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 input_section_position_(),
414 input_section_glob_(),
415 incremental_base_(NULL
),
418 // Make space for more than enough segments for a typical file.
419 // This is just for efficiency--it's OK if we wind up needing more.
420 this->segment_list_
.reserve(12);
422 // We expect two unattached Output_data objects: the file header and
423 // the segment headers.
424 this->special_output_list_
.reserve(2);
426 // Initialize structure needed for an incremental build.
427 if (parameters
->incremental())
428 this->incremental_inputs_
= new Incremental_inputs
;
430 // The section name pool is worth optimizing in all cases, because
431 // it is small, but there are often overlaps due to .rel sections.
432 this->namepool_
.set_optimize();
435 // For incremental links, record the base file to be modified.
438 Layout::set_incremental_base(Incremental_binary
* base
)
440 this->incremental_base_
= base
;
441 this->free_list_
.init(base
->output_file()->filesize(), true);
444 // Hash a key we use to look up an output section mapping.
447 Layout::Hash_key::operator()(const Layout::Key
& k
) const
449 return k
.first
+ k
.second
.first
+ k
.second
.second
;
452 // Returns whether the given section is in the list of
453 // debug-sections-used-by-some-version-of-gdb. Currently,
454 // we've checked versions of gdb up to and including 6.7.1.
456 static const char* gdb_sections
[] =
458 // ".debug_aranges", // not used by gdb as of 6.7.1
465 // ".debug_pubnames", // not used by gdb as of 6.7.1
470 static const char* lines_only_debug_sections
[] =
472 // ".debug_aranges", // not used by gdb as of 6.7.1
479 // ".debug_pubnames", // not used by gdb as of 6.7.1
485 is_gdb_debug_section(const char* str
)
487 // We can do this faster: binary search or a hashtable. But why bother?
488 for (size_t i
= 0; i
< sizeof(gdb_sections
)/sizeof(*gdb_sections
); ++i
)
489 if (strcmp(str
, gdb_sections
[i
]) == 0)
495 is_lines_only_debug_section(const char* str
)
497 // We can do this faster: binary search or a hashtable. But why bother?
499 i
< sizeof(lines_only_debug_sections
)/sizeof(*lines_only_debug_sections
);
501 if (strcmp(str
, lines_only_debug_sections
[i
]) == 0)
506 // Sometimes we compress sections. This is typically done for
507 // sections that are not part of normal program execution (such as
508 // .debug_* sections), and where the readers of these sections know
509 // how to deal with compressed sections. This routine doesn't say for
510 // certain whether we'll compress -- it depends on commandline options
511 // as well -- just whether this section is a candidate for compression.
512 // (The Output_compressed_section class decides whether to compress
513 // a given section, and picks the name of the compressed section.)
516 is_compressible_debug_section(const char* secname
)
518 return (is_prefix_of(".debug", secname
));
521 // We may see compressed debug sections in input files. Return TRUE
522 // if this is the name of a compressed debug section.
525 is_compressed_debug_section(const char* secname
)
527 return (is_prefix_of(".zdebug", secname
));
530 // Whether to include this section in the link.
532 template<int size
, bool big_endian
>
534 Layout::include_section(Sized_relobj_file
<size
, big_endian
>*, const char* name
,
535 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
537 if (shdr
.get_sh_flags() & elfcpp::SHF_EXCLUDE
)
540 switch (shdr
.get_sh_type())
542 case elfcpp::SHT_NULL
:
543 case elfcpp::SHT_SYMTAB
:
544 case elfcpp::SHT_DYNSYM
:
545 case elfcpp::SHT_HASH
:
546 case elfcpp::SHT_DYNAMIC
:
547 case elfcpp::SHT_SYMTAB_SHNDX
:
550 case elfcpp::SHT_STRTAB
:
551 // Discard the sections which have special meanings in the ELF
552 // ABI. Keep others (e.g., .stabstr). We could also do this by
553 // checking the sh_link fields of the appropriate sections.
554 return (strcmp(name
, ".dynstr") != 0
555 && strcmp(name
, ".strtab") != 0
556 && strcmp(name
, ".shstrtab") != 0);
558 case elfcpp::SHT_RELA
:
559 case elfcpp::SHT_REL
:
560 case elfcpp::SHT_GROUP
:
561 // If we are emitting relocations these should be handled
563 gold_assert(!parameters
->options().relocatable()
564 && !parameters
->options().emit_relocs());
567 case elfcpp::SHT_PROGBITS
:
568 if (parameters
->options().strip_debug()
569 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
571 if (is_debug_info_section(name
))
574 if (parameters
->options().strip_debug_non_line()
575 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
577 // Debugging sections can only be recognized by name.
578 if (is_prefix_of(".debug", name
)
579 && !is_lines_only_debug_section(name
))
582 if (parameters
->options().strip_debug_gdb()
583 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
585 // Debugging sections can only be recognized by name.
586 if (is_prefix_of(".debug", name
)
587 && !is_gdb_debug_section(name
))
590 if (parameters
->options().strip_lto_sections()
591 && !parameters
->options().relocatable()
592 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
594 // Ignore LTO sections containing intermediate code.
595 if (is_prefix_of(".gnu.lto_", name
))
598 // The GNU linker strips .gnu_debuglink sections, so we do too.
599 // This is a feature used to keep debugging information in
601 if (strcmp(name
, ".gnu_debuglink") == 0)
610 // Return an output section named NAME, or NULL if there is none.
613 Layout::find_output_section(const char* name
) const
615 for (Section_list::const_iterator p
= this->section_list_
.begin();
616 p
!= this->section_list_
.end();
618 if (strcmp((*p
)->name(), name
) == 0)
623 // Return an output segment of type TYPE, with segment flags SET set
624 // and segment flags CLEAR clear. Return NULL if there is none.
627 Layout::find_output_segment(elfcpp::PT type
, elfcpp::Elf_Word set
,
628 elfcpp::Elf_Word clear
) const
630 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
631 p
!= this->segment_list_
.end();
633 if (static_cast<elfcpp::PT
>((*p
)->type()) == type
634 && ((*p
)->flags() & set
) == set
635 && ((*p
)->flags() & clear
) == 0)
640 // When we put a .ctors or .dtors section with more than one word into
641 // a .init_array or .fini_array section, we need to reverse the words
642 // in the .ctors/.dtors section. This is because .init_array executes
643 // constructors front to back, where .ctors executes them back to
644 // front, and vice-versa for .fini_array/.dtors. Although we do want
645 // to remap .ctors/.dtors into .init_array/.fini_array because it can
646 // be more efficient, we don't want to change the order in which
647 // constructors/destructors are run. This set just keeps track of
648 // these sections which need to be reversed. It is only changed by
649 // Layout::layout. It should be a private member of Layout, but that
650 // would require layout.h to #include object.h to get the definition
652 static Unordered_set
<Section_id
, Section_id_hash
> ctors_sections_in_init_array
;
654 // Return whether OBJECT/SHNDX is a .ctors/.dtors section mapped to a
655 // .init_array/.fini_array section.
658 Layout::is_ctors_in_init_array(Relobj
* relobj
, unsigned int shndx
) const
660 return (ctors_sections_in_init_array
.find(Section_id(relobj
, shndx
))
661 != ctors_sections_in_init_array
.end());
664 // Return the output section to use for section NAME with type TYPE
665 // and section flags FLAGS. NAME must be canonicalized in the string
666 // pool, and NAME_KEY is the key. ORDER is where this should appear
667 // in the output sections. IS_RELRO is true for a relro section.
670 Layout::get_output_section(const char* name
, Stringpool::Key name_key
,
671 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
672 Output_section_order order
, bool is_relro
)
674 elfcpp::Elf_Word lookup_type
= type
;
676 // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and
677 // PREINIT_ARRAY like PROGBITS. This ensures that we combine
678 // .init_array, .fini_array, and .preinit_array sections by name
679 // whatever their type in the input file. We do this because the
680 // types are not always right in the input files.
681 if (lookup_type
== elfcpp::SHT_INIT_ARRAY
682 || lookup_type
== elfcpp::SHT_FINI_ARRAY
683 || lookup_type
== elfcpp::SHT_PREINIT_ARRAY
)
684 lookup_type
= elfcpp::SHT_PROGBITS
;
686 elfcpp::Elf_Xword lookup_flags
= flags
;
688 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
689 // read-write with read-only sections. Some other ELF linkers do
690 // not do this. FIXME: Perhaps there should be an option
692 lookup_flags
&= ~(elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
694 const Key
key(name_key
, std::make_pair(lookup_type
, lookup_flags
));
695 const std::pair
<Key
, Output_section
*> v(key
, NULL
);
696 std::pair
<Section_name_map::iterator
, bool> ins(
697 this->section_name_map_
.insert(v
));
700 return ins
.first
->second
;
703 // This is the first time we've seen this name/type/flags
704 // combination. For compatibility with the GNU linker, we
705 // combine sections with contents and zero flags with sections
706 // with non-zero flags. This is a workaround for cases where
707 // assembler code forgets to set section flags. FIXME: Perhaps
708 // there should be an option to control this.
709 Output_section
* os
= NULL
;
711 if (lookup_type
== elfcpp::SHT_PROGBITS
)
715 Output_section
* same_name
= this->find_output_section(name
);
716 if (same_name
!= NULL
717 && (same_name
->type() == elfcpp::SHT_PROGBITS
718 || same_name
->type() == elfcpp::SHT_INIT_ARRAY
719 || same_name
->type() == elfcpp::SHT_FINI_ARRAY
720 || same_name
->type() == elfcpp::SHT_PREINIT_ARRAY
)
721 && (same_name
->flags() & elfcpp::SHF_TLS
) == 0)
724 else if ((flags
& elfcpp::SHF_TLS
) == 0)
726 elfcpp::Elf_Xword zero_flags
= 0;
727 const Key
zero_key(name_key
, std::make_pair(lookup_type
,
729 Section_name_map::iterator p
=
730 this->section_name_map_
.find(zero_key
);
731 if (p
!= this->section_name_map_
.end())
737 os
= this->make_output_section(name
, type
, flags
, order
, is_relro
);
739 ins
.first
->second
= os
;
744 // Pick the output section to use for section NAME, in input file
745 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
746 // linker created section. IS_INPUT_SECTION is true if we are
747 // choosing an output section for an input section found in a input
748 // file. ORDER is where this section should appear in the output
749 // sections. IS_RELRO is true for a relro section. This will return
750 // NULL if the input section should be discarded.
753 Layout::choose_output_section(const Relobj
* relobj
, const char* name
,
754 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
755 bool is_input_section
, Output_section_order order
,
758 // We should not see any input sections after we have attached
759 // sections to segments.
760 gold_assert(!is_input_section
|| !this->sections_are_attached_
);
762 // Some flags in the input section should not be automatically
763 // copied to the output section.
764 flags
&= ~ (elfcpp::SHF_INFO_LINK
767 | elfcpp::SHF_STRINGS
);
769 // We only clear the SHF_LINK_ORDER flag in for
770 // a non-relocatable link.
771 if (!parameters
->options().relocatable())
772 flags
&= ~elfcpp::SHF_LINK_ORDER
;
774 if (this->script_options_
->saw_sections_clause())
776 // We are using a SECTIONS clause, so the output section is
777 // chosen based only on the name.
779 Script_sections
* ss
= this->script_options_
->script_sections();
780 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
781 Output_section
** output_section_slot
;
782 Script_sections::Section_type script_section_type
;
783 const char* orig_name
= name
;
784 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
785 &script_section_type
);
788 gold_debug(DEBUG_SCRIPT
, _("Unable to create output section '%s' "
789 "because it is not allowed by the "
790 "SECTIONS clause of the linker script"),
792 // The SECTIONS clause says to discard this input section.
796 // We can only handle script section types ST_NONE and ST_NOLOAD.
797 switch (script_section_type
)
799 case Script_sections::ST_NONE
:
801 case Script_sections::ST_NOLOAD
:
802 flags
&= elfcpp::SHF_ALLOC
;
808 // If this is an orphan section--one not mentioned in the linker
809 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
810 // default processing below.
812 if (output_section_slot
!= NULL
)
814 if (*output_section_slot
!= NULL
)
816 (*output_section_slot
)->update_flags_for_input_section(flags
);
817 return *output_section_slot
;
820 // We don't put sections found in the linker script into
821 // SECTION_NAME_MAP_. That keeps us from getting confused
822 // if an orphan section is mapped to a section with the same
823 // name as one in the linker script.
825 name
= this->namepool_
.add(name
, false, NULL
);
827 Output_section
* os
= this->make_output_section(name
, type
, flags
,
830 os
->set_found_in_sections_clause();
832 // Special handling for NOLOAD sections.
833 if (script_section_type
== Script_sections::ST_NOLOAD
)
837 // The constructor of Output_section sets addresses of non-ALLOC
838 // sections to 0 by default. We don't want that for NOLOAD
839 // sections even if they have no SHF_ALLOC flag.
840 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0
841 && os
->is_address_valid())
843 gold_assert(os
->address() == 0
844 && !os
->is_offset_valid()
845 && !os
->is_data_size_valid());
846 os
->reset_address_and_file_offset();
850 *output_section_slot
= os
;
855 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
857 size_t len
= strlen(name
);
858 char* uncompressed_name
= NULL
;
860 // Compressed debug sections should be mapped to the corresponding
861 // uncompressed section.
862 if (is_compressed_debug_section(name
))
864 uncompressed_name
= new char[len
];
865 uncompressed_name
[0] = '.';
866 gold_assert(name
[0] == '.' && name
[1] == 'z');
867 strncpy(&uncompressed_name
[1], &name
[2], len
- 2);
868 uncompressed_name
[len
- 1] = '\0';
870 name
= uncompressed_name
;
873 // Turn NAME from the name of the input section into the name of the
876 && !this->script_options_
->saw_sections_clause()
877 && !parameters
->options().relocatable())
878 name
= Layout::output_section_name(relobj
, name
, &len
);
880 Stringpool::Key name_key
;
881 name
= this->namepool_
.add_with_length(name
, len
, true, &name_key
);
883 if (uncompressed_name
!= NULL
)
884 delete[] uncompressed_name
;
886 // Find or make the output section. The output section is selected
887 // based on the section name, type, and flags.
888 return this->get_output_section(name
, name_key
, type
, flags
, order
, is_relro
);
891 // For incremental links, record the initial fixed layout of a section
892 // from the base file, and return a pointer to the Output_section.
894 template<int size
, bool big_endian
>
896 Layout::init_fixed_output_section(const char* name
,
897 elfcpp::Shdr
<size
, big_endian
>& shdr
)
899 unsigned int sh_type
= shdr
.get_sh_type();
901 // We preserve the layout of PROGBITS, NOBITS, INIT_ARRAY, FINI_ARRAY,
902 // PRE_INIT_ARRAY, and NOTE sections.
903 // All others will be created from scratch and reallocated.
904 if (!can_incremental_update(sh_type
))
907 typename
elfcpp::Elf_types
<size
>::Elf_Addr sh_addr
= shdr
.get_sh_addr();
908 typename
elfcpp::Elf_types
<size
>::Elf_Off sh_offset
= shdr
.get_sh_offset();
909 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
910 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_flags
= shdr
.get_sh_flags();
911 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_addralign
=
912 shdr
.get_sh_addralign();
914 // Make the output section.
915 Stringpool::Key name_key
;
916 name
= this->namepool_
.add(name
, true, &name_key
);
917 Output_section
* os
= this->get_output_section(name
, name_key
, sh_type
,
918 sh_flags
, ORDER_INVALID
, false);
919 os
->set_fixed_layout(sh_addr
, sh_offset
, sh_size
, sh_addralign
);
920 if (sh_type
!= elfcpp::SHT_NOBITS
)
921 this->free_list_
.remove(sh_offset
, sh_offset
+ sh_size
);
925 // Return the output section to use for input section SHNDX, with name
926 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
927 // index of a relocation section which applies to this section, or 0
928 // if none, or -1U if more than one. RELOC_TYPE is the type of the
929 // relocation section if there is one. Set *OFF to the offset of this
930 // input section without the output section. Return NULL if the
931 // section should be discarded. Set *OFF to -1 if the section
932 // contents should not be written directly to the output file, but
933 // will instead receive special handling.
935 template<int size
, bool big_endian
>
937 Layout::layout(Sized_relobj_file
<size
, big_endian
>* object
, unsigned int shndx
,
938 const char* name
, const elfcpp::Shdr
<size
, big_endian
>& shdr
,
939 unsigned int reloc_shndx
, unsigned int, off_t
* off
)
943 if (!this->include_section(object
, name
, shdr
))
946 elfcpp::Elf_Word sh_type
= shdr
.get_sh_type();
948 // In a relocatable link a grouped section must not be combined with
949 // any other sections.
951 if (parameters
->options().relocatable()
952 && (shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) != 0)
954 name
= this->namepool_
.add(name
, true, NULL
);
955 os
= this->make_output_section(name
, sh_type
, shdr
.get_sh_flags(),
956 ORDER_INVALID
, false);
960 os
= this->choose_output_section(object
, name
, sh_type
,
961 shdr
.get_sh_flags(), true,
962 ORDER_INVALID
, false);
967 // By default the GNU linker sorts input sections whose names match
968 // .ctors.*, .dtors.*, .init_array.*, or .fini_array.*. The
969 // sections are sorted by name. This is used to implement
970 // constructor priority ordering. We are compatible. When we put
971 // .ctor sections in .init_array and .dtor sections in .fini_array,
972 // we must also sort plain .ctor and .dtor sections.
973 if (!this->script_options_
->saw_sections_clause()
974 && !parameters
->options().relocatable()
975 && (is_prefix_of(".ctors.", name
)
976 || is_prefix_of(".dtors.", name
)
977 || is_prefix_of(".init_array.", name
)
978 || is_prefix_of(".fini_array.", name
)
979 || (parameters
->options().ctors_in_init_array()
980 && (strcmp(name
, ".ctors") == 0
981 || strcmp(name
, ".dtors") == 0))))
982 os
->set_must_sort_attached_input_sections();
984 // If this is a .ctors or .ctors.* section being mapped to a
985 // .init_array section, or a .dtors or .dtors.* section being mapped
986 // to a .fini_array section, we will need to reverse the words if
987 // there is more than one. Record this section for later. See
988 // ctors_sections_in_init_array above.
989 if (!this->script_options_
->saw_sections_clause()
990 && !parameters
->options().relocatable()
991 && shdr
.get_sh_size() > size
/ 8
992 && (((strcmp(name
, ".ctors") == 0
993 || is_prefix_of(".ctors.", name
))
994 && strcmp(os
->name(), ".init_array") == 0)
995 || ((strcmp(name
, ".dtors") == 0
996 || is_prefix_of(".dtors.", name
))
997 && strcmp(os
->name(), ".fini_array") == 0)))
998 ctors_sections_in_init_array
.insert(Section_id(object
, shndx
));
1000 // FIXME: Handle SHF_LINK_ORDER somewhere.
1002 elfcpp::Elf_Xword orig_flags
= os
->flags();
1004 *off
= os
->add_input_section(this, object
, shndx
, name
, shdr
, reloc_shndx
,
1005 this->script_options_
->saw_sections_clause());
1007 // If the flags changed, we may have to change the order.
1008 if ((orig_flags
& elfcpp::SHF_ALLOC
) != 0)
1010 orig_flags
&= (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1011 elfcpp::Elf_Xword new_flags
=
1012 os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1013 if (orig_flags
!= new_flags
)
1014 os
->set_order(this->default_section_order(os
, false));
1017 this->have_added_input_section_
= true;
1022 // Handle a relocation section when doing a relocatable link.
1024 template<int size
, bool big_endian
>
1026 Layout::layout_reloc(Sized_relobj_file
<size
, big_endian
>* object
,
1028 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1029 Output_section
* data_section
,
1030 Relocatable_relocs
* rr
)
1032 gold_assert(parameters
->options().relocatable()
1033 || parameters
->options().emit_relocs());
1035 int sh_type
= shdr
.get_sh_type();
1038 if (sh_type
== elfcpp::SHT_REL
)
1040 else if (sh_type
== elfcpp::SHT_RELA
)
1044 name
+= data_section
->name();
1046 // In a relocatable link relocs for a grouped section must not be
1047 // combined with other reloc sections.
1049 if (!parameters
->options().relocatable()
1050 || (data_section
->flags() & elfcpp::SHF_GROUP
) == 0)
1051 os
= this->choose_output_section(object
, name
.c_str(), sh_type
,
1052 shdr
.get_sh_flags(), false,
1053 ORDER_INVALID
, false);
1056 const char* n
= this->namepool_
.add(name
.c_str(), true, NULL
);
1057 os
= this->make_output_section(n
, sh_type
, shdr
.get_sh_flags(),
1058 ORDER_INVALID
, false);
1061 os
->set_should_link_to_symtab();
1062 os
->set_info_section(data_section
);
1064 Output_section_data
* posd
;
1065 if (sh_type
== elfcpp::SHT_REL
)
1067 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rel_size
);
1068 posd
= new Output_relocatable_relocs
<elfcpp::SHT_REL
,
1072 else if (sh_type
== elfcpp::SHT_RELA
)
1074 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rela_size
);
1075 posd
= new Output_relocatable_relocs
<elfcpp::SHT_RELA
,
1082 os
->add_output_section_data(posd
);
1083 rr
->set_output_data(posd
);
1088 // Handle a group section when doing a relocatable link.
1090 template<int size
, bool big_endian
>
1092 Layout::layout_group(Symbol_table
* symtab
,
1093 Sized_relobj_file
<size
, big_endian
>* object
,
1095 const char* group_section_name
,
1096 const char* signature
,
1097 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1098 elfcpp::Elf_Word flags
,
1099 std::vector
<unsigned int>* shndxes
)
1101 gold_assert(parameters
->options().relocatable());
1102 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_GROUP
);
1103 group_section_name
= this->namepool_
.add(group_section_name
, true, NULL
);
1104 Output_section
* os
= this->make_output_section(group_section_name
,
1106 shdr
.get_sh_flags(),
1107 ORDER_INVALID
, false);
1109 // We need to find a symbol with the signature in the symbol table.
1110 // If we don't find one now, we need to look again later.
1111 Symbol
* sym
= symtab
->lookup(signature
, NULL
);
1113 os
->set_info_symndx(sym
);
1116 // Reserve some space to minimize reallocations.
1117 if (this->group_signatures_
.empty())
1118 this->group_signatures_
.reserve(this->number_of_input_files_
* 16);
1120 // We will wind up using a symbol whose name is the signature.
1121 // So just put the signature in the symbol name pool to save it.
1122 signature
= symtab
->canonicalize_name(signature
);
1123 this->group_signatures_
.push_back(Group_signature(os
, signature
));
1126 os
->set_should_link_to_symtab();
1129 section_size_type entry_count
=
1130 convert_to_section_size_type(shdr
.get_sh_size() / 4);
1131 Output_section_data
* posd
=
1132 new Output_data_group
<size
, big_endian
>(object
, entry_count
, flags
,
1134 os
->add_output_section_data(posd
);
1137 // Special GNU handling of sections name .eh_frame. They will
1138 // normally hold exception frame data as defined by the C++ ABI
1139 // (http://codesourcery.com/cxx-abi/).
1141 template<int size
, bool big_endian
>
1143 Layout::layout_eh_frame(Sized_relobj_file
<size
, big_endian
>* object
,
1144 const unsigned char* symbols
,
1146 const unsigned char* symbol_names
,
1147 off_t symbol_names_size
,
1149 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1150 unsigned int reloc_shndx
, unsigned int reloc_type
,
1153 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
1154 || shdr
.get_sh_type() == elfcpp::SHT_X86_64_UNWIND
);
1155 gold_assert((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
1157 Output_section
* os
= this->make_eh_frame_section(object
);
1161 gold_assert(this->eh_frame_section_
== os
);
1163 elfcpp::Elf_Xword orig_flags
= os
->flags();
1165 if (!parameters
->incremental()
1166 && this->eh_frame_data_
->add_ehframe_input_section(object
,
1175 os
->update_flags_for_input_section(shdr
.get_sh_flags());
1177 // A writable .eh_frame section is a RELRO section.
1178 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1179 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1182 os
->set_order(ORDER_RELRO
);
1185 // We found a .eh_frame section we are going to optimize, so now
1186 // we can add the set of optimized sections to the output
1187 // section. We need to postpone adding this until we've found a
1188 // section we can optimize so that the .eh_frame section in
1189 // crtbegin.o winds up at the start of the output section.
1190 if (!this->added_eh_frame_data_
)
1192 os
->add_output_section_data(this->eh_frame_data_
);
1193 this->added_eh_frame_data_
= true;
1199 // We couldn't handle this .eh_frame section for some reason.
1200 // Add it as a normal section.
1201 bool saw_sections_clause
= this->script_options_
->saw_sections_clause();
1202 *off
= os
->add_input_section(this, object
, shndx
, ".eh_frame", shdr
,
1203 reloc_shndx
, saw_sections_clause
);
1204 this->have_added_input_section_
= true;
1206 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1207 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1208 os
->set_order(this->default_section_order(os
, false));
1214 // Create and return the magic .eh_frame section. Create
1215 // .eh_frame_hdr also if appropriate. OBJECT is the object with the
1216 // input .eh_frame section; it may be NULL.
1219 Layout::make_eh_frame_section(const Relobj
* object
)
1221 // FIXME: On x86_64, this could use SHT_X86_64_UNWIND rather than
1223 Output_section
* os
= this->choose_output_section(object
, ".eh_frame",
1224 elfcpp::SHT_PROGBITS
,
1225 elfcpp::SHF_ALLOC
, false,
1226 ORDER_EHFRAME
, false);
1230 if (this->eh_frame_section_
== NULL
)
1232 this->eh_frame_section_
= os
;
1233 this->eh_frame_data_
= new Eh_frame();
1235 // For incremental linking, we do not optimize .eh_frame sections
1236 // or create a .eh_frame_hdr section.
1237 if (parameters
->options().eh_frame_hdr() && !parameters
->incremental())
1239 Output_section
* hdr_os
=
1240 this->choose_output_section(NULL
, ".eh_frame_hdr",
1241 elfcpp::SHT_PROGBITS
,
1242 elfcpp::SHF_ALLOC
, false,
1243 ORDER_EHFRAME
, false);
1247 Eh_frame_hdr
* hdr_posd
= new Eh_frame_hdr(os
,
1248 this->eh_frame_data_
);
1249 hdr_os
->add_output_section_data(hdr_posd
);
1251 hdr_os
->set_after_input_sections();
1253 if (!this->script_options_
->saw_phdrs_clause())
1255 Output_segment
* hdr_oseg
;
1256 hdr_oseg
= this->make_output_segment(elfcpp::PT_GNU_EH_FRAME
,
1258 hdr_oseg
->add_output_section_to_nonload(hdr_os
,
1262 this->eh_frame_data_
->set_eh_frame_hdr(hdr_posd
);
1270 // Add an exception frame for a PLT. This is called from target code.
1273 Layout::add_eh_frame_for_plt(Output_data
* plt
, const unsigned char* cie_data
,
1274 size_t cie_length
, const unsigned char* fde_data
,
1277 if (parameters
->incremental())
1279 // FIXME: Maybe this could work some day....
1282 Output_section
* os
= this->make_eh_frame_section(NULL
);
1285 this->eh_frame_data_
->add_ehframe_for_plt(plt
, cie_data
, cie_length
,
1286 fde_data
, fde_length
);
1287 if (!this->added_eh_frame_data_
)
1289 os
->add_output_section_data(this->eh_frame_data_
);
1290 this->added_eh_frame_data_
= true;
1294 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
1295 // the output section.
1298 Layout::add_output_section_data(const char* name
, elfcpp::Elf_Word type
,
1299 elfcpp::Elf_Xword flags
,
1300 Output_section_data
* posd
,
1301 Output_section_order order
, bool is_relro
)
1303 Output_section
* os
= this->choose_output_section(NULL
, name
, type
, flags
,
1304 false, order
, is_relro
);
1306 os
->add_output_section_data(posd
);
1310 // Map section flags to segment flags.
1313 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags
)
1315 elfcpp::Elf_Word ret
= elfcpp::PF_R
;
1316 if ((flags
& elfcpp::SHF_WRITE
) != 0)
1317 ret
|= elfcpp::PF_W
;
1318 if ((flags
& elfcpp::SHF_EXECINSTR
) != 0)
1319 ret
|= elfcpp::PF_X
;
1323 // Make a new Output_section, and attach it to segments as
1324 // appropriate. ORDER is the order in which this section should
1325 // appear in the output segment. IS_RELRO is true if this is a relro
1326 // (read-only after relocations) section.
1329 Layout::make_output_section(const char* name
, elfcpp::Elf_Word type
,
1330 elfcpp::Elf_Xword flags
,
1331 Output_section_order order
, bool is_relro
)
1334 if ((flags
& elfcpp::SHF_ALLOC
) == 0
1335 && strcmp(parameters
->options().compress_debug_sections(), "none") != 0
1336 && is_compressible_debug_section(name
))
1337 os
= new Output_compressed_section(¶meters
->options(), name
, type
,
1339 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1340 && parameters
->options().strip_debug_non_line()
1341 && strcmp(".debug_abbrev", name
) == 0)
1343 os
= this->debug_abbrev_
= new Output_reduced_debug_abbrev_section(
1345 if (this->debug_info_
)
1346 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1348 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1349 && parameters
->options().strip_debug_non_line()
1350 && strcmp(".debug_info", name
) == 0)
1352 os
= this->debug_info_
= new Output_reduced_debug_info_section(
1354 if (this->debug_abbrev_
)
1355 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1359 // Sometimes .init_array*, .preinit_array* and .fini_array* do
1360 // not have correct section types. Force them here.
1361 if (type
== elfcpp::SHT_PROGBITS
)
1363 if (is_prefix_of(".init_array", name
))
1364 type
= elfcpp::SHT_INIT_ARRAY
;
1365 else if (is_prefix_of(".preinit_array", name
))
1366 type
= elfcpp::SHT_PREINIT_ARRAY
;
1367 else if (is_prefix_of(".fini_array", name
))
1368 type
= elfcpp::SHT_FINI_ARRAY
;
1371 // FIXME: const_cast is ugly.
1372 Target
* target
= const_cast<Target
*>(¶meters
->target());
1373 os
= target
->make_output_section(name
, type
, flags
);
1376 // With -z relro, we have to recognize the special sections by name.
1377 // There is no other way.
1378 bool is_relro_local
= false;
1379 if (!this->script_options_
->saw_sections_clause()
1380 && parameters
->options().relro()
1381 && type
== elfcpp::SHT_PROGBITS
1382 && (flags
& elfcpp::SHF_ALLOC
) != 0
1383 && (flags
& elfcpp::SHF_WRITE
) != 0)
1385 if (strcmp(name
, ".data.rel.ro") == 0)
1387 else if (strcmp(name
, ".data.rel.ro.local") == 0)
1390 is_relro_local
= true;
1392 else if (type
== elfcpp::SHT_INIT_ARRAY
1393 || type
== elfcpp::SHT_FINI_ARRAY
1394 || type
== elfcpp::SHT_PREINIT_ARRAY
)
1396 else if (strcmp(name
, ".ctors") == 0
1397 || strcmp(name
, ".dtors") == 0
1398 || strcmp(name
, ".jcr") == 0)
1405 if (order
== ORDER_INVALID
&& (flags
& elfcpp::SHF_ALLOC
) != 0)
1406 order
= this->default_section_order(os
, is_relro_local
);
1408 os
->set_order(order
);
1410 parameters
->target().new_output_section(os
);
1412 this->section_list_
.push_back(os
);
1414 // The GNU linker by default sorts some sections by priority, so we
1415 // do the same. We need to know that this might happen before we
1416 // attach any input sections.
1417 if (!this->script_options_
->saw_sections_clause()
1418 && !parameters
->options().relocatable()
1419 && (strcmp(name
, ".init_array") == 0
1420 || strcmp(name
, ".fini_array") == 0
1421 || (!parameters
->options().ctors_in_init_array()
1422 && (strcmp(name
, ".ctors") == 0
1423 || strcmp(name
, ".dtors") == 0))))
1424 os
->set_may_sort_attached_input_sections();
1426 // Check for .stab*str sections, as .stab* sections need to link to
1428 if (type
== elfcpp::SHT_STRTAB
1429 && !this->have_stabstr_section_
1430 && strncmp(name
, ".stab", 5) == 0
1431 && strcmp(name
+ strlen(name
) - 3, "str") == 0)
1432 this->have_stabstr_section_
= true;
1434 // During a full incremental link, we add patch space to most
1435 // PROGBITS and NOBITS sections. Flag those that may be
1436 // arbitrarily padded.
1437 if ((type
== elfcpp::SHT_PROGBITS
|| type
== elfcpp::SHT_NOBITS
)
1438 && order
!= ORDER_INTERP
1439 && order
!= ORDER_INIT
1440 && order
!= ORDER_PLT
1441 && order
!= ORDER_FINI
1442 && order
!= ORDER_RELRO_LAST
1443 && order
!= ORDER_NON_RELRO_FIRST
1444 && strcmp(name
, ".eh_frame") != 0
1445 && strcmp(name
, ".ctors") != 0
1446 && strcmp(name
, ".dtors") != 0
1447 && strcmp(name
, ".jcr") != 0)
1449 os
->set_is_patch_space_allowed();
1451 // Certain sections require "holes" to be filled with
1452 // specific fill patterns. These fill patterns may have
1453 // a minimum size, so we must prevent allocations from the
1454 // free list that leave a hole smaller than the minimum.
1455 if (strcmp(name
, ".debug_info") == 0)
1456 os
->set_free_space_fill(new Output_fill_debug_info(false));
1457 else if (strcmp(name
, ".debug_types") == 0)
1458 os
->set_free_space_fill(new Output_fill_debug_info(true));
1459 else if (strcmp(name
, ".debug_line") == 0)
1460 os
->set_free_space_fill(new Output_fill_debug_line());
1463 // If we have already attached the sections to segments, then we
1464 // need to attach this one now. This happens for sections created
1465 // directly by the linker.
1466 if (this->sections_are_attached_
)
1467 this->attach_section_to_segment(os
);
1472 // Return the default order in which a section should be placed in an
1473 // output segment. This function captures a lot of the ideas in
1474 // ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
1475 // linker created section is normally set when the section is created;
1476 // this function is used for input sections.
1478 Output_section_order
1479 Layout::default_section_order(Output_section
* os
, bool is_relro_local
)
1481 gold_assert((os
->flags() & elfcpp::SHF_ALLOC
) != 0);
1482 bool is_write
= (os
->flags() & elfcpp::SHF_WRITE
) != 0;
1483 bool is_execinstr
= (os
->flags() & elfcpp::SHF_EXECINSTR
) != 0;
1484 bool is_bss
= false;
1489 case elfcpp::SHT_PROGBITS
:
1491 case elfcpp::SHT_NOBITS
:
1494 case elfcpp::SHT_RELA
:
1495 case elfcpp::SHT_REL
:
1497 return ORDER_DYNAMIC_RELOCS
;
1499 case elfcpp::SHT_HASH
:
1500 case elfcpp::SHT_DYNAMIC
:
1501 case elfcpp::SHT_SHLIB
:
1502 case elfcpp::SHT_DYNSYM
:
1503 case elfcpp::SHT_GNU_HASH
:
1504 case elfcpp::SHT_GNU_verdef
:
1505 case elfcpp::SHT_GNU_verneed
:
1506 case elfcpp::SHT_GNU_versym
:
1508 return ORDER_DYNAMIC_LINKER
;
1510 case elfcpp::SHT_NOTE
:
1511 return is_write
? ORDER_RW_NOTE
: ORDER_RO_NOTE
;
1514 if ((os
->flags() & elfcpp::SHF_TLS
) != 0)
1515 return is_bss
? ORDER_TLS_BSS
: ORDER_TLS_DATA
;
1517 if (!is_bss
&& !is_write
)
1521 if (strcmp(os
->name(), ".init") == 0)
1523 else if (strcmp(os
->name(), ".fini") == 0)
1526 return is_execinstr
? ORDER_TEXT
: ORDER_READONLY
;
1530 return is_relro_local
? ORDER_RELRO_LOCAL
: ORDER_RELRO
;
1532 if (os
->is_small_section())
1533 return is_bss
? ORDER_SMALL_BSS
: ORDER_SMALL_DATA
;
1534 if (os
->is_large_section())
1535 return is_bss
? ORDER_LARGE_BSS
: ORDER_LARGE_DATA
;
1537 return is_bss
? ORDER_BSS
: ORDER_DATA
;
1540 // Attach output sections to segments. This is called after we have
1541 // seen all the input sections.
1544 Layout::attach_sections_to_segments()
1546 for (Section_list::iterator p
= this->section_list_
.begin();
1547 p
!= this->section_list_
.end();
1549 this->attach_section_to_segment(*p
);
1551 this->sections_are_attached_
= true;
1554 // Attach an output section to a segment.
1557 Layout::attach_section_to_segment(Output_section
* os
)
1559 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0)
1560 this->unattached_section_list_
.push_back(os
);
1562 this->attach_allocated_section_to_segment(os
);
1565 // Attach an allocated output section to a segment.
1568 Layout::attach_allocated_section_to_segment(Output_section
* os
)
1570 elfcpp::Elf_Xword flags
= os
->flags();
1571 gold_assert((flags
& elfcpp::SHF_ALLOC
) != 0);
1573 if (parameters
->options().relocatable())
1576 // If we have a SECTIONS clause, we can't handle the attachment to
1577 // segments until after we've seen all the sections.
1578 if (this->script_options_
->saw_sections_clause())
1581 gold_assert(!this->script_options_
->saw_phdrs_clause());
1583 // This output section goes into a PT_LOAD segment.
1585 elfcpp::Elf_Word seg_flags
= Layout::section_flags_to_segment(flags
);
1587 // Check for --section-start.
1589 bool is_address_set
= parameters
->options().section_start(os
->name(), &addr
);
1591 // In general the only thing we really care about for PT_LOAD
1592 // segments is whether or not they are writable or executable,
1593 // so that is how we search for them.
1594 // Large data sections also go into their own PT_LOAD segment.
1595 // People who need segments sorted on some other basis will
1596 // have to use a linker script.
1598 Segment_list::const_iterator p
;
1599 for (p
= this->segment_list_
.begin();
1600 p
!= this->segment_list_
.end();
1603 if ((*p
)->type() != elfcpp::PT_LOAD
)
1605 if (!parameters
->options().omagic()
1606 && ((*p
)->flags() & elfcpp::PF_W
) != (seg_flags
& elfcpp::PF_W
))
1608 if (parameters
->options().rosegment()
1609 && ((*p
)->flags() & elfcpp::PF_X
) != (seg_flags
& elfcpp::PF_X
))
1611 // If -Tbss was specified, we need to separate the data and BSS
1613 if (parameters
->options().user_set_Tbss())
1615 if ((os
->type() == elfcpp::SHT_NOBITS
)
1616 == (*p
)->has_any_data_sections())
1619 if (os
->is_large_data_section() && !(*p
)->is_large_data_segment())
1624 if ((*p
)->are_addresses_set())
1627 (*p
)->add_initial_output_data(os
);
1628 (*p
)->update_flags_for_output_section(seg_flags
);
1629 (*p
)->set_addresses(addr
, addr
);
1633 (*p
)->add_output_section_to_load(this, os
, seg_flags
);
1637 if (p
== this->segment_list_
.end())
1639 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_LOAD
,
1641 if (os
->is_large_data_section())
1642 oseg
->set_is_large_data_segment();
1643 oseg
->add_output_section_to_load(this, os
, seg_flags
);
1645 oseg
->set_addresses(addr
, addr
);
1648 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1650 if (os
->type() == elfcpp::SHT_NOTE
)
1652 // See if we already have an equivalent PT_NOTE segment.
1653 for (p
= this->segment_list_
.begin();
1654 p
!= segment_list_
.end();
1657 if ((*p
)->type() == elfcpp::PT_NOTE
1658 && (((*p
)->flags() & elfcpp::PF_W
)
1659 == (seg_flags
& elfcpp::PF_W
)))
1661 (*p
)->add_output_section_to_nonload(os
, seg_flags
);
1666 if (p
== this->segment_list_
.end())
1668 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_NOTE
,
1670 oseg
->add_output_section_to_nonload(os
, seg_flags
);
1674 // If we see a loadable SHF_TLS section, we create a PT_TLS
1675 // segment. There can only be one such segment.
1676 if ((flags
& elfcpp::SHF_TLS
) != 0)
1678 if (this->tls_segment_
== NULL
)
1679 this->make_output_segment(elfcpp::PT_TLS
, seg_flags
);
1680 this->tls_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1683 // If -z relro is in effect, and we see a relro section, we create a
1684 // PT_GNU_RELRO segment. There can only be one such segment.
1685 if (os
->is_relro() && parameters
->options().relro())
1687 gold_assert(seg_flags
== (elfcpp::PF_R
| elfcpp::PF_W
));
1688 if (this->relro_segment_
== NULL
)
1689 this->make_output_segment(elfcpp::PT_GNU_RELRO
, seg_flags
);
1690 this->relro_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1693 // If we see a section named .interp, put it into a PT_INTERP
1694 // segment. This seems broken to me, but this is what GNU ld does,
1695 // and glibc expects it.
1696 if (strcmp(os
->name(), ".interp") == 0
1697 && !this->script_options_
->saw_phdrs_clause())
1699 if (this->interp_segment_
== NULL
)
1700 this->make_output_segment(elfcpp::PT_INTERP
, seg_flags
);
1702 gold_warning(_("multiple '.interp' sections in input files "
1703 "may cause confusing PT_INTERP segment"));
1704 this->interp_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1708 // Make an output section for a script.
1711 Layout::make_output_section_for_script(
1713 Script_sections::Section_type section_type
)
1715 name
= this->namepool_
.add(name
, false, NULL
);
1716 elfcpp::Elf_Xword sh_flags
= elfcpp::SHF_ALLOC
;
1717 if (section_type
== Script_sections::ST_NOLOAD
)
1719 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_PROGBITS
,
1720 sh_flags
, ORDER_INVALID
,
1722 os
->set_found_in_sections_clause();
1723 if (section_type
== Script_sections::ST_NOLOAD
)
1724 os
->set_is_noload();
1728 // Return the number of segments we expect to see.
1731 Layout::expected_segment_count() const
1733 size_t ret
= this->segment_list_
.size();
1735 // If we didn't see a SECTIONS clause in a linker script, we should
1736 // already have the complete list of segments. Otherwise we ask the
1737 // SECTIONS clause how many segments it expects, and add in the ones
1738 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1740 if (!this->script_options_
->saw_sections_clause())
1744 const Script_sections
* ss
= this->script_options_
->script_sections();
1745 return ret
+ ss
->expected_segment_count(this);
1749 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
1750 // is whether we saw a .note.GNU-stack section in the object file.
1751 // GNU_STACK_FLAGS is the section flags. The flags give the
1752 // protection required for stack memory. We record this in an
1753 // executable as a PT_GNU_STACK segment. If an object file does not
1754 // have a .note.GNU-stack segment, we must assume that it is an old
1755 // object. On some targets that will force an executable stack.
1758 Layout::layout_gnu_stack(bool seen_gnu_stack
, uint64_t gnu_stack_flags
,
1761 if (!seen_gnu_stack
)
1763 this->input_without_gnu_stack_note_
= true;
1764 if (parameters
->options().warn_execstack()
1765 && parameters
->target().is_default_stack_executable())
1766 gold_warning(_("%s: missing .note.GNU-stack section"
1767 " implies executable stack"),
1768 obj
->name().c_str());
1772 this->input_with_gnu_stack_note_
= true;
1773 if ((gnu_stack_flags
& elfcpp::SHF_EXECINSTR
) != 0)
1775 this->input_requires_executable_stack_
= true;
1776 if (parameters
->options().warn_execstack()
1777 || parameters
->options().is_stack_executable())
1778 gold_warning(_("%s: requires executable stack"),
1779 obj
->name().c_str());
1784 // Create automatic note sections.
1787 Layout::create_notes()
1789 this->create_gold_note();
1790 this->create_executable_stack_info();
1791 this->create_build_id();
1794 // Create the dynamic sections which are needed before we read the
1798 Layout::create_initial_dynamic_sections(Symbol_table
* symtab
)
1800 if (parameters
->doing_static_link())
1803 this->dynamic_section_
= this->choose_output_section(NULL
, ".dynamic",
1804 elfcpp::SHT_DYNAMIC
,
1806 | elfcpp::SHF_WRITE
),
1810 // A linker script may discard .dynamic, so check for NULL.
1811 if (this->dynamic_section_
!= NULL
)
1813 this->dynamic_symbol_
=
1814 symtab
->define_in_output_data("_DYNAMIC", NULL
,
1815 Symbol_table::PREDEFINED
,
1816 this->dynamic_section_
, 0, 0,
1817 elfcpp::STT_OBJECT
, elfcpp::STB_LOCAL
,
1818 elfcpp::STV_HIDDEN
, 0, false, false);
1820 this->dynamic_data_
= new Output_data_dynamic(&this->dynpool_
);
1822 this->dynamic_section_
->add_output_section_data(this->dynamic_data_
);
1826 // For each output section whose name can be represented as C symbol,
1827 // define __start and __stop symbols for the section. This is a GNU
1831 Layout::define_section_symbols(Symbol_table
* symtab
)
1833 for (Section_list::const_iterator p
= this->section_list_
.begin();
1834 p
!= this->section_list_
.end();
1837 const char* const name
= (*p
)->name();
1838 if (is_cident(name
))
1840 const std::string
name_string(name
);
1841 const std::string
start_name(cident_section_start_prefix
1843 const std::string
stop_name(cident_section_stop_prefix
1846 symtab
->define_in_output_data(start_name
.c_str(),
1848 Symbol_table::PREDEFINED
,
1854 elfcpp::STV_DEFAULT
,
1856 false, // offset_is_from_end
1857 true); // only_if_ref
1859 symtab
->define_in_output_data(stop_name
.c_str(),
1861 Symbol_table::PREDEFINED
,
1867 elfcpp::STV_DEFAULT
,
1869 true, // offset_is_from_end
1870 true); // only_if_ref
1875 // Define symbols for group signatures.
1878 Layout::define_group_signatures(Symbol_table
* symtab
)
1880 for (Group_signatures::iterator p
= this->group_signatures_
.begin();
1881 p
!= this->group_signatures_
.end();
1884 Symbol
* sym
= symtab
->lookup(p
->signature
, NULL
);
1886 p
->section
->set_info_symndx(sym
);
1889 // Force the name of the group section to the group
1890 // signature, and use the group's section symbol as the
1891 // signature symbol.
1892 if (strcmp(p
->section
->name(), p
->signature
) != 0)
1894 const char* name
= this->namepool_
.add(p
->signature
,
1896 p
->section
->set_name(name
);
1898 p
->section
->set_needs_symtab_index();
1899 p
->section
->set_info_section_symndx(p
->section
);
1903 this->group_signatures_
.clear();
1906 // Find the first read-only PT_LOAD segment, creating one if
1910 Layout::find_first_load_seg()
1912 Output_segment
* best
= NULL
;
1913 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
1914 p
!= this->segment_list_
.end();
1917 if ((*p
)->type() == elfcpp::PT_LOAD
1918 && ((*p
)->flags() & elfcpp::PF_R
) != 0
1919 && (parameters
->options().omagic()
1920 || ((*p
)->flags() & elfcpp::PF_W
) == 0))
1922 if (best
== NULL
|| this->segment_precedes(*p
, best
))
1929 gold_assert(!this->script_options_
->saw_phdrs_clause());
1931 Output_segment
* load_seg
= this->make_output_segment(elfcpp::PT_LOAD
,
1936 // Save states of all current output segments. Store saved states
1937 // in SEGMENT_STATES.
1940 Layout::save_segments(Segment_states
* segment_states
)
1942 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
1943 p
!= this->segment_list_
.end();
1946 Output_segment
* segment
= *p
;
1948 Output_segment
* copy
= new Output_segment(*segment
);
1949 (*segment_states
)[segment
] = copy
;
1953 // Restore states of output segments and delete any segment not found in
1957 Layout::restore_segments(const Segment_states
* segment_states
)
1959 // Go through the segment list and remove any segment added in the
1961 this->tls_segment_
= NULL
;
1962 this->relro_segment_
= NULL
;
1963 Segment_list::iterator list_iter
= this->segment_list_
.begin();
1964 while (list_iter
!= this->segment_list_
.end())
1966 Output_segment
* segment
= *list_iter
;
1967 Segment_states::const_iterator states_iter
=
1968 segment_states
->find(segment
);
1969 if (states_iter
!= segment_states
->end())
1971 const Output_segment
* copy
= states_iter
->second
;
1972 // Shallow copy to restore states.
1975 // Also fix up TLS and RELRO segment pointers as appropriate.
1976 if (segment
->type() == elfcpp::PT_TLS
)
1977 this->tls_segment_
= segment
;
1978 else if (segment
->type() == elfcpp::PT_GNU_RELRO
)
1979 this->relro_segment_
= segment
;
1985 list_iter
= this->segment_list_
.erase(list_iter
);
1986 // This is a segment created during section layout. It should be
1987 // safe to remove it since we should have removed all pointers to it.
1993 // Clean up after relaxation so that sections can be laid out again.
1996 Layout::clean_up_after_relaxation()
1998 // Restore the segments to point state just prior to the relaxation loop.
1999 Script_sections
* script_section
= this->script_options_
->script_sections();
2000 script_section
->release_segments();
2001 this->restore_segments(this->segment_states_
);
2003 // Reset section addresses and file offsets
2004 for (Section_list::iterator p
= this->section_list_
.begin();
2005 p
!= this->section_list_
.end();
2008 (*p
)->restore_states();
2010 // If an input section changes size because of relaxation,
2011 // we need to adjust the section offsets of all input sections.
2012 // after such a section.
2013 if ((*p
)->section_offsets_need_adjustment())
2014 (*p
)->adjust_section_offsets();
2016 (*p
)->reset_address_and_file_offset();
2019 // Reset special output object address and file offsets.
2020 for (Data_list::iterator p
= this->special_output_list_
.begin();
2021 p
!= this->special_output_list_
.end();
2023 (*p
)->reset_address_and_file_offset();
2025 // A linker script may have created some output section data objects.
2026 // They are useless now.
2027 for (Output_section_data_list::const_iterator p
=
2028 this->script_output_section_data_list_
.begin();
2029 p
!= this->script_output_section_data_list_
.end();
2032 this->script_output_section_data_list_
.clear();
2035 // Prepare for relaxation.
2038 Layout::prepare_for_relaxation()
2040 // Create an relaxation debug check if in debugging mode.
2041 if (is_debugging_enabled(DEBUG_RELAXATION
))
2042 this->relaxation_debug_check_
= new Relaxation_debug_check();
2044 // Save segment states.
2045 this->segment_states_
= new Segment_states();
2046 this->save_segments(this->segment_states_
);
2048 for(Section_list::const_iterator p
= this->section_list_
.begin();
2049 p
!= this->section_list_
.end();
2051 (*p
)->save_states();
2053 if (is_debugging_enabled(DEBUG_RELAXATION
))
2054 this->relaxation_debug_check_
->check_output_data_for_reset_values(
2055 this->section_list_
, this->special_output_list_
);
2057 // Also enable recording of output section data from scripts.
2058 this->record_output_section_data_from_script_
= true;
2061 // Relaxation loop body: If target has no relaxation, this runs only once
2062 // Otherwise, the target relaxation hook is called at the end of
2063 // each iteration. If the hook returns true, it means re-layout of
2064 // section is required.
2066 // The number of segments created by a linking script without a PHDRS
2067 // clause may be affected by section sizes and alignments. There is
2068 // a remote chance that relaxation causes different number of PT_LOAD
2069 // segments are created and sections are attached to different segments.
2070 // Therefore, we always throw away all segments created during section
2071 // layout. In order to be able to restart the section layout, we keep
2072 // a copy of the segment list right before the relaxation loop and use
2073 // that to restore the segments.
2075 // PASS is the current relaxation pass number.
2076 // SYMTAB is a symbol table.
2077 // PLOAD_SEG is the address of a pointer for the load segment.
2078 // PHDR_SEG is a pointer to the PHDR segment.
2079 // SEGMENT_HEADERS points to the output segment header.
2080 // FILE_HEADER points to the output file header.
2081 // PSHNDX is the address to store the output section index.
2084 Layout::relaxation_loop_body(
2087 Symbol_table
* symtab
,
2088 Output_segment
** pload_seg
,
2089 Output_segment
* phdr_seg
,
2090 Output_segment_headers
* segment_headers
,
2091 Output_file_header
* file_header
,
2092 unsigned int* pshndx
)
2094 // If this is not the first iteration, we need to clean up after
2095 // relaxation so that we can lay out the sections again.
2097 this->clean_up_after_relaxation();
2099 // If there is a SECTIONS clause, put all the input sections into
2100 // the required order.
2101 Output_segment
* load_seg
;
2102 if (this->script_options_
->saw_sections_clause())
2103 load_seg
= this->set_section_addresses_from_script(symtab
);
2104 else if (parameters
->options().relocatable())
2107 load_seg
= this->find_first_load_seg();
2109 if (parameters
->options().oformat_enum()
2110 != General_options::OBJECT_FORMAT_ELF
)
2113 // If the user set the address of the text segment, that may not be
2114 // compatible with putting the segment headers and file headers into
2116 if (parameters
->options().user_set_Ttext()
2117 && parameters
->options().Ttext() % target
->common_pagesize() != 0)
2123 gold_assert(phdr_seg
== NULL
2125 || this->script_options_
->saw_sections_clause());
2127 // If the address of the load segment we found has been set by
2128 // --section-start rather than by a script, then adjust the VMA and
2129 // LMA downward if possible to include the file and section headers.
2130 uint64_t header_gap
= 0;
2131 if (load_seg
!= NULL
2132 && load_seg
->are_addresses_set()
2133 && !this->script_options_
->saw_sections_clause()
2134 && !parameters
->options().relocatable())
2136 file_header
->finalize_data_size();
2137 segment_headers
->finalize_data_size();
2138 size_t sizeof_headers
= (file_header
->data_size()
2139 + segment_headers
->data_size());
2140 const uint64_t abi_pagesize
= target
->abi_pagesize();
2141 uint64_t hdr_paddr
= load_seg
->paddr() - sizeof_headers
;
2142 hdr_paddr
&= ~(abi_pagesize
- 1);
2143 uint64_t subtract
= load_seg
->paddr() - hdr_paddr
;
2144 if (load_seg
->paddr() < subtract
|| load_seg
->vaddr() < subtract
)
2148 load_seg
->set_addresses(load_seg
->vaddr() - subtract
,
2149 load_seg
->paddr() - subtract
);
2150 header_gap
= subtract
- sizeof_headers
;
2154 // Lay out the segment headers.
2155 if (!parameters
->options().relocatable())
2157 gold_assert(segment_headers
!= NULL
);
2158 if (header_gap
!= 0 && load_seg
!= NULL
)
2160 Output_data_zero_fill
* z
= new Output_data_zero_fill(header_gap
, 1);
2161 load_seg
->add_initial_output_data(z
);
2163 if (load_seg
!= NULL
)
2164 load_seg
->add_initial_output_data(segment_headers
);
2165 if (phdr_seg
!= NULL
)
2166 phdr_seg
->add_initial_output_data(segment_headers
);
2169 // Lay out the file header.
2170 if (load_seg
!= NULL
)
2171 load_seg
->add_initial_output_data(file_header
);
2173 if (this->script_options_
->saw_phdrs_clause()
2174 && !parameters
->options().relocatable())
2176 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2177 // clause in a linker script.
2178 Script_sections
* ss
= this->script_options_
->script_sections();
2179 ss
->put_headers_in_phdrs(file_header
, segment_headers
);
2182 // We set the output section indexes in set_segment_offsets and
2183 // set_section_indexes.
2186 // Set the file offsets of all the segments, and all the sections
2189 if (!parameters
->options().relocatable())
2190 off
= this->set_segment_offsets(target
, load_seg
, pshndx
);
2192 off
= this->set_relocatable_section_offsets(file_header
, pshndx
);
2194 // Verify that the dummy relaxation does not change anything.
2195 if (is_debugging_enabled(DEBUG_RELAXATION
))
2198 this->relaxation_debug_check_
->read_sections(this->section_list_
);
2200 this->relaxation_debug_check_
->verify_sections(this->section_list_
);
2203 *pload_seg
= load_seg
;
2207 // Search the list of patterns and find the postion of the given section
2208 // name in the output section. If the section name matches a glob
2209 // pattern and a non-glob name, then the non-glob position takes
2210 // precedence. Return 0 if no match is found.
2213 Layout::find_section_order_index(const std::string
& section_name
)
2215 Unordered_map
<std::string
, unsigned int>::iterator map_it
;
2216 map_it
= this->input_section_position_
.find(section_name
);
2217 if (map_it
!= this->input_section_position_
.end())
2218 return map_it
->second
;
2220 // Absolute match failed. Linear search the glob patterns.
2221 std::vector
<std::string
>::iterator it
;
2222 for (it
= this->input_section_glob_
.begin();
2223 it
!= this->input_section_glob_
.end();
2226 if (fnmatch((*it
).c_str(), section_name
.c_str(), FNM_NOESCAPE
) == 0)
2228 map_it
= this->input_section_position_
.find(*it
);
2229 gold_assert(map_it
!= this->input_section_position_
.end());
2230 return map_it
->second
;
2236 // Read the sequence of input sections from the file specified with
2237 // option --section-ordering-file.
2240 Layout::read_layout_from_file()
2242 const char* filename
= parameters
->options().section_ordering_file();
2248 gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2249 filename
, strerror(errno
));
2251 std::getline(in
, line
); // this chops off the trailing \n, if any
2252 unsigned int position
= 1;
2253 this->set_section_ordering_specified();
2257 if (!line
.empty() && line
[line
.length() - 1] == '\r') // Windows
2258 line
.resize(line
.length() - 1);
2259 // Ignore comments, beginning with '#'
2262 std::getline(in
, line
);
2265 this->input_section_position_
[line
] = position
;
2266 // Store all glob patterns in a vector.
2267 if (is_wildcard_string(line
.c_str()))
2268 this->input_section_glob_
.push_back(line
);
2270 std::getline(in
, line
);
2274 // Finalize the layout. When this is called, we have created all the
2275 // output sections and all the output segments which are based on
2276 // input sections. We have several things to do, and we have to do
2277 // them in the right order, so that we get the right results correctly
2280 // 1) Finalize the list of output segments and create the segment
2283 // 2) Finalize the dynamic symbol table and associated sections.
2285 // 3) Determine the final file offset of all the output segments.
2287 // 4) Determine the final file offset of all the SHF_ALLOC output
2290 // 5) Create the symbol table sections and the section name table
2293 // 6) Finalize the symbol table: set symbol values to their final
2294 // value and make a final determination of which symbols are going
2295 // into the output symbol table.
2297 // 7) Create the section table header.
2299 // 8) Determine the final file offset of all the output sections which
2300 // are not SHF_ALLOC, including the section table header.
2302 // 9) Finalize the ELF file header.
2304 // This function returns the size of the output file.
2307 Layout::finalize(const Input_objects
* input_objects
, Symbol_table
* symtab
,
2308 Target
* target
, const Task
* task
)
2310 target
->finalize_sections(this, input_objects
, symtab
);
2312 this->count_local_symbols(task
, input_objects
);
2314 this->link_stabs_sections();
2316 Output_segment
* phdr_seg
= NULL
;
2317 if (!parameters
->options().relocatable() && !parameters
->doing_static_link())
2319 // There was a dynamic object in the link. We need to create
2320 // some information for the dynamic linker.
2322 // Create the PT_PHDR segment which will hold the program
2324 if (!this->script_options_
->saw_phdrs_clause())
2325 phdr_seg
= this->make_output_segment(elfcpp::PT_PHDR
, elfcpp::PF_R
);
2327 // Create the dynamic symbol table, including the hash table.
2328 Output_section
* dynstr
;
2329 std::vector
<Symbol
*> dynamic_symbols
;
2330 unsigned int local_dynamic_count
;
2331 Versions
versions(*this->script_options()->version_script_info(),
2333 this->create_dynamic_symtab(input_objects
, symtab
, &dynstr
,
2334 &local_dynamic_count
, &dynamic_symbols
,
2337 // Create the .interp section to hold the name of the
2338 // interpreter, and put it in a PT_INTERP segment. Don't do it
2339 // if we saw a .interp section in an input file.
2340 if ((!parameters
->options().shared()
2341 || parameters
->options().dynamic_linker() != NULL
)
2342 && this->interp_segment_
== NULL
)
2343 this->create_interp(target
);
2345 // Finish the .dynamic section to hold the dynamic data, and put
2346 // it in a PT_DYNAMIC segment.
2347 this->finish_dynamic_section(input_objects
, symtab
);
2349 // We should have added everything we need to the dynamic string
2351 this->dynpool_
.set_string_offsets();
2353 // Create the version sections. We can't do this until the
2354 // dynamic string table is complete.
2355 this->create_version_sections(&versions
, symtab
, local_dynamic_count
,
2356 dynamic_symbols
, dynstr
);
2358 // Set the size of the _DYNAMIC symbol. We can't do this until
2359 // after we call create_version_sections.
2360 this->set_dynamic_symbol_size(symtab
);
2363 // Create segment headers.
2364 Output_segment_headers
* segment_headers
=
2365 (parameters
->options().relocatable()
2367 : new Output_segment_headers(this->segment_list_
));
2369 // Lay out the file header.
2370 Output_file_header
* file_header
= new Output_file_header(target
, symtab
,
2373 this->special_output_list_
.push_back(file_header
);
2374 if (segment_headers
!= NULL
)
2375 this->special_output_list_
.push_back(segment_headers
);
2377 // Find approriate places for orphan output sections if we are using
2379 if (this->script_options_
->saw_sections_clause())
2380 this->place_orphan_sections_in_script();
2382 Output_segment
* load_seg
;
2387 // Take a snapshot of the section layout as needed.
2388 if (target
->may_relax())
2389 this->prepare_for_relaxation();
2391 // Run the relaxation loop to lay out sections.
2394 off
= this->relaxation_loop_body(pass
, target
, symtab
, &load_seg
,
2395 phdr_seg
, segment_headers
, file_header
,
2399 while (target
->may_relax()
2400 && target
->relax(pass
, input_objects
, symtab
, this, task
));
2402 // Set the file offsets of all the non-data sections we've seen so
2403 // far which don't have to wait for the input sections. We need
2404 // this in order to finalize local symbols in non-allocated
2406 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2408 // Set the section indexes of all unallocated sections seen so far,
2409 // in case any of them are somehow referenced by a symbol.
2410 shndx
= this->set_section_indexes(shndx
);
2412 // Create the symbol table sections.
2413 this->create_symtab_sections(input_objects
, symtab
, shndx
, &off
);
2414 if (!parameters
->doing_static_link())
2415 this->assign_local_dynsym_offsets(input_objects
);
2417 // Process any symbol assignments from a linker script. This must
2418 // be called after the symbol table has been finalized.
2419 this->script_options_
->finalize_symbols(symtab
, this);
2421 // Create the incremental inputs sections.
2422 if (this->incremental_inputs_
)
2424 this->incremental_inputs_
->finalize();
2425 this->create_incremental_info_sections(symtab
);
2428 // Create the .shstrtab section.
2429 Output_section
* shstrtab_section
= this->create_shstrtab();
2431 // Set the file offsets of the rest of the non-data sections which
2432 // don't have to wait for the input sections.
2433 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2435 // Now that all sections have been created, set the section indexes
2436 // for any sections which haven't been done yet.
2437 shndx
= this->set_section_indexes(shndx
);
2439 // Create the section table header.
2440 this->create_shdrs(shstrtab_section
, &off
);
2442 // If there are no sections which require postprocessing, we can
2443 // handle the section names now, and avoid a resize later.
2444 if (!this->any_postprocessing_sections_
)
2446 off
= this->set_section_offsets(off
,
2447 POSTPROCESSING_SECTIONS_PASS
);
2449 this->set_section_offsets(off
,
2450 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
2453 file_header
->set_section_info(this->section_headers_
, shstrtab_section
);
2455 // Now we know exactly where everything goes in the output file
2456 // (except for non-allocated sections which require postprocessing).
2457 Output_data::layout_complete();
2459 this->output_file_size_
= off
;
2464 // Create a note header following the format defined in the ELF ABI.
2465 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
2466 // of the section to create, DESCSZ is the size of the descriptor.
2467 // ALLOCATE is true if the section should be allocated in memory.
2468 // This returns the new note section. It sets *TRAILING_PADDING to
2469 // the number of trailing zero bytes required.
2472 Layout::create_note(const char* name
, int note_type
,
2473 const char* section_name
, size_t descsz
,
2474 bool allocate
, size_t* trailing_padding
)
2476 // Authorities all agree that the values in a .note field should
2477 // be aligned on 4-byte boundaries for 32-bit binaries. However,
2478 // they differ on what the alignment is for 64-bit binaries.
2479 // The GABI says unambiguously they take 8-byte alignment:
2480 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2481 // Other documentation says alignment should always be 4 bytes:
2482 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2483 // GNU ld and GNU readelf both support the latter (at least as of
2484 // version 2.16.91), and glibc always generates the latter for
2485 // .note.ABI-tag (as of version 1.6), so that's the one we go with
2487 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
2488 const int size
= parameters
->target().get_size();
2490 const int size
= 32;
2493 // The contents of the .note section.
2494 size_t namesz
= strlen(name
) + 1;
2495 size_t aligned_namesz
= align_address(namesz
, size
/ 8);
2496 size_t aligned_descsz
= align_address(descsz
, size
/ 8);
2498 size_t notehdrsz
= 3 * (size
/ 8) + aligned_namesz
;
2500 unsigned char* buffer
= new unsigned char[notehdrsz
];
2501 memset(buffer
, 0, notehdrsz
);
2503 bool is_big_endian
= parameters
->target().is_big_endian();
2509 elfcpp::Swap
<32, false>::writeval(buffer
, namesz
);
2510 elfcpp::Swap
<32, false>::writeval(buffer
+ 4, descsz
);
2511 elfcpp::Swap
<32, false>::writeval(buffer
+ 8, note_type
);
2515 elfcpp::Swap
<32, true>::writeval(buffer
, namesz
);
2516 elfcpp::Swap
<32, true>::writeval(buffer
+ 4, descsz
);
2517 elfcpp::Swap
<32, true>::writeval(buffer
+ 8, note_type
);
2520 else if (size
== 64)
2524 elfcpp::Swap
<64, false>::writeval(buffer
, namesz
);
2525 elfcpp::Swap
<64, false>::writeval(buffer
+ 8, descsz
);
2526 elfcpp::Swap
<64, false>::writeval(buffer
+ 16, note_type
);
2530 elfcpp::Swap
<64, true>::writeval(buffer
, namesz
);
2531 elfcpp::Swap
<64, true>::writeval(buffer
+ 8, descsz
);
2532 elfcpp::Swap
<64, true>::writeval(buffer
+ 16, note_type
);
2538 memcpy(buffer
+ 3 * (size
/ 8), name
, namesz
);
2540 elfcpp::Elf_Xword flags
= 0;
2541 Output_section_order order
= ORDER_INVALID
;
2544 flags
= elfcpp::SHF_ALLOC
;
2545 order
= ORDER_RO_NOTE
;
2547 Output_section
* os
= this->choose_output_section(NULL
, section_name
,
2549 flags
, false, order
, false);
2553 Output_section_data
* posd
= new Output_data_const_buffer(buffer
, notehdrsz
,
2556 os
->add_output_section_data(posd
);
2558 *trailing_padding
= aligned_descsz
- descsz
;
2563 // For an executable or shared library, create a note to record the
2564 // version of gold used to create the binary.
2567 Layout::create_gold_note()
2569 if (parameters
->options().relocatable()
2570 || parameters
->incremental_update())
2573 std::string desc
= std::string("gold ") + gold::get_version_string();
2575 size_t trailing_padding
;
2576 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION
,
2577 ".note.gnu.gold-version", desc
.size(),
2578 false, &trailing_padding
);
2582 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2583 os
->add_output_section_data(posd
);
2585 if (trailing_padding
> 0)
2587 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2588 os
->add_output_section_data(posd
);
2592 // Record whether the stack should be executable. This can be set
2593 // from the command line using the -z execstack or -z noexecstack
2594 // options. Otherwise, if any input file has a .note.GNU-stack
2595 // section with the SHF_EXECINSTR flag set, the stack should be
2596 // executable. Otherwise, if at least one input file a
2597 // .note.GNU-stack section, and some input file has no .note.GNU-stack
2598 // section, we use the target default for whether the stack should be
2599 // executable. Otherwise, we don't generate a stack note. When
2600 // generating a object file, we create a .note.GNU-stack section with
2601 // the appropriate marking. When generating an executable or shared
2602 // library, we create a PT_GNU_STACK segment.
2605 Layout::create_executable_stack_info()
2607 bool is_stack_executable
;
2608 if (parameters
->options().is_execstack_set())
2609 is_stack_executable
= parameters
->options().is_stack_executable();
2610 else if (!this->input_with_gnu_stack_note_
)
2614 if (this->input_requires_executable_stack_
)
2615 is_stack_executable
= true;
2616 else if (this->input_without_gnu_stack_note_
)
2617 is_stack_executable
=
2618 parameters
->target().is_default_stack_executable();
2620 is_stack_executable
= false;
2623 if (parameters
->options().relocatable())
2625 const char* name
= this->namepool_
.add(".note.GNU-stack", false, NULL
);
2626 elfcpp::Elf_Xword flags
= 0;
2627 if (is_stack_executable
)
2628 flags
|= elfcpp::SHF_EXECINSTR
;
2629 this->make_output_section(name
, elfcpp::SHT_PROGBITS
, flags
,
2630 ORDER_INVALID
, false);
2634 if (this->script_options_
->saw_phdrs_clause())
2636 int flags
= elfcpp::PF_R
| elfcpp::PF_W
;
2637 if (is_stack_executable
)
2638 flags
|= elfcpp::PF_X
;
2639 this->make_output_segment(elfcpp::PT_GNU_STACK
, flags
);
2643 // If --build-id was used, set up the build ID note.
2646 Layout::create_build_id()
2648 if (!parameters
->options().user_set_build_id())
2651 const char* style
= parameters
->options().build_id();
2652 if (strcmp(style
, "none") == 0)
2655 // Set DESCSZ to the size of the note descriptor. When possible,
2656 // set DESC to the note descriptor contents.
2659 if (strcmp(style
, "md5") == 0)
2661 else if (strcmp(style
, "sha1") == 0)
2663 else if (strcmp(style
, "uuid") == 0)
2665 const size_t uuidsz
= 128 / 8;
2667 char buffer
[uuidsz
];
2668 memset(buffer
, 0, uuidsz
);
2670 int descriptor
= open_descriptor(-1, "/dev/urandom", O_RDONLY
);
2672 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
2676 ssize_t got
= ::read(descriptor
, buffer
, uuidsz
);
2677 release_descriptor(descriptor
, true);
2679 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno
));
2680 else if (static_cast<size_t>(got
) != uuidsz
)
2681 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
2685 desc
.assign(buffer
, uuidsz
);
2688 else if (strncmp(style
, "0x", 2) == 0)
2691 const char* p
= style
+ 2;
2694 if (hex_p(p
[0]) && hex_p(p
[1]))
2696 char c
= (hex_value(p
[0]) << 4) | hex_value(p
[1]);
2700 else if (*p
== '-' || *p
== ':')
2703 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
2706 descsz
= desc
.size();
2709 gold_fatal(_("unrecognized --build-id argument '%s'"), style
);
2712 size_t trailing_padding
;
2713 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID
,
2714 ".note.gnu.build-id", descsz
, true,
2721 // We know the value already, so we fill it in now.
2722 gold_assert(desc
.size() == descsz
);
2724 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2725 os
->add_output_section_data(posd
);
2727 if (trailing_padding
!= 0)
2729 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2730 os
->add_output_section_data(posd
);
2735 // We need to compute a checksum after we have completed the
2737 gold_assert(trailing_padding
== 0);
2738 this->build_id_note_
= new Output_data_zero_fill(descsz
, 4);
2739 os
->add_output_section_data(this->build_id_note_
);
2743 // If we have both .stabXX and .stabXXstr sections, then the sh_link
2744 // field of the former should point to the latter. I'm not sure who
2745 // started this, but the GNU linker does it, and some tools depend
2749 Layout::link_stabs_sections()
2751 if (!this->have_stabstr_section_
)
2754 for (Section_list::iterator p
= this->section_list_
.begin();
2755 p
!= this->section_list_
.end();
2758 if ((*p
)->type() != elfcpp::SHT_STRTAB
)
2761 const char* name
= (*p
)->name();
2762 if (strncmp(name
, ".stab", 5) != 0)
2765 size_t len
= strlen(name
);
2766 if (strcmp(name
+ len
- 3, "str") != 0)
2769 std::string
stab_name(name
, len
- 3);
2770 Output_section
* stab_sec
;
2771 stab_sec
= this->find_output_section(stab_name
.c_str());
2772 if (stab_sec
!= NULL
)
2773 stab_sec
->set_link_section(*p
);
2777 // Create .gnu_incremental_inputs and related sections needed
2778 // for the next run of incremental linking to check what has changed.
2781 Layout::create_incremental_info_sections(Symbol_table
* symtab
)
2783 Incremental_inputs
* incr
= this->incremental_inputs_
;
2785 gold_assert(incr
!= NULL
);
2787 // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
2788 incr
->create_data_sections(symtab
);
2790 // Add the .gnu_incremental_inputs section.
2791 const char* incremental_inputs_name
=
2792 this->namepool_
.add(".gnu_incremental_inputs", false, NULL
);
2793 Output_section
* incremental_inputs_os
=
2794 this->make_output_section(incremental_inputs_name
,
2795 elfcpp::SHT_GNU_INCREMENTAL_INPUTS
, 0,
2796 ORDER_INVALID
, false);
2797 incremental_inputs_os
->add_output_section_data(incr
->inputs_section());
2799 // Add the .gnu_incremental_symtab section.
2800 const char* incremental_symtab_name
=
2801 this->namepool_
.add(".gnu_incremental_symtab", false, NULL
);
2802 Output_section
* incremental_symtab_os
=
2803 this->make_output_section(incremental_symtab_name
,
2804 elfcpp::SHT_GNU_INCREMENTAL_SYMTAB
, 0,
2805 ORDER_INVALID
, false);
2806 incremental_symtab_os
->add_output_section_data(incr
->symtab_section());
2807 incremental_symtab_os
->set_entsize(4);
2809 // Add the .gnu_incremental_relocs section.
2810 const char* incremental_relocs_name
=
2811 this->namepool_
.add(".gnu_incremental_relocs", false, NULL
);
2812 Output_section
* incremental_relocs_os
=
2813 this->make_output_section(incremental_relocs_name
,
2814 elfcpp::SHT_GNU_INCREMENTAL_RELOCS
, 0,
2815 ORDER_INVALID
, false);
2816 incremental_relocs_os
->add_output_section_data(incr
->relocs_section());
2817 incremental_relocs_os
->set_entsize(incr
->relocs_entsize());
2819 // Add the .gnu_incremental_got_plt section.
2820 const char* incremental_got_plt_name
=
2821 this->namepool_
.add(".gnu_incremental_got_plt", false, NULL
);
2822 Output_section
* incremental_got_plt_os
=
2823 this->make_output_section(incremental_got_plt_name
,
2824 elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT
, 0,
2825 ORDER_INVALID
, false);
2826 incremental_got_plt_os
->add_output_section_data(incr
->got_plt_section());
2828 // Add the .gnu_incremental_strtab section.
2829 const char* incremental_strtab_name
=
2830 this->namepool_
.add(".gnu_incremental_strtab", false, NULL
);
2831 Output_section
* incremental_strtab_os
= this->make_output_section(incremental_strtab_name
,
2832 elfcpp::SHT_STRTAB
, 0,
2833 ORDER_INVALID
, false);
2834 Output_data_strtab
* strtab_data
=
2835 new Output_data_strtab(incr
->get_stringpool());
2836 incremental_strtab_os
->add_output_section_data(strtab_data
);
2838 incremental_inputs_os
->set_after_input_sections();
2839 incremental_symtab_os
->set_after_input_sections();
2840 incremental_relocs_os
->set_after_input_sections();
2841 incremental_got_plt_os
->set_after_input_sections();
2843 incremental_inputs_os
->set_link_section(incremental_strtab_os
);
2844 incremental_symtab_os
->set_link_section(incremental_inputs_os
);
2845 incremental_relocs_os
->set_link_section(incremental_inputs_os
);
2846 incremental_got_plt_os
->set_link_section(incremental_inputs_os
);
2849 // Return whether SEG1 should be before SEG2 in the output file. This
2850 // is based entirely on the segment type and flags. When this is
2851 // called the segment addresses have normally not yet been set.
2854 Layout::segment_precedes(const Output_segment
* seg1
,
2855 const Output_segment
* seg2
)
2857 elfcpp::Elf_Word type1
= seg1
->type();
2858 elfcpp::Elf_Word type2
= seg2
->type();
2860 // The single PT_PHDR segment is required to precede any loadable
2861 // segment. We simply make it always first.
2862 if (type1
== elfcpp::PT_PHDR
)
2864 gold_assert(type2
!= elfcpp::PT_PHDR
);
2867 if (type2
== elfcpp::PT_PHDR
)
2870 // The single PT_INTERP segment is required to precede any loadable
2871 // segment. We simply make it always second.
2872 if (type1
== elfcpp::PT_INTERP
)
2874 gold_assert(type2
!= elfcpp::PT_INTERP
);
2877 if (type2
== elfcpp::PT_INTERP
)
2880 // We then put PT_LOAD segments before any other segments.
2881 if (type1
== elfcpp::PT_LOAD
&& type2
!= elfcpp::PT_LOAD
)
2883 if (type2
== elfcpp::PT_LOAD
&& type1
!= elfcpp::PT_LOAD
)
2886 // We put the PT_TLS segment last except for the PT_GNU_RELRO
2887 // segment, because that is where the dynamic linker expects to find
2888 // it (this is just for efficiency; other positions would also work
2890 if (type1
== elfcpp::PT_TLS
2891 && type2
!= elfcpp::PT_TLS
2892 && type2
!= elfcpp::PT_GNU_RELRO
)
2894 if (type2
== elfcpp::PT_TLS
2895 && type1
!= elfcpp::PT_TLS
2896 && type1
!= elfcpp::PT_GNU_RELRO
)
2899 // We put the PT_GNU_RELRO segment last, because that is where the
2900 // dynamic linker expects to find it (as with PT_TLS, this is just
2902 if (type1
== elfcpp::PT_GNU_RELRO
&& type2
!= elfcpp::PT_GNU_RELRO
)
2904 if (type2
== elfcpp::PT_GNU_RELRO
&& type1
!= elfcpp::PT_GNU_RELRO
)
2907 const elfcpp::Elf_Word flags1
= seg1
->flags();
2908 const elfcpp::Elf_Word flags2
= seg2
->flags();
2910 // The order of non-PT_LOAD segments is unimportant. We simply sort
2911 // by the numeric segment type and flags values. There should not
2912 // be more than one segment with the same type and flags.
2913 if (type1
!= elfcpp::PT_LOAD
)
2916 return type1
< type2
;
2917 gold_assert(flags1
!= flags2
);
2918 return flags1
< flags2
;
2921 // If the addresses are set already, sort by load address.
2922 if (seg1
->are_addresses_set())
2924 if (!seg2
->are_addresses_set())
2927 unsigned int section_count1
= seg1
->output_section_count();
2928 unsigned int section_count2
= seg2
->output_section_count();
2929 if (section_count1
== 0 && section_count2
> 0)
2931 if (section_count1
> 0 && section_count2
== 0)
2934 uint64_t paddr1
= (seg1
->are_addresses_set()
2936 : seg1
->first_section_load_address());
2937 uint64_t paddr2
= (seg2
->are_addresses_set()
2939 : seg2
->first_section_load_address());
2941 if (paddr1
!= paddr2
)
2942 return paddr1
< paddr2
;
2944 else if (seg2
->are_addresses_set())
2947 // A segment which holds large data comes after a segment which does
2948 // not hold large data.
2949 if (seg1
->is_large_data_segment())
2951 if (!seg2
->is_large_data_segment())
2954 else if (seg2
->is_large_data_segment())
2957 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
2958 // segments come before writable segments. Then writable segments
2959 // with data come before writable segments without data. Then
2960 // executable segments come before non-executable segments. Then
2961 // the unlikely case of a non-readable segment comes before the
2962 // normal case of a readable segment. If there are multiple
2963 // segments with the same type and flags, we require that the
2964 // address be set, and we sort by virtual address and then physical
2966 if ((flags1
& elfcpp::PF_W
) != (flags2
& elfcpp::PF_W
))
2967 return (flags1
& elfcpp::PF_W
) == 0;
2968 if ((flags1
& elfcpp::PF_W
) != 0
2969 && seg1
->has_any_data_sections() != seg2
->has_any_data_sections())
2970 return seg1
->has_any_data_sections();
2971 if ((flags1
& elfcpp::PF_X
) != (flags2
& elfcpp::PF_X
))
2972 return (flags1
& elfcpp::PF_X
) != 0;
2973 if ((flags1
& elfcpp::PF_R
) != (flags2
& elfcpp::PF_R
))
2974 return (flags1
& elfcpp::PF_R
) == 0;
2976 // We shouldn't get here--we shouldn't create segments which we
2977 // can't distinguish. Unless of course we are using a weird linker
2979 gold_assert(this->script_options_
->saw_phdrs_clause());
2983 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
2986 align_file_offset(off_t off
, uint64_t addr
, uint64_t abi_pagesize
)
2988 uint64_t unsigned_off
= off
;
2989 uint64_t aligned_off
= ((unsigned_off
& ~(abi_pagesize
- 1))
2990 | (addr
& (abi_pagesize
- 1)));
2991 if (aligned_off
< unsigned_off
)
2992 aligned_off
+= abi_pagesize
;
2996 // Set the file offsets of all the segments, and all the sections they
2997 // contain. They have all been created. LOAD_SEG must be be laid out
2998 // first. Return the offset of the data to follow.
3001 Layout::set_segment_offsets(const Target
* target
, Output_segment
* load_seg
,
3002 unsigned int* pshndx
)
3004 // Sort them into the final order. We use a stable sort so that we
3005 // don't randomize the order of indistinguishable segments created
3006 // by linker scripts.
3007 std::stable_sort(this->segment_list_
.begin(), this->segment_list_
.end(),
3008 Layout::Compare_segments(this));
3010 // Find the PT_LOAD segments, and set their addresses and offsets
3011 // and their section's addresses and offsets.
3013 if (parameters
->options().user_set_Ttext())
3014 addr
= parameters
->options().Ttext();
3015 else if (parameters
->options().output_is_position_independent())
3018 addr
= target
->default_text_segment_address();
3021 // If LOAD_SEG is NULL, then the file header and segment headers
3022 // will not be loadable. But they still need to be at offset 0 in
3023 // the file. Set their offsets now.
3024 if (load_seg
== NULL
)
3026 for (Data_list::iterator p
= this->special_output_list_
.begin();
3027 p
!= this->special_output_list_
.end();
3030 off
= align_address(off
, (*p
)->addralign());
3031 (*p
)->set_address_and_file_offset(0, off
);
3032 off
+= (*p
)->data_size();
3036 unsigned int increase_relro
= this->increase_relro_
;
3037 if (this->script_options_
->saw_sections_clause())
3040 const bool check_sections
= parameters
->options().check_sections();
3041 Output_segment
* last_load_segment
= NULL
;
3043 for (Segment_list::iterator p
= this->segment_list_
.begin();
3044 p
!= this->segment_list_
.end();
3047 if ((*p
)->type() == elfcpp::PT_LOAD
)
3049 if (load_seg
!= NULL
&& load_seg
!= *p
)
3053 bool are_addresses_set
= (*p
)->are_addresses_set();
3054 if (are_addresses_set
)
3056 // When it comes to setting file offsets, we care about
3057 // the physical address.
3058 addr
= (*p
)->paddr();
3060 else if (parameters
->options().user_set_Ttext()
3061 && ((*p
)->flags() & elfcpp::PF_W
) == 0)
3063 are_addresses_set
= true;
3065 else if (parameters
->options().user_set_Tdata()
3066 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3067 && (!parameters
->options().user_set_Tbss()
3068 || (*p
)->has_any_data_sections()))
3070 addr
= parameters
->options().Tdata();
3071 are_addresses_set
= true;
3073 else if (parameters
->options().user_set_Tbss()
3074 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3075 && !(*p
)->has_any_data_sections())
3077 addr
= parameters
->options().Tbss();
3078 are_addresses_set
= true;
3081 uint64_t orig_addr
= addr
;
3082 uint64_t orig_off
= off
;
3084 uint64_t aligned_addr
= 0;
3085 uint64_t abi_pagesize
= target
->abi_pagesize();
3086 uint64_t common_pagesize
= target
->common_pagesize();
3088 if (!parameters
->options().nmagic()
3089 && !parameters
->options().omagic())
3090 (*p
)->set_minimum_p_align(common_pagesize
);
3092 if (!are_addresses_set
)
3094 // Skip the address forward one page, maintaining the same
3095 // position within the page. This lets us store both segments
3096 // overlapping on a single page in the file, but the loader will
3097 // put them on different pages in memory. We will revisit this
3098 // decision once we know the size of the segment.
3100 addr
= align_address(addr
, (*p
)->maximum_alignment());
3101 aligned_addr
= addr
;
3103 if ((addr
& (abi_pagesize
- 1)) != 0)
3104 addr
= addr
+ abi_pagesize
;
3106 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3109 if (!parameters
->options().nmagic()
3110 && !parameters
->options().omagic())
3111 off
= align_file_offset(off
, addr
, abi_pagesize
);
3112 else if (load_seg
== NULL
)
3114 // This is -N or -n with a section script which prevents
3115 // us from using a load segment. We need to ensure that
3116 // the file offset is aligned to the alignment of the
3117 // segment. This is because the linker script
3118 // implicitly assumed a zero offset. If we don't align
3119 // here, then the alignment of the sections in the
3120 // linker script may not match the alignment of the
3121 // sections in the set_section_addresses call below,
3122 // causing an error about dot moving backward.
3123 off
= align_address(off
, (*p
)->maximum_alignment());
3126 unsigned int shndx_hold
= *pshndx
;
3127 bool has_relro
= false;
3128 uint64_t new_addr
= (*p
)->set_section_addresses(this, false, addr
,
3133 // Now that we know the size of this segment, we may be able
3134 // to save a page in memory, at the cost of wasting some
3135 // file space, by instead aligning to the start of a new
3136 // page. Here we use the real machine page size rather than
3137 // the ABI mandated page size. If the segment has been
3138 // aligned so that the relro data ends at a page boundary,
3139 // we do not try to realign it.
3141 if (!are_addresses_set
3143 && aligned_addr
!= addr
3144 && !parameters
->incremental())
3146 uint64_t first_off
= (common_pagesize
3148 & (common_pagesize
- 1)));
3149 uint64_t last_off
= new_addr
& (common_pagesize
- 1);
3152 && ((aligned_addr
& ~ (common_pagesize
- 1))
3153 != (new_addr
& ~ (common_pagesize
- 1)))
3154 && first_off
+ last_off
<= common_pagesize
)
3156 *pshndx
= shndx_hold
;
3157 addr
= align_address(aligned_addr
, common_pagesize
);
3158 addr
= align_address(addr
, (*p
)->maximum_alignment());
3159 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3160 off
= align_file_offset(off
, addr
, abi_pagesize
);
3162 increase_relro
= this->increase_relro_
;
3163 if (this->script_options_
->saw_sections_clause())
3167 new_addr
= (*p
)->set_section_addresses(this, true, addr
,
3176 // Implement --check-sections. We know that the segments
3177 // are sorted by LMA.
3178 if (check_sections
&& last_load_segment
!= NULL
)
3180 gold_assert(last_load_segment
->paddr() <= (*p
)->paddr());
3181 if (last_load_segment
->paddr() + last_load_segment
->memsz()
3184 unsigned long long lb1
= last_load_segment
->paddr();
3185 unsigned long long le1
= lb1
+ last_load_segment
->memsz();
3186 unsigned long long lb2
= (*p
)->paddr();
3187 unsigned long long le2
= lb2
+ (*p
)->memsz();
3188 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3189 "[0x%llx -> 0x%llx]"),
3190 lb1
, le1
, lb2
, le2
);
3193 last_load_segment
= *p
;
3197 // Handle the non-PT_LOAD segments, setting their offsets from their
3198 // section's offsets.
3199 for (Segment_list::iterator p
= this->segment_list_
.begin();
3200 p
!= this->segment_list_
.end();
3203 if ((*p
)->type() != elfcpp::PT_LOAD
)
3204 (*p
)->set_offset((*p
)->type() == elfcpp::PT_GNU_RELRO
3209 // Set the TLS offsets for each section in the PT_TLS segment.
3210 if (this->tls_segment_
!= NULL
)
3211 this->tls_segment_
->set_tls_offsets();
3216 // Set the offsets of all the allocated sections when doing a
3217 // relocatable link. This does the same jobs as set_segment_offsets,
3218 // only for a relocatable link.
3221 Layout::set_relocatable_section_offsets(Output_data
* file_header
,
3222 unsigned int* pshndx
)
3226 file_header
->set_address_and_file_offset(0, 0);
3227 off
+= file_header
->data_size();
3229 for (Section_list::iterator p
= this->section_list_
.begin();
3230 p
!= this->section_list_
.end();
3233 // We skip unallocated sections here, except that group sections
3234 // have to come first.
3235 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) == 0
3236 && (*p
)->type() != elfcpp::SHT_GROUP
)
3239 off
= align_address(off
, (*p
)->addralign());
3241 // The linker script might have set the address.
3242 if (!(*p
)->is_address_valid())
3243 (*p
)->set_address(0);
3244 (*p
)->set_file_offset(off
);
3245 (*p
)->finalize_data_size();
3246 off
+= (*p
)->data_size();
3248 (*p
)->set_out_shndx(*pshndx
);
3255 // Set the file offset of all the sections not associated with a
3259 Layout::set_section_offsets(off_t off
, Layout::Section_offset_pass pass
)
3261 off_t startoff
= off
;
3264 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3265 p
!= this->unattached_section_list_
.end();
3268 // The symtab section is handled in create_symtab_sections.
3269 if (*p
== this->symtab_section_
)
3272 // If we've already set the data size, don't set it again.
3273 if ((*p
)->is_offset_valid() && (*p
)->is_data_size_valid())
3276 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3277 && (*p
)->requires_postprocessing())
3279 (*p
)->create_postprocessing_buffer();
3280 this->any_postprocessing_sections_
= true;
3283 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3284 && (*p
)->after_input_sections())
3286 else if (pass
== POSTPROCESSING_SECTIONS_PASS
3287 && (!(*p
)->after_input_sections()
3288 || (*p
)->type() == elfcpp::SHT_STRTAB
))
3290 else if (pass
== STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
3291 && (!(*p
)->after_input_sections()
3292 || (*p
)->type() != elfcpp::SHT_STRTAB
))
3295 if (!parameters
->incremental_update())
3297 off
= align_address(off
, (*p
)->addralign());
3298 (*p
)->set_file_offset(off
);
3299 (*p
)->finalize_data_size();
3303 // Incremental update: allocate file space from free list.
3304 (*p
)->pre_finalize_data_size();
3305 off_t current_size
= (*p
)->current_data_size();
3306 off
= this->allocate(current_size
, (*p
)->addralign(), startoff
);
3309 if (is_debugging_enabled(DEBUG_INCREMENTAL
))
3310 this->free_list_
.dump();
3311 gold_assert((*p
)->output_section() != NULL
);
3312 gold_fallback(_("out of patch space for section %s; "
3313 "relink with --incremental-full"),
3314 (*p
)->output_section()->name());
3316 (*p
)->set_file_offset(off
);
3317 (*p
)->finalize_data_size();
3318 if ((*p
)->data_size() > current_size
)
3320 gold_assert((*p
)->output_section() != NULL
);
3321 gold_fallback(_("%s: section changed size; "
3322 "relink with --incremental-full"),
3323 (*p
)->output_section()->name());
3325 gold_debug(DEBUG_INCREMENTAL
,
3326 "set_section_offsets: %08lx %08lx %s",
3327 static_cast<long>(off
),
3328 static_cast<long>((*p
)->data_size()),
3329 ((*p
)->output_section() != NULL
3330 ? (*p
)->output_section()->name() : "(special)"));
3333 off
+= (*p
)->data_size();
3337 // At this point the name must be set.
3338 if (pass
!= STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
)
3339 this->namepool_
.add((*p
)->name(), false, NULL
);
3344 // Set the section indexes of all the sections not associated with a
3348 Layout::set_section_indexes(unsigned int shndx
)
3350 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3351 p
!= this->unattached_section_list_
.end();
3354 if (!(*p
)->has_out_shndx())
3356 (*p
)->set_out_shndx(shndx
);
3363 // Set the section addresses according to the linker script. This is
3364 // only called when we see a SECTIONS clause. This returns the
3365 // program segment which should hold the file header and segment
3366 // headers, if any. It will return NULL if they should not be in a
3370 Layout::set_section_addresses_from_script(Symbol_table
* symtab
)
3372 Script_sections
* ss
= this->script_options_
->script_sections();
3373 gold_assert(ss
->saw_sections_clause());
3374 return this->script_options_
->set_section_addresses(symtab
, this);
3377 // Place the orphan sections in the linker script.
3380 Layout::place_orphan_sections_in_script()
3382 Script_sections
* ss
= this->script_options_
->script_sections();
3383 gold_assert(ss
->saw_sections_clause());
3385 // Place each orphaned output section in the script.
3386 for (Section_list::iterator p
= this->section_list_
.begin();
3387 p
!= this->section_list_
.end();
3390 if (!(*p
)->found_in_sections_clause())
3391 ss
->place_orphan(*p
);
3395 // Count the local symbols in the regular symbol table and the dynamic
3396 // symbol table, and build the respective string pools.
3399 Layout::count_local_symbols(const Task
* task
,
3400 const Input_objects
* input_objects
)
3402 // First, figure out an upper bound on the number of symbols we'll
3403 // be inserting into each pool. This helps us create the pools with
3404 // the right size, to avoid unnecessary hashtable resizing.
3405 unsigned int symbol_count
= 0;
3406 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3407 p
!= input_objects
->relobj_end();
3409 symbol_count
+= (*p
)->local_symbol_count();
3411 // Go from "upper bound" to "estimate." We overcount for two
3412 // reasons: we double-count symbols that occur in more than one
3413 // object file, and we count symbols that are dropped from the
3414 // output. Add it all together and assume we overcount by 100%.
3417 // We assume all symbols will go into both the sympool and dynpool.
3418 this->sympool_
.reserve(symbol_count
);
3419 this->dynpool_
.reserve(symbol_count
);
3421 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3422 p
!= input_objects
->relobj_end();
3425 Task_lock_obj
<Object
> tlo(task
, *p
);
3426 (*p
)->count_local_symbols(&this->sympool_
, &this->dynpool_
);
3430 // Create the symbol table sections. Here we also set the final
3431 // values of the symbols. At this point all the loadable sections are
3432 // fully laid out. SHNUM is the number of sections so far.
3435 Layout::create_symtab_sections(const Input_objects
* input_objects
,
3436 Symbol_table
* symtab
,
3442 if (parameters
->target().get_size() == 32)
3444 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
3447 else if (parameters
->target().get_size() == 64)
3449 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
3455 // Compute file offsets relative to the start of the symtab section.
3458 // Save space for the dummy symbol at the start of the section. We
3459 // never bother to write this out--it will just be left as zero.
3461 unsigned int local_symbol_index
= 1;
3463 // Add STT_SECTION symbols for each Output section which needs one.
3464 for (Section_list::iterator p
= this->section_list_
.begin();
3465 p
!= this->section_list_
.end();
3468 if (!(*p
)->needs_symtab_index())
3469 (*p
)->set_symtab_index(-1U);
3472 (*p
)->set_symtab_index(local_symbol_index
);
3473 ++local_symbol_index
;
3478 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3479 p
!= input_objects
->relobj_end();
3482 unsigned int index
= (*p
)->finalize_local_symbols(local_symbol_index
,
3484 off
+= (index
- local_symbol_index
) * symsize
;
3485 local_symbol_index
= index
;
3488 unsigned int local_symcount
= local_symbol_index
;
3489 gold_assert(static_cast<off_t
>(local_symcount
* symsize
) == off
);
3492 size_t dyn_global_index
;
3494 if (this->dynsym_section_
== NULL
)
3497 dyn_global_index
= 0;
3502 dyn_global_index
= this->dynsym_section_
->info();
3503 off_t locsize
= dyn_global_index
* this->dynsym_section_
->entsize();
3504 dynoff
= this->dynsym_section_
->offset() + locsize
;
3505 dyncount
= (this->dynsym_section_
->data_size() - locsize
) / symsize
;
3506 gold_assert(static_cast<off_t
>(dyncount
* symsize
)
3507 == this->dynsym_section_
->data_size() - locsize
);
3510 off_t global_off
= off
;
3511 off
= symtab
->finalize(off
, dynoff
, dyn_global_index
, dyncount
,
3512 &this->sympool_
, &local_symcount
);
3514 if (!parameters
->options().strip_all())
3516 this->sympool_
.set_string_offsets();
3518 const char* symtab_name
= this->namepool_
.add(".symtab", false, NULL
);
3519 Output_section
* osymtab
= this->make_output_section(symtab_name
,
3523 this->symtab_section_
= osymtab
;
3525 Output_section_data
* pos
= new Output_data_fixed_space(off
, align
,
3527 osymtab
->add_output_section_data(pos
);
3529 // We generate a .symtab_shndx section if we have more than
3530 // SHN_LORESERVE sections. Technically it is possible that we
3531 // don't need one, because it is possible that there are no
3532 // symbols in any of sections with indexes larger than
3533 // SHN_LORESERVE. That is probably unusual, though, and it is
3534 // easier to always create one than to compute section indexes
3535 // twice (once here, once when writing out the symbols).
3536 if (shnum
>= elfcpp::SHN_LORESERVE
)
3538 const char* symtab_xindex_name
= this->namepool_
.add(".symtab_shndx",
3540 Output_section
* osymtab_xindex
=
3541 this->make_output_section(symtab_xindex_name
,
3542 elfcpp::SHT_SYMTAB_SHNDX
, 0,
3543 ORDER_INVALID
, false);
3545 size_t symcount
= off
/ symsize
;
3546 this->symtab_xindex_
= new Output_symtab_xindex(symcount
);
3548 osymtab_xindex
->add_output_section_data(this->symtab_xindex_
);
3550 osymtab_xindex
->set_link_section(osymtab
);
3551 osymtab_xindex
->set_addralign(4);
3552 osymtab_xindex
->set_entsize(4);
3554 osymtab_xindex
->set_after_input_sections();
3556 // This tells the driver code to wait until the symbol table
3557 // has written out before writing out the postprocessing
3558 // sections, including the .symtab_shndx section.
3559 this->any_postprocessing_sections_
= true;
3562 const char* strtab_name
= this->namepool_
.add(".strtab", false, NULL
);
3563 Output_section
* ostrtab
= this->make_output_section(strtab_name
,
3568 Output_section_data
* pstr
= new Output_data_strtab(&this->sympool_
);
3569 ostrtab
->add_output_section_data(pstr
);
3572 if (!parameters
->incremental_update())
3573 symtab_off
= align_address(*poff
, align
);
3576 symtab_off
= this->allocate(off
, align
, *poff
);
3578 gold_fallback(_("out of patch space for symbol table; "
3579 "relink with --incremental-full"));
3580 gold_debug(DEBUG_INCREMENTAL
,
3581 "create_symtab_sections: %08lx %08lx .symtab",
3582 static_cast<long>(symtab_off
),
3583 static_cast<long>(off
));
3586 symtab
->set_file_offset(symtab_off
+ global_off
);
3587 osymtab
->set_file_offset(symtab_off
);
3588 osymtab
->finalize_data_size();
3589 osymtab
->set_link_section(ostrtab
);
3590 osymtab
->set_info(local_symcount
);
3591 osymtab
->set_entsize(symsize
);
3593 if (symtab_off
+ off
> *poff
)
3594 *poff
= symtab_off
+ off
;
3598 // Create the .shstrtab section, which holds the names of the
3599 // sections. At the time this is called, we have created all the
3600 // output sections except .shstrtab itself.
3603 Layout::create_shstrtab()
3605 // FIXME: We don't need to create a .shstrtab section if we are
3606 // stripping everything.
3608 const char* name
= this->namepool_
.add(".shstrtab", false, NULL
);
3610 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_STRTAB
, 0,
3611 ORDER_INVALID
, false);
3613 if (strcmp(parameters
->options().compress_debug_sections(), "none") != 0)
3615 // We can't write out this section until we've set all the
3616 // section names, and we don't set the names of compressed
3617 // output sections until relocations are complete. FIXME: With
3618 // the current names we use, this is unnecessary.
3619 os
->set_after_input_sections();
3622 Output_section_data
* posd
= new Output_data_strtab(&this->namepool_
);
3623 os
->add_output_section_data(posd
);
3628 // Create the section headers. SIZE is 32 or 64. OFF is the file
3632 Layout::create_shdrs(const Output_section
* shstrtab_section
, off_t
* poff
)
3634 Output_section_headers
* oshdrs
;
3635 oshdrs
= new Output_section_headers(this,
3636 &this->segment_list_
,
3637 &this->section_list_
,
3638 &this->unattached_section_list_
,
3642 if (!parameters
->incremental_update())
3643 off
= align_address(*poff
, oshdrs
->addralign());
3646 oshdrs
->pre_finalize_data_size();
3647 off
= this->allocate(oshdrs
->data_size(), oshdrs
->addralign(), *poff
);
3649 gold_fallback(_("out of patch space for section header table; "
3650 "relink with --incremental-full"));
3651 gold_debug(DEBUG_INCREMENTAL
,
3652 "create_shdrs: %08lx %08lx (section header table)",
3653 static_cast<long>(off
),
3654 static_cast<long>(off
+ oshdrs
->data_size()));
3656 oshdrs
->set_address_and_file_offset(0, off
);
3657 off
+= oshdrs
->data_size();
3660 this->section_headers_
= oshdrs
;
3663 // Count the allocated sections.
3666 Layout::allocated_output_section_count() const
3668 size_t section_count
= 0;
3669 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
3670 p
!= this->segment_list_
.end();
3672 section_count
+= (*p
)->output_section_count();
3673 return section_count
;
3676 // Create the dynamic symbol table.
3679 Layout::create_dynamic_symtab(const Input_objects
* input_objects
,
3680 Symbol_table
* symtab
,
3681 Output_section
** pdynstr
,
3682 unsigned int* plocal_dynamic_count
,
3683 std::vector
<Symbol
*>* pdynamic_symbols
,
3684 Versions
* pversions
)
3686 // Count all the symbols in the dynamic symbol table, and set the
3687 // dynamic symbol indexes.
3689 // Skip symbol 0, which is always all zeroes.
3690 unsigned int index
= 1;
3692 // Add STT_SECTION symbols for each Output section which needs one.
3693 for (Section_list::iterator p
= this->section_list_
.begin();
3694 p
!= this->section_list_
.end();
3697 if (!(*p
)->needs_dynsym_index())
3698 (*p
)->set_dynsym_index(-1U);
3701 (*p
)->set_dynsym_index(index
);
3706 // Count the local symbols that need to go in the dynamic symbol table,
3707 // and set the dynamic symbol indexes.
3708 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3709 p
!= input_objects
->relobj_end();
3712 unsigned int new_index
= (*p
)->set_local_dynsym_indexes(index
);
3716 unsigned int local_symcount
= index
;
3717 *plocal_dynamic_count
= local_symcount
;
3719 index
= symtab
->set_dynsym_indexes(index
, pdynamic_symbols
,
3720 &this->dynpool_
, pversions
);
3724 const int size
= parameters
->target().get_size();
3727 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
3730 else if (size
== 64)
3732 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
3738 // Create the dynamic symbol table section.
3740 Output_section
* dynsym
= this->choose_output_section(NULL
, ".dynsym",
3744 ORDER_DYNAMIC_LINKER
,
3747 // Check for NULL as a linker script may discard .dynsym.
3750 Output_section_data
* odata
= new Output_data_fixed_space(index
* symsize
,
3753 dynsym
->add_output_section_data(odata
);
3755 dynsym
->set_info(local_symcount
);
3756 dynsym
->set_entsize(symsize
);
3757 dynsym
->set_addralign(align
);
3759 this->dynsym_section_
= dynsym
;
3762 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
3765 odyn
->add_section_address(elfcpp::DT_SYMTAB
, dynsym
);
3766 odyn
->add_constant(elfcpp::DT_SYMENT
, symsize
);
3769 // If there are more than SHN_LORESERVE allocated sections, we
3770 // create a .dynsym_shndx section. It is possible that we don't
3771 // need one, because it is possible that there are no dynamic
3772 // symbols in any of the sections with indexes larger than
3773 // SHN_LORESERVE. This is probably unusual, though, and at this
3774 // time we don't know the actual section indexes so it is
3775 // inconvenient to check.
3776 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE
)
3778 Output_section
* dynsym_xindex
=
3779 this->choose_output_section(NULL
, ".dynsym_shndx",
3780 elfcpp::SHT_SYMTAB_SHNDX
,
3782 false, ORDER_DYNAMIC_LINKER
, false);
3784 if (dynsym_xindex
!= NULL
)
3786 this->dynsym_xindex_
= new Output_symtab_xindex(index
);
3788 dynsym_xindex
->add_output_section_data(this->dynsym_xindex_
);
3790 dynsym_xindex
->set_link_section(dynsym
);
3791 dynsym_xindex
->set_addralign(4);
3792 dynsym_xindex
->set_entsize(4);
3794 dynsym_xindex
->set_after_input_sections();
3796 // This tells the driver code to wait until the symbol table
3797 // has written out before writing out the postprocessing
3798 // sections, including the .dynsym_shndx section.
3799 this->any_postprocessing_sections_
= true;
3803 // Create the dynamic string table section.
3805 Output_section
* dynstr
= this->choose_output_section(NULL
, ".dynstr",
3809 ORDER_DYNAMIC_LINKER
,
3814 Output_section_data
* strdata
= new Output_data_strtab(&this->dynpool_
);
3815 dynstr
->add_output_section_data(strdata
);
3818 dynsym
->set_link_section(dynstr
);
3819 if (this->dynamic_section_
!= NULL
)
3820 this->dynamic_section_
->set_link_section(dynstr
);
3824 odyn
->add_section_address(elfcpp::DT_STRTAB
, dynstr
);
3825 odyn
->add_section_size(elfcpp::DT_STRSZ
, dynstr
);
3831 // Create the hash tables.
3833 if (strcmp(parameters
->options().hash_style(), "sysv") == 0
3834 || strcmp(parameters
->options().hash_style(), "both") == 0)
3836 unsigned char* phash
;
3837 unsigned int hashlen
;
3838 Dynobj::create_elf_hash_table(*pdynamic_symbols
, local_symcount
,
3841 Output_section
* hashsec
=
3842 this->choose_output_section(NULL
, ".hash", elfcpp::SHT_HASH
,
3843 elfcpp::SHF_ALLOC
, false,
3844 ORDER_DYNAMIC_LINKER
, false);
3846 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
3850 if (hashsec
!= NULL
&& hashdata
!= NULL
)
3851 hashsec
->add_output_section_data(hashdata
);
3853 if (hashsec
!= NULL
)
3856 hashsec
->set_link_section(dynsym
);
3857 hashsec
->set_entsize(4);
3861 odyn
->add_section_address(elfcpp::DT_HASH
, hashsec
);
3864 if (strcmp(parameters
->options().hash_style(), "gnu") == 0
3865 || strcmp(parameters
->options().hash_style(), "both") == 0)
3867 unsigned char* phash
;
3868 unsigned int hashlen
;
3869 Dynobj::create_gnu_hash_table(*pdynamic_symbols
, local_symcount
,
3872 Output_section
* hashsec
=
3873 this->choose_output_section(NULL
, ".gnu.hash", elfcpp::SHT_GNU_HASH
,
3874 elfcpp::SHF_ALLOC
, false,
3875 ORDER_DYNAMIC_LINKER
, false);
3877 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
3881 if (hashsec
!= NULL
&& hashdata
!= NULL
)
3882 hashsec
->add_output_section_data(hashdata
);
3884 if (hashsec
!= NULL
)
3887 hashsec
->set_link_section(dynsym
);
3889 // For a 64-bit target, the entries in .gnu.hash do not have
3890 // a uniform size, so we only set the entry size for a
3892 if (parameters
->target().get_size() == 32)
3893 hashsec
->set_entsize(4);
3896 odyn
->add_section_address(elfcpp::DT_GNU_HASH
, hashsec
);
3901 // Assign offsets to each local portion of the dynamic symbol table.
3904 Layout::assign_local_dynsym_offsets(const Input_objects
* input_objects
)
3906 Output_section
* dynsym
= this->dynsym_section_
;
3910 off_t off
= dynsym
->offset();
3912 // Skip the dummy symbol at the start of the section.
3913 off
+= dynsym
->entsize();
3915 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3916 p
!= input_objects
->relobj_end();
3919 unsigned int count
= (*p
)->set_local_dynsym_offset(off
);
3920 off
+= count
* dynsym
->entsize();
3924 // Create the version sections.
3927 Layout::create_version_sections(const Versions
* versions
,
3928 const Symbol_table
* symtab
,
3929 unsigned int local_symcount
,
3930 const std::vector
<Symbol
*>& dynamic_symbols
,
3931 const Output_section
* dynstr
)
3933 if (!versions
->any_defs() && !versions
->any_needs())
3936 switch (parameters
->size_and_endianness())
3938 #ifdef HAVE_TARGET_32_LITTLE
3939 case Parameters::TARGET_32_LITTLE
:
3940 this->sized_create_version_sections
<32, false>(versions
, symtab
,
3942 dynamic_symbols
, dynstr
);
3945 #ifdef HAVE_TARGET_32_BIG
3946 case Parameters::TARGET_32_BIG
:
3947 this->sized_create_version_sections
<32, true>(versions
, symtab
,
3949 dynamic_symbols
, dynstr
);
3952 #ifdef HAVE_TARGET_64_LITTLE
3953 case Parameters::TARGET_64_LITTLE
:
3954 this->sized_create_version_sections
<64, false>(versions
, symtab
,
3956 dynamic_symbols
, dynstr
);
3959 #ifdef HAVE_TARGET_64_BIG
3960 case Parameters::TARGET_64_BIG
:
3961 this->sized_create_version_sections
<64, true>(versions
, symtab
,
3963 dynamic_symbols
, dynstr
);
3971 // Create the version sections, sized version.
3973 template<int size
, bool big_endian
>
3975 Layout::sized_create_version_sections(
3976 const Versions
* versions
,
3977 const Symbol_table
* symtab
,
3978 unsigned int local_symcount
,
3979 const std::vector
<Symbol
*>& dynamic_symbols
,
3980 const Output_section
* dynstr
)
3982 Output_section
* vsec
= this->choose_output_section(NULL
, ".gnu.version",
3983 elfcpp::SHT_GNU_versym
,
3986 ORDER_DYNAMIC_LINKER
,
3989 // Check for NULL since a linker script may discard this section.
3992 unsigned char* vbuf
;
3994 versions
->symbol_section_contents
<size
, big_endian
>(symtab
,
4000 Output_section_data
* vdata
= new Output_data_const_buffer(vbuf
, vsize
, 2,
4003 vsec
->add_output_section_data(vdata
);
4004 vsec
->set_entsize(2);
4005 vsec
->set_link_section(this->dynsym_section_
);
4008 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4009 if (odyn
!= NULL
&& vsec
!= NULL
)
4010 odyn
->add_section_address(elfcpp::DT_VERSYM
, vsec
);
4012 if (versions
->any_defs())
4014 Output_section
* vdsec
;
4015 vdsec
= this->choose_output_section(NULL
, ".gnu.version_d",
4016 elfcpp::SHT_GNU_verdef
,
4018 false, ORDER_DYNAMIC_LINKER
, false);
4022 unsigned char* vdbuf
;
4023 unsigned int vdsize
;
4024 unsigned int vdentries
;
4025 versions
->def_section_contents
<size
, big_endian
>(&this->dynpool_
,
4029 Output_section_data
* vddata
=
4030 new Output_data_const_buffer(vdbuf
, vdsize
, 4, "** version defs");
4032 vdsec
->add_output_section_data(vddata
);
4033 vdsec
->set_link_section(dynstr
);
4034 vdsec
->set_info(vdentries
);
4038 odyn
->add_section_address(elfcpp::DT_VERDEF
, vdsec
);
4039 odyn
->add_constant(elfcpp::DT_VERDEFNUM
, vdentries
);
4044 if (versions
->any_needs())
4046 Output_section
* vnsec
;
4047 vnsec
= this->choose_output_section(NULL
, ".gnu.version_r",
4048 elfcpp::SHT_GNU_verneed
,
4050 false, ORDER_DYNAMIC_LINKER
, false);
4054 unsigned char* vnbuf
;
4055 unsigned int vnsize
;
4056 unsigned int vnentries
;
4057 versions
->need_section_contents
<size
, big_endian
>(&this->dynpool_
,
4061 Output_section_data
* vndata
=
4062 new Output_data_const_buffer(vnbuf
, vnsize
, 4, "** version refs");
4064 vnsec
->add_output_section_data(vndata
);
4065 vnsec
->set_link_section(dynstr
);
4066 vnsec
->set_info(vnentries
);
4070 odyn
->add_section_address(elfcpp::DT_VERNEED
, vnsec
);
4071 odyn
->add_constant(elfcpp::DT_VERNEEDNUM
, vnentries
);
4077 // Create the .interp section and PT_INTERP segment.
4080 Layout::create_interp(const Target
* target
)
4082 gold_assert(this->interp_segment_
== NULL
);
4084 const char* interp
= parameters
->options().dynamic_linker();
4087 interp
= target
->dynamic_linker();
4088 gold_assert(interp
!= NULL
);
4091 size_t len
= strlen(interp
) + 1;
4093 Output_section_data
* odata
= new Output_data_const(interp
, len
, 1);
4095 Output_section
* osec
= this->choose_output_section(NULL
, ".interp",
4096 elfcpp::SHT_PROGBITS
,
4098 false, ORDER_INTERP
,
4101 osec
->add_output_section_data(odata
);
4104 // Add dynamic tags for the PLT and the dynamic relocs. This is
4105 // called by the target-specific code. This does nothing if not doing
4108 // USE_REL is true for REL relocs rather than RELA relocs.
4110 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
4112 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
4113 // and we also set DT_PLTREL. We use PLT_REL's output section, since
4114 // some targets have multiple reloc sections in PLT_REL.
4116 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
4117 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT. Again we use the output
4120 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
4124 Layout::add_target_dynamic_tags(bool use_rel
, const Output_data
* plt_got
,
4125 const Output_data
* plt_rel
,
4126 const Output_data_reloc_generic
* dyn_rel
,
4127 bool add_debug
, bool dynrel_includes_plt
)
4129 Output_data_dynamic
* odyn
= this->dynamic_data_
;
4133 if (plt_got
!= NULL
&& plt_got
->output_section() != NULL
)
4134 odyn
->add_section_address(elfcpp::DT_PLTGOT
, plt_got
);
4136 if (plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
)
4138 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, plt_rel
->output_section());
4139 odyn
->add_section_address(elfcpp::DT_JMPREL
, plt_rel
->output_section());
4140 odyn
->add_constant(elfcpp::DT_PLTREL
,
4141 use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
);
4144 if (dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
)
4146 odyn
->add_section_address(use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
,
4147 dyn_rel
->output_section());
4149 && plt_rel
->output_section() != NULL
4150 && dynrel_includes_plt
)
4151 odyn
->add_section_size(use_rel
? elfcpp::DT_RELSZ
: elfcpp::DT_RELASZ
,
4152 dyn_rel
->output_section(),
4153 plt_rel
->output_section());
4155 odyn
->add_section_size(use_rel
? elfcpp::DT_RELSZ
: elfcpp::DT_RELASZ
,
4156 dyn_rel
->output_section());
4157 const int size
= parameters
->target().get_size();
4162 rel_tag
= elfcpp::DT_RELENT
;
4164 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 32, false>::reloc_size
;
4165 else if (size
== 64)
4166 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 64, false>::reloc_size
;
4172 rel_tag
= elfcpp::DT_RELAENT
;
4174 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 32, false>::reloc_size
;
4175 else if (size
== 64)
4176 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 64, false>::reloc_size
;
4180 odyn
->add_constant(rel_tag
, rel_size
);
4182 if (parameters
->options().combreloc())
4184 size_t c
= dyn_rel
->relative_reloc_count();
4186 odyn
->add_constant((use_rel
4187 ? elfcpp::DT_RELCOUNT
4188 : elfcpp::DT_RELACOUNT
),
4193 if (add_debug
&& !parameters
->options().shared())
4195 // The value of the DT_DEBUG tag is filled in by the dynamic
4196 // linker at run time, and used by the debugger.
4197 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
4201 // Finish the .dynamic section and PT_DYNAMIC segment.
4204 Layout::finish_dynamic_section(const Input_objects
* input_objects
,
4205 const Symbol_table
* symtab
)
4207 if (!this->script_options_
->saw_phdrs_clause()
4208 && this->dynamic_section_
!= NULL
)
4210 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_DYNAMIC
,
4213 oseg
->add_output_section_to_nonload(this->dynamic_section_
,
4214 elfcpp::PF_R
| elfcpp::PF_W
);
4217 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4221 for (Input_objects::Dynobj_iterator p
= input_objects
->dynobj_begin();
4222 p
!= input_objects
->dynobj_end();
4225 if (!(*p
)->is_needed() && (*p
)->as_needed())
4227 // This dynamic object was linked with --as-needed, but it
4232 odyn
->add_string(elfcpp::DT_NEEDED
, (*p
)->soname());
4235 if (parameters
->options().shared())
4237 const char* soname
= parameters
->options().soname();
4239 odyn
->add_string(elfcpp::DT_SONAME
, soname
);
4242 Symbol
* sym
= symtab
->lookup(parameters
->options().init());
4243 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4244 odyn
->add_symbol(elfcpp::DT_INIT
, sym
);
4246 sym
= symtab
->lookup(parameters
->options().fini());
4247 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4248 odyn
->add_symbol(elfcpp::DT_FINI
, sym
);
4250 // Look for .init_array, .preinit_array and .fini_array by checking
4252 for(Layout::Section_list::const_iterator p
= this->section_list_
.begin();
4253 p
!= this->section_list_
.end();
4255 switch((*p
)->type())
4257 case elfcpp::SHT_FINI_ARRAY
:
4258 odyn
->add_section_address(elfcpp::DT_FINI_ARRAY
, *p
);
4259 odyn
->add_section_size(elfcpp::DT_FINI_ARRAYSZ
, *p
);
4261 case elfcpp::SHT_INIT_ARRAY
:
4262 odyn
->add_section_address(elfcpp::DT_INIT_ARRAY
, *p
);
4263 odyn
->add_section_size(elfcpp::DT_INIT_ARRAYSZ
, *p
);
4265 case elfcpp::SHT_PREINIT_ARRAY
:
4266 odyn
->add_section_address(elfcpp::DT_PREINIT_ARRAY
, *p
);
4267 odyn
->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ
, *p
);
4273 // Add a DT_RPATH entry if needed.
4274 const General_options::Dir_list
& rpath(parameters
->options().rpath());
4277 std::string rpath_val
;
4278 for (General_options::Dir_list::const_iterator p
= rpath
.begin();
4282 if (rpath_val
.empty())
4283 rpath_val
= p
->name();
4286 // Eliminate duplicates.
4287 General_options::Dir_list::const_iterator q
;
4288 for (q
= rpath
.begin(); q
!= p
; ++q
)
4289 if (q
->name() == p
->name())
4294 rpath_val
+= p
->name();
4299 odyn
->add_string(elfcpp::DT_RPATH
, rpath_val
);
4300 if (parameters
->options().enable_new_dtags())
4301 odyn
->add_string(elfcpp::DT_RUNPATH
, rpath_val
);
4304 // Look for text segments that have dynamic relocations.
4305 bool have_textrel
= false;
4306 if (!this->script_options_
->saw_sections_clause())
4308 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4309 p
!= this->segment_list_
.end();
4312 if ((*p
)->type() == elfcpp::PT_LOAD
4313 && ((*p
)->flags() & elfcpp::PF_W
) == 0
4314 && (*p
)->has_dynamic_reloc())
4316 have_textrel
= true;
4323 // We don't know the section -> segment mapping, so we are
4324 // conservative and just look for readonly sections with
4325 // relocations. If those sections wind up in writable segments,
4326 // then we have created an unnecessary DT_TEXTREL entry.
4327 for (Section_list::const_iterator p
= this->section_list_
.begin();
4328 p
!= this->section_list_
.end();
4331 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0
4332 && ((*p
)->flags() & elfcpp::SHF_WRITE
) == 0
4333 && (*p
)->has_dynamic_reloc())
4335 have_textrel
= true;
4341 if (parameters
->options().filter() != NULL
)
4342 odyn
->add_string(elfcpp::DT_FILTER
, parameters
->options().filter());
4343 if (parameters
->options().any_auxiliary())
4345 for (options::String_set::const_iterator p
=
4346 parameters
->options().auxiliary_begin();
4347 p
!= parameters
->options().auxiliary_end();
4349 odyn
->add_string(elfcpp::DT_AUXILIARY
, *p
);
4352 // Add a DT_FLAGS entry if necessary.
4353 unsigned int flags
= 0;
4356 // Add a DT_TEXTREL for compatibility with older loaders.
4357 odyn
->add_constant(elfcpp::DT_TEXTREL
, 0);
4358 flags
|= elfcpp::DF_TEXTREL
;
4360 if (parameters
->options().text())
4361 gold_error(_("read-only segment has dynamic relocations"));
4362 else if (parameters
->options().warn_shared_textrel()
4363 && parameters
->options().shared())
4364 gold_warning(_("shared library text segment is not shareable"));
4366 if (parameters
->options().shared() && this->has_static_tls())
4367 flags
|= elfcpp::DF_STATIC_TLS
;
4368 if (parameters
->options().origin())
4369 flags
|= elfcpp::DF_ORIGIN
;
4370 if (parameters
->options().Bsymbolic())
4372 flags
|= elfcpp::DF_SYMBOLIC
;
4373 // Add DT_SYMBOLIC for compatibility with older loaders.
4374 odyn
->add_constant(elfcpp::DT_SYMBOLIC
, 0);
4376 if (parameters
->options().now())
4377 flags
|= elfcpp::DF_BIND_NOW
;
4379 odyn
->add_constant(elfcpp::DT_FLAGS
, flags
);
4382 if (parameters
->options().initfirst())
4383 flags
|= elfcpp::DF_1_INITFIRST
;
4384 if (parameters
->options().interpose())
4385 flags
|= elfcpp::DF_1_INTERPOSE
;
4386 if (parameters
->options().loadfltr())
4387 flags
|= elfcpp::DF_1_LOADFLTR
;
4388 if (parameters
->options().nodefaultlib())
4389 flags
|= elfcpp::DF_1_NODEFLIB
;
4390 if (parameters
->options().nodelete())
4391 flags
|= elfcpp::DF_1_NODELETE
;
4392 if (parameters
->options().nodlopen())
4393 flags
|= elfcpp::DF_1_NOOPEN
;
4394 if (parameters
->options().nodump())
4395 flags
|= elfcpp::DF_1_NODUMP
;
4396 if (!parameters
->options().shared())
4397 flags
&= ~(elfcpp::DF_1_INITFIRST
4398 | elfcpp::DF_1_NODELETE
4399 | elfcpp::DF_1_NOOPEN
);
4400 if (parameters
->options().origin())
4401 flags
|= elfcpp::DF_1_ORIGIN
;
4402 if (parameters
->options().now())
4403 flags
|= elfcpp::DF_1_NOW
;
4404 if (parameters
->options().Bgroup())
4405 flags
|= elfcpp::DF_1_GROUP
;
4407 odyn
->add_constant(elfcpp::DT_FLAGS_1
, flags
);
4410 // Set the size of the _DYNAMIC symbol table to be the size of the
4414 Layout::set_dynamic_symbol_size(const Symbol_table
* symtab
)
4416 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4419 odyn
->finalize_data_size();
4420 if (this->dynamic_symbol_
== NULL
)
4422 off_t data_size
= odyn
->data_size();
4423 const int size
= parameters
->target().get_size();
4425 symtab
->get_sized_symbol
<32>(this->dynamic_symbol_
)->set_symsize(data_size
);
4426 else if (size
== 64)
4427 symtab
->get_sized_symbol
<64>(this->dynamic_symbol_
)->set_symsize(data_size
);
4432 // The mapping of input section name prefixes to output section names.
4433 // In some cases one prefix is itself a prefix of another prefix; in
4434 // such a case the longer prefix must come first. These prefixes are
4435 // based on the GNU linker default ELF linker script.
4437 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
4438 const Layout::Section_name_mapping
Layout::section_name_mapping
[] =
4440 MAPPING_INIT(".text.", ".text"),
4441 MAPPING_INIT(".rodata.", ".rodata"),
4442 MAPPING_INIT(".data.rel.ro.local", ".data.rel.ro.local"),
4443 MAPPING_INIT(".data.rel.ro", ".data.rel.ro"),
4444 MAPPING_INIT(".data.", ".data"),
4445 MAPPING_INIT(".bss.", ".bss"),
4446 MAPPING_INIT(".tdata.", ".tdata"),
4447 MAPPING_INIT(".tbss.", ".tbss"),
4448 MAPPING_INIT(".init_array.", ".init_array"),
4449 MAPPING_INIT(".fini_array.", ".fini_array"),
4450 MAPPING_INIT(".sdata.", ".sdata"),
4451 MAPPING_INIT(".sbss.", ".sbss"),
4452 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
4453 // differently depending on whether it is creating a shared library.
4454 MAPPING_INIT(".sdata2.", ".sdata"),
4455 MAPPING_INIT(".sbss2.", ".sbss"),
4456 MAPPING_INIT(".lrodata.", ".lrodata"),
4457 MAPPING_INIT(".ldata.", ".ldata"),
4458 MAPPING_INIT(".lbss.", ".lbss"),
4459 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
4460 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
4461 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
4462 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
4463 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
4464 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
4465 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
4466 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
4467 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
4468 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
4469 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
4470 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
4471 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
4472 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
4473 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
4474 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
4475 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
4476 MAPPING_INIT(".ARM.extab", ".ARM.extab"),
4477 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
4478 MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
4479 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
4483 const int Layout::section_name_mapping_count
=
4484 (sizeof(Layout::section_name_mapping
)
4485 / sizeof(Layout::section_name_mapping
[0]));
4487 // Choose the output section name to use given an input section name.
4488 // Set *PLEN to the length of the name. *PLEN is initialized to the
4492 Layout::output_section_name(const Relobj
* relobj
, const char* name
,
4495 // gcc 4.3 generates the following sorts of section names when it
4496 // needs a section name specific to a function:
4502 // .data.rel.local.FN
4504 // .data.rel.ro.local.FN
4511 // The GNU linker maps all of those to the part before the .FN,
4512 // except that .data.rel.local.FN is mapped to .data, and
4513 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
4514 // beginning with .data.rel.ro.local are grouped together.
4516 // For an anonymous namespace, the string FN can contain a '.'.
4518 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
4519 // GNU linker maps to .rodata.
4521 // The .data.rel.ro sections are used with -z relro. The sections
4522 // are recognized by name. We use the same names that the GNU
4523 // linker does for these sections.
4525 // It is hard to handle this in a principled way, so we don't even
4526 // try. We use a table of mappings. If the input section name is
4527 // not found in the table, we simply use it as the output section
4530 const Section_name_mapping
* psnm
= section_name_mapping
;
4531 for (int i
= 0; i
< section_name_mapping_count
; ++i
, ++psnm
)
4533 if (strncmp(name
, psnm
->from
, psnm
->fromlen
) == 0)
4535 *plen
= psnm
->tolen
;
4540 // As an additional complication, .ctors sections are output in
4541 // either .ctors or .init_array sections, and .dtors sections are
4542 // output in either .dtors or .fini_array sections.
4543 if (is_prefix_of(".ctors.", name
) || is_prefix_of(".dtors.", name
))
4545 if (parameters
->options().ctors_in_init_array())
4548 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4553 return name
[1] == 'c' ? ".ctors" : ".dtors";
4556 if (parameters
->options().ctors_in_init_array()
4557 && (strcmp(name
, ".ctors") == 0 || strcmp(name
, ".dtors") == 0))
4559 // To make .init_array/.fini_array work with gcc we must exclude
4560 // .ctors and .dtors sections from the crtbegin and crtend
4563 || (!Layout::match_file_name(relobj
, "crtbegin")
4564 && !Layout::match_file_name(relobj
, "crtend")))
4567 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4574 // Return true if RELOBJ is an input file whose base name matches
4575 // FILE_NAME. The base name must have an extension of ".o", and must
4576 // be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is
4577 // to match crtbegin.o as well as crtbeginS.o without getting confused
4578 // by other possibilities. Overall matching the file name this way is
4579 // a dreadful hack, but the GNU linker does it in order to better
4580 // support gcc, and we need to be compatible.
4583 Layout::match_file_name(const Relobj
* relobj
, const char* match
)
4585 const std::string
& file_name(relobj
->name());
4586 const char* base_name
= lbasename(file_name
.c_str());
4587 size_t match_len
= strlen(match
);
4588 if (strncmp(base_name
, match
, match_len
) != 0)
4590 size_t base_len
= strlen(base_name
);
4591 if (base_len
!= match_len
+ 2 && base_len
!= match_len
+ 3)
4593 return memcmp(base_name
+ base_len
- 2, ".o", 2) == 0;
4596 // Check if a comdat group or .gnu.linkonce section with the given
4597 // NAME is selected for the link. If there is already a section,
4598 // *KEPT_SECTION is set to point to the existing section and the
4599 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
4600 // IS_GROUP_NAME are recorded for this NAME in the layout object,
4601 // *KEPT_SECTION is set to the internal copy and the function returns
4605 Layout::find_or_add_kept_section(const std::string
& name
,
4610 Kept_section
** kept_section
)
4612 // It's normal to see a couple of entries here, for the x86 thunk
4613 // sections. If we see more than a few, we're linking a C++
4614 // program, and we resize to get more space to minimize rehashing.
4615 if (this->signatures_
.size() > 4
4616 && !this->resized_signatures_
)
4618 reserve_unordered_map(&this->signatures_
,
4619 this->number_of_input_files_
* 64);
4620 this->resized_signatures_
= true;
4623 Kept_section candidate
;
4624 std::pair
<Signatures::iterator
, bool> ins
=
4625 this->signatures_
.insert(std::make_pair(name
, candidate
));
4627 if (kept_section
!= NULL
)
4628 *kept_section
= &ins
.first
->second
;
4631 // This is the first time we've seen this signature.
4632 ins
.first
->second
.set_object(object
);
4633 ins
.first
->second
.set_shndx(shndx
);
4635 ins
.first
->second
.set_is_comdat();
4637 ins
.first
->second
.set_is_group_name();
4641 // We have already seen this signature.
4643 if (ins
.first
->second
.is_group_name())
4645 // We've already seen a real section group with this signature.
4646 // If the kept group is from a plugin object, and we're in the
4647 // replacement phase, accept the new one as a replacement.
4648 if (ins
.first
->second
.object() == NULL
4649 && parameters
->options().plugins()->in_replacement_phase())
4651 ins
.first
->second
.set_object(object
);
4652 ins
.first
->second
.set_shndx(shndx
);
4657 else if (is_group_name
)
4659 // This is a real section group, and we've already seen a
4660 // linkonce section with this signature. Record that we've seen
4661 // a section group, and don't include this section group.
4662 ins
.first
->second
.set_is_group_name();
4667 // We've already seen a linkonce section and this is a linkonce
4668 // section. These don't block each other--this may be the same
4669 // symbol name with different section types.
4674 // Store the allocated sections into the section list.
4677 Layout::get_allocated_sections(Section_list
* section_list
) const
4679 for (Section_list::const_iterator p
= this->section_list_
.begin();
4680 p
!= this->section_list_
.end();
4682 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0)
4683 section_list
->push_back(*p
);
4686 // Create an output segment.
4689 Layout::make_output_segment(elfcpp::Elf_Word type
, elfcpp::Elf_Word flags
)
4691 gold_assert(!parameters
->options().relocatable());
4692 Output_segment
* oseg
= new Output_segment(type
, flags
);
4693 this->segment_list_
.push_back(oseg
);
4695 if (type
== elfcpp::PT_TLS
)
4696 this->tls_segment_
= oseg
;
4697 else if (type
== elfcpp::PT_GNU_RELRO
)
4698 this->relro_segment_
= oseg
;
4699 else if (type
== elfcpp::PT_INTERP
)
4700 this->interp_segment_
= oseg
;
4705 // Return the file offset of the normal symbol table.
4708 Layout::symtab_section_offset() const
4710 if (this->symtab_section_
!= NULL
)
4711 return this->symtab_section_
->offset();
4715 // Return the section index of the normal symbol table. It may have
4716 // been stripped by the -s/--strip-all option.
4719 Layout::symtab_section_shndx() const
4721 if (this->symtab_section_
!= NULL
)
4722 return this->symtab_section_
->out_shndx();
4726 // Write out the Output_sections. Most won't have anything to write,
4727 // since most of the data will come from input sections which are
4728 // handled elsewhere. But some Output_sections do have Output_data.
4731 Layout::write_output_sections(Output_file
* of
) const
4733 for (Section_list::const_iterator p
= this->section_list_
.begin();
4734 p
!= this->section_list_
.end();
4737 if (!(*p
)->after_input_sections())
4742 // Write out data not associated with a section or the symbol table.
4745 Layout::write_data(const Symbol_table
* symtab
, Output_file
* of
) const
4747 if (!parameters
->options().strip_all())
4749 const Output_section
* symtab_section
= this->symtab_section_
;
4750 for (Section_list::const_iterator p
= this->section_list_
.begin();
4751 p
!= this->section_list_
.end();
4754 if ((*p
)->needs_symtab_index())
4756 gold_assert(symtab_section
!= NULL
);
4757 unsigned int index
= (*p
)->symtab_index();
4758 gold_assert(index
> 0 && index
!= -1U);
4759 off_t off
= (symtab_section
->offset()
4760 + index
* symtab_section
->entsize());
4761 symtab
->write_section_symbol(*p
, this->symtab_xindex_
, of
, off
);
4766 const Output_section
* dynsym_section
= this->dynsym_section_
;
4767 for (Section_list::const_iterator p
= this->section_list_
.begin();
4768 p
!= this->section_list_
.end();
4771 if ((*p
)->needs_dynsym_index())
4773 gold_assert(dynsym_section
!= NULL
);
4774 unsigned int index
= (*p
)->dynsym_index();
4775 gold_assert(index
> 0 && index
!= -1U);
4776 off_t off
= (dynsym_section
->offset()
4777 + index
* dynsym_section
->entsize());
4778 symtab
->write_section_symbol(*p
, this->dynsym_xindex_
, of
, off
);
4782 // Write out the Output_data which are not in an Output_section.
4783 for (Data_list::const_iterator p
= this->special_output_list_
.begin();
4784 p
!= this->special_output_list_
.end();
4789 // Write out the Output_sections which can only be written after the
4790 // input sections are complete.
4793 Layout::write_sections_after_input_sections(Output_file
* of
)
4795 // Determine the final section offsets, and thus the final output
4796 // file size. Note we finalize the .shstrab last, to allow the
4797 // after_input_section sections to modify their section-names before
4799 if (this->any_postprocessing_sections_
)
4801 off_t off
= this->output_file_size_
;
4802 off
= this->set_section_offsets(off
, POSTPROCESSING_SECTIONS_PASS
);
4804 // Now that we've finalized the names, we can finalize the shstrab.
4806 this->set_section_offsets(off
,
4807 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
4809 if (off
> this->output_file_size_
)
4812 this->output_file_size_
= off
;
4816 for (Section_list::const_iterator p
= this->section_list_
.begin();
4817 p
!= this->section_list_
.end();
4820 if ((*p
)->after_input_sections())
4824 this->section_headers_
->write(of
);
4827 // If the build ID requires computing a checksum, do so here, and
4828 // write it out. We compute a checksum over the entire file because
4829 // that is simplest.
4832 Layout::write_build_id(Output_file
* of
) const
4834 if (this->build_id_note_
== NULL
)
4837 const unsigned char* iv
= of
->get_input_view(0, this->output_file_size_
);
4839 unsigned char* ov
= of
->get_output_view(this->build_id_note_
->offset(),
4840 this->build_id_note_
->data_size());
4842 const char* style
= parameters
->options().build_id();
4843 if (strcmp(style
, "sha1") == 0)
4846 sha1_init_ctx(&ctx
);
4847 sha1_process_bytes(iv
, this->output_file_size_
, &ctx
);
4848 sha1_finish_ctx(&ctx
, ov
);
4850 else if (strcmp(style
, "md5") == 0)
4854 md5_process_bytes(iv
, this->output_file_size_
, &ctx
);
4855 md5_finish_ctx(&ctx
, ov
);
4860 of
->write_output_view(this->build_id_note_
->offset(),
4861 this->build_id_note_
->data_size(),
4864 of
->free_input_view(0, this->output_file_size_
, iv
);
4867 // Write out a binary file. This is called after the link is
4868 // complete. IN is the temporary output file we used to generate the
4869 // ELF code. We simply walk through the segments, read them from
4870 // their file offset in IN, and write them to their load address in
4871 // the output file. FIXME: with a bit more work, we could support
4872 // S-records and/or Intel hex format here.
4875 Layout::write_binary(Output_file
* in
) const
4877 gold_assert(parameters
->options().oformat_enum()
4878 == General_options::OBJECT_FORMAT_BINARY
);
4880 // Get the size of the binary file.
4881 uint64_t max_load_address
= 0;
4882 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4883 p
!= this->segment_list_
.end();
4886 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
4888 uint64_t max_paddr
= (*p
)->paddr() + (*p
)->filesz();
4889 if (max_paddr
> max_load_address
)
4890 max_load_address
= max_paddr
;
4894 Output_file
out(parameters
->options().output_file_name());
4895 out
.open(max_load_address
);
4897 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4898 p
!= this->segment_list_
.end();
4901 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
4903 const unsigned char* vin
= in
->get_input_view((*p
)->offset(),
4905 unsigned char* vout
= out
.get_output_view((*p
)->paddr(),
4907 memcpy(vout
, vin
, (*p
)->filesz());
4908 out
.write_output_view((*p
)->paddr(), (*p
)->filesz(), vout
);
4909 in
->free_input_view((*p
)->offset(), (*p
)->filesz(), vin
);
4916 // Print the output sections to the map file.
4919 Layout::print_to_mapfile(Mapfile
* mapfile
) const
4921 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4922 p
!= this->segment_list_
.end();
4924 (*p
)->print_sections_to_mapfile(mapfile
);
4927 // Print statistical information to stderr. This is used for --stats.
4930 Layout::print_stats() const
4932 this->namepool_
.print_stats("section name pool");
4933 this->sympool_
.print_stats("output symbol name pool");
4934 this->dynpool_
.print_stats("dynamic name pool");
4936 for (Section_list::const_iterator p
= this->section_list_
.begin();
4937 p
!= this->section_list_
.end();
4939 (*p
)->print_merge_stats();
4942 // Write_sections_task methods.
4944 // We can always run this task.
4947 Write_sections_task::is_runnable()
4952 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
4956 Write_sections_task::locks(Task_locker
* tl
)
4958 tl
->add(this, this->output_sections_blocker_
);
4959 tl
->add(this, this->final_blocker_
);
4962 // Run the task--write out the data.
4965 Write_sections_task::run(Workqueue
*)
4967 this->layout_
->write_output_sections(this->of_
);
4970 // Write_data_task methods.
4972 // We can always run this task.
4975 Write_data_task::is_runnable()
4980 // We need to unlock FINAL_BLOCKER when finished.
4983 Write_data_task::locks(Task_locker
* tl
)
4985 tl
->add(this, this->final_blocker_
);
4988 // Run the task--write out the data.
4991 Write_data_task::run(Workqueue
*)
4993 this->layout_
->write_data(this->symtab_
, this->of_
);
4996 // Write_symbols_task methods.
4998 // We can always run this task.
5001 Write_symbols_task::is_runnable()
5006 // We need to unlock FINAL_BLOCKER when finished.
5009 Write_symbols_task::locks(Task_locker
* tl
)
5011 tl
->add(this, this->final_blocker_
);
5014 // Run the task--write out the symbols.
5017 Write_symbols_task::run(Workqueue
*)
5019 this->symtab_
->write_globals(this->sympool_
, this->dynpool_
,
5020 this->layout_
->symtab_xindex(),
5021 this->layout_
->dynsym_xindex(), this->of_
);
5024 // Write_after_input_sections_task methods.
5026 // We can only run this task after the input sections have completed.
5029 Write_after_input_sections_task::is_runnable()
5031 if (this->input_sections_blocker_
->is_blocked())
5032 return this->input_sections_blocker_
;
5036 // We need to unlock FINAL_BLOCKER when finished.
5039 Write_after_input_sections_task::locks(Task_locker
* tl
)
5041 tl
->add(this, this->final_blocker_
);
5047 Write_after_input_sections_task::run(Workqueue
*)
5049 this->layout_
->write_sections_after_input_sections(this->of_
);
5052 // Close_task_runner methods.
5054 // Run the task--close the file.
5057 Close_task_runner::run(Workqueue
*, const Task
*)
5059 // If we need to compute a checksum for the BUILD if, we do so here.
5060 this->layout_
->write_build_id(this->of_
);
5062 // If we've been asked to create a binary file, we do so here.
5063 if (this->options_
->oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
5064 this->layout_
->write_binary(this->of_
);
5069 // Instantiate the templates we need. We could use the configure
5070 // script to restrict this to only the ones for implemented targets.
5072 #ifdef HAVE_TARGET_32_LITTLE
5075 Layout::init_fixed_output_section
<32, false>(
5077 elfcpp::Shdr
<32, false>& shdr
);
5080 #ifdef HAVE_TARGET_32_BIG
5083 Layout::init_fixed_output_section
<32, true>(
5085 elfcpp::Shdr
<32, true>& shdr
);
5088 #ifdef HAVE_TARGET_64_LITTLE
5091 Layout::init_fixed_output_section
<64, false>(
5093 elfcpp::Shdr
<64, false>& shdr
);
5096 #ifdef HAVE_TARGET_64_BIG
5099 Layout::init_fixed_output_section
<64, true>(
5101 elfcpp::Shdr
<64, true>& shdr
);
5104 #ifdef HAVE_TARGET_32_LITTLE
5107 Layout::layout
<32, false>(Sized_relobj_file
<32, false>* object
,
5110 const elfcpp::Shdr
<32, false>& shdr
,
5111 unsigned int, unsigned int, off_t
*);
5114 #ifdef HAVE_TARGET_32_BIG
5117 Layout::layout
<32, true>(Sized_relobj_file
<32, true>* object
,
5120 const elfcpp::Shdr
<32, true>& shdr
,
5121 unsigned int, unsigned int, off_t
*);
5124 #ifdef HAVE_TARGET_64_LITTLE
5127 Layout::layout
<64, false>(Sized_relobj_file
<64, false>* object
,
5130 const elfcpp::Shdr
<64, false>& shdr
,
5131 unsigned int, unsigned int, off_t
*);
5134 #ifdef HAVE_TARGET_64_BIG
5137 Layout::layout
<64, true>(Sized_relobj_file
<64, true>* object
,
5140 const elfcpp::Shdr
<64, true>& shdr
,
5141 unsigned int, unsigned int, off_t
*);
5144 #ifdef HAVE_TARGET_32_LITTLE
5147 Layout::layout_reloc
<32, false>(Sized_relobj_file
<32, false>* object
,
5148 unsigned int reloc_shndx
,
5149 const elfcpp::Shdr
<32, false>& shdr
,
5150 Output_section
* data_section
,
5151 Relocatable_relocs
* rr
);
5154 #ifdef HAVE_TARGET_32_BIG
5157 Layout::layout_reloc
<32, true>(Sized_relobj_file
<32, true>* object
,
5158 unsigned int reloc_shndx
,
5159 const elfcpp::Shdr
<32, true>& shdr
,
5160 Output_section
* data_section
,
5161 Relocatable_relocs
* rr
);
5164 #ifdef HAVE_TARGET_64_LITTLE
5167 Layout::layout_reloc
<64, false>(Sized_relobj_file
<64, false>* object
,
5168 unsigned int reloc_shndx
,
5169 const elfcpp::Shdr
<64, false>& shdr
,
5170 Output_section
* data_section
,
5171 Relocatable_relocs
* rr
);
5174 #ifdef HAVE_TARGET_64_BIG
5177 Layout::layout_reloc
<64, true>(Sized_relobj_file
<64, true>* object
,
5178 unsigned int reloc_shndx
,
5179 const elfcpp::Shdr
<64, true>& shdr
,
5180 Output_section
* data_section
,
5181 Relocatable_relocs
* rr
);
5184 #ifdef HAVE_TARGET_32_LITTLE
5187 Layout::layout_group
<32, false>(Symbol_table
* symtab
,
5188 Sized_relobj_file
<32, false>* object
,
5190 const char* group_section_name
,
5191 const char* signature
,
5192 const elfcpp::Shdr
<32, false>& shdr
,
5193 elfcpp::Elf_Word flags
,
5194 std::vector
<unsigned int>* shndxes
);
5197 #ifdef HAVE_TARGET_32_BIG
5200 Layout::layout_group
<32, true>(Symbol_table
* symtab
,
5201 Sized_relobj_file
<32, true>* object
,
5203 const char* group_section_name
,
5204 const char* signature
,
5205 const elfcpp::Shdr
<32, true>& shdr
,
5206 elfcpp::Elf_Word flags
,
5207 std::vector
<unsigned int>* shndxes
);
5210 #ifdef HAVE_TARGET_64_LITTLE
5213 Layout::layout_group
<64, false>(Symbol_table
* symtab
,
5214 Sized_relobj_file
<64, false>* object
,
5216 const char* group_section_name
,
5217 const char* signature
,
5218 const elfcpp::Shdr
<64, false>& shdr
,
5219 elfcpp::Elf_Word flags
,
5220 std::vector
<unsigned int>* shndxes
);
5223 #ifdef HAVE_TARGET_64_BIG
5226 Layout::layout_group
<64, true>(Symbol_table
* symtab
,
5227 Sized_relobj_file
<64, true>* object
,
5229 const char* group_section_name
,
5230 const char* signature
,
5231 const elfcpp::Shdr
<64, true>& shdr
,
5232 elfcpp::Elf_Word flags
,
5233 std::vector
<unsigned int>* shndxes
);
5236 #ifdef HAVE_TARGET_32_LITTLE
5239 Layout::layout_eh_frame
<32, false>(Sized_relobj_file
<32, false>* object
,
5240 const unsigned char* symbols
,
5242 const unsigned char* symbol_names
,
5243 off_t symbol_names_size
,
5245 const elfcpp::Shdr
<32, false>& shdr
,
5246 unsigned int reloc_shndx
,
5247 unsigned int reloc_type
,
5251 #ifdef HAVE_TARGET_32_BIG
5254 Layout::layout_eh_frame
<32, true>(Sized_relobj_file
<32, true>* object
,
5255 const unsigned char* symbols
,
5257 const unsigned char* symbol_names
,
5258 off_t symbol_names_size
,
5260 const elfcpp::Shdr
<32, true>& shdr
,
5261 unsigned int reloc_shndx
,
5262 unsigned int reloc_type
,
5266 #ifdef HAVE_TARGET_64_LITTLE
5269 Layout::layout_eh_frame
<64, false>(Sized_relobj_file
<64, false>* object
,
5270 const unsigned char* symbols
,
5272 const unsigned char* symbol_names
,
5273 off_t symbol_names_size
,
5275 const elfcpp::Shdr
<64, false>& shdr
,
5276 unsigned int reloc_shndx
,
5277 unsigned int reloc_type
,
5281 #ifdef HAVE_TARGET_64_BIG
5284 Layout::layout_eh_frame
<64, true>(Sized_relobj_file
<64, true>* object
,
5285 const unsigned char* symbols
,
5287 const unsigned char* symbol_names
,
5288 off_t symbol_names_size
,
5290 const elfcpp::Shdr
<64, true>& shdr
,
5291 unsigned int reloc_shndx
,
5292 unsigned int reloc_type
,
5296 } // End namespace gold.