1 // layout.cc -- lay out output file sections for gold
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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"
38 #include "parameters.h"
42 #include "script-sections.h"
47 #include "compressed_output.h"
48 #include "reduced_debug_output.h"
51 #include "descriptors.h"
53 #include "incremental.h"
61 // The total number of free lists used.
62 unsigned int Free_list::num_lists
= 0;
63 // The total number of free list nodes used.
64 unsigned int Free_list::num_nodes
= 0;
65 // The total number of calls to Free_list::remove.
66 unsigned int Free_list::num_removes
= 0;
67 // The total number of nodes visited during calls to Free_list::remove.
68 unsigned int Free_list::num_remove_visits
= 0;
69 // The total number of calls to Free_list::allocate.
70 unsigned int Free_list::num_allocates
= 0;
71 // The total number of nodes visited during calls to Free_list::allocate.
72 unsigned int Free_list::num_allocate_visits
= 0;
74 // Initialize the free list. Creates a single free list node that
75 // describes the entire region of length LEN. If EXTEND is true,
76 // allocate() is allowed to extend the region beyond its initial
80 Free_list::init(off_t len
, bool extend
)
82 this->list_
.push_front(Free_list_node(0, len
));
83 this->last_remove_
= this->list_
.begin();
84 this->extend_
= extend
;
86 ++Free_list::num_lists
;
87 ++Free_list::num_nodes
;
90 // Remove a chunk from the free list. Because we start with a single
91 // node that covers the entire section, and remove chunks from it one
92 // at a time, we do not need to coalesce chunks or handle cases that
93 // span more than one free node. We expect to remove chunks from the
94 // free list in order, and we expect to have only a few chunks of free
95 // space left (corresponding to files that have changed since the last
96 // incremental link), so a simple linear list should provide sufficient
100 Free_list::remove(off_t start
, off_t end
)
104 gold_assert(start
< end
);
106 ++Free_list::num_removes
;
108 Iterator p
= this->last_remove_
;
109 if (p
->start_
> start
)
110 p
= this->list_
.begin();
112 for (; p
!= this->list_
.end(); ++p
)
114 ++Free_list::num_remove_visits
;
115 // Find a node that wholly contains the indicated region.
116 if (p
->start_
<= start
&& p
->end_
>= end
)
118 // Case 1: the indicated region spans the whole node.
119 // Add some fuzz to avoid creating tiny free chunks.
120 if (p
->start_
+ 3 >= start
&& p
->end_
<= end
+ 3)
121 p
= this->list_
.erase(p
);
122 // Case 2: remove a chunk from the start of the node.
123 else if (p
->start_
+ 3 >= start
)
125 // Case 3: remove a chunk from the end of the node.
126 else if (p
->end_
<= end
+ 3)
128 // Case 4: remove a chunk from the middle, and split
129 // the node into two.
132 Free_list_node
newnode(p
->start_
, start
);
134 this->list_
.insert(p
, newnode
);
135 ++Free_list::num_nodes
;
137 this->last_remove_
= p
;
142 // Did not find a node containing the given chunk. This could happen
143 // because a small chunk was already removed due to the fuzz.
144 gold_debug(DEBUG_INCREMENTAL
,
145 "Free_list::remove(%d,%d) not found",
146 static_cast<int>(start
), static_cast<int>(end
));
149 // Allocate a chunk of size LEN from the free list. Returns -1ULL
150 // if a sufficiently large chunk of free space is not found.
151 // We use a simple first-fit algorithm.
154 Free_list::allocate(off_t len
, uint64_t align
, off_t minoff
)
156 gold_debug(DEBUG_INCREMENTAL
,
157 "Free_list::allocate(%08lx, %d, %08lx)",
158 static_cast<long>(len
), static_cast<int>(align
),
159 static_cast<long>(minoff
));
161 return align_address(minoff
, align
);
163 ++Free_list::num_allocates
;
165 // We usually want to drop free chunks smaller than 4 bytes.
166 // If we need to guarantee a minimum hole size, though, we need
167 // to keep track of all free chunks.
168 const int fuzz
= this->min_hole_
> 0 ? 0 : 3;
170 for (Iterator p
= this->list_
.begin(); p
!= this->list_
.end(); ++p
)
172 ++Free_list::num_allocate_visits
;
173 off_t start
= p
->start_
> minoff
? p
->start_
: minoff
;
174 start
= align_address(start
, align
);
175 off_t end
= start
+ len
;
176 if (end
> p
->end_
&& p
->end_
== this->length_
&& this->extend_
)
181 if (end
== p
->end_
|| (end
<= p
->end_
- this->min_hole_
))
183 if (p
->start_
+ fuzz
>= start
&& p
->end_
<= end
+ fuzz
)
184 this->list_
.erase(p
);
185 else if (p
->start_
+ fuzz
>= start
)
187 else if (p
->end_
<= end
+ fuzz
)
191 Free_list_node
newnode(p
->start_
, start
);
193 this->list_
.insert(p
, newnode
);
194 ++Free_list::num_nodes
;
201 off_t start
= align_address(this->length_
, align
);
202 this->length_
= start
+ len
;
208 // Dump the free list (for debugging).
212 gold_info("Free list:\n start end length\n");
213 for (Iterator p
= this->list_
.begin(); p
!= this->list_
.end(); ++p
)
214 gold_info(" %08lx %08lx %08lx", static_cast<long>(p
->start_
),
215 static_cast<long>(p
->end_
),
216 static_cast<long>(p
->end_
- p
->start_
));
219 // Print the statistics for the free lists.
221 Free_list::print_stats()
223 fprintf(stderr
, _("%s: total free lists: %u\n"),
224 program_name
, Free_list::num_lists
);
225 fprintf(stderr
, _("%s: total free list nodes: %u\n"),
226 program_name
, Free_list::num_nodes
);
227 fprintf(stderr
, _("%s: calls to Free_list::remove: %u\n"),
228 program_name
, Free_list::num_removes
);
229 fprintf(stderr
, _("%s: nodes visited: %u\n"),
230 program_name
, Free_list::num_remove_visits
);
231 fprintf(stderr
, _("%s: calls to Free_list::allocate: %u\n"),
232 program_name
, Free_list::num_allocates
);
233 fprintf(stderr
, _("%s: nodes visited: %u\n"),
234 program_name
, Free_list::num_allocate_visits
);
237 // Layout::Relaxation_debug_check methods.
239 // Check that sections and special data are in reset states.
240 // We do not save states for Output_sections and special Output_data.
241 // So we check that they have not assigned any addresses or offsets.
242 // clean_up_after_relaxation simply resets their addresses and offsets.
244 Layout::Relaxation_debug_check::check_output_data_for_reset_values(
245 const Layout::Section_list
& sections
,
246 const Layout::Data_list
& special_outputs
)
248 for(Layout::Section_list::const_iterator p
= sections
.begin();
251 gold_assert((*p
)->address_and_file_offset_have_reset_values());
253 for(Layout::Data_list::const_iterator p
= special_outputs
.begin();
254 p
!= special_outputs
.end();
256 gold_assert((*p
)->address_and_file_offset_have_reset_values());
259 // Save information of SECTIONS for checking later.
262 Layout::Relaxation_debug_check::read_sections(
263 const Layout::Section_list
& sections
)
265 for(Layout::Section_list::const_iterator p
= sections
.begin();
269 Output_section
* os
= *p
;
271 info
.output_section
= os
;
272 info
.address
= os
->is_address_valid() ? os
->address() : 0;
273 info
.data_size
= os
->is_data_size_valid() ? os
->data_size() : -1;
274 info
.offset
= os
->is_offset_valid()? os
->offset() : -1 ;
275 this->section_infos_
.push_back(info
);
279 // Verify SECTIONS using previously recorded information.
282 Layout::Relaxation_debug_check::verify_sections(
283 const Layout::Section_list
& sections
)
286 for(Layout::Section_list::const_iterator p
= sections
.begin();
290 Output_section
* os
= *p
;
291 uint64_t address
= os
->is_address_valid() ? os
->address() : 0;
292 off_t data_size
= os
->is_data_size_valid() ? os
->data_size() : -1;
293 off_t offset
= os
->is_offset_valid()? os
->offset() : -1 ;
295 if (i
>= this->section_infos_
.size())
297 gold_fatal("Section_info of %s missing.\n", os
->name());
299 const Section_info
& info
= this->section_infos_
[i
];
300 if (os
!= info
.output_section
)
301 gold_fatal("Section order changed. Expecting %s but see %s\n",
302 info
.output_section
->name(), os
->name());
303 if (address
!= info
.address
304 || data_size
!= info
.data_size
305 || offset
!= info
.offset
)
306 gold_fatal("Section %s changed.\n", os
->name());
310 // Layout_task_runner methods.
312 // Lay out the sections. This is called after all the input objects
316 Layout_task_runner::run(Workqueue
* workqueue
, const Task
* task
)
318 Layout
* layout
= this->layout_
;
319 off_t file_size
= layout
->finalize(this->input_objects_
,
324 // Now we know the final size of the output file and we know where
325 // each piece of information goes.
327 if (this->mapfile_
!= NULL
)
329 this->mapfile_
->print_discarded_sections(this->input_objects_
);
330 layout
->print_to_mapfile(this->mapfile_
);
334 if (layout
->incremental_base() == NULL
)
336 of
= new Output_file(parameters
->options().output_file_name());
337 if (this->options_
.oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
338 of
->set_is_temporary();
343 of
= layout
->incremental_base()->output_file();
345 // Apply the incremental relocations for symbols whose values
346 // have changed. We do this before we resize the file and start
347 // writing anything else to it, so that we can read the old
348 // incremental information from the file before (possibly)
350 if (parameters
->incremental_update())
351 layout
->incremental_base()->apply_incremental_relocs(this->symtab_
,
355 of
->resize(file_size
);
358 // Queue up the final set of tasks.
359 gold::queue_final_tasks(this->options_
, this->input_objects_
,
360 this->symtab_
, layout
, workqueue
, of
);
365 Layout::Layout(int number_of_input_files
, Script_options
* script_options
)
366 : number_of_input_files_(number_of_input_files
),
367 script_options_(script_options
),
375 unattached_section_list_(),
376 special_output_list_(),
377 section_headers_(NULL
),
379 relro_segment_(NULL
),
380 interp_segment_(NULL
),
382 symtab_section_(NULL
),
383 symtab_xindex_(NULL
),
384 dynsym_section_(NULL
),
385 dynsym_xindex_(NULL
),
386 dynamic_section_(NULL
),
387 dynamic_symbol_(NULL
),
389 eh_frame_section_(NULL
),
390 eh_frame_data_(NULL
),
391 added_eh_frame_data_(false),
392 eh_frame_hdr_section_(NULL
),
393 build_id_note_(NULL
),
397 output_file_size_(-1),
398 have_added_input_section_(false),
399 sections_are_attached_(false),
400 input_requires_executable_stack_(false),
401 input_with_gnu_stack_note_(false),
402 input_without_gnu_stack_note_(false),
403 has_static_tls_(false),
404 any_postprocessing_sections_(false),
405 resized_signatures_(false),
406 have_stabstr_section_(false),
407 section_ordering_specified_(false),
408 incremental_inputs_(NULL
),
409 record_output_section_data_from_script_(false),
410 script_output_section_data_list_(),
411 segment_states_(NULL
),
412 relaxation_debug_check_(NULL
),
413 section_order_map_(),
414 input_section_position_(),
415 input_section_glob_(),
416 incremental_base_(NULL
),
419 // Make space for more than enough segments for a typical file.
420 // This is just for efficiency--it's OK if we wind up needing more.
421 this->segment_list_
.reserve(12);
423 // We expect two unattached Output_data objects: the file header and
424 // the segment headers.
425 this->special_output_list_
.reserve(2);
427 // Initialize structure needed for an incremental build.
428 if (parameters
->incremental())
429 this->incremental_inputs_
= new Incremental_inputs
;
431 // The section name pool is worth optimizing in all cases, because
432 // it is small, but there are often overlaps due to .rel sections.
433 this->namepool_
.set_optimize();
436 // For incremental links, record the base file to be modified.
439 Layout::set_incremental_base(Incremental_binary
* base
)
441 this->incremental_base_
= base
;
442 this->free_list_
.init(base
->output_file()->filesize(), true);
445 // Hash a key we use to look up an output section mapping.
448 Layout::Hash_key::operator()(const Layout::Key
& k
) const
450 return k
.first
+ k
.second
.first
+ k
.second
.second
;
453 // Returns whether the given section is in the list of
454 // debug-sections-used-by-some-version-of-gdb. Currently,
455 // we've checked versions of gdb up to and including 6.7.1.
457 static const char* gdb_sections
[] =
459 // ".debug_aranges", // not used by gdb as of 6.7.1
466 // ".debug_pubnames", // not used by gdb as of 6.7.1
471 static const char* lines_only_debug_sections
[] =
473 // ".debug_aranges", // not used by gdb as of 6.7.1
480 // ".debug_pubnames", // not used by gdb as of 6.7.1
486 is_gdb_debug_section(const char* str
)
488 // We can do this faster: binary search or a hashtable. But why bother?
489 for (size_t i
= 0; i
< sizeof(gdb_sections
)/sizeof(*gdb_sections
); ++i
)
490 if (strcmp(str
, gdb_sections
[i
]) == 0)
496 is_lines_only_debug_section(const char* str
)
498 // We can do this faster: binary search or a hashtable. But why bother?
500 i
< sizeof(lines_only_debug_sections
)/sizeof(*lines_only_debug_sections
);
502 if (strcmp(str
, lines_only_debug_sections
[i
]) == 0)
507 // Sometimes we compress sections. This is typically done for
508 // sections that are not part of normal program execution (such as
509 // .debug_* sections), and where the readers of these sections know
510 // how to deal with compressed sections. This routine doesn't say for
511 // certain whether we'll compress -- it depends on commandline options
512 // as well -- just whether this section is a candidate for compression.
513 // (The Output_compressed_section class decides whether to compress
514 // a given section, and picks the name of the compressed section.)
517 is_compressible_debug_section(const char* secname
)
519 return (is_prefix_of(".debug", secname
));
522 // We may see compressed debug sections in input files. Return TRUE
523 // if this is the name of a compressed debug section.
526 is_compressed_debug_section(const char* secname
)
528 return (is_prefix_of(".zdebug", secname
));
531 // Whether to include this section in the link.
533 template<int size
, bool big_endian
>
535 Layout::include_section(Sized_relobj_file
<size
, big_endian
>*, const char* name
,
536 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
538 if (shdr
.get_sh_flags() & elfcpp::SHF_EXCLUDE
)
541 switch (shdr
.get_sh_type())
543 case elfcpp::SHT_NULL
:
544 case elfcpp::SHT_SYMTAB
:
545 case elfcpp::SHT_DYNSYM
:
546 case elfcpp::SHT_HASH
:
547 case elfcpp::SHT_DYNAMIC
:
548 case elfcpp::SHT_SYMTAB_SHNDX
:
551 case elfcpp::SHT_STRTAB
:
552 // Discard the sections which have special meanings in the ELF
553 // ABI. Keep others (e.g., .stabstr). We could also do this by
554 // checking the sh_link fields of the appropriate sections.
555 return (strcmp(name
, ".dynstr") != 0
556 && strcmp(name
, ".strtab") != 0
557 && strcmp(name
, ".shstrtab") != 0);
559 case elfcpp::SHT_RELA
:
560 case elfcpp::SHT_REL
:
561 case elfcpp::SHT_GROUP
:
562 // If we are emitting relocations these should be handled
564 gold_assert(!parameters
->options().relocatable()
565 && !parameters
->options().emit_relocs());
568 case elfcpp::SHT_PROGBITS
:
569 if (parameters
->options().strip_debug()
570 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
572 if (is_debug_info_section(name
))
575 if (parameters
->options().strip_debug_non_line()
576 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
578 // Debugging sections can only be recognized by name.
579 if (is_prefix_of(".debug", name
)
580 && !is_lines_only_debug_section(name
))
583 if (parameters
->options().strip_debug_gdb()
584 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
586 // Debugging sections can only be recognized by name.
587 if (is_prefix_of(".debug", name
)
588 && !is_gdb_debug_section(name
))
591 if (parameters
->options().strip_lto_sections()
592 && !parameters
->options().relocatable()
593 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
595 // Ignore LTO sections containing intermediate code.
596 if (is_prefix_of(".gnu.lto_", name
))
599 // The GNU linker strips .gnu_debuglink sections, so we do too.
600 // This is a feature used to keep debugging information in
602 if (strcmp(name
, ".gnu_debuglink") == 0)
611 // Return an output section named NAME, or NULL if there is none.
614 Layout::find_output_section(const char* name
) const
616 for (Section_list::const_iterator p
= this->section_list_
.begin();
617 p
!= this->section_list_
.end();
619 if (strcmp((*p
)->name(), name
) == 0)
624 // Return an output segment of type TYPE, with segment flags SET set
625 // and segment flags CLEAR clear. Return NULL if there is none.
628 Layout::find_output_segment(elfcpp::PT type
, elfcpp::Elf_Word set
,
629 elfcpp::Elf_Word clear
) const
631 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
632 p
!= this->segment_list_
.end();
634 if (static_cast<elfcpp::PT
>((*p
)->type()) == type
635 && ((*p
)->flags() & set
) == set
636 && ((*p
)->flags() & clear
) == 0)
641 // When we put a .ctors or .dtors section with more than one word into
642 // a .init_array or .fini_array section, we need to reverse the words
643 // in the .ctors/.dtors section. This is because .init_array executes
644 // constructors front to back, where .ctors executes them back to
645 // front, and vice-versa for .fini_array/.dtors. Although we do want
646 // to remap .ctors/.dtors into .init_array/.fini_array because it can
647 // be more efficient, we don't want to change the order in which
648 // constructors/destructors are run. This set just keeps track of
649 // these sections which need to be reversed. It is only changed by
650 // Layout::layout. It should be a private member of Layout, but that
651 // would require layout.h to #include object.h to get the definition
653 static Unordered_set
<Section_id
, Section_id_hash
> ctors_sections_in_init_array
;
655 // Return whether OBJECT/SHNDX is a .ctors/.dtors section mapped to a
656 // .init_array/.fini_array section.
659 Layout::is_ctors_in_init_array(Relobj
* relobj
, unsigned int shndx
) const
661 return (ctors_sections_in_init_array
.find(Section_id(relobj
, shndx
))
662 != ctors_sections_in_init_array
.end());
665 // Return the output section to use for section NAME with type TYPE
666 // and section flags FLAGS. NAME must be canonicalized in the string
667 // pool, and NAME_KEY is the key. ORDER is where this should appear
668 // in the output sections. IS_RELRO is true for a relro section.
671 Layout::get_output_section(const char* name
, Stringpool::Key name_key
,
672 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
673 Output_section_order order
, bool is_relro
)
675 elfcpp::Elf_Word lookup_type
= type
;
677 // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and
678 // PREINIT_ARRAY like PROGBITS. This ensures that we combine
679 // .init_array, .fini_array, and .preinit_array sections by name
680 // whatever their type in the input file. We do this because the
681 // types are not always right in the input files.
682 if (lookup_type
== elfcpp::SHT_INIT_ARRAY
683 || lookup_type
== elfcpp::SHT_FINI_ARRAY
684 || lookup_type
== elfcpp::SHT_PREINIT_ARRAY
)
685 lookup_type
= elfcpp::SHT_PROGBITS
;
687 elfcpp::Elf_Xword lookup_flags
= flags
;
689 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
690 // read-write with read-only sections. Some other ELF linkers do
691 // not do this. FIXME: Perhaps there should be an option
693 lookup_flags
&= ~(elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
695 const Key
key(name_key
, std::make_pair(lookup_type
, lookup_flags
));
696 const std::pair
<Key
, Output_section
*> v(key
, NULL
);
697 std::pair
<Section_name_map::iterator
, bool> ins(
698 this->section_name_map_
.insert(v
));
701 return ins
.first
->second
;
704 // This is the first time we've seen this name/type/flags
705 // combination. For compatibility with the GNU linker, we
706 // combine sections with contents and zero flags with sections
707 // with non-zero flags. This is a workaround for cases where
708 // assembler code forgets to set section flags. FIXME: Perhaps
709 // there should be an option to control this.
710 Output_section
* os
= NULL
;
712 if (lookup_type
== elfcpp::SHT_PROGBITS
)
716 Output_section
* same_name
= this->find_output_section(name
);
717 if (same_name
!= NULL
718 && (same_name
->type() == elfcpp::SHT_PROGBITS
719 || same_name
->type() == elfcpp::SHT_INIT_ARRAY
720 || same_name
->type() == elfcpp::SHT_FINI_ARRAY
721 || same_name
->type() == elfcpp::SHT_PREINIT_ARRAY
)
722 && (same_name
->flags() & elfcpp::SHF_TLS
) == 0)
725 else if ((flags
& elfcpp::SHF_TLS
) == 0)
727 elfcpp::Elf_Xword zero_flags
= 0;
728 const Key
zero_key(name_key
, std::make_pair(lookup_type
,
730 Section_name_map::iterator p
=
731 this->section_name_map_
.find(zero_key
);
732 if (p
!= this->section_name_map_
.end())
738 os
= this->make_output_section(name
, type
, flags
, order
, is_relro
);
740 ins
.first
->second
= os
;
745 // Pick the output section to use for section NAME, in input file
746 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
747 // linker created section. IS_INPUT_SECTION is true if we are
748 // choosing an output section for an input section found in a input
749 // file. ORDER is where this section should appear in the output
750 // sections. IS_RELRO is true for a relro section. This will return
751 // NULL if the input section should be discarded.
754 Layout::choose_output_section(const Relobj
* relobj
, const char* name
,
755 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
756 bool is_input_section
, Output_section_order order
,
759 // We should not see any input sections after we have attached
760 // sections to segments.
761 gold_assert(!is_input_section
|| !this->sections_are_attached_
);
763 // Some flags in the input section should not be automatically
764 // copied to the output section.
765 flags
&= ~ (elfcpp::SHF_INFO_LINK
768 | elfcpp::SHF_STRINGS
);
770 // We only clear the SHF_LINK_ORDER flag in for
771 // a non-relocatable link.
772 if (!parameters
->options().relocatable())
773 flags
&= ~elfcpp::SHF_LINK_ORDER
;
775 if (this->script_options_
->saw_sections_clause())
777 // We are using a SECTIONS clause, so the output section is
778 // chosen based only on the name.
780 Script_sections
* ss
= this->script_options_
->script_sections();
781 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
782 Output_section
** output_section_slot
;
783 Script_sections::Section_type script_section_type
;
784 const char* orig_name
= name
;
785 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
786 &script_section_type
);
789 gold_debug(DEBUG_SCRIPT
, _("Unable to create output section '%s' "
790 "because it is not allowed by the "
791 "SECTIONS clause of the linker script"),
793 // The SECTIONS clause says to discard this input section.
797 // We can only handle script section types ST_NONE and ST_NOLOAD.
798 switch (script_section_type
)
800 case Script_sections::ST_NONE
:
802 case Script_sections::ST_NOLOAD
:
803 flags
&= elfcpp::SHF_ALLOC
;
809 // If this is an orphan section--one not mentioned in the linker
810 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
811 // default processing below.
813 if (output_section_slot
!= NULL
)
815 if (*output_section_slot
!= NULL
)
817 (*output_section_slot
)->update_flags_for_input_section(flags
);
818 return *output_section_slot
;
821 // We don't put sections found in the linker script into
822 // SECTION_NAME_MAP_. That keeps us from getting confused
823 // if an orphan section is mapped to a section with the same
824 // name as one in the linker script.
826 name
= this->namepool_
.add(name
, false, NULL
);
828 Output_section
* os
= this->make_output_section(name
, type
, flags
,
831 os
->set_found_in_sections_clause();
833 // Special handling for NOLOAD sections.
834 if (script_section_type
== Script_sections::ST_NOLOAD
)
838 // The constructor of Output_section sets addresses of non-ALLOC
839 // sections to 0 by default. We don't want that for NOLOAD
840 // sections even if they have no SHF_ALLOC flag.
841 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0
842 && os
->is_address_valid())
844 gold_assert(os
->address() == 0
845 && !os
->is_offset_valid()
846 && !os
->is_data_size_valid());
847 os
->reset_address_and_file_offset();
851 *output_section_slot
= os
;
856 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
858 size_t len
= strlen(name
);
859 char* uncompressed_name
= NULL
;
861 // Compressed debug sections should be mapped to the corresponding
862 // uncompressed section.
863 if (is_compressed_debug_section(name
))
865 uncompressed_name
= new char[len
];
866 uncompressed_name
[0] = '.';
867 gold_assert(name
[0] == '.' && name
[1] == 'z');
868 strncpy(&uncompressed_name
[1], &name
[2], len
- 2);
869 uncompressed_name
[len
- 1] = '\0';
871 name
= uncompressed_name
;
874 // Turn NAME from the name of the input section into the name of the
877 && !this->script_options_
->saw_sections_clause()
878 && !parameters
->options().relocatable())
879 name
= Layout::output_section_name(relobj
, name
, &len
);
881 Stringpool::Key name_key
;
882 name
= this->namepool_
.add_with_length(name
, len
, true, &name_key
);
884 if (uncompressed_name
!= NULL
)
885 delete[] uncompressed_name
;
887 // Find or make the output section. The output section is selected
888 // based on the section name, type, and flags.
889 return this->get_output_section(name
, name_key
, type
, flags
, order
, is_relro
);
892 // For incremental links, record the initial fixed layout of a section
893 // from the base file, and return a pointer to the Output_section.
895 template<int size
, bool big_endian
>
897 Layout::init_fixed_output_section(const char* name
,
898 elfcpp::Shdr
<size
, big_endian
>& shdr
)
900 unsigned int sh_type
= shdr
.get_sh_type();
902 // We preserve the layout of PROGBITS, NOBITS, INIT_ARRAY, FINI_ARRAY,
903 // PRE_INIT_ARRAY, and NOTE sections.
904 // All others will be created from scratch and reallocated.
905 if (!can_incremental_update(sh_type
))
908 typename
elfcpp::Elf_types
<size
>::Elf_Addr sh_addr
= shdr
.get_sh_addr();
909 typename
elfcpp::Elf_types
<size
>::Elf_Off sh_offset
= shdr
.get_sh_offset();
910 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
911 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_flags
= shdr
.get_sh_flags();
912 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_addralign
=
913 shdr
.get_sh_addralign();
915 // Make the output section.
916 Stringpool::Key name_key
;
917 name
= this->namepool_
.add(name
, true, &name_key
);
918 Output_section
* os
= this->get_output_section(name
, name_key
, sh_type
,
919 sh_flags
, ORDER_INVALID
, false);
920 os
->set_fixed_layout(sh_addr
, sh_offset
, sh_size
, sh_addralign
);
921 if (sh_type
!= elfcpp::SHT_NOBITS
)
922 this->free_list_
.remove(sh_offset
, sh_offset
+ sh_size
);
926 // Return the output section to use for input section SHNDX, with name
927 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
928 // index of a relocation section which applies to this section, or 0
929 // if none, or -1U if more than one. RELOC_TYPE is the type of the
930 // relocation section if there is one. Set *OFF to the offset of this
931 // input section without the output section. Return NULL if the
932 // section should be discarded. Set *OFF to -1 if the section
933 // contents should not be written directly to the output file, but
934 // will instead receive special handling.
936 template<int size
, bool big_endian
>
938 Layout::layout(Sized_relobj_file
<size
, big_endian
>* object
, unsigned int shndx
,
939 const char* name
, const elfcpp::Shdr
<size
, big_endian
>& shdr
,
940 unsigned int reloc_shndx
, unsigned int, off_t
* off
)
944 if (!this->include_section(object
, name
, shdr
))
947 elfcpp::Elf_Word sh_type
= shdr
.get_sh_type();
949 // In a relocatable link a grouped section must not be combined with
950 // any other sections.
952 if (parameters
->options().relocatable()
953 && (shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) != 0)
955 name
= this->namepool_
.add(name
, true, NULL
);
956 os
= this->make_output_section(name
, sh_type
, shdr
.get_sh_flags(),
957 ORDER_INVALID
, false);
961 os
= this->choose_output_section(object
, name
, sh_type
,
962 shdr
.get_sh_flags(), true,
963 ORDER_INVALID
, false);
968 // By default the GNU linker sorts input sections whose names match
969 // .ctors.*, .dtors.*, .init_array.*, or .fini_array.*. The
970 // sections are sorted by name. This is used to implement
971 // constructor priority ordering. We are compatible. When we put
972 // .ctor sections in .init_array and .dtor sections in .fini_array,
973 // we must also sort plain .ctor and .dtor sections.
974 if (!this->script_options_
->saw_sections_clause()
975 && !parameters
->options().relocatable()
976 && (is_prefix_of(".ctors.", name
)
977 || is_prefix_of(".dtors.", name
)
978 || is_prefix_of(".init_array.", name
)
979 || is_prefix_of(".fini_array.", name
)
980 || (parameters
->options().ctors_in_init_array()
981 && (strcmp(name
, ".ctors") == 0
982 || strcmp(name
, ".dtors") == 0))))
983 os
->set_must_sort_attached_input_sections();
985 // If this is a .ctors or .ctors.* section being mapped to a
986 // .init_array section, or a .dtors or .dtors.* section being mapped
987 // to a .fini_array section, we will need to reverse the words if
988 // there is more than one. Record this section for later. See
989 // ctors_sections_in_init_array above.
990 if (!this->script_options_
->saw_sections_clause()
991 && !parameters
->options().relocatable()
992 && shdr
.get_sh_size() > size
/ 8
993 && (((strcmp(name
, ".ctors") == 0
994 || is_prefix_of(".ctors.", name
))
995 && strcmp(os
->name(), ".init_array") == 0)
996 || ((strcmp(name
, ".dtors") == 0
997 || is_prefix_of(".dtors.", name
))
998 && strcmp(os
->name(), ".fini_array") == 0)))
999 ctors_sections_in_init_array
.insert(Section_id(object
, shndx
));
1001 // FIXME: Handle SHF_LINK_ORDER somewhere.
1003 elfcpp::Elf_Xword orig_flags
= os
->flags();
1005 *off
= os
->add_input_section(this, object
, shndx
, name
, shdr
, reloc_shndx
,
1006 this->script_options_
->saw_sections_clause());
1008 // If the flags changed, we may have to change the order.
1009 if ((orig_flags
& elfcpp::SHF_ALLOC
) != 0)
1011 orig_flags
&= (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1012 elfcpp::Elf_Xword new_flags
=
1013 os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1014 if (orig_flags
!= new_flags
)
1015 os
->set_order(this->default_section_order(os
, false));
1018 this->have_added_input_section_
= true;
1023 // Handle a relocation section when doing a relocatable link.
1025 template<int size
, bool big_endian
>
1027 Layout::layout_reloc(Sized_relobj_file
<size
, big_endian
>* object
,
1029 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1030 Output_section
* data_section
,
1031 Relocatable_relocs
* rr
)
1033 gold_assert(parameters
->options().relocatable()
1034 || parameters
->options().emit_relocs());
1036 int sh_type
= shdr
.get_sh_type();
1039 if (sh_type
== elfcpp::SHT_REL
)
1041 else if (sh_type
== elfcpp::SHT_RELA
)
1045 name
+= data_section
->name();
1047 // In a relocatable link relocs for a grouped section must not be
1048 // combined with other reloc sections.
1050 if (!parameters
->options().relocatable()
1051 || (data_section
->flags() & elfcpp::SHF_GROUP
) == 0)
1052 os
= this->choose_output_section(object
, name
.c_str(), sh_type
,
1053 shdr
.get_sh_flags(), false,
1054 ORDER_INVALID
, false);
1057 const char* n
= this->namepool_
.add(name
.c_str(), true, NULL
);
1058 os
= this->make_output_section(n
, sh_type
, shdr
.get_sh_flags(),
1059 ORDER_INVALID
, false);
1062 os
->set_should_link_to_symtab();
1063 os
->set_info_section(data_section
);
1065 Output_section_data
* posd
;
1066 if (sh_type
== elfcpp::SHT_REL
)
1068 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rel_size
);
1069 posd
= new Output_relocatable_relocs
<elfcpp::SHT_REL
,
1073 else if (sh_type
== elfcpp::SHT_RELA
)
1075 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rela_size
);
1076 posd
= new Output_relocatable_relocs
<elfcpp::SHT_RELA
,
1083 os
->add_output_section_data(posd
);
1084 rr
->set_output_data(posd
);
1089 // Handle a group section when doing a relocatable link.
1091 template<int size
, bool big_endian
>
1093 Layout::layout_group(Symbol_table
* symtab
,
1094 Sized_relobj_file
<size
, big_endian
>* object
,
1096 const char* group_section_name
,
1097 const char* signature
,
1098 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1099 elfcpp::Elf_Word flags
,
1100 std::vector
<unsigned int>* shndxes
)
1102 gold_assert(parameters
->options().relocatable());
1103 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_GROUP
);
1104 group_section_name
= this->namepool_
.add(group_section_name
, true, NULL
);
1105 Output_section
* os
= this->make_output_section(group_section_name
,
1107 shdr
.get_sh_flags(),
1108 ORDER_INVALID
, false);
1110 // We need to find a symbol with the signature in the symbol table.
1111 // If we don't find one now, we need to look again later.
1112 Symbol
* sym
= symtab
->lookup(signature
, NULL
);
1114 os
->set_info_symndx(sym
);
1117 // Reserve some space to minimize reallocations.
1118 if (this->group_signatures_
.empty())
1119 this->group_signatures_
.reserve(this->number_of_input_files_
* 16);
1121 // We will wind up using a symbol whose name is the signature.
1122 // So just put the signature in the symbol name pool to save it.
1123 signature
= symtab
->canonicalize_name(signature
);
1124 this->group_signatures_
.push_back(Group_signature(os
, signature
));
1127 os
->set_should_link_to_symtab();
1130 section_size_type entry_count
=
1131 convert_to_section_size_type(shdr
.get_sh_size() / 4);
1132 Output_section_data
* posd
=
1133 new Output_data_group
<size
, big_endian
>(object
, entry_count
, flags
,
1135 os
->add_output_section_data(posd
);
1138 // Special GNU handling of sections name .eh_frame. They will
1139 // normally hold exception frame data as defined by the C++ ABI
1140 // (http://codesourcery.com/cxx-abi/).
1142 template<int size
, bool big_endian
>
1144 Layout::layout_eh_frame(Sized_relobj_file
<size
, big_endian
>* object
,
1145 const unsigned char* symbols
,
1147 const unsigned char* symbol_names
,
1148 off_t symbol_names_size
,
1150 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1151 unsigned int reloc_shndx
, unsigned int reloc_type
,
1154 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
1155 || shdr
.get_sh_type() == elfcpp::SHT_X86_64_UNWIND
);
1156 gold_assert((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
1158 Output_section
* os
= this->make_eh_frame_section(object
);
1162 gold_assert(this->eh_frame_section_
== os
);
1164 elfcpp::Elf_Xword orig_flags
= os
->flags();
1166 if (!parameters
->incremental()
1167 && this->eh_frame_data_
->add_ehframe_input_section(object
,
1176 os
->update_flags_for_input_section(shdr
.get_sh_flags());
1178 // A writable .eh_frame section is a RELRO section.
1179 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1180 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1183 os
->set_order(ORDER_RELRO
);
1186 // We found a .eh_frame section we are going to optimize, so now
1187 // we can add the set of optimized sections to the output
1188 // section. We need to postpone adding this until we've found a
1189 // section we can optimize so that the .eh_frame section in
1190 // crtbegin.o winds up at the start of the output section.
1191 if (!this->added_eh_frame_data_
)
1193 os
->add_output_section_data(this->eh_frame_data_
);
1194 this->added_eh_frame_data_
= true;
1200 // We couldn't handle this .eh_frame section for some reason.
1201 // Add it as a normal section.
1202 bool saw_sections_clause
= this->script_options_
->saw_sections_clause();
1203 *off
= os
->add_input_section(this, object
, shndx
, ".eh_frame", shdr
,
1204 reloc_shndx
, saw_sections_clause
);
1205 this->have_added_input_section_
= true;
1207 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1208 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1209 os
->set_order(this->default_section_order(os
, false));
1215 // Create and return the magic .eh_frame section. Create
1216 // .eh_frame_hdr also if appropriate. OBJECT is the object with the
1217 // input .eh_frame section; it may be NULL.
1220 Layout::make_eh_frame_section(const Relobj
* object
)
1222 // FIXME: On x86_64, this could use SHT_X86_64_UNWIND rather than
1224 Output_section
* os
= this->choose_output_section(object
, ".eh_frame",
1225 elfcpp::SHT_PROGBITS
,
1226 elfcpp::SHF_ALLOC
, false,
1227 ORDER_EHFRAME
, false);
1231 if (this->eh_frame_section_
== NULL
)
1233 this->eh_frame_section_
= os
;
1234 this->eh_frame_data_
= new Eh_frame();
1236 // For incremental linking, we do not optimize .eh_frame sections
1237 // or create a .eh_frame_hdr section.
1238 if (parameters
->options().eh_frame_hdr() && !parameters
->incremental())
1240 Output_section
* hdr_os
=
1241 this->choose_output_section(NULL
, ".eh_frame_hdr",
1242 elfcpp::SHT_PROGBITS
,
1243 elfcpp::SHF_ALLOC
, false,
1244 ORDER_EHFRAME
, false);
1248 Eh_frame_hdr
* hdr_posd
= new Eh_frame_hdr(os
,
1249 this->eh_frame_data_
);
1250 hdr_os
->add_output_section_data(hdr_posd
);
1252 hdr_os
->set_after_input_sections();
1254 if (!this->script_options_
->saw_phdrs_clause())
1256 Output_segment
* hdr_oseg
;
1257 hdr_oseg
= this->make_output_segment(elfcpp::PT_GNU_EH_FRAME
,
1259 hdr_oseg
->add_output_section_to_nonload(hdr_os
,
1263 this->eh_frame_data_
->set_eh_frame_hdr(hdr_posd
);
1271 // Add an exception frame for a PLT. This is called from target code.
1274 Layout::add_eh_frame_for_plt(Output_data
* plt
, const unsigned char* cie_data
,
1275 size_t cie_length
, const unsigned char* fde_data
,
1278 if (parameters
->incremental())
1280 // FIXME: Maybe this could work some day....
1283 Output_section
* os
= this->make_eh_frame_section(NULL
);
1286 this->eh_frame_data_
->add_ehframe_for_plt(plt
, cie_data
, cie_length
,
1287 fde_data
, fde_length
);
1288 if (!this->added_eh_frame_data_
)
1290 os
->add_output_section_data(this->eh_frame_data_
);
1291 this->added_eh_frame_data_
= true;
1295 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
1296 // the output section.
1299 Layout::add_output_section_data(const char* name
, elfcpp::Elf_Word type
,
1300 elfcpp::Elf_Xword flags
,
1301 Output_section_data
* posd
,
1302 Output_section_order order
, bool is_relro
)
1304 Output_section
* os
= this->choose_output_section(NULL
, name
, type
, flags
,
1305 false, order
, is_relro
);
1307 os
->add_output_section_data(posd
);
1311 // Map section flags to segment flags.
1314 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags
)
1316 elfcpp::Elf_Word ret
= elfcpp::PF_R
;
1317 if ((flags
& elfcpp::SHF_WRITE
) != 0)
1318 ret
|= elfcpp::PF_W
;
1319 if ((flags
& elfcpp::SHF_EXECINSTR
) != 0)
1320 ret
|= elfcpp::PF_X
;
1324 // Make a new Output_section, and attach it to segments as
1325 // appropriate. ORDER is the order in which this section should
1326 // appear in the output segment. IS_RELRO is true if this is a relro
1327 // (read-only after relocations) section.
1330 Layout::make_output_section(const char* name
, elfcpp::Elf_Word type
,
1331 elfcpp::Elf_Xword flags
,
1332 Output_section_order order
, bool is_relro
)
1335 if ((flags
& elfcpp::SHF_ALLOC
) == 0
1336 && strcmp(parameters
->options().compress_debug_sections(), "none") != 0
1337 && is_compressible_debug_section(name
))
1338 os
= new Output_compressed_section(¶meters
->options(), name
, type
,
1340 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1341 && parameters
->options().strip_debug_non_line()
1342 && strcmp(".debug_abbrev", name
) == 0)
1344 os
= this->debug_abbrev_
= new Output_reduced_debug_abbrev_section(
1346 if (this->debug_info_
)
1347 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1349 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1350 && parameters
->options().strip_debug_non_line()
1351 && strcmp(".debug_info", name
) == 0)
1353 os
= this->debug_info_
= new Output_reduced_debug_info_section(
1355 if (this->debug_abbrev_
)
1356 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1360 // Sometimes .init_array*, .preinit_array* and .fini_array* do
1361 // not have correct section types. Force them here.
1362 if (type
== elfcpp::SHT_PROGBITS
)
1364 if (is_prefix_of(".init_array", name
))
1365 type
= elfcpp::SHT_INIT_ARRAY
;
1366 else if (is_prefix_of(".preinit_array", name
))
1367 type
= elfcpp::SHT_PREINIT_ARRAY
;
1368 else if (is_prefix_of(".fini_array", name
))
1369 type
= elfcpp::SHT_FINI_ARRAY
;
1372 // FIXME: const_cast is ugly.
1373 Target
* target
= const_cast<Target
*>(¶meters
->target());
1374 os
= target
->make_output_section(name
, type
, flags
);
1377 // With -z relro, we have to recognize the special sections by name.
1378 // There is no other way.
1379 bool is_relro_local
= false;
1380 if (!this->script_options_
->saw_sections_clause()
1381 && parameters
->options().relro()
1382 && (flags
& elfcpp::SHF_ALLOC
) != 0
1383 && (flags
& elfcpp::SHF_WRITE
) != 0)
1385 if (type
== elfcpp::SHT_PROGBITS
)
1387 if (strcmp(name
, ".data.rel.ro") == 0)
1389 else if (strcmp(name
, ".data.rel.ro.local") == 0)
1392 is_relro_local
= true;
1394 else if (strcmp(name
, ".ctors") == 0
1395 || strcmp(name
, ".dtors") == 0
1396 || strcmp(name
, ".jcr") == 0)
1399 else if (type
== elfcpp::SHT_INIT_ARRAY
1400 || type
== elfcpp::SHT_FINI_ARRAY
1401 || type
== elfcpp::SHT_PREINIT_ARRAY
)
1408 if (order
== ORDER_INVALID
&& (flags
& elfcpp::SHF_ALLOC
) != 0)
1409 order
= this->default_section_order(os
, is_relro_local
);
1411 os
->set_order(order
);
1413 parameters
->target().new_output_section(os
);
1415 this->section_list_
.push_back(os
);
1417 // The GNU linker by default sorts some sections by priority, so we
1418 // do the same. We need to know that this might happen before we
1419 // attach any input sections.
1420 if (!this->script_options_
->saw_sections_clause()
1421 && !parameters
->options().relocatable()
1422 && (strcmp(name
, ".init_array") == 0
1423 || strcmp(name
, ".fini_array") == 0
1424 || (!parameters
->options().ctors_in_init_array()
1425 && (strcmp(name
, ".ctors") == 0
1426 || strcmp(name
, ".dtors") == 0))))
1427 os
->set_may_sort_attached_input_sections();
1429 // Check for .stab*str sections, as .stab* sections need to link to
1431 if (type
== elfcpp::SHT_STRTAB
1432 && !this->have_stabstr_section_
1433 && strncmp(name
, ".stab", 5) == 0
1434 && strcmp(name
+ strlen(name
) - 3, "str") == 0)
1435 this->have_stabstr_section_
= true;
1437 // During a full incremental link, we add patch space to most
1438 // PROGBITS and NOBITS sections. Flag those that may be
1439 // arbitrarily padded.
1440 if ((type
== elfcpp::SHT_PROGBITS
|| type
== elfcpp::SHT_NOBITS
)
1441 && order
!= ORDER_INTERP
1442 && order
!= ORDER_INIT
1443 && order
!= ORDER_PLT
1444 && order
!= ORDER_FINI
1445 && order
!= ORDER_RELRO_LAST
1446 && order
!= ORDER_NON_RELRO_FIRST
1447 && strcmp(name
, ".eh_frame") != 0
1448 && strcmp(name
, ".ctors") != 0
1449 && strcmp(name
, ".dtors") != 0
1450 && strcmp(name
, ".jcr") != 0)
1452 os
->set_is_patch_space_allowed();
1454 // Certain sections require "holes" to be filled with
1455 // specific fill patterns. These fill patterns may have
1456 // a minimum size, so we must prevent allocations from the
1457 // free list that leave a hole smaller than the minimum.
1458 if (strcmp(name
, ".debug_info") == 0)
1459 os
->set_free_space_fill(new Output_fill_debug_info(false));
1460 else if (strcmp(name
, ".debug_types") == 0)
1461 os
->set_free_space_fill(new Output_fill_debug_info(true));
1462 else if (strcmp(name
, ".debug_line") == 0)
1463 os
->set_free_space_fill(new Output_fill_debug_line());
1466 // If we have already attached the sections to segments, then we
1467 // need to attach this one now. This happens for sections created
1468 // directly by the linker.
1469 if (this->sections_are_attached_
)
1470 this->attach_section_to_segment(os
);
1475 // Return the default order in which a section should be placed in an
1476 // output segment. This function captures a lot of the ideas in
1477 // ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
1478 // linker created section is normally set when the section is created;
1479 // this function is used for input sections.
1481 Output_section_order
1482 Layout::default_section_order(Output_section
* os
, bool is_relro_local
)
1484 gold_assert((os
->flags() & elfcpp::SHF_ALLOC
) != 0);
1485 bool is_write
= (os
->flags() & elfcpp::SHF_WRITE
) != 0;
1486 bool is_execinstr
= (os
->flags() & elfcpp::SHF_EXECINSTR
) != 0;
1487 bool is_bss
= false;
1492 case elfcpp::SHT_PROGBITS
:
1494 case elfcpp::SHT_NOBITS
:
1497 case elfcpp::SHT_RELA
:
1498 case elfcpp::SHT_REL
:
1500 return ORDER_DYNAMIC_RELOCS
;
1502 case elfcpp::SHT_HASH
:
1503 case elfcpp::SHT_DYNAMIC
:
1504 case elfcpp::SHT_SHLIB
:
1505 case elfcpp::SHT_DYNSYM
:
1506 case elfcpp::SHT_GNU_HASH
:
1507 case elfcpp::SHT_GNU_verdef
:
1508 case elfcpp::SHT_GNU_verneed
:
1509 case elfcpp::SHT_GNU_versym
:
1511 return ORDER_DYNAMIC_LINKER
;
1513 case elfcpp::SHT_NOTE
:
1514 return is_write
? ORDER_RW_NOTE
: ORDER_RO_NOTE
;
1517 if ((os
->flags() & elfcpp::SHF_TLS
) != 0)
1518 return is_bss
? ORDER_TLS_BSS
: ORDER_TLS_DATA
;
1520 if (!is_bss
&& !is_write
)
1524 if (strcmp(os
->name(), ".init") == 0)
1526 else if (strcmp(os
->name(), ".fini") == 0)
1529 return is_execinstr
? ORDER_TEXT
: ORDER_READONLY
;
1533 return is_relro_local
? ORDER_RELRO_LOCAL
: ORDER_RELRO
;
1535 if (os
->is_small_section())
1536 return is_bss
? ORDER_SMALL_BSS
: ORDER_SMALL_DATA
;
1537 if (os
->is_large_section())
1538 return is_bss
? ORDER_LARGE_BSS
: ORDER_LARGE_DATA
;
1540 return is_bss
? ORDER_BSS
: ORDER_DATA
;
1543 // Attach output sections to segments. This is called after we have
1544 // seen all the input sections.
1547 Layout::attach_sections_to_segments()
1549 for (Section_list::iterator p
= this->section_list_
.begin();
1550 p
!= this->section_list_
.end();
1552 this->attach_section_to_segment(*p
);
1554 this->sections_are_attached_
= true;
1557 // Attach an output section to a segment.
1560 Layout::attach_section_to_segment(Output_section
* os
)
1562 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0)
1563 this->unattached_section_list_
.push_back(os
);
1565 this->attach_allocated_section_to_segment(os
);
1568 // Attach an allocated output section to a segment.
1571 Layout::attach_allocated_section_to_segment(Output_section
* os
)
1573 elfcpp::Elf_Xword flags
= os
->flags();
1574 gold_assert((flags
& elfcpp::SHF_ALLOC
) != 0);
1576 if (parameters
->options().relocatable())
1579 // If we have a SECTIONS clause, we can't handle the attachment to
1580 // segments until after we've seen all the sections.
1581 if (this->script_options_
->saw_sections_clause())
1584 gold_assert(!this->script_options_
->saw_phdrs_clause());
1586 // This output section goes into a PT_LOAD segment.
1588 elfcpp::Elf_Word seg_flags
= Layout::section_flags_to_segment(flags
);
1590 // Check for --section-start.
1592 bool is_address_set
= parameters
->options().section_start(os
->name(), &addr
);
1594 // In general the only thing we really care about for PT_LOAD
1595 // segments is whether or not they are writable or executable,
1596 // so that is how we search for them.
1597 // Large data sections also go into their own PT_LOAD segment.
1598 // People who need segments sorted on some other basis will
1599 // have to use a linker script.
1601 Segment_list::const_iterator p
;
1602 for (p
= this->segment_list_
.begin();
1603 p
!= this->segment_list_
.end();
1606 if ((*p
)->type() != elfcpp::PT_LOAD
)
1608 if (!parameters
->options().omagic()
1609 && ((*p
)->flags() & elfcpp::PF_W
) != (seg_flags
& elfcpp::PF_W
))
1611 if (parameters
->options().rosegment()
1612 && ((*p
)->flags() & elfcpp::PF_X
) != (seg_flags
& elfcpp::PF_X
))
1614 // If -Tbss was specified, we need to separate the data and BSS
1616 if (parameters
->options().user_set_Tbss())
1618 if ((os
->type() == elfcpp::SHT_NOBITS
)
1619 == (*p
)->has_any_data_sections())
1622 if (os
->is_large_data_section() && !(*p
)->is_large_data_segment())
1627 if ((*p
)->are_addresses_set())
1630 (*p
)->add_initial_output_data(os
);
1631 (*p
)->update_flags_for_output_section(seg_flags
);
1632 (*p
)->set_addresses(addr
, addr
);
1636 (*p
)->add_output_section_to_load(this, os
, seg_flags
);
1640 if (p
== this->segment_list_
.end())
1642 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_LOAD
,
1644 if (os
->is_large_data_section())
1645 oseg
->set_is_large_data_segment();
1646 oseg
->add_output_section_to_load(this, os
, seg_flags
);
1648 oseg
->set_addresses(addr
, addr
);
1651 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1653 if (os
->type() == elfcpp::SHT_NOTE
)
1655 // See if we already have an equivalent PT_NOTE segment.
1656 for (p
= this->segment_list_
.begin();
1657 p
!= segment_list_
.end();
1660 if ((*p
)->type() == elfcpp::PT_NOTE
1661 && (((*p
)->flags() & elfcpp::PF_W
)
1662 == (seg_flags
& elfcpp::PF_W
)))
1664 (*p
)->add_output_section_to_nonload(os
, seg_flags
);
1669 if (p
== this->segment_list_
.end())
1671 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_NOTE
,
1673 oseg
->add_output_section_to_nonload(os
, seg_flags
);
1677 // If we see a loadable SHF_TLS section, we create a PT_TLS
1678 // segment. There can only be one such segment.
1679 if ((flags
& elfcpp::SHF_TLS
) != 0)
1681 if (this->tls_segment_
== NULL
)
1682 this->make_output_segment(elfcpp::PT_TLS
, seg_flags
);
1683 this->tls_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1686 // If -z relro is in effect, and we see a relro section, we create a
1687 // PT_GNU_RELRO segment. There can only be one such segment.
1688 if (os
->is_relro() && parameters
->options().relro())
1690 gold_assert(seg_flags
== (elfcpp::PF_R
| elfcpp::PF_W
));
1691 if (this->relro_segment_
== NULL
)
1692 this->make_output_segment(elfcpp::PT_GNU_RELRO
, seg_flags
);
1693 this->relro_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1696 // If we see a section named .interp, put it into a PT_INTERP
1697 // segment. This seems broken to me, but this is what GNU ld does,
1698 // and glibc expects it.
1699 if (strcmp(os
->name(), ".interp") == 0
1700 && !this->script_options_
->saw_phdrs_clause())
1702 if (this->interp_segment_
== NULL
)
1703 this->make_output_segment(elfcpp::PT_INTERP
, seg_flags
);
1705 gold_warning(_("multiple '.interp' sections in input files "
1706 "may cause confusing PT_INTERP segment"));
1707 this->interp_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1711 // Make an output section for a script.
1714 Layout::make_output_section_for_script(
1716 Script_sections::Section_type section_type
)
1718 name
= this->namepool_
.add(name
, false, NULL
);
1719 elfcpp::Elf_Xword sh_flags
= elfcpp::SHF_ALLOC
;
1720 if (section_type
== Script_sections::ST_NOLOAD
)
1722 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_PROGBITS
,
1723 sh_flags
, ORDER_INVALID
,
1725 os
->set_found_in_sections_clause();
1726 if (section_type
== Script_sections::ST_NOLOAD
)
1727 os
->set_is_noload();
1731 // Return the number of segments we expect to see.
1734 Layout::expected_segment_count() const
1736 size_t ret
= this->segment_list_
.size();
1738 // If we didn't see a SECTIONS clause in a linker script, we should
1739 // already have the complete list of segments. Otherwise we ask the
1740 // SECTIONS clause how many segments it expects, and add in the ones
1741 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1743 if (!this->script_options_
->saw_sections_clause())
1747 const Script_sections
* ss
= this->script_options_
->script_sections();
1748 return ret
+ ss
->expected_segment_count(this);
1752 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
1753 // is whether we saw a .note.GNU-stack section in the object file.
1754 // GNU_STACK_FLAGS is the section flags. The flags give the
1755 // protection required for stack memory. We record this in an
1756 // executable as a PT_GNU_STACK segment. If an object file does not
1757 // have a .note.GNU-stack segment, we must assume that it is an old
1758 // object. On some targets that will force an executable stack.
1761 Layout::layout_gnu_stack(bool seen_gnu_stack
, uint64_t gnu_stack_flags
,
1764 if (!seen_gnu_stack
)
1766 this->input_without_gnu_stack_note_
= true;
1767 if (parameters
->options().warn_execstack()
1768 && parameters
->target().is_default_stack_executable())
1769 gold_warning(_("%s: missing .note.GNU-stack section"
1770 " implies executable stack"),
1771 obj
->name().c_str());
1775 this->input_with_gnu_stack_note_
= true;
1776 if ((gnu_stack_flags
& elfcpp::SHF_EXECINSTR
) != 0)
1778 this->input_requires_executable_stack_
= true;
1779 if (parameters
->options().warn_execstack()
1780 || parameters
->options().is_stack_executable())
1781 gold_warning(_("%s: requires executable stack"),
1782 obj
->name().c_str());
1787 // Create automatic note sections.
1790 Layout::create_notes()
1792 this->create_gold_note();
1793 this->create_executable_stack_info();
1794 this->create_build_id();
1797 // Create the dynamic sections which are needed before we read the
1801 Layout::create_initial_dynamic_sections(Symbol_table
* symtab
)
1803 if (parameters
->doing_static_link())
1806 this->dynamic_section_
= this->choose_output_section(NULL
, ".dynamic",
1807 elfcpp::SHT_DYNAMIC
,
1809 | elfcpp::SHF_WRITE
),
1813 // A linker script may discard .dynamic, so check for NULL.
1814 if (this->dynamic_section_
!= NULL
)
1816 this->dynamic_symbol_
=
1817 symtab
->define_in_output_data("_DYNAMIC", NULL
,
1818 Symbol_table::PREDEFINED
,
1819 this->dynamic_section_
, 0, 0,
1820 elfcpp::STT_OBJECT
, elfcpp::STB_LOCAL
,
1821 elfcpp::STV_HIDDEN
, 0, false, false);
1823 this->dynamic_data_
= new Output_data_dynamic(&this->dynpool_
);
1825 this->dynamic_section_
->add_output_section_data(this->dynamic_data_
);
1829 // For each output section whose name can be represented as C symbol,
1830 // define __start and __stop symbols for the section. This is a GNU
1834 Layout::define_section_symbols(Symbol_table
* symtab
)
1836 for (Section_list::const_iterator p
= this->section_list_
.begin();
1837 p
!= this->section_list_
.end();
1840 const char* const name
= (*p
)->name();
1841 if (is_cident(name
))
1843 const std::string
name_string(name
);
1844 const std::string
start_name(cident_section_start_prefix
1846 const std::string
stop_name(cident_section_stop_prefix
1849 symtab
->define_in_output_data(start_name
.c_str(),
1851 Symbol_table::PREDEFINED
,
1857 elfcpp::STV_DEFAULT
,
1859 false, // offset_is_from_end
1860 true); // only_if_ref
1862 symtab
->define_in_output_data(stop_name
.c_str(),
1864 Symbol_table::PREDEFINED
,
1870 elfcpp::STV_DEFAULT
,
1872 true, // offset_is_from_end
1873 true); // only_if_ref
1878 // Define symbols for group signatures.
1881 Layout::define_group_signatures(Symbol_table
* symtab
)
1883 for (Group_signatures::iterator p
= this->group_signatures_
.begin();
1884 p
!= this->group_signatures_
.end();
1887 Symbol
* sym
= symtab
->lookup(p
->signature
, NULL
);
1889 p
->section
->set_info_symndx(sym
);
1892 // Force the name of the group section to the group
1893 // signature, and use the group's section symbol as the
1894 // signature symbol.
1895 if (strcmp(p
->section
->name(), p
->signature
) != 0)
1897 const char* name
= this->namepool_
.add(p
->signature
,
1899 p
->section
->set_name(name
);
1901 p
->section
->set_needs_symtab_index();
1902 p
->section
->set_info_section_symndx(p
->section
);
1906 this->group_signatures_
.clear();
1909 // Find the first read-only PT_LOAD segment, creating one if
1913 Layout::find_first_load_seg()
1915 Output_segment
* best
= NULL
;
1916 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
1917 p
!= this->segment_list_
.end();
1920 if ((*p
)->type() == elfcpp::PT_LOAD
1921 && ((*p
)->flags() & elfcpp::PF_R
) != 0
1922 && (parameters
->options().omagic()
1923 || ((*p
)->flags() & elfcpp::PF_W
) == 0))
1925 if (best
== NULL
|| this->segment_precedes(*p
, best
))
1932 gold_assert(!this->script_options_
->saw_phdrs_clause());
1934 Output_segment
* load_seg
= this->make_output_segment(elfcpp::PT_LOAD
,
1939 // Save states of all current output segments. Store saved states
1940 // in SEGMENT_STATES.
1943 Layout::save_segments(Segment_states
* segment_states
)
1945 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
1946 p
!= this->segment_list_
.end();
1949 Output_segment
* segment
= *p
;
1951 Output_segment
* copy
= new Output_segment(*segment
);
1952 (*segment_states
)[segment
] = copy
;
1956 // Restore states of output segments and delete any segment not found in
1960 Layout::restore_segments(const Segment_states
* segment_states
)
1962 // Go through the segment list and remove any segment added in the
1964 this->tls_segment_
= NULL
;
1965 this->relro_segment_
= NULL
;
1966 Segment_list::iterator list_iter
= this->segment_list_
.begin();
1967 while (list_iter
!= this->segment_list_
.end())
1969 Output_segment
* segment
= *list_iter
;
1970 Segment_states::const_iterator states_iter
=
1971 segment_states
->find(segment
);
1972 if (states_iter
!= segment_states
->end())
1974 const Output_segment
* copy
= states_iter
->second
;
1975 // Shallow copy to restore states.
1978 // Also fix up TLS and RELRO segment pointers as appropriate.
1979 if (segment
->type() == elfcpp::PT_TLS
)
1980 this->tls_segment_
= segment
;
1981 else if (segment
->type() == elfcpp::PT_GNU_RELRO
)
1982 this->relro_segment_
= segment
;
1988 list_iter
= this->segment_list_
.erase(list_iter
);
1989 // This is a segment created during section layout. It should be
1990 // safe to remove it since we should have removed all pointers to it.
1996 // Clean up after relaxation so that sections can be laid out again.
1999 Layout::clean_up_after_relaxation()
2001 // Restore the segments to point state just prior to the relaxation loop.
2002 Script_sections
* script_section
= this->script_options_
->script_sections();
2003 script_section
->release_segments();
2004 this->restore_segments(this->segment_states_
);
2006 // Reset section addresses and file offsets
2007 for (Section_list::iterator p
= this->section_list_
.begin();
2008 p
!= this->section_list_
.end();
2011 (*p
)->restore_states();
2013 // If an input section changes size because of relaxation,
2014 // we need to adjust the section offsets of all input sections.
2015 // after such a section.
2016 if ((*p
)->section_offsets_need_adjustment())
2017 (*p
)->adjust_section_offsets();
2019 (*p
)->reset_address_and_file_offset();
2022 // Reset special output object address and file offsets.
2023 for (Data_list::iterator p
= this->special_output_list_
.begin();
2024 p
!= this->special_output_list_
.end();
2026 (*p
)->reset_address_and_file_offset();
2028 // A linker script may have created some output section data objects.
2029 // They are useless now.
2030 for (Output_section_data_list::const_iterator p
=
2031 this->script_output_section_data_list_
.begin();
2032 p
!= this->script_output_section_data_list_
.end();
2035 this->script_output_section_data_list_
.clear();
2038 // Prepare for relaxation.
2041 Layout::prepare_for_relaxation()
2043 // Create an relaxation debug check if in debugging mode.
2044 if (is_debugging_enabled(DEBUG_RELAXATION
))
2045 this->relaxation_debug_check_
= new Relaxation_debug_check();
2047 // Save segment states.
2048 this->segment_states_
= new Segment_states();
2049 this->save_segments(this->segment_states_
);
2051 for(Section_list::const_iterator p
= this->section_list_
.begin();
2052 p
!= this->section_list_
.end();
2054 (*p
)->save_states();
2056 if (is_debugging_enabled(DEBUG_RELAXATION
))
2057 this->relaxation_debug_check_
->check_output_data_for_reset_values(
2058 this->section_list_
, this->special_output_list_
);
2060 // Also enable recording of output section data from scripts.
2061 this->record_output_section_data_from_script_
= true;
2064 // Relaxation loop body: If target has no relaxation, this runs only once
2065 // Otherwise, the target relaxation hook is called at the end of
2066 // each iteration. If the hook returns true, it means re-layout of
2067 // section is required.
2069 // The number of segments created by a linking script without a PHDRS
2070 // clause may be affected by section sizes and alignments. There is
2071 // a remote chance that relaxation causes different number of PT_LOAD
2072 // segments are created and sections are attached to different segments.
2073 // Therefore, we always throw away all segments created during section
2074 // layout. In order to be able to restart the section layout, we keep
2075 // a copy of the segment list right before the relaxation loop and use
2076 // that to restore the segments.
2078 // PASS is the current relaxation pass number.
2079 // SYMTAB is a symbol table.
2080 // PLOAD_SEG is the address of a pointer for the load segment.
2081 // PHDR_SEG is a pointer to the PHDR segment.
2082 // SEGMENT_HEADERS points to the output segment header.
2083 // FILE_HEADER points to the output file header.
2084 // PSHNDX is the address to store the output section index.
2087 Layout::relaxation_loop_body(
2090 Symbol_table
* symtab
,
2091 Output_segment
** pload_seg
,
2092 Output_segment
* phdr_seg
,
2093 Output_segment_headers
* segment_headers
,
2094 Output_file_header
* file_header
,
2095 unsigned int* pshndx
)
2097 // If this is not the first iteration, we need to clean up after
2098 // relaxation so that we can lay out the sections again.
2100 this->clean_up_after_relaxation();
2102 // If there is a SECTIONS clause, put all the input sections into
2103 // the required order.
2104 Output_segment
* load_seg
;
2105 if (this->script_options_
->saw_sections_clause())
2106 load_seg
= this->set_section_addresses_from_script(symtab
);
2107 else if (parameters
->options().relocatable())
2110 load_seg
= this->find_first_load_seg();
2112 if (parameters
->options().oformat_enum()
2113 != General_options::OBJECT_FORMAT_ELF
)
2116 // If the user set the address of the text segment, that may not be
2117 // compatible with putting the segment headers and file headers into
2119 if (parameters
->options().user_set_Ttext()
2120 && parameters
->options().Ttext() % target
->common_pagesize() != 0)
2126 gold_assert(phdr_seg
== NULL
2128 || this->script_options_
->saw_sections_clause());
2130 // If the address of the load segment we found has been set by
2131 // --section-start rather than by a script, then adjust the VMA and
2132 // LMA downward if possible to include the file and section headers.
2133 uint64_t header_gap
= 0;
2134 if (load_seg
!= NULL
2135 && load_seg
->are_addresses_set()
2136 && !this->script_options_
->saw_sections_clause()
2137 && !parameters
->options().relocatable())
2139 file_header
->finalize_data_size();
2140 segment_headers
->finalize_data_size();
2141 size_t sizeof_headers
= (file_header
->data_size()
2142 + segment_headers
->data_size());
2143 const uint64_t abi_pagesize
= target
->abi_pagesize();
2144 uint64_t hdr_paddr
= load_seg
->paddr() - sizeof_headers
;
2145 hdr_paddr
&= ~(abi_pagesize
- 1);
2146 uint64_t subtract
= load_seg
->paddr() - hdr_paddr
;
2147 if (load_seg
->paddr() < subtract
|| load_seg
->vaddr() < subtract
)
2151 load_seg
->set_addresses(load_seg
->vaddr() - subtract
,
2152 load_seg
->paddr() - subtract
);
2153 header_gap
= subtract
- sizeof_headers
;
2157 // Lay out the segment headers.
2158 if (!parameters
->options().relocatable())
2160 gold_assert(segment_headers
!= NULL
);
2161 if (header_gap
!= 0 && load_seg
!= NULL
)
2163 Output_data_zero_fill
* z
= new Output_data_zero_fill(header_gap
, 1);
2164 load_seg
->add_initial_output_data(z
);
2166 if (load_seg
!= NULL
)
2167 load_seg
->add_initial_output_data(segment_headers
);
2168 if (phdr_seg
!= NULL
)
2169 phdr_seg
->add_initial_output_data(segment_headers
);
2172 // Lay out the file header.
2173 if (load_seg
!= NULL
)
2174 load_seg
->add_initial_output_data(file_header
);
2176 if (this->script_options_
->saw_phdrs_clause()
2177 && !parameters
->options().relocatable())
2179 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2180 // clause in a linker script.
2181 Script_sections
* ss
= this->script_options_
->script_sections();
2182 ss
->put_headers_in_phdrs(file_header
, segment_headers
);
2185 // We set the output section indexes in set_segment_offsets and
2186 // set_section_indexes.
2189 // Set the file offsets of all the segments, and all the sections
2192 if (!parameters
->options().relocatable())
2193 off
= this->set_segment_offsets(target
, load_seg
, pshndx
);
2195 off
= this->set_relocatable_section_offsets(file_header
, pshndx
);
2197 // Verify that the dummy relaxation does not change anything.
2198 if (is_debugging_enabled(DEBUG_RELAXATION
))
2201 this->relaxation_debug_check_
->read_sections(this->section_list_
);
2203 this->relaxation_debug_check_
->verify_sections(this->section_list_
);
2206 *pload_seg
= load_seg
;
2210 // Search the list of patterns and find the postion of the given section
2211 // name in the output section. If the section name matches a glob
2212 // pattern and a non-glob name, then the non-glob position takes
2213 // precedence. Return 0 if no match is found.
2216 Layout::find_section_order_index(const std::string
& section_name
)
2218 Unordered_map
<std::string
, unsigned int>::iterator map_it
;
2219 map_it
= this->input_section_position_
.find(section_name
);
2220 if (map_it
!= this->input_section_position_
.end())
2221 return map_it
->second
;
2223 // Absolute match failed. Linear search the glob patterns.
2224 std::vector
<std::string
>::iterator it
;
2225 for (it
= this->input_section_glob_
.begin();
2226 it
!= this->input_section_glob_
.end();
2229 if (fnmatch((*it
).c_str(), section_name
.c_str(), FNM_NOESCAPE
) == 0)
2231 map_it
= this->input_section_position_
.find(*it
);
2232 gold_assert(map_it
!= this->input_section_position_
.end());
2233 return map_it
->second
;
2239 // Read the sequence of input sections from the file specified with
2240 // option --section-ordering-file.
2243 Layout::read_layout_from_file()
2245 const char* filename
= parameters
->options().section_ordering_file();
2251 gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2252 filename
, strerror(errno
));
2254 std::getline(in
, line
); // this chops off the trailing \n, if any
2255 unsigned int position
= 1;
2256 this->set_section_ordering_specified();
2260 if (!line
.empty() && line
[line
.length() - 1] == '\r') // Windows
2261 line
.resize(line
.length() - 1);
2262 // Ignore comments, beginning with '#'
2265 std::getline(in
, line
);
2268 this->input_section_position_
[line
] = position
;
2269 // Store all glob patterns in a vector.
2270 if (is_wildcard_string(line
.c_str()))
2271 this->input_section_glob_
.push_back(line
);
2273 std::getline(in
, line
);
2277 // Finalize the layout. When this is called, we have created all the
2278 // output sections and all the output segments which are based on
2279 // input sections. We have several things to do, and we have to do
2280 // them in the right order, so that we get the right results correctly
2283 // 1) Finalize the list of output segments and create the segment
2286 // 2) Finalize the dynamic symbol table and associated sections.
2288 // 3) Determine the final file offset of all the output segments.
2290 // 4) Determine the final file offset of all the SHF_ALLOC output
2293 // 5) Create the symbol table sections and the section name table
2296 // 6) Finalize the symbol table: set symbol values to their final
2297 // value and make a final determination of which symbols are going
2298 // into the output symbol table.
2300 // 7) Create the section table header.
2302 // 8) Determine the final file offset of all the output sections which
2303 // are not SHF_ALLOC, including the section table header.
2305 // 9) Finalize the ELF file header.
2307 // This function returns the size of the output file.
2310 Layout::finalize(const Input_objects
* input_objects
, Symbol_table
* symtab
,
2311 Target
* target
, const Task
* task
)
2313 target
->finalize_sections(this, input_objects
, symtab
);
2315 this->count_local_symbols(task
, input_objects
);
2317 this->link_stabs_sections();
2319 Output_segment
* phdr_seg
= NULL
;
2320 if (!parameters
->options().relocatable() && !parameters
->doing_static_link())
2322 // There was a dynamic object in the link. We need to create
2323 // some information for the dynamic linker.
2325 // Create the PT_PHDR segment which will hold the program
2327 if (!this->script_options_
->saw_phdrs_clause())
2328 phdr_seg
= this->make_output_segment(elfcpp::PT_PHDR
, elfcpp::PF_R
);
2330 // Create the dynamic symbol table, including the hash table.
2331 Output_section
* dynstr
;
2332 std::vector
<Symbol
*> dynamic_symbols
;
2333 unsigned int local_dynamic_count
;
2334 Versions
versions(*this->script_options()->version_script_info(),
2336 this->create_dynamic_symtab(input_objects
, symtab
, &dynstr
,
2337 &local_dynamic_count
, &dynamic_symbols
,
2340 // Create the .interp section to hold the name of the
2341 // interpreter, and put it in a PT_INTERP segment. Don't do it
2342 // if we saw a .interp section in an input file.
2343 if ((!parameters
->options().shared()
2344 || parameters
->options().dynamic_linker() != NULL
)
2345 && this->interp_segment_
== NULL
)
2346 this->create_interp(target
);
2348 // Finish the .dynamic section to hold the dynamic data, and put
2349 // it in a PT_DYNAMIC segment.
2350 this->finish_dynamic_section(input_objects
, symtab
);
2352 // We should have added everything we need to the dynamic string
2354 this->dynpool_
.set_string_offsets();
2356 // Create the version sections. We can't do this until the
2357 // dynamic string table is complete.
2358 this->create_version_sections(&versions
, symtab
, local_dynamic_count
,
2359 dynamic_symbols
, dynstr
);
2361 // Set the size of the _DYNAMIC symbol. We can't do this until
2362 // after we call create_version_sections.
2363 this->set_dynamic_symbol_size(symtab
);
2366 // Create segment headers.
2367 Output_segment_headers
* segment_headers
=
2368 (parameters
->options().relocatable()
2370 : new Output_segment_headers(this->segment_list_
));
2372 // Lay out the file header.
2373 Output_file_header
* file_header
= new Output_file_header(target
, symtab
,
2376 this->special_output_list_
.push_back(file_header
);
2377 if (segment_headers
!= NULL
)
2378 this->special_output_list_
.push_back(segment_headers
);
2380 // Find approriate places for orphan output sections if we are using
2382 if (this->script_options_
->saw_sections_clause())
2383 this->place_orphan_sections_in_script();
2385 Output_segment
* load_seg
;
2390 // Take a snapshot of the section layout as needed.
2391 if (target
->may_relax())
2392 this->prepare_for_relaxation();
2394 // Run the relaxation loop to lay out sections.
2397 off
= this->relaxation_loop_body(pass
, target
, symtab
, &load_seg
,
2398 phdr_seg
, segment_headers
, file_header
,
2402 while (target
->may_relax()
2403 && target
->relax(pass
, input_objects
, symtab
, this, task
));
2405 // Set the file offsets of all the non-data sections we've seen so
2406 // far which don't have to wait for the input sections. We need
2407 // this in order to finalize local symbols in non-allocated
2409 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2411 // Set the section indexes of all unallocated sections seen so far,
2412 // in case any of them are somehow referenced by a symbol.
2413 shndx
= this->set_section_indexes(shndx
);
2415 // Create the symbol table sections.
2416 this->create_symtab_sections(input_objects
, symtab
, shndx
, &off
);
2417 if (!parameters
->doing_static_link())
2418 this->assign_local_dynsym_offsets(input_objects
);
2420 // Process any symbol assignments from a linker script. This must
2421 // be called after the symbol table has been finalized.
2422 this->script_options_
->finalize_symbols(symtab
, this);
2424 // Create the incremental inputs sections.
2425 if (this->incremental_inputs_
)
2427 this->incremental_inputs_
->finalize();
2428 this->create_incremental_info_sections(symtab
);
2431 // Create the .shstrtab section.
2432 Output_section
* shstrtab_section
= this->create_shstrtab();
2434 // Set the file offsets of the rest of the non-data sections which
2435 // don't have to wait for the input sections.
2436 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2438 // Now that all sections have been created, set the section indexes
2439 // for any sections which haven't been done yet.
2440 shndx
= this->set_section_indexes(shndx
);
2442 // Create the section table header.
2443 this->create_shdrs(shstrtab_section
, &off
);
2445 // If there are no sections which require postprocessing, we can
2446 // handle the section names now, and avoid a resize later.
2447 if (!this->any_postprocessing_sections_
)
2449 off
= this->set_section_offsets(off
,
2450 POSTPROCESSING_SECTIONS_PASS
);
2452 this->set_section_offsets(off
,
2453 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
2456 file_header
->set_section_info(this->section_headers_
, shstrtab_section
);
2458 // Now we know exactly where everything goes in the output file
2459 // (except for non-allocated sections which require postprocessing).
2460 Output_data::layout_complete();
2462 this->output_file_size_
= off
;
2467 // Create a note header following the format defined in the ELF ABI.
2468 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
2469 // of the section to create, DESCSZ is the size of the descriptor.
2470 // ALLOCATE is true if the section should be allocated in memory.
2471 // This returns the new note section. It sets *TRAILING_PADDING to
2472 // the number of trailing zero bytes required.
2475 Layout::create_note(const char* name
, int note_type
,
2476 const char* section_name
, size_t descsz
,
2477 bool allocate
, size_t* trailing_padding
)
2479 // Authorities all agree that the values in a .note field should
2480 // be aligned on 4-byte boundaries for 32-bit binaries. However,
2481 // they differ on what the alignment is for 64-bit binaries.
2482 // The GABI says unambiguously they take 8-byte alignment:
2483 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2484 // Other documentation says alignment should always be 4 bytes:
2485 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2486 // GNU ld and GNU readelf both support the latter (at least as of
2487 // version 2.16.91), and glibc always generates the latter for
2488 // .note.ABI-tag (as of version 1.6), so that's the one we go with
2490 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
2491 const int size
= parameters
->target().get_size();
2493 const int size
= 32;
2496 // The contents of the .note section.
2497 size_t namesz
= strlen(name
) + 1;
2498 size_t aligned_namesz
= align_address(namesz
, size
/ 8);
2499 size_t aligned_descsz
= align_address(descsz
, size
/ 8);
2501 size_t notehdrsz
= 3 * (size
/ 8) + aligned_namesz
;
2503 unsigned char* buffer
= new unsigned char[notehdrsz
];
2504 memset(buffer
, 0, notehdrsz
);
2506 bool is_big_endian
= parameters
->target().is_big_endian();
2512 elfcpp::Swap
<32, false>::writeval(buffer
, namesz
);
2513 elfcpp::Swap
<32, false>::writeval(buffer
+ 4, descsz
);
2514 elfcpp::Swap
<32, false>::writeval(buffer
+ 8, note_type
);
2518 elfcpp::Swap
<32, true>::writeval(buffer
, namesz
);
2519 elfcpp::Swap
<32, true>::writeval(buffer
+ 4, descsz
);
2520 elfcpp::Swap
<32, true>::writeval(buffer
+ 8, note_type
);
2523 else if (size
== 64)
2527 elfcpp::Swap
<64, false>::writeval(buffer
, namesz
);
2528 elfcpp::Swap
<64, false>::writeval(buffer
+ 8, descsz
);
2529 elfcpp::Swap
<64, false>::writeval(buffer
+ 16, note_type
);
2533 elfcpp::Swap
<64, true>::writeval(buffer
, namesz
);
2534 elfcpp::Swap
<64, true>::writeval(buffer
+ 8, descsz
);
2535 elfcpp::Swap
<64, true>::writeval(buffer
+ 16, note_type
);
2541 memcpy(buffer
+ 3 * (size
/ 8), name
, namesz
);
2543 elfcpp::Elf_Xword flags
= 0;
2544 Output_section_order order
= ORDER_INVALID
;
2547 flags
= elfcpp::SHF_ALLOC
;
2548 order
= ORDER_RO_NOTE
;
2550 Output_section
* os
= this->choose_output_section(NULL
, section_name
,
2552 flags
, false, order
, false);
2556 Output_section_data
* posd
= new Output_data_const_buffer(buffer
, notehdrsz
,
2559 os
->add_output_section_data(posd
);
2561 *trailing_padding
= aligned_descsz
- descsz
;
2566 // For an executable or shared library, create a note to record the
2567 // version of gold used to create the binary.
2570 Layout::create_gold_note()
2572 if (parameters
->options().relocatable()
2573 || parameters
->incremental_update())
2576 std::string desc
= std::string("gold ") + gold::get_version_string();
2578 size_t trailing_padding
;
2579 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION
,
2580 ".note.gnu.gold-version", desc
.size(),
2581 false, &trailing_padding
);
2585 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2586 os
->add_output_section_data(posd
);
2588 if (trailing_padding
> 0)
2590 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2591 os
->add_output_section_data(posd
);
2595 // Record whether the stack should be executable. This can be set
2596 // from the command line using the -z execstack or -z noexecstack
2597 // options. Otherwise, if any input file has a .note.GNU-stack
2598 // section with the SHF_EXECINSTR flag set, the stack should be
2599 // executable. Otherwise, if at least one input file a
2600 // .note.GNU-stack section, and some input file has no .note.GNU-stack
2601 // section, we use the target default for whether the stack should be
2602 // executable. Otherwise, we don't generate a stack note. When
2603 // generating a object file, we create a .note.GNU-stack section with
2604 // the appropriate marking. When generating an executable or shared
2605 // library, we create a PT_GNU_STACK segment.
2608 Layout::create_executable_stack_info()
2610 bool is_stack_executable
;
2611 if (parameters
->options().is_execstack_set())
2612 is_stack_executable
= parameters
->options().is_stack_executable();
2613 else if (!this->input_with_gnu_stack_note_
)
2617 if (this->input_requires_executable_stack_
)
2618 is_stack_executable
= true;
2619 else if (this->input_without_gnu_stack_note_
)
2620 is_stack_executable
=
2621 parameters
->target().is_default_stack_executable();
2623 is_stack_executable
= false;
2626 if (parameters
->options().relocatable())
2628 const char* name
= this->namepool_
.add(".note.GNU-stack", false, NULL
);
2629 elfcpp::Elf_Xword flags
= 0;
2630 if (is_stack_executable
)
2631 flags
|= elfcpp::SHF_EXECINSTR
;
2632 this->make_output_section(name
, elfcpp::SHT_PROGBITS
, flags
,
2633 ORDER_INVALID
, false);
2637 if (this->script_options_
->saw_phdrs_clause())
2639 int flags
= elfcpp::PF_R
| elfcpp::PF_W
;
2640 if (is_stack_executable
)
2641 flags
|= elfcpp::PF_X
;
2642 this->make_output_segment(elfcpp::PT_GNU_STACK
, flags
);
2646 // If --build-id was used, set up the build ID note.
2649 Layout::create_build_id()
2651 if (!parameters
->options().user_set_build_id())
2654 const char* style
= parameters
->options().build_id();
2655 if (strcmp(style
, "none") == 0)
2658 // Set DESCSZ to the size of the note descriptor. When possible,
2659 // set DESC to the note descriptor contents.
2662 if (strcmp(style
, "md5") == 0)
2664 else if (strcmp(style
, "sha1") == 0)
2666 else if (strcmp(style
, "uuid") == 0)
2668 const size_t uuidsz
= 128 / 8;
2670 char buffer
[uuidsz
];
2671 memset(buffer
, 0, uuidsz
);
2673 int descriptor
= open_descriptor(-1, "/dev/urandom", O_RDONLY
);
2675 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
2679 ssize_t got
= ::read(descriptor
, buffer
, uuidsz
);
2680 release_descriptor(descriptor
, true);
2682 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno
));
2683 else if (static_cast<size_t>(got
) != uuidsz
)
2684 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
2688 desc
.assign(buffer
, uuidsz
);
2691 else if (strncmp(style
, "0x", 2) == 0)
2694 const char* p
= style
+ 2;
2697 if (hex_p(p
[0]) && hex_p(p
[1]))
2699 char c
= (hex_value(p
[0]) << 4) | hex_value(p
[1]);
2703 else if (*p
== '-' || *p
== ':')
2706 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
2709 descsz
= desc
.size();
2712 gold_fatal(_("unrecognized --build-id argument '%s'"), style
);
2715 size_t trailing_padding
;
2716 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID
,
2717 ".note.gnu.build-id", descsz
, true,
2724 // We know the value already, so we fill it in now.
2725 gold_assert(desc
.size() == descsz
);
2727 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2728 os
->add_output_section_data(posd
);
2730 if (trailing_padding
!= 0)
2732 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2733 os
->add_output_section_data(posd
);
2738 // We need to compute a checksum after we have completed the
2740 gold_assert(trailing_padding
== 0);
2741 this->build_id_note_
= new Output_data_zero_fill(descsz
, 4);
2742 os
->add_output_section_data(this->build_id_note_
);
2746 // If we have both .stabXX and .stabXXstr sections, then the sh_link
2747 // field of the former should point to the latter. I'm not sure who
2748 // started this, but the GNU linker does it, and some tools depend
2752 Layout::link_stabs_sections()
2754 if (!this->have_stabstr_section_
)
2757 for (Section_list::iterator p
= this->section_list_
.begin();
2758 p
!= this->section_list_
.end();
2761 if ((*p
)->type() != elfcpp::SHT_STRTAB
)
2764 const char* name
= (*p
)->name();
2765 if (strncmp(name
, ".stab", 5) != 0)
2768 size_t len
= strlen(name
);
2769 if (strcmp(name
+ len
- 3, "str") != 0)
2772 std::string
stab_name(name
, len
- 3);
2773 Output_section
* stab_sec
;
2774 stab_sec
= this->find_output_section(stab_name
.c_str());
2775 if (stab_sec
!= NULL
)
2776 stab_sec
->set_link_section(*p
);
2780 // Create .gnu_incremental_inputs and related sections needed
2781 // for the next run of incremental linking to check what has changed.
2784 Layout::create_incremental_info_sections(Symbol_table
* symtab
)
2786 Incremental_inputs
* incr
= this->incremental_inputs_
;
2788 gold_assert(incr
!= NULL
);
2790 // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
2791 incr
->create_data_sections(symtab
);
2793 // Add the .gnu_incremental_inputs section.
2794 const char* incremental_inputs_name
=
2795 this->namepool_
.add(".gnu_incremental_inputs", false, NULL
);
2796 Output_section
* incremental_inputs_os
=
2797 this->make_output_section(incremental_inputs_name
,
2798 elfcpp::SHT_GNU_INCREMENTAL_INPUTS
, 0,
2799 ORDER_INVALID
, false);
2800 incremental_inputs_os
->add_output_section_data(incr
->inputs_section());
2802 // Add the .gnu_incremental_symtab section.
2803 const char* incremental_symtab_name
=
2804 this->namepool_
.add(".gnu_incremental_symtab", false, NULL
);
2805 Output_section
* incremental_symtab_os
=
2806 this->make_output_section(incremental_symtab_name
,
2807 elfcpp::SHT_GNU_INCREMENTAL_SYMTAB
, 0,
2808 ORDER_INVALID
, false);
2809 incremental_symtab_os
->add_output_section_data(incr
->symtab_section());
2810 incremental_symtab_os
->set_entsize(4);
2812 // Add the .gnu_incremental_relocs section.
2813 const char* incremental_relocs_name
=
2814 this->namepool_
.add(".gnu_incremental_relocs", false, NULL
);
2815 Output_section
* incremental_relocs_os
=
2816 this->make_output_section(incremental_relocs_name
,
2817 elfcpp::SHT_GNU_INCREMENTAL_RELOCS
, 0,
2818 ORDER_INVALID
, false);
2819 incremental_relocs_os
->add_output_section_data(incr
->relocs_section());
2820 incremental_relocs_os
->set_entsize(incr
->relocs_entsize());
2822 // Add the .gnu_incremental_got_plt section.
2823 const char* incremental_got_plt_name
=
2824 this->namepool_
.add(".gnu_incremental_got_plt", false, NULL
);
2825 Output_section
* incremental_got_plt_os
=
2826 this->make_output_section(incremental_got_plt_name
,
2827 elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT
, 0,
2828 ORDER_INVALID
, false);
2829 incremental_got_plt_os
->add_output_section_data(incr
->got_plt_section());
2831 // Add the .gnu_incremental_strtab section.
2832 const char* incremental_strtab_name
=
2833 this->namepool_
.add(".gnu_incremental_strtab", false, NULL
);
2834 Output_section
* incremental_strtab_os
= this->make_output_section(incremental_strtab_name
,
2835 elfcpp::SHT_STRTAB
, 0,
2836 ORDER_INVALID
, false);
2837 Output_data_strtab
* strtab_data
=
2838 new Output_data_strtab(incr
->get_stringpool());
2839 incremental_strtab_os
->add_output_section_data(strtab_data
);
2841 incremental_inputs_os
->set_after_input_sections();
2842 incremental_symtab_os
->set_after_input_sections();
2843 incremental_relocs_os
->set_after_input_sections();
2844 incremental_got_plt_os
->set_after_input_sections();
2846 incremental_inputs_os
->set_link_section(incremental_strtab_os
);
2847 incremental_symtab_os
->set_link_section(incremental_inputs_os
);
2848 incremental_relocs_os
->set_link_section(incremental_inputs_os
);
2849 incremental_got_plt_os
->set_link_section(incremental_inputs_os
);
2852 // Return whether SEG1 should be before SEG2 in the output file. This
2853 // is based entirely on the segment type and flags. When this is
2854 // called the segment addresses have normally not yet been set.
2857 Layout::segment_precedes(const Output_segment
* seg1
,
2858 const Output_segment
* seg2
)
2860 elfcpp::Elf_Word type1
= seg1
->type();
2861 elfcpp::Elf_Word type2
= seg2
->type();
2863 // The single PT_PHDR segment is required to precede any loadable
2864 // segment. We simply make it always first.
2865 if (type1
== elfcpp::PT_PHDR
)
2867 gold_assert(type2
!= elfcpp::PT_PHDR
);
2870 if (type2
== elfcpp::PT_PHDR
)
2873 // The single PT_INTERP segment is required to precede any loadable
2874 // segment. We simply make it always second.
2875 if (type1
== elfcpp::PT_INTERP
)
2877 gold_assert(type2
!= elfcpp::PT_INTERP
);
2880 if (type2
== elfcpp::PT_INTERP
)
2883 // We then put PT_LOAD segments before any other segments.
2884 if (type1
== elfcpp::PT_LOAD
&& type2
!= elfcpp::PT_LOAD
)
2886 if (type2
== elfcpp::PT_LOAD
&& type1
!= elfcpp::PT_LOAD
)
2889 // We put the PT_TLS segment last except for the PT_GNU_RELRO
2890 // segment, because that is where the dynamic linker expects to find
2891 // it (this is just for efficiency; other positions would also work
2893 if (type1
== elfcpp::PT_TLS
2894 && type2
!= elfcpp::PT_TLS
2895 && type2
!= elfcpp::PT_GNU_RELRO
)
2897 if (type2
== elfcpp::PT_TLS
2898 && type1
!= elfcpp::PT_TLS
2899 && type1
!= elfcpp::PT_GNU_RELRO
)
2902 // We put the PT_GNU_RELRO segment last, because that is where the
2903 // dynamic linker expects to find it (as with PT_TLS, this is just
2905 if (type1
== elfcpp::PT_GNU_RELRO
&& type2
!= elfcpp::PT_GNU_RELRO
)
2907 if (type2
== elfcpp::PT_GNU_RELRO
&& type1
!= elfcpp::PT_GNU_RELRO
)
2910 const elfcpp::Elf_Word flags1
= seg1
->flags();
2911 const elfcpp::Elf_Word flags2
= seg2
->flags();
2913 // The order of non-PT_LOAD segments is unimportant. We simply sort
2914 // by the numeric segment type and flags values. There should not
2915 // be more than one segment with the same type and flags.
2916 if (type1
!= elfcpp::PT_LOAD
)
2919 return type1
< type2
;
2920 gold_assert(flags1
!= flags2
);
2921 return flags1
< flags2
;
2924 // If the addresses are set already, sort by load address.
2925 if (seg1
->are_addresses_set())
2927 if (!seg2
->are_addresses_set())
2930 unsigned int section_count1
= seg1
->output_section_count();
2931 unsigned int section_count2
= seg2
->output_section_count();
2932 if (section_count1
== 0 && section_count2
> 0)
2934 if (section_count1
> 0 && section_count2
== 0)
2937 uint64_t paddr1
= (seg1
->are_addresses_set()
2939 : seg1
->first_section_load_address());
2940 uint64_t paddr2
= (seg2
->are_addresses_set()
2942 : seg2
->first_section_load_address());
2944 if (paddr1
!= paddr2
)
2945 return paddr1
< paddr2
;
2947 else if (seg2
->are_addresses_set())
2950 // A segment which holds large data comes after a segment which does
2951 // not hold large data.
2952 if (seg1
->is_large_data_segment())
2954 if (!seg2
->is_large_data_segment())
2957 else if (seg2
->is_large_data_segment())
2960 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
2961 // segments come before writable segments. Then writable segments
2962 // with data come before writable segments without data. Then
2963 // executable segments come before non-executable segments. Then
2964 // the unlikely case of a non-readable segment comes before the
2965 // normal case of a readable segment. If there are multiple
2966 // segments with the same type and flags, we require that the
2967 // address be set, and we sort by virtual address and then physical
2969 if ((flags1
& elfcpp::PF_W
) != (flags2
& elfcpp::PF_W
))
2970 return (flags1
& elfcpp::PF_W
) == 0;
2971 if ((flags1
& elfcpp::PF_W
) != 0
2972 && seg1
->has_any_data_sections() != seg2
->has_any_data_sections())
2973 return seg1
->has_any_data_sections();
2974 if ((flags1
& elfcpp::PF_X
) != (flags2
& elfcpp::PF_X
))
2975 return (flags1
& elfcpp::PF_X
) != 0;
2976 if ((flags1
& elfcpp::PF_R
) != (flags2
& elfcpp::PF_R
))
2977 return (flags1
& elfcpp::PF_R
) == 0;
2979 // We shouldn't get here--we shouldn't create segments which we
2980 // can't distinguish. Unless of course we are using a weird linker
2981 // script or overlapping --section-start options.
2982 gold_assert(this->script_options_
->saw_phdrs_clause()
2983 || parameters
->options().any_section_start());
2987 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
2990 align_file_offset(off_t off
, uint64_t addr
, uint64_t abi_pagesize
)
2992 uint64_t unsigned_off
= off
;
2993 uint64_t aligned_off
= ((unsigned_off
& ~(abi_pagesize
- 1))
2994 | (addr
& (abi_pagesize
- 1)));
2995 if (aligned_off
< unsigned_off
)
2996 aligned_off
+= abi_pagesize
;
3000 // Set the file offsets of all the segments, and all the sections they
3001 // contain. They have all been created. LOAD_SEG must be be laid out
3002 // first. Return the offset of the data to follow.
3005 Layout::set_segment_offsets(const Target
* target
, Output_segment
* load_seg
,
3006 unsigned int* pshndx
)
3008 // Sort them into the final order. We use a stable sort so that we
3009 // don't randomize the order of indistinguishable segments created
3010 // by linker scripts.
3011 std::stable_sort(this->segment_list_
.begin(), this->segment_list_
.end(),
3012 Layout::Compare_segments(this));
3014 // Find the PT_LOAD segments, and set their addresses and offsets
3015 // and their section's addresses and offsets.
3017 if (parameters
->options().user_set_Ttext())
3018 addr
= parameters
->options().Ttext();
3019 else if (parameters
->options().output_is_position_independent())
3022 addr
= target
->default_text_segment_address();
3025 // If LOAD_SEG is NULL, then the file header and segment headers
3026 // will not be loadable. But they still need to be at offset 0 in
3027 // the file. Set their offsets now.
3028 if (load_seg
== NULL
)
3030 for (Data_list::iterator p
= this->special_output_list_
.begin();
3031 p
!= this->special_output_list_
.end();
3034 off
= align_address(off
, (*p
)->addralign());
3035 (*p
)->set_address_and_file_offset(0, off
);
3036 off
+= (*p
)->data_size();
3040 unsigned int increase_relro
= this->increase_relro_
;
3041 if (this->script_options_
->saw_sections_clause())
3044 const bool check_sections
= parameters
->options().check_sections();
3045 Output_segment
* last_load_segment
= NULL
;
3047 for (Segment_list::iterator p
= this->segment_list_
.begin();
3048 p
!= this->segment_list_
.end();
3051 if ((*p
)->type() == elfcpp::PT_LOAD
)
3053 if (load_seg
!= NULL
&& load_seg
!= *p
)
3057 bool are_addresses_set
= (*p
)->are_addresses_set();
3058 if (are_addresses_set
)
3060 // When it comes to setting file offsets, we care about
3061 // the physical address.
3062 addr
= (*p
)->paddr();
3064 else if (parameters
->options().user_set_Ttext()
3065 && ((*p
)->flags() & elfcpp::PF_W
) == 0)
3067 are_addresses_set
= true;
3069 else if (parameters
->options().user_set_Tdata()
3070 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3071 && (!parameters
->options().user_set_Tbss()
3072 || (*p
)->has_any_data_sections()))
3074 addr
= parameters
->options().Tdata();
3075 are_addresses_set
= true;
3077 else if (parameters
->options().user_set_Tbss()
3078 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3079 && !(*p
)->has_any_data_sections())
3081 addr
= parameters
->options().Tbss();
3082 are_addresses_set
= true;
3085 uint64_t orig_addr
= addr
;
3086 uint64_t orig_off
= off
;
3088 uint64_t aligned_addr
= 0;
3089 uint64_t abi_pagesize
= target
->abi_pagesize();
3090 uint64_t common_pagesize
= target
->common_pagesize();
3092 if (!parameters
->options().nmagic()
3093 && !parameters
->options().omagic())
3094 (*p
)->set_minimum_p_align(common_pagesize
);
3096 if (!are_addresses_set
)
3098 // Skip the address forward one page, maintaining the same
3099 // position within the page. This lets us store both segments
3100 // overlapping on a single page in the file, but the loader will
3101 // put them on different pages in memory. We will revisit this
3102 // decision once we know the size of the segment.
3104 addr
= align_address(addr
, (*p
)->maximum_alignment());
3105 aligned_addr
= addr
;
3107 if ((addr
& (abi_pagesize
- 1)) != 0)
3108 addr
= addr
+ abi_pagesize
;
3110 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3113 if (!parameters
->options().nmagic()
3114 && !parameters
->options().omagic())
3115 off
= align_file_offset(off
, addr
, abi_pagesize
);
3116 else if (load_seg
== NULL
)
3118 // This is -N or -n with a section script which prevents
3119 // us from using a load segment. We need to ensure that
3120 // the file offset is aligned to the alignment of the
3121 // segment. This is because the linker script
3122 // implicitly assumed a zero offset. If we don't align
3123 // here, then the alignment of the sections in the
3124 // linker script may not match the alignment of the
3125 // sections in the set_section_addresses call below,
3126 // causing an error about dot moving backward.
3127 off
= align_address(off
, (*p
)->maximum_alignment());
3130 unsigned int shndx_hold
= *pshndx
;
3131 bool has_relro
= false;
3132 uint64_t new_addr
= (*p
)->set_section_addresses(this, false, addr
,
3137 // Now that we know the size of this segment, we may be able
3138 // to save a page in memory, at the cost of wasting some
3139 // file space, by instead aligning to the start of a new
3140 // page. Here we use the real machine page size rather than
3141 // the ABI mandated page size. If the segment has been
3142 // aligned so that the relro data ends at a page boundary,
3143 // we do not try to realign it.
3145 if (!are_addresses_set
3147 && aligned_addr
!= addr
3148 && !parameters
->incremental())
3150 uint64_t first_off
= (common_pagesize
3152 & (common_pagesize
- 1)));
3153 uint64_t last_off
= new_addr
& (common_pagesize
- 1);
3156 && ((aligned_addr
& ~ (common_pagesize
- 1))
3157 != (new_addr
& ~ (common_pagesize
- 1)))
3158 && first_off
+ last_off
<= common_pagesize
)
3160 *pshndx
= shndx_hold
;
3161 addr
= align_address(aligned_addr
, common_pagesize
);
3162 addr
= align_address(addr
, (*p
)->maximum_alignment());
3163 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3164 off
= align_file_offset(off
, addr
, abi_pagesize
);
3166 increase_relro
= this->increase_relro_
;
3167 if (this->script_options_
->saw_sections_clause())
3171 new_addr
= (*p
)->set_section_addresses(this, true, addr
,
3180 // Implement --check-sections. We know that the segments
3181 // are sorted by LMA.
3182 if (check_sections
&& last_load_segment
!= NULL
)
3184 gold_assert(last_load_segment
->paddr() <= (*p
)->paddr());
3185 if (last_load_segment
->paddr() + last_load_segment
->memsz()
3188 unsigned long long lb1
= last_load_segment
->paddr();
3189 unsigned long long le1
= lb1
+ last_load_segment
->memsz();
3190 unsigned long long lb2
= (*p
)->paddr();
3191 unsigned long long le2
= lb2
+ (*p
)->memsz();
3192 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3193 "[0x%llx -> 0x%llx]"),
3194 lb1
, le1
, lb2
, le2
);
3197 last_load_segment
= *p
;
3201 // Handle the non-PT_LOAD segments, setting their offsets from their
3202 // section's offsets.
3203 for (Segment_list::iterator p
= this->segment_list_
.begin();
3204 p
!= this->segment_list_
.end();
3207 if ((*p
)->type() != elfcpp::PT_LOAD
)
3208 (*p
)->set_offset((*p
)->type() == elfcpp::PT_GNU_RELRO
3213 // Set the TLS offsets for each section in the PT_TLS segment.
3214 if (this->tls_segment_
!= NULL
)
3215 this->tls_segment_
->set_tls_offsets();
3220 // Set the offsets of all the allocated sections when doing a
3221 // relocatable link. This does the same jobs as set_segment_offsets,
3222 // only for a relocatable link.
3225 Layout::set_relocatable_section_offsets(Output_data
* file_header
,
3226 unsigned int* pshndx
)
3230 file_header
->set_address_and_file_offset(0, 0);
3231 off
+= file_header
->data_size();
3233 for (Section_list::iterator p
= this->section_list_
.begin();
3234 p
!= this->section_list_
.end();
3237 // We skip unallocated sections here, except that group sections
3238 // have to come first.
3239 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) == 0
3240 && (*p
)->type() != elfcpp::SHT_GROUP
)
3243 off
= align_address(off
, (*p
)->addralign());
3245 // The linker script might have set the address.
3246 if (!(*p
)->is_address_valid())
3247 (*p
)->set_address(0);
3248 (*p
)->set_file_offset(off
);
3249 (*p
)->finalize_data_size();
3250 off
+= (*p
)->data_size();
3252 (*p
)->set_out_shndx(*pshndx
);
3259 // Set the file offset of all the sections not associated with a
3263 Layout::set_section_offsets(off_t off
, Layout::Section_offset_pass pass
)
3265 off_t startoff
= off
;
3268 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3269 p
!= this->unattached_section_list_
.end();
3272 // The symtab section is handled in create_symtab_sections.
3273 if (*p
== this->symtab_section_
)
3276 // If we've already set the data size, don't set it again.
3277 if ((*p
)->is_offset_valid() && (*p
)->is_data_size_valid())
3280 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3281 && (*p
)->requires_postprocessing())
3283 (*p
)->create_postprocessing_buffer();
3284 this->any_postprocessing_sections_
= true;
3287 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3288 && (*p
)->after_input_sections())
3290 else if (pass
== POSTPROCESSING_SECTIONS_PASS
3291 && (!(*p
)->after_input_sections()
3292 || (*p
)->type() == elfcpp::SHT_STRTAB
))
3294 else if (pass
== STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
3295 && (!(*p
)->after_input_sections()
3296 || (*p
)->type() != elfcpp::SHT_STRTAB
))
3299 if (!parameters
->incremental_update())
3301 off
= align_address(off
, (*p
)->addralign());
3302 (*p
)->set_file_offset(off
);
3303 (*p
)->finalize_data_size();
3307 // Incremental update: allocate file space from free list.
3308 (*p
)->pre_finalize_data_size();
3309 off_t current_size
= (*p
)->current_data_size();
3310 off
= this->allocate(current_size
, (*p
)->addralign(), startoff
);
3313 if (is_debugging_enabled(DEBUG_INCREMENTAL
))
3314 this->free_list_
.dump();
3315 gold_assert((*p
)->output_section() != NULL
);
3316 gold_fallback(_("out of patch space for section %s; "
3317 "relink with --incremental-full"),
3318 (*p
)->output_section()->name());
3320 (*p
)->set_file_offset(off
);
3321 (*p
)->finalize_data_size();
3322 if ((*p
)->data_size() > current_size
)
3324 gold_assert((*p
)->output_section() != NULL
);
3325 gold_fallback(_("%s: section changed size; "
3326 "relink with --incremental-full"),
3327 (*p
)->output_section()->name());
3329 gold_debug(DEBUG_INCREMENTAL
,
3330 "set_section_offsets: %08lx %08lx %s",
3331 static_cast<long>(off
),
3332 static_cast<long>((*p
)->data_size()),
3333 ((*p
)->output_section() != NULL
3334 ? (*p
)->output_section()->name() : "(special)"));
3337 off
+= (*p
)->data_size();
3341 // At this point the name must be set.
3342 if (pass
!= STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
)
3343 this->namepool_
.add((*p
)->name(), false, NULL
);
3348 // Set the section indexes of all the sections not associated with a
3352 Layout::set_section_indexes(unsigned int shndx
)
3354 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3355 p
!= this->unattached_section_list_
.end();
3358 if (!(*p
)->has_out_shndx())
3360 (*p
)->set_out_shndx(shndx
);
3367 // Set the section addresses according to the linker script. This is
3368 // only called when we see a SECTIONS clause. This returns the
3369 // program segment which should hold the file header and segment
3370 // headers, if any. It will return NULL if they should not be in a
3374 Layout::set_section_addresses_from_script(Symbol_table
* symtab
)
3376 Script_sections
* ss
= this->script_options_
->script_sections();
3377 gold_assert(ss
->saw_sections_clause());
3378 return this->script_options_
->set_section_addresses(symtab
, this);
3381 // Place the orphan sections in the linker script.
3384 Layout::place_orphan_sections_in_script()
3386 Script_sections
* ss
= this->script_options_
->script_sections();
3387 gold_assert(ss
->saw_sections_clause());
3389 // Place each orphaned output section in the script.
3390 for (Section_list::iterator p
= this->section_list_
.begin();
3391 p
!= this->section_list_
.end();
3394 if (!(*p
)->found_in_sections_clause())
3395 ss
->place_orphan(*p
);
3399 // Count the local symbols in the regular symbol table and the dynamic
3400 // symbol table, and build the respective string pools.
3403 Layout::count_local_symbols(const Task
* task
,
3404 const Input_objects
* input_objects
)
3406 // First, figure out an upper bound on the number of symbols we'll
3407 // be inserting into each pool. This helps us create the pools with
3408 // the right size, to avoid unnecessary hashtable resizing.
3409 unsigned int symbol_count
= 0;
3410 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3411 p
!= input_objects
->relobj_end();
3413 symbol_count
+= (*p
)->local_symbol_count();
3415 // Go from "upper bound" to "estimate." We overcount for two
3416 // reasons: we double-count symbols that occur in more than one
3417 // object file, and we count symbols that are dropped from the
3418 // output. Add it all together and assume we overcount by 100%.
3421 // We assume all symbols will go into both the sympool and dynpool.
3422 this->sympool_
.reserve(symbol_count
);
3423 this->dynpool_
.reserve(symbol_count
);
3425 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3426 p
!= input_objects
->relobj_end();
3429 Task_lock_obj
<Object
> tlo(task
, *p
);
3430 (*p
)->count_local_symbols(&this->sympool_
, &this->dynpool_
);
3434 // Create the symbol table sections. Here we also set the final
3435 // values of the symbols. At this point all the loadable sections are
3436 // fully laid out. SHNUM is the number of sections so far.
3439 Layout::create_symtab_sections(const Input_objects
* input_objects
,
3440 Symbol_table
* symtab
,
3446 if (parameters
->target().get_size() == 32)
3448 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
3451 else if (parameters
->target().get_size() == 64)
3453 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
3459 // Compute file offsets relative to the start of the symtab section.
3462 // Save space for the dummy symbol at the start of the section. We
3463 // never bother to write this out--it will just be left as zero.
3465 unsigned int local_symbol_index
= 1;
3467 // Add STT_SECTION symbols for each Output section which needs one.
3468 for (Section_list::iterator p
= this->section_list_
.begin();
3469 p
!= this->section_list_
.end();
3472 if (!(*p
)->needs_symtab_index())
3473 (*p
)->set_symtab_index(-1U);
3476 (*p
)->set_symtab_index(local_symbol_index
);
3477 ++local_symbol_index
;
3482 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3483 p
!= input_objects
->relobj_end();
3486 unsigned int index
= (*p
)->finalize_local_symbols(local_symbol_index
,
3488 off
+= (index
- local_symbol_index
) * symsize
;
3489 local_symbol_index
= index
;
3492 unsigned int local_symcount
= local_symbol_index
;
3493 gold_assert(static_cast<off_t
>(local_symcount
* symsize
) == off
);
3496 size_t dyn_global_index
;
3498 if (this->dynsym_section_
== NULL
)
3501 dyn_global_index
= 0;
3506 dyn_global_index
= this->dynsym_section_
->info();
3507 off_t locsize
= dyn_global_index
* this->dynsym_section_
->entsize();
3508 dynoff
= this->dynsym_section_
->offset() + locsize
;
3509 dyncount
= (this->dynsym_section_
->data_size() - locsize
) / symsize
;
3510 gold_assert(static_cast<off_t
>(dyncount
* symsize
)
3511 == this->dynsym_section_
->data_size() - locsize
);
3514 off_t global_off
= off
;
3515 off
= symtab
->finalize(off
, dynoff
, dyn_global_index
, dyncount
,
3516 &this->sympool_
, &local_symcount
);
3518 if (!parameters
->options().strip_all())
3520 this->sympool_
.set_string_offsets();
3522 const char* symtab_name
= this->namepool_
.add(".symtab", false, NULL
);
3523 Output_section
* osymtab
= this->make_output_section(symtab_name
,
3527 this->symtab_section_
= osymtab
;
3529 Output_section_data
* pos
= new Output_data_fixed_space(off
, align
,
3531 osymtab
->add_output_section_data(pos
);
3533 // We generate a .symtab_shndx section if we have more than
3534 // SHN_LORESERVE sections. Technically it is possible that we
3535 // don't need one, because it is possible that there are no
3536 // symbols in any of sections with indexes larger than
3537 // SHN_LORESERVE. That is probably unusual, though, and it is
3538 // easier to always create one than to compute section indexes
3539 // twice (once here, once when writing out the symbols).
3540 if (shnum
>= elfcpp::SHN_LORESERVE
)
3542 const char* symtab_xindex_name
= this->namepool_
.add(".symtab_shndx",
3544 Output_section
* osymtab_xindex
=
3545 this->make_output_section(symtab_xindex_name
,
3546 elfcpp::SHT_SYMTAB_SHNDX
, 0,
3547 ORDER_INVALID
, false);
3549 size_t symcount
= off
/ symsize
;
3550 this->symtab_xindex_
= new Output_symtab_xindex(symcount
);
3552 osymtab_xindex
->add_output_section_data(this->symtab_xindex_
);
3554 osymtab_xindex
->set_link_section(osymtab
);
3555 osymtab_xindex
->set_addralign(4);
3556 osymtab_xindex
->set_entsize(4);
3558 osymtab_xindex
->set_after_input_sections();
3560 // This tells the driver code to wait until the symbol table
3561 // has written out before writing out the postprocessing
3562 // sections, including the .symtab_shndx section.
3563 this->any_postprocessing_sections_
= true;
3566 const char* strtab_name
= this->namepool_
.add(".strtab", false, NULL
);
3567 Output_section
* ostrtab
= this->make_output_section(strtab_name
,
3572 Output_section_data
* pstr
= new Output_data_strtab(&this->sympool_
);
3573 ostrtab
->add_output_section_data(pstr
);
3576 if (!parameters
->incremental_update())
3577 symtab_off
= align_address(*poff
, align
);
3580 symtab_off
= this->allocate(off
, align
, *poff
);
3582 gold_fallback(_("out of patch space for symbol table; "
3583 "relink with --incremental-full"));
3584 gold_debug(DEBUG_INCREMENTAL
,
3585 "create_symtab_sections: %08lx %08lx .symtab",
3586 static_cast<long>(symtab_off
),
3587 static_cast<long>(off
));
3590 symtab
->set_file_offset(symtab_off
+ global_off
);
3591 osymtab
->set_file_offset(symtab_off
);
3592 osymtab
->finalize_data_size();
3593 osymtab
->set_link_section(ostrtab
);
3594 osymtab
->set_info(local_symcount
);
3595 osymtab
->set_entsize(symsize
);
3597 if (symtab_off
+ off
> *poff
)
3598 *poff
= symtab_off
+ off
;
3602 // Create the .shstrtab section, which holds the names of the
3603 // sections. At the time this is called, we have created all the
3604 // output sections except .shstrtab itself.
3607 Layout::create_shstrtab()
3609 // FIXME: We don't need to create a .shstrtab section if we are
3610 // stripping everything.
3612 const char* name
= this->namepool_
.add(".shstrtab", false, NULL
);
3614 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_STRTAB
, 0,
3615 ORDER_INVALID
, false);
3617 if (strcmp(parameters
->options().compress_debug_sections(), "none") != 0)
3619 // We can't write out this section until we've set all the
3620 // section names, and we don't set the names of compressed
3621 // output sections until relocations are complete. FIXME: With
3622 // the current names we use, this is unnecessary.
3623 os
->set_after_input_sections();
3626 Output_section_data
* posd
= new Output_data_strtab(&this->namepool_
);
3627 os
->add_output_section_data(posd
);
3632 // Create the section headers. SIZE is 32 or 64. OFF is the file
3636 Layout::create_shdrs(const Output_section
* shstrtab_section
, off_t
* poff
)
3638 Output_section_headers
* oshdrs
;
3639 oshdrs
= new Output_section_headers(this,
3640 &this->segment_list_
,
3641 &this->section_list_
,
3642 &this->unattached_section_list_
,
3646 if (!parameters
->incremental_update())
3647 off
= align_address(*poff
, oshdrs
->addralign());
3650 oshdrs
->pre_finalize_data_size();
3651 off
= this->allocate(oshdrs
->data_size(), oshdrs
->addralign(), *poff
);
3653 gold_fallback(_("out of patch space for section header table; "
3654 "relink with --incremental-full"));
3655 gold_debug(DEBUG_INCREMENTAL
,
3656 "create_shdrs: %08lx %08lx (section header table)",
3657 static_cast<long>(off
),
3658 static_cast<long>(off
+ oshdrs
->data_size()));
3660 oshdrs
->set_address_and_file_offset(0, off
);
3661 off
+= oshdrs
->data_size();
3664 this->section_headers_
= oshdrs
;
3667 // Count the allocated sections.
3670 Layout::allocated_output_section_count() const
3672 size_t section_count
= 0;
3673 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
3674 p
!= this->segment_list_
.end();
3676 section_count
+= (*p
)->output_section_count();
3677 return section_count
;
3680 // Create the dynamic symbol table.
3683 Layout::create_dynamic_symtab(const Input_objects
* input_objects
,
3684 Symbol_table
* symtab
,
3685 Output_section
** pdynstr
,
3686 unsigned int* plocal_dynamic_count
,
3687 std::vector
<Symbol
*>* pdynamic_symbols
,
3688 Versions
* pversions
)
3690 // Count all the symbols in the dynamic symbol table, and set the
3691 // dynamic symbol indexes.
3693 // Skip symbol 0, which is always all zeroes.
3694 unsigned int index
= 1;
3696 // Add STT_SECTION symbols for each Output section which needs one.
3697 for (Section_list::iterator p
= this->section_list_
.begin();
3698 p
!= this->section_list_
.end();
3701 if (!(*p
)->needs_dynsym_index())
3702 (*p
)->set_dynsym_index(-1U);
3705 (*p
)->set_dynsym_index(index
);
3710 // Count the local symbols that need to go in the dynamic symbol table,
3711 // and set the dynamic symbol indexes.
3712 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3713 p
!= input_objects
->relobj_end();
3716 unsigned int new_index
= (*p
)->set_local_dynsym_indexes(index
);
3720 unsigned int local_symcount
= index
;
3721 *plocal_dynamic_count
= local_symcount
;
3723 index
= symtab
->set_dynsym_indexes(index
, pdynamic_symbols
,
3724 &this->dynpool_
, pversions
);
3728 const int size
= parameters
->target().get_size();
3731 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
3734 else if (size
== 64)
3736 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
3742 // Create the dynamic symbol table section.
3744 Output_section
* dynsym
= this->choose_output_section(NULL
, ".dynsym",
3748 ORDER_DYNAMIC_LINKER
,
3751 // Check for NULL as a linker script may discard .dynsym.
3754 Output_section_data
* odata
= new Output_data_fixed_space(index
* symsize
,
3757 dynsym
->add_output_section_data(odata
);
3759 dynsym
->set_info(local_symcount
);
3760 dynsym
->set_entsize(symsize
);
3761 dynsym
->set_addralign(align
);
3763 this->dynsym_section_
= dynsym
;
3766 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
3769 odyn
->add_section_address(elfcpp::DT_SYMTAB
, dynsym
);
3770 odyn
->add_constant(elfcpp::DT_SYMENT
, symsize
);
3773 // If there are more than SHN_LORESERVE allocated sections, we
3774 // create a .dynsym_shndx section. It is possible that we don't
3775 // need one, because it is possible that there are no dynamic
3776 // symbols in any of the sections with indexes larger than
3777 // SHN_LORESERVE. This is probably unusual, though, and at this
3778 // time we don't know the actual section indexes so it is
3779 // inconvenient to check.
3780 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE
)
3782 Output_section
* dynsym_xindex
=
3783 this->choose_output_section(NULL
, ".dynsym_shndx",
3784 elfcpp::SHT_SYMTAB_SHNDX
,
3786 false, ORDER_DYNAMIC_LINKER
, false);
3788 if (dynsym_xindex
!= NULL
)
3790 this->dynsym_xindex_
= new Output_symtab_xindex(index
);
3792 dynsym_xindex
->add_output_section_data(this->dynsym_xindex_
);
3794 dynsym_xindex
->set_link_section(dynsym
);
3795 dynsym_xindex
->set_addralign(4);
3796 dynsym_xindex
->set_entsize(4);
3798 dynsym_xindex
->set_after_input_sections();
3800 // This tells the driver code to wait until the symbol table
3801 // has written out before writing out the postprocessing
3802 // sections, including the .dynsym_shndx section.
3803 this->any_postprocessing_sections_
= true;
3807 // Create the dynamic string table section.
3809 Output_section
* dynstr
= this->choose_output_section(NULL
, ".dynstr",
3813 ORDER_DYNAMIC_LINKER
,
3818 Output_section_data
* strdata
= new Output_data_strtab(&this->dynpool_
);
3819 dynstr
->add_output_section_data(strdata
);
3822 dynsym
->set_link_section(dynstr
);
3823 if (this->dynamic_section_
!= NULL
)
3824 this->dynamic_section_
->set_link_section(dynstr
);
3828 odyn
->add_section_address(elfcpp::DT_STRTAB
, dynstr
);
3829 odyn
->add_section_size(elfcpp::DT_STRSZ
, dynstr
);
3835 // Create the hash tables.
3837 if (strcmp(parameters
->options().hash_style(), "sysv") == 0
3838 || strcmp(parameters
->options().hash_style(), "both") == 0)
3840 unsigned char* phash
;
3841 unsigned int hashlen
;
3842 Dynobj::create_elf_hash_table(*pdynamic_symbols
, local_symcount
,
3845 Output_section
* hashsec
=
3846 this->choose_output_section(NULL
, ".hash", elfcpp::SHT_HASH
,
3847 elfcpp::SHF_ALLOC
, false,
3848 ORDER_DYNAMIC_LINKER
, false);
3850 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
3854 if (hashsec
!= NULL
&& hashdata
!= NULL
)
3855 hashsec
->add_output_section_data(hashdata
);
3857 if (hashsec
!= NULL
)
3860 hashsec
->set_link_section(dynsym
);
3861 hashsec
->set_entsize(4);
3865 odyn
->add_section_address(elfcpp::DT_HASH
, hashsec
);
3868 if (strcmp(parameters
->options().hash_style(), "gnu") == 0
3869 || strcmp(parameters
->options().hash_style(), "both") == 0)
3871 unsigned char* phash
;
3872 unsigned int hashlen
;
3873 Dynobj::create_gnu_hash_table(*pdynamic_symbols
, local_symcount
,
3876 Output_section
* hashsec
=
3877 this->choose_output_section(NULL
, ".gnu.hash", elfcpp::SHT_GNU_HASH
,
3878 elfcpp::SHF_ALLOC
, false,
3879 ORDER_DYNAMIC_LINKER
, false);
3881 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
3885 if (hashsec
!= NULL
&& hashdata
!= NULL
)
3886 hashsec
->add_output_section_data(hashdata
);
3888 if (hashsec
!= NULL
)
3891 hashsec
->set_link_section(dynsym
);
3893 // For a 64-bit target, the entries in .gnu.hash do not have
3894 // a uniform size, so we only set the entry size for a
3896 if (parameters
->target().get_size() == 32)
3897 hashsec
->set_entsize(4);
3900 odyn
->add_section_address(elfcpp::DT_GNU_HASH
, hashsec
);
3905 // Assign offsets to each local portion of the dynamic symbol table.
3908 Layout::assign_local_dynsym_offsets(const Input_objects
* input_objects
)
3910 Output_section
* dynsym
= this->dynsym_section_
;
3914 off_t off
= dynsym
->offset();
3916 // Skip the dummy symbol at the start of the section.
3917 off
+= dynsym
->entsize();
3919 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3920 p
!= input_objects
->relobj_end();
3923 unsigned int count
= (*p
)->set_local_dynsym_offset(off
);
3924 off
+= count
* dynsym
->entsize();
3928 // Create the version sections.
3931 Layout::create_version_sections(const Versions
* versions
,
3932 const Symbol_table
* symtab
,
3933 unsigned int local_symcount
,
3934 const std::vector
<Symbol
*>& dynamic_symbols
,
3935 const Output_section
* dynstr
)
3937 if (!versions
->any_defs() && !versions
->any_needs())
3940 switch (parameters
->size_and_endianness())
3942 #ifdef HAVE_TARGET_32_LITTLE
3943 case Parameters::TARGET_32_LITTLE
:
3944 this->sized_create_version_sections
<32, false>(versions
, symtab
,
3946 dynamic_symbols
, dynstr
);
3949 #ifdef HAVE_TARGET_32_BIG
3950 case Parameters::TARGET_32_BIG
:
3951 this->sized_create_version_sections
<32, true>(versions
, symtab
,
3953 dynamic_symbols
, dynstr
);
3956 #ifdef HAVE_TARGET_64_LITTLE
3957 case Parameters::TARGET_64_LITTLE
:
3958 this->sized_create_version_sections
<64, false>(versions
, symtab
,
3960 dynamic_symbols
, dynstr
);
3963 #ifdef HAVE_TARGET_64_BIG
3964 case Parameters::TARGET_64_BIG
:
3965 this->sized_create_version_sections
<64, true>(versions
, symtab
,
3967 dynamic_symbols
, dynstr
);
3975 // Create the version sections, sized version.
3977 template<int size
, bool big_endian
>
3979 Layout::sized_create_version_sections(
3980 const Versions
* versions
,
3981 const Symbol_table
* symtab
,
3982 unsigned int local_symcount
,
3983 const std::vector
<Symbol
*>& dynamic_symbols
,
3984 const Output_section
* dynstr
)
3986 Output_section
* vsec
= this->choose_output_section(NULL
, ".gnu.version",
3987 elfcpp::SHT_GNU_versym
,
3990 ORDER_DYNAMIC_LINKER
,
3993 // Check for NULL since a linker script may discard this section.
3996 unsigned char* vbuf
;
3998 versions
->symbol_section_contents
<size
, big_endian
>(symtab
,
4004 Output_section_data
* vdata
= new Output_data_const_buffer(vbuf
, vsize
, 2,
4007 vsec
->add_output_section_data(vdata
);
4008 vsec
->set_entsize(2);
4009 vsec
->set_link_section(this->dynsym_section_
);
4012 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4013 if (odyn
!= NULL
&& vsec
!= NULL
)
4014 odyn
->add_section_address(elfcpp::DT_VERSYM
, vsec
);
4016 if (versions
->any_defs())
4018 Output_section
* vdsec
;
4019 vdsec
= this->choose_output_section(NULL
, ".gnu.version_d",
4020 elfcpp::SHT_GNU_verdef
,
4022 false, ORDER_DYNAMIC_LINKER
, false);
4026 unsigned char* vdbuf
;
4027 unsigned int vdsize
;
4028 unsigned int vdentries
;
4029 versions
->def_section_contents
<size
, big_endian
>(&this->dynpool_
,
4033 Output_section_data
* vddata
=
4034 new Output_data_const_buffer(vdbuf
, vdsize
, 4, "** version defs");
4036 vdsec
->add_output_section_data(vddata
);
4037 vdsec
->set_link_section(dynstr
);
4038 vdsec
->set_info(vdentries
);
4042 odyn
->add_section_address(elfcpp::DT_VERDEF
, vdsec
);
4043 odyn
->add_constant(elfcpp::DT_VERDEFNUM
, vdentries
);
4048 if (versions
->any_needs())
4050 Output_section
* vnsec
;
4051 vnsec
= this->choose_output_section(NULL
, ".gnu.version_r",
4052 elfcpp::SHT_GNU_verneed
,
4054 false, ORDER_DYNAMIC_LINKER
, false);
4058 unsigned char* vnbuf
;
4059 unsigned int vnsize
;
4060 unsigned int vnentries
;
4061 versions
->need_section_contents
<size
, big_endian
>(&this->dynpool_
,
4065 Output_section_data
* vndata
=
4066 new Output_data_const_buffer(vnbuf
, vnsize
, 4, "** version refs");
4068 vnsec
->add_output_section_data(vndata
);
4069 vnsec
->set_link_section(dynstr
);
4070 vnsec
->set_info(vnentries
);
4074 odyn
->add_section_address(elfcpp::DT_VERNEED
, vnsec
);
4075 odyn
->add_constant(elfcpp::DT_VERNEEDNUM
, vnentries
);
4081 // Create the .interp section and PT_INTERP segment.
4084 Layout::create_interp(const Target
* target
)
4086 gold_assert(this->interp_segment_
== NULL
);
4088 const char* interp
= parameters
->options().dynamic_linker();
4091 interp
= target
->dynamic_linker();
4092 gold_assert(interp
!= NULL
);
4095 size_t len
= strlen(interp
) + 1;
4097 Output_section_data
* odata
= new Output_data_const(interp
, len
, 1);
4099 Output_section
* osec
= this->choose_output_section(NULL
, ".interp",
4100 elfcpp::SHT_PROGBITS
,
4102 false, ORDER_INTERP
,
4105 osec
->add_output_section_data(odata
);
4108 // Add dynamic tags for the PLT and the dynamic relocs. This is
4109 // called by the target-specific code. This does nothing if not doing
4112 // USE_REL is true for REL relocs rather than RELA relocs.
4114 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
4116 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
4117 // and we also set DT_PLTREL. We use PLT_REL's output section, since
4118 // some targets have multiple reloc sections in PLT_REL.
4120 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
4121 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT. Again we use the output
4124 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
4128 Layout::add_target_dynamic_tags(bool use_rel
, const Output_data
* plt_got
,
4129 const Output_data
* plt_rel
,
4130 const Output_data_reloc_generic
* dyn_rel
,
4131 bool add_debug
, bool dynrel_includes_plt
)
4133 Output_data_dynamic
* odyn
= this->dynamic_data_
;
4137 if (plt_got
!= NULL
&& plt_got
->output_section() != NULL
)
4138 odyn
->add_section_address(elfcpp::DT_PLTGOT
, plt_got
);
4140 if (plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
)
4142 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, plt_rel
->output_section());
4143 odyn
->add_section_address(elfcpp::DT_JMPREL
, plt_rel
->output_section());
4144 odyn
->add_constant(elfcpp::DT_PLTREL
,
4145 use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
);
4148 if (dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
)
4150 odyn
->add_section_address(use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
,
4151 dyn_rel
->output_section());
4153 && plt_rel
->output_section() != NULL
4154 && dynrel_includes_plt
)
4155 odyn
->add_section_size(use_rel
? elfcpp::DT_RELSZ
: elfcpp::DT_RELASZ
,
4156 dyn_rel
->output_section(),
4157 plt_rel
->output_section());
4159 odyn
->add_section_size(use_rel
? elfcpp::DT_RELSZ
: elfcpp::DT_RELASZ
,
4160 dyn_rel
->output_section());
4161 const int size
= parameters
->target().get_size();
4166 rel_tag
= elfcpp::DT_RELENT
;
4168 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 32, false>::reloc_size
;
4169 else if (size
== 64)
4170 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 64, false>::reloc_size
;
4176 rel_tag
= elfcpp::DT_RELAENT
;
4178 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 32, false>::reloc_size
;
4179 else if (size
== 64)
4180 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 64, false>::reloc_size
;
4184 odyn
->add_constant(rel_tag
, rel_size
);
4186 if (parameters
->options().combreloc())
4188 size_t c
= dyn_rel
->relative_reloc_count();
4190 odyn
->add_constant((use_rel
4191 ? elfcpp::DT_RELCOUNT
4192 : elfcpp::DT_RELACOUNT
),
4197 if (add_debug
&& !parameters
->options().shared())
4199 // The value of the DT_DEBUG tag is filled in by the dynamic
4200 // linker at run time, and used by the debugger.
4201 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
4205 // Finish the .dynamic section and PT_DYNAMIC segment.
4208 Layout::finish_dynamic_section(const Input_objects
* input_objects
,
4209 const Symbol_table
* symtab
)
4211 if (!this->script_options_
->saw_phdrs_clause()
4212 && this->dynamic_section_
!= NULL
)
4214 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_DYNAMIC
,
4217 oseg
->add_output_section_to_nonload(this->dynamic_section_
,
4218 elfcpp::PF_R
| elfcpp::PF_W
);
4221 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4225 for (Input_objects::Dynobj_iterator p
= input_objects
->dynobj_begin();
4226 p
!= input_objects
->dynobj_end();
4229 if (!(*p
)->is_needed() && (*p
)->as_needed())
4231 // This dynamic object was linked with --as-needed, but it
4236 odyn
->add_string(elfcpp::DT_NEEDED
, (*p
)->soname());
4239 if (parameters
->options().shared())
4241 const char* soname
= parameters
->options().soname();
4243 odyn
->add_string(elfcpp::DT_SONAME
, soname
);
4246 Symbol
* sym
= symtab
->lookup(parameters
->options().init());
4247 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4248 odyn
->add_symbol(elfcpp::DT_INIT
, sym
);
4250 sym
= symtab
->lookup(parameters
->options().fini());
4251 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4252 odyn
->add_symbol(elfcpp::DT_FINI
, sym
);
4254 // Look for .init_array, .preinit_array and .fini_array by checking
4256 for(Layout::Section_list::const_iterator p
= this->section_list_
.begin();
4257 p
!= this->section_list_
.end();
4259 switch((*p
)->type())
4261 case elfcpp::SHT_FINI_ARRAY
:
4262 odyn
->add_section_address(elfcpp::DT_FINI_ARRAY
, *p
);
4263 odyn
->add_section_size(elfcpp::DT_FINI_ARRAYSZ
, *p
);
4265 case elfcpp::SHT_INIT_ARRAY
:
4266 odyn
->add_section_address(elfcpp::DT_INIT_ARRAY
, *p
);
4267 odyn
->add_section_size(elfcpp::DT_INIT_ARRAYSZ
, *p
);
4269 case elfcpp::SHT_PREINIT_ARRAY
:
4270 odyn
->add_section_address(elfcpp::DT_PREINIT_ARRAY
, *p
);
4271 odyn
->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ
, *p
);
4277 // Add a DT_RPATH entry if needed.
4278 const General_options::Dir_list
& rpath(parameters
->options().rpath());
4281 std::string rpath_val
;
4282 for (General_options::Dir_list::const_iterator p
= rpath
.begin();
4286 if (rpath_val
.empty())
4287 rpath_val
= p
->name();
4290 // Eliminate duplicates.
4291 General_options::Dir_list::const_iterator q
;
4292 for (q
= rpath
.begin(); q
!= p
; ++q
)
4293 if (q
->name() == p
->name())
4298 rpath_val
+= p
->name();
4303 odyn
->add_string(elfcpp::DT_RPATH
, rpath_val
);
4304 if (parameters
->options().enable_new_dtags())
4305 odyn
->add_string(elfcpp::DT_RUNPATH
, rpath_val
);
4308 // Look for text segments that have dynamic relocations.
4309 bool have_textrel
= false;
4310 if (!this->script_options_
->saw_sections_clause())
4312 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4313 p
!= this->segment_list_
.end();
4316 if ((*p
)->type() == elfcpp::PT_LOAD
4317 && ((*p
)->flags() & elfcpp::PF_W
) == 0
4318 && (*p
)->has_dynamic_reloc())
4320 have_textrel
= true;
4327 // We don't know the section -> segment mapping, so we are
4328 // conservative and just look for readonly sections with
4329 // relocations. If those sections wind up in writable segments,
4330 // then we have created an unnecessary DT_TEXTREL entry.
4331 for (Section_list::const_iterator p
= this->section_list_
.begin();
4332 p
!= this->section_list_
.end();
4335 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0
4336 && ((*p
)->flags() & elfcpp::SHF_WRITE
) == 0
4337 && (*p
)->has_dynamic_reloc())
4339 have_textrel
= true;
4345 if (parameters
->options().filter() != NULL
)
4346 odyn
->add_string(elfcpp::DT_FILTER
, parameters
->options().filter());
4347 if (parameters
->options().any_auxiliary())
4349 for (options::String_set::const_iterator p
=
4350 parameters
->options().auxiliary_begin();
4351 p
!= parameters
->options().auxiliary_end();
4353 odyn
->add_string(elfcpp::DT_AUXILIARY
, *p
);
4356 // Add a DT_FLAGS entry if necessary.
4357 unsigned int flags
= 0;
4360 // Add a DT_TEXTREL for compatibility with older loaders.
4361 odyn
->add_constant(elfcpp::DT_TEXTREL
, 0);
4362 flags
|= elfcpp::DF_TEXTREL
;
4364 if (parameters
->options().text())
4365 gold_error(_("read-only segment has dynamic relocations"));
4366 else if (parameters
->options().warn_shared_textrel()
4367 && parameters
->options().shared())
4368 gold_warning(_("shared library text segment is not shareable"));
4370 if (parameters
->options().shared() && this->has_static_tls())
4371 flags
|= elfcpp::DF_STATIC_TLS
;
4372 if (parameters
->options().origin())
4373 flags
|= elfcpp::DF_ORIGIN
;
4374 if (parameters
->options().Bsymbolic())
4376 flags
|= elfcpp::DF_SYMBOLIC
;
4377 // Add DT_SYMBOLIC for compatibility with older loaders.
4378 odyn
->add_constant(elfcpp::DT_SYMBOLIC
, 0);
4380 if (parameters
->options().now())
4381 flags
|= elfcpp::DF_BIND_NOW
;
4383 odyn
->add_constant(elfcpp::DT_FLAGS
, flags
);
4386 if (parameters
->options().initfirst())
4387 flags
|= elfcpp::DF_1_INITFIRST
;
4388 if (parameters
->options().interpose())
4389 flags
|= elfcpp::DF_1_INTERPOSE
;
4390 if (parameters
->options().loadfltr())
4391 flags
|= elfcpp::DF_1_LOADFLTR
;
4392 if (parameters
->options().nodefaultlib())
4393 flags
|= elfcpp::DF_1_NODEFLIB
;
4394 if (parameters
->options().nodelete())
4395 flags
|= elfcpp::DF_1_NODELETE
;
4396 if (parameters
->options().nodlopen())
4397 flags
|= elfcpp::DF_1_NOOPEN
;
4398 if (parameters
->options().nodump())
4399 flags
|= elfcpp::DF_1_NODUMP
;
4400 if (!parameters
->options().shared())
4401 flags
&= ~(elfcpp::DF_1_INITFIRST
4402 | elfcpp::DF_1_NODELETE
4403 | elfcpp::DF_1_NOOPEN
);
4404 if (parameters
->options().origin())
4405 flags
|= elfcpp::DF_1_ORIGIN
;
4406 if (parameters
->options().now())
4407 flags
|= elfcpp::DF_1_NOW
;
4408 if (parameters
->options().Bgroup())
4409 flags
|= elfcpp::DF_1_GROUP
;
4411 odyn
->add_constant(elfcpp::DT_FLAGS_1
, flags
);
4414 // Set the size of the _DYNAMIC symbol table to be the size of the
4418 Layout::set_dynamic_symbol_size(const Symbol_table
* symtab
)
4420 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4423 odyn
->finalize_data_size();
4424 if (this->dynamic_symbol_
== NULL
)
4426 off_t data_size
= odyn
->data_size();
4427 const int size
= parameters
->target().get_size();
4429 symtab
->get_sized_symbol
<32>(this->dynamic_symbol_
)->set_symsize(data_size
);
4430 else if (size
== 64)
4431 symtab
->get_sized_symbol
<64>(this->dynamic_symbol_
)->set_symsize(data_size
);
4436 // The mapping of input section name prefixes to output section names.
4437 // In some cases one prefix is itself a prefix of another prefix; in
4438 // such a case the longer prefix must come first. These prefixes are
4439 // based on the GNU linker default ELF linker script.
4441 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
4442 const Layout::Section_name_mapping
Layout::section_name_mapping
[] =
4444 MAPPING_INIT(".text.", ".text"),
4445 MAPPING_INIT(".rodata.", ".rodata"),
4446 MAPPING_INIT(".data.rel.ro.local", ".data.rel.ro.local"),
4447 MAPPING_INIT(".data.rel.ro", ".data.rel.ro"),
4448 MAPPING_INIT(".data.", ".data"),
4449 MAPPING_INIT(".bss.", ".bss"),
4450 MAPPING_INIT(".tdata.", ".tdata"),
4451 MAPPING_INIT(".tbss.", ".tbss"),
4452 MAPPING_INIT(".init_array.", ".init_array"),
4453 MAPPING_INIT(".fini_array.", ".fini_array"),
4454 MAPPING_INIT(".sdata.", ".sdata"),
4455 MAPPING_INIT(".sbss.", ".sbss"),
4456 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
4457 // differently depending on whether it is creating a shared library.
4458 MAPPING_INIT(".sdata2.", ".sdata"),
4459 MAPPING_INIT(".sbss2.", ".sbss"),
4460 MAPPING_INIT(".lrodata.", ".lrodata"),
4461 MAPPING_INIT(".ldata.", ".ldata"),
4462 MAPPING_INIT(".lbss.", ".lbss"),
4463 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
4464 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
4465 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
4466 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
4467 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
4468 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
4469 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
4470 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
4471 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
4472 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
4473 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
4474 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
4475 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
4476 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
4477 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
4478 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
4479 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
4480 MAPPING_INIT(".ARM.extab", ".ARM.extab"),
4481 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
4482 MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
4483 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
4487 const int Layout::section_name_mapping_count
=
4488 (sizeof(Layout::section_name_mapping
)
4489 / sizeof(Layout::section_name_mapping
[0]));
4491 // Choose the output section name to use given an input section name.
4492 // Set *PLEN to the length of the name. *PLEN is initialized to the
4496 Layout::output_section_name(const Relobj
* relobj
, const char* name
,
4499 // gcc 4.3 generates the following sorts of section names when it
4500 // needs a section name specific to a function:
4506 // .data.rel.local.FN
4508 // .data.rel.ro.local.FN
4515 // The GNU linker maps all of those to the part before the .FN,
4516 // except that .data.rel.local.FN is mapped to .data, and
4517 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
4518 // beginning with .data.rel.ro.local are grouped together.
4520 // For an anonymous namespace, the string FN can contain a '.'.
4522 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
4523 // GNU linker maps to .rodata.
4525 // The .data.rel.ro sections are used with -z relro. The sections
4526 // are recognized by name. We use the same names that the GNU
4527 // linker does for these sections.
4529 // It is hard to handle this in a principled way, so we don't even
4530 // try. We use a table of mappings. If the input section name is
4531 // not found in the table, we simply use it as the output section
4534 const Section_name_mapping
* psnm
= section_name_mapping
;
4535 for (int i
= 0; i
< section_name_mapping_count
; ++i
, ++psnm
)
4537 if (strncmp(name
, psnm
->from
, psnm
->fromlen
) == 0)
4539 *plen
= psnm
->tolen
;
4544 // As an additional complication, .ctors sections are output in
4545 // either .ctors or .init_array sections, and .dtors sections are
4546 // output in either .dtors or .fini_array sections.
4547 if (is_prefix_of(".ctors.", name
) || is_prefix_of(".dtors.", name
))
4549 if (parameters
->options().ctors_in_init_array())
4552 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4557 return name
[1] == 'c' ? ".ctors" : ".dtors";
4560 if (parameters
->options().ctors_in_init_array()
4561 && (strcmp(name
, ".ctors") == 0 || strcmp(name
, ".dtors") == 0))
4563 // To make .init_array/.fini_array work with gcc we must exclude
4564 // .ctors and .dtors sections from the crtbegin and crtend
4567 || (!Layout::match_file_name(relobj
, "crtbegin")
4568 && !Layout::match_file_name(relobj
, "crtend")))
4571 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4578 // Return true if RELOBJ is an input file whose base name matches
4579 // FILE_NAME. The base name must have an extension of ".o", and must
4580 // be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is
4581 // to match crtbegin.o as well as crtbeginS.o without getting confused
4582 // by other possibilities. Overall matching the file name this way is
4583 // a dreadful hack, but the GNU linker does it in order to better
4584 // support gcc, and we need to be compatible.
4587 Layout::match_file_name(const Relobj
* relobj
, const char* match
)
4589 const std::string
& file_name(relobj
->name());
4590 const char* base_name
= lbasename(file_name
.c_str());
4591 size_t match_len
= strlen(match
);
4592 if (strncmp(base_name
, match
, match_len
) != 0)
4594 size_t base_len
= strlen(base_name
);
4595 if (base_len
!= match_len
+ 2 && base_len
!= match_len
+ 3)
4597 return memcmp(base_name
+ base_len
- 2, ".o", 2) == 0;
4600 // Check if a comdat group or .gnu.linkonce section with the given
4601 // NAME is selected for the link. If there is already a section,
4602 // *KEPT_SECTION is set to point to the existing section and the
4603 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
4604 // IS_GROUP_NAME are recorded for this NAME in the layout object,
4605 // *KEPT_SECTION is set to the internal copy and the function returns
4609 Layout::find_or_add_kept_section(const std::string
& name
,
4614 Kept_section
** kept_section
)
4616 // It's normal to see a couple of entries here, for the x86 thunk
4617 // sections. If we see more than a few, we're linking a C++
4618 // program, and we resize to get more space to minimize rehashing.
4619 if (this->signatures_
.size() > 4
4620 && !this->resized_signatures_
)
4622 reserve_unordered_map(&this->signatures_
,
4623 this->number_of_input_files_
* 64);
4624 this->resized_signatures_
= true;
4627 Kept_section candidate
;
4628 std::pair
<Signatures::iterator
, bool> ins
=
4629 this->signatures_
.insert(std::make_pair(name
, candidate
));
4631 if (kept_section
!= NULL
)
4632 *kept_section
= &ins
.first
->second
;
4635 // This is the first time we've seen this signature.
4636 ins
.first
->second
.set_object(object
);
4637 ins
.first
->second
.set_shndx(shndx
);
4639 ins
.first
->second
.set_is_comdat();
4641 ins
.first
->second
.set_is_group_name();
4645 // We have already seen this signature.
4647 if (ins
.first
->second
.is_group_name())
4649 // We've already seen a real section group with this signature.
4650 // If the kept group is from a plugin object, and we're in the
4651 // replacement phase, accept the new one as a replacement.
4652 if (ins
.first
->second
.object() == NULL
4653 && parameters
->options().plugins()->in_replacement_phase())
4655 ins
.first
->second
.set_object(object
);
4656 ins
.first
->second
.set_shndx(shndx
);
4661 else if (is_group_name
)
4663 // This is a real section group, and we've already seen a
4664 // linkonce section with this signature. Record that we've seen
4665 // a section group, and don't include this section group.
4666 ins
.first
->second
.set_is_group_name();
4671 // We've already seen a linkonce section and this is a linkonce
4672 // section. These don't block each other--this may be the same
4673 // symbol name with different section types.
4678 // Store the allocated sections into the section list.
4681 Layout::get_allocated_sections(Section_list
* section_list
) const
4683 for (Section_list::const_iterator p
= this->section_list_
.begin();
4684 p
!= this->section_list_
.end();
4686 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0)
4687 section_list
->push_back(*p
);
4690 // Create an output segment.
4693 Layout::make_output_segment(elfcpp::Elf_Word type
, elfcpp::Elf_Word flags
)
4695 gold_assert(!parameters
->options().relocatable());
4696 Output_segment
* oseg
= new Output_segment(type
, flags
);
4697 this->segment_list_
.push_back(oseg
);
4699 if (type
== elfcpp::PT_TLS
)
4700 this->tls_segment_
= oseg
;
4701 else if (type
== elfcpp::PT_GNU_RELRO
)
4702 this->relro_segment_
= oseg
;
4703 else if (type
== elfcpp::PT_INTERP
)
4704 this->interp_segment_
= oseg
;
4709 // Return the file offset of the normal symbol table.
4712 Layout::symtab_section_offset() const
4714 if (this->symtab_section_
!= NULL
)
4715 return this->symtab_section_
->offset();
4719 // Return the section index of the normal symbol table. It may have
4720 // been stripped by the -s/--strip-all option.
4723 Layout::symtab_section_shndx() const
4725 if (this->symtab_section_
!= NULL
)
4726 return this->symtab_section_
->out_shndx();
4730 // Write out the Output_sections. Most won't have anything to write,
4731 // since most of the data will come from input sections which are
4732 // handled elsewhere. But some Output_sections do have Output_data.
4735 Layout::write_output_sections(Output_file
* of
) const
4737 for (Section_list::const_iterator p
= this->section_list_
.begin();
4738 p
!= this->section_list_
.end();
4741 if (!(*p
)->after_input_sections())
4746 // Write out data not associated with a section or the symbol table.
4749 Layout::write_data(const Symbol_table
* symtab
, Output_file
* of
) const
4751 if (!parameters
->options().strip_all())
4753 const Output_section
* symtab_section
= this->symtab_section_
;
4754 for (Section_list::const_iterator p
= this->section_list_
.begin();
4755 p
!= this->section_list_
.end();
4758 if ((*p
)->needs_symtab_index())
4760 gold_assert(symtab_section
!= NULL
);
4761 unsigned int index
= (*p
)->symtab_index();
4762 gold_assert(index
> 0 && index
!= -1U);
4763 off_t off
= (symtab_section
->offset()
4764 + index
* symtab_section
->entsize());
4765 symtab
->write_section_symbol(*p
, this->symtab_xindex_
, of
, off
);
4770 const Output_section
* dynsym_section
= this->dynsym_section_
;
4771 for (Section_list::const_iterator p
= this->section_list_
.begin();
4772 p
!= this->section_list_
.end();
4775 if ((*p
)->needs_dynsym_index())
4777 gold_assert(dynsym_section
!= NULL
);
4778 unsigned int index
= (*p
)->dynsym_index();
4779 gold_assert(index
> 0 && index
!= -1U);
4780 off_t off
= (dynsym_section
->offset()
4781 + index
* dynsym_section
->entsize());
4782 symtab
->write_section_symbol(*p
, this->dynsym_xindex_
, of
, off
);
4786 // Write out the Output_data which are not in an Output_section.
4787 for (Data_list::const_iterator p
= this->special_output_list_
.begin();
4788 p
!= this->special_output_list_
.end();
4793 // Write out the Output_sections which can only be written after the
4794 // input sections are complete.
4797 Layout::write_sections_after_input_sections(Output_file
* of
)
4799 // Determine the final section offsets, and thus the final output
4800 // file size. Note we finalize the .shstrab last, to allow the
4801 // after_input_section sections to modify their section-names before
4803 if (this->any_postprocessing_sections_
)
4805 off_t off
= this->output_file_size_
;
4806 off
= this->set_section_offsets(off
, POSTPROCESSING_SECTIONS_PASS
);
4808 // Now that we've finalized the names, we can finalize the shstrab.
4810 this->set_section_offsets(off
,
4811 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
4813 if (off
> this->output_file_size_
)
4816 this->output_file_size_
= off
;
4820 for (Section_list::const_iterator p
= this->section_list_
.begin();
4821 p
!= this->section_list_
.end();
4824 if ((*p
)->after_input_sections())
4828 this->section_headers_
->write(of
);
4831 // If the build ID requires computing a checksum, do so here, and
4832 // write it out. We compute a checksum over the entire file because
4833 // that is simplest.
4836 Layout::write_build_id(Output_file
* of
) const
4838 if (this->build_id_note_
== NULL
)
4841 const unsigned char* iv
= of
->get_input_view(0, this->output_file_size_
);
4843 unsigned char* ov
= of
->get_output_view(this->build_id_note_
->offset(),
4844 this->build_id_note_
->data_size());
4846 const char* style
= parameters
->options().build_id();
4847 if (strcmp(style
, "sha1") == 0)
4850 sha1_init_ctx(&ctx
);
4851 sha1_process_bytes(iv
, this->output_file_size_
, &ctx
);
4852 sha1_finish_ctx(&ctx
, ov
);
4854 else if (strcmp(style
, "md5") == 0)
4858 md5_process_bytes(iv
, this->output_file_size_
, &ctx
);
4859 md5_finish_ctx(&ctx
, ov
);
4864 of
->write_output_view(this->build_id_note_
->offset(),
4865 this->build_id_note_
->data_size(),
4868 of
->free_input_view(0, this->output_file_size_
, iv
);
4871 // Write out a binary file. This is called after the link is
4872 // complete. IN is the temporary output file we used to generate the
4873 // ELF code. We simply walk through the segments, read them from
4874 // their file offset in IN, and write them to their load address in
4875 // the output file. FIXME: with a bit more work, we could support
4876 // S-records and/or Intel hex format here.
4879 Layout::write_binary(Output_file
* in
) const
4881 gold_assert(parameters
->options().oformat_enum()
4882 == General_options::OBJECT_FORMAT_BINARY
);
4884 // Get the size of the binary file.
4885 uint64_t max_load_address
= 0;
4886 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4887 p
!= this->segment_list_
.end();
4890 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
4892 uint64_t max_paddr
= (*p
)->paddr() + (*p
)->filesz();
4893 if (max_paddr
> max_load_address
)
4894 max_load_address
= max_paddr
;
4898 Output_file
out(parameters
->options().output_file_name());
4899 out
.open(max_load_address
);
4901 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4902 p
!= this->segment_list_
.end();
4905 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
4907 const unsigned char* vin
= in
->get_input_view((*p
)->offset(),
4909 unsigned char* vout
= out
.get_output_view((*p
)->paddr(),
4911 memcpy(vout
, vin
, (*p
)->filesz());
4912 out
.write_output_view((*p
)->paddr(), (*p
)->filesz(), vout
);
4913 in
->free_input_view((*p
)->offset(), (*p
)->filesz(), vin
);
4920 // Print the output sections to the map file.
4923 Layout::print_to_mapfile(Mapfile
* mapfile
) const
4925 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4926 p
!= this->segment_list_
.end();
4928 (*p
)->print_sections_to_mapfile(mapfile
);
4931 // Print statistical information to stderr. This is used for --stats.
4934 Layout::print_stats() const
4936 this->namepool_
.print_stats("section name pool");
4937 this->sympool_
.print_stats("output symbol name pool");
4938 this->dynpool_
.print_stats("dynamic name pool");
4940 for (Section_list::const_iterator p
= this->section_list_
.begin();
4941 p
!= this->section_list_
.end();
4943 (*p
)->print_merge_stats();
4946 // Write_sections_task methods.
4948 // We can always run this task.
4951 Write_sections_task::is_runnable()
4956 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
4960 Write_sections_task::locks(Task_locker
* tl
)
4962 tl
->add(this, this->output_sections_blocker_
);
4963 tl
->add(this, this->final_blocker_
);
4966 // Run the task--write out the data.
4969 Write_sections_task::run(Workqueue
*)
4971 this->layout_
->write_output_sections(this->of_
);
4974 // Write_data_task methods.
4976 // We can always run this task.
4979 Write_data_task::is_runnable()
4984 // We need to unlock FINAL_BLOCKER when finished.
4987 Write_data_task::locks(Task_locker
* tl
)
4989 tl
->add(this, this->final_blocker_
);
4992 // Run the task--write out the data.
4995 Write_data_task::run(Workqueue
*)
4997 this->layout_
->write_data(this->symtab_
, this->of_
);
5000 // Write_symbols_task methods.
5002 // We can always run this task.
5005 Write_symbols_task::is_runnable()
5010 // We need to unlock FINAL_BLOCKER when finished.
5013 Write_symbols_task::locks(Task_locker
* tl
)
5015 tl
->add(this, this->final_blocker_
);
5018 // Run the task--write out the symbols.
5021 Write_symbols_task::run(Workqueue
*)
5023 this->symtab_
->write_globals(this->sympool_
, this->dynpool_
,
5024 this->layout_
->symtab_xindex(),
5025 this->layout_
->dynsym_xindex(), this->of_
);
5028 // Write_after_input_sections_task methods.
5030 // We can only run this task after the input sections have completed.
5033 Write_after_input_sections_task::is_runnable()
5035 if (this->input_sections_blocker_
->is_blocked())
5036 return this->input_sections_blocker_
;
5040 // We need to unlock FINAL_BLOCKER when finished.
5043 Write_after_input_sections_task::locks(Task_locker
* tl
)
5045 tl
->add(this, this->final_blocker_
);
5051 Write_after_input_sections_task::run(Workqueue
*)
5053 this->layout_
->write_sections_after_input_sections(this->of_
);
5056 // Close_task_runner methods.
5058 // Run the task--close the file.
5061 Close_task_runner::run(Workqueue
*, const Task
*)
5063 // If we need to compute a checksum for the BUILD if, we do so here.
5064 this->layout_
->write_build_id(this->of_
);
5066 // If we've been asked to create a binary file, we do so here.
5067 if (this->options_
->oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
5068 this->layout_
->write_binary(this->of_
);
5073 // Instantiate the templates we need. We could use the configure
5074 // script to restrict this to only the ones for implemented targets.
5076 #ifdef HAVE_TARGET_32_LITTLE
5079 Layout::init_fixed_output_section
<32, false>(
5081 elfcpp::Shdr
<32, false>& shdr
);
5084 #ifdef HAVE_TARGET_32_BIG
5087 Layout::init_fixed_output_section
<32, true>(
5089 elfcpp::Shdr
<32, true>& shdr
);
5092 #ifdef HAVE_TARGET_64_LITTLE
5095 Layout::init_fixed_output_section
<64, false>(
5097 elfcpp::Shdr
<64, false>& shdr
);
5100 #ifdef HAVE_TARGET_64_BIG
5103 Layout::init_fixed_output_section
<64, true>(
5105 elfcpp::Shdr
<64, true>& shdr
);
5108 #ifdef HAVE_TARGET_32_LITTLE
5111 Layout::layout
<32, false>(Sized_relobj_file
<32, false>* object
,
5114 const elfcpp::Shdr
<32, false>& shdr
,
5115 unsigned int, unsigned int, off_t
*);
5118 #ifdef HAVE_TARGET_32_BIG
5121 Layout::layout
<32, true>(Sized_relobj_file
<32, true>* object
,
5124 const elfcpp::Shdr
<32, true>& shdr
,
5125 unsigned int, unsigned int, off_t
*);
5128 #ifdef HAVE_TARGET_64_LITTLE
5131 Layout::layout
<64, false>(Sized_relobj_file
<64, false>* object
,
5134 const elfcpp::Shdr
<64, false>& shdr
,
5135 unsigned int, unsigned int, off_t
*);
5138 #ifdef HAVE_TARGET_64_BIG
5141 Layout::layout
<64, true>(Sized_relobj_file
<64, true>* object
,
5144 const elfcpp::Shdr
<64, true>& shdr
,
5145 unsigned int, unsigned int, off_t
*);
5148 #ifdef HAVE_TARGET_32_LITTLE
5151 Layout::layout_reloc
<32, false>(Sized_relobj_file
<32, false>* object
,
5152 unsigned int reloc_shndx
,
5153 const elfcpp::Shdr
<32, false>& shdr
,
5154 Output_section
* data_section
,
5155 Relocatable_relocs
* rr
);
5158 #ifdef HAVE_TARGET_32_BIG
5161 Layout::layout_reloc
<32, true>(Sized_relobj_file
<32, true>* object
,
5162 unsigned int reloc_shndx
,
5163 const elfcpp::Shdr
<32, true>& shdr
,
5164 Output_section
* data_section
,
5165 Relocatable_relocs
* rr
);
5168 #ifdef HAVE_TARGET_64_LITTLE
5171 Layout::layout_reloc
<64, false>(Sized_relobj_file
<64, false>* object
,
5172 unsigned int reloc_shndx
,
5173 const elfcpp::Shdr
<64, false>& shdr
,
5174 Output_section
* data_section
,
5175 Relocatable_relocs
* rr
);
5178 #ifdef HAVE_TARGET_64_BIG
5181 Layout::layout_reloc
<64, true>(Sized_relobj_file
<64, true>* object
,
5182 unsigned int reloc_shndx
,
5183 const elfcpp::Shdr
<64, true>& shdr
,
5184 Output_section
* data_section
,
5185 Relocatable_relocs
* rr
);
5188 #ifdef HAVE_TARGET_32_LITTLE
5191 Layout::layout_group
<32, false>(Symbol_table
* symtab
,
5192 Sized_relobj_file
<32, false>* object
,
5194 const char* group_section_name
,
5195 const char* signature
,
5196 const elfcpp::Shdr
<32, false>& shdr
,
5197 elfcpp::Elf_Word flags
,
5198 std::vector
<unsigned int>* shndxes
);
5201 #ifdef HAVE_TARGET_32_BIG
5204 Layout::layout_group
<32, true>(Symbol_table
* symtab
,
5205 Sized_relobj_file
<32, true>* object
,
5207 const char* group_section_name
,
5208 const char* signature
,
5209 const elfcpp::Shdr
<32, true>& shdr
,
5210 elfcpp::Elf_Word flags
,
5211 std::vector
<unsigned int>* shndxes
);
5214 #ifdef HAVE_TARGET_64_LITTLE
5217 Layout::layout_group
<64, false>(Symbol_table
* symtab
,
5218 Sized_relobj_file
<64, false>* object
,
5220 const char* group_section_name
,
5221 const char* signature
,
5222 const elfcpp::Shdr
<64, false>& shdr
,
5223 elfcpp::Elf_Word flags
,
5224 std::vector
<unsigned int>* shndxes
);
5227 #ifdef HAVE_TARGET_64_BIG
5230 Layout::layout_group
<64, true>(Symbol_table
* symtab
,
5231 Sized_relobj_file
<64, true>* object
,
5233 const char* group_section_name
,
5234 const char* signature
,
5235 const elfcpp::Shdr
<64, true>& shdr
,
5236 elfcpp::Elf_Word flags
,
5237 std::vector
<unsigned int>* shndxes
);
5240 #ifdef HAVE_TARGET_32_LITTLE
5243 Layout::layout_eh_frame
<32, false>(Sized_relobj_file
<32, false>* object
,
5244 const unsigned char* symbols
,
5246 const unsigned char* symbol_names
,
5247 off_t symbol_names_size
,
5249 const elfcpp::Shdr
<32, false>& shdr
,
5250 unsigned int reloc_shndx
,
5251 unsigned int reloc_type
,
5255 #ifdef HAVE_TARGET_32_BIG
5258 Layout::layout_eh_frame
<32, true>(Sized_relobj_file
<32, true>* object
,
5259 const unsigned char* symbols
,
5261 const unsigned char* symbol_names
,
5262 off_t symbol_names_size
,
5264 const elfcpp::Shdr
<32, true>& shdr
,
5265 unsigned int reloc_shndx
,
5266 unsigned int reloc_type
,
5270 #ifdef HAVE_TARGET_64_LITTLE
5273 Layout::layout_eh_frame
<64, false>(Sized_relobj_file
<64, false>* object
,
5274 const unsigned char* symbols
,
5276 const unsigned char* symbol_names
,
5277 off_t symbol_names_size
,
5279 const elfcpp::Shdr
<64, false>& shdr
,
5280 unsigned int reloc_shndx
,
5281 unsigned int reloc_type
,
5285 #ifdef HAVE_TARGET_64_BIG
5288 Layout::layout_eh_frame
<64, true>(Sized_relobj_file
<64, true>* object
,
5289 const unsigned char* symbols
,
5291 const unsigned char* symbol_names
,
5292 off_t symbol_names_size
,
5294 const elfcpp::Shdr
<64, true>& shdr
,
5295 unsigned int reloc_shndx
,
5296 unsigned int reloc_type
,
5300 } // End namespace gold.