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()
610 && !parameters
->options().emit_relocs());
613 case elfcpp::SHT_PROGBITS
:
614 if (parameters
->options().strip_debug()
615 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
617 if (is_debug_info_section(name
))
620 if (parameters
->options().strip_debug_non_line()
621 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
623 // Debugging sections can only be recognized by name.
624 if (is_prefix_of(".debug_", name
)
625 && !is_lines_only_debug_section(name
+ 7))
627 if (is_prefix_of(".zdebug_", name
)
628 && !is_lines_only_debug_section(name
+ 8))
631 if (parameters
->options().strip_debug_gdb()
632 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
634 // Debugging sections can only be recognized by name.
635 if (is_prefix_of(".debug_", name
)
636 && !is_gdb_debug_section(name
+ 7))
638 if (is_prefix_of(".zdebug_", name
)
639 && !is_gdb_debug_section(name
+ 8))
642 if (parameters
->options().gdb_index()
643 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
645 // When building .gdb_index, we can strip .debug_pubnames,
646 // .debug_pubtypes, and .debug_aranges sections.
647 if (is_prefix_of(".debug_", name
)
648 && is_gdb_fast_lookup_section(name
+ 7))
650 if (is_prefix_of(".zdebug_", name
)
651 && is_gdb_fast_lookup_section(name
+ 8))
654 if (parameters
->options().strip_lto_sections()
655 && !parameters
->options().relocatable()
656 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
658 // Ignore LTO sections containing intermediate code.
659 if (is_prefix_of(".gnu.lto_", name
))
662 // The GNU linker strips .gnu_debuglink sections, so we do too.
663 // This is a feature used to keep debugging information in
665 if (strcmp(name
, ".gnu_debuglink") == 0)
674 // Return an output section named NAME, or NULL if there is none.
677 Layout::find_output_section(const char* name
) const
679 for (Section_list::const_iterator p
= this->section_list_
.begin();
680 p
!= this->section_list_
.end();
682 if (strcmp((*p
)->name(), name
) == 0)
687 // Return an output segment of type TYPE, with segment flags SET set
688 // and segment flags CLEAR clear. Return NULL if there is none.
691 Layout::find_output_segment(elfcpp::PT type
, elfcpp::Elf_Word set
,
692 elfcpp::Elf_Word clear
) const
694 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
695 p
!= this->segment_list_
.end();
697 if (static_cast<elfcpp::PT
>((*p
)->type()) == type
698 && ((*p
)->flags() & set
) == set
699 && ((*p
)->flags() & clear
) == 0)
704 // When we put a .ctors or .dtors section with more than one word into
705 // a .init_array or .fini_array section, we need to reverse the words
706 // in the .ctors/.dtors section. This is because .init_array executes
707 // constructors front to back, where .ctors executes them back to
708 // front, and vice-versa for .fini_array/.dtors. Although we do want
709 // to remap .ctors/.dtors into .init_array/.fini_array because it can
710 // be more efficient, we don't want to change the order in which
711 // constructors/destructors are run. This set just keeps track of
712 // these sections which need to be reversed. It is only changed by
713 // Layout::layout. It should be a private member of Layout, but that
714 // would require layout.h to #include object.h to get the definition
716 static Unordered_set
<Section_id
, Section_id_hash
> ctors_sections_in_init_array
;
718 // Return whether OBJECT/SHNDX is a .ctors/.dtors section mapped to a
719 // .init_array/.fini_array section.
722 Layout::is_ctors_in_init_array(Relobj
* relobj
, unsigned int shndx
) const
724 return (ctors_sections_in_init_array
.find(Section_id(relobj
, shndx
))
725 != ctors_sections_in_init_array
.end());
728 // Return the output section to use for section NAME with type TYPE
729 // and section flags FLAGS. NAME must be canonicalized in the string
730 // pool, and NAME_KEY is the key. ORDER is where this should appear
731 // in the output sections. IS_RELRO is true for a relro section.
734 Layout::get_output_section(const char* name
, Stringpool::Key name_key
,
735 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
736 Output_section_order order
, bool is_relro
)
738 elfcpp::Elf_Word lookup_type
= type
;
740 // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and
741 // PREINIT_ARRAY like PROGBITS. This ensures that we combine
742 // .init_array, .fini_array, and .preinit_array sections by name
743 // whatever their type in the input file. We do this because the
744 // types are not always right in the input files.
745 if (lookup_type
== elfcpp::SHT_INIT_ARRAY
746 || lookup_type
== elfcpp::SHT_FINI_ARRAY
747 || lookup_type
== elfcpp::SHT_PREINIT_ARRAY
)
748 lookup_type
= elfcpp::SHT_PROGBITS
;
750 elfcpp::Elf_Xword lookup_flags
= flags
;
752 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
753 // read-write with read-only sections. Some other ELF linkers do
754 // not do this. FIXME: Perhaps there should be an option
756 lookup_flags
&= ~(elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
758 const Key
key(name_key
, std::make_pair(lookup_type
, lookup_flags
));
759 const std::pair
<Key
, Output_section
*> v(key
, NULL
);
760 std::pair
<Section_name_map::iterator
, bool> ins(
761 this->section_name_map_
.insert(v
));
764 return ins
.first
->second
;
767 // This is the first time we've seen this name/type/flags
768 // combination. For compatibility with the GNU linker, we
769 // combine sections with contents and zero flags with sections
770 // with non-zero flags. This is a workaround for cases where
771 // assembler code forgets to set section flags. FIXME: Perhaps
772 // there should be an option to control this.
773 Output_section
* os
= NULL
;
775 if (lookup_type
== elfcpp::SHT_PROGBITS
)
779 Output_section
* same_name
= this->find_output_section(name
);
780 if (same_name
!= NULL
781 && (same_name
->type() == elfcpp::SHT_PROGBITS
782 || same_name
->type() == elfcpp::SHT_INIT_ARRAY
783 || same_name
->type() == elfcpp::SHT_FINI_ARRAY
784 || same_name
->type() == elfcpp::SHT_PREINIT_ARRAY
)
785 && (same_name
->flags() & elfcpp::SHF_TLS
) == 0)
788 else if ((flags
& elfcpp::SHF_TLS
) == 0)
790 elfcpp::Elf_Xword zero_flags
= 0;
791 const Key
zero_key(name_key
, std::make_pair(lookup_type
,
793 Section_name_map::iterator p
=
794 this->section_name_map_
.find(zero_key
);
795 if (p
!= this->section_name_map_
.end())
801 os
= this->make_output_section(name
, type
, flags
, order
, is_relro
);
803 ins
.first
->second
= os
;
808 // Pick the output section to use for section NAME, in input file
809 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
810 // linker created section. IS_INPUT_SECTION is true if we are
811 // choosing an output section for an input section found in a input
812 // file. ORDER is where this section should appear in the output
813 // sections. IS_RELRO is true for a relro section. This will return
814 // NULL if the input section should be discarded.
817 Layout::choose_output_section(const Relobj
* relobj
, const char* name
,
818 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
819 bool is_input_section
, Output_section_order order
,
822 // We should not see any input sections after we have attached
823 // sections to segments.
824 gold_assert(!is_input_section
|| !this->sections_are_attached_
);
826 // Some flags in the input section should not be automatically
827 // copied to the output section.
828 flags
&= ~ (elfcpp::SHF_INFO_LINK
831 | elfcpp::SHF_STRINGS
);
833 // We only clear the SHF_LINK_ORDER flag in for
834 // a non-relocatable link.
835 if (!parameters
->options().relocatable())
836 flags
&= ~elfcpp::SHF_LINK_ORDER
;
838 if (this->script_options_
->saw_sections_clause())
840 // We are using a SECTIONS clause, so the output section is
841 // chosen based only on the name.
843 Script_sections
* ss
= this->script_options_
->script_sections();
844 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
845 Output_section
** output_section_slot
;
846 Script_sections::Section_type script_section_type
;
847 const char* orig_name
= name
;
848 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
849 &script_section_type
);
852 gold_debug(DEBUG_SCRIPT
, _("Unable to create output section '%s' "
853 "because it is not allowed by the "
854 "SECTIONS clause of the linker script"),
856 // The SECTIONS clause says to discard this input section.
860 // We can only handle script section types ST_NONE and ST_NOLOAD.
861 switch (script_section_type
)
863 case Script_sections::ST_NONE
:
865 case Script_sections::ST_NOLOAD
:
866 flags
&= elfcpp::SHF_ALLOC
;
872 // If this is an orphan section--one not mentioned in the linker
873 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
874 // default processing below.
876 if (output_section_slot
!= NULL
)
878 if (*output_section_slot
!= NULL
)
880 (*output_section_slot
)->update_flags_for_input_section(flags
);
881 return *output_section_slot
;
884 // We don't put sections found in the linker script into
885 // SECTION_NAME_MAP_. That keeps us from getting confused
886 // if an orphan section is mapped to a section with the same
887 // name as one in the linker script.
889 name
= this->namepool_
.add(name
, false, NULL
);
891 Output_section
* os
= this->make_output_section(name
, type
, flags
,
894 os
->set_found_in_sections_clause();
896 // Special handling for NOLOAD sections.
897 if (script_section_type
== Script_sections::ST_NOLOAD
)
901 // The constructor of Output_section sets addresses of non-ALLOC
902 // sections to 0 by default. We don't want that for NOLOAD
903 // sections even if they have no SHF_ALLOC flag.
904 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0
905 && os
->is_address_valid())
907 gold_assert(os
->address() == 0
908 && !os
->is_offset_valid()
909 && !os
->is_data_size_valid());
910 os
->reset_address_and_file_offset();
914 *output_section_slot
= os
;
919 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
921 size_t len
= strlen(name
);
922 char* uncompressed_name
= NULL
;
924 // Compressed debug sections should be mapped to the corresponding
925 // uncompressed section.
926 if (is_compressed_debug_section(name
))
928 uncompressed_name
= new char[len
];
929 uncompressed_name
[0] = '.';
930 gold_assert(name
[0] == '.' && name
[1] == 'z');
931 strncpy(&uncompressed_name
[1], &name
[2], len
- 2);
932 uncompressed_name
[len
- 1] = '\0';
934 name
= uncompressed_name
;
937 // Turn NAME from the name of the input section into the name of the
940 && !this->script_options_
->saw_sections_clause()
941 && !parameters
->options().relocatable())
943 const char *orig_name
= name
;
944 name
= parameters
->target().output_section_name(relobj
, name
, &len
);
946 name
= Layout::output_section_name(relobj
, orig_name
, &len
);
949 Stringpool::Key name_key
;
950 name
= this->namepool_
.add_with_length(name
, len
, true, &name_key
);
952 if (uncompressed_name
!= NULL
)
953 delete[] uncompressed_name
;
955 // Find or make the output section. The output section is selected
956 // based on the section name, type, and flags.
957 return this->get_output_section(name
, name_key
, type
, flags
, order
, is_relro
);
960 // For incremental links, record the initial fixed layout of a section
961 // from the base file, and return a pointer to the Output_section.
963 template<int size
, bool big_endian
>
965 Layout::init_fixed_output_section(const char* name
,
966 elfcpp::Shdr
<size
, big_endian
>& shdr
)
968 unsigned int sh_type
= shdr
.get_sh_type();
970 // We preserve the layout of PROGBITS, NOBITS, INIT_ARRAY, FINI_ARRAY,
971 // PRE_INIT_ARRAY, and NOTE sections.
972 // All others will be created from scratch and reallocated.
973 if (!can_incremental_update(sh_type
))
976 // If we're generating a .gdb_index section, we need to regenerate
978 if (parameters
->options().gdb_index()
979 && sh_type
== elfcpp::SHT_PROGBITS
980 && strcmp(name
, ".gdb_index") == 0)
983 typename
elfcpp::Elf_types
<size
>::Elf_Addr sh_addr
= shdr
.get_sh_addr();
984 typename
elfcpp::Elf_types
<size
>::Elf_Off sh_offset
= shdr
.get_sh_offset();
985 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
986 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_flags
= shdr
.get_sh_flags();
987 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_addralign
=
988 shdr
.get_sh_addralign();
990 // Make the output section.
991 Stringpool::Key name_key
;
992 name
= this->namepool_
.add(name
, true, &name_key
);
993 Output_section
* os
= this->get_output_section(name
, name_key
, sh_type
,
994 sh_flags
, ORDER_INVALID
, false);
995 os
->set_fixed_layout(sh_addr
, sh_offset
, sh_size
, sh_addralign
);
996 if (sh_type
!= elfcpp::SHT_NOBITS
)
997 this->free_list_
.remove(sh_offset
, sh_offset
+ sh_size
);
1001 // Return the output section to use for input section SHNDX, with name
1002 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
1003 // index of a relocation section which applies to this section, or 0
1004 // if none, or -1U if more than one. RELOC_TYPE is the type of the
1005 // relocation section if there is one. Set *OFF to the offset of this
1006 // input section without the output section. Return NULL if the
1007 // section should be discarded. Set *OFF to -1 if the section
1008 // contents should not be written directly to the output file, but
1009 // will instead receive special handling.
1011 template<int size
, bool big_endian
>
1013 Layout::layout(Sized_relobj_file
<size
, big_endian
>* object
, unsigned int shndx
,
1014 const char* name
, const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1015 unsigned int reloc_shndx
, unsigned int, off_t
* off
)
1019 if (!this->include_section(object
, name
, shdr
))
1022 elfcpp::Elf_Word sh_type
= shdr
.get_sh_type();
1024 // In a relocatable link a grouped section must not be combined with
1025 // any other sections.
1027 if (parameters
->options().relocatable()
1028 && (shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) != 0)
1030 name
= this->namepool_
.add(name
, true, NULL
);
1031 os
= this->make_output_section(name
, sh_type
, shdr
.get_sh_flags(),
1032 ORDER_INVALID
, false);
1036 os
= this->choose_output_section(object
, name
, sh_type
,
1037 shdr
.get_sh_flags(), true,
1038 ORDER_INVALID
, false);
1043 // By default the GNU linker sorts input sections whose names match
1044 // .ctors.*, .dtors.*, .init_array.*, or .fini_array.*. The
1045 // sections are sorted by name. This is used to implement
1046 // constructor priority ordering. We are compatible. When we put
1047 // .ctor sections in .init_array and .dtor sections in .fini_array,
1048 // we must also sort plain .ctor and .dtor sections.
1049 if (!this->script_options_
->saw_sections_clause()
1050 && !parameters
->options().relocatable()
1051 && (is_prefix_of(".ctors.", name
)
1052 || is_prefix_of(".dtors.", name
)
1053 || is_prefix_of(".init_array.", name
)
1054 || is_prefix_of(".fini_array.", name
)
1055 || (parameters
->options().ctors_in_init_array()
1056 && (strcmp(name
, ".ctors") == 0
1057 || strcmp(name
, ".dtors") == 0))))
1058 os
->set_must_sort_attached_input_sections();
1060 // If this is a .ctors or .ctors.* section being mapped to a
1061 // .init_array section, or a .dtors or .dtors.* section being mapped
1062 // to a .fini_array section, we will need to reverse the words if
1063 // there is more than one. Record this section for later. See
1064 // ctors_sections_in_init_array above.
1065 if (!this->script_options_
->saw_sections_clause()
1066 && !parameters
->options().relocatable()
1067 && shdr
.get_sh_size() > size
/ 8
1068 && (((strcmp(name
, ".ctors") == 0
1069 || is_prefix_of(".ctors.", name
))
1070 && strcmp(os
->name(), ".init_array") == 0)
1071 || ((strcmp(name
, ".dtors") == 0
1072 || is_prefix_of(".dtors.", name
))
1073 && strcmp(os
->name(), ".fini_array") == 0)))
1074 ctors_sections_in_init_array
.insert(Section_id(object
, shndx
));
1076 // FIXME: Handle SHF_LINK_ORDER somewhere.
1078 elfcpp::Elf_Xword orig_flags
= os
->flags();
1080 *off
= os
->add_input_section(this, object
, shndx
, name
, shdr
, reloc_shndx
,
1081 this->script_options_
->saw_sections_clause());
1083 // If the flags changed, we may have to change the order.
1084 if ((orig_flags
& elfcpp::SHF_ALLOC
) != 0)
1086 orig_flags
&= (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1087 elfcpp::Elf_Xword new_flags
=
1088 os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1089 if (orig_flags
!= new_flags
)
1090 os
->set_order(this->default_section_order(os
, false));
1093 this->have_added_input_section_
= true;
1098 // Handle a relocation section when doing a relocatable link.
1100 template<int size
, bool big_endian
>
1102 Layout::layout_reloc(Sized_relobj_file
<size
, big_endian
>* object
,
1104 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1105 Output_section
* data_section
,
1106 Relocatable_relocs
* rr
)
1108 gold_assert(parameters
->options().relocatable()
1109 || parameters
->options().emit_relocs());
1111 int sh_type
= shdr
.get_sh_type();
1114 if (sh_type
== elfcpp::SHT_REL
)
1116 else if (sh_type
== elfcpp::SHT_RELA
)
1120 name
+= data_section
->name();
1122 // In a relocatable link relocs for a grouped section must not be
1123 // combined with other reloc sections.
1125 if (!parameters
->options().relocatable()
1126 || (data_section
->flags() & elfcpp::SHF_GROUP
) == 0)
1127 os
= this->choose_output_section(object
, name
.c_str(), sh_type
,
1128 shdr
.get_sh_flags(), false,
1129 ORDER_INVALID
, false);
1132 const char* n
= this->namepool_
.add(name
.c_str(), true, NULL
);
1133 os
= this->make_output_section(n
, sh_type
, shdr
.get_sh_flags(),
1134 ORDER_INVALID
, false);
1137 os
->set_should_link_to_symtab();
1138 os
->set_info_section(data_section
);
1140 Output_section_data
* posd
;
1141 if (sh_type
== elfcpp::SHT_REL
)
1143 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rel_size
);
1144 posd
= new Output_relocatable_relocs
<elfcpp::SHT_REL
,
1148 else if (sh_type
== elfcpp::SHT_RELA
)
1150 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rela_size
);
1151 posd
= new Output_relocatable_relocs
<elfcpp::SHT_RELA
,
1158 os
->add_output_section_data(posd
);
1159 rr
->set_output_data(posd
);
1164 // Handle a group section when doing a relocatable link.
1166 template<int size
, bool big_endian
>
1168 Layout::layout_group(Symbol_table
* symtab
,
1169 Sized_relobj_file
<size
, big_endian
>* object
,
1171 const char* group_section_name
,
1172 const char* signature
,
1173 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1174 elfcpp::Elf_Word flags
,
1175 std::vector
<unsigned int>* shndxes
)
1177 gold_assert(parameters
->options().relocatable());
1178 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_GROUP
);
1179 group_section_name
= this->namepool_
.add(group_section_name
, true, NULL
);
1180 Output_section
* os
= this->make_output_section(group_section_name
,
1182 shdr
.get_sh_flags(),
1183 ORDER_INVALID
, false);
1185 // We need to find a symbol with the signature in the symbol table.
1186 // If we don't find one now, we need to look again later.
1187 Symbol
* sym
= symtab
->lookup(signature
, NULL
);
1189 os
->set_info_symndx(sym
);
1192 // Reserve some space to minimize reallocations.
1193 if (this->group_signatures_
.empty())
1194 this->group_signatures_
.reserve(this->number_of_input_files_
* 16);
1196 // We will wind up using a symbol whose name is the signature.
1197 // So just put the signature in the symbol name pool to save it.
1198 signature
= symtab
->canonicalize_name(signature
);
1199 this->group_signatures_
.push_back(Group_signature(os
, signature
));
1202 os
->set_should_link_to_symtab();
1205 section_size_type entry_count
=
1206 convert_to_section_size_type(shdr
.get_sh_size() / 4);
1207 Output_section_data
* posd
=
1208 new Output_data_group
<size
, big_endian
>(object
, entry_count
, flags
,
1210 os
->add_output_section_data(posd
);
1213 // Special GNU handling of sections name .eh_frame. They will
1214 // normally hold exception frame data as defined by the C++ ABI
1215 // (http://codesourcery.com/cxx-abi/).
1217 template<int size
, bool big_endian
>
1219 Layout::layout_eh_frame(Sized_relobj_file
<size
, big_endian
>* object
,
1220 const unsigned char* symbols
,
1222 const unsigned char* symbol_names
,
1223 off_t symbol_names_size
,
1225 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1226 unsigned int reloc_shndx
, unsigned int reloc_type
,
1229 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
1230 || shdr
.get_sh_type() == elfcpp::SHT_X86_64_UNWIND
);
1231 gold_assert((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
1233 Output_section
* os
= this->make_eh_frame_section(object
);
1237 gold_assert(this->eh_frame_section_
== os
);
1239 elfcpp::Elf_Xword orig_flags
= os
->flags();
1241 if (!parameters
->incremental()
1242 && this->eh_frame_data_
->add_ehframe_input_section(object
,
1251 os
->update_flags_for_input_section(shdr
.get_sh_flags());
1253 // A writable .eh_frame section is a RELRO section.
1254 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1255 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1258 os
->set_order(ORDER_RELRO
);
1261 // We found a .eh_frame section we are going to optimize, so now
1262 // we can add the set of optimized sections to the output
1263 // section. We need to postpone adding this until we've found a
1264 // section we can optimize so that the .eh_frame section in
1265 // crtbegin.o winds up at the start of the output section.
1266 if (!this->added_eh_frame_data_
)
1268 os
->add_output_section_data(this->eh_frame_data_
);
1269 this->added_eh_frame_data_
= true;
1275 // We couldn't handle this .eh_frame section for some reason.
1276 // Add it as a normal section.
1277 bool saw_sections_clause
= this->script_options_
->saw_sections_clause();
1278 *off
= os
->add_input_section(this, object
, shndx
, ".eh_frame", shdr
,
1279 reloc_shndx
, saw_sections_clause
);
1280 this->have_added_input_section_
= true;
1282 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1283 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1284 os
->set_order(this->default_section_order(os
, false));
1290 // Create and return the magic .eh_frame section. Create
1291 // .eh_frame_hdr also if appropriate. OBJECT is the object with the
1292 // input .eh_frame section; it may be NULL.
1295 Layout::make_eh_frame_section(const Relobj
* object
)
1297 // FIXME: On x86_64, this could use SHT_X86_64_UNWIND rather than
1299 Output_section
* os
= this->choose_output_section(object
, ".eh_frame",
1300 elfcpp::SHT_PROGBITS
,
1301 elfcpp::SHF_ALLOC
, false,
1302 ORDER_EHFRAME
, false);
1306 if (this->eh_frame_section_
== NULL
)
1308 this->eh_frame_section_
= os
;
1309 this->eh_frame_data_
= new Eh_frame();
1311 // For incremental linking, we do not optimize .eh_frame sections
1312 // or create a .eh_frame_hdr section.
1313 if (parameters
->options().eh_frame_hdr() && !parameters
->incremental())
1315 Output_section
* hdr_os
=
1316 this->choose_output_section(NULL
, ".eh_frame_hdr",
1317 elfcpp::SHT_PROGBITS
,
1318 elfcpp::SHF_ALLOC
, false,
1319 ORDER_EHFRAME
, false);
1323 Eh_frame_hdr
* hdr_posd
= new Eh_frame_hdr(os
,
1324 this->eh_frame_data_
);
1325 hdr_os
->add_output_section_data(hdr_posd
);
1327 hdr_os
->set_after_input_sections();
1329 if (!this->script_options_
->saw_phdrs_clause())
1331 Output_segment
* hdr_oseg
;
1332 hdr_oseg
= this->make_output_segment(elfcpp::PT_GNU_EH_FRAME
,
1334 hdr_oseg
->add_output_section_to_nonload(hdr_os
,
1338 this->eh_frame_data_
->set_eh_frame_hdr(hdr_posd
);
1346 // Add an exception frame for a PLT. This is called from target code.
1349 Layout::add_eh_frame_for_plt(Output_data
* plt
, const unsigned char* cie_data
,
1350 size_t cie_length
, const unsigned char* fde_data
,
1353 if (parameters
->incremental())
1355 // FIXME: Maybe this could work some day....
1358 Output_section
* os
= this->make_eh_frame_section(NULL
);
1361 this->eh_frame_data_
->add_ehframe_for_plt(plt
, cie_data
, cie_length
,
1362 fde_data
, fde_length
);
1363 if (!this->added_eh_frame_data_
)
1365 os
->add_output_section_data(this->eh_frame_data_
);
1366 this->added_eh_frame_data_
= true;
1370 // Scan a .debug_info or .debug_types section, and add summary
1371 // information to the .gdb_index section.
1373 template<int size
, bool big_endian
>
1375 Layout::add_to_gdb_index(bool is_type_unit
,
1376 Sized_relobj
<size
, big_endian
>* object
,
1377 const unsigned char* symbols
,
1380 unsigned int reloc_shndx
,
1381 unsigned int reloc_type
)
1383 if (this->gdb_index_data_
== NULL
)
1385 Output_section
* os
= this->choose_output_section(NULL
, ".gdb_index",
1386 elfcpp::SHT_PROGBITS
, 0,
1387 false, ORDER_INVALID
,
1392 this->gdb_index_data_
= new Gdb_index(os
);
1393 os
->add_output_section_data(this->gdb_index_data_
);
1394 os
->set_after_input_sections();
1397 this->gdb_index_data_
->scan_debug_info(is_type_unit
, object
, symbols
,
1398 symbols_size
, shndx
, reloc_shndx
,
1402 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
1403 // the output section.
1406 Layout::add_output_section_data(const char* name
, elfcpp::Elf_Word type
,
1407 elfcpp::Elf_Xword flags
,
1408 Output_section_data
* posd
,
1409 Output_section_order order
, bool is_relro
)
1411 Output_section
* os
= this->choose_output_section(NULL
, name
, type
, flags
,
1412 false, order
, is_relro
);
1414 os
->add_output_section_data(posd
);
1418 // Map section flags to segment flags.
1421 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags
)
1423 elfcpp::Elf_Word ret
= elfcpp::PF_R
;
1424 if ((flags
& elfcpp::SHF_WRITE
) != 0)
1425 ret
|= elfcpp::PF_W
;
1426 if ((flags
& elfcpp::SHF_EXECINSTR
) != 0)
1427 ret
|= elfcpp::PF_X
;
1431 // Make a new Output_section, and attach it to segments as
1432 // appropriate. ORDER is the order in which this section should
1433 // appear in the output segment. IS_RELRO is true if this is a relro
1434 // (read-only after relocations) section.
1437 Layout::make_output_section(const char* name
, elfcpp::Elf_Word type
,
1438 elfcpp::Elf_Xword flags
,
1439 Output_section_order order
, bool is_relro
)
1442 if ((flags
& elfcpp::SHF_ALLOC
) == 0
1443 && strcmp(parameters
->options().compress_debug_sections(), "none") != 0
1444 && is_compressible_debug_section(name
))
1445 os
= new Output_compressed_section(¶meters
->options(), name
, type
,
1447 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1448 && parameters
->options().strip_debug_non_line()
1449 && strcmp(".debug_abbrev", name
) == 0)
1451 os
= this->debug_abbrev_
= new Output_reduced_debug_abbrev_section(
1453 if (this->debug_info_
)
1454 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1456 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1457 && parameters
->options().strip_debug_non_line()
1458 && strcmp(".debug_info", name
) == 0)
1460 os
= this->debug_info_
= new Output_reduced_debug_info_section(
1462 if (this->debug_abbrev_
)
1463 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1467 // Sometimes .init_array*, .preinit_array* and .fini_array* do
1468 // not have correct section types. Force them here.
1469 if (type
== elfcpp::SHT_PROGBITS
)
1471 if (is_prefix_of(".init_array", name
))
1472 type
= elfcpp::SHT_INIT_ARRAY
;
1473 else if (is_prefix_of(".preinit_array", name
))
1474 type
= elfcpp::SHT_PREINIT_ARRAY
;
1475 else if (is_prefix_of(".fini_array", name
))
1476 type
= elfcpp::SHT_FINI_ARRAY
;
1479 // FIXME: const_cast is ugly.
1480 Target
* target
= const_cast<Target
*>(¶meters
->target());
1481 os
= target
->make_output_section(name
, type
, flags
);
1484 // With -z relro, we have to recognize the special sections by name.
1485 // There is no other way.
1486 bool is_relro_local
= false;
1487 if (!this->script_options_
->saw_sections_clause()
1488 && parameters
->options().relro()
1489 && (flags
& elfcpp::SHF_ALLOC
) != 0
1490 && (flags
& elfcpp::SHF_WRITE
) != 0)
1492 if (type
== elfcpp::SHT_PROGBITS
)
1494 if ((flags
& elfcpp::SHF_TLS
) != 0)
1496 else if (strcmp(name
, ".data.rel.ro") == 0)
1498 else if (strcmp(name
, ".data.rel.ro.local") == 0)
1501 is_relro_local
= true;
1503 else if (strcmp(name
, ".ctors") == 0
1504 || strcmp(name
, ".dtors") == 0
1505 || strcmp(name
, ".jcr") == 0)
1508 else if (type
== elfcpp::SHT_INIT_ARRAY
1509 || type
== elfcpp::SHT_FINI_ARRAY
1510 || type
== elfcpp::SHT_PREINIT_ARRAY
)
1517 if (order
== ORDER_INVALID
&& (flags
& elfcpp::SHF_ALLOC
) != 0)
1518 order
= this->default_section_order(os
, is_relro_local
);
1520 os
->set_order(order
);
1522 parameters
->target().new_output_section(os
);
1524 this->section_list_
.push_back(os
);
1526 // The GNU linker by default sorts some sections by priority, so we
1527 // do the same. We need to know that this might happen before we
1528 // attach any input sections.
1529 if (!this->script_options_
->saw_sections_clause()
1530 && !parameters
->options().relocatable()
1531 && (strcmp(name
, ".init_array") == 0
1532 || strcmp(name
, ".fini_array") == 0
1533 || (!parameters
->options().ctors_in_init_array()
1534 && (strcmp(name
, ".ctors") == 0
1535 || strcmp(name
, ".dtors") == 0))))
1536 os
->set_may_sort_attached_input_sections();
1538 // Check for .stab*str sections, as .stab* sections need to link to
1540 if (type
== elfcpp::SHT_STRTAB
1541 && !this->have_stabstr_section_
1542 && strncmp(name
, ".stab", 5) == 0
1543 && strcmp(name
+ strlen(name
) - 3, "str") == 0)
1544 this->have_stabstr_section_
= true;
1546 // During a full incremental link, we add patch space to most
1547 // PROGBITS and NOBITS sections. Flag those that may be
1548 // arbitrarily padded.
1549 if ((type
== elfcpp::SHT_PROGBITS
|| type
== elfcpp::SHT_NOBITS
)
1550 && order
!= ORDER_INTERP
1551 && order
!= ORDER_INIT
1552 && order
!= ORDER_PLT
1553 && order
!= ORDER_FINI
1554 && order
!= ORDER_RELRO_LAST
1555 && order
!= ORDER_NON_RELRO_FIRST
1556 && strcmp(name
, ".eh_frame") != 0
1557 && strcmp(name
, ".ctors") != 0
1558 && strcmp(name
, ".dtors") != 0
1559 && strcmp(name
, ".jcr") != 0)
1561 os
->set_is_patch_space_allowed();
1563 // Certain sections require "holes" to be filled with
1564 // specific fill patterns. These fill patterns may have
1565 // a minimum size, so we must prevent allocations from the
1566 // free list that leave a hole smaller than the minimum.
1567 if (strcmp(name
, ".debug_info") == 0)
1568 os
->set_free_space_fill(new Output_fill_debug_info(false));
1569 else if (strcmp(name
, ".debug_types") == 0)
1570 os
->set_free_space_fill(new Output_fill_debug_info(true));
1571 else if (strcmp(name
, ".debug_line") == 0)
1572 os
->set_free_space_fill(new Output_fill_debug_line());
1575 // If we have already attached the sections to segments, then we
1576 // need to attach this one now. This happens for sections created
1577 // directly by the linker.
1578 if (this->sections_are_attached_
)
1579 this->attach_section_to_segment(¶meters
->target(), os
);
1584 // Return the default order in which a section should be placed in an
1585 // output segment. This function captures a lot of the ideas in
1586 // ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
1587 // linker created section is normally set when the section is created;
1588 // this function is used for input sections.
1590 Output_section_order
1591 Layout::default_section_order(Output_section
* os
, bool is_relro_local
)
1593 gold_assert((os
->flags() & elfcpp::SHF_ALLOC
) != 0);
1594 bool is_write
= (os
->flags() & elfcpp::SHF_WRITE
) != 0;
1595 bool is_execinstr
= (os
->flags() & elfcpp::SHF_EXECINSTR
) != 0;
1596 bool is_bss
= false;
1601 case elfcpp::SHT_PROGBITS
:
1603 case elfcpp::SHT_NOBITS
:
1606 case elfcpp::SHT_RELA
:
1607 case elfcpp::SHT_REL
:
1609 return ORDER_DYNAMIC_RELOCS
;
1611 case elfcpp::SHT_HASH
:
1612 case elfcpp::SHT_DYNAMIC
:
1613 case elfcpp::SHT_SHLIB
:
1614 case elfcpp::SHT_DYNSYM
:
1615 case elfcpp::SHT_GNU_HASH
:
1616 case elfcpp::SHT_GNU_verdef
:
1617 case elfcpp::SHT_GNU_verneed
:
1618 case elfcpp::SHT_GNU_versym
:
1620 return ORDER_DYNAMIC_LINKER
;
1622 case elfcpp::SHT_NOTE
:
1623 return is_write
? ORDER_RW_NOTE
: ORDER_RO_NOTE
;
1626 if ((os
->flags() & elfcpp::SHF_TLS
) != 0)
1627 return is_bss
? ORDER_TLS_BSS
: ORDER_TLS_DATA
;
1629 if (!is_bss
&& !is_write
)
1633 if (strcmp(os
->name(), ".init") == 0)
1635 else if (strcmp(os
->name(), ".fini") == 0)
1638 return is_execinstr
? ORDER_TEXT
: ORDER_READONLY
;
1642 return is_relro_local
? ORDER_RELRO_LOCAL
: ORDER_RELRO
;
1644 if (os
->is_small_section())
1645 return is_bss
? ORDER_SMALL_BSS
: ORDER_SMALL_DATA
;
1646 if (os
->is_large_section())
1647 return is_bss
? ORDER_LARGE_BSS
: ORDER_LARGE_DATA
;
1649 return is_bss
? ORDER_BSS
: ORDER_DATA
;
1652 // Attach output sections to segments. This is called after we have
1653 // seen all the input sections.
1656 Layout::attach_sections_to_segments(const Target
* target
)
1658 for (Section_list::iterator p
= this->section_list_
.begin();
1659 p
!= this->section_list_
.end();
1661 this->attach_section_to_segment(target
, *p
);
1663 this->sections_are_attached_
= true;
1666 // Attach an output section to a segment.
1669 Layout::attach_section_to_segment(const Target
* target
, Output_section
* os
)
1671 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0)
1672 this->unattached_section_list_
.push_back(os
);
1674 this->attach_allocated_section_to_segment(target
, os
);
1677 // Attach an allocated output section to a segment.
1680 Layout::attach_allocated_section_to_segment(const Target
* target
,
1683 elfcpp::Elf_Xword flags
= os
->flags();
1684 gold_assert((flags
& elfcpp::SHF_ALLOC
) != 0);
1686 if (parameters
->options().relocatable())
1689 // If we have a SECTIONS clause, we can't handle the attachment to
1690 // segments until after we've seen all the sections.
1691 if (this->script_options_
->saw_sections_clause())
1694 gold_assert(!this->script_options_
->saw_phdrs_clause());
1696 // This output section goes into a PT_LOAD segment.
1698 elfcpp::Elf_Word seg_flags
= Layout::section_flags_to_segment(flags
);
1700 // Check for --section-start.
1702 bool is_address_set
= parameters
->options().section_start(os
->name(), &addr
);
1704 // In general the only thing we really care about for PT_LOAD
1705 // segments is whether or not they are writable or executable,
1706 // so that is how we search for them.
1707 // Large data sections also go into their own PT_LOAD segment.
1708 // People who need segments sorted on some other basis will
1709 // have to use a linker script.
1711 Segment_list::const_iterator p
;
1712 for (p
= this->segment_list_
.begin();
1713 p
!= this->segment_list_
.end();
1716 if ((*p
)->type() != elfcpp::PT_LOAD
)
1718 if (!parameters
->options().omagic()
1719 && ((*p
)->flags() & elfcpp::PF_W
) != (seg_flags
& elfcpp::PF_W
))
1721 if ((target
->isolate_execinstr() || parameters
->options().rosegment())
1722 && ((*p
)->flags() & elfcpp::PF_X
) != (seg_flags
& elfcpp::PF_X
))
1724 // If -Tbss was specified, we need to separate the data and BSS
1726 if (parameters
->options().user_set_Tbss())
1728 if ((os
->type() == elfcpp::SHT_NOBITS
)
1729 == (*p
)->has_any_data_sections())
1732 if (os
->is_large_data_section() && !(*p
)->is_large_data_segment())
1737 if ((*p
)->are_addresses_set())
1740 (*p
)->add_initial_output_data(os
);
1741 (*p
)->update_flags_for_output_section(seg_flags
);
1742 (*p
)->set_addresses(addr
, addr
);
1746 (*p
)->add_output_section_to_load(this, os
, seg_flags
);
1750 if (p
== this->segment_list_
.end())
1752 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_LOAD
,
1754 if (os
->is_large_data_section())
1755 oseg
->set_is_large_data_segment();
1756 oseg
->add_output_section_to_load(this, os
, seg_flags
);
1758 oseg
->set_addresses(addr
, addr
);
1761 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1763 if (os
->type() == elfcpp::SHT_NOTE
)
1765 // See if we already have an equivalent PT_NOTE segment.
1766 for (p
= this->segment_list_
.begin();
1767 p
!= segment_list_
.end();
1770 if ((*p
)->type() == elfcpp::PT_NOTE
1771 && (((*p
)->flags() & elfcpp::PF_W
)
1772 == (seg_flags
& elfcpp::PF_W
)))
1774 (*p
)->add_output_section_to_nonload(os
, seg_flags
);
1779 if (p
== this->segment_list_
.end())
1781 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_NOTE
,
1783 oseg
->add_output_section_to_nonload(os
, seg_flags
);
1787 // If we see a loadable SHF_TLS section, we create a PT_TLS
1788 // segment. There can only be one such segment.
1789 if ((flags
& elfcpp::SHF_TLS
) != 0)
1791 if (this->tls_segment_
== NULL
)
1792 this->make_output_segment(elfcpp::PT_TLS
, seg_flags
);
1793 this->tls_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1796 // If -z relro is in effect, and we see a relro section, we create a
1797 // PT_GNU_RELRO segment. There can only be one such segment.
1798 if (os
->is_relro() && parameters
->options().relro())
1800 gold_assert(seg_flags
== (elfcpp::PF_R
| elfcpp::PF_W
));
1801 if (this->relro_segment_
== NULL
)
1802 this->make_output_segment(elfcpp::PT_GNU_RELRO
, seg_flags
);
1803 this->relro_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1806 // If we see a section named .interp, put it into a PT_INTERP
1807 // segment. This seems broken to me, but this is what GNU ld does,
1808 // and glibc expects it.
1809 if (strcmp(os
->name(), ".interp") == 0
1810 && !this->script_options_
->saw_phdrs_clause())
1812 if (this->interp_segment_
== NULL
)
1813 this->make_output_segment(elfcpp::PT_INTERP
, seg_flags
);
1815 gold_warning(_("multiple '.interp' sections in input files "
1816 "may cause confusing PT_INTERP segment"));
1817 this->interp_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1821 // Make an output section for a script.
1824 Layout::make_output_section_for_script(
1826 Script_sections::Section_type section_type
)
1828 name
= this->namepool_
.add(name
, false, NULL
);
1829 elfcpp::Elf_Xword sh_flags
= elfcpp::SHF_ALLOC
;
1830 if (section_type
== Script_sections::ST_NOLOAD
)
1832 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_PROGBITS
,
1833 sh_flags
, ORDER_INVALID
,
1835 os
->set_found_in_sections_clause();
1836 if (section_type
== Script_sections::ST_NOLOAD
)
1837 os
->set_is_noload();
1841 // Return the number of segments we expect to see.
1844 Layout::expected_segment_count() const
1846 size_t ret
= this->segment_list_
.size();
1848 // If we didn't see a SECTIONS clause in a linker script, we should
1849 // already have the complete list of segments. Otherwise we ask the
1850 // SECTIONS clause how many segments it expects, and add in the ones
1851 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1853 if (!this->script_options_
->saw_sections_clause())
1857 const Script_sections
* ss
= this->script_options_
->script_sections();
1858 return ret
+ ss
->expected_segment_count(this);
1862 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
1863 // is whether we saw a .note.GNU-stack section in the object file.
1864 // GNU_STACK_FLAGS is the section flags. The flags give the
1865 // protection required for stack memory. We record this in an
1866 // executable as a PT_GNU_STACK segment. If an object file does not
1867 // have a .note.GNU-stack segment, we must assume that it is an old
1868 // object. On some targets that will force an executable stack.
1871 Layout::layout_gnu_stack(bool seen_gnu_stack
, uint64_t gnu_stack_flags
,
1874 if (!seen_gnu_stack
)
1876 this->input_without_gnu_stack_note_
= true;
1877 if (parameters
->options().warn_execstack()
1878 && parameters
->target().is_default_stack_executable())
1879 gold_warning(_("%s: missing .note.GNU-stack section"
1880 " implies executable stack"),
1881 obj
->name().c_str());
1885 this->input_with_gnu_stack_note_
= true;
1886 if ((gnu_stack_flags
& elfcpp::SHF_EXECINSTR
) != 0)
1888 this->input_requires_executable_stack_
= true;
1889 if (parameters
->options().warn_execstack()
1890 || parameters
->options().is_stack_executable())
1891 gold_warning(_("%s: requires executable stack"),
1892 obj
->name().c_str());
1897 // Create automatic note sections.
1900 Layout::create_notes()
1902 this->create_gold_note();
1903 this->create_executable_stack_info();
1904 this->create_build_id();
1907 // Create the dynamic sections which are needed before we read the
1911 Layout::create_initial_dynamic_sections(Symbol_table
* symtab
)
1913 if (parameters
->doing_static_link())
1916 this->dynamic_section_
= this->choose_output_section(NULL
, ".dynamic",
1917 elfcpp::SHT_DYNAMIC
,
1919 | elfcpp::SHF_WRITE
),
1923 // A linker script may discard .dynamic, so check for NULL.
1924 if (this->dynamic_section_
!= NULL
)
1926 this->dynamic_symbol_
=
1927 symtab
->define_in_output_data("_DYNAMIC", NULL
,
1928 Symbol_table::PREDEFINED
,
1929 this->dynamic_section_
, 0, 0,
1930 elfcpp::STT_OBJECT
, elfcpp::STB_LOCAL
,
1931 elfcpp::STV_HIDDEN
, 0, false, false);
1933 this->dynamic_data_
= new Output_data_dynamic(&this->dynpool_
);
1935 this->dynamic_section_
->add_output_section_data(this->dynamic_data_
);
1939 // For each output section whose name can be represented as C symbol,
1940 // define __start and __stop symbols for the section. This is a GNU
1944 Layout::define_section_symbols(Symbol_table
* symtab
)
1946 for (Section_list::const_iterator p
= this->section_list_
.begin();
1947 p
!= this->section_list_
.end();
1950 const char* const name
= (*p
)->name();
1951 if (is_cident(name
))
1953 const std::string
name_string(name
);
1954 const std::string
start_name(cident_section_start_prefix
1956 const std::string
stop_name(cident_section_stop_prefix
1959 symtab
->define_in_output_data(start_name
.c_str(),
1961 Symbol_table::PREDEFINED
,
1967 elfcpp::STV_DEFAULT
,
1969 false, // offset_is_from_end
1970 true); // only_if_ref
1972 symtab
->define_in_output_data(stop_name
.c_str(),
1974 Symbol_table::PREDEFINED
,
1980 elfcpp::STV_DEFAULT
,
1982 true, // offset_is_from_end
1983 true); // only_if_ref
1988 // Define symbols for group signatures.
1991 Layout::define_group_signatures(Symbol_table
* symtab
)
1993 for (Group_signatures::iterator p
= this->group_signatures_
.begin();
1994 p
!= this->group_signatures_
.end();
1997 Symbol
* sym
= symtab
->lookup(p
->signature
, NULL
);
1999 p
->section
->set_info_symndx(sym
);
2002 // Force the name of the group section to the group
2003 // signature, and use the group's section symbol as the
2004 // signature symbol.
2005 if (strcmp(p
->section
->name(), p
->signature
) != 0)
2007 const char* name
= this->namepool_
.add(p
->signature
,
2009 p
->section
->set_name(name
);
2011 p
->section
->set_needs_symtab_index();
2012 p
->section
->set_info_section_symndx(p
->section
);
2016 this->group_signatures_
.clear();
2019 // Find the first read-only PT_LOAD segment, creating one if
2023 Layout::find_first_load_seg(const Target
* target
)
2025 Output_segment
* best
= NULL
;
2026 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2027 p
!= this->segment_list_
.end();
2030 if ((*p
)->type() == elfcpp::PT_LOAD
2031 && ((*p
)->flags() & elfcpp::PF_R
) != 0
2032 && (parameters
->options().omagic()
2033 || ((*p
)->flags() & elfcpp::PF_W
) == 0)
2034 && (!target
->isolate_execinstr()
2035 || ((*p
)->flags() & elfcpp::PF_X
) == 0))
2037 if (best
== NULL
|| this->segment_precedes(*p
, best
))
2044 gold_assert(!this->script_options_
->saw_phdrs_clause());
2046 Output_segment
* load_seg
= this->make_output_segment(elfcpp::PT_LOAD
,
2051 // Save states of all current output segments. Store saved states
2052 // in SEGMENT_STATES.
2055 Layout::save_segments(Segment_states
* segment_states
)
2057 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2058 p
!= this->segment_list_
.end();
2061 Output_segment
* segment
= *p
;
2063 Output_segment
* copy
= new Output_segment(*segment
);
2064 (*segment_states
)[segment
] = copy
;
2068 // Restore states of output segments and delete any segment not found in
2072 Layout::restore_segments(const Segment_states
* segment_states
)
2074 // Go through the segment list and remove any segment added in the
2076 this->tls_segment_
= NULL
;
2077 this->relro_segment_
= NULL
;
2078 Segment_list::iterator list_iter
= this->segment_list_
.begin();
2079 while (list_iter
!= this->segment_list_
.end())
2081 Output_segment
* segment
= *list_iter
;
2082 Segment_states::const_iterator states_iter
=
2083 segment_states
->find(segment
);
2084 if (states_iter
!= segment_states
->end())
2086 const Output_segment
* copy
= states_iter
->second
;
2087 // Shallow copy to restore states.
2090 // Also fix up TLS and RELRO segment pointers as appropriate.
2091 if (segment
->type() == elfcpp::PT_TLS
)
2092 this->tls_segment_
= segment
;
2093 else if (segment
->type() == elfcpp::PT_GNU_RELRO
)
2094 this->relro_segment_
= segment
;
2100 list_iter
= this->segment_list_
.erase(list_iter
);
2101 // This is a segment created during section layout. It should be
2102 // safe to remove it since we should have removed all pointers to it.
2108 // Clean up after relaxation so that sections can be laid out again.
2111 Layout::clean_up_after_relaxation()
2113 // Restore the segments to point state just prior to the relaxation loop.
2114 Script_sections
* script_section
= this->script_options_
->script_sections();
2115 script_section
->release_segments();
2116 this->restore_segments(this->segment_states_
);
2118 // Reset section addresses and file offsets
2119 for (Section_list::iterator p
= this->section_list_
.begin();
2120 p
!= this->section_list_
.end();
2123 (*p
)->restore_states();
2125 // If an input section changes size because of relaxation,
2126 // we need to adjust the section offsets of all input sections.
2127 // after such a section.
2128 if ((*p
)->section_offsets_need_adjustment())
2129 (*p
)->adjust_section_offsets();
2131 (*p
)->reset_address_and_file_offset();
2134 // Reset special output object address and file offsets.
2135 for (Data_list::iterator p
= this->special_output_list_
.begin();
2136 p
!= this->special_output_list_
.end();
2138 (*p
)->reset_address_and_file_offset();
2140 // A linker script may have created some output section data objects.
2141 // They are useless now.
2142 for (Output_section_data_list::const_iterator p
=
2143 this->script_output_section_data_list_
.begin();
2144 p
!= this->script_output_section_data_list_
.end();
2147 this->script_output_section_data_list_
.clear();
2150 // Prepare for relaxation.
2153 Layout::prepare_for_relaxation()
2155 // Create an relaxation debug check if in debugging mode.
2156 if (is_debugging_enabled(DEBUG_RELAXATION
))
2157 this->relaxation_debug_check_
= new Relaxation_debug_check();
2159 // Save segment states.
2160 this->segment_states_
= new Segment_states();
2161 this->save_segments(this->segment_states_
);
2163 for(Section_list::const_iterator p
= this->section_list_
.begin();
2164 p
!= this->section_list_
.end();
2166 (*p
)->save_states();
2168 if (is_debugging_enabled(DEBUG_RELAXATION
))
2169 this->relaxation_debug_check_
->check_output_data_for_reset_values(
2170 this->section_list_
, this->special_output_list_
);
2172 // Also enable recording of output section data from scripts.
2173 this->record_output_section_data_from_script_
= true;
2176 // Relaxation loop body: If target has no relaxation, this runs only once
2177 // Otherwise, the target relaxation hook is called at the end of
2178 // each iteration. If the hook returns true, it means re-layout of
2179 // section is required.
2181 // The number of segments created by a linking script without a PHDRS
2182 // clause may be affected by section sizes and alignments. There is
2183 // a remote chance that relaxation causes different number of PT_LOAD
2184 // segments are created and sections are attached to different segments.
2185 // Therefore, we always throw away all segments created during section
2186 // layout. In order to be able to restart the section layout, we keep
2187 // a copy of the segment list right before the relaxation loop and use
2188 // that to restore the segments.
2190 // PASS is the current relaxation pass number.
2191 // SYMTAB is a symbol table.
2192 // PLOAD_SEG is the address of a pointer for the load segment.
2193 // PHDR_SEG is a pointer to the PHDR segment.
2194 // SEGMENT_HEADERS points to the output segment header.
2195 // FILE_HEADER points to the output file header.
2196 // PSHNDX is the address to store the output section index.
2199 Layout::relaxation_loop_body(
2202 Symbol_table
* symtab
,
2203 Output_segment
** pload_seg
,
2204 Output_segment
* phdr_seg
,
2205 Output_segment_headers
* segment_headers
,
2206 Output_file_header
* file_header
,
2207 unsigned int* pshndx
)
2209 // If this is not the first iteration, we need to clean up after
2210 // relaxation so that we can lay out the sections again.
2212 this->clean_up_after_relaxation();
2214 // If there is a SECTIONS clause, put all the input sections into
2215 // the required order.
2216 Output_segment
* load_seg
;
2217 if (this->script_options_
->saw_sections_clause())
2218 load_seg
= this->set_section_addresses_from_script(symtab
);
2219 else if (parameters
->options().relocatable())
2222 load_seg
= this->find_first_load_seg(target
);
2224 if (parameters
->options().oformat_enum()
2225 != General_options::OBJECT_FORMAT_ELF
)
2228 // If the user set the address of the text segment, that may not be
2229 // compatible with putting the segment headers and file headers into
2231 if (parameters
->options().user_set_Ttext()
2232 && parameters
->options().Ttext() % target
->common_pagesize() != 0)
2238 gold_assert(phdr_seg
== NULL
2240 || this->script_options_
->saw_sections_clause());
2242 // If the address of the load segment we found has been set by
2243 // --section-start rather than by a script, then adjust the VMA and
2244 // LMA downward if possible to include the file and section headers.
2245 uint64_t header_gap
= 0;
2246 if (load_seg
!= NULL
2247 && load_seg
->are_addresses_set()
2248 && !this->script_options_
->saw_sections_clause()
2249 && !parameters
->options().relocatable())
2251 file_header
->finalize_data_size();
2252 segment_headers
->finalize_data_size();
2253 size_t sizeof_headers
= (file_header
->data_size()
2254 + segment_headers
->data_size());
2255 const uint64_t abi_pagesize
= target
->abi_pagesize();
2256 uint64_t hdr_paddr
= load_seg
->paddr() - sizeof_headers
;
2257 hdr_paddr
&= ~(abi_pagesize
- 1);
2258 uint64_t subtract
= load_seg
->paddr() - hdr_paddr
;
2259 if (load_seg
->paddr() < subtract
|| load_seg
->vaddr() < subtract
)
2263 load_seg
->set_addresses(load_seg
->vaddr() - subtract
,
2264 load_seg
->paddr() - subtract
);
2265 header_gap
= subtract
- sizeof_headers
;
2269 // Lay out the segment headers.
2270 if (!parameters
->options().relocatable())
2272 gold_assert(segment_headers
!= NULL
);
2273 if (header_gap
!= 0 && load_seg
!= NULL
)
2275 Output_data_zero_fill
* z
= new Output_data_zero_fill(header_gap
, 1);
2276 load_seg
->add_initial_output_data(z
);
2278 if (load_seg
!= NULL
)
2279 load_seg
->add_initial_output_data(segment_headers
);
2280 if (phdr_seg
!= NULL
)
2281 phdr_seg
->add_initial_output_data(segment_headers
);
2284 // Lay out the file header.
2285 if (load_seg
!= NULL
)
2286 load_seg
->add_initial_output_data(file_header
);
2288 if (this->script_options_
->saw_phdrs_clause()
2289 && !parameters
->options().relocatable())
2291 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2292 // clause in a linker script.
2293 Script_sections
* ss
= this->script_options_
->script_sections();
2294 ss
->put_headers_in_phdrs(file_header
, segment_headers
);
2297 // We set the output section indexes in set_segment_offsets and
2298 // set_section_indexes.
2301 // Set the file offsets of all the segments, and all the sections
2304 if (!parameters
->options().relocatable())
2305 off
= this->set_segment_offsets(target
, load_seg
, pshndx
);
2307 off
= this->set_relocatable_section_offsets(file_header
, pshndx
);
2309 // Verify that the dummy relaxation does not change anything.
2310 if (is_debugging_enabled(DEBUG_RELAXATION
))
2313 this->relaxation_debug_check_
->read_sections(this->section_list_
);
2315 this->relaxation_debug_check_
->verify_sections(this->section_list_
);
2318 *pload_seg
= load_seg
;
2322 // Search the list of patterns and find the postion of the given section
2323 // name in the output section. If the section name matches a glob
2324 // pattern and a non-glob name, then the non-glob position takes
2325 // precedence. Return 0 if no match is found.
2328 Layout::find_section_order_index(const std::string
& section_name
)
2330 Unordered_map
<std::string
, unsigned int>::iterator map_it
;
2331 map_it
= this->input_section_position_
.find(section_name
);
2332 if (map_it
!= this->input_section_position_
.end())
2333 return map_it
->second
;
2335 // Absolute match failed. Linear search the glob patterns.
2336 std::vector
<std::string
>::iterator it
;
2337 for (it
= this->input_section_glob_
.begin();
2338 it
!= this->input_section_glob_
.end();
2341 if (fnmatch((*it
).c_str(), section_name
.c_str(), FNM_NOESCAPE
) == 0)
2343 map_it
= this->input_section_position_
.find(*it
);
2344 gold_assert(map_it
!= this->input_section_position_
.end());
2345 return map_it
->second
;
2351 // Read the sequence of input sections from the file specified with
2352 // option --section-ordering-file.
2355 Layout::read_layout_from_file()
2357 const char* filename
= parameters
->options().section_ordering_file();
2363 gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2364 filename
, strerror(errno
));
2366 std::getline(in
, line
); // this chops off the trailing \n, if any
2367 unsigned int position
= 1;
2368 this->set_section_ordering_specified();
2372 if (!line
.empty() && line
[line
.length() - 1] == '\r') // Windows
2373 line
.resize(line
.length() - 1);
2374 // Ignore comments, beginning with '#'
2377 std::getline(in
, line
);
2380 this->input_section_position_
[line
] = position
;
2381 // Store all glob patterns in a vector.
2382 if (is_wildcard_string(line
.c_str()))
2383 this->input_section_glob_
.push_back(line
);
2385 std::getline(in
, line
);
2389 // Finalize the layout. When this is called, we have created all the
2390 // output sections and all the output segments which are based on
2391 // input sections. We have several things to do, and we have to do
2392 // them in the right order, so that we get the right results correctly
2395 // 1) Finalize the list of output segments and create the segment
2398 // 2) Finalize the dynamic symbol table and associated sections.
2400 // 3) Determine the final file offset of all the output segments.
2402 // 4) Determine the final file offset of all the SHF_ALLOC output
2405 // 5) Create the symbol table sections and the section name table
2408 // 6) Finalize the symbol table: set symbol values to their final
2409 // value and make a final determination of which symbols are going
2410 // into the output symbol table.
2412 // 7) Create the section table header.
2414 // 8) Determine the final file offset of all the output sections which
2415 // are not SHF_ALLOC, including the section table header.
2417 // 9) Finalize the ELF file header.
2419 // This function returns the size of the output file.
2422 Layout::finalize(const Input_objects
* input_objects
, Symbol_table
* symtab
,
2423 Target
* target
, const Task
* task
)
2425 target
->finalize_sections(this, input_objects
, symtab
);
2427 this->count_local_symbols(task
, input_objects
);
2429 this->link_stabs_sections();
2431 Output_segment
* phdr_seg
= NULL
;
2432 if (!parameters
->options().relocatable() && !parameters
->doing_static_link())
2434 // There was a dynamic object in the link. We need to create
2435 // some information for the dynamic linker.
2437 // Create the PT_PHDR segment which will hold the program
2439 if (!this->script_options_
->saw_phdrs_clause())
2440 phdr_seg
= this->make_output_segment(elfcpp::PT_PHDR
, elfcpp::PF_R
);
2442 // Create the dynamic symbol table, including the hash table.
2443 Output_section
* dynstr
;
2444 std::vector
<Symbol
*> dynamic_symbols
;
2445 unsigned int local_dynamic_count
;
2446 Versions
versions(*this->script_options()->version_script_info(),
2448 this->create_dynamic_symtab(input_objects
, symtab
, &dynstr
,
2449 &local_dynamic_count
, &dynamic_symbols
,
2452 // Create the .interp section to hold the name of the
2453 // interpreter, and put it in a PT_INTERP segment. Don't do it
2454 // if we saw a .interp section in an input file.
2455 if ((!parameters
->options().shared()
2456 || parameters
->options().dynamic_linker() != NULL
)
2457 && this->interp_segment_
== NULL
)
2458 this->create_interp(target
);
2460 // Finish the .dynamic section to hold the dynamic data, and put
2461 // it in a PT_DYNAMIC segment.
2462 this->finish_dynamic_section(input_objects
, symtab
);
2464 // We should have added everything we need to the dynamic string
2466 this->dynpool_
.set_string_offsets();
2468 // Create the version sections. We can't do this until the
2469 // dynamic string table is complete.
2470 this->create_version_sections(&versions
, symtab
, local_dynamic_count
,
2471 dynamic_symbols
, dynstr
);
2473 // Set the size of the _DYNAMIC symbol. We can't do this until
2474 // after we call create_version_sections.
2475 this->set_dynamic_symbol_size(symtab
);
2478 // Create segment headers.
2479 Output_segment_headers
* segment_headers
=
2480 (parameters
->options().relocatable()
2482 : new Output_segment_headers(this->segment_list_
));
2484 // Lay out the file header.
2485 Output_file_header
* file_header
= new Output_file_header(target
, symtab
,
2488 this->special_output_list_
.push_back(file_header
);
2489 if (segment_headers
!= NULL
)
2490 this->special_output_list_
.push_back(segment_headers
);
2492 // Find approriate places for orphan output sections if we are using
2494 if (this->script_options_
->saw_sections_clause())
2495 this->place_orphan_sections_in_script();
2497 Output_segment
* load_seg
;
2502 // Take a snapshot of the section layout as needed.
2503 if (target
->may_relax())
2504 this->prepare_for_relaxation();
2506 // Run the relaxation loop to lay out sections.
2509 off
= this->relaxation_loop_body(pass
, target
, symtab
, &load_seg
,
2510 phdr_seg
, segment_headers
, file_header
,
2514 while (target
->may_relax()
2515 && target
->relax(pass
, input_objects
, symtab
, this, task
));
2517 // If there is a load segment that contains the file and program headers,
2518 // provide a symbol __ehdr_start pointing there.
2519 // A program can use this to examine itself robustly.
2520 if (load_seg
!= NULL
)
2521 symtab
->define_in_output_segment("__ehdr_start", NULL
,
2522 Symbol_table::PREDEFINED
, load_seg
, 0, 0,
2523 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
2524 elfcpp::STV_DEFAULT
, 0,
2525 Symbol::SEGMENT_START
, true);
2527 // Set the file offsets of all the non-data sections we've seen so
2528 // far which don't have to wait for the input sections. We need
2529 // this in order to finalize local symbols in non-allocated
2531 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2533 // Set the section indexes of all unallocated sections seen so far,
2534 // in case any of them are somehow referenced by a symbol.
2535 shndx
= this->set_section_indexes(shndx
);
2537 // Create the symbol table sections.
2538 this->create_symtab_sections(input_objects
, symtab
, shndx
, &off
);
2539 if (!parameters
->doing_static_link())
2540 this->assign_local_dynsym_offsets(input_objects
);
2542 // Process any symbol assignments from a linker script. This must
2543 // be called after the symbol table has been finalized.
2544 this->script_options_
->finalize_symbols(symtab
, this);
2546 // Create the incremental inputs sections.
2547 if (this->incremental_inputs_
)
2549 this->incremental_inputs_
->finalize();
2550 this->create_incremental_info_sections(symtab
);
2553 // Create the .shstrtab section.
2554 Output_section
* shstrtab_section
= this->create_shstrtab();
2556 // Set the file offsets of the rest of the non-data sections which
2557 // don't have to wait for the input sections.
2558 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2560 // Now that all sections have been created, set the section indexes
2561 // for any sections which haven't been done yet.
2562 shndx
= this->set_section_indexes(shndx
);
2564 // Create the section table header.
2565 this->create_shdrs(shstrtab_section
, &off
);
2567 // If there are no sections which require postprocessing, we can
2568 // handle the section names now, and avoid a resize later.
2569 if (!this->any_postprocessing_sections_
)
2571 off
= this->set_section_offsets(off
,
2572 POSTPROCESSING_SECTIONS_PASS
);
2574 this->set_section_offsets(off
,
2575 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
2578 file_header
->set_section_info(this->section_headers_
, shstrtab_section
);
2580 // Now we know exactly where everything goes in the output file
2581 // (except for non-allocated sections which require postprocessing).
2582 Output_data::layout_complete();
2584 this->output_file_size_
= off
;
2589 // Create a note header following the format defined in the ELF ABI.
2590 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
2591 // of the section to create, DESCSZ is the size of the descriptor.
2592 // ALLOCATE is true if the section should be allocated in memory.
2593 // This returns the new note section. It sets *TRAILING_PADDING to
2594 // the number of trailing zero bytes required.
2597 Layout::create_note(const char* name
, int note_type
,
2598 const char* section_name
, size_t descsz
,
2599 bool allocate
, size_t* trailing_padding
)
2601 // Authorities all agree that the values in a .note field should
2602 // be aligned on 4-byte boundaries for 32-bit binaries. However,
2603 // they differ on what the alignment is for 64-bit binaries.
2604 // The GABI says unambiguously they take 8-byte alignment:
2605 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2606 // Other documentation says alignment should always be 4 bytes:
2607 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2608 // GNU ld and GNU readelf both support the latter (at least as of
2609 // version 2.16.91), and glibc always generates the latter for
2610 // .note.ABI-tag (as of version 1.6), so that's the one we go with
2612 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
2613 const int size
= parameters
->target().get_size();
2615 const int size
= 32;
2618 // The contents of the .note section.
2619 size_t namesz
= strlen(name
) + 1;
2620 size_t aligned_namesz
= align_address(namesz
, size
/ 8);
2621 size_t aligned_descsz
= align_address(descsz
, size
/ 8);
2623 size_t notehdrsz
= 3 * (size
/ 8) + aligned_namesz
;
2625 unsigned char* buffer
= new unsigned char[notehdrsz
];
2626 memset(buffer
, 0, notehdrsz
);
2628 bool is_big_endian
= parameters
->target().is_big_endian();
2634 elfcpp::Swap
<32, false>::writeval(buffer
, namesz
);
2635 elfcpp::Swap
<32, false>::writeval(buffer
+ 4, descsz
);
2636 elfcpp::Swap
<32, false>::writeval(buffer
+ 8, note_type
);
2640 elfcpp::Swap
<32, true>::writeval(buffer
, namesz
);
2641 elfcpp::Swap
<32, true>::writeval(buffer
+ 4, descsz
);
2642 elfcpp::Swap
<32, true>::writeval(buffer
+ 8, note_type
);
2645 else if (size
== 64)
2649 elfcpp::Swap
<64, false>::writeval(buffer
, namesz
);
2650 elfcpp::Swap
<64, false>::writeval(buffer
+ 8, descsz
);
2651 elfcpp::Swap
<64, false>::writeval(buffer
+ 16, note_type
);
2655 elfcpp::Swap
<64, true>::writeval(buffer
, namesz
);
2656 elfcpp::Swap
<64, true>::writeval(buffer
+ 8, descsz
);
2657 elfcpp::Swap
<64, true>::writeval(buffer
+ 16, note_type
);
2663 memcpy(buffer
+ 3 * (size
/ 8), name
, namesz
);
2665 elfcpp::Elf_Xword flags
= 0;
2666 Output_section_order order
= ORDER_INVALID
;
2669 flags
= elfcpp::SHF_ALLOC
;
2670 order
= ORDER_RO_NOTE
;
2672 Output_section
* os
= this->choose_output_section(NULL
, section_name
,
2674 flags
, false, order
, false);
2678 Output_section_data
* posd
= new Output_data_const_buffer(buffer
, notehdrsz
,
2681 os
->add_output_section_data(posd
);
2683 *trailing_padding
= aligned_descsz
- descsz
;
2688 // For an executable or shared library, create a note to record the
2689 // version of gold used to create the binary.
2692 Layout::create_gold_note()
2694 if (parameters
->options().relocatable()
2695 || parameters
->incremental_update())
2698 std::string desc
= std::string("gold ") + gold::get_version_string();
2700 size_t trailing_padding
;
2701 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION
,
2702 ".note.gnu.gold-version", desc
.size(),
2703 false, &trailing_padding
);
2707 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2708 os
->add_output_section_data(posd
);
2710 if (trailing_padding
> 0)
2712 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2713 os
->add_output_section_data(posd
);
2717 // Record whether the stack should be executable. This can be set
2718 // from the command line using the -z execstack or -z noexecstack
2719 // options. Otherwise, if any input file has a .note.GNU-stack
2720 // section with the SHF_EXECINSTR flag set, the stack should be
2721 // executable. Otherwise, if at least one input file a
2722 // .note.GNU-stack section, and some input file has no .note.GNU-stack
2723 // section, we use the target default for whether the stack should be
2724 // executable. Otherwise, we don't generate a stack note. When
2725 // generating a object file, we create a .note.GNU-stack section with
2726 // the appropriate marking. When generating an executable or shared
2727 // library, we create a PT_GNU_STACK segment.
2730 Layout::create_executable_stack_info()
2732 bool is_stack_executable
;
2733 if (parameters
->options().is_execstack_set())
2734 is_stack_executable
= parameters
->options().is_stack_executable();
2735 else if (!this->input_with_gnu_stack_note_
)
2739 if (this->input_requires_executable_stack_
)
2740 is_stack_executable
= true;
2741 else if (this->input_without_gnu_stack_note_
)
2742 is_stack_executable
=
2743 parameters
->target().is_default_stack_executable();
2745 is_stack_executable
= false;
2748 if (parameters
->options().relocatable())
2750 const char* name
= this->namepool_
.add(".note.GNU-stack", false, NULL
);
2751 elfcpp::Elf_Xword flags
= 0;
2752 if (is_stack_executable
)
2753 flags
|= elfcpp::SHF_EXECINSTR
;
2754 this->make_output_section(name
, elfcpp::SHT_PROGBITS
, flags
,
2755 ORDER_INVALID
, false);
2759 if (this->script_options_
->saw_phdrs_clause())
2761 int flags
= elfcpp::PF_R
| elfcpp::PF_W
;
2762 if (is_stack_executable
)
2763 flags
|= elfcpp::PF_X
;
2764 this->make_output_segment(elfcpp::PT_GNU_STACK
, flags
);
2768 // If --build-id was used, set up the build ID note.
2771 Layout::create_build_id()
2773 if (!parameters
->options().user_set_build_id())
2776 const char* style
= parameters
->options().build_id();
2777 if (strcmp(style
, "none") == 0)
2780 // Set DESCSZ to the size of the note descriptor. When possible,
2781 // set DESC to the note descriptor contents.
2784 if (strcmp(style
, "md5") == 0)
2786 else if (strcmp(style
, "sha1") == 0)
2788 else if (strcmp(style
, "uuid") == 0)
2790 const size_t uuidsz
= 128 / 8;
2792 char buffer
[uuidsz
];
2793 memset(buffer
, 0, uuidsz
);
2795 int descriptor
= open_descriptor(-1, "/dev/urandom", O_RDONLY
);
2797 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
2801 ssize_t got
= ::read(descriptor
, buffer
, uuidsz
);
2802 release_descriptor(descriptor
, true);
2804 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno
));
2805 else if (static_cast<size_t>(got
) != uuidsz
)
2806 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
2810 desc
.assign(buffer
, uuidsz
);
2813 else if (strncmp(style
, "0x", 2) == 0)
2816 const char* p
= style
+ 2;
2819 if (hex_p(p
[0]) && hex_p(p
[1]))
2821 char c
= (hex_value(p
[0]) << 4) | hex_value(p
[1]);
2825 else if (*p
== '-' || *p
== ':')
2828 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
2831 descsz
= desc
.size();
2834 gold_fatal(_("unrecognized --build-id argument '%s'"), style
);
2837 size_t trailing_padding
;
2838 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID
,
2839 ".note.gnu.build-id", descsz
, true,
2846 // We know the value already, so we fill it in now.
2847 gold_assert(desc
.size() == descsz
);
2849 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2850 os
->add_output_section_data(posd
);
2852 if (trailing_padding
!= 0)
2854 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2855 os
->add_output_section_data(posd
);
2860 // We need to compute a checksum after we have completed the
2862 gold_assert(trailing_padding
== 0);
2863 this->build_id_note_
= new Output_data_zero_fill(descsz
, 4);
2864 os
->add_output_section_data(this->build_id_note_
);
2868 // If we have both .stabXX and .stabXXstr sections, then the sh_link
2869 // field of the former should point to the latter. I'm not sure who
2870 // started this, but the GNU linker does it, and some tools depend
2874 Layout::link_stabs_sections()
2876 if (!this->have_stabstr_section_
)
2879 for (Section_list::iterator p
= this->section_list_
.begin();
2880 p
!= this->section_list_
.end();
2883 if ((*p
)->type() != elfcpp::SHT_STRTAB
)
2886 const char* name
= (*p
)->name();
2887 if (strncmp(name
, ".stab", 5) != 0)
2890 size_t len
= strlen(name
);
2891 if (strcmp(name
+ len
- 3, "str") != 0)
2894 std::string
stab_name(name
, len
- 3);
2895 Output_section
* stab_sec
;
2896 stab_sec
= this->find_output_section(stab_name
.c_str());
2897 if (stab_sec
!= NULL
)
2898 stab_sec
->set_link_section(*p
);
2902 // Create .gnu_incremental_inputs and related sections needed
2903 // for the next run of incremental linking to check what has changed.
2906 Layout::create_incremental_info_sections(Symbol_table
* symtab
)
2908 Incremental_inputs
* incr
= this->incremental_inputs_
;
2910 gold_assert(incr
!= NULL
);
2912 // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
2913 incr
->create_data_sections(symtab
);
2915 // Add the .gnu_incremental_inputs section.
2916 const char* incremental_inputs_name
=
2917 this->namepool_
.add(".gnu_incremental_inputs", false, NULL
);
2918 Output_section
* incremental_inputs_os
=
2919 this->make_output_section(incremental_inputs_name
,
2920 elfcpp::SHT_GNU_INCREMENTAL_INPUTS
, 0,
2921 ORDER_INVALID
, false);
2922 incremental_inputs_os
->add_output_section_data(incr
->inputs_section());
2924 // Add the .gnu_incremental_symtab section.
2925 const char* incremental_symtab_name
=
2926 this->namepool_
.add(".gnu_incremental_symtab", false, NULL
);
2927 Output_section
* incremental_symtab_os
=
2928 this->make_output_section(incremental_symtab_name
,
2929 elfcpp::SHT_GNU_INCREMENTAL_SYMTAB
, 0,
2930 ORDER_INVALID
, false);
2931 incremental_symtab_os
->add_output_section_data(incr
->symtab_section());
2932 incremental_symtab_os
->set_entsize(4);
2934 // Add the .gnu_incremental_relocs section.
2935 const char* incremental_relocs_name
=
2936 this->namepool_
.add(".gnu_incremental_relocs", false, NULL
);
2937 Output_section
* incremental_relocs_os
=
2938 this->make_output_section(incremental_relocs_name
,
2939 elfcpp::SHT_GNU_INCREMENTAL_RELOCS
, 0,
2940 ORDER_INVALID
, false);
2941 incremental_relocs_os
->add_output_section_data(incr
->relocs_section());
2942 incremental_relocs_os
->set_entsize(incr
->relocs_entsize());
2944 // Add the .gnu_incremental_got_plt section.
2945 const char* incremental_got_plt_name
=
2946 this->namepool_
.add(".gnu_incremental_got_plt", false, NULL
);
2947 Output_section
* incremental_got_plt_os
=
2948 this->make_output_section(incremental_got_plt_name
,
2949 elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT
, 0,
2950 ORDER_INVALID
, false);
2951 incremental_got_plt_os
->add_output_section_data(incr
->got_plt_section());
2953 // Add the .gnu_incremental_strtab section.
2954 const char* incremental_strtab_name
=
2955 this->namepool_
.add(".gnu_incremental_strtab", false, NULL
);
2956 Output_section
* incremental_strtab_os
= this->make_output_section(incremental_strtab_name
,
2957 elfcpp::SHT_STRTAB
, 0,
2958 ORDER_INVALID
, false);
2959 Output_data_strtab
* strtab_data
=
2960 new Output_data_strtab(incr
->get_stringpool());
2961 incremental_strtab_os
->add_output_section_data(strtab_data
);
2963 incremental_inputs_os
->set_after_input_sections();
2964 incremental_symtab_os
->set_after_input_sections();
2965 incremental_relocs_os
->set_after_input_sections();
2966 incremental_got_plt_os
->set_after_input_sections();
2968 incremental_inputs_os
->set_link_section(incremental_strtab_os
);
2969 incremental_symtab_os
->set_link_section(incremental_inputs_os
);
2970 incremental_relocs_os
->set_link_section(incremental_inputs_os
);
2971 incremental_got_plt_os
->set_link_section(incremental_inputs_os
);
2974 // Return whether SEG1 should be before SEG2 in the output file. This
2975 // is based entirely on the segment type and flags. When this is
2976 // called the segment addresses have normally not yet been set.
2979 Layout::segment_precedes(const Output_segment
* seg1
,
2980 const Output_segment
* seg2
)
2982 elfcpp::Elf_Word type1
= seg1
->type();
2983 elfcpp::Elf_Word type2
= seg2
->type();
2985 // The single PT_PHDR segment is required to precede any loadable
2986 // segment. We simply make it always first.
2987 if (type1
== elfcpp::PT_PHDR
)
2989 gold_assert(type2
!= elfcpp::PT_PHDR
);
2992 if (type2
== elfcpp::PT_PHDR
)
2995 // The single PT_INTERP segment is required to precede any loadable
2996 // segment. We simply make it always second.
2997 if (type1
== elfcpp::PT_INTERP
)
2999 gold_assert(type2
!= elfcpp::PT_INTERP
);
3002 if (type2
== elfcpp::PT_INTERP
)
3005 // We then put PT_LOAD segments before any other segments.
3006 if (type1
== elfcpp::PT_LOAD
&& type2
!= elfcpp::PT_LOAD
)
3008 if (type2
== elfcpp::PT_LOAD
&& type1
!= elfcpp::PT_LOAD
)
3011 // We put the PT_TLS segment last except for the PT_GNU_RELRO
3012 // segment, because that is where the dynamic linker expects to find
3013 // it (this is just for efficiency; other positions would also work
3015 if (type1
== elfcpp::PT_TLS
3016 && type2
!= elfcpp::PT_TLS
3017 && type2
!= elfcpp::PT_GNU_RELRO
)
3019 if (type2
== elfcpp::PT_TLS
3020 && type1
!= elfcpp::PT_TLS
3021 && type1
!= elfcpp::PT_GNU_RELRO
)
3024 // We put the PT_GNU_RELRO segment last, because that is where the
3025 // dynamic linker expects to find it (as with PT_TLS, this is just
3027 if (type1
== elfcpp::PT_GNU_RELRO
&& type2
!= elfcpp::PT_GNU_RELRO
)
3029 if (type2
== elfcpp::PT_GNU_RELRO
&& type1
!= elfcpp::PT_GNU_RELRO
)
3032 const elfcpp::Elf_Word flags1
= seg1
->flags();
3033 const elfcpp::Elf_Word flags2
= seg2
->flags();
3035 // The order of non-PT_LOAD segments is unimportant. We simply sort
3036 // by the numeric segment type and flags values. There should not
3037 // be more than one segment with the same type and flags.
3038 if (type1
!= elfcpp::PT_LOAD
)
3041 return type1
< type2
;
3042 gold_assert(flags1
!= flags2
);
3043 return flags1
< flags2
;
3046 // If the addresses are set already, sort by load address.
3047 if (seg1
->are_addresses_set())
3049 if (!seg2
->are_addresses_set())
3052 unsigned int section_count1
= seg1
->output_section_count();
3053 unsigned int section_count2
= seg2
->output_section_count();
3054 if (section_count1
== 0 && section_count2
> 0)
3056 if (section_count1
> 0 && section_count2
== 0)
3059 uint64_t paddr1
= (seg1
->are_addresses_set()
3061 : seg1
->first_section_load_address());
3062 uint64_t paddr2
= (seg2
->are_addresses_set()
3064 : seg2
->first_section_load_address());
3066 if (paddr1
!= paddr2
)
3067 return paddr1
< paddr2
;
3069 else if (seg2
->are_addresses_set())
3072 // A segment which holds large data comes after a segment which does
3073 // not hold large data.
3074 if (seg1
->is_large_data_segment())
3076 if (!seg2
->is_large_data_segment())
3079 else if (seg2
->is_large_data_segment())
3082 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
3083 // segments come before writable segments. Then writable segments
3084 // with data come before writable segments without data. Then
3085 // executable segments come before non-executable segments. Then
3086 // the unlikely case of a non-readable segment comes before the
3087 // normal case of a readable segment. If there are multiple
3088 // segments with the same type and flags, we require that the
3089 // address be set, and we sort by virtual address and then physical
3091 if ((flags1
& elfcpp::PF_W
) != (flags2
& elfcpp::PF_W
))
3092 return (flags1
& elfcpp::PF_W
) == 0;
3093 if ((flags1
& elfcpp::PF_W
) != 0
3094 && seg1
->has_any_data_sections() != seg2
->has_any_data_sections())
3095 return seg1
->has_any_data_sections();
3096 if ((flags1
& elfcpp::PF_X
) != (flags2
& elfcpp::PF_X
))
3097 return (flags1
& elfcpp::PF_X
) != 0;
3098 if ((flags1
& elfcpp::PF_R
) != (flags2
& elfcpp::PF_R
))
3099 return (flags1
& elfcpp::PF_R
) == 0;
3101 // We shouldn't get here--we shouldn't create segments which we
3102 // can't distinguish. Unless of course we are using a weird linker
3103 // script or overlapping --section-start options.
3104 gold_assert(this->script_options_
->saw_phdrs_clause()
3105 || parameters
->options().any_section_start());
3109 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
3112 align_file_offset(off_t off
, uint64_t addr
, uint64_t abi_pagesize
)
3114 uint64_t unsigned_off
= off
;
3115 uint64_t aligned_off
= ((unsigned_off
& ~(abi_pagesize
- 1))
3116 | (addr
& (abi_pagesize
- 1)));
3117 if (aligned_off
< unsigned_off
)
3118 aligned_off
+= abi_pagesize
;
3122 // Set the file offsets of all the segments, and all the sections they
3123 // contain. They have all been created. LOAD_SEG must be be laid out
3124 // first. Return the offset of the data to follow.
3127 Layout::set_segment_offsets(const Target
* target
, Output_segment
* load_seg
,
3128 unsigned int* pshndx
)
3130 // Sort them into the final order. We use a stable sort so that we
3131 // don't randomize the order of indistinguishable segments created
3132 // by linker scripts.
3133 std::stable_sort(this->segment_list_
.begin(), this->segment_list_
.end(),
3134 Layout::Compare_segments(this));
3136 // Find the PT_LOAD segments, and set their addresses and offsets
3137 // and their section's addresses and offsets.
3138 uint64_t start_addr
;
3139 if (parameters
->options().user_set_Ttext())
3140 start_addr
= parameters
->options().Ttext();
3141 else if (parameters
->options().output_is_position_independent())
3144 start_addr
= target
->default_text_segment_address();
3146 uint64_t addr
= start_addr
;
3149 // If LOAD_SEG is NULL, then the file header and segment headers
3150 // will not be loadable. But they still need to be at offset 0 in
3151 // the file. Set their offsets now.
3152 if (load_seg
== NULL
)
3154 for (Data_list::iterator p
= this->special_output_list_
.begin();
3155 p
!= this->special_output_list_
.end();
3158 off
= align_address(off
, (*p
)->addralign());
3159 (*p
)->set_address_and_file_offset(0, off
);
3160 off
+= (*p
)->data_size();
3164 unsigned int increase_relro
= this->increase_relro_
;
3165 if (this->script_options_
->saw_sections_clause())
3168 const bool check_sections
= parameters
->options().check_sections();
3169 Output_segment
* last_load_segment
= NULL
;
3171 unsigned int shndx_begin
= *pshndx
;
3172 unsigned int shndx_load_seg
= *pshndx
;
3174 for (Segment_list::iterator p
= this->segment_list_
.begin();
3175 p
!= this->segment_list_
.end();
3178 if ((*p
)->type() == elfcpp::PT_LOAD
)
3180 if (target
->isolate_execinstr())
3182 // When we hit the segment that should contain the
3183 // file headers, reset the file offset so we place
3184 // it and subsequent segments appropriately.
3185 // We'll fix up the preceding segments below.
3193 shndx_load_seg
= *pshndx
;
3199 // Verify that the file headers fall into the first segment.
3200 if (load_seg
!= NULL
&& load_seg
!= *p
)
3205 bool are_addresses_set
= (*p
)->are_addresses_set();
3206 if (are_addresses_set
)
3208 // When it comes to setting file offsets, we care about
3209 // the physical address.
3210 addr
= (*p
)->paddr();
3212 else if (parameters
->options().user_set_Ttext()
3213 && ((*p
)->flags() & elfcpp::PF_W
) == 0)
3215 are_addresses_set
= true;
3217 else if (parameters
->options().user_set_Tdata()
3218 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3219 && (!parameters
->options().user_set_Tbss()
3220 || (*p
)->has_any_data_sections()))
3222 addr
= parameters
->options().Tdata();
3223 are_addresses_set
= true;
3225 else if (parameters
->options().user_set_Tbss()
3226 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3227 && !(*p
)->has_any_data_sections())
3229 addr
= parameters
->options().Tbss();
3230 are_addresses_set
= true;
3233 uint64_t orig_addr
= addr
;
3234 uint64_t orig_off
= off
;
3236 uint64_t aligned_addr
= 0;
3237 uint64_t abi_pagesize
= target
->abi_pagesize();
3238 uint64_t common_pagesize
= target
->common_pagesize();
3240 if (!parameters
->options().nmagic()
3241 && !parameters
->options().omagic())
3242 (*p
)->set_minimum_p_align(common_pagesize
);
3244 if (!are_addresses_set
)
3246 // Skip the address forward one page, maintaining the same
3247 // position within the page. This lets us store both segments
3248 // overlapping on a single page in the file, but the loader will
3249 // put them on different pages in memory. We will revisit this
3250 // decision once we know the size of the segment.
3252 addr
= align_address(addr
, (*p
)->maximum_alignment());
3253 aligned_addr
= addr
;
3257 // This is the segment that will contain the file
3258 // headers, so its offset will have to be exactly zero.
3259 gold_assert(orig_off
== 0);
3261 // If the target wants a fixed minimum distance from the
3262 // text segment to the read-only segment, move up now.
3263 uint64_t min_addr
= start_addr
+ target
->rosegment_gap();
3264 if (addr
< min_addr
)
3267 // But this is not the first segment! To make its
3268 // address congruent with its offset, that address better
3269 // be aligned to the ABI-mandated page size.
3270 addr
= align_address(addr
, abi_pagesize
);
3271 aligned_addr
= addr
;
3275 if ((addr
& (abi_pagesize
- 1)) != 0)
3276 addr
= addr
+ abi_pagesize
;
3278 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3282 if (!parameters
->options().nmagic()
3283 && !parameters
->options().omagic())
3284 off
= align_file_offset(off
, addr
, abi_pagesize
);
3287 // This is -N or -n with a section script which prevents
3288 // us from using a load segment. We need to ensure that
3289 // the file offset is aligned to the alignment of the
3290 // segment. This is because the linker script
3291 // implicitly assumed a zero offset. If we don't align
3292 // here, then the alignment of the sections in the
3293 // linker script may not match the alignment of the
3294 // sections in the set_section_addresses call below,
3295 // causing an error about dot moving backward.
3296 off
= align_address(off
, (*p
)->maximum_alignment());
3299 unsigned int shndx_hold
= *pshndx
;
3300 bool has_relro
= false;
3301 uint64_t new_addr
= (*p
)->set_section_addresses(this, false, addr
,
3306 // Now that we know the size of this segment, we may be able
3307 // to save a page in memory, at the cost of wasting some
3308 // file space, by instead aligning to the start of a new
3309 // page. Here we use the real machine page size rather than
3310 // the ABI mandated page size. If the segment has been
3311 // aligned so that the relro data ends at a page boundary,
3312 // we do not try to realign it.
3314 if (!are_addresses_set
3316 && aligned_addr
!= addr
3317 && !parameters
->incremental())
3319 uint64_t first_off
= (common_pagesize
3321 & (common_pagesize
- 1)));
3322 uint64_t last_off
= new_addr
& (common_pagesize
- 1);
3325 && ((aligned_addr
& ~ (common_pagesize
- 1))
3326 != (new_addr
& ~ (common_pagesize
- 1)))
3327 && first_off
+ last_off
<= common_pagesize
)
3329 *pshndx
= shndx_hold
;
3330 addr
= align_address(aligned_addr
, common_pagesize
);
3331 addr
= align_address(addr
, (*p
)->maximum_alignment());
3332 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3333 off
= align_file_offset(off
, addr
, abi_pagesize
);
3335 increase_relro
= this->increase_relro_
;
3336 if (this->script_options_
->saw_sections_clause())
3340 new_addr
= (*p
)->set_section_addresses(this, true, addr
,
3349 // Implement --check-sections. We know that the segments
3350 // are sorted by LMA.
3351 if (check_sections
&& last_load_segment
!= NULL
)
3353 gold_assert(last_load_segment
->paddr() <= (*p
)->paddr());
3354 if (last_load_segment
->paddr() + last_load_segment
->memsz()
3357 unsigned long long lb1
= last_load_segment
->paddr();
3358 unsigned long long le1
= lb1
+ last_load_segment
->memsz();
3359 unsigned long long lb2
= (*p
)->paddr();
3360 unsigned long long le2
= lb2
+ (*p
)->memsz();
3361 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3362 "[0x%llx -> 0x%llx]"),
3363 lb1
, le1
, lb2
, le2
);
3366 last_load_segment
= *p
;
3370 if (load_seg
!= NULL
&& target
->isolate_execinstr())
3372 // Process the early segments again, setting their file offsets
3373 // so they land after the segments starting at LOAD_SEG.
3374 off
= align_file_offset(off
, 0, target
->abi_pagesize());
3376 for (Segment_list::iterator p
= this->segment_list_
.begin();
3380 if ((*p
)->type() == elfcpp::PT_LOAD
)
3382 // We repeat the whole job of assigning addresses and
3383 // offsets, but we really only want to change the offsets and
3384 // must ensure that the addresses all come out the same as
3385 // they did the first time through.
3386 bool has_relro
= false;
3387 const uint64_t old_addr
= (*p
)->vaddr();
3388 const uint64_t old_end
= old_addr
+ (*p
)->memsz();
3389 uint64_t new_addr
= (*p
)->set_section_addresses(this, true,
3395 gold_assert(new_addr
== old_end
);
3399 gold_assert(shndx_begin
== shndx_load_seg
);
3402 // Handle the non-PT_LOAD segments, setting their offsets from their
3403 // section's offsets.
3404 for (Segment_list::iterator p
= this->segment_list_
.begin();
3405 p
!= this->segment_list_
.end();
3408 if ((*p
)->type() != elfcpp::PT_LOAD
)
3409 (*p
)->set_offset((*p
)->type() == elfcpp::PT_GNU_RELRO
3414 // Set the TLS offsets for each section in the PT_TLS segment.
3415 if (this->tls_segment_
!= NULL
)
3416 this->tls_segment_
->set_tls_offsets();
3421 // Set the offsets of all the allocated sections when doing a
3422 // relocatable link. This does the same jobs as set_segment_offsets,
3423 // only for a relocatable link.
3426 Layout::set_relocatable_section_offsets(Output_data
* file_header
,
3427 unsigned int* pshndx
)
3431 file_header
->set_address_and_file_offset(0, 0);
3432 off
+= file_header
->data_size();
3434 for (Section_list::iterator p
= this->section_list_
.begin();
3435 p
!= this->section_list_
.end();
3438 // We skip unallocated sections here, except that group sections
3439 // have to come first.
3440 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) == 0
3441 && (*p
)->type() != elfcpp::SHT_GROUP
)
3444 off
= align_address(off
, (*p
)->addralign());
3446 // The linker script might have set the address.
3447 if (!(*p
)->is_address_valid())
3448 (*p
)->set_address(0);
3449 (*p
)->set_file_offset(off
);
3450 (*p
)->finalize_data_size();
3451 off
+= (*p
)->data_size();
3453 (*p
)->set_out_shndx(*pshndx
);
3460 // Set the file offset of all the sections not associated with a
3464 Layout::set_section_offsets(off_t off
, Layout::Section_offset_pass pass
)
3466 off_t startoff
= off
;
3469 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3470 p
!= this->unattached_section_list_
.end();
3473 // The symtab section is handled in create_symtab_sections.
3474 if (*p
== this->symtab_section_
)
3477 // If we've already set the data size, don't set it again.
3478 if ((*p
)->is_offset_valid() && (*p
)->is_data_size_valid())
3481 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3482 && (*p
)->requires_postprocessing())
3484 (*p
)->create_postprocessing_buffer();
3485 this->any_postprocessing_sections_
= true;
3488 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3489 && (*p
)->after_input_sections())
3491 else if (pass
== POSTPROCESSING_SECTIONS_PASS
3492 && (!(*p
)->after_input_sections()
3493 || (*p
)->type() == elfcpp::SHT_STRTAB
))
3495 else if (pass
== STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
3496 && (!(*p
)->after_input_sections()
3497 || (*p
)->type() != elfcpp::SHT_STRTAB
))
3500 if (!parameters
->incremental_update())
3502 off
= align_address(off
, (*p
)->addralign());
3503 (*p
)->set_file_offset(off
);
3504 (*p
)->finalize_data_size();
3508 // Incremental update: allocate file space from free list.
3509 (*p
)->pre_finalize_data_size();
3510 off_t current_size
= (*p
)->current_data_size();
3511 off
= this->allocate(current_size
, (*p
)->addralign(), startoff
);
3514 if (is_debugging_enabled(DEBUG_INCREMENTAL
))
3515 this->free_list_
.dump();
3516 gold_assert((*p
)->output_section() != NULL
);
3517 gold_fallback(_("out of patch space for section %s; "
3518 "relink with --incremental-full"),
3519 (*p
)->output_section()->name());
3521 (*p
)->set_file_offset(off
);
3522 (*p
)->finalize_data_size();
3523 if ((*p
)->data_size() > current_size
)
3525 gold_assert((*p
)->output_section() != NULL
);
3526 gold_fallback(_("%s: section changed size; "
3527 "relink with --incremental-full"),
3528 (*p
)->output_section()->name());
3530 gold_debug(DEBUG_INCREMENTAL
,
3531 "set_section_offsets: %08lx %08lx %s",
3532 static_cast<long>(off
),
3533 static_cast<long>((*p
)->data_size()),
3534 ((*p
)->output_section() != NULL
3535 ? (*p
)->output_section()->name() : "(special)"));
3538 off
+= (*p
)->data_size();
3542 // At this point the name must be set.
3543 if (pass
!= STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
)
3544 this->namepool_
.add((*p
)->name(), false, NULL
);
3549 // Set the section indexes of all the sections not associated with a
3553 Layout::set_section_indexes(unsigned int shndx
)
3555 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3556 p
!= this->unattached_section_list_
.end();
3559 if (!(*p
)->has_out_shndx())
3561 (*p
)->set_out_shndx(shndx
);
3568 // Set the section addresses according to the linker script. This is
3569 // only called when we see a SECTIONS clause. This returns the
3570 // program segment which should hold the file header and segment
3571 // headers, if any. It will return NULL if they should not be in a
3575 Layout::set_section_addresses_from_script(Symbol_table
* symtab
)
3577 Script_sections
* ss
= this->script_options_
->script_sections();
3578 gold_assert(ss
->saw_sections_clause());
3579 return this->script_options_
->set_section_addresses(symtab
, this);
3582 // Place the orphan sections in the linker script.
3585 Layout::place_orphan_sections_in_script()
3587 Script_sections
* ss
= this->script_options_
->script_sections();
3588 gold_assert(ss
->saw_sections_clause());
3590 // Place each orphaned output section in the script.
3591 for (Section_list::iterator p
= this->section_list_
.begin();
3592 p
!= this->section_list_
.end();
3595 if (!(*p
)->found_in_sections_clause())
3596 ss
->place_orphan(*p
);
3600 // Count the local symbols in the regular symbol table and the dynamic
3601 // symbol table, and build the respective string pools.
3604 Layout::count_local_symbols(const Task
* task
,
3605 const Input_objects
* input_objects
)
3607 // First, figure out an upper bound on the number of symbols we'll
3608 // be inserting into each pool. This helps us create the pools with
3609 // the right size, to avoid unnecessary hashtable resizing.
3610 unsigned int symbol_count
= 0;
3611 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3612 p
!= input_objects
->relobj_end();
3614 symbol_count
+= (*p
)->local_symbol_count();
3616 // Go from "upper bound" to "estimate." We overcount for two
3617 // reasons: we double-count symbols that occur in more than one
3618 // object file, and we count symbols that are dropped from the
3619 // output. Add it all together and assume we overcount by 100%.
3622 // We assume all symbols will go into both the sympool and dynpool.
3623 this->sympool_
.reserve(symbol_count
);
3624 this->dynpool_
.reserve(symbol_count
);
3626 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3627 p
!= input_objects
->relobj_end();
3630 Task_lock_obj
<Object
> tlo(task
, *p
);
3631 (*p
)->count_local_symbols(&this->sympool_
, &this->dynpool_
);
3635 // Create the symbol table sections. Here we also set the final
3636 // values of the symbols. At this point all the loadable sections are
3637 // fully laid out. SHNUM is the number of sections so far.
3640 Layout::create_symtab_sections(const Input_objects
* input_objects
,
3641 Symbol_table
* symtab
,
3647 if (parameters
->target().get_size() == 32)
3649 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
3652 else if (parameters
->target().get_size() == 64)
3654 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
3660 // Compute file offsets relative to the start of the symtab section.
3663 // Save space for the dummy symbol at the start of the section. We
3664 // never bother to write this out--it will just be left as zero.
3666 unsigned int local_symbol_index
= 1;
3668 // Add STT_SECTION symbols for each Output section which needs one.
3669 for (Section_list::iterator p
= this->section_list_
.begin();
3670 p
!= this->section_list_
.end();
3673 if (!(*p
)->needs_symtab_index())
3674 (*p
)->set_symtab_index(-1U);
3677 (*p
)->set_symtab_index(local_symbol_index
);
3678 ++local_symbol_index
;
3683 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3684 p
!= input_objects
->relobj_end();
3687 unsigned int index
= (*p
)->finalize_local_symbols(local_symbol_index
,
3689 off
+= (index
- local_symbol_index
) * symsize
;
3690 local_symbol_index
= index
;
3693 unsigned int local_symcount
= local_symbol_index
;
3694 gold_assert(static_cast<off_t
>(local_symcount
* symsize
) == off
);
3697 size_t dyn_global_index
;
3699 if (this->dynsym_section_
== NULL
)
3702 dyn_global_index
= 0;
3707 dyn_global_index
= this->dynsym_section_
->info();
3708 off_t locsize
= dyn_global_index
* this->dynsym_section_
->entsize();
3709 dynoff
= this->dynsym_section_
->offset() + locsize
;
3710 dyncount
= (this->dynsym_section_
->data_size() - locsize
) / symsize
;
3711 gold_assert(static_cast<off_t
>(dyncount
* symsize
)
3712 == this->dynsym_section_
->data_size() - locsize
);
3715 off_t global_off
= off
;
3716 off
= symtab
->finalize(off
, dynoff
, dyn_global_index
, dyncount
,
3717 &this->sympool_
, &local_symcount
);
3719 if (!parameters
->options().strip_all())
3721 this->sympool_
.set_string_offsets();
3723 const char* symtab_name
= this->namepool_
.add(".symtab", false, NULL
);
3724 Output_section
* osymtab
= this->make_output_section(symtab_name
,
3728 this->symtab_section_
= osymtab
;
3730 Output_section_data
* pos
= new Output_data_fixed_space(off
, align
,
3732 osymtab
->add_output_section_data(pos
);
3734 // We generate a .symtab_shndx section if we have more than
3735 // SHN_LORESERVE sections. Technically it is possible that we
3736 // don't need one, because it is possible that there are no
3737 // symbols in any of sections with indexes larger than
3738 // SHN_LORESERVE. That is probably unusual, though, and it is
3739 // easier to always create one than to compute section indexes
3740 // twice (once here, once when writing out the symbols).
3741 if (shnum
>= elfcpp::SHN_LORESERVE
)
3743 const char* symtab_xindex_name
= this->namepool_
.add(".symtab_shndx",
3745 Output_section
* osymtab_xindex
=
3746 this->make_output_section(symtab_xindex_name
,
3747 elfcpp::SHT_SYMTAB_SHNDX
, 0,
3748 ORDER_INVALID
, false);
3750 size_t symcount
= off
/ symsize
;
3751 this->symtab_xindex_
= new Output_symtab_xindex(symcount
);
3753 osymtab_xindex
->add_output_section_data(this->symtab_xindex_
);
3755 osymtab_xindex
->set_link_section(osymtab
);
3756 osymtab_xindex
->set_addralign(4);
3757 osymtab_xindex
->set_entsize(4);
3759 osymtab_xindex
->set_after_input_sections();
3761 // This tells the driver code to wait until the symbol table
3762 // has written out before writing out the postprocessing
3763 // sections, including the .symtab_shndx section.
3764 this->any_postprocessing_sections_
= true;
3767 const char* strtab_name
= this->namepool_
.add(".strtab", false, NULL
);
3768 Output_section
* ostrtab
= this->make_output_section(strtab_name
,
3773 Output_section_data
* pstr
= new Output_data_strtab(&this->sympool_
);
3774 ostrtab
->add_output_section_data(pstr
);
3777 if (!parameters
->incremental_update())
3778 symtab_off
= align_address(*poff
, align
);
3781 symtab_off
= this->allocate(off
, align
, *poff
);
3783 gold_fallback(_("out of patch space for symbol table; "
3784 "relink with --incremental-full"));
3785 gold_debug(DEBUG_INCREMENTAL
,
3786 "create_symtab_sections: %08lx %08lx .symtab",
3787 static_cast<long>(symtab_off
),
3788 static_cast<long>(off
));
3791 symtab
->set_file_offset(symtab_off
+ global_off
);
3792 osymtab
->set_file_offset(symtab_off
);
3793 osymtab
->finalize_data_size();
3794 osymtab
->set_link_section(ostrtab
);
3795 osymtab
->set_info(local_symcount
);
3796 osymtab
->set_entsize(symsize
);
3798 if (symtab_off
+ off
> *poff
)
3799 *poff
= symtab_off
+ off
;
3803 // Create the .shstrtab section, which holds the names of the
3804 // sections. At the time this is called, we have created all the
3805 // output sections except .shstrtab itself.
3808 Layout::create_shstrtab()
3810 // FIXME: We don't need to create a .shstrtab section if we are
3811 // stripping everything.
3813 const char* name
= this->namepool_
.add(".shstrtab", false, NULL
);
3815 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_STRTAB
, 0,
3816 ORDER_INVALID
, false);
3818 if (strcmp(parameters
->options().compress_debug_sections(), "none") != 0)
3820 // We can't write out this section until we've set all the
3821 // section names, and we don't set the names of compressed
3822 // output sections until relocations are complete. FIXME: With
3823 // the current names we use, this is unnecessary.
3824 os
->set_after_input_sections();
3827 Output_section_data
* posd
= new Output_data_strtab(&this->namepool_
);
3828 os
->add_output_section_data(posd
);
3833 // Create the section headers. SIZE is 32 or 64. OFF is the file
3837 Layout::create_shdrs(const Output_section
* shstrtab_section
, off_t
* poff
)
3839 Output_section_headers
* oshdrs
;
3840 oshdrs
= new Output_section_headers(this,
3841 &this->segment_list_
,
3842 &this->section_list_
,
3843 &this->unattached_section_list_
,
3847 if (!parameters
->incremental_update())
3848 off
= align_address(*poff
, oshdrs
->addralign());
3851 oshdrs
->pre_finalize_data_size();
3852 off
= this->allocate(oshdrs
->data_size(), oshdrs
->addralign(), *poff
);
3854 gold_fallback(_("out of patch space for section header table; "
3855 "relink with --incremental-full"));
3856 gold_debug(DEBUG_INCREMENTAL
,
3857 "create_shdrs: %08lx %08lx (section header table)",
3858 static_cast<long>(off
),
3859 static_cast<long>(off
+ oshdrs
->data_size()));
3861 oshdrs
->set_address_and_file_offset(0, off
);
3862 off
+= oshdrs
->data_size();
3865 this->section_headers_
= oshdrs
;
3868 // Count the allocated sections.
3871 Layout::allocated_output_section_count() const
3873 size_t section_count
= 0;
3874 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
3875 p
!= this->segment_list_
.end();
3877 section_count
+= (*p
)->output_section_count();
3878 return section_count
;
3881 // Create the dynamic symbol table.
3884 Layout::create_dynamic_symtab(const Input_objects
* input_objects
,
3885 Symbol_table
* symtab
,
3886 Output_section
** pdynstr
,
3887 unsigned int* plocal_dynamic_count
,
3888 std::vector
<Symbol
*>* pdynamic_symbols
,
3889 Versions
* pversions
)
3891 // Count all the symbols in the dynamic symbol table, and set the
3892 // dynamic symbol indexes.
3894 // Skip symbol 0, which is always all zeroes.
3895 unsigned int index
= 1;
3897 // Add STT_SECTION symbols for each Output section which needs one.
3898 for (Section_list::iterator p
= this->section_list_
.begin();
3899 p
!= this->section_list_
.end();
3902 if (!(*p
)->needs_dynsym_index())
3903 (*p
)->set_dynsym_index(-1U);
3906 (*p
)->set_dynsym_index(index
);
3911 // Count the local symbols that need to go in the dynamic symbol table,
3912 // and set the dynamic symbol indexes.
3913 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3914 p
!= input_objects
->relobj_end();
3917 unsigned int new_index
= (*p
)->set_local_dynsym_indexes(index
);
3921 unsigned int local_symcount
= index
;
3922 *plocal_dynamic_count
= local_symcount
;
3924 index
= symtab
->set_dynsym_indexes(index
, pdynamic_symbols
,
3925 &this->dynpool_
, pversions
);
3929 const int size
= parameters
->target().get_size();
3932 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
3935 else if (size
== 64)
3937 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
3943 // Create the dynamic symbol table section.
3945 Output_section
* dynsym
= this->choose_output_section(NULL
, ".dynsym",
3949 ORDER_DYNAMIC_LINKER
,
3952 // Check for NULL as a linker script may discard .dynsym.
3955 Output_section_data
* odata
= new Output_data_fixed_space(index
* symsize
,
3958 dynsym
->add_output_section_data(odata
);
3960 dynsym
->set_info(local_symcount
);
3961 dynsym
->set_entsize(symsize
);
3962 dynsym
->set_addralign(align
);
3964 this->dynsym_section_
= dynsym
;
3967 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
3970 odyn
->add_section_address(elfcpp::DT_SYMTAB
, dynsym
);
3971 odyn
->add_constant(elfcpp::DT_SYMENT
, symsize
);
3974 // If there are more than SHN_LORESERVE allocated sections, we
3975 // create a .dynsym_shndx section. It is possible that we don't
3976 // need one, because it is possible that there are no dynamic
3977 // symbols in any of the sections with indexes larger than
3978 // SHN_LORESERVE. This is probably unusual, though, and at this
3979 // time we don't know the actual section indexes so it is
3980 // inconvenient to check.
3981 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE
)
3983 Output_section
* dynsym_xindex
=
3984 this->choose_output_section(NULL
, ".dynsym_shndx",
3985 elfcpp::SHT_SYMTAB_SHNDX
,
3987 false, ORDER_DYNAMIC_LINKER
, false);
3989 if (dynsym_xindex
!= NULL
)
3991 this->dynsym_xindex_
= new Output_symtab_xindex(index
);
3993 dynsym_xindex
->add_output_section_data(this->dynsym_xindex_
);
3995 dynsym_xindex
->set_link_section(dynsym
);
3996 dynsym_xindex
->set_addralign(4);
3997 dynsym_xindex
->set_entsize(4);
3999 dynsym_xindex
->set_after_input_sections();
4001 // This tells the driver code to wait until the symbol table
4002 // has written out before writing out the postprocessing
4003 // sections, including the .dynsym_shndx section.
4004 this->any_postprocessing_sections_
= true;
4008 // Create the dynamic string table section.
4010 Output_section
* dynstr
= this->choose_output_section(NULL
, ".dynstr",
4014 ORDER_DYNAMIC_LINKER
,
4019 Output_section_data
* strdata
= new Output_data_strtab(&this->dynpool_
);
4020 dynstr
->add_output_section_data(strdata
);
4023 dynsym
->set_link_section(dynstr
);
4024 if (this->dynamic_section_
!= NULL
)
4025 this->dynamic_section_
->set_link_section(dynstr
);
4029 odyn
->add_section_address(elfcpp::DT_STRTAB
, dynstr
);
4030 odyn
->add_section_size(elfcpp::DT_STRSZ
, dynstr
);
4036 // Create the hash tables.
4038 if (strcmp(parameters
->options().hash_style(), "sysv") == 0
4039 || strcmp(parameters
->options().hash_style(), "both") == 0)
4041 unsigned char* phash
;
4042 unsigned int hashlen
;
4043 Dynobj::create_elf_hash_table(*pdynamic_symbols
, local_symcount
,
4046 Output_section
* hashsec
=
4047 this->choose_output_section(NULL
, ".hash", elfcpp::SHT_HASH
,
4048 elfcpp::SHF_ALLOC
, false,
4049 ORDER_DYNAMIC_LINKER
, false);
4051 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4055 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4056 hashsec
->add_output_section_data(hashdata
);
4058 if (hashsec
!= NULL
)
4061 hashsec
->set_link_section(dynsym
);
4062 hashsec
->set_entsize(4);
4066 odyn
->add_section_address(elfcpp::DT_HASH
, hashsec
);
4069 if (strcmp(parameters
->options().hash_style(), "gnu") == 0
4070 || strcmp(parameters
->options().hash_style(), "both") == 0)
4072 unsigned char* phash
;
4073 unsigned int hashlen
;
4074 Dynobj::create_gnu_hash_table(*pdynamic_symbols
, local_symcount
,
4077 Output_section
* hashsec
=
4078 this->choose_output_section(NULL
, ".gnu.hash", elfcpp::SHT_GNU_HASH
,
4079 elfcpp::SHF_ALLOC
, false,
4080 ORDER_DYNAMIC_LINKER
, false);
4082 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4086 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4087 hashsec
->add_output_section_data(hashdata
);
4089 if (hashsec
!= NULL
)
4092 hashsec
->set_link_section(dynsym
);
4094 // For a 64-bit target, the entries in .gnu.hash do not have
4095 // a uniform size, so we only set the entry size for a
4097 if (parameters
->target().get_size() == 32)
4098 hashsec
->set_entsize(4);
4101 odyn
->add_section_address(elfcpp::DT_GNU_HASH
, hashsec
);
4106 // Assign offsets to each local portion of the dynamic symbol table.
4109 Layout::assign_local_dynsym_offsets(const Input_objects
* input_objects
)
4111 Output_section
* dynsym
= this->dynsym_section_
;
4115 off_t off
= dynsym
->offset();
4117 // Skip the dummy symbol at the start of the section.
4118 off
+= dynsym
->entsize();
4120 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4121 p
!= input_objects
->relobj_end();
4124 unsigned int count
= (*p
)->set_local_dynsym_offset(off
);
4125 off
+= count
* dynsym
->entsize();
4129 // Create the version sections.
4132 Layout::create_version_sections(const Versions
* versions
,
4133 const Symbol_table
* symtab
,
4134 unsigned int local_symcount
,
4135 const std::vector
<Symbol
*>& dynamic_symbols
,
4136 const Output_section
* dynstr
)
4138 if (!versions
->any_defs() && !versions
->any_needs())
4141 switch (parameters
->size_and_endianness())
4143 #ifdef HAVE_TARGET_32_LITTLE
4144 case Parameters::TARGET_32_LITTLE
:
4145 this->sized_create_version_sections
<32, false>(versions
, symtab
,
4147 dynamic_symbols
, dynstr
);
4150 #ifdef HAVE_TARGET_32_BIG
4151 case Parameters::TARGET_32_BIG
:
4152 this->sized_create_version_sections
<32, true>(versions
, symtab
,
4154 dynamic_symbols
, dynstr
);
4157 #ifdef HAVE_TARGET_64_LITTLE
4158 case Parameters::TARGET_64_LITTLE
:
4159 this->sized_create_version_sections
<64, false>(versions
, symtab
,
4161 dynamic_symbols
, dynstr
);
4164 #ifdef HAVE_TARGET_64_BIG
4165 case Parameters::TARGET_64_BIG
:
4166 this->sized_create_version_sections
<64, true>(versions
, symtab
,
4168 dynamic_symbols
, dynstr
);
4176 // Create the version sections, sized version.
4178 template<int size
, bool big_endian
>
4180 Layout::sized_create_version_sections(
4181 const Versions
* versions
,
4182 const Symbol_table
* symtab
,
4183 unsigned int local_symcount
,
4184 const std::vector
<Symbol
*>& dynamic_symbols
,
4185 const Output_section
* dynstr
)
4187 Output_section
* vsec
= this->choose_output_section(NULL
, ".gnu.version",
4188 elfcpp::SHT_GNU_versym
,
4191 ORDER_DYNAMIC_LINKER
,
4194 // Check for NULL since a linker script may discard this section.
4197 unsigned char* vbuf
;
4199 versions
->symbol_section_contents
<size
, big_endian
>(symtab
,
4205 Output_section_data
* vdata
= new Output_data_const_buffer(vbuf
, vsize
, 2,
4208 vsec
->add_output_section_data(vdata
);
4209 vsec
->set_entsize(2);
4210 vsec
->set_link_section(this->dynsym_section_
);
4213 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4214 if (odyn
!= NULL
&& vsec
!= NULL
)
4215 odyn
->add_section_address(elfcpp::DT_VERSYM
, vsec
);
4217 if (versions
->any_defs())
4219 Output_section
* vdsec
;
4220 vdsec
= this->choose_output_section(NULL
, ".gnu.version_d",
4221 elfcpp::SHT_GNU_verdef
,
4223 false, ORDER_DYNAMIC_LINKER
, false);
4227 unsigned char* vdbuf
;
4228 unsigned int vdsize
;
4229 unsigned int vdentries
;
4230 versions
->def_section_contents
<size
, big_endian
>(&this->dynpool_
,
4234 Output_section_data
* vddata
=
4235 new Output_data_const_buffer(vdbuf
, vdsize
, 4, "** version defs");
4237 vdsec
->add_output_section_data(vddata
);
4238 vdsec
->set_link_section(dynstr
);
4239 vdsec
->set_info(vdentries
);
4243 odyn
->add_section_address(elfcpp::DT_VERDEF
, vdsec
);
4244 odyn
->add_constant(elfcpp::DT_VERDEFNUM
, vdentries
);
4249 if (versions
->any_needs())
4251 Output_section
* vnsec
;
4252 vnsec
= this->choose_output_section(NULL
, ".gnu.version_r",
4253 elfcpp::SHT_GNU_verneed
,
4255 false, ORDER_DYNAMIC_LINKER
, false);
4259 unsigned char* vnbuf
;
4260 unsigned int vnsize
;
4261 unsigned int vnentries
;
4262 versions
->need_section_contents
<size
, big_endian
>(&this->dynpool_
,
4266 Output_section_data
* vndata
=
4267 new Output_data_const_buffer(vnbuf
, vnsize
, 4, "** version refs");
4269 vnsec
->add_output_section_data(vndata
);
4270 vnsec
->set_link_section(dynstr
);
4271 vnsec
->set_info(vnentries
);
4275 odyn
->add_section_address(elfcpp::DT_VERNEED
, vnsec
);
4276 odyn
->add_constant(elfcpp::DT_VERNEEDNUM
, vnentries
);
4282 // Create the .interp section and PT_INTERP segment.
4285 Layout::create_interp(const Target
* target
)
4287 gold_assert(this->interp_segment_
== NULL
);
4289 const char* interp
= parameters
->options().dynamic_linker();
4292 interp
= target
->dynamic_linker();
4293 gold_assert(interp
!= NULL
);
4296 size_t len
= strlen(interp
) + 1;
4298 Output_section_data
* odata
= new Output_data_const(interp
, len
, 1);
4300 Output_section
* osec
= this->choose_output_section(NULL
, ".interp",
4301 elfcpp::SHT_PROGBITS
,
4303 false, ORDER_INTERP
,
4306 osec
->add_output_section_data(odata
);
4309 // Add dynamic tags for the PLT and the dynamic relocs. This is
4310 // called by the target-specific code. This does nothing if not doing
4313 // USE_REL is true for REL relocs rather than RELA relocs.
4315 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
4317 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
4318 // and we also set DT_PLTREL. We use PLT_REL's output section, since
4319 // some targets have multiple reloc sections in PLT_REL.
4321 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
4322 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT. Again we use the output
4325 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
4329 Layout::add_target_dynamic_tags(bool use_rel
, const Output_data
* plt_got
,
4330 const Output_data
* plt_rel
,
4331 const Output_data_reloc_generic
* dyn_rel
,
4332 bool add_debug
, bool dynrel_includes_plt
)
4334 Output_data_dynamic
* odyn
= this->dynamic_data_
;
4338 if (plt_got
!= NULL
&& plt_got
->output_section() != NULL
)
4339 odyn
->add_section_address(elfcpp::DT_PLTGOT
, plt_got
);
4341 if (plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
)
4343 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, plt_rel
->output_section());
4344 odyn
->add_section_address(elfcpp::DT_JMPREL
, plt_rel
->output_section());
4345 odyn
->add_constant(elfcpp::DT_PLTREL
,
4346 use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
);
4349 if ((dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
)
4350 || (dynrel_includes_plt
4352 && plt_rel
->output_section() != NULL
))
4354 bool have_dyn_rel
= dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
;
4355 bool have_plt_rel
= plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
;
4356 odyn
->add_section_address(use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
,
4358 ? dyn_rel
->output_section()
4359 : plt_rel
->output_section()));
4360 elfcpp::DT size_tag
= use_rel
? elfcpp::DT_RELSZ
: elfcpp::DT_RELASZ
;
4361 if (have_dyn_rel
&& have_plt_rel
&& dynrel_includes_plt
)
4362 odyn
->add_section_size(size_tag
,
4363 dyn_rel
->output_section(),
4364 plt_rel
->output_section());
4365 else if (have_dyn_rel
)
4366 odyn
->add_section_size(size_tag
, dyn_rel
->output_section());
4368 odyn
->add_section_size(size_tag
, plt_rel
->output_section());
4369 const int size
= parameters
->target().get_size();
4374 rel_tag
= elfcpp::DT_RELENT
;
4376 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 32, false>::reloc_size
;
4377 else if (size
== 64)
4378 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 64, false>::reloc_size
;
4384 rel_tag
= elfcpp::DT_RELAENT
;
4386 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 32, false>::reloc_size
;
4387 else if (size
== 64)
4388 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 64, false>::reloc_size
;
4392 odyn
->add_constant(rel_tag
, rel_size
);
4394 if (parameters
->options().combreloc() && have_dyn_rel
)
4396 size_t c
= dyn_rel
->relative_reloc_count();
4398 odyn
->add_constant((use_rel
4399 ? elfcpp::DT_RELCOUNT
4400 : elfcpp::DT_RELACOUNT
),
4405 if (add_debug
&& !parameters
->options().shared())
4407 // The value of the DT_DEBUG tag is filled in by the dynamic
4408 // linker at run time, and used by the debugger.
4409 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
4413 // Finish the .dynamic section and PT_DYNAMIC segment.
4416 Layout::finish_dynamic_section(const Input_objects
* input_objects
,
4417 const Symbol_table
* symtab
)
4419 if (!this->script_options_
->saw_phdrs_clause()
4420 && this->dynamic_section_
!= NULL
)
4422 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_DYNAMIC
,
4425 oseg
->add_output_section_to_nonload(this->dynamic_section_
,
4426 elfcpp::PF_R
| elfcpp::PF_W
);
4429 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4433 for (Input_objects::Dynobj_iterator p
= input_objects
->dynobj_begin();
4434 p
!= input_objects
->dynobj_end();
4437 if (!(*p
)->is_needed() && (*p
)->as_needed())
4439 // This dynamic object was linked with --as-needed, but it
4444 odyn
->add_string(elfcpp::DT_NEEDED
, (*p
)->soname());
4447 if (parameters
->options().shared())
4449 const char* soname
= parameters
->options().soname();
4451 odyn
->add_string(elfcpp::DT_SONAME
, soname
);
4454 Symbol
* sym
= symtab
->lookup(parameters
->options().init());
4455 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4456 odyn
->add_symbol(elfcpp::DT_INIT
, sym
);
4458 sym
= symtab
->lookup(parameters
->options().fini());
4459 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4460 odyn
->add_symbol(elfcpp::DT_FINI
, sym
);
4462 // Look for .init_array, .preinit_array and .fini_array by checking
4464 for(Layout::Section_list::const_iterator p
= this->section_list_
.begin();
4465 p
!= this->section_list_
.end();
4467 switch((*p
)->type())
4469 case elfcpp::SHT_FINI_ARRAY
:
4470 odyn
->add_section_address(elfcpp::DT_FINI_ARRAY
, *p
);
4471 odyn
->add_section_size(elfcpp::DT_FINI_ARRAYSZ
, *p
);
4473 case elfcpp::SHT_INIT_ARRAY
:
4474 odyn
->add_section_address(elfcpp::DT_INIT_ARRAY
, *p
);
4475 odyn
->add_section_size(elfcpp::DT_INIT_ARRAYSZ
, *p
);
4477 case elfcpp::SHT_PREINIT_ARRAY
:
4478 odyn
->add_section_address(elfcpp::DT_PREINIT_ARRAY
, *p
);
4479 odyn
->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ
, *p
);
4485 // Add a DT_RPATH entry if needed.
4486 const General_options::Dir_list
& rpath(parameters
->options().rpath());
4489 std::string rpath_val
;
4490 for (General_options::Dir_list::const_iterator p
= rpath
.begin();
4494 if (rpath_val
.empty())
4495 rpath_val
= p
->name();
4498 // Eliminate duplicates.
4499 General_options::Dir_list::const_iterator q
;
4500 for (q
= rpath
.begin(); q
!= p
; ++q
)
4501 if (q
->name() == p
->name())
4506 rpath_val
+= p
->name();
4511 odyn
->add_string(elfcpp::DT_RPATH
, rpath_val
);
4512 if (parameters
->options().enable_new_dtags())
4513 odyn
->add_string(elfcpp::DT_RUNPATH
, rpath_val
);
4516 // Look for text segments that have dynamic relocations.
4517 bool have_textrel
= false;
4518 if (!this->script_options_
->saw_sections_clause())
4520 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4521 p
!= this->segment_list_
.end();
4524 if ((*p
)->type() == elfcpp::PT_LOAD
4525 && ((*p
)->flags() & elfcpp::PF_W
) == 0
4526 && (*p
)->has_dynamic_reloc())
4528 have_textrel
= true;
4535 // We don't know the section -> segment mapping, so we are
4536 // conservative and just look for readonly sections with
4537 // relocations. If those sections wind up in writable segments,
4538 // then we have created an unnecessary DT_TEXTREL entry.
4539 for (Section_list::const_iterator p
= this->section_list_
.begin();
4540 p
!= this->section_list_
.end();
4543 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0
4544 && ((*p
)->flags() & elfcpp::SHF_WRITE
) == 0
4545 && (*p
)->has_dynamic_reloc())
4547 have_textrel
= true;
4553 if (parameters
->options().filter() != NULL
)
4554 odyn
->add_string(elfcpp::DT_FILTER
, parameters
->options().filter());
4555 if (parameters
->options().any_auxiliary())
4557 for (options::String_set::const_iterator p
=
4558 parameters
->options().auxiliary_begin();
4559 p
!= parameters
->options().auxiliary_end();
4561 odyn
->add_string(elfcpp::DT_AUXILIARY
, *p
);
4564 // Add a DT_FLAGS entry if necessary.
4565 unsigned int flags
= 0;
4568 // Add a DT_TEXTREL for compatibility with older loaders.
4569 odyn
->add_constant(elfcpp::DT_TEXTREL
, 0);
4570 flags
|= elfcpp::DF_TEXTREL
;
4572 if (parameters
->options().text())
4573 gold_error(_("read-only segment has dynamic relocations"));
4574 else if (parameters
->options().warn_shared_textrel()
4575 && parameters
->options().shared())
4576 gold_warning(_("shared library text segment is not shareable"));
4578 if (parameters
->options().shared() && this->has_static_tls())
4579 flags
|= elfcpp::DF_STATIC_TLS
;
4580 if (parameters
->options().origin())
4581 flags
|= elfcpp::DF_ORIGIN
;
4582 if (parameters
->options().Bsymbolic())
4584 flags
|= elfcpp::DF_SYMBOLIC
;
4585 // Add DT_SYMBOLIC for compatibility with older loaders.
4586 odyn
->add_constant(elfcpp::DT_SYMBOLIC
, 0);
4588 if (parameters
->options().now())
4589 flags
|= elfcpp::DF_BIND_NOW
;
4591 odyn
->add_constant(elfcpp::DT_FLAGS
, flags
);
4594 if (parameters
->options().initfirst())
4595 flags
|= elfcpp::DF_1_INITFIRST
;
4596 if (parameters
->options().interpose())
4597 flags
|= elfcpp::DF_1_INTERPOSE
;
4598 if (parameters
->options().loadfltr())
4599 flags
|= elfcpp::DF_1_LOADFLTR
;
4600 if (parameters
->options().nodefaultlib())
4601 flags
|= elfcpp::DF_1_NODEFLIB
;
4602 if (parameters
->options().nodelete())
4603 flags
|= elfcpp::DF_1_NODELETE
;
4604 if (parameters
->options().nodlopen())
4605 flags
|= elfcpp::DF_1_NOOPEN
;
4606 if (parameters
->options().nodump())
4607 flags
|= elfcpp::DF_1_NODUMP
;
4608 if (!parameters
->options().shared())
4609 flags
&= ~(elfcpp::DF_1_INITFIRST
4610 | elfcpp::DF_1_NODELETE
4611 | elfcpp::DF_1_NOOPEN
);
4612 if (parameters
->options().origin())
4613 flags
|= elfcpp::DF_1_ORIGIN
;
4614 if (parameters
->options().now())
4615 flags
|= elfcpp::DF_1_NOW
;
4616 if (parameters
->options().Bgroup())
4617 flags
|= elfcpp::DF_1_GROUP
;
4619 odyn
->add_constant(elfcpp::DT_FLAGS_1
, flags
);
4622 // Set the size of the _DYNAMIC symbol table to be the size of the
4626 Layout::set_dynamic_symbol_size(const Symbol_table
* symtab
)
4628 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4631 odyn
->finalize_data_size();
4632 if (this->dynamic_symbol_
== NULL
)
4634 off_t data_size
= odyn
->data_size();
4635 const int size
= parameters
->target().get_size();
4637 symtab
->get_sized_symbol
<32>(this->dynamic_symbol_
)->set_symsize(data_size
);
4638 else if (size
== 64)
4639 symtab
->get_sized_symbol
<64>(this->dynamic_symbol_
)->set_symsize(data_size
);
4644 // The mapping of input section name prefixes to output section names.
4645 // In some cases one prefix is itself a prefix of another prefix; in
4646 // such a case the longer prefix must come first. These prefixes are
4647 // based on the GNU linker default ELF linker script.
4649 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
4650 #define MAPPING_INIT_EXACT(f, t) { f, 0, t, sizeof(t) - 1 }
4651 const Layout::Section_name_mapping
Layout::section_name_mapping
[] =
4653 MAPPING_INIT(".text.", ".text"),
4654 MAPPING_INIT(".rodata.", ".rodata"),
4655 MAPPING_INIT(".data.rel.ro.local.", ".data.rel.ro.local"),
4656 MAPPING_INIT_EXACT(".data.rel.ro.local", ".data.rel.ro.local"),
4657 MAPPING_INIT(".data.rel.ro.", ".data.rel.ro"),
4658 MAPPING_INIT_EXACT(".data.rel.ro", ".data.rel.ro"),
4659 MAPPING_INIT(".data.", ".data"),
4660 MAPPING_INIT(".bss.", ".bss"),
4661 MAPPING_INIT(".tdata.", ".tdata"),
4662 MAPPING_INIT(".tbss.", ".tbss"),
4663 MAPPING_INIT(".init_array.", ".init_array"),
4664 MAPPING_INIT(".fini_array.", ".fini_array"),
4665 MAPPING_INIT(".sdata.", ".sdata"),
4666 MAPPING_INIT(".sbss.", ".sbss"),
4667 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
4668 // differently depending on whether it is creating a shared library.
4669 MAPPING_INIT(".sdata2.", ".sdata"),
4670 MAPPING_INIT(".sbss2.", ".sbss"),
4671 MAPPING_INIT(".lrodata.", ".lrodata"),
4672 MAPPING_INIT(".ldata.", ".ldata"),
4673 MAPPING_INIT(".lbss.", ".lbss"),
4674 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
4675 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
4676 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
4677 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
4678 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
4679 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
4680 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
4681 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
4682 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
4683 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
4684 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
4685 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
4686 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
4687 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
4688 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
4689 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
4690 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
4691 MAPPING_INIT(".ARM.extab", ".ARM.extab"),
4692 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
4693 MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
4694 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
4697 #undef MAPPING_INIT_EXACT
4699 const int Layout::section_name_mapping_count
=
4700 (sizeof(Layout::section_name_mapping
)
4701 / sizeof(Layout::section_name_mapping
[0]));
4703 // Choose the output section name to use given an input section name.
4704 // Set *PLEN to the length of the name. *PLEN is initialized to the
4708 Layout::output_section_name(const Relobj
* relobj
, const char* name
,
4711 // gcc 4.3 generates the following sorts of section names when it
4712 // needs a section name specific to a function:
4718 // .data.rel.local.FN
4720 // .data.rel.ro.local.FN
4727 // The GNU linker maps all of those to the part before the .FN,
4728 // except that .data.rel.local.FN is mapped to .data, and
4729 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
4730 // beginning with .data.rel.ro.local are grouped together.
4732 // For an anonymous namespace, the string FN can contain a '.'.
4734 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
4735 // GNU linker maps to .rodata.
4737 // The .data.rel.ro sections are used with -z relro. The sections
4738 // are recognized by name. We use the same names that the GNU
4739 // linker does for these sections.
4741 // It is hard to handle this in a principled way, so we don't even
4742 // try. We use a table of mappings. If the input section name is
4743 // not found in the table, we simply use it as the output section
4746 const Section_name_mapping
* psnm
= section_name_mapping
;
4747 for (int i
= 0; i
< section_name_mapping_count
; ++i
, ++psnm
)
4749 if (psnm
->fromlen
> 0)
4751 if (strncmp(name
, psnm
->from
, psnm
->fromlen
) == 0)
4753 *plen
= psnm
->tolen
;
4759 if (strcmp(name
, psnm
->from
) == 0)
4761 *plen
= psnm
->tolen
;
4767 // As an additional complication, .ctors sections are output in
4768 // either .ctors or .init_array sections, and .dtors sections are
4769 // output in either .dtors or .fini_array sections.
4770 if (is_prefix_of(".ctors.", name
) || is_prefix_of(".dtors.", name
))
4772 if (parameters
->options().ctors_in_init_array())
4775 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4780 return name
[1] == 'c' ? ".ctors" : ".dtors";
4783 if (parameters
->options().ctors_in_init_array()
4784 && (strcmp(name
, ".ctors") == 0 || strcmp(name
, ".dtors") == 0))
4786 // To make .init_array/.fini_array work with gcc we must exclude
4787 // .ctors and .dtors sections from the crtbegin and crtend
4790 || (!Layout::match_file_name(relobj
, "crtbegin")
4791 && !Layout::match_file_name(relobj
, "crtend")))
4794 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4801 // Return true if RELOBJ is an input file whose base name matches
4802 // FILE_NAME. The base name must have an extension of ".o", and must
4803 // be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is
4804 // to match crtbegin.o as well as crtbeginS.o without getting confused
4805 // by other possibilities. Overall matching the file name this way is
4806 // a dreadful hack, but the GNU linker does it in order to better
4807 // support gcc, and we need to be compatible.
4810 Layout::match_file_name(const Relobj
* relobj
, const char* match
)
4812 const std::string
& file_name(relobj
->name());
4813 const char* base_name
= lbasename(file_name
.c_str());
4814 size_t match_len
= strlen(match
);
4815 if (strncmp(base_name
, match
, match_len
) != 0)
4817 size_t base_len
= strlen(base_name
);
4818 if (base_len
!= match_len
+ 2 && base_len
!= match_len
+ 3)
4820 return memcmp(base_name
+ base_len
- 2, ".o", 2) == 0;
4823 // Check if a comdat group or .gnu.linkonce section with the given
4824 // NAME is selected for the link. If there is already a section,
4825 // *KEPT_SECTION is set to point to the existing section and the
4826 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
4827 // IS_GROUP_NAME are recorded for this NAME in the layout object,
4828 // *KEPT_SECTION is set to the internal copy and the function returns
4832 Layout::find_or_add_kept_section(const std::string
& name
,
4837 Kept_section
** kept_section
)
4839 // It's normal to see a couple of entries here, for the x86 thunk
4840 // sections. If we see more than a few, we're linking a C++
4841 // program, and we resize to get more space to minimize rehashing.
4842 if (this->signatures_
.size() > 4
4843 && !this->resized_signatures_
)
4845 reserve_unordered_map(&this->signatures_
,
4846 this->number_of_input_files_
* 64);
4847 this->resized_signatures_
= true;
4850 Kept_section candidate
;
4851 std::pair
<Signatures::iterator
, bool> ins
=
4852 this->signatures_
.insert(std::make_pair(name
, candidate
));
4854 if (kept_section
!= NULL
)
4855 *kept_section
= &ins
.first
->second
;
4858 // This is the first time we've seen this signature.
4859 ins
.first
->second
.set_object(object
);
4860 ins
.first
->second
.set_shndx(shndx
);
4862 ins
.first
->second
.set_is_comdat();
4864 ins
.first
->second
.set_is_group_name();
4868 // We have already seen this signature.
4870 if (ins
.first
->second
.is_group_name())
4872 // We've already seen a real section group with this signature.
4873 // If the kept group is from a plugin object, and we're in the
4874 // replacement phase, accept the new one as a replacement.
4875 if (ins
.first
->second
.object() == NULL
4876 && parameters
->options().plugins()->in_replacement_phase())
4878 ins
.first
->second
.set_object(object
);
4879 ins
.first
->second
.set_shndx(shndx
);
4884 else if (is_group_name
)
4886 // This is a real section group, and we've already seen a
4887 // linkonce section with this signature. Record that we've seen
4888 // a section group, and don't include this section group.
4889 ins
.first
->second
.set_is_group_name();
4894 // We've already seen a linkonce section and this is a linkonce
4895 // section. These don't block each other--this may be the same
4896 // symbol name with different section types.
4901 // Store the allocated sections into the section list.
4904 Layout::get_allocated_sections(Section_list
* section_list
) const
4906 for (Section_list::const_iterator p
= this->section_list_
.begin();
4907 p
!= this->section_list_
.end();
4909 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0)
4910 section_list
->push_back(*p
);
4913 // Create an output segment.
4916 Layout::make_output_segment(elfcpp::Elf_Word type
, elfcpp::Elf_Word flags
)
4918 gold_assert(!parameters
->options().relocatable());
4919 Output_segment
* oseg
= new Output_segment(type
, flags
);
4920 this->segment_list_
.push_back(oseg
);
4922 if (type
== elfcpp::PT_TLS
)
4923 this->tls_segment_
= oseg
;
4924 else if (type
== elfcpp::PT_GNU_RELRO
)
4925 this->relro_segment_
= oseg
;
4926 else if (type
== elfcpp::PT_INTERP
)
4927 this->interp_segment_
= oseg
;
4932 // Return the file offset of the normal symbol table.
4935 Layout::symtab_section_offset() const
4937 if (this->symtab_section_
!= NULL
)
4938 return this->symtab_section_
->offset();
4942 // Return the section index of the normal symbol table. It may have
4943 // been stripped by the -s/--strip-all option.
4946 Layout::symtab_section_shndx() const
4948 if (this->symtab_section_
!= NULL
)
4949 return this->symtab_section_
->out_shndx();
4953 // Write out the Output_sections. Most won't have anything to write,
4954 // since most of the data will come from input sections which are
4955 // handled elsewhere. But some Output_sections do have Output_data.
4958 Layout::write_output_sections(Output_file
* of
) const
4960 for (Section_list::const_iterator p
= this->section_list_
.begin();
4961 p
!= this->section_list_
.end();
4964 if (!(*p
)->after_input_sections())
4969 // Write out data not associated with a section or the symbol table.
4972 Layout::write_data(const Symbol_table
* symtab
, Output_file
* of
) const
4974 if (!parameters
->options().strip_all())
4976 const Output_section
* symtab_section
= this->symtab_section_
;
4977 for (Section_list::const_iterator p
= this->section_list_
.begin();
4978 p
!= this->section_list_
.end();
4981 if ((*p
)->needs_symtab_index())
4983 gold_assert(symtab_section
!= NULL
);
4984 unsigned int index
= (*p
)->symtab_index();
4985 gold_assert(index
> 0 && index
!= -1U);
4986 off_t off
= (symtab_section
->offset()
4987 + index
* symtab_section
->entsize());
4988 symtab
->write_section_symbol(*p
, this->symtab_xindex_
, of
, off
);
4993 const Output_section
* dynsym_section
= this->dynsym_section_
;
4994 for (Section_list::const_iterator p
= this->section_list_
.begin();
4995 p
!= this->section_list_
.end();
4998 if ((*p
)->needs_dynsym_index())
5000 gold_assert(dynsym_section
!= NULL
);
5001 unsigned int index
= (*p
)->dynsym_index();
5002 gold_assert(index
> 0 && index
!= -1U);
5003 off_t off
= (dynsym_section
->offset()
5004 + index
* dynsym_section
->entsize());
5005 symtab
->write_section_symbol(*p
, this->dynsym_xindex_
, of
, off
);
5009 // Write out the Output_data which are not in an Output_section.
5010 for (Data_list::const_iterator p
= this->special_output_list_
.begin();
5011 p
!= this->special_output_list_
.end();
5016 // Write out the Output_sections which can only be written after the
5017 // input sections are complete.
5020 Layout::write_sections_after_input_sections(Output_file
* of
)
5022 // Determine the final section offsets, and thus the final output
5023 // file size. Note we finalize the .shstrab last, to allow the
5024 // after_input_section sections to modify their section-names before
5026 if (this->any_postprocessing_sections_
)
5028 off_t off
= this->output_file_size_
;
5029 off
= this->set_section_offsets(off
, POSTPROCESSING_SECTIONS_PASS
);
5031 // Now that we've finalized the names, we can finalize the shstrab.
5033 this->set_section_offsets(off
,
5034 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
5036 if (off
> this->output_file_size_
)
5039 this->output_file_size_
= off
;
5043 for (Section_list::const_iterator p
= this->section_list_
.begin();
5044 p
!= this->section_list_
.end();
5047 if ((*p
)->after_input_sections())
5051 this->section_headers_
->write(of
);
5054 // If the build ID requires computing a checksum, do so here, and
5055 // write it out. We compute a checksum over the entire file because
5056 // that is simplest.
5059 Layout::write_build_id(Output_file
* of
) const
5061 if (this->build_id_note_
== NULL
)
5064 const unsigned char* iv
= of
->get_input_view(0, this->output_file_size_
);
5066 unsigned char* ov
= of
->get_output_view(this->build_id_note_
->offset(),
5067 this->build_id_note_
->data_size());
5069 const char* style
= parameters
->options().build_id();
5070 if (strcmp(style
, "sha1") == 0)
5073 sha1_init_ctx(&ctx
);
5074 sha1_process_bytes(iv
, this->output_file_size_
, &ctx
);
5075 sha1_finish_ctx(&ctx
, ov
);
5077 else if (strcmp(style
, "md5") == 0)
5081 md5_process_bytes(iv
, this->output_file_size_
, &ctx
);
5082 md5_finish_ctx(&ctx
, ov
);
5087 of
->write_output_view(this->build_id_note_
->offset(),
5088 this->build_id_note_
->data_size(),
5091 of
->free_input_view(0, this->output_file_size_
, iv
);
5094 // Write out a binary file. This is called after the link is
5095 // complete. IN is the temporary output file we used to generate the
5096 // ELF code. We simply walk through the segments, read them from
5097 // their file offset in IN, and write them to their load address in
5098 // the output file. FIXME: with a bit more work, we could support
5099 // S-records and/or Intel hex format here.
5102 Layout::write_binary(Output_file
* in
) const
5104 gold_assert(parameters
->options().oformat_enum()
5105 == General_options::OBJECT_FORMAT_BINARY
);
5107 // Get the size of the binary file.
5108 uint64_t max_load_address
= 0;
5109 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5110 p
!= this->segment_list_
.end();
5113 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5115 uint64_t max_paddr
= (*p
)->paddr() + (*p
)->filesz();
5116 if (max_paddr
> max_load_address
)
5117 max_load_address
= max_paddr
;
5121 Output_file
out(parameters
->options().output_file_name());
5122 out
.open(max_load_address
);
5124 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5125 p
!= this->segment_list_
.end();
5128 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5130 const unsigned char* vin
= in
->get_input_view((*p
)->offset(),
5132 unsigned char* vout
= out
.get_output_view((*p
)->paddr(),
5134 memcpy(vout
, vin
, (*p
)->filesz());
5135 out
.write_output_view((*p
)->paddr(), (*p
)->filesz(), vout
);
5136 in
->free_input_view((*p
)->offset(), (*p
)->filesz(), vin
);
5143 // Print the output sections to the map file.
5146 Layout::print_to_mapfile(Mapfile
* mapfile
) const
5148 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5149 p
!= this->segment_list_
.end();
5151 (*p
)->print_sections_to_mapfile(mapfile
);
5154 // Print statistical information to stderr. This is used for --stats.
5157 Layout::print_stats() const
5159 this->namepool_
.print_stats("section name pool");
5160 this->sympool_
.print_stats("output symbol name pool");
5161 this->dynpool_
.print_stats("dynamic name pool");
5163 for (Section_list::const_iterator p
= this->section_list_
.begin();
5164 p
!= this->section_list_
.end();
5166 (*p
)->print_merge_stats();
5169 // Write_sections_task methods.
5171 // We can always run this task.
5174 Write_sections_task::is_runnable()
5179 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
5183 Write_sections_task::locks(Task_locker
* tl
)
5185 tl
->add(this, this->output_sections_blocker_
);
5186 tl
->add(this, this->final_blocker_
);
5189 // Run the task--write out the data.
5192 Write_sections_task::run(Workqueue
*)
5194 this->layout_
->write_output_sections(this->of_
);
5197 // Write_data_task methods.
5199 // We can always run this task.
5202 Write_data_task::is_runnable()
5207 // We need to unlock FINAL_BLOCKER when finished.
5210 Write_data_task::locks(Task_locker
* tl
)
5212 tl
->add(this, this->final_blocker_
);
5215 // Run the task--write out the data.
5218 Write_data_task::run(Workqueue
*)
5220 this->layout_
->write_data(this->symtab_
, this->of_
);
5223 // Write_symbols_task methods.
5225 // We can always run this task.
5228 Write_symbols_task::is_runnable()
5233 // We need to unlock FINAL_BLOCKER when finished.
5236 Write_symbols_task::locks(Task_locker
* tl
)
5238 tl
->add(this, this->final_blocker_
);
5241 // Run the task--write out the symbols.
5244 Write_symbols_task::run(Workqueue
*)
5246 this->symtab_
->write_globals(this->sympool_
, this->dynpool_
,
5247 this->layout_
->symtab_xindex(),
5248 this->layout_
->dynsym_xindex(), this->of_
);
5251 // Write_after_input_sections_task methods.
5253 // We can only run this task after the input sections have completed.
5256 Write_after_input_sections_task::is_runnable()
5258 if (this->input_sections_blocker_
->is_blocked())
5259 return this->input_sections_blocker_
;
5263 // We need to unlock FINAL_BLOCKER when finished.
5266 Write_after_input_sections_task::locks(Task_locker
* tl
)
5268 tl
->add(this, this->final_blocker_
);
5274 Write_after_input_sections_task::run(Workqueue
*)
5276 this->layout_
->write_sections_after_input_sections(this->of_
);
5279 // Close_task_runner methods.
5281 // Run the task--close the file.
5284 Close_task_runner::run(Workqueue
*, const Task
*)
5286 // If we need to compute a checksum for the BUILD if, we do so here.
5287 this->layout_
->write_build_id(this->of_
);
5289 // If we've been asked to create a binary file, we do so here.
5290 if (this->options_
->oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
5291 this->layout_
->write_binary(this->of_
);
5296 // Instantiate the templates we need. We could use the configure
5297 // script to restrict this to only the ones for implemented targets.
5299 #ifdef HAVE_TARGET_32_LITTLE
5302 Layout::init_fixed_output_section
<32, false>(
5304 elfcpp::Shdr
<32, false>& shdr
);
5307 #ifdef HAVE_TARGET_32_BIG
5310 Layout::init_fixed_output_section
<32, true>(
5312 elfcpp::Shdr
<32, true>& shdr
);
5315 #ifdef HAVE_TARGET_64_LITTLE
5318 Layout::init_fixed_output_section
<64, false>(
5320 elfcpp::Shdr
<64, false>& shdr
);
5323 #ifdef HAVE_TARGET_64_BIG
5326 Layout::init_fixed_output_section
<64, true>(
5328 elfcpp::Shdr
<64, true>& shdr
);
5331 #ifdef HAVE_TARGET_32_LITTLE
5334 Layout::layout
<32, false>(Sized_relobj_file
<32, false>* object
,
5337 const elfcpp::Shdr
<32, false>& shdr
,
5338 unsigned int, unsigned int, off_t
*);
5341 #ifdef HAVE_TARGET_32_BIG
5344 Layout::layout
<32, true>(Sized_relobj_file
<32, true>* object
,
5347 const elfcpp::Shdr
<32, true>& shdr
,
5348 unsigned int, unsigned int, off_t
*);
5351 #ifdef HAVE_TARGET_64_LITTLE
5354 Layout::layout
<64, false>(Sized_relobj_file
<64, false>* object
,
5357 const elfcpp::Shdr
<64, false>& shdr
,
5358 unsigned int, unsigned int, off_t
*);
5361 #ifdef HAVE_TARGET_64_BIG
5364 Layout::layout
<64, true>(Sized_relobj_file
<64, true>* object
,
5367 const elfcpp::Shdr
<64, true>& shdr
,
5368 unsigned int, unsigned int, off_t
*);
5371 #ifdef HAVE_TARGET_32_LITTLE
5374 Layout::layout_reloc
<32, false>(Sized_relobj_file
<32, false>* object
,
5375 unsigned int reloc_shndx
,
5376 const elfcpp::Shdr
<32, false>& shdr
,
5377 Output_section
* data_section
,
5378 Relocatable_relocs
* rr
);
5381 #ifdef HAVE_TARGET_32_BIG
5384 Layout::layout_reloc
<32, true>(Sized_relobj_file
<32, true>* object
,
5385 unsigned int reloc_shndx
,
5386 const elfcpp::Shdr
<32, true>& shdr
,
5387 Output_section
* data_section
,
5388 Relocatable_relocs
* rr
);
5391 #ifdef HAVE_TARGET_64_LITTLE
5394 Layout::layout_reloc
<64, false>(Sized_relobj_file
<64, false>* object
,
5395 unsigned int reloc_shndx
,
5396 const elfcpp::Shdr
<64, false>& shdr
,
5397 Output_section
* data_section
,
5398 Relocatable_relocs
* rr
);
5401 #ifdef HAVE_TARGET_64_BIG
5404 Layout::layout_reloc
<64, true>(Sized_relobj_file
<64, true>* object
,
5405 unsigned int reloc_shndx
,
5406 const elfcpp::Shdr
<64, true>& shdr
,
5407 Output_section
* data_section
,
5408 Relocatable_relocs
* rr
);
5411 #ifdef HAVE_TARGET_32_LITTLE
5414 Layout::layout_group
<32, false>(Symbol_table
* symtab
,
5415 Sized_relobj_file
<32, false>* object
,
5417 const char* group_section_name
,
5418 const char* signature
,
5419 const elfcpp::Shdr
<32, false>& shdr
,
5420 elfcpp::Elf_Word flags
,
5421 std::vector
<unsigned int>* shndxes
);
5424 #ifdef HAVE_TARGET_32_BIG
5427 Layout::layout_group
<32, true>(Symbol_table
* symtab
,
5428 Sized_relobj_file
<32, true>* object
,
5430 const char* group_section_name
,
5431 const char* signature
,
5432 const elfcpp::Shdr
<32, true>& shdr
,
5433 elfcpp::Elf_Word flags
,
5434 std::vector
<unsigned int>* shndxes
);
5437 #ifdef HAVE_TARGET_64_LITTLE
5440 Layout::layout_group
<64, false>(Symbol_table
* symtab
,
5441 Sized_relobj_file
<64, false>* object
,
5443 const char* group_section_name
,
5444 const char* signature
,
5445 const elfcpp::Shdr
<64, false>& shdr
,
5446 elfcpp::Elf_Word flags
,
5447 std::vector
<unsigned int>* shndxes
);
5450 #ifdef HAVE_TARGET_64_BIG
5453 Layout::layout_group
<64, true>(Symbol_table
* symtab
,
5454 Sized_relobj_file
<64, true>* object
,
5456 const char* group_section_name
,
5457 const char* signature
,
5458 const elfcpp::Shdr
<64, true>& shdr
,
5459 elfcpp::Elf_Word flags
,
5460 std::vector
<unsigned int>* shndxes
);
5463 #ifdef HAVE_TARGET_32_LITTLE
5466 Layout::layout_eh_frame
<32, false>(Sized_relobj_file
<32, false>* object
,
5467 const unsigned char* symbols
,
5469 const unsigned char* symbol_names
,
5470 off_t symbol_names_size
,
5472 const elfcpp::Shdr
<32, false>& shdr
,
5473 unsigned int reloc_shndx
,
5474 unsigned int reloc_type
,
5478 #ifdef HAVE_TARGET_32_BIG
5481 Layout::layout_eh_frame
<32, true>(Sized_relobj_file
<32, true>* object
,
5482 const unsigned char* symbols
,
5484 const unsigned char* symbol_names
,
5485 off_t symbol_names_size
,
5487 const elfcpp::Shdr
<32, true>& shdr
,
5488 unsigned int reloc_shndx
,
5489 unsigned int reloc_type
,
5493 #ifdef HAVE_TARGET_64_LITTLE
5496 Layout::layout_eh_frame
<64, false>(Sized_relobj_file
<64, false>* object
,
5497 const unsigned char* symbols
,
5499 const unsigned char* symbol_names
,
5500 off_t symbol_names_size
,
5502 const elfcpp::Shdr
<64, false>& shdr
,
5503 unsigned int reloc_shndx
,
5504 unsigned int reloc_type
,
5508 #ifdef HAVE_TARGET_64_BIG
5511 Layout::layout_eh_frame
<64, true>(Sized_relobj_file
<64, true>* object
,
5512 const unsigned char* symbols
,
5514 const unsigned char* symbol_names
,
5515 off_t symbol_names_size
,
5517 const elfcpp::Shdr
<64, true>& shdr
,
5518 unsigned int reloc_shndx
,
5519 unsigned int reloc_type
,
5523 #ifdef HAVE_TARGET_32_LITTLE
5526 Layout::add_to_gdb_index(bool is_type_unit
,
5527 Sized_relobj
<32, false>* object
,
5528 const unsigned char* symbols
,
5531 unsigned int reloc_shndx
,
5532 unsigned int reloc_type
);
5535 #ifdef HAVE_TARGET_32_BIG
5538 Layout::add_to_gdb_index(bool is_type_unit
,
5539 Sized_relobj
<32, true>* object
,
5540 const unsigned char* symbols
,
5543 unsigned int reloc_shndx
,
5544 unsigned int reloc_type
);
5547 #ifdef HAVE_TARGET_64_LITTLE
5550 Layout::add_to_gdb_index(bool is_type_unit
,
5551 Sized_relobj
<64, false>* object
,
5552 const unsigned char* symbols
,
5555 unsigned int reloc_shndx
,
5556 unsigned int reloc_type
);
5559 #ifdef HAVE_TARGET_64_BIG
5562 Layout::add_to_gdb_index(bool is_type_unit
,
5563 Sized_relobj
<64, true>* object
,
5564 const unsigned char* symbols
,
5567 unsigned int reloc_shndx
,
5568 unsigned int reloc_type
);
5571 } // End namespace gold.