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 (at) 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 39 namespace gold 40 { 41 42 class General_options; 43 class Incremental_inputs; 44 class Incremental_binary; 45 class Input_objects; 46 class Mapfile; 47 class Symbol_table; 48 class Output_section_data; 49 class Output_section; 50 class Output_section_headers; 51 class Output_segment_headers; 52 class Output_file_header; 53 class Output_segment; 54 class Output_data; 55 class Output_data_reloc_generic; 56 class Output_data_dynamic; 57 class Output_symtab_xindex; 58 class Output_reduced_debug_abbrev_section; 59 class Output_reduced_debug_info_section; 60 class Eh_frame; 61 class Gdb_index; 62 class Target; 63 struct Timespec; 64 65 // Return TRUE if SECNAME is the name of a compressed debug section. 66 extern bool 67 is_compressed_debug_section(const char* secname); 68 69 // Return the name of the corresponding uncompressed debug section. 70 extern std::string 71 corresponding_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 76 class 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. 168 169 class 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. 203 204 class 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. 391 392 enum 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. 491 492 class 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 const Output_data_reloc_generic* dyn_relr = NULL); 905 906 // Add a target-specific dynamic tag with constant value. 907 void 908 add_target_specific_dynamic_tag(elfcpp::DT tag, unsigned int val); 909 910 // Compute and write out the build ID if needed. 911 void 912 write_build_id(Output_file*, unsigned char*, size_t) const; 913 914 // Rewrite output file in binary format. 915 void 916 write_binary(Output_file* in) const; 917 918 // Print output sections to the map file. 919 void 920 print_to_mapfile(Mapfile*) const; 921 922 // Dump statistical information to stderr. 923 void 924 print_stats() const; 925 926 // A list of segments. 927 928 typedef std::vector<Output_segment*> Segment_list; 929 930 // A list of sections. 931 932 typedef std::vector<Output_section*> Section_list; 933 934 // The list of information to write out which is not attached to 935 // either a section or a segment. 936 typedef std::vector<Output_data*> Data_list; 937 938 // Store the allocated sections into the section list. This is used 939 // by the linker script code. 940 void 941 get_allocated_sections(Section_list*) const; 942 943 // Store the executable sections into the section list. 944 void 945 get_executable_sections(Section_list*) const; 946 947 // Make a section for a linker script to hold data. 948 Output_section* 949 make_output_section_for_script(const char* name, 950 Script_sections::Section_type section_type); 951 952 // Make a segment. This is used by the linker script code. 953 Output_segment* 954 make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags); 955 956 // Return the number of segments. 957 size_t 958 segment_count() const 959 { return this->segment_list_.size(); } 960 961 // Map from section flags to segment flags. 962 static elfcpp::Elf_Word 963 section_flags_to_segment(elfcpp::Elf_Xword flags); 964 965 // Attach sections to segments. 966 void 967 attach_sections_to_segments(const Target*); 968 969 // For relaxation clean up, we need to know output section data created 970 // from a linker script. 971 void 972 new_output_section_data_from_script(Output_section_data* posd) 973 { 974 if (this->record_output_section_data_from_script_) 975 this->script_output_section_data_list_.push_back(posd); 976 } 977 978 // Return section list. 979 const Section_list& 980 section_list() const 981 { return this->section_list_; } 982 983 // Returns TRUE iff NAME (an input section from RELOBJ) will 984 // be mapped to an output section that should be KEPT. 985 bool 986 keep_input_section(const Relobj*, const char*); 987 988 // Add a special output object that will be recreated afresh 989 // if there is another relaxation iteration. 990 void 991 add_relax_output(Output_data* data) 992 { this->relax_output_list_.push_back(data); } 993 994 // Clear out (and free) everything added by add_relax_output. 995 void 996 reset_relax_output(); 997 998 private: 999 Layout(const Layout&); 1000 Layout& operator=(const Layout&); 1001 1002 // Mapping from input section names to output section names. 1003 struct Section_name_mapping 1004 { 1005 const char* from; 1006 int fromlen; 1007 const char* to; 1008 int tolen; 1009 }; 1010 static const Section_name_mapping section_name_mapping[]; 1011 static const int section_name_mapping_count; 1012 1013 // During a relocatable link, a list of group sections and 1014 // signatures. 1015 struct Group_signature 1016 { 1017 // The group section. 1018 Output_section* section; 1019 // The signature. 1020 const char* signature; 1021 1022 Group_signature() 1023 : section(NULL), signature(NULL) 1024 { } 1025 1026 Group_signature(Output_section* sectiona, const char* signaturea) 1027 : section(sectiona), signature(signaturea) 1028 { } 1029 }; 1030 typedef std::vector<Group_signature> Group_signatures; 1031 1032 // Create a note section, filling in the header. 1033 Output_section* 1034 create_note(const char* name, int note_type, const char* section_name, 1035 size_t descsz, bool allocate, size_t* trailing_padding); 1036 1037 // Create a note section for gold version. 1038 void 1039 create_gold_note(); 1040 1041 // Record whether the stack must be executable, and a user-supplied size. 1042 void 1043 create_stack_segment(); 1044 1045 // Create a build ID note if needed. 1046 void 1047 create_build_id(); 1048 1049 // Link .stab and .stabstr sections. 1050 void 1051 link_stabs_sections(); 1052 1053 // Create .gnu_incremental_inputs and .gnu_incremental_strtab sections needed 1054 // for the next run of incremental linking to check what has changed. 1055 void 1056 create_incremental_info_sections(Symbol_table*); 1057 1058 // Find the first read-only PT_LOAD segment, creating one if 1059 // necessary. 1060 Output_segment* 1061 find_first_load_seg(const Target*); 1062 1063 // Count the local symbols in the regular symbol table and the dynamic 1064 // symbol table, and build the respective string pools. 1065 void 1066 count_local_symbols(const Task*, const Input_objects*); 1067 1068 // Create the output sections for the symbol table. 1069 void 1070 create_symtab_sections(const Input_objects*, Symbol_table*, 1071 unsigned int, off_t*); 1072 1073 // Create the .shstrtab section. 1074 Output_section* 1075 create_shstrtab(); 1076 1077 // Create the section header table. 1078 void 1079 create_shdrs(const Output_section* shstrtab_section, off_t*); 1080 1081 // Create the dynamic symbol table. 1082 void 1083 create_dynamic_symtab(const Input_objects*, Symbol_table*, 1084 Output_section** pdynstr, 1085 unsigned int* plocal_dynamic_count, 1086 std::vector<Symbol*>* pdynamic_symbols, 1087 Versions* versions); 1088 1089 // Assign offsets to each local portion of the dynamic symbol table. 1090 void 1091 assign_local_dynsym_offsets(const Input_objects*); 1092 1093 // Finish the .dynamic section and PT_DYNAMIC segment. 1094 void 1095 finish_dynamic_section(const Input_objects*, const Symbol_table*); 1096 1097 // Set the size of the _DYNAMIC symbol. 1098 void 1099 set_dynamic_symbol_size(const Symbol_table*); 1100 1101 // Create the .interp section and PT_INTERP segment. 1102 void 1103 create_interp(const Target* target); 1104 1105 // Create the version sections. 1106 void 1107 create_version_sections(const Versions*, 1108 const Symbol_table*, 1109 unsigned int local_symcount, 1110 const std::vector<Symbol*>& dynamic_symbols, 1111 const Output_section* dynstr); 1112 1113 template<int size, bool big_endian> 1114 void 1115 sized_create_version_sections(const Versions* versions, 1116 const Symbol_table*, 1117 unsigned int local_symcount, 1118 const std::vector<Symbol*>& dynamic_symbols, 1119 const Output_section* dynstr); 1120 1121 // Return whether to include this section in the link. 1122 template<int size, bool big_endian> 1123 bool 1124 include_section(Sized_relobj_file<size, big_endian>* object, const char* name, 1125 const elfcpp::Shdr<size, big_endian>&); 1126 1127 // Return the output section name to use given an input section 1128 // name. Set *PLEN to the length of the name. *PLEN must be 1129 // initialized to the length of NAME. 1130 static const char* 1131 output_section_name(const Relobj*, const char* name, size_t* plen); 1132 1133 // Return the number of allocated output sections. 1134 size_t 1135 allocated_output_section_count() const; 1136 1137 // Return the output section for NAME, TYPE and FLAGS. 1138 Output_section* 1139 get_output_section(const char* name, Stringpool::Key name_key, 1140 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, 1141 Output_section_order order, bool is_relro); 1142 1143 // Clear the input section flags that should not be copied to the 1144 // output section. 1145 elfcpp::Elf_Xword 1146 get_output_section_flags (elfcpp::Elf_Xword input_section_flags); 1147 1148 // Choose the output section for NAME in RELOBJ. 1149 Output_section* 1150 choose_output_section(const Relobj* relobj, const char* name, 1151 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, 1152 bool is_input_section, Output_section_order order, 1153 bool is_relro); 1154 1155 // Create a new Output_section. 1156 Output_section* 1157 make_output_section(const char* name, elfcpp::Elf_Word type, 1158 elfcpp::Elf_Xword flags, Output_section_order order, 1159 bool is_relro); 1160 1161 // Attach a section to a segment. 1162 void 1163 attach_section_to_segment(const Target*, Output_section*); 1164 1165 // Get section order. 1166 Output_section_order 1167 default_section_order(Output_section*, bool is_relro_local); 1168 1169 // Attach an allocated section to a segment. 1170 void 1171 attach_allocated_section_to_segment(const Target*, Output_section*); 1172 1173 // Make the .eh_frame section. 1174 Output_section* 1175 make_eh_frame_section(const Relobj*); 1176 1177 // Set the final file offsets of all the segments. 1178 off_t 1179 set_segment_offsets(const Target*, Output_segment*, unsigned int* pshndx); 1180 1181 // Set the file offsets of the sections when doing a relocatable 1182 // link. 1183 off_t 1184 set_relocatable_section_offsets(Output_data*, unsigned int* pshndx); 1185 1186 // Set the final file offsets of all the sections not associated 1187 // with a segment. We set section offsets in three passes: the 1188 // first handles all allocated sections, the second sections that 1189 // require postprocessing, and the last the late-bound STRTAB 1190 // sections (probably only shstrtab, which is the one we care about 1191 // because it holds section names). 1192 enum Section_offset_pass 1193 { 1194 BEFORE_INPUT_SECTIONS_PASS, 1195 POSTPROCESSING_SECTIONS_PASS, 1196 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS 1197 }; 1198 off_t 1199 set_section_offsets(off_t, Section_offset_pass pass); 1200 1201 // Set the final section indexes of all the sections not associated 1202 // with a segment. Returns the next unused index. 1203 unsigned int 1204 set_section_indexes(unsigned int pshndx); 1205 1206 // Set the section addresses when using a script. 1207 Output_segment* 1208 set_section_addresses_from_script(Symbol_table*); 1209 1210 // Find appropriate places or orphan sections in a script. 1211 void 1212 place_orphan_sections_in_script(); 1213 1214 // Return whether SEG1 comes before SEG2 in the output file. 1215 bool 1216 segment_precedes(const Output_segment* seg1, const Output_segment* seg2); 1217 1218 // Use to save and restore segments during relaxation. 1219 typedef Unordered_map<const Output_segment*, const Output_segment*> 1220 Segment_states; 1221 1222 // Save states of current output segments. 1223 void 1224 save_segments(Segment_states*); 1225 1226 // Restore output segment states. 1227 void 1228 restore_segments(const Segment_states*); 1229 1230 // Clean up after relaxation so that it is possible to lay out the 1231 // sections and segments again. 1232 void 1233 clean_up_after_relaxation(); 1234 1235 // Doing preparation work for relaxation. This is factored out to make 1236 // Layout::finalized a bit smaller and easier to read. 1237 void 1238 prepare_for_relaxation(); 1239 1240 // Main body of the relaxation loop, which lays out the section. 1241 off_t 1242 relaxation_loop_body(int, Target*, Symbol_table*, Output_segment**, 1243 Output_segment*, Output_segment_headers*, 1244 Output_file_header*, unsigned int*); 1245 1246 // A mapping used for kept comdats/.gnu.linkonce group signatures. 1247 typedef Unordered_map<std::string, Kept_section> Signatures; 1248 1249 // Mapping from input section name/type/flags to output section. We 1250 // use canonicalized strings here. 1251 1252 typedef std::pair<Stringpool::Key, 1253 std::pair<elfcpp::Elf_Word, elfcpp::Elf_Xword> > Key; 1254 1255 struct Hash_key 1256 { 1257 size_t 1258 operator()(const Key& k) const; 1259 }; 1260 1261 typedef Unordered_map<Key, Output_section*, Hash_key> Section_name_map; 1262 1263 // A comparison class for segments. 1264 1265 class Compare_segments 1266 { 1267 public: 1268 Compare_segments(Layout* layout) 1269 : layout_(layout) 1270 { } 1271 1272 bool 1273 operator()(const Output_segment* seg1, const Output_segment* seg2) 1274 { return this->layout_->segment_precedes(seg1, seg2); } 1275 1276 private: 1277 Layout* layout_; 1278 }; 1279 1280 typedef std::vector<Output_section_data*> Output_section_data_list; 1281 1282 // Debug checker class. 1283 class Relaxation_debug_check 1284 { 1285 public: 1286 Relaxation_debug_check() 1287 : section_infos_() 1288 { } 1289 1290 // Check that sections and special data are in reset states. 1291 void 1292 check_output_data_for_reset_values(const Layout::Section_list&, 1293 const Layout::Data_list& special_outputs, 1294 const Layout::Data_list& relax_outputs); 1295 1296 // Record information of a section list. 1297 void 1298 read_sections(const Layout::Section_list&); 1299 1300 // Verify a section list with recorded information. 1301 void 1302 verify_sections(const Layout::Section_list&); 1303 1304 private: 1305 // Information we care about a section. 1306 struct Section_info 1307 { 1308 // Output section described by this. 1309 Output_section* output_section; 1310 // Load address. 1311 uint64_t address; 1312 // Data size. 1313 off_t data_size; 1314 // File offset. 1315 off_t offset; 1316 }; 1317 1318 // Section information. 1319 std::vector<Section_info> section_infos_; 1320 }; 1321 1322 // The number of input files, for sizing tables. 1323 int number_of_input_files_; 1324 // Information set by scripts or by command line options. 1325 Script_options* script_options_; 1326 // The output section names. 1327 Stringpool namepool_; 1328 // The output symbol names. 1329 Stringpool sympool_; 1330 // The dynamic strings, if needed. 1331 Stringpool dynpool_; 1332 // The list of group sections and linkonce sections which we have seen. 1333 Signatures signatures_; 1334 // The mapping from input section name/type/flags to output sections. 1335 Section_name_map section_name_map_; 1336 // The list of output segments. 1337 Segment_list segment_list_; 1338 // The list of output sections. 1339 Section_list section_list_; 1340 // The list of output sections which are not attached to any output 1341 // segment. 1342 Section_list unattached_section_list_; 1343 // The list of unattached Output_data objects which require special 1344 // handling because they are not Output_sections. 1345 Data_list special_output_list_; 1346 // Like special_output_list_, but cleared and recreated on each 1347 // iteration of relaxation. 1348 Data_list relax_output_list_; 1349 // The section headers. 1350 Output_section_headers* section_headers_; 1351 // A pointer to the PT_TLS segment if there is one. 1352 Output_segment* tls_segment_; 1353 // A pointer to the PT_GNU_RELRO segment if there is one. 1354 Output_segment* relro_segment_; 1355 // A pointer to the PT_INTERP segment if there is one. 1356 Output_segment* interp_segment_; 1357 // A backend may increase the size of the PT_GNU_RELRO segment if 1358 // there is one. This is the amount to increase it by. 1359 unsigned int increase_relro_; 1360 // The SHT_SYMTAB output section. 1361 Output_section* symtab_section_; 1362 // The SHT_SYMTAB_SHNDX for the regular symbol table if there is one. 1363 Output_symtab_xindex* symtab_xindex_; 1364 // The SHT_DYNSYM output section if there is one. 1365 Output_section* dynsym_section_; 1366 // The SHT_SYMTAB_SHNDX for the dynamic symbol table if there is one. 1367 Output_symtab_xindex* dynsym_xindex_; 1368 // The SHT_DYNAMIC output section if there is one. 1369 Output_section* dynamic_section_; 1370 // The _DYNAMIC symbol if there is one. 1371 Symbol* dynamic_symbol_; 1372 // The dynamic data which goes into dynamic_section_. 1373 Output_data_dynamic* dynamic_data_; 1374 // The exception frame output section if there is one. 1375 Output_section* eh_frame_section_; 1376 // The exception frame data for eh_frame_section_. 1377 Eh_frame* eh_frame_data_; 1378 // Whether we have added eh_frame_data_ to the .eh_frame section. 1379 bool added_eh_frame_data_; 1380 // The exception frame header output section if there is one. 1381 Output_section* eh_frame_hdr_section_; 1382 // The data for the .gdb_index section. 1383 Gdb_index* gdb_index_data_; 1384 // The space for the build ID checksum if there is one. 1385 Output_section_data* build_id_note_; 1386 // The output section containing dwarf abbreviations 1387 Output_reduced_debug_abbrev_section* debug_abbrev_; 1388 // The output section containing the dwarf debug info tree 1389 Output_reduced_debug_info_section* debug_info_; 1390 // A list of group sections and their signatures. 1391 Group_signatures group_signatures_; 1392 // The size of the output file. 1393 off_t output_file_size_; 1394 // Whether we have added an input section to an output section. 1395 bool have_added_input_section_; 1396 // Whether we have attached the sections to the segments. 1397 bool sections_are_attached_; 1398 // Whether we have seen an object file marked to require an 1399 // executable stack. 1400 bool input_requires_executable_stack_; 1401 // Whether we have seen at least one object file with an executable 1402 // stack marker. 1403 bool input_with_gnu_stack_note_; 1404 // Whether we have seen at least one object file without an 1405 // executable stack marker. 1406 bool input_without_gnu_stack_note_; 1407 // Whether we have seen an object file that uses the static TLS model. 1408 bool has_static_tls_; 1409 // Whether any sections require postprocessing. 1410 bool any_postprocessing_sections_; 1411 // Whether we have resized the signatures_ hash table. 1412 bool resized_signatures_; 1413 // Whether we have created a .stab*str output section. 1414 bool have_stabstr_section_; 1415 // True if the input sections in the output sections should be sorted 1416 // as specified in a section ordering file. 1417 bool section_ordering_specified_; 1418 // True if some input sections need to be mapped to a unique segment, 1419 // after being mapped to a unique Output_section. 1420 bool unique_segment_for_sections_specified_; 1421 // In incremental build, holds information check the inputs and build the 1422 // .gnu_incremental_inputs section. 1423 Incremental_inputs* incremental_inputs_; 1424 // Whether we record output section data created in script 1425 bool record_output_section_data_from_script_; 1426 // List of output data that needs to be removed at relaxation clean up. 1427 Output_section_data_list script_output_section_data_list_; 1428 // Structure to save segment states before entering the relaxation loop. 1429 Segment_states* segment_states_; 1430 // A relaxation debug checker. We only create one when in debugging mode. 1431 Relaxation_debug_check* relaxation_debug_check_; 1432 // Plugins specify section_ordering using this map. This is set in 1433 // update_section_order in plugin.cc 1434 std::map<Section_id, unsigned int> section_order_map_; 1435 // This maps an input section to a unique segment. This is done by first 1436 // placing such input sections in unique output sections and then mapping 1437 // the output section to a unique segment. Unique_segment_info stores 1438 // any additional flags and alignment of the new segment. 1439 Section_segment_map section_segment_map_; 1440 // Hash a pattern to its position in the section ordering file. 1441 Unordered_map<std::string, unsigned int> input_section_position_; 1442 // Vector of glob only patterns in the section_ordering file. 1443 std::vector<std::string> input_section_glob_; 1444 // For incremental links, the base file to be modified. 1445 Incremental_binary* incremental_base_; 1446 // For incremental links, a list of free space within the file. 1447 Free_list free_list_; 1448 }; 1449 1450 // This task handles writing out data in output sections which is not 1451 // part of an input section, or which requires special handling. When 1452 // this is done, it unblocks both output_sections_blocker and 1453 // final_blocker. 1454 1455 class Write_sections_task : public Task 1456 { 1457 public: 1458 Write_sections_task(const Layout* layout, Output_file* of, 1459 Task_token* output_sections_blocker, 1460 Task_token* input_sections_blocker, 1461 Task_token* final_blocker) 1462 : layout_(layout), of_(of), 1463 output_sections_blocker_(output_sections_blocker), 1464 input_sections_blocker_(input_sections_blocker), 1465 final_blocker_(final_blocker) 1466 { } 1467 1468 // The standard Task methods. 1469 1470 Task_token* 1471 is_runnable(); 1472 1473 void 1474 locks(Task_locker*); 1475 1476 void 1477 run(Workqueue*); 1478 1479 std::string 1480 get_name() const 1481 { return "Write_sections_task"; } 1482 1483 private: 1484 class Write_sections_locker; 1485 1486 const Layout* layout_; 1487 Output_file* of_; 1488 Task_token* output_sections_blocker_; 1489 Task_token* input_sections_blocker_; 1490 Task_token* final_blocker_; 1491 }; 1492 1493 // This task handles writing out data which is not part of a section 1494 // or segment. 1495 1496 class Write_data_task : public Task 1497 { 1498 public: 1499 Write_data_task(const Layout* layout, const Symbol_table* symtab, 1500 Output_file* of, Task_token* final_blocker) 1501 : layout_(layout), symtab_(symtab), of_(of), final_blocker_(final_blocker) 1502 { } 1503 1504 // The standard Task methods. 1505 1506 Task_token* 1507 is_runnable(); 1508 1509 void 1510 locks(Task_locker*); 1511 1512 void 1513 run(Workqueue*); 1514 1515 std::string 1516 get_name() const 1517 { return "Write_data_task"; } 1518 1519 private: 1520 const Layout* layout_; 1521 const Symbol_table* symtab_; 1522 Output_file* of_; 1523 Task_token* final_blocker_; 1524 }; 1525 1526 // This task handles writing out the global symbols. 1527 1528 class Write_symbols_task : public Task 1529 { 1530 public: 1531 Write_symbols_task(const Layout* layout, const Symbol_table* symtab, 1532 const Input_objects* /*input_objects*/, 1533 const Stringpool* sympool, const Stringpool* dynpool, 1534 Output_file* of, Task_token* final_blocker) 1535 : layout_(layout), symtab_(symtab), 1536 sympool_(sympool), dynpool_(dynpool), of_(of), 1537 final_blocker_(final_blocker) 1538 { } 1539 1540 // The standard Task methods. 1541 1542 Task_token* 1543 is_runnable(); 1544 1545 void 1546 locks(Task_locker*); 1547 1548 void 1549 run(Workqueue*); 1550 1551 std::string 1552 get_name() const 1553 { return "Write_symbols_task"; } 1554 1555 private: 1556 const Layout* layout_; 1557 const Symbol_table* symtab_; 1558 const Stringpool* sympool_; 1559 const Stringpool* dynpool_; 1560 Output_file* of_; 1561 Task_token* final_blocker_; 1562 }; 1563 1564 // This task handles writing out data in output sections which can't 1565 // be written out until all the input sections have been handled. 1566 // This is for sections whose contents is based on the contents of 1567 // other output sections. 1568 1569 class Write_after_input_sections_task : public Task 1570 { 1571 public: 1572 Write_after_input_sections_task(Layout* layout, Output_file* of, 1573 Task_token* input_sections_blocker, 1574 Task_token* final_blocker) 1575 : layout_(layout), of_(of), 1576 input_sections_blocker_(input_sections_blocker), 1577 final_blocker_(final_blocker) 1578 { } 1579 1580 // The standard Task methods. 1581 1582 Task_token* 1583 is_runnable(); 1584 1585 void 1586 locks(Task_locker*); 1587 1588 void 1589 run(Workqueue*); 1590 1591 std::string 1592 get_name() const 1593 { return "Write_after_input_sections_task"; } 1594 1595 private: 1596 Layout* layout_; 1597 Output_file* of_; 1598 Task_token* input_sections_blocker_; 1599 Task_token* final_blocker_; 1600 }; 1601 1602 // This task function handles computation of the build id. 1603 // When using --build-id=tree, it schedules the tasks that 1604 // compute the hashes for each chunk of the file. This task 1605 // cannot run until we have finalized the size of the output 1606 // file, after the completion of Write_after_input_sections_task. 1607 1608 class Build_id_task_runner : public Task_function_runner 1609 { 1610 public: 1611 Build_id_task_runner(const General_options* options, const Layout* layout, 1612 Output_file* of) 1613 : options_(options), layout_(layout), of_(of) 1614 { } 1615 1616 // Run the operation. 1617 void 1618 run(Workqueue*, const Task*); 1619 1620 private: 1621 const General_options* options_; 1622 const Layout* layout_; 1623 Output_file* of_; 1624 }; 1625 1626 // This task function handles closing the file. 1627 1628 class Close_task_runner : public Task_function_runner 1629 { 1630 public: 1631 Close_task_runner(const General_options* options, const Layout* layout, 1632 Output_file* of, unsigned char* array_of_hashes, 1633 size_t size_of_hashes) 1634 : options_(options), layout_(layout), of_(of), 1635 array_of_hashes_(array_of_hashes), size_of_hashes_(size_of_hashes) 1636 { } 1637 1638 // Run the operation. 1639 void 1640 run(Workqueue*, const Task*); 1641 1642 private: 1643 const General_options* options_; 1644 const Layout* layout_; 1645 Output_file* of_; 1646 unsigned char* const array_of_hashes_; 1647 const size_t size_of_hashes_; 1648 }; 1649 1650 // A small helper function to align an address. 1651 1652 inline uint64_t 1653 align_address(uint64_t address, uint64_t addralign) 1654 { 1655 if (addralign != 0) 1656 address = (address + addralign - 1) &~ (addralign - 1); 1657 return address; 1658 } 1659 1660 } // End namespace gold. 1661 1662 #endif // !defined(GOLD_LAYOUT_H) 1663