layout.h revision 1.1.1.5
1// layout.h -- lay out output file sections for gold -*- C++ -*- 2 3// Copyright (C) 2006-2016 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 // Loadable read-only note sections come next so that the PT_NOTE 403 // segment is on the first page of the executable. 404 ORDER_RO_NOTE, 405 406 // Put read-only sections used by the dynamic linker early in the 407 // executable to minimize paging. 408 ORDER_DYNAMIC_LINKER, 409 410 // Put reloc sections used by the dynamic linker after other 411 // sections used by the dynamic linker; otherwise, objcopy and strip 412 // get confused. 413 ORDER_DYNAMIC_RELOCS, 414 415 // Put the PLT reloc section after the other dynamic relocs; 416 // otherwise, prelink gets confused. 417 ORDER_DYNAMIC_PLT_RELOCS, 418 419 // The .init section. 420 ORDER_INIT, 421 422 // The PLT. 423 ORDER_PLT, 424 425 // The regular text sections. 426 ORDER_TEXT, 427 428 // The .fini section. 429 ORDER_FINI, 430 431 // The read-only sections. 432 ORDER_READONLY, 433 434 // The exception frame sections. 435 ORDER_EHFRAME, 436 437 // The TLS sections come first in the data section. 438 ORDER_TLS_DATA, 439 ORDER_TLS_BSS, 440 441 // Local RELRO (read-only after relocation) sections come before 442 // non-local RELRO sections. This data will be fully resolved by 443 // the prelinker. 444 ORDER_RELRO_LOCAL, 445 446 // Non-local RELRO sections are grouped together after local RELRO 447 // sections. All RELRO sections must be adjacent so that they can 448 // all be put into a PT_GNU_RELRO segment. 449 ORDER_RELRO, 450 451 // We permit marking exactly one output section as the last RELRO 452 // section. We do this so that the read-only GOT can be adjacent to 453 // the writable GOT. 454 ORDER_RELRO_LAST, 455 456 // Similarly, we permit marking exactly one output section as the 457 // first non-RELRO section. 458 ORDER_NON_RELRO_FIRST, 459 460 // The regular data sections come after the RELRO sections. 461 ORDER_DATA, 462 463 // Large data sections normally go in large data segments. 464 ORDER_LARGE_DATA, 465 466 // Group writable notes so that we can have a single PT_NOTE 467 // segment. 468 ORDER_RW_NOTE, 469 470 // The small data sections must be at the end of the data sections, 471 // so that they can be adjacent to the small BSS sections. 472 ORDER_SMALL_DATA, 473 474 // The BSS sections start here. 475 476 // The small BSS sections must be at the start of the BSS sections, 477 // so that they can be adjacent to the small data sections. 478 ORDER_SMALL_BSS, 479 480 // The regular BSS sections. 481 ORDER_BSS, 482 483 // The large BSS sections come after the other BSS sections. 484 ORDER_LARGE_BSS, 485 486 // Maximum value. 487 ORDER_MAX 488}; 489 490// This class handles the details of laying out input sections. 491 492class Layout 493{ 494 public: 495 Layout(int number_of_input_files, Script_options*); 496 497 ~Layout() 498 { 499 delete this->relaxation_debug_check_; 500 delete this->segment_states_; 501 } 502 503 // For incremental links, record the base file to be modified. 504 void 505 set_incremental_base(Incremental_binary* base); 506 507 Incremental_binary* 508 incremental_base() 509 { return this->incremental_base_; } 510 511 // For incremental links, record the initial fixed layout of a section 512 // from the base file, and return a pointer to the Output_section. 513 template<int size, bool big_endian> 514 Output_section* 515 init_fixed_output_section(const char*, elfcpp::Shdr<size, big_endian>&); 516 517 // Given an input section SHNDX, named NAME, with data in SHDR, from 518 // the object file OBJECT, return the output section where this 519 // input section should go. RELOC_SHNDX is the index of a 520 // relocation section which applies to this section, or 0 if none, 521 // or -1U if more than one. RELOC_TYPE is the type of the 522 // relocation section if there is one. Set *OFFSET to the offset 523 // within the output section. 524 template<int size, bool big_endian> 525 Output_section* 526 layout(Sized_relobj_file<size, big_endian> *object, unsigned int shndx, 527 const char* name, const elfcpp::Shdr<size, big_endian>& shdr, 528 unsigned int reloc_shndx, unsigned int reloc_type, off_t* offset); 529 530 std::map<Section_id, unsigned int>* 531 get_section_order_map() 532 { return &this->section_order_map_; } 533 534 // Struct to store segment info when mapping some input sections to 535 // unique segments using linker plugins. Mapping an input section to 536 // a unique segment is done by first placing such input sections in 537 // unique output sections and then mapping the output section to a 538 // unique segment. NAME is the name of the output section. FLAGS 539 // and ALIGN are the extra flags and alignment of the segment. 540 struct Unique_segment_info 541 { 542 // Identifier for the segment. ELF segments dont have names. This 543 // is used as the name of the output section mapped to the segment. 544 const char* name; 545 // Additional segment flags. 546 uint64_t flags; 547 // Segment alignment. 548 uint64_t align; 549 }; 550 551 // Mapping from input section to segment. 552 typedef std::map<Const_section_id, Unique_segment_info*> 553 Section_segment_map; 554 555 // Maps section SECN to SEGMENT s. 556 void 557 insert_section_segment_map(Const_section_id secn, Unique_segment_info *s); 558 559 // Some input sections require special ordering, for compatibility 560 // with GNU ld. Given the name of an input section, return -1 if it 561 // does not require special ordering. Otherwise, return the index 562 // by which it should be ordered compared to other input sections 563 // that require special ordering. 564 static int 565 special_ordering_of_input_section(const char* name); 566 567 bool 568 is_section_ordering_specified() 569 { return this->section_ordering_specified_; } 570 571 void 572 set_section_ordering_specified() 573 { this->section_ordering_specified_ = true; } 574 575 bool 576 is_unique_segment_for_sections_specified() const 577 { return this->unique_segment_for_sections_specified_; } 578 579 void 580 set_unique_segment_for_sections_specified() 581 { this->unique_segment_for_sections_specified_ = true; } 582 583 // For incremental updates, allocate a block of memory from the 584 // free list. Find a block starting at or after MINOFF. 585 off_t 586 allocate(off_t len, uint64_t align, off_t minoff) 587 { return this->free_list_.allocate(len, align, minoff); } 588 589 unsigned int 590 find_section_order_index(const std::string&); 591 592 // Read the sequence of input sections from the file specified with 593 // linker option --section-ordering-file. 594 void 595 read_layout_from_file(); 596 597 // Layout an input reloc section when doing a relocatable link. The 598 // section is RELOC_SHNDX in OBJECT, with data in SHDR. 599 // DATA_SECTION is the reloc section to which it refers. RR is the 600 // relocatable information. 601 template<int size, bool big_endian> 602 Output_section* 603 layout_reloc(Sized_relobj_file<size, big_endian>* object, 604 unsigned int reloc_shndx, 605 const elfcpp::Shdr<size, big_endian>& shdr, 606 Output_section* data_section, 607 Relocatable_relocs* rr); 608 609 // Layout a group section when doing a relocatable link. 610 template<int size, bool big_endian> 611 void 612 layout_group(Symbol_table* symtab, 613 Sized_relobj_file<size, big_endian>* object, 614 unsigned int group_shndx, 615 const char* group_section_name, 616 const char* signature, 617 const elfcpp::Shdr<size, big_endian>& shdr, 618 elfcpp::Elf_Word flags, 619 std::vector<unsigned int>* shndxes); 620 621 // Like layout, only for exception frame sections. OBJECT is an 622 // object file. SYMBOLS is the contents of the symbol table 623 // section, with size SYMBOLS_SIZE. SYMBOL_NAMES is the contents of 624 // the symbol name section, with size SYMBOL_NAMES_SIZE. SHNDX is a 625 // .eh_frame section in OBJECT. SHDR is the section header. 626 // RELOC_SHNDX is the index of a relocation section which applies to 627 // this section, or 0 if none, or -1U if more than one. RELOC_TYPE 628 // is the type of the relocation section if there is one. This 629 // returns the output section, and sets *OFFSET to the offset. 630 template<int size, bool big_endian> 631 Output_section* 632 layout_eh_frame(Sized_relobj_file<size, big_endian>* object, 633 const unsigned char* symbols, 634 off_t symbols_size, 635 const unsigned char* symbol_names, 636 off_t symbol_names_size, 637 unsigned int shndx, 638 const elfcpp::Shdr<size, big_endian>& shdr, 639 unsigned int reloc_shndx, unsigned int reloc_type, 640 off_t* offset); 641 642 // After processing all input files, we call this to make sure that 643 // the optimized .eh_frame sections have been added to the output 644 // section. 645 void 646 finalize_eh_frame_section(); 647 648 // Add .eh_frame information for a PLT. The FDE must start with a 649 // 4-byte PC-relative reference to the start of the PLT, followed by 650 // a 4-byte size of PLT. 651 void 652 add_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data, 653 size_t cie_length, const unsigned char* fde_data, 654 size_t fde_length); 655 656 // Scan a .debug_info or .debug_types section, and add summary 657 // information to the .gdb_index section. 658 template<int size, bool big_endian> 659 void 660 add_to_gdb_index(bool is_type_unit, 661 Sized_relobj<size, big_endian>* object, 662 const unsigned char* symbols, 663 off_t symbols_size, 664 unsigned int shndx, 665 unsigned int reloc_shndx, 666 unsigned int reloc_type); 667 668 // Handle a GNU stack note. This is called once per input object 669 // file. SEEN_GNU_STACK is true if the object file has a 670 // .note.GNU-stack section. GNU_STACK_FLAGS is the section flags 671 // from that section if there was one. 672 void 673 layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags, 674 const Object*); 675 676 // Add an Output_section_data to the layout. This is used for 677 // special sections like the GOT section. ORDER is where the 678 // section should wind up in the output segment. IS_RELRO is true 679 // for relro sections. 680 Output_section* 681 add_output_section_data(const char* name, elfcpp::Elf_Word type, 682 elfcpp::Elf_Xword flags, 683 Output_section_data*, Output_section_order order, 684 bool is_relro); 685 686 // Increase the size of the relro segment by this much. 687 void 688 increase_relro(unsigned int s) 689 { this->increase_relro_ += s; } 690 691 // Create dynamic sections if necessary. 692 void 693 create_initial_dynamic_sections(Symbol_table*); 694 695 // Define __start and __stop symbols for output sections. 696 void 697 define_section_symbols(Symbol_table*); 698 699 // Create automatic note sections. 700 void 701 create_notes(); 702 703 // Create sections for linker scripts. 704 void 705 create_script_sections() 706 { this->script_options_->create_script_sections(this); } 707 708 // Define symbols from any linker script. 709 void 710 define_script_symbols(Symbol_table* symtab) 711 { this->script_options_->add_symbols_to_table(symtab); } 712 713 // Define symbols for group signatures. 714 void 715 define_group_signatures(Symbol_table*); 716 717 // Return the Stringpool used for symbol names. 718 const Stringpool* 719 sympool() const 720 { return &this->sympool_; } 721 722 // Return the Stringpool used for dynamic symbol names and dynamic 723 // tags. 724 const Stringpool* 725 dynpool() const 726 { return &this->dynpool_; } 727 728 // Return the .dynamic output section. This is only valid after the 729 // layout has been finalized. 730 Output_section* 731 dynamic_section() const 732 { return this->dynamic_section_; } 733 734 // Return the symtab_xindex section used to hold large section 735 // indexes for the normal symbol table. 736 Output_symtab_xindex* 737 symtab_xindex() const 738 { return this->symtab_xindex_; } 739 740 // Return the dynsym_xindex section used to hold large section 741 // indexes for the dynamic symbol table. 742 Output_symtab_xindex* 743 dynsym_xindex() const 744 { return this->dynsym_xindex_; } 745 746 // Return whether a section is a .gnu.linkonce section, given the 747 // section name. 748 static inline bool 749 is_linkonce(const char* name) 750 { return strncmp(name, ".gnu.linkonce", sizeof(".gnu.linkonce") - 1) == 0; } 751 752 // Whether we have added an input section. 753 bool 754 have_added_input_section() const 755 { return this->have_added_input_section_; } 756 757 // Return true if a section is a debugging section. 758 static inline bool 759 is_debug_info_section(const char* name) 760 { 761 // Debugging sections can only be recognized by name. 762 return (strncmp(name, ".debug", sizeof(".debug") - 1) == 0 763 || strncmp(name, ".zdebug", sizeof(".zdebug") - 1) == 0 764 || strncmp(name, ".gnu.linkonce.wi.", 765 sizeof(".gnu.linkonce.wi.") - 1) == 0 766 || strncmp(name, ".line", sizeof(".line") - 1) == 0 767 || strncmp(name, ".stab", sizeof(".stab") - 1) == 0 768 || strncmp(name, ".pdr", sizeof(".pdr") - 1) == 0); 769 } 770 771 // Return true if RELOBJ is an input file whose base name matches 772 // FILE_NAME. The base name must have an extension of ".o", and 773 // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o". 774 static bool 775 match_file_name(const Relobj* relobj, const char* file_name); 776 777 // Return whether section SHNDX in RELOBJ is a .ctors/.dtors section 778 // with more than one word being mapped to a .init_array/.fini_array 779 // section. 780 bool 781 is_ctors_in_init_array(Relobj* relobj, unsigned int shndx) const; 782 783 // Check if a comdat group or .gnu.linkonce section with the given 784 // NAME is selected for the link. If there is already a section, 785 // *KEPT_SECTION is set to point to the signature and the function 786 // returns false. Otherwise, OBJECT, SHNDX,IS_COMDAT, and 787 // IS_GROUP_NAME are recorded for this NAME in the layout object, 788 // *KEPT_SECTION is set to the internal copy and the function return 789 // false. 790 bool 791 find_or_add_kept_section(const std::string& name, Relobj* object, 792 unsigned int shndx, bool is_comdat, 793 bool is_group_name, Kept_section** kept_section); 794 795 // Finalize the layout after all the input sections have been added. 796 off_t 797 finalize(const Input_objects*, Symbol_table*, Target*, const Task*); 798 799 // Return whether any sections require postprocessing. 800 bool 801 any_postprocessing_sections() const 802 { return this->any_postprocessing_sections_; } 803 804 // Return the size of the output file. 805 off_t 806 output_file_size() const 807 { return this->output_file_size_; } 808 809 // Return the TLS segment. This will return NULL if there isn't 810 // one. 811 Output_segment* 812 tls_segment() const 813 { return this->tls_segment_; } 814 815 // Return the normal symbol table. 816 Output_section* 817 symtab_section() const 818 { 819 gold_assert(this->symtab_section_ != NULL); 820 return this->symtab_section_; 821 } 822 823 // Return the file offset of the normal symbol table. 824 off_t 825 symtab_section_offset() const; 826 827 // Return the section index of the normal symbol tabl.e 828 unsigned int 829 symtab_section_shndx() const; 830 831 // Return the dynamic symbol table. 832 Output_section* 833 dynsym_section() const 834 { 835 gold_assert(this->dynsym_section_ != NULL); 836 return this->dynsym_section_; 837 } 838 839 // Return the dynamic tags. 840 Output_data_dynamic* 841 dynamic_data() const 842 { return this->dynamic_data_; } 843 844 // Write out the output sections. 845 void 846 write_output_sections(Output_file* of) const; 847 848 // Write out data not associated with an input file or the symbol 849 // table. 850 void 851 write_data(const Symbol_table*, Output_file*) const; 852 853 // Write out output sections which can not be written until all the 854 // input sections are complete. 855 void 856 write_sections_after_input_sections(Output_file* of); 857 858 // Return an output section named NAME, or NULL if there is none. 859 Output_section* 860 find_output_section(const char* name) const; 861 862 // Return an output segment of type TYPE, with segment flags SET set 863 // and segment flags CLEAR clear. Return NULL if there is none. 864 Output_segment* 865 find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set, 866 elfcpp::Elf_Word clear) const; 867 868 // Return the number of segments we expect to produce. 869 size_t 870 expected_segment_count() const; 871 872 // Set a flag to indicate that an object file uses the static TLS model. 873 void 874 set_has_static_tls() 875 { this->has_static_tls_ = true; } 876 877 // Return true if any object file uses the static TLS model. 878 bool 879 has_static_tls() const 880 { return this->has_static_tls_; } 881 882 // Return the options which may be set by a linker script. 883 Script_options* 884 script_options() 885 { return this->script_options_; } 886 887 const Script_options* 888 script_options() const 889 { return this->script_options_; } 890 891 // Return the object managing inputs in incremental build. NULL in 892 // non-incremental builds. 893 Incremental_inputs* 894 incremental_inputs() const 895 { return this->incremental_inputs_; } 896 897 // For the target-specific code to add dynamic tags which are common 898 // to most targets. 899 void 900 add_target_dynamic_tags(bool use_rel, const Output_data* plt_got, 901 const Output_data* plt_rel, 902 const Output_data_reloc_generic* dyn_rel, 903 bool add_debug, bool dynrel_includes_plt); 904 905 // Add a target-specific dynamic tag with constant value. 906 void 907 add_target_specific_dynamic_tag(elfcpp::DT tag, unsigned int val); 908 909 // Compute and write out the build ID if needed. 910 void 911 write_build_id(Output_file*, unsigned char*, size_t) const; 912 913 // Rewrite output file in binary format. 914 void 915 write_binary(Output_file* in) const; 916 917 // Print output sections to the map file. 918 void 919 print_to_mapfile(Mapfile*) const; 920 921 // Dump statistical information to stderr. 922 void 923 print_stats() const; 924 925 // A list of segments. 926 927 typedef std::vector<Output_segment*> Segment_list; 928 929 // A list of sections. 930 931 typedef std::vector<Output_section*> Section_list; 932 933 // The list of information to write out which is not attached to 934 // either a section or a segment. 935 typedef std::vector<Output_data*> Data_list; 936 937 // Store the allocated sections into the section list. This is used 938 // by the linker script code. 939 void 940 get_allocated_sections(Section_list*) const; 941 942 // Store the executable sections into the section list. 943 void 944 get_executable_sections(Section_list*) const; 945 946 // Make a section for a linker script to hold data. 947 Output_section* 948 make_output_section_for_script(const char* name, 949 Script_sections::Section_type section_type); 950 951 // Make a segment. This is used by the linker script code. 952 Output_segment* 953 make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags); 954 955 // Return the number of segments. 956 size_t 957 segment_count() const 958 { return this->segment_list_.size(); } 959 960 // Map from section flags to segment flags. 961 static elfcpp::Elf_Word 962 section_flags_to_segment(elfcpp::Elf_Xword flags); 963 964 // Attach sections to segments. 965 void 966 attach_sections_to_segments(const Target*); 967 968 // For relaxation clean up, we need to know output section data created 969 // from a linker script. 970 void 971 new_output_section_data_from_script(Output_section_data* posd) 972 { 973 if (this->record_output_section_data_from_script_) 974 this->script_output_section_data_list_.push_back(posd); 975 } 976 977 // Return section list. 978 const Section_list& 979 section_list() const 980 { return this->section_list_; } 981 982 // Returns TRUE iff NAME (an input section from RELOBJ) will 983 // be mapped to an output section that should be KEPT. 984 bool 985 keep_input_section(const Relobj*, const char*); 986 987 // Add a special output object that will be recreated afresh 988 // if there is another relaxation iteration. 989 void 990 add_relax_output(Output_data* data) 991 { this->relax_output_list_.push_back(data); } 992 993 // Clear out (and free) everything added by add_relax_output. 994 void 995 reset_relax_output(); 996 997 private: 998 Layout(const Layout&); 999 Layout& operator=(const Layout&); 1000 1001 // Mapping from input section names to output section names. 1002 struct Section_name_mapping 1003 { 1004 const char* from; 1005 int fromlen; 1006 const char* to; 1007 int tolen; 1008 }; 1009 static const Section_name_mapping section_name_mapping[]; 1010 static const int section_name_mapping_count; 1011 1012 // During a relocatable link, a list of group sections and 1013 // signatures. 1014 struct Group_signature 1015 { 1016 // The group section. 1017 Output_section* section; 1018 // The signature. 1019 const char* signature; 1020 1021 Group_signature() 1022 : section(NULL), signature(NULL) 1023 { } 1024 1025 Group_signature(Output_section* sectiona, const char* signaturea) 1026 : section(sectiona), signature(signaturea) 1027 { } 1028 }; 1029 typedef std::vector<Group_signature> Group_signatures; 1030 1031 // Create a note section, filling in the header. 1032 Output_section* 1033 create_note(const char* name, int note_type, const char* section_name, 1034 size_t descsz, bool allocate, size_t* trailing_padding); 1035 1036 // Create a note section for gold version. 1037 void 1038 create_gold_note(); 1039 1040 // Record whether the stack must be executable. 1041 void 1042 create_executable_stack_info(); 1043 1044 // Create a build ID note if needed. 1045 void 1046 create_build_id(); 1047 1048 // Link .stab and .stabstr sections. 1049 void 1050 link_stabs_sections(); 1051 1052 // Create .gnu_incremental_inputs and .gnu_incremental_strtab sections needed 1053 // for the next run of incremental linking to check what has changed. 1054 void 1055 create_incremental_info_sections(Symbol_table*); 1056 1057 // Find the first read-only PT_LOAD segment, creating one if 1058 // necessary. 1059 Output_segment* 1060 find_first_load_seg(const Target*); 1061 1062 // Count the local symbols in the regular symbol table and the dynamic 1063 // symbol table, and build the respective string pools. 1064 void 1065 count_local_symbols(const Task*, const Input_objects*); 1066 1067 // Create the output sections for the symbol table. 1068 void 1069 create_symtab_sections(const Input_objects*, Symbol_table*, 1070 unsigned int, off_t*); 1071 1072 // Create the .shstrtab section. 1073 Output_section* 1074 create_shstrtab(); 1075 1076 // Create the section header table. 1077 void 1078 create_shdrs(const Output_section* shstrtab_section, off_t*); 1079 1080 // Create the dynamic symbol table. 1081 void 1082 create_dynamic_symtab(const Input_objects*, Symbol_table*, 1083 Output_section** pdynstr, 1084 unsigned int* plocal_dynamic_count, 1085 std::vector<Symbol*>* pdynamic_symbols, 1086 Versions* versions); 1087 1088 // Assign offsets to each local portion of the dynamic symbol table. 1089 void 1090 assign_local_dynsym_offsets(const Input_objects*); 1091 1092 // Finish the .dynamic section and PT_DYNAMIC segment. 1093 void 1094 finish_dynamic_section(const Input_objects*, const Symbol_table*); 1095 1096 // Set the size of the _DYNAMIC symbol. 1097 void 1098 set_dynamic_symbol_size(const Symbol_table*); 1099 1100 // Create the .interp section and PT_INTERP segment. 1101 void 1102 create_interp(const Target* target); 1103 1104 // Create the version sections. 1105 void 1106 create_version_sections(const Versions*, 1107 const Symbol_table*, 1108 unsigned int local_symcount, 1109 const std::vector<Symbol*>& dynamic_symbols, 1110 const Output_section* dynstr); 1111 1112 template<int size, bool big_endian> 1113 void 1114 sized_create_version_sections(const Versions* versions, 1115 const Symbol_table*, 1116 unsigned int local_symcount, 1117 const std::vector<Symbol*>& dynamic_symbols, 1118 const Output_section* dynstr); 1119 1120 // Return whether to include this section in the link. 1121 template<int size, bool big_endian> 1122 bool 1123 include_section(Sized_relobj_file<size, big_endian>* object, const char* name, 1124 const elfcpp::Shdr<size, big_endian>&); 1125 1126 // Return the output section name to use given an input section 1127 // name. Set *PLEN to the length of the name. *PLEN must be 1128 // initialized to the length of NAME. 1129 static const char* 1130 output_section_name(const Relobj*, const char* name, size_t* plen); 1131 1132 // Return the number of allocated output sections. 1133 size_t 1134 allocated_output_section_count() const; 1135 1136 // Return the output section for NAME, TYPE and FLAGS. 1137 Output_section* 1138 get_output_section(const char* name, Stringpool::Key name_key, 1139 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, 1140 Output_section_order order, bool is_relro); 1141 1142 // Clear the input section flags that should not be copied to the 1143 // output section. 1144 elfcpp::Elf_Xword 1145 get_output_section_flags (elfcpp::Elf_Xword input_section_flags); 1146 1147 // Choose the output section for NAME in RELOBJ. 1148 Output_section* 1149 choose_output_section(const Relobj* relobj, const char* name, 1150 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, 1151 bool is_input_section, Output_section_order order, 1152 bool is_relro); 1153 1154 // Create a new Output_section. 1155 Output_section* 1156 make_output_section(const char* name, elfcpp::Elf_Word type, 1157 elfcpp::Elf_Xword flags, Output_section_order order, 1158 bool is_relro); 1159 1160 // Attach a section to a segment. 1161 void 1162 attach_section_to_segment(const Target*, Output_section*); 1163 1164 // Get section order. 1165 Output_section_order 1166 default_section_order(Output_section*, bool is_relro_local); 1167 1168 // Attach an allocated section to a segment. 1169 void 1170 attach_allocated_section_to_segment(const Target*, Output_section*); 1171 1172 // Make the .eh_frame section. 1173 Output_section* 1174 make_eh_frame_section(const Relobj*); 1175 1176 // Set the final file offsets of all the segments. 1177 off_t 1178 set_segment_offsets(const Target*, Output_segment*, unsigned int* pshndx); 1179 1180 // Set the file offsets of the sections when doing a relocatable 1181 // link. 1182 off_t 1183 set_relocatable_section_offsets(Output_data*, unsigned int* pshndx); 1184 1185 // Set the final file offsets of all the sections not associated 1186 // with a segment. We set section offsets in three passes: the 1187 // first handles all allocated sections, the second sections that 1188 // require postprocessing, and the last the late-bound STRTAB 1189 // sections (probably only shstrtab, which is the one we care about 1190 // because it holds section names). 1191 enum Section_offset_pass 1192 { 1193 BEFORE_INPUT_SECTIONS_PASS, 1194 POSTPROCESSING_SECTIONS_PASS, 1195 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS 1196 }; 1197 off_t 1198 set_section_offsets(off_t, Section_offset_pass pass); 1199 1200 // Set the final section indexes of all the sections not associated 1201 // with a segment. Returns the next unused index. 1202 unsigned int 1203 set_section_indexes(unsigned int pshndx); 1204 1205 // Set the section addresses when using a script. 1206 Output_segment* 1207 set_section_addresses_from_script(Symbol_table*); 1208 1209 // Find appropriate places or orphan sections in a script. 1210 void 1211 place_orphan_sections_in_script(); 1212 1213 // Return whether SEG1 comes before SEG2 in the output file. 1214 bool 1215 segment_precedes(const Output_segment* seg1, const Output_segment* seg2); 1216 1217 // Use to save and restore segments during relaxation. 1218 typedef Unordered_map<const Output_segment*, const Output_segment*> 1219 Segment_states; 1220 1221 // Save states of current output segments. 1222 void 1223 save_segments(Segment_states*); 1224 1225 // Restore output segment states. 1226 void 1227 restore_segments(const Segment_states*); 1228 1229 // Clean up after relaxation so that it is possible to lay out the 1230 // sections and segments again. 1231 void 1232 clean_up_after_relaxation(); 1233 1234 // Doing preparation work for relaxation. This is factored out to make 1235 // Layout::finalized a bit smaller and easier to read. 1236 void 1237 prepare_for_relaxation(); 1238 1239 // Main body of the relaxation loop, which lays out the section. 1240 off_t 1241 relaxation_loop_body(int, Target*, Symbol_table*, Output_segment**, 1242 Output_segment*, Output_segment_headers*, 1243 Output_file_header*, unsigned int*); 1244 1245 // A mapping used for kept comdats/.gnu.linkonce group signatures. 1246 typedef Unordered_map<std::string, Kept_section> Signatures; 1247 1248 // Mapping from input section name/type/flags to output section. We 1249 // use canonicalized strings here. 1250 1251 typedef std::pair<Stringpool::Key, 1252 std::pair<elfcpp::Elf_Word, elfcpp::Elf_Xword> > Key; 1253 1254 struct Hash_key 1255 { 1256 size_t 1257 operator()(const Key& k) const; 1258 }; 1259 1260 typedef Unordered_map<Key, Output_section*, Hash_key> Section_name_map; 1261 1262 // A comparison class for segments. 1263 1264 class Compare_segments 1265 { 1266 public: 1267 Compare_segments(Layout* layout) 1268 : layout_(layout) 1269 { } 1270 1271 bool 1272 operator()(const Output_segment* seg1, const Output_segment* seg2) 1273 { return this->layout_->segment_precedes(seg1, seg2); } 1274 1275 private: 1276 Layout* layout_; 1277 }; 1278 1279 typedef std::vector<Output_section_data*> Output_section_data_list; 1280 1281 // Debug checker class. 1282 class Relaxation_debug_check 1283 { 1284 public: 1285 Relaxation_debug_check() 1286 : section_infos_() 1287 { } 1288 1289 // Check that sections and special data are in reset states. 1290 void 1291 check_output_data_for_reset_values(const Layout::Section_list&, 1292 const Layout::Data_list& special_outputs, 1293 const Layout::Data_list& relax_outputs); 1294 1295 // Record information of a section list. 1296 void 1297 read_sections(const Layout::Section_list&); 1298 1299 // Verify a section list with recorded information. 1300 void 1301 verify_sections(const Layout::Section_list&); 1302 1303 private: 1304 // Information we care about a section. 1305 struct Section_info 1306 { 1307 // Output section described by this. 1308 Output_section* output_section; 1309 // Load address. 1310 uint64_t address; 1311 // Data size. 1312 off_t data_size; 1313 // File offset. 1314 off_t offset; 1315 }; 1316 1317 // Section information. 1318 std::vector<Section_info> section_infos_; 1319 }; 1320 1321 // The number of input files, for sizing tables. 1322 int number_of_input_files_; 1323 // Information set by scripts or by command line options. 1324 Script_options* script_options_; 1325 // The output section names. 1326 Stringpool namepool_; 1327 // The output symbol names. 1328 Stringpool sympool_; 1329 // The dynamic strings, if needed. 1330 Stringpool dynpool_; 1331 // The list of group sections and linkonce sections which we have seen. 1332 Signatures signatures_; 1333 // The mapping from input section name/type/flags to output sections. 1334 Section_name_map section_name_map_; 1335 // The list of output segments. 1336 Segment_list segment_list_; 1337 // The list of output sections. 1338 Section_list section_list_; 1339 // The list of output sections which are not attached to any output 1340 // segment. 1341 Section_list unattached_section_list_; 1342 // The list of unattached Output_data objects which require special 1343 // handling because they are not Output_sections. 1344 Data_list special_output_list_; 1345 // Like special_output_list_, but cleared and recreated on each 1346 // iteration of relaxation. 1347 Data_list relax_output_list_; 1348 // The section headers. 1349 Output_section_headers* section_headers_; 1350 // A pointer to the PT_TLS segment if there is one. 1351 Output_segment* tls_segment_; 1352 // A pointer to the PT_GNU_RELRO segment if there is one. 1353 Output_segment* relro_segment_; 1354 // A pointer to the PT_INTERP segment if there is one. 1355 Output_segment* interp_segment_; 1356 // A backend may increase the size of the PT_GNU_RELRO segment if 1357 // there is one. This is the amount to increase it by. 1358 unsigned int increase_relro_; 1359 // The SHT_SYMTAB output section. 1360 Output_section* symtab_section_; 1361 // The SHT_SYMTAB_SHNDX for the regular symbol table if there is one. 1362 Output_symtab_xindex* symtab_xindex_; 1363 // The SHT_DYNSYM output section if there is one. 1364 Output_section* dynsym_section_; 1365 // The SHT_SYMTAB_SHNDX for the dynamic symbol table if there is one. 1366 Output_symtab_xindex* dynsym_xindex_; 1367 // The SHT_DYNAMIC output section if there is one. 1368 Output_section* dynamic_section_; 1369 // The _DYNAMIC symbol if there is one. 1370 Symbol* dynamic_symbol_; 1371 // The dynamic data which goes into dynamic_section_. 1372 Output_data_dynamic* dynamic_data_; 1373 // The exception frame output section if there is one. 1374 Output_section* eh_frame_section_; 1375 // The exception frame data for eh_frame_section_. 1376 Eh_frame* eh_frame_data_; 1377 // Whether we have added eh_frame_data_ to the .eh_frame section. 1378 bool added_eh_frame_data_; 1379 // The exception frame header output section if there is one. 1380 Output_section* eh_frame_hdr_section_; 1381 // The data for the .gdb_index section. 1382 Gdb_index* gdb_index_data_; 1383 // The space for the build ID checksum if there is one. 1384 Output_section_data* build_id_note_; 1385 // The output section containing dwarf abbreviations 1386 Output_reduced_debug_abbrev_section* debug_abbrev_; 1387 // The output section containing the dwarf debug info tree 1388 Output_reduced_debug_info_section* debug_info_; 1389 // A list of group sections and their signatures. 1390 Group_signatures group_signatures_; 1391 // The size of the output file. 1392 off_t output_file_size_; 1393 // Whether we have added an input section to an output section. 1394 bool have_added_input_section_; 1395 // Whether we have attached the sections to the segments. 1396 bool sections_are_attached_; 1397 // Whether we have seen an object file marked to require an 1398 // executable stack. 1399 bool input_requires_executable_stack_; 1400 // Whether we have seen at least one object file with an executable 1401 // stack marker. 1402 bool input_with_gnu_stack_note_; 1403 // Whether we have seen at least one object file without an 1404 // executable stack marker. 1405 bool input_without_gnu_stack_note_; 1406 // Whether we have seen an object file that uses the static TLS model. 1407 bool has_static_tls_; 1408 // Whether any sections require postprocessing. 1409 bool any_postprocessing_sections_; 1410 // Whether we have resized the signatures_ hash table. 1411 bool resized_signatures_; 1412 // Whether we have created a .stab*str output section. 1413 bool have_stabstr_section_; 1414 // True if the input sections in the output sections should be sorted 1415 // as specified in a section ordering file. 1416 bool section_ordering_specified_; 1417 // True if some input sections need to be mapped to a unique segment, 1418 // after being mapped to a unique Output_section. 1419 bool unique_segment_for_sections_specified_; 1420 // In incremental build, holds information check the inputs and build the 1421 // .gnu_incremental_inputs section. 1422 Incremental_inputs* incremental_inputs_; 1423 // Whether we record output section data created in script 1424 bool record_output_section_data_from_script_; 1425 // List of output data that needs to be removed at relaxation clean up. 1426 Output_section_data_list script_output_section_data_list_; 1427 // Structure to save segment states before entering the relaxation loop. 1428 Segment_states* segment_states_; 1429 // A relaxation debug checker. We only create one when in debugging mode. 1430 Relaxation_debug_check* relaxation_debug_check_; 1431 // Plugins specify section_ordering using this map. This is set in 1432 // update_section_order in plugin.cc 1433 std::map<Section_id, unsigned int> section_order_map_; 1434 // This maps an input section to a unique segment. This is done by first 1435 // placing such input sections in unique output sections and then mapping 1436 // the output section to a unique segment. Unique_segment_info stores 1437 // any additional flags and alignment of the new segment. 1438 Section_segment_map section_segment_map_; 1439 // Hash a pattern to its position in the section ordering file. 1440 Unordered_map<std::string, unsigned int> input_section_position_; 1441 // Vector of glob only patterns in the section_ordering file. 1442 std::vector<std::string> input_section_glob_; 1443 // For incremental links, the base file to be modified. 1444 Incremental_binary* incremental_base_; 1445 // For incremental links, a list of free space within the file. 1446 Free_list free_list_; 1447}; 1448 1449// This task handles writing out data in output sections which is not 1450// part of an input section, or which requires special handling. When 1451// this is done, it unblocks both output_sections_blocker and 1452// final_blocker. 1453 1454class Write_sections_task : public Task 1455{ 1456 public: 1457 Write_sections_task(const Layout* layout, Output_file* of, 1458 Task_token* output_sections_blocker, 1459 Task_token* input_sections_blocker, 1460 Task_token* final_blocker) 1461 : layout_(layout), of_(of), 1462 output_sections_blocker_(output_sections_blocker), 1463 input_sections_blocker_(input_sections_blocker), 1464 final_blocker_(final_blocker) 1465 { } 1466 1467 // The standard Task methods. 1468 1469 Task_token* 1470 is_runnable(); 1471 1472 void 1473 locks(Task_locker*); 1474 1475 void 1476 run(Workqueue*); 1477 1478 std::string 1479 get_name() const 1480 { return "Write_sections_task"; } 1481 1482 private: 1483 class Write_sections_locker; 1484 1485 const Layout* layout_; 1486 Output_file* of_; 1487 Task_token* output_sections_blocker_; 1488 Task_token* input_sections_blocker_; 1489 Task_token* final_blocker_; 1490}; 1491 1492// This task handles writing out data which is not part of a section 1493// or segment. 1494 1495class Write_data_task : public Task 1496{ 1497 public: 1498 Write_data_task(const Layout* layout, const Symbol_table* symtab, 1499 Output_file* of, Task_token* final_blocker) 1500 : layout_(layout), symtab_(symtab), of_(of), final_blocker_(final_blocker) 1501 { } 1502 1503 // The standard Task methods. 1504 1505 Task_token* 1506 is_runnable(); 1507 1508 void 1509 locks(Task_locker*); 1510 1511 void 1512 run(Workqueue*); 1513 1514 std::string 1515 get_name() const 1516 { return "Write_data_task"; } 1517 1518 private: 1519 const Layout* layout_; 1520 const Symbol_table* symtab_; 1521 Output_file* of_; 1522 Task_token* final_blocker_; 1523}; 1524 1525// This task handles writing out the global symbols. 1526 1527class Write_symbols_task : public Task 1528{ 1529 public: 1530 Write_symbols_task(const Layout* layout, const Symbol_table* symtab, 1531 const Input_objects* /*input_objects*/, 1532 const Stringpool* sympool, const Stringpool* dynpool, 1533 Output_file* of, Task_token* final_blocker) 1534 : layout_(layout), symtab_(symtab), 1535 sympool_(sympool), dynpool_(dynpool), of_(of), 1536 final_blocker_(final_blocker) 1537 { } 1538 1539 // The standard Task methods. 1540 1541 Task_token* 1542 is_runnable(); 1543 1544 void 1545 locks(Task_locker*); 1546 1547 void 1548 run(Workqueue*); 1549 1550 std::string 1551 get_name() const 1552 { return "Write_symbols_task"; } 1553 1554 private: 1555 const Layout* layout_; 1556 const Symbol_table* symtab_; 1557 const Stringpool* sympool_; 1558 const Stringpool* dynpool_; 1559 Output_file* of_; 1560 Task_token* final_blocker_; 1561}; 1562 1563// This task handles writing out data in output sections which can't 1564// be written out until all the input sections have been handled. 1565// This is for sections whose contents is based on the contents of 1566// other output sections. 1567 1568class Write_after_input_sections_task : public Task 1569{ 1570 public: 1571 Write_after_input_sections_task(Layout* layout, Output_file* of, 1572 Task_token* input_sections_blocker, 1573 Task_token* final_blocker) 1574 : layout_(layout), of_(of), 1575 input_sections_blocker_(input_sections_blocker), 1576 final_blocker_(final_blocker) 1577 { } 1578 1579 // The standard Task methods. 1580 1581 Task_token* 1582 is_runnable(); 1583 1584 void 1585 locks(Task_locker*); 1586 1587 void 1588 run(Workqueue*); 1589 1590 std::string 1591 get_name() const 1592 { return "Write_after_input_sections_task"; } 1593 1594 private: 1595 Layout* layout_; 1596 Output_file* of_; 1597 Task_token* input_sections_blocker_; 1598 Task_token* final_blocker_; 1599}; 1600 1601// This task function handles computation of the build id. 1602// When using --build-id=tree, it schedules the tasks that 1603// compute the hashes for each chunk of the file. This task 1604// cannot run until we have finalized the size of the output 1605// file, after the completion of Write_after_input_sections_task. 1606 1607class Build_id_task_runner : public Task_function_runner 1608{ 1609 public: 1610 Build_id_task_runner(const General_options* options, const Layout* layout, 1611 Output_file* of) 1612 : options_(options), layout_(layout), of_(of) 1613 { } 1614 1615 // Run the operation. 1616 void 1617 run(Workqueue*, const Task*); 1618 1619 private: 1620 const General_options* options_; 1621 const Layout* layout_; 1622 Output_file* of_; 1623}; 1624 1625// This task function handles closing the file. 1626 1627class Close_task_runner : public Task_function_runner 1628{ 1629 public: 1630 Close_task_runner(const General_options* options, const Layout* layout, 1631 Output_file* of, unsigned char* array_of_hashes, 1632 size_t size_of_hashes) 1633 : options_(options), layout_(layout), of_(of), 1634 array_of_hashes_(array_of_hashes), size_of_hashes_(size_of_hashes) 1635 { } 1636 1637 // Run the operation. 1638 void 1639 run(Workqueue*, const Task*); 1640 1641 private: 1642 const General_options* options_; 1643 const Layout* layout_; 1644 Output_file* of_; 1645 unsigned char* const array_of_hashes_; 1646 const size_t size_of_hashes_; 1647}; 1648 1649// A small helper function to align an address. 1650 1651inline uint64_t 1652align_address(uint64_t address, uint64_t addralign) 1653{ 1654 if (addralign != 0) 1655 address = (address + addralign - 1) &~ (addralign - 1); 1656 return address; 1657} 1658 1659} // End namespace gold. 1660 1661#endif // !defined(GOLD_LAYOUT_H) 1662