1 // layout.cc -- lay out output file sections for gold
3 // Copyright (C) 2006-2016 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
),
479 // Make space for more than enough segments for a typical file.
480 // This is just for efficiency--it's OK if we wind up needing more.
481 this->segment_list_
.reserve(12);
483 // We expect two unattached Output_data objects: the file header and
484 // the segment headers.
485 this->special_output_list_
.reserve(2);
487 // Initialize structure needed for an incremental build.
488 if (parameters
->incremental())
489 this->incremental_inputs_
= new Incremental_inputs
;
491 // The section name pool is worth optimizing in all cases, because
492 // it is small, but there are often overlaps due to .rel sections.
493 this->namepool_
.set_optimize();
496 // For incremental links, record the base file to be modified.
499 Layout::set_incremental_base(Incremental_binary
* base
)
501 this->incremental_base_
= base
;
502 this->free_list_
.init(base
->output_file()->filesize(), true);
505 // Hash a key we use to look up an output section mapping.
508 Layout::Hash_key::operator()(const Layout::Key
& k
) const
510 return k
.first
+ k
.second
.first
+ k
.second
.second
;
513 // These are the debug sections that are actually used by gdb.
514 // Currently, we've checked versions of gdb up to and including 7.4.
515 // We only check the part of the name that follows ".debug_" or
518 static const char* gdb_sections
[] =
521 "addr", // Fission extension
522 // "aranges", // not used by gdb as of 7.4
531 // "pubnames", // not used by gdb as of 7.4
532 // "pubtypes", // not used by gdb as of 7.4
533 // "gnu_pubnames", // Fission extension
534 // "gnu_pubtypes", // Fission extension
540 // This is the minimum set of sections needed for line numbers.
542 static const char* lines_only_debug_sections
[] =
545 // "addr", // Fission extension
546 // "aranges", // not used by gdb as of 7.4
555 // "pubnames", // not used by gdb as of 7.4
556 // "pubtypes", // not used by gdb as of 7.4
557 // "gnu_pubnames", // Fission extension
558 // "gnu_pubtypes", // Fission extension
561 "str_offsets", // Fission extension
564 // These sections are the DWARF fast-lookup tables, and are not needed
565 // when building a .gdb_index section.
567 static const char* gdb_fast_lookup_sections
[] =
576 // Returns whether the given debug section is in the list of
577 // debug-sections-used-by-some-version-of-gdb. SUFFIX is the
578 // portion of the name following ".debug_" or ".zdebug_".
581 is_gdb_debug_section(const char* suffix
)
583 // We can do this faster: binary search or a hashtable. But why bother?
584 for (size_t i
= 0; i
< sizeof(gdb_sections
)/sizeof(*gdb_sections
); ++i
)
585 if (strcmp(suffix
, gdb_sections
[i
]) == 0)
590 // Returns whether the given section is needed for lines-only debugging.
593 is_lines_only_debug_section(const char* suffix
)
595 // We can do this faster: binary search or a hashtable. But why bother?
597 i
< sizeof(lines_only_debug_sections
)/sizeof(*lines_only_debug_sections
);
599 if (strcmp(suffix
, lines_only_debug_sections
[i
]) == 0)
604 // Returns whether the given section is a fast-lookup section that
605 // will not be needed when building a .gdb_index section.
608 is_gdb_fast_lookup_section(const char* suffix
)
610 // We can do this faster: binary search or a hashtable. But why bother?
612 i
< sizeof(gdb_fast_lookup_sections
)/sizeof(*gdb_fast_lookup_sections
);
614 if (strcmp(suffix
, gdb_fast_lookup_sections
[i
]) == 0)
619 // Sometimes we compress sections. This is typically done for
620 // sections that are not part of normal program execution (such as
621 // .debug_* sections), and where the readers of these sections know
622 // how to deal with compressed sections. This routine doesn't say for
623 // certain whether we'll compress -- it depends on commandline options
624 // as well -- just whether this section is a candidate for compression.
625 // (The Output_compressed_section class decides whether to compress
626 // a given section, and picks the name of the compressed section.)
629 is_compressible_debug_section(const char* secname
)
631 return (is_prefix_of(".debug", secname
));
634 // We may see compressed debug sections in input files. Return TRUE
635 // if this is the name of a compressed debug section.
638 is_compressed_debug_section(const char* secname
)
640 return (is_prefix_of(".zdebug", secname
));
644 corresponding_uncompressed_section_name(std::string secname
)
646 gold_assert(secname
[0] == '.' && secname
[1] == 'z');
647 std::string
ret(".");
648 ret
.append(secname
, 2, std::string::npos
);
652 // Whether to include this section in the link.
654 template<int size
, bool big_endian
>
656 Layout::include_section(Sized_relobj_file
<size
, big_endian
>*, const char* name
,
657 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
659 if (!parameters
->options().relocatable()
660 && (shdr
.get_sh_flags() & elfcpp::SHF_EXCLUDE
))
663 elfcpp::Elf_Word sh_type
= shdr
.get_sh_type();
665 if ((sh_type
>= elfcpp::SHT_LOOS
&& sh_type
<= elfcpp::SHT_HIOS
)
666 || (sh_type
>= elfcpp::SHT_LOPROC
&& sh_type
<= elfcpp::SHT_HIPROC
))
667 return parameters
->target().should_include_section(sh_type
);
671 case elfcpp::SHT_NULL
:
672 case elfcpp::SHT_SYMTAB
:
673 case elfcpp::SHT_DYNSYM
:
674 case elfcpp::SHT_HASH
:
675 case elfcpp::SHT_DYNAMIC
:
676 case elfcpp::SHT_SYMTAB_SHNDX
:
679 case elfcpp::SHT_STRTAB
:
680 // Discard the sections which have special meanings in the ELF
681 // ABI. Keep others (e.g., .stabstr). We could also do this by
682 // checking the sh_link fields of the appropriate sections.
683 return (strcmp(name
, ".dynstr") != 0
684 && strcmp(name
, ".strtab") != 0
685 && strcmp(name
, ".shstrtab") != 0);
687 case elfcpp::SHT_RELA
:
688 case elfcpp::SHT_REL
:
689 case elfcpp::SHT_GROUP
:
690 // If we are emitting relocations these should be handled
692 gold_assert(!parameters
->options().relocatable());
695 case elfcpp::SHT_PROGBITS
:
696 if (parameters
->options().strip_debug()
697 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
699 if (is_debug_info_section(name
))
702 if (parameters
->options().strip_debug_non_line()
703 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
705 // Debugging sections can only be recognized by name.
706 if (is_prefix_of(".debug_", name
)
707 && !is_lines_only_debug_section(name
+ 7))
709 if (is_prefix_of(".zdebug_", name
)
710 && !is_lines_only_debug_section(name
+ 8))
713 if (parameters
->options().strip_debug_gdb()
714 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
716 // Debugging sections can only be recognized by name.
717 if (is_prefix_of(".debug_", name
)
718 && !is_gdb_debug_section(name
+ 7))
720 if (is_prefix_of(".zdebug_", name
)
721 && !is_gdb_debug_section(name
+ 8))
724 if (parameters
->options().gdb_index()
725 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
727 // When building .gdb_index, we can strip .debug_pubnames,
728 // .debug_pubtypes, and .debug_aranges sections.
729 if (is_prefix_of(".debug_", name
)
730 && is_gdb_fast_lookup_section(name
+ 7))
732 if (is_prefix_of(".zdebug_", name
)
733 && is_gdb_fast_lookup_section(name
+ 8))
736 if (parameters
->options().strip_lto_sections()
737 && !parameters
->options().relocatable()
738 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
740 // Ignore LTO sections containing intermediate code.
741 if (is_prefix_of(".gnu.lto_", name
))
744 // The GNU linker strips .gnu_debuglink sections, so we do too.
745 // This is a feature used to keep debugging information in
747 if (strcmp(name
, ".gnu_debuglink") == 0)
756 // Return an output section named NAME, or NULL if there is none.
759 Layout::find_output_section(const char* name
) const
761 for (Section_list::const_iterator p
= this->section_list_
.begin();
762 p
!= this->section_list_
.end();
764 if (strcmp((*p
)->name(), name
) == 0)
769 // Return an output segment of type TYPE, with segment flags SET set
770 // and segment flags CLEAR clear. Return NULL if there is none.
773 Layout::find_output_segment(elfcpp::PT type
, elfcpp::Elf_Word set
,
774 elfcpp::Elf_Word clear
) const
776 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
777 p
!= this->segment_list_
.end();
779 if (static_cast<elfcpp::PT
>((*p
)->type()) == type
780 && ((*p
)->flags() & set
) == set
781 && ((*p
)->flags() & clear
) == 0)
786 // When we put a .ctors or .dtors section with more than one word into
787 // a .init_array or .fini_array section, we need to reverse the words
788 // in the .ctors/.dtors section. This is because .init_array executes
789 // constructors front to back, where .ctors executes them back to
790 // front, and vice-versa for .fini_array/.dtors. Although we do want
791 // to remap .ctors/.dtors into .init_array/.fini_array because it can
792 // be more efficient, we don't want to change the order in which
793 // constructors/destructors are run. This set just keeps track of
794 // these sections which need to be reversed. It is only changed by
795 // Layout::layout. It should be a private member of Layout, but that
796 // would require layout.h to #include object.h to get the definition
798 static Unordered_set
<Section_id
, Section_id_hash
> ctors_sections_in_init_array
;
800 // Return whether OBJECT/SHNDX is a .ctors/.dtors section mapped to a
801 // .init_array/.fini_array section.
804 Layout::is_ctors_in_init_array(Relobj
* relobj
, unsigned int shndx
) const
806 return (ctors_sections_in_init_array
.find(Section_id(relobj
, shndx
))
807 != ctors_sections_in_init_array
.end());
810 // Return the output section to use for section NAME with type TYPE
811 // and section flags FLAGS. NAME must be canonicalized in the string
812 // pool, and NAME_KEY is the key. ORDER is where this should appear
813 // in the output sections. IS_RELRO is true for a relro section.
816 Layout::get_output_section(const char* name
, Stringpool::Key name_key
,
817 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
818 Output_section_order order
, bool is_relro
)
820 elfcpp::Elf_Word lookup_type
= type
;
822 // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and
823 // PREINIT_ARRAY like PROGBITS. This ensures that we combine
824 // .init_array, .fini_array, and .preinit_array sections by name
825 // whatever their type in the input file. We do this because the
826 // types are not always right in the input files.
827 if (lookup_type
== elfcpp::SHT_INIT_ARRAY
828 || lookup_type
== elfcpp::SHT_FINI_ARRAY
829 || lookup_type
== elfcpp::SHT_PREINIT_ARRAY
)
830 lookup_type
= elfcpp::SHT_PROGBITS
;
832 elfcpp::Elf_Xword lookup_flags
= flags
;
834 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
835 // read-write with read-only sections. Some other ELF linkers do
836 // not do this. FIXME: Perhaps there should be an option
838 lookup_flags
&= ~(elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
840 const Key
key(name_key
, std::make_pair(lookup_type
, lookup_flags
));
841 const std::pair
<Key
, Output_section
*> v(key
, NULL
);
842 std::pair
<Section_name_map::iterator
, bool> ins(
843 this->section_name_map_
.insert(v
));
846 return ins
.first
->second
;
849 // This is the first time we've seen this name/type/flags
850 // combination. For compatibility with the GNU linker, we
851 // combine sections with contents and zero flags with sections
852 // with non-zero flags. This is a workaround for cases where
853 // assembler code forgets to set section flags. FIXME: Perhaps
854 // there should be an option to control this.
855 Output_section
* os
= NULL
;
857 if (lookup_type
== elfcpp::SHT_PROGBITS
)
861 Output_section
* same_name
= this->find_output_section(name
);
862 if (same_name
!= NULL
863 && (same_name
->type() == elfcpp::SHT_PROGBITS
864 || same_name
->type() == elfcpp::SHT_INIT_ARRAY
865 || same_name
->type() == elfcpp::SHT_FINI_ARRAY
866 || same_name
->type() == elfcpp::SHT_PREINIT_ARRAY
)
867 && (same_name
->flags() & elfcpp::SHF_TLS
) == 0)
870 else if ((flags
& elfcpp::SHF_TLS
) == 0)
872 elfcpp::Elf_Xword zero_flags
= 0;
873 const Key
zero_key(name_key
, std::make_pair(lookup_type
,
875 Section_name_map::iterator p
=
876 this->section_name_map_
.find(zero_key
);
877 if (p
!= this->section_name_map_
.end())
883 os
= this->make_output_section(name
, type
, flags
, order
, is_relro
);
885 ins
.first
->second
= os
;
890 // Returns TRUE iff NAME (an input section from RELOBJ) will
891 // be mapped to an output section that should be KEPT.
894 Layout::keep_input_section(const Relobj
* relobj
, const char* name
)
896 if (! this->script_options_
->saw_sections_clause())
899 Script_sections
* ss
= this->script_options_
->script_sections();
900 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
901 Output_section
** output_section_slot
;
902 Script_sections::Section_type script_section_type
;
905 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
906 &script_section_type
, &keep
);
907 return name
!= NULL
&& keep
;
910 // Clear the input section flags that should not be copied to the
914 Layout::get_output_section_flags(elfcpp::Elf_Xword input_section_flags
)
916 // Some flags in the input section should not be automatically
917 // copied to the output section.
918 input_section_flags
&= ~ (elfcpp::SHF_INFO_LINK
920 | elfcpp::SHF_COMPRESSED
922 | elfcpp::SHF_STRINGS
);
924 // We only clear the SHF_LINK_ORDER flag in for
925 // a non-relocatable link.
926 if (!parameters
->options().relocatable())
927 input_section_flags
&= ~elfcpp::SHF_LINK_ORDER
;
929 return input_section_flags
;
932 // Pick the output section to use for section NAME, in input file
933 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
934 // linker created section. IS_INPUT_SECTION is true if we are
935 // choosing an output section for an input section found in a input
936 // file. ORDER is where this section should appear in the output
937 // sections. IS_RELRO is true for a relro section. This will return
938 // NULL if the input section should be discarded.
941 Layout::choose_output_section(const Relobj
* relobj
, const char* name
,
942 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
943 bool is_input_section
, Output_section_order order
,
946 // We should not see any input sections after we have attached
947 // sections to segments.
948 gold_assert(!is_input_section
|| !this->sections_are_attached_
);
950 flags
= this->get_output_section_flags(flags
);
952 if (this->script_options_
->saw_sections_clause())
954 // We are using a SECTIONS clause, so the output section is
955 // chosen based only on the name.
957 Script_sections
* ss
= this->script_options_
->script_sections();
958 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
959 Output_section
** output_section_slot
;
960 Script_sections::Section_type script_section_type
;
961 const char* orig_name
= name
;
963 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
964 &script_section_type
, &keep
);
968 gold_debug(DEBUG_SCRIPT
, _("Unable to create output section '%s' "
969 "because it is not allowed by the "
970 "SECTIONS clause of the linker script"),
972 // The SECTIONS clause says to discard this input section.
976 // We can only handle script section types ST_NONE and ST_NOLOAD.
977 switch (script_section_type
)
979 case Script_sections::ST_NONE
:
981 case Script_sections::ST_NOLOAD
:
982 flags
&= elfcpp::SHF_ALLOC
;
988 // If this is an orphan section--one not mentioned in the linker
989 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
990 // default processing below.
992 if (output_section_slot
!= NULL
)
994 if (*output_section_slot
!= NULL
)
996 (*output_section_slot
)->update_flags_for_input_section(flags
);
997 return *output_section_slot
;
1000 // We don't put sections found in the linker script into
1001 // SECTION_NAME_MAP_. That keeps us from getting confused
1002 // if an orphan section is mapped to a section with the same
1003 // name as one in the linker script.
1005 name
= this->namepool_
.add(name
, false, NULL
);
1007 Output_section
* os
= this->make_output_section(name
, type
, flags
,
1010 os
->set_found_in_sections_clause();
1012 // Special handling for NOLOAD sections.
1013 if (script_section_type
== Script_sections::ST_NOLOAD
)
1015 os
->set_is_noload();
1017 // The constructor of Output_section sets addresses of non-ALLOC
1018 // sections to 0 by default. We don't want that for NOLOAD
1019 // sections even if they have no SHF_ALLOC flag.
1020 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0
1021 && os
->is_address_valid())
1023 gold_assert(os
->address() == 0
1024 && !os
->is_offset_valid()
1025 && !os
->is_data_size_valid());
1026 os
->reset_address_and_file_offset();
1030 *output_section_slot
= os
;
1035 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
1037 size_t len
= strlen(name
);
1038 std::string uncompressed_name
;
1040 // Compressed debug sections should be mapped to the corresponding
1041 // uncompressed section.
1042 if (is_compressed_debug_section(name
))
1045 corresponding_uncompressed_section_name(std::string(name
, len
));
1046 name
= uncompressed_name
.c_str();
1047 len
= uncompressed_name
.length();
1050 // Turn NAME from the name of the input section into the name of the
1052 if (is_input_section
1053 && !this->script_options_
->saw_sections_clause()
1054 && !parameters
->options().relocatable())
1056 const char *orig_name
= name
;
1057 name
= parameters
->target().output_section_name(relobj
, name
, &len
);
1059 name
= Layout::output_section_name(relobj
, orig_name
, &len
);
1062 Stringpool::Key name_key
;
1063 name
= this->namepool_
.add_with_length(name
, len
, true, &name_key
);
1065 // Find or make the output section. The output section is selected
1066 // based on the section name, type, and flags.
1067 return this->get_output_section(name
, name_key
, type
, flags
, order
, is_relro
);
1070 // For incremental links, record the initial fixed layout of a section
1071 // from the base file, and return a pointer to the Output_section.
1073 template<int size
, bool big_endian
>
1075 Layout::init_fixed_output_section(const char* name
,
1076 elfcpp::Shdr
<size
, big_endian
>& shdr
)
1078 unsigned int sh_type
= shdr
.get_sh_type();
1080 // We preserve the layout of PROGBITS, NOBITS, INIT_ARRAY, FINI_ARRAY,
1081 // PRE_INIT_ARRAY, and NOTE sections.
1082 // All others will be created from scratch and reallocated.
1083 if (!can_incremental_update(sh_type
))
1086 // If we're generating a .gdb_index section, we need to regenerate
1088 if (parameters
->options().gdb_index()
1089 && sh_type
== elfcpp::SHT_PROGBITS
1090 && strcmp(name
, ".gdb_index") == 0)
1093 typename
elfcpp::Elf_types
<size
>::Elf_Addr sh_addr
= shdr
.get_sh_addr();
1094 typename
elfcpp::Elf_types
<size
>::Elf_Off sh_offset
= shdr
.get_sh_offset();
1095 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
1096 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_flags
= shdr
.get_sh_flags();
1097 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_addralign
=
1098 shdr
.get_sh_addralign();
1100 // Make the output section.
1101 Stringpool::Key name_key
;
1102 name
= this->namepool_
.add(name
, true, &name_key
);
1103 Output_section
* os
= this->get_output_section(name
, name_key
, sh_type
,
1104 sh_flags
, ORDER_INVALID
, false);
1105 os
->set_fixed_layout(sh_addr
, sh_offset
, sh_size
, sh_addralign
);
1106 if (sh_type
!= elfcpp::SHT_NOBITS
)
1107 this->free_list_
.remove(sh_offset
, sh_offset
+ sh_size
);
1111 // Return the index by which an input section should be ordered. This
1112 // is used to sort some .text sections, for compatibility with GNU ld.
1115 Layout::special_ordering_of_input_section(const char* name
)
1117 // The GNU linker has some special handling for some sections that
1118 // wind up in the .text section. Sections that start with these
1119 // prefixes must appear first, and must appear in the order listed
1121 static const char* const text_section_sort
[] =
1130 i
< sizeof(text_section_sort
) / sizeof(text_section_sort
[0]);
1132 if (is_prefix_of(text_section_sort
[i
], name
))
1138 // Return the output section to use for input section SHNDX, with name
1139 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
1140 // index of a relocation section which applies to this section, or 0
1141 // if none, or -1U if more than one. RELOC_TYPE is the type of the
1142 // relocation section if there is one. Set *OFF to the offset of this
1143 // input section without the output section. Return NULL if the
1144 // section should be discarded. Set *OFF to -1 if the section
1145 // contents should not be written directly to the output file, but
1146 // will instead receive special handling.
1148 template<int size
, bool big_endian
>
1150 Layout::layout(Sized_relobj_file
<size
, big_endian
>* object
, unsigned int shndx
,
1151 const char* name
, const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1152 unsigned int reloc_shndx
, unsigned int, off_t
* off
)
1156 if (!this->include_section(object
, name
, shdr
))
1159 elfcpp::Elf_Word sh_type
= shdr
.get_sh_type();
1161 // In a relocatable link a grouped section must not be combined with
1162 // any other sections.
1164 if (parameters
->options().relocatable()
1165 && (shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) != 0)
1167 // Some flags in the input section should not be automatically
1168 // copied to the output section.
1169 elfcpp::Elf_Xword flags
= (shdr
.get_sh_flags()
1170 & ~ elfcpp::SHF_COMPRESSED
);
1171 name
= this->namepool_
.add(name
, true, NULL
);
1172 os
= this->make_output_section(name
, sh_type
, flags
,
1173 ORDER_INVALID
, false);
1177 // Plugins can choose to place one or more subsets of sections in
1178 // unique segments and this is done by mapping these section subsets
1179 // to unique output sections. Check if this section needs to be
1180 // remapped to a unique output section.
1181 Section_segment_map::iterator it
1182 = this->section_segment_map_
.find(Const_section_id(object
, shndx
));
1183 if (it
== this->section_segment_map_
.end())
1185 os
= this->choose_output_section(object
, name
, sh_type
,
1186 shdr
.get_sh_flags(), true,
1187 ORDER_INVALID
, false);
1191 // We know the name of the output section, directly call
1192 // get_output_section here by-passing choose_output_section.
1193 elfcpp::Elf_Xword flags
1194 = this->get_output_section_flags(shdr
.get_sh_flags());
1196 const char* os_name
= it
->second
->name
;
1197 Stringpool::Key name_key
;
1198 os_name
= this->namepool_
.add(os_name
, true, &name_key
);
1199 os
= this->get_output_section(os_name
, name_key
, sh_type
, flags
,
1200 ORDER_INVALID
, false);
1201 if (!os
->is_unique_segment())
1203 os
->set_is_unique_segment();
1204 os
->set_extra_segment_flags(it
->second
->flags
);
1205 os
->set_segment_alignment(it
->second
->align
);
1212 // By default the GNU linker sorts input sections whose names match
1213 // .ctors.*, .dtors.*, .init_array.*, or .fini_array.*. The
1214 // sections are sorted by name. This is used to implement
1215 // constructor priority ordering. We are compatible. When we put
1216 // .ctor sections in .init_array and .dtor sections in .fini_array,
1217 // we must also sort plain .ctor and .dtor sections.
1218 if (!this->script_options_
->saw_sections_clause()
1219 && !parameters
->options().relocatable()
1220 && (is_prefix_of(".ctors.", name
)
1221 || is_prefix_of(".dtors.", name
)
1222 || is_prefix_of(".init_array.", name
)
1223 || is_prefix_of(".fini_array.", name
)
1224 || (parameters
->options().ctors_in_init_array()
1225 && (strcmp(name
, ".ctors") == 0
1226 || strcmp(name
, ".dtors") == 0))))
1227 os
->set_must_sort_attached_input_sections();
1229 // By default the GNU linker sorts some special text sections ahead
1230 // of others. We are compatible.
1231 if (parameters
->options().text_reorder()
1232 && !this->script_options_
->saw_sections_clause()
1233 && !this->is_section_ordering_specified()
1234 && !parameters
->options().relocatable()
1235 && Layout::special_ordering_of_input_section(name
) >= 0)
1236 os
->set_must_sort_attached_input_sections();
1238 // If this is a .ctors or .ctors.* section being mapped to a
1239 // .init_array section, or a .dtors or .dtors.* section being mapped
1240 // to a .fini_array section, we will need to reverse the words if
1241 // there is more than one. Record this section for later. See
1242 // ctors_sections_in_init_array above.
1243 if (!this->script_options_
->saw_sections_clause()
1244 && !parameters
->options().relocatable()
1245 && shdr
.get_sh_size() > size
/ 8
1246 && (((strcmp(name
, ".ctors") == 0
1247 || is_prefix_of(".ctors.", name
))
1248 && strcmp(os
->name(), ".init_array") == 0)
1249 || ((strcmp(name
, ".dtors") == 0
1250 || is_prefix_of(".dtors.", name
))
1251 && strcmp(os
->name(), ".fini_array") == 0)))
1252 ctors_sections_in_init_array
.insert(Section_id(object
, shndx
));
1254 // FIXME: Handle SHF_LINK_ORDER somewhere.
1256 elfcpp::Elf_Xword orig_flags
= os
->flags();
1258 *off
= os
->add_input_section(this, object
, shndx
, name
, shdr
, reloc_shndx
,
1259 this->script_options_
->saw_sections_clause());
1261 // If the flags changed, we may have to change the order.
1262 if ((orig_flags
& elfcpp::SHF_ALLOC
) != 0)
1264 orig_flags
&= (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1265 elfcpp::Elf_Xword new_flags
=
1266 os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1267 if (orig_flags
!= new_flags
)
1268 os
->set_order(this->default_section_order(os
, false));
1271 this->have_added_input_section_
= true;
1276 // Maps section SECN to SEGMENT s.
1278 Layout::insert_section_segment_map(Const_section_id secn
,
1279 Unique_segment_info
*s
)
1281 gold_assert(this->unique_segment_for_sections_specified_
);
1282 this->section_segment_map_
[secn
] = s
;
1285 // Handle a relocation section when doing a relocatable link.
1287 template<int size
, bool big_endian
>
1289 Layout::layout_reloc(Sized_relobj_file
<size
, big_endian
>* object
,
1291 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1292 Output_section
* data_section
,
1293 Relocatable_relocs
* rr
)
1295 gold_assert(parameters
->options().relocatable()
1296 || parameters
->options().emit_relocs());
1298 int sh_type
= shdr
.get_sh_type();
1301 if (sh_type
== elfcpp::SHT_REL
)
1303 else if (sh_type
== elfcpp::SHT_RELA
)
1307 name
+= data_section
->name();
1309 // In a relocatable link relocs for a grouped section must not be
1310 // combined with other reloc sections.
1312 if (!parameters
->options().relocatable()
1313 || (data_section
->flags() & elfcpp::SHF_GROUP
) == 0)
1314 os
= this->choose_output_section(object
, name
.c_str(), sh_type
,
1315 shdr
.get_sh_flags(), false,
1316 ORDER_INVALID
, false);
1319 const char* n
= this->namepool_
.add(name
.c_str(), true, NULL
);
1320 os
= this->make_output_section(n
, sh_type
, shdr
.get_sh_flags(),
1321 ORDER_INVALID
, false);
1324 os
->set_should_link_to_symtab();
1325 os
->set_info_section(data_section
);
1327 Output_section_data
* posd
;
1328 if (sh_type
== elfcpp::SHT_REL
)
1330 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rel_size
);
1331 posd
= new Output_relocatable_relocs
<elfcpp::SHT_REL
,
1335 else if (sh_type
== elfcpp::SHT_RELA
)
1337 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rela_size
);
1338 posd
= new Output_relocatable_relocs
<elfcpp::SHT_RELA
,
1345 os
->add_output_section_data(posd
);
1346 rr
->set_output_data(posd
);
1351 // Handle a group section when doing a relocatable link.
1353 template<int size
, bool big_endian
>
1355 Layout::layout_group(Symbol_table
* symtab
,
1356 Sized_relobj_file
<size
, big_endian
>* object
,
1358 const char* group_section_name
,
1359 const char* signature
,
1360 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1361 elfcpp::Elf_Word flags
,
1362 std::vector
<unsigned int>* shndxes
)
1364 gold_assert(parameters
->options().relocatable());
1365 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_GROUP
);
1366 group_section_name
= this->namepool_
.add(group_section_name
, true, NULL
);
1367 Output_section
* os
= this->make_output_section(group_section_name
,
1369 shdr
.get_sh_flags(),
1370 ORDER_INVALID
, false);
1372 // We need to find a symbol with the signature in the symbol table.
1373 // If we don't find one now, we need to look again later.
1374 Symbol
* sym
= symtab
->lookup(signature
, NULL
);
1376 os
->set_info_symndx(sym
);
1379 // Reserve some space to minimize reallocations.
1380 if (this->group_signatures_
.empty())
1381 this->group_signatures_
.reserve(this->number_of_input_files_
* 16);
1383 // We will wind up using a symbol whose name is the signature.
1384 // So just put the signature in the symbol name pool to save it.
1385 signature
= symtab
->canonicalize_name(signature
);
1386 this->group_signatures_
.push_back(Group_signature(os
, signature
));
1389 os
->set_should_link_to_symtab();
1392 section_size_type entry_count
=
1393 convert_to_section_size_type(shdr
.get_sh_size() / 4);
1394 Output_section_data
* posd
=
1395 new Output_data_group
<size
, big_endian
>(object
, entry_count
, flags
,
1397 os
->add_output_section_data(posd
);
1400 // Special GNU handling of sections name .eh_frame. They will
1401 // normally hold exception frame data as defined by the C++ ABI
1402 // (http://codesourcery.com/cxx-abi/).
1404 template<int size
, bool big_endian
>
1406 Layout::layout_eh_frame(Sized_relobj_file
<size
, big_endian
>* object
,
1407 const unsigned char* symbols
,
1409 const unsigned char* symbol_names
,
1410 off_t symbol_names_size
,
1412 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1413 unsigned int reloc_shndx
, unsigned int reloc_type
,
1416 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
1417 || shdr
.get_sh_type() == elfcpp::SHT_X86_64_UNWIND
);
1418 gold_assert((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
1420 Output_section
* os
= this->make_eh_frame_section(object
);
1424 gold_assert(this->eh_frame_section_
== os
);
1426 elfcpp::Elf_Xword orig_flags
= os
->flags();
1428 Eh_frame::Eh_frame_section_disposition disp
=
1429 Eh_frame::EH_UNRECOGNIZED_SECTION
;
1430 if (!parameters
->incremental())
1432 disp
= this->eh_frame_data_
->add_ehframe_input_section(object
,
1442 if (disp
== Eh_frame::EH_OPTIMIZABLE_SECTION
)
1444 os
->update_flags_for_input_section(shdr
.get_sh_flags());
1446 // A writable .eh_frame section is a RELRO section.
1447 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1448 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1451 os
->set_order(ORDER_RELRO
);
1458 if (disp
== Eh_frame::EH_END_MARKER_SECTION
&& !this->added_eh_frame_data_
)
1460 // We found the end marker section, so now we can add the set of
1461 // optimized sections to the output section. We need to postpone
1462 // adding this until we've found a section we can optimize so that
1463 // the .eh_frame section in crtbeginT.o winds up at the start of
1464 // the output section.
1465 os
->add_output_section_data(this->eh_frame_data_
);
1466 this->added_eh_frame_data_
= true;
1469 // We couldn't handle this .eh_frame section for some reason.
1470 // Add it as a normal section.
1471 bool saw_sections_clause
= this->script_options_
->saw_sections_clause();
1472 *off
= os
->add_input_section(this, object
, shndx
, ".eh_frame", shdr
,
1473 reloc_shndx
, saw_sections_clause
);
1474 this->have_added_input_section_
= true;
1476 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1477 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1478 os
->set_order(this->default_section_order(os
, false));
1484 Layout::finalize_eh_frame_section()
1486 // If we never found an end marker section, we need to add the
1487 // optimized eh sections to the output section now.
1488 if (!parameters
->incremental()
1489 && this->eh_frame_section_
!= NULL
1490 && !this->added_eh_frame_data_
)
1492 this->eh_frame_section_
->add_output_section_data(this->eh_frame_data_
);
1493 this->added_eh_frame_data_
= true;
1497 // Create and return the magic .eh_frame section. Create
1498 // .eh_frame_hdr also if appropriate. OBJECT is the object with the
1499 // input .eh_frame section; it may be NULL.
1502 Layout::make_eh_frame_section(const Relobj
* object
)
1504 // FIXME: On x86_64, this could use SHT_X86_64_UNWIND rather than
1506 Output_section
* os
= this->choose_output_section(object
, ".eh_frame",
1507 elfcpp::SHT_PROGBITS
,
1508 elfcpp::SHF_ALLOC
, false,
1509 ORDER_EHFRAME
, false);
1513 if (this->eh_frame_section_
== NULL
)
1515 this->eh_frame_section_
= os
;
1516 this->eh_frame_data_
= new Eh_frame();
1518 // For incremental linking, we do not optimize .eh_frame sections
1519 // or create a .eh_frame_hdr section.
1520 if (parameters
->options().eh_frame_hdr() && !parameters
->incremental())
1522 Output_section
* hdr_os
=
1523 this->choose_output_section(NULL
, ".eh_frame_hdr",
1524 elfcpp::SHT_PROGBITS
,
1525 elfcpp::SHF_ALLOC
, false,
1526 ORDER_EHFRAME
, false);
1530 Eh_frame_hdr
* hdr_posd
= new Eh_frame_hdr(os
,
1531 this->eh_frame_data_
);
1532 hdr_os
->add_output_section_data(hdr_posd
);
1534 hdr_os
->set_after_input_sections();
1536 if (!this->script_options_
->saw_phdrs_clause())
1538 Output_segment
* hdr_oseg
;
1539 hdr_oseg
= this->make_output_segment(elfcpp::PT_GNU_EH_FRAME
,
1541 hdr_oseg
->add_output_section_to_nonload(hdr_os
,
1545 this->eh_frame_data_
->set_eh_frame_hdr(hdr_posd
);
1553 // Add an exception frame for a PLT. This is called from target code.
1556 Layout::add_eh_frame_for_plt(Output_data
* plt
, const unsigned char* cie_data
,
1557 size_t cie_length
, const unsigned char* fde_data
,
1560 if (parameters
->incremental())
1562 // FIXME: Maybe this could work some day....
1565 Output_section
* os
= this->make_eh_frame_section(NULL
);
1568 this->eh_frame_data_
->add_ehframe_for_plt(plt
, cie_data
, cie_length
,
1569 fde_data
, fde_length
);
1570 if (!this->added_eh_frame_data_
)
1572 os
->add_output_section_data(this->eh_frame_data_
);
1573 this->added_eh_frame_data_
= true;
1577 // Scan a .debug_info or .debug_types section, and add summary
1578 // information to the .gdb_index section.
1580 template<int size
, bool big_endian
>
1582 Layout::add_to_gdb_index(bool is_type_unit
,
1583 Sized_relobj
<size
, big_endian
>* object
,
1584 const unsigned char* symbols
,
1587 unsigned int reloc_shndx
,
1588 unsigned int reloc_type
)
1590 if (this->gdb_index_data_
== NULL
)
1592 Output_section
* os
= this->choose_output_section(NULL
, ".gdb_index",
1593 elfcpp::SHT_PROGBITS
, 0,
1594 false, ORDER_INVALID
,
1599 this->gdb_index_data_
= new Gdb_index(os
);
1600 os
->add_output_section_data(this->gdb_index_data_
);
1601 os
->set_after_input_sections();
1604 this->gdb_index_data_
->scan_debug_info(is_type_unit
, object
, symbols
,
1605 symbols_size
, shndx
, reloc_shndx
,
1609 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
1610 // the output section.
1613 Layout::add_output_section_data(const char* name
, elfcpp::Elf_Word type
,
1614 elfcpp::Elf_Xword flags
,
1615 Output_section_data
* posd
,
1616 Output_section_order order
, bool is_relro
)
1618 Output_section
* os
= this->choose_output_section(NULL
, name
, type
, flags
,
1619 false, order
, is_relro
);
1621 os
->add_output_section_data(posd
);
1625 // Map section flags to segment flags.
1628 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags
)
1630 elfcpp::Elf_Word ret
= elfcpp::PF_R
;
1631 if ((flags
& elfcpp::SHF_WRITE
) != 0)
1632 ret
|= elfcpp::PF_W
;
1633 if ((flags
& elfcpp::SHF_EXECINSTR
) != 0)
1634 ret
|= elfcpp::PF_X
;
1638 // Make a new Output_section, and attach it to segments as
1639 // appropriate. ORDER is the order in which this section should
1640 // appear in the output segment. IS_RELRO is true if this is a relro
1641 // (read-only after relocations) section.
1644 Layout::make_output_section(const char* name
, elfcpp::Elf_Word type
,
1645 elfcpp::Elf_Xword flags
,
1646 Output_section_order order
, bool is_relro
)
1649 if ((flags
& elfcpp::SHF_ALLOC
) == 0
1650 && strcmp(parameters
->options().compress_debug_sections(), "none") != 0
1651 && is_compressible_debug_section(name
))
1652 os
= new Output_compressed_section(¶meters
->options(), name
, type
,
1654 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1655 && parameters
->options().strip_debug_non_line()
1656 && strcmp(".debug_abbrev", name
) == 0)
1658 os
= this->debug_abbrev_
= new Output_reduced_debug_abbrev_section(
1660 if (this->debug_info_
)
1661 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1663 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1664 && parameters
->options().strip_debug_non_line()
1665 && strcmp(".debug_info", name
) == 0)
1667 os
= this->debug_info_
= new Output_reduced_debug_info_section(
1669 if (this->debug_abbrev_
)
1670 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1674 // Sometimes .init_array*, .preinit_array* and .fini_array* do
1675 // not have correct section types. Force them here.
1676 if (type
== elfcpp::SHT_PROGBITS
)
1678 if (is_prefix_of(".init_array", name
))
1679 type
= elfcpp::SHT_INIT_ARRAY
;
1680 else if (is_prefix_of(".preinit_array", name
))
1681 type
= elfcpp::SHT_PREINIT_ARRAY
;
1682 else if (is_prefix_of(".fini_array", name
))
1683 type
= elfcpp::SHT_FINI_ARRAY
;
1686 // FIXME: const_cast is ugly.
1687 Target
* target
= const_cast<Target
*>(¶meters
->target());
1688 os
= target
->make_output_section(name
, type
, flags
);
1691 // With -z relro, we have to recognize the special sections by name.
1692 // There is no other way.
1693 bool is_relro_local
= false;
1694 if (!this->script_options_
->saw_sections_clause()
1695 && parameters
->options().relro()
1696 && (flags
& elfcpp::SHF_ALLOC
) != 0
1697 && (flags
& elfcpp::SHF_WRITE
) != 0)
1699 if (type
== elfcpp::SHT_PROGBITS
)
1701 if ((flags
& elfcpp::SHF_TLS
) != 0)
1703 else if (strcmp(name
, ".data.rel.ro") == 0)
1705 else if (strcmp(name
, ".data.rel.ro.local") == 0)
1708 is_relro_local
= true;
1710 else if (strcmp(name
, ".ctors") == 0
1711 || strcmp(name
, ".dtors") == 0
1712 || strcmp(name
, ".jcr") == 0)
1715 else if (type
== elfcpp::SHT_INIT_ARRAY
1716 || type
== elfcpp::SHT_FINI_ARRAY
1717 || type
== elfcpp::SHT_PREINIT_ARRAY
)
1724 if (order
== ORDER_INVALID
&& (flags
& elfcpp::SHF_ALLOC
) != 0)
1725 order
= this->default_section_order(os
, is_relro_local
);
1727 os
->set_order(order
);
1729 parameters
->target().new_output_section(os
);
1731 this->section_list_
.push_back(os
);
1733 // The GNU linker by default sorts some sections by priority, so we
1734 // do the same. We need to know that this might happen before we
1735 // attach any input sections.
1736 if (!this->script_options_
->saw_sections_clause()
1737 && !parameters
->options().relocatable()
1738 && (strcmp(name
, ".init_array") == 0
1739 || strcmp(name
, ".fini_array") == 0
1740 || (!parameters
->options().ctors_in_init_array()
1741 && (strcmp(name
, ".ctors") == 0
1742 || strcmp(name
, ".dtors") == 0))))
1743 os
->set_may_sort_attached_input_sections();
1745 // The GNU linker by default sorts .text.{unlikely,exit,startup,hot}
1746 // sections before other .text sections. We are compatible. We
1747 // need to know that this might happen before we attach any input
1749 if (parameters
->options().text_reorder()
1750 && !this->script_options_
->saw_sections_clause()
1751 && !this->is_section_ordering_specified()
1752 && !parameters
->options().relocatable()
1753 && strcmp(name
, ".text") == 0)
1754 os
->set_may_sort_attached_input_sections();
1756 // GNU linker sorts section by name with --sort-section=name.
1757 if (strcmp(parameters
->options().sort_section(), "name") == 0)
1758 os
->set_must_sort_attached_input_sections();
1760 // Check for .stab*str sections, as .stab* sections need to link to
1762 if (type
== elfcpp::SHT_STRTAB
1763 && !this->have_stabstr_section_
1764 && strncmp(name
, ".stab", 5) == 0
1765 && strcmp(name
+ strlen(name
) - 3, "str") == 0)
1766 this->have_stabstr_section_
= true;
1768 // During a full incremental link, we add patch space to most
1769 // PROGBITS and NOBITS sections. Flag those that may be
1770 // arbitrarily padded.
1771 if ((type
== elfcpp::SHT_PROGBITS
|| type
== elfcpp::SHT_NOBITS
)
1772 && order
!= ORDER_INTERP
1773 && order
!= ORDER_INIT
1774 && order
!= ORDER_PLT
1775 && order
!= ORDER_FINI
1776 && order
!= ORDER_RELRO_LAST
1777 && order
!= ORDER_NON_RELRO_FIRST
1778 && strcmp(name
, ".eh_frame") != 0
1779 && strcmp(name
, ".ctors") != 0
1780 && strcmp(name
, ".dtors") != 0
1781 && strcmp(name
, ".jcr") != 0)
1783 os
->set_is_patch_space_allowed();
1785 // Certain sections require "holes" to be filled with
1786 // specific fill patterns. These fill patterns may have
1787 // a minimum size, so we must prevent allocations from the
1788 // free list that leave a hole smaller than the minimum.
1789 if (strcmp(name
, ".debug_info") == 0)
1790 os
->set_free_space_fill(new Output_fill_debug_info(false));
1791 else if (strcmp(name
, ".debug_types") == 0)
1792 os
->set_free_space_fill(new Output_fill_debug_info(true));
1793 else if (strcmp(name
, ".debug_line") == 0)
1794 os
->set_free_space_fill(new Output_fill_debug_line());
1797 // If we have already attached the sections to segments, then we
1798 // need to attach this one now. This happens for sections created
1799 // directly by the linker.
1800 if (this->sections_are_attached_
)
1801 this->attach_section_to_segment(¶meters
->target(), os
);
1806 // Return the default order in which a section should be placed in an
1807 // output segment. This function captures a lot of the ideas in
1808 // ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
1809 // linker created section is normally set when the section is created;
1810 // this function is used for input sections.
1812 Output_section_order
1813 Layout::default_section_order(Output_section
* os
, bool is_relro_local
)
1815 gold_assert((os
->flags() & elfcpp::SHF_ALLOC
) != 0);
1816 bool is_write
= (os
->flags() & elfcpp::SHF_WRITE
) != 0;
1817 bool is_execinstr
= (os
->flags() & elfcpp::SHF_EXECINSTR
) != 0;
1818 bool is_bss
= false;
1823 case elfcpp::SHT_PROGBITS
:
1825 case elfcpp::SHT_NOBITS
:
1828 case elfcpp::SHT_RELA
:
1829 case elfcpp::SHT_REL
:
1831 return ORDER_DYNAMIC_RELOCS
;
1833 case elfcpp::SHT_HASH
:
1834 case elfcpp::SHT_DYNAMIC
:
1835 case elfcpp::SHT_SHLIB
:
1836 case elfcpp::SHT_DYNSYM
:
1837 case elfcpp::SHT_GNU_HASH
:
1838 case elfcpp::SHT_GNU_verdef
:
1839 case elfcpp::SHT_GNU_verneed
:
1840 case elfcpp::SHT_GNU_versym
:
1842 return ORDER_DYNAMIC_LINKER
;
1844 case elfcpp::SHT_NOTE
:
1845 return is_write
? ORDER_RW_NOTE
: ORDER_RO_NOTE
;
1848 if ((os
->flags() & elfcpp::SHF_TLS
) != 0)
1849 return is_bss
? ORDER_TLS_BSS
: ORDER_TLS_DATA
;
1851 if (!is_bss
&& !is_write
)
1855 if (strcmp(os
->name(), ".init") == 0)
1857 else if (strcmp(os
->name(), ".fini") == 0)
1860 return is_execinstr
? ORDER_TEXT
: ORDER_READONLY
;
1864 return is_relro_local
? ORDER_RELRO_LOCAL
: ORDER_RELRO
;
1866 if (os
->is_small_section())
1867 return is_bss
? ORDER_SMALL_BSS
: ORDER_SMALL_DATA
;
1868 if (os
->is_large_section())
1869 return is_bss
? ORDER_LARGE_BSS
: ORDER_LARGE_DATA
;
1871 return is_bss
? ORDER_BSS
: ORDER_DATA
;
1874 // Attach output sections to segments. This is called after we have
1875 // seen all the input sections.
1878 Layout::attach_sections_to_segments(const Target
* target
)
1880 for (Section_list::iterator p
= this->section_list_
.begin();
1881 p
!= this->section_list_
.end();
1883 this->attach_section_to_segment(target
, *p
);
1885 this->sections_are_attached_
= true;
1888 // Attach an output section to a segment.
1891 Layout::attach_section_to_segment(const Target
* target
, Output_section
* os
)
1893 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0)
1894 this->unattached_section_list_
.push_back(os
);
1896 this->attach_allocated_section_to_segment(target
, os
);
1899 // Attach an allocated output section to a segment.
1902 Layout::attach_allocated_section_to_segment(const Target
* target
,
1905 elfcpp::Elf_Xword flags
= os
->flags();
1906 gold_assert((flags
& elfcpp::SHF_ALLOC
) != 0);
1908 if (parameters
->options().relocatable())
1911 // If we have a SECTIONS clause, we can't handle the attachment to
1912 // segments until after we've seen all the sections.
1913 if (this->script_options_
->saw_sections_clause())
1916 gold_assert(!this->script_options_
->saw_phdrs_clause());
1918 // This output section goes into a PT_LOAD segment.
1920 elfcpp::Elf_Word seg_flags
= Layout::section_flags_to_segment(flags
);
1922 // If this output section's segment has extra flags that need to be set,
1923 // coming from a linker plugin, do that.
1924 seg_flags
|= os
->extra_segment_flags();
1926 // Check for --section-start.
1928 bool is_address_set
= parameters
->options().section_start(os
->name(), &addr
);
1930 // In general the only thing we really care about for PT_LOAD
1931 // segments is whether or not they are writable or executable,
1932 // so that is how we search for them.
1933 // Large data sections also go into their own PT_LOAD segment.
1934 // People who need segments sorted on some other basis will
1935 // have to use a linker script.
1937 Segment_list::const_iterator p
;
1938 if (!os
->is_unique_segment())
1940 for (p
= this->segment_list_
.begin();
1941 p
!= this->segment_list_
.end();
1944 if ((*p
)->type() != elfcpp::PT_LOAD
)
1946 if ((*p
)->is_unique_segment())
1948 if (!parameters
->options().omagic()
1949 && ((*p
)->flags() & elfcpp::PF_W
) != (seg_flags
& elfcpp::PF_W
))
1951 if ((target
->isolate_execinstr() || parameters
->options().rosegment())
1952 && ((*p
)->flags() & elfcpp::PF_X
) != (seg_flags
& elfcpp::PF_X
))
1954 // If -Tbss was specified, we need to separate the data and BSS
1956 if (parameters
->options().user_set_Tbss())
1958 if ((os
->type() == elfcpp::SHT_NOBITS
)
1959 == (*p
)->has_any_data_sections())
1962 if (os
->is_large_data_section() && !(*p
)->is_large_data_segment())
1967 if ((*p
)->are_addresses_set())
1970 (*p
)->add_initial_output_data(os
);
1971 (*p
)->update_flags_for_output_section(seg_flags
);
1972 (*p
)->set_addresses(addr
, addr
);
1976 (*p
)->add_output_section_to_load(this, os
, seg_flags
);
1981 if (p
== this->segment_list_
.end()
1982 || os
->is_unique_segment())
1984 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_LOAD
,
1986 if (os
->is_large_data_section())
1987 oseg
->set_is_large_data_segment();
1988 oseg
->add_output_section_to_load(this, os
, seg_flags
);
1990 oseg
->set_addresses(addr
, addr
);
1991 // Check if segment should be marked unique. For segments marked
1992 // unique by linker plugins, set the new alignment if specified.
1993 if (os
->is_unique_segment())
1995 oseg
->set_is_unique_segment();
1996 if (os
->segment_alignment() != 0)
1997 oseg
->set_minimum_p_align(os
->segment_alignment());
2001 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
2003 if (os
->type() == elfcpp::SHT_NOTE
)
2005 // See if we already have an equivalent PT_NOTE segment.
2006 for (p
= this->segment_list_
.begin();
2007 p
!= segment_list_
.end();
2010 if ((*p
)->type() == elfcpp::PT_NOTE
2011 && (((*p
)->flags() & elfcpp::PF_W
)
2012 == (seg_flags
& elfcpp::PF_W
)))
2014 (*p
)->add_output_section_to_nonload(os
, seg_flags
);
2019 if (p
== this->segment_list_
.end())
2021 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_NOTE
,
2023 oseg
->add_output_section_to_nonload(os
, seg_flags
);
2027 // If we see a loadable SHF_TLS section, we create a PT_TLS
2028 // segment. There can only be one such segment.
2029 if ((flags
& elfcpp::SHF_TLS
) != 0)
2031 if (this->tls_segment_
== NULL
)
2032 this->make_output_segment(elfcpp::PT_TLS
, seg_flags
);
2033 this->tls_segment_
->add_output_section_to_nonload(os
, seg_flags
);
2036 // If -z relro is in effect, and we see a relro section, we create a
2037 // PT_GNU_RELRO segment. There can only be one such segment.
2038 if (os
->is_relro() && parameters
->options().relro())
2040 gold_assert(seg_flags
== (elfcpp::PF_R
| elfcpp::PF_W
));
2041 if (this->relro_segment_
== NULL
)
2042 this->make_output_segment(elfcpp::PT_GNU_RELRO
, seg_flags
);
2043 this->relro_segment_
->add_output_section_to_nonload(os
, seg_flags
);
2046 // If we see a section named .interp, put it into a PT_INTERP
2047 // segment. This seems broken to me, but this is what GNU ld does,
2048 // and glibc expects it.
2049 if (strcmp(os
->name(), ".interp") == 0
2050 && !this->script_options_
->saw_phdrs_clause())
2052 if (this->interp_segment_
== NULL
)
2053 this->make_output_segment(elfcpp::PT_INTERP
, seg_flags
);
2055 gold_warning(_("multiple '.interp' sections in input files "
2056 "may cause confusing PT_INTERP segment"));
2057 this->interp_segment_
->add_output_section_to_nonload(os
, seg_flags
);
2061 // Make an output section for a script.
2064 Layout::make_output_section_for_script(
2066 Script_sections::Section_type section_type
)
2068 name
= this->namepool_
.add(name
, false, NULL
);
2069 elfcpp::Elf_Xword sh_flags
= elfcpp::SHF_ALLOC
;
2070 if (section_type
== Script_sections::ST_NOLOAD
)
2072 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_PROGBITS
,
2073 sh_flags
, ORDER_INVALID
,
2075 os
->set_found_in_sections_clause();
2076 if (section_type
== Script_sections::ST_NOLOAD
)
2077 os
->set_is_noload();
2081 // Return the number of segments we expect to see.
2084 Layout::expected_segment_count() const
2086 size_t ret
= this->segment_list_
.size();
2088 // If we didn't see a SECTIONS clause in a linker script, we should
2089 // already have the complete list of segments. Otherwise we ask the
2090 // SECTIONS clause how many segments it expects, and add in the ones
2091 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
2093 if (!this->script_options_
->saw_sections_clause())
2097 const Script_sections
* ss
= this->script_options_
->script_sections();
2098 return ret
+ ss
->expected_segment_count(this);
2102 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
2103 // is whether we saw a .note.GNU-stack section in the object file.
2104 // GNU_STACK_FLAGS is the section flags. The flags give the
2105 // protection required for stack memory. We record this in an
2106 // executable as a PT_GNU_STACK segment. If an object file does not
2107 // have a .note.GNU-stack segment, we must assume that it is an old
2108 // object. On some targets that will force an executable stack.
2111 Layout::layout_gnu_stack(bool seen_gnu_stack
, uint64_t gnu_stack_flags
,
2114 if (!seen_gnu_stack
)
2116 this->input_without_gnu_stack_note_
= true;
2117 if (parameters
->options().warn_execstack()
2118 && parameters
->target().is_default_stack_executable())
2119 gold_warning(_("%s: missing .note.GNU-stack section"
2120 " implies executable stack"),
2121 obj
->name().c_str());
2125 this->input_with_gnu_stack_note_
= true;
2126 if ((gnu_stack_flags
& elfcpp::SHF_EXECINSTR
) != 0)
2128 this->input_requires_executable_stack_
= true;
2129 if (parameters
->options().warn_execstack())
2130 gold_warning(_("%s: requires executable stack"),
2131 obj
->name().c_str());
2136 // Create automatic note sections.
2139 Layout::create_notes()
2141 this->create_gold_note();
2142 this->create_stack_segment();
2143 this->create_build_id();
2146 // Create the dynamic sections which are needed before we read the
2150 Layout::create_initial_dynamic_sections(Symbol_table
* symtab
)
2152 if (parameters
->doing_static_link())
2155 this->dynamic_section_
= this->choose_output_section(NULL
, ".dynamic",
2156 elfcpp::SHT_DYNAMIC
,
2158 | elfcpp::SHF_WRITE
),
2162 // A linker script may discard .dynamic, so check for NULL.
2163 if (this->dynamic_section_
!= NULL
)
2165 this->dynamic_symbol_
=
2166 symtab
->define_in_output_data("_DYNAMIC", NULL
,
2167 Symbol_table::PREDEFINED
,
2168 this->dynamic_section_
, 0, 0,
2169 elfcpp::STT_OBJECT
, elfcpp::STB_LOCAL
,
2170 elfcpp::STV_HIDDEN
, 0, false, false);
2172 this->dynamic_data_
= new Output_data_dynamic(&this->dynpool_
);
2174 this->dynamic_section_
->add_output_section_data(this->dynamic_data_
);
2178 // For each output section whose name can be represented as C symbol,
2179 // define __start and __stop symbols for the section. This is a GNU
2183 Layout::define_section_symbols(Symbol_table
* symtab
)
2185 for (Section_list::const_iterator p
= this->section_list_
.begin();
2186 p
!= this->section_list_
.end();
2189 const char* const name
= (*p
)->name();
2190 if (is_cident(name
))
2192 const std::string
name_string(name
);
2193 const std::string
start_name(cident_section_start_prefix
2195 const std::string
stop_name(cident_section_stop_prefix
2198 symtab
->define_in_output_data(start_name
.c_str(),
2200 Symbol_table::PREDEFINED
,
2206 elfcpp::STV_DEFAULT
,
2208 false, // offset_is_from_end
2209 true); // only_if_ref
2211 symtab
->define_in_output_data(stop_name
.c_str(),
2213 Symbol_table::PREDEFINED
,
2219 elfcpp::STV_DEFAULT
,
2221 true, // offset_is_from_end
2222 true); // only_if_ref
2227 // Define symbols for group signatures.
2230 Layout::define_group_signatures(Symbol_table
* symtab
)
2232 for (Group_signatures::iterator p
= this->group_signatures_
.begin();
2233 p
!= this->group_signatures_
.end();
2236 Symbol
* sym
= symtab
->lookup(p
->signature
, NULL
);
2238 p
->section
->set_info_symndx(sym
);
2241 // Force the name of the group section to the group
2242 // signature, and use the group's section symbol as the
2243 // signature symbol.
2244 if (strcmp(p
->section
->name(), p
->signature
) != 0)
2246 const char* name
= this->namepool_
.add(p
->signature
,
2248 p
->section
->set_name(name
);
2250 p
->section
->set_needs_symtab_index();
2251 p
->section
->set_info_section_symndx(p
->section
);
2255 this->group_signatures_
.clear();
2258 // Find the first read-only PT_LOAD segment, creating one if
2262 Layout::find_first_load_seg(const Target
* target
)
2264 Output_segment
* best
= NULL
;
2265 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2266 p
!= this->segment_list_
.end();
2269 if ((*p
)->type() == elfcpp::PT_LOAD
2270 && ((*p
)->flags() & elfcpp::PF_R
) != 0
2271 && (parameters
->options().omagic()
2272 || ((*p
)->flags() & elfcpp::PF_W
) == 0)
2273 && (!target
->isolate_execinstr()
2274 || ((*p
)->flags() & elfcpp::PF_X
) == 0))
2276 if (best
== NULL
|| this->segment_precedes(*p
, best
))
2283 gold_assert(!this->script_options_
->saw_phdrs_clause());
2285 Output_segment
* load_seg
= this->make_output_segment(elfcpp::PT_LOAD
,
2290 // Save states of all current output segments. Store saved states
2291 // in SEGMENT_STATES.
2294 Layout::save_segments(Segment_states
* segment_states
)
2296 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2297 p
!= this->segment_list_
.end();
2300 Output_segment
* segment
= *p
;
2302 Output_segment
* copy
= new Output_segment(*segment
);
2303 (*segment_states
)[segment
] = copy
;
2307 // Restore states of output segments and delete any segment not found in
2311 Layout::restore_segments(const Segment_states
* segment_states
)
2313 // Go through the segment list and remove any segment added in the
2315 this->tls_segment_
= NULL
;
2316 this->relro_segment_
= NULL
;
2317 Segment_list::iterator list_iter
= this->segment_list_
.begin();
2318 while (list_iter
!= this->segment_list_
.end())
2320 Output_segment
* segment
= *list_iter
;
2321 Segment_states::const_iterator states_iter
=
2322 segment_states
->find(segment
);
2323 if (states_iter
!= segment_states
->end())
2325 const Output_segment
* copy
= states_iter
->second
;
2326 // Shallow copy to restore states.
2329 // Also fix up TLS and RELRO segment pointers as appropriate.
2330 if (segment
->type() == elfcpp::PT_TLS
)
2331 this->tls_segment_
= segment
;
2332 else if (segment
->type() == elfcpp::PT_GNU_RELRO
)
2333 this->relro_segment_
= segment
;
2339 list_iter
= this->segment_list_
.erase(list_iter
);
2340 // This is a segment created during section layout. It should be
2341 // safe to remove it since we should have removed all pointers to it.
2347 // Clean up after relaxation so that sections can be laid out again.
2350 Layout::clean_up_after_relaxation()
2352 // Restore the segments to point state just prior to the relaxation loop.
2353 Script_sections
* script_section
= this->script_options_
->script_sections();
2354 script_section
->release_segments();
2355 this->restore_segments(this->segment_states_
);
2357 // Reset section addresses and file offsets
2358 for (Section_list::iterator p
= this->section_list_
.begin();
2359 p
!= this->section_list_
.end();
2362 (*p
)->restore_states();
2364 // If an input section changes size because of relaxation,
2365 // we need to adjust the section offsets of all input sections.
2366 // after such a section.
2367 if ((*p
)->section_offsets_need_adjustment())
2368 (*p
)->adjust_section_offsets();
2370 (*p
)->reset_address_and_file_offset();
2373 // Reset special output object address and file offsets.
2374 for (Data_list::iterator p
= this->special_output_list_
.begin();
2375 p
!= this->special_output_list_
.end();
2377 (*p
)->reset_address_and_file_offset();
2379 // A linker script may have created some output section data objects.
2380 // They are useless now.
2381 for (Output_section_data_list::const_iterator p
=
2382 this->script_output_section_data_list_
.begin();
2383 p
!= this->script_output_section_data_list_
.end();
2386 this->script_output_section_data_list_
.clear();
2388 // Special-case fill output objects are recreated each time through
2389 // the relaxation loop.
2390 this->reset_relax_output();
2394 Layout::reset_relax_output()
2396 for (Data_list::const_iterator p
= this->relax_output_list_
.begin();
2397 p
!= this->relax_output_list_
.end();
2400 this->relax_output_list_
.clear();
2403 // Prepare for relaxation.
2406 Layout::prepare_for_relaxation()
2408 // Create an relaxation debug check if in debugging mode.
2409 if (is_debugging_enabled(DEBUG_RELAXATION
))
2410 this->relaxation_debug_check_
= new Relaxation_debug_check();
2412 // Save segment states.
2413 this->segment_states_
= new Segment_states();
2414 this->save_segments(this->segment_states_
);
2416 for(Section_list::const_iterator p
= this->section_list_
.begin();
2417 p
!= this->section_list_
.end();
2419 (*p
)->save_states();
2421 if (is_debugging_enabled(DEBUG_RELAXATION
))
2422 this->relaxation_debug_check_
->check_output_data_for_reset_values(
2423 this->section_list_
, this->special_output_list_
,
2424 this->relax_output_list_
);
2426 // Also enable recording of output section data from scripts.
2427 this->record_output_section_data_from_script_
= true;
2430 // If the user set the address of the text segment, that may not be
2431 // compatible with putting the segment headers and file headers into
2432 // that segment. For isolate_execinstr() targets, it's the rodata
2433 // segment rather than text where we might put the headers.
2435 load_seg_unusable_for_headers(const Target
* target
)
2437 const General_options
& options
= parameters
->options();
2438 if (target
->isolate_execinstr())
2439 return (options
.user_set_Trodata_segment()
2440 && options
.Trodata_segment() % target
->abi_pagesize() != 0);
2442 return (options
.user_set_Ttext()
2443 && options
.Ttext() % target
->abi_pagesize() != 0);
2446 // Relaxation loop body: If target has no relaxation, this runs only once
2447 // Otherwise, the target relaxation hook is called at the end of
2448 // each iteration. If the hook returns true, it means re-layout of
2449 // section is required.
2451 // The number of segments created by a linking script without a PHDRS
2452 // clause may be affected by section sizes and alignments. There is
2453 // a remote chance that relaxation causes different number of PT_LOAD
2454 // segments are created and sections are attached to different segments.
2455 // Therefore, we always throw away all segments created during section
2456 // layout. In order to be able to restart the section layout, we keep
2457 // a copy of the segment list right before the relaxation loop and use
2458 // that to restore the segments.
2460 // PASS is the current relaxation pass number.
2461 // SYMTAB is a symbol table.
2462 // PLOAD_SEG is the address of a pointer for the load segment.
2463 // PHDR_SEG is a pointer to the PHDR segment.
2464 // SEGMENT_HEADERS points to the output segment header.
2465 // FILE_HEADER points to the output file header.
2466 // PSHNDX is the address to store the output section index.
2469 Layout::relaxation_loop_body(
2472 Symbol_table
* symtab
,
2473 Output_segment
** pload_seg
,
2474 Output_segment
* phdr_seg
,
2475 Output_segment_headers
* segment_headers
,
2476 Output_file_header
* file_header
,
2477 unsigned int* pshndx
)
2479 // If this is not the first iteration, we need to clean up after
2480 // relaxation so that we can lay out the sections again.
2482 this->clean_up_after_relaxation();
2484 // If there is a SECTIONS clause, put all the input sections into
2485 // the required order.
2486 Output_segment
* load_seg
;
2487 if (this->script_options_
->saw_sections_clause())
2488 load_seg
= this->set_section_addresses_from_script(symtab
);
2489 else if (parameters
->options().relocatable())
2492 load_seg
= this->find_first_load_seg(target
);
2494 if (parameters
->options().oformat_enum()
2495 != General_options::OBJECT_FORMAT_ELF
)
2498 if (load_seg_unusable_for_headers(target
))
2504 gold_assert(phdr_seg
== NULL
2506 || this->script_options_
->saw_sections_clause());
2508 // If the address of the load segment we found has been set by
2509 // --section-start rather than by a script, then adjust the VMA and
2510 // LMA downward if possible to include the file and section headers.
2511 uint64_t header_gap
= 0;
2512 if (load_seg
!= NULL
2513 && load_seg
->are_addresses_set()
2514 && !this->script_options_
->saw_sections_clause()
2515 && !parameters
->options().relocatable())
2517 file_header
->finalize_data_size();
2518 segment_headers
->finalize_data_size();
2519 size_t sizeof_headers
= (file_header
->data_size()
2520 + segment_headers
->data_size());
2521 const uint64_t abi_pagesize
= target
->abi_pagesize();
2522 uint64_t hdr_paddr
= load_seg
->paddr() - sizeof_headers
;
2523 hdr_paddr
&= ~(abi_pagesize
- 1);
2524 uint64_t subtract
= load_seg
->paddr() - hdr_paddr
;
2525 if (load_seg
->paddr() < subtract
|| load_seg
->vaddr() < subtract
)
2529 load_seg
->set_addresses(load_seg
->vaddr() - subtract
,
2530 load_seg
->paddr() - subtract
);
2531 header_gap
= subtract
- sizeof_headers
;
2535 // Lay out the segment headers.
2536 if (!parameters
->options().relocatable())
2538 gold_assert(segment_headers
!= NULL
);
2539 if (header_gap
!= 0 && load_seg
!= NULL
)
2541 Output_data_zero_fill
* z
= new Output_data_zero_fill(header_gap
, 1);
2542 load_seg
->add_initial_output_data(z
);
2544 if (load_seg
!= NULL
)
2545 load_seg
->add_initial_output_data(segment_headers
);
2546 if (phdr_seg
!= NULL
)
2547 phdr_seg
->add_initial_output_data(segment_headers
);
2550 // Lay out the file header.
2551 if (load_seg
!= NULL
)
2552 load_seg
->add_initial_output_data(file_header
);
2554 if (this->script_options_
->saw_phdrs_clause()
2555 && !parameters
->options().relocatable())
2557 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2558 // clause in a linker script.
2559 Script_sections
* ss
= this->script_options_
->script_sections();
2560 ss
->put_headers_in_phdrs(file_header
, segment_headers
);
2563 // We set the output section indexes in set_segment_offsets and
2564 // set_section_indexes.
2567 // Set the file offsets of all the segments, and all the sections
2570 if (!parameters
->options().relocatable())
2571 off
= this->set_segment_offsets(target
, load_seg
, pshndx
);
2573 off
= this->set_relocatable_section_offsets(file_header
, pshndx
);
2575 // Verify that the dummy relaxation does not change anything.
2576 if (is_debugging_enabled(DEBUG_RELAXATION
))
2579 this->relaxation_debug_check_
->read_sections(this->section_list_
);
2581 this->relaxation_debug_check_
->verify_sections(this->section_list_
);
2584 *pload_seg
= load_seg
;
2588 // Search the list of patterns and find the position of the given section
2589 // name in the output section. If the section name matches a glob
2590 // pattern and a non-glob name, then the non-glob position takes
2591 // precedence. Return 0 if no match is found.
2594 Layout::find_section_order_index(const std::string
& section_name
)
2596 Unordered_map
<std::string
, unsigned int>::iterator map_it
;
2597 map_it
= this->input_section_position_
.find(section_name
);
2598 if (map_it
!= this->input_section_position_
.end())
2599 return map_it
->second
;
2601 // Absolute match failed. Linear search the glob patterns.
2602 std::vector
<std::string
>::iterator it
;
2603 for (it
= this->input_section_glob_
.begin();
2604 it
!= this->input_section_glob_
.end();
2607 if (fnmatch((*it
).c_str(), section_name
.c_str(), FNM_NOESCAPE
) == 0)
2609 map_it
= this->input_section_position_
.find(*it
);
2610 gold_assert(map_it
!= this->input_section_position_
.end());
2611 return map_it
->second
;
2617 // Read the sequence of input sections from the file specified with
2618 // option --section-ordering-file.
2621 Layout::read_layout_from_file()
2623 const char* filename
= parameters
->options().section_ordering_file();
2629 gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2630 filename
, strerror(errno
));
2632 std::getline(in
, line
); // this chops off the trailing \n, if any
2633 unsigned int position
= 1;
2634 this->set_section_ordering_specified();
2638 if (!line
.empty() && line
[line
.length() - 1] == '\r') // Windows
2639 line
.resize(line
.length() - 1);
2640 // Ignore comments, beginning with '#'
2643 std::getline(in
, line
);
2646 this->input_section_position_
[line
] = position
;
2647 // Store all glob patterns in a vector.
2648 if (is_wildcard_string(line
.c_str()))
2649 this->input_section_glob_
.push_back(line
);
2651 std::getline(in
, line
);
2655 // Finalize the layout. When this is called, we have created all the
2656 // output sections and all the output segments which are based on
2657 // input sections. We have several things to do, and we have to do
2658 // them in the right order, so that we get the right results correctly
2661 // 1) Finalize the list of output segments and create the segment
2664 // 2) Finalize the dynamic symbol table and associated sections.
2666 // 3) Determine the final file offset of all the output segments.
2668 // 4) Determine the final file offset of all the SHF_ALLOC output
2671 // 5) Create the symbol table sections and the section name table
2674 // 6) Finalize the symbol table: set symbol values to their final
2675 // value and make a final determination of which symbols are going
2676 // into the output symbol table.
2678 // 7) Create the section table header.
2680 // 8) Determine the final file offset of all the output sections which
2681 // are not SHF_ALLOC, including the section table header.
2683 // 9) Finalize the ELF file header.
2685 // This function returns the size of the output file.
2688 Layout::finalize(const Input_objects
* input_objects
, Symbol_table
* symtab
,
2689 Target
* target
, const Task
* task
)
2691 target
->finalize_sections(this, input_objects
, symtab
);
2693 this->count_local_symbols(task
, input_objects
);
2695 this->link_stabs_sections();
2697 Output_segment
* phdr_seg
= NULL
;
2698 if (!parameters
->options().relocatable() && !parameters
->doing_static_link())
2700 // There was a dynamic object in the link. We need to create
2701 // some information for the dynamic linker.
2703 // Create the PT_PHDR segment which will hold the program
2705 if (!this->script_options_
->saw_phdrs_clause())
2706 phdr_seg
= this->make_output_segment(elfcpp::PT_PHDR
, elfcpp::PF_R
);
2708 // Create the dynamic symbol table, including the hash table.
2709 Output_section
* dynstr
;
2710 std::vector
<Symbol
*> dynamic_symbols
;
2711 unsigned int local_dynamic_count
;
2712 Versions
versions(*this->script_options()->version_script_info(),
2714 this->create_dynamic_symtab(input_objects
, symtab
, &dynstr
,
2715 &local_dynamic_count
, &dynamic_symbols
,
2718 // Create the .interp section to hold the name of the
2719 // interpreter, and put it in a PT_INTERP segment. Don't do it
2720 // if we saw a .interp section in an input file.
2721 if ((!parameters
->options().shared()
2722 || parameters
->options().dynamic_linker() != NULL
)
2723 && this->interp_segment_
== NULL
)
2724 this->create_interp(target
);
2726 // Finish the .dynamic section to hold the dynamic data, and put
2727 // it in a PT_DYNAMIC segment.
2728 this->finish_dynamic_section(input_objects
, symtab
);
2730 // We should have added everything we need to the dynamic string
2732 this->dynpool_
.set_string_offsets();
2734 // Create the version sections. We can't do this until the
2735 // dynamic string table is complete.
2736 this->create_version_sections(&versions
, symtab
, local_dynamic_count
,
2737 dynamic_symbols
, dynstr
);
2739 // Set the size of the _DYNAMIC symbol. We can't do this until
2740 // after we call create_version_sections.
2741 this->set_dynamic_symbol_size(symtab
);
2744 // Create segment headers.
2745 Output_segment_headers
* segment_headers
=
2746 (parameters
->options().relocatable()
2748 : new Output_segment_headers(this->segment_list_
));
2750 // Lay out the file header.
2751 Output_file_header
* file_header
= new Output_file_header(target
, symtab
,
2754 this->special_output_list_
.push_back(file_header
);
2755 if (segment_headers
!= NULL
)
2756 this->special_output_list_
.push_back(segment_headers
);
2758 // Find approriate places for orphan output sections if we are using
2760 if (this->script_options_
->saw_sections_clause())
2761 this->place_orphan_sections_in_script();
2763 Output_segment
* load_seg
;
2768 // Take a snapshot of the section layout as needed.
2769 if (target
->may_relax())
2770 this->prepare_for_relaxation();
2772 // Run the relaxation loop to lay out sections.
2775 off
= this->relaxation_loop_body(pass
, target
, symtab
, &load_seg
,
2776 phdr_seg
, segment_headers
, file_header
,
2780 while (target
->may_relax()
2781 && target
->relax(pass
, input_objects
, symtab
, this, task
));
2783 // If there is a load segment that contains the file and program headers,
2784 // provide a symbol __ehdr_start pointing there.
2785 // A program can use this to examine itself robustly.
2786 Symbol
*ehdr_start
= symtab
->lookup("__ehdr_start");
2787 if (ehdr_start
!= NULL
&& ehdr_start
->is_predefined())
2789 if (load_seg
!= NULL
)
2790 ehdr_start
->set_output_segment(load_seg
, Symbol::SEGMENT_START
);
2792 ehdr_start
->set_undefined();
2795 // Set the file offsets of all the non-data sections we've seen so
2796 // far which don't have to wait for the input sections. We need
2797 // this in order to finalize local symbols in non-allocated
2799 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2801 // Set the section indexes of all unallocated sections seen so far,
2802 // in case any of them are somehow referenced by a symbol.
2803 shndx
= this->set_section_indexes(shndx
);
2805 // Create the symbol table sections.
2806 this->create_symtab_sections(input_objects
, symtab
, shndx
, &off
);
2807 if (!parameters
->doing_static_link())
2808 this->assign_local_dynsym_offsets(input_objects
);
2810 // Process any symbol assignments from a linker script. This must
2811 // be called after the symbol table has been finalized.
2812 this->script_options_
->finalize_symbols(symtab
, this);
2814 // Create the incremental inputs sections.
2815 if (this->incremental_inputs_
)
2817 this->incremental_inputs_
->finalize();
2818 this->create_incremental_info_sections(symtab
);
2821 // Create the .shstrtab section.
2822 Output_section
* shstrtab_section
= this->create_shstrtab();
2824 // Set the file offsets of the rest of the non-data sections which
2825 // don't have to wait for the input sections.
2826 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2828 // Now that all sections have been created, set the section indexes
2829 // for any sections which haven't been done yet.
2830 shndx
= this->set_section_indexes(shndx
);
2832 // Create the section table header.
2833 this->create_shdrs(shstrtab_section
, &off
);
2835 // If there are no sections which require postprocessing, we can
2836 // handle the section names now, and avoid a resize later.
2837 if (!this->any_postprocessing_sections_
)
2839 off
= this->set_section_offsets(off
,
2840 POSTPROCESSING_SECTIONS_PASS
);
2842 this->set_section_offsets(off
,
2843 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
2846 file_header
->set_section_info(this->section_headers_
, shstrtab_section
);
2848 // Now we know exactly where everything goes in the output file
2849 // (except for non-allocated sections which require postprocessing).
2850 Output_data::layout_complete();
2852 this->output_file_size_
= off
;
2857 // Create a note header following the format defined in the ELF ABI.
2858 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
2859 // of the section to create, DESCSZ is the size of the descriptor.
2860 // ALLOCATE is true if the section should be allocated in memory.
2861 // This returns the new note section. It sets *TRAILING_PADDING to
2862 // the number of trailing zero bytes required.
2865 Layout::create_note(const char* name
, int note_type
,
2866 const char* section_name
, size_t descsz
,
2867 bool allocate
, size_t* trailing_padding
)
2869 // Authorities all agree that the values in a .note field should
2870 // be aligned on 4-byte boundaries for 32-bit binaries. However,
2871 // they differ on what the alignment is for 64-bit binaries.
2872 // The GABI says unambiguously they take 8-byte alignment:
2873 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2874 // Other documentation says alignment should always be 4 bytes:
2875 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2876 // GNU ld and GNU readelf both support the latter (at least as of
2877 // version 2.16.91), and glibc always generates the latter for
2878 // .note.ABI-tag (as of version 1.6), so that's the one we go with
2880 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
2881 const int size
= parameters
->target().get_size();
2883 const int size
= 32;
2886 // The contents of the .note section.
2887 size_t namesz
= strlen(name
) + 1;
2888 size_t aligned_namesz
= align_address(namesz
, size
/ 8);
2889 size_t aligned_descsz
= align_address(descsz
, size
/ 8);
2891 size_t notehdrsz
= 3 * (size
/ 8) + aligned_namesz
;
2893 unsigned char* buffer
= new unsigned char[notehdrsz
];
2894 memset(buffer
, 0, notehdrsz
);
2896 bool is_big_endian
= parameters
->target().is_big_endian();
2902 elfcpp::Swap
<32, false>::writeval(buffer
, namesz
);
2903 elfcpp::Swap
<32, false>::writeval(buffer
+ 4, descsz
);
2904 elfcpp::Swap
<32, false>::writeval(buffer
+ 8, note_type
);
2908 elfcpp::Swap
<32, true>::writeval(buffer
, namesz
);
2909 elfcpp::Swap
<32, true>::writeval(buffer
+ 4, descsz
);
2910 elfcpp::Swap
<32, true>::writeval(buffer
+ 8, note_type
);
2913 else if (size
== 64)
2917 elfcpp::Swap
<64, false>::writeval(buffer
, namesz
);
2918 elfcpp::Swap
<64, false>::writeval(buffer
+ 8, descsz
);
2919 elfcpp::Swap
<64, false>::writeval(buffer
+ 16, note_type
);
2923 elfcpp::Swap
<64, true>::writeval(buffer
, namesz
);
2924 elfcpp::Swap
<64, true>::writeval(buffer
+ 8, descsz
);
2925 elfcpp::Swap
<64, true>::writeval(buffer
+ 16, note_type
);
2931 memcpy(buffer
+ 3 * (size
/ 8), name
, namesz
);
2933 elfcpp::Elf_Xword flags
= 0;
2934 Output_section_order order
= ORDER_INVALID
;
2937 flags
= elfcpp::SHF_ALLOC
;
2938 order
= ORDER_RO_NOTE
;
2940 Output_section
* os
= this->choose_output_section(NULL
, section_name
,
2942 flags
, false, order
, false);
2946 Output_section_data
* posd
= new Output_data_const_buffer(buffer
, notehdrsz
,
2949 os
->add_output_section_data(posd
);
2951 *trailing_padding
= aligned_descsz
- descsz
;
2956 // For an executable or shared library, create a note to record the
2957 // version of gold used to create the binary.
2960 Layout::create_gold_note()
2962 if (parameters
->options().relocatable()
2963 || parameters
->incremental_update())
2966 std::string desc
= std::string("gold ") + gold::get_version_string();
2968 size_t trailing_padding
;
2969 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION
,
2970 ".note.gnu.gold-version", desc
.size(),
2971 false, &trailing_padding
);
2975 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2976 os
->add_output_section_data(posd
);
2978 if (trailing_padding
> 0)
2980 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2981 os
->add_output_section_data(posd
);
2985 // Record whether the stack should be executable. This can be set
2986 // from the command line using the -z execstack or -z noexecstack
2987 // options. Otherwise, if any input file has a .note.GNU-stack
2988 // section with the SHF_EXECINSTR flag set, the stack should be
2989 // executable. Otherwise, if at least one input file a
2990 // .note.GNU-stack section, and some input file has no .note.GNU-stack
2991 // section, we use the target default for whether the stack should be
2992 // executable. If -z stack-size was used to set a p_memsz value for
2993 // PT_GNU_STACK, we generate the segment regardless. Otherwise, we
2994 // don't generate a stack note. When generating a object file, we
2995 // create a .note.GNU-stack section with the appropriate marking.
2996 // When generating an executable or shared library, we create a
2997 // PT_GNU_STACK segment.
3000 Layout::create_stack_segment()
3002 bool is_stack_executable
;
3003 if (parameters
->options().is_execstack_set())
3005 is_stack_executable
= parameters
->options().is_stack_executable();
3006 if (!is_stack_executable
3007 && this->input_requires_executable_stack_
3008 && parameters
->options().warn_execstack())
3009 gold_warning(_("one or more inputs require executable stack, "
3010 "but -z noexecstack was given"));
3012 else if (!this->input_with_gnu_stack_note_
3013 && (!parameters
->options().user_set_stack_size()
3014 || parameters
->options().relocatable()))
3018 if (this->input_requires_executable_stack_
)
3019 is_stack_executable
= true;
3020 else if (this->input_without_gnu_stack_note_
)
3021 is_stack_executable
=
3022 parameters
->target().is_default_stack_executable();
3024 is_stack_executable
= false;
3027 if (parameters
->options().relocatable())
3029 const char* name
= this->namepool_
.add(".note.GNU-stack", false, NULL
);
3030 elfcpp::Elf_Xword flags
= 0;
3031 if (is_stack_executable
)
3032 flags
|= elfcpp::SHF_EXECINSTR
;
3033 this->make_output_section(name
, elfcpp::SHT_PROGBITS
, flags
,
3034 ORDER_INVALID
, false);
3038 if (this->script_options_
->saw_phdrs_clause())
3040 int flags
= elfcpp::PF_R
| elfcpp::PF_W
;
3041 if (is_stack_executable
)
3042 flags
|= elfcpp::PF_X
;
3043 Output_segment
* seg
=
3044 this->make_output_segment(elfcpp::PT_GNU_STACK
, flags
);
3045 seg
->set_size(parameters
->options().stack_size());
3046 // BFD lets targets override this default alignment, but the only
3047 // targets that do so are ones that Gold does not support so far.
3048 seg
->set_minimum_p_align(16);
3052 // If --build-id was used, set up the build ID note.
3055 Layout::create_build_id()
3057 if (!parameters
->options().user_set_build_id())
3060 const char* style
= parameters
->options().build_id();
3061 if (strcmp(style
, "none") == 0)
3064 // Set DESCSZ to the size of the note descriptor. When possible,
3065 // set DESC to the note descriptor contents.
3068 if (strcmp(style
, "md5") == 0)
3070 else if ((strcmp(style
, "sha1") == 0) || (strcmp(style
, "tree") == 0))
3072 else if (strcmp(style
, "uuid") == 0)
3075 const size_t uuidsz
= 128 / 8;
3077 char buffer
[uuidsz
];
3078 memset(buffer
, 0, uuidsz
);
3080 int descriptor
= open_descriptor(-1, "/dev/urandom", O_RDONLY
);
3082 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
3086 ssize_t got
= ::read(descriptor
, buffer
, uuidsz
);
3087 release_descriptor(descriptor
, true);
3089 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno
));
3090 else if (static_cast<size_t>(got
) != uuidsz
)
3091 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
3095 desc
.assign(buffer
, uuidsz
);
3097 #else // __MINGW32__
3099 typedef RPC_STATUS (RPC_ENTRY
*UuidCreateFn
)(UUID
*Uuid
);
3101 HMODULE rpc_library
= LoadLibrary("rpcrt4.dll");
3103 gold_error(_("--build-id=uuid failed: could not load rpcrt4.dll"));
3106 UuidCreateFn uuid_create
= reinterpret_cast<UuidCreateFn
>(
3107 GetProcAddress(rpc_library
, "UuidCreate"));
3109 gold_error(_("--build-id=uuid failed: could not find UuidCreate"));
3110 else if (uuid_create(&uuid
) != RPC_S_OK
)
3111 gold_error(_("__build_id=uuid failed: call UuidCreate() failed"));
3112 FreeLibrary(rpc_library
);
3114 desc
.assign(reinterpret_cast<const char *>(&uuid
), sizeof(UUID
));
3115 descsz
= sizeof(UUID
);
3116 #endif // __MINGW32__
3118 else if (strncmp(style
, "0x", 2) == 0)
3121 const char* p
= style
+ 2;
3124 if (hex_p(p
[0]) && hex_p(p
[1]))
3126 char c
= (hex_value(p
[0]) << 4) | hex_value(p
[1]);
3130 else if (*p
== '-' || *p
== ':')
3133 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
3136 descsz
= desc
.size();
3139 gold_fatal(_("unrecognized --build-id argument '%s'"), style
);
3142 size_t trailing_padding
;
3143 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID
,
3144 ".note.gnu.build-id", descsz
, true,
3151 // We know the value already, so we fill it in now.
3152 gold_assert(desc
.size() == descsz
);
3154 Output_section_data
* posd
= new Output_data_const(desc
, 4);
3155 os
->add_output_section_data(posd
);
3157 if (trailing_padding
!= 0)
3159 posd
= new Output_data_zero_fill(trailing_padding
, 0);
3160 os
->add_output_section_data(posd
);
3165 // We need to compute a checksum after we have completed the
3167 gold_assert(trailing_padding
== 0);
3168 this->build_id_note_
= new Output_data_zero_fill(descsz
, 4);
3169 os
->add_output_section_data(this->build_id_note_
);
3173 // If we have both .stabXX and .stabXXstr sections, then the sh_link
3174 // field of the former should point to the latter. I'm not sure who
3175 // started this, but the GNU linker does it, and some tools depend
3179 Layout::link_stabs_sections()
3181 if (!this->have_stabstr_section_
)
3184 for (Section_list::iterator p
= this->section_list_
.begin();
3185 p
!= this->section_list_
.end();
3188 if ((*p
)->type() != elfcpp::SHT_STRTAB
)
3191 const char* name
= (*p
)->name();
3192 if (strncmp(name
, ".stab", 5) != 0)
3195 size_t len
= strlen(name
);
3196 if (strcmp(name
+ len
- 3, "str") != 0)
3199 std::string
stab_name(name
, len
- 3);
3200 Output_section
* stab_sec
;
3201 stab_sec
= this->find_output_section(stab_name
.c_str());
3202 if (stab_sec
!= NULL
)
3203 stab_sec
->set_link_section(*p
);
3207 // Create .gnu_incremental_inputs and related sections needed
3208 // for the next run of incremental linking to check what has changed.
3211 Layout::create_incremental_info_sections(Symbol_table
* symtab
)
3213 Incremental_inputs
* incr
= this->incremental_inputs_
;
3215 gold_assert(incr
!= NULL
);
3217 // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
3218 incr
->create_data_sections(symtab
);
3220 // Add the .gnu_incremental_inputs section.
3221 const char* incremental_inputs_name
=
3222 this->namepool_
.add(".gnu_incremental_inputs", false, NULL
);
3223 Output_section
* incremental_inputs_os
=
3224 this->make_output_section(incremental_inputs_name
,
3225 elfcpp::SHT_GNU_INCREMENTAL_INPUTS
, 0,
3226 ORDER_INVALID
, false);
3227 incremental_inputs_os
->add_output_section_data(incr
->inputs_section());
3229 // Add the .gnu_incremental_symtab section.
3230 const char* incremental_symtab_name
=
3231 this->namepool_
.add(".gnu_incremental_symtab", false, NULL
);
3232 Output_section
* incremental_symtab_os
=
3233 this->make_output_section(incremental_symtab_name
,
3234 elfcpp::SHT_GNU_INCREMENTAL_SYMTAB
, 0,
3235 ORDER_INVALID
, false);
3236 incremental_symtab_os
->add_output_section_data(incr
->symtab_section());
3237 incremental_symtab_os
->set_entsize(4);
3239 // Add the .gnu_incremental_relocs section.
3240 const char* incremental_relocs_name
=
3241 this->namepool_
.add(".gnu_incremental_relocs", false, NULL
);
3242 Output_section
* incremental_relocs_os
=
3243 this->make_output_section(incremental_relocs_name
,
3244 elfcpp::SHT_GNU_INCREMENTAL_RELOCS
, 0,
3245 ORDER_INVALID
, false);
3246 incremental_relocs_os
->add_output_section_data(incr
->relocs_section());
3247 incremental_relocs_os
->set_entsize(incr
->relocs_entsize());
3249 // Add the .gnu_incremental_got_plt section.
3250 const char* incremental_got_plt_name
=
3251 this->namepool_
.add(".gnu_incremental_got_plt", false, NULL
);
3252 Output_section
* incremental_got_plt_os
=
3253 this->make_output_section(incremental_got_plt_name
,
3254 elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT
, 0,
3255 ORDER_INVALID
, false);
3256 incremental_got_plt_os
->add_output_section_data(incr
->got_plt_section());
3258 // Add the .gnu_incremental_strtab section.
3259 const char* incremental_strtab_name
=
3260 this->namepool_
.add(".gnu_incremental_strtab", false, NULL
);
3261 Output_section
* incremental_strtab_os
= this->make_output_section(incremental_strtab_name
,
3262 elfcpp::SHT_STRTAB
, 0,
3263 ORDER_INVALID
, false);
3264 Output_data_strtab
* strtab_data
=
3265 new Output_data_strtab(incr
->get_stringpool());
3266 incremental_strtab_os
->add_output_section_data(strtab_data
);
3268 incremental_inputs_os
->set_after_input_sections();
3269 incremental_symtab_os
->set_after_input_sections();
3270 incremental_relocs_os
->set_after_input_sections();
3271 incremental_got_plt_os
->set_after_input_sections();
3273 incremental_inputs_os
->set_link_section(incremental_strtab_os
);
3274 incremental_symtab_os
->set_link_section(incremental_inputs_os
);
3275 incremental_relocs_os
->set_link_section(incremental_inputs_os
);
3276 incremental_got_plt_os
->set_link_section(incremental_inputs_os
);
3279 // Return whether SEG1 should be before SEG2 in the output file. This
3280 // is based entirely on the segment type and flags. When this is
3281 // called the segment addresses have normally not yet been set.
3284 Layout::segment_precedes(const Output_segment
* seg1
,
3285 const Output_segment
* seg2
)
3287 elfcpp::Elf_Word type1
= seg1
->type();
3288 elfcpp::Elf_Word type2
= seg2
->type();
3290 // The single PT_PHDR segment is required to precede any loadable
3291 // segment. We simply make it always first.
3292 if (type1
== elfcpp::PT_PHDR
)
3294 gold_assert(type2
!= elfcpp::PT_PHDR
);
3297 if (type2
== elfcpp::PT_PHDR
)
3300 // The single PT_INTERP segment is required to precede any loadable
3301 // segment. We simply make it always second.
3302 if (type1
== elfcpp::PT_INTERP
)
3304 gold_assert(type2
!= elfcpp::PT_INTERP
);
3307 if (type2
== elfcpp::PT_INTERP
)
3310 // We then put PT_LOAD segments before any other segments.
3311 if (type1
== elfcpp::PT_LOAD
&& type2
!= elfcpp::PT_LOAD
)
3313 if (type2
== elfcpp::PT_LOAD
&& type1
!= elfcpp::PT_LOAD
)
3316 // We put the PT_TLS segment last except for the PT_GNU_RELRO
3317 // segment, because that is where the dynamic linker expects to find
3318 // it (this is just for efficiency; other positions would also work
3320 if (type1
== elfcpp::PT_TLS
3321 && type2
!= elfcpp::PT_TLS
3322 && type2
!= elfcpp::PT_GNU_RELRO
)
3324 if (type2
== elfcpp::PT_TLS
3325 && type1
!= elfcpp::PT_TLS
3326 && type1
!= elfcpp::PT_GNU_RELRO
)
3329 // We put the PT_GNU_RELRO segment last, because that is where the
3330 // dynamic linker expects to find it (as with PT_TLS, this is just
3332 if (type1
== elfcpp::PT_GNU_RELRO
&& type2
!= elfcpp::PT_GNU_RELRO
)
3334 if (type2
== elfcpp::PT_GNU_RELRO
&& type1
!= elfcpp::PT_GNU_RELRO
)
3337 const elfcpp::Elf_Word flags1
= seg1
->flags();
3338 const elfcpp::Elf_Word flags2
= seg2
->flags();
3340 // The order of non-PT_LOAD segments is unimportant. We simply sort
3341 // by the numeric segment type and flags values. There should not
3342 // be more than one segment with the same type and flags, except
3343 // when a linker script specifies such.
3344 if (type1
!= elfcpp::PT_LOAD
)
3347 return type1
< type2
;
3348 gold_assert(flags1
!= flags2
3349 || this->script_options_
->saw_phdrs_clause());
3350 return flags1
< flags2
;
3353 // If the addresses are set already, sort by load address.
3354 if (seg1
->are_addresses_set())
3356 if (!seg2
->are_addresses_set())
3359 unsigned int section_count1
= seg1
->output_section_count();
3360 unsigned int section_count2
= seg2
->output_section_count();
3361 if (section_count1
== 0 && section_count2
> 0)
3363 if (section_count1
> 0 && section_count2
== 0)
3366 uint64_t paddr1
= (seg1
->are_addresses_set()
3368 : seg1
->first_section_load_address());
3369 uint64_t paddr2
= (seg2
->are_addresses_set()
3371 : seg2
->first_section_load_address());
3373 if (paddr1
!= paddr2
)
3374 return paddr1
< paddr2
;
3376 else if (seg2
->are_addresses_set())
3379 // A segment which holds large data comes after a segment which does
3380 // not hold large data.
3381 if (seg1
->is_large_data_segment())
3383 if (!seg2
->is_large_data_segment())
3386 else if (seg2
->is_large_data_segment())
3389 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
3390 // segments come before writable segments. Then writable segments
3391 // with data come before writable segments without data. Then
3392 // executable segments come before non-executable segments. Then
3393 // the unlikely case of a non-readable segment comes before the
3394 // normal case of a readable segment. If there are multiple
3395 // segments with the same type and flags, we require that the
3396 // address be set, and we sort by virtual address and then physical
3398 if ((flags1
& elfcpp::PF_W
) != (flags2
& elfcpp::PF_W
))
3399 return (flags1
& elfcpp::PF_W
) == 0;
3400 if ((flags1
& elfcpp::PF_W
) != 0
3401 && seg1
->has_any_data_sections() != seg2
->has_any_data_sections())
3402 return seg1
->has_any_data_sections();
3403 if ((flags1
& elfcpp::PF_X
) != (flags2
& elfcpp::PF_X
))
3404 return (flags1
& elfcpp::PF_X
) != 0;
3405 if ((flags1
& elfcpp::PF_R
) != (flags2
& elfcpp::PF_R
))
3406 return (flags1
& elfcpp::PF_R
) == 0;
3408 // We shouldn't get here--we shouldn't create segments which we
3409 // can't distinguish. Unless of course we are using a weird linker
3410 // script or overlapping --section-start options. We could also get
3411 // here if plugins want unique segments for subsets of sections.
3412 gold_assert(this->script_options_
->saw_phdrs_clause()
3413 || parameters
->options().any_section_start()
3414 || this->is_unique_segment_for_sections_specified());
3418 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
3421 align_file_offset(off_t off
, uint64_t addr
, uint64_t abi_pagesize
)
3423 uint64_t unsigned_off
= off
;
3424 uint64_t aligned_off
= ((unsigned_off
& ~(abi_pagesize
- 1))
3425 | (addr
& (abi_pagesize
- 1)));
3426 if (aligned_off
< unsigned_off
)
3427 aligned_off
+= abi_pagesize
;
3431 // On targets where the text segment contains only executable code,
3432 // a non-executable segment is never the text segment.
3435 is_text_segment(const Target
* target
, const Output_segment
* seg
)
3437 elfcpp::Elf_Xword flags
= seg
->flags();
3438 if ((flags
& elfcpp::PF_W
) != 0)
3440 if ((flags
& elfcpp::PF_X
) == 0)
3441 return !target
->isolate_execinstr();
3445 // Set the file offsets of all the segments, and all the sections they
3446 // contain. They have all been created. LOAD_SEG must be be laid out
3447 // first. Return the offset of the data to follow.
3450 Layout::set_segment_offsets(const Target
* target
, Output_segment
* load_seg
,
3451 unsigned int* pshndx
)
3453 // Sort them into the final order. We use a stable sort so that we
3454 // don't randomize the order of indistinguishable segments created
3455 // by linker scripts.
3456 std::stable_sort(this->segment_list_
.begin(), this->segment_list_
.end(),
3457 Layout::Compare_segments(this));
3459 // Find the PT_LOAD segments, and set their addresses and offsets
3460 // and their section's addresses and offsets.
3461 uint64_t start_addr
;
3462 if (parameters
->options().user_set_Ttext())
3463 start_addr
= parameters
->options().Ttext();
3464 else if (parameters
->options().output_is_position_independent())
3467 start_addr
= target
->default_text_segment_address();
3469 uint64_t addr
= start_addr
;
3472 // If LOAD_SEG is NULL, then the file header and segment headers
3473 // will not be loadable. But they still need to be at offset 0 in
3474 // the file. Set their offsets now.
3475 if (load_seg
== NULL
)
3477 for (Data_list::iterator p
= this->special_output_list_
.begin();
3478 p
!= this->special_output_list_
.end();
3481 off
= align_address(off
, (*p
)->addralign());
3482 (*p
)->set_address_and_file_offset(0, off
);
3483 off
+= (*p
)->data_size();
3487 unsigned int increase_relro
= this->increase_relro_
;
3488 if (this->script_options_
->saw_sections_clause())
3491 const bool check_sections
= parameters
->options().check_sections();
3492 Output_segment
* last_load_segment
= NULL
;
3494 unsigned int shndx_begin
= *pshndx
;
3495 unsigned int shndx_load_seg
= *pshndx
;
3497 for (Segment_list::iterator p
= this->segment_list_
.begin();
3498 p
!= this->segment_list_
.end();
3501 if ((*p
)->type() == elfcpp::PT_LOAD
)
3503 if (target
->isolate_execinstr())
3505 // When we hit the segment that should contain the
3506 // file headers, reset the file offset so we place
3507 // it and subsequent segments appropriately.
3508 // We'll fix up the preceding segments below.
3516 shndx_load_seg
= *pshndx
;
3522 // Verify that the file headers fall into the first segment.
3523 if (load_seg
!= NULL
&& load_seg
!= *p
)
3528 bool are_addresses_set
= (*p
)->are_addresses_set();
3529 if (are_addresses_set
)
3531 // When it comes to setting file offsets, we care about
3532 // the physical address.
3533 addr
= (*p
)->paddr();
3535 else if (parameters
->options().user_set_Ttext()
3536 && (parameters
->options().omagic()
3537 || is_text_segment(target
, *p
)))
3539 are_addresses_set
= true;
3541 else if (parameters
->options().user_set_Trodata_segment()
3542 && ((*p
)->flags() & (elfcpp::PF_W
| elfcpp::PF_X
)) == 0)
3544 addr
= parameters
->options().Trodata_segment();
3545 are_addresses_set
= true;
3547 else if (parameters
->options().user_set_Tdata()
3548 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3549 && (!parameters
->options().user_set_Tbss()
3550 || (*p
)->has_any_data_sections()))
3552 addr
= parameters
->options().Tdata();
3553 are_addresses_set
= true;
3555 else if (parameters
->options().user_set_Tbss()
3556 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3557 && !(*p
)->has_any_data_sections())
3559 addr
= parameters
->options().Tbss();
3560 are_addresses_set
= true;
3563 uint64_t orig_addr
= addr
;
3564 uint64_t orig_off
= off
;
3566 uint64_t aligned_addr
= 0;
3567 uint64_t abi_pagesize
= target
->abi_pagesize();
3568 uint64_t common_pagesize
= target
->common_pagesize();
3570 if (!parameters
->options().nmagic()
3571 && !parameters
->options().omagic())
3572 (*p
)->set_minimum_p_align(abi_pagesize
);
3574 if (!are_addresses_set
)
3576 // Skip the address forward one page, maintaining the same
3577 // position within the page. This lets us store both segments
3578 // overlapping on a single page in the file, but the loader will
3579 // put them on different pages in memory. We will revisit this
3580 // decision once we know the size of the segment.
3582 uint64_t max_align
= (*p
)->maximum_alignment();
3583 if (max_align
> abi_pagesize
)
3584 addr
= align_address(addr
, max_align
);
3585 aligned_addr
= addr
;
3589 // This is the segment that will contain the file
3590 // headers, so its offset will have to be exactly zero.
3591 gold_assert(orig_off
== 0);
3593 // If the target wants a fixed minimum distance from the
3594 // text segment to the read-only segment, move up now.
3596 start_addr
+ (parameters
->options().user_set_rosegment_gap()
3597 ? parameters
->options().rosegment_gap()
3598 : target
->rosegment_gap());
3599 if (addr
< min_addr
)
3602 // But this is not the first segment! To make its
3603 // address congruent with its offset, that address better
3604 // be aligned to the ABI-mandated page size.
3605 addr
= align_address(addr
, abi_pagesize
);
3606 aligned_addr
= addr
;
3610 if ((addr
& (abi_pagesize
- 1)) != 0)
3611 addr
= addr
+ abi_pagesize
;
3613 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3617 if (!parameters
->options().nmagic()
3618 && !parameters
->options().omagic())
3620 // Here we are also taking care of the case when
3621 // the maximum segment alignment is larger than the page size.
3622 off
= align_file_offset(off
, addr
,
3623 std::max(abi_pagesize
,
3624 (*p
)->maximum_alignment()));
3628 // This is -N or -n with a section script which prevents
3629 // us from using a load segment. We need to ensure that
3630 // the file offset is aligned to the alignment of the
3631 // segment. This is because the linker script
3632 // implicitly assumed a zero offset. If we don't align
3633 // here, then the alignment of the sections in the
3634 // linker script may not match the alignment of the
3635 // sections in the set_section_addresses call below,
3636 // causing an error about dot moving backward.
3637 off
= align_address(off
, (*p
)->maximum_alignment());
3640 unsigned int shndx_hold
= *pshndx
;
3641 bool has_relro
= false;
3642 uint64_t new_addr
= (*p
)->set_section_addresses(target
, this,
3648 // Now that we know the size of this segment, we may be able
3649 // to save a page in memory, at the cost of wasting some
3650 // file space, by instead aligning to the start of a new
3651 // page. Here we use the real machine page size rather than
3652 // the ABI mandated page size. If the segment has been
3653 // aligned so that the relro data ends at a page boundary,
3654 // we do not try to realign it.
3656 if (!are_addresses_set
3658 && aligned_addr
!= addr
3659 && !parameters
->incremental())
3661 uint64_t first_off
= (common_pagesize
3663 & (common_pagesize
- 1)));
3664 uint64_t last_off
= new_addr
& (common_pagesize
- 1);
3667 && ((aligned_addr
& ~ (common_pagesize
- 1))
3668 != (new_addr
& ~ (common_pagesize
- 1)))
3669 && first_off
+ last_off
<= common_pagesize
)
3671 *pshndx
= shndx_hold
;
3672 addr
= align_address(aligned_addr
, common_pagesize
);
3673 addr
= align_address(addr
, (*p
)->maximum_alignment());
3674 if ((addr
& (abi_pagesize
- 1)) != 0)
3675 addr
= addr
+ abi_pagesize
;
3676 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3677 off
= align_file_offset(off
, addr
, abi_pagesize
);
3679 increase_relro
= this->increase_relro_
;
3680 if (this->script_options_
->saw_sections_clause())
3684 new_addr
= (*p
)->set_section_addresses(target
, this,
3694 // Implement --check-sections. We know that the segments
3695 // are sorted by LMA.
3696 if (check_sections
&& last_load_segment
!= NULL
)
3698 gold_assert(last_load_segment
->paddr() <= (*p
)->paddr());
3699 if (last_load_segment
->paddr() + last_load_segment
->memsz()
3702 unsigned long long lb1
= last_load_segment
->paddr();
3703 unsigned long long le1
= lb1
+ last_load_segment
->memsz();
3704 unsigned long long lb2
= (*p
)->paddr();
3705 unsigned long long le2
= lb2
+ (*p
)->memsz();
3706 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3707 "[0x%llx -> 0x%llx]"),
3708 lb1
, le1
, lb2
, le2
);
3711 last_load_segment
= *p
;
3715 if (load_seg
!= NULL
&& target
->isolate_execinstr())
3717 // Process the early segments again, setting their file offsets
3718 // so they land after the segments starting at LOAD_SEG.
3719 off
= align_file_offset(off
, 0, target
->abi_pagesize());
3721 this->reset_relax_output();
3723 for (Segment_list::iterator p
= this->segment_list_
.begin();
3727 if ((*p
)->type() == elfcpp::PT_LOAD
)
3729 // We repeat the whole job of assigning addresses and
3730 // offsets, but we really only want to change the offsets and
3731 // must ensure that the addresses all come out the same as
3732 // they did the first time through.
3733 bool has_relro
= false;
3734 const uint64_t old_addr
= (*p
)->vaddr();
3735 const uint64_t old_end
= old_addr
+ (*p
)->memsz();
3736 uint64_t new_addr
= (*p
)->set_section_addresses(target
, this,
3742 gold_assert(new_addr
== old_end
);
3746 gold_assert(shndx_begin
== shndx_load_seg
);
3749 // Handle the non-PT_LOAD segments, setting their offsets from their
3750 // section's offsets.
3751 for (Segment_list::iterator p
= this->segment_list_
.begin();
3752 p
!= this->segment_list_
.end();
3755 // PT_GNU_STACK was set up correctly when it was created.
3756 if ((*p
)->type() != elfcpp::PT_LOAD
3757 && (*p
)->type() != elfcpp::PT_GNU_STACK
)
3758 (*p
)->set_offset((*p
)->type() == elfcpp::PT_GNU_RELRO
3763 // Set the TLS offsets for each section in the PT_TLS segment.
3764 if (this->tls_segment_
!= NULL
)
3765 this->tls_segment_
->set_tls_offsets();
3770 // Set the offsets of all the allocated sections when doing a
3771 // relocatable link. This does the same jobs as set_segment_offsets,
3772 // only for a relocatable link.
3775 Layout::set_relocatable_section_offsets(Output_data
* file_header
,
3776 unsigned int* pshndx
)
3780 file_header
->set_address_and_file_offset(0, 0);
3781 off
+= file_header
->data_size();
3783 for (Section_list::iterator p
= this->section_list_
.begin();
3784 p
!= this->section_list_
.end();
3787 // We skip unallocated sections here, except that group sections
3788 // have to come first.
3789 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) == 0
3790 && (*p
)->type() != elfcpp::SHT_GROUP
)
3793 off
= align_address(off
, (*p
)->addralign());
3795 // The linker script might have set the address.
3796 if (!(*p
)->is_address_valid())
3797 (*p
)->set_address(0);
3798 (*p
)->set_file_offset(off
);
3799 (*p
)->finalize_data_size();
3800 if ((*p
)->type() != elfcpp::SHT_NOBITS
)
3801 off
+= (*p
)->data_size();
3803 (*p
)->set_out_shndx(*pshndx
);
3810 // Set the file offset of all the sections not associated with a
3814 Layout::set_section_offsets(off_t off
, Layout::Section_offset_pass pass
)
3816 off_t startoff
= off
;
3819 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3820 p
!= this->unattached_section_list_
.end();
3823 // The symtab section is handled in create_symtab_sections.
3824 if (*p
== this->symtab_section_
)
3827 // If we've already set the data size, don't set it again.
3828 if ((*p
)->is_offset_valid() && (*p
)->is_data_size_valid())
3831 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3832 && (*p
)->requires_postprocessing())
3834 (*p
)->create_postprocessing_buffer();
3835 this->any_postprocessing_sections_
= true;
3838 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3839 && (*p
)->after_input_sections())
3841 else if (pass
== POSTPROCESSING_SECTIONS_PASS
3842 && (!(*p
)->after_input_sections()
3843 || (*p
)->type() == elfcpp::SHT_STRTAB
))
3845 else if (pass
== STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
3846 && (!(*p
)->after_input_sections()
3847 || (*p
)->type() != elfcpp::SHT_STRTAB
))
3850 if (!parameters
->incremental_update())
3852 off
= align_address(off
, (*p
)->addralign());
3853 (*p
)->set_file_offset(off
);
3854 (*p
)->finalize_data_size();
3858 // Incremental update: allocate file space from free list.
3859 (*p
)->pre_finalize_data_size();
3860 off_t current_size
= (*p
)->current_data_size();
3861 off
= this->allocate(current_size
, (*p
)->addralign(), startoff
);
3864 if (is_debugging_enabled(DEBUG_INCREMENTAL
))
3865 this->free_list_
.dump();
3866 gold_assert((*p
)->output_section() != NULL
);
3867 gold_fallback(_("out of patch space for section %s; "
3868 "relink with --incremental-full"),
3869 (*p
)->output_section()->name());
3871 (*p
)->set_file_offset(off
);
3872 (*p
)->finalize_data_size();
3873 if ((*p
)->data_size() > current_size
)
3875 gold_assert((*p
)->output_section() != NULL
);
3876 gold_fallback(_("%s: section changed size; "
3877 "relink with --incremental-full"),
3878 (*p
)->output_section()->name());
3880 gold_debug(DEBUG_INCREMENTAL
,
3881 "set_section_offsets: %08lx %08lx %s",
3882 static_cast<long>(off
),
3883 static_cast<long>((*p
)->data_size()),
3884 ((*p
)->output_section() != NULL
3885 ? (*p
)->output_section()->name() : "(special)"));
3888 off
+= (*p
)->data_size();
3892 // At this point the name must be set.
3893 if (pass
!= STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
)
3894 this->namepool_
.add((*p
)->name(), false, NULL
);
3899 // Set the section indexes of all the sections not associated with a
3903 Layout::set_section_indexes(unsigned int shndx
)
3905 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3906 p
!= this->unattached_section_list_
.end();
3909 if (!(*p
)->has_out_shndx())
3911 (*p
)->set_out_shndx(shndx
);
3918 // Set the section addresses according to the linker script. This is
3919 // only called when we see a SECTIONS clause. This returns the
3920 // program segment which should hold the file header and segment
3921 // headers, if any. It will return NULL if they should not be in a
3925 Layout::set_section_addresses_from_script(Symbol_table
* symtab
)
3927 Script_sections
* ss
= this->script_options_
->script_sections();
3928 gold_assert(ss
->saw_sections_clause());
3929 return this->script_options_
->set_section_addresses(symtab
, this);
3932 // Place the orphan sections in the linker script.
3935 Layout::place_orphan_sections_in_script()
3937 Script_sections
* ss
= this->script_options_
->script_sections();
3938 gold_assert(ss
->saw_sections_clause());
3940 // Place each orphaned output section in the script.
3941 for (Section_list::iterator p
= this->section_list_
.begin();
3942 p
!= this->section_list_
.end();
3945 if (!(*p
)->found_in_sections_clause())
3946 ss
->place_orphan(*p
);
3950 // Count the local symbols in the regular symbol table and the dynamic
3951 // symbol table, and build the respective string pools.
3954 Layout::count_local_symbols(const Task
* task
,
3955 const Input_objects
* input_objects
)
3957 // First, figure out an upper bound on the number of symbols we'll
3958 // be inserting into each pool. This helps us create the pools with
3959 // the right size, to avoid unnecessary hashtable resizing.
3960 unsigned int symbol_count
= 0;
3961 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3962 p
!= input_objects
->relobj_end();
3964 symbol_count
+= (*p
)->local_symbol_count();
3966 // Go from "upper bound" to "estimate." We overcount for two
3967 // reasons: we double-count symbols that occur in more than one
3968 // object file, and we count symbols that are dropped from the
3969 // output. Add it all together and assume we overcount by 100%.
3972 // We assume all symbols will go into both the sympool and dynpool.
3973 this->sympool_
.reserve(symbol_count
);
3974 this->dynpool_
.reserve(symbol_count
);
3976 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3977 p
!= input_objects
->relobj_end();
3980 Task_lock_obj
<Object
> tlo(task
, *p
);
3981 (*p
)->count_local_symbols(&this->sympool_
, &this->dynpool_
);
3985 // Create the symbol table sections. Here we also set the final
3986 // values of the symbols. At this point all the loadable sections are
3987 // fully laid out. SHNUM is the number of sections so far.
3990 Layout::create_symtab_sections(const Input_objects
* input_objects
,
3991 Symbol_table
* symtab
,
3997 if (parameters
->target().get_size() == 32)
3999 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
4002 else if (parameters
->target().get_size() == 64)
4004 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
4010 // Compute file offsets relative to the start of the symtab section.
4013 // Save space for the dummy symbol at the start of the section. We
4014 // never bother to write this out--it will just be left as zero.
4016 unsigned int local_symbol_index
= 1;
4018 // Add STT_SECTION symbols for each Output section which needs one.
4019 for (Section_list::iterator p
= this->section_list_
.begin();
4020 p
!= this->section_list_
.end();
4023 if (!(*p
)->needs_symtab_index())
4024 (*p
)->set_symtab_index(-1U);
4027 (*p
)->set_symtab_index(local_symbol_index
);
4028 ++local_symbol_index
;
4033 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4034 p
!= input_objects
->relobj_end();
4037 unsigned int index
= (*p
)->finalize_local_symbols(local_symbol_index
,
4039 off
+= (index
- local_symbol_index
) * symsize
;
4040 local_symbol_index
= index
;
4043 unsigned int local_symcount
= local_symbol_index
;
4044 gold_assert(static_cast<off_t
>(local_symcount
* symsize
) == off
);
4047 size_t dyn_global_index
;
4049 if (this->dynsym_section_
== NULL
)
4052 dyn_global_index
= 0;
4057 dyn_global_index
= this->dynsym_section_
->info();
4058 off_t locsize
= dyn_global_index
* this->dynsym_section_
->entsize();
4059 dynoff
= this->dynsym_section_
->offset() + locsize
;
4060 dyncount
= (this->dynsym_section_
->data_size() - locsize
) / symsize
;
4061 gold_assert(static_cast<off_t
>(dyncount
* symsize
)
4062 == this->dynsym_section_
->data_size() - locsize
);
4065 off_t global_off
= off
;
4066 off
= symtab
->finalize(off
, dynoff
, dyn_global_index
, dyncount
,
4067 &this->sympool_
, &local_symcount
);
4069 if (!parameters
->options().strip_all())
4071 this->sympool_
.set_string_offsets();
4073 const char* symtab_name
= this->namepool_
.add(".symtab", false, NULL
);
4074 Output_section
* osymtab
= this->make_output_section(symtab_name
,
4078 this->symtab_section_
= osymtab
;
4080 Output_section_data
* pos
= new Output_data_fixed_space(off
, align
,
4082 osymtab
->add_output_section_data(pos
);
4084 // We generate a .symtab_shndx section if we have more than
4085 // SHN_LORESERVE sections. Technically it is possible that we
4086 // don't need one, because it is possible that there are no
4087 // symbols in any of sections with indexes larger than
4088 // SHN_LORESERVE. That is probably unusual, though, and it is
4089 // easier to always create one than to compute section indexes
4090 // twice (once here, once when writing out the symbols).
4091 if (shnum
>= elfcpp::SHN_LORESERVE
)
4093 const char* symtab_xindex_name
= this->namepool_
.add(".symtab_shndx",
4095 Output_section
* osymtab_xindex
=
4096 this->make_output_section(symtab_xindex_name
,
4097 elfcpp::SHT_SYMTAB_SHNDX
, 0,
4098 ORDER_INVALID
, false);
4100 size_t symcount
= off
/ symsize
;
4101 this->symtab_xindex_
= new Output_symtab_xindex(symcount
);
4103 osymtab_xindex
->add_output_section_data(this->symtab_xindex_
);
4105 osymtab_xindex
->set_link_section(osymtab
);
4106 osymtab_xindex
->set_addralign(4);
4107 osymtab_xindex
->set_entsize(4);
4109 osymtab_xindex
->set_after_input_sections();
4111 // This tells the driver code to wait until the symbol table
4112 // has written out before writing out the postprocessing
4113 // sections, including the .symtab_shndx section.
4114 this->any_postprocessing_sections_
= true;
4117 const char* strtab_name
= this->namepool_
.add(".strtab", false, NULL
);
4118 Output_section
* ostrtab
= this->make_output_section(strtab_name
,
4123 Output_section_data
* pstr
= new Output_data_strtab(&this->sympool_
);
4124 ostrtab
->add_output_section_data(pstr
);
4127 if (!parameters
->incremental_update())
4128 symtab_off
= align_address(*poff
, align
);
4131 symtab_off
= this->allocate(off
, align
, *poff
);
4133 gold_fallback(_("out of patch space for symbol table; "
4134 "relink with --incremental-full"));
4135 gold_debug(DEBUG_INCREMENTAL
,
4136 "create_symtab_sections: %08lx %08lx .symtab",
4137 static_cast<long>(symtab_off
),
4138 static_cast<long>(off
));
4141 symtab
->set_file_offset(symtab_off
+ global_off
);
4142 osymtab
->set_file_offset(symtab_off
);
4143 osymtab
->finalize_data_size();
4144 osymtab
->set_link_section(ostrtab
);
4145 osymtab
->set_info(local_symcount
);
4146 osymtab
->set_entsize(symsize
);
4148 if (symtab_off
+ off
> *poff
)
4149 *poff
= symtab_off
+ off
;
4153 // Create the .shstrtab section, which holds the names of the
4154 // sections. At the time this is called, we have created all the
4155 // output sections except .shstrtab itself.
4158 Layout::create_shstrtab()
4160 // FIXME: We don't need to create a .shstrtab section if we are
4161 // stripping everything.
4163 const char* name
= this->namepool_
.add(".shstrtab", false, NULL
);
4165 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_STRTAB
, 0,
4166 ORDER_INVALID
, false);
4168 if (strcmp(parameters
->options().compress_debug_sections(), "none") != 0)
4170 // We can't write out this section until we've set all the
4171 // section names, and we don't set the names of compressed
4172 // output sections until relocations are complete. FIXME: With
4173 // the current names we use, this is unnecessary.
4174 os
->set_after_input_sections();
4177 Output_section_data
* posd
= new Output_data_strtab(&this->namepool_
);
4178 os
->add_output_section_data(posd
);
4183 // Create the section headers. SIZE is 32 or 64. OFF is the file
4187 Layout::create_shdrs(const Output_section
* shstrtab_section
, off_t
* poff
)
4189 Output_section_headers
* oshdrs
;
4190 oshdrs
= new Output_section_headers(this,
4191 &this->segment_list_
,
4192 &this->section_list_
,
4193 &this->unattached_section_list_
,
4197 if (!parameters
->incremental_update())
4198 off
= align_address(*poff
, oshdrs
->addralign());
4201 oshdrs
->pre_finalize_data_size();
4202 off
= this->allocate(oshdrs
->data_size(), oshdrs
->addralign(), *poff
);
4204 gold_fallback(_("out of patch space for section header table; "
4205 "relink with --incremental-full"));
4206 gold_debug(DEBUG_INCREMENTAL
,
4207 "create_shdrs: %08lx %08lx (section header table)",
4208 static_cast<long>(off
),
4209 static_cast<long>(off
+ oshdrs
->data_size()));
4211 oshdrs
->set_address_and_file_offset(0, off
);
4212 off
+= oshdrs
->data_size();
4215 this->section_headers_
= oshdrs
;
4218 // Count the allocated sections.
4221 Layout::allocated_output_section_count() const
4223 size_t section_count
= 0;
4224 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4225 p
!= this->segment_list_
.end();
4227 section_count
+= (*p
)->output_section_count();
4228 return section_count
;
4231 // Create the dynamic symbol table.
4234 Layout::create_dynamic_symtab(const Input_objects
* input_objects
,
4235 Symbol_table
* symtab
,
4236 Output_section
** pdynstr
,
4237 unsigned int* plocal_dynamic_count
,
4238 std::vector
<Symbol
*>* pdynamic_symbols
,
4239 Versions
* pversions
)
4241 // Count all the symbols in the dynamic symbol table, and set the
4242 // dynamic symbol indexes.
4244 // Skip symbol 0, which is always all zeroes.
4245 unsigned int index
= 1;
4247 // Add STT_SECTION symbols for each Output section which needs one.
4248 for (Section_list::iterator p
= this->section_list_
.begin();
4249 p
!= this->section_list_
.end();
4252 if (!(*p
)->needs_dynsym_index())
4253 (*p
)->set_dynsym_index(-1U);
4256 (*p
)->set_dynsym_index(index
);
4261 // Count the local symbols that need to go in the dynamic symbol table,
4262 // and set the dynamic symbol indexes.
4263 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4264 p
!= input_objects
->relobj_end();
4267 unsigned int new_index
= (*p
)->set_local_dynsym_indexes(index
);
4271 unsigned int local_symcount
= index
;
4272 *plocal_dynamic_count
= local_symcount
;
4274 index
= symtab
->set_dynsym_indexes(index
, pdynamic_symbols
,
4275 &this->dynpool_
, pversions
);
4279 const int size
= parameters
->target().get_size();
4282 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
4285 else if (size
== 64)
4287 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
4293 // Create the dynamic symbol table section.
4295 Output_section
* dynsym
= this->choose_output_section(NULL
, ".dynsym",
4299 ORDER_DYNAMIC_LINKER
,
4302 // Check for NULL as a linker script may discard .dynsym.
4305 Output_section_data
* odata
= new Output_data_fixed_space(index
* symsize
,
4308 dynsym
->add_output_section_data(odata
);
4310 dynsym
->set_info(local_symcount
);
4311 dynsym
->set_entsize(symsize
);
4312 dynsym
->set_addralign(align
);
4314 this->dynsym_section_
= dynsym
;
4317 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4320 odyn
->add_section_address(elfcpp::DT_SYMTAB
, dynsym
);
4321 odyn
->add_constant(elfcpp::DT_SYMENT
, symsize
);
4324 // If there are more than SHN_LORESERVE allocated sections, we
4325 // create a .dynsym_shndx section. It is possible that we don't
4326 // need one, because it is possible that there are no dynamic
4327 // symbols in any of the sections with indexes larger than
4328 // SHN_LORESERVE. This is probably unusual, though, and at this
4329 // time we don't know the actual section indexes so it is
4330 // inconvenient to check.
4331 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE
)
4333 Output_section
* dynsym_xindex
=
4334 this->choose_output_section(NULL
, ".dynsym_shndx",
4335 elfcpp::SHT_SYMTAB_SHNDX
,
4337 false, ORDER_DYNAMIC_LINKER
, false);
4339 if (dynsym_xindex
!= NULL
)
4341 this->dynsym_xindex_
= new Output_symtab_xindex(index
);
4343 dynsym_xindex
->add_output_section_data(this->dynsym_xindex_
);
4345 dynsym_xindex
->set_link_section(dynsym
);
4346 dynsym_xindex
->set_addralign(4);
4347 dynsym_xindex
->set_entsize(4);
4349 dynsym_xindex
->set_after_input_sections();
4351 // This tells the driver code to wait until the symbol table
4352 // has written out before writing out the postprocessing
4353 // sections, including the .dynsym_shndx section.
4354 this->any_postprocessing_sections_
= true;
4358 // Create the dynamic string table section.
4360 Output_section
* dynstr
= this->choose_output_section(NULL
, ".dynstr",
4364 ORDER_DYNAMIC_LINKER
,
4369 Output_section_data
* strdata
= new Output_data_strtab(&this->dynpool_
);
4370 dynstr
->add_output_section_data(strdata
);
4373 dynsym
->set_link_section(dynstr
);
4374 if (this->dynamic_section_
!= NULL
)
4375 this->dynamic_section_
->set_link_section(dynstr
);
4379 odyn
->add_section_address(elfcpp::DT_STRTAB
, dynstr
);
4380 odyn
->add_section_size(elfcpp::DT_STRSZ
, dynstr
);
4384 // Create the hash tables. The Gnu-style hash table must be
4385 // built first, because it changes the order of the symbols
4386 // in the dynamic symbol table.
4388 if (strcmp(parameters
->options().hash_style(), "gnu") == 0
4389 || strcmp(parameters
->options().hash_style(), "both") == 0)
4391 unsigned char* phash
;
4392 unsigned int hashlen
;
4393 Dynobj::create_gnu_hash_table(*pdynamic_symbols
, local_symcount
,
4396 Output_section
* hashsec
=
4397 this->choose_output_section(NULL
, ".gnu.hash", elfcpp::SHT_GNU_HASH
,
4398 elfcpp::SHF_ALLOC
, false,
4399 ORDER_DYNAMIC_LINKER
, false);
4401 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4405 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4406 hashsec
->add_output_section_data(hashdata
);
4408 if (hashsec
!= NULL
)
4411 hashsec
->set_link_section(dynsym
);
4413 // For a 64-bit target, the entries in .gnu.hash do not have
4414 // a uniform size, so we only set the entry size for a
4416 if (parameters
->target().get_size() == 32)
4417 hashsec
->set_entsize(4);
4420 odyn
->add_section_address(elfcpp::DT_GNU_HASH
, hashsec
);
4424 if (strcmp(parameters
->options().hash_style(), "sysv") == 0
4425 || strcmp(parameters
->options().hash_style(), "both") == 0)
4427 unsigned char* phash
;
4428 unsigned int hashlen
;
4429 Dynobj::create_elf_hash_table(*pdynamic_symbols
, local_symcount
,
4432 Output_section
* hashsec
=
4433 this->choose_output_section(NULL
, ".hash", elfcpp::SHT_HASH
,
4434 elfcpp::SHF_ALLOC
, false,
4435 ORDER_DYNAMIC_LINKER
, false);
4437 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4441 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4442 hashsec
->add_output_section_data(hashdata
);
4444 if (hashsec
!= NULL
)
4447 hashsec
->set_link_section(dynsym
);
4448 hashsec
->set_entsize(parameters
->target().hash_entry_size() / 8);
4452 odyn
->add_section_address(elfcpp::DT_HASH
, hashsec
);
4456 // Assign offsets to each local portion of the dynamic symbol table.
4459 Layout::assign_local_dynsym_offsets(const Input_objects
* input_objects
)
4461 Output_section
* dynsym
= this->dynsym_section_
;
4465 off_t off
= dynsym
->offset();
4467 // Skip the dummy symbol at the start of the section.
4468 off
+= dynsym
->entsize();
4470 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4471 p
!= input_objects
->relobj_end();
4474 unsigned int count
= (*p
)->set_local_dynsym_offset(off
);
4475 off
+= count
* dynsym
->entsize();
4479 // Create the version sections.
4482 Layout::create_version_sections(const Versions
* versions
,
4483 const Symbol_table
* symtab
,
4484 unsigned int local_symcount
,
4485 const std::vector
<Symbol
*>& dynamic_symbols
,
4486 const Output_section
* dynstr
)
4488 if (!versions
->any_defs() && !versions
->any_needs())
4491 switch (parameters
->size_and_endianness())
4493 #ifdef HAVE_TARGET_32_LITTLE
4494 case Parameters::TARGET_32_LITTLE
:
4495 this->sized_create_version_sections
<32, false>(versions
, symtab
,
4497 dynamic_symbols
, dynstr
);
4500 #ifdef HAVE_TARGET_32_BIG
4501 case Parameters::TARGET_32_BIG
:
4502 this->sized_create_version_sections
<32, true>(versions
, symtab
,
4504 dynamic_symbols
, dynstr
);
4507 #ifdef HAVE_TARGET_64_LITTLE
4508 case Parameters::TARGET_64_LITTLE
:
4509 this->sized_create_version_sections
<64, false>(versions
, symtab
,
4511 dynamic_symbols
, dynstr
);
4514 #ifdef HAVE_TARGET_64_BIG
4515 case Parameters::TARGET_64_BIG
:
4516 this->sized_create_version_sections
<64, true>(versions
, symtab
,
4518 dynamic_symbols
, dynstr
);
4526 // Create the version sections, sized version.
4528 template<int size
, bool big_endian
>
4530 Layout::sized_create_version_sections(
4531 const Versions
* versions
,
4532 const Symbol_table
* symtab
,
4533 unsigned int local_symcount
,
4534 const std::vector
<Symbol
*>& dynamic_symbols
,
4535 const Output_section
* dynstr
)
4537 Output_section
* vsec
= this->choose_output_section(NULL
, ".gnu.version",
4538 elfcpp::SHT_GNU_versym
,
4541 ORDER_DYNAMIC_LINKER
,
4544 // Check for NULL since a linker script may discard this section.
4547 unsigned char* vbuf
;
4549 versions
->symbol_section_contents
<size
, big_endian
>(symtab
,
4555 Output_section_data
* vdata
= new Output_data_const_buffer(vbuf
, vsize
, 2,
4558 vsec
->add_output_section_data(vdata
);
4559 vsec
->set_entsize(2);
4560 vsec
->set_link_section(this->dynsym_section_
);
4563 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4564 if (odyn
!= NULL
&& vsec
!= NULL
)
4565 odyn
->add_section_address(elfcpp::DT_VERSYM
, vsec
);
4567 if (versions
->any_defs())
4569 Output_section
* vdsec
;
4570 vdsec
= this->choose_output_section(NULL
, ".gnu.version_d",
4571 elfcpp::SHT_GNU_verdef
,
4573 false, ORDER_DYNAMIC_LINKER
, false);
4577 unsigned char* vdbuf
;
4578 unsigned int vdsize
;
4579 unsigned int vdentries
;
4580 versions
->def_section_contents
<size
, big_endian
>(&this->dynpool_
,
4584 Output_section_data
* vddata
=
4585 new Output_data_const_buffer(vdbuf
, vdsize
, 4, "** version defs");
4587 vdsec
->add_output_section_data(vddata
);
4588 vdsec
->set_link_section(dynstr
);
4589 vdsec
->set_info(vdentries
);
4593 odyn
->add_section_address(elfcpp::DT_VERDEF
, vdsec
);
4594 odyn
->add_constant(elfcpp::DT_VERDEFNUM
, vdentries
);
4599 if (versions
->any_needs())
4601 Output_section
* vnsec
;
4602 vnsec
= this->choose_output_section(NULL
, ".gnu.version_r",
4603 elfcpp::SHT_GNU_verneed
,
4605 false, ORDER_DYNAMIC_LINKER
, false);
4609 unsigned char* vnbuf
;
4610 unsigned int vnsize
;
4611 unsigned int vnentries
;
4612 versions
->need_section_contents
<size
, big_endian
>(&this->dynpool_
,
4616 Output_section_data
* vndata
=
4617 new Output_data_const_buffer(vnbuf
, vnsize
, 4, "** version refs");
4619 vnsec
->add_output_section_data(vndata
);
4620 vnsec
->set_link_section(dynstr
);
4621 vnsec
->set_info(vnentries
);
4625 odyn
->add_section_address(elfcpp::DT_VERNEED
, vnsec
);
4626 odyn
->add_constant(elfcpp::DT_VERNEEDNUM
, vnentries
);
4632 // Create the .interp section and PT_INTERP segment.
4635 Layout::create_interp(const Target
* target
)
4637 gold_assert(this->interp_segment_
== NULL
);
4639 const char* interp
= parameters
->options().dynamic_linker();
4642 interp
= target
->dynamic_linker();
4643 gold_assert(interp
!= NULL
);
4646 size_t len
= strlen(interp
) + 1;
4648 Output_section_data
* odata
= new Output_data_const(interp
, len
, 1);
4650 Output_section
* osec
= this->choose_output_section(NULL
, ".interp",
4651 elfcpp::SHT_PROGBITS
,
4653 false, ORDER_INTERP
,
4656 osec
->add_output_section_data(odata
);
4659 // Add dynamic tags for the PLT and the dynamic relocs. This is
4660 // called by the target-specific code. This does nothing if not doing
4663 // USE_REL is true for REL relocs rather than RELA relocs.
4665 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
4667 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
4668 // and we also set DT_PLTREL. We use PLT_REL's output section, since
4669 // some targets have multiple reloc sections in PLT_REL.
4671 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
4672 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT. Again we use the output
4675 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
4679 Layout::add_target_dynamic_tags(bool use_rel
, const Output_data
* plt_got
,
4680 const Output_data
* plt_rel
,
4681 const Output_data_reloc_generic
* dyn_rel
,
4682 bool add_debug
, bool dynrel_includes_plt
)
4684 Output_data_dynamic
* odyn
= this->dynamic_data_
;
4688 if (plt_got
!= NULL
&& plt_got
->output_section() != NULL
)
4689 odyn
->add_section_address(elfcpp::DT_PLTGOT
, plt_got
);
4691 if (plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
)
4693 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, plt_rel
->output_section());
4694 odyn
->add_section_address(elfcpp::DT_JMPREL
, plt_rel
->output_section());
4695 odyn
->add_constant(elfcpp::DT_PLTREL
,
4696 use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
);
4699 if ((dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
)
4700 || (dynrel_includes_plt
4702 && plt_rel
->output_section() != NULL
))
4704 bool have_dyn_rel
= dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
;
4705 bool have_plt_rel
= plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
;
4706 odyn
->add_section_address(use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
,
4708 ? dyn_rel
->output_section()
4709 : plt_rel
->output_section()));
4710 elfcpp::DT size_tag
= use_rel
? elfcpp::DT_RELSZ
: elfcpp::DT_RELASZ
;
4711 if (have_dyn_rel
&& have_plt_rel
&& dynrel_includes_plt
)
4712 odyn
->add_section_size(size_tag
,
4713 dyn_rel
->output_section(),
4714 plt_rel
->output_section());
4715 else if (have_dyn_rel
)
4716 odyn
->add_section_size(size_tag
, dyn_rel
->output_section());
4718 odyn
->add_section_size(size_tag
, plt_rel
->output_section());
4719 const int size
= parameters
->target().get_size();
4724 rel_tag
= elfcpp::DT_RELENT
;
4726 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 32, false>::reloc_size
;
4727 else if (size
== 64)
4728 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 64, false>::reloc_size
;
4734 rel_tag
= elfcpp::DT_RELAENT
;
4736 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 32, false>::reloc_size
;
4737 else if (size
== 64)
4738 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 64, false>::reloc_size
;
4742 odyn
->add_constant(rel_tag
, rel_size
);
4744 if (parameters
->options().combreloc() && have_dyn_rel
)
4746 size_t c
= dyn_rel
->relative_reloc_count();
4748 odyn
->add_constant((use_rel
4749 ? elfcpp::DT_RELCOUNT
4750 : elfcpp::DT_RELACOUNT
),
4755 if (add_debug
&& !parameters
->options().shared())
4757 // The value of the DT_DEBUG tag is filled in by the dynamic
4758 // linker at run time, and used by the debugger.
4759 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
4764 Layout::add_target_specific_dynamic_tag(elfcpp::DT tag
, unsigned int val
)
4766 Output_data_dynamic
* odyn
= this->dynamic_data_
;
4769 odyn
->add_constant(tag
, val
);
4772 // Finish the .dynamic section and PT_DYNAMIC segment.
4775 Layout::finish_dynamic_section(const Input_objects
* input_objects
,
4776 const Symbol_table
* symtab
)
4778 if (!this->script_options_
->saw_phdrs_clause()
4779 && this->dynamic_section_
!= NULL
)
4781 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_DYNAMIC
,
4784 oseg
->add_output_section_to_nonload(this->dynamic_section_
,
4785 elfcpp::PF_R
| elfcpp::PF_W
);
4788 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4792 for (Input_objects::Dynobj_iterator p
= input_objects
->dynobj_begin();
4793 p
!= input_objects
->dynobj_end();
4796 if (!(*p
)->is_needed() && (*p
)->as_needed())
4798 // This dynamic object was linked with --as-needed, but it
4803 odyn
->add_string(elfcpp::DT_NEEDED
, (*p
)->soname());
4806 if (parameters
->options().shared())
4808 const char* soname
= parameters
->options().soname();
4810 odyn
->add_string(elfcpp::DT_SONAME
, soname
);
4813 Symbol
* sym
= symtab
->lookup(parameters
->options().init());
4814 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4815 odyn
->add_symbol(elfcpp::DT_INIT
, sym
);
4817 sym
= symtab
->lookup(parameters
->options().fini());
4818 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4819 odyn
->add_symbol(elfcpp::DT_FINI
, sym
);
4821 // Look for .init_array, .preinit_array and .fini_array by checking
4823 for(Layout::Section_list::const_iterator p
= this->section_list_
.begin();
4824 p
!= this->section_list_
.end();
4826 switch((*p
)->type())
4828 case elfcpp::SHT_FINI_ARRAY
:
4829 odyn
->add_section_address(elfcpp::DT_FINI_ARRAY
, *p
);
4830 odyn
->add_section_size(elfcpp::DT_FINI_ARRAYSZ
, *p
);
4832 case elfcpp::SHT_INIT_ARRAY
:
4833 odyn
->add_section_address(elfcpp::DT_INIT_ARRAY
, *p
);
4834 odyn
->add_section_size(elfcpp::DT_INIT_ARRAYSZ
, *p
);
4836 case elfcpp::SHT_PREINIT_ARRAY
:
4837 odyn
->add_section_address(elfcpp::DT_PREINIT_ARRAY
, *p
);
4838 odyn
->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ
, *p
);
4844 // Add a DT_RPATH entry if needed.
4845 const General_options::Dir_list
& rpath(parameters
->options().rpath());
4848 std::string rpath_val
;
4849 for (General_options::Dir_list::const_iterator p
= rpath
.begin();
4853 if (rpath_val
.empty())
4854 rpath_val
= p
->name();
4857 // Eliminate duplicates.
4858 General_options::Dir_list::const_iterator q
;
4859 for (q
= rpath
.begin(); q
!= p
; ++q
)
4860 if (q
->name() == p
->name())
4865 rpath_val
+= p
->name();
4870 if (!parameters
->options().enable_new_dtags())
4871 odyn
->add_string(elfcpp::DT_RPATH
, rpath_val
);
4873 odyn
->add_string(elfcpp::DT_RUNPATH
, rpath_val
);
4876 // Look for text segments that have dynamic relocations.
4877 bool have_textrel
= false;
4878 if (!this->script_options_
->saw_sections_clause())
4880 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4881 p
!= this->segment_list_
.end();
4884 if ((*p
)->type() == elfcpp::PT_LOAD
4885 && ((*p
)->flags() & elfcpp::PF_W
) == 0
4886 && (*p
)->has_dynamic_reloc())
4888 have_textrel
= true;
4895 // We don't know the section -> segment mapping, so we are
4896 // conservative and just look for readonly sections with
4897 // relocations. If those sections wind up in writable segments,
4898 // then we have created an unnecessary DT_TEXTREL entry.
4899 for (Section_list::const_iterator p
= this->section_list_
.begin();
4900 p
!= this->section_list_
.end();
4903 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0
4904 && ((*p
)->flags() & elfcpp::SHF_WRITE
) == 0
4905 && (*p
)->has_dynamic_reloc())
4907 have_textrel
= true;
4913 if (parameters
->options().filter() != NULL
)
4914 odyn
->add_string(elfcpp::DT_FILTER
, parameters
->options().filter());
4915 if (parameters
->options().any_auxiliary())
4917 for (options::String_set::const_iterator p
=
4918 parameters
->options().auxiliary_begin();
4919 p
!= parameters
->options().auxiliary_end();
4921 odyn
->add_string(elfcpp::DT_AUXILIARY
, *p
);
4924 // Add a DT_FLAGS entry if necessary.
4925 unsigned int flags
= 0;
4928 // Add a DT_TEXTREL for compatibility with older loaders.
4929 odyn
->add_constant(elfcpp::DT_TEXTREL
, 0);
4930 flags
|= elfcpp::DF_TEXTREL
;
4932 if (parameters
->options().text())
4933 gold_error(_("read-only segment has dynamic relocations"));
4934 else if (parameters
->options().warn_shared_textrel()
4935 && parameters
->options().shared())
4936 gold_warning(_("shared library text segment is not shareable"));
4938 if (parameters
->options().shared() && this->has_static_tls())
4939 flags
|= elfcpp::DF_STATIC_TLS
;
4940 if (parameters
->options().origin())
4941 flags
|= elfcpp::DF_ORIGIN
;
4942 if (parameters
->options().Bsymbolic()
4943 && !parameters
->options().have_dynamic_list())
4945 flags
|= elfcpp::DF_SYMBOLIC
;
4946 // Add DT_SYMBOLIC for compatibility with older loaders.
4947 odyn
->add_constant(elfcpp::DT_SYMBOLIC
, 0);
4949 if (parameters
->options().now())
4950 flags
|= elfcpp::DF_BIND_NOW
;
4952 odyn
->add_constant(elfcpp::DT_FLAGS
, flags
);
4955 if (parameters
->options().global())
4956 flags
|= elfcpp::DF_1_GLOBAL
;
4957 if (parameters
->options().initfirst())
4958 flags
|= elfcpp::DF_1_INITFIRST
;
4959 if (parameters
->options().interpose())
4960 flags
|= elfcpp::DF_1_INTERPOSE
;
4961 if (parameters
->options().loadfltr())
4962 flags
|= elfcpp::DF_1_LOADFLTR
;
4963 if (parameters
->options().nodefaultlib())
4964 flags
|= elfcpp::DF_1_NODEFLIB
;
4965 if (parameters
->options().nodelete())
4966 flags
|= elfcpp::DF_1_NODELETE
;
4967 if (parameters
->options().nodlopen())
4968 flags
|= elfcpp::DF_1_NOOPEN
;
4969 if (parameters
->options().nodump())
4970 flags
|= elfcpp::DF_1_NODUMP
;
4971 if (!parameters
->options().shared())
4972 flags
&= ~(elfcpp::DF_1_INITFIRST
4973 | elfcpp::DF_1_NODELETE
4974 | elfcpp::DF_1_NOOPEN
);
4975 if (parameters
->options().origin())
4976 flags
|= elfcpp::DF_1_ORIGIN
;
4977 if (parameters
->options().now())
4978 flags
|= elfcpp::DF_1_NOW
;
4979 if (parameters
->options().Bgroup())
4980 flags
|= elfcpp::DF_1_GROUP
;
4982 odyn
->add_constant(elfcpp::DT_FLAGS_1
, flags
);
4985 // Set the size of the _DYNAMIC symbol table to be the size of the
4989 Layout::set_dynamic_symbol_size(const Symbol_table
* symtab
)
4991 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4994 odyn
->finalize_data_size();
4995 if (this->dynamic_symbol_
== NULL
)
4997 off_t data_size
= odyn
->data_size();
4998 const int size
= parameters
->target().get_size();
5000 symtab
->get_sized_symbol
<32>(this->dynamic_symbol_
)->set_symsize(data_size
);
5001 else if (size
== 64)
5002 symtab
->get_sized_symbol
<64>(this->dynamic_symbol_
)->set_symsize(data_size
);
5007 // The mapping of input section name prefixes to output section names.
5008 // In some cases one prefix is itself a prefix of another prefix; in
5009 // such a case the longer prefix must come first. These prefixes are
5010 // based on the GNU linker default ELF linker script.
5012 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
5013 #define MAPPING_INIT_EXACT(f, t) { f, 0, t, sizeof(t) - 1 }
5014 const Layout::Section_name_mapping
Layout::section_name_mapping
[] =
5016 MAPPING_INIT(".text.", ".text"),
5017 MAPPING_INIT(".rodata.", ".rodata"),
5018 MAPPING_INIT(".data.rel.ro.local.", ".data.rel.ro.local"),
5019 MAPPING_INIT_EXACT(".data.rel.ro.local", ".data.rel.ro.local"),
5020 MAPPING_INIT(".data.rel.ro.", ".data.rel.ro"),
5021 MAPPING_INIT_EXACT(".data.rel.ro", ".data.rel.ro"),
5022 MAPPING_INIT(".data.", ".data"),
5023 MAPPING_INIT(".bss.", ".bss"),
5024 MAPPING_INIT(".tdata.", ".tdata"),
5025 MAPPING_INIT(".tbss.", ".tbss"),
5026 MAPPING_INIT(".init_array.", ".init_array"),
5027 MAPPING_INIT(".fini_array.", ".fini_array"),
5028 MAPPING_INIT(".sdata.", ".sdata"),
5029 MAPPING_INIT(".sbss.", ".sbss"),
5030 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
5031 // differently depending on whether it is creating a shared library.
5032 MAPPING_INIT(".sdata2.", ".sdata"),
5033 MAPPING_INIT(".sbss2.", ".sbss"),
5034 MAPPING_INIT(".lrodata.", ".lrodata"),
5035 MAPPING_INIT(".ldata.", ".ldata"),
5036 MAPPING_INIT(".lbss.", ".lbss"),
5037 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
5038 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
5039 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
5040 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
5041 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
5042 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
5043 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
5044 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
5045 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
5046 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
5047 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
5048 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
5049 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
5050 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
5051 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
5052 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
5053 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
5054 MAPPING_INIT(".ARM.extab", ".ARM.extab"),
5055 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
5056 MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
5057 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
5060 #undef MAPPING_INIT_EXACT
5062 const int Layout::section_name_mapping_count
=
5063 (sizeof(Layout::section_name_mapping
)
5064 / sizeof(Layout::section_name_mapping
[0]));
5066 // Choose the output section name to use given an input section name.
5067 // Set *PLEN to the length of the name. *PLEN is initialized to the
5071 Layout::output_section_name(const Relobj
* relobj
, const char* name
,
5074 // gcc 4.3 generates the following sorts of section names when it
5075 // needs a section name specific to a function:
5081 // .data.rel.local.FN
5083 // .data.rel.ro.local.FN
5090 // The GNU linker maps all of those to the part before the .FN,
5091 // except that .data.rel.local.FN is mapped to .data, and
5092 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
5093 // beginning with .data.rel.ro.local are grouped together.
5095 // For an anonymous namespace, the string FN can contain a '.'.
5097 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
5098 // GNU linker maps to .rodata.
5100 // The .data.rel.ro sections are used with -z relro. The sections
5101 // are recognized by name. We use the same names that the GNU
5102 // linker does for these sections.
5104 // It is hard to handle this in a principled way, so we don't even
5105 // try. We use a table of mappings. If the input section name is
5106 // not found in the table, we simply use it as the output section
5109 const Section_name_mapping
* psnm
= section_name_mapping
;
5110 for (int i
= 0; i
< section_name_mapping_count
; ++i
, ++psnm
)
5112 if (psnm
->fromlen
> 0)
5114 if (strncmp(name
, psnm
->from
, psnm
->fromlen
) == 0)
5116 *plen
= psnm
->tolen
;
5122 if (strcmp(name
, psnm
->from
) == 0)
5124 *plen
= psnm
->tolen
;
5130 // As an additional complication, .ctors sections are output in
5131 // either .ctors or .init_array sections, and .dtors sections are
5132 // output in either .dtors or .fini_array sections.
5133 if (is_prefix_of(".ctors.", name
) || is_prefix_of(".dtors.", name
))
5135 if (parameters
->options().ctors_in_init_array())
5138 return name
[1] == 'c' ? ".init_array" : ".fini_array";
5143 return name
[1] == 'c' ? ".ctors" : ".dtors";
5146 if (parameters
->options().ctors_in_init_array()
5147 && (strcmp(name
, ".ctors") == 0 || strcmp(name
, ".dtors") == 0))
5149 // To make .init_array/.fini_array work with gcc we must exclude
5150 // .ctors and .dtors sections from the crtbegin and crtend
5153 || (!Layout::match_file_name(relobj
, "crtbegin")
5154 && !Layout::match_file_name(relobj
, "crtend")))
5157 return name
[1] == 'c' ? ".init_array" : ".fini_array";
5164 // Return true if RELOBJ is an input file whose base name matches
5165 // FILE_NAME. The base name must have an extension of ".o", and must
5166 // be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is
5167 // to match crtbegin.o as well as crtbeginS.o without getting confused
5168 // by other possibilities. Overall matching the file name this way is
5169 // a dreadful hack, but the GNU linker does it in order to better
5170 // support gcc, and we need to be compatible.
5173 Layout::match_file_name(const Relobj
* relobj
, const char* match
)
5175 const std::string
& file_name(relobj
->name());
5176 const char* base_name
= lbasename(file_name
.c_str());
5177 size_t match_len
= strlen(match
);
5178 if (strncmp(base_name
, match
, match_len
) != 0)
5180 size_t base_len
= strlen(base_name
);
5181 if (base_len
!= match_len
+ 2 && base_len
!= match_len
+ 3)
5183 return memcmp(base_name
+ base_len
- 2, ".o", 2) == 0;
5186 // Check if a comdat group or .gnu.linkonce section with the given
5187 // NAME is selected for the link. If there is already a section,
5188 // *KEPT_SECTION is set to point to the existing section and the
5189 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
5190 // IS_GROUP_NAME are recorded for this NAME in the layout object,
5191 // *KEPT_SECTION is set to the internal copy and the function returns
5195 Layout::find_or_add_kept_section(const std::string
& name
,
5200 Kept_section
** kept_section
)
5202 // It's normal to see a couple of entries here, for the x86 thunk
5203 // sections. If we see more than a few, we're linking a C++
5204 // program, and we resize to get more space to minimize rehashing.
5205 if (this->signatures_
.size() > 4
5206 && !this->resized_signatures_
)
5208 reserve_unordered_map(&this->signatures_
,
5209 this->number_of_input_files_
* 64);
5210 this->resized_signatures_
= true;
5213 Kept_section candidate
;
5214 std::pair
<Signatures::iterator
, bool> ins
=
5215 this->signatures_
.insert(std::make_pair(name
, candidate
));
5217 if (kept_section
!= NULL
)
5218 *kept_section
= &ins
.first
->second
;
5221 // This is the first time we've seen this signature.
5222 ins
.first
->second
.set_object(object
);
5223 ins
.first
->second
.set_shndx(shndx
);
5225 ins
.first
->second
.set_is_comdat();
5227 ins
.first
->second
.set_is_group_name();
5231 // We have already seen this signature.
5233 if (ins
.first
->second
.is_group_name())
5235 // We've already seen a real section group with this signature.
5236 // If the kept group is from a plugin object, and we're in the
5237 // replacement phase, accept the new one as a replacement.
5238 if (ins
.first
->second
.object() == NULL
5239 && parameters
->options().plugins()->in_replacement_phase())
5241 ins
.first
->second
.set_object(object
);
5242 ins
.first
->second
.set_shndx(shndx
);
5247 else if (is_group_name
)
5249 // This is a real section group, and we've already seen a
5250 // linkonce section with this signature. Record that we've seen
5251 // a section group, and don't include this section group.
5252 ins
.first
->second
.set_is_group_name();
5257 // We've already seen a linkonce section and this is a linkonce
5258 // section. These don't block each other--this may be the same
5259 // symbol name with different section types.
5264 // Store the allocated sections into the section list.
5267 Layout::get_allocated_sections(Section_list
* section_list
) const
5269 for (Section_list::const_iterator p
= this->section_list_
.begin();
5270 p
!= this->section_list_
.end();
5272 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0)
5273 section_list
->push_back(*p
);
5276 // Store the executable sections into the section list.
5279 Layout::get_executable_sections(Section_list
* section_list
) const
5281 for (Section_list::const_iterator p
= this->section_list_
.begin();
5282 p
!= this->section_list_
.end();
5284 if (((*p
)->flags() & (elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
))
5285 == (elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
))
5286 section_list
->push_back(*p
);
5289 // Create an output segment.
5292 Layout::make_output_segment(elfcpp::Elf_Word type
, elfcpp::Elf_Word flags
)
5294 gold_assert(!parameters
->options().relocatable());
5295 Output_segment
* oseg
= new Output_segment(type
, flags
);
5296 this->segment_list_
.push_back(oseg
);
5298 if (type
== elfcpp::PT_TLS
)
5299 this->tls_segment_
= oseg
;
5300 else if (type
== elfcpp::PT_GNU_RELRO
)
5301 this->relro_segment_
= oseg
;
5302 else if (type
== elfcpp::PT_INTERP
)
5303 this->interp_segment_
= oseg
;
5308 // Return the file offset of the normal symbol table.
5311 Layout::symtab_section_offset() const
5313 if (this->symtab_section_
!= NULL
)
5314 return this->symtab_section_
->offset();
5318 // Return the section index of the normal symbol table. It may have
5319 // been stripped by the -s/--strip-all option.
5322 Layout::symtab_section_shndx() const
5324 if (this->symtab_section_
!= NULL
)
5325 return this->symtab_section_
->out_shndx();
5329 // Write out the Output_sections. Most won't have anything to write,
5330 // since most of the data will come from input sections which are
5331 // handled elsewhere. But some Output_sections do have Output_data.
5334 Layout::write_output_sections(Output_file
* of
) const
5336 for (Section_list::const_iterator p
= this->section_list_
.begin();
5337 p
!= this->section_list_
.end();
5340 if (!(*p
)->after_input_sections())
5345 // Write out data not associated with a section or the symbol table.
5348 Layout::write_data(const Symbol_table
* symtab
, Output_file
* of
) const
5350 if (!parameters
->options().strip_all())
5352 const Output_section
* symtab_section
= this->symtab_section_
;
5353 for (Section_list::const_iterator p
= this->section_list_
.begin();
5354 p
!= this->section_list_
.end();
5357 if ((*p
)->needs_symtab_index())
5359 gold_assert(symtab_section
!= NULL
);
5360 unsigned int index
= (*p
)->symtab_index();
5361 gold_assert(index
> 0 && index
!= -1U);
5362 off_t off
= (symtab_section
->offset()
5363 + index
* symtab_section
->entsize());
5364 symtab
->write_section_symbol(*p
, this->symtab_xindex_
, of
, off
);
5369 const Output_section
* dynsym_section
= this->dynsym_section_
;
5370 for (Section_list::const_iterator p
= this->section_list_
.begin();
5371 p
!= this->section_list_
.end();
5374 if ((*p
)->needs_dynsym_index())
5376 gold_assert(dynsym_section
!= NULL
);
5377 unsigned int index
= (*p
)->dynsym_index();
5378 gold_assert(index
> 0 && index
!= -1U);
5379 off_t off
= (dynsym_section
->offset()
5380 + index
* dynsym_section
->entsize());
5381 symtab
->write_section_symbol(*p
, this->dynsym_xindex_
, of
, off
);
5385 // Write out the Output_data which are not in an Output_section.
5386 for (Data_list::const_iterator p
= this->special_output_list_
.begin();
5387 p
!= this->special_output_list_
.end();
5391 // Write out the Output_data which are not in an Output_section
5392 // and are regenerated in each iteration of relaxation.
5393 for (Data_list::const_iterator p
= this->relax_output_list_
.begin();
5394 p
!= this->relax_output_list_
.end();
5399 // Write out the Output_sections which can only be written after the
5400 // input sections are complete.
5403 Layout::write_sections_after_input_sections(Output_file
* of
)
5405 // Determine the final section offsets, and thus the final output
5406 // file size. Note we finalize the .shstrab last, to allow the
5407 // after_input_section sections to modify their section-names before
5409 if (this->any_postprocessing_sections_
)
5411 off_t off
= this->output_file_size_
;
5412 off
= this->set_section_offsets(off
, POSTPROCESSING_SECTIONS_PASS
);
5414 // Now that we've finalized the names, we can finalize the shstrab.
5416 this->set_section_offsets(off
,
5417 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
5419 if (off
> this->output_file_size_
)
5422 this->output_file_size_
= off
;
5426 for (Section_list::const_iterator p
= this->section_list_
.begin();
5427 p
!= this->section_list_
.end();
5430 if ((*p
)->after_input_sections())
5434 this->section_headers_
->write(of
);
5437 // If a tree-style build ID was requested, the parallel part of that computation
5438 // is already done, and the final hash-of-hashes is computed here. For other
5439 // types of build IDs, all the work is done here.
5442 Layout::write_build_id(Output_file
* of
, unsigned char* array_of_hashes
,
5443 size_t size_of_hashes
) const
5445 if (this->build_id_note_
== NULL
)
5448 unsigned char* ov
= of
->get_output_view(this->build_id_note_
->offset(),
5449 this->build_id_note_
->data_size());
5451 if (array_of_hashes
== NULL
)
5453 const size_t output_file_size
= this->output_file_size();
5454 const unsigned char* iv
= of
->get_input_view(0, output_file_size
);
5455 const char* style
= parameters
->options().build_id();
5457 // If we get here with style == "tree" then the output must be
5458 // too small for chunking, and we use SHA-1 in that case.
5459 if ((strcmp(style
, "sha1") == 0) || (strcmp(style
, "tree") == 0))
5460 sha1_buffer(reinterpret_cast<const char*>(iv
), output_file_size
, ov
);
5461 else if (strcmp(style
, "md5") == 0)
5462 md5_buffer(reinterpret_cast<const char*>(iv
), output_file_size
, ov
);
5466 of
->free_input_view(0, output_file_size
, iv
);
5470 // Non-overlapping substrings of the output file have been hashed.
5471 // Compute SHA-1 hash of the hashes.
5472 sha1_buffer(reinterpret_cast<const char*>(array_of_hashes
),
5473 size_of_hashes
, ov
);
5474 delete[] array_of_hashes
;
5477 of
->write_output_view(this->build_id_note_
->offset(),
5478 this->build_id_note_
->data_size(),
5482 // Write out a binary file. This is called after the link is
5483 // complete. IN is the temporary output file we used to generate the
5484 // ELF code. We simply walk through the segments, read them from
5485 // their file offset in IN, and write them to their load address in
5486 // the output file. FIXME: with a bit more work, we could support
5487 // S-records and/or Intel hex format here.
5490 Layout::write_binary(Output_file
* in
) const
5492 gold_assert(parameters
->options().oformat_enum()
5493 == General_options::OBJECT_FORMAT_BINARY
);
5495 // Get the size of the binary file.
5496 uint64_t max_load_address
= 0;
5497 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5498 p
!= this->segment_list_
.end();
5501 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5503 uint64_t max_paddr
= (*p
)->paddr() + (*p
)->filesz();
5504 if (max_paddr
> max_load_address
)
5505 max_load_address
= max_paddr
;
5509 Output_file
out(parameters
->options().output_file_name());
5510 out
.open(max_load_address
);
5512 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5513 p
!= this->segment_list_
.end();
5516 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5518 const unsigned char* vin
= in
->get_input_view((*p
)->offset(),
5520 unsigned char* vout
= out
.get_output_view((*p
)->paddr(),
5522 memcpy(vout
, vin
, (*p
)->filesz());
5523 out
.write_output_view((*p
)->paddr(), (*p
)->filesz(), vout
);
5524 in
->free_input_view((*p
)->offset(), (*p
)->filesz(), vin
);
5531 // Print the output sections to the map file.
5534 Layout::print_to_mapfile(Mapfile
* mapfile
) const
5536 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5537 p
!= this->segment_list_
.end();
5539 (*p
)->print_sections_to_mapfile(mapfile
);
5540 for (Section_list::const_iterator p
= this->unattached_section_list_
.begin();
5541 p
!= this->unattached_section_list_
.end();
5543 (*p
)->print_to_mapfile(mapfile
);
5546 // Print statistical information to stderr. This is used for --stats.
5549 Layout::print_stats() const
5551 this->namepool_
.print_stats("section name pool");
5552 this->sympool_
.print_stats("output symbol name pool");
5553 this->dynpool_
.print_stats("dynamic name pool");
5555 for (Section_list::const_iterator p
= this->section_list_
.begin();
5556 p
!= this->section_list_
.end();
5558 (*p
)->print_merge_stats();
5561 // Write_sections_task methods.
5563 // We can always run this task.
5566 Write_sections_task::is_runnable()
5571 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
5575 Write_sections_task::locks(Task_locker
* tl
)
5577 tl
->add(this, this->output_sections_blocker_
);
5578 if (this->input_sections_blocker_
!= NULL
)
5579 tl
->add(this, this->input_sections_blocker_
);
5580 tl
->add(this, this->final_blocker_
);
5583 // Run the task--write out the data.
5586 Write_sections_task::run(Workqueue
*)
5588 this->layout_
->write_output_sections(this->of_
);
5591 // Write_data_task methods.
5593 // We can always run this task.
5596 Write_data_task::is_runnable()
5601 // We need to unlock FINAL_BLOCKER when finished.
5604 Write_data_task::locks(Task_locker
* tl
)
5606 tl
->add(this, this->final_blocker_
);
5609 // Run the task--write out the data.
5612 Write_data_task::run(Workqueue
*)
5614 this->layout_
->write_data(this->symtab_
, this->of_
);
5617 // Write_symbols_task methods.
5619 // We can always run this task.
5622 Write_symbols_task::is_runnable()
5627 // We need to unlock FINAL_BLOCKER when finished.
5630 Write_symbols_task::locks(Task_locker
* tl
)
5632 tl
->add(this, this->final_blocker_
);
5635 // Run the task--write out the symbols.
5638 Write_symbols_task::run(Workqueue
*)
5640 this->symtab_
->write_globals(this->sympool_
, this->dynpool_
,
5641 this->layout_
->symtab_xindex(),
5642 this->layout_
->dynsym_xindex(), this->of_
);
5645 // Write_after_input_sections_task methods.
5647 // We can only run this task after the input sections have completed.
5650 Write_after_input_sections_task::is_runnable()
5652 if (this->input_sections_blocker_
->is_blocked())
5653 return this->input_sections_blocker_
;
5657 // We need to unlock FINAL_BLOCKER when finished.
5660 Write_after_input_sections_task::locks(Task_locker
* tl
)
5662 tl
->add(this, this->final_blocker_
);
5668 Write_after_input_sections_task::run(Workqueue
*)
5670 this->layout_
->write_sections_after_input_sections(this->of_
);
5673 // Build IDs can be computed as a "flat" sha1 or md5 of a string of bytes,
5674 // or as a "tree" where each chunk of the string is hashed and then those
5675 // hashes are put into a (much smaller) string which is hashed with sha1.
5676 // We compute a checksum over the entire file because that is simplest.
5679 Build_id_task_runner::run(Workqueue
* workqueue
, const Task
*)
5681 Task_token
* post_hash_tasks_blocker
= new Task_token(true);
5682 const Layout
* layout
= this->layout_
;
5683 Output_file
* of
= this->of_
;
5684 const size_t filesize
= (layout
->output_file_size() <= 0 ? 0
5685 : static_cast<size_t>(layout
->output_file_size()));
5686 unsigned char* array_of_hashes
= NULL
;
5687 size_t size_of_hashes
= 0;
5689 if (strcmp(this->options_
->build_id(), "tree") == 0
5690 && this->options_
->build_id_chunk_size_for_treehash() > 0
5692 && (filesize
>= this->options_
->build_id_min_file_size_for_treehash()))
5694 static const size_t MD5_OUTPUT_SIZE_IN_BYTES
= 16;
5695 const size_t chunk_size
=
5696 this->options_
->build_id_chunk_size_for_treehash();
5697 const size_t num_hashes
= ((filesize
- 1) / chunk_size
) + 1;
5698 post_hash_tasks_blocker
->add_blockers(num_hashes
);
5699 size_of_hashes
= num_hashes
* MD5_OUTPUT_SIZE_IN_BYTES
;
5700 array_of_hashes
= new unsigned char[size_of_hashes
];
5701 unsigned char *dst
= array_of_hashes
;
5702 for (size_t i
= 0, src_offset
= 0; i
< num_hashes
;
5703 i
++, dst
+= MD5_OUTPUT_SIZE_IN_BYTES
, src_offset
+= chunk_size
)
5705 size_t size
= std::min(chunk_size
, filesize
- src_offset
);
5706 workqueue
->queue(new Hash_task(of
,
5710 post_hash_tasks_blocker
));
5714 // Queue the final task to write the build id and close the output file.
5715 workqueue
->queue(new Task_function(new Close_task_runner(this->options_
,
5720 post_hash_tasks_blocker
,
5721 "Task_function Close_task_runner"));
5724 // Close_task_runner methods.
5726 // Finish up the build ID computation, if necessary, and write a binary file,
5727 // if necessary. Then close the output file.
5730 Close_task_runner::run(Workqueue
*, const Task
*)
5732 // At this point the multi-threaded part of the build ID computation,
5733 // if any, is done. See Build_id_task_runner.
5734 this->layout_
->write_build_id(this->of_
, this->array_of_hashes_
,
5735 this->size_of_hashes_
);
5737 // If we've been asked to create a binary file, we do so here.
5738 if (this->options_
->oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
5739 this->layout_
->write_binary(this->of_
);
5744 // Instantiate the templates we need. We could use the configure
5745 // script to restrict this to only the ones for implemented targets.
5747 #ifdef HAVE_TARGET_32_LITTLE
5750 Layout::init_fixed_output_section
<32, false>(
5752 elfcpp::Shdr
<32, false>& shdr
);
5755 #ifdef HAVE_TARGET_32_BIG
5758 Layout::init_fixed_output_section
<32, true>(
5760 elfcpp::Shdr
<32, true>& shdr
);
5763 #ifdef HAVE_TARGET_64_LITTLE
5766 Layout::init_fixed_output_section
<64, false>(
5768 elfcpp::Shdr
<64, false>& shdr
);
5771 #ifdef HAVE_TARGET_64_BIG
5774 Layout::init_fixed_output_section
<64, true>(
5776 elfcpp::Shdr
<64, true>& shdr
);
5779 #ifdef HAVE_TARGET_32_LITTLE
5782 Layout::layout
<32, false>(Sized_relobj_file
<32, false>* object
,
5785 const elfcpp::Shdr
<32, false>& shdr
,
5786 unsigned int, unsigned int, off_t
*);
5789 #ifdef HAVE_TARGET_32_BIG
5792 Layout::layout
<32, true>(Sized_relobj_file
<32, true>* object
,
5795 const elfcpp::Shdr
<32, true>& shdr
,
5796 unsigned int, unsigned int, off_t
*);
5799 #ifdef HAVE_TARGET_64_LITTLE
5802 Layout::layout
<64, false>(Sized_relobj_file
<64, false>* object
,
5805 const elfcpp::Shdr
<64, false>& shdr
,
5806 unsigned int, unsigned int, off_t
*);
5809 #ifdef HAVE_TARGET_64_BIG
5812 Layout::layout
<64, true>(Sized_relobj_file
<64, true>* object
,
5815 const elfcpp::Shdr
<64, true>& shdr
,
5816 unsigned int, unsigned int, off_t
*);
5819 #ifdef HAVE_TARGET_32_LITTLE
5822 Layout::layout_reloc
<32, false>(Sized_relobj_file
<32, false>* object
,
5823 unsigned int reloc_shndx
,
5824 const elfcpp::Shdr
<32, false>& shdr
,
5825 Output_section
* data_section
,
5826 Relocatable_relocs
* rr
);
5829 #ifdef HAVE_TARGET_32_BIG
5832 Layout::layout_reloc
<32, true>(Sized_relobj_file
<32, true>* object
,
5833 unsigned int reloc_shndx
,
5834 const elfcpp::Shdr
<32, true>& shdr
,
5835 Output_section
* data_section
,
5836 Relocatable_relocs
* rr
);
5839 #ifdef HAVE_TARGET_64_LITTLE
5842 Layout::layout_reloc
<64, false>(Sized_relobj_file
<64, false>* object
,
5843 unsigned int reloc_shndx
,
5844 const elfcpp::Shdr
<64, false>& shdr
,
5845 Output_section
* data_section
,
5846 Relocatable_relocs
* rr
);
5849 #ifdef HAVE_TARGET_64_BIG
5852 Layout::layout_reloc
<64, true>(Sized_relobj_file
<64, true>* object
,
5853 unsigned int reloc_shndx
,
5854 const elfcpp::Shdr
<64, true>& shdr
,
5855 Output_section
* data_section
,
5856 Relocatable_relocs
* rr
);
5859 #ifdef HAVE_TARGET_32_LITTLE
5862 Layout::layout_group
<32, false>(Symbol_table
* symtab
,
5863 Sized_relobj_file
<32, false>* object
,
5865 const char* group_section_name
,
5866 const char* signature
,
5867 const elfcpp::Shdr
<32, false>& shdr
,
5868 elfcpp::Elf_Word flags
,
5869 std::vector
<unsigned int>* shndxes
);
5872 #ifdef HAVE_TARGET_32_BIG
5875 Layout::layout_group
<32, true>(Symbol_table
* symtab
,
5876 Sized_relobj_file
<32, true>* object
,
5878 const char* group_section_name
,
5879 const char* signature
,
5880 const elfcpp::Shdr
<32, true>& shdr
,
5881 elfcpp::Elf_Word flags
,
5882 std::vector
<unsigned int>* shndxes
);
5885 #ifdef HAVE_TARGET_64_LITTLE
5888 Layout::layout_group
<64, false>(Symbol_table
* symtab
,
5889 Sized_relobj_file
<64, false>* object
,
5891 const char* group_section_name
,
5892 const char* signature
,
5893 const elfcpp::Shdr
<64, false>& shdr
,
5894 elfcpp::Elf_Word flags
,
5895 std::vector
<unsigned int>* shndxes
);
5898 #ifdef HAVE_TARGET_64_BIG
5901 Layout::layout_group
<64, true>(Symbol_table
* symtab
,
5902 Sized_relobj_file
<64, true>* object
,
5904 const char* group_section_name
,
5905 const char* signature
,
5906 const elfcpp::Shdr
<64, true>& shdr
,
5907 elfcpp::Elf_Word flags
,
5908 std::vector
<unsigned int>* shndxes
);
5911 #ifdef HAVE_TARGET_32_LITTLE
5914 Layout::layout_eh_frame
<32, false>(Sized_relobj_file
<32, false>* object
,
5915 const unsigned char* symbols
,
5917 const unsigned char* symbol_names
,
5918 off_t symbol_names_size
,
5920 const elfcpp::Shdr
<32, false>& shdr
,
5921 unsigned int reloc_shndx
,
5922 unsigned int reloc_type
,
5926 #ifdef HAVE_TARGET_32_BIG
5929 Layout::layout_eh_frame
<32, true>(Sized_relobj_file
<32, true>* object
,
5930 const unsigned char* symbols
,
5932 const unsigned char* symbol_names
,
5933 off_t symbol_names_size
,
5935 const elfcpp::Shdr
<32, true>& shdr
,
5936 unsigned int reloc_shndx
,
5937 unsigned int reloc_type
,
5941 #ifdef HAVE_TARGET_64_LITTLE
5944 Layout::layout_eh_frame
<64, false>(Sized_relobj_file
<64, false>* object
,
5945 const unsigned char* symbols
,
5947 const unsigned char* symbol_names
,
5948 off_t symbol_names_size
,
5950 const elfcpp::Shdr
<64, false>& shdr
,
5951 unsigned int reloc_shndx
,
5952 unsigned int reloc_type
,
5956 #ifdef HAVE_TARGET_64_BIG
5959 Layout::layout_eh_frame
<64, true>(Sized_relobj_file
<64, true>* object
,
5960 const unsigned char* symbols
,
5962 const unsigned char* symbol_names
,
5963 off_t symbol_names_size
,
5965 const elfcpp::Shdr
<64, true>& shdr
,
5966 unsigned int reloc_shndx
,
5967 unsigned int reloc_type
,
5971 #ifdef HAVE_TARGET_32_LITTLE
5974 Layout::add_to_gdb_index(bool is_type_unit
,
5975 Sized_relobj
<32, false>* object
,
5976 const unsigned char* symbols
,
5979 unsigned int reloc_shndx
,
5980 unsigned int reloc_type
);
5983 #ifdef HAVE_TARGET_32_BIG
5986 Layout::add_to_gdb_index(bool is_type_unit
,
5987 Sized_relobj
<32, true>* object
,
5988 const unsigned char* symbols
,
5991 unsigned int reloc_shndx
,
5992 unsigned int reloc_type
);
5995 #ifdef HAVE_TARGET_64_LITTLE
5998 Layout::add_to_gdb_index(bool is_type_unit
,
5999 Sized_relobj
<64, false>* object
,
6000 const unsigned char* symbols
,
6003 unsigned int reloc_shndx
,
6004 unsigned int reloc_type
);
6007 #ifdef HAVE_TARGET_64_BIG
6010 Layout::add_to_gdb_index(bool is_type_unit
,
6011 Sized_relobj
<64, true>* object
,
6012 const unsigned char* symbols
,
6015 unsigned int reloc_shndx
,
6016 unsigned int reloc_type
);
6019 } // End namespace gold.