::const_iterator p
= this->section_list_
.begin();
2600 p
!= this->section_list_
.end();
2602 (*p
)->save_states();
2604 if (is_debugging_enabled(DEBUG_RELAXATION
))
2605 this->relaxation_debug_check_
->check_output_data_for_reset_values(
2606 this->section_list_
, this->special_output_list_
,
2607 this->relax_output_list_
);
2609 // Also enable recording of output section data from scripts.
2610 this->record_output_section_data_from_script_
= true;
2613 // If the user set the address of the text segment, that may not be
2614 // compatible with putting the segment headers and file headers into
2615 // that segment. For isolate_execinstr() targets, it's the rodata
2616 // segment rather than text where we might put the headers.
2618 load_seg_unusable_for_headers(const Target
* target
)
2620 const General_options
& options
= parameters
->options();
2621 if (target
->isolate_execinstr())
2622 return (options
.user_set_Trodata_segment()
2623 && options
.Trodata_segment() % target
->abi_pagesize() != 0);
2625 return (options
.user_set_Ttext()
2626 && options
.Ttext() % target
->abi_pagesize() != 0);
2629 // Relaxation loop body: If target has no relaxation, this runs only once
2630 // Otherwise, the target relaxation hook is called at the end of
2631 // each iteration. If the hook returns true, it means re-layout of
2632 // section is required.
2634 // The number of segments created by a linking script without a PHDRS
2635 // clause may be affected by section sizes and alignments. There is
2636 // a remote chance that relaxation causes different number of PT_LOAD
2637 // segments are created and sections are attached to different segments.
2638 // Therefore, we always throw away all segments created during section
2639 // layout. In order to be able to restart the section layout, we keep
2640 // a copy of the segment list right before the relaxation loop and use
2641 // that to restore the segments.
2643 // PASS is the current relaxation pass number.
2644 // SYMTAB is a symbol table.
2645 // PLOAD_SEG is the address of a pointer for the load segment.
2646 // PHDR_SEG is a pointer to the PHDR segment.
2647 // SEGMENT_HEADERS points to the output segment header.
2648 // FILE_HEADER points to the output file header.
2649 // PSHNDX is the address to store the output section index.
2652 Layout::relaxation_loop_body(
2655 Symbol_table
* symtab
,
2656 Output_segment
** pload_seg
,
2657 Output_segment
* phdr_seg
,
2658 Output_segment_headers
* segment_headers
,
2659 Output_file_header
* file_header
,
2660 unsigned int* pshndx
)
2662 // If this is not the first iteration, we need to clean up after
2663 // relaxation so that we can lay out the sections again.
2665 this->clean_up_after_relaxation();
2667 // If there is a SECTIONS clause, put all the input sections into
2668 // the required order.
2669 Output_segment
* load_seg
;
2670 if (this->script_options_
->saw_sections_clause())
2671 load_seg
= this->set_section_addresses_from_script(symtab
);
2672 else if (parameters
->options().relocatable())
2675 load_seg
= this->find_first_load_seg(target
);
2677 if (parameters
->options().oformat_enum()
2678 != General_options::OBJECT_FORMAT_ELF
)
2681 if (load_seg_unusable_for_headers(target
))
2687 gold_assert(phdr_seg
== NULL
2689 || this->script_options_
->saw_sections_clause());
2691 // If the address of the load segment we found has been set by
2692 // --section-start rather than by a script, then adjust the VMA and
2693 // LMA downward if possible to include the file and section headers.
2694 uint64_t header_gap
= 0;
2695 if (load_seg
!= NULL
2696 && load_seg
->are_addresses_set()
2697 && !this->script_options_
->saw_sections_clause()
2698 && !parameters
->options().relocatable())
2700 file_header
->finalize_data_size();
2701 segment_headers
->finalize_data_size();
2702 size_t sizeof_headers
= (file_header
->data_size()
2703 + segment_headers
->data_size());
2704 const uint64_t abi_pagesize
= target
->abi_pagesize();
2705 uint64_t hdr_paddr
= load_seg
->paddr() - sizeof_headers
;
2706 hdr_paddr
&= ~(abi_pagesize
- 1);
2707 uint64_t subtract
= load_seg
->paddr() - hdr_paddr
;
2708 if (load_seg
->paddr() < subtract
|| load_seg
->vaddr() < subtract
)
2712 load_seg
->set_addresses(load_seg
->vaddr() - subtract
,
2713 load_seg
->paddr() - subtract
);
2714 header_gap
= subtract
- sizeof_headers
;
2718 // Lay out the segment headers.
2719 if (!parameters
->options().relocatable())
2721 gold_assert(segment_headers
!= NULL
);
2722 if (header_gap
!= 0 && load_seg
!= NULL
)
2724 Output_data_zero_fill
* z
= new Output_data_zero_fill(header_gap
, 1);
2725 load_seg
->add_initial_output_data(z
);
2727 if (load_seg
!= NULL
)
2728 load_seg
->add_initial_output_data(segment_headers
);
2729 if (phdr_seg
!= NULL
)
2730 phdr_seg
->add_initial_output_data(segment_headers
);
2733 // Lay out the file header.
2734 if (load_seg
!= NULL
)
2735 load_seg
->add_initial_output_data(file_header
);
2737 if (this->script_options_
->saw_phdrs_clause()
2738 && !parameters
->options().relocatable())
2740 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2741 // clause in a linker script.
2742 Script_sections
* ss
= this->script_options_
->script_sections();
2743 ss
->put_headers_in_phdrs(file_header
, segment_headers
);
2746 // We set the output section indexes in set_segment_offsets and
2747 // set_section_indexes.
2750 // Set the file offsets of all the segments, and all the sections
2753 if (!parameters
->options().relocatable())
2754 off
= this->set_segment_offsets(target
, load_seg
, pshndx
);
2756 off
= this->set_relocatable_section_offsets(file_header
, pshndx
);
2758 // Verify that the dummy relaxation does not change anything.
2759 if (is_debugging_enabled(DEBUG_RELAXATION
))
2762 this->relaxation_debug_check_
->read_sections(this->section_list_
);
2764 this->relaxation_debug_check_
->verify_sections(this->section_list_
);
2767 *pload_seg
= load_seg
;
2771 // Search the list of patterns and find the position of the given section
2772 // name in the output section. If the section name matches a glob
2773 // pattern and a non-glob name, then the non-glob position takes
2774 // precedence. Return 0 if no match is found.
2777 Layout::find_section_order_index(const std::string
& section_name
)
2779 Unordered_map
<std::string
, unsigned int>::iterator map_it
;
2780 map_it
= this->input_section_position_
.find(section_name
);
2781 if (map_it
!= this->input_section_position_
.end())
2782 return map_it
->second
;
2784 // Absolute match failed. Linear search the glob patterns.
2785 std::vector
<std::string
>::iterator it
;
2786 for (it
= this->input_section_glob_
.begin();
2787 it
!= this->input_section_glob_
.end();
2790 if (fnmatch((*it
).c_str(), section_name
.c_str(), FNM_NOESCAPE
) == 0)
2792 map_it
= this->input_section_position_
.find(*it
);
2793 gold_assert(map_it
!= this->input_section_position_
.end());
2794 return map_it
->second
;
2800 // Read the sequence of input sections from the file specified with
2801 // option --section-ordering-file.
2804 Layout::read_layout_from_file()
2806 const char* filename
= parameters
->options().section_ordering_file();
2812 gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2813 filename
, strerror(errno
));
2815 std::getline(in
, line
); // this chops off the trailing \n, if any
2816 unsigned int position
= 1;
2817 this->set_section_ordering_specified();
2821 if (!line
.empty() && line
[line
.length() - 1] == '\r') // Windows
2822 line
.resize(line
.length() - 1);
2823 // Ignore comments, beginning with '#'
2826 std::getline(in
, line
);
2829 this->input_section_position_
[line
] = position
;
2830 // Store all glob patterns in a vector.
2831 if (is_wildcard_string(line
.c_str()))
2832 this->input_section_glob_
.push_back(line
);
2834 std::getline(in
, line
);
2838 // Finalize the layout. When this is called, we have created all the
2839 // output sections and all the output segments which are based on
2840 // input sections. We have several things to do, and we have to do
2841 // them in the right order, so that we get the right results correctly
2844 // 1) Finalize the list of output segments and create the segment
2847 // 2) Finalize the dynamic symbol table and associated sections.
2849 // 3) Determine the final file offset of all the output segments.
2851 // 4) Determine the final file offset of all the SHF_ALLOC output
2854 // 5) Create the symbol table sections and the section name table
2857 // 6) Finalize the symbol table: set symbol values to their final
2858 // value and make a final determination of which symbols are going
2859 // into the output symbol table.
2861 // 7) Create the section table header.
2863 // 8) Determine the final file offset of all the output sections which
2864 // are not SHF_ALLOC, including the section table header.
2866 // 9) Finalize the ELF file header.
2868 // This function returns the size of the output file.
2871 Layout::finalize(const Input_objects
* input_objects
, Symbol_table
* symtab
,
2872 Target
* target
, const Task
* task
)
2874 unsigned int local_dynamic_count
= 0;
2875 unsigned int forced_local_dynamic_count
= 0;
2877 target
->finalize_sections(this, input_objects
, symtab
);
2879 this->count_local_symbols(task
, input_objects
);
2881 this->link_stabs_sections();
2883 Output_segment
* phdr_seg
= NULL
;
2884 if (!parameters
->options().relocatable() && !parameters
->doing_static_link())
2886 // There was a dynamic object in the link. We need to create
2887 // some information for the dynamic linker.
2889 // Create the PT_PHDR segment which will hold the program
2891 if (!this->script_options_
->saw_phdrs_clause())
2892 phdr_seg
= this->make_output_segment(elfcpp::PT_PHDR
, elfcpp::PF_R
);
2894 // Create the dynamic symbol table, including the hash table.
2895 Output_section
* dynstr
;
2896 std::vector
<Symbol
*> dynamic_symbols
;
2897 Versions
versions(*this->script_options()->version_script_info(),
2899 this->create_dynamic_symtab(input_objects
, symtab
, &dynstr
,
2900 &local_dynamic_count
,
2901 &forced_local_dynamic_count
,
2905 // Create the .interp section to hold the name of the
2906 // interpreter, and put it in a PT_INTERP segment. Don't do it
2907 // if we saw a .interp section in an input file.
2908 if ((!parameters
->options().shared()
2909 || parameters
->options().dynamic_linker() != NULL
)
2910 && this->interp_segment_
== NULL
)
2911 this->create_interp(target
);
2913 // Finish the .dynamic section to hold the dynamic data, and put
2914 // it in a PT_DYNAMIC segment.
2915 this->finish_dynamic_section(input_objects
, symtab
);
2917 // We should have added everything we need to the dynamic string
2919 this->dynpool_
.set_string_offsets();
2921 // Create the version sections. We can't do this until the
2922 // dynamic string table is complete.
2923 this->create_version_sections(&versions
, symtab
,
2924 (local_dynamic_count
2925 + forced_local_dynamic_count
),
2926 dynamic_symbols
, dynstr
);
2928 // Set the size of the _DYNAMIC symbol. We can't do this until
2929 // after we call create_version_sections.
2930 this->set_dynamic_symbol_size(symtab
);
2933 // Create segment headers.
2934 Output_segment_headers
* segment_headers
=
2935 (parameters
->options().relocatable()
2937 : new Output_segment_headers(this->segment_list_
));
2939 // Lay out the file header.
2940 Output_file_header
* file_header
= new Output_file_header(target
, symtab
,
2943 this->special_output_list_
.push_back(file_header
);
2944 if (segment_headers
!= NULL
)
2945 this->special_output_list_
.push_back(segment_headers
);
2947 // Find approriate places for orphan output sections if we are using
2949 if (this->script_options_
->saw_sections_clause())
2950 this->place_orphan_sections_in_script();
2952 Output_segment
* load_seg
;
2957 // Take a snapshot of the section layout as needed.
2958 if (target
->may_relax())
2959 this->prepare_for_relaxation();
2961 // Run the relaxation loop to lay out sections.
2964 off
= this->relaxation_loop_body(pass
, target
, symtab
, &load_seg
,
2965 phdr_seg
, segment_headers
, file_header
,
2969 while (target
->may_relax()
2970 && target
->relax(pass
, input_objects
, symtab
, this, task
));
2972 // If there is a load segment that contains the file and program headers,
2973 // provide a symbol __ehdr_start pointing there.
2974 // A program can use this to examine itself robustly.
2975 Symbol
*ehdr_start
= symtab
->lookup("__ehdr_start");
2976 if (ehdr_start
!= NULL
&& ehdr_start
->is_predefined())
2978 if (load_seg
!= NULL
)
2979 ehdr_start
->set_output_segment(load_seg
, Symbol::SEGMENT_START
);
2981 ehdr_start
->set_undefined();
2984 // Set the file offsets of all the non-data sections we've seen so
2985 // far which don't have to wait for the input sections. We need
2986 // this in order to finalize local symbols in non-allocated
2988 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2990 // Set the section indexes of all unallocated sections seen so far,
2991 // in case any of them are somehow referenced by a symbol.
2992 shndx
= this->set_section_indexes(shndx
);
2994 // Create the symbol table sections.
2995 this->create_symtab_sections(input_objects
, symtab
, shndx
, &off
,
2996 local_dynamic_count
);
2997 if (!parameters
->doing_static_link())
2998 this->assign_local_dynsym_offsets(input_objects
);
3000 // Process any symbol assignments from a linker script. This must
3001 // be called after the symbol table has been finalized.
3002 this->script_options_
->finalize_symbols(symtab
, this);
3004 // Create the incremental inputs sections.
3005 if (this->incremental_inputs_
)
3007 this->incremental_inputs_
->finalize();
3008 this->create_incremental_info_sections(symtab
);
3011 // Create the .shstrtab section.
3012 Output_section
* shstrtab_section
= this->create_shstrtab();
3014 // Set the file offsets of the rest of the non-data sections which
3015 // don't have to wait for the input sections.
3016 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
3018 // Now that all sections have been created, set the section indexes
3019 // for any sections which haven't been done yet.
3020 shndx
= this->set_section_indexes(shndx
);
3022 // Create the section table header.
3023 this->create_shdrs(shstrtab_section
, &off
);
3025 // If there are no sections which require postprocessing, we can
3026 // handle the section names now, and avoid a resize later.
3027 if (!this->any_postprocessing_sections_
)
3029 off
= this->set_section_offsets(off
,
3030 POSTPROCESSING_SECTIONS_PASS
);
3032 this->set_section_offsets(off
,
3033 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
3036 file_header
->set_section_info(this->section_headers_
, shstrtab_section
);
3038 // Now we know exactly where everything goes in the output file
3039 // (except for non-allocated sections which require postprocessing).
3040 Output_data::layout_complete();
3042 this->output_file_size_
= off
;
3047 // Create a note header following the format defined in the ELF ABI.
3048 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
3049 // of the section to create, DESCSZ is the size of the descriptor.
3050 // ALLOCATE is true if the section should be allocated in memory.
3051 // This returns the new note section. It sets *TRAILING_PADDING to
3052 // the number of trailing zero bytes required.
3055 Layout::create_note(const char* name
, int note_type
,
3056 const char* section_name
, size_t descsz
,
3057 bool allocate
, size_t* trailing_padding
)
3059 // Authorities all agree that the values in a .note field should
3060 // be aligned on 4-byte boundaries for 32-bit binaries. However,
3061 // they differ on what the alignment is for 64-bit binaries.
3062 // The GABI says unambiguously they take 8-byte alignment:
3063 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
3064 // Other documentation says alignment should always be 4 bytes:
3065 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
3066 // GNU ld and GNU readelf both support the latter (at least as of
3067 // version 2.16.91), and glibc always generates the latter for
3068 // .note.ABI-tag (as of version 1.6), so that's the one we go with
3070 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
3071 const int size
= parameters
->target().get_size();
3073 const int size
= 32;
3076 // The contents of the .note section.
3077 size_t namesz
= strlen(name
) + 1;
3078 size_t aligned_namesz
= align_address(namesz
, size
/ 8);
3079 size_t aligned_descsz
= align_address(descsz
, size
/ 8);
3081 size_t notehdrsz
= 3 * (size
/ 8) + aligned_namesz
;
3083 unsigned char* buffer
= new unsigned char[notehdrsz
];
3084 memset(buffer
, 0, notehdrsz
);
3086 bool is_big_endian
= parameters
->target().is_big_endian();
3092 elfcpp::Swap
<32, false>::writeval(buffer
, namesz
);
3093 elfcpp::Swap
<32, false>::writeval(buffer
+ 4, descsz
);
3094 elfcpp::Swap
<32, false>::writeval(buffer
+ 8, note_type
);
3098 elfcpp::Swap
<32, true>::writeval(buffer
, namesz
);
3099 elfcpp::Swap
<32, true>::writeval(buffer
+ 4, descsz
);
3100 elfcpp::Swap
<32, true>::writeval(buffer
+ 8, note_type
);
3103 else if (size
== 64)
3107 elfcpp::Swap
<64, false>::writeval(buffer
, namesz
);
3108 elfcpp::Swap
<64, false>::writeval(buffer
+ 8, descsz
);
3109 elfcpp::Swap
<64, false>::writeval(buffer
+ 16, note_type
);
3113 elfcpp::Swap
<64, true>::writeval(buffer
, namesz
);
3114 elfcpp::Swap
<64, true>::writeval(buffer
+ 8, descsz
);
3115 elfcpp::Swap
<64, true>::writeval(buffer
+ 16, note_type
);
3121 memcpy(buffer
+ 3 * (size
/ 8), name
, namesz
);
3123 elfcpp::Elf_Xword flags
= 0;
3124 Output_section_order order
= ORDER_INVALID
;
3127 flags
= elfcpp::SHF_ALLOC
;
3128 order
= ORDER_RO_NOTE
;
3130 Output_section
* os
= this->choose_output_section(NULL
, section_name
,
3132 flags
, false, order
, false,
3137 Output_section_data
* posd
= new Output_data_const_buffer(buffer
, notehdrsz
,
3140 os
->add_output_section_data(posd
);
3142 *trailing_padding
= aligned_descsz
- descsz
;
3147 // Create a .note.gnu.properties section to record program properties
3148 // accumulated from the input files.
3151 Layout::create_gnu_properties_note()
3153 if (this->gnu_properties_
.empty())
3156 const unsigned int size
= parameters
->target().get_size();
3157 const bool is_big_endian
= parameters
->target().is_big_endian();
3159 // Compute the total size of the properties array.
3161 for (Gnu_properties::const_iterator prop
= this->gnu_properties_
.begin();
3162 prop
!= this->gnu_properties_
.end();
3165 descsz
= align_address(descsz
+ 8 + prop
->second
.pr_datasz
, size
/ 8);
3168 // Create the note section.
3169 size_t trailing_padding
;
3170 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_PROPERTY_TYPE_0
,
3171 ".note.gnu.properties", descsz
,
3172 true, &trailing_padding
);
3175 gold_assert(trailing_padding
== 0);
3177 // Allocate and fill the properties array.
3178 unsigned char* desc
= new unsigned char[descsz
];
3179 unsigned char* p
= desc
;
3180 for (Gnu_properties::const_iterator prop
= this->gnu_properties_
.begin();
3181 prop
!= this->gnu_properties_
.end();
3184 size_t datasz
= prop
->second
.pr_datasz
;
3185 size_t aligned_datasz
= align_address(prop
->second
.pr_datasz
, size
/ 8);
3186 write_sized_value(prop
->first
, 4, p
, is_big_endian
);
3187 write_sized_value(datasz
, 4, p
+ 4, is_big_endian
);
3188 memcpy(p
+ 8, prop
->second
.pr_data
, datasz
);
3189 if (aligned_datasz
> datasz
)
3190 memset(p
+ 8 + datasz
, 0, aligned_datasz
- datasz
);
3191 p
+= 8 + aligned_datasz
;
3193 Output_section_data
* posd
= new Output_data_const(desc
, descsz
, 4);
3194 os
->add_output_section_data(posd
);
3197 // For an executable or shared library, create a note to record the
3198 // version of gold used to create the binary.
3201 Layout::create_gold_note()
3203 if (parameters
->options().relocatable()
3204 || parameters
->incremental_update())
3207 std::string desc
= std::string("gold ") + gold::get_version_string();
3209 size_t trailing_padding
;
3210 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION
,
3211 ".note.gnu.gold-version", desc
.size(),
3212 false, &trailing_padding
);
3216 Output_section_data
* posd
= new Output_data_const(desc
, 4);
3217 os
->add_output_section_data(posd
);
3219 if (trailing_padding
> 0)
3221 posd
= new Output_data_zero_fill(trailing_padding
, 0);
3222 os
->add_output_section_data(posd
);
3226 // Record whether the stack should be executable. This can be set
3227 // from the command line using the -z execstack or -z noexecstack
3228 // options. Otherwise, if any input file has a .note.GNU-stack
3229 // section with the SHF_EXECINSTR flag set, the stack should be
3230 // executable. Otherwise, if at least one input file a
3231 // .note.GNU-stack section, and some input file has no .note.GNU-stack
3232 // section, we use the target default for whether the stack should be
3233 // executable. If -z stack-size was used to set a p_memsz value for
3234 // PT_GNU_STACK, we generate the segment regardless. Otherwise, we
3235 // don't generate a stack note. When generating a object file, we
3236 // create a .note.GNU-stack section with the appropriate marking.
3237 // When generating an executable or shared library, we create a
3238 // PT_GNU_STACK segment.
3241 Layout::create_stack_segment()
3243 bool is_stack_executable
;
3244 if (parameters
->options().is_execstack_set())
3246 is_stack_executable
= parameters
->options().is_stack_executable();
3247 if (!is_stack_executable
3248 && this->input_requires_executable_stack_
3249 && parameters
->options().warn_execstack())
3250 gold_warning(_("one or more inputs require executable stack, "
3251 "but -z noexecstack was given"));
3253 else if (!this->input_with_gnu_stack_note_
3254 && (!parameters
->options().user_set_stack_size()
3255 || parameters
->options().relocatable()))
3259 if (this->input_requires_executable_stack_
)
3260 is_stack_executable
= true;
3261 else if (this->input_without_gnu_stack_note_
)
3262 is_stack_executable
=
3263 parameters
->target().is_default_stack_executable();
3265 is_stack_executable
= false;
3268 if (parameters
->options().relocatable())
3270 const char* name
= this->namepool_
.add(".note.GNU-stack", false, NULL
);
3271 elfcpp::Elf_Xword flags
= 0;
3272 if (is_stack_executable
)
3273 flags
|= elfcpp::SHF_EXECINSTR
;
3274 this->make_output_section(name
, elfcpp::SHT_PROGBITS
, flags
,
3275 ORDER_INVALID
, false);
3279 if (this->script_options_
->saw_phdrs_clause())
3281 int flags
= elfcpp::PF_R
| elfcpp::PF_W
;
3282 if (is_stack_executable
)
3283 flags
|= elfcpp::PF_X
;
3284 Output_segment
* seg
=
3285 this->make_output_segment(elfcpp::PT_GNU_STACK
, flags
);
3286 seg
->set_size(parameters
->options().stack_size());
3287 // BFD lets targets override this default alignment, but the only
3288 // targets that do so are ones that Gold does not support so far.
3289 seg
->set_minimum_p_align(16);
3293 // If --build-id was used, set up the build ID note.
3296 Layout::create_build_id()
3298 if (!parameters
->options().user_set_build_id())
3301 const char* style
= parameters
->options().build_id();
3302 if (strcmp(style
, "none") == 0)
3305 // Set DESCSZ to the size of the note descriptor. When possible,
3306 // set DESC to the note descriptor contents.
3309 if (strcmp(style
, "md5") == 0)
3311 else if ((strcmp(style
, "sha1") == 0) || (strcmp(style
, "tree") == 0))
3313 else if (strcmp(style
, "uuid") == 0)
3316 const size_t uuidsz
= 128 / 8;
3318 char buffer
[uuidsz
];
3319 memset(buffer
, 0, uuidsz
);
3321 int descriptor
= open_descriptor(-1, "/dev/urandom", O_RDONLY
);
3323 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
3327 ssize_t got
= ::read(descriptor
, buffer
, uuidsz
);
3328 release_descriptor(descriptor
, true);
3330 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno
));
3331 else if (static_cast<size_t>(got
) != uuidsz
)
3332 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
3336 desc
.assign(buffer
, uuidsz
);
3338 #else // __MINGW32__
3340 typedef RPC_STATUS (RPC_ENTRY
*UuidCreateFn
)(UUID
*Uuid
);
3342 HMODULE rpc_library
= LoadLibrary("rpcrt4.dll");
3344 gold_error(_("--build-id=uuid failed: could not load rpcrt4.dll"));
3347 UuidCreateFn uuid_create
= reinterpret_cast<UuidCreateFn
>(
3348 GetProcAddress(rpc_library
, "UuidCreate"));
3350 gold_error(_("--build-id=uuid failed: could not find UuidCreate"));
3351 else if (uuid_create(&uuid
) != RPC_S_OK
)
3352 gold_error(_("__build_id=uuid failed: call UuidCreate() failed"));
3353 FreeLibrary(rpc_library
);
3355 desc
.assign(reinterpret_cast<const char *>(&uuid
), sizeof(UUID
));
3356 descsz
= sizeof(UUID
);
3357 #endif // __MINGW32__
3359 else if (strncmp(style
, "0x", 2) == 0)
3362 const char* p
= style
+ 2;
3365 if (hex_p(p
[0]) && hex_p(p
[1]))
3367 char c
= (hex_value(p
[0]) << 4) | hex_value(p
[1]);
3371 else if (*p
== '-' || *p
== ':')
3374 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
3377 descsz
= desc
.size();
3380 gold_fatal(_("unrecognized --build-id argument '%s'"), style
);
3383 size_t trailing_padding
;
3384 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID
,
3385 ".note.gnu.build-id", descsz
, true,
3392 // We know the value already, so we fill it in now.
3393 gold_assert(desc
.size() == descsz
);
3395 Output_section_data
* posd
= new Output_data_const(desc
, 4);
3396 os
->add_output_section_data(posd
);
3398 if (trailing_padding
!= 0)
3400 posd
= new Output_data_zero_fill(trailing_padding
, 0);
3401 os
->add_output_section_data(posd
);
3406 // We need to compute a checksum after we have completed the
3408 gold_assert(trailing_padding
== 0);
3409 this->build_id_note_
= new Output_data_zero_fill(descsz
, 4);
3410 os
->add_output_section_data(this->build_id_note_
);
3414 // If we have both .stabXX and .stabXXstr sections, then the sh_link
3415 // field of the former should point to the latter. I'm not sure who
3416 // started this, but the GNU linker does it, and some tools depend
3420 Layout::link_stabs_sections()
3422 if (!this->have_stabstr_section_
)
3425 for (Section_list::iterator p
= this->section_list_
.begin();
3426 p
!= this->section_list_
.end();
3429 if ((*p
)->type() != elfcpp::SHT_STRTAB
)
3432 const char* name
= (*p
)->name();
3433 if (strncmp(name
, ".stab", 5) != 0)
3436 size_t len
= strlen(name
);
3437 if (strcmp(name
+ len
- 3, "str") != 0)
3440 std::string
stab_name(name
, len
- 3);
3441 Output_section
* stab_sec
;
3442 stab_sec
= this->find_output_section(stab_name
.c_str());
3443 if (stab_sec
!= NULL
)
3444 stab_sec
->set_link_section(*p
);
3448 // Create .gnu_incremental_inputs and related sections needed
3449 // for the next run of incremental linking to check what has changed.
3452 Layout::create_incremental_info_sections(Symbol_table
* symtab
)
3454 Incremental_inputs
* incr
= this->incremental_inputs_
;
3456 gold_assert(incr
!= NULL
);
3458 // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
3459 incr
->create_data_sections(symtab
);
3461 // Add the .gnu_incremental_inputs section.
3462 const char* incremental_inputs_name
=
3463 this->namepool_
.add(".gnu_incremental_inputs", false, NULL
);
3464 Output_section
* incremental_inputs_os
=
3465 this->make_output_section(incremental_inputs_name
,
3466 elfcpp::SHT_GNU_INCREMENTAL_INPUTS
, 0,
3467 ORDER_INVALID
, false);
3468 incremental_inputs_os
->add_output_section_data(incr
->inputs_section());
3470 // Add the .gnu_incremental_symtab section.
3471 const char* incremental_symtab_name
=
3472 this->namepool_
.add(".gnu_incremental_symtab", false, NULL
);
3473 Output_section
* incremental_symtab_os
=
3474 this->make_output_section(incremental_symtab_name
,
3475 elfcpp::SHT_GNU_INCREMENTAL_SYMTAB
, 0,
3476 ORDER_INVALID
, false);
3477 incremental_symtab_os
->add_output_section_data(incr
->symtab_section());
3478 incremental_symtab_os
->set_entsize(4);
3480 // Add the .gnu_incremental_relocs section.
3481 const char* incremental_relocs_name
=
3482 this->namepool_
.add(".gnu_incremental_relocs", false, NULL
);
3483 Output_section
* incremental_relocs_os
=
3484 this->make_output_section(incremental_relocs_name
,
3485 elfcpp::SHT_GNU_INCREMENTAL_RELOCS
, 0,
3486 ORDER_INVALID
, false);
3487 incremental_relocs_os
->add_output_section_data(incr
->relocs_section());
3488 incremental_relocs_os
->set_entsize(incr
->relocs_entsize());
3490 // Add the .gnu_incremental_got_plt section.
3491 const char* incremental_got_plt_name
=
3492 this->namepool_
.add(".gnu_incremental_got_plt", false, NULL
);
3493 Output_section
* incremental_got_plt_os
=
3494 this->make_output_section(incremental_got_plt_name
,
3495 elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT
, 0,
3496 ORDER_INVALID
, false);
3497 incremental_got_plt_os
->add_output_section_data(incr
->got_plt_section());
3499 // Add the .gnu_incremental_strtab section.
3500 const char* incremental_strtab_name
=
3501 this->namepool_
.add(".gnu_incremental_strtab", false, NULL
);
3502 Output_section
* incremental_strtab_os
= this->make_output_section(incremental_strtab_name
,
3503 elfcpp::SHT_STRTAB
, 0,
3504 ORDER_INVALID
, false);
3505 Output_data_strtab
* strtab_data
=
3506 new Output_data_strtab(incr
->get_stringpool());
3507 incremental_strtab_os
->add_output_section_data(strtab_data
);
3509 incremental_inputs_os
->set_after_input_sections();
3510 incremental_symtab_os
->set_after_input_sections();
3511 incremental_relocs_os
->set_after_input_sections();
3512 incremental_got_plt_os
->set_after_input_sections();
3514 incremental_inputs_os
->set_link_section(incremental_strtab_os
);
3515 incremental_symtab_os
->set_link_section(incremental_inputs_os
);
3516 incremental_relocs_os
->set_link_section(incremental_inputs_os
);
3517 incremental_got_plt_os
->set_link_section(incremental_inputs_os
);
3520 // Return whether SEG1 should be before SEG2 in the output file. This
3521 // is based entirely on the segment type and flags. When this is
3522 // called the segment addresses have normally not yet been set.
3525 Layout::segment_precedes(const Output_segment
* seg1
,
3526 const Output_segment
* seg2
)
3528 // In order to produce a stable ordering if we're called with the same pointer
3533 elfcpp::Elf_Word type1
= seg1
->type();
3534 elfcpp::Elf_Word type2
= seg2
->type();
3536 // The single PT_PHDR segment is required to precede any loadable
3537 // segment. We simply make it always first.
3538 if (type1
== elfcpp::PT_PHDR
)
3540 gold_assert(type2
!= elfcpp::PT_PHDR
);
3543 if (type2
== elfcpp::PT_PHDR
)
3546 // The single PT_INTERP segment is required to precede any loadable
3547 // segment. We simply make it always second.
3548 if (type1
== elfcpp::PT_INTERP
)
3550 gold_assert(type2
!= elfcpp::PT_INTERP
);
3553 if (type2
== elfcpp::PT_INTERP
)
3556 // We then put PT_LOAD segments before any other segments.
3557 if (type1
== elfcpp::PT_LOAD
&& type2
!= elfcpp::PT_LOAD
)
3559 if (type2
== elfcpp::PT_LOAD
&& type1
!= elfcpp::PT_LOAD
)
3562 // We put the PT_TLS segment last except for the PT_GNU_RELRO
3563 // segment, because that is where the dynamic linker expects to find
3564 // it (this is just for efficiency; other positions would also work
3566 if (type1
== elfcpp::PT_TLS
3567 && type2
!= elfcpp::PT_TLS
3568 && type2
!= elfcpp::PT_GNU_RELRO
)
3570 if (type2
== elfcpp::PT_TLS
3571 && type1
!= elfcpp::PT_TLS
3572 && type1
!= elfcpp::PT_GNU_RELRO
)
3575 // We put the PT_GNU_RELRO segment last, because that is where the
3576 // dynamic linker expects to find it (as with PT_TLS, this is just
3578 if (type1
== elfcpp::PT_GNU_RELRO
&& type2
!= elfcpp::PT_GNU_RELRO
)
3580 if (type2
== elfcpp::PT_GNU_RELRO
&& type1
!= elfcpp::PT_GNU_RELRO
)
3583 const elfcpp::Elf_Word flags1
= seg1
->flags();
3584 const elfcpp::Elf_Word flags2
= seg2
->flags();
3586 // The order of non-PT_LOAD segments is unimportant. We simply sort
3587 // by the numeric segment type and flags values. There should not
3588 // be more than one segment with the same type and flags, except
3589 // when a linker script specifies such.
3590 if (type1
!= elfcpp::PT_LOAD
)
3593 return type1
< type2
;
3594 gold_assert(flags1
!= flags2
3595 || this->script_options_
->saw_phdrs_clause());
3596 return flags1
< flags2
;
3599 // If the addresses are set already, sort by load address.
3600 if (seg1
->are_addresses_set())
3602 if (!seg2
->are_addresses_set())
3605 unsigned int section_count1
= seg1
->output_section_count();
3606 unsigned int section_count2
= seg2
->output_section_count();
3607 if (section_count1
== 0 && section_count2
> 0)
3609 if (section_count1
> 0 && section_count2
== 0)
3612 uint64_t paddr1
= (seg1
->are_addresses_set()
3614 : seg1
->first_section_load_address());
3615 uint64_t paddr2
= (seg2
->are_addresses_set()
3617 : seg2
->first_section_load_address());
3619 if (paddr1
!= paddr2
)
3620 return paddr1
< paddr2
;
3622 else if (seg2
->are_addresses_set())
3625 // A segment which holds large data comes after a segment which does
3626 // not hold large data.
3627 if (seg1
->is_large_data_segment())
3629 if (!seg2
->is_large_data_segment())
3632 else if (seg2
->is_large_data_segment())
3635 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
3636 // segments come before writable segments. Then writable segments
3637 // with data come before writable segments without data. Then
3638 // executable segments come before non-executable segments. Then
3639 // the unlikely case of a non-readable segment comes before the
3640 // normal case of a readable segment. If there are multiple
3641 // segments with the same type and flags, we require that the
3642 // address be set, and we sort by virtual address and then physical
3644 if ((flags1
& elfcpp::PF_W
) != (flags2
& elfcpp::PF_W
))
3645 return (flags1
& elfcpp::PF_W
) == 0;
3646 if ((flags1
& elfcpp::PF_W
) != 0
3647 && seg1
->has_any_data_sections() != seg2
->has_any_data_sections())
3648 return seg1
->has_any_data_sections();
3649 if ((flags1
& elfcpp::PF_X
) != (flags2
& elfcpp::PF_X
))
3650 return (flags1
& elfcpp::PF_X
) != 0;
3651 if ((flags1
& elfcpp::PF_R
) != (flags2
& elfcpp::PF_R
))
3652 return (flags1
& elfcpp::PF_R
) == 0;
3654 // We shouldn't get here--we shouldn't create segments which we
3655 // can't distinguish. Unless of course we are using a weird linker
3656 // script or overlapping --section-start options. We could also get
3657 // here if plugins want unique segments for subsets of sections.
3658 gold_assert(this->script_options_
->saw_phdrs_clause()
3659 || parameters
->options().any_section_start()
3660 || this->is_unique_segment_for_sections_specified()
3661 || parameters
->options().text_unlikely_segment());
3665 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
3668 align_file_offset(off_t off
, uint64_t addr
, uint64_t abi_pagesize
)
3670 uint64_t unsigned_off
= off
;
3671 uint64_t aligned_off
= ((unsigned_off
& ~(abi_pagesize
- 1))
3672 | (addr
& (abi_pagesize
- 1)));
3673 if (aligned_off
< unsigned_off
)
3674 aligned_off
+= abi_pagesize
;
3678 // On targets where the text segment contains only executable code,
3679 // a non-executable segment is never the text segment.
3682 is_text_segment(const Target
* target
, const Output_segment
* seg
)
3684 elfcpp::Elf_Xword flags
= seg
->flags();
3685 if ((flags
& elfcpp::PF_W
) != 0)
3687 if ((flags
& elfcpp::PF_X
) == 0)
3688 return !target
->isolate_execinstr();
3692 // Set the file offsets of all the segments, and all the sections they
3693 // contain. They have all been created. LOAD_SEG must be laid out
3694 // first. Return the offset of the data to follow.
3697 Layout::set_segment_offsets(const Target
* target
, Output_segment
* load_seg
,
3698 unsigned int* pshndx
)
3700 // Sort them into the final order. We use a stable sort so that we
3701 // don't randomize the order of indistinguishable segments created
3702 // by linker scripts.
3703 std::stable_sort(this->segment_list_
.begin(), this->segment_list_
.end(),
3704 Layout::Compare_segments(this));
3706 // Find the PT_LOAD segments, and set their addresses and offsets
3707 // and their section's addresses and offsets.
3708 uint64_t start_addr
;
3709 if (parameters
->options().user_set_Ttext())
3710 start_addr
= parameters
->options().Ttext();
3711 else if (parameters
->options().output_is_position_independent())
3714 start_addr
= target
->default_text_segment_address();
3716 uint64_t addr
= start_addr
;
3719 // If LOAD_SEG is NULL, then the file header and segment headers
3720 // will not be loadable. But they still need to be at offset 0 in
3721 // the file. Set their offsets now.
3722 if (load_seg
== NULL
)
3724 for (Data_list::iterator p
= this->special_output_list_
.begin();
3725 p
!= this->special_output_list_
.end();
3728 off
= align_address(off
, (*p
)->addralign());
3729 (*p
)->set_address_and_file_offset(0, off
);
3730 off
+= (*p
)->data_size();
3734 unsigned int increase_relro
= this->increase_relro_
;
3735 if (this->script_options_
->saw_sections_clause())
3738 const bool check_sections
= parameters
->options().check_sections();
3739 Output_segment
* last_load_segment
= NULL
;
3741 unsigned int shndx_begin
= *pshndx
;
3742 unsigned int shndx_load_seg
= *pshndx
;
3744 for (Segment_list::iterator p
= this->segment_list_
.begin();
3745 p
!= this->segment_list_
.end();
3748 if ((*p
)->type() == elfcpp::PT_LOAD
)
3750 if (target
->isolate_execinstr())
3752 // When we hit the segment that should contain the
3753 // file headers, reset the file offset so we place
3754 // it and subsequent segments appropriately.
3755 // We'll fix up the preceding segments below.
3763 shndx_load_seg
= *pshndx
;
3769 // Verify that the file headers fall into the first segment.
3770 if (load_seg
!= NULL
&& load_seg
!= *p
)
3775 bool are_addresses_set
= (*p
)->are_addresses_set();
3776 if (are_addresses_set
)
3778 // When it comes to setting file offsets, we care about
3779 // the physical address.
3780 addr
= (*p
)->paddr();
3782 else if (parameters
->options().user_set_Ttext()
3783 && (parameters
->options().omagic()
3784 || is_text_segment(target
, *p
)))
3786 are_addresses_set
= true;
3788 else if (parameters
->options().user_set_Trodata_segment()
3789 && ((*p
)->flags() & (elfcpp::PF_W
| elfcpp::PF_X
)) == 0)
3791 addr
= parameters
->options().Trodata_segment();
3792 are_addresses_set
= true;
3794 else if (parameters
->options().user_set_Tdata()
3795 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3796 && (!parameters
->options().user_set_Tbss()
3797 || (*p
)->has_any_data_sections()))
3799 addr
= parameters
->options().Tdata();
3800 are_addresses_set
= true;
3802 else if (parameters
->options().user_set_Tbss()
3803 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3804 && !(*p
)->has_any_data_sections())
3806 addr
= parameters
->options().Tbss();
3807 are_addresses_set
= true;
3810 uint64_t orig_addr
= addr
;
3811 uint64_t orig_off
= off
;
3813 uint64_t aligned_addr
= 0;
3814 uint64_t abi_pagesize
= target
->abi_pagesize();
3815 uint64_t common_pagesize
= target
->common_pagesize();
3817 if (!parameters
->options().nmagic()
3818 && !parameters
->options().omagic())
3819 (*p
)->set_minimum_p_align(abi_pagesize
);
3821 if (!are_addresses_set
)
3823 // Skip the address forward one page, maintaining the same
3824 // position within the page. This lets us store both segments
3825 // overlapping on a single page in the file, but the loader will
3826 // put them on different pages in memory. We will revisit this
3827 // decision once we know the size of the segment.
3829 uint64_t max_align
= (*p
)->maximum_alignment();
3830 if (max_align
> abi_pagesize
)
3831 addr
= align_address(addr
, max_align
);
3832 aligned_addr
= addr
;
3836 // This is the segment that will contain the file
3837 // headers, so its offset will have to be exactly zero.
3838 gold_assert(orig_off
== 0);
3840 // If the target wants a fixed minimum distance from the
3841 // text segment to the read-only segment, move up now.
3843 start_addr
+ (parameters
->options().user_set_rosegment_gap()
3844 ? parameters
->options().rosegment_gap()
3845 : target
->rosegment_gap());
3846 if (addr
< min_addr
)
3849 // But this is not the first segment! To make its
3850 // address congruent with its offset, that address better
3851 // be aligned to the ABI-mandated page size.
3852 addr
= align_address(addr
, abi_pagesize
);
3853 aligned_addr
= addr
;
3857 if ((addr
& (abi_pagesize
- 1)) != 0)
3858 addr
= addr
+ abi_pagesize
;
3860 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3864 if (!parameters
->options().nmagic()
3865 && !parameters
->options().omagic())
3867 // Here we are also taking care of the case when
3868 // the maximum segment alignment is larger than the page size.
3869 off
= align_file_offset(off
, addr
,
3870 std::max(abi_pagesize
,
3871 (*p
)->maximum_alignment()));
3875 // This is -N or -n with a section script which prevents
3876 // us from using a load segment. We need to ensure that
3877 // the file offset is aligned to the alignment of the
3878 // segment. This is because the linker script
3879 // implicitly assumed a zero offset. If we don't align
3880 // here, then the alignment of the sections in the
3881 // linker script may not match the alignment of the
3882 // sections in the set_section_addresses call below,
3883 // causing an error about dot moving backward.
3884 off
= align_address(off
, (*p
)->maximum_alignment());
3887 unsigned int shndx_hold
= *pshndx
;
3888 bool has_relro
= false;
3889 uint64_t new_addr
= (*p
)->set_section_addresses(target
, this,
3895 // Now that we know the size of this segment, we may be able
3896 // to save a page in memory, at the cost of wasting some
3897 // file space, by instead aligning to the start of a new
3898 // page. Here we use the real machine page size rather than
3899 // the ABI mandated page size. If the segment has been
3900 // aligned so that the relro data ends at a page boundary,
3901 // we do not try to realign it.
3903 if (!are_addresses_set
3905 && aligned_addr
!= addr
3906 && !parameters
->incremental())
3908 uint64_t first_off
= (common_pagesize
3910 & (common_pagesize
- 1)));
3911 uint64_t last_off
= new_addr
& (common_pagesize
- 1);
3914 && ((aligned_addr
& ~ (common_pagesize
- 1))
3915 != (new_addr
& ~ (common_pagesize
- 1)))
3916 && first_off
+ last_off
<= common_pagesize
)
3918 *pshndx
= shndx_hold
;
3919 addr
= align_address(aligned_addr
, common_pagesize
);
3920 addr
= align_address(addr
, (*p
)->maximum_alignment());
3921 if ((addr
& (abi_pagesize
- 1)) != 0)
3922 addr
= addr
+ abi_pagesize
;
3923 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3924 off
= align_file_offset(off
, addr
, abi_pagesize
);
3926 increase_relro
= this->increase_relro_
;
3927 if (this->script_options_
->saw_sections_clause())
3931 new_addr
= (*p
)->set_section_addresses(target
, this,
3941 // Implement --check-sections. We know that the segments
3942 // are sorted by LMA.
3943 if (check_sections
&& last_load_segment
!= NULL
)
3945 gold_assert(last_load_segment
->paddr() <= (*p
)->paddr());
3946 if (last_load_segment
->paddr() + last_load_segment
->memsz()
3949 unsigned long long lb1
= last_load_segment
->paddr();
3950 unsigned long long le1
= lb1
+ last_load_segment
->memsz();
3951 unsigned long long lb2
= (*p
)->paddr();
3952 unsigned long long le2
= lb2
+ (*p
)->memsz();
3953 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3954 "[0x%llx -> 0x%llx]"),
3955 lb1
, le1
, lb2
, le2
);
3958 last_load_segment
= *p
;
3962 if (load_seg
!= NULL
&& target
->isolate_execinstr())
3964 // Process the early segments again, setting their file offsets
3965 // so they land after the segments starting at LOAD_SEG.
3966 off
= align_file_offset(off
, 0, target
->abi_pagesize());
3968 this->reset_relax_output();
3970 for (Segment_list::iterator p
= this->segment_list_
.begin();
3974 if ((*p
)->type() == elfcpp::PT_LOAD
)
3976 // We repeat the whole job of assigning addresses and
3977 // offsets, but we really only want to change the offsets and
3978 // must ensure that the addresses all come out the same as
3979 // they did the first time through.
3980 bool has_relro
= false;
3981 const uint64_t old_addr
= (*p
)->vaddr();
3982 const uint64_t old_end
= old_addr
+ (*p
)->memsz();
3983 uint64_t new_addr
= (*p
)->set_section_addresses(target
, this,
3989 gold_assert(new_addr
== old_end
);
3993 gold_assert(shndx_begin
== shndx_load_seg
);
3996 // Handle the non-PT_LOAD segments, setting their offsets from their
3997 // section's offsets.
3998 for (Segment_list::iterator p
= this->segment_list_
.begin();
3999 p
!= this->segment_list_
.end();
4002 // PT_GNU_STACK was set up correctly when it was created.
4003 if ((*p
)->type() != elfcpp::PT_LOAD
4004 && (*p
)->type() != elfcpp::PT_GNU_STACK
)
4005 (*p
)->set_offset((*p
)->type() == elfcpp::PT_GNU_RELRO
4010 // Set the TLS offsets for each section in the PT_TLS segment.
4011 if (this->tls_segment_
!= NULL
)
4012 this->tls_segment_
->set_tls_offsets();
4017 // Set the offsets of all the allocated sections when doing a
4018 // relocatable link. This does the same jobs as set_segment_offsets,
4019 // only for a relocatable link.
4022 Layout::set_relocatable_section_offsets(Output_data
* file_header
,
4023 unsigned int* pshndx
)
4027 file_header
->set_address_and_file_offset(0, 0);
4028 off
+= file_header
->data_size();
4030 for (Section_list::iterator p
= this->section_list_
.begin();
4031 p
!= this->section_list_
.end();
4034 // We skip unallocated sections here, except that group sections
4035 // have to come first.
4036 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) == 0
4037 && (*p
)->type() != elfcpp::SHT_GROUP
)
4040 off
= align_address(off
, (*p
)->addralign());
4042 // The linker script might have set the address.
4043 if (!(*p
)->is_address_valid())
4044 (*p
)->set_address(0);
4045 (*p
)->set_file_offset(off
);
4046 (*p
)->finalize_data_size();
4047 if ((*p
)->type() != elfcpp::SHT_NOBITS
)
4048 off
+= (*p
)->data_size();
4050 (*p
)->set_out_shndx(*pshndx
);
4057 // Set the file offset of all the sections not associated with a
4061 Layout::set_section_offsets(off_t off
, Layout::Section_offset_pass pass
)
4063 off_t startoff
= off
;
4066 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
4067 p
!= this->unattached_section_list_
.end();
4070 // The symtab section is handled in create_symtab_sections.
4071 if (*p
== this->symtab_section_
)
4074 // If we've already set the data size, don't set it again.
4075 if ((*p
)->is_offset_valid() && (*p
)->is_data_size_valid())
4078 if (pass
== BEFORE_INPUT_SECTIONS_PASS
4079 && (*p
)->requires_postprocessing())
4081 (*p
)->create_postprocessing_buffer();
4082 this->any_postprocessing_sections_
= true;
4085 if (pass
== BEFORE_INPUT_SECTIONS_PASS
4086 && (*p
)->after_input_sections())
4088 else if (pass
== POSTPROCESSING_SECTIONS_PASS
4089 && (!(*p
)->after_input_sections()
4090 || (*p
)->type() == elfcpp::SHT_STRTAB
))
4092 else if (pass
== STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
4093 && (!(*p
)->after_input_sections()
4094 || (*p
)->type() != elfcpp::SHT_STRTAB
))
4097 if (!parameters
->incremental_update())
4099 off
= align_address(off
, (*p
)->addralign());
4100 (*p
)->set_file_offset(off
);
4101 (*p
)->finalize_data_size();
4105 // Incremental update: allocate file space from free list.
4106 (*p
)->pre_finalize_data_size();
4107 off_t current_size
= (*p
)->current_data_size();
4108 off
= this->allocate(current_size
, (*p
)->addralign(), startoff
);
4111 if (is_debugging_enabled(DEBUG_INCREMENTAL
))
4112 this->free_list_
.dump();
4113 gold_assert((*p
)->output_section() != NULL
);
4114 gold_fallback(_("out of patch space for section %s; "
4115 "relink with --incremental-full"),
4116 (*p
)->output_section()->name());
4118 (*p
)->set_file_offset(off
);
4119 (*p
)->finalize_data_size();
4120 if ((*p
)->data_size() > current_size
)
4122 gold_assert((*p
)->output_section() != NULL
);
4123 gold_fallback(_("%s: section changed size; "
4124 "relink with --incremental-full"),
4125 (*p
)->output_section()->name());
4127 gold_debug(DEBUG_INCREMENTAL
,
4128 "set_section_offsets: %08lx %08lx %s",
4129 static_cast<long>(off
),
4130 static_cast<long>((*p
)->data_size()),
4131 ((*p
)->output_section() != NULL
4132 ? (*p
)->output_section()->name() : "(special)"));
4135 off
+= (*p
)->data_size();
4139 // At this point the name must be set.
4140 if (pass
!= STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
)
4141 this->namepool_
.add((*p
)->name(), false, NULL
);
4146 // Set the section indexes of all the sections not associated with a
4150 Layout::set_section_indexes(unsigned int shndx
)
4152 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
4153 p
!= this->unattached_section_list_
.end();
4156 if (!(*p
)->has_out_shndx())
4158 (*p
)->set_out_shndx(shndx
);
4165 // Set the section addresses according to the linker script. This is
4166 // only called when we see a SECTIONS clause. This returns the
4167 // program segment which should hold the file header and segment
4168 // headers, if any. It will return NULL if they should not be in a
4172 Layout::set_section_addresses_from_script(Symbol_table
* symtab
)
4174 Script_sections
* ss
= this->script_options_
->script_sections();
4175 gold_assert(ss
->saw_sections_clause());
4176 return this->script_options_
->set_section_addresses(symtab
, this);
4179 // Place the orphan sections in the linker script.
4182 Layout::place_orphan_sections_in_script()
4184 Script_sections
* ss
= this->script_options_
->script_sections();
4185 gold_assert(ss
->saw_sections_clause());
4187 // Place each orphaned output section in the script.
4188 for (Section_list::iterator p
= this->section_list_
.begin();
4189 p
!= this->section_list_
.end();
4192 if (!(*p
)->found_in_sections_clause())
4193 ss
->place_orphan(*p
);
4197 // Count the local symbols in the regular symbol table and the dynamic
4198 // symbol table, and build the respective string pools.
4201 Layout::count_local_symbols(const Task
* task
,
4202 const Input_objects
* input_objects
)
4204 // First, figure out an upper bound on the number of symbols we'll
4205 // be inserting into each pool. This helps us create the pools with
4206 // the right size, to avoid unnecessary hashtable resizing.
4207 unsigned int symbol_count
= 0;
4208 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4209 p
!= input_objects
->relobj_end();
4211 symbol_count
+= (*p
)->local_symbol_count();
4213 // Go from "upper bound" to "estimate." We overcount for two
4214 // reasons: we double-count symbols that occur in more than one
4215 // object file, and we count symbols that are dropped from the
4216 // output. Add it all together and assume we overcount by 100%.
4219 // We assume all symbols will go into both the sympool and dynpool.
4220 this->sympool_
.reserve(symbol_count
);
4221 this->dynpool_
.reserve(symbol_count
);
4223 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4224 p
!= input_objects
->relobj_end();
4227 Task_lock_obj
<Object
> tlo(task
, *p
);
4228 (*p
)->count_local_symbols(&this->sympool_
, &this->dynpool_
);
4232 // Create the symbol table sections. Here we also set the final
4233 // values of the symbols. At this point all the loadable sections are
4234 // fully laid out. SHNUM is the number of sections so far.
4237 Layout::create_symtab_sections(const Input_objects
* input_objects
,
4238 Symbol_table
* symtab
,
4241 unsigned int local_dynamic_count
)
4245 if (parameters
->target().get_size() == 32)
4247 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
4250 else if (parameters
->target().get_size() == 64)
4252 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
4258 // Compute file offsets relative to the start of the symtab section.
4261 // Save space for the dummy symbol at the start of the section. We
4262 // never bother to write this out--it will just be left as zero.
4264 unsigned int local_symbol_index
= 1;
4266 // Add STT_SECTION symbols for each Output section which needs one.
4267 for (Section_list::iterator p
= this->section_list_
.begin();
4268 p
!= this->section_list_
.end();
4271 if (!(*p
)->needs_symtab_index())
4272 (*p
)->set_symtab_index(-1U);
4275 (*p
)->set_symtab_index(local_symbol_index
);
4276 ++local_symbol_index
;
4281 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4282 p
!= input_objects
->relobj_end();
4285 unsigned int index
= (*p
)->finalize_local_symbols(local_symbol_index
,
4287 off
+= (index
- local_symbol_index
) * symsize
;
4288 local_symbol_index
= index
;
4291 unsigned int local_symcount
= local_symbol_index
;
4292 gold_assert(static_cast<off_t
>(local_symcount
* symsize
) == off
);
4296 if (this->dynsym_section_
== NULL
)
4303 off_t locsize
= local_dynamic_count
* this->dynsym_section_
->entsize();
4304 dynoff
= this->dynsym_section_
->offset() + locsize
;
4305 dyncount
= (this->dynsym_section_
->data_size() - locsize
) / symsize
;
4306 gold_assert(static_cast<off_t
>(dyncount
* symsize
)
4307 == this->dynsym_section_
->data_size() - locsize
);
4310 off_t global_off
= off
;
4311 off
= symtab
->finalize(off
, dynoff
, local_dynamic_count
, dyncount
,
4312 &this->sympool_
, &local_symcount
);
4314 if (!parameters
->options().strip_all())
4316 this->sympool_
.set_string_offsets();
4318 const char* symtab_name
= this->namepool_
.add(".symtab", false, NULL
);
4319 Output_section
* osymtab
= this->make_output_section(symtab_name
,
4323 this->symtab_section_
= osymtab
;
4325 Output_section_data
* pos
= new Output_data_fixed_space(off
, align
,
4327 osymtab
->add_output_section_data(pos
);
4329 // We generate a .symtab_shndx section if we have more than
4330 // SHN_LORESERVE sections. Technically it is possible that we
4331 // don't need one, because it is possible that there are no
4332 // symbols in any of sections with indexes larger than
4333 // SHN_LORESERVE. That is probably unusual, though, and it is
4334 // easier to always create one than to compute section indexes
4335 // twice (once here, once when writing out the symbols).
4336 if (shnum
>= elfcpp::SHN_LORESERVE
)
4338 const char* symtab_xindex_name
= this->namepool_
.add(".symtab_shndx",
4340 Output_section
* osymtab_xindex
=
4341 this->make_output_section(symtab_xindex_name
,
4342 elfcpp::SHT_SYMTAB_SHNDX
, 0,
4343 ORDER_INVALID
, false);
4345 size_t symcount
= off
/ symsize
;
4346 this->symtab_xindex_
= new Output_symtab_xindex(symcount
);
4348 osymtab_xindex
->add_output_section_data(this->symtab_xindex_
);
4350 osymtab_xindex
->set_link_section(osymtab
);
4351 osymtab_xindex
->set_addralign(4);
4352 osymtab_xindex
->set_entsize(4);
4354 osymtab_xindex
->set_after_input_sections();
4356 // This tells the driver code to wait until the symbol table
4357 // has written out before writing out the postprocessing
4358 // sections, including the .symtab_shndx section.
4359 this->any_postprocessing_sections_
= true;
4362 const char* strtab_name
= this->namepool_
.add(".strtab", false, NULL
);
4363 Output_section
* ostrtab
= this->make_output_section(strtab_name
,
4368 Output_section_data
* pstr
= new Output_data_strtab(&this->sympool_
);
4369 ostrtab
->add_output_section_data(pstr
);
4372 if (!parameters
->incremental_update())
4373 symtab_off
= align_address(*poff
, align
);
4376 symtab_off
= this->allocate(off
, align
, *poff
);
4378 gold_fallback(_("out of patch space for symbol table; "
4379 "relink with --incremental-full"));
4380 gold_debug(DEBUG_INCREMENTAL
,
4381 "create_symtab_sections: %08lx %08lx .symtab",
4382 static_cast<long>(symtab_off
),
4383 static_cast<long>(off
));
4386 symtab
->set_file_offset(symtab_off
+ global_off
);
4387 osymtab
->set_file_offset(symtab_off
);
4388 osymtab
->finalize_data_size();
4389 osymtab
->set_link_section(ostrtab
);
4390 osymtab
->set_info(local_symcount
);
4391 osymtab
->set_entsize(symsize
);
4393 if (symtab_off
+ off
> *poff
)
4394 *poff
= symtab_off
+ off
;
4398 // Create the .shstrtab section, which holds the names of the
4399 // sections. At the time this is called, we have created all the
4400 // output sections except .shstrtab itself.
4403 Layout::create_shstrtab()
4405 // FIXME: We don't need to create a .shstrtab section if we are
4406 // stripping everything.
4408 const char* name
= this->namepool_
.add(".shstrtab", false, NULL
);
4410 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_STRTAB
, 0,
4411 ORDER_INVALID
, false);
4413 if (strcmp(parameters
->options().compress_debug_sections(), "none") != 0)
4415 // We can't write out this section until we've set all the
4416 // section names, and we don't set the names of compressed
4417 // output sections until relocations are complete. FIXME: With
4418 // the current names we use, this is unnecessary.
4419 os
->set_after_input_sections();
4422 Output_section_data
* posd
= new Output_data_strtab(&this->namepool_
);
4423 os
->add_output_section_data(posd
);
4428 // Create the section headers. SIZE is 32 or 64. OFF is the file
4432 Layout::create_shdrs(const Output_section
* shstrtab_section
, off_t
* poff
)
4434 Output_section_headers
* oshdrs
;
4435 oshdrs
= new Output_section_headers(this,
4436 &this->segment_list_
,
4437 &this->section_list_
,
4438 &this->unattached_section_list_
,
4442 if (!parameters
->incremental_update())
4443 off
= align_address(*poff
, oshdrs
->addralign());
4446 oshdrs
->pre_finalize_data_size();
4447 off
= this->allocate(oshdrs
->data_size(), oshdrs
->addralign(), *poff
);
4449 gold_fallback(_("out of patch space for section header table; "
4450 "relink with --incremental-full"));
4451 gold_debug(DEBUG_INCREMENTAL
,
4452 "create_shdrs: %08lx %08lx (section header table)",
4453 static_cast<long>(off
),
4454 static_cast<long>(off
+ oshdrs
->data_size()));
4456 oshdrs
->set_address_and_file_offset(0, off
);
4457 off
+= oshdrs
->data_size();
4460 this->section_headers_
= oshdrs
;
4463 // Count the allocated sections.
4466 Layout::allocated_output_section_count() const
4468 size_t section_count
= 0;
4469 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4470 p
!= this->segment_list_
.end();
4472 section_count
+= (*p
)->output_section_count();
4473 return section_count
;
4476 // Create the dynamic symbol table.
4477 // *PLOCAL_DYNAMIC_COUNT will be set to the number of local symbols
4478 // from input objects, and *PFORCED_LOCAL_DYNAMIC_COUNT will be set
4479 // to the number of global symbols that have been forced local.
4480 // We need to remember the former because the forced-local symbols are
4481 // written along with the global symbols in Symtab::write_globals().
4484 Layout::create_dynamic_symtab(const Input_objects
* input_objects
,
4485 Symbol_table
* symtab
,
4486 Output_section
** pdynstr
,
4487 unsigned int* plocal_dynamic_count
,
4488 unsigned int* pforced_local_dynamic_count
,
4489 std::vector
<Symbol
*>* pdynamic_symbols
,
4490 Versions
* pversions
)
4492 // Count all the symbols in the dynamic symbol table, and set the
4493 // dynamic symbol indexes.
4495 // Skip symbol 0, which is always all zeroes.
4496 unsigned int index
= 1;
4498 // Add STT_SECTION symbols for each Output section which needs one.
4499 for (Section_list::iterator p
= this->section_list_
.begin();
4500 p
!= this->section_list_
.end();
4503 if (!(*p
)->needs_dynsym_index())
4504 (*p
)->set_dynsym_index(-1U);
4507 (*p
)->set_dynsym_index(index
);
4512 // Count the local symbols that need to go in the dynamic symbol table,
4513 // and set the dynamic symbol indexes.
4514 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4515 p
!= input_objects
->relobj_end();
4518 unsigned int new_index
= (*p
)->set_local_dynsym_indexes(index
);
4522 unsigned int local_symcount
= index
;
4523 unsigned int forced_local_count
= 0;
4525 index
= symtab
->set_dynsym_indexes(index
, &forced_local_count
,
4526 pdynamic_symbols
, &this->dynpool_
,
4529 *plocal_dynamic_count
= local_symcount
;
4530 *pforced_local_dynamic_count
= forced_local_count
;
4534 const int size
= parameters
->target().get_size();
4537 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
4540 else if (size
== 64)
4542 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
4548 // Create the dynamic symbol table section.
4550 Output_section
* dynsym
= this->choose_output_section(NULL
, ".dynsym",
4554 ORDER_DYNAMIC_LINKER
,
4555 false, false, false);
4557 // Check for NULL as a linker script may discard .dynsym.
4560 Output_section_data
* odata
= new Output_data_fixed_space(index
* symsize
,
4563 dynsym
->add_output_section_data(odata
);
4565 dynsym
->set_info(local_symcount
+ forced_local_count
);
4566 dynsym
->set_entsize(symsize
);
4567 dynsym
->set_addralign(align
);
4569 this->dynsym_section_
= dynsym
;
4572 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4575 odyn
->add_section_address(elfcpp::DT_SYMTAB
, dynsym
);
4576 odyn
->add_constant(elfcpp::DT_SYMENT
, symsize
);
4579 // If there are more than SHN_LORESERVE allocated sections, we
4580 // create a .dynsym_shndx section. It is possible that we don't
4581 // need one, because it is possible that there are no dynamic
4582 // symbols in any of the sections with indexes larger than
4583 // SHN_LORESERVE. This is probably unusual, though, and at this
4584 // time we don't know the actual section indexes so it is
4585 // inconvenient to check.
4586 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE
)
4588 Output_section
* dynsym_xindex
=
4589 this->choose_output_section(NULL
, ".dynsym_shndx",
4590 elfcpp::SHT_SYMTAB_SHNDX
,
4592 false, ORDER_DYNAMIC_LINKER
, false, false,
4595 if (dynsym_xindex
!= NULL
)
4597 this->dynsym_xindex_
= new Output_symtab_xindex(index
);
4599 dynsym_xindex
->add_output_section_data(this->dynsym_xindex_
);
4601 dynsym_xindex
->set_link_section(dynsym
);
4602 dynsym_xindex
->set_addralign(4);
4603 dynsym_xindex
->set_entsize(4);
4605 dynsym_xindex
->set_after_input_sections();
4607 // This tells the driver code to wait until the symbol table
4608 // has written out before writing out the postprocessing
4609 // sections, including the .dynsym_shndx section.
4610 this->any_postprocessing_sections_
= true;
4614 // Create the dynamic string table section.
4616 Output_section
* dynstr
= this->choose_output_section(NULL
, ".dynstr",
4620 ORDER_DYNAMIC_LINKER
,
4621 false, false, false);
4625 Output_section_data
* strdata
= new Output_data_strtab(&this->dynpool_
);
4626 dynstr
->add_output_section_data(strdata
);
4629 dynsym
->set_link_section(dynstr
);
4630 if (this->dynamic_section_
!= NULL
)
4631 this->dynamic_section_
->set_link_section(dynstr
);
4635 odyn
->add_section_address(elfcpp::DT_STRTAB
, dynstr
);
4636 odyn
->add_section_size(elfcpp::DT_STRSZ
, dynstr
);
4640 // Create the hash tables. The Gnu-style hash table must be
4641 // built first, because it changes the order of the symbols
4642 // in the dynamic symbol table.
4644 if (strcmp(parameters
->options().hash_style(), "gnu") == 0
4645 || strcmp(parameters
->options().hash_style(), "both") == 0)
4647 unsigned char* phash
;
4648 unsigned int hashlen
;
4649 Dynobj::create_gnu_hash_table(*pdynamic_symbols
,
4650 local_symcount
+ forced_local_count
,
4653 Output_section
* hashsec
=
4654 this->choose_output_section(NULL
, ".gnu.hash", elfcpp::SHT_GNU_HASH
,
4655 elfcpp::SHF_ALLOC
, false,
4656 ORDER_DYNAMIC_LINKER
, false, false,
4659 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4663 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4664 hashsec
->add_output_section_data(hashdata
);
4666 if (hashsec
!= NULL
)
4669 hashsec
->set_link_section(dynsym
);
4671 // For a 64-bit target, the entries in .gnu.hash do not have
4672 // a uniform size, so we only set the entry size for a
4674 if (parameters
->target().get_size() == 32)
4675 hashsec
->set_entsize(4);
4678 odyn
->add_section_address(elfcpp::DT_GNU_HASH
, hashsec
);
4682 if (strcmp(parameters
->options().hash_style(), "sysv") == 0
4683 || strcmp(parameters
->options().hash_style(), "both") == 0)
4685 unsigned char* phash
;
4686 unsigned int hashlen
;
4687 Dynobj::create_elf_hash_table(*pdynamic_symbols
,
4688 local_symcount
+ forced_local_count
,
4691 Output_section
* hashsec
=
4692 this->choose_output_section(NULL
, ".hash", elfcpp::SHT_HASH
,
4693 elfcpp::SHF_ALLOC
, false,
4694 ORDER_DYNAMIC_LINKER
, false, false,
4697 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4701 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4702 hashsec
->add_output_section_data(hashdata
);
4704 if (hashsec
!= NULL
)
4707 hashsec
->set_link_section(dynsym
);
4708 hashsec
->set_entsize(parameters
->target().hash_entry_size() / 8);
4712 odyn
->add_section_address(elfcpp::DT_HASH
, hashsec
);
4716 // Assign offsets to each local portion of the dynamic symbol table.
4719 Layout::assign_local_dynsym_offsets(const Input_objects
* input_objects
)
4721 Output_section
* dynsym
= this->dynsym_section_
;
4725 off_t off
= dynsym
->offset();
4727 // Skip the dummy symbol at the start of the section.
4728 off
+= dynsym
->entsize();
4730 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4731 p
!= input_objects
->relobj_end();
4734 unsigned int count
= (*p
)->set_local_dynsym_offset(off
);
4735 off
+= count
* dynsym
->entsize();
4739 // Create the version sections.
4742 Layout::create_version_sections(const Versions
* versions
,
4743 const Symbol_table
* symtab
,
4744 unsigned int local_symcount
,
4745 const std::vector
<Symbol
*>& dynamic_symbols
,
4746 const Output_section
* dynstr
)
4748 if (!versions
->any_defs() && !versions
->any_needs())
4751 switch (parameters
->size_and_endianness())
4753 #ifdef HAVE_TARGET_32_LITTLE
4754 case Parameters::TARGET_32_LITTLE
:
4755 this->sized_create_version_sections
<32, false>(versions
, symtab
,
4757 dynamic_symbols
, dynstr
);
4760 #ifdef HAVE_TARGET_32_BIG
4761 case Parameters::TARGET_32_BIG
:
4762 this->sized_create_version_sections
<32, true>(versions
, symtab
,
4764 dynamic_symbols
, dynstr
);
4767 #ifdef HAVE_TARGET_64_LITTLE
4768 case Parameters::TARGET_64_LITTLE
:
4769 this->sized_create_version_sections
<64, false>(versions
, symtab
,
4771 dynamic_symbols
, dynstr
);
4774 #ifdef HAVE_TARGET_64_BIG
4775 case Parameters::TARGET_64_BIG
:
4776 this->sized_create_version_sections
<64, true>(versions
, symtab
,
4778 dynamic_symbols
, dynstr
);
4786 // Create the version sections, sized version.
4788 template<int size
, bool big_endian
>
4790 Layout::sized_create_version_sections(
4791 const Versions
* versions
,
4792 const Symbol_table
* symtab
,
4793 unsigned int local_symcount
,
4794 const std::vector
<Symbol
*>& dynamic_symbols
,
4795 const Output_section
* dynstr
)
4797 Output_section
* vsec
= this->choose_output_section(NULL
, ".gnu.version",
4798 elfcpp::SHT_GNU_versym
,
4801 ORDER_DYNAMIC_LINKER
,
4802 false, false, false);
4804 // Check for NULL since a linker script may discard this section.
4807 unsigned char* vbuf
;
4809 versions
->symbol_section_contents
<size
, big_endian
>(symtab
,
4815 Output_section_data
* vdata
= new Output_data_const_buffer(vbuf
, vsize
, 2,
4818 vsec
->add_output_section_data(vdata
);
4819 vsec
->set_entsize(2);
4820 vsec
->set_link_section(this->dynsym_section_
);
4823 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4824 if (odyn
!= NULL
&& vsec
!= NULL
)
4825 odyn
->add_section_address(elfcpp::DT_VERSYM
, vsec
);
4827 if (versions
->any_defs())
4829 Output_section
* vdsec
;
4830 vdsec
= this->choose_output_section(NULL
, ".gnu.version_d",
4831 elfcpp::SHT_GNU_verdef
,
4833 false, ORDER_DYNAMIC_LINKER
, false,
4838 unsigned char* vdbuf
;
4839 unsigned int vdsize
;
4840 unsigned int vdentries
;
4841 versions
->def_section_contents
<size
, big_endian
>(&this->dynpool_
,
4845 Output_section_data
* vddata
=
4846 new Output_data_const_buffer(vdbuf
, vdsize
, 4, "** version defs");
4848 vdsec
->add_output_section_data(vddata
);
4849 vdsec
->set_link_section(dynstr
);
4850 vdsec
->set_info(vdentries
);
4854 odyn
->add_section_address(elfcpp::DT_VERDEF
, vdsec
);
4855 odyn
->add_constant(elfcpp::DT_VERDEFNUM
, vdentries
);
4860 if (versions
->any_needs())
4862 Output_section
* vnsec
;
4863 vnsec
= this->choose_output_section(NULL
, ".gnu.version_r",
4864 elfcpp::SHT_GNU_verneed
,
4866 false, ORDER_DYNAMIC_LINKER
, false,
4871 unsigned char* vnbuf
;
4872 unsigned int vnsize
;
4873 unsigned int vnentries
;
4874 versions
->need_section_contents
<size
, big_endian
>(&this->dynpool_
,
4878 Output_section_data
* vndata
=
4879 new Output_data_const_buffer(vnbuf
, vnsize
, 4, "** version refs");
4881 vnsec
->add_output_section_data(vndata
);
4882 vnsec
->set_link_section(dynstr
);
4883 vnsec
->set_info(vnentries
);
4887 odyn
->add_section_address(elfcpp::DT_VERNEED
, vnsec
);
4888 odyn
->add_constant(elfcpp::DT_VERNEEDNUM
, vnentries
);
4894 // Create the .interp section and PT_INTERP segment.
4897 Layout::create_interp(const Target
* target
)
4899 gold_assert(this->interp_segment_
== NULL
);
4901 const char* interp
= parameters
->options().dynamic_linker();
4904 interp
= target
->dynamic_linker();
4905 gold_assert(interp
!= NULL
);
4908 size_t len
= strlen(interp
) + 1;
4910 Output_section_data
* odata
= new Output_data_const(interp
, len
, 1);
4912 Output_section
* osec
= this->choose_output_section(NULL
, ".interp",
4913 elfcpp::SHT_PROGBITS
,
4915 false, ORDER_INTERP
,
4916 false, false, false);
4918 osec
->add_output_section_data(odata
);
4921 // Add dynamic tags for the PLT and the dynamic relocs. This is
4922 // called by the target-specific code. This does nothing if not doing
4925 // USE_REL is true for REL relocs rather than RELA relocs.
4927 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
4929 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
4930 // and we also set DT_PLTREL. We use PLT_REL's output section, since
4931 // some targets have multiple reloc sections in PLT_REL.
4933 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
4934 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT. Again we use the output
4937 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
4941 Layout::add_target_dynamic_tags(bool use_rel
, const Output_data
* plt_got
,
4942 const Output_data
* plt_rel
,
4943 const Output_data_reloc_generic
* dyn_rel
,
4944 bool add_debug
, bool dynrel_includes_plt
)
4946 Output_data_dynamic
* odyn
= this->dynamic_data_
;
4950 if (plt_got
!= NULL
&& plt_got
->output_section() != NULL
)
4951 odyn
->add_section_address(elfcpp::DT_PLTGOT
, plt_got
);
4953 if (plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
)
4955 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, plt_rel
->output_section());
4956 odyn
->add_section_address(elfcpp::DT_JMPREL
, plt_rel
->output_section());
4957 odyn
->add_constant(elfcpp::DT_PLTREL
,
4958 use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
);
4961 if ((dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
)
4962 || (dynrel_includes_plt
4964 && plt_rel
->output_section() != NULL
))
4966 bool have_dyn_rel
= dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
;
4967 bool have_plt_rel
= plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
;
4968 odyn
->add_section_address(use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
,
4970 ? dyn_rel
->output_section()
4971 : plt_rel
->output_section()));
4972 elfcpp::DT size_tag
= use_rel
? elfcpp::DT_RELSZ
: elfcpp::DT_RELASZ
;
4973 if (have_dyn_rel
&& have_plt_rel
&& dynrel_includes_plt
)
4974 odyn
->add_section_size(size_tag
,
4975 dyn_rel
->output_section(),
4976 plt_rel
->output_section());
4977 else if (have_dyn_rel
)
4978 odyn
->add_section_size(size_tag
, dyn_rel
->output_section());
4980 odyn
->add_section_size(size_tag
, plt_rel
->output_section());
4981 const int size
= parameters
->target().get_size();
4986 rel_tag
= elfcpp::DT_RELENT
;
4988 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 32, false>::reloc_size
;
4989 else if (size
== 64)
4990 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 64, false>::reloc_size
;
4996 rel_tag
= elfcpp::DT_RELAENT
;
4998 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 32, false>::reloc_size
;
4999 else if (size
== 64)
5000 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 64, false>::reloc_size
;
5004 odyn
->add_constant(rel_tag
, rel_size
);
5006 if (parameters
->options().combreloc() && have_dyn_rel
)
5008 size_t c
= dyn_rel
->relative_reloc_count();
5010 odyn
->add_constant((use_rel
5011 ? elfcpp::DT_RELCOUNT
5012 : elfcpp::DT_RELACOUNT
),
5017 if (add_debug
&& !parameters
->options().shared())
5019 // The value of the DT_DEBUG tag is filled in by the dynamic
5020 // linker at run time, and used by the debugger.
5021 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
5026 Layout::add_target_specific_dynamic_tag(elfcpp::DT tag
, unsigned int val
)
5028 Output_data_dynamic
* odyn
= this->dynamic_data_
;
5031 odyn
->add_constant(tag
, val
);
5034 // Finish the .dynamic section and PT_DYNAMIC segment.
5037 Layout::finish_dynamic_section(const Input_objects
* input_objects
,
5038 const Symbol_table
* symtab
)
5040 if (!this->script_options_
->saw_phdrs_clause()
5041 && this->dynamic_section_
!= NULL
)
5043 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_DYNAMIC
,
5046 oseg
->add_output_section_to_nonload(this->dynamic_section_
,
5047 elfcpp::PF_R
| elfcpp::PF_W
);
5050 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
5054 for (Input_objects::Dynobj_iterator p
= input_objects
->dynobj_begin();
5055 p
!= input_objects
->dynobj_end();
5058 if (!(*p
)->is_needed() && (*p
)->as_needed())
5060 // This dynamic object was linked with --as-needed, but it
5065 odyn
->add_string(elfcpp::DT_NEEDED
, (*p
)->soname());
5068 if (parameters
->options().shared())
5070 const char* soname
= parameters
->options().soname();
5072 odyn
->add_string(elfcpp::DT_SONAME
, soname
);
5075 Symbol
* sym
= symtab
->lookup(parameters
->options().init());
5076 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
5077 odyn
->add_symbol(elfcpp::DT_INIT
, sym
);
5079 sym
= symtab
->lookup(parameters
->options().fini());
5080 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
5081 odyn
->add_symbol(elfcpp::DT_FINI
, sym
);
5083 // Look for .init_array, .preinit_array and .fini_array by checking
5085 for(Layout::Section_list::const_iterator p
= this->section_list_
.begin();
5086 p
!= this->section_list_
.end();
5088 switch((*p
)->type())
5090 case elfcpp::SHT_FINI_ARRAY
:
5091 odyn
->add_section_address(elfcpp::DT_FINI_ARRAY
, *p
);
5092 odyn
->add_section_size(elfcpp::DT_FINI_ARRAYSZ
, *p
);
5094 case elfcpp::SHT_INIT_ARRAY
:
5095 odyn
->add_section_address(elfcpp::DT_INIT_ARRAY
, *p
);
5096 odyn
->add_section_size(elfcpp::DT_INIT_ARRAYSZ
, *p
);
5098 case elfcpp::SHT_PREINIT_ARRAY
:
5099 odyn
->add_section_address(elfcpp::DT_PREINIT_ARRAY
, *p
);
5100 odyn
->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ
, *p
);
5106 // Add a DT_RPATH entry if needed.
5107 const General_options::Dir_list
& rpath(parameters
->options().rpath());
5110 std::string rpath_val
;
5111 for (General_options::Dir_list::const_iterator p
= rpath
.begin();
5115 if (rpath_val
.empty())
5116 rpath_val
= p
->name();
5119 // Eliminate duplicates.
5120 General_options::Dir_list::const_iterator q
;
5121 for (q
= rpath
.begin(); q
!= p
; ++q
)
5122 if (q
->name() == p
->name())
5127 rpath_val
+= p
->name();
5132 if (!parameters
->options().enable_new_dtags())
5133 odyn
->add_string(elfcpp::DT_RPATH
, rpath_val
);
5135 odyn
->add_string(elfcpp::DT_RUNPATH
, rpath_val
);
5138 // Look for text segments that have dynamic relocations.
5139 bool have_textrel
= false;
5140 if (!this->script_options_
->saw_sections_clause())
5142 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5143 p
!= this->segment_list_
.end();
5146 if ((*p
)->type() == elfcpp::PT_LOAD
5147 && ((*p
)->flags() & elfcpp::PF_W
) == 0
5148 && (*p
)->has_dynamic_reloc())
5150 have_textrel
= true;
5157 // We don't know the section -> segment mapping, so we are
5158 // conservative and just look for readonly sections with
5159 // relocations. If those sections wind up in writable segments,
5160 // then we have created an unnecessary DT_TEXTREL entry.
5161 for (Section_list::const_iterator p
= this->section_list_
.begin();
5162 p
!= this->section_list_
.end();
5165 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0
5166 && ((*p
)->flags() & elfcpp::SHF_WRITE
) == 0
5167 && (*p
)->has_dynamic_reloc())
5169 have_textrel
= true;
5175 if (parameters
->options().filter() != NULL
)
5176 odyn
->add_string(elfcpp::DT_FILTER
, parameters
->options().filter());
5177 if (parameters
->options().any_auxiliary())
5179 for (options::String_set::const_iterator p
=
5180 parameters
->options().auxiliary_begin();
5181 p
!= parameters
->options().auxiliary_end();
5183 odyn
->add_string(elfcpp::DT_AUXILIARY
, *p
);
5186 // Add a DT_FLAGS entry if necessary.
5187 unsigned int flags
= 0;
5190 // Add a DT_TEXTREL for compatibility with older loaders.
5191 odyn
->add_constant(elfcpp::DT_TEXTREL
, 0);
5192 flags
|= elfcpp::DF_TEXTREL
;
5194 if (parameters
->options().text())
5195 gold_error(_("read-only segment has dynamic relocations"));
5196 else if (parameters
->options().warn_shared_textrel()
5197 && parameters
->options().shared())
5198 gold_warning(_("shared library text segment is not shareable"));
5200 if (parameters
->options().shared() && this->has_static_tls())
5201 flags
|= elfcpp::DF_STATIC_TLS
;
5202 if (parameters
->options().origin())
5203 flags
|= elfcpp::DF_ORIGIN
;
5204 if (parameters
->options().Bsymbolic()
5205 && !parameters
->options().have_dynamic_list())
5207 flags
|= elfcpp::DF_SYMBOLIC
;
5208 // Add DT_SYMBOLIC for compatibility with older loaders.
5209 odyn
->add_constant(elfcpp::DT_SYMBOLIC
, 0);
5211 if (parameters
->options().now())
5212 flags
|= elfcpp::DF_BIND_NOW
;
5214 odyn
->add_constant(elfcpp::DT_FLAGS
, flags
);
5217 if (parameters
->options().global())
5218 flags
|= elfcpp::DF_1_GLOBAL
;
5219 if (parameters
->options().initfirst())
5220 flags
|= elfcpp::DF_1_INITFIRST
;
5221 if (parameters
->options().interpose())
5222 flags
|= elfcpp::DF_1_INTERPOSE
;
5223 if (parameters
->options().loadfltr())
5224 flags
|= elfcpp::DF_1_LOADFLTR
;
5225 if (parameters
->options().nodefaultlib())
5226 flags
|= elfcpp::DF_1_NODEFLIB
;
5227 if (parameters
->options().nodelete())
5228 flags
|= elfcpp::DF_1_NODELETE
;
5229 if (parameters
->options().nodlopen())
5230 flags
|= elfcpp::DF_1_NOOPEN
;
5231 if (parameters
->options().nodump())
5232 flags
|= elfcpp::DF_1_NODUMP
;
5233 if (!parameters
->options().shared())
5234 flags
&= ~(elfcpp::DF_1_INITFIRST
5235 | elfcpp::DF_1_NODELETE
5236 | elfcpp::DF_1_NOOPEN
);
5237 if (parameters
->options().origin())
5238 flags
|= elfcpp::DF_1_ORIGIN
;
5239 if (parameters
->options().now())
5240 flags
|= elfcpp::DF_1_NOW
;
5241 if (parameters
->options().Bgroup())
5242 flags
|= elfcpp::DF_1_GROUP
;
5244 odyn
->add_constant(elfcpp::DT_FLAGS_1
, flags
);
5247 // Set the size of the _DYNAMIC symbol table to be the size of the
5251 Layout::set_dynamic_symbol_size(const Symbol_table
* symtab
)
5253 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
5256 odyn
->finalize_data_size();
5257 if (this->dynamic_symbol_
== NULL
)
5259 off_t data_size
= odyn
->data_size();
5260 const int size
= parameters
->target().get_size();
5262 symtab
->get_sized_symbol
<32>(this->dynamic_symbol_
)->set_symsize(data_size
);
5263 else if (size
== 64)
5264 symtab
->get_sized_symbol
<64>(this->dynamic_symbol_
)->set_symsize(data_size
);
5269 // The mapping of input section name prefixes to output section names.
5270 // In some cases one prefix is itself a prefix of another prefix; in
5271 // such a case the longer prefix must come first. These prefixes are
5272 // based on the GNU linker default ELF linker script.
5274 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
5275 #define MAPPING_INIT_EXACT(f, t) { f, 0, t, sizeof(t) - 1 }
5276 const Layout::Section_name_mapping
Layout::section_name_mapping
[] =
5278 MAPPING_INIT(".text.", ".text"),
5279 MAPPING_INIT(".rodata.", ".rodata"),
5280 MAPPING_INIT(".data.rel.ro.local.", ".data.rel.ro.local"),
5281 MAPPING_INIT_EXACT(".data.rel.ro.local", ".data.rel.ro.local"),
5282 MAPPING_INIT(".data.rel.ro.", ".data.rel.ro"),
5283 MAPPING_INIT_EXACT(".data.rel.ro", ".data.rel.ro"),
5284 MAPPING_INIT(".data.", ".data"),
5285 MAPPING_INIT(".bss.", ".bss"),
5286 MAPPING_INIT(".tdata.", ".tdata"),
5287 MAPPING_INIT(".tbss.", ".tbss"),
5288 MAPPING_INIT(".init_array.", ".init_array"),
5289 MAPPING_INIT(".fini_array.", ".fini_array"),
5290 MAPPING_INIT(".sdata.", ".sdata"),
5291 MAPPING_INIT(".sbss.", ".sbss"),
5292 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
5293 // differently depending on whether it is creating a shared library.
5294 MAPPING_INIT(".sdata2.", ".sdata"),
5295 MAPPING_INIT(".sbss2.", ".sbss"),
5296 MAPPING_INIT(".lrodata.", ".lrodata"),
5297 MAPPING_INIT(".ldata.", ".ldata"),
5298 MAPPING_INIT(".lbss.", ".lbss"),
5299 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
5300 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
5301 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
5302 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
5303 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
5304 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
5305 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
5306 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
5307 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
5308 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
5309 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
5310 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
5311 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
5312 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
5313 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
5314 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
5315 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
5316 MAPPING_INIT(".ARM.extab", ".ARM.extab"),
5317 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
5318 MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
5319 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
5322 // Mapping for ".text" section prefixes with -z,keep-text-section-prefix.
5323 const Layout::Section_name_mapping
Layout::text_section_name_mapping
[] =
5325 MAPPING_INIT(".text.hot.", ".text.hot"),
5326 MAPPING_INIT_EXACT(".text.hot", ".text.hot"),
5327 MAPPING_INIT(".text.unlikely.", ".text.unlikely"),
5328 MAPPING_INIT_EXACT(".text.unlikely", ".text.unlikely"),
5329 MAPPING_INIT(".text.startup.", ".text.startup"),
5330 MAPPING_INIT_EXACT(".text.startup", ".text.startup"),
5331 MAPPING_INIT(".text.exit.", ".text.exit"),
5332 MAPPING_INIT_EXACT(".text.exit", ".text.exit"),
5333 MAPPING_INIT(".text.", ".text"),
5336 #undef MAPPING_INIT_EXACT
5338 const int Layout::section_name_mapping_count
=
5339 (sizeof(Layout::section_name_mapping
)
5340 / sizeof(Layout::section_name_mapping
[0]));
5342 const int Layout::text_section_name_mapping_count
=
5343 (sizeof(Layout::text_section_name_mapping
)
5344 / sizeof(Layout::text_section_name_mapping
[0]));
5346 // Find section name NAME in PSNM and return the mapped name if found
5347 // with the length set in PLEN.
5349 Layout::match_section_name(const Layout::Section_name_mapping
* psnm
,
5351 const char* name
, size_t* plen
)
5353 for (int i
= 0; i
< count
; ++i
, ++psnm
)
5355 if (psnm
->fromlen
> 0)
5357 if (strncmp(name
, psnm
->from
, psnm
->fromlen
) == 0)
5359 *plen
= psnm
->tolen
;
5365 if (strcmp(name
, psnm
->from
) == 0)
5367 *plen
= psnm
->tolen
;
5375 // Choose the output section name to use given an input section name.
5376 // Set *PLEN to the length of the name. *PLEN is initialized to the
5380 Layout::output_section_name(const Relobj
* relobj
, const char* name
,
5383 // gcc 4.3 generates the following sorts of section names when it
5384 // needs a section name specific to a function:
5390 // .data.rel.local.FN
5392 // .data.rel.ro.local.FN
5399 // The GNU linker maps all of those to the part before the .FN,
5400 // except that .data.rel.local.FN is mapped to .data, and
5401 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
5402 // beginning with .data.rel.ro.local are grouped together.
5404 // For an anonymous namespace, the string FN can contain a '.'.
5406 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
5407 // GNU linker maps to .rodata.
5409 // The .data.rel.ro sections are used with -z relro. The sections
5410 // are recognized by name. We use the same names that the GNU
5411 // linker does for these sections.
5413 // It is hard to handle this in a principled way, so we don't even
5414 // try. We use a table of mappings. If the input section name is
5415 // not found in the table, we simply use it as the output section
5418 if (parameters
->options().keep_text_section_prefix()
5419 && is_prefix_of(".text", name
))
5421 const char* match
= match_section_name(text_section_name_mapping
,
5422 text_section_name_mapping_count
,
5428 const char* match
= match_section_name(section_name_mapping
,
5429 section_name_mapping_count
, name
, plen
);
5433 // As an additional complication, .ctors sections are output in
5434 // either .ctors or .init_array sections, and .dtors sections are
5435 // output in either .dtors or .fini_array sections.
5436 if (is_prefix_of(".ctors.", name
) || is_prefix_of(".dtors.", name
))
5438 if (parameters
->options().ctors_in_init_array())
5441 return name
[1] == 'c' ? ".init_array" : ".fini_array";
5446 return name
[1] == 'c' ? ".ctors" : ".dtors";
5449 if (parameters
->options().ctors_in_init_array()
5450 && (strcmp(name
, ".ctors") == 0 || strcmp(name
, ".dtors") == 0))
5452 // To make .init_array/.fini_array work with gcc we must exclude
5453 // .ctors and .dtors sections from the crtbegin and crtend
5456 || (!Layout::match_file_name(relobj
, "crtbegin")
5457 && !Layout::match_file_name(relobj
, "crtend")))
5460 return name
[1] == 'c' ? ".init_array" : ".fini_array";
5467 // Return true if RELOBJ is an input file whose base name matches
5468 // FILE_NAME. The base name must have an extension of ".o", and must
5469 // be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is
5470 // to match crtbegin.o as well as crtbeginS.o without getting confused
5471 // by other possibilities. Overall matching the file name this way is
5472 // a dreadful hack, but the GNU linker does it in order to better
5473 // support gcc, and we need to be compatible.
5476 Layout::match_file_name(const Relobj
* relobj
, const char* match
)
5478 const std::string
& file_name(relobj
->name());
5479 const char* base_name
= lbasename(file_name
.c_str());
5480 size_t match_len
= strlen(match
);
5481 if (strncmp(base_name
, match
, match_len
) != 0)
5483 size_t base_len
= strlen(base_name
);
5484 if (base_len
!= match_len
+ 2 && base_len
!= match_len
+ 3)
5486 return memcmp(base_name
+ base_len
- 2, ".o", 2) == 0;
5489 // Check if a comdat group or .gnu.linkonce section with the given
5490 // NAME is selected for the link. If there is already a section,
5491 // *KEPT_SECTION is set to point to the existing section and the
5492 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
5493 // IS_GROUP_NAME are recorded for this NAME in the layout object,
5494 // *KEPT_SECTION is set to the internal copy and the function returns
5498 Layout::find_or_add_kept_section(const std::string
& name
,
5503 Kept_section
** kept_section
)
5505 // It's normal to see a couple of entries here, for the x86 thunk
5506 // sections. If we see more than a few, we're linking a C++
5507 // program, and we resize to get more space to minimize rehashing.
5508 if (this->signatures_
.size() > 4
5509 && !this->resized_signatures_
)
5511 reserve_unordered_map(&this->signatures_
,
5512 this->number_of_input_files_
* 64);
5513 this->resized_signatures_
= true;
5516 Kept_section candidate
;
5517 std::pair
<Signatures::iterator
, bool> ins
=
5518 this->signatures_
.insert(std::make_pair(name
, candidate
));
5520 if (kept_section
!= NULL
)
5521 *kept_section
= &ins
.first
->second
;
5524 // This is the first time we've seen this signature.
5525 ins
.first
->second
.set_object(object
);
5526 ins
.first
->second
.set_shndx(shndx
);
5528 ins
.first
->second
.set_is_comdat();
5530 ins
.first
->second
.set_is_group_name();
5534 // We have already seen this signature.
5536 if (ins
.first
->second
.is_group_name())
5538 // We've already seen a real section group with this signature.
5539 // If the kept group is from a plugin object, and we're in the
5540 // replacement phase, accept the new one as a replacement.
5541 if (ins
.first
->second
.object() == NULL
5542 && parameters
->options().plugins()->in_replacement_phase())
5544 ins
.first
->second
.set_object(object
);
5545 ins
.first
->second
.set_shndx(shndx
);
5550 else if (is_group_name
)
5552 // This is a real section group, and we've already seen a
5553 // linkonce section with this signature. Record that we've seen
5554 // a section group, and don't include this section group.
5555 ins
.first
->second
.set_is_group_name();
5560 // We've already seen a linkonce section and this is a linkonce
5561 // section. These don't block each other--this may be the same
5562 // symbol name with different section types.
5567 // Store the allocated sections into the section list.
5570 Layout::get_allocated_sections(Section_list
* section_list
) const
5572 for (Section_list::const_iterator p
= this->section_list_
.begin();
5573 p
!= this->section_list_
.end();
5575 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0)
5576 section_list
->push_back(*p
);
5579 // Store the executable sections into the section list.
5582 Layout::get_executable_sections(Section_list
* section_list
) const
5584 for (Section_list::const_iterator p
= this->section_list_
.begin();
5585 p
!= this->section_list_
.end();
5587 if (((*p
)->flags() & (elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
))
5588 == (elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
))
5589 section_list
->push_back(*p
);
5592 // Create an output segment.
5595 Layout::make_output_segment(elfcpp::Elf_Word type
, elfcpp::Elf_Word flags
)
5597 gold_assert(!parameters
->options().relocatable());
5598 Output_segment
* oseg
= new Output_segment(type
, flags
);
5599 this->segment_list_
.push_back(oseg
);
5601 if (type
== elfcpp::PT_TLS
)
5602 this->tls_segment_
= oseg
;
5603 else if (type
== elfcpp::PT_GNU_RELRO
)
5604 this->relro_segment_
= oseg
;
5605 else if (type
== elfcpp::PT_INTERP
)
5606 this->interp_segment_
= oseg
;
5611 // Return the file offset of the normal symbol table.
5614 Layout::symtab_section_offset() const
5616 if (this->symtab_section_
!= NULL
)
5617 return this->symtab_section_
->offset();
5621 // Return the section index of the normal symbol table. It may have
5622 // been stripped by the -s/--strip-all option.
5625 Layout::symtab_section_shndx() const
5627 if (this->symtab_section_
!= NULL
)
5628 return this->symtab_section_
->out_shndx();
5632 // Write out the Output_sections. Most won't have anything to write,
5633 // since most of the data will come from input sections which are
5634 // handled elsewhere. But some Output_sections do have Output_data.
5637 Layout::write_output_sections(Output_file
* of
) const
5639 for (Section_list::const_iterator p
= this->section_list_
.begin();
5640 p
!= this->section_list_
.end();
5643 if (!(*p
)->after_input_sections())
5648 // Write out data not associated with a section or the symbol table.
5651 Layout::write_data(const Symbol_table
* symtab
, Output_file
* of
) const
5653 if (!parameters
->options().strip_all())
5655 const Output_section
* symtab_section
= this->symtab_section_
;
5656 for (Section_list::const_iterator p
= this->section_list_
.begin();
5657 p
!= this->section_list_
.end();
5660 if ((*p
)->needs_symtab_index())
5662 gold_assert(symtab_section
!= NULL
);
5663 unsigned int index
= (*p
)->symtab_index();
5664 gold_assert(index
> 0 && index
!= -1U);
5665 off_t off
= (symtab_section
->offset()
5666 + index
* symtab_section
->entsize());
5667 symtab
->write_section_symbol(*p
, this->symtab_xindex_
, of
, off
);
5672 const Output_section
* dynsym_section
= this->dynsym_section_
;
5673 for (Section_list::const_iterator p
= this->section_list_
.begin();
5674 p
!= this->section_list_
.end();
5677 if ((*p
)->needs_dynsym_index())
5679 gold_assert(dynsym_section
!= NULL
);
5680 unsigned int index
= (*p
)->dynsym_index();
5681 gold_assert(index
> 0 && index
!= -1U);
5682 off_t off
= (dynsym_section
->offset()
5683 + index
* dynsym_section
->entsize());
5684 symtab
->write_section_symbol(*p
, this->dynsym_xindex_
, of
, off
);
5688 // Write out the Output_data which are not in an Output_section.
5689 for (Data_list::const_iterator p
= this->special_output_list_
.begin();
5690 p
!= this->special_output_list_
.end();
5694 // Write out the Output_data which are not in an Output_section
5695 // and are regenerated in each iteration of relaxation.
5696 for (Data_list::const_iterator p
= this->relax_output_list_
.begin();
5697 p
!= this->relax_output_list_
.end();
5702 // Write out the Output_sections which can only be written after the
5703 // input sections are complete.
5706 Layout::write_sections_after_input_sections(Output_file
* of
)
5708 // Determine the final section offsets, and thus the final output
5709 // file size. Note we finalize the .shstrab last, to allow the
5710 // after_input_section sections to modify their section-names before
5712 if (this->any_postprocessing_sections_
)
5714 off_t off
= this->output_file_size_
;
5715 off
= this->set_section_offsets(off
, POSTPROCESSING_SECTIONS_PASS
);
5717 // Now that we've finalized the names, we can finalize the shstrab.
5719 this->set_section_offsets(off
,
5720 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
5722 if (off
> this->output_file_size_
)
5725 this->output_file_size_
= off
;
5729 for (Section_list::const_iterator p
= this->section_list_
.begin();
5730 p
!= this->section_list_
.end();
5733 if ((*p
)->after_input_sections())
5737 this->section_headers_
->write(of
);
5740 // If a tree-style build ID was requested, the parallel part of that computation
5741 // is already done, and the final hash-of-hashes is computed here. For other
5742 // types of build IDs, all the work is done here.
5745 Layout::write_build_id(Output_file
* of
, unsigned char* array_of_hashes
,
5746 size_t size_of_hashes
) const
5748 if (this->build_id_note_
== NULL
)
5751 unsigned char* ov
= of
->get_output_view(this->build_id_note_
->offset(),
5752 this->build_id_note_
->data_size());
5754 if (array_of_hashes
== NULL
)
5756 const size_t output_file_size
= this->output_file_size();
5757 const unsigned char* iv
= of
->get_input_view(0, output_file_size
);
5758 const char* style
= parameters
->options().build_id();
5760 // If we get here with style == "tree" then the output must be
5761 // too small for chunking, and we use SHA-1 in that case.
5762 if ((strcmp(style
, "sha1") == 0) || (strcmp(style
, "tree") == 0))
5763 sha1_buffer(reinterpret_cast<const char*>(iv
), output_file_size
, ov
);
5764 else if (strcmp(style
, "md5") == 0)
5765 md5_buffer(reinterpret_cast<const char*>(iv
), output_file_size
, ov
);
5769 of
->free_input_view(0, output_file_size
, iv
);
5773 // Non-overlapping substrings of the output file have been hashed.
5774 // Compute SHA-1 hash of the hashes.
5775 sha1_buffer(reinterpret_cast<const char*>(array_of_hashes
),
5776 size_of_hashes
, ov
);
5777 delete[] array_of_hashes
;
5780 of
->write_output_view(this->build_id_note_
->offset(),
5781 this->build_id_note_
->data_size(),
5785 // Write out a binary file. This is called after the link is
5786 // complete. IN is the temporary output file we used to generate the
5787 // ELF code. We simply walk through the segments, read them from
5788 // their file offset in IN, and write them to their load address in
5789 // the output file. FIXME: with a bit more work, we could support
5790 // S-records and/or Intel hex format here.
5793 Layout::write_binary(Output_file
* in
) const
5795 gold_assert(parameters
->options().oformat_enum()
5796 == General_options::OBJECT_FORMAT_BINARY
);
5798 // Get the size of the binary file.
5799 uint64_t max_load_address
= 0;
5800 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5801 p
!= this->segment_list_
.end();
5804 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5806 uint64_t max_paddr
= (*p
)->paddr() + (*p
)->filesz();
5807 if (max_paddr
> max_load_address
)
5808 max_load_address
= max_paddr
;
5812 Output_file
out(parameters
->options().output_file_name());
5813 out
.open(max_load_address
);
5815 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5816 p
!= this->segment_list_
.end();
5819 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5821 const unsigned char* vin
= in
->get_input_view((*p
)->offset(),
5823 unsigned char* vout
= out
.get_output_view((*p
)->paddr(),
5825 memcpy(vout
, vin
, (*p
)->filesz());
5826 out
.write_output_view((*p
)->paddr(), (*p
)->filesz(), vout
);
5827 in
->free_input_view((*p
)->offset(), (*p
)->filesz(), vin
);
5834 // Print the output sections to the map file.
5837 Layout::print_to_mapfile(Mapfile
* mapfile
) const
5839 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5840 p
!= this->segment_list_
.end();
5842 (*p
)->print_sections_to_mapfile(mapfile
);
5843 for (Section_list::const_iterator p
= this->unattached_section_list_
.begin();
5844 p
!= this->unattached_section_list_
.end();
5846 (*p
)->print_to_mapfile(mapfile
);
5849 // Print statistical information to stderr. This is used for --stats.
5852 Layout::print_stats() const
5854 this->namepool_
.print_stats("section name pool");
5855 this->sympool_
.print_stats("output symbol name pool");
5856 this->dynpool_
.print_stats("dynamic name pool");
5858 for (Section_list::const_iterator p
= this->section_list_
.begin();
5859 p
!= this->section_list_
.end();
5861 (*p
)->print_merge_stats();
5864 // Write_sections_task methods.
5866 // We can always run this task.
5869 Write_sections_task::is_runnable()
5874 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
5878 Write_sections_task::locks(Task_locker
* tl
)
5880 tl
->add(this, this->output_sections_blocker_
);
5881 if (this->input_sections_blocker_
!= NULL
)
5882 tl
->add(this, this->input_sections_blocker_
);
5883 tl
->add(this, this->final_blocker_
);
5886 // Run the task--write out the data.
5889 Write_sections_task::run(Workqueue
*)
5891 this->layout_
->write_output_sections(this->of_
);
5894 // Write_data_task methods.
5896 // We can always run this task.
5899 Write_data_task::is_runnable()
5904 // We need to unlock FINAL_BLOCKER when finished.
5907 Write_data_task::locks(Task_locker
* tl
)
5909 tl
->add(this, this->final_blocker_
);
5912 // Run the task--write out the data.
5915 Write_data_task::run(Workqueue
*)
5917 this->layout_
->write_data(this->symtab_
, this->of_
);
5920 // Write_symbols_task methods.
5922 // We can always run this task.
5925 Write_symbols_task::is_runnable()
5930 // We need to unlock FINAL_BLOCKER when finished.
5933 Write_symbols_task::locks(Task_locker
* tl
)
5935 tl
->add(this, this->final_blocker_
);
5938 // Run the task--write out the symbols.
5941 Write_symbols_task::run(Workqueue
*)
5943 this->symtab_
->write_globals(this->sympool_
, this->dynpool_
,
5944 this->layout_
->symtab_xindex(),
5945 this->layout_
->dynsym_xindex(), this->of_
);
5948 // Write_after_input_sections_task methods.
5950 // We can only run this task after the input sections have completed.
5953 Write_after_input_sections_task::is_runnable()
5955 if (this->input_sections_blocker_
->is_blocked())
5956 return this->input_sections_blocker_
;
5960 // We need to unlock FINAL_BLOCKER when finished.
5963 Write_after_input_sections_task::locks(Task_locker
* tl
)
5965 tl
->add(this, this->final_blocker_
);
5971 Write_after_input_sections_task::run(Workqueue
*)
5973 this->layout_
->write_sections_after_input_sections(this->of_
);
5976 // Build IDs can be computed as a "flat" sha1 or md5 of a string of bytes,
5977 // or as a "tree" where each chunk of the string is hashed and then those
5978 // hashes are put into a (much smaller) string which is hashed with sha1.
5979 // We compute a checksum over the entire file because that is simplest.
5982 Build_id_task_runner::run(Workqueue
* workqueue
, const Task
*)
5984 Task_token
* post_hash_tasks_blocker
= new Task_token(true);
5985 const Layout
* layout
= this->layout_
;
5986 Output_file
* of
= this->of_
;
5987 const size_t filesize
= (layout
->output_file_size() <= 0 ? 0
5988 : static_cast<size_t>(layout
->output_file_size()));
5989 unsigned char* array_of_hashes
= NULL
;
5990 size_t size_of_hashes
= 0;
5992 if (strcmp(this->options_
->build_id(), "tree") == 0
5993 && this->options_
->build_id_chunk_size_for_treehash() > 0
5995 && (filesize
>= this->options_
->build_id_min_file_size_for_treehash()))
5997 static const size_t MD5_OUTPUT_SIZE_IN_BYTES
= 16;
5998 const size_t chunk_size
=
5999 this->options_
->build_id_chunk_size_for_treehash();
6000 const size_t num_hashes
= ((filesize
- 1) / chunk_size
) + 1;
6001 post_hash_tasks_blocker
->add_blockers(num_hashes
);
6002 size_of_hashes
= num_hashes
* MD5_OUTPUT_SIZE_IN_BYTES
;
6003 array_of_hashes
= new unsigned char[size_of_hashes
];
6004 unsigned char *dst
= array_of_hashes
;
6005 for (size_t i
= 0, src_offset
= 0; i
< num_hashes
;
6006 i
++, dst
+= MD5_OUTPUT_SIZE_IN_BYTES
, src_offset
+= chunk_size
)
6008 size_t size
= std::min(chunk_size
, filesize
- src_offset
);
6009 workqueue
->queue(new Hash_task(of
,
6013 post_hash_tasks_blocker
));
6017 // Queue the final task to write the build id and close the output file.
6018 workqueue
->queue(new Task_function(new Close_task_runner(this->options_
,
6023 post_hash_tasks_blocker
,
6024 "Task_function Close_task_runner"));
6027 // Close_task_runner methods.
6029 // Finish up the build ID computation, if necessary, and write a binary file,
6030 // if necessary. Then close the output file.
6033 Close_task_runner::run(Workqueue
*, const Task
*)
6035 // At this point the multi-threaded part of the build ID computation,
6036 // if any, is done. See Build_id_task_runner.
6037 this->layout_
->write_build_id(this->of_
, this->array_of_hashes_
,
6038 this->size_of_hashes_
);
6040 // If we've been asked to create a binary file, we do so here.
6041 if (this->options_
->oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
6042 this->layout_
->write_binary(this->of_
);
6047 // Instantiate the templates we need. We could use the configure
6048 // script to restrict this to only the ones for implemented targets.
6050 #ifdef HAVE_TARGET_32_LITTLE
6053 Layout::init_fixed_output_section
<32, false>(
6055 elfcpp::Shdr
<32, false>& shdr
);
6058 #ifdef HAVE_TARGET_32_BIG
6061 Layout::init_fixed_output_section
<32, true>(
6063 elfcpp::Shdr
<32, true>& shdr
);
6066 #ifdef HAVE_TARGET_64_LITTLE
6069 Layout::init_fixed_output_section
<64, false>(
6071 elfcpp::Shdr
<64, false>& shdr
);
6074 #ifdef HAVE_TARGET_64_BIG
6077 Layout::init_fixed_output_section
<64, true>(
6079 elfcpp::Shdr
<64, true>& shdr
);
6082 #ifdef HAVE_TARGET_32_LITTLE
6085 Layout::layout
<32, false>(Sized_relobj_file
<32, false>* object
,
6088 const elfcpp::Shdr
<32, false>& shdr
,
6089 unsigned int, unsigned int, unsigned int, off_t
*);
6092 #ifdef HAVE_TARGET_32_BIG
6095 Layout::layout
<32, true>(Sized_relobj_file
<32, true>* object
,
6098 const elfcpp::Shdr
<32, true>& shdr
,
6099 unsigned int, unsigned int, unsigned int, off_t
*);
6102 #ifdef HAVE_TARGET_64_LITTLE
6105 Layout::layout
<64, false>(Sized_relobj_file
<64, false>* object
,
6108 const elfcpp::Shdr
<64, false>& shdr
,
6109 unsigned int, unsigned int, unsigned int, off_t
*);
6112 #ifdef HAVE_TARGET_64_BIG
6115 Layout::layout
<64, true>(Sized_relobj_file
<64, true>* object
,
6118 const elfcpp::Shdr
<64, true>& shdr
,
6119 unsigned int, unsigned int, unsigned int, off_t
*);
6122 #ifdef HAVE_TARGET_32_LITTLE
6125 Layout::layout_reloc
<32, false>(Sized_relobj_file
<32, false>* object
,
6126 unsigned int reloc_shndx
,
6127 const elfcpp::Shdr
<32, false>& shdr
,
6128 Output_section
* data_section
,
6129 Relocatable_relocs
* rr
);
6132 #ifdef HAVE_TARGET_32_BIG
6135 Layout::layout_reloc
<32, true>(Sized_relobj_file
<32, true>* object
,
6136 unsigned int reloc_shndx
,
6137 const elfcpp::Shdr
<32, true>& shdr
,
6138 Output_section
* data_section
,
6139 Relocatable_relocs
* rr
);
6142 #ifdef HAVE_TARGET_64_LITTLE
6145 Layout::layout_reloc
<64, false>(Sized_relobj_file
<64, false>* object
,
6146 unsigned int reloc_shndx
,
6147 const elfcpp::Shdr
<64, false>& shdr
,
6148 Output_section
* data_section
,
6149 Relocatable_relocs
* rr
);
6152 #ifdef HAVE_TARGET_64_BIG
6155 Layout::layout_reloc
<64, true>(Sized_relobj_file
<64, true>* object
,
6156 unsigned int reloc_shndx
,
6157 const elfcpp::Shdr
<64, true>& shdr
,
6158 Output_section
* data_section
,
6159 Relocatable_relocs
* rr
);
6162 #ifdef HAVE_TARGET_32_LITTLE
6165 Layout::layout_group
<32, false>(Symbol_table
* symtab
,
6166 Sized_relobj_file
<32, false>* object
,
6168 const char* group_section_name
,
6169 const char* signature
,
6170 const elfcpp::Shdr
<32, false>& shdr
,
6171 elfcpp::Elf_Word flags
,
6172 std::vector
<unsigned int>* shndxes
);
6175 #ifdef HAVE_TARGET_32_BIG
6178 Layout::layout_group
<32, true>(Symbol_table
* symtab
,
6179 Sized_relobj_file
<32, true>* object
,
6181 const char* group_section_name
,
6182 const char* signature
,
6183 const elfcpp::Shdr
<32, true>& shdr
,
6184 elfcpp::Elf_Word flags
,
6185 std::vector
<unsigned int>* shndxes
);
6188 #ifdef HAVE_TARGET_64_LITTLE
6191 Layout::layout_group
<64, false>(Symbol_table
* symtab
,
6192 Sized_relobj_file
<64, false>* object
,
6194 const char* group_section_name
,
6195 const char* signature
,
6196 const elfcpp::Shdr
<64, false>& shdr
,
6197 elfcpp::Elf_Word flags
,
6198 std::vector
<unsigned int>* shndxes
);
6201 #ifdef HAVE_TARGET_64_BIG
6204 Layout::layout_group
<64, true>(Symbol_table
* symtab
,
6205 Sized_relobj_file
<64, true>* object
,
6207 const char* group_section_name
,
6208 const char* signature
,
6209 const elfcpp::Shdr
<64, true>& shdr
,
6210 elfcpp::Elf_Word flags
,
6211 std::vector
<unsigned int>* shndxes
);
6214 #ifdef HAVE_TARGET_32_LITTLE
6217 Layout::layout_eh_frame
<32, false>(Sized_relobj_file
<32, false>* object
,
6218 const unsigned char* symbols
,
6220 const unsigned char* symbol_names
,
6221 off_t symbol_names_size
,
6223 const elfcpp::Shdr
<32, false>& shdr
,
6224 unsigned int reloc_shndx
,
6225 unsigned int reloc_type
,
6229 #ifdef HAVE_TARGET_32_BIG
6232 Layout::layout_eh_frame
<32, true>(Sized_relobj_file
<32, true>* object
,
6233 const unsigned char* symbols
,
6235 const unsigned char* symbol_names
,
6236 off_t symbol_names_size
,
6238 const elfcpp::Shdr
<32, true>& shdr
,
6239 unsigned int reloc_shndx
,
6240 unsigned int reloc_type
,
6244 #ifdef HAVE_TARGET_64_LITTLE
6247 Layout::layout_eh_frame
<64, false>(Sized_relobj_file
<64, false>* object
,
6248 const unsigned char* symbols
,
6250 const unsigned char* symbol_names
,
6251 off_t symbol_names_size
,
6253 const elfcpp::Shdr
<64, false>& shdr
,
6254 unsigned int reloc_shndx
,
6255 unsigned int reloc_type
,
6259 #ifdef HAVE_TARGET_64_BIG
6262 Layout::layout_eh_frame
<64, true>(Sized_relobj_file
<64, true>* object
,
6263 const unsigned char* symbols
,
6265 const unsigned char* symbol_names
,
6266 off_t symbol_names_size
,
6268 const elfcpp::Shdr
<64, true>& shdr
,
6269 unsigned int reloc_shndx
,
6270 unsigned int reloc_type
,
6274 #ifdef HAVE_TARGET_32_LITTLE
6277 Layout::add_to_gdb_index(bool is_type_unit
,
6278 Sized_relobj
<32, false>* object
,
6279 const unsigned char* symbols
,
6282 unsigned int reloc_shndx
,
6283 unsigned int reloc_type
);
6286 #ifdef HAVE_TARGET_32_BIG
6289 Layout::add_to_gdb_index(bool is_type_unit
,
6290 Sized_relobj
<32, true>* object
,
6291 const unsigned char* symbols
,
6294 unsigned int reloc_shndx
,
6295 unsigned int reloc_type
);
6298 #ifdef HAVE_TARGET_64_LITTLE
6301 Layout::add_to_gdb_index(bool is_type_unit
,
6302 Sized_relobj
<64, false>* object
,
6303 const unsigned char* symbols
,
6306 unsigned int reloc_shndx
,
6307 unsigned int reloc_type
);
6310 #ifdef HAVE_TARGET_64_BIG
6313 Layout::add_to_gdb_index(bool is_type_unit
,
6314 Sized_relobj
<64, true>* object
,
6315 const unsigned char* symbols
,
6318 unsigned int reloc_shndx
,
6319 unsigned int reloc_type
);
6322 } // End namespace gold.