layout.h revision 1.1.1.9
1// layout.h -- lay out output file sections for gold -*- C++ -*- 2 3// Copyright (C) 2006-2022 Free Software Foundation, Inc. 4// Written by Ian Lance Taylor <iant@google.com>. 5 6// This file is part of gold. 7 8// This program is free software; you can redistribute it and/or modify 9// it under the terms of the GNU General Public License as published by 10// the Free Software Foundation; either version 3 of the License, or 11// (at your option) any later version. 12 13// This program is distributed in the hope that it will be useful, 14// but WITHOUT ANY WARRANTY; without even the implied warranty of 15// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16// GNU General Public License for more details. 17 18// You should have received a copy of the GNU General Public License 19// along with this program; if not, write to the Free Software 20// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 21// MA 02110-1301, USA. 22 23#ifndef GOLD_LAYOUT_H 24#define GOLD_LAYOUT_H 25 26#include <cstring> 27#include <list> 28#include <map> 29#include <string> 30#include <utility> 31#include <vector> 32 33#include "script.h" 34#include "workqueue.h" 35#include "object.h" 36#include "dynobj.h" 37#include "stringpool.h" 38 39namespace gold 40{ 41 42class General_options; 43class Incremental_inputs; 44class Incremental_binary; 45class Input_objects; 46class Mapfile; 47class Symbol_table; 48class Output_section_data; 49class Output_section; 50class Output_section_headers; 51class Output_segment_headers; 52class Output_file_header; 53class Output_segment; 54class Output_data; 55class Output_data_reloc_generic; 56class Output_data_dynamic; 57class Output_symtab_xindex; 58class Output_reduced_debug_abbrev_section; 59class Output_reduced_debug_info_section; 60class Eh_frame; 61class Gdb_index; 62class Target; 63struct Timespec; 64 65// Return TRUE if SECNAME is the name of a compressed debug section. 66extern bool 67is_compressed_debug_section(const char* secname); 68 69// Return the name of the corresponding uncompressed debug section. 70extern std::string 71corresponding_uncompressed_section_name(std::string secname); 72 73// Maintain a list of free space within a section, segment, or file. 74// Used for incremental update links. 75 76class Free_list 77{ 78 public: 79 struct Free_list_node 80 { 81 Free_list_node(off_t start, off_t end) 82 : start_(start), end_(end) 83 { } 84 off_t start_; 85 off_t end_; 86 }; 87 typedef std::list<Free_list_node>::const_iterator Const_iterator; 88 89 Free_list() 90 : list_(), last_remove_(list_.begin()), extend_(false), length_(0), 91 min_hole_(0) 92 { } 93 94 // Initialize the free list for a section of length LEN. 95 // If EXTEND is true, free space may be allocated past the end. 96 void 97 init(off_t len, bool extend); 98 99 // Set the minimum hole size that is allowed when allocating 100 // from the free list. 101 void 102 set_min_hole_size(off_t min_hole) 103 { this->min_hole_ = min_hole; } 104 105 // Remove a chunk from the free list. 106 void 107 remove(off_t start, off_t end); 108 109 // Allocate a chunk of space from the free list of length LEN, 110 // with alignment ALIGN, and minimum offset MINOFF. 111 off_t 112 allocate(off_t len, uint64_t align, off_t minoff); 113 114 // Return an iterator for the beginning of the free list. 115 Const_iterator 116 begin() const 117 { return this->list_.begin(); } 118 119 // Return an iterator for the end of the free list. 120 Const_iterator 121 end() const 122 { return this->list_.end(); } 123 124 // Dump the free list (for debugging). 125 void 126 dump(); 127 128 // Print usage statistics. 129 static void 130 print_stats(); 131 132 private: 133 typedef std::list<Free_list_node>::iterator Iterator; 134 135 // The free list. 136 std::list<Free_list_node> list_; 137 138 // The last node visited during a remove operation. 139 Iterator last_remove_; 140 141 // Whether we can extend past the original length. 142 bool extend_; 143 144 // The total length of the section, segment, or file. 145 off_t length_; 146 147 // The minimum hole size allowed. When allocating from the free list, 148 // we must not leave a hole smaller than this. 149 off_t min_hole_; 150 151 // Statistics: 152 // The total number of free lists used. 153 static unsigned int num_lists; 154 // The total number of free list nodes used. 155 static unsigned int num_nodes; 156 // The total number of calls to Free_list::remove. 157 static unsigned int num_removes; 158 // The total number of nodes visited during calls to Free_list::remove. 159 static unsigned int num_remove_visits; 160 // The total number of calls to Free_list::allocate. 161 static unsigned int num_allocates; 162 // The total number of nodes visited during calls to Free_list::allocate. 163 static unsigned int num_allocate_visits; 164}; 165 166// This task function handles mapping the input sections to output 167// sections and laying them out in memory. 168 169class Layout_task_runner : public Task_function_runner 170{ 171 public: 172 // OPTIONS is the command line options, INPUT_OBJECTS is the list of 173 // input objects, SYMTAB is the symbol table, LAYOUT is the layout 174 // object. 175 Layout_task_runner(const General_options& options, 176 const Input_objects* input_objects, 177 Symbol_table* symtab, 178 Target* target, 179 Layout* layout, 180 Mapfile* mapfile) 181 : options_(options), input_objects_(input_objects), symtab_(symtab), 182 target_(target), layout_(layout), mapfile_(mapfile) 183 { } 184 185 // Run the operation. 186 void 187 run(Workqueue*, const Task*); 188 189 private: 190 Layout_task_runner(const Layout_task_runner&); 191 Layout_task_runner& operator=(const Layout_task_runner&); 192 193 const General_options& options_; 194 const Input_objects* input_objects_; 195 Symbol_table* symtab_; 196 Target* target_; 197 Layout* layout_; 198 Mapfile* mapfile_; 199}; 200 201// This class holds information about the comdat group or 202// .gnu.linkonce section that will be kept for a given signature. 203 204class Kept_section 205{ 206 private: 207 // For a comdat group, we build a mapping from the name of each 208 // section in the group to the section index and the size in object. 209 // When we discard a group in some other object file, we use this 210 // map to figure out which kept section the discarded section is 211 // associated with. We then use that mapping when processing relocs 212 // against discarded sections. 213 struct Comdat_section_info 214 { 215 // The section index. 216 unsigned int shndx; 217 // The section size. 218 uint64_t size; 219 220 Comdat_section_info(unsigned int a_shndx, uint64_t a_size) 221 : shndx(a_shndx), size(a_size) 222 { } 223 }; 224 225 // Most comdat groups have only one or two sections, so we use a 226 // std::map rather than an Unordered_map to optimize for that case 227 // without paying too heavily for groups with more sections. 228 typedef std::map<std::string, Comdat_section_info> Comdat_group; 229 230 public: 231 Kept_section() 232 : object_(NULL), shndx_(0), is_comdat_(false), is_group_name_(false) 233 { this->u_.linkonce_size = 0; } 234 235 // We need to support copies for the signature map in the Layout 236 // object, but we should never copy an object after it has been 237 // marked as a comdat section. 238 Kept_section(const Kept_section& k) 239 : object_(k.object_), shndx_(k.shndx_), is_comdat_(false), 240 is_group_name_(k.is_group_name_) 241 { 242 gold_assert(!k.is_comdat_); 243 this->u_.linkonce_size = 0; 244 } 245 246 ~Kept_section() 247 { 248 if (this->is_comdat_) 249 delete this->u_.group_sections; 250 } 251 252 // The object where this section lives. 253 Relobj* 254 object() const 255 { return this->object_; } 256 257 // Set the object. 258 void 259 set_object(Relobj* object) 260 { 261 gold_assert(this->object_ == NULL); 262 this->object_ = object; 263 } 264 265 // The section index. 266 unsigned int 267 shndx() const 268 { return this->shndx_; } 269 270 // Set the section index. 271 void 272 set_shndx(unsigned int shndx) 273 { 274 gold_assert(this->shndx_ == 0); 275 this->shndx_ = shndx; 276 } 277 278 // Whether this is a comdat group. 279 bool 280 is_comdat() const 281 { return this->is_comdat_; } 282 283 // Set that this is a comdat group. 284 void 285 set_is_comdat() 286 { 287 gold_assert(!this->is_comdat_); 288 this->is_comdat_ = true; 289 this->u_.group_sections = new Comdat_group(); 290 } 291 292 // Whether this is associated with the name of a group or section 293 // rather than the symbol name derived from a linkonce section. 294 bool 295 is_group_name() const 296 { return this->is_group_name_; } 297 298 // Note that this represents a comdat group rather than a single 299 // linkonce section. 300 void 301 set_is_group_name() 302 { this->is_group_name_ = true; } 303 304 // Add a section to the group list. 305 void 306 add_comdat_section(const std::string& name, unsigned int shndx, 307 uint64_t size) 308 { 309 gold_assert(this->is_comdat_); 310 Comdat_section_info sinfo(shndx, size); 311 this->u_.group_sections->insert(std::make_pair(name, sinfo)); 312 } 313 314 // Look for a section name in the group list, and return whether it 315 // was found. If found, returns the section index and size. 316 bool 317 find_comdat_section(const std::string& name, unsigned int* pshndx, 318 uint64_t* psize) const 319 { 320 gold_assert(this->is_comdat_); 321 Comdat_group::const_iterator p = this->u_.group_sections->find(name); 322 if (p == this->u_.group_sections->end()) 323 return false; 324 *pshndx = p->second.shndx; 325 *psize = p->second.size; 326 return true; 327 } 328 329 // If there is only one section in the group list, return true, and 330 // return the section index and size. 331 bool 332 find_single_comdat_section(unsigned int* pshndx, uint64_t* psize) const 333 { 334 gold_assert(this->is_comdat_); 335 if (this->u_.group_sections->size() != 1) 336 return false; 337 Comdat_group::const_iterator p = this->u_.group_sections->begin(); 338 *pshndx = p->second.shndx; 339 *psize = p->second.size; 340 return true; 341 } 342 343 // Return the size of a linkonce section. 344 uint64_t 345 linkonce_size() const 346 { 347 gold_assert(!this->is_comdat_); 348 return this->u_.linkonce_size; 349 } 350 351 // Set the size of a linkonce section. 352 void 353 set_linkonce_size(uint64_t size) 354 { 355 gold_assert(!this->is_comdat_); 356 this->u_.linkonce_size = size; 357 } 358 359 private: 360 // No assignment. 361 Kept_section& operator=(const Kept_section&); 362 363 // The object containing the comdat group or .gnu.linkonce section. 364 Relobj* object_; 365 // Index of the group section for comdats and the section itself for 366 // .gnu.linkonce. 367 unsigned int shndx_; 368 // True if this is for a comdat group rather than a .gnu.linkonce 369 // section. 370 bool is_comdat_; 371 // The Kept_sections are values of a mapping, that maps names to 372 // them. This field is true if this struct is associated with the 373 // name of a comdat or .gnu.linkonce, false if it is associated with 374 // the name of a symbol obtained from the .gnu.linkonce.* name 375 // through some heuristics. 376 bool is_group_name_; 377 union 378 { 379 // If the is_comdat_ field is true, this holds a map from names of 380 // the sections in the group to section indexes in object_ and to 381 // section sizes. 382 Comdat_group* group_sections; 383 // If the is_comdat_ field is false, this holds the size of the 384 // single section. 385 uint64_t linkonce_size; 386 } u_; 387}; 388 389// The ordering for output sections. This controls how output 390// sections are ordered within a PT_LOAD output segment. 391 392enum Output_section_order 393{ 394 // Unspecified. Used for non-load segments. Also used for the file 395 // and segment headers. 396 ORDER_INVALID, 397 398 // The PT_INTERP section should come first, so that the dynamic 399 // linker can pick it up quickly. 400 ORDER_INTERP, 401 402 // The .note.gnu.property section comes next so that the PT_NOTE 403 // segment is on the first page of the executable and it won't be 404 // placed between other note sections with different alignments. 405 ORDER_PROPERTY_NOTE, 406 407 // Loadable read-only note sections come after the .note.gnu.property 408 // section. 409 ORDER_RO_NOTE, 410 411 // Put read-only sections used by the dynamic linker early in the 412 // executable to minimize paging. 413 ORDER_DYNAMIC_LINKER, 414 415 // Put reloc sections used by the dynamic linker after other 416 // sections used by the dynamic linker; otherwise, objcopy and strip 417 // get confused. 418 ORDER_DYNAMIC_RELOCS, 419 420 // Put the PLT reloc section after the other dynamic relocs; 421 // otherwise, prelink gets confused. 422 ORDER_DYNAMIC_PLT_RELOCS, 423 424 // The .init section. 425 ORDER_INIT, 426 427 // The PLT. 428 ORDER_PLT, 429 430 // The hot text sections, prefixed by .text.hot. 431 ORDER_TEXT_HOT, 432 433 // The regular text sections. 434 ORDER_TEXT, 435 436 // The startup text sections, prefixed by .text.startup. 437 ORDER_TEXT_STARTUP, 438 439 // The startup text sections, prefixed by .text.startup. 440 ORDER_TEXT_EXIT, 441 442 // The unlikely text sections, prefixed by .text.unlikely. 443 ORDER_TEXT_UNLIKELY, 444 445 // The .fini section. 446 ORDER_FINI, 447 448 // The read-only sections. 449 ORDER_READONLY, 450 451 // The exception frame sections. 452 ORDER_EHFRAME, 453 454 // The TLS sections come first in the data section. 455 ORDER_TLS_DATA, 456 ORDER_TLS_BSS, 457 458 // Local RELRO (read-only after relocation) sections come before 459 // non-local RELRO sections. This data will be fully resolved by 460 // the prelinker. 461 ORDER_RELRO_LOCAL, 462 463 // Non-local RELRO sections are grouped together after local RELRO 464 // sections. All RELRO sections must be adjacent so that they can 465 // all be put into a PT_GNU_RELRO segment. 466 ORDER_RELRO, 467 468 // We permit marking exactly one output section as the last RELRO 469 // section. We do this so that the read-only GOT can be adjacent to 470 // the writable GOT. 471 ORDER_RELRO_LAST, 472 473 // Similarly, we permit marking exactly one output section as the 474 // first non-RELRO section. 475 ORDER_NON_RELRO_FIRST, 476 477 // The regular data sections come after the RELRO sections. 478 ORDER_DATA, 479 480 // Large data sections normally go in large data segments. 481 ORDER_LARGE_DATA, 482 483 // Group writable notes so that we can have a single PT_NOTE 484 // segment. 485 ORDER_RW_NOTE, 486 487 // The small data sections must be at the end of the data sections, 488 // so that they can be adjacent to the small BSS sections. 489 ORDER_SMALL_DATA, 490 491 // The BSS sections start here. 492 493 // The small BSS sections must be at the start of the BSS sections, 494 // so that they can be adjacent to the small data sections. 495 ORDER_SMALL_BSS, 496 497 // The regular BSS sections. 498 ORDER_BSS, 499 500 // The large BSS sections come after the other BSS sections. 501 ORDER_LARGE_BSS, 502 503 // Maximum value. 504 ORDER_MAX 505}; 506 507// This class handles the details of laying out input sections. 508 509class Layout 510{ 511 public: 512 Layout(int number_of_input_files, Script_options*); 513 514 ~Layout() 515 { 516 delete this->relaxation_debug_check_; 517 delete this->segment_states_; 518 } 519 520 // For incremental links, record the base file to be modified. 521 void 522 set_incremental_base(Incremental_binary* base); 523 524 Incremental_binary* 525 incremental_base() 526 { return this->incremental_base_; } 527 528 // For incremental links, record the initial fixed layout of a section 529 // from the base file, and return a pointer to the Output_section. 530 template<int size, bool big_endian> 531 Output_section* 532 init_fixed_output_section(const char*, elfcpp::Shdr<size, big_endian>&); 533 534 // Given an input section SHNDX, named NAME, with data in SHDR, from 535 // the object file OBJECT, return the output section where this 536 // input section should go. RELOC_SHNDX is the index of a 537 // relocation section which applies to this section, or 0 if none, 538 // or -1U if more than one. RELOC_TYPE is the type of the 539 // relocation section if there is one. Set *OFFSET to the offset 540 // within the output section. 541 template<int size, bool big_endian> 542 Output_section* 543 layout(Sized_relobj_file<size, big_endian> *object, unsigned int shndx, 544 const char* name, const elfcpp::Shdr<size, big_endian>& shdr, 545 unsigned int sh_type, unsigned int reloc_shndx, 546 unsigned int reloc_type, off_t* offset); 547 548 std::map<Section_id, unsigned int>* 549 get_section_order_map() 550 { return &this->section_order_map_; } 551 552 // Struct to store segment info when mapping some input sections to 553 // unique segments using linker plugins. Mapping an input section to 554 // a unique segment is done by first placing such input sections in 555 // unique output sections and then mapping the output section to a 556 // unique segment. NAME is the name of the output section. FLAGS 557 // and ALIGN are the extra flags and alignment of the segment. 558 struct Unique_segment_info 559 { 560 // Identifier for the segment. ELF segments don't have names. This 561 // is used as the name of the output section mapped to the segment. 562 const char* name; 563 // Additional segment flags. 564 uint64_t flags; 565 // Segment alignment. 566 uint64_t align; 567 }; 568 569 // Mapping from input section to segment. 570 typedef std::map<Const_section_id, Unique_segment_info*> 571 Section_segment_map; 572 573 // Maps section SECN to SEGMENT s. 574 void 575 insert_section_segment_map(Const_section_id secn, Unique_segment_info *s); 576 577 // Some input sections require special ordering, for compatibility 578 // with GNU ld. Given the name of an input section, return -1 if it 579 // does not require special ordering. Otherwise, return the index 580 // by which it should be ordered compared to other input sections 581 // that require special ordering. 582 static int 583 special_ordering_of_input_section(const char* name); 584 585 bool 586 is_section_ordering_specified() 587 { return this->section_ordering_specified_; } 588 589 void 590 set_section_ordering_specified() 591 { this->section_ordering_specified_ = true; } 592 593 bool 594 is_unique_segment_for_sections_specified() const 595 { return this->unique_segment_for_sections_specified_; } 596 597 void 598 set_unique_segment_for_sections_specified() 599 { this->unique_segment_for_sections_specified_ = true; } 600 601 bool 602 is_lto_slim_object () const 603 { return this->lto_slim_object_; } 604 605 void 606 set_lto_slim_object () 607 { this->lto_slim_object_ = true; } 608 609 // For incremental updates, allocate a block of memory from the 610 // free list. Find a block starting at or after MINOFF. 611 off_t 612 allocate(off_t len, uint64_t align, off_t minoff) 613 { return this->free_list_.allocate(len, align, minoff); } 614 615 unsigned int 616 find_section_order_index(const std::string&); 617 618 // Read the sequence of input sections from the file specified with 619 // linker option --section-ordering-file. 620 void 621 read_layout_from_file(); 622 623 // Layout an input reloc section when doing a relocatable link. The 624 // section is RELOC_SHNDX in OBJECT, with data in SHDR. 625 // DATA_SECTION is the reloc section to which it refers. RR is the 626 // relocatable information. 627 template<int size, bool big_endian> 628 Output_section* 629 layout_reloc(Sized_relobj_file<size, big_endian>* object, 630 unsigned int reloc_shndx, 631 const elfcpp::Shdr<size, big_endian>& shdr, 632 Output_section* data_section, 633 Relocatable_relocs* rr); 634 635 // Layout a group section when doing a relocatable link. 636 template<int size, bool big_endian> 637 void 638 layout_group(Symbol_table* symtab, 639 Sized_relobj_file<size, big_endian>* object, 640 unsigned int group_shndx, 641 const char* group_section_name, 642 const char* signature, 643 const elfcpp::Shdr<size, big_endian>& shdr, 644 elfcpp::Elf_Word flags, 645 std::vector<unsigned int>* shndxes); 646 647 // Like layout, only for exception frame sections. OBJECT is an 648 // object file. SYMBOLS is the contents of the symbol table 649 // section, with size SYMBOLS_SIZE. SYMBOL_NAMES is the contents of 650 // the symbol name section, with size SYMBOL_NAMES_SIZE. SHNDX is a 651 // .eh_frame section in OBJECT. SHDR is the section header. 652 // RELOC_SHNDX is the index of a relocation section which applies to 653 // this section, or 0 if none, or -1U if more than one. RELOC_TYPE 654 // is the type of the relocation section if there is one. This 655 // returns the output section, and sets *OFFSET to the offset. 656 template<int size, bool big_endian> 657 Output_section* 658 layout_eh_frame(Sized_relobj_file<size, big_endian>* object, 659 const unsigned char* symbols, 660 off_t symbols_size, 661 const unsigned char* symbol_names, 662 off_t symbol_names_size, 663 unsigned int shndx, 664 const elfcpp::Shdr<size, big_endian>& shdr, 665 unsigned int reloc_shndx, unsigned int reloc_type, 666 off_t* offset); 667 668 // After processing all input files, we call this to make sure that 669 // the optimized .eh_frame sections have been added to the output 670 // section. 671 void 672 finalize_eh_frame_section(); 673 674 // Add .eh_frame information for a PLT. The FDE must start with a 675 // 4-byte PC-relative reference to the start of the PLT, followed by 676 // a 4-byte size of PLT. 677 void 678 add_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data, 679 size_t cie_length, const unsigned char* fde_data, 680 size_t fde_length); 681 682 // Remove all post-map .eh_frame information for a PLT. 683 void 684 remove_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data, 685 size_t cie_length); 686 687 // Scan a .debug_info or .debug_types section, and add summary 688 // information to the .gdb_index section. 689 template<int size, bool big_endian> 690 void 691 add_to_gdb_index(bool is_type_unit, 692 Sized_relobj<size, big_endian>* object, 693 const unsigned char* symbols, 694 off_t symbols_size, 695 unsigned int shndx, 696 unsigned int reloc_shndx, 697 unsigned int reloc_type); 698 699 // Handle a GNU stack note. This is called once per input object 700 // file. SEEN_GNU_STACK is true if the object file has a 701 // .note.GNU-stack section. GNU_STACK_FLAGS is the section flags 702 // from that section if there was one. 703 void 704 layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags, 705 const Object*); 706 707 // Layout a .note.gnu.property section. 708 void 709 layout_gnu_property(unsigned int note_type, 710 unsigned int pr_type, 711 size_t pr_datasz, 712 const unsigned char* pr_data, 713 const Object* object); 714 715 // Merge per-object properties with program properties. 716 void 717 merge_gnu_properties(const Object* object); 718 719 // Add a target-specific property for the output .note.gnu.property section. 720 void 721 add_gnu_property(unsigned int note_type, 722 unsigned int pr_type, 723 size_t pr_datasz, 724 const unsigned char* pr_data); 725 726 // Add an Output_section_data to the layout. This is used for 727 // special sections like the GOT section. ORDER is where the 728 // section should wind up in the output segment. IS_RELRO is true 729 // for relro sections. 730 Output_section* 731 add_output_section_data(const char* name, elfcpp::Elf_Word type, 732 elfcpp::Elf_Xword flags, 733 Output_section_data*, Output_section_order order, 734 bool is_relro); 735 736 // Increase the size of the relro segment by this much. 737 void 738 increase_relro(unsigned int s) 739 { this->increase_relro_ += s; } 740 741 // Create dynamic sections if necessary. 742 void 743 create_initial_dynamic_sections(Symbol_table*); 744 745 // Define __start and __stop symbols for output sections. 746 void 747 define_section_symbols(Symbol_table*); 748 749 // Create automatic note sections. 750 void 751 create_notes(); 752 753 // Create sections for linker scripts. 754 void 755 create_script_sections() 756 { this->script_options_->create_script_sections(this); } 757 758 // Define symbols from any linker script. 759 void 760 define_script_symbols(Symbol_table* symtab) 761 { this->script_options_->add_symbols_to_table(symtab); } 762 763 // Define symbols for group signatures. 764 void 765 define_group_signatures(Symbol_table*); 766 767 // Return the Stringpool used for symbol names. 768 const Stringpool* 769 sympool() const 770 { return &this->sympool_; } 771 772 // Return the Stringpool used for dynamic symbol names and dynamic 773 // tags. 774 const Stringpool* 775 dynpool() const 776 { return &this->dynpool_; } 777 778 // Return the .dynamic output section. This is only valid after the 779 // layout has been finalized. 780 Output_section* 781 dynamic_section() const 782 { return this->dynamic_section_; } 783 784 // Return the symtab_xindex section used to hold large section 785 // indexes for the normal symbol table. 786 Output_symtab_xindex* 787 symtab_xindex() const 788 { return this->symtab_xindex_; } 789 790 // Return the dynsym_xindex section used to hold large section 791 // indexes for the dynamic symbol table. 792 Output_symtab_xindex* 793 dynsym_xindex() const 794 { return this->dynsym_xindex_; } 795 796 // Return whether a section is a .gnu.linkonce section, given the 797 // section name. 798 static inline bool 799 is_linkonce(const char* name) 800 { return strncmp(name, ".gnu.linkonce", sizeof(".gnu.linkonce") - 1) == 0; } 801 802 // Whether we have added an input section. 803 bool 804 have_added_input_section() const 805 { return this->have_added_input_section_; } 806 807 // Return true if a section is a debugging section. 808 static inline bool 809 is_debug_info_section(const char* name) 810 { 811 // Debugging sections can only be recognized by name. 812 return (strncmp(name, ".debug", sizeof(".debug") - 1) == 0 813 || strncmp(name, ".zdebug", sizeof(".zdebug") - 1) == 0 814 || strncmp(name, ".gnu.linkonce.wi.", 815 sizeof(".gnu.linkonce.wi.") - 1) == 0 816 || strncmp(name, ".line", sizeof(".line") - 1) == 0 817 || strncmp(name, ".stab", sizeof(".stab") - 1) == 0 818 || strncmp(name, ".pdr", sizeof(".pdr") - 1) == 0); 819 } 820 821 // Return true if RELOBJ is an input file whose base name matches 822 // FILE_NAME. The base name must have an extension of ".o", and 823 // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o". 824 static bool 825 match_file_name(const Relobj* relobj, const char* file_name); 826 827 // Return whether section SHNDX in RELOBJ is a .ctors/.dtors section 828 // with more than one word being mapped to a .init_array/.fini_array 829 // section. 830 bool 831 is_ctors_in_init_array(Relobj* relobj, unsigned int shndx) const; 832 833 // Check if a comdat group or .gnu.linkonce section with the given 834 // NAME is selected for the link. If there is already a section, 835 // *KEPT_SECTION is set to point to the signature and the function 836 // returns false. Otherwise, OBJECT, SHNDX,IS_COMDAT, and 837 // IS_GROUP_NAME are recorded for this NAME in the layout object, 838 // *KEPT_SECTION is set to the internal copy and the function return 839 // false. 840 bool 841 find_or_add_kept_section(const std::string& name, Relobj* object, 842 unsigned int shndx, bool is_comdat, 843 bool is_group_name, Kept_section** kept_section); 844 845 // Finalize the layout after all the input sections have been added. 846 off_t 847 finalize(const Input_objects*, Symbol_table*, Target*, const Task*); 848 849 // Return whether any sections require postprocessing. 850 bool 851 any_postprocessing_sections() const 852 { return this->any_postprocessing_sections_; } 853 854 // Return the size of the output file. 855 off_t 856 output_file_size() const 857 { return this->output_file_size_; } 858 859 // Return the TLS segment. This will return NULL if there isn't 860 // one. 861 Output_segment* 862 tls_segment() const 863 { return this->tls_segment_; } 864 865 // Return the normal symbol table. 866 Output_section* 867 symtab_section() const 868 { 869 gold_assert(this->symtab_section_ != NULL); 870 return this->symtab_section_; 871 } 872 873 // Return the file offset of the normal symbol table. 874 off_t 875 symtab_section_offset() const; 876 877 // Return the section index of the normal symbol tabl.e 878 unsigned int 879 symtab_section_shndx() const; 880 881 // Return the dynamic symbol table. 882 Output_section* 883 dynsym_section() const 884 { 885 gold_assert(this->dynsym_section_ != NULL); 886 return this->dynsym_section_; 887 } 888 889 // Return the dynamic tags. 890 Output_data_dynamic* 891 dynamic_data() const 892 { return this->dynamic_data_; } 893 894 // Write out the output sections. 895 void 896 write_output_sections(Output_file* of) const; 897 898 // Write out data not associated with an input file or the symbol 899 // table. 900 void 901 write_data(const Symbol_table*, Output_file*) const; 902 903 // Write out output sections which can not be written until all the 904 // input sections are complete. 905 void 906 write_sections_after_input_sections(Output_file* of); 907 908 // Return an output section named NAME, or NULL if there is none. 909 Output_section* 910 find_output_section(const char* name) const; 911 912 // Return an output segment of type TYPE, with segment flags SET set 913 // and segment flags CLEAR clear. Return NULL if there is none. 914 Output_segment* 915 find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set, 916 elfcpp::Elf_Word clear) const; 917 918 // Return the number of segments we expect to produce. 919 size_t 920 expected_segment_count() const; 921 922 // Set a flag to indicate that an object file uses the static TLS model. 923 void 924 set_has_static_tls() 925 { this->has_static_tls_ = true; } 926 927 // Return true if any object file uses the static TLS model. 928 bool 929 has_static_tls() const 930 { return this->has_static_tls_; } 931 932 // Return the options which may be set by a linker script. 933 Script_options* 934 script_options() 935 { return this->script_options_; } 936 937 const Script_options* 938 script_options() const 939 { return this->script_options_; } 940 941 // Return the object managing inputs in incremental build. NULL in 942 // non-incremental builds. 943 Incremental_inputs* 944 incremental_inputs() const 945 { return this->incremental_inputs_; } 946 947 // For the target-specific code to add dynamic tags which are common 948 // to most targets. 949 void 950 add_target_dynamic_tags(bool use_rel, const Output_data* plt_got, 951 const Output_data* plt_rel, 952 const Output_data_reloc_generic* dyn_rel, 953 bool add_debug, bool dynrel_includes_plt); 954 955 // Add a target-specific dynamic tag with constant value. 956 void 957 add_target_specific_dynamic_tag(elfcpp::DT tag, unsigned int val); 958 959 // Compute and write out the build ID if needed. 960 void 961 write_build_id(Output_file*, unsigned char*, size_t) const; 962 963 // Rewrite output file in binary format. 964 void 965 write_binary(Output_file* in) const; 966 967 // Print output sections to the map file. 968 void 969 print_to_mapfile(Mapfile*) const; 970 971 // Dump statistical information to stderr. 972 void 973 print_stats() const; 974 975 // A list of segments. 976 977 typedef std::vector<Output_segment*> Segment_list; 978 979 // A list of sections. 980 981 typedef std::vector<Output_section*> Section_list; 982 983 // The list of information to write out which is not attached to 984 // either a section or a segment. 985 typedef std::vector<Output_data*> Data_list; 986 987 // Store the allocated sections into the section list. This is used 988 // by the linker script code. 989 void 990 get_allocated_sections(Section_list*) const; 991 992 // Store the executable sections into the section list. 993 void 994 get_executable_sections(Section_list*) const; 995 996 // Make a section for a linker script to hold data. 997 Output_section* 998 make_output_section_for_script(const char* name, 999 Script_sections::Section_type section_type); 1000 1001 // Make a segment. This is used by the linker script code. 1002 Output_segment* 1003 make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags); 1004 1005 // Return the number of segments. 1006 size_t 1007 segment_count() const 1008 { return this->segment_list_.size(); } 1009 1010 // Map from section flags to segment flags. 1011 static elfcpp::Elf_Word 1012 section_flags_to_segment(elfcpp::Elf_Xword flags); 1013 1014 // Attach sections to segments. 1015 void 1016 attach_sections_to_segments(const Target*); 1017 1018 // For relaxation clean up, we need to know output section data created 1019 // from a linker script. 1020 void 1021 new_output_section_data_from_script(Output_section_data* posd) 1022 { 1023 if (this->record_output_section_data_from_script_) 1024 this->script_output_section_data_list_.push_back(posd); 1025 } 1026 1027 // Return section list. 1028 const Section_list& 1029 section_list() const 1030 { return this->section_list_; } 1031 1032 // Returns TRUE iff NAME (an input section from RELOBJ) will 1033 // be mapped to an output section that should be KEPT. 1034 bool 1035 keep_input_section(const Relobj*, const char*); 1036 1037 // Add a special output object that will be recreated afresh 1038 // if there is another relaxation iteration. 1039 void 1040 add_relax_output(Output_data* data) 1041 { this->relax_output_list_.push_back(data); } 1042 1043 // Clear out (and free) everything added by add_relax_output. 1044 void 1045 reset_relax_output(); 1046 1047 private: 1048 Layout(const Layout&); 1049 Layout& operator=(const Layout&); 1050 1051 // Mapping from input section names to output section names. 1052 struct Section_name_mapping 1053 { 1054 const char* from; 1055 int fromlen; 1056 const char* to; 1057 int tolen; 1058 }; 1059 static const Section_name_mapping section_name_mapping[]; 1060 static const int section_name_mapping_count; 1061 static const Section_name_mapping text_section_name_mapping[]; 1062 static const int text_section_name_mapping_count; 1063 1064 // Find section name NAME in map and return the mapped name if found 1065 // with the length set in PLEN. 1066 static const char* match_section_name(const Section_name_mapping* map, 1067 const int count, const char* name, 1068 size_t* plen); 1069 1070 // During a relocatable link, a list of group sections and 1071 // signatures. 1072 struct Group_signature 1073 { 1074 // The group section. 1075 Output_section* section; 1076 // The signature. 1077 const char* signature; 1078 1079 Group_signature() 1080 : section(NULL), signature(NULL) 1081 { } 1082 1083 Group_signature(Output_section* sectiona, const char* signaturea) 1084 : section(sectiona), signature(signaturea) 1085 { } 1086 }; 1087 typedef std::vector<Group_signature> Group_signatures; 1088 1089 // Create a note section, filling in the header. 1090 Output_section* 1091 create_note(const char* name, int note_type, const char* section_name, 1092 size_t descsz, bool allocate, size_t* trailing_padding); 1093 1094 // Create a note section for gnu program properties. 1095 void 1096 create_gnu_properties_note(); 1097 1098 // Create a note section for gold version. 1099 void 1100 create_gold_note(); 1101 1102 // Record whether the stack must be executable, and a user-supplied size. 1103 void 1104 create_stack_segment(); 1105 1106 // Create a build ID note if needed. 1107 void 1108 create_build_id(); 1109 1110 // Link .stab and .stabstr sections. 1111 void 1112 link_stabs_sections(); 1113 1114 // Create .gnu_incremental_inputs and .gnu_incremental_strtab sections needed 1115 // for the next run of incremental linking to check what has changed. 1116 void 1117 create_incremental_info_sections(Symbol_table*); 1118 1119 // Find the first read-only PT_LOAD segment, creating one if 1120 // necessary. 1121 Output_segment* 1122 find_first_load_seg(const Target*); 1123 1124 // Count the local symbols in the regular symbol table and the dynamic 1125 // symbol table, and build the respective string pools. 1126 void 1127 count_local_symbols(const Task*, const Input_objects*); 1128 1129 // Create the output sections for the symbol table. 1130 void 1131 create_symtab_sections(const Input_objects*, Symbol_table*, 1132 unsigned int, off_t*, unsigned int); 1133 1134 // Create the .shstrtab section. 1135 Output_section* 1136 create_shstrtab(); 1137 1138 // Create the section header table. 1139 void 1140 create_shdrs(const Output_section* shstrtab_section, off_t*); 1141 1142 // Create the dynamic symbol table. 1143 void 1144 create_dynamic_symtab(const Input_objects*, Symbol_table*, 1145 Output_section** pdynstr, 1146 unsigned int* plocal_dynamic_count, 1147 unsigned int* pforced_local_dynamic_count, 1148 std::vector<Symbol*>* pdynamic_symbols, 1149 Versions* versions); 1150 1151 // Assign offsets to each local portion of the dynamic symbol table. 1152 void 1153 assign_local_dynsym_offsets(const Input_objects*); 1154 1155 // Finish the .dynamic section and PT_DYNAMIC segment. 1156 void 1157 finish_dynamic_section(const Input_objects*, const Symbol_table*); 1158 1159 // Set the size of the _DYNAMIC symbol. 1160 void 1161 set_dynamic_symbol_size(const Symbol_table*); 1162 1163 // Create the .interp section and PT_INTERP segment. 1164 void 1165 create_interp(const Target* target); 1166 1167 // Create the version sections. 1168 void 1169 create_version_sections(const Versions*, 1170 const Symbol_table*, 1171 unsigned int local_symcount, 1172 const std::vector<Symbol*>& dynamic_symbols, 1173 const Output_section* dynstr); 1174 1175 template<int size, bool big_endian> 1176 void 1177 sized_create_version_sections(const Versions* versions, 1178 const Symbol_table*, 1179 unsigned int local_symcount, 1180 const std::vector<Symbol*>& dynamic_symbols, 1181 const Output_section* dynstr); 1182 1183 // Return whether to include this section in the link. 1184 template<int size, bool big_endian> 1185 bool 1186 include_section(Sized_relobj_file<size, big_endian>* object, const char* name, 1187 const elfcpp::Shdr<size, big_endian>&); 1188 1189 // Return the output section name to use given an input section 1190 // name. Set *PLEN to the length of the name. *PLEN must be 1191 // initialized to the length of NAME. 1192 static const char* 1193 output_section_name(const Relobj*, const char* name, size_t* plen); 1194 1195 // Return the number of allocated output sections. 1196 size_t 1197 allocated_output_section_count() const; 1198 1199 // Return the output section for NAME, TYPE and FLAGS. 1200 Output_section* 1201 get_output_section(const char* name, Stringpool::Key name_key, 1202 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, 1203 Output_section_order order, bool is_relro); 1204 1205 // Clear the input section flags that should not be copied to the 1206 // output section. 1207 elfcpp::Elf_Xword 1208 get_output_section_flags (elfcpp::Elf_Xword input_section_flags); 1209 1210 // Choose the output section for NAME in RELOBJ. 1211 Output_section* 1212 choose_output_section(const Relobj* relobj, const char* name, 1213 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, 1214 bool is_input_section, Output_section_order order, 1215 bool is_relro, bool is_reloc, bool match_input_spec); 1216 1217 // Create a new Output_section. 1218 Output_section* 1219 make_output_section(const char* name, elfcpp::Elf_Word type, 1220 elfcpp::Elf_Xword flags, Output_section_order order, 1221 bool is_relro); 1222 1223 // Attach a section to a segment. 1224 void 1225 attach_section_to_segment(const Target*, Output_section*); 1226 1227 // Get section order. 1228 Output_section_order 1229 default_section_order(Output_section*, bool is_relro_local); 1230 1231 // Attach an allocated section to a segment. 1232 void 1233 attach_allocated_section_to_segment(const Target*, Output_section*); 1234 1235 // Make the .eh_frame section. 1236 Output_section* 1237 make_eh_frame_section(const Relobj*); 1238 1239 // Set the final file offsets of all the segments. 1240 off_t 1241 set_segment_offsets(const Target*, Output_segment*, unsigned int* pshndx); 1242 1243 // Set the file offsets of the sections when doing a relocatable 1244 // link. 1245 off_t 1246 set_relocatable_section_offsets(Output_data*, unsigned int* pshndx); 1247 1248 // Set the final file offsets of all the sections not associated 1249 // with a segment. We set section offsets in three passes: the 1250 // first handles all allocated sections, the second sections that 1251 // require postprocessing, and the last the late-bound STRTAB 1252 // sections (probably only shstrtab, which is the one we care about 1253 // because it holds section names). 1254 enum Section_offset_pass 1255 { 1256 BEFORE_INPUT_SECTIONS_PASS, 1257 POSTPROCESSING_SECTIONS_PASS, 1258 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS 1259 }; 1260 off_t 1261 set_section_offsets(off_t, Section_offset_pass pass); 1262 1263 // Set the final section indexes of all the sections not associated 1264 // with a segment. Returns the next unused index. 1265 unsigned int 1266 set_section_indexes(unsigned int pshndx); 1267 1268 // Set the section addresses when using a script. 1269 Output_segment* 1270 set_section_addresses_from_script(Symbol_table*); 1271 1272 // Find appropriate places or orphan sections in a script. 1273 void 1274 place_orphan_sections_in_script(); 1275 1276 // Return whether SEG1 comes before SEG2 in the output file. 1277 bool 1278 segment_precedes(const Output_segment* seg1, const Output_segment* seg2); 1279 1280 // Use to save and restore segments during relaxation. 1281 typedef Unordered_map<const Output_segment*, const Output_segment*> 1282 Segment_states; 1283 1284 // Save states of current output segments. 1285 void 1286 save_segments(Segment_states*); 1287 1288 // Restore output segment states. 1289 void 1290 restore_segments(const Segment_states*); 1291 1292 // Clean up after relaxation so that it is possible to lay out the 1293 // sections and segments again. 1294 void 1295 clean_up_after_relaxation(); 1296 1297 // Doing preparation work for relaxation. This is factored out to make 1298 // Layout::finalized a bit smaller and easier to read. 1299 void 1300 prepare_for_relaxation(); 1301 1302 // Main body of the relaxation loop, which lays out the section. 1303 off_t 1304 relaxation_loop_body(int, Target*, Symbol_table*, Output_segment**, 1305 Output_segment*, Output_segment_headers*, 1306 Output_file_header*, unsigned int*); 1307 1308 // A mapping used for kept comdats/.gnu.linkonce group signatures. 1309 typedef Unordered_map<std::string, Kept_section> Signatures; 1310 1311 // Mapping from input section name/type/flags to output section. We 1312 // use canonicalized strings here. 1313 1314 typedef std::pair<Stringpool::Key, 1315 std::pair<elfcpp::Elf_Word, elfcpp::Elf_Xword> > Key; 1316 1317 struct Hash_key 1318 { 1319 size_t 1320 operator()(const Key& k) const; 1321 }; 1322 1323 typedef Unordered_map<Key, Output_section*, Hash_key> Section_name_map; 1324 1325 // A comparison class for segments. 1326 1327 class Compare_segments 1328 { 1329 public: 1330 Compare_segments(Layout* layout) 1331 : layout_(layout) 1332 { } 1333 1334 bool 1335 operator()(const Output_segment* seg1, const Output_segment* seg2) 1336 { return this->layout_->segment_precedes(seg1, seg2); } 1337 1338 private: 1339 Layout* layout_; 1340 }; 1341 1342 typedef std::vector<Output_section_data*> Output_section_data_list; 1343 1344 // Debug checker class. 1345 class Relaxation_debug_check 1346 { 1347 public: 1348 Relaxation_debug_check() 1349 : section_infos_() 1350 { } 1351 1352 // Check that sections and special data are in reset states. 1353 void 1354 check_output_data_for_reset_values(const Layout::Section_list&, 1355 const Layout::Data_list& special_outputs, 1356 const Layout::Data_list& relax_outputs); 1357 1358 // Record information of a section list. 1359 void 1360 read_sections(const Layout::Section_list&); 1361 1362 // Verify a section list with recorded information. 1363 void 1364 verify_sections(const Layout::Section_list&); 1365 1366 private: 1367 // Information we care about a section. 1368 struct Section_info 1369 { 1370 // Output section described by this. 1371 Output_section* output_section; 1372 // Load address. 1373 uint64_t address; 1374 // Data size. 1375 off_t data_size; 1376 // File offset. 1377 off_t offset; 1378 }; 1379 1380 // Section information. 1381 std::vector<Section_info> section_infos_; 1382 }; 1383 1384 // Program properties from .note.gnu.property sections. 1385 struct Gnu_property 1386 { 1387 size_t pr_datasz; 1388 unsigned char* pr_data; 1389 }; 1390 typedef std::map<unsigned int, Gnu_property> Gnu_properties; 1391 1392 // The number of input files, for sizing tables. 1393 int number_of_input_files_; 1394 // Information set by scripts or by command line options. 1395 Script_options* script_options_; 1396 // The output section names. 1397 Stringpool namepool_; 1398 // The output symbol names. 1399 Stringpool sympool_; 1400 // The dynamic strings, if needed. 1401 Stringpool dynpool_; 1402 // The list of group sections and linkonce sections which we have seen. 1403 Signatures signatures_; 1404 // The mapping from input section name/type/flags to output sections. 1405 Section_name_map section_name_map_; 1406 // The list of output segments. 1407 Segment_list segment_list_; 1408 // The list of output sections. 1409 Section_list section_list_; 1410 // The list of output sections which are not attached to any output 1411 // segment. 1412 Section_list unattached_section_list_; 1413 // The list of unattached Output_data objects which require special 1414 // handling because they are not Output_sections. 1415 Data_list special_output_list_; 1416 // Like special_output_list_, but cleared and recreated on each 1417 // iteration of relaxation. 1418 Data_list relax_output_list_; 1419 // The section headers. 1420 Output_section_headers* section_headers_; 1421 // A pointer to the PT_TLS segment if there is one. 1422 Output_segment* tls_segment_; 1423 // A pointer to the PT_GNU_RELRO segment if there is one. 1424 Output_segment* relro_segment_; 1425 // A pointer to the PT_INTERP segment if there is one. 1426 Output_segment* interp_segment_; 1427 // A backend may increase the size of the PT_GNU_RELRO segment if 1428 // there is one. This is the amount to increase it by. 1429 unsigned int increase_relro_; 1430 // The SHT_SYMTAB output section. 1431 Output_section* symtab_section_; 1432 // The SHT_SYMTAB_SHNDX for the regular symbol table if there is one. 1433 Output_symtab_xindex* symtab_xindex_; 1434 // The SHT_DYNSYM output section if there is one. 1435 Output_section* dynsym_section_; 1436 // The SHT_SYMTAB_SHNDX for the dynamic symbol table if there is one. 1437 Output_symtab_xindex* dynsym_xindex_; 1438 // The SHT_DYNAMIC output section if there is one. 1439 Output_section* dynamic_section_; 1440 // The _DYNAMIC symbol if there is one. 1441 Symbol* dynamic_symbol_; 1442 // The dynamic data which goes into dynamic_section_. 1443 Output_data_dynamic* dynamic_data_; 1444 // The exception frame output section if there is one. 1445 Output_section* eh_frame_section_; 1446 // The exception frame data for eh_frame_section_. 1447 Eh_frame* eh_frame_data_; 1448 // Whether we have added eh_frame_data_ to the .eh_frame section. 1449 bool added_eh_frame_data_; 1450 // The exception frame header output section if there is one. 1451 Output_section* eh_frame_hdr_section_; 1452 // The data for the .gdb_index section. 1453 Gdb_index* gdb_index_data_; 1454 // The space for the build ID checksum if there is one. 1455 Output_section_data* build_id_note_; 1456 // The output section containing dwarf abbreviations 1457 Output_reduced_debug_abbrev_section* debug_abbrev_; 1458 // The output section containing the dwarf debug info tree 1459 Output_reduced_debug_info_section* debug_info_; 1460 // A list of group sections and their signatures. 1461 Group_signatures group_signatures_; 1462 // The size of the output file. 1463 off_t output_file_size_; 1464 // Whether we have added an input section to an output section. 1465 bool have_added_input_section_; 1466 // Whether we have attached the sections to the segments. 1467 bool sections_are_attached_; 1468 // Whether we have seen an object file marked to require an 1469 // executable stack. 1470 bool input_requires_executable_stack_; 1471 // Whether we have seen at least one object file with an executable 1472 // stack marker. 1473 bool input_with_gnu_stack_note_; 1474 // Whether we have seen at least one object file without an 1475 // executable stack marker. 1476 bool input_without_gnu_stack_note_; 1477 // Whether we have seen an object file that uses the static TLS model. 1478 bool has_static_tls_; 1479 // Whether any sections require postprocessing. 1480 bool any_postprocessing_sections_; 1481 // Whether we have resized the signatures_ hash table. 1482 bool resized_signatures_; 1483 // Whether we have created a .stab*str output section. 1484 bool have_stabstr_section_; 1485 // True if the input sections in the output sections should be sorted 1486 // as specified in a section ordering file. 1487 bool section_ordering_specified_; 1488 // True if some input sections need to be mapped to a unique segment, 1489 // after being mapped to a unique Output_section. 1490 bool unique_segment_for_sections_specified_; 1491 // In incremental build, holds information check the inputs and build the 1492 // .gnu_incremental_inputs section. 1493 Incremental_inputs* incremental_inputs_; 1494 // Whether we record output section data created in script 1495 bool record_output_section_data_from_script_; 1496 // Set if this is a slim LTO object not loaded with a compiler plugin 1497 bool lto_slim_object_; 1498 // List of output data that needs to be removed at relaxation clean up. 1499 Output_section_data_list script_output_section_data_list_; 1500 // Structure to save segment states before entering the relaxation loop. 1501 Segment_states* segment_states_; 1502 // A relaxation debug checker. We only create one when in debugging mode. 1503 Relaxation_debug_check* relaxation_debug_check_; 1504 // Plugins specify section_ordering using this map. This is set in 1505 // update_section_order in plugin.cc 1506 std::map<Section_id, unsigned int> section_order_map_; 1507 // This maps an input section to a unique segment. This is done by first 1508 // placing such input sections in unique output sections and then mapping 1509 // the output section to a unique segment. Unique_segment_info stores 1510 // any additional flags and alignment of the new segment. 1511 Section_segment_map section_segment_map_; 1512 // Hash a pattern to its position in the section ordering file. 1513 Unordered_map<std::string, unsigned int> input_section_position_; 1514 // Vector of glob only patterns in the section_ordering file. 1515 std::vector<std::string> input_section_glob_; 1516 // For incremental links, the base file to be modified. 1517 Incremental_binary* incremental_base_; 1518 // For incremental links, a list of free space within the file. 1519 Free_list free_list_; 1520 // Program properties. 1521 Gnu_properties gnu_properties_; 1522}; 1523 1524// This task handles writing out data in output sections which is not 1525// part of an input section, or which requires special handling. When 1526// this is done, it unblocks both output_sections_blocker and 1527// final_blocker. 1528 1529class Write_sections_task : public Task 1530{ 1531 public: 1532 Write_sections_task(const Layout* layout, Output_file* of, 1533 Task_token* output_sections_blocker, 1534 Task_token* input_sections_blocker, 1535 Task_token* final_blocker) 1536 : layout_(layout), of_(of), 1537 output_sections_blocker_(output_sections_blocker), 1538 input_sections_blocker_(input_sections_blocker), 1539 final_blocker_(final_blocker) 1540 { } 1541 1542 // The standard Task methods. 1543 1544 Task_token* 1545 is_runnable(); 1546 1547 void 1548 locks(Task_locker*); 1549 1550 void 1551 run(Workqueue*); 1552 1553 std::string 1554 get_name() const 1555 { return "Write_sections_task"; } 1556 1557 private: 1558 class Write_sections_locker; 1559 1560 const Layout* layout_; 1561 Output_file* of_; 1562 Task_token* output_sections_blocker_; 1563 Task_token* input_sections_blocker_; 1564 Task_token* final_blocker_; 1565}; 1566 1567// This task handles writing out data which is not part of a section 1568// or segment. 1569 1570class Write_data_task : public Task 1571{ 1572 public: 1573 Write_data_task(const Layout* layout, const Symbol_table* symtab, 1574 Output_file* of, Task_token* final_blocker) 1575 : layout_(layout), symtab_(symtab), of_(of), final_blocker_(final_blocker) 1576 { } 1577 1578 // The standard Task methods. 1579 1580 Task_token* 1581 is_runnable(); 1582 1583 void 1584 locks(Task_locker*); 1585 1586 void 1587 run(Workqueue*); 1588 1589 std::string 1590 get_name() const 1591 { return "Write_data_task"; } 1592 1593 private: 1594 const Layout* layout_; 1595 const Symbol_table* symtab_; 1596 Output_file* of_; 1597 Task_token* final_blocker_; 1598}; 1599 1600// This task handles writing out the global symbols. 1601 1602class Write_symbols_task : public Task 1603{ 1604 public: 1605 Write_symbols_task(const Layout* layout, const Symbol_table* symtab, 1606 const Input_objects* /*input_objects*/, 1607 const Stringpool* sympool, const Stringpool* dynpool, 1608 Output_file* of, Task_token* final_blocker) 1609 : layout_(layout), symtab_(symtab), 1610 sympool_(sympool), dynpool_(dynpool), of_(of), 1611 final_blocker_(final_blocker) 1612 { } 1613 1614 // The standard Task methods. 1615 1616 Task_token* 1617 is_runnable(); 1618 1619 void 1620 locks(Task_locker*); 1621 1622 void 1623 run(Workqueue*); 1624 1625 std::string 1626 get_name() const 1627 { return "Write_symbols_task"; } 1628 1629 private: 1630 const Layout* layout_; 1631 const Symbol_table* symtab_; 1632 const Stringpool* sympool_; 1633 const Stringpool* dynpool_; 1634 Output_file* of_; 1635 Task_token* final_blocker_; 1636}; 1637 1638// This task handles writing out data in output sections which can't 1639// be written out until all the input sections have been handled. 1640// This is for sections whose contents is based on the contents of 1641// other output sections. 1642 1643class Write_after_input_sections_task : public Task 1644{ 1645 public: 1646 Write_after_input_sections_task(Layout* layout, Output_file* of, 1647 Task_token* input_sections_blocker, 1648 Task_token* final_blocker) 1649 : layout_(layout), of_(of), 1650 input_sections_blocker_(input_sections_blocker), 1651 final_blocker_(final_blocker) 1652 { } 1653 1654 // The standard Task methods. 1655 1656 Task_token* 1657 is_runnable(); 1658 1659 void 1660 locks(Task_locker*); 1661 1662 void 1663 run(Workqueue*); 1664 1665 std::string 1666 get_name() const 1667 { return "Write_after_input_sections_task"; } 1668 1669 private: 1670 Layout* layout_; 1671 Output_file* of_; 1672 Task_token* input_sections_blocker_; 1673 Task_token* final_blocker_; 1674}; 1675 1676// This task function handles computation of the build id. 1677// When using --build-id=tree, it schedules the tasks that 1678// compute the hashes for each chunk of the file. This task 1679// cannot run until we have finalized the size of the output 1680// file, after the completion of Write_after_input_sections_task. 1681 1682class Build_id_task_runner : public Task_function_runner 1683{ 1684 public: 1685 Build_id_task_runner(const General_options* options, const Layout* layout, 1686 Output_file* of) 1687 : options_(options), layout_(layout), of_(of) 1688 { } 1689 1690 // Run the operation. 1691 void 1692 run(Workqueue*, const Task*); 1693 1694 private: 1695 const General_options* options_; 1696 const Layout* layout_; 1697 Output_file* of_; 1698}; 1699 1700// This task function handles closing the file. 1701 1702class Close_task_runner : public Task_function_runner 1703{ 1704 public: 1705 Close_task_runner(const General_options* options, const Layout* layout, 1706 Output_file* of, unsigned char* array_of_hashes, 1707 size_t size_of_hashes) 1708 : options_(options), layout_(layout), of_(of), 1709 array_of_hashes_(array_of_hashes), size_of_hashes_(size_of_hashes) 1710 { } 1711 1712 // Run the operation. 1713 void 1714 run(Workqueue*, const Task*); 1715 1716 private: 1717 const General_options* options_; 1718 const Layout* layout_; 1719 Output_file* of_; 1720 unsigned char* const array_of_hashes_; 1721 const size_t size_of_hashes_; 1722}; 1723 1724// A small helper function to align an address. 1725 1726inline uint64_t 1727align_address(uint64_t address, uint64_t addralign) 1728{ 1729 if (addralign != 0) 1730 address = (address + addralign - 1) &~ (addralign - 1); 1731 return address; 1732} 1733 1734} // End namespace gold. 1735 1736#endif // !defined(GOLD_LAYOUT_H) 1737