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 unique_segment_for_sections_specified_(false),
412 incremental_inputs_(NULL
),
413 record_output_section_data_from_script_(false),
414 script_output_section_data_list_(),
415 segment_states_(NULL
),
416 relaxation_debug_check_(NULL
),
417 section_order_map_(),
418 section_segment_map_(),
419 input_section_position_(),
420 input_section_glob_(),
421 incremental_base_(NULL
),
424 // Make space for more than enough segments for a typical file.
425 // This is just for efficiency--it's OK if we wind up needing more.
426 this->segment_list_
.reserve(12);
428 // We expect two unattached Output_data objects: the file header and
429 // the segment headers.
430 this->special_output_list_
.reserve(2);
432 // Initialize structure needed for an incremental build.
433 if (parameters
->incremental())
434 this->incremental_inputs_
= new Incremental_inputs
;
436 // The section name pool is worth optimizing in all cases, because
437 // it is small, but there are often overlaps due to .rel sections.
438 this->namepool_
.set_optimize();
441 // For incremental links, record the base file to be modified.
444 Layout::set_incremental_base(Incremental_binary
* base
)
446 this->incremental_base_
= base
;
447 this->free_list_
.init(base
->output_file()->filesize(), true);
450 // Hash a key we use to look up an output section mapping.
453 Layout::Hash_key::operator()(const Layout::Key
& k
) const
455 return k
.first
+ k
.second
.first
+ k
.second
.second
;
458 // These are the debug sections that are actually used by gdb.
459 // Currently, we've checked versions of gdb up to and including 7.4.
460 // We only check the part of the name that follows ".debug_" or
463 static const char* gdb_sections
[] =
466 "addr", // Fission extension
467 // "aranges", // not used by gdb as of 7.4
475 // "pubnames", // not used by gdb as of 7.4
476 // "pubtypes", // not used by gdb as of 7.4
481 // This is the minimum set of sections needed for line numbers.
483 static const char* lines_only_debug_sections
[] =
486 // "addr", // Fission extension
487 // "aranges", // not used by gdb as of 7.4
495 // "pubnames", // not used by gdb as of 7.4
496 // "pubtypes", // not used by gdb as of 7.4
501 // These sections are the DWARF fast-lookup tables, and are not needed
502 // when building a .gdb_index section.
504 static const char* gdb_fast_lookup_sections
[] =
511 // Returns whether the given debug section is in the list of
512 // debug-sections-used-by-some-version-of-gdb. SUFFIX is the
513 // portion of the name following ".debug_" or ".zdebug_".
516 is_gdb_debug_section(const char* suffix
)
518 // We can do this faster: binary search or a hashtable. But why bother?
519 for (size_t i
= 0; i
< sizeof(gdb_sections
)/sizeof(*gdb_sections
); ++i
)
520 if (strcmp(suffix
, gdb_sections
[i
]) == 0)
525 // Returns whether the given section is needed for lines-only debugging.
528 is_lines_only_debug_section(const char* suffix
)
530 // We can do this faster: binary search or a hashtable. But why bother?
532 i
< sizeof(lines_only_debug_sections
)/sizeof(*lines_only_debug_sections
);
534 if (strcmp(suffix
, lines_only_debug_sections
[i
]) == 0)
539 // Returns whether the given section is a fast-lookup section that
540 // will not be needed when building a .gdb_index section.
543 is_gdb_fast_lookup_section(const char* suffix
)
545 // We can do this faster: binary search or a hashtable. But why bother?
547 i
< sizeof(gdb_fast_lookup_sections
)/sizeof(*gdb_fast_lookup_sections
);
549 if (strcmp(suffix
, gdb_fast_lookup_sections
[i
]) == 0)
554 // Sometimes we compress sections. This is typically done for
555 // sections that are not part of normal program execution (such as
556 // .debug_* sections), and where the readers of these sections know
557 // how to deal with compressed sections. This routine doesn't say for
558 // certain whether we'll compress -- it depends on commandline options
559 // as well -- just whether this section is a candidate for compression.
560 // (The Output_compressed_section class decides whether to compress
561 // a given section, and picks the name of the compressed section.)
564 is_compressible_debug_section(const char* secname
)
566 return (is_prefix_of(".debug", secname
));
569 // We may see compressed debug sections in input files. Return TRUE
570 // if this is the name of a compressed debug section.
573 is_compressed_debug_section(const char* secname
)
575 return (is_prefix_of(".zdebug", secname
));
578 // Whether to include this section in the link.
580 template<int size
, bool big_endian
>
582 Layout::include_section(Sized_relobj_file
<size
, big_endian
>*, const char* name
,
583 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
585 if (shdr
.get_sh_flags() & elfcpp::SHF_EXCLUDE
)
588 switch (shdr
.get_sh_type())
590 case elfcpp::SHT_NULL
:
591 case elfcpp::SHT_SYMTAB
:
592 case elfcpp::SHT_DYNSYM
:
593 case elfcpp::SHT_HASH
:
594 case elfcpp::SHT_DYNAMIC
:
595 case elfcpp::SHT_SYMTAB_SHNDX
:
598 case elfcpp::SHT_STRTAB
:
599 // Discard the sections which have special meanings in the ELF
600 // ABI. Keep others (e.g., .stabstr). We could also do this by
601 // checking the sh_link fields of the appropriate sections.
602 return (strcmp(name
, ".dynstr") != 0
603 && strcmp(name
, ".strtab") != 0
604 && strcmp(name
, ".shstrtab") != 0);
606 case elfcpp::SHT_RELA
:
607 case elfcpp::SHT_REL
:
608 case elfcpp::SHT_GROUP
:
609 // If we are emitting relocations these should be handled
611 gold_assert(!parameters
->options().relocatable());
614 case elfcpp::SHT_PROGBITS
:
615 if (parameters
->options().strip_debug()
616 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
618 if (is_debug_info_section(name
))
621 if (parameters
->options().strip_debug_non_line()
622 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
624 // Debugging sections can only be recognized by name.
625 if (is_prefix_of(".debug_", name
)
626 && !is_lines_only_debug_section(name
+ 7))
628 if (is_prefix_of(".zdebug_", name
)
629 && !is_lines_only_debug_section(name
+ 8))
632 if (parameters
->options().strip_debug_gdb()
633 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
635 // Debugging sections can only be recognized by name.
636 if (is_prefix_of(".debug_", name
)
637 && !is_gdb_debug_section(name
+ 7))
639 if (is_prefix_of(".zdebug_", name
)
640 && !is_gdb_debug_section(name
+ 8))
643 if (parameters
->options().gdb_index()
644 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
646 // When building .gdb_index, we can strip .debug_pubnames,
647 // .debug_pubtypes, and .debug_aranges sections.
648 if (is_prefix_of(".debug_", name
)
649 && is_gdb_fast_lookup_section(name
+ 7))
651 if (is_prefix_of(".zdebug_", name
)
652 && is_gdb_fast_lookup_section(name
+ 8))
655 if (parameters
->options().strip_lto_sections()
656 && !parameters
->options().relocatable()
657 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
659 // Ignore LTO sections containing intermediate code.
660 if (is_prefix_of(".gnu.lto_", name
))
663 // The GNU linker strips .gnu_debuglink sections, so we do too.
664 // This is a feature used to keep debugging information in
666 if (strcmp(name
, ".gnu_debuglink") == 0)
675 // Return an output section named NAME, or NULL if there is none.
678 Layout::find_output_section(const char* name
) const
680 for (Section_list::const_iterator p
= this->section_list_
.begin();
681 p
!= this->section_list_
.end();
683 if (strcmp((*p
)->name(), name
) == 0)
688 // Return an output segment of type TYPE, with segment flags SET set
689 // and segment flags CLEAR clear. Return NULL if there is none.
692 Layout::find_output_segment(elfcpp::PT type
, elfcpp::Elf_Word set
,
693 elfcpp::Elf_Word clear
) const
695 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
696 p
!= this->segment_list_
.end();
698 if (static_cast<elfcpp::PT
>((*p
)->type()) == type
699 && ((*p
)->flags() & set
) == set
700 && ((*p
)->flags() & clear
) == 0)
705 // When we put a .ctors or .dtors section with more than one word into
706 // a .init_array or .fini_array section, we need to reverse the words
707 // in the .ctors/.dtors section. This is because .init_array executes
708 // constructors front to back, where .ctors executes them back to
709 // front, and vice-versa for .fini_array/.dtors. Although we do want
710 // to remap .ctors/.dtors into .init_array/.fini_array because it can
711 // be more efficient, we don't want to change the order in which
712 // constructors/destructors are run. This set just keeps track of
713 // these sections which need to be reversed. It is only changed by
714 // Layout::layout. It should be a private member of Layout, but that
715 // would require layout.h to #include object.h to get the definition
717 static Unordered_set
<Section_id
, Section_id_hash
> ctors_sections_in_init_array
;
719 // Return whether OBJECT/SHNDX is a .ctors/.dtors section mapped to a
720 // .init_array/.fini_array section.
723 Layout::is_ctors_in_init_array(Relobj
* relobj
, unsigned int shndx
) const
725 return (ctors_sections_in_init_array
.find(Section_id(relobj
, shndx
))
726 != ctors_sections_in_init_array
.end());
729 // Return the output section to use for section NAME with type TYPE
730 // and section flags FLAGS. NAME must be canonicalized in the string
731 // pool, and NAME_KEY is the key. ORDER is where this should appear
732 // in the output sections. IS_RELRO is true for a relro section.
735 Layout::get_output_section(const char* name
, Stringpool::Key name_key
,
736 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
737 Output_section_order order
, bool is_relro
)
739 elfcpp::Elf_Word lookup_type
= type
;
741 // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and
742 // PREINIT_ARRAY like PROGBITS. This ensures that we combine
743 // .init_array, .fini_array, and .preinit_array sections by name
744 // whatever their type in the input file. We do this because the
745 // types are not always right in the input files.
746 if (lookup_type
== elfcpp::SHT_INIT_ARRAY
747 || lookup_type
== elfcpp::SHT_FINI_ARRAY
748 || lookup_type
== elfcpp::SHT_PREINIT_ARRAY
)
749 lookup_type
= elfcpp::SHT_PROGBITS
;
751 elfcpp::Elf_Xword lookup_flags
= flags
;
753 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
754 // read-write with read-only sections. Some other ELF linkers do
755 // not do this. FIXME: Perhaps there should be an option
757 lookup_flags
&= ~(elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
759 const Key
key(name_key
, std::make_pair(lookup_type
, lookup_flags
));
760 const std::pair
<Key
, Output_section
*> v(key
, NULL
);
761 std::pair
<Section_name_map::iterator
, bool> ins(
762 this->section_name_map_
.insert(v
));
765 return ins
.first
->second
;
768 // This is the first time we've seen this name/type/flags
769 // combination. For compatibility with the GNU linker, we
770 // combine sections with contents and zero flags with sections
771 // with non-zero flags. This is a workaround for cases where
772 // assembler code forgets to set section flags. FIXME: Perhaps
773 // there should be an option to control this.
774 Output_section
* os
= NULL
;
776 if (lookup_type
== elfcpp::SHT_PROGBITS
)
780 Output_section
* same_name
= this->find_output_section(name
);
781 if (same_name
!= NULL
782 && (same_name
->type() == elfcpp::SHT_PROGBITS
783 || same_name
->type() == elfcpp::SHT_INIT_ARRAY
784 || same_name
->type() == elfcpp::SHT_FINI_ARRAY
785 || same_name
->type() == elfcpp::SHT_PREINIT_ARRAY
)
786 && (same_name
->flags() & elfcpp::SHF_TLS
) == 0)
789 else if ((flags
& elfcpp::SHF_TLS
) == 0)
791 elfcpp::Elf_Xword zero_flags
= 0;
792 const Key
zero_key(name_key
, std::make_pair(lookup_type
,
794 Section_name_map::iterator p
=
795 this->section_name_map_
.find(zero_key
);
796 if (p
!= this->section_name_map_
.end())
802 os
= this->make_output_section(name
, type
, flags
, order
, is_relro
);
804 ins
.first
->second
= os
;
809 // Returns TRUE iff NAME (an input section from RELOBJ) will
810 // be mapped to an output section that should be KEPT.
813 Layout::keep_input_section(const Relobj
* relobj
, const char* name
)
815 if (! this->script_options_
->saw_sections_clause())
818 Script_sections
* ss
= this->script_options_
->script_sections();
819 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
820 Output_section
** output_section_slot
;
821 Script_sections::Section_type script_section_type
;
824 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
825 &script_section_type
, &keep
);
826 return name
!= NULL
&& keep
;
829 // Clear the input section flags that should not be copied to the
833 Layout::get_output_section_flags(elfcpp::Elf_Xword input_section_flags
)
835 // Some flags in the input section should not be automatically
836 // copied to the output section.
837 input_section_flags
&= ~ (elfcpp::SHF_INFO_LINK
840 | elfcpp::SHF_STRINGS
);
842 // We only clear the SHF_LINK_ORDER flag in for
843 // a non-relocatable link.
844 if (!parameters
->options().relocatable())
845 input_section_flags
&= ~elfcpp::SHF_LINK_ORDER
;
847 return input_section_flags
;
850 // Pick the output section to use for section NAME, in input file
851 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
852 // linker created section. IS_INPUT_SECTION is true if we are
853 // choosing an output section for an input section found in a input
854 // file. ORDER is where this section should appear in the output
855 // sections. IS_RELRO is true for a relro section. This will return
856 // NULL if the input section should be discarded.
859 Layout::choose_output_section(const Relobj
* relobj
, const char* name
,
860 elfcpp::Elf_Word type
, elfcpp::Elf_Xword flags
,
861 bool is_input_section
, Output_section_order order
,
864 // We should not see any input sections after we have attached
865 // sections to segments.
866 gold_assert(!is_input_section
|| !this->sections_are_attached_
);
868 flags
= this->get_output_section_flags(flags
);
870 if (this->script_options_
->saw_sections_clause())
872 // We are using a SECTIONS clause, so the output section is
873 // chosen based only on the name.
875 Script_sections
* ss
= this->script_options_
->script_sections();
876 const char* file_name
= relobj
== NULL
? NULL
: relobj
->name().c_str();
877 Output_section
** output_section_slot
;
878 Script_sections::Section_type script_section_type
;
879 const char* orig_name
= name
;
881 name
= ss
->output_section_name(file_name
, name
, &output_section_slot
,
882 &script_section_type
, &keep
);
886 gold_debug(DEBUG_SCRIPT
, _("Unable to create output section '%s' "
887 "because it is not allowed by the "
888 "SECTIONS clause of the linker script"),
890 // The SECTIONS clause says to discard this input section.
894 // We can only handle script section types ST_NONE and ST_NOLOAD.
895 switch (script_section_type
)
897 case Script_sections::ST_NONE
:
899 case Script_sections::ST_NOLOAD
:
900 flags
&= elfcpp::SHF_ALLOC
;
906 // If this is an orphan section--one not mentioned in the linker
907 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
908 // default processing below.
910 if (output_section_slot
!= NULL
)
912 if (*output_section_slot
!= NULL
)
914 (*output_section_slot
)->update_flags_for_input_section(flags
);
915 return *output_section_slot
;
918 // We don't put sections found in the linker script into
919 // SECTION_NAME_MAP_. That keeps us from getting confused
920 // if an orphan section is mapped to a section with the same
921 // name as one in the linker script.
923 name
= this->namepool_
.add(name
, false, NULL
);
925 Output_section
* os
= this->make_output_section(name
, type
, flags
,
928 os
->set_found_in_sections_clause();
930 // Special handling for NOLOAD sections.
931 if (script_section_type
== Script_sections::ST_NOLOAD
)
935 // The constructor of Output_section sets addresses of non-ALLOC
936 // sections to 0 by default. We don't want that for NOLOAD
937 // sections even if they have no SHF_ALLOC flag.
938 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0
939 && os
->is_address_valid())
941 gold_assert(os
->address() == 0
942 && !os
->is_offset_valid()
943 && !os
->is_data_size_valid());
944 os
->reset_address_and_file_offset();
948 *output_section_slot
= os
;
953 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
955 size_t len
= strlen(name
);
956 char* uncompressed_name
= NULL
;
958 // Compressed debug sections should be mapped to the corresponding
959 // uncompressed section.
960 if (is_compressed_debug_section(name
))
962 uncompressed_name
= new char[len
];
963 uncompressed_name
[0] = '.';
964 gold_assert(name
[0] == '.' && name
[1] == 'z');
965 strncpy(&uncompressed_name
[1], &name
[2], len
- 2);
966 uncompressed_name
[len
- 1] = '\0';
968 name
= uncompressed_name
;
971 // Turn NAME from the name of the input section into the name of the
974 && !this->script_options_
->saw_sections_clause()
975 && !parameters
->options().relocatable())
977 const char *orig_name
= name
;
978 name
= parameters
->target().output_section_name(relobj
, name
, &len
);
980 name
= Layout::output_section_name(relobj
, orig_name
, &len
);
983 Stringpool::Key name_key
;
984 name
= this->namepool_
.add_with_length(name
, len
, true, &name_key
);
986 if (uncompressed_name
!= NULL
)
987 delete[] uncompressed_name
;
989 // Find or make the output section. The output section is selected
990 // based on the section name, type, and flags.
991 return this->get_output_section(name
, name_key
, type
, flags
, order
, is_relro
);
994 // For incremental links, record the initial fixed layout of a section
995 // from the base file, and return a pointer to the Output_section.
997 template<int size
, bool big_endian
>
999 Layout::init_fixed_output_section(const char* name
,
1000 elfcpp::Shdr
<size
, big_endian
>& shdr
)
1002 unsigned int sh_type
= shdr
.get_sh_type();
1004 // We preserve the layout of PROGBITS, NOBITS, INIT_ARRAY, FINI_ARRAY,
1005 // PRE_INIT_ARRAY, and NOTE sections.
1006 // All others will be created from scratch and reallocated.
1007 if (!can_incremental_update(sh_type
))
1010 // If we're generating a .gdb_index section, we need to regenerate
1012 if (parameters
->options().gdb_index()
1013 && sh_type
== elfcpp::SHT_PROGBITS
1014 && strcmp(name
, ".gdb_index") == 0)
1017 typename
elfcpp::Elf_types
<size
>::Elf_Addr sh_addr
= shdr
.get_sh_addr();
1018 typename
elfcpp::Elf_types
<size
>::Elf_Off sh_offset
= shdr
.get_sh_offset();
1019 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
1020 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_flags
= shdr
.get_sh_flags();
1021 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_addralign
=
1022 shdr
.get_sh_addralign();
1024 // Make the output section.
1025 Stringpool::Key name_key
;
1026 name
= this->namepool_
.add(name
, true, &name_key
);
1027 Output_section
* os
= this->get_output_section(name
, name_key
, sh_type
,
1028 sh_flags
, ORDER_INVALID
, false);
1029 os
->set_fixed_layout(sh_addr
, sh_offset
, sh_size
, sh_addralign
);
1030 if (sh_type
!= elfcpp::SHT_NOBITS
)
1031 this->free_list_
.remove(sh_offset
, sh_offset
+ sh_size
);
1035 // Return the output section to use for input section SHNDX, with name
1036 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
1037 // index of a relocation section which applies to this section, or 0
1038 // if none, or -1U if more than one. RELOC_TYPE is the type of the
1039 // relocation section if there is one. Set *OFF to the offset of this
1040 // input section without the output section. Return NULL if the
1041 // section should be discarded. Set *OFF to -1 if the section
1042 // contents should not be written directly to the output file, but
1043 // will instead receive special handling.
1045 template<int size
, bool big_endian
>
1047 Layout::layout(Sized_relobj_file
<size
, big_endian
>* object
, unsigned int shndx
,
1048 const char* name
, const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1049 unsigned int reloc_shndx
, unsigned int, off_t
* off
)
1053 if (!this->include_section(object
, name
, shdr
))
1056 elfcpp::Elf_Word sh_type
= shdr
.get_sh_type();
1058 // In a relocatable link a grouped section must not be combined with
1059 // any other sections.
1061 if (parameters
->options().relocatable()
1062 && (shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) != 0)
1064 name
= this->namepool_
.add(name
, true, NULL
);
1065 os
= this->make_output_section(name
, sh_type
, shdr
.get_sh_flags(),
1066 ORDER_INVALID
, false);
1070 // Plugins can choose to place one or more subsets of sections in
1071 // unique segments and this is done by mapping these section subsets
1072 // to unique output sections. Check if this section needs to be
1073 // remapped to a unique output section.
1074 Section_segment_map::iterator it
1075 = this->section_segment_map_
.find(Const_section_id(object
, shndx
));
1076 if (it
== this->section_segment_map_
.end())
1078 os
= this->choose_output_section(object
, name
, sh_type
,
1079 shdr
.get_sh_flags(), true,
1080 ORDER_INVALID
, false);
1084 // We know the name of the output section, directly call
1085 // get_output_section here by-passing choose_output_section.
1086 elfcpp::Elf_Xword flags
1087 = this->get_output_section_flags(shdr
.get_sh_flags());
1089 const char* os_name
= it
->second
->name
;
1090 Stringpool::Key name_key
;
1091 os_name
= this->namepool_
.add(os_name
, true, &name_key
);
1092 os
= this->get_output_section(os_name
, name_key
, sh_type
, flags
,
1093 ORDER_INVALID
, false);
1094 if (!os
->is_unique_segment())
1096 os
->set_is_unique_segment();
1097 os
->set_extra_segment_flags(it
->second
->flags
);
1098 os
->set_segment_alignment(it
->second
->align
);
1105 // By default the GNU linker sorts input sections whose names match
1106 // .ctors.*, .dtors.*, .init_array.*, or .fini_array.*. The
1107 // sections are sorted by name. This is used to implement
1108 // constructor priority ordering. We are compatible. When we put
1109 // .ctor sections in .init_array and .dtor sections in .fini_array,
1110 // we must also sort plain .ctor and .dtor sections.
1111 if (!this->script_options_
->saw_sections_clause()
1112 && !parameters
->options().relocatable()
1113 && (is_prefix_of(".ctors.", name
)
1114 || is_prefix_of(".dtors.", name
)
1115 || is_prefix_of(".init_array.", name
)
1116 || is_prefix_of(".fini_array.", name
)
1117 || (parameters
->options().ctors_in_init_array()
1118 && (strcmp(name
, ".ctors") == 0
1119 || strcmp(name
, ".dtors") == 0))))
1120 os
->set_must_sort_attached_input_sections();
1122 // If this is a .ctors or .ctors.* section being mapped to a
1123 // .init_array section, or a .dtors or .dtors.* section being mapped
1124 // to a .fini_array section, we will need to reverse the words if
1125 // there is more than one. Record this section for later. See
1126 // ctors_sections_in_init_array above.
1127 if (!this->script_options_
->saw_sections_clause()
1128 && !parameters
->options().relocatable()
1129 && shdr
.get_sh_size() > size
/ 8
1130 && (((strcmp(name
, ".ctors") == 0
1131 || is_prefix_of(".ctors.", name
))
1132 && strcmp(os
->name(), ".init_array") == 0)
1133 || ((strcmp(name
, ".dtors") == 0
1134 || is_prefix_of(".dtors.", name
))
1135 && strcmp(os
->name(), ".fini_array") == 0)))
1136 ctors_sections_in_init_array
.insert(Section_id(object
, shndx
));
1138 // FIXME: Handle SHF_LINK_ORDER somewhere.
1140 elfcpp::Elf_Xword orig_flags
= os
->flags();
1142 *off
= os
->add_input_section(this, object
, shndx
, name
, shdr
, reloc_shndx
,
1143 this->script_options_
->saw_sections_clause());
1145 // If the flags changed, we may have to change the order.
1146 if ((orig_flags
& elfcpp::SHF_ALLOC
) != 0)
1148 orig_flags
&= (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1149 elfcpp::Elf_Xword new_flags
=
1150 os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
);
1151 if (orig_flags
!= new_flags
)
1152 os
->set_order(this->default_section_order(os
, false));
1155 this->have_added_input_section_
= true;
1160 // Maps section SECN to SEGMENT s.
1162 Layout::insert_section_segment_map(Const_section_id secn
,
1163 Unique_segment_info
*s
)
1165 gold_assert(this->unique_segment_for_sections_specified_
);
1166 this->section_segment_map_
[secn
] = s
;
1169 // Handle a relocation section when doing a relocatable link.
1171 template<int size
, bool big_endian
>
1173 Layout::layout_reloc(Sized_relobj_file
<size
, big_endian
>* object
,
1175 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1176 Output_section
* data_section
,
1177 Relocatable_relocs
* rr
)
1179 gold_assert(parameters
->options().relocatable()
1180 || parameters
->options().emit_relocs());
1182 int sh_type
= shdr
.get_sh_type();
1185 if (sh_type
== elfcpp::SHT_REL
)
1187 else if (sh_type
== elfcpp::SHT_RELA
)
1191 name
+= data_section
->name();
1193 // In a relocatable link relocs for a grouped section must not be
1194 // combined with other reloc sections.
1196 if (!parameters
->options().relocatable()
1197 || (data_section
->flags() & elfcpp::SHF_GROUP
) == 0)
1198 os
= this->choose_output_section(object
, name
.c_str(), sh_type
,
1199 shdr
.get_sh_flags(), false,
1200 ORDER_INVALID
, false);
1203 const char* n
= this->namepool_
.add(name
.c_str(), true, NULL
);
1204 os
= this->make_output_section(n
, sh_type
, shdr
.get_sh_flags(),
1205 ORDER_INVALID
, false);
1208 os
->set_should_link_to_symtab();
1209 os
->set_info_section(data_section
);
1211 Output_section_data
* posd
;
1212 if (sh_type
== elfcpp::SHT_REL
)
1214 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rel_size
);
1215 posd
= new Output_relocatable_relocs
<elfcpp::SHT_REL
,
1219 else if (sh_type
== elfcpp::SHT_RELA
)
1221 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rela_size
);
1222 posd
= new Output_relocatable_relocs
<elfcpp::SHT_RELA
,
1229 os
->add_output_section_data(posd
);
1230 rr
->set_output_data(posd
);
1235 // Handle a group section when doing a relocatable link.
1237 template<int size
, bool big_endian
>
1239 Layout::layout_group(Symbol_table
* symtab
,
1240 Sized_relobj_file
<size
, big_endian
>* object
,
1242 const char* group_section_name
,
1243 const char* signature
,
1244 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1245 elfcpp::Elf_Word flags
,
1246 std::vector
<unsigned int>* shndxes
)
1248 gold_assert(parameters
->options().relocatable());
1249 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_GROUP
);
1250 group_section_name
= this->namepool_
.add(group_section_name
, true, NULL
);
1251 Output_section
* os
= this->make_output_section(group_section_name
,
1253 shdr
.get_sh_flags(),
1254 ORDER_INVALID
, false);
1256 // We need to find a symbol with the signature in the symbol table.
1257 // If we don't find one now, we need to look again later.
1258 Symbol
* sym
= symtab
->lookup(signature
, NULL
);
1260 os
->set_info_symndx(sym
);
1263 // Reserve some space to minimize reallocations.
1264 if (this->group_signatures_
.empty())
1265 this->group_signatures_
.reserve(this->number_of_input_files_
* 16);
1267 // We will wind up using a symbol whose name is the signature.
1268 // So just put the signature in the symbol name pool to save it.
1269 signature
= symtab
->canonicalize_name(signature
);
1270 this->group_signatures_
.push_back(Group_signature(os
, signature
));
1273 os
->set_should_link_to_symtab();
1276 section_size_type entry_count
=
1277 convert_to_section_size_type(shdr
.get_sh_size() / 4);
1278 Output_section_data
* posd
=
1279 new Output_data_group
<size
, big_endian
>(object
, entry_count
, flags
,
1281 os
->add_output_section_data(posd
);
1284 // Special GNU handling of sections name .eh_frame. They will
1285 // normally hold exception frame data as defined by the C++ ABI
1286 // (http://codesourcery.com/cxx-abi/).
1288 template<int size
, bool big_endian
>
1290 Layout::layout_eh_frame(Sized_relobj_file
<size
, big_endian
>* object
,
1291 const unsigned char* symbols
,
1293 const unsigned char* symbol_names
,
1294 off_t symbol_names_size
,
1296 const elfcpp::Shdr
<size
, big_endian
>& shdr
,
1297 unsigned int reloc_shndx
, unsigned int reloc_type
,
1300 gold_assert(shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
1301 || shdr
.get_sh_type() == elfcpp::SHT_X86_64_UNWIND
);
1302 gold_assert((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
1304 Output_section
* os
= this->make_eh_frame_section(object
);
1308 gold_assert(this->eh_frame_section_
== os
);
1310 elfcpp::Elf_Xword orig_flags
= os
->flags();
1312 if (!parameters
->incremental()
1313 && this->eh_frame_data_
->add_ehframe_input_section(object
,
1322 os
->update_flags_for_input_section(shdr
.get_sh_flags());
1324 // A writable .eh_frame section is a RELRO section.
1325 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1326 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1329 os
->set_order(ORDER_RELRO
);
1332 // We found a .eh_frame section we are going to optimize, so now
1333 // we can add the set of optimized sections to the output
1334 // section. We need to postpone adding this until we've found a
1335 // section we can optimize so that the .eh_frame section in
1336 // crtbegin.o winds up at the start of the output section.
1337 if (!this->added_eh_frame_data_
)
1339 os
->add_output_section_data(this->eh_frame_data_
);
1340 this->added_eh_frame_data_
= true;
1346 // We couldn't handle this .eh_frame section for some reason.
1347 // Add it as a normal section.
1348 bool saw_sections_clause
= this->script_options_
->saw_sections_clause();
1349 *off
= os
->add_input_section(this, object
, shndx
, ".eh_frame", shdr
,
1350 reloc_shndx
, saw_sections_clause
);
1351 this->have_added_input_section_
= true;
1353 if ((orig_flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
))
1354 != (os
->flags() & (elfcpp::SHF_WRITE
| elfcpp::SHF_EXECINSTR
)))
1355 os
->set_order(this->default_section_order(os
, false));
1361 // Create and return the magic .eh_frame section. Create
1362 // .eh_frame_hdr also if appropriate. OBJECT is the object with the
1363 // input .eh_frame section; it may be NULL.
1366 Layout::make_eh_frame_section(const Relobj
* object
)
1368 // FIXME: On x86_64, this could use SHT_X86_64_UNWIND rather than
1370 Output_section
* os
= this->choose_output_section(object
, ".eh_frame",
1371 elfcpp::SHT_PROGBITS
,
1372 elfcpp::SHF_ALLOC
, false,
1373 ORDER_EHFRAME
, false);
1377 if (this->eh_frame_section_
== NULL
)
1379 this->eh_frame_section_
= os
;
1380 this->eh_frame_data_
= new Eh_frame();
1382 // For incremental linking, we do not optimize .eh_frame sections
1383 // or create a .eh_frame_hdr section.
1384 if (parameters
->options().eh_frame_hdr() && !parameters
->incremental())
1386 Output_section
* hdr_os
=
1387 this->choose_output_section(NULL
, ".eh_frame_hdr",
1388 elfcpp::SHT_PROGBITS
,
1389 elfcpp::SHF_ALLOC
, false,
1390 ORDER_EHFRAME
, false);
1394 Eh_frame_hdr
* hdr_posd
= new Eh_frame_hdr(os
,
1395 this->eh_frame_data_
);
1396 hdr_os
->add_output_section_data(hdr_posd
);
1398 hdr_os
->set_after_input_sections();
1400 if (!this->script_options_
->saw_phdrs_clause())
1402 Output_segment
* hdr_oseg
;
1403 hdr_oseg
= this->make_output_segment(elfcpp::PT_GNU_EH_FRAME
,
1405 hdr_oseg
->add_output_section_to_nonload(hdr_os
,
1409 this->eh_frame_data_
->set_eh_frame_hdr(hdr_posd
);
1417 // Add an exception frame for a PLT. This is called from target code.
1420 Layout::add_eh_frame_for_plt(Output_data
* plt
, const unsigned char* cie_data
,
1421 size_t cie_length
, const unsigned char* fde_data
,
1424 if (parameters
->incremental())
1426 // FIXME: Maybe this could work some day....
1429 Output_section
* os
= this->make_eh_frame_section(NULL
);
1432 this->eh_frame_data_
->add_ehframe_for_plt(plt
, cie_data
, cie_length
,
1433 fde_data
, fde_length
);
1434 if (!this->added_eh_frame_data_
)
1436 os
->add_output_section_data(this->eh_frame_data_
);
1437 this->added_eh_frame_data_
= true;
1441 // Scan a .debug_info or .debug_types section, and add summary
1442 // information to the .gdb_index section.
1444 template<int size
, bool big_endian
>
1446 Layout::add_to_gdb_index(bool is_type_unit
,
1447 Sized_relobj
<size
, big_endian
>* object
,
1448 const unsigned char* symbols
,
1451 unsigned int reloc_shndx
,
1452 unsigned int reloc_type
)
1454 if (this->gdb_index_data_
== NULL
)
1456 Output_section
* os
= this->choose_output_section(NULL
, ".gdb_index",
1457 elfcpp::SHT_PROGBITS
, 0,
1458 false, ORDER_INVALID
,
1463 this->gdb_index_data_
= new Gdb_index(os
);
1464 os
->add_output_section_data(this->gdb_index_data_
);
1465 os
->set_after_input_sections();
1468 this->gdb_index_data_
->scan_debug_info(is_type_unit
, object
, symbols
,
1469 symbols_size
, shndx
, reloc_shndx
,
1473 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
1474 // the output section.
1477 Layout::add_output_section_data(const char* name
, elfcpp::Elf_Word type
,
1478 elfcpp::Elf_Xword flags
,
1479 Output_section_data
* posd
,
1480 Output_section_order order
, bool is_relro
)
1482 Output_section
* os
= this->choose_output_section(NULL
, name
, type
, flags
,
1483 false, order
, is_relro
);
1485 os
->add_output_section_data(posd
);
1489 // Map section flags to segment flags.
1492 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags
)
1494 elfcpp::Elf_Word ret
= elfcpp::PF_R
;
1495 if ((flags
& elfcpp::SHF_WRITE
) != 0)
1496 ret
|= elfcpp::PF_W
;
1497 if ((flags
& elfcpp::SHF_EXECINSTR
) != 0)
1498 ret
|= elfcpp::PF_X
;
1502 // Make a new Output_section, and attach it to segments as
1503 // appropriate. ORDER is the order in which this section should
1504 // appear in the output segment. IS_RELRO is true if this is a relro
1505 // (read-only after relocations) section.
1508 Layout::make_output_section(const char* name
, elfcpp::Elf_Word type
,
1509 elfcpp::Elf_Xword flags
,
1510 Output_section_order order
, bool is_relro
)
1513 if ((flags
& elfcpp::SHF_ALLOC
) == 0
1514 && strcmp(parameters
->options().compress_debug_sections(), "none") != 0
1515 && is_compressible_debug_section(name
))
1516 os
= new Output_compressed_section(¶meters
->options(), name
, type
,
1518 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1519 && parameters
->options().strip_debug_non_line()
1520 && strcmp(".debug_abbrev", name
) == 0)
1522 os
= this->debug_abbrev_
= new Output_reduced_debug_abbrev_section(
1524 if (this->debug_info_
)
1525 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1527 else if ((flags
& elfcpp::SHF_ALLOC
) == 0
1528 && parameters
->options().strip_debug_non_line()
1529 && strcmp(".debug_info", name
) == 0)
1531 os
= this->debug_info_
= new Output_reduced_debug_info_section(
1533 if (this->debug_abbrev_
)
1534 this->debug_info_
->set_abbreviations(this->debug_abbrev_
);
1538 // Sometimes .init_array*, .preinit_array* and .fini_array* do
1539 // not have correct section types. Force them here.
1540 if (type
== elfcpp::SHT_PROGBITS
)
1542 if (is_prefix_of(".init_array", name
))
1543 type
= elfcpp::SHT_INIT_ARRAY
;
1544 else if (is_prefix_of(".preinit_array", name
))
1545 type
= elfcpp::SHT_PREINIT_ARRAY
;
1546 else if (is_prefix_of(".fini_array", name
))
1547 type
= elfcpp::SHT_FINI_ARRAY
;
1550 // FIXME: const_cast is ugly.
1551 Target
* target
= const_cast<Target
*>(¶meters
->target());
1552 os
= target
->make_output_section(name
, type
, flags
);
1555 // With -z relro, we have to recognize the special sections by name.
1556 // There is no other way.
1557 bool is_relro_local
= false;
1558 if (!this->script_options_
->saw_sections_clause()
1559 && parameters
->options().relro()
1560 && (flags
& elfcpp::SHF_ALLOC
) != 0
1561 && (flags
& elfcpp::SHF_WRITE
) != 0)
1563 if (type
== elfcpp::SHT_PROGBITS
)
1565 if ((flags
& elfcpp::SHF_TLS
) != 0)
1567 else if (strcmp(name
, ".data.rel.ro") == 0)
1569 else if (strcmp(name
, ".data.rel.ro.local") == 0)
1572 is_relro_local
= true;
1574 else if (strcmp(name
, ".ctors") == 0
1575 || strcmp(name
, ".dtors") == 0
1576 || strcmp(name
, ".jcr") == 0)
1579 else if (type
== elfcpp::SHT_INIT_ARRAY
1580 || type
== elfcpp::SHT_FINI_ARRAY
1581 || type
== elfcpp::SHT_PREINIT_ARRAY
)
1588 if (order
== ORDER_INVALID
&& (flags
& elfcpp::SHF_ALLOC
) != 0)
1589 order
= this->default_section_order(os
, is_relro_local
);
1591 os
->set_order(order
);
1593 parameters
->target().new_output_section(os
);
1595 this->section_list_
.push_back(os
);
1597 // The GNU linker by default sorts some sections by priority, so we
1598 // do the same. We need to know that this might happen before we
1599 // attach any input sections.
1600 if (!this->script_options_
->saw_sections_clause()
1601 && !parameters
->options().relocatable()
1602 && (strcmp(name
, ".init_array") == 0
1603 || strcmp(name
, ".fini_array") == 0
1604 || (!parameters
->options().ctors_in_init_array()
1605 && (strcmp(name
, ".ctors") == 0
1606 || strcmp(name
, ".dtors") == 0))))
1607 os
->set_may_sort_attached_input_sections();
1609 // Check for .stab*str sections, as .stab* sections need to link to
1611 if (type
== elfcpp::SHT_STRTAB
1612 && !this->have_stabstr_section_
1613 && strncmp(name
, ".stab", 5) == 0
1614 && strcmp(name
+ strlen(name
) - 3, "str") == 0)
1615 this->have_stabstr_section_
= true;
1617 // During a full incremental link, we add patch space to most
1618 // PROGBITS and NOBITS sections. Flag those that may be
1619 // arbitrarily padded.
1620 if ((type
== elfcpp::SHT_PROGBITS
|| type
== elfcpp::SHT_NOBITS
)
1621 && order
!= ORDER_INTERP
1622 && order
!= ORDER_INIT
1623 && order
!= ORDER_PLT
1624 && order
!= ORDER_FINI
1625 && order
!= ORDER_RELRO_LAST
1626 && order
!= ORDER_NON_RELRO_FIRST
1627 && strcmp(name
, ".eh_frame") != 0
1628 && strcmp(name
, ".ctors") != 0
1629 && strcmp(name
, ".dtors") != 0
1630 && strcmp(name
, ".jcr") != 0)
1632 os
->set_is_patch_space_allowed();
1634 // Certain sections require "holes" to be filled with
1635 // specific fill patterns. These fill patterns may have
1636 // a minimum size, so we must prevent allocations from the
1637 // free list that leave a hole smaller than the minimum.
1638 if (strcmp(name
, ".debug_info") == 0)
1639 os
->set_free_space_fill(new Output_fill_debug_info(false));
1640 else if (strcmp(name
, ".debug_types") == 0)
1641 os
->set_free_space_fill(new Output_fill_debug_info(true));
1642 else if (strcmp(name
, ".debug_line") == 0)
1643 os
->set_free_space_fill(new Output_fill_debug_line());
1646 // If we have already attached the sections to segments, then we
1647 // need to attach this one now. This happens for sections created
1648 // directly by the linker.
1649 if (this->sections_are_attached_
)
1650 this->attach_section_to_segment(¶meters
->target(), os
);
1655 // Return the default order in which a section should be placed in an
1656 // output segment. This function captures a lot of the ideas in
1657 // ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
1658 // linker created section is normally set when the section is created;
1659 // this function is used for input sections.
1661 Output_section_order
1662 Layout::default_section_order(Output_section
* os
, bool is_relro_local
)
1664 gold_assert((os
->flags() & elfcpp::SHF_ALLOC
) != 0);
1665 bool is_write
= (os
->flags() & elfcpp::SHF_WRITE
) != 0;
1666 bool is_execinstr
= (os
->flags() & elfcpp::SHF_EXECINSTR
) != 0;
1667 bool is_bss
= false;
1672 case elfcpp::SHT_PROGBITS
:
1674 case elfcpp::SHT_NOBITS
:
1677 case elfcpp::SHT_RELA
:
1678 case elfcpp::SHT_REL
:
1680 return ORDER_DYNAMIC_RELOCS
;
1682 case elfcpp::SHT_HASH
:
1683 case elfcpp::SHT_DYNAMIC
:
1684 case elfcpp::SHT_SHLIB
:
1685 case elfcpp::SHT_DYNSYM
:
1686 case elfcpp::SHT_GNU_HASH
:
1687 case elfcpp::SHT_GNU_verdef
:
1688 case elfcpp::SHT_GNU_verneed
:
1689 case elfcpp::SHT_GNU_versym
:
1691 return ORDER_DYNAMIC_LINKER
;
1693 case elfcpp::SHT_NOTE
:
1694 return is_write
? ORDER_RW_NOTE
: ORDER_RO_NOTE
;
1697 if ((os
->flags() & elfcpp::SHF_TLS
) != 0)
1698 return is_bss
? ORDER_TLS_BSS
: ORDER_TLS_DATA
;
1700 if (!is_bss
&& !is_write
)
1704 if (strcmp(os
->name(), ".init") == 0)
1706 else if (strcmp(os
->name(), ".fini") == 0)
1709 return is_execinstr
? ORDER_TEXT
: ORDER_READONLY
;
1713 return is_relro_local
? ORDER_RELRO_LOCAL
: ORDER_RELRO
;
1715 if (os
->is_small_section())
1716 return is_bss
? ORDER_SMALL_BSS
: ORDER_SMALL_DATA
;
1717 if (os
->is_large_section())
1718 return is_bss
? ORDER_LARGE_BSS
: ORDER_LARGE_DATA
;
1720 return is_bss
? ORDER_BSS
: ORDER_DATA
;
1723 // Attach output sections to segments. This is called after we have
1724 // seen all the input sections.
1727 Layout::attach_sections_to_segments(const Target
* target
)
1729 for (Section_list::iterator p
= this->section_list_
.begin();
1730 p
!= this->section_list_
.end();
1732 this->attach_section_to_segment(target
, *p
);
1734 this->sections_are_attached_
= true;
1737 // Attach an output section to a segment.
1740 Layout::attach_section_to_segment(const Target
* target
, Output_section
* os
)
1742 if ((os
->flags() & elfcpp::SHF_ALLOC
) == 0)
1743 this->unattached_section_list_
.push_back(os
);
1745 this->attach_allocated_section_to_segment(target
, os
);
1748 // Attach an allocated output section to a segment.
1751 Layout::attach_allocated_section_to_segment(const Target
* target
,
1754 elfcpp::Elf_Xword flags
= os
->flags();
1755 gold_assert((flags
& elfcpp::SHF_ALLOC
) != 0);
1757 if (parameters
->options().relocatable())
1760 // If we have a SECTIONS clause, we can't handle the attachment to
1761 // segments until after we've seen all the sections.
1762 if (this->script_options_
->saw_sections_clause())
1765 gold_assert(!this->script_options_
->saw_phdrs_clause());
1767 // This output section goes into a PT_LOAD segment.
1769 elfcpp::Elf_Word seg_flags
= Layout::section_flags_to_segment(flags
);
1771 // If this output section's segment has extra flags that need to be set,
1772 // coming from a linker plugin, do that.
1773 seg_flags
|= os
->extra_segment_flags();
1775 // Check for --section-start.
1777 bool is_address_set
= parameters
->options().section_start(os
->name(), &addr
);
1779 // In general the only thing we really care about for PT_LOAD
1780 // segments is whether or not they are writable or executable,
1781 // so that is how we search for them.
1782 // Large data sections also go into their own PT_LOAD segment.
1783 // People who need segments sorted on some other basis will
1784 // have to use a linker script.
1786 Segment_list::const_iterator p
;
1787 if (!os
->is_unique_segment())
1789 for (p
= this->segment_list_
.begin();
1790 p
!= this->segment_list_
.end();
1793 if ((*p
)->type() != elfcpp::PT_LOAD
)
1795 if ((*p
)->is_unique_segment())
1797 if (!parameters
->options().omagic()
1798 && ((*p
)->flags() & elfcpp::PF_W
) != (seg_flags
& elfcpp::PF_W
))
1800 if ((target
->isolate_execinstr() || parameters
->options().rosegment())
1801 && ((*p
)->flags() & elfcpp::PF_X
) != (seg_flags
& elfcpp::PF_X
))
1803 // If -Tbss was specified, we need to separate the data and BSS
1805 if (parameters
->options().user_set_Tbss())
1807 if ((os
->type() == elfcpp::SHT_NOBITS
)
1808 == (*p
)->has_any_data_sections())
1811 if (os
->is_large_data_section() && !(*p
)->is_large_data_segment())
1816 if ((*p
)->are_addresses_set())
1819 (*p
)->add_initial_output_data(os
);
1820 (*p
)->update_flags_for_output_section(seg_flags
);
1821 (*p
)->set_addresses(addr
, addr
);
1825 (*p
)->add_output_section_to_load(this, os
, seg_flags
);
1830 if (p
== this->segment_list_
.end()
1831 || os
->is_unique_segment())
1833 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_LOAD
,
1835 if (os
->is_large_data_section())
1836 oseg
->set_is_large_data_segment();
1837 oseg
->add_output_section_to_load(this, os
, seg_flags
);
1839 oseg
->set_addresses(addr
, addr
);
1840 // Check if segment should be marked unique. For segments marked
1841 // unique by linker plugins, set the new alignment if specified.
1842 if (os
->is_unique_segment())
1844 oseg
->set_is_unique_segment();
1845 if (os
->segment_alignment() != 0)
1846 oseg
->set_minimum_p_align(os
->segment_alignment());
1850 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1852 if (os
->type() == elfcpp::SHT_NOTE
)
1854 // See if we already have an equivalent PT_NOTE segment.
1855 for (p
= this->segment_list_
.begin();
1856 p
!= segment_list_
.end();
1859 if ((*p
)->type() == elfcpp::PT_NOTE
1860 && (((*p
)->flags() & elfcpp::PF_W
)
1861 == (seg_flags
& elfcpp::PF_W
)))
1863 (*p
)->add_output_section_to_nonload(os
, seg_flags
);
1868 if (p
== this->segment_list_
.end())
1870 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_NOTE
,
1872 oseg
->add_output_section_to_nonload(os
, seg_flags
);
1876 // If we see a loadable SHF_TLS section, we create a PT_TLS
1877 // segment. There can only be one such segment.
1878 if ((flags
& elfcpp::SHF_TLS
) != 0)
1880 if (this->tls_segment_
== NULL
)
1881 this->make_output_segment(elfcpp::PT_TLS
, seg_flags
);
1882 this->tls_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1885 // If -z relro is in effect, and we see a relro section, we create a
1886 // PT_GNU_RELRO segment. There can only be one such segment.
1887 if (os
->is_relro() && parameters
->options().relro())
1889 gold_assert(seg_flags
== (elfcpp::PF_R
| elfcpp::PF_W
));
1890 if (this->relro_segment_
== NULL
)
1891 this->make_output_segment(elfcpp::PT_GNU_RELRO
, seg_flags
);
1892 this->relro_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1895 // If we see a section named .interp, put it into a PT_INTERP
1896 // segment. This seems broken to me, but this is what GNU ld does,
1897 // and glibc expects it.
1898 if (strcmp(os
->name(), ".interp") == 0
1899 && !this->script_options_
->saw_phdrs_clause())
1901 if (this->interp_segment_
== NULL
)
1902 this->make_output_segment(elfcpp::PT_INTERP
, seg_flags
);
1904 gold_warning(_("multiple '.interp' sections in input files "
1905 "may cause confusing PT_INTERP segment"));
1906 this->interp_segment_
->add_output_section_to_nonload(os
, seg_flags
);
1910 // Make an output section for a script.
1913 Layout::make_output_section_for_script(
1915 Script_sections::Section_type section_type
)
1917 name
= this->namepool_
.add(name
, false, NULL
);
1918 elfcpp::Elf_Xword sh_flags
= elfcpp::SHF_ALLOC
;
1919 if (section_type
== Script_sections::ST_NOLOAD
)
1921 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_PROGBITS
,
1922 sh_flags
, ORDER_INVALID
,
1924 os
->set_found_in_sections_clause();
1925 if (section_type
== Script_sections::ST_NOLOAD
)
1926 os
->set_is_noload();
1930 // Return the number of segments we expect to see.
1933 Layout::expected_segment_count() const
1935 size_t ret
= this->segment_list_
.size();
1937 // If we didn't see a SECTIONS clause in a linker script, we should
1938 // already have the complete list of segments. Otherwise we ask the
1939 // SECTIONS clause how many segments it expects, and add in the ones
1940 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1942 if (!this->script_options_
->saw_sections_clause())
1946 const Script_sections
* ss
= this->script_options_
->script_sections();
1947 return ret
+ ss
->expected_segment_count(this);
1951 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
1952 // is whether we saw a .note.GNU-stack section in the object file.
1953 // GNU_STACK_FLAGS is the section flags. The flags give the
1954 // protection required for stack memory. We record this in an
1955 // executable as a PT_GNU_STACK segment. If an object file does not
1956 // have a .note.GNU-stack segment, we must assume that it is an old
1957 // object. On some targets that will force an executable stack.
1960 Layout::layout_gnu_stack(bool seen_gnu_stack
, uint64_t gnu_stack_flags
,
1963 if (!seen_gnu_stack
)
1965 this->input_without_gnu_stack_note_
= true;
1966 if (parameters
->options().warn_execstack()
1967 && parameters
->target().is_default_stack_executable())
1968 gold_warning(_("%s: missing .note.GNU-stack section"
1969 " implies executable stack"),
1970 obj
->name().c_str());
1974 this->input_with_gnu_stack_note_
= true;
1975 if ((gnu_stack_flags
& elfcpp::SHF_EXECINSTR
) != 0)
1977 this->input_requires_executable_stack_
= true;
1978 if (parameters
->options().warn_execstack()
1979 || parameters
->options().is_stack_executable())
1980 gold_warning(_("%s: requires executable stack"),
1981 obj
->name().c_str());
1986 // Create automatic note sections.
1989 Layout::create_notes()
1991 this->create_gold_note();
1992 this->create_executable_stack_info();
1993 this->create_build_id();
1996 // Create the dynamic sections which are needed before we read the
2000 Layout::create_initial_dynamic_sections(Symbol_table
* symtab
)
2002 if (parameters
->doing_static_link())
2005 this->dynamic_section_
= this->choose_output_section(NULL
, ".dynamic",
2006 elfcpp::SHT_DYNAMIC
,
2008 | elfcpp::SHF_WRITE
),
2012 // A linker script may discard .dynamic, so check for NULL.
2013 if (this->dynamic_section_
!= NULL
)
2015 this->dynamic_symbol_
=
2016 symtab
->define_in_output_data("_DYNAMIC", NULL
,
2017 Symbol_table::PREDEFINED
,
2018 this->dynamic_section_
, 0, 0,
2019 elfcpp::STT_OBJECT
, elfcpp::STB_LOCAL
,
2020 elfcpp::STV_HIDDEN
, 0, false, false);
2022 this->dynamic_data_
= new Output_data_dynamic(&this->dynpool_
);
2024 this->dynamic_section_
->add_output_section_data(this->dynamic_data_
);
2028 // For each output section whose name can be represented as C symbol,
2029 // define __start and __stop symbols for the section. This is a GNU
2033 Layout::define_section_symbols(Symbol_table
* symtab
)
2035 for (Section_list::const_iterator p
= this->section_list_
.begin();
2036 p
!= this->section_list_
.end();
2039 const char* const name
= (*p
)->name();
2040 if (is_cident(name
))
2042 const std::string
name_string(name
);
2043 const std::string
start_name(cident_section_start_prefix
2045 const std::string
stop_name(cident_section_stop_prefix
2048 symtab
->define_in_output_data(start_name
.c_str(),
2050 Symbol_table::PREDEFINED
,
2056 elfcpp::STV_DEFAULT
,
2058 false, // offset_is_from_end
2059 true); // only_if_ref
2061 symtab
->define_in_output_data(stop_name
.c_str(),
2063 Symbol_table::PREDEFINED
,
2069 elfcpp::STV_DEFAULT
,
2071 true, // offset_is_from_end
2072 true); // only_if_ref
2077 // Define symbols for group signatures.
2080 Layout::define_group_signatures(Symbol_table
* symtab
)
2082 for (Group_signatures::iterator p
= this->group_signatures_
.begin();
2083 p
!= this->group_signatures_
.end();
2086 Symbol
* sym
= symtab
->lookup(p
->signature
, NULL
);
2088 p
->section
->set_info_symndx(sym
);
2091 // Force the name of the group section to the group
2092 // signature, and use the group's section symbol as the
2093 // signature symbol.
2094 if (strcmp(p
->section
->name(), p
->signature
) != 0)
2096 const char* name
= this->namepool_
.add(p
->signature
,
2098 p
->section
->set_name(name
);
2100 p
->section
->set_needs_symtab_index();
2101 p
->section
->set_info_section_symndx(p
->section
);
2105 this->group_signatures_
.clear();
2108 // Find the first read-only PT_LOAD segment, creating one if
2112 Layout::find_first_load_seg(const Target
* target
)
2114 Output_segment
* best
= NULL
;
2115 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2116 p
!= this->segment_list_
.end();
2119 if ((*p
)->type() == elfcpp::PT_LOAD
2120 && ((*p
)->flags() & elfcpp::PF_R
) != 0
2121 && (parameters
->options().omagic()
2122 || ((*p
)->flags() & elfcpp::PF_W
) == 0)
2123 && (!target
->isolate_execinstr()
2124 || ((*p
)->flags() & elfcpp::PF_X
) == 0))
2126 if (best
== NULL
|| this->segment_precedes(*p
, best
))
2133 gold_assert(!this->script_options_
->saw_phdrs_clause());
2135 Output_segment
* load_seg
= this->make_output_segment(elfcpp::PT_LOAD
,
2140 // Save states of all current output segments. Store saved states
2141 // in SEGMENT_STATES.
2144 Layout::save_segments(Segment_states
* segment_states
)
2146 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
2147 p
!= this->segment_list_
.end();
2150 Output_segment
* segment
= *p
;
2152 Output_segment
* copy
= new Output_segment(*segment
);
2153 (*segment_states
)[segment
] = copy
;
2157 // Restore states of output segments and delete any segment not found in
2161 Layout::restore_segments(const Segment_states
* segment_states
)
2163 // Go through the segment list and remove any segment added in the
2165 this->tls_segment_
= NULL
;
2166 this->relro_segment_
= NULL
;
2167 Segment_list::iterator list_iter
= this->segment_list_
.begin();
2168 while (list_iter
!= this->segment_list_
.end())
2170 Output_segment
* segment
= *list_iter
;
2171 Segment_states::const_iterator states_iter
=
2172 segment_states
->find(segment
);
2173 if (states_iter
!= segment_states
->end())
2175 const Output_segment
* copy
= states_iter
->second
;
2176 // Shallow copy to restore states.
2179 // Also fix up TLS and RELRO segment pointers as appropriate.
2180 if (segment
->type() == elfcpp::PT_TLS
)
2181 this->tls_segment_
= segment
;
2182 else if (segment
->type() == elfcpp::PT_GNU_RELRO
)
2183 this->relro_segment_
= segment
;
2189 list_iter
= this->segment_list_
.erase(list_iter
);
2190 // This is a segment created during section layout. It should be
2191 // safe to remove it since we should have removed all pointers to it.
2197 // Clean up after relaxation so that sections can be laid out again.
2200 Layout::clean_up_after_relaxation()
2202 // Restore the segments to point state just prior to the relaxation loop.
2203 Script_sections
* script_section
= this->script_options_
->script_sections();
2204 script_section
->release_segments();
2205 this->restore_segments(this->segment_states_
);
2207 // Reset section addresses and file offsets
2208 for (Section_list::iterator p
= this->section_list_
.begin();
2209 p
!= this->section_list_
.end();
2212 (*p
)->restore_states();
2214 // If an input section changes size because of relaxation,
2215 // we need to adjust the section offsets of all input sections.
2216 // after such a section.
2217 if ((*p
)->section_offsets_need_adjustment())
2218 (*p
)->adjust_section_offsets();
2220 (*p
)->reset_address_and_file_offset();
2223 // Reset special output object address and file offsets.
2224 for (Data_list::iterator p
= this->special_output_list_
.begin();
2225 p
!= this->special_output_list_
.end();
2227 (*p
)->reset_address_and_file_offset();
2229 // A linker script may have created some output section data objects.
2230 // They are useless now.
2231 for (Output_section_data_list::const_iterator p
=
2232 this->script_output_section_data_list_
.begin();
2233 p
!= this->script_output_section_data_list_
.end();
2236 this->script_output_section_data_list_
.clear();
2239 // Prepare for relaxation.
2242 Layout::prepare_for_relaxation()
2244 // Create an relaxation debug check if in debugging mode.
2245 if (is_debugging_enabled(DEBUG_RELAXATION
))
2246 this->relaxation_debug_check_
= new Relaxation_debug_check();
2248 // Save segment states.
2249 this->segment_states_
= new Segment_states();
2250 this->save_segments(this->segment_states_
);
2252 for(Section_list::const_iterator p
= this->section_list_
.begin();
2253 p
!= this->section_list_
.end();
2255 (*p
)->save_states();
2257 if (is_debugging_enabled(DEBUG_RELAXATION
))
2258 this->relaxation_debug_check_
->check_output_data_for_reset_values(
2259 this->section_list_
, this->special_output_list_
);
2261 // Also enable recording of output section data from scripts.
2262 this->record_output_section_data_from_script_
= true;
2265 // Relaxation loop body: If target has no relaxation, this runs only once
2266 // Otherwise, the target relaxation hook is called at the end of
2267 // each iteration. If the hook returns true, it means re-layout of
2268 // section is required.
2270 // The number of segments created by a linking script without a PHDRS
2271 // clause may be affected by section sizes and alignments. There is
2272 // a remote chance that relaxation causes different number of PT_LOAD
2273 // segments are created and sections are attached to different segments.
2274 // Therefore, we always throw away all segments created during section
2275 // layout. In order to be able to restart the section layout, we keep
2276 // a copy of the segment list right before the relaxation loop and use
2277 // that to restore the segments.
2279 // PASS is the current relaxation pass number.
2280 // SYMTAB is a symbol table.
2281 // PLOAD_SEG is the address of a pointer for the load segment.
2282 // PHDR_SEG is a pointer to the PHDR segment.
2283 // SEGMENT_HEADERS points to the output segment header.
2284 // FILE_HEADER points to the output file header.
2285 // PSHNDX is the address to store the output section index.
2288 Layout::relaxation_loop_body(
2291 Symbol_table
* symtab
,
2292 Output_segment
** pload_seg
,
2293 Output_segment
* phdr_seg
,
2294 Output_segment_headers
* segment_headers
,
2295 Output_file_header
* file_header
,
2296 unsigned int* pshndx
)
2298 // If this is not the first iteration, we need to clean up after
2299 // relaxation so that we can lay out the sections again.
2301 this->clean_up_after_relaxation();
2303 // If there is a SECTIONS clause, put all the input sections into
2304 // the required order.
2305 Output_segment
* load_seg
;
2306 if (this->script_options_
->saw_sections_clause())
2307 load_seg
= this->set_section_addresses_from_script(symtab
);
2308 else if (parameters
->options().relocatable())
2311 load_seg
= this->find_first_load_seg(target
);
2313 if (parameters
->options().oformat_enum()
2314 != General_options::OBJECT_FORMAT_ELF
)
2317 // If the user set the address of the text segment, that may not be
2318 // compatible with putting the segment headers and file headers into
2320 if (parameters
->options().user_set_Ttext()
2321 && parameters
->options().Ttext() % target
->abi_pagesize() != 0)
2327 gold_assert(phdr_seg
== NULL
2329 || this->script_options_
->saw_sections_clause());
2331 // If the address of the load segment we found has been set by
2332 // --section-start rather than by a script, then adjust the VMA and
2333 // LMA downward if possible to include the file and section headers.
2334 uint64_t header_gap
= 0;
2335 if (load_seg
!= NULL
2336 && load_seg
->are_addresses_set()
2337 && !this->script_options_
->saw_sections_clause()
2338 && !parameters
->options().relocatable())
2340 file_header
->finalize_data_size();
2341 segment_headers
->finalize_data_size();
2342 size_t sizeof_headers
= (file_header
->data_size()
2343 + segment_headers
->data_size());
2344 const uint64_t abi_pagesize
= target
->abi_pagesize();
2345 uint64_t hdr_paddr
= load_seg
->paddr() - sizeof_headers
;
2346 hdr_paddr
&= ~(abi_pagesize
- 1);
2347 uint64_t subtract
= load_seg
->paddr() - hdr_paddr
;
2348 if (load_seg
->paddr() < subtract
|| load_seg
->vaddr() < subtract
)
2352 load_seg
->set_addresses(load_seg
->vaddr() - subtract
,
2353 load_seg
->paddr() - subtract
);
2354 header_gap
= subtract
- sizeof_headers
;
2358 // Lay out the segment headers.
2359 if (!parameters
->options().relocatable())
2361 gold_assert(segment_headers
!= NULL
);
2362 if (header_gap
!= 0 && load_seg
!= NULL
)
2364 Output_data_zero_fill
* z
= new Output_data_zero_fill(header_gap
, 1);
2365 load_seg
->add_initial_output_data(z
);
2367 if (load_seg
!= NULL
)
2368 load_seg
->add_initial_output_data(segment_headers
);
2369 if (phdr_seg
!= NULL
)
2370 phdr_seg
->add_initial_output_data(segment_headers
);
2373 // Lay out the file header.
2374 if (load_seg
!= NULL
)
2375 load_seg
->add_initial_output_data(file_header
);
2377 if (this->script_options_
->saw_phdrs_clause()
2378 && !parameters
->options().relocatable())
2380 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2381 // clause in a linker script.
2382 Script_sections
* ss
= this->script_options_
->script_sections();
2383 ss
->put_headers_in_phdrs(file_header
, segment_headers
);
2386 // We set the output section indexes in set_segment_offsets and
2387 // set_section_indexes.
2390 // Set the file offsets of all the segments, and all the sections
2393 if (!parameters
->options().relocatable())
2394 off
= this->set_segment_offsets(target
, load_seg
, pshndx
);
2396 off
= this->set_relocatable_section_offsets(file_header
, pshndx
);
2398 // Verify that the dummy relaxation does not change anything.
2399 if (is_debugging_enabled(DEBUG_RELAXATION
))
2402 this->relaxation_debug_check_
->read_sections(this->section_list_
);
2404 this->relaxation_debug_check_
->verify_sections(this->section_list_
);
2407 *pload_seg
= load_seg
;
2411 // Search the list of patterns and find the postion of the given section
2412 // name in the output section. If the section name matches a glob
2413 // pattern and a non-glob name, then the non-glob position takes
2414 // precedence. Return 0 if no match is found.
2417 Layout::find_section_order_index(const std::string
& section_name
)
2419 Unordered_map
<std::string
, unsigned int>::iterator map_it
;
2420 map_it
= this->input_section_position_
.find(section_name
);
2421 if (map_it
!= this->input_section_position_
.end())
2422 return map_it
->second
;
2424 // Absolute match failed. Linear search the glob patterns.
2425 std::vector
<std::string
>::iterator it
;
2426 for (it
= this->input_section_glob_
.begin();
2427 it
!= this->input_section_glob_
.end();
2430 if (fnmatch((*it
).c_str(), section_name
.c_str(), FNM_NOESCAPE
) == 0)
2432 map_it
= this->input_section_position_
.find(*it
);
2433 gold_assert(map_it
!= this->input_section_position_
.end());
2434 return map_it
->second
;
2440 // Read the sequence of input sections from the file specified with
2441 // option --section-ordering-file.
2444 Layout::read_layout_from_file()
2446 const char* filename
= parameters
->options().section_ordering_file();
2452 gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2453 filename
, strerror(errno
));
2455 std::getline(in
, line
); // this chops off the trailing \n, if any
2456 unsigned int position
= 1;
2457 this->set_section_ordering_specified();
2461 if (!line
.empty() && line
[line
.length() - 1] == '\r') // Windows
2462 line
.resize(line
.length() - 1);
2463 // Ignore comments, beginning with '#'
2466 std::getline(in
, line
);
2469 this->input_section_position_
[line
] = position
;
2470 // Store all glob patterns in a vector.
2471 if (is_wildcard_string(line
.c_str()))
2472 this->input_section_glob_
.push_back(line
);
2474 std::getline(in
, line
);
2478 // Finalize the layout. When this is called, we have created all the
2479 // output sections and all the output segments which are based on
2480 // input sections. We have several things to do, and we have to do
2481 // them in the right order, so that we get the right results correctly
2484 // 1) Finalize the list of output segments and create the segment
2487 // 2) Finalize the dynamic symbol table and associated sections.
2489 // 3) Determine the final file offset of all the output segments.
2491 // 4) Determine the final file offset of all the SHF_ALLOC output
2494 // 5) Create the symbol table sections and the section name table
2497 // 6) Finalize the symbol table: set symbol values to their final
2498 // value and make a final determination of which symbols are going
2499 // into the output symbol table.
2501 // 7) Create the section table header.
2503 // 8) Determine the final file offset of all the output sections which
2504 // are not SHF_ALLOC, including the section table header.
2506 // 9) Finalize the ELF file header.
2508 // This function returns the size of the output file.
2511 Layout::finalize(const Input_objects
* input_objects
, Symbol_table
* symtab
,
2512 Target
* target
, const Task
* task
)
2514 target
->finalize_sections(this, input_objects
, symtab
);
2516 this->count_local_symbols(task
, input_objects
);
2518 this->link_stabs_sections();
2520 Output_segment
* phdr_seg
= NULL
;
2521 if (!parameters
->options().relocatable() && !parameters
->doing_static_link())
2523 // There was a dynamic object in the link. We need to create
2524 // some information for the dynamic linker.
2526 // Create the PT_PHDR segment which will hold the program
2528 if (!this->script_options_
->saw_phdrs_clause())
2529 phdr_seg
= this->make_output_segment(elfcpp::PT_PHDR
, elfcpp::PF_R
);
2531 // Create the dynamic symbol table, including the hash table.
2532 Output_section
* dynstr
;
2533 std::vector
<Symbol
*> dynamic_symbols
;
2534 unsigned int local_dynamic_count
;
2535 Versions
versions(*this->script_options()->version_script_info(),
2537 this->create_dynamic_symtab(input_objects
, symtab
, &dynstr
,
2538 &local_dynamic_count
, &dynamic_symbols
,
2541 // Create the .interp section to hold the name of the
2542 // interpreter, and put it in a PT_INTERP segment. Don't do it
2543 // if we saw a .interp section in an input file.
2544 if ((!parameters
->options().shared()
2545 || parameters
->options().dynamic_linker() != NULL
)
2546 && this->interp_segment_
== NULL
)
2547 this->create_interp(target
);
2549 // Finish the .dynamic section to hold the dynamic data, and put
2550 // it in a PT_DYNAMIC segment.
2551 this->finish_dynamic_section(input_objects
, symtab
);
2553 // We should have added everything we need to the dynamic string
2555 this->dynpool_
.set_string_offsets();
2557 // Create the version sections. We can't do this until the
2558 // dynamic string table is complete.
2559 this->create_version_sections(&versions
, symtab
, local_dynamic_count
,
2560 dynamic_symbols
, dynstr
);
2562 // Set the size of the _DYNAMIC symbol. We can't do this until
2563 // after we call create_version_sections.
2564 this->set_dynamic_symbol_size(symtab
);
2567 // Create segment headers.
2568 Output_segment_headers
* segment_headers
=
2569 (parameters
->options().relocatable()
2571 : new Output_segment_headers(this->segment_list_
));
2573 // Lay out the file header.
2574 Output_file_header
* file_header
= new Output_file_header(target
, symtab
,
2577 this->special_output_list_
.push_back(file_header
);
2578 if (segment_headers
!= NULL
)
2579 this->special_output_list_
.push_back(segment_headers
);
2581 // Find approriate places for orphan output sections if we are using
2583 if (this->script_options_
->saw_sections_clause())
2584 this->place_orphan_sections_in_script();
2586 Output_segment
* load_seg
;
2591 // Take a snapshot of the section layout as needed.
2592 if (target
->may_relax())
2593 this->prepare_for_relaxation();
2595 // Run the relaxation loop to lay out sections.
2598 off
= this->relaxation_loop_body(pass
, target
, symtab
, &load_seg
,
2599 phdr_seg
, segment_headers
, file_header
,
2603 while (target
->may_relax()
2604 && target
->relax(pass
, input_objects
, symtab
, this, task
));
2606 // If there is a load segment that contains the file and program headers,
2607 // provide a symbol __ehdr_start pointing there.
2608 // A program can use this to examine itself robustly.
2609 if (load_seg
!= NULL
)
2610 symtab
->define_in_output_segment("__ehdr_start", NULL
,
2611 Symbol_table::PREDEFINED
, load_seg
, 0, 0,
2612 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
2613 elfcpp::STV_DEFAULT
, 0,
2614 Symbol::SEGMENT_START
, true);
2616 // Set the file offsets of all the non-data sections we've seen so
2617 // far which don't have to wait for the input sections. We need
2618 // this in order to finalize local symbols in non-allocated
2620 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2622 // Set the section indexes of all unallocated sections seen so far,
2623 // in case any of them are somehow referenced by a symbol.
2624 shndx
= this->set_section_indexes(shndx
);
2626 // Create the symbol table sections.
2627 this->create_symtab_sections(input_objects
, symtab
, shndx
, &off
);
2628 if (!parameters
->doing_static_link())
2629 this->assign_local_dynsym_offsets(input_objects
);
2631 // Process any symbol assignments from a linker script. This must
2632 // be called after the symbol table has been finalized.
2633 this->script_options_
->finalize_symbols(symtab
, this);
2635 // Create the incremental inputs sections.
2636 if (this->incremental_inputs_
)
2638 this->incremental_inputs_
->finalize();
2639 this->create_incremental_info_sections(symtab
);
2642 // Create the .shstrtab section.
2643 Output_section
* shstrtab_section
= this->create_shstrtab();
2645 // Set the file offsets of the rest of the non-data sections which
2646 // don't have to wait for the input sections.
2647 off
= this->set_section_offsets(off
, BEFORE_INPUT_SECTIONS_PASS
);
2649 // Now that all sections have been created, set the section indexes
2650 // for any sections which haven't been done yet.
2651 shndx
= this->set_section_indexes(shndx
);
2653 // Create the section table header.
2654 this->create_shdrs(shstrtab_section
, &off
);
2656 // If there are no sections which require postprocessing, we can
2657 // handle the section names now, and avoid a resize later.
2658 if (!this->any_postprocessing_sections_
)
2660 off
= this->set_section_offsets(off
,
2661 POSTPROCESSING_SECTIONS_PASS
);
2663 this->set_section_offsets(off
,
2664 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
2667 file_header
->set_section_info(this->section_headers_
, shstrtab_section
);
2669 // Now we know exactly where everything goes in the output file
2670 // (except for non-allocated sections which require postprocessing).
2671 Output_data::layout_complete();
2673 this->output_file_size_
= off
;
2678 // Create a note header following the format defined in the ELF ABI.
2679 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
2680 // of the section to create, DESCSZ is the size of the descriptor.
2681 // ALLOCATE is true if the section should be allocated in memory.
2682 // This returns the new note section. It sets *TRAILING_PADDING to
2683 // the number of trailing zero bytes required.
2686 Layout::create_note(const char* name
, int note_type
,
2687 const char* section_name
, size_t descsz
,
2688 bool allocate
, size_t* trailing_padding
)
2690 // Authorities all agree that the values in a .note field should
2691 // be aligned on 4-byte boundaries for 32-bit binaries. However,
2692 // they differ on what the alignment is for 64-bit binaries.
2693 // The GABI says unambiguously they take 8-byte alignment:
2694 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2695 // Other documentation says alignment should always be 4 bytes:
2696 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2697 // GNU ld and GNU readelf both support the latter (at least as of
2698 // version 2.16.91), and glibc always generates the latter for
2699 // .note.ABI-tag (as of version 1.6), so that's the one we go with
2701 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
2702 const int size
= parameters
->target().get_size();
2704 const int size
= 32;
2707 // The contents of the .note section.
2708 size_t namesz
= strlen(name
) + 1;
2709 size_t aligned_namesz
= align_address(namesz
, size
/ 8);
2710 size_t aligned_descsz
= align_address(descsz
, size
/ 8);
2712 size_t notehdrsz
= 3 * (size
/ 8) + aligned_namesz
;
2714 unsigned char* buffer
= new unsigned char[notehdrsz
];
2715 memset(buffer
, 0, notehdrsz
);
2717 bool is_big_endian
= parameters
->target().is_big_endian();
2723 elfcpp::Swap
<32, false>::writeval(buffer
, namesz
);
2724 elfcpp::Swap
<32, false>::writeval(buffer
+ 4, descsz
);
2725 elfcpp::Swap
<32, false>::writeval(buffer
+ 8, note_type
);
2729 elfcpp::Swap
<32, true>::writeval(buffer
, namesz
);
2730 elfcpp::Swap
<32, true>::writeval(buffer
+ 4, descsz
);
2731 elfcpp::Swap
<32, true>::writeval(buffer
+ 8, note_type
);
2734 else if (size
== 64)
2738 elfcpp::Swap
<64, false>::writeval(buffer
, namesz
);
2739 elfcpp::Swap
<64, false>::writeval(buffer
+ 8, descsz
);
2740 elfcpp::Swap
<64, false>::writeval(buffer
+ 16, note_type
);
2744 elfcpp::Swap
<64, true>::writeval(buffer
, namesz
);
2745 elfcpp::Swap
<64, true>::writeval(buffer
+ 8, descsz
);
2746 elfcpp::Swap
<64, true>::writeval(buffer
+ 16, note_type
);
2752 memcpy(buffer
+ 3 * (size
/ 8), name
, namesz
);
2754 elfcpp::Elf_Xword flags
= 0;
2755 Output_section_order order
= ORDER_INVALID
;
2758 flags
= elfcpp::SHF_ALLOC
;
2759 order
= ORDER_RO_NOTE
;
2761 Output_section
* os
= this->choose_output_section(NULL
, section_name
,
2763 flags
, false, order
, false);
2767 Output_section_data
* posd
= new Output_data_const_buffer(buffer
, notehdrsz
,
2770 os
->add_output_section_data(posd
);
2772 *trailing_padding
= aligned_descsz
- descsz
;
2777 // For an executable or shared library, create a note to record the
2778 // version of gold used to create the binary.
2781 Layout::create_gold_note()
2783 if (parameters
->options().relocatable()
2784 || parameters
->incremental_update())
2787 std::string desc
= std::string("gold ") + gold::get_version_string();
2789 size_t trailing_padding
;
2790 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION
,
2791 ".note.gnu.gold-version", desc
.size(),
2792 false, &trailing_padding
);
2796 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2797 os
->add_output_section_data(posd
);
2799 if (trailing_padding
> 0)
2801 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2802 os
->add_output_section_data(posd
);
2806 // Record whether the stack should be executable. This can be set
2807 // from the command line using the -z execstack or -z noexecstack
2808 // options. Otherwise, if any input file has a .note.GNU-stack
2809 // section with the SHF_EXECINSTR flag set, the stack should be
2810 // executable. Otherwise, if at least one input file a
2811 // .note.GNU-stack section, and some input file has no .note.GNU-stack
2812 // section, we use the target default for whether the stack should be
2813 // executable. Otherwise, we don't generate a stack note. When
2814 // generating a object file, we create a .note.GNU-stack section with
2815 // the appropriate marking. When generating an executable or shared
2816 // library, we create a PT_GNU_STACK segment.
2819 Layout::create_executable_stack_info()
2821 bool is_stack_executable
;
2822 if (parameters
->options().is_execstack_set())
2823 is_stack_executable
= parameters
->options().is_stack_executable();
2824 else if (!this->input_with_gnu_stack_note_
)
2828 if (this->input_requires_executable_stack_
)
2829 is_stack_executable
= true;
2830 else if (this->input_without_gnu_stack_note_
)
2831 is_stack_executable
=
2832 parameters
->target().is_default_stack_executable();
2834 is_stack_executable
= false;
2837 if (parameters
->options().relocatable())
2839 const char* name
= this->namepool_
.add(".note.GNU-stack", false, NULL
);
2840 elfcpp::Elf_Xword flags
= 0;
2841 if (is_stack_executable
)
2842 flags
|= elfcpp::SHF_EXECINSTR
;
2843 this->make_output_section(name
, elfcpp::SHT_PROGBITS
, flags
,
2844 ORDER_INVALID
, false);
2848 if (this->script_options_
->saw_phdrs_clause())
2850 int flags
= elfcpp::PF_R
| elfcpp::PF_W
;
2851 if (is_stack_executable
)
2852 flags
|= elfcpp::PF_X
;
2853 this->make_output_segment(elfcpp::PT_GNU_STACK
, flags
);
2857 // If --build-id was used, set up the build ID note.
2860 Layout::create_build_id()
2862 if (!parameters
->options().user_set_build_id())
2865 const char* style
= parameters
->options().build_id();
2866 if (strcmp(style
, "none") == 0)
2869 // Set DESCSZ to the size of the note descriptor. When possible,
2870 // set DESC to the note descriptor contents.
2873 if (strcmp(style
, "md5") == 0)
2875 else if (strcmp(style
, "sha1") == 0)
2877 else if (strcmp(style
, "uuid") == 0)
2879 const size_t uuidsz
= 128 / 8;
2881 char buffer
[uuidsz
];
2882 memset(buffer
, 0, uuidsz
);
2884 int descriptor
= open_descriptor(-1, "/dev/urandom", O_RDONLY
);
2886 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
2890 ssize_t got
= ::read(descriptor
, buffer
, uuidsz
);
2891 release_descriptor(descriptor
, true);
2893 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno
));
2894 else if (static_cast<size_t>(got
) != uuidsz
)
2895 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
2899 desc
.assign(buffer
, uuidsz
);
2902 else if (strncmp(style
, "0x", 2) == 0)
2905 const char* p
= style
+ 2;
2908 if (hex_p(p
[0]) && hex_p(p
[1]))
2910 char c
= (hex_value(p
[0]) << 4) | hex_value(p
[1]);
2914 else if (*p
== '-' || *p
== ':')
2917 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
2920 descsz
= desc
.size();
2923 gold_fatal(_("unrecognized --build-id argument '%s'"), style
);
2926 size_t trailing_padding
;
2927 Output_section
* os
= this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID
,
2928 ".note.gnu.build-id", descsz
, true,
2935 // We know the value already, so we fill it in now.
2936 gold_assert(desc
.size() == descsz
);
2938 Output_section_data
* posd
= new Output_data_const(desc
, 4);
2939 os
->add_output_section_data(posd
);
2941 if (trailing_padding
!= 0)
2943 posd
= new Output_data_zero_fill(trailing_padding
, 0);
2944 os
->add_output_section_data(posd
);
2949 // We need to compute a checksum after we have completed the
2951 gold_assert(trailing_padding
== 0);
2952 this->build_id_note_
= new Output_data_zero_fill(descsz
, 4);
2953 os
->add_output_section_data(this->build_id_note_
);
2957 // If we have both .stabXX and .stabXXstr sections, then the sh_link
2958 // field of the former should point to the latter. I'm not sure who
2959 // started this, but the GNU linker does it, and some tools depend
2963 Layout::link_stabs_sections()
2965 if (!this->have_stabstr_section_
)
2968 for (Section_list::iterator p
= this->section_list_
.begin();
2969 p
!= this->section_list_
.end();
2972 if ((*p
)->type() != elfcpp::SHT_STRTAB
)
2975 const char* name
= (*p
)->name();
2976 if (strncmp(name
, ".stab", 5) != 0)
2979 size_t len
= strlen(name
);
2980 if (strcmp(name
+ len
- 3, "str") != 0)
2983 std::string
stab_name(name
, len
- 3);
2984 Output_section
* stab_sec
;
2985 stab_sec
= this->find_output_section(stab_name
.c_str());
2986 if (stab_sec
!= NULL
)
2987 stab_sec
->set_link_section(*p
);
2991 // Create .gnu_incremental_inputs and related sections needed
2992 // for the next run of incremental linking to check what has changed.
2995 Layout::create_incremental_info_sections(Symbol_table
* symtab
)
2997 Incremental_inputs
* incr
= this->incremental_inputs_
;
2999 gold_assert(incr
!= NULL
);
3001 // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
3002 incr
->create_data_sections(symtab
);
3004 // Add the .gnu_incremental_inputs section.
3005 const char* incremental_inputs_name
=
3006 this->namepool_
.add(".gnu_incremental_inputs", false, NULL
);
3007 Output_section
* incremental_inputs_os
=
3008 this->make_output_section(incremental_inputs_name
,
3009 elfcpp::SHT_GNU_INCREMENTAL_INPUTS
, 0,
3010 ORDER_INVALID
, false);
3011 incremental_inputs_os
->add_output_section_data(incr
->inputs_section());
3013 // Add the .gnu_incremental_symtab section.
3014 const char* incremental_symtab_name
=
3015 this->namepool_
.add(".gnu_incremental_symtab", false, NULL
);
3016 Output_section
* incremental_symtab_os
=
3017 this->make_output_section(incremental_symtab_name
,
3018 elfcpp::SHT_GNU_INCREMENTAL_SYMTAB
, 0,
3019 ORDER_INVALID
, false);
3020 incremental_symtab_os
->add_output_section_data(incr
->symtab_section());
3021 incremental_symtab_os
->set_entsize(4);
3023 // Add the .gnu_incremental_relocs section.
3024 const char* incremental_relocs_name
=
3025 this->namepool_
.add(".gnu_incremental_relocs", false, NULL
);
3026 Output_section
* incremental_relocs_os
=
3027 this->make_output_section(incremental_relocs_name
,
3028 elfcpp::SHT_GNU_INCREMENTAL_RELOCS
, 0,
3029 ORDER_INVALID
, false);
3030 incremental_relocs_os
->add_output_section_data(incr
->relocs_section());
3031 incremental_relocs_os
->set_entsize(incr
->relocs_entsize());
3033 // Add the .gnu_incremental_got_plt section.
3034 const char* incremental_got_plt_name
=
3035 this->namepool_
.add(".gnu_incremental_got_plt", false, NULL
);
3036 Output_section
* incremental_got_plt_os
=
3037 this->make_output_section(incremental_got_plt_name
,
3038 elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT
, 0,
3039 ORDER_INVALID
, false);
3040 incremental_got_plt_os
->add_output_section_data(incr
->got_plt_section());
3042 // Add the .gnu_incremental_strtab section.
3043 const char* incremental_strtab_name
=
3044 this->namepool_
.add(".gnu_incremental_strtab", false, NULL
);
3045 Output_section
* incremental_strtab_os
= this->make_output_section(incremental_strtab_name
,
3046 elfcpp::SHT_STRTAB
, 0,
3047 ORDER_INVALID
, false);
3048 Output_data_strtab
* strtab_data
=
3049 new Output_data_strtab(incr
->get_stringpool());
3050 incremental_strtab_os
->add_output_section_data(strtab_data
);
3052 incremental_inputs_os
->set_after_input_sections();
3053 incremental_symtab_os
->set_after_input_sections();
3054 incremental_relocs_os
->set_after_input_sections();
3055 incremental_got_plt_os
->set_after_input_sections();
3057 incremental_inputs_os
->set_link_section(incremental_strtab_os
);
3058 incremental_symtab_os
->set_link_section(incremental_inputs_os
);
3059 incremental_relocs_os
->set_link_section(incremental_inputs_os
);
3060 incremental_got_plt_os
->set_link_section(incremental_inputs_os
);
3063 // Return whether SEG1 should be before SEG2 in the output file. This
3064 // is based entirely on the segment type and flags. When this is
3065 // called the segment addresses have normally not yet been set.
3068 Layout::segment_precedes(const Output_segment
* seg1
,
3069 const Output_segment
* seg2
)
3071 elfcpp::Elf_Word type1
= seg1
->type();
3072 elfcpp::Elf_Word type2
= seg2
->type();
3074 // The single PT_PHDR segment is required to precede any loadable
3075 // segment. We simply make it always first.
3076 if (type1
== elfcpp::PT_PHDR
)
3078 gold_assert(type2
!= elfcpp::PT_PHDR
);
3081 if (type2
== elfcpp::PT_PHDR
)
3084 // The single PT_INTERP segment is required to precede any loadable
3085 // segment. We simply make it always second.
3086 if (type1
== elfcpp::PT_INTERP
)
3088 gold_assert(type2
!= elfcpp::PT_INTERP
);
3091 if (type2
== elfcpp::PT_INTERP
)
3094 // We then put PT_LOAD segments before any other segments.
3095 if (type1
== elfcpp::PT_LOAD
&& type2
!= elfcpp::PT_LOAD
)
3097 if (type2
== elfcpp::PT_LOAD
&& type1
!= elfcpp::PT_LOAD
)
3100 // We put the PT_TLS segment last except for the PT_GNU_RELRO
3101 // segment, because that is where the dynamic linker expects to find
3102 // it (this is just for efficiency; other positions would also work
3104 if (type1
== elfcpp::PT_TLS
3105 && type2
!= elfcpp::PT_TLS
3106 && type2
!= elfcpp::PT_GNU_RELRO
)
3108 if (type2
== elfcpp::PT_TLS
3109 && type1
!= elfcpp::PT_TLS
3110 && type1
!= elfcpp::PT_GNU_RELRO
)
3113 // We put the PT_GNU_RELRO segment last, because that is where the
3114 // dynamic linker expects to find it (as with PT_TLS, this is just
3116 if (type1
== elfcpp::PT_GNU_RELRO
&& type2
!= elfcpp::PT_GNU_RELRO
)
3118 if (type2
== elfcpp::PT_GNU_RELRO
&& type1
!= elfcpp::PT_GNU_RELRO
)
3121 const elfcpp::Elf_Word flags1
= seg1
->flags();
3122 const elfcpp::Elf_Word flags2
= seg2
->flags();
3124 // The order of non-PT_LOAD segments is unimportant. We simply sort
3125 // by the numeric segment type and flags values. There should not
3126 // be more than one segment with the same type and flags.
3127 if (type1
!= elfcpp::PT_LOAD
)
3130 return type1
< type2
;
3131 gold_assert(flags1
!= flags2
);
3132 return flags1
< flags2
;
3135 // If the addresses are set already, sort by load address.
3136 if (seg1
->are_addresses_set())
3138 if (!seg2
->are_addresses_set())
3141 unsigned int section_count1
= seg1
->output_section_count();
3142 unsigned int section_count2
= seg2
->output_section_count();
3143 if (section_count1
== 0 && section_count2
> 0)
3145 if (section_count1
> 0 && section_count2
== 0)
3148 uint64_t paddr1
= (seg1
->are_addresses_set()
3150 : seg1
->first_section_load_address());
3151 uint64_t paddr2
= (seg2
->are_addresses_set()
3153 : seg2
->first_section_load_address());
3155 if (paddr1
!= paddr2
)
3156 return paddr1
< paddr2
;
3158 else if (seg2
->are_addresses_set())
3161 // A segment which holds large data comes after a segment which does
3162 // not hold large data.
3163 if (seg1
->is_large_data_segment())
3165 if (!seg2
->is_large_data_segment())
3168 else if (seg2
->is_large_data_segment())
3171 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
3172 // segments come before writable segments. Then writable segments
3173 // with data come before writable segments without data. Then
3174 // executable segments come before non-executable segments. Then
3175 // the unlikely case of a non-readable segment comes before the
3176 // normal case of a readable segment. If there are multiple
3177 // segments with the same type and flags, we require that the
3178 // address be set, and we sort by virtual address and then physical
3180 if ((flags1
& elfcpp::PF_W
) != (flags2
& elfcpp::PF_W
))
3181 return (flags1
& elfcpp::PF_W
) == 0;
3182 if ((flags1
& elfcpp::PF_W
) != 0
3183 && seg1
->has_any_data_sections() != seg2
->has_any_data_sections())
3184 return seg1
->has_any_data_sections();
3185 if ((flags1
& elfcpp::PF_X
) != (flags2
& elfcpp::PF_X
))
3186 return (flags1
& elfcpp::PF_X
) != 0;
3187 if ((flags1
& elfcpp::PF_R
) != (flags2
& elfcpp::PF_R
))
3188 return (flags1
& elfcpp::PF_R
) == 0;
3190 // We shouldn't get here--we shouldn't create segments which we
3191 // can't distinguish. Unless of course we are using a weird linker
3192 // script or overlapping --section-start options. We could also get
3193 // here if plugins want unique segments for subsets of sections.
3194 gold_assert(this->script_options_
->saw_phdrs_clause()
3195 || parameters
->options().any_section_start()
3196 || this->is_unique_segment_for_sections_specified());
3200 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
3203 align_file_offset(off_t off
, uint64_t addr
, uint64_t abi_pagesize
)
3205 uint64_t unsigned_off
= off
;
3206 uint64_t aligned_off
= ((unsigned_off
& ~(abi_pagesize
- 1))
3207 | (addr
& (abi_pagesize
- 1)));
3208 if (aligned_off
< unsigned_off
)
3209 aligned_off
+= abi_pagesize
;
3213 // Set the file offsets of all the segments, and all the sections they
3214 // contain. They have all been created. LOAD_SEG must be be laid out
3215 // first. Return the offset of the data to follow.
3218 Layout::set_segment_offsets(const Target
* target
, Output_segment
* load_seg
,
3219 unsigned int* pshndx
)
3221 // Sort them into the final order. We use a stable sort so that we
3222 // don't randomize the order of indistinguishable segments created
3223 // by linker scripts.
3224 std::stable_sort(this->segment_list_
.begin(), this->segment_list_
.end(),
3225 Layout::Compare_segments(this));
3227 // Find the PT_LOAD segments, and set their addresses and offsets
3228 // and their section's addresses and offsets.
3229 uint64_t start_addr
;
3230 if (parameters
->options().user_set_Ttext())
3231 start_addr
= parameters
->options().Ttext();
3232 else if (parameters
->options().output_is_position_independent())
3235 start_addr
= target
->default_text_segment_address();
3237 uint64_t addr
= start_addr
;
3240 // If LOAD_SEG is NULL, then the file header and segment headers
3241 // will not be loadable. But they still need to be at offset 0 in
3242 // the file. Set their offsets now.
3243 if (load_seg
== NULL
)
3245 for (Data_list::iterator p
= this->special_output_list_
.begin();
3246 p
!= this->special_output_list_
.end();
3249 off
= align_address(off
, (*p
)->addralign());
3250 (*p
)->set_address_and_file_offset(0, off
);
3251 off
+= (*p
)->data_size();
3255 unsigned int increase_relro
= this->increase_relro_
;
3256 if (this->script_options_
->saw_sections_clause())
3259 const bool check_sections
= parameters
->options().check_sections();
3260 Output_segment
* last_load_segment
= NULL
;
3262 unsigned int shndx_begin
= *pshndx
;
3263 unsigned int shndx_load_seg
= *pshndx
;
3265 for (Segment_list::iterator p
= this->segment_list_
.begin();
3266 p
!= this->segment_list_
.end();
3269 if ((*p
)->type() == elfcpp::PT_LOAD
)
3271 if (target
->isolate_execinstr())
3273 // When we hit the segment that should contain the
3274 // file headers, reset the file offset so we place
3275 // it and subsequent segments appropriately.
3276 // We'll fix up the preceding segments below.
3284 shndx_load_seg
= *pshndx
;
3290 // Verify that the file headers fall into the first segment.
3291 if (load_seg
!= NULL
&& load_seg
!= *p
)
3296 bool are_addresses_set
= (*p
)->are_addresses_set();
3297 if (are_addresses_set
)
3299 // When it comes to setting file offsets, we care about
3300 // the physical address.
3301 addr
= (*p
)->paddr();
3303 else if (parameters
->options().user_set_Ttext()
3304 && ((*p
)->flags() & elfcpp::PF_W
) == 0)
3306 are_addresses_set
= true;
3308 else if (parameters
->options().user_set_Tdata()
3309 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3310 && (!parameters
->options().user_set_Tbss()
3311 || (*p
)->has_any_data_sections()))
3313 addr
= parameters
->options().Tdata();
3314 are_addresses_set
= true;
3316 else if (parameters
->options().user_set_Tbss()
3317 && ((*p
)->flags() & elfcpp::PF_W
) != 0
3318 && !(*p
)->has_any_data_sections())
3320 addr
= parameters
->options().Tbss();
3321 are_addresses_set
= true;
3324 uint64_t orig_addr
= addr
;
3325 uint64_t orig_off
= off
;
3327 uint64_t aligned_addr
= 0;
3328 uint64_t abi_pagesize
= target
->abi_pagesize();
3329 uint64_t common_pagesize
= target
->common_pagesize();
3331 if (!parameters
->options().nmagic()
3332 && !parameters
->options().omagic())
3333 (*p
)->set_minimum_p_align(abi_pagesize
);
3335 if (!are_addresses_set
)
3337 // Skip the address forward one page, maintaining the same
3338 // position within the page. This lets us store both segments
3339 // overlapping on a single page in the file, but the loader will
3340 // put them on different pages in memory. We will revisit this
3341 // decision once we know the size of the segment.
3343 addr
= align_address(addr
, (*p
)->maximum_alignment());
3344 aligned_addr
= addr
;
3348 // This is the segment that will contain the file
3349 // headers, so its offset will have to be exactly zero.
3350 gold_assert(orig_off
== 0);
3352 // If the target wants a fixed minimum distance from the
3353 // text segment to the read-only segment, move up now.
3354 uint64_t min_addr
= start_addr
+ target
->rosegment_gap();
3355 if (addr
< min_addr
)
3358 // But this is not the first segment! To make its
3359 // address congruent with its offset, that address better
3360 // be aligned to the ABI-mandated page size.
3361 addr
= align_address(addr
, abi_pagesize
);
3362 aligned_addr
= addr
;
3366 if ((addr
& (abi_pagesize
- 1)) != 0)
3367 addr
= addr
+ abi_pagesize
;
3369 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3373 if (!parameters
->options().nmagic()
3374 && !parameters
->options().omagic())
3375 off
= align_file_offset(off
, addr
, abi_pagesize
);
3378 // This is -N or -n with a section script which prevents
3379 // us from using a load segment. We need to ensure that
3380 // the file offset is aligned to the alignment of the
3381 // segment. This is because the linker script
3382 // implicitly assumed a zero offset. If we don't align
3383 // here, then the alignment of the sections in the
3384 // linker script may not match the alignment of the
3385 // sections in the set_section_addresses call below,
3386 // causing an error about dot moving backward.
3387 off
= align_address(off
, (*p
)->maximum_alignment());
3390 unsigned int shndx_hold
= *pshndx
;
3391 bool has_relro
= false;
3392 uint64_t new_addr
= (*p
)->set_section_addresses(this, false, addr
,
3397 // Now that we know the size of this segment, we may be able
3398 // to save a page in memory, at the cost of wasting some
3399 // file space, by instead aligning to the start of a new
3400 // page. Here we use the real machine page size rather than
3401 // the ABI mandated page size. If the segment has been
3402 // aligned so that the relro data ends at a page boundary,
3403 // we do not try to realign it.
3405 if (!are_addresses_set
3407 && aligned_addr
!= addr
3408 && !parameters
->incremental())
3410 uint64_t first_off
= (common_pagesize
3412 & (common_pagesize
- 1)));
3413 uint64_t last_off
= new_addr
& (common_pagesize
- 1);
3416 && ((aligned_addr
& ~ (common_pagesize
- 1))
3417 != (new_addr
& ~ (common_pagesize
- 1)))
3418 && first_off
+ last_off
<= common_pagesize
)
3420 *pshndx
= shndx_hold
;
3421 addr
= align_address(aligned_addr
, common_pagesize
);
3422 addr
= align_address(addr
, (*p
)->maximum_alignment());
3423 off
= orig_off
+ ((addr
- orig_addr
) & (abi_pagesize
- 1));
3424 off
= align_file_offset(off
, addr
, abi_pagesize
);
3426 increase_relro
= this->increase_relro_
;
3427 if (this->script_options_
->saw_sections_clause())
3431 new_addr
= (*p
)->set_section_addresses(this, true, addr
,
3440 // Implement --check-sections. We know that the segments
3441 // are sorted by LMA.
3442 if (check_sections
&& last_load_segment
!= NULL
)
3444 gold_assert(last_load_segment
->paddr() <= (*p
)->paddr());
3445 if (last_load_segment
->paddr() + last_load_segment
->memsz()
3448 unsigned long long lb1
= last_load_segment
->paddr();
3449 unsigned long long le1
= lb1
+ last_load_segment
->memsz();
3450 unsigned long long lb2
= (*p
)->paddr();
3451 unsigned long long le2
= lb2
+ (*p
)->memsz();
3452 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3453 "[0x%llx -> 0x%llx]"),
3454 lb1
, le1
, lb2
, le2
);
3457 last_load_segment
= *p
;
3461 if (load_seg
!= NULL
&& target
->isolate_execinstr())
3463 // Process the early segments again, setting their file offsets
3464 // so they land after the segments starting at LOAD_SEG.
3465 off
= align_file_offset(off
, 0, target
->abi_pagesize());
3467 for (Segment_list::iterator p
= this->segment_list_
.begin();
3471 if ((*p
)->type() == elfcpp::PT_LOAD
)
3473 // We repeat the whole job of assigning addresses and
3474 // offsets, but we really only want to change the offsets and
3475 // must ensure that the addresses all come out the same as
3476 // they did the first time through.
3477 bool has_relro
= false;
3478 const uint64_t old_addr
= (*p
)->vaddr();
3479 const uint64_t old_end
= old_addr
+ (*p
)->memsz();
3480 uint64_t new_addr
= (*p
)->set_section_addresses(this, true,
3486 gold_assert(new_addr
== old_end
);
3490 gold_assert(shndx_begin
== shndx_load_seg
);
3493 // Handle the non-PT_LOAD segments, setting their offsets from their
3494 // section's offsets.
3495 for (Segment_list::iterator p
= this->segment_list_
.begin();
3496 p
!= this->segment_list_
.end();
3499 if ((*p
)->type() != elfcpp::PT_LOAD
)
3500 (*p
)->set_offset((*p
)->type() == elfcpp::PT_GNU_RELRO
3505 // Set the TLS offsets for each section in the PT_TLS segment.
3506 if (this->tls_segment_
!= NULL
)
3507 this->tls_segment_
->set_tls_offsets();
3512 // Set the offsets of all the allocated sections when doing a
3513 // relocatable link. This does the same jobs as set_segment_offsets,
3514 // only for a relocatable link.
3517 Layout::set_relocatable_section_offsets(Output_data
* file_header
,
3518 unsigned int* pshndx
)
3522 file_header
->set_address_and_file_offset(0, 0);
3523 off
+= file_header
->data_size();
3525 for (Section_list::iterator p
= this->section_list_
.begin();
3526 p
!= this->section_list_
.end();
3529 // We skip unallocated sections here, except that group sections
3530 // have to come first.
3531 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) == 0
3532 && (*p
)->type() != elfcpp::SHT_GROUP
)
3535 off
= align_address(off
, (*p
)->addralign());
3537 // The linker script might have set the address.
3538 if (!(*p
)->is_address_valid())
3539 (*p
)->set_address(0);
3540 (*p
)->set_file_offset(off
);
3541 (*p
)->finalize_data_size();
3542 off
+= (*p
)->data_size();
3544 (*p
)->set_out_shndx(*pshndx
);
3551 // Set the file offset of all the sections not associated with a
3555 Layout::set_section_offsets(off_t off
, Layout::Section_offset_pass pass
)
3557 off_t startoff
= off
;
3560 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3561 p
!= this->unattached_section_list_
.end();
3564 // The symtab section is handled in create_symtab_sections.
3565 if (*p
== this->symtab_section_
)
3568 // If we've already set the data size, don't set it again.
3569 if ((*p
)->is_offset_valid() && (*p
)->is_data_size_valid())
3572 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3573 && (*p
)->requires_postprocessing())
3575 (*p
)->create_postprocessing_buffer();
3576 this->any_postprocessing_sections_
= true;
3579 if (pass
== BEFORE_INPUT_SECTIONS_PASS
3580 && (*p
)->after_input_sections())
3582 else if (pass
== POSTPROCESSING_SECTIONS_PASS
3583 && (!(*p
)->after_input_sections()
3584 || (*p
)->type() == elfcpp::SHT_STRTAB
))
3586 else if (pass
== STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
3587 && (!(*p
)->after_input_sections()
3588 || (*p
)->type() != elfcpp::SHT_STRTAB
))
3591 if (!parameters
->incremental_update())
3593 off
= align_address(off
, (*p
)->addralign());
3594 (*p
)->set_file_offset(off
);
3595 (*p
)->finalize_data_size();
3599 // Incremental update: allocate file space from free list.
3600 (*p
)->pre_finalize_data_size();
3601 off_t current_size
= (*p
)->current_data_size();
3602 off
= this->allocate(current_size
, (*p
)->addralign(), startoff
);
3605 if (is_debugging_enabled(DEBUG_INCREMENTAL
))
3606 this->free_list_
.dump();
3607 gold_assert((*p
)->output_section() != NULL
);
3608 gold_fallback(_("out of patch space for section %s; "
3609 "relink with --incremental-full"),
3610 (*p
)->output_section()->name());
3612 (*p
)->set_file_offset(off
);
3613 (*p
)->finalize_data_size();
3614 if ((*p
)->data_size() > current_size
)
3616 gold_assert((*p
)->output_section() != NULL
);
3617 gold_fallback(_("%s: section changed size; "
3618 "relink with --incremental-full"),
3619 (*p
)->output_section()->name());
3621 gold_debug(DEBUG_INCREMENTAL
,
3622 "set_section_offsets: %08lx %08lx %s",
3623 static_cast<long>(off
),
3624 static_cast<long>((*p
)->data_size()),
3625 ((*p
)->output_section() != NULL
3626 ? (*p
)->output_section()->name() : "(special)"));
3629 off
+= (*p
)->data_size();
3633 // At this point the name must be set.
3634 if (pass
!= STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
)
3635 this->namepool_
.add((*p
)->name(), false, NULL
);
3640 // Set the section indexes of all the sections not associated with a
3644 Layout::set_section_indexes(unsigned int shndx
)
3646 for (Section_list::iterator p
= this->unattached_section_list_
.begin();
3647 p
!= this->unattached_section_list_
.end();
3650 if (!(*p
)->has_out_shndx())
3652 (*p
)->set_out_shndx(shndx
);
3659 // Set the section addresses according to the linker script. This is
3660 // only called when we see a SECTIONS clause. This returns the
3661 // program segment which should hold the file header and segment
3662 // headers, if any. It will return NULL if they should not be in a
3666 Layout::set_section_addresses_from_script(Symbol_table
* symtab
)
3668 Script_sections
* ss
= this->script_options_
->script_sections();
3669 gold_assert(ss
->saw_sections_clause());
3670 return this->script_options_
->set_section_addresses(symtab
, this);
3673 // Place the orphan sections in the linker script.
3676 Layout::place_orphan_sections_in_script()
3678 Script_sections
* ss
= this->script_options_
->script_sections();
3679 gold_assert(ss
->saw_sections_clause());
3681 // Place each orphaned output section in the script.
3682 for (Section_list::iterator p
= this->section_list_
.begin();
3683 p
!= this->section_list_
.end();
3686 if (!(*p
)->found_in_sections_clause())
3687 ss
->place_orphan(*p
);
3691 // Count the local symbols in the regular symbol table and the dynamic
3692 // symbol table, and build the respective string pools.
3695 Layout::count_local_symbols(const Task
* task
,
3696 const Input_objects
* input_objects
)
3698 // First, figure out an upper bound on the number of symbols we'll
3699 // be inserting into each pool. This helps us create the pools with
3700 // the right size, to avoid unnecessary hashtable resizing.
3701 unsigned int symbol_count
= 0;
3702 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3703 p
!= input_objects
->relobj_end();
3705 symbol_count
+= (*p
)->local_symbol_count();
3707 // Go from "upper bound" to "estimate." We overcount for two
3708 // reasons: we double-count symbols that occur in more than one
3709 // object file, and we count symbols that are dropped from the
3710 // output. Add it all together and assume we overcount by 100%.
3713 // We assume all symbols will go into both the sympool and dynpool.
3714 this->sympool_
.reserve(symbol_count
);
3715 this->dynpool_
.reserve(symbol_count
);
3717 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3718 p
!= input_objects
->relobj_end();
3721 Task_lock_obj
<Object
> tlo(task
, *p
);
3722 (*p
)->count_local_symbols(&this->sympool_
, &this->dynpool_
);
3726 // Create the symbol table sections. Here we also set the final
3727 // values of the symbols. At this point all the loadable sections are
3728 // fully laid out. SHNUM is the number of sections so far.
3731 Layout::create_symtab_sections(const Input_objects
* input_objects
,
3732 Symbol_table
* symtab
,
3738 if (parameters
->target().get_size() == 32)
3740 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
3743 else if (parameters
->target().get_size() == 64)
3745 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
3751 // Compute file offsets relative to the start of the symtab section.
3754 // Save space for the dummy symbol at the start of the section. We
3755 // never bother to write this out--it will just be left as zero.
3757 unsigned int local_symbol_index
= 1;
3759 // Add STT_SECTION symbols for each Output section which needs one.
3760 for (Section_list::iterator p
= this->section_list_
.begin();
3761 p
!= this->section_list_
.end();
3764 if (!(*p
)->needs_symtab_index())
3765 (*p
)->set_symtab_index(-1U);
3768 (*p
)->set_symtab_index(local_symbol_index
);
3769 ++local_symbol_index
;
3774 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
3775 p
!= input_objects
->relobj_end();
3778 unsigned int index
= (*p
)->finalize_local_symbols(local_symbol_index
,
3780 off
+= (index
- local_symbol_index
) * symsize
;
3781 local_symbol_index
= index
;
3784 unsigned int local_symcount
= local_symbol_index
;
3785 gold_assert(static_cast<off_t
>(local_symcount
* symsize
) == off
);
3788 size_t dyn_global_index
;
3790 if (this->dynsym_section_
== NULL
)
3793 dyn_global_index
= 0;
3798 dyn_global_index
= this->dynsym_section_
->info();
3799 off_t locsize
= dyn_global_index
* this->dynsym_section_
->entsize();
3800 dynoff
= this->dynsym_section_
->offset() + locsize
;
3801 dyncount
= (this->dynsym_section_
->data_size() - locsize
) / symsize
;
3802 gold_assert(static_cast<off_t
>(dyncount
* symsize
)
3803 == this->dynsym_section_
->data_size() - locsize
);
3806 off_t global_off
= off
;
3807 off
= symtab
->finalize(off
, dynoff
, dyn_global_index
, dyncount
,
3808 &this->sympool_
, &local_symcount
);
3810 if (!parameters
->options().strip_all())
3812 this->sympool_
.set_string_offsets();
3814 const char* symtab_name
= this->namepool_
.add(".symtab", false, NULL
);
3815 Output_section
* osymtab
= this->make_output_section(symtab_name
,
3819 this->symtab_section_
= osymtab
;
3821 Output_section_data
* pos
= new Output_data_fixed_space(off
, align
,
3823 osymtab
->add_output_section_data(pos
);
3825 // We generate a .symtab_shndx section if we have more than
3826 // SHN_LORESERVE sections. Technically it is possible that we
3827 // don't need one, because it is possible that there are no
3828 // symbols in any of sections with indexes larger than
3829 // SHN_LORESERVE. That is probably unusual, though, and it is
3830 // easier to always create one than to compute section indexes
3831 // twice (once here, once when writing out the symbols).
3832 if (shnum
>= elfcpp::SHN_LORESERVE
)
3834 const char* symtab_xindex_name
= this->namepool_
.add(".symtab_shndx",
3836 Output_section
* osymtab_xindex
=
3837 this->make_output_section(symtab_xindex_name
,
3838 elfcpp::SHT_SYMTAB_SHNDX
, 0,
3839 ORDER_INVALID
, false);
3841 size_t symcount
= off
/ symsize
;
3842 this->symtab_xindex_
= new Output_symtab_xindex(symcount
);
3844 osymtab_xindex
->add_output_section_data(this->symtab_xindex_
);
3846 osymtab_xindex
->set_link_section(osymtab
);
3847 osymtab_xindex
->set_addralign(4);
3848 osymtab_xindex
->set_entsize(4);
3850 osymtab_xindex
->set_after_input_sections();
3852 // This tells the driver code to wait until the symbol table
3853 // has written out before writing out the postprocessing
3854 // sections, including the .symtab_shndx section.
3855 this->any_postprocessing_sections_
= true;
3858 const char* strtab_name
= this->namepool_
.add(".strtab", false, NULL
);
3859 Output_section
* ostrtab
= this->make_output_section(strtab_name
,
3864 Output_section_data
* pstr
= new Output_data_strtab(&this->sympool_
);
3865 ostrtab
->add_output_section_data(pstr
);
3868 if (!parameters
->incremental_update())
3869 symtab_off
= align_address(*poff
, align
);
3872 symtab_off
= this->allocate(off
, align
, *poff
);
3874 gold_fallback(_("out of patch space for symbol table; "
3875 "relink with --incremental-full"));
3876 gold_debug(DEBUG_INCREMENTAL
,
3877 "create_symtab_sections: %08lx %08lx .symtab",
3878 static_cast<long>(symtab_off
),
3879 static_cast<long>(off
));
3882 symtab
->set_file_offset(symtab_off
+ global_off
);
3883 osymtab
->set_file_offset(symtab_off
);
3884 osymtab
->finalize_data_size();
3885 osymtab
->set_link_section(ostrtab
);
3886 osymtab
->set_info(local_symcount
);
3887 osymtab
->set_entsize(symsize
);
3889 if (symtab_off
+ off
> *poff
)
3890 *poff
= symtab_off
+ off
;
3894 // Create the .shstrtab section, which holds the names of the
3895 // sections. At the time this is called, we have created all the
3896 // output sections except .shstrtab itself.
3899 Layout::create_shstrtab()
3901 // FIXME: We don't need to create a .shstrtab section if we are
3902 // stripping everything.
3904 const char* name
= this->namepool_
.add(".shstrtab", false, NULL
);
3906 Output_section
* os
= this->make_output_section(name
, elfcpp::SHT_STRTAB
, 0,
3907 ORDER_INVALID
, false);
3909 if (strcmp(parameters
->options().compress_debug_sections(), "none") != 0)
3911 // We can't write out this section until we've set all the
3912 // section names, and we don't set the names of compressed
3913 // output sections until relocations are complete. FIXME: With
3914 // the current names we use, this is unnecessary.
3915 os
->set_after_input_sections();
3918 Output_section_data
* posd
= new Output_data_strtab(&this->namepool_
);
3919 os
->add_output_section_data(posd
);
3924 // Create the section headers. SIZE is 32 or 64. OFF is the file
3928 Layout::create_shdrs(const Output_section
* shstrtab_section
, off_t
* poff
)
3930 Output_section_headers
* oshdrs
;
3931 oshdrs
= new Output_section_headers(this,
3932 &this->segment_list_
,
3933 &this->section_list_
,
3934 &this->unattached_section_list_
,
3938 if (!parameters
->incremental_update())
3939 off
= align_address(*poff
, oshdrs
->addralign());
3942 oshdrs
->pre_finalize_data_size();
3943 off
= this->allocate(oshdrs
->data_size(), oshdrs
->addralign(), *poff
);
3945 gold_fallback(_("out of patch space for section header table; "
3946 "relink with --incremental-full"));
3947 gold_debug(DEBUG_INCREMENTAL
,
3948 "create_shdrs: %08lx %08lx (section header table)",
3949 static_cast<long>(off
),
3950 static_cast<long>(off
+ oshdrs
->data_size()));
3952 oshdrs
->set_address_and_file_offset(0, off
);
3953 off
+= oshdrs
->data_size();
3956 this->section_headers_
= oshdrs
;
3959 // Count the allocated sections.
3962 Layout::allocated_output_section_count() const
3964 size_t section_count
= 0;
3965 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
3966 p
!= this->segment_list_
.end();
3968 section_count
+= (*p
)->output_section_count();
3969 return section_count
;
3972 // Create the dynamic symbol table.
3975 Layout::create_dynamic_symtab(const Input_objects
* input_objects
,
3976 Symbol_table
* symtab
,
3977 Output_section
** pdynstr
,
3978 unsigned int* plocal_dynamic_count
,
3979 std::vector
<Symbol
*>* pdynamic_symbols
,
3980 Versions
* pversions
)
3982 // Count all the symbols in the dynamic symbol table, and set the
3983 // dynamic symbol indexes.
3985 // Skip symbol 0, which is always all zeroes.
3986 unsigned int index
= 1;
3988 // Add STT_SECTION symbols for each Output section which needs one.
3989 for (Section_list::iterator p
= this->section_list_
.begin();
3990 p
!= this->section_list_
.end();
3993 if (!(*p
)->needs_dynsym_index())
3994 (*p
)->set_dynsym_index(-1U);
3997 (*p
)->set_dynsym_index(index
);
4002 // Count the local symbols that need to go in the dynamic symbol table,
4003 // and set the dynamic symbol indexes.
4004 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4005 p
!= input_objects
->relobj_end();
4008 unsigned int new_index
= (*p
)->set_local_dynsym_indexes(index
);
4012 unsigned int local_symcount
= index
;
4013 *plocal_dynamic_count
= local_symcount
;
4015 index
= symtab
->set_dynsym_indexes(index
, pdynamic_symbols
,
4016 &this->dynpool_
, pversions
);
4020 const int size
= parameters
->target().get_size();
4023 symsize
= elfcpp::Elf_sizes
<32>::sym_size
;
4026 else if (size
== 64)
4028 symsize
= elfcpp::Elf_sizes
<64>::sym_size
;
4034 // Create the dynamic symbol table section.
4036 Output_section
* dynsym
= this->choose_output_section(NULL
, ".dynsym",
4040 ORDER_DYNAMIC_LINKER
,
4043 // Check for NULL as a linker script may discard .dynsym.
4046 Output_section_data
* odata
= new Output_data_fixed_space(index
* symsize
,
4049 dynsym
->add_output_section_data(odata
);
4051 dynsym
->set_info(local_symcount
);
4052 dynsym
->set_entsize(symsize
);
4053 dynsym
->set_addralign(align
);
4055 this->dynsym_section_
= dynsym
;
4058 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4061 odyn
->add_section_address(elfcpp::DT_SYMTAB
, dynsym
);
4062 odyn
->add_constant(elfcpp::DT_SYMENT
, symsize
);
4065 // If there are more than SHN_LORESERVE allocated sections, we
4066 // create a .dynsym_shndx section. It is possible that we don't
4067 // need one, because it is possible that there are no dynamic
4068 // symbols in any of the sections with indexes larger than
4069 // SHN_LORESERVE. This is probably unusual, though, and at this
4070 // time we don't know the actual section indexes so it is
4071 // inconvenient to check.
4072 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE
)
4074 Output_section
* dynsym_xindex
=
4075 this->choose_output_section(NULL
, ".dynsym_shndx",
4076 elfcpp::SHT_SYMTAB_SHNDX
,
4078 false, ORDER_DYNAMIC_LINKER
, false);
4080 if (dynsym_xindex
!= NULL
)
4082 this->dynsym_xindex_
= new Output_symtab_xindex(index
);
4084 dynsym_xindex
->add_output_section_data(this->dynsym_xindex_
);
4086 dynsym_xindex
->set_link_section(dynsym
);
4087 dynsym_xindex
->set_addralign(4);
4088 dynsym_xindex
->set_entsize(4);
4090 dynsym_xindex
->set_after_input_sections();
4092 // This tells the driver code to wait until the symbol table
4093 // has written out before writing out the postprocessing
4094 // sections, including the .dynsym_shndx section.
4095 this->any_postprocessing_sections_
= true;
4099 // Create the dynamic string table section.
4101 Output_section
* dynstr
= this->choose_output_section(NULL
, ".dynstr",
4105 ORDER_DYNAMIC_LINKER
,
4110 Output_section_data
* strdata
= new Output_data_strtab(&this->dynpool_
);
4111 dynstr
->add_output_section_data(strdata
);
4114 dynsym
->set_link_section(dynstr
);
4115 if (this->dynamic_section_
!= NULL
)
4116 this->dynamic_section_
->set_link_section(dynstr
);
4120 odyn
->add_section_address(elfcpp::DT_STRTAB
, dynstr
);
4121 odyn
->add_section_size(elfcpp::DT_STRSZ
, dynstr
);
4127 // Create the hash tables.
4129 if (strcmp(parameters
->options().hash_style(), "sysv") == 0
4130 || strcmp(parameters
->options().hash_style(), "both") == 0)
4132 unsigned char* phash
;
4133 unsigned int hashlen
;
4134 Dynobj::create_elf_hash_table(*pdynamic_symbols
, local_symcount
,
4137 Output_section
* hashsec
=
4138 this->choose_output_section(NULL
, ".hash", elfcpp::SHT_HASH
,
4139 elfcpp::SHF_ALLOC
, false,
4140 ORDER_DYNAMIC_LINKER
, false);
4142 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4146 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4147 hashsec
->add_output_section_data(hashdata
);
4149 if (hashsec
!= NULL
)
4152 hashsec
->set_link_section(dynsym
);
4153 hashsec
->set_entsize(4);
4157 odyn
->add_section_address(elfcpp::DT_HASH
, hashsec
);
4160 if (strcmp(parameters
->options().hash_style(), "gnu") == 0
4161 || strcmp(parameters
->options().hash_style(), "both") == 0)
4163 unsigned char* phash
;
4164 unsigned int hashlen
;
4165 Dynobj::create_gnu_hash_table(*pdynamic_symbols
, local_symcount
,
4168 Output_section
* hashsec
=
4169 this->choose_output_section(NULL
, ".gnu.hash", elfcpp::SHT_GNU_HASH
,
4170 elfcpp::SHF_ALLOC
, false,
4171 ORDER_DYNAMIC_LINKER
, false);
4173 Output_section_data
* hashdata
= new Output_data_const_buffer(phash
,
4177 if (hashsec
!= NULL
&& hashdata
!= NULL
)
4178 hashsec
->add_output_section_data(hashdata
);
4180 if (hashsec
!= NULL
)
4183 hashsec
->set_link_section(dynsym
);
4185 // For a 64-bit target, the entries in .gnu.hash do not have
4186 // a uniform size, so we only set the entry size for a
4188 if (parameters
->target().get_size() == 32)
4189 hashsec
->set_entsize(4);
4192 odyn
->add_section_address(elfcpp::DT_GNU_HASH
, hashsec
);
4197 // Assign offsets to each local portion of the dynamic symbol table.
4200 Layout::assign_local_dynsym_offsets(const Input_objects
* input_objects
)
4202 Output_section
* dynsym
= this->dynsym_section_
;
4206 off_t off
= dynsym
->offset();
4208 // Skip the dummy symbol at the start of the section.
4209 off
+= dynsym
->entsize();
4211 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
4212 p
!= input_objects
->relobj_end();
4215 unsigned int count
= (*p
)->set_local_dynsym_offset(off
);
4216 off
+= count
* dynsym
->entsize();
4220 // Create the version sections.
4223 Layout::create_version_sections(const Versions
* versions
,
4224 const Symbol_table
* symtab
,
4225 unsigned int local_symcount
,
4226 const std::vector
<Symbol
*>& dynamic_symbols
,
4227 const Output_section
* dynstr
)
4229 if (!versions
->any_defs() && !versions
->any_needs())
4232 switch (parameters
->size_and_endianness())
4234 #ifdef HAVE_TARGET_32_LITTLE
4235 case Parameters::TARGET_32_LITTLE
:
4236 this->sized_create_version_sections
<32, false>(versions
, symtab
,
4238 dynamic_symbols
, dynstr
);
4241 #ifdef HAVE_TARGET_32_BIG
4242 case Parameters::TARGET_32_BIG
:
4243 this->sized_create_version_sections
<32, true>(versions
, symtab
,
4245 dynamic_symbols
, dynstr
);
4248 #ifdef HAVE_TARGET_64_LITTLE
4249 case Parameters::TARGET_64_LITTLE
:
4250 this->sized_create_version_sections
<64, false>(versions
, symtab
,
4252 dynamic_symbols
, dynstr
);
4255 #ifdef HAVE_TARGET_64_BIG
4256 case Parameters::TARGET_64_BIG
:
4257 this->sized_create_version_sections
<64, true>(versions
, symtab
,
4259 dynamic_symbols
, dynstr
);
4267 // Create the version sections, sized version.
4269 template<int size
, bool big_endian
>
4271 Layout::sized_create_version_sections(
4272 const Versions
* versions
,
4273 const Symbol_table
* symtab
,
4274 unsigned int local_symcount
,
4275 const std::vector
<Symbol
*>& dynamic_symbols
,
4276 const Output_section
* dynstr
)
4278 Output_section
* vsec
= this->choose_output_section(NULL
, ".gnu.version",
4279 elfcpp::SHT_GNU_versym
,
4282 ORDER_DYNAMIC_LINKER
,
4285 // Check for NULL since a linker script may discard this section.
4288 unsigned char* vbuf
;
4290 versions
->symbol_section_contents
<size
, big_endian
>(symtab
,
4296 Output_section_data
* vdata
= new Output_data_const_buffer(vbuf
, vsize
, 2,
4299 vsec
->add_output_section_data(vdata
);
4300 vsec
->set_entsize(2);
4301 vsec
->set_link_section(this->dynsym_section_
);
4304 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4305 if (odyn
!= NULL
&& vsec
!= NULL
)
4306 odyn
->add_section_address(elfcpp::DT_VERSYM
, vsec
);
4308 if (versions
->any_defs())
4310 Output_section
* vdsec
;
4311 vdsec
= this->choose_output_section(NULL
, ".gnu.version_d",
4312 elfcpp::SHT_GNU_verdef
,
4314 false, ORDER_DYNAMIC_LINKER
, false);
4318 unsigned char* vdbuf
;
4319 unsigned int vdsize
;
4320 unsigned int vdentries
;
4321 versions
->def_section_contents
<size
, big_endian
>(&this->dynpool_
,
4325 Output_section_data
* vddata
=
4326 new Output_data_const_buffer(vdbuf
, vdsize
, 4, "** version defs");
4328 vdsec
->add_output_section_data(vddata
);
4329 vdsec
->set_link_section(dynstr
);
4330 vdsec
->set_info(vdentries
);
4334 odyn
->add_section_address(elfcpp::DT_VERDEF
, vdsec
);
4335 odyn
->add_constant(elfcpp::DT_VERDEFNUM
, vdentries
);
4340 if (versions
->any_needs())
4342 Output_section
* vnsec
;
4343 vnsec
= this->choose_output_section(NULL
, ".gnu.version_r",
4344 elfcpp::SHT_GNU_verneed
,
4346 false, ORDER_DYNAMIC_LINKER
, false);
4350 unsigned char* vnbuf
;
4351 unsigned int vnsize
;
4352 unsigned int vnentries
;
4353 versions
->need_section_contents
<size
, big_endian
>(&this->dynpool_
,
4357 Output_section_data
* vndata
=
4358 new Output_data_const_buffer(vnbuf
, vnsize
, 4, "** version refs");
4360 vnsec
->add_output_section_data(vndata
);
4361 vnsec
->set_link_section(dynstr
);
4362 vnsec
->set_info(vnentries
);
4366 odyn
->add_section_address(elfcpp::DT_VERNEED
, vnsec
);
4367 odyn
->add_constant(elfcpp::DT_VERNEEDNUM
, vnentries
);
4373 // Create the .interp section and PT_INTERP segment.
4376 Layout::create_interp(const Target
* target
)
4378 gold_assert(this->interp_segment_
== NULL
);
4380 const char* interp
= parameters
->options().dynamic_linker();
4383 interp
= target
->dynamic_linker();
4384 gold_assert(interp
!= NULL
);
4387 size_t len
= strlen(interp
) + 1;
4389 Output_section_data
* odata
= new Output_data_const(interp
, len
, 1);
4391 Output_section
* osec
= this->choose_output_section(NULL
, ".interp",
4392 elfcpp::SHT_PROGBITS
,
4394 false, ORDER_INTERP
,
4397 osec
->add_output_section_data(odata
);
4400 // Add dynamic tags for the PLT and the dynamic relocs. This is
4401 // called by the target-specific code. This does nothing if not doing
4404 // USE_REL is true for REL relocs rather than RELA relocs.
4406 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
4408 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
4409 // and we also set DT_PLTREL. We use PLT_REL's output section, since
4410 // some targets have multiple reloc sections in PLT_REL.
4412 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
4413 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT. Again we use the output
4416 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
4420 Layout::add_target_dynamic_tags(bool use_rel
, const Output_data
* plt_got
,
4421 const Output_data
* plt_rel
,
4422 const Output_data_reloc_generic
* dyn_rel
,
4423 bool add_debug
, bool dynrel_includes_plt
)
4425 Output_data_dynamic
* odyn
= this->dynamic_data_
;
4429 if (plt_got
!= NULL
&& plt_got
->output_section() != NULL
)
4430 odyn
->add_section_address(elfcpp::DT_PLTGOT
, plt_got
);
4432 if (plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
)
4434 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, plt_rel
->output_section());
4435 odyn
->add_section_address(elfcpp::DT_JMPREL
, plt_rel
->output_section());
4436 odyn
->add_constant(elfcpp::DT_PLTREL
,
4437 use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
);
4440 if ((dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
)
4441 || (dynrel_includes_plt
4443 && plt_rel
->output_section() != NULL
))
4445 bool have_dyn_rel
= dyn_rel
!= NULL
&& dyn_rel
->output_section() != NULL
;
4446 bool have_plt_rel
= plt_rel
!= NULL
&& plt_rel
->output_section() != NULL
;
4447 odyn
->add_section_address(use_rel
? elfcpp::DT_REL
: elfcpp::DT_RELA
,
4449 ? dyn_rel
->output_section()
4450 : plt_rel
->output_section()));
4451 elfcpp::DT size_tag
= use_rel
? elfcpp::DT_RELSZ
: elfcpp::DT_RELASZ
;
4452 if (have_dyn_rel
&& have_plt_rel
&& dynrel_includes_plt
)
4453 odyn
->add_section_size(size_tag
,
4454 dyn_rel
->output_section(),
4455 plt_rel
->output_section());
4456 else if (have_dyn_rel
)
4457 odyn
->add_section_size(size_tag
, dyn_rel
->output_section());
4459 odyn
->add_section_size(size_tag
, plt_rel
->output_section());
4460 const int size
= parameters
->target().get_size();
4465 rel_tag
= elfcpp::DT_RELENT
;
4467 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 32, false>::reloc_size
;
4468 else if (size
== 64)
4469 rel_size
= Reloc_types
<elfcpp::SHT_REL
, 64, false>::reloc_size
;
4475 rel_tag
= elfcpp::DT_RELAENT
;
4477 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 32, false>::reloc_size
;
4478 else if (size
== 64)
4479 rel_size
= Reloc_types
<elfcpp::SHT_RELA
, 64, false>::reloc_size
;
4483 odyn
->add_constant(rel_tag
, rel_size
);
4485 if (parameters
->options().combreloc() && have_dyn_rel
)
4487 size_t c
= dyn_rel
->relative_reloc_count();
4489 odyn
->add_constant((use_rel
4490 ? elfcpp::DT_RELCOUNT
4491 : elfcpp::DT_RELACOUNT
),
4496 if (add_debug
&& !parameters
->options().shared())
4498 // The value of the DT_DEBUG tag is filled in by the dynamic
4499 // linker at run time, and used by the debugger.
4500 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
4504 // Finish the .dynamic section and PT_DYNAMIC segment.
4507 Layout::finish_dynamic_section(const Input_objects
* input_objects
,
4508 const Symbol_table
* symtab
)
4510 if (!this->script_options_
->saw_phdrs_clause()
4511 && this->dynamic_section_
!= NULL
)
4513 Output_segment
* oseg
= this->make_output_segment(elfcpp::PT_DYNAMIC
,
4516 oseg
->add_output_section_to_nonload(this->dynamic_section_
,
4517 elfcpp::PF_R
| elfcpp::PF_W
);
4520 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4524 for (Input_objects::Dynobj_iterator p
= input_objects
->dynobj_begin();
4525 p
!= input_objects
->dynobj_end();
4528 if (!(*p
)->is_needed() && (*p
)->as_needed())
4530 // This dynamic object was linked with --as-needed, but it
4535 odyn
->add_string(elfcpp::DT_NEEDED
, (*p
)->soname());
4538 if (parameters
->options().shared())
4540 const char* soname
= parameters
->options().soname();
4542 odyn
->add_string(elfcpp::DT_SONAME
, soname
);
4545 Symbol
* sym
= symtab
->lookup(parameters
->options().init());
4546 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4547 odyn
->add_symbol(elfcpp::DT_INIT
, sym
);
4549 sym
= symtab
->lookup(parameters
->options().fini());
4550 if (sym
!= NULL
&& sym
->is_defined() && !sym
->is_from_dynobj())
4551 odyn
->add_symbol(elfcpp::DT_FINI
, sym
);
4553 // Look for .init_array, .preinit_array and .fini_array by checking
4555 for(Layout::Section_list::const_iterator p
= this->section_list_
.begin();
4556 p
!= this->section_list_
.end();
4558 switch((*p
)->type())
4560 case elfcpp::SHT_FINI_ARRAY
:
4561 odyn
->add_section_address(elfcpp::DT_FINI_ARRAY
, *p
);
4562 odyn
->add_section_size(elfcpp::DT_FINI_ARRAYSZ
, *p
);
4564 case elfcpp::SHT_INIT_ARRAY
:
4565 odyn
->add_section_address(elfcpp::DT_INIT_ARRAY
, *p
);
4566 odyn
->add_section_size(elfcpp::DT_INIT_ARRAYSZ
, *p
);
4568 case elfcpp::SHT_PREINIT_ARRAY
:
4569 odyn
->add_section_address(elfcpp::DT_PREINIT_ARRAY
, *p
);
4570 odyn
->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ
, *p
);
4576 // Add a DT_RPATH entry if needed.
4577 const General_options::Dir_list
& rpath(parameters
->options().rpath());
4580 std::string rpath_val
;
4581 for (General_options::Dir_list::const_iterator p
= rpath
.begin();
4585 if (rpath_val
.empty())
4586 rpath_val
= p
->name();
4589 // Eliminate duplicates.
4590 General_options::Dir_list::const_iterator q
;
4591 for (q
= rpath
.begin(); q
!= p
; ++q
)
4592 if (q
->name() == p
->name())
4597 rpath_val
+= p
->name();
4602 odyn
->add_string(elfcpp::DT_RPATH
, rpath_val
);
4603 if (parameters
->options().enable_new_dtags())
4604 odyn
->add_string(elfcpp::DT_RUNPATH
, rpath_val
);
4607 // Look for text segments that have dynamic relocations.
4608 bool have_textrel
= false;
4609 if (!this->script_options_
->saw_sections_clause())
4611 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
4612 p
!= this->segment_list_
.end();
4615 if ((*p
)->type() == elfcpp::PT_LOAD
4616 && ((*p
)->flags() & elfcpp::PF_W
) == 0
4617 && (*p
)->has_dynamic_reloc())
4619 have_textrel
= true;
4626 // We don't know the section -> segment mapping, so we are
4627 // conservative and just look for readonly sections with
4628 // relocations. If those sections wind up in writable segments,
4629 // then we have created an unnecessary DT_TEXTREL entry.
4630 for (Section_list::const_iterator p
= this->section_list_
.begin();
4631 p
!= this->section_list_
.end();
4634 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0
4635 && ((*p
)->flags() & elfcpp::SHF_WRITE
) == 0
4636 && (*p
)->has_dynamic_reloc())
4638 have_textrel
= true;
4644 if (parameters
->options().filter() != NULL
)
4645 odyn
->add_string(elfcpp::DT_FILTER
, parameters
->options().filter());
4646 if (parameters
->options().any_auxiliary())
4648 for (options::String_set::const_iterator p
=
4649 parameters
->options().auxiliary_begin();
4650 p
!= parameters
->options().auxiliary_end();
4652 odyn
->add_string(elfcpp::DT_AUXILIARY
, *p
);
4655 // Add a DT_FLAGS entry if necessary.
4656 unsigned int flags
= 0;
4659 // Add a DT_TEXTREL for compatibility with older loaders.
4660 odyn
->add_constant(elfcpp::DT_TEXTREL
, 0);
4661 flags
|= elfcpp::DF_TEXTREL
;
4663 if (parameters
->options().text())
4664 gold_error(_("read-only segment has dynamic relocations"));
4665 else if (parameters
->options().warn_shared_textrel()
4666 && parameters
->options().shared())
4667 gold_warning(_("shared library text segment is not shareable"));
4669 if (parameters
->options().shared() && this->has_static_tls())
4670 flags
|= elfcpp::DF_STATIC_TLS
;
4671 if (parameters
->options().origin())
4672 flags
|= elfcpp::DF_ORIGIN
;
4673 if (parameters
->options().Bsymbolic())
4675 flags
|= elfcpp::DF_SYMBOLIC
;
4676 // Add DT_SYMBOLIC for compatibility with older loaders.
4677 odyn
->add_constant(elfcpp::DT_SYMBOLIC
, 0);
4679 if (parameters
->options().now())
4680 flags
|= elfcpp::DF_BIND_NOW
;
4682 odyn
->add_constant(elfcpp::DT_FLAGS
, flags
);
4685 if (parameters
->options().initfirst())
4686 flags
|= elfcpp::DF_1_INITFIRST
;
4687 if (parameters
->options().interpose())
4688 flags
|= elfcpp::DF_1_INTERPOSE
;
4689 if (parameters
->options().loadfltr())
4690 flags
|= elfcpp::DF_1_LOADFLTR
;
4691 if (parameters
->options().nodefaultlib())
4692 flags
|= elfcpp::DF_1_NODEFLIB
;
4693 if (parameters
->options().nodelete())
4694 flags
|= elfcpp::DF_1_NODELETE
;
4695 if (parameters
->options().nodlopen())
4696 flags
|= elfcpp::DF_1_NOOPEN
;
4697 if (parameters
->options().nodump())
4698 flags
|= elfcpp::DF_1_NODUMP
;
4699 if (!parameters
->options().shared())
4700 flags
&= ~(elfcpp::DF_1_INITFIRST
4701 | elfcpp::DF_1_NODELETE
4702 | elfcpp::DF_1_NOOPEN
);
4703 if (parameters
->options().origin())
4704 flags
|= elfcpp::DF_1_ORIGIN
;
4705 if (parameters
->options().now())
4706 flags
|= elfcpp::DF_1_NOW
;
4707 if (parameters
->options().Bgroup())
4708 flags
|= elfcpp::DF_1_GROUP
;
4710 odyn
->add_constant(elfcpp::DT_FLAGS_1
, flags
);
4713 // Set the size of the _DYNAMIC symbol table to be the size of the
4717 Layout::set_dynamic_symbol_size(const Symbol_table
* symtab
)
4719 Output_data_dynamic
* const odyn
= this->dynamic_data_
;
4722 odyn
->finalize_data_size();
4723 if (this->dynamic_symbol_
== NULL
)
4725 off_t data_size
= odyn
->data_size();
4726 const int size
= parameters
->target().get_size();
4728 symtab
->get_sized_symbol
<32>(this->dynamic_symbol_
)->set_symsize(data_size
);
4729 else if (size
== 64)
4730 symtab
->get_sized_symbol
<64>(this->dynamic_symbol_
)->set_symsize(data_size
);
4735 // The mapping of input section name prefixes to output section names.
4736 // In some cases one prefix is itself a prefix of another prefix; in
4737 // such a case the longer prefix must come first. These prefixes are
4738 // based on the GNU linker default ELF linker script.
4740 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
4741 #define MAPPING_INIT_EXACT(f, t) { f, 0, t, sizeof(t) - 1 }
4742 const Layout::Section_name_mapping
Layout::section_name_mapping
[] =
4744 MAPPING_INIT(".text.", ".text"),
4745 MAPPING_INIT(".rodata.", ".rodata"),
4746 MAPPING_INIT(".data.rel.ro.local.", ".data.rel.ro.local"),
4747 MAPPING_INIT_EXACT(".data.rel.ro.local", ".data.rel.ro.local"),
4748 MAPPING_INIT(".data.rel.ro.", ".data.rel.ro"),
4749 MAPPING_INIT_EXACT(".data.rel.ro", ".data.rel.ro"),
4750 MAPPING_INIT(".data.", ".data"),
4751 MAPPING_INIT(".bss.", ".bss"),
4752 MAPPING_INIT(".tdata.", ".tdata"),
4753 MAPPING_INIT(".tbss.", ".tbss"),
4754 MAPPING_INIT(".init_array.", ".init_array"),
4755 MAPPING_INIT(".fini_array.", ".fini_array"),
4756 MAPPING_INIT(".sdata.", ".sdata"),
4757 MAPPING_INIT(".sbss.", ".sbss"),
4758 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
4759 // differently depending on whether it is creating a shared library.
4760 MAPPING_INIT(".sdata2.", ".sdata"),
4761 MAPPING_INIT(".sbss2.", ".sbss"),
4762 MAPPING_INIT(".lrodata.", ".lrodata"),
4763 MAPPING_INIT(".ldata.", ".ldata"),
4764 MAPPING_INIT(".lbss.", ".lbss"),
4765 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
4766 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
4767 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
4768 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
4769 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
4770 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
4771 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
4772 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
4773 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
4774 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
4775 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
4776 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
4777 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
4778 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
4779 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
4780 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
4781 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
4782 MAPPING_INIT(".ARM.extab", ".ARM.extab"),
4783 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
4784 MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
4785 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
4788 #undef MAPPING_INIT_EXACT
4790 const int Layout::section_name_mapping_count
=
4791 (sizeof(Layout::section_name_mapping
)
4792 / sizeof(Layout::section_name_mapping
[0]));
4794 // Choose the output section name to use given an input section name.
4795 // Set *PLEN to the length of the name. *PLEN is initialized to the
4799 Layout::output_section_name(const Relobj
* relobj
, const char* name
,
4802 // gcc 4.3 generates the following sorts of section names when it
4803 // needs a section name specific to a function:
4809 // .data.rel.local.FN
4811 // .data.rel.ro.local.FN
4818 // The GNU linker maps all of those to the part before the .FN,
4819 // except that .data.rel.local.FN is mapped to .data, and
4820 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
4821 // beginning with .data.rel.ro.local are grouped together.
4823 // For an anonymous namespace, the string FN can contain a '.'.
4825 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
4826 // GNU linker maps to .rodata.
4828 // The .data.rel.ro sections are used with -z relro. The sections
4829 // are recognized by name. We use the same names that the GNU
4830 // linker does for these sections.
4832 // It is hard to handle this in a principled way, so we don't even
4833 // try. We use a table of mappings. If the input section name is
4834 // not found in the table, we simply use it as the output section
4837 const Section_name_mapping
* psnm
= section_name_mapping
;
4838 for (int i
= 0; i
< section_name_mapping_count
; ++i
, ++psnm
)
4840 if (psnm
->fromlen
> 0)
4842 if (strncmp(name
, psnm
->from
, psnm
->fromlen
) == 0)
4844 *plen
= psnm
->tolen
;
4850 if (strcmp(name
, psnm
->from
) == 0)
4852 *plen
= psnm
->tolen
;
4858 // As an additional complication, .ctors sections are output in
4859 // either .ctors or .init_array sections, and .dtors sections are
4860 // output in either .dtors or .fini_array sections.
4861 if (is_prefix_of(".ctors.", name
) || is_prefix_of(".dtors.", name
))
4863 if (parameters
->options().ctors_in_init_array())
4866 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4871 return name
[1] == 'c' ? ".ctors" : ".dtors";
4874 if (parameters
->options().ctors_in_init_array()
4875 && (strcmp(name
, ".ctors") == 0 || strcmp(name
, ".dtors") == 0))
4877 // To make .init_array/.fini_array work with gcc we must exclude
4878 // .ctors and .dtors sections from the crtbegin and crtend
4881 || (!Layout::match_file_name(relobj
, "crtbegin")
4882 && !Layout::match_file_name(relobj
, "crtend")))
4885 return name
[1] == 'c' ? ".init_array" : ".fini_array";
4892 // Return true if RELOBJ is an input file whose base name matches
4893 // FILE_NAME. The base name must have an extension of ".o", and must
4894 // be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is
4895 // to match crtbegin.o as well as crtbeginS.o without getting confused
4896 // by other possibilities. Overall matching the file name this way is
4897 // a dreadful hack, but the GNU linker does it in order to better
4898 // support gcc, and we need to be compatible.
4901 Layout::match_file_name(const Relobj
* relobj
, const char* match
)
4903 const std::string
& file_name(relobj
->name());
4904 const char* base_name
= lbasename(file_name
.c_str());
4905 size_t match_len
= strlen(match
);
4906 if (strncmp(base_name
, match
, match_len
) != 0)
4908 size_t base_len
= strlen(base_name
);
4909 if (base_len
!= match_len
+ 2 && base_len
!= match_len
+ 3)
4911 return memcmp(base_name
+ base_len
- 2, ".o", 2) == 0;
4914 // Check if a comdat group or .gnu.linkonce section with the given
4915 // NAME is selected for the link. If there is already a section,
4916 // *KEPT_SECTION is set to point to the existing section and the
4917 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
4918 // IS_GROUP_NAME are recorded for this NAME in the layout object,
4919 // *KEPT_SECTION is set to the internal copy and the function returns
4923 Layout::find_or_add_kept_section(const std::string
& name
,
4928 Kept_section
** kept_section
)
4930 // It's normal to see a couple of entries here, for the x86 thunk
4931 // sections. If we see more than a few, we're linking a C++
4932 // program, and we resize to get more space to minimize rehashing.
4933 if (this->signatures_
.size() > 4
4934 && !this->resized_signatures_
)
4936 reserve_unordered_map(&this->signatures_
,
4937 this->number_of_input_files_
* 64);
4938 this->resized_signatures_
= true;
4941 Kept_section candidate
;
4942 std::pair
<Signatures::iterator
, bool> ins
=
4943 this->signatures_
.insert(std::make_pair(name
, candidate
));
4945 if (kept_section
!= NULL
)
4946 *kept_section
= &ins
.first
->second
;
4949 // This is the first time we've seen this signature.
4950 ins
.first
->second
.set_object(object
);
4951 ins
.first
->second
.set_shndx(shndx
);
4953 ins
.first
->second
.set_is_comdat();
4955 ins
.first
->second
.set_is_group_name();
4959 // We have already seen this signature.
4961 if (ins
.first
->second
.is_group_name())
4963 // We've already seen a real section group with this signature.
4964 // If the kept group is from a plugin object, and we're in the
4965 // replacement phase, accept the new one as a replacement.
4966 if (ins
.first
->second
.object() == NULL
4967 && parameters
->options().plugins()->in_replacement_phase())
4969 ins
.first
->second
.set_object(object
);
4970 ins
.first
->second
.set_shndx(shndx
);
4975 else if (is_group_name
)
4977 // This is a real section group, and we've already seen a
4978 // linkonce section with this signature. Record that we've seen
4979 // a section group, and don't include this section group.
4980 ins
.first
->second
.set_is_group_name();
4985 // We've already seen a linkonce section and this is a linkonce
4986 // section. These don't block each other--this may be the same
4987 // symbol name with different section types.
4992 // Store the allocated sections into the section list.
4995 Layout::get_allocated_sections(Section_list
* section_list
) const
4997 for (Section_list::const_iterator p
= this->section_list_
.begin();
4998 p
!= this->section_list_
.end();
5000 if (((*p
)->flags() & elfcpp::SHF_ALLOC
) != 0)
5001 section_list
->push_back(*p
);
5004 // Create an output segment.
5007 Layout::make_output_segment(elfcpp::Elf_Word type
, elfcpp::Elf_Word flags
)
5009 gold_assert(!parameters
->options().relocatable());
5010 Output_segment
* oseg
= new Output_segment(type
, flags
);
5011 this->segment_list_
.push_back(oseg
);
5013 if (type
== elfcpp::PT_TLS
)
5014 this->tls_segment_
= oseg
;
5015 else if (type
== elfcpp::PT_GNU_RELRO
)
5016 this->relro_segment_
= oseg
;
5017 else if (type
== elfcpp::PT_INTERP
)
5018 this->interp_segment_
= oseg
;
5023 // Return the file offset of the normal symbol table.
5026 Layout::symtab_section_offset() const
5028 if (this->symtab_section_
!= NULL
)
5029 return this->symtab_section_
->offset();
5033 // Return the section index of the normal symbol table. It may have
5034 // been stripped by the -s/--strip-all option.
5037 Layout::symtab_section_shndx() const
5039 if (this->symtab_section_
!= NULL
)
5040 return this->symtab_section_
->out_shndx();
5044 // Write out the Output_sections. Most won't have anything to write,
5045 // since most of the data will come from input sections which are
5046 // handled elsewhere. But some Output_sections do have Output_data.
5049 Layout::write_output_sections(Output_file
* of
) const
5051 for (Section_list::const_iterator p
= this->section_list_
.begin();
5052 p
!= this->section_list_
.end();
5055 if (!(*p
)->after_input_sections())
5060 // Write out data not associated with a section or the symbol table.
5063 Layout::write_data(const Symbol_table
* symtab
, Output_file
* of
) const
5065 if (!parameters
->options().strip_all())
5067 const Output_section
* symtab_section
= this->symtab_section_
;
5068 for (Section_list::const_iterator p
= this->section_list_
.begin();
5069 p
!= this->section_list_
.end();
5072 if ((*p
)->needs_symtab_index())
5074 gold_assert(symtab_section
!= NULL
);
5075 unsigned int index
= (*p
)->symtab_index();
5076 gold_assert(index
> 0 && index
!= -1U);
5077 off_t off
= (symtab_section
->offset()
5078 + index
* symtab_section
->entsize());
5079 symtab
->write_section_symbol(*p
, this->symtab_xindex_
, of
, off
);
5084 const Output_section
* dynsym_section
= this->dynsym_section_
;
5085 for (Section_list::const_iterator p
= this->section_list_
.begin();
5086 p
!= this->section_list_
.end();
5089 if ((*p
)->needs_dynsym_index())
5091 gold_assert(dynsym_section
!= NULL
);
5092 unsigned int index
= (*p
)->dynsym_index();
5093 gold_assert(index
> 0 && index
!= -1U);
5094 off_t off
= (dynsym_section
->offset()
5095 + index
* dynsym_section
->entsize());
5096 symtab
->write_section_symbol(*p
, this->dynsym_xindex_
, of
, off
);
5100 // Write out the Output_data which are not in an Output_section.
5101 for (Data_list::const_iterator p
= this->special_output_list_
.begin();
5102 p
!= this->special_output_list_
.end();
5107 // Write out the Output_sections which can only be written after the
5108 // input sections are complete.
5111 Layout::write_sections_after_input_sections(Output_file
* of
)
5113 // Determine the final section offsets, and thus the final output
5114 // file size. Note we finalize the .shstrab last, to allow the
5115 // after_input_section sections to modify their section-names before
5117 if (this->any_postprocessing_sections_
)
5119 off_t off
= this->output_file_size_
;
5120 off
= this->set_section_offsets(off
, POSTPROCESSING_SECTIONS_PASS
);
5122 // Now that we've finalized the names, we can finalize the shstrab.
5124 this->set_section_offsets(off
,
5125 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
);
5127 if (off
> this->output_file_size_
)
5130 this->output_file_size_
= off
;
5134 for (Section_list::const_iterator p
= this->section_list_
.begin();
5135 p
!= this->section_list_
.end();
5138 if ((*p
)->after_input_sections())
5142 this->section_headers_
->write(of
);
5145 // If the build ID requires computing a checksum, do so here, and
5146 // write it out. We compute a checksum over the entire file because
5147 // that is simplest.
5150 Layout::write_build_id(Output_file
* of
) const
5152 if (this->build_id_note_
== NULL
)
5155 const unsigned char* iv
= of
->get_input_view(0, this->output_file_size_
);
5157 unsigned char* ov
= of
->get_output_view(this->build_id_note_
->offset(),
5158 this->build_id_note_
->data_size());
5160 const char* style
= parameters
->options().build_id();
5161 if (strcmp(style
, "sha1") == 0)
5164 sha1_init_ctx(&ctx
);
5165 sha1_process_bytes(iv
, this->output_file_size_
, &ctx
);
5166 sha1_finish_ctx(&ctx
, ov
);
5168 else if (strcmp(style
, "md5") == 0)
5172 md5_process_bytes(iv
, this->output_file_size_
, &ctx
);
5173 md5_finish_ctx(&ctx
, ov
);
5178 of
->write_output_view(this->build_id_note_
->offset(),
5179 this->build_id_note_
->data_size(),
5182 of
->free_input_view(0, this->output_file_size_
, iv
);
5185 // Write out a binary file. This is called after the link is
5186 // complete. IN is the temporary output file we used to generate the
5187 // ELF code. We simply walk through the segments, read them from
5188 // their file offset in IN, and write them to their load address in
5189 // the output file. FIXME: with a bit more work, we could support
5190 // S-records and/or Intel hex format here.
5193 Layout::write_binary(Output_file
* in
) const
5195 gold_assert(parameters
->options().oformat_enum()
5196 == General_options::OBJECT_FORMAT_BINARY
);
5198 // Get the size of the binary file.
5199 uint64_t max_load_address
= 0;
5200 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5201 p
!= this->segment_list_
.end();
5204 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5206 uint64_t max_paddr
= (*p
)->paddr() + (*p
)->filesz();
5207 if (max_paddr
> max_load_address
)
5208 max_load_address
= max_paddr
;
5212 Output_file
out(parameters
->options().output_file_name());
5213 out
.open(max_load_address
);
5215 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5216 p
!= this->segment_list_
.end();
5219 if ((*p
)->type() == elfcpp::PT_LOAD
&& (*p
)->filesz() > 0)
5221 const unsigned char* vin
= in
->get_input_view((*p
)->offset(),
5223 unsigned char* vout
= out
.get_output_view((*p
)->paddr(),
5225 memcpy(vout
, vin
, (*p
)->filesz());
5226 out
.write_output_view((*p
)->paddr(), (*p
)->filesz(), vout
);
5227 in
->free_input_view((*p
)->offset(), (*p
)->filesz(), vin
);
5234 // Print the output sections to the map file.
5237 Layout::print_to_mapfile(Mapfile
* mapfile
) const
5239 for (Segment_list::const_iterator p
= this->segment_list_
.begin();
5240 p
!= this->segment_list_
.end();
5242 (*p
)->print_sections_to_mapfile(mapfile
);
5245 // Print statistical information to stderr. This is used for --stats.
5248 Layout::print_stats() const
5250 this->namepool_
.print_stats("section name pool");
5251 this->sympool_
.print_stats("output symbol name pool");
5252 this->dynpool_
.print_stats("dynamic name pool");
5254 for (Section_list::const_iterator p
= this->section_list_
.begin();
5255 p
!= this->section_list_
.end();
5257 (*p
)->print_merge_stats();
5260 // Write_sections_task methods.
5262 // We can always run this task.
5265 Write_sections_task::is_runnable()
5270 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
5274 Write_sections_task::locks(Task_locker
* tl
)
5276 tl
->add(this, this->output_sections_blocker_
);
5277 tl
->add(this, this->final_blocker_
);
5280 // Run the task--write out the data.
5283 Write_sections_task::run(Workqueue
*)
5285 this->layout_
->write_output_sections(this->of_
);
5288 // Write_data_task methods.
5290 // We can always run this task.
5293 Write_data_task::is_runnable()
5298 // We need to unlock FINAL_BLOCKER when finished.
5301 Write_data_task::locks(Task_locker
* tl
)
5303 tl
->add(this, this->final_blocker_
);
5306 // Run the task--write out the data.
5309 Write_data_task::run(Workqueue
*)
5311 this->layout_
->write_data(this->symtab_
, this->of_
);
5314 // Write_symbols_task methods.
5316 // We can always run this task.
5319 Write_symbols_task::is_runnable()
5324 // We need to unlock FINAL_BLOCKER when finished.
5327 Write_symbols_task::locks(Task_locker
* tl
)
5329 tl
->add(this, this->final_blocker_
);
5332 // Run the task--write out the symbols.
5335 Write_symbols_task::run(Workqueue
*)
5337 this->symtab_
->write_globals(this->sympool_
, this->dynpool_
,
5338 this->layout_
->symtab_xindex(),
5339 this->layout_
->dynsym_xindex(), this->of_
);
5342 // Write_after_input_sections_task methods.
5344 // We can only run this task after the input sections have completed.
5347 Write_after_input_sections_task::is_runnable()
5349 if (this->input_sections_blocker_
->is_blocked())
5350 return this->input_sections_blocker_
;
5354 // We need to unlock FINAL_BLOCKER when finished.
5357 Write_after_input_sections_task::locks(Task_locker
* tl
)
5359 tl
->add(this, this->final_blocker_
);
5365 Write_after_input_sections_task::run(Workqueue
*)
5367 this->layout_
->write_sections_after_input_sections(this->of_
);
5370 // Close_task_runner methods.
5372 // Run the task--close the file.
5375 Close_task_runner::run(Workqueue
*, const Task
*)
5377 // If we need to compute a checksum for the BUILD if, we do so here.
5378 this->layout_
->write_build_id(this->of_
);
5380 // If we've been asked to create a binary file, we do so here.
5381 if (this->options_
->oformat_enum() != General_options::OBJECT_FORMAT_ELF
)
5382 this->layout_
->write_binary(this->of_
);
5387 // Instantiate the templates we need. We could use the configure
5388 // script to restrict this to only the ones for implemented targets.
5390 #ifdef HAVE_TARGET_32_LITTLE
5393 Layout::init_fixed_output_section
<32, false>(
5395 elfcpp::Shdr
<32, false>& shdr
);
5398 #ifdef HAVE_TARGET_32_BIG
5401 Layout::init_fixed_output_section
<32, true>(
5403 elfcpp::Shdr
<32, true>& shdr
);
5406 #ifdef HAVE_TARGET_64_LITTLE
5409 Layout::init_fixed_output_section
<64, false>(
5411 elfcpp::Shdr
<64, false>& shdr
);
5414 #ifdef HAVE_TARGET_64_BIG
5417 Layout::init_fixed_output_section
<64, true>(
5419 elfcpp::Shdr
<64, true>& shdr
);
5422 #ifdef HAVE_TARGET_32_LITTLE
5425 Layout::layout
<32, false>(Sized_relobj_file
<32, false>* object
,
5428 const elfcpp::Shdr
<32, false>& shdr
,
5429 unsigned int, unsigned int, off_t
*);
5432 #ifdef HAVE_TARGET_32_BIG
5435 Layout::layout
<32, true>(Sized_relobj_file
<32, true>* object
,
5438 const elfcpp::Shdr
<32, true>& shdr
,
5439 unsigned int, unsigned int, off_t
*);
5442 #ifdef HAVE_TARGET_64_LITTLE
5445 Layout::layout
<64, false>(Sized_relobj_file
<64, false>* object
,
5448 const elfcpp::Shdr
<64, false>& shdr
,
5449 unsigned int, unsigned int, off_t
*);
5452 #ifdef HAVE_TARGET_64_BIG
5455 Layout::layout
<64, true>(Sized_relobj_file
<64, true>* object
,
5458 const elfcpp::Shdr
<64, true>& shdr
,
5459 unsigned int, unsigned int, off_t
*);
5462 #ifdef HAVE_TARGET_32_LITTLE
5465 Layout::layout_reloc
<32, false>(Sized_relobj_file
<32, false>* object
,
5466 unsigned int reloc_shndx
,
5467 const elfcpp::Shdr
<32, false>& shdr
,
5468 Output_section
* data_section
,
5469 Relocatable_relocs
* rr
);
5472 #ifdef HAVE_TARGET_32_BIG
5475 Layout::layout_reloc
<32, true>(Sized_relobj_file
<32, true>* object
,
5476 unsigned int reloc_shndx
,
5477 const elfcpp::Shdr
<32, true>& shdr
,
5478 Output_section
* data_section
,
5479 Relocatable_relocs
* rr
);
5482 #ifdef HAVE_TARGET_64_LITTLE
5485 Layout::layout_reloc
<64, false>(Sized_relobj_file
<64, false>* object
,
5486 unsigned int reloc_shndx
,
5487 const elfcpp::Shdr
<64, false>& shdr
,
5488 Output_section
* data_section
,
5489 Relocatable_relocs
* rr
);
5492 #ifdef HAVE_TARGET_64_BIG
5495 Layout::layout_reloc
<64, true>(Sized_relobj_file
<64, true>* object
,
5496 unsigned int reloc_shndx
,
5497 const elfcpp::Shdr
<64, true>& shdr
,
5498 Output_section
* data_section
,
5499 Relocatable_relocs
* rr
);
5502 #ifdef HAVE_TARGET_32_LITTLE
5505 Layout::layout_group
<32, false>(Symbol_table
* symtab
,
5506 Sized_relobj_file
<32, false>* object
,
5508 const char* group_section_name
,
5509 const char* signature
,
5510 const elfcpp::Shdr
<32, false>& shdr
,
5511 elfcpp::Elf_Word flags
,
5512 std::vector
<unsigned int>* shndxes
);
5515 #ifdef HAVE_TARGET_32_BIG
5518 Layout::layout_group
<32, true>(Symbol_table
* symtab
,
5519 Sized_relobj_file
<32, true>* object
,
5521 const char* group_section_name
,
5522 const char* signature
,
5523 const elfcpp::Shdr
<32, true>& shdr
,
5524 elfcpp::Elf_Word flags
,
5525 std::vector
<unsigned int>* shndxes
);
5528 #ifdef HAVE_TARGET_64_LITTLE
5531 Layout::layout_group
<64, false>(Symbol_table
* symtab
,
5532 Sized_relobj_file
<64, false>* object
,
5534 const char* group_section_name
,
5535 const char* signature
,
5536 const elfcpp::Shdr
<64, false>& shdr
,
5537 elfcpp::Elf_Word flags
,
5538 std::vector
<unsigned int>* shndxes
);
5541 #ifdef HAVE_TARGET_64_BIG
5544 Layout::layout_group
<64, true>(Symbol_table
* symtab
,
5545 Sized_relobj_file
<64, true>* object
,
5547 const char* group_section_name
,
5548 const char* signature
,
5549 const elfcpp::Shdr
<64, true>& shdr
,
5550 elfcpp::Elf_Word flags
,
5551 std::vector
<unsigned int>* shndxes
);
5554 #ifdef HAVE_TARGET_32_LITTLE
5557 Layout::layout_eh_frame
<32, false>(Sized_relobj_file
<32, false>* object
,
5558 const unsigned char* symbols
,
5560 const unsigned char* symbol_names
,
5561 off_t symbol_names_size
,
5563 const elfcpp::Shdr
<32, false>& shdr
,
5564 unsigned int reloc_shndx
,
5565 unsigned int reloc_type
,
5569 #ifdef HAVE_TARGET_32_BIG
5572 Layout::layout_eh_frame
<32, true>(Sized_relobj_file
<32, true>* object
,
5573 const unsigned char* symbols
,
5575 const unsigned char* symbol_names
,
5576 off_t symbol_names_size
,
5578 const elfcpp::Shdr
<32, true>& shdr
,
5579 unsigned int reloc_shndx
,
5580 unsigned int reloc_type
,
5584 #ifdef HAVE_TARGET_64_LITTLE
5587 Layout::layout_eh_frame
<64, false>(Sized_relobj_file
<64, false>* object
,
5588 const unsigned char* symbols
,
5590 const unsigned char* symbol_names
,
5591 off_t symbol_names_size
,
5593 const elfcpp::Shdr
<64, false>& shdr
,
5594 unsigned int reloc_shndx
,
5595 unsigned int reloc_type
,
5599 #ifdef HAVE_TARGET_64_BIG
5602 Layout::layout_eh_frame
<64, true>(Sized_relobj_file
<64, true>* object
,
5603 const unsigned char* symbols
,
5605 const unsigned char* symbol_names
,
5606 off_t symbol_names_size
,
5608 const elfcpp::Shdr
<64, true>& shdr
,
5609 unsigned int reloc_shndx
,
5610 unsigned int reloc_type
,
5614 #ifdef HAVE_TARGET_32_LITTLE
5617 Layout::add_to_gdb_index(bool is_type_unit
,
5618 Sized_relobj
<32, false>* object
,
5619 const unsigned char* symbols
,
5622 unsigned int reloc_shndx
,
5623 unsigned int reloc_type
);
5626 #ifdef HAVE_TARGET_32_BIG
5629 Layout::add_to_gdb_index(bool is_type_unit
,
5630 Sized_relobj
<32, true>* object
,
5631 const unsigned char* symbols
,
5634 unsigned int reloc_shndx
,
5635 unsigned int reloc_type
);
5638 #ifdef HAVE_TARGET_64_LITTLE
5641 Layout::add_to_gdb_index(bool is_type_unit
,
5642 Sized_relobj
<64, false>* object
,
5643 const unsigned char* symbols
,
5646 unsigned int reloc_shndx
,
5647 unsigned int reloc_type
);
5650 #ifdef HAVE_TARGET_64_BIG
5653 Layout::add_to_gdb_index(bool is_type_unit
,
5654 Sized_relobj
<64, true>* object
,
5655 const unsigned char* symbols
,
5658 unsigned int reloc_shndx
,
5659 unsigned int reloc_type
);
5662 } // End namespace gold.