1 // layout.cc -- lay out output file sections for gold
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 // Free Software Foundation, Inc.
5 // Written by Ian Lance Taylor <iant@google.com>.
7 // This file is part of gold.
9 // This program is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 3 of the License, or
12 // (at your option) any later version.
14 // This program is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 // MA 02110-1301, USA.
35 #include "libiberty.h"
39 #include "parameters.h"
43 #include "script-sections.h"
48 #include "gdb-index.h"
49 #include "compressed_output.h"
50 #include "reduced_debug_output.h"
53 #include "descriptors.h"
55 #include "incremental.h"
63 // The total number of free lists used.
64 unsigned int Free_list::num_lists
= 0;
65 // The total number of free list nodes used.
66 unsigned int Free_list::num_nodes
= 0;
67 // The total number of calls to Free_list::remove.
68 unsigned int Free_list::num_removes
= 0;
69 // The total number of nodes visited during calls to Free_list::remove.
70 unsigned int Free_list::num_remove_visits
= 0;
71 // The total number of calls to Free_list::allocate.
72 unsigned int Free_list::num_allocates
= 0;
73 // The total number of nodes visited during calls to Free_list::allocate.
74 unsigned int Free_list::num_allocate_visits
= 0;
76 // Initialize the free list. Creates a single free list node that
77 // describes the entire region of length LEN. If EXTEND is true,
78 // allocate() is allowed to extend the region beyond its initial
82 Free_list::init(off_t len
, bool extend
)
84 this->list_
.push_front(Free_list_node(0, len
));
85 this->last_remove_
= this->list_
.begin();
86 this->extend_
= extend
;
88 ++Free_list::num_lists
;
89 ++Free_list::num_nodes
;
92 // Remove a chunk from the free list. Because we start with a single
93 // node that covers the entire section, and remove chunks from it one
94 // at a time, we do not need to coalesce chunks or handle cases that
95 // span more than one free node. We expect to remove chunks from the
96 // free list in order, and we expect to have only a few chunks of free
97 // space left (corresponding to files that have changed since the last
98 // incremental link), so a simple linear list should provide sufficient
102 Free_list::remove(off_t start
, off_t end
)
106 gold_assert(start
< end
);
108 ++Free_list::num_removes
;
110 Iterator p
= this->last_remove_
;
111 if (p
->start_
> start
)
112 p
= this->list_
.begin();
114 for (; p
!= this->list_
.end(); ++p
)
116 ++Free_list::num_remove_visits
;
117 // Find a node that wholly contains the indicated region.
118 if (p
->start_
<= start
&& p
->end_
>= end
)
120 // Case 1: the indicated region spans the whole node.
121 // Add some fuzz to avoid creating tiny free chunks.
122 if (p
->start_
+ 3 >= start
&& p
->end_
<= end
+ 3)
123 p
= this->list_
.erase(p
);
124 // Case 2: remove a chunk from the start of the node.
125 else if (p
->start_
+ 3 >= start
)
127 // Case 3: remove a chunk from the end of the node.
128 else if (p
->end_
<= end
+ 3)
130 // Case 4: remove a chunk from the middle, and split
131 // the node into two.
134 Free_list_node
newnode(p
->start_
, start
);
136 this->list_
.insert(p
, newnode
);
137 ++Free_list::num_nodes
;
139 this->last_remove_
= p
;
144 // Did not find a node containing the given chunk. This could happen
145 // because a small chunk was already removed due to the fuzz.
146 gold_debug(DEBUG_INCREMENTAL
,
147 "Free_list::remove(%d,%d) not found",
148 static_cast<int>(start
), static_cast<int>(end
));
151 // Allocate a chunk of size LEN from the free list. Returns -1ULL
152 // if a sufficiently large chunk of free space is not found.
153 // We use a simple first-fit algorithm.
156 Free_list::allocate(off_t len
, uint64_t align
, off_t minoff
)
158 gold_debug(DEBUG_INCREMENTAL
,
159 "Free_list::allocate(%08lx, %d, %08lx)",
160 static_cast<long>(len
), static_cast<int>(align
),
161 static_cast<long>(minoff
));
163 return align_address(minoff
, align
);
165 ++Free_list::num_allocates
;
167 // We usually want to drop free chunks smaller than 4 bytes.
168 // If we need to guarantee a minimum hole size, though, we need
169 // to keep track of all free chunks.
170 const int fuzz
= this->min_hole_
> 0 ? 0 : 3;
172 for (Iterator p
= this->list_
.begin(); p
!= this->list_
.end(); ++p
)
174 ++Free_list::num_allocate_visits
;
175 off_t start
= p
->start_
> minoff
? p
->start_
: minoff
;
176 start
= align_address(start
, align
);
177 off_t end
= start
+ len
;
178 if (end
> p
->end_
&& p
->end_
== this->length_
&& this->extend_
)
183 if (end
== p
->end_
|| (end
<= p
->end_
- this->min_hole_
))
185 if (p
->start_
+ fuzz
>= start
&& p
->end_
<= end
+ fuzz
)
186 this->list_
.erase(p
);
187 else if (p
->start_
+ fuzz
>= start
)
189 else if (p
->end_
<= end
+ fuzz
)
193 Free_list_node
newnode(p
->start_
, start
);
195 this->list_
.insert(p
, newnode
);
196 ++Free_list::num_nodes
;
203 off_t start
= align_address(this->length_
, align
);
204 this->length_
= start
+ len
;
210 // Dump the free list (for debugging).
214 gold_info("Free list:\n start end length\n");
215 for (Iterator p
= this->list_
.begin(); p
!= this->list_
.end(); ++p
)
216 gold_info(" %08lx %08lx %08lx", static_cast<long>(p
->start_
),
217 static_cast<long>(p
->end_
),
218 static_cast<long>(p
->end_
- p
->start_
));
221 // Print the statistics for the free lists.
223 Free_list::print_stats()
225 fprintf(stderr
, _("%s: total free lists: %u\n"),
226 program_name
, Free_list::num_lists
);
227 fprintf(stderr
, _("%s: total free list nodes: %u\n"),
228 program_name
, Free_list::num_nodes
);
229 fprintf(stderr
, _("%s: calls to Free_list::remove: %u\n"),
230 program_name
, Free_list::num_removes
);
231 fprintf(stderr
, _("%s: nodes visited: %u\n"),
232 program_name
, Free_list::num_remove_visits
);
233 fprintf(stderr
, _("%s: calls to Free_list::allocate: %u\n"),
234 program_name
, Free_list::num_allocates
);
235 fprintf(stderr
, _("%s: nodes visited: %u\n"),
236 program_name
, Free_list::num_allocate_visits
);
239 // Layout::Relaxation_debug_check methods.
241 // Check that sections and special data are in reset states.
242 // We do not save states for Output_sections and special Output_data.
243 // So we check that they have not assigned any addresses or offsets.
244 // clean_up_after_relaxation simply resets their addresses and offsets.
246 Layout::Relaxation_debug_check::check_output_data_for_reset_values(
247 const Layout::Section_list
& sections
,
248 const Layout::Data_list
& special_outputs
)
250 for(Layout::Section_list::const_iterator p
= sections
.begin();
253 gold_assert((*p
)->address_and_file_offset_have_reset_values());
255 for(Layout::Data_list::const_iterator p
= special_outputs
.begin();
256 p
!= special_outputs
.end();
258 gold_assert((*p
)->address_and_file_offset_have_reset_values());
261 // Save information of SECTIONS for checking later.
264 Layout::Relaxation_debug_check::read_sections(
265 const Layout::Section_list
& sections
)
267 for(Layout::Section_list::const_iterator p
= sections
.begin();
271 Output_section
* os
= *p
;
273 info
.output_section
= os
;
274 info
.address
= os
->is_address_valid() ? os
->address() : 0;
275 info
.data_size
= os
->is_data_size_valid() ? os
->data_size() : -1;
276 info
.offset
= os
->is_offset_valid()? os
->offset() : -1 ;
277 this->section_infos_
.push_back(info
);
281 // Verify SECTIONS using previously recorded information.
284 Layout::Relaxation_debug_check::verify_sections(
285 const Layout::Section_list
& sections
)
288 for(Layout::Section_list::const_iterator p
= sections
.begin();
292 Output_section
* os
= *p
;
293 uint64_t address
= os
->is_address_valid() ? os
->address() : 0;
294 off_t data_size
= os
->is_data_size_valid() ? os
->data_size() : -1;
295 off_t offset
= os
->is_offset_valid()? os
->offset() : -1 ;
297 if (i
>= this->section_infos_
.size())
299 gold_fatal("Section_info of %s missing.\n", os
->name());
301 const Section_info
& info
= this->section_infos_
[i
];
302 if (os
!= info
.output_section
)
303 gold_fatal("Section order changed. Expecting %s but see %s\n",
304 info
.output_section
->name(), os
->name());
305 if (address
!= info
.address
306 || data_size
!= info
.data_size
307 || offset
!= info
.offset
)
308 gold_fatal("Section %s changed.\n", os
->name());
312 // Layout_task_runner methods.
314 // Lay out the sections. This is called after all the input objects
318 Layout_task_runner::run(Workqueue
* workqueue
, const Task
* task
)
320 Layout
* layout
= this->layout_
;
321 off_t file_size
= layout
->finalize(this->input_objects_
,
326 // Now we know the final size of the output file and we know where
327 // each piece of information goes.
329 if (this->mapfile_
!= NULL
)
331 this->mapfile_
->print_discarded_sections(this->input_objects_
);
332 layout
->print_to_mapfile(this->mapfile_
);
336 if (layout
->incremental_base() == NULL
)
338 of
= new Output_file(parameters
->options().output_file_name());
339 if (this->options_
.oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
340 of
->set_is_temporary();
345 of
= layout
->incremental_base()->output_file();
347 // Apply the incremental relocations for symbols whose values
348 // have changed. We do this before we resize the file and start
349 // writing anything else to it, so that we can read the old
350 // incremental information from the file before (possibly)
352 if (parameters
->incremental_update())
353 layout
->incremental_base()->apply_incremental_relocs(this->symtab_
,
357 of
->resize(file_size
);
360 // Queue up the final set of tasks.
361 gold::queue_final_tasks(this->options_
, this->input_objects_
,
362 this->symtab_
, layout
, workqueue
, of
);
367 Layout::Layout(int number_of_input_files
, Script_options
* script_options
)
368 : number_of_input_files_(number_of_input_files
),
369 script_options_(script_options
),
377 unattached_section_list_(),
378 special_output_list_(),
379 section_headers_(NULL
),
381 relro_segment_(NULL
),
382 interp_segment_(NULL
),
384 symtab_section_(NULL
),
385 symtab_xindex_(NULL
),
386 dynsym_section_(NULL
),
387 dynsym_xindex_(NULL
),
388 dynamic_section_(NULL
),
389 dynamic_symbol_(NULL
),
391 eh_frame_section_(NULL
),
392 eh_frame_data_(NULL
),
393 added_eh_frame_data_(false),
394 eh_frame_hdr_section_(NULL
),
395 gdb_index_data_(NULL
),
396 build_id_note_(NULL
),
400 output_file_size_(-1),
401 have_added_input_section_(false),
402 sections_are_attached_(false),
403 input_requires_executable_stack_(false),
404 input_with_gnu_stack_note_(false),
405 input_without_gnu_stack_note_(false),
406 has_static_tls_(false),
407 any_postprocessing_sections_(false),
408 resized_signatures_(false),
409 have_stabstr_section_(false),
410 section_ordering_specified_(false),
411 incremental_inputs_(NULL
),
412 record_output_section_data_from_script_(false),
413 script_output_section_data_list_(),
414 segment_states_(NULL
),
415 relaxation_debug_check_(NULL
),
416 section_order_map_(),
417 input_section_position_(),
418 input_section_glob_(),
419 incremental_base_(NULL
),
422 // Make space for more than enough segments for a typical file.
423 // This is just for efficiency--it's OK if we wind up needing more.
424 this->segment_list_
.reserve(12);
426 // We expect two unattached Output_data objects: the file header and
427 // the segment headers.
428 this->special_output_list_
.reserve(2);
430 // Initialize structure needed for an incremental build.
431 if (parameters
->incremental())
432 this->incremental_inputs_
= new Incremental_inputs
;
434 // The section name pool is worth optimizing in all cases, because
435 // it is small, but there are often overlaps due to .rel sections.
436 this->namepool_
.set_optimize();
439 // For incremental links, record the base file to be modified.
442 Layout::set_incremental_base(Incremental_binary
* base
)
444 this->incremental_base_
= base
;
445 this->free_list_
.init(base
->output_file()->filesize(), true);
448 // Hash a key we use to look up an output section mapping.
451 Layout::Hash_key::operator()(const Layout::Key
& k
) const
453 return k
.first
+ k
.second
.first
+ k
.second
.second
;
456 // These are the debug sections that are actually used by gdb.
457 // Currently, we've checked versions of gdb up to and including 7.4.
458 // We only check the part of the name that follows ".debug_" or
461 static const char* gdb_sections
[] =
464 "addr", // Fission extension
465 // "aranges", // not used by gdb as of 7.4
473 // "pubnames", // not used by gdb as of 7.4
474 // "pubtypes", // not used by gdb as of 7.4
479 // This is the minimum set of sections needed for line numbers.
481 static const char* lines_only_debug_sections
[] =
484 // "addr", // Fission extension
485 // "aranges", // not used by gdb as of 7.4
493 // "pubnames", // not used by gdb as of 7.4
494 // "pubtypes", // not used by gdb as of 7.4
499 // These sections are the DWARF fast-lookup tables, and are not needed
500 // when building a .gdb_index section.
502 static const char* gdb_fast_lookup_sections
[] =
509 // Returns whether the given debug section is in the list of
510 // debug-sections-used-by-some-version-of-gdb. SUFFIX is the
511 // portion of the name following ".debug_" or ".zdebug_".
514 is_gdb_debug_section(const char* suffix
)
516 // We can do this faster: binary search or a hashtable. But why bother?
517 for (size_t i
= 0; i
< sizeof(gdb_sections
)/sizeof(*gdb_sections
); ++i
)
518 if (strcmp(suffix
, gdb_sections
[i
]) == 0)
523 // Returns whether the given section is needed for lines-only debugging.
526 is_lines_only_debug_section(const char* suffix
)
528 // We can do this faster: binary search or a hashtable. But why bother?
530 i
< sizeof(lines_only_debug_sections
)/sizeof(*lines_only_debug_sections
);
532 if (strcmp(suffix
, lines_only_debug_sections
[i
]) == 0)
537 // Returns whether the given section is a fast-lookup section that
538 // will not be needed when building a .gdb_index section.
541 is_gdb_fast_lookup_section(const char* suffix
)
543 // We can do this faster: binary search or a hashtable. But why bother?
545 i
< sizeof(gdb_fast_lookup_sections
)/sizeof(*gdb_fast_lookup_sections
);
547 if (strcmp(suffix
, gdb_fast_lookup_sections
[i
]) == 0)
552 // Sometimes we compress sections. This is typically done for
553 // sections that are not part of normal program execution (such as
554 // .debug_* sections), and where the readers of these sections know
555 // how to deal with compressed sections. This routine doesn't say for
556 // certain whether we'll compress -- it depends on commandline options
557 // as well -- just whether this section is a candidate for compression.
558 // (The Output_compressed_section class decides whether to compress
559 // a given section, and picks the name of the compressed section.)
562 is_compressible_debug_section(const char* secname
)
564 return (is_prefix_of(".debug", secname
));
567 // We may see compressed debug sections in input files. Return TRUE
568 // if this is the name of a compressed debug section.
571 is_compressed_debug_section(const char* secname
)
573 return (is_prefix_of(".zdebug", secname
));
576 // Whether to include this section in the link.
578 template<int size
, bool big_endian
>
580 Layout::include_section(Sized_relobj_file
<size
, big_endian
>*, const char* name
,
581 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
583 if (shdr
.get_sh_flags() & elfcpp::SHF_EXCLUDE
)
586 switch (shdr
.get_sh_type())
588 case elfcpp::SHT_NULL
:
589 case elfcpp::SHT_SYMTAB
:
590 case elfcpp::SHT_DYNSYM
:
591 case elfcpp::SHT_HASH
:
592 case elfcpp::SHT_DYNAMIC
:
593 case elfcpp::SHT_SYMTAB_SHNDX
:
596 case elfcpp::SHT_STRTAB
:
597 // Discard the sections which have special meanings in the ELF
598 // ABI. Keep others (e.g., .stabstr). We could also do this by
599 // checking the sh_link fields of the appropriate sections.
600 return (strcmp(name
, ".dynstr") != 0
601 && strcmp(name
, ".strtab") != 0
602 && strcmp(name
, ".shstrtab") != 0);
604 case elfcpp::SHT_RELA
:
605 case elfcpp::SHT_REL
:
606 case elfcpp::SHT_GROUP
:
607 // If we are emitting relocations these should be handled
609 gold_assert(!parameters
->options().relocatable());
612 case elfcpp::SHT_PROGBITS
:
613 if (parameters
->options().strip_debug()
614 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
616 if (is_debug_info_section(name
))
619 if (parameters
->options().strip_debug_non_line()
620 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
622 // Debugging sections can only be recognized by name.
623 if (is_prefix_of(".debug_", name
)
624 && !is_lines_only_debug_section(name
+ 7))
626 if (is_prefix_of(".zdebug_", name
)
627 && !is_lines_only_debug_section(name
+ 8))
630 if (parameters
->options().strip_debug_gdb()
631 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
633 // Debugging sections can only be recognized by name.
634 if (is_prefix_of(".debug_", name
)
635 && !is_gdb_debug_section(name
+ 7))
637 if (is_prefix_of(".zdebug_", name
)
638 && !is_gdb_debug_section(name
+ 8))
641 if (parameters
->options().gdb_index()
642 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
644 // When building .gdb_index, we can strip .debug_pubnames,
645 // .debug_pubtypes, and .debug_aranges sections.
646 if (is_prefix_of(".debug_", name
)
647 && is_gdb_fast_lookup_section(name
+ 7))
649 if (is_prefix_of(".zdebug_", name
)
650 && is_gdb_fast_lookup_section(name
+ 8))
653 if (parameters
->options().strip_lto_sections()
654 && !parameters
->options().relocatable()
655 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
657 // Ignore LTO sections containing intermediate code.
658 if (is_prefix_of(".gnu.lto_", name
))
661 // The GNU linker strips .gnu_debuglink sections, so we do too.
662 // This is a feature used to keep debugging information in
664 if (strcmp(name
, ".gnu_debuglink") == 0)
673 // Return an output section named NAME, or NULL if there is none.
676 Layout::find_output_section(const char* name
) const
678 for (Section_list::const_iterator p
= this->section_list_
.begin();
679 p
!= this->section_list_
.end();
681 if (strcmp((*p
)->name(), name
) == 0)
686 // Return an output segment of type TYPE, with segment flags SET set
687 // and segment flags CLEAR clear. Return NULL if there is none.
690 Layout::find_output_segment(elfcpp::PT type
, elfcpp::Elf_Word set
,
691 elfcpp::Elf_Word clear
) const
693 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
694 p
!= this->segment_list_
.end();
696 if (static_cast<elfcpp::PT
>((*p
)->type()) == type
697 && ((*p
)->flags() & set
) == set
698 && ((*p
)->flags() & clear
) == 0)
703 // When we put a .ctors or .dtors section with more than one word into
704 // a .init_array or .fini_array section, we need to reverse the words
705 // in the .ctors/.dtors section. This is because .init_array executes
706 // constructors front to back, where .ctors executes them back to
707 // front, and vice-versa for .fini_array/.dtors. Although we do want
708 // to remap .ctors/.dtors into .init_array/.fini_array because it can
709 // be more efficient, we don't want to change the order in which
710 // constructors/destructors are run. This set just keeps track of
711 // these sections which need to be reversed. It is only changed by
712 // Layout::layout. It should be a private member of Layout, but that
713 // would require layout.h to #include object.h to get the definition
715 static Unordered_set
<Section_id
, Section_id_hash
> ctors_sections_in_init_array
;
717 // Return whether OBJECT/SHNDX is a .ctors/.dtors section mapped to a
718 // .init_array/.fini_array section.
721 Layout::is_ctors_in_init_array(Relobj
* relobj
, unsigned int shndx
) const
723 return (ctors_sections_in_init_array
.find(Section_id(relobj
, shndx
))
724 != ctors_sections_in_init_array
.end());
727 // Return the output section to use for section NAME with type TYPE
728 // and section flags FLAGS. NAME must be canonicalized in the string
729 // pool, and NAME_KEY is the key. ORDER is where this should appear
730 // in the output sections. IS_RELRO is true for a relro section.
733 Layout::get_output_section(const char* name
, Stringpool::Key name_key
,
734 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
735 Output_section_order order
, bool is_relro
)
737 elfcpp::Elf_Word lookup_type
= type
;
739 // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and
740 // PREINIT_ARRAY like PROGBITS. This ensures that we combine
741 // .init_array, .fini_array, and .preinit_array sections by name
742 // whatever their type in the input file. We do this because the
743 // types are not always right in the input files.
744 if (lookup_type
== elfcpp::SHT_INIT_ARRAY
745 || lookup_type
== elfcpp::SHT_FINI_ARRAY
746 || lookup_type
== elfcpp::SHT_PREINIT_ARRAY
)
747 lookup_type
= elfcpp::SHT_PROGBITS
;
749 elfcpp::Elf_Xword lookup_flags
= flags
;
751 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
752 // read-write with read-only sections. Some other ELF linkers do
753 // not do this. FIXME: Perhaps there should be an option
755 lookup_flags
&= ~(elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
757 const Key
key(name_key
, std::make_pair(lookup_type
, lookup_flags
));
758 const std::pair
<Key
, Output_section
*> v(key
, NULL
);
759 std::pair
<Section_name_map::iterator
, bool> ins(
760 this->section_name_map_
.insert(v
));
763 return ins
.first
->second
;
766 // This is the first time we've seen this name/type/flags
767 // combination. For compatibility with the GNU linker, we
768 // combine sections with contents and zero flags with sections
769 // with non-zero flags. This is a workaround for cases where
770 // assembler code forgets to set section flags. FIXME: Perhaps
771 // there should be an option to control this.
772 Output_section
* os
= NULL
;
774 if (lookup_type
== elfcpp::SHT_PROGBITS
)
778 Output_section
* same_name
= this->find_output_section(name
);
779 if (same_name
!= NULL
780 && (same_name
->type() == elfcpp::SHT_PROGBITS
781 || same_name
->type() == elfcpp::SHT_INIT_ARRAY
782 || same_name
->type() == elfcpp::SHT_FINI_ARRAY
783 || same_name
->type() == elfcpp::SHT_PREINIT_ARRAY
)
784 && (same_name
->flags() & elfcpp::SHF_TLS
) == 0)
787 else if ((flags
& elfcpp::SHF_TLS
) == 0)
789 elfcpp::Elf_Xword zero_flags
= 0;
790 const Key
zero_key(name_key
, std::make_pair(lookup_type
,
792 Section_name_map::iterator p
=
793 this->section_name_map_
.find(zero_key
);
794 if (p
!= this->section_name_map_
.end())
800 os
= this->make_output_section(name
, type
, flags
, order
, is_relro
);
802 ins
.first
->second
= os
;
807 // Returns TRUE iff NAME (an input section from RELOBJ) will
808 // be mapped to an output section that should be KEPT.
811 Layout::keep_input_section(const Relobj
* relobj
, const char* name
)
813 if (! this->script_options_
->saw_sections_clause())
816 Script_sections
* ss
= this->script_options_
->script_sections();
817 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
818 Output_section
** output_section_slot
;
819 Script_sections::Section_type script_section_type
;
822 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
823 &script_section_type
, &keep
);
824 return name
!= NULL
&& keep
;
827 // Pick the output section to use for section NAME, in input file
828 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
829 // linker created section. IS_INPUT_SECTION is true if we are
830 // choosing an output section for an input section found in a input
831 // file. ORDER is where this section should appear in the output
832 // sections. IS_RELRO is true for a relro section. This will return
833 // NULL if the input section should be discarded.
836 Layout::choose_output_section(const Relobj
* relobj
, const char* name
,
837 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
838 bool is_input_section
, Output_section_order order
,
841 // We should not see any input sections after we have attached
842 // sections to segments.
843 gold_assert(!is_input_section
|| !this->sections_are_attached_
);
845 // Some flags in the input section should not be automatically
846 // copied to the output section.
847 flags
&= ~ (elfcpp::SHF_INFO_LINK
850 | elfcpp::SHF_STRINGS
);
852 // We only clear the SHF_LINK_ORDER flag in for
853 // a non-relocatable link.
854 if (!parameters
->options().relocatable())
855 flags
&= ~elfcpp::SHF_LINK_ORDER
;
857 if (this->script_options_
->saw_sections_clause())
859 // We are using a SECTIONS clause, so the output section is
860 // chosen based only on the name.
862 Script_sections
* ss
= this->script_options_
->script_sections();
863 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
864 Output_section
** output_section_slot
;
865 Script_sections::Section_type script_section_type
;
866 const char* orig_name
= name
;
868 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
869 &script_section_type
, &keep
);
873 gold_debug(DEBUG_SCRIPT
, _("Unable to create output section '%s' "
874 "because it is not allowed by the "
875 "SECTIONS clause of the linker script"),
877 // The SECTIONS clause says to discard this input section.
881 // We can only handle script section types ST_NONE and ST_NOLOAD.
882 switch (script_section_type
)
884 case Script_sections::ST_NONE
:
886 case Script_sections::ST_NOLOAD
:
887 flags
&= elfcpp::SHF_ALLOC
;
893 // If this is an orphan section--one not mentioned in the linker
894 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
895 // default processing below.
897 if (output_section_slot
!= NULL
)
899 if (*output_section_slot
!= NULL
)
901 (*output_section_slot
)->update_flags_for_input_section(flags
);
902 return *output_section_slot
;
905 // We don't put sections found in the linker script into
906 // SECTION_NAME_MAP_. That keeps us from getting confused
907 // if an orphan section is mapped to a section with the same
908 // name as one in the linker script.
910 name
= this->namepool_
.add(name
, false, NULL
);
912 Output_section
* os
= this->make_output_section(name
, type
, flags
,
915 os
->set_found_in_sections_clause();
917 // Special handling for NOLOAD sections.
918 if (script_section_type
== Script_sections::ST_NOLOAD
)
922 // The constructor of Output_section sets addresses of non-ALLOC
923 // sections to 0 by default. We don't want that for NOLOAD
924 // sections even if they have no SHF_ALLOC flag.
925 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0
926 && os
->is_address_valid())
928 gold_assert(os
->address() == 0
929 && !os
->is_offset_valid()
930 && !os
->is_data_size_valid());
931 os
->reset_address_and_file_offset();
935 *output_section_slot
= os
;
940 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
942 size_t len
= strlen(name
);
943 char* uncompressed_name
= NULL
;
945 // Compressed debug sections should be mapped to the corresponding
946 // uncompressed section.
947 if (is_compressed_debug_section(name
))
949 uncompressed_name
= new char[len
];
950 uncompressed_name
[0] = '.';
951 gold_assert(name
[0] == '.' && name
[1] == 'z');
952 strncpy(&uncompressed_name
[1], &name
[2], len
- 2);
953 uncompressed_name
[len
- 1] = '\0';
955 name
= uncompressed_name
;
958 // Turn NAME from the name of the input section into the name of the
961 && !this->script_options_
->saw_sections_clause()
962 && !parameters
->options().relocatable())
964 const char *orig_name
= name
;
965 name
= parameters
->target().output_section_name(relobj
, name
, &len
);
967 name
= Layout::output_section_name(relobj
, orig_name
, &len
);
970 Stringpool::Key name_key
;
971 name
= this->namepool_
.add_with_length(name
, len
, true, &name_key
);
973 if (uncompressed_name
!= NULL
)
974 delete[] uncompressed_name
;
976 // Find or make the output section. The output section is selected
977 // based on the section name, type, and flags.
978 return this->get_output_section(name
, name_key
, type
, flags
, order
, is_relro
);
981 // For incremental links, record the initial fixed layout of a section
982 // from the base file, and return a pointer to the Output_section.
984 template<int size
, bool big_endian
>
986 Layout::init_fixed_output_section(const char* name
,
987 elfcpp::Shdr
<size
, big_endian
>& shdr
)
989 unsigned int sh_type
= shdr
.get_sh_type();
991 // We preserve the layout of PROGBITS, NOBITS, INIT_ARRAY, FINI_ARRAY,
992 // PRE_INIT_ARRAY, and NOTE sections.
993 // All others will be created from scratch and reallocated.
994 if (!can_incremental_update(sh_type
))
997 // If we're generating a .gdb_index section, we need to regenerate
999 if (parameters
->options().gdb_index()
1000 && sh_type
== elfcpp::SHT_PROGBITS
1001 && strcmp(name
, ".gdb_index") == 0)
1004 typename
elfcpp::Elf_types
<size
>::Elf_Addr sh_addr
= shdr
.get_sh_addr();
1005 typename
elfcpp::Elf_types
<size
>::Elf_Off sh_offset
= shdr
.get_sh_offset();
1006 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
1007 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_flags
= shdr
.get_sh_flags();
1008 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_addralign
=
1009 shdr
.get_sh_addralign();
1011 // Make the output section.
1012 Stringpool::Key name_key
;
1013 name
= this->namepool_
.add(name
, true, &name_key
);
1014 Output_section
* os
= this->get_output_section(name
, name_key
, sh_type
,
1015 sh_flags
, ORDER_INVALID
, false);
1016 os
->set_fixed_layout(sh_addr
, sh_offset
, sh_size
, sh_addralign
);
1017 if (sh_type
!= elfcpp::SHT_NOBITS
)
1018 this->free_list_
.remove(sh_offset
, sh_offset
+ sh_size
);
1022 // Return the output section to use for input section SHNDX, with name
1023 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
1024 // index of a relocation section which applies to this section, or 0
1025 // if none, or -1U if more than one. RELOC_TYPE is the type of the
1026 // relocation section if there is one. Set *OFF to the offset of this
1027 // input section without the output section. Return NULL if the
1028 // section should be discarded. Set *OFF to -1 if the section
1029 // contents should not be written directly to the output file, but
1030 // will instead receive special handling.
1032 template<int size
, bool big_endian
>
1034 Layout::layout(Sized_relobj_file
<size
, big_endian
>* object
, unsigned int shndx
,
1035 const char* name
, const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1036 unsigned int reloc_shndx
, unsigned int, off_t
* off
)
1040 if (!this->include_section(object
, name
, shdr
))
1043 elfcpp::Elf_Word sh_type
= shdr
.get_sh_type();
1045 // In a relocatable link a grouped section must not be combined with
1046 // any other sections.
1048 if (parameters
->options().relocatable()
1049 && (shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) != 0)
1051 name
= this->namepool_
.add(name
, true, NULL
);
1052 os
= this->make_output_section(name
, sh_type
, shdr
.get_sh_flags(),
1053 ORDER_INVALID
, false);
1057 os
= this->choose_output_section(object
, name
, sh_type
,
1058 shdr
.get_sh_flags(), true,
1059 ORDER_INVALID
, false);
1064 // By default the GNU linker sorts input sections whose names match
1065 // .ctors.*, .dtors.*, .init_array.*, or .fini_array.*. The
1066 // sections are sorted by name. This is used to implement
1067 // constructor priority ordering. We are compatible. When we put
1068 // .ctor sections in .init_array and .dtor sections in .fini_array,
1069 // we must also sort plain .ctor and .dtor sections.
1070 if (!this->script_options_
->saw_sections_clause()
1071 && !parameters
->options().relocatable()
1072 && (is_prefix_of(".ctors.", name
)
1073 || is_prefix_of(".dtors.", name
)
1074 || is_prefix_of(".init_array.", name
)
1075 || is_prefix_of(".fini_array.", name
)
1076 || (parameters
->options().ctors_in_init_array()
1077 && (strcmp(name
, ".ctors") == 0
1078 || strcmp(name
, ".dtors") == 0))))
1079 os
->set_must_sort_attached_input_sections();
1081 // If this is a .ctors or .ctors.* section being mapped to a
1082 // .init_array section, or a .dtors or .dtors.* section being mapped
1083 // to a .fini_array section, we will need to reverse the words if
1084 // there is more than one. Record this section for later. See
1085 // ctors_sections_in_init_array above.
1086 if (!this->script_options_
->saw_sections_clause()
1087 && !parameters
->options().relocatable()
1088 && shdr
.get_sh_size() > size
/ 8
1089 && (((strcmp(name
, ".ctors") == 0
1090 || is_prefix_of(".ctors.", name
))
1091 && strcmp(os
->name(), ".init_array") == 0)
1092 || ((strcmp(name
, ".dtors") == 0
1093 || is_prefix_of(".dtors.", name
))
1094 && strcmp(os
->name(), ".fini_array") == 0)))
1095 ctors_sections_in_init_array
.insert(Section_id(object
, shndx
));
1097 // FIXME: Handle SHF_LINK_ORDER somewhere.
1099 elfcpp::Elf_Xword orig_flags
= os
->flags();
1101 *off
= os
->add_input_section(this, object
, shndx
, name
, shdr
, reloc_shndx
,
1102 this->script_options_
->saw_sections_clause());
1104 // If the flags changed, we may have to change the order.
1105 if ((orig_flags
& elfcpp::SHF_ALLOC
) != 0)
1107 orig_flags
&= (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1108 elfcpp::Elf_Xword new_flags
=
1109 os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1110 if (orig_flags
!= new_flags
)
1111 os
->set_order(this->default_section_order(os
, false));
1114 this->have_added_input_section_
= true;
1119 // Handle a relocation section when doing a relocatable link.
1121 template<int size
, bool big_endian
>
1123 Layout::layout_reloc(Sized_relobj_file
<size
, big_endian
>* object
,
1125 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1126 Output_section
* data_section
,
1127 Relocatable_relocs
* rr
)
1129 gold_assert(parameters
->options().relocatable()
1130 || parameters
->options().emit_relocs());
1132 int sh_type
= shdr
.get_sh_type();
1135 if (sh_type
== elfcpp::SHT_REL
)
1137 else if (sh_type
== elfcpp::SHT_RELA
)
1141 name
+= data_section
->name();
1143 // In a relocatable link relocs for a grouped section must not be
1144 // combined with other reloc sections.
1146 if (!parameters
->options().relocatable()
1147 || (data_section
->flags() & elfcpp::SHF_GROUP
) == 0)
1148 os
= this->choose_output_section(object
, name
.c_str(), sh_type
,
1149 shdr
.get_sh_flags(), false,
1150 ORDER_INVALID
, false);
1153 const char* n
= this->namepool_
.add(name
.c_str(), true, NULL
);
1154 os
= this->make_output_section(n
, sh_type
, shdr
.get_sh_flags(),
1155 ORDER_INVALID
, false);
1158 os
->set_should_link_to_symtab();
1159 os
->set_info_section(data_section
);
1161 Output_section_data
* posd
;
1162 if (sh_type
== elfcpp::SHT_REL
)
1164 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rel_size
);
1165 posd
= new Output_relocatable_relocs
<elfcpp::SHT_REL
,
1169 else if (sh_type
== elfcpp::SHT_RELA
)
1171 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rela_size
);
1172 posd
= new Output_relocatable_relocs
<elfcpp::SHT_RELA
,
1179 os
->add_output_section_data(posd
);
1180 rr
->set_output_data(posd
);
1185 // Handle a group section when doing a relocatable link.
1187 template<int size
, bool big_endian
>
1189 Layout::layout_group(Symbol_table
* symtab
,
1190 Sized_relobj_file
<size
, big_endian
>* object
,
1192 const char* group_section_name
,
1193 const char* signature
,
1194 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1195 elfcpp::Elf_Word flags
,
1196 std::vector
<unsigned int>* shndxes
)
1198 gold_assert(parameters
->options().relocatable());
1199 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_GROUP
);
1200 group_section_name
= this->namepool_
.add(group_section_name
, true, NULL
);
1201 Output_section
* os
= this->make_output_section(group_section_name
,
1203 shdr
.get_sh_flags(),
1204 ORDER_INVALID
, false);
1206 // We need to find a symbol with the signature in the symbol table.
1207 // If we don't find one now, we need to look again later.
1208 Symbol
* sym
= symtab
->lookup(signature
, NULL
);
1210 os
->set_info_symndx(sym
);
1213 // Reserve some space to minimize reallocations.
1214 if (this->group_signatures_
.empty())
1215 this->group_signatures_
.reserve(this->number_of_input_files_
* 16);
1217 // We will wind up using a symbol whose name is the signature.
1218 // So just put the signature in the symbol name pool to save it.
1219 signature
= symtab
->canonicalize_name(signature
);
1220 this->group_signatures_
.push_back(Group_signature(os
, signature
));
1223 os
->set_should_link_to_symtab();
1226 section_size_type entry_count
=
1227 convert_to_section_size_type(shdr
.get_sh_size() / 4);
1228 Output_section_data
* posd
=
1229 new Output_data_group
<size
, big_endian
>(object
, entry_count
, flags
,
1231 os
->add_output_section_data(posd
);
1234 // Special GNU handling of sections name .eh_frame. They will
1235 // normally hold exception frame data as defined by the C++ ABI
1236 // (http://codesourcery.com/cxx-abi/).
1238 template<int size
, bool big_endian
>
1240 Layout::layout_eh_frame(Sized_relobj_file
<size
, big_endian
>* object
,
1241 const unsigned char* symbols
,
1243 const unsigned char* symbol_names
,
1244 off_t symbol_names_size
,
1246 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1247 unsigned int reloc_shndx
, unsigned int reloc_type
,
1250 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
1251 || shdr
.get_sh_type() == elfcpp::SHT_X86_64_UNWIND
);
1252 gold_assert((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
1254 Output_section
* os
= this->make_eh_frame_section(object
);
1258 gold_assert(this->eh_frame_section_
== os
);
1260 elfcpp::Elf_Xword orig_flags
= os
->flags();
1262 if (!parameters
->incremental()
1263 && this->eh_frame_data_
->add_ehframe_input_section(object
,
1272 os
->update_flags_for_input_section(shdr
.get_sh_flags());
1274 // A writable .eh_frame section is a RELRO section.
1275 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1276 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1279 os
->set_order(ORDER_RELRO
);
1282 // We found a .eh_frame section we are going to optimize, so now
1283 // we can add the set of optimized sections to the output
1284 // section. We need to postpone adding this until we've found a
1285 // section we can optimize so that the .eh_frame section in
1286 // crtbegin.o winds up at the start of the output section.
1287 if (!this->added_eh_frame_data_
)
1289 os
->add_output_section_data(this->eh_frame_data_
);
1290 this->added_eh_frame_data_
= true;
1296 // We couldn't handle this .eh_frame section for some reason.
1297 // Add it as a normal section.
1298 bool saw_sections_clause
= this->script_options_
->saw_sections_clause();
1299 *off
= os
->add_input_section(this, object
, shndx
, ".eh_frame", shdr
,
1300 reloc_shndx
, saw_sections_clause
);
1301 this->have_added_input_section_
= true;
1303 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1304 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1305 os
->set_order(this->default_section_order(os
, false));
1311 // Create and return the magic .eh_frame section. Create
1312 // .eh_frame_hdr also if appropriate. OBJECT is the object with the
1313 // input .eh_frame section; it may be NULL.
1316 Layout::make_eh_frame_section(const Relobj
* object
)
1318 // FIXME: On x86_64, this could use SHT_X86_64_UNWIND rather than
1320 Output_section
* os
= this->choose_output_section(object
, ".eh_frame",
1321 elfcpp::SHT_PROGBITS
,
1322 elfcpp::SHF_ALLOC
, false,
1323 ORDER_EHFRAME
, false);
1327 if (this->eh_frame_section_
== NULL
)
1329 this->eh_frame_section_
= os
;
1330 this->eh_frame_data_
= new Eh_frame();
1332 // For incremental linking, we do not optimize .eh_frame sections
1333 // or create a .eh_frame_hdr section.
1334 if (parameters
->options().eh_frame_hdr() && !parameters
->incremental())
1336 Output_section
* hdr_os
=
1337 this->choose_output_section(NULL
, ".eh_frame_hdr",
1338 elfcpp::SHT_PROGBITS
,
1339 elfcpp::SHF_ALLOC
, false,
1340 ORDER_EHFRAME
, false);
1344 Eh_frame_hdr
* hdr_posd
= new Eh_frame_hdr(os
,
1345 this->eh_frame_data_
);
1346 hdr_os
->add_output_section_data(hdr_posd
);
1348 hdr_os
->set_after_input_sections();
1350 if (!this->script_options_
->saw_phdrs_clause())
1352 Output_segment
* hdr_oseg
;
1353 hdr_oseg
= this->make_output_segment(elfcpp::PT_GNU_EH_FRAME
,
1355 hdr_oseg
->add_output_section_to_nonload(hdr_os
,
1359 this->eh_frame_data_
->set_eh_frame_hdr(hdr_posd
);
1367 // Add an exception frame for a PLT. This is called from target code.
1370 Layout::add_eh_frame_for_plt(Output_data
* plt
, const unsigned char* cie_data
,
1371 size_t cie_length
, const unsigned char* fde_data
,
1374 if (parameters
->incremental())
1376 // FIXME: Maybe this could work some day....
1379 Output_section
* os
= this->make_eh_frame_section(NULL
);
1382 this->eh_frame_data_
->add_ehframe_for_plt(plt
, cie_data
, cie_length
,
1383 fde_data
, fde_length
);
1384 if (!this->added_eh_frame_data_
)
1386 os
->add_output_section_data(this->eh_frame_data_
);
1387 this->added_eh_frame_data_
= true;
1391 // Scan a .debug_info or .debug_types section, and add summary
1392 // information to the .gdb_index section.
1394 template<int size
, bool big_endian
>
1396 Layout::add_to_gdb_index(bool is_type_unit
,
1397 Sized_relobj
<size
, big_endian
>* object
,
1398 const unsigned char* symbols
,
1401 unsigned int reloc_shndx
,
1402 unsigned int reloc_type
)
1404 if (this->gdb_index_data_
== NULL
)
1406 Output_section
* os
= this->choose_output_section(NULL
, ".gdb_index",
1407 elfcpp::SHT_PROGBITS
, 0,
1408 false, ORDER_INVALID
,
1413 this->gdb_index_data_
= new Gdb_index(os
);
1414 os
->add_output_section_data(this->gdb_index_data_
);
1415 os
->set_after_input_sections();
1418 this->gdb_index_data_
->scan_debug_info(is_type_unit
, object
, symbols
,
1419 symbols_size
, shndx
, reloc_shndx
,
1423 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
1424 // the output section.
1427 Layout::add_output_section_data(const char* name
, elfcpp::Elf_Word type
,
1428 elfcpp::Elf_Xword flags
,
1429 Output_section_data
* posd
,
1430 Output_section_order order
, bool is_relro
)
1432 Output_section
* os
= this->choose_output_section(NULL
, name
, type
, flags
,
1433 false, order
, is_relro
);
1435 os
->add_output_section_data(posd
);
1439 // Map section flags to segment flags.
1442 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags
)
1444 elfcpp::Elf_Word ret
= elfcpp::PF_R
;
1445 if ((flags
& elfcpp::SHF_WRITE
) != 0)
1446 ret
|= elfcpp::PF_W
;
1447 if ((flags
& elfcpp::SHF_EXECINSTR
) != 0)
1448 ret
|= elfcpp::PF_X
;
1452 // Make a new Output_section, and attach it to segments as
1453 // appropriate. ORDER is the order in which this section should
1454 // appear in the output segment. IS_RELRO is true if this is a relro
1455 // (read-only after relocations) section.
1458 Layout::make_output_section(const char* name
, elfcpp::Elf_Word type
,
1459 elfcpp::Elf_Xword flags
,
1460 Output_section_order order
, bool is_relro
)
1463 if ((flags
& elfcpp::SHF_ALLOC
) == 0
1464 && strcmp(parameters
->options().compress_debug_sections(), "none") != 0
1465 && is_compressible_debug_section(name
))
1466 os
= new Output_compressed_section(¶meters
->options(), name
, type
,
1468 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1469 && parameters
->options().strip_debug_non_line()
1470 && strcmp(".debug_abbrev", name
) == 0)
1472 os
= this->debug_abbrev_
= new Output_reduced_debug_abbrev_section(
1474 if (this->debug_info_
)
1475 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1477 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1478 && parameters
->options().strip_debug_non_line()
1479 && strcmp(".debug_info", name
) == 0)
1481 os
= this->debug_info_
= new Output_reduced_debug_info_section(
1483 if (this->debug_abbrev_
)
1484 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1488 // Sometimes .init_array*, .preinit_array* and .fini_array* do
1489 // not have correct section types. Force them here.
1490 if (type
== elfcpp::SHT_PROGBITS
)
1492 if (is_prefix_of(".init_array", name
))
1493 type
= elfcpp::SHT_INIT_ARRAY
;
1494 else if (is_prefix_of(".preinit_array", name
))
1495 type
= elfcpp::SHT_PREINIT_ARRAY
;
1496 else if (is_prefix_of(".fini_array", name
))
1497 type
= elfcpp::SHT_FINI_ARRAY
;
1500 // FIXME: const_cast is ugly.
1501 Target
* target
= const_cast<Target
*>(¶meters
->target());
1502 os
= target
->make_output_section(name
, type
, flags
);
1505 // With -z relro, we have to recognize the special sections by name.
1506 // There is no other way.
1507 bool is_relro_local
= false;
1508 if (!this->script_options_
->saw_sections_clause()
1509 && parameters
->options().relro()
1510 && (flags
& elfcpp::SHF_ALLOC
) != 0
1511 && (flags
& elfcpp::SHF_WRITE
) != 0)
1513 if (type
== elfcpp::SHT_PROGBITS
)
1515 if ((flags
& elfcpp::SHF_TLS
) != 0)
1517 else if (strcmp(name
, ".data.rel.ro") == 0)
1519 else if (strcmp(name
, ".data.rel.ro.local") == 0)
1522 is_relro_local
= true;
1524 else if (strcmp(name
, ".ctors") == 0
1525 || strcmp(name
, ".dtors") == 0
1526 || strcmp(name
, ".jcr") == 0)
1529 else if (type
== elfcpp::SHT_INIT_ARRAY
1530 || type
== elfcpp::SHT_FINI_ARRAY
1531 || type
== elfcpp::SHT_PREINIT_ARRAY
)
1538 if (order
== ORDER_INVALID
&& (flags
& elfcpp::SHF_ALLOC
) != 0)
1539 order
= this->default_section_order(os
, is_relro_local
);
1541 os
->set_order(order
);
1543 parameters
->target().new_output_section(os
);
1545 this->section_list_
.push_back(os
);
1547 // The GNU linker by default sorts some sections by priority, so we
1548 // do the same. We need to know that this might happen before we
1549 // attach any input sections.
1550 if (!this->script_options_
->saw_sections_clause()
1551 && !parameters
->options().relocatable()
1552 && (strcmp(name
, ".init_array") == 0
1553 || strcmp(name
, ".fini_array") == 0
1554 || (!parameters
->options().ctors_in_init_array()
1555 && (strcmp(name
, ".ctors") == 0
1556 || strcmp(name
, ".dtors") == 0))))
1557 os
->set_may_sort_attached_input_sections();
1559 // Check for .stab*str sections, as .stab* sections need to link to
1561 if (type
== elfcpp::SHT_STRTAB
1562 && !this->have_stabstr_section_
1563 && strncmp(name
, ".stab", 5) == 0
1564 && strcmp(name
+ strlen(name
) - 3, "str") == 0)
1565 this->have_stabstr_section_
= true;
1567 // During a full incremental link, we add patch space to most
1568 // PROGBITS and NOBITS sections. Flag those that may be
1569 // arbitrarily padded.
1570 if ((type
== elfcpp::SHT_PROGBITS
|| type
== elfcpp::SHT_NOBITS
)
1571 && order
!= ORDER_INTERP
1572 && order
!= ORDER_INIT
1573 && order
!= ORDER_PLT
1574 && order
!= ORDER_FINI
1575 && order
!= ORDER_RELRO_LAST
1576 && order
!= ORDER_NON_RELRO_FIRST
1577 && strcmp(name
, ".eh_frame") != 0
1578 && strcmp(name
, ".ctors") != 0
1579 && strcmp(name
, ".dtors") != 0
1580 && strcmp(name
, ".jcr") != 0)
1582 os
->set_is_patch_space_allowed();
1584 // Certain sections require "holes" to be filled with
1585 // specific fill patterns. These fill patterns may have
1586 // a minimum size, so we must prevent allocations from the
1587 // free list that leave a hole smaller than the minimum.
1588 if (strcmp(name
, ".debug_info") == 0)
1589 os
->set_free_space_fill(new Output_fill_debug_info(false));
1590 else if (strcmp(name
, ".debug_types") == 0)
1591 os
->set_free_space_fill(new Output_fill_debug_info(true));
1592 else if (strcmp(name
, ".debug_line") == 0)
1593 os
->set_free_space_fill(new Output_fill_debug_line());
1596 // If we have already attached the sections to segments, then we
1597 // need to attach this one now. This happens for sections created
1598 // directly by the linker.
1599 if (this->sections_are_attached_
)
1600 this->attach_section_to_segment(¶meters
->target(), os
);
1605 // Return the default order in which a section should be placed in an
1606 // output segment. This function captures a lot of the ideas in
1607 // ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
1608 // linker created section is normally set when the section is created;
1609 // this function is used for input sections.
1611 Output_section_order
1612 Layout::default_section_order(Output_section
* os
, bool is_relro_local
)
1614 gold_assert((os
->flags() & elfcpp::SHF_ALLOC
) != 0);
1615 bool is_write
= (os
->flags() & elfcpp::SHF_WRITE
) != 0;
1616 bool is_execinstr
= (os
->flags() & elfcpp::SHF_EXECINSTR
) != 0;
1617 bool is_bss
= false;
1622 case elfcpp::SHT_PROGBITS
:
1624 case elfcpp::SHT_NOBITS
:
1627 case elfcpp::SHT_RELA
:
1628 case elfcpp::SHT_REL
:
1630 return ORDER_DYNAMIC_RELOCS
;
1632 case elfcpp::SHT_HASH
:
1633 case elfcpp::SHT_DYNAMIC
:
1634 case elfcpp::SHT_SHLIB
:
1635 case elfcpp::SHT_DYNSYM
:
1636 case elfcpp::SHT_GNU_HASH
:
1637 case elfcpp::SHT_GNU_verdef
:
1638 case elfcpp::SHT_GNU_verneed
:
1639 case elfcpp::SHT_GNU_versym
:
1641 return ORDER_DYNAMIC_LINKER
;
1643 case elfcpp::SHT_NOTE
:
1644 return is_write
? ORDER_RW_NOTE
: ORDER_RO_NOTE
;
1647 if ((os
->flags() & elfcpp::SHF_TLS
) != 0)
1648 return is_bss
? ORDER_TLS_BSS
: ORDER_TLS_DATA
;
1650 if (!is_bss
&& !is_write
)
1654 if (strcmp(os
->name(), ".init") == 0)
1656 else if (strcmp(os
->name(), ".fini") == 0)
1659 return is_execinstr
? ORDER_TEXT
: ORDER_READONLY
;
1663 return is_relro_local
? ORDER_RELRO_LOCAL
: ORDER_RELRO
;
1665 if (os
->is_small_section())
1666 return is_bss
? ORDER_SMALL_BSS
: ORDER_SMALL_DATA
;
1667 if (os
->is_large_section())
1668 return is_bss
? ORDER_LARGE_BSS
: ORDER_LARGE_DATA
;
1670 return is_bss
? ORDER_BSS
: ORDER_DATA
;
1673 // Attach output sections to segments. This is called after we have
1674 // seen all the input sections.
1677 Layout::attach_sections_to_segments(const Target
* target
)
1679 for (Section_list::iterator p
= this->section_list_
.begin();
1680 p
!= this->section_list_
.end();
1682 this->attach_section_to_segment(target
, *p
);
1684 this->sections_are_attached_
= true;
1687 // Attach an output section to a segment.
1690 Layout::attach_section_to_segment(const Target
* target
, Output_section
* os
)
1692 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0)
1693 this->unattached_section_list_
.push_back(os
);
1695 this->attach_allocated_section_to_segment(target
, os
);
1698 // Attach an allocated output section to a segment.
1701 Layout::attach_allocated_section_to_segment(const Target
* target
,
1704 elfcpp::Elf_Xword flags
= os
->flags();
1705 gold_assert((flags
& elfcpp::SHF_ALLOC
) != 0);
1707 if (parameters
->options().relocatable())
1710 // If we have a SECTIONS clause, we can't handle the attachment to
1711 // segments until after we've seen all the sections.
1712 if (this->script_options_
->saw_sections_clause())
1715 gold_assert(!this->script_options_
->saw_phdrs_clause());
1717 // This output section goes into a PT_LOAD segment.
1719 elfcpp::Elf_Word seg_flags
= Layout::section_flags_to_segment(flags
);
1721 // Check for --section-start.
1723 bool is_address_set
= parameters
->options().section_start(os
->name(), &addr
);
1725 // In general the only thing we really care about for PT_LOAD
1726 // segments is whether or not they are writable or executable,
1727 // so that is how we search for them.
1728 // Large data sections also go into their own PT_LOAD segment.
1729 // People who need segments sorted on some other basis will
1730 // have to use a linker script.
1732 Segment_list::const_iterator p
;
1733 for (p
= this->segment_list_
.begin();
1734 p
!= this->segment_list_
.end();
1737 if ((*p
)->type() != elfcpp::PT_LOAD
)
1739 if (!parameters
->options().omagic()
1740 && ((*p
)->flags() & elfcpp::PF_W
) != (seg_flags
& elfcpp::PF_W
))
1742 if ((target
->isolate_execinstr() || parameters
->options().rosegment())
1743 && ((*p
)->flags() & elfcpp::PF_X
) != (seg_flags
& elfcpp::PF_X
))
1745 // If -Tbss was specified, we need to separate the data and BSS
1747 if (parameters
->options().user_set_Tbss())
1749 if ((os
->type() == elfcpp::SHT_NOBITS
)
1750 == (*p
)->has_any_data_sections())
1753 if (os
->is_large_data_section() && !(*p
)->is_large_data_segment())
1758 if ((*p
)->are_addresses_set())
1761 (*p
)->add_initial_output_data(os
);
1762 (*p
)->update_flags_for_output_section(seg_flags
);
1763 (*p
)->set_addresses(addr
, addr
);
1767 (*p
)->add_output_section_to_load(this, os
, seg_flags
);
1771 if (p
== this->segment_list_
.end())
1773 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_LOAD
,
1775 if (os
->is_large_data_section())
1776 oseg
->set_is_large_data_segment();
1777 oseg
->add_output_section_to_load(this, os
, seg_flags
);
1779 oseg
->set_addresses(addr
, addr
);
1782 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1784 if (os
->type() == elfcpp::SHT_NOTE
)
1786 // See if we already have an equivalent PT_NOTE segment.
1787 for (p
= this->segment_list_
.begin();
1788 p
!= segment_list_
.end();
1791 if ((*p
)->type() == elfcpp::PT_NOTE
1792 && (((*p
)->flags() & elfcpp::PF_W
)
1793 == (seg_flags
& elfcpp::PF_W
)))
1795 (*p
)->add_output_section_to_nonload(os
, seg_flags
);
1800 if (p
== this->segment_list_
.end())
1802 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_NOTE
,
1804 oseg
->add_output_section_to_nonload(os
, seg_flags
);
1808 // If we see a loadable SHF_TLS section, we create a PT_TLS
1809 // segment. There can only be one such segment.
1810 if ((flags
& elfcpp::SHF_TLS
) != 0)
1812 if (this->tls_segment_
== NULL
)
1813 this->make_output_segment(elfcpp::PT_TLS
, seg_flags
);
1814 this->tls_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1817 // If -z relro is in effect, and we see a relro section, we create a
1818 // PT_GNU_RELRO segment. There can only be one such segment.
1819 if (os
->is_relro() && parameters
->options().relro())
1821 gold_assert(seg_flags
== (elfcpp::PF_R
| elfcpp::PF_W
));
1822 if (this->relro_segment_
== NULL
)
1823 this->make_output_segment(elfcpp::PT_GNU_RELRO
, seg_flags
);
1824 this->relro_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1827 // If we see a section named .interp, put it into a PT_INTERP
1828 // segment. This seems broken to me, but this is what GNU ld does,
1829 // and glibc expects it.
1830 if (strcmp(os
->name(), ".interp") == 0
1831 && !this->script_options_
->saw_phdrs_clause())
1833 if (this->interp_segment_
== NULL
)
1834 this->make_output_segment(elfcpp::PT_INTERP
, seg_flags
);
1836 gold_warning(_("multiple '.interp' sections in input files "
1837 "may cause confusing PT_INTERP segment"));
1838 this->interp_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1842 // Make an output section for a script.
1845 Layout::make_output_section_for_script(
1847 Script_sections::Section_type section_type
)
1849 name
= this->namepool_
.add(name
, false, NULL
);
1850 elfcpp::Elf_Xword sh_flags
= elfcpp::SHF_ALLOC
;
1851 if (section_type
== Script_sections::ST_NOLOAD
)
1853 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_PROGBITS
,
1854 sh_flags
, ORDER_INVALID
,
1856 os
->set_found_in_sections_clause();
1857 if (section_type
== Script_sections::ST_NOLOAD
)
1858 os
->set_is_noload();
1862 // Return the number of segments we expect to see.
1865 Layout::expected_segment_count() const
1867 size_t ret
= this->segment_list_
.size();
1869 // If we didn't see a SECTIONS clause in a linker script, we should
1870 // already have the complete list of segments. Otherwise we ask the
1871 // SECTIONS clause how many segments it expects, and add in the ones
1872 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1874 if (!this->script_options_
->saw_sections_clause())
1878 const Script_sections
* ss
= this->script_options_
->script_sections();
1879 return ret
+ ss
->expected_segment_count(this);
1883 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
1884 // is whether we saw a .note.GNU-stack section in the object file.
1885 // GNU_STACK_FLAGS is the section flags. The flags give the
1886 // protection required for stack memory. We record this in an
1887 // executable as a PT_GNU_STACK segment. If an object file does not
1888 // have a .note.GNU-stack segment, we must assume that it is an old
1889 // object. On some targets that will force an executable stack.
1892 Layout::layout_gnu_stack(bool seen_gnu_stack
, uint64_t gnu_stack_flags
,
1895 if (!seen_gnu_stack
)
1897 this->input_without_gnu_stack_note_
= true;
1898 if (parameters
->options().warn_execstack()
1899 && parameters
->target().is_default_stack_executable())
1900 gold_warning(_("%s: missing .note.GNU-stack section"
1901 " implies executable stack"),
1902 obj
->name().c_str());
1906 this->input_with_gnu_stack_note_
= true;
1907 if ((gnu_stack_flags
& elfcpp::SHF_EXECINSTR
) != 0)
1909 this->input_requires_executable_stack_
= true;
1910 if (parameters
->options().warn_execstack()
1911 || parameters
->options().is_stack_executable())
1912 gold_warning(_("%s: requires executable stack"),
1913 obj
->name().c_str());
1918 // Create automatic note sections.
1921 Layout::create_notes()
1923 this->create_gold_note();
1924 this->create_executable_stack_info();
1925 this->create_build_id();
1928 // Create the dynamic sections which are needed before we read the
1932 Layout::create_initial_dynamic_sections(Symbol_table
* symtab
)
1934 if (parameters
->doing_static_link())
1937 this->dynamic_section_
= this->choose_output_section(NULL
, ".dynamic",
1938 elfcpp::SHT_DYNAMIC
,
1940 | elfcpp::SHF_WRITE
),
1944 // A linker script may discard .dynamic, so check for NULL.
1945 if (this->dynamic_section_
!= NULL
)
1947 this->dynamic_symbol_
=
1948 symtab
->define_in_output_data("_DYNAMIC", NULL
,
1949 Symbol_table::PREDEFINED
,
1950 this->dynamic_section_
, 0, 0,
1951 elfcpp::STT_OBJECT
, elfcpp::STB_LOCAL
,
1952 elfcpp::STV_HIDDEN
, 0, false, false);
1954 this->dynamic_data_
= new Output_data_dynamic(&this->dynpool_
);
1956 this->dynamic_section_
->add_output_section_data(this->dynamic_data_
);
1960 // For each output section whose name can be represented as C symbol,
1961 // define __start and __stop symbols for the section. This is a GNU
1965 Layout::define_section_symbols(Symbol_table
* symtab
)
1967 for (Section_list::const_iterator p
= this->section_list_
.begin();
1968 p
!= this->section_list_
.end();
1971 const char* const name
= (*p
)->name();
1972 if (is_cident(name
))
1974 const std::string
name_string(name
);
1975 const std::string
start_name(cident_section_start_prefix
1977 const std::string
stop_name(cident_section_stop_prefix
1980 symtab
->define_in_output_data(start_name
.c_str(),
1982 Symbol_table::PREDEFINED
,
1988 elfcpp::STV_DEFAULT
,
1990 false, // offset_is_from_end
1991 true); // only_if_ref
1993 symtab
->define_in_output_data(stop_name
.c_str(),
1995 Symbol_table::PREDEFINED
,
2001 elfcpp::STV_DEFAULT
,
2003 true, // offset_is_from_end
2004 true); // only_if_ref
2009 // Define symbols for group signatures.
2012 Layout::define_group_signatures(Symbol_table
* symtab
)
2014 for (Group_signatures::iterator p
= this->group_signatures_
.begin();
2015 p
!= this->group_signatures_
.end();
2018 Symbol
* sym
= symtab
->lookup(p
->signature
, NULL
);
2020 p
->section
->set_info_symndx(sym
);
2023 // Force the name of the group section to the group
2024 // signature, and use the group's section symbol as the
2025 // signature symbol.
2026 if (strcmp(p
->section
->name(), p
->signature
) != 0)
2028 const char* name
= this->namepool_
.add(p
->signature
,
2030 p
->section
->set_name(name
);
2032 p
->section
->set_needs_symtab_index();
2033 p
->section
->set_info_section_symndx(p
->section
);
2037 this->group_signatures_
.clear();
2040 // Find the first read-only PT_LOAD segment, creating one if
2044 Layout::find_first_load_seg(const Target
* target
)
2046 Output_segment
* best
= NULL
;
2047 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2048 p
!= this->segment_list_
.end();
2051 if ((*p
)->type() == elfcpp::PT_LOAD
2052 && ((*p
)->flags() & elfcpp::PF_R
) != 0
2053 && (parameters
->options().omagic()
2054 || ((*p
)->flags() & elfcpp::PF_W
) == 0)
2055 && (!target
->isolate_execinstr()
2056 || ((*p
)->flags() & elfcpp::PF_X
) == 0))
2058 if (best
== NULL
|| this->segment_precedes(*p
, best
))
2065 gold_assert(!this->script_options_
->saw_phdrs_clause());
2067 Output_segment
* load_seg
= this->make_output_segment(elfcpp::PT_LOAD
,
2072 // Save states of all current output segments. Store saved states
2073 // in SEGMENT_STATES.
2076 Layout::save_segments(Segment_states
* segment_states
)
2078 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2079 p
!= this->segment_list_
.end();
2082 Output_segment
* segment
= *p
;
2084 Output_segment
* copy
= new Output_segment(*segment
);
2085 (*segment_states
)[segment
] = copy
;
2089 // Restore states of output segments and delete any segment not found in
2093 Layout::restore_segments(const Segment_states
* segment_states
)
2095 // Go through the segment list and remove any segment added in the
2097 this->tls_segment_
= NULL
;
2098 this->relro_segment_
= NULL
;
2099 Segment_list::iterator list_iter
= this->segment_list_
.begin();
2100 while (list_iter
!= this->segment_list_
.end())
2102 Output_segment
* segment
= *list_iter
;
2103 Segment_states::const_iterator states_iter
=
2104 segment_states
->find(segment
);
2105 if (states_iter
!= segment_states
->end())
2107 const Output_segment
* copy
= states_iter
->second
;
2108 // Shallow copy to restore states.
2111 // Also fix up TLS and RELRO segment pointers as appropriate.
2112 if (segment
->type() == elfcpp::PT_TLS
)
2113 this->tls_segment_
= segment
;
2114 else if (segment
->type() == elfcpp::PT_GNU_RELRO
)
2115 this->relro_segment_
= segment
;
2121 list_iter
= this->segment_list_
.erase(list_iter
);
2122 // This is a segment created during section layout. It should be
2123 // safe to remove it since we should have removed all pointers to it.
2129 // Clean up after relaxation so that sections can be laid out again.
2132 Layout::clean_up_after_relaxation()
2134 // Restore the segments to point state just prior to the relaxation loop.
2135 Script_sections
* script_section
= this->script_options_
->script_sections();
2136 script_section
->release_segments();
2137 this->restore_segments(this->segment_states_
);
2139 // Reset section addresses and file offsets
2140 for (Section_list::iterator p
= this->section_list_
.begin();
2141 p
!= this->section_list_
.end();
2144 (*p
)->restore_states();
2146 // If an input section changes size because of relaxation,
2147 // we need to adjust the section offsets of all input sections.
2148 // after such a section.
2149 if ((*p
)->section_offsets_need_adjustment())
2150 (*p
)->adjust_section_offsets();
2152 (*p
)->reset_address_and_file_offset();
2155 // Reset special output object address and file offsets.
2156 for (Data_list::iterator p
= this->special_output_list_
.begin();
2157 p
!= this->special_output_list_
.end();
2159 (*p
)->reset_address_and_file_offset();
2161 // A linker script may have created some output section data objects.
2162 // They are useless now.
2163 for (Output_section_data_list::const_iterator p
=
2164 this->script_output_section_data_list_
.begin();
2165 p
!= this->script_output_section_data_list_
.end();
2168 this->script_output_section_data_list_
.clear();
2171 // Prepare for relaxation.
2174 Layout::prepare_for_relaxation()
2176 // Create an relaxation debug check if in debugging mode.
2177 if (is_debugging_enabled(DEBUG_RELAXATION
))
2178 this->relaxation_debug_check_
= new Relaxation_debug_check();
2180 // Save segment states.
2181 this->segment_states_
= new Segment_states();
2182 this->save_segments(this->segment_states_
);
2184 for(Section_list::const_iterator p
= this->section_list_
.begin();
2185 p
!= this->section_list_
.end();
2187 (*p
)->save_states();
2189 if (is_debugging_enabled(DEBUG_RELAXATION
))
2190 this->relaxation_debug_check_
->check_output_data_for_reset_values(
2191 this->section_list_
, this->special_output_list_
);
2193 // Also enable recording of output section data from scripts.
2194 this->record_output_section_data_from_script_
= true;
2197 // Relaxation loop body: If target has no relaxation, this runs only once
2198 // Otherwise, the target relaxation hook is called at the end of
2199 // each iteration. If the hook returns true, it means re-layout of
2200 // section is required.
2202 // The number of segments created by a linking script without a PHDRS
2203 // clause may be affected by section sizes and alignments. There is
2204 // a remote chance that relaxation causes different number of PT_LOAD
2205 // segments are created and sections are attached to different segments.
2206 // Therefore, we always throw away all segments created during section
2207 // layout. In order to be able to restart the section layout, we keep
2208 // a copy of the segment list right before the relaxation loop and use
2209 // that to restore the segments.
2211 // PASS is the current relaxation pass number.
2212 // SYMTAB is a symbol table.
2213 // PLOAD_SEG is the address of a pointer for the load segment.
2214 // PHDR_SEG is a pointer to the PHDR segment.
2215 // SEGMENT_HEADERS points to the output segment header.
2216 // FILE_HEADER points to the output file header.
2217 // PSHNDX is the address to store the output section index.
2220 Layout::relaxation_loop_body(
2223 Symbol_table
* symtab
,
2224 Output_segment
** pload_seg
,
2225 Output_segment
* phdr_seg
,
2226 Output_segment_headers
* segment_headers
,
2227 Output_file_header
* file_header
,
2228 unsigned int* pshndx
)
2230 // If this is not the first iteration, we need to clean up after
2231 // relaxation so that we can lay out the sections again.
2233 this->clean_up_after_relaxation();
2235 // If there is a SECTIONS clause, put all the input sections into
2236 // the required order.
2237 Output_segment
* load_seg
;
2238 if (this->script_options_
->saw_sections_clause())
2239 load_seg
= this->set_section_addresses_from_script(symtab
);
2240 else if (parameters
->options().relocatable())
2243 load_seg
= this->find_first_load_seg(target
);
2245 if (parameters
->options().oformat_enum()
2246 != General_options::OBJECT_FORMAT_ELF
)
2249 // If the user set the address of the text segment, that may not be
2250 // compatible with putting the segment headers and file headers into
2252 if (parameters
->options().user_set_Ttext()
2253 && parameters
->options().Ttext() % target
->common_pagesize() != 0)
2259 gold_assert(phdr_seg
== NULL
2261 || this->script_options_
->saw_sections_clause());
2263 // If the address of the load segment we found has been set by
2264 // --section-start rather than by a script, then adjust the VMA and
2265 // LMA downward if possible to include the file and section headers.
2266 uint64_t header_gap
= 0;
2267 if (load_seg
!= NULL
2268 && load_seg
->are_addresses_set()
2269 && !this->script_options_
->saw_sections_clause()
2270 && !parameters
->options().relocatable())
2272 file_header
->finalize_data_size();
2273 segment_headers
->finalize_data_size();
2274 size_t sizeof_headers
= (file_header
->data_size()
2275 + segment_headers
->data_size());
2276 const uint64_t abi_pagesize
= target
->abi_pagesize();
2277 uint64_t hdr_paddr
= load_seg
->paddr() - sizeof_headers
;
2278 hdr_paddr
&= ~(abi_pagesize
- 1);
2279 uint64_t subtract
= load_seg
->paddr() - hdr_paddr
;
2280 if (load_seg
->paddr() < subtract
|| load_seg
->vaddr() < subtract
)
2284 load_seg
->set_addresses(load_seg
->vaddr() - subtract
,
2285 load_seg
->paddr() - subtract
);
2286 header_gap
= subtract
- sizeof_headers
;
2290 // Lay out the segment headers.
2291 if (!parameters
->options().relocatable())
2293 gold_assert(segment_headers
!= NULL
);
2294 if (header_gap
!= 0 && load_seg
!= NULL
)
2296 Output_data_zero_fill
* z
= new Output_data_zero_fill(header_gap
, 1);
2297 load_seg
->add_initial_output_data(z
);
2299 if (load_seg
!= NULL
)
2300 load_seg
->add_initial_output_data(segment_headers
);
2301 if (phdr_seg
!= NULL
)
2302 phdr_seg
->add_initial_output_data(segment_headers
);
2305 // Lay out the file header.
2306 if (load_seg
!= NULL
)
2307 load_seg
->add_initial_output_data(file_header
);
2309 if (this->script_options_
->saw_phdrs_clause()
2310 && !parameters
->options().relocatable())
2312 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2313 // clause in a linker script.
2314 Script_sections
* ss
= this->script_options_
->script_sections();
2315 ss
->put_headers_in_phdrs(file_header
, segment_headers
);
2318 // We set the output section indexes in set_segment_offsets and
2319 // set_section_indexes.
2322 // Set the file offsets of all the segments, and all the sections
2325 if (!parameters
->options().relocatable())
2326 off
= this->set_segment_offsets(target
, load_seg
, pshndx
);
2328 off
= this->set_relocatable_section_offsets(file_header
, pshndx
);
2330 // Verify that the dummy relaxation does not change anything.
2331 if (is_debugging_enabled(DEBUG_RELAXATION
))
2334 this->relaxation_debug_check_
->read_sections(this->section_list_
);
2336 this->relaxation_debug_check_
->verify_sections(this->section_list_
);
2339 *pload_seg
= load_seg
;
2343 // Search the list of patterns and find the postion of the given section
2344 // name in the output section. If the section name matches a glob
2345 // pattern and a non-glob name, then the non-glob position takes
2346 // precedence. Return 0 if no match is found.
2349 Layout::find_section_order_index(const std::string
& section_name
)
2351 Unordered_map
<std::string
, unsigned int>::iterator map_it
;
2352 map_it
= this->input_section_position_
.find(section_name
);
2353 if (map_it
!= this->input_section_position_
.end())
2354 return map_it
->second
;
2356 // Absolute match failed. Linear search the glob patterns.
2357 std::vector
<std::string
>::iterator it
;
2358 for (it
= this->input_section_glob_
.begin();
2359 it
!= this->input_section_glob_
.end();
2362 if (fnmatch((*it
).c_str(), section_name
.c_str(), FNM_NOESCAPE
) == 0)
2364 map_it
= this->input_section_position_
.find(*it
);
2365 gold_assert(map_it
!= this->input_section_position_
.end());
2366 return map_it
->second
;
2372 // Read the sequence of input sections from the file specified with
2373 // option --section-ordering-file.
2376 Layout::read_layout_from_file()
2378 const char* filename
= parameters
->options().section_ordering_file();
2384 gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2385 filename
, strerror(errno
));
2387 std::getline(in
, line
); // this chops off the trailing \n, if any
2388 unsigned int position
= 1;
2389 this->set_section_ordering_specified();
2393 if (!line
.empty() && line
[line
.length() - 1] == '\r') // Windows
2394 line
.resize(line
.length() - 1);
2395 // Ignore comments, beginning with '#'
2398 std::getline(in
, line
);
2401 this->input_section_position_
[line
] = position
;
2402 // Store all glob patterns in a vector.
2403 if (is_wildcard_string(line
.c_str()))
2404 this->input_section_glob_
.push_back(line
);
2406 std::getline(in
, line
);
2410 // Finalize the layout. When this is called, we have created all the
2411 // output sections and all the output segments which are based on
2412 // input sections. We have several things to do, and we have to do
2413 // them in the right order, so that we get the right results correctly
2416 // 1) Finalize the list of output segments and create the segment
2419 // 2) Finalize the dynamic symbol table and associated sections.
2421 // 3) Determine the final file offset of all the output segments.
2423 // 4) Determine the final file offset of all the SHF_ALLOC output
2426 // 5) Create the symbol table sections and the section name table
2429 // 6) Finalize the symbol table: set symbol values to their final
2430 // value and make a final determination of which symbols are going
2431 // into the output symbol table.
2433 // 7) Create the section table header.
2435 // 8) Determine the final file offset of all the output sections which
2436 // are not SHF_ALLOC, including the section table header.
2438 // 9) Finalize the ELF file header.
2440 // This function returns the size of the output file.
2443 Layout::finalize(const Input_objects
* input_objects
, Symbol_table
* symtab
,
2444 Target
* target
, const Task
* task
)
2446 target
->finalize_sections(this, input_objects
, symtab
);
2448 this->count_local_symbols(task
, input_objects
);
2450 this->link_stabs_sections();
2452 Output_segment
* phdr_seg
= NULL
;
2453 if (!parameters
->options().relocatable() && !parameters
->doing_static_link())
2455 // There was a dynamic object in the link. We need to create
2456 // some information for the dynamic linker.
2458 // Create the PT_PHDR segment which will hold the program
2460 if (!this->script_options_
->saw_phdrs_clause())
2461 phdr_seg
= this->make_output_segment(elfcpp::PT_PHDR
, elfcpp::PF_R
);
2463 // Create the dynamic symbol table, including the hash table.
2464 Output_section
* dynstr
;
2465 std::vector
<Symbol
*> dynamic_symbols
;
2466 unsigned int local_dynamic_count
;
2467 Versions
versions(*this->script_options()->version_script_info(),
2469 this->create_dynamic_symtab(input_objects
, symtab
, &dynstr
,
2470 &local_dynamic_count
, &dynamic_symbols
,
2473 // Create the .interp section to hold the name of the
2474 // interpreter, and put it in a PT_INTERP segment. Don't do it
2475 // if we saw a .interp section in an input file.
2476 if ((!parameters
->options().shared()
2477 || parameters
->options().dynamic_linker() != NULL
)
2478 && this->interp_segment_
== NULL
)
2479 this->create_interp(target
);
2481 // Finish the .dynamic section to hold the dynamic data, and put
2482 // it in a PT_DYNAMIC segment.
2483 this->finish_dynamic_section(input_objects
, symtab
);
2485 // We should have added everything we need to the dynamic string
2487 this->dynpool_
.set_string_offsets();
2489 // Create the version sections. We can't do this until the
2490 // dynamic string table is complete.
2491 this->create_version_sections(&versions
, symtab
, local_dynamic_count
,
2492 dynamic_symbols
, dynstr
);
2494 // Set the size of the _DYNAMIC symbol. We can't do this until
2495 // after we call create_version_sections.
2496 this->set_dynamic_symbol_size(symtab
);
2499 // Create segment headers.
2500 Output_segment_headers
* segment_headers
=
2501 (parameters
->options().relocatable()
2503 : new Output_segment_headers(this->segment_list_
));
2505 // Lay out the file header.
2506 Output_file_header
* file_header
= new Output_file_header(target
, symtab
,
2509 this->special_output_list_
.push_back(file_header
);
2510 if (segment_headers
!= NULL
)
2511 this->special_output_list_
.push_back(segment_headers
);
2513 // Find approriate places for orphan output sections if we are using
2515 if (this->script_options_
->saw_sections_clause())
2516 this->place_orphan_sections_in_script();
2518 Output_segment
* load_seg
;
2523 // Take a snapshot of the section layout as needed.
2524 if (target
->may_relax())
2525 this->prepare_for_relaxation();
2527 // Run the relaxation loop to lay out sections.
2530 off
= this->relaxation_loop_body(pass
, target
, symtab
, &load_seg
,
2531 phdr_seg
, segment_headers
, file_header
,
2535 while (target
->may_relax()
2536 && target
->relax(pass
, input_objects
, symtab
, this, task
));
2538 // If there is a load segment that contains the file and program headers,
2539 // provide a symbol __ehdr_start pointing there.
2540 // A program can use this to examine itself robustly.
2541 if (load_seg
!= NULL
)
2542 symtab
->define_in_output_segment("__ehdr_start", NULL
,
2543 Symbol_table::PREDEFINED
, load_seg
, 0, 0,
2544 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
2545 elfcpp::STV_DEFAULT
, 0,
2546 Symbol::SEGMENT_START
, true);
2548 // Set the file offsets of all the non-data sections we've seen so
2549 // far which don't have to wait for the input sections. We need
2550 // this in order to finalize local symbols in non-allocated
2552 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2554 // Set the section indexes of all unallocated sections seen so far,
2555 // in case any of them are somehow referenced by a symbol.
2556 shndx
= this->set_section_indexes(shndx
);
2558 // Create the symbol table sections.
2559 this->create_symtab_sections(input_objects
, symtab
, shndx
, &off
);
2560 if (!parameters
->doing_static_link())
2561 this->assign_local_dynsym_offsets(input_objects
);
2563 // Process any symbol assignments from a linker script. This must
2564 // be called after the symbol table has been finalized.
2565 this->script_options_
->finalize_symbols(symtab
, this);
2567 // Create the incremental inputs sections.
2568 if (this->incremental_inputs_
)
2570 this->incremental_inputs_
->finalize();
2571 this->create_incremental_info_sections(symtab
);
2574 // Create the .shstrtab section.
2575 Output_section
* shstrtab_section
= this->create_shstrtab();
2577 // Set the file offsets of the rest of the non-data sections which
2578 // don't have to wait for the input sections.
2579 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2581 // Now that all sections have been created, set the section indexes
2582 // for any sections which haven't been done yet.
2583 shndx
= this->set_section_indexes(shndx
);
2585 // Create the section table header.
2586 this->create_shdrs(shstrtab_section
, &off
);
2588 // If there are no sections which require postprocessing, we can
2589 // handle the section names now, and avoid a resize later.
2590 if (!this->any_postprocessing_sections_
)
2592 off
= this->set_section_offsets(off
,
2593 POSTPROCESSING_SECTIONS_PASS
);
2595 this->set_section_offsets(off
,
2596 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
2599 file_header
->set_section_info(this->section_headers_
, shstrtab_section
);
2601 // Now we know exactly where everything goes in the output file
2602 // (except for non-allocated sections which require postprocessing).
2603 Output_data::layout_complete();
2605 this->output_file_size_
= off
;
2610 // Create a note header following the format defined in the ELF ABI.
2611 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
2612 // of the section to create, DESCSZ is the size of the descriptor.
2613 // ALLOCATE is true if the section should be allocated in memory.
2614 // This returns the new note section. It sets *TRAILING_PADDING to
2615 // the number of trailing zero bytes required.
2618 Layout::create_note(const char* name
, int note_type
,
2619 const char* section_name
, size_t descsz
,
2620 bool allocate
, size_t* trailing_padding
)
2622 // Authorities all agree that the values in a .note field should
2623 // be aligned on 4-byte boundaries for 32-bit binaries. However,
2624 // they differ on what the alignment is for 64-bit binaries.
2625 // The GABI says unambiguously they take 8-byte alignment:
2626 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2627 // Other documentation says alignment should always be 4 bytes:
2628 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2629 // GNU ld and GNU readelf both support the latter (at least as of
2630 // version 2.16.91), and glibc always generates the latter for
2631 // .note.ABI-tag (as of version 1.6), so that's the one we go with
2633 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
2634 const int size
= parameters
->target().get_size();
2636 const int size
= 32;
2639 // The contents of the .note section.
2640 size_t namesz
= strlen(name
) + 1;
2641 size_t aligned_namesz
= align_address(namesz
, size
/ 8);
2642 size_t aligned_descsz
= align_address(descsz
, size
/ 8);
2644 size_t notehdrsz
= 3 * (size
/ 8) + aligned_namesz
;
2646 unsigned char* buffer
= new unsigned char[notehdrsz
];
2647 memset(buffer
, 0, notehdrsz
);
2649 bool is_big_endian
= parameters
->target().is_big_endian();
2655 elfcpp::Swap
<32, false>::writeval(buffer
, namesz
);
2656 elfcpp::Swap
<32, false>::writeval(buffer
+ 4, descsz
);
2657 elfcpp::Swap
<32, false>::writeval(buffer
+ 8, note_type
);
2661 elfcpp::Swap
<32, true>::writeval(buffer
, namesz
);
2662 elfcpp::Swap
<32, true>::writeval(buffer
+ 4, descsz
);
2663 elfcpp::Swap
<32, true>::writeval(buffer
+ 8, note_type
);
2666 else if (size
== 64)
2670 elfcpp::Swap
<64, false>::writeval(buffer
, namesz
);
2671 elfcpp::Swap
<64, false>::writeval(buffer
+ 8, descsz
);
2672 elfcpp::Swap
<64, false>::writeval(buffer
+ 16, note_type
);
2676 elfcpp::Swap
<64, true>::writeval(buffer
, namesz
);
2677 elfcpp::Swap
<64, true>::writeval(buffer
+ 8, descsz
);
2678 elfcpp::Swap
<64, true>::writeval(buffer
+ 16, note_type
);
2684 memcpy(buffer
+ 3 * (size
/ 8), name
, namesz
);
2686 elfcpp::Elf_Xword flags
= 0;
2687 Output_section_order order
= ORDER_INVALID
;
2690 flags
= elfcpp::SHF_ALLOC
;
2691 order
= ORDER_RO_NOTE
;
2693 Output_section
* os
= this->choose_output_section(NULL
, section_name
,
2695 flags
, false, order
, false);
2699 Output_section_data
* posd
= new Output_data_const_buffer(buffer
, notehdrsz
,
2702 os
->add_output_section_data(posd
);
2704 *trailing_padding
= aligned_descsz
- descsz
;
2709 // For an executable or shared library, create a note to record the
2710 // version of gold used to create the binary.
2713 Layout::create_gold_note()
2715 if (parameters
->options().relocatable()
2716 || parameters
->incremental_update())
2719 std::string desc
= std::string("gold ") + gold::get_version_string();
2721 size_t trailing_padding
;
2722 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION
,
2723 ".note.gnu.gold-version", desc
.size(),
2724 false, &trailing_padding
);
2728 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2729 os
->add_output_section_data(posd
);
2731 if (trailing_padding
> 0)
2733 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2734 os
->add_output_section_data(posd
);
2738 // Record whether the stack should be executable. This can be set
2739 // from the command line using the -z execstack or -z noexecstack
2740 // options. Otherwise, if any input file has a .note.GNU-stack
2741 // section with the SHF_EXECINSTR flag set, the stack should be
2742 // executable. Otherwise, if at least one input file a
2743 // .note.GNU-stack section, and some input file has no .note.GNU-stack
2744 // section, we use the target default for whether the stack should be
2745 // executable. Otherwise, we don't generate a stack note. When
2746 // generating a object file, we create a .note.GNU-stack section with
2747 // the appropriate marking. When generating an executable or shared
2748 // library, we create a PT_GNU_STACK segment.
2751 Layout::create_executable_stack_info()
2753 bool is_stack_executable
;
2754 if (parameters
->options().is_execstack_set())
2755 is_stack_executable
= parameters
->options().is_stack_executable();
2756 else if (!this->input_with_gnu_stack_note_
)
2760 if (this->input_requires_executable_stack_
)
2761 is_stack_executable
= true;
2762 else if (this->input_without_gnu_stack_note_
)
2763 is_stack_executable
=
2764 parameters
->target().is_default_stack_executable();
2766 is_stack_executable
= false;
2769 if (parameters
->options().relocatable())
2771 const char* name
= this->namepool_
.add(".note.GNU-stack", false, NULL
);
2772 elfcpp::Elf_Xword flags
= 0;
2773 if (is_stack_executable
)
2774 flags
|= elfcpp::SHF_EXECINSTR
;
2775 this->make_output_section(name
, elfcpp::SHT_PROGBITS
, flags
,
2776 ORDER_INVALID
, false);
2780 if (this->script_options_
->saw_phdrs_clause())
2782 int flags
= elfcpp::PF_R
| elfcpp::PF_W
;
2783 if (is_stack_executable
)
2784 flags
|= elfcpp::PF_X
;
2785 this->make_output_segment(elfcpp::PT_GNU_STACK
, flags
);
2789 // If --build-id was used, set up the build ID note.
2792 Layout::create_build_id()
2794 if (!parameters
->options().user_set_build_id())
2797 const char* style
= parameters
->options().build_id();
2798 if (strcmp(style
, "none") == 0)
2801 // Set DESCSZ to the size of the note descriptor. When possible,
2802 // set DESC to the note descriptor contents.
2805 if (strcmp(style
, "md5") == 0)
2807 else if (strcmp(style
, "sha1") == 0)
2809 else if (strcmp(style
, "uuid") == 0)
2811 const size_t uuidsz
= 128 / 8;
2813 char buffer
[uuidsz
];
2814 memset(buffer
, 0, uuidsz
);
2816 int descriptor
= open_descriptor(-1, "/dev/urandom", O_RDONLY
);
2818 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
2822 ssize_t got
= ::read(descriptor
, buffer
, uuidsz
);
2823 release_descriptor(descriptor
, true);
2825 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno
));
2826 else if (static_cast<size_t>(got
) != uuidsz
)
2827 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
2831 desc
.assign(buffer
, uuidsz
);
2834 else if (strncmp(style
, "0x", 2) == 0)
2837 const char* p
= style
+ 2;
2840 if (hex_p(p
[0]) && hex_p(p
[1]))
2842 char c
= (hex_value(p
[0]) << 4) | hex_value(p
[1]);
2846 else if (*p
== '-' || *p
== ':')
2849 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
2852 descsz
= desc
.size();
2855 gold_fatal(_("unrecognized --build-id argument '%s'"), style
);
2858 size_t trailing_padding
;
2859 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID
,
2860 ".note.gnu.build-id", descsz
, true,
2867 // We know the value already, so we fill it in now.
2868 gold_assert(desc
.size() == descsz
);
2870 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2871 os
->add_output_section_data(posd
);
2873 if (trailing_padding
!= 0)
2875 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2876 os
->add_output_section_data(posd
);
2881 // We need to compute a checksum after we have completed the
2883 gold_assert(trailing_padding
== 0);
2884 this->build_id_note_
= new Output_data_zero_fill(descsz
, 4);
2885 os
->add_output_section_data(this->build_id_note_
);
2889 // If we have both .stabXX and .stabXXstr sections, then the sh_link
2890 // field of the former should point to the latter. I'm not sure who
2891 // started this, but the GNU linker does it, and some tools depend
2895 Layout::link_stabs_sections()
2897 if (!this->have_stabstr_section_
)
2900 for (Section_list::iterator p
= this->section_list_
.begin();
2901 p
!= this->section_list_
.end();
2904 if ((*p
)->type() != elfcpp::SHT_STRTAB
)
2907 const char* name
= (*p
)->name();
2908 if (strncmp(name
, ".stab", 5) != 0)
2911 size_t len
= strlen(name
);
2912 if (strcmp(name
+ len
- 3, "str") != 0)
2915 std::string
stab_name(name
, len
- 3);
2916 Output_section
* stab_sec
;
2917 stab_sec
= this->find_output_section(stab_name
.c_str());
2918 if (stab_sec
!= NULL
)
2919 stab_sec
->set_link_section(*p
);
2923 // Create .gnu_incremental_inputs and related sections needed
2924 // for the next run of incremental linking to check what has changed.
2927 Layout::create_incremental_info_sections(Symbol_table
* symtab
)
2929 Incremental_inputs
* incr
= this->incremental_inputs_
;
2931 gold_assert(incr
!= NULL
);
2933 // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
2934 incr
->create_data_sections(symtab
);
2936 // Add the .gnu_incremental_inputs section.
2937 const char* incremental_inputs_name
=
2938 this->namepool_
.add(".gnu_incremental_inputs", false, NULL
);
2939 Output_section
* incremental_inputs_os
=
2940 this->make_output_section(incremental_inputs_name
,
2941 elfcpp::SHT_GNU_INCREMENTAL_INPUTS
, 0,
2942 ORDER_INVALID
, false);
2943 incremental_inputs_os
->add_output_section_data(incr
->inputs_section());
2945 // Add the .gnu_incremental_symtab section.
2946 const char* incremental_symtab_name
=
2947 this->namepool_
.add(".gnu_incremental_symtab", false, NULL
);
2948 Output_section
* incremental_symtab_os
=
2949 this->make_output_section(incremental_symtab_name
,
2950 elfcpp::SHT_GNU_INCREMENTAL_SYMTAB
, 0,
2951 ORDER_INVALID
, false);
2952 incremental_symtab_os
->add_output_section_data(incr
->symtab_section());
2953 incremental_symtab_os
->set_entsize(4);
2955 // Add the .gnu_incremental_relocs section.
2956 const char* incremental_relocs_name
=
2957 this->namepool_
.add(".gnu_incremental_relocs", false, NULL
);
2958 Output_section
* incremental_relocs_os
=
2959 this->make_output_section(incremental_relocs_name
,
2960 elfcpp::SHT_GNU_INCREMENTAL_RELOCS
, 0,
2961 ORDER_INVALID
, false);
2962 incremental_relocs_os
->add_output_section_data(incr
->relocs_section());
2963 incremental_relocs_os
->set_entsize(incr
->relocs_entsize());
2965 // Add the .gnu_incremental_got_plt section.
2966 const char* incremental_got_plt_name
=
2967 this->namepool_
.add(".gnu_incremental_got_plt", false, NULL
);
2968 Output_section
* incremental_got_plt_os
=
2969 this->make_output_section(incremental_got_plt_name
,
2970 elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT
, 0,
2971 ORDER_INVALID
, false);
2972 incremental_got_plt_os
->add_output_section_data(incr
->got_plt_section());
2974 // Add the .gnu_incremental_strtab section.
2975 const char* incremental_strtab_name
=
2976 this->namepool_
.add(".gnu_incremental_strtab", false, NULL
);
2977 Output_section
* incremental_strtab_os
= this->make_output_section(incremental_strtab_name
,
2978 elfcpp::SHT_STRTAB
, 0,
2979 ORDER_INVALID
, false);
2980 Output_data_strtab
* strtab_data
=
2981 new Output_data_strtab(incr
->get_stringpool());
2982 incremental_strtab_os
->add_output_section_data(strtab_data
);
2984 incremental_inputs_os
->set_after_input_sections();
2985 incremental_symtab_os
->set_after_input_sections();
2986 incremental_relocs_os
->set_after_input_sections();
2987 incremental_got_plt_os
->set_after_input_sections();
2989 incremental_inputs_os
->set_link_section(incremental_strtab_os
);
2990 incremental_symtab_os
->set_link_section(incremental_inputs_os
);
2991 incremental_relocs_os
->set_link_section(incremental_inputs_os
);
2992 incremental_got_plt_os
->set_link_section(incremental_inputs_os
);
2995 // Return whether SEG1 should be before SEG2 in the output file. This
2996 // is based entirely on the segment type and flags. When this is
2997 // called the segment addresses have normally not yet been set.
3000 Layout::segment_precedes(const Output_segment
* seg1
,
3001 const Output_segment
* seg2
)
3003 elfcpp::Elf_Word type1
= seg1
->type();
3004 elfcpp::Elf_Word type2
= seg2
->type();
3006 // The single PT_PHDR segment is required to precede any loadable
3007 // segment. We simply make it always first.
3008 if (type1
== elfcpp::PT_PHDR
)
3010 gold_assert(type2
!= elfcpp::PT_PHDR
);
3013 if (type2
== elfcpp::PT_PHDR
)
3016 // The single PT_INTERP segment is required to precede any loadable
3017 // segment. We simply make it always second.
3018 if (type1
== elfcpp::PT_INTERP
)
3020 gold_assert(type2
!= elfcpp::PT_INTERP
);
3023 if (type2
== elfcpp::PT_INTERP
)
3026 // We then put PT_LOAD segments before any other segments.
3027 if (type1
== elfcpp::PT_LOAD
&& type2
!= elfcpp::PT_LOAD
)
3029 if (type2
== elfcpp::PT_LOAD
&& type1
!= elfcpp::PT_LOAD
)
3032 // We put the PT_TLS segment last except for the PT_GNU_RELRO
3033 // segment, because that is where the dynamic linker expects to find
3034 // it (this is just for efficiency; other positions would also work
3036 if (type1
== elfcpp::PT_TLS
3037 && type2
!= elfcpp::PT_TLS
3038 && type2
!= elfcpp::PT_GNU_RELRO
)
3040 if (type2
== elfcpp::PT_TLS
3041 && type1
!= elfcpp::PT_TLS
3042 && type1
!= elfcpp::PT_GNU_RELRO
)
3045 // We put the PT_GNU_RELRO segment last, because that is where the
3046 // dynamic linker expects to find it (as with PT_TLS, this is just
3048 if (type1
== elfcpp::PT_GNU_RELRO
&& type2
!= elfcpp::PT_GNU_RELRO
)
3050 if (type2
== elfcpp::PT_GNU_RELRO
&& type1
!= elfcpp::PT_GNU_RELRO
)
3053 const elfcpp::Elf_Word flags1
= seg1
->flags();
3054 const elfcpp::Elf_Word flags2
= seg2
->flags();
3056 // The order of non-PT_LOAD segments is unimportant. We simply sort
3057 // by the numeric segment type and flags values. There should not
3058 // be more than one segment with the same type and flags.
3059 if (type1
!= elfcpp::PT_LOAD
)
3062 return type1
< type2
;
3063 gold_assert(flags1
!= flags2
);
3064 return flags1
< flags2
;
3067 // If the addresses are set already, sort by load address.
3068 if (seg1
->are_addresses_set())
3070 if (!seg2
->are_addresses_set())
3073 unsigned int section_count1
= seg1
->output_section_count();
3074 unsigned int section_count2
= seg2
->output_section_count();
3075 if (section_count1
== 0 && section_count2
> 0)
3077 if (section_count1
> 0 && section_count2
== 0)
3080 uint64_t paddr1
= (seg1
->are_addresses_set()
3082 : seg1
->first_section_load_address());
3083 uint64_t paddr2
= (seg2
->are_addresses_set()
3085 : seg2
->first_section_load_address());
3087 if (paddr1
!= paddr2
)
3088 return paddr1
< paddr2
;
3090 else if (seg2
->are_addresses_set())
3093 // A segment which holds large data comes after a segment which does
3094 // not hold large data.
3095 if (seg1
->is_large_data_segment())
3097 if (!seg2
->is_large_data_segment())
3100 else if (seg2
->is_large_data_segment())
3103 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
3104 // segments come before writable segments. Then writable segments
3105 // with data come before writable segments without data. Then
3106 // executable segments come before non-executable segments. Then
3107 // the unlikely case of a non-readable segment comes before the
3108 // normal case of a readable segment. If there are multiple
3109 // segments with the same type and flags, we require that the
3110 // address be set, and we sort by virtual address and then physical
3112 if ((flags1
& elfcpp::PF_W
) != (flags2
& elfcpp::PF_W
))
3113 return (flags1
& elfcpp::PF_W
) == 0;
3114 if ((flags1
& elfcpp::PF_W
) != 0
3115 && seg1
->has_any_data_sections() != seg2
->has_any_data_sections())
3116 return seg1
->has_any_data_sections();
3117 if ((flags1
& elfcpp::PF_X
) != (flags2
& elfcpp::PF_X
))
3118 return (flags1
& elfcpp::PF_X
) != 0;
3119 if ((flags1
& elfcpp::PF_R
) != (flags2
& elfcpp::PF_R
))
3120 return (flags1
& elfcpp::PF_R
) == 0;
3122 // We shouldn't get here--we shouldn't create segments which we
3123 // can't distinguish. Unless of course we are using a weird linker
3124 // script or overlapping --section-start options.
3125 gold_assert(this->script_options_
->saw_phdrs_clause()
3126 || parameters
->options().any_section_start());
3130 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
3133 align_file_offset(off_t off
, uint64_t addr
, uint64_t abi_pagesize
)
3135 uint64_t unsigned_off
= off
;
3136 uint64_t aligned_off
= ((unsigned_off
& ~(abi_pagesize
- 1))
3137 | (addr
& (abi_pagesize
- 1)));
3138 if (aligned_off
< unsigned_off
)
3139 aligned_off
+= abi_pagesize
;
3143 // Set the file offsets of all the segments, and all the sections they
3144 // contain. They have all been created. LOAD_SEG must be be laid out
3145 // first. Return the offset of the data to follow.
3148 Layout::set_segment_offsets(const Target
* target
, Output_segment
* load_seg
,
3149 unsigned int* pshndx
)
3151 // Sort them into the final order. We use a stable sort so that we
3152 // don't randomize the order of indistinguishable segments created
3153 // by linker scripts.
3154 std::stable_sort(this->segment_list_
.begin(), this->segment_list_
.end(),
3155 Layout::Compare_segments(this));
3157 // Find the PT_LOAD segments, and set their addresses and offsets
3158 // and their section's addresses and offsets.
3159 uint64_t start_addr
;
3160 if (parameters
->options().user_set_Ttext())
3161 start_addr
= parameters
->options().Ttext();
3162 else if (parameters
->options().output_is_position_independent())
3165 start_addr
= target
->default_text_segment_address();
3167 uint64_t addr
= start_addr
;
3170 // If LOAD_SEG is NULL, then the file header and segment headers
3171 // will not be loadable. But they still need to be at offset 0 in
3172 // the file. Set their offsets now.
3173 if (load_seg
== NULL
)
3175 for (Data_list::iterator p
= this->special_output_list_
.begin();
3176 p
!= this->special_output_list_
.end();
3179 off
= align_address(off
, (*p
)->addralign());
3180 (*p
)->set_address_and_file_offset(0, off
);
3181 off
+= (*p
)->data_size();
3185 unsigned int increase_relro
= this->increase_relro_
;
3186 if (this->script_options_
->saw_sections_clause())
3189 const bool check_sections
= parameters
->options().check_sections();
3190 Output_segment
* last_load_segment
= NULL
;
3192 unsigned int shndx_begin
= *pshndx
;
3193 unsigned int shndx_load_seg
= *pshndx
;
3195 for (Segment_list::iterator p
= this->segment_list_
.begin();
3196 p
!= this->segment_list_
.end();
3199 if ((*p
)->type() == elfcpp::PT_LOAD
)
3201 if (target
->isolate_execinstr())
3203 // When we hit the segment that should contain the
3204 // file headers, reset the file offset so we place
3205 // it and subsequent segments appropriately.
3206 // We'll fix up the preceding segments below.
3214 shndx_load_seg
= *pshndx
;
3220 // Verify that the file headers fall into the first segment.
3221 if (load_seg
!= NULL
&& load_seg
!= *p
)
3226 bool are_addresses_set
= (*p
)->are_addresses_set();
3227 if (are_addresses_set
)
3229 // When it comes to setting file offsets, we care about
3230 // the physical address.
3231 addr
= (*p
)->paddr();
3233 else if (parameters
->options().user_set_Ttext()
3234 && ((*p
)->flags() & elfcpp::PF_W
) == 0)
3236 are_addresses_set
= true;
3238 else if (parameters
->options().user_set_Tdata()
3239 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3240 && (!parameters
->options().user_set_Tbss()
3241 || (*p
)->has_any_data_sections()))
3243 addr
= parameters
->options().Tdata();
3244 are_addresses_set
= true;
3246 else if (parameters
->options().user_set_Tbss()
3247 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3248 && !(*p
)->has_any_data_sections())
3250 addr
= parameters
->options().Tbss();
3251 are_addresses_set
= true;
3254 uint64_t orig_addr
= addr
;
3255 uint64_t orig_off
= off
;
3257 uint64_t aligned_addr
= 0;
3258 uint64_t abi_pagesize
= target
->abi_pagesize();
3259 uint64_t common_pagesize
= target
->common_pagesize();
3261 if (!parameters
->options().nmagic()
3262 && !parameters
->options().omagic())
3263 (*p
)->set_minimum_p_align(common_pagesize
);
3265 if (!are_addresses_set
)
3267 // Skip the address forward one page, maintaining the same
3268 // position within the page. This lets us store both segments
3269 // overlapping on a single page in the file, but the loader will
3270 // put them on different pages in memory. We will revisit this
3271 // decision once we know the size of the segment.
3273 addr
= align_address(addr
, (*p
)->maximum_alignment());
3274 aligned_addr
= addr
;
3278 // This is the segment that will contain the file
3279 // headers, so its offset will have to be exactly zero.
3280 gold_assert(orig_off
== 0);
3282 // If the target wants a fixed minimum distance from the
3283 // text segment to the read-only segment, move up now.
3284 uint64_t min_addr
= start_addr
+ target
->rosegment_gap();
3285 if (addr
< min_addr
)
3288 // But this is not the first segment! To make its
3289 // address congruent with its offset, that address better
3290 // be aligned to the ABI-mandated page size.
3291 addr
= align_address(addr
, abi_pagesize
);
3292 aligned_addr
= addr
;
3296 if ((addr
& (abi_pagesize
- 1)) != 0)
3297 addr
= addr
+ abi_pagesize
;
3299 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3303 if (!parameters
->options().nmagic()
3304 && !parameters
->options().omagic())
3305 off
= align_file_offset(off
, addr
, abi_pagesize
);
3308 // This is -N or -n with a section script which prevents
3309 // us from using a load segment. We need to ensure that
3310 // the file offset is aligned to the alignment of the
3311 // segment. This is because the linker script
3312 // implicitly assumed a zero offset. If we don't align
3313 // here, then the alignment of the sections in the
3314 // linker script may not match the alignment of the
3315 // sections in the set_section_addresses call below,
3316 // causing an error about dot moving backward.
3317 off
= align_address(off
, (*p
)->maximum_alignment());
3320 unsigned int shndx_hold
= *pshndx
;
3321 bool has_relro
= false;
3322 uint64_t new_addr
= (*p
)->set_section_addresses(this, false, addr
,
3327 // Now that we know the size of this segment, we may be able
3328 // to save a page in memory, at the cost of wasting some
3329 // file space, by instead aligning to the start of a new
3330 // page. Here we use the real machine page size rather than
3331 // the ABI mandated page size. If the segment has been
3332 // aligned so that the relro data ends at a page boundary,
3333 // we do not try to realign it.
3335 if (!are_addresses_set
3337 && aligned_addr
!= addr
3338 && !parameters
->incremental())
3340 uint64_t first_off
= (common_pagesize
3342 & (common_pagesize
- 1)));
3343 uint64_t last_off
= new_addr
& (common_pagesize
- 1);
3346 && ((aligned_addr
& ~ (common_pagesize
- 1))
3347 != (new_addr
& ~ (common_pagesize
- 1)))
3348 && first_off
+ last_off
<= common_pagesize
)
3350 *pshndx
= shndx_hold
;
3351 addr
= align_address(aligned_addr
, common_pagesize
);
3352 addr
= align_address(addr
, (*p
)->maximum_alignment());
3353 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3354 off
= align_file_offset(off
, addr
, abi_pagesize
);
3356 increase_relro
= this->increase_relro_
;
3357 if (this->script_options_
->saw_sections_clause())
3361 new_addr
= (*p
)->set_section_addresses(this, true, addr
,
3370 // Implement --check-sections. We know that the segments
3371 // are sorted by LMA.
3372 if (check_sections
&& last_load_segment
!= NULL
)
3374 gold_assert(last_load_segment
->paddr() <= (*p
)->paddr());
3375 if (last_load_segment
->paddr() + last_load_segment
->memsz()
3378 unsigned long long lb1
= last_load_segment
->paddr();
3379 unsigned long long le1
= lb1
+ last_load_segment
->memsz();
3380 unsigned long long lb2
= (*p
)->paddr();
3381 unsigned long long le2
= lb2
+ (*p
)->memsz();
3382 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3383 "[0x%llx -> 0x%llx]"),
3384 lb1
, le1
, lb2
, le2
);
3387 last_load_segment
= *p
;
3391 if (load_seg
!= NULL
&& target
->isolate_execinstr())
3393 // Process the early segments again, setting their file offsets
3394 // so they land after the segments starting at LOAD_SEG.
3395 off
= align_file_offset(off
, 0, target
->abi_pagesize());
3397 for (Segment_list::iterator p
= this->segment_list_
.begin();
3401 if ((*p
)->type() == elfcpp::PT_LOAD
)
3403 // We repeat the whole job of assigning addresses and
3404 // offsets, but we really only want to change the offsets and
3405 // must ensure that the addresses all come out the same as
3406 // they did the first time through.
3407 bool has_relro
= false;
3408 const uint64_t old_addr
= (*p
)->vaddr();
3409 const uint64_t old_end
= old_addr
+ (*p
)->memsz();
3410 uint64_t new_addr
= (*p
)->set_section_addresses(this, true,
3416 gold_assert(new_addr
== old_end
);
3420 gold_assert(shndx_begin
== shndx_load_seg
);
3423 // Handle the non-PT_LOAD segments, setting their offsets from their
3424 // section's offsets.
3425 for (Segment_list::iterator p
= this->segment_list_
.begin();
3426 p
!= this->segment_list_
.end();
3429 if ((*p
)->type() != elfcpp::PT_LOAD
)
3430 (*p
)->set_offset((*p
)->type() == elfcpp::PT_GNU_RELRO
3435 // Set the TLS offsets for each section in the PT_TLS segment.
3436 if (this->tls_segment_
!= NULL
)
3437 this->tls_segment_
->set_tls_offsets();
3442 // Set the offsets of all the allocated sections when doing a
3443 // relocatable link. This does the same jobs as set_segment_offsets,
3444 // only for a relocatable link.
3447 Layout::set_relocatable_section_offsets(Output_data
* file_header
,
3448 unsigned int* pshndx
)
3452 file_header
->set_address_and_file_offset(0, 0);
3453 off
+= file_header
->data_size();
3455 for (Section_list::iterator p
= this->section_list_
.begin();
3456 p
!= this->section_list_
.end();
3459 // We skip unallocated sections here, except that group sections
3460 // have to come first.
3461 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) == 0
3462 && (*p
)->type() != elfcpp::SHT_GROUP
)
3465 off
= align_address(off
, (*p
)->addralign());
3467 // The linker script might have set the address.
3468 if (!(*p
)->is_address_valid())
3469 (*p
)->set_address(0);
3470 (*p
)->set_file_offset(off
);
3471 (*p
)->finalize_data_size();
3472 off
+= (*p
)->data_size();
3474 (*p
)->set_out_shndx(*pshndx
);
3481 // Set the file offset of all the sections not associated with a
3485 Layout::set_section_offsets(off_t off
, Layout::Section_offset_pass pass
)
3487 off_t startoff
= off
;
3490 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3491 p
!= this->unattached_section_list_
.end();
3494 // The symtab section is handled in create_symtab_sections.
3495 if (*p
== this->symtab_section_
)
3498 // If we've already set the data size, don't set it again.
3499 if ((*p
)->is_offset_valid() && (*p
)->is_data_size_valid())
3502 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3503 && (*p
)->requires_postprocessing())
3505 (*p
)->create_postprocessing_buffer();
3506 this->any_postprocessing_sections_
= true;
3509 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3510 && (*p
)->after_input_sections())
3512 else if (pass
== POSTPROCESSING_SECTIONS_PASS
3513 && (!(*p
)->after_input_sections()
3514 || (*p
)->type() == elfcpp::SHT_STRTAB
))
3516 else if (pass
== STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
3517 && (!(*p
)->after_input_sections()
3518 || (*p
)->type() != elfcpp::SHT_STRTAB
))
3521 if (!parameters
->incremental_update())
3523 off
= align_address(off
, (*p
)->addralign());
3524 (*p
)->set_file_offset(off
);
3525 (*p
)->finalize_data_size();
3529 // Incremental update: allocate file space from free list.
3530 (*p
)->pre_finalize_data_size();
3531 off_t current_size
= (*p
)->current_data_size();
3532 off
= this->allocate(current_size
, (*p
)->addralign(), startoff
);
3535 if (is_debugging_enabled(DEBUG_INCREMENTAL
))
3536 this->free_list_
.dump();
3537 gold_assert((*p
)->output_section() != NULL
);
3538 gold_fallback(_("out of patch space for section %s; "
3539 "relink with --incremental-full"),
3540 (*p
)->output_section()->name());
3542 (*p
)->set_file_offset(off
);
3543 (*p
)->finalize_data_size();
3544 if ((*p
)->data_size() > current_size
)
3546 gold_assert((*p
)->output_section() != NULL
);
3547 gold_fallback(_("%s: section changed size; "
3548 "relink with --incremental-full"),
3549 (*p
)->output_section()->name());
3551 gold_debug(DEBUG_INCREMENTAL
,
3552 "set_section_offsets: %08lx %08lx %s",
3553 static_cast<long>(off
),
3554 static_cast<long>((*p
)->data_size()),
3555 ((*p
)->output_section() != NULL
3556 ? (*p
)->output_section()->name() : "(special)"));
3559 off
+= (*p
)->data_size();
3563 // At this point the name must be set.
3564 if (pass
!= STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
)
3565 this->namepool_
.add((*p
)->name(), false, NULL
);
3570 // Set the section indexes of all the sections not associated with a
3574 Layout::set_section_indexes(unsigned int shndx
)
3576 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3577 p
!= this->unattached_section_list_
.end();
3580 if (!(*p
)->has_out_shndx())
3582 (*p
)->set_out_shndx(shndx
);
3589 // Set the section addresses according to the linker script. This is
3590 // only called when we see a SECTIONS clause. This returns the
3591 // program segment which should hold the file header and segment
3592 // headers, if any. It will return NULL if they should not be in a
3596 Layout::set_section_addresses_from_script(Symbol_table
* symtab
)
3598 Script_sections
* ss
= this->script_options_
->script_sections();
3599 gold_assert(ss
->saw_sections_clause());
3600 return this->script_options_
->set_section_addresses(symtab
, this);
3603 // Place the orphan sections in the linker script.
3606 Layout::place_orphan_sections_in_script()
3608 Script_sections
* ss
= this->script_options_
->script_sections();
3609 gold_assert(ss
->saw_sections_clause());
3611 // Place each orphaned output section in the script.
3612 for (Section_list::iterator p
= this->section_list_
.begin();
3613 p
!= this->section_list_
.end();
3616 if (!(*p
)->found_in_sections_clause())
3617 ss
->place_orphan(*p
);
3621 // Count the local symbols in the regular symbol table and the dynamic
3622 // symbol table, and build the respective string pools.
3625 Layout::count_local_symbols(const Task
* task
,
3626 const Input_objects
* input_objects
)
3628 // First, figure out an upper bound on the number of symbols we'll
3629 // be inserting into each pool. This helps us create the pools with
3630 // the right size, to avoid unnecessary hashtable resizing.
3631 unsigned int symbol_count
= 0;
3632 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3633 p
!= input_objects
->relobj_end();
3635 symbol_count
+= (*p
)->local_symbol_count();
3637 // Go from "upper bound" to "estimate." We overcount for two
3638 // reasons: we double-count symbols that occur in more than one
3639 // object file, and we count symbols that are dropped from the
3640 // output. Add it all together and assume we overcount by 100%.
3643 // We assume all symbols will go into both the sympool and dynpool.
3644 this->sympool_
.reserve(symbol_count
);
3645 this->dynpool_
.reserve(symbol_count
);
3647 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3648 p
!= input_objects
->relobj_end();
3651 Task_lock_obj
<Object
> tlo(task
, *p
);
3652 (*p
)->count_local_symbols(&this->sympool_
, &this->dynpool_
);
3656 // Create the symbol table sections. Here we also set the final
3657 // values of the symbols. At this point all the loadable sections are
3658 // fully laid out. SHNUM is the number of sections so far.
3661 Layout::create_symtab_sections(const Input_objects
* input_objects
,
3662 Symbol_table
* symtab
,
3668 if (parameters
->target().get_size() == 32)
3670 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
3673 else if (parameters
->target().get_size() == 64)
3675 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
3681 // Compute file offsets relative to the start of the symtab section.
3684 // Save space for the dummy symbol at the start of the section. We
3685 // never bother to write this out--it will just be left as zero.
3687 unsigned int local_symbol_index
= 1;
3689 // Add STT_SECTION symbols for each Output section which needs one.
3690 for (Section_list::iterator p
= this->section_list_
.begin();
3691 p
!= this->section_list_
.end();
3694 if (!(*p
)->needs_symtab_index())
3695 (*p
)->set_symtab_index(-1U);
3698 (*p
)->set_symtab_index(local_symbol_index
);
3699 ++local_symbol_index
;
3704 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3705 p
!= input_objects
->relobj_end();
3708 unsigned int index
= (*p
)->finalize_local_symbols(local_symbol_index
,
3710 off
+= (index
- local_symbol_index
) * symsize
;
3711 local_symbol_index
= index
;
3714 unsigned int local_symcount
= local_symbol_index
;
3715 gold_assert(static_cast<off_t
>(local_symcount
* symsize
) == off
);
3718 size_t dyn_global_index
;
3720 if (this->dynsym_section_
== NULL
)
3723 dyn_global_index
= 0;
3728 dyn_global_index
= this->dynsym_section_
->info();
3729 off_t locsize
= dyn_global_index
* this->dynsym_section_
->entsize();
3730 dynoff
= this->dynsym_section_
->offset() + locsize
;
3731 dyncount
= (this->dynsym_section_
->data_size() - locsize
) / symsize
;
3732 gold_assert(static_cast<off_t
>(dyncount
* symsize
)
3733 == this->dynsym_section_
->data_size() - locsize
);
3736 off_t global_off
= off
;
3737 off
= symtab
->finalize(off
, dynoff
, dyn_global_index
, dyncount
,
3738 &this->sympool_
, &local_symcount
);
3740 if (!parameters
->options().strip_all())
3742 this->sympool_
.set_string_offsets();
3744 const char* symtab_name
= this->namepool_
.add(".symtab", false, NULL
);
3745 Output_section
* osymtab
= this->make_output_section(symtab_name
,
3749 this->symtab_section_
= osymtab
;
3751 Output_section_data
* pos
= new Output_data_fixed_space(off
, align
,
3753 osymtab
->add_output_section_data(pos
);
3755 // We generate a .symtab_shndx section if we have more than
3756 // SHN_LORESERVE sections. Technically it is possible that we
3757 // don't need one, because it is possible that there are no
3758 // symbols in any of sections with indexes larger than
3759 // SHN_LORESERVE. That is probably unusual, though, and it is
3760 // easier to always create one than to compute section indexes
3761 // twice (once here, once when writing out the symbols).
3762 if (shnum
>= elfcpp::SHN_LORESERVE
)
3764 const char* symtab_xindex_name
= this->namepool_
.add(".symtab_shndx",
3766 Output_section
* osymtab_xindex
=
3767 this->make_output_section(symtab_xindex_name
,
3768 elfcpp::SHT_SYMTAB_SHNDX
, 0,
3769 ORDER_INVALID
, false);
3771 size_t symcount
= off
/ symsize
;
3772 this->symtab_xindex_
= new Output_symtab_xindex(symcount
);
3774 osymtab_xindex
->add_output_section_data(this->symtab_xindex_
);
3776 osymtab_xindex
->set_link_section(osymtab
);
3777 osymtab_xindex
->set_addralign(4);
3778 osymtab_xindex
->set_entsize(4);
3780 osymtab_xindex
->set_after_input_sections();
3782 // This tells the driver code to wait until the symbol table
3783 // has written out before writing out the postprocessing
3784 // sections, including the .symtab_shndx section.
3785 this->any_postprocessing_sections_
= true;
3788 const char* strtab_name
= this->namepool_
.add(".strtab", false, NULL
);
3789 Output_section
* ostrtab
= this->make_output_section(strtab_name
,
3794 Output_section_data
* pstr
= new Output_data_strtab(&this->sympool_
);
3795 ostrtab
->add_output_section_data(pstr
);
3798 if (!parameters
->incremental_update())
3799 symtab_off
= align_address(*poff
, align
);
3802 symtab_off
= this->allocate(off
, align
, *poff
);
3804 gold_fallback(_("out of patch space for symbol table; "
3805 "relink with --incremental-full"));
3806 gold_debug(DEBUG_INCREMENTAL
,
3807 "create_symtab_sections: %08lx %08lx .symtab",
3808 static_cast<long>(symtab_off
),
3809 static_cast<long>(off
));
3812 symtab
->set_file_offset(symtab_off
+ global_off
);
3813 osymtab
->set_file_offset(symtab_off
);
3814 osymtab
->finalize_data_size();
3815 osymtab
->set_link_section(ostrtab
);
3816 osymtab
->set_info(local_symcount
);
3817 osymtab
->set_entsize(symsize
);
3819 if (symtab_off
+ off
> *poff
)
3820 *poff
= symtab_off
+ off
;
3824 // Create the .shstrtab section, which holds the names of the
3825 // sections. At the time this is called, we have created all the
3826 // output sections except .shstrtab itself.
3829 Layout::create_shstrtab()
3831 // FIXME: We don't need to create a .shstrtab section if we are
3832 // stripping everything.
3834 const char* name
= this->namepool_
.add(".shstrtab", false, NULL
);
3836 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_STRTAB
, 0,
3837 ORDER_INVALID
, false);
3839 if (strcmp(parameters
->options().compress_debug_sections(), "none") != 0)
3841 // We can't write out this section until we've set all the
3842 // section names, and we don't set the names of compressed
3843 // output sections until relocations are complete. FIXME: With
3844 // the current names we use, this is unnecessary.
3845 os
->set_after_input_sections();
3848 Output_section_data
* posd
= new Output_data_strtab(&this->namepool_
);
3849 os
->add_output_section_data(posd
);
3854 // Create the section headers. SIZE is 32 or 64. OFF is the file
3858 Layout::create_shdrs(const Output_section
* shstrtab_section
, off_t
* poff
)
3860 Output_section_headers
* oshdrs
;
3861 oshdrs
= new Output_section_headers(this,
3862 &this->segment_list_
,
3863 &this->section_list_
,
3864 &this->unattached_section_list_
,
3868 if (!parameters
->incremental_update())
3869 off
= align_address(*poff
, oshdrs
->addralign());
3872 oshdrs
->pre_finalize_data_size();
3873 off
= this->allocate(oshdrs
->data_size(), oshdrs
->addralign(), *poff
);
3875 gold_fallback(_("out of patch space for section header table; "
3876 "relink with --incremental-full"));
3877 gold_debug(DEBUG_INCREMENTAL
,
3878 "create_shdrs: %08lx %08lx (section header table)",
3879 static_cast<long>(off
),
3880 static_cast<long>(off
+ oshdrs
->data_size()));
3882 oshdrs
->set_address_and_file_offset(0, off
);
3883 off
+= oshdrs
->data_size();
3886 this->section_headers_
= oshdrs
;
3889 // Count the allocated sections.
3892 Layout::allocated_output_section_count() const
3894 size_t section_count
= 0;
3895 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
3896 p
!= this->segment_list_
.end();
3898 section_count
+= (*p
)->output_section_count();
3899 return section_count
;
3902 // Create the dynamic symbol table.
3905 Layout::create_dynamic_symtab(const Input_objects
* input_objects
,
3906 Symbol_table
* symtab
,
3907 Output_section
** pdynstr
,
3908 unsigned int* plocal_dynamic_count
,
3909 std::vector
<Symbol
*>* pdynamic_symbols
,
3910 Versions
* pversions
)
3912 // Count all the symbols in the dynamic symbol table, and set the
3913 // dynamic symbol indexes.
3915 // Skip symbol 0, which is always all zeroes.
3916 unsigned int index
= 1;
3918 // Add STT_SECTION symbols for each Output section which needs one.
3919 for (Section_list::iterator p
= this->section_list_
.begin();
3920 p
!= this->section_list_
.end();
3923 if (!(*p
)->needs_dynsym_index())
3924 (*p
)->set_dynsym_index(-1U);
3927 (*p
)->set_dynsym_index(index
);
3932 // Count the local symbols that need to go in the dynamic symbol table,
3933 // and set the dynamic symbol indexes.
3934 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3935 p
!= input_objects
->relobj_end();
3938 unsigned int new_index
= (*p
)->set_local_dynsym_indexes(index
);
3942 unsigned int local_symcount
= index
;
3943 *plocal_dynamic_count
= local_symcount
;
3945 index
= symtab
->set_dynsym_indexes(index
, pdynamic_symbols
,
3946 &this->dynpool_
, pversions
);
3950 const int size
= parameters
->target().get_size();
3953 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
3956 else if (size
== 64)
3958 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
3964 // Create the dynamic symbol table section.
3966 Output_section
* dynsym
= this->choose_output_section(NULL
, ".dynsym",
3970 ORDER_DYNAMIC_LINKER
,
3973 // Check for NULL as a linker script may discard .dynsym.
3976 Output_section_data
* odata
= new Output_data_fixed_space(index
* symsize
,
3979 dynsym
->add_output_section_data(odata
);
3981 dynsym
->set_info(local_symcount
);
3982 dynsym
->set_entsize(symsize
);
3983 dynsym
->set_addralign(align
);
3985 this->dynsym_section_
= dynsym
;
3988 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
3991 odyn
->add_section_address(elfcpp::DT_SYMTAB
, dynsym
);
3992 odyn
->add_constant(elfcpp::DT_SYMENT
, symsize
);
3995 // If there are more than SHN_LORESERVE allocated sections, we
3996 // create a .dynsym_shndx section. It is possible that we don't
3997 // need one, because it is possible that there are no dynamic
3998 // symbols in any of the sections with indexes larger than
3999 // SHN_LORESERVE. This is probably unusual, though, and at this
4000 // time we don't know the actual section indexes so it is
4001 // inconvenient to check.
4002 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE
)
4004 Output_section
* dynsym_xindex
=
4005 this->choose_output_section(NULL
, ".dynsym_shndx",
4006 elfcpp::SHT_SYMTAB_SHNDX
,
4008 false, ORDER_DYNAMIC_LINKER
, false);
4010 if (dynsym_xindex
!= NULL
)
4012 this->dynsym_xindex_
= new Output_symtab_xindex(index
);
4014 dynsym_xindex
->add_output_section_data(this->dynsym_xindex_
);
4016 dynsym_xindex
->set_link_section(dynsym
);
4017 dynsym_xindex
->set_addralign(4);
4018 dynsym_xindex
->set_entsize(4);
4020 dynsym_xindex
->set_after_input_sections();
4022 // This tells the driver code to wait until the symbol table
4023 // has written out before writing out the postprocessing
4024 // sections, including the .dynsym_shndx section.
4025 this->any_postprocessing_sections_
= true;
4029 // Create the dynamic string table section.
4031 Output_section
* dynstr
= this->choose_output_section(NULL
, ".dynstr",
4035 ORDER_DYNAMIC_LINKER
,
4040 Output_section_data
* strdata
= new Output_data_strtab(&this->dynpool_
);
4041 dynstr
->add_output_section_data(strdata
);
4044 dynsym
->set_link_section(dynstr
);
4045 if (this->dynamic_section_
!= NULL
)
4046 this->dynamic_section_
->set_link_section(dynstr
);
4050 odyn
->add_section_address(elfcpp::DT_STRTAB
, dynstr
);
4051 odyn
->add_section_size(elfcpp::DT_STRSZ
, dynstr
);
4057 // Create the hash tables.
4059 if (strcmp(parameters
->options().hash_style(), "sysv") == 0
4060 || strcmp(parameters
->options().hash_style(), "both") == 0)
4062 unsigned char* phash
;
4063 unsigned int hashlen
;
4064 Dynobj::create_elf_hash_table(*pdynamic_symbols
, local_symcount
,
4067 Output_section
* hashsec
=
4068 this->choose_output_section(NULL
, ".hash", elfcpp::SHT_HASH
,
4069 elfcpp::SHF_ALLOC
, false,
4070 ORDER_DYNAMIC_LINKER
, false);
4072 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4076 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4077 hashsec
->add_output_section_data(hashdata
);
4079 if (hashsec
!= NULL
)
4082 hashsec
->set_link_section(dynsym
);
4083 hashsec
->set_entsize(4);
4087 odyn
->add_section_address(elfcpp::DT_HASH
, hashsec
);
4090 if (strcmp(parameters
->options().hash_style(), "gnu") == 0
4091 || strcmp(parameters
->options().hash_style(), "both") == 0)
4093 unsigned char* phash
;
4094 unsigned int hashlen
;
4095 Dynobj::create_gnu_hash_table(*pdynamic_symbols
, local_symcount
,
4098 Output_section
* hashsec
=
4099 this->choose_output_section(NULL
, ".gnu.hash", elfcpp::SHT_GNU_HASH
,
4100 elfcpp::SHF_ALLOC
, false,
4101 ORDER_DYNAMIC_LINKER
, false);
4103 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4107 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4108 hashsec
->add_output_section_data(hashdata
);
4110 if (hashsec
!= NULL
)
4113 hashsec
->set_link_section(dynsym
);
4115 // For a 64-bit target, the entries in .gnu.hash do not have
4116 // a uniform size, so we only set the entry size for a
4118 if (parameters
->target().get_size() == 32)
4119 hashsec
->set_entsize(4);
4122 odyn
->add_section_address(elfcpp::DT_GNU_HASH
, hashsec
);
4127 // Assign offsets to each local portion of the dynamic symbol table.
4130 Layout::assign_local_dynsym_offsets(const Input_objects
* input_objects
)
4132 Output_section
* dynsym
= this->dynsym_section_
;
4136 off_t off
= dynsym
->offset();
4138 // Skip the dummy symbol at the start of the section.
4139 off
+= dynsym
->entsize();
4141 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4142 p
!= input_objects
->relobj_end();
4145 unsigned int count
= (*p
)->set_local_dynsym_offset(off
);
4146 off
+= count
* dynsym
->entsize();
4150 // Create the version sections.
4153 Layout::create_version_sections(const Versions
* versions
,
4154 const Symbol_table
* symtab
,
4155 unsigned int local_symcount
,
4156 const std::vector
<Symbol
*>& dynamic_symbols
,
4157 const Output_section
* dynstr
)
4159 if (!versions
->any_defs() && !versions
->any_needs())
4162 switch (parameters
->size_and_endianness())
4164 #ifdef HAVE_TARGET_32_LITTLE
4165 case Parameters::TARGET_32_LITTLE
:
4166 this->sized_create_version_sections
<32, false>(versions
, symtab
,
4168 dynamic_symbols
, dynstr
);
4171 #ifdef HAVE_TARGET_32_BIG
4172 case Parameters::TARGET_32_BIG
:
4173 this->sized_create_version_sections
<32, true>(versions
, symtab
,
4175 dynamic_symbols
, dynstr
);
4178 #ifdef HAVE_TARGET_64_LITTLE
4179 case Parameters::TARGET_64_LITTLE
:
4180 this->sized_create_version_sections
<64, false>(versions
, symtab
,
4182 dynamic_symbols
, dynstr
);
4185 #ifdef HAVE_TARGET_64_BIG
4186 case Parameters::TARGET_64_BIG
:
4187 this->sized_create_version_sections
<64, true>(versions
, symtab
,
4189 dynamic_symbols
, dynstr
);
4197 // Create the version sections, sized version.
4199 template<int size
, bool big_endian
>
4201 Layout::sized_create_version_sections(
4202 const Versions
* versions
,
4203 const Symbol_table
* symtab
,
4204 unsigned int local_symcount
,
4205 const std::vector
<Symbol
*>& dynamic_symbols
,
4206 const Output_section
* dynstr
)
4208 Output_section
* vsec
= this->choose_output_section(NULL
, ".gnu.version",
4209 elfcpp::SHT_GNU_versym
,
4212 ORDER_DYNAMIC_LINKER
,
4215 // Check for NULL since a linker script may discard this section.
4218 unsigned char* vbuf
;
4220 versions
->symbol_section_contents
<size
, big_endian
>(symtab
,
4226 Output_section_data
* vdata
= new Output_data_const_buffer(vbuf
, vsize
, 2,
4229 vsec
->add_output_section_data(vdata
);
4230 vsec
->set_entsize(2);
4231 vsec
->set_link_section(this->dynsym_section_
);
4234 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4235 if (odyn
!= NULL
&& vsec
!= NULL
)
4236 odyn
->add_section_address(elfcpp::DT_VERSYM
, vsec
);
4238 if (versions
->any_defs())
4240 Output_section
* vdsec
;
4241 vdsec
= this->choose_output_section(NULL
, ".gnu.version_d",
4242 elfcpp::SHT_GNU_verdef
,
4244 false, ORDER_DYNAMIC_LINKER
, false);
4248 unsigned char* vdbuf
;
4249 unsigned int vdsize
;
4250 unsigned int vdentries
;
4251 versions
->def_section_contents
<size
, big_endian
>(&this->dynpool_
,
4255 Output_section_data
* vddata
=
4256 new Output_data_const_buffer(vdbuf
, vdsize
, 4, "** version defs");
4258 vdsec
->add_output_section_data(vddata
);
4259 vdsec
->set_link_section(dynstr
);
4260 vdsec
->set_info(vdentries
);
4264 odyn
->add_section_address(elfcpp::DT_VERDEF
, vdsec
);
4265 odyn
->add_constant(elfcpp::DT_VERDEFNUM
, vdentries
);
4270 if (versions
->any_needs())
4272 Output_section
* vnsec
;
4273 vnsec
= this->choose_output_section(NULL
, ".gnu.version_r",
4274 elfcpp::SHT_GNU_verneed
,
4276 false, ORDER_DYNAMIC_LINKER
, false);
4280 unsigned char* vnbuf
;
4281 unsigned int vnsize
;
4282 unsigned int vnentries
;
4283 versions
->need_section_contents
<size
, big_endian
>(&this->dynpool_
,
4287 Output_section_data
* vndata
=
4288 new Output_data_const_buffer(vnbuf
, vnsize
, 4, "** version refs");
4290 vnsec
->add_output_section_data(vndata
);
4291 vnsec
->set_link_section(dynstr
);
4292 vnsec
->set_info(vnentries
);
4296 odyn
->add_section_address(elfcpp::DT_VERNEED
, vnsec
);
4297 odyn
->add_constant(elfcpp::DT_VERNEEDNUM
, vnentries
);
4303 // Create the .interp section and PT_INTERP segment.
4306 Layout::create_interp(const Target
* target
)
4308 gold_assert(this->interp_segment_
== NULL
);
4310 const char* interp
= parameters
->options().dynamic_linker();
4313 interp
= target
->dynamic_linker();
4314 gold_assert(interp
!= NULL
);
4317 size_t len
= strlen(interp
) + 1;
4319 Output_section_data
* odata
= new Output_data_const(interp
, len
, 1);
4321 Output_section
* osec
= this->choose_output_section(NULL
, ".interp",
4322 elfcpp::SHT_PROGBITS
,
4324 false, ORDER_INTERP
,
4327 osec
->add_output_section_data(odata
);
4330 // Add dynamic tags for the PLT and the dynamic relocs. This is
4331 // called by the target-specific code. This does nothing if not doing
4334 // USE_REL is true for REL relocs rather than RELA relocs.
4336 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
4338 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
4339 // and we also set DT_PLTREL. We use PLT_REL's output section, since
4340 // some targets have multiple reloc sections in PLT_REL.
4342 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
4343 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT. Again we use the output
4346 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
4350 Layout::add_target_dynamic_tags(bool use_rel
, const Output_data
* plt_got
,
4351 const Output_data
* plt_rel
,
4352 const Output_data_reloc_generic
* dyn_rel
,
4353 bool add_debug
, bool dynrel_includes_plt
)
4355 Output_data_dynamic
* odyn
= this->dynamic_data_
;
4359 if (plt_got
!= NULL
&& plt_got
->output_section() != NULL
)
4360 odyn
->add_section_address(elfcpp::DT_PLTGOT
, plt_got
);
4362 if (plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
)
4364 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, plt_rel
->output_section());
4365 odyn
->add_section_address(elfcpp::DT_JMPREL
, plt_rel
->output_section());
4366 odyn
->add_constant(elfcpp::DT_PLTREL
,
4367 use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
);
4370 if ((dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
)
4371 || (dynrel_includes_plt
4373 && plt_rel
->output_section() != NULL
))
4375 bool have_dyn_rel
= dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
;
4376 bool have_plt_rel
= plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
;
4377 odyn
->add_section_address(use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
,
4379 ? dyn_rel
->output_section()
4380 : plt_rel
->output_section()));
4381 elfcpp::DT size_tag
= use_rel
? elfcpp::DT_RELSZ
: elfcpp::DT_RELASZ
;
4382 if (have_dyn_rel
&& have_plt_rel
&& dynrel_includes_plt
)
4383 odyn
->add_section_size(size_tag
,
4384 dyn_rel
->output_section(),
4385 plt_rel
->output_section());
4386 else if (have_dyn_rel
)
4387 odyn
->add_section_size(size_tag
, dyn_rel
->output_section());
4389 odyn
->add_section_size(size_tag
, plt_rel
->output_section());
4390 const int size
= parameters
->target().get_size();
4395 rel_tag
= elfcpp::DT_RELENT
;
4397 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 32, false>::reloc_size
;
4398 else if (size
== 64)
4399 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 64, false>::reloc_size
;
4405 rel_tag
= elfcpp::DT_RELAENT
;
4407 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 32, false>::reloc_size
;
4408 else if (size
== 64)
4409 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 64, false>::reloc_size
;
4413 odyn
->add_constant(rel_tag
, rel_size
);
4415 if (parameters
->options().combreloc() && have_dyn_rel
)
4417 size_t c
= dyn_rel
->relative_reloc_count();
4419 odyn
->add_constant((use_rel
4420 ? elfcpp::DT_RELCOUNT
4421 : elfcpp::DT_RELACOUNT
),
4426 if (add_debug
&& !parameters
->options().shared())
4428 // The value of the DT_DEBUG tag is filled in by the dynamic
4429 // linker at run time, and used by the debugger.
4430 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
4434 // Finish the .dynamic section and PT_DYNAMIC segment.
4437 Layout::finish_dynamic_section(const Input_objects
* input_objects
,
4438 const Symbol_table
* symtab
)
4440 if (!this->script_options_
->saw_phdrs_clause()
4441 && this->dynamic_section_
!= NULL
)
4443 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_DYNAMIC
,
4446 oseg
->add_output_section_to_nonload(this->dynamic_section_
,
4447 elfcpp::PF_R
| elfcpp::PF_W
);
4450 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4454 for (Input_objects::Dynobj_iterator p
= input_objects
->dynobj_begin();
4455 p
!= input_objects
->dynobj_end();
4458 if (!(*p
)->is_needed() && (*p
)->as_needed())
4460 // This dynamic object was linked with --as-needed, but it
4465 odyn
->add_string(elfcpp::DT_NEEDED
, (*p
)->soname());
4468 if (parameters
->options().shared())
4470 const char* soname
= parameters
->options().soname();
4472 odyn
->add_string(elfcpp::DT_SONAME
, soname
);
4475 Symbol
* sym
= symtab
->lookup(parameters
->options().init());
4476 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4477 odyn
->add_symbol(elfcpp::DT_INIT
, sym
);
4479 sym
= symtab
->lookup(parameters
->options().fini());
4480 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4481 odyn
->add_symbol(elfcpp::DT_FINI
, sym
);
4483 // Look for .init_array, .preinit_array and .fini_array by checking
4485 for(Layout::Section_list::const_iterator p
= this->section_list_
.begin();
4486 p
!= this->section_list_
.end();
4488 switch((*p
)->type())
4490 case elfcpp::SHT_FINI_ARRAY
:
4491 odyn
->add_section_address(elfcpp::DT_FINI_ARRAY
, *p
);
4492 odyn
->add_section_size(elfcpp::DT_FINI_ARRAYSZ
, *p
);
4494 case elfcpp::SHT_INIT_ARRAY
:
4495 odyn
->add_section_address(elfcpp::DT_INIT_ARRAY
, *p
);
4496 odyn
->add_section_size(elfcpp::DT_INIT_ARRAYSZ
, *p
);
4498 case elfcpp::SHT_PREINIT_ARRAY
:
4499 odyn
->add_section_address(elfcpp::DT_PREINIT_ARRAY
, *p
);
4500 odyn
->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ
, *p
);
4506 // Add a DT_RPATH entry if needed.
4507 const General_options::Dir_list
& rpath(parameters
->options().rpath());
4510 std::string rpath_val
;
4511 for (General_options::Dir_list::const_iterator p
= rpath
.begin();
4515 if (rpath_val
.empty())
4516 rpath_val
= p
->name();
4519 // Eliminate duplicates.
4520 General_options::Dir_list::const_iterator q
;
4521 for (q
= rpath
.begin(); q
!= p
; ++q
)
4522 if (q
->name() == p
->name())
4527 rpath_val
+= p
->name();
4532 odyn
->add_string(elfcpp::DT_RPATH
, rpath_val
);
4533 if (parameters
->options().enable_new_dtags())
4534 odyn
->add_string(elfcpp::DT_RUNPATH
, rpath_val
);
4537 // Look for text segments that have dynamic relocations.
4538 bool have_textrel
= false;
4539 if (!this->script_options_
->saw_sections_clause())
4541 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4542 p
!= this->segment_list_
.end();
4545 if ((*p
)->type() == elfcpp::PT_LOAD
4546 && ((*p
)->flags() & elfcpp::PF_W
) == 0
4547 && (*p
)->has_dynamic_reloc())
4549 have_textrel
= true;
4556 // We don't know the section -> segment mapping, so we are
4557 // conservative and just look for readonly sections with
4558 // relocations. If those sections wind up in writable segments,
4559 // then we have created an unnecessary DT_TEXTREL entry.
4560 for (Section_list::const_iterator p
= this->section_list_
.begin();
4561 p
!= this->section_list_
.end();
4564 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0
4565 && ((*p
)->flags() & elfcpp::SHF_WRITE
) == 0
4566 && (*p
)->has_dynamic_reloc())
4568 have_textrel
= true;
4574 if (parameters
->options().filter() != NULL
)
4575 odyn
->add_string(elfcpp::DT_FILTER
, parameters
->options().filter());
4576 if (parameters
->options().any_auxiliary())
4578 for (options::String_set::const_iterator p
=
4579 parameters
->options().auxiliary_begin();
4580 p
!= parameters
->options().auxiliary_end();
4582 odyn
->add_string(elfcpp::DT_AUXILIARY
, *p
);
4585 // Add a DT_FLAGS entry if necessary.
4586 unsigned int flags
= 0;
4589 // Add a DT_TEXTREL for compatibility with older loaders.
4590 odyn
->add_constant(elfcpp::DT_TEXTREL
, 0);
4591 flags
|= elfcpp::DF_TEXTREL
;
4593 if (parameters
->options().text())
4594 gold_error(_("read-only segment has dynamic relocations"));
4595 else if (parameters
->options().warn_shared_textrel()
4596 && parameters
->options().shared())
4597 gold_warning(_("shared library text segment is not shareable"));
4599 if (parameters
->options().shared() && this->has_static_tls())
4600 flags
|= elfcpp::DF_STATIC_TLS
;
4601 if (parameters
->options().origin())
4602 flags
|= elfcpp::DF_ORIGIN
;
4603 if (parameters
->options().Bsymbolic())
4605 flags
|= elfcpp::DF_SYMBOLIC
;
4606 // Add DT_SYMBOLIC for compatibility with older loaders.
4607 odyn
->add_constant(elfcpp::DT_SYMBOLIC
, 0);
4609 if (parameters
->options().now())
4610 flags
|= elfcpp::DF_BIND_NOW
;
4612 odyn
->add_constant(elfcpp::DT_FLAGS
, flags
);
4615 if (parameters
->options().initfirst())
4616 flags
|= elfcpp::DF_1_INITFIRST
;
4617 if (parameters
->options().interpose())
4618 flags
|= elfcpp::DF_1_INTERPOSE
;
4619 if (parameters
->options().loadfltr())
4620 flags
|= elfcpp::DF_1_LOADFLTR
;
4621 if (parameters
->options().nodefaultlib())
4622 flags
|= elfcpp::DF_1_NODEFLIB
;
4623 if (parameters
->options().nodelete())
4624 flags
|= elfcpp::DF_1_NODELETE
;
4625 if (parameters
->options().nodlopen())
4626 flags
|= elfcpp::DF_1_NOOPEN
;
4627 if (parameters
->options().nodump())
4628 flags
|= elfcpp::DF_1_NODUMP
;
4629 if (!parameters
->options().shared())
4630 flags
&= ~(elfcpp::DF_1_INITFIRST
4631 | elfcpp::DF_1_NODELETE
4632 | elfcpp::DF_1_NOOPEN
);
4633 if (parameters
->options().origin())
4634 flags
|= elfcpp::DF_1_ORIGIN
;
4635 if (parameters
->options().now())
4636 flags
|= elfcpp::DF_1_NOW
;
4637 if (parameters
->options().Bgroup())
4638 flags
|= elfcpp::DF_1_GROUP
;
4640 odyn
->add_constant(elfcpp::DT_FLAGS_1
, flags
);
4643 // Set the size of the _DYNAMIC symbol table to be the size of the
4647 Layout::set_dynamic_symbol_size(const Symbol_table
* symtab
)
4649 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4652 odyn
->finalize_data_size();
4653 if (this->dynamic_symbol_
== NULL
)
4655 off_t data_size
= odyn
->data_size();
4656 const int size
= parameters
->target().get_size();
4658 symtab
->get_sized_symbol
<32>(this->dynamic_symbol_
)->set_symsize(data_size
);
4659 else if (size
== 64)
4660 symtab
->get_sized_symbol
<64>(this->dynamic_symbol_
)->set_symsize(data_size
);
4665 // The mapping of input section name prefixes to output section names.
4666 // In some cases one prefix is itself a prefix of another prefix; in
4667 // such a case the longer prefix must come first. These prefixes are
4668 // based on the GNU linker default ELF linker script.
4670 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
4671 #define MAPPING_INIT_EXACT(f, t) { f, 0, t, sizeof(t) - 1 }
4672 const Layout::Section_name_mapping
Layout::section_name_mapping
[] =
4674 MAPPING_INIT(".text.", ".text"),
4675 MAPPING_INIT(".rodata.", ".rodata"),
4676 MAPPING_INIT(".data.rel.ro.local.", ".data.rel.ro.local"),
4677 MAPPING_INIT_EXACT(".data.rel.ro.local", ".data.rel.ro.local"),
4678 MAPPING_INIT(".data.rel.ro.", ".data.rel.ro"),
4679 MAPPING_INIT_EXACT(".data.rel.ro", ".data.rel.ro"),
4680 MAPPING_INIT(".data.", ".data"),
4681 MAPPING_INIT(".bss.", ".bss"),
4682 MAPPING_INIT(".tdata.", ".tdata"),
4683 MAPPING_INIT(".tbss.", ".tbss"),
4684 MAPPING_INIT(".init_array.", ".init_array"),
4685 MAPPING_INIT(".fini_array.", ".fini_array"),
4686 MAPPING_INIT(".sdata.", ".sdata"),
4687 MAPPING_INIT(".sbss.", ".sbss"),
4688 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
4689 // differently depending on whether it is creating a shared library.
4690 MAPPING_INIT(".sdata2.", ".sdata"),
4691 MAPPING_INIT(".sbss2.", ".sbss"),
4692 MAPPING_INIT(".lrodata.", ".lrodata"),
4693 MAPPING_INIT(".ldata.", ".ldata"),
4694 MAPPING_INIT(".lbss.", ".lbss"),
4695 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
4696 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
4697 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
4698 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
4699 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
4700 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
4701 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
4702 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
4703 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
4704 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
4705 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
4706 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
4707 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
4708 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
4709 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
4710 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
4711 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
4712 MAPPING_INIT(".ARM.extab", ".ARM.extab"),
4713 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
4714 MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
4715 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
4718 #undef MAPPING_INIT_EXACT
4720 const int Layout::section_name_mapping_count
=
4721 (sizeof(Layout::section_name_mapping
)
4722 / sizeof(Layout::section_name_mapping
[0]));
4724 // Choose the output section name to use given an input section name.
4725 // Set *PLEN to the length of the name. *PLEN is initialized to the
4729 Layout::output_section_name(const Relobj
* relobj
, const char* name
,
4732 // gcc 4.3 generates the following sorts of section names when it
4733 // needs a section name specific to a function:
4739 // .data.rel.local.FN
4741 // .data.rel.ro.local.FN
4748 // The GNU linker maps all of those to the part before the .FN,
4749 // except that .data.rel.local.FN is mapped to .data, and
4750 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
4751 // beginning with .data.rel.ro.local are grouped together.
4753 // For an anonymous namespace, the string FN can contain a '.'.
4755 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
4756 // GNU linker maps to .rodata.
4758 // The .data.rel.ro sections are used with -z relro. The sections
4759 // are recognized by name. We use the same names that the GNU
4760 // linker does for these sections.
4762 // It is hard to handle this in a principled way, so we don't even
4763 // try. We use a table of mappings. If the input section name is
4764 // not found in the table, we simply use it as the output section
4767 const Section_name_mapping
* psnm
= section_name_mapping
;
4768 for (int i
= 0; i
< section_name_mapping_count
; ++i
, ++psnm
)
4770 if (psnm
->fromlen
> 0)
4772 if (strncmp(name
, psnm
->from
, psnm
->fromlen
) == 0)
4774 *plen
= psnm
->tolen
;
4780 if (strcmp(name
, psnm
->from
) == 0)
4782 *plen
= psnm
->tolen
;
4788 // As an additional complication, .ctors sections are output in
4789 // either .ctors or .init_array sections, and .dtors sections are
4790 // output in either .dtors or .fini_array sections.
4791 if (is_prefix_of(".ctors.", name
) || is_prefix_of(".dtors.", name
))
4793 if (parameters
->options().ctors_in_init_array())
4796 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4801 return name
[1] == 'c' ? ".ctors" : ".dtors";
4804 if (parameters
->options().ctors_in_init_array()
4805 && (strcmp(name
, ".ctors") == 0 || strcmp(name
, ".dtors") == 0))
4807 // To make .init_array/.fini_array work with gcc we must exclude
4808 // .ctors and .dtors sections from the crtbegin and crtend
4811 || (!Layout::match_file_name(relobj
, "crtbegin")
4812 && !Layout::match_file_name(relobj
, "crtend")))
4815 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4822 // Return true if RELOBJ is an input file whose base name matches
4823 // FILE_NAME. The base name must have an extension of ".o", and must
4824 // be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is
4825 // to match crtbegin.o as well as crtbeginS.o without getting confused
4826 // by other possibilities. Overall matching the file name this way is
4827 // a dreadful hack, but the GNU linker does it in order to better
4828 // support gcc, and we need to be compatible.
4831 Layout::match_file_name(const Relobj
* relobj
, const char* match
)
4833 const std::string
& file_name(relobj
->name());
4834 const char* base_name
= lbasename(file_name
.c_str());
4835 size_t match_len
= strlen(match
);
4836 if (strncmp(base_name
, match
, match_len
) != 0)
4838 size_t base_len
= strlen(base_name
);
4839 if (base_len
!= match_len
+ 2 && base_len
!= match_len
+ 3)
4841 return memcmp(base_name
+ base_len
- 2, ".o", 2) == 0;
4844 // Check if a comdat group or .gnu.linkonce section with the given
4845 // NAME is selected for the link. If there is already a section,
4846 // *KEPT_SECTION is set to point to the existing section and the
4847 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
4848 // IS_GROUP_NAME are recorded for this NAME in the layout object,
4849 // *KEPT_SECTION is set to the internal copy and the function returns
4853 Layout::find_or_add_kept_section(const std::string
& name
,
4858 Kept_section
** kept_section
)
4860 // It's normal to see a couple of entries here, for the x86 thunk
4861 // sections. If we see more than a few, we're linking a C++
4862 // program, and we resize to get more space to minimize rehashing.
4863 if (this->signatures_
.size() > 4
4864 && !this->resized_signatures_
)
4866 reserve_unordered_map(&this->signatures_
,
4867 this->number_of_input_files_
* 64);
4868 this->resized_signatures_
= true;
4871 Kept_section candidate
;
4872 std::pair
<Signatures::iterator
, bool> ins
=
4873 this->signatures_
.insert(std::make_pair(name
, candidate
));
4875 if (kept_section
!= NULL
)
4876 *kept_section
= &ins
.first
->second
;
4879 // This is the first time we've seen this signature.
4880 ins
.first
->second
.set_object(object
);
4881 ins
.first
->second
.set_shndx(shndx
);
4883 ins
.first
->second
.set_is_comdat();
4885 ins
.first
->second
.set_is_group_name();
4889 // We have already seen this signature.
4891 if (ins
.first
->second
.is_group_name())
4893 // We've already seen a real section group with this signature.
4894 // If the kept group is from a plugin object, and we're in the
4895 // replacement phase, accept the new one as a replacement.
4896 if (ins
.first
->second
.object() == NULL
4897 && parameters
->options().plugins()->in_replacement_phase())
4899 ins
.first
->second
.set_object(object
);
4900 ins
.first
->second
.set_shndx(shndx
);
4905 else if (is_group_name
)
4907 // This is a real section group, and we've already seen a
4908 // linkonce section with this signature. Record that we've seen
4909 // a section group, and don't include this section group.
4910 ins
.first
->second
.set_is_group_name();
4915 // We've already seen a linkonce section and this is a linkonce
4916 // section. These don't block each other--this may be the same
4917 // symbol name with different section types.
4922 // Store the allocated sections into the section list.
4925 Layout::get_allocated_sections(Section_list
* section_list
) const
4927 for (Section_list::const_iterator p
= this->section_list_
.begin();
4928 p
!= this->section_list_
.end();
4930 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0)
4931 section_list
->push_back(*p
);
4934 // Create an output segment.
4937 Layout::make_output_segment(elfcpp::Elf_Word type
, elfcpp::Elf_Word flags
)
4939 gold_assert(!parameters
->options().relocatable());
4940 Output_segment
* oseg
= new Output_segment(type
, flags
);
4941 this->segment_list_
.push_back(oseg
);
4943 if (type
== elfcpp::PT_TLS
)
4944 this->tls_segment_
= oseg
;
4945 else if (type
== elfcpp::PT_GNU_RELRO
)
4946 this->relro_segment_
= oseg
;
4947 else if (type
== elfcpp::PT_INTERP
)
4948 this->interp_segment_
= oseg
;
4953 // Return the file offset of the normal symbol table.
4956 Layout::symtab_section_offset() const
4958 if (this->symtab_section_
!= NULL
)
4959 return this->symtab_section_
->offset();
4963 // Return the section index of the normal symbol table. It may have
4964 // been stripped by the -s/--strip-all option.
4967 Layout::symtab_section_shndx() const
4969 if (this->symtab_section_
!= NULL
)
4970 return this->symtab_section_
->out_shndx();
4974 // Write out the Output_sections. Most won't have anything to write,
4975 // since most of the data will come from input sections which are
4976 // handled elsewhere. But some Output_sections do have Output_data.
4979 Layout::write_output_sections(Output_file
* of
) const
4981 for (Section_list::const_iterator p
= this->section_list_
.begin();
4982 p
!= this->section_list_
.end();
4985 if (!(*p
)->after_input_sections())
4990 // Write out data not associated with a section or the symbol table.
4993 Layout::write_data(const Symbol_table
* symtab
, Output_file
* of
) const
4995 if (!parameters
->options().strip_all())
4997 const Output_section
* symtab_section
= this->symtab_section_
;
4998 for (Section_list::const_iterator p
= this->section_list_
.begin();
4999 p
!= this->section_list_
.end();
5002 if ((*p
)->needs_symtab_index())
5004 gold_assert(symtab_section
!= NULL
);
5005 unsigned int index
= (*p
)->symtab_index();
5006 gold_assert(index
> 0 && index
!= -1U);
5007 off_t off
= (symtab_section
->offset()
5008 + index
* symtab_section
->entsize());
5009 symtab
->write_section_symbol(*p
, this->symtab_xindex_
, of
, off
);
5014 const Output_section
* dynsym_section
= this->dynsym_section_
;
5015 for (Section_list::const_iterator p
= this->section_list_
.begin();
5016 p
!= this->section_list_
.end();
5019 if ((*p
)->needs_dynsym_index())
5021 gold_assert(dynsym_section
!= NULL
);
5022 unsigned int index
= (*p
)->dynsym_index();
5023 gold_assert(index
> 0 && index
!= -1U);
5024 off_t off
= (dynsym_section
->offset()
5025 + index
* dynsym_section
->entsize());
5026 symtab
->write_section_symbol(*p
, this->dynsym_xindex_
, of
, off
);
5030 // Write out the Output_data which are not in an Output_section.
5031 for (Data_list::const_iterator p
= this->special_output_list_
.begin();
5032 p
!= this->special_output_list_
.end();
5037 // Write out the Output_sections which can only be written after the
5038 // input sections are complete.
5041 Layout::write_sections_after_input_sections(Output_file
* of
)
5043 // Determine the final section offsets, and thus the final output
5044 // file size. Note we finalize the .shstrab last, to allow the
5045 // after_input_section sections to modify their section-names before
5047 if (this->any_postprocessing_sections_
)
5049 off_t off
= this->output_file_size_
;
5050 off
= this->set_section_offsets(off
, POSTPROCESSING_SECTIONS_PASS
);
5052 // Now that we've finalized the names, we can finalize the shstrab.
5054 this->set_section_offsets(off
,
5055 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
5057 if (off
> this->output_file_size_
)
5060 this->output_file_size_
= off
;
5064 for (Section_list::const_iterator p
= this->section_list_
.begin();
5065 p
!= this->section_list_
.end();
5068 if ((*p
)->after_input_sections())
5072 this->section_headers_
->write(of
);
5075 // If the build ID requires computing a checksum, do so here, and
5076 // write it out. We compute a checksum over the entire file because
5077 // that is simplest.
5080 Layout::write_build_id(Output_file
* of
) const
5082 if (this->build_id_note_
== NULL
)
5085 const unsigned char* iv
= of
->get_input_view(0, this->output_file_size_
);
5087 unsigned char* ov
= of
->get_output_view(this->build_id_note_
->offset(),
5088 this->build_id_note_
->data_size());
5090 const char* style
= parameters
->options().build_id();
5091 if (strcmp(style
, "sha1") == 0)
5094 sha1_init_ctx(&ctx
);
5095 sha1_process_bytes(iv
, this->output_file_size_
, &ctx
);
5096 sha1_finish_ctx(&ctx
, ov
);
5098 else if (strcmp(style
, "md5") == 0)
5102 md5_process_bytes(iv
, this->output_file_size_
, &ctx
);
5103 md5_finish_ctx(&ctx
, ov
);
5108 of
->write_output_view(this->build_id_note_
->offset(),
5109 this->build_id_note_
->data_size(),
5112 of
->free_input_view(0, this->output_file_size_
, iv
);
5115 // Write out a binary file. This is called after the link is
5116 // complete. IN is the temporary output file we used to generate the
5117 // ELF code. We simply walk through the segments, read them from
5118 // their file offset in IN, and write them to their load address in
5119 // the output file. FIXME: with a bit more work, we could support
5120 // S-records and/or Intel hex format here.
5123 Layout::write_binary(Output_file
* in
) const
5125 gold_assert(parameters
->options().oformat_enum()
5126 == General_options::OBJECT_FORMAT_BINARY
);
5128 // Get the size of the binary file.
5129 uint64_t max_load_address
= 0;
5130 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5131 p
!= this->segment_list_
.end();
5134 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5136 uint64_t max_paddr
= (*p
)->paddr() + (*p
)->filesz();
5137 if (max_paddr
> max_load_address
)
5138 max_load_address
= max_paddr
;
5142 Output_file
out(parameters
->options().output_file_name());
5143 out
.open(max_load_address
);
5145 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5146 p
!= this->segment_list_
.end();
5149 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5151 const unsigned char* vin
= in
->get_input_view((*p
)->offset(),
5153 unsigned char* vout
= out
.get_output_view((*p
)->paddr(),
5155 memcpy(vout
, vin
, (*p
)->filesz());
5156 out
.write_output_view((*p
)->paddr(), (*p
)->filesz(), vout
);
5157 in
->free_input_view((*p
)->offset(), (*p
)->filesz(), vin
);
5164 // Print the output sections to the map file.
5167 Layout::print_to_mapfile(Mapfile
* mapfile
) const
5169 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5170 p
!= this->segment_list_
.end();
5172 (*p
)->print_sections_to_mapfile(mapfile
);
5175 // Print statistical information to stderr. This is used for --stats.
5178 Layout::print_stats() const
5180 this->namepool_
.print_stats("section name pool");
5181 this->sympool_
.print_stats("output symbol name pool");
5182 this->dynpool_
.print_stats("dynamic name pool");
5184 for (Section_list::const_iterator p
= this->section_list_
.begin();
5185 p
!= this->section_list_
.end();
5187 (*p
)->print_merge_stats();
5190 // Write_sections_task methods.
5192 // We can always run this task.
5195 Write_sections_task::is_runnable()
5200 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
5204 Write_sections_task::locks(Task_locker
* tl
)
5206 tl
->add(this, this->output_sections_blocker_
);
5207 tl
->add(this, this->final_blocker_
);
5210 // Run the task--write out the data.
5213 Write_sections_task::run(Workqueue
*)
5215 this->layout_
->write_output_sections(this->of_
);
5218 // Write_data_task methods.
5220 // We can always run this task.
5223 Write_data_task::is_runnable()
5228 // We need to unlock FINAL_BLOCKER when finished.
5231 Write_data_task::locks(Task_locker
* tl
)
5233 tl
->add(this, this->final_blocker_
);
5236 // Run the task--write out the data.
5239 Write_data_task::run(Workqueue
*)
5241 this->layout_
->write_data(this->symtab_
, this->of_
);
5244 // Write_symbols_task methods.
5246 // We can always run this task.
5249 Write_symbols_task::is_runnable()
5254 // We need to unlock FINAL_BLOCKER when finished.
5257 Write_symbols_task::locks(Task_locker
* tl
)
5259 tl
->add(this, this->final_blocker_
);
5262 // Run the task--write out the symbols.
5265 Write_symbols_task::run(Workqueue
*)
5267 this->symtab_
->write_globals(this->sympool_
, this->dynpool_
,
5268 this->layout_
->symtab_xindex(),
5269 this->layout_
->dynsym_xindex(), this->of_
);
5272 // Write_after_input_sections_task methods.
5274 // We can only run this task after the input sections have completed.
5277 Write_after_input_sections_task::is_runnable()
5279 if (this->input_sections_blocker_
->is_blocked())
5280 return this->input_sections_blocker_
;
5284 // We need to unlock FINAL_BLOCKER when finished.
5287 Write_after_input_sections_task::locks(Task_locker
* tl
)
5289 tl
->add(this, this->final_blocker_
);
5295 Write_after_input_sections_task::run(Workqueue
*)
5297 this->layout_
->write_sections_after_input_sections(this->of_
);
5300 // Close_task_runner methods.
5302 // Run the task--close the file.
5305 Close_task_runner::run(Workqueue
*, const Task
*)
5307 // If we need to compute a checksum for the BUILD if, we do so here.
5308 this->layout_
->write_build_id(this->of_
);
5310 // If we've been asked to create a binary file, we do so here.
5311 if (this->options_
->oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
5312 this->layout_
->write_binary(this->of_
);
5317 // Instantiate the templates we need. We could use the configure
5318 // script to restrict this to only the ones for implemented targets.
5320 #ifdef HAVE_TARGET_32_LITTLE
5323 Layout::init_fixed_output_section
<32, false>(
5325 elfcpp::Shdr
<32, false>& shdr
);
5328 #ifdef HAVE_TARGET_32_BIG
5331 Layout::init_fixed_output_section
<32, true>(
5333 elfcpp::Shdr
<32, true>& shdr
);
5336 #ifdef HAVE_TARGET_64_LITTLE
5339 Layout::init_fixed_output_section
<64, false>(
5341 elfcpp::Shdr
<64, false>& shdr
);
5344 #ifdef HAVE_TARGET_64_BIG
5347 Layout::init_fixed_output_section
<64, true>(
5349 elfcpp::Shdr
<64, true>& shdr
);
5352 #ifdef HAVE_TARGET_32_LITTLE
5355 Layout::layout
<32, false>(Sized_relobj_file
<32, false>* object
,
5358 const elfcpp::Shdr
<32, false>& shdr
,
5359 unsigned int, unsigned int, off_t
*);
5362 #ifdef HAVE_TARGET_32_BIG
5365 Layout::layout
<32, true>(Sized_relobj_file
<32, true>* object
,
5368 const elfcpp::Shdr
<32, true>& shdr
,
5369 unsigned int, unsigned int, off_t
*);
5372 #ifdef HAVE_TARGET_64_LITTLE
5375 Layout::layout
<64, false>(Sized_relobj_file
<64, false>* object
,
5378 const elfcpp::Shdr
<64, false>& shdr
,
5379 unsigned int, unsigned int, off_t
*);
5382 #ifdef HAVE_TARGET_64_BIG
5385 Layout::layout
<64, true>(Sized_relobj_file
<64, true>* object
,
5388 const elfcpp::Shdr
<64, true>& shdr
,
5389 unsigned int, unsigned int, off_t
*);
5392 #ifdef HAVE_TARGET_32_LITTLE
5395 Layout::layout_reloc
<32, false>(Sized_relobj_file
<32, false>* object
,
5396 unsigned int reloc_shndx
,
5397 const elfcpp::Shdr
<32, false>& shdr
,
5398 Output_section
* data_section
,
5399 Relocatable_relocs
* rr
);
5402 #ifdef HAVE_TARGET_32_BIG
5405 Layout::layout_reloc
<32, true>(Sized_relobj_file
<32, true>* object
,
5406 unsigned int reloc_shndx
,
5407 const elfcpp::Shdr
<32, true>& shdr
,
5408 Output_section
* data_section
,
5409 Relocatable_relocs
* rr
);
5412 #ifdef HAVE_TARGET_64_LITTLE
5415 Layout::layout_reloc
<64, false>(Sized_relobj_file
<64, false>* object
,
5416 unsigned int reloc_shndx
,
5417 const elfcpp::Shdr
<64, false>& shdr
,
5418 Output_section
* data_section
,
5419 Relocatable_relocs
* rr
);
5422 #ifdef HAVE_TARGET_64_BIG
5425 Layout::layout_reloc
<64, true>(Sized_relobj_file
<64, true>* object
,
5426 unsigned int reloc_shndx
,
5427 const elfcpp::Shdr
<64, true>& shdr
,
5428 Output_section
* data_section
,
5429 Relocatable_relocs
* rr
);
5432 #ifdef HAVE_TARGET_32_LITTLE
5435 Layout::layout_group
<32, false>(Symbol_table
* symtab
,
5436 Sized_relobj_file
<32, false>* object
,
5438 const char* group_section_name
,
5439 const char* signature
,
5440 const elfcpp::Shdr
<32, false>& shdr
,
5441 elfcpp::Elf_Word flags
,
5442 std::vector
<unsigned int>* shndxes
);
5445 #ifdef HAVE_TARGET_32_BIG
5448 Layout::layout_group
<32, true>(Symbol_table
* symtab
,
5449 Sized_relobj_file
<32, true>* object
,
5451 const char* group_section_name
,
5452 const char* signature
,
5453 const elfcpp::Shdr
<32, true>& shdr
,
5454 elfcpp::Elf_Word flags
,
5455 std::vector
<unsigned int>* shndxes
);
5458 #ifdef HAVE_TARGET_64_LITTLE
5461 Layout::layout_group
<64, false>(Symbol_table
* symtab
,
5462 Sized_relobj_file
<64, false>* object
,
5464 const char* group_section_name
,
5465 const char* signature
,
5466 const elfcpp::Shdr
<64, false>& shdr
,
5467 elfcpp::Elf_Word flags
,
5468 std::vector
<unsigned int>* shndxes
);
5471 #ifdef HAVE_TARGET_64_BIG
5474 Layout::layout_group
<64, true>(Symbol_table
* symtab
,
5475 Sized_relobj_file
<64, true>* object
,
5477 const char* group_section_name
,
5478 const char* signature
,
5479 const elfcpp::Shdr
<64, true>& shdr
,
5480 elfcpp::Elf_Word flags
,
5481 std::vector
<unsigned int>* shndxes
);
5484 #ifdef HAVE_TARGET_32_LITTLE
5487 Layout::layout_eh_frame
<32, false>(Sized_relobj_file
<32, false>* object
,
5488 const unsigned char* symbols
,
5490 const unsigned char* symbol_names
,
5491 off_t symbol_names_size
,
5493 const elfcpp::Shdr
<32, false>& shdr
,
5494 unsigned int reloc_shndx
,
5495 unsigned int reloc_type
,
5499 #ifdef HAVE_TARGET_32_BIG
5502 Layout::layout_eh_frame
<32, true>(Sized_relobj_file
<32, true>* object
,
5503 const unsigned char* symbols
,
5505 const unsigned char* symbol_names
,
5506 off_t symbol_names_size
,
5508 const elfcpp::Shdr
<32, true>& shdr
,
5509 unsigned int reloc_shndx
,
5510 unsigned int reloc_type
,
5514 #ifdef HAVE_TARGET_64_LITTLE
5517 Layout::layout_eh_frame
<64, false>(Sized_relobj_file
<64, false>* object
,
5518 const unsigned char* symbols
,
5520 const unsigned char* symbol_names
,
5521 off_t symbol_names_size
,
5523 const elfcpp::Shdr
<64, false>& shdr
,
5524 unsigned int reloc_shndx
,
5525 unsigned int reloc_type
,
5529 #ifdef HAVE_TARGET_64_BIG
5532 Layout::layout_eh_frame
<64, true>(Sized_relobj_file
<64, true>* object
,
5533 const unsigned char* symbols
,
5535 const unsigned char* symbol_names
,
5536 off_t symbol_names_size
,
5538 const elfcpp::Shdr
<64, true>& shdr
,
5539 unsigned int reloc_shndx
,
5540 unsigned int reloc_type
,
5544 #ifdef HAVE_TARGET_32_LITTLE
5547 Layout::add_to_gdb_index(bool is_type_unit
,
5548 Sized_relobj
<32, false>* object
,
5549 const unsigned char* symbols
,
5552 unsigned int reloc_shndx
,
5553 unsigned int reloc_type
);
5556 #ifdef HAVE_TARGET_32_BIG
5559 Layout::add_to_gdb_index(bool is_type_unit
,
5560 Sized_relobj
<32, true>* object
,
5561 const unsigned char* symbols
,
5564 unsigned int reloc_shndx
,
5565 unsigned int reloc_type
);
5568 #ifdef HAVE_TARGET_64_LITTLE
5571 Layout::add_to_gdb_index(bool is_type_unit
,
5572 Sized_relobj
<64, false>* object
,
5573 const unsigned char* symbols
,
5576 unsigned int reloc_shndx
,
5577 unsigned int reloc_type
);
5580 #ifdef HAVE_TARGET_64_BIG
5583 Layout::add_to_gdb_index(bool is_type_unit
,
5584 Sized_relobj
<64, true>* object
,
5585 const unsigned char* symbols
,
5588 unsigned int reloc_shndx
,
5589 unsigned int reloc_type
);
5592 } // End namespace gold.