1 // output.h -- manage the output file for gold -*- C++ -*- 2 3 // Copyright (C) 2006-2021 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_OUTPUT_H 24 #define GOLD_OUTPUT_H 25 26 #include <algorithm> 27 #include <list> 28 #include <vector> 29 30 #include "elfcpp.h" 31 #include "mapfile.h" 32 #include "layout.h" 33 #include "reloc-types.h" 34 35 namespace gold 36 { 37 38 class General_options; 39 class Object; 40 class Symbol; 41 class Output_merge_base; 42 class Output_section; 43 class Relocatable_relocs; 44 class Target; 45 template<int size, bool big_endian> 46 class Sized_target; 47 template<int size, bool big_endian> 48 class Sized_relobj; 49 template<int size, bool big_endian> 50 class Sized_relobj_file; 51 52 // This class represents the output file. 53 54 class Output_file 55 { 56 public: 57 Output_file(const char* name); 58 59 // Indicate that this is a temporary file which should not be 60 // output. 61 void set_is_temporary()62 set_is_temporary() 63 { this->is_temporary_ = true; } 64 65 // Try to open an existing file. Returns false if the file doesn't 66 // exist, has a size of 0 or can't be mmaped. This method is 67 // thread-unsafe. If BASE_NAME is not NULL, use the contents of 68 // that file as the base for incremental linking. 69 bool 70 open_base_file(const char* base_name, bool writable); 71 72 // Open the output file. FILE_SIZE is the final size of the file. 73 // If the file already exists, it is deleted/truncated. This method 74 // is thread-unsafe. 75 void 76 open(off_t file_size); 77 78 // Resize the output file. This method is thread-unsafe. 79 void 80 resize(off_t file_size); 81 82 // Close the output file (flushing all buffered data) and make sure 83 // there are no errors. This method is thread-unsafe. 84 void 85 close(); 86 87 // Return the size of this file. 88 off_t filesize()89 filesize() 90 { return this->file_size_; } 91 92 // Return the name of this file. 93 const char* filename()94 filename() 95 { return this->name_; } 96 97 // We currently always use mmap which makes the view handling quite 98 // simple. In the future we may support other approaches. 99 100 // Write data to the output file. 101 void write(off_t offset,const void * data,size_t len)102 write(off_t offset, const void* data, size_t len) 103 { memcpy(this->base_ + offset, data, len); } 104 105 // Get a buffer to use to write to the file, given the offset into 106 // the file and the size. 107 unsigned char* get_output_view(off_t start,size_t size)108 get_output_view(off_t start, size_t size) 109 { 110 gold_assert(start >= 0 111 && start + static_cast<off_t>(size) <= this->file_size_); 112 return this->base_ + start; 113 } 114 115 // VIEW must have been returned by get_output_view. Write the 116 // buffer to the file, passing in the offset and the size. 117 void write_output_view(off_t,size_t,unsigned char *)118 write_output_view(off_t, size_t, unsigned char*) 119 { } 120 121 // Get a read/write buffer. This is used when we want to write part 122 // of the file, read it in, and write it again. 123 unsigned char* get_input_output_view(off_t start,size_t size)124 get_input_output_view(off_t start, size_t size) 125 { return this->get_output_view(start, size); } 126 127 // Write a read/write buffer back to the file. 128 void write_input_output_view(off_t,size_t,unsigned char *)129 write_input_output_view(off_t, size_t, unsigned char*) 130 { } 131 132 // Get a read buffer. This is used when we just want to read part 133 // of the file back it in. 134 const unsigned char* get_input_view(off_t start,size_t size)135 get_input_view(off_t start, size_t size) 136 { return this->get_output_view(start, size); } 137 138 // Release a read bfufer. 139 void free_input_view(off_t,size_t,const unsigned char *)140 free_input_view(off_t, size_t, const unsigned char*) 141 { } 142 143 private: 144 // Map the file into memory or, if that fails, allocate anonymous 145 // memory. 146 void 147 map(); 148 149 // Allocate anonymous memory for the file. 150 bool 151 map_anonymous(); 152 153 // Map the file into memory. 154 bool 155 map_no_anonymous(bool); 156 157 // Unmap the file from memory (and flush to disk buffers). 158 void 159 unmap(); 160 161 // File name. 162 const char* name_; 163 // File descriptor. 164 int o_; 165 // File size. 166 off_t file_size_; 167 // Base of file mapped into memory. 168 unsigned char* base_; 169 // True iff base_ points to a memory buffer rather than an output file. 170 bool map_is_anonymous_; 171 // True if base_ was allocated using new rather than mmap. 172 bool map_is_allocated_; 173 // True if this is a temporary file which should not be output. 174 bool is_temporary_; 175 }; 176 177 // An abtract class for data which has to go into the output file. 178 179 class Output_data 180 { 181 public: Output_data()182 explicit Output_data() 183 : address_(0), data_size_(0), offset_(-1), 184 is_address_valid_(false), is_data_size_valid_(false), 185 is_offset_valid_(false), is_data_size_fixed_(false), 186 has_dynamic_reloc_(false) 187 { } 188 189 virtual 190 ~Output_data(); 191 192 // Return the address. For allocated sections, this is only valid 193 // after Layout::finalize is finished. 194 uint64_t address()195 address() const 196 { 197 gold_assert(this->is_address_valid_); 198 return this->address_; 199 } 200 201 // Return the size of the data. For allocated sections, this must 202 // be valid after Layout::finalize calls set_address, but need not 203 // be valid before then. 204 off_t data_size()205 data_size() const 206 { 207 gold_assert(this->is_data_size_valid_); 208 return this->data_size_; 209 } 210 211 // Get the current data size. 212 off_t current_data_size()213 current_data_size() const 214 { return this->current_data_size_for_child(); } 215 216 // Return true if data size is fixed. 217 bool is_data_size_fixed()218 is_data_size_fixed() const 219 { return this->is_data_size_fixed_; } 220 221 // Return the file offset. This is only valid after 222 // Layout::finalize is finished. For some non-allocated sections, 223 // it may not be valid until near the end of the link. 224 off_t offset()225 offset() const 226 { 227 gold_assert(this->is_offset_valid_); 228 return this->offset_; 229 } 230 231 // Reset the address, file offset and data size. This essentially 232 // disables the sanity testing about duplicate and unknown settings. 233 void reset_address_and_file_offset()234 reset_address_and_file_offset() 235 { 236 this->is_address_valid_ = false; 237 this->is_offset_valid_ = false; 238 if (!this->is_data_size_fixed_) 239 this->is_data_size_valid_ = false; 240 this->do_reset_address_and_file_offset(); 241 } 242 243 // As above, but just for data size. 244 void reset_data_size()245 reset_data_size() 246 { 247 if (!this->is_data_size_fixed_) 248 this->is_data_size_valid_ = false; 249 } 250 251 // Return true if address and file offset already have reset values. In 252 // other words, calling reset_address_and_file_offset will not change them. 253 bool address_and_file_offset_have_reset_values()254 address_and_file_offset_have_reset_values() const 255 { return this->do_address_and_file_offset_have_reset_values(); } 256 257 // Return the required alignment. 258 uint64_t addralign()259 addralign() const 260 { return this->do_addralign(); } 261 262 // Return whether this has a load address. 263 bool has_load_address()264 has_load_address() const 265 { return this->do_has_load_address(); } 266 267 // Return the load address. 268 uint64_t load_address()269 load_address() const 270 { return this->do_load_address(); } 271 272 // Return whether this is an Output_section. 273 bool is_section()274 is_section() const 275 { return this->do_is_section(); } 276 277 // Return whether this is an Output_section of the specified type. 278 bool is_section_type(elfcpp::Elf_Word stt)279 is_section_type(elfcpp::Elf_Word stt) const 280 { return this->do_is_section_type(stt); } 281 282 // Return whether this is an Output_section with the specified flag 283 // set. 284 bool is_section_flag_set(elfcpp::Elf_Xword shf)285 is_section_flag_set(elfcpp::Elf_Xword shf) const 286 { return this->do_is_section_flag_set(shf); } 287 288 // Return the output section that this goes in, if there is one. 289 Output_section* output_section()290 output_section() 291 { return this->do_output_section(); } 292 293 const Output_section* output_section()294 output_section() const 295 { return this->do_output_section(); } 296 297 // Return the output section index, if there is an output section. 298 unsigned int out_shndx()299 out_shndx() const 300 { return this->do_out_shndx(); } 301 302 // Set the output section index, if this is an output section. 303 void set_out_shndx(unsigned int shndx)304 set_out_shndx(unsigned int shndx) 305 { this->do_set_out_shndx(shndx); } 306 307 // Set the address and file offset of this data, and finalize the 308 // size of the data. This is called during Layout::finalize for 309 // allocated sections. 310 void set_address_and_file_offset(uint64_t addr,off_t off)311 set_address_and_file_offset(uint64_t addr, off_t off) 312 { 313 this->set_address(addr); 314 this->set_file_offset(off); 315 this->finalize_data_size(); 316 } 317 318 // Set the address. 319 void set_address(uint64_t addr)320 set_address(uint64_t addr) 321 { 322 gold_assert(!this->is_address_valid_); 323 this->address_ = addr; 324 this->is_address_valid_ = true; 325 } 326 327 // Set the file offset. 328 void set_file_offset(off_t off)329 set_file_offset(off_t off) 330 { 331 gold_assert(!this->is_offset_valid_); 332 this->offset_ = off; 333 this->is_offset_valid_ = true; 334 } 335 336 // Update the data size without finalizing it. 337 void pre_finalize_data_size()338 pre_finalize_data_size() 339 { 340 if (!this->is_data_size_valid_) 341 { 342 // Tell the child class to update the data size. 343 this->update_data_size(); 344 } 345 } 346 347 // Finalize the data size. 348 void finalize_data_size()349 finalize_data_size() 350 { 351 if (!this->is_data_size_valid_) 352 { 353 // Tell the child class to set the data size. 354 this->set_final_data_size(); 355 gold_assert(this->is_data_size_valid_); 356 } 357 } 358 359 // Set the TLS offset. Called only for SHT_TLS sections. 360 void set_tls_offset(uint64_t tls_base)361 set_tls_offset(uint64_t tls_base) 362 { this->do_set_tls_offset(tls_base); } 363 364 // Return the TLS offset, relative to the base of the TLS segment. 365 // Valid only for SHT_TLS sections. 366 uint64_t tls_offset()367 tls_offset() const 368 { return this->do_tls_offset(); } 369 370 // Write the data to the output file. This is called after 371 // Layout::finalize is complete. 372 void write(Output_file * file)373 write(Output_file* file) 374 { this->do_write(file); } 375 376 // This is called by Layout::finalize to note that the sizes of 377 // allocated sections must now be fixed. 378 static void layout_complete()379 layout_complete() 380 { Output_data::allocated_sizes_are_fixed = true; } 381 382 // Used to check that layout has been done. 383 static bool is_layout_complete()384 is_layout_complete() 385 { return Output_data::allocated_sizes_are_fixed; } 386 387 // Note that a dynamic reloc has been applied to this data. 388 void add_dynamic_reloc()389 add_dynamic_reloc() 390 { this->has_dynamic_reloc_ = true; } 391 392 // Return whether a dynamic reloc has been applied. 393 bool has_dynamic_reloc()394 has_dynamic_reloc() const 395 { return this->has_dynamic_reloc_; } 396 397 // Whether the address is valid. 398 bool is_address_valid()399 is_address_valid() const 400 { return this->is_address_valid_; } 401 402 // Whether the file offset is valid. 403 bool is_offset_valid()404 is_offset_valid() const 405 { return this->is_offset_valid_; } 406 407 // Whether the data size is valid. 408 bool is_data_size_valid()409 is_data_size_valid() const 410 { return this->is_data_size_valid_; } 411 412 // Print information to the map file. 413 void print_to_mapfile(Mapfile * mapfile)414 print_to_mapfile(Mapfile* mapfile) const 415 { return this->do_print_to_mapfile(mapfile); } 416 417 protected: 418 // Functions that child classes may or in some cases must implement. 419 420 // Write the data to the output file. 421 virtual void 422 do_write(Output_file*) = 0; 423 424 // Return the required alignment. 425 virtual uint64_t 426 do_addralign() const = 0; 427 428 // Return whether this has a load address. 429 virtual bool do_has_load_address()430 do_has_load_address() const 431 { return false; } 432 433 // Return the load address. 434 virtual uint64_t do_load_address()435 do_load_address() const 436 { gold_unreachable(); } 437 438 // Return whether this is an Output_section. 439 virtual bool do_is_section()440 do_is_section() const 441 { return false; } 442 443 // Return whether this is an Output_section of the specified type. 444 // This only needs to be implement by Output_section. 445 virtual bool do_is_section_type(elfcpp::Elf_Word)446 do_is_section_type(elfcpp::Elf_Word) const 447 { return false; } 448 449 // Return whether this is an Output_section with the specific flag 450 // set. This only needs to be implemented by Output_section. 451 virtual bool do_is_section_flag_set(elfcpp::Elf_Xword)452 do_is_section_flag_set(elfcpp::Elf_Xword) const 453 { return false; } 454 455 // Return the output section, if there is one. 456 virtual Output_section* do_output_section()457 do_output_section() 458 { return NULL; } 459 460 virtual const Output_section* do_output_section()461 do_output_section() const 462 { return NULL; } 463 464 // Return the output section index, if there is an output section. 465 virtual unsigned int do_out_shndx()466 do_out_shndx() const 467 { gold_unreachable(); } 468 469 // Set the output section index, if this is an output section. 470 virtual void do_set_out_shndx(unsigned int)471 do_set_out_shndx(unsigned int) 472 { gold_unreachable(); } 473 474 // This is a hook for derived classes to set the preliminary data size. 475 // This is called by pre_finalize_data_size, normally called during 476 // Layout::finalize, before the section address is set, and is used 477 // during an incremental update, when we need to know the size of a 478 // section before allocating space in the output file. For classes 479 // where the current data size is up to date, this default version of 480 // the method can be inherited. 481 virtual void update_data_size()482 update_data_size() 483 { } 484 485 // This is a hook for derived classes to set the data size. This is 486 // called by finalize_data_size, normally called during 487 // Layout::finalize, when the section address is set. 488 virtual void set_final_data_size()489 set_final_data_size() 490 { gold_unreachable(); } 491 492 // A hook for resetting the address and file offset. 493 virtual void do_reset_address_and_file_offset()494 do_reset_address_and_file_offset() 495 { } 496 497 // Return true if address and file offset already have reset values. In 498 // other words, calling reset_address_and_file_offset will not change them. 499 // A child class overriding do_reset_address_and_file_offset may need to 500 // also override this. 501 virtual bool do_address_and_file_offset_have_reset_values()502 do_address_and_file_offset_have_reset_values() const 503 { return !this->is_address_valid_ && !this->is_offset_valid_; } 504 505 // Set the TLS offset. Called only for SHT_TLS sections. 506 virtual void do_set_tls_offset(uint64_t)507 do_set_tls_offset(uint64_t) 508 { gold_unreachable(); } 509 510 // Return the TLS offset, relative to the base of the TLS segment. 511 // Valid only for SHT_TLS sections. 512 virtual uint64_t do_tls_offset()513 do_tls_offset() const 514 { gold_unreachable(); } 515 516 // Print to the map file. This only needs to be implemented by 517 // classes which may appear in a PT_LOAD segment. 518 virtual void do_print_to_mapfile(Mapfile *)519 do_print_to_mapfile(Mapfile*) const 520 { gold_unreachable(); } 521 522 // Functions that child classes may call. 523 524 // Reset the address. The Output_section class needs this when an 525 // SHF_ALLOC input section is added to an output section which was 526 // formerly not SHF_ALLOC. 527 void mark_address_invalid()528 mark_address_invalid() 529 { this->is_address_valid_ = false; } 530 531 // Set the size of the data. 532 void set_data_size(off_t data_size)533 set_data_size(off_t data_size) 534 { 535 gold_assert(!this->is_data_size_valid_ 536 && !this->is_data_size_fixed_); 537 this->data_size_ = data_size; 538 this->is_data_size_valid_ = true; 539 } 540 541 // Fix the data size. Once it is fixed, it cannot be changed 542 // and the data size remains always valid. 543 void fix_data_size()544 fix_data_size() 545 { 546 gold_assert(this->is_data_size_valid_); 547 this->is_data_size_fixed_ = true; 548 } 549 550 // Get the current data size--this is for the convenience of 551 // sections which build up their size over time. 552 off_t current_data_size_for_child()553 current_data_size_for_child() const 554 { return this->data_size_; } 555 556 // Set the current data size--this is for the convenience of 557 // sections which build up their size over time. 558 void set_current_data_size_for_child(off_t data_size)559 set_current_data_size_for_child(off_t data_size) 560 { 561 gold_assert(!this->is_data_size_valid_); 562 this->data_size_ = data_size; 563 } 564 565 // Return default alignment for the target size. 566 static uint64_t 567 default_alignment(); 568 569 // Return default alignment for a specified size--32 or 64. 570 static uint64_t 571 default_alignment_for_size(int size); 572 573 private: 574 Output_data(const Output_data&); 575 Output_data& operator=(const Output_data&); 576 577 // This is used for verification, to make sure that we don't try to 578 // change any sizes of allocated sections after we set the section 579 // addresses. 580 static bool allocated_sizes_are_fixed; 581 582 // Memory address in output file. 583 uint64_t address_; 584 // Size of data in output file. 585 off_t data_size_; 586 // File offset of contents in output file. 587 off_t offset_; 588 // Whether address_ is valid. 589 bool is_address_valid_ : 1; 590 // Whether data_size_ is valid. 591 bool is_data_size_valid_ : 1; 592 // Whether offset_ is valid. 593 bool is_offset_valid_ : 1; 594 // Whether data size is fixed. 595 bool is_data_size_fixed_ : 1; 596 // Whether any dynamic relocs have been applied to this section. 597 bool has_dynamic_reloc_ : 1; 598 }; 599 600 // Output the section headers. 601 602 class Output_section_headers : public Output_data 603 { 604 public: 605 Output_section_headers(const Layout*, 606 const Layout::Segment_list*, 607 const Layout::Section_list*, 608 const Layout::Section_list*, 609 const Stringpool*, 610 const Output_section*); 611 612 protected: 613 // Write the data to the file. 614 void 615 do_write(Output_file*); 616 617 // Return the required alignment. 618 uint64_t do_addralign()619 do_addralign() const 620 { return Output_data::default_alignment(); } 621 622 // Write to a map file. 623 void do_print_to_mapfile(Mapfile * mapfile)624 do_print_to_mapfile(Mapfile* mapfile) const 625 { mapfile->print_output_data(this, _("** section headers")); } 626 627 // Update the data size. 628 void update_data_size()629 update_data_size() 630 { this->set_data_size(this->do_size()); } 631 632 // Set final data size. 633 void set_final_data_size()634 set_final_data_size() 635 { this->set_data_size(this->do_size()); } 636 637 private: 638 // Write the data to the file with the right size and endianness. 639 template<int size, bool big_endian> 640 void 641 do_sized_write(Output_file*); 642 643 // Compute data size. 644 off_t 645 do_size() const; 646 647 const Layout* layout_; 648 const Layout::Segment_list* segment_list_; 649 const Layout::Section_list* section_list_; 650 const Layout::Section_list* unattached_section_list_; 651 const Stringpool* secnamepool_; 652 const Output_section* shstrtab_section_; 653 }; 654 655 // Output the segment headers. 656 657 class Output_segment_headers : public Output_data 658 { 659 public: 660 Output_segment_headers(const Layout::Segment_list& segment_list); 661 662 protected: 663 // Write the data to the file. 664 void 665 do_write(Output_file*); 666 667 // Return the required alignment. 668 uint64_t do_addralign()669 do_addralign() const 670 { return Output_data::default_alignment(); } 671 672 // Write to a map file. 673 void do_print_to_mapfile(Mapfile * mapfile)674 do_print_to_mapfile(Mapfile* mapfile) const 675 { mapfile->print_output_data(this, _("** segment headers")); } 676 677 // Set final data size. 678 void set_final_data_size()679 set_final_data_size() 680 { this->set_data_size(this->do_size()); } 681 682 private: 683 // Write the data to the file with the right size and endianness. 684 template<int size, bool big_endian> 685 void 686 do_sized_write(Output_file*); 687 688 // Compute the current size. 689 off_t 690 do_size() const; 691 692 const Layout::Segment_list& segment_list_; 693 }; 694 695 // Output the ELF file header. 696 697 class Output_file_header : public Output_data 698 { 699 public: 700 Output_file_header(Target*, 701 const Symbol_table*, 702 const Output_segment_headers*); 703 704 // Add information about the section headers. We lay out the ELF 705 // file header before we create the section headers. 706 void set_section_info(const Output_section_headers*, 707 const Output_section* shstrtab); 708 709 protected: 710 // Write the data to the file. 711 void 712 do_write(Output_file*); 713 714 // Return the required alignment. 715 uint64_t do_addralign()716 do_addralign() const 717 { return Output_data::default_alignment(); } 718 719 // Write to a map file. 720 void do_print_to_mapfile(Mapfile * mapfile)721 do_print_to_mapfile(Mapfile* mapfile) const 722 { mapfile->print_output_data(this, _("** file header")); } 723 724 // Set final data size. 725 void set_final_data_size(void)726 set_final_data_size(void) 727 { this->set_data_size(this->do_size()); } 728 729 private: 730 // Write the data to the file with the right size and endianness. 731 template<int size, bool big_endian> 732 void 733 do_sized_write(Output_file*); 734 735 // Return the value to use for the entry address. 736 template<int size> 737 typename elfcpp::Elf_types<size>::Elf_Addr 738 entry(); 739 740 // Compute the current data size. 741 off_t 742 do_size() const; 743 744 Target* target_; 745 const Symbol_table* symtab_; 746 const Output_segment_headers* segment_header_; 747 const Output_section_headers* section_header_; 748 const Output_section* shstrtab_; 749 }; 750 751 // Output sections are mainly comprised of input sections. However, 752 // there are cases where we have data to write out which is not in an 753 // input section. Output_section_data is used in such cases. This is 754 // an abstract base class. 755 756 class Output_section_data : public Output_data 757 { 758 public: Output_section_data(off_t data_size,uint64_t addralign,bool is_data_size_fixed)759 Output_section_data(off_t data_size, uint64_t addralign, 760 bool is_data_size_fixed) 761 : Output_data(), output_section_(NULL), addralign_(addralign) 762 { 763 this->set_data_size(data_size); 764 if (is_data_size_fixed) 765 this->fix_data_size(); 766 } 767 Output_section_data(uint64_t addralign)768 Output_section_data(uint64_t addralign) 769 : Output_data(), output_section_(NULL), addralign_(addralign) 770 { } 771 772 // Return the output section. 773 Output_section* output_section()774 output_section() 775 { return this->output_section_; } 776 777 const Output_section* output_section()778 output_section() const 779 { return this->output_section_; } 780 781 // Record the output section. 782 void 783 set_output_section(Output_section* os); 784 785 // Add an input section, for SHF_MERGE sections. This returns true 786 // if the section was handled. 787 bool add_input_section(Relobj * object,unsigned int shndx)788 add_input_section(Relobj* object, unsigned int shndx) 789 { return this->do_add_input_section(object, shndx); } 790 791 // Given an input OBJECT, an input section index SHNDX within that 792 // object, and an OFFSET relative to the start of that input 793 // section, return whether or not the corresponding offset within 794 // the output section is known. If this function returns true, it 795 // sets *POUTPUT to the output offset. The value -1 indicates that 796 // this input offset is being discarded. 797 bool output_offset(const Relobj * object,unsigned int shndx,section_offset_type offset,section_offset_type * poutput)798 output_offset(const Relobj* object, unsigned int shndx, 799 section_offset_type offset, 800 section_offset_type* poutput) const 801 { return this->do_output_offset(object, shndx, offset, poutput); } 802 803 // Write the contents to a buffer. This is used for sections which 804 // require postprocessing, such as compression. 805 void write_to_buffer(unsigned char * buffer)806 write_to_buffer(unsigned char* buffer) 807 { this->do_write_to_buffer(buffer); } 808 809 // Print merge stats to stderr. This should only be called for 810 // SHF_MERGE sections. 811 void print_merge_stats(const char * section_name)812 print_merge_stats(const char* section_name) 813 { this->do_print_merge_stats(section_name); } 814 815 protected: 816 // The child class must implement do_write. 817 818 // The child class may implement specific adjustments to the output 819 // section. 820 virtual void do_adjust_output_section(Output_section *)821 do_adjust_output_section(Output_section*) 822 { } 823 824 // May be implemented by child class. Return true if the section 825 // was handled. 826 virtual bool do_add_input_section(Relobj *,unsigned int)827 do_add_input_section(Relobj*, unsigned int) 828 { gold_unreachable(); } 829 830 // The child class may implement output_offset. 831 virtual bool do_output_offset(const Relobj *,unsigned int,section_offset_type,section_offset_type *)832 do_output_offset(const Relobj*, unsigned int, section_offset_type, 833 section_offset_type*) const 834 { return false; } 835 836 // The child class may implement write_to_buffer. Most child 837 // classes can not appear in a compressed section, and they do not 838 // implement this. 839 virtual void do_write_to_buffer(unsigned char *)840 do_write_to_buffer(unsigned char*) 841 { gold_unreachable(); } 842 843 // Print merge statistics. 844 virtual void do_print_merge_stats(const char *)845 do_print_merge_stats(const char*) 846 { gold_unreachable(); } 847 848 // Return the required alignment. 849 uint64_t do_addralign()850 do_addralign() const 851 { return this->addralign_; } 852 853 // Return the output section. 854 Output_section* do_output_section()855 do_output_section() 856 { return this->output_section_; } 857 858 const Output_section* do_output_section()859 do_output_section() const 860 { return this->output_section_; } 861 862 // Return the section index of the output section. 863 unsigned int 864 do_out_shndx() const; 865 866 // Set the alignment. 867 void 868 set_addralign(uint64_t addralign); 869 870 private: 871 // The output section for this section. 872 Output_section* output_section_; 873 // The required alignment. 874 uint64_t addralign_; 875 }; 876 877 // Some Output_section_data classes build up their data step by step, 878 // rather than all at once. This class provides an interface for 879 // them. 880 881 class Output_section_data_build : public Output_section_data 882 { 883 public: Output_section_data_build(uint64_t addralign)884 Output_section_data_build(uint64_t addralign) 885 : Output_section_data(addralign) 886 { } 887 Output_section_data_build(off_t data_size,uint64_t addralign)888 Output_section_data_build(off_t data_size, uint64_t addralign) 889 : Output_section_data(data_size, addralign, false) 890 { } 891 892 // Set the current data size. 893 void set_current_data_size(off_t data_size)894 set_current_data_size(off_t data_size) 895 { this->set_current_data_size_for_child(data_size); } 896 897 protected: 898 // Set the final data size. 899 virtual void set_final_data_size()900 set_final_data_size() 901 { this->set_data_size(this->current_data_size_for_child()); } 902 }; 903 904 // A simple case of Output_data in which we have constant data to 905 // output. 906 907 class Output_data_const : public Output_section_data 908 { 909 public: Output_data_const(const std::string & data,uint64_t addralign)910 Output_data_const(const std::string& data, uint64_t addralign) 911 : Output_section_data(data.size(), addralign, true), data_(data) 912 { } 913 Output_data_const(const char * p,off_t len,uint64_t addralign)914 Output_data_const(const char* p, off_t len, uint64_t addralign) 915 : Output_section_data(len, addralign, true), data_(p, len) 916 { } 917 Output_data_const(const unsigned char * p,off_t len,uint64_t addralign)918 Output_data_const(const unsigned char* p, off_t len, uint64_t addralign) 919 : Output_section_data(len, addralign, true), 920 data_(reinterpret_cast<const char*>(p), len) 921 { } 922 923 protected: 924 // Write the data to the output file. 925 void 926 do_write(Output_file*); 927 928 // Write the data to a buffer. 929 void do_write_to_buffer(unsigned char * buffer)930 do_write_to_buffer(unsigned char* buffer) 931 { memcpy(buffer, this->data_.data(), this->data_.size()); } 932 933 // Write to a map file. 934 void do_print_to_mapfile(Mapfile * mapfile)935 do_print_to_mapfile(Mapfile* mapfile) const 936 { mapfile->print_output_data(this, _("** fill")); } 937 938 private: 939 std::string data_; 940 }; 941 942 // Another version of Output_data with constant data, in which the 943 // buffer is allocated by the caller. 944 945 class Output_data_const_buffer : public Output_section_data 946 { 947 public: Output_data_const_buffer(const unsigned char * p,off_t len,uint64_t addralign,const char * map_name)948 Output_data_const_buffer(const unsigned char* p, off_t len, 949 uint64_t addralign, const char* map_name) 950 : Output_section_data(len, addralign, true), 951 p_(p), map_name_(map_name) 952 { } 953 954 protected: 955 // Write the data the output file. 956 void 957 do_write(Output_file*); 958 959 // Write the data to a buffer. 960 void do_write_to_buffer(unsigned char * buffer)961 do_write_to_buffer(unsigned char* buffer) 962 { memcpy(buffer, this->p_, this->data_size()); } 963 964 // Write to a map file. 965 void do_print_to_mapfile(Mapfile * mapfile)966 do_print_to_mapfile(Mapfile* mapfile) const 967 { mapfile->print_output_data(this, _(this->map_name_)); } 968 969 private: 970 // The data to output. 971 const unsigned char* p_; 972 // Name to use in a map file. Maps are a rarely used feature, but 973 // the space usage is minor as aren't very many of these objects. 974 const char* map_name_; 975 }; 976 977 // A place holder for a fixed amount of data written out via some 978 // other mechanism. 979 980 class Output_data_fixed_space : public Output_section_data 981 { 982 public: Output_data_fixed_space(off_t data_size,uint64_t addralign,const char * map_name)983 Output_data_fixed_space(off_t data_size, uint64_t addralign, 984 const char* map_name) 985 : Output_section_data(data_size, addralign, true), 986 map_name_(map_name) 987 { } 988 989 protected: 990 // Write out the data--the actual data must be written out 991 // elsewhere. 992 void do_write(Output_file *)993 do_write(Output_file*) 994 { } 995 996 // Write to a map file. 997 void do_print_to_mapfile(Mapfile * mapfile)998 do_print_to_mapfile(Mapfile* mapfile) const 999 { mapfile->print_output_data(this, _(this->map_name_)); } 1000 1001 private: 1002 // Name to use in a map file. Maps are a rarely used feature, but 1003 // the space usage is minor as aren't very many of these objects. 1004 const char* map_name_; 1005 }; 1006 1007 // A place holder for variable sized data written out via some other 1008 // mechanism. 1009 1010 class Output_data_space : public Output_section_data_build 1011 { 1012 public: Output_data_space(uint64_t addralign,const char * map_name)1013 explicit Output_data_space(uint64_t addralign, const char* map_name) 1014 : Output_section_data_build(addralign), 1015 map_name_(map_name) 1016 { } 1017 Output_data_space(off_t data_size,uint64_t addralign,const char * map_name)1018 explicit Output_data_space(off_t data_size, uint64_t addralign, 1019 const char* map_name) 1020 : Output_section_data_build(data_size, addralign), 1021 map_name_(map_name) 1022 { } 1023 1024 // Set the alignment. 1025 void set_space_alignment(uint64_t align)1026 set_space_alignment(uint64_t align) 1027 { this->set_addralign(align); } 1028 1029 protected: 1030 // Write out the data--the actual data must be written out 1031 // elsewhere. 1032 void do_write(Output_file *)1033 do_write(Output_file*) 1034 { } 1035 1036 // Write to a map file. 1037 void do_print_to_mapfile(Mapfile * mapfile)1038 do_print_to_mapfile(Mapfile* mapfile) const 1039 { mapfile->print_output_data(this, _(this->map_name_)); } 1040 1041 private: 1042 // Name to use in a map file. Maps are a rarely used feature, but 1043 // the space usage is minor as aren't very many of these objects. 1044 const char* map_name_; 1045 }; 1046 1047 // Fill fixed space with zeroes. This is just like 1048 // Output_data_fixed_space, except that the map name is known. 1049 1050 class Output_data_zero_fill : public Output_section_data 1051 { 1052 public: Output_data_zero_fill(off_t data_size,uint64_t addralign)1053 Output_data_zero_fill(off_t data_size, uint64_t addralign) 1054 : Output_section_data(data_size, addralign, true) 1055 { } 1056 1057 protected: 1058 // There is no data to write out. 1059 void do_write(Output_file *)1060 do_write(Output_file*) 1061 { } 1062 1063 // Write to a map file. 1064 void do_print_to_mapfile(Mapfile * mapfile)1065 do_print_to_mapfile(Mapfile* mapfile) const 1066 { mapfile->print_output_data(this, "** zero fill"); } 1067 }; 1068 1069 // A string table which goes into an output section. 1070 1071 class Output_data_strtab : public Output_section_data 1072 { 1073 public: Output_data_strtab(Stringpool * strtab)1074 Output_data_strtab(Stringpool* strtab) 1075 : Output_section_data(1), strtab_(strtab) 1076 { } 1077 1078 protected: 1079 // This is called to update the section size prior to assigning 1080 // the address and file offset. 1081 void update_data_size()1082 update_data_size() 1083 { this->set_final_data_size(); } 1084 1085 // This is called to set the address and file offset. Here we make 1086 // sure that the Stringpool is finalized. 1087 void 1088 set_final_data_size(); 1089 1090 // Write out the data. 1091 void 1092 do_write(Output_file*); 1093 1094 // Write the data to a buffer. 1095 void do_write_to_buffer(unsigned char * buffer)1096 do_write_to_buffer(unsigned char* buffer) 1097 { this->strtab_->write_to_buffer(buffer, this->data_size()); } 1098 1099 // Write to a map file. 1100 void do_print_to_mapfile(Mapfile * mapfile)1101 do_print_to_mapfile(Mapfile* mapfile) const 1102 { mapfile->print_output_data(this, _("** string table")); } 1103 1104 private: 1105 Stringpool* strtab_; 1106 }; 1107 1108 // This POD class is used to represent a single reloc in the output 1109 // file. This could be a private class within Output_data_reloc, but 1110 // the templatization is complex enough that I broke it out into a 1111 // separate class. The class is templatized on either elfcpp::SHT_REL 1112 // or elfcpp::SHT_RELA, and also on whether this is a dynamic 1113 // relocation or an ordinary relocation. 1114 1115 // A relocation can be against a global symbol, a local symbol, a 1116 // local section symbol, an output section, or the undefined symbol at 1117 // index 0. We represent the latter by using a NULL global symbol. 1118 1119 template<int sh_type, bool dynamic, int size, bool big_endian> 1120 class Output_reloc; 1121 1122 template<bool dynamic, int size, bool big_endian> 1123 class Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian> 1124 { 1125 public: 1126 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; 1127 typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend; 1128 1129 static const Address invalid_address = static_cast<Address>(0) - 1; 1130 1131 // An uninitialized entry. We need this because we want to put 1132 // instances of this class into an STL container. Output_reloc()1133 Output_reloc() 1134 : local_sym_index_(INVALID_CODE) 1135 { } 1136 1137 // We have a bunch of different constructors. They come in pairs 1138 // depending on how the address of the relocation is specified. It 1139 // can either be an offset in an Output_data or an offset in an 1140 // input section. 1141 1142 // A reloc against a global symbol. 1143 1144 Output_reloc(Symbol* gsym, unsigned int type, Output_data* od, 1145 Address address, bool is_relative, bool is_symbolless, 1146 bool use_plt_offset); 1147 1148 Output_reloc(Symbol* gsym, unsigned int type, 1149 Sized_relobj<size, big_endian>* relobj, 1150 unsigned int shndx, Address address, bool is_relative, 1151 bool is_symbolless, bool use_plt_offset); 1152 1153 // A reloc against a local symbol or local section symbol. 1154 1155 Output_reloc(Sized_relobj<size, big_endian>* relobj, 1156 unsigned int local_sym_index, unsigned int type, 1157 Output_data* od, Address address, bool is_relative, 1158 bool is_symbolless, bool is_section_symbol, 1159 bool use_plt_offset); 1160 1161 Output_reloc(Sized_relobj<size, big_endian>* relobj, 1162 unsigned int local_sym_index, unsigned int type, 1163 unsigned int shndx, Address address, bool is_relative, 1164 bool is_symbolless, bool is_section_symbol, 1165 bool use_plt_offset); 1166 1167 // A reloc against the STT_SECTION symbol of an output section. 1168 1169 Output_reloc(Output_section* os, unsigned int type, Output_data* od, 1170 Address address, bool is_relative); 1171 1172 Output_reloc(Output_section* os, unsigned int type, 1173 Sized_relobj<size, big_endian>* relobj, unsigned int shndx, 1174 Address address, bool is_relative); 1175 1176 // An absolute or relative relocation with no symbol. 1177 1178 Output_reloc(unsigned int type, Output_data* od, Address address, 1179 bool is_relative); 1180 1181 Output_reloc(unsigned int type, Sized_relobj<size, big_endian>* relobj, 1182 unsigned int shndx, Address address, bool is_relative); 1183 1184 // A target specific relocation. The target will be called to get 1185 // the symbol index, passing ARG. The type and offset will be set 1186 // as for other relocation types. 1187 1188 Output_reloc(unsigned int type, void* arg, Output_data* od, 1189 Address address); 1190 1191 Output_reloc(unsigned int type, void* arg, 1192 Sized_relobj<size, big_endian>* relobj, 1193 unsigned int shndx, Address address); 1194 1195 // Return the reloc type. 1196 unsigned int type()1197 type() const 1198 { return this->type_; } 1199 1200 // Return whether this is a RELATIVE relocation. 1201 bool is_relative()1202 is_relative() const 1203 { return this->is_relative_; } 1204 1205 // Return whether this is a relocation which should not use 1206 // a symbol, but which obtains its addend from a symbol. 1207 bool is_symbolless()1208 is_symbolless() const 1209 { return this->is_symbolless_; } 1210 1211 // Return whether this is against a local section symbol. 1212 bool is_local_section_symbol()1213 is_local_section_symbol() const 1214 { 1215 return (this->local_sym_index_ != GSYM_CODE 1216 && this->local_sym_index_ != SECTION_CODE 1217 && this->local_sym_index_ != INVALID_CODE 1218 && this->local_sym_index_ != TARGET_CODE 1219 && this->is_section_symbol_); 1220 } 1221 1222 // Return whether this is a target specific relocation. 1223 bool is_target_specific()1224 is_target_specific() const 1225 { return this->local_sym_index_ == TARGET_CODE; } 1226 1227 // Return the argument to pass to the target for a target specific 1228 // relocation. 1229 void* target_arg()1230 target_arg() const 1231 { 1232 gold_assert(this->local_sym_index_ == TARGET_CODE); 1233 return this->u1_.arg; 1234 } 1235 1236 // For a local section symbol, return the offset of the input 1237 // section within the output section. ADDEND is the addend being 1238 // applied to the input section. 1239 Address 1240 local_section_offset(Addend addend) const; 1241 1242 // Get the value of the symbol referred to by a Rel relocation when 1243 // we are adding the given ADDEND. 1244 Address 1245 symbol_value(Addend addend) const; 1246 1247 // If this relocation is against an input section, return the 1248 // relocatable object containing the input section. 1249 Sized_relobj<size, big_endian>* get_relobj()1250 get_relobj() const 1251 { 1252 if (this->shndx_ == INVALID_CODE) 1253 return NULL; 1254 return this->u2_.relobj; 1255 } 1256 1257 // Write the reloc entry to an output view. 1258 void 1259 write(unsigned char* pov) const; 1260 1261 // Write the offset and info fields to Write_rel. 1262 template<typename Write_rel> 1263 void write_rel(Write_rel*) const; 1264 1265 // This is used when sorting dynamic relocs. Return -1 to sort this 1266 // reloc before R2, 0 to sort the same as R2, 1 to sort after R2. 1267 int 1268 compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2) 1269 const; 1270 1271 // Return whether this reloc should be sorted before the argument 1272 // when sorting dynamic relocs. 1273 bool sort_before(const Output_reloc<elfcpp::SHT_REL,dynamic,size,big_endian> & r2)1274 sort_before(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& 1275 r2) const 1276 { return this->compare(r2) < 0; } 1277 1278 // Return the symbol index. 1279 unsigned int 1280 get_symbol_index() const; 1281 1282 // Return the output address. 1283 Address 1284 get_address() const; 1285 1286 private: 1287 // Record that we need a dynamic symbol index. 1288 void 1289 set_needs_dynsym_index(); 1290 1291 // Codes for local_sym_index_. 1292 enum 1293 { 1294 // Global symbol. 1295 GSYM_CODE = -1U, 1296 // Output section. 1297 SECTION_CODE = -2U, 1298 // Target specific. 1299 TARGET_CODE = -3U, 1300 // Invalid uninitialized entry. 1301 INVALID_CODE = -4U 1302 }; 1303 1304 union 1305 { 1306 // For a local symbol or local section symbol 1307 // (this->local_sym_index_ >= 0), the object. We will never 1308 // generate a relocation against a local symbol in a dynamic 1309 // object; that doesn't make sense. And our callers will always 1310 // be templatized, so we use Sized_relobj here. 1311 Sized_relobj<size, big_endian>* relobj; 1312 // For a global symbol (this->local_sym_index_ == GSYM_CODE, the 1313 // symbol. If this is NULL, it indicates a relocation against the 1314 // undefined 0 symbol. 1315 Symbol* gsym; 1316 // For a relocation against an output section 1317 // (this->local_sym_index_ == SECTION_CODE), the output section. 1318 Output_section* os; 1319 // For a target specific relocation, an argument to pass to the 1320 // target. 1321 void* arg; 1322 } u1_; 1323 union 1324 { 1325 // If this->shndx_ is not INVALID CODE, the object which holds the 1326 // input section being used to specify the reloc address. 1327 Sized_relobj<size, big_endian>* relobj; 1328 // If this->shndx_ is INVALID_CODE, the output data being used to 1329 // specify the reloc address. This may be NULL if the reloc 1330 // address is absolute. 1331 Output_data* od; 1332 } u2_; 1333 // The address offset within the input section or the Output_data. 1334 Address address_; 1335 // This is GSYM_CODE for a global symbol, or SECTION_CODE for a 1336 // relocation against an output section, or TARGET_CODE for a target 1337 // specific relocation, or INVALID_CODE for an uninitialized value. 1338 // Otherwise, for a local symbol (this->is_section_symbol_ is 1339 // false), the local symbol index. For a local section symbol 1340 // (this->is_section_symbol_ is true), the section index in the 1341 // input file. 1342 unsigned int local_sym_index_; 1343 // The reloc type--a processor specific code. 1344 unsigned int type_ : 28; 1345 // True if the relocation is a RELATIVE relocation. 1346 bool is_relative_ : 1; 1347 // True if the relocation is one which should not use 1348 // a symbol, but which obtains its addend from a symbol. 1349 bool is_symbolless_ : 1; 1350 // True if the relocation is against a section symbol. 1351 bool is_section_symbol_ : 1; 1352 // True if the addend should be the PLT offset. 1353 // (Used only for RELA, but stored here for space.) 1354 bool use_plt_offset_ : 1; 1355 // If the reloc address is an input section in an object, the 1356 // section index. This is INVALID_CODE if the reloc address is 1357 // specified in some other way. 1358 unsigned int shndx_; 1359 }; 1360 1361 // The SHT_RELA version of Output_reloc<>. This is just derived from 1362 // the SHT_REL version of Output_reloc, but it adds an addend. 1363 1364 template<bool dynamic, int size, bool big_endian> 1365 class Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian> 1366 { 1367 public: 1368 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; 1369 typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend; 1370 1371 // An uninitialized entry. Output_reloc()1372 Output_reloc() 1373 : rel_() 1374 { } 1375 1376 // A reloc against a global symbol. 1377 Output_reloc(Symbol * gsym,unsigned int type,Output_data * od,Address address,Addend addend,bool is_relative,bool is_symbolless,bool use_plt_offset)1378 Output_reloc(Symbol* gsym, unsigned int type, Output_data* od, 1379 Address address, Addend addend, bool is_relative, 1380 bool is_symbolless, bool use_plt_offset) 1381 : rel_(gsym, type, od, address, is_relative, is_symbolless, 1382 use_plt_offset), 1383 addend_(addend) 1384 { } 1385 Output_reloc(Symbol * gsym,unsigned int type,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend,bool is_relative,bool is_symbolless,bool use_plt_offset)1386 Output_reloc(Symbol* gsym, unsigned int type, 1387 Sized_relobj<size, big_endian>* relobj, 1388 unsigned int shndx, Address address, Addend addend, 1389 bool is_relative, bool is_symbolless, bool use_plt_offset) 1390 : rel_(gsym, type, relobj, shndx, address, is_relative, 1391 is_symbolless, use_plt_offset), addend_(addend) 1392 { } 1393 1394 // A reloc against a local symbol. 1395 Output_reloc(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,Address address,Addend addend,bool is_relative,bool is_symbolless,bool is_section_symbol,bool use_plt_offset)1396 Output_reloc(Sized_relobj<size, big_endian>* relobj, 1397 unsigned int local_sym_index, unsigned int type, 1398 Output_data* od, Address address, 1399 Addend addend, bool is_relative, 1400 bool is_symbolless, bool is_section_symbol, 1401 bool use_plt_offset) 1402 : rel_(relobj, local_sym_index, type, od, address, is_relative, 1403 is_symbolless, is_section_symbol, use_plt_offset), 1404 addend_(addend) 1405 { } 1406 Output_reloc(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,unsigned int shndx,Address address,Addend addend,bool is_relative,bool is_symbolless,bool is_section_symbol,bool use_plt_offset)1407 Output_reloc(Sized_relobj<size, big_endian>* relobj, 1408 unsigned int local_sym_index, unsigned int type, 1409 unsigned int shndx, Address address, 1410 Addend addend, bool is_relative, 1411 bool is_symbolless, bool is_section_symbol, 1412 bool use_plt_offset) 1413 : rel_(relobj, local_sym_index, type, shndx, address, is_relative, 1414 is_symbolless, is_section_symbol, use_plt_offset), 1415 addend_(addend) 1416 { } 1417 1418 // A reloc against the STT_SECTION symbol of an output section. 1419 Output_reloc(Output_section * os,unsigned int type,Output_data * od,Address address,Addend addend,bool is_relative)1420 Output_reloc(Output_section* os, unsigned int type, Output_data* od, 1421 Address address, Addend addend, bool is_relative) 1422 : rel_(os, type, od, address, is_relative), addend_(addend) 1423 { } 1424 Output_reloc(Output_section * os,unsigned int type,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend,bool is_relative)1425 Output_reloc(Output_section* os, unsigned int type, 1426 Sized_relobj<size, big_endian>* relobj, 1427 unsigned int shndx, Address address, Addend addend, 1428 bool is_relative) 1429 : rel_(os, type, relobj, shndx, address, is_relative), addend_(addend) 1430 { } 1431 1432 // An absolute or relative relocation with no symbol. 1433 Output_reloc(unsigned int type,Output_data * od,Address address,Addend addend,bool is_relative)1434 Output_reloc(unsigned int type, Output_data* od, Address address, 1435 Addend addend, bool is_relative) 1436 : rel_(type, od, address, is_relative), addend_(addend) 1437 { } 1438 Output_reloc(unsigned int type,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend,bool is_relative)1439 Output_reloc(unsigned int type, Sized_relobj<size, big_endian>* relobj, 1440 unsigned int shndx, Address address, Addend addend, 1441 bool is_relative) 1442 : rel_(type, relobj, shndx, address, is_relative), addend_(addend) 1443 { } 1444 1445 // A target specific relocation. The target will be called to get 1446 // the symbol index and the addend, passing ARG. The type and 1447 // offset will be set as for other relocation types. 1448 Output_reloc(unsigned int type,void * arg,Output_data * od,Address address,Addend addend)1449 Output_reloc(unsigned int type, void* arg, Output_data* od, 1450 Address address, Addend addend) 1451 : rel_(type, arg, od, address), addend_(addend) 1452 { } 1453 Output_reloc(unsigned int type,void * arg,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend)1454 Output_reloc(unsigned int type, void* arg, 1455 Sized_relobj<size, big_endian>* relobj, 1456 unsigned int shndx, Address address, Addend addend) 1457 : rel_(type, arg, relobj, shndx, address), addend_(addend) 1458 { } 1459 1460 // Return whether this is a RELATIVE relocation. 1461 bool is_relative()1462 is_relative() const 1463 { return this->rel_.is_relative(); } 1464 1465 // Return whether this is a relocation which should not use 1466 // a symbol, but which obtains its addend from a symbol. 1467 bool is_symbolless()1468 is_symbolless() const 1469 { return this->rel_.is_symbolless(); } 1470 1471 // If this relocation is against an input section, return the 1472 // relocatable object containing the input section. 1473 Sized_relobj<size, big_endian>* get_relobj()1474 get_relobj() const 1475 { return this->rel_.get_relobj(); } 1476 1477 // Write the reloc entry to an output view. 1478 void 1479 write(unsigned char* pov) const; 1480 1481 // Return whether this reloc should be sorted before the argument 1482 // when sorting dynamic relocs. 1483 bool sort_before(const Output_reloc<elfcpp::SHT_RELA,dynamic,size,big_endian> & r2)1484 sort_before(const Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>& 1485 r2) const 1486 { 1487 int i = this->rel_.compare(r2.rel_); 1488 if (i < 0) 1489 return true; 1490 else if (i > 0) 1491 return false; 1492 else 1493 return this->addend_ < r2.addend_; 1494 } 1495 1496 private: 1497 // The basic reloc. 1498 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian> rel_; 1499 // The addend. 1500 Addend addend_; 1501 }; 1502 1503 // Output_data_reloc_generic is a non-template base class for 1504 // Output_data_reloc_base. This gives the generic code a way to hold 1505 // a pointer to a reloc section. 1506 1507 class Output_data_reloc_generic : public Output_section_data_build 1508 { 1509 public: Output_data_reloc_generic(int size,bool sort_relocs)1510 Output_data_reloc_generic(int size, bool sort_relocs) 1511 : Output_section_data_build(Output_data::default_alignment_for_size(size)), 1512 relative_reloc_count_(0), sort_relocs_(sort_relocs) 1513 { } 1514 1515 // Return the number of relative relocs in this section. 1516 size_t relative_reloc_count()1517 relative_reloc_count() const 1518 { return this->relative_reloc_count_; } 1519 1520 // Whether we should sort the relocs. 1521 bool sort_relocs()1522 sort_relocs() const 1523 { return this->sort_relocs_; } 1524 1525 // Add a reloc of type TYPE against the global symbol GSYM. The 1526 // relocation applies to the data at offset ADDRESS within OD. 1527 virtual void 1528 add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, 1529 uint64_t address, uint64_t addend) = 0; 1530 1531 // Add a reloc of type TYPE against the global symbol GSYM. The 1532 // relocation applies to data at offset ADDRESS within section SHNDX 1533 // of object file RELOBJ. OD is the associated output section. 1534 virtual void 1535 add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, 1536 Relobj* relobj, unsigned int shndx, uint64_t address, 1537 uint64_t addend) = 0; 1538 1539 // Add a reloc of type TYPE against the local symbol LOCAL_SYM_INDEX 1540 // in RELOBJ. The relocation applies to the data at offset ADDRESS 1541 // within OD. 1542 virtual void 1543 add_local_generic(Relobj* relobj, unsigned int local_sym_index, 1544 unsigned int type, Output_data* od, uint64_t address, 1545 uint64_t addend) = 0; 1546 1547 // Add a reloc of type TYPE against the local symbol LOCAL_SYM_INDEX 1548 // in RELOBJ. The relocation applies to the data at offset ADDRESS 1549 // within section SHNDX of RELOBJ. OD is the associated output 1550 // section. 1551 virtual void 1552 add_local_generic(Relobj* relobj, unsigned int local_sym_index, 1553 unsigned int type, Output_data* od, unsigned int shndx, 1554 uint64_t address, uint64_t addend) = 0; 1555 1556 // Add a reloc of type TYPE against the STT_SECTION symbol of the 1557 // output section OS. The relocation applies to the data at offset 1558 // ADDRESS within OD. 1559 virtual void 1560 add_output_section_generic(Output_section *os, unsigned int type, 1561 Output_data* od, uint64_t address, 1562 uint64_t addend) = 0; 1563 1564 // Add a reloc of type TYPE against the STT_SECTION symbol of the 1565 // output section OS. The relocation applies to the data at offset 1566 // ADDRESS within section SHNDX of RELOBJ. OD is the associated 1567 // output section. 1568 virtual void 1569 add_output_section_generic(Output_section* os, unsigned int type, 1570 Output_data* od, Relobj* relobj, 1571 unsigned int shndx, uint64_t address, 1572 uint64_t addend) = 0; 1573 1574 protected: 1575 // Note that we've added another relative reloc. 1576 void bump_relative_reloc_count()1577 bump_relative_reloc_count() 1578 { ++this->relative_reloc_count_; } 1579 1580 private: 1581 // The number of relative relocs added to this section. This is to 1582 // support DT_RELCOUNT. 1583 size_t relative_reloc_count_; 1584 // Whether to sort the relocations when writing them out, to make 1585 // the dynamic linker more efficient. 1586 bool sort_relocs_; 1587 }; 1588 1589 // Output_data_reloc is used to manage a section containing relocs. 1590 // SH_TYPE is either elfcpp::SHT_REL or elfcpp::SHT_RELA. DYNAMIC 1591 // indicates whether this is a dynamic relocation or a normal 1592 // relocation. Output_data_reloc_base is a base class. 1593 // Output_data_reloc is the real class, which we specialize based on 1594 // the reloc type. 1595 1596 template<int sh_type, bool dynamic, int size, bool big_endian> 1597 class Output_data_reloc_base : public Output_data_reloc_generic 1598 { 1599 public: 1600 typedef Output_reloc<sh_type, dynamic, size, big_endian> Output_reloc_type; 1601 typedef typename Output_reloc_type::Address Address; 1602 static const int reloc_size = 1603 Reloc_types<sh_type, size, big_endian>::reloc_size; 1604 1605 // Construct the section. Output_data_reloc_base(bool sort_relocs)1606 Output_data_reloc_base(bool sort_relocs) 1607 : Output_data_reloc_generic(size, sort_relocs) 1608 { } 1609 1610 protected: 1611 // Write out the data. 1612 void 1613 do_write(Output_file*); 1614 1615 // Generic implementation of do_write, allowing a customized 1616 // class for writing the output relocation (e.g., for MIPS-64). 1617 template<class Output_reloc_writer> 1618 void do_write_generic(Output_file * of)1619 do_write_generic(Output_file* of) 1620 { 1621 const off_t off = this->offset(); 1622 const off_t oview_size = this->data_size(); 1623 unsigned char* const oview = of->get_output_view(off, oview_size); 1624 1625 if (this->sort_relocs()) 1626 { 1627 gold_assert(dynamic); 1628 std::sort(this->relocs_.begin(), this->relocs_.end(), 1629 Sort_relocs_comparison()); 1630 } 1631 1632 unsigned char* pov = oview; 1633 for (typename Relocs::const_iterator p = this->relocs_.begin(); 1634 p != this->relocs_.end(); 1635 ++p) 1636 { 1637 Output_reloc_writer::write(p, pov); 1638 pov += reloc_size; 1639 } 1640 1641 gold_assert(pov - oview == oview_size); 1642 1643 of->write_output_view(off, oview_size, oview); 1644 1645 // We no longer need the relocation entries. 1646 this->relocs_.clear(); 1647 } 1648 1649 // Set the entry size and the link. 1650 void 1651 do_adjust_output_section(Output_section* os); 1652 1653 // Write to a map file. 1654 void do_print_to_mapfile(Mapfile * mapfile)1655 do_print_to_mapfile(Mapfile* mapfile) const 1656 { 1657 mapfile->print_output_data(this, 1658 (dynamic 1659 ? _("** dynamic relocs") 1660 : _("** relocs"))); 1661 } 1662 1663 // Add a relocation entry. 1664 void add(Output_data * od,const Output_reloc_type & reloc)1665 add(Output_data* od, const Output_reloc_type& reloc) 1666 { 1667 this->relocs_.push_back(reloc); 1668 this->set_current_data_size(this->relocs_.size() * reloc_size); 1669 if (dynamic) 1670 od->add_dynamic_reloc(); 1671 if (reloc.is_relative()) 1672 this->bump_relative_reloc_count(); 1673 Sized_relobj<size, big_endian>* relobj = reloc.get_relobj(); 1674 if (relobj != NULL) 1675 relobj->add_dyn_reloc(this->relocs_.size() - 1); 1676 } 1677 1678 private: 1679 typedef std::vector<Output_reloc_type> Relocs; 1680 1681 // The class used to sort the relocations. 1682 struct Sort_relocs_comparison 1683 { 1684 bool operatorSort_relocs_comparison1685 operator()(const Output_reloc_type& r1, const Output_reloc_type& r2) const 1686 { return r1.sort_before(r2); } 1687 }; 1688 1689 // The relocations in this section. 1690 Relocs relocs_; 1691 }; 1692 1693 // The class which callers actually create. 1694 1695 template<int sh_type, bool dynamic, int size, bool big_endian> 1696 class Output_data_reloc; 1697 1698 // The SHT_REL version of Output_data_reloc. 1699 1700 template<bool dynamic, int size, bool big_endian> 1701 class Output_data_reloc<elfcpp::SHT_REL, dynamic, size, big_endian> 1702 : public Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, big_endian> 1703 { 1704 private: 1705 typedef Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, 1706 big_endian> Base; 1707 1708 public: 1709 typedef typename Base::Output_reloc_type Output_reloc_type; 1710 typedef typename Output_reloc_type::Address Address; 1711 Output_data_reloc(bool sr)1712 Output_data_reloc(bool sr) 1713 : Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, big_endian>(sr) 1714 { } 1715 1716 // Add a reloc against a global symbol. 1717 1718 void add_global(Symbol * gsym,unsigned int type,Output_data * od,Address address)1719 add_global(Symbol* gsym, unsigned int type, Output_data* od, Address address) 1720 { 1721 this->add(od, Output_reloc_type(gsym, type, od, address, 1722 false, false, false)); 1723 } 1724 1725 void add_global(Symbol * gsym,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address)1726 add_global(Symbol* gsym, unsigned int type, Output_data* od, 1727 Sized_relobj<size, big_endian>* relobj, 1728 unsigned int shndx, Address address) 1729 { 1730 this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, 1731 false, false, false)); 1732 } 1733 1734 void add_global_generic(Symbol * gsym,unsigned int type,Output_data * od,uint64_t address,uint64_t addend)1735 add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, 1736 uint64_t address, uint64_t addend) 1737 { 1738 gold_assert(addend == 0); 1739 this->add(od, Output_reloc_type(gsym, type, od, 1740 convert_types<Address, uint64_t>(address), 1741 false, false, false)); 1742 } 1743 1744 void add_global_generic(Symbol * gsym,unsigned int type,Output_data * od,Relobj * relobj,unsigned int shndx,uint64_t address,uint64_t addend)1745 add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, 1746 Relobj* relobj, unsigned int shndx, uint64_t address, 1747 uint64_t addend) 1748 { 1749 gold_assert(addend == 0); 1750 Sized_relobj<size, big_endian>* sized_relobj = 1751 static_cast<Sized_relobj<size, big_endian>*>(relobj); 1752 this->add(od, Output_reloc_type(gsym, type, sized_relobj, shndx, 1753 convert_types<Address, uint64_t>(address), 1754 false, false, false)); 1755 } 1756 1757 // Add a RELATIVE reloc against a global symbol. The final relocation 1758 // will not reference the symbol. 1759 1760 void add_global_relative(Symbol * gsym,unsigned int type,Output_data * od,Address address)1761 add_global_relative(Symbol* gsym, unsigned int type, Output_data* od, 1762 Address address) 1763 { 1764 this->add(od, Output_reloc_type(gsym, type, od, address, true, true, 1765 false)); 1766 } 1767 1768 void add_global_relative(Symbol * gsym,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address)1769 add_global_relative(Symbol* gsym, unsigned int type, Output_data* od, 1770 Sized_relobj<size, big_endian>* relobj, 1771 unsigned int shndx, Address address) 1772 { 1773 this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, 1774 true, true, false)); 1775 } 1776 1777 // Add a global relocation which does not use a symbol for the relocation, 1778 // but which gets its addend from a symbol. 1779 1780 void add_symbolless_global_addend(Symbol * gsym,unsigned int type,Output_data * od,Address address)1781 add_symbolless_global_addend(Symbol* gsym, unsigned int type, 1782 Output_data* od, Address address) 1783 { 1784 this->add(od, Output_reloc_type(gsym, type, od, address, false, true, 1785 false)); 1786 } 1787 1788 void add_symbolless_global_addend(Symbol * gsym,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address)1789 add_symbolless_global_addend(Symbol* gsym, unsigned int type, 1790 Output_data* od, 1791 Sized_relobj<size, big_endian>* relobj, 1792 unsigned int shndx, Address address) 1793 { 1794 this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, 1795 false, true, false)); 1796 } 1797 1798 // Add a reloc against a local symbol. 1799 1800 void add_local(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,Address address)1801 add_local(Sized_relobj<size, big_endian>* relobj, 1802 unsigned int local_sym_index, unsigned int type, 1803 Output_data* od, Address address) 1804 { 1805 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, 1806 address, false, false, false, false)); 1807 } 1808 1809 void add_local(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,unsigned int shndx,Address address)1810 add_local(Sized_relobj<size, big_endian>* relobj, 1811 unsigned int local_sym_index, unsigned int type, 1812 Output_data* od, unsigned int shndx, Address address) 1813 { 1814 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, 1815 address, false, false, false, false)); 1816 } 1817 1818 void add_local_generic(Relobj * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,uint64_t address,uint64_t addend)1819 add_local_generic(Relobj* relobj, unsigned int local_sym_index, 1820 unsigned int type, Output_data* od, uint64_t address, 1821 uint64_t addend) 1822 { 1823 gold_assert(addend == 0); 1824 Sized_relobj<size, big_endian>* sized_relobj = 1825 static_cast<Sized_relobj<size, big_endian> *>(relobj); 1826 this->add(od, Output_reloc_type(sized_relobj, local_sym_index, type, od, 1827 convert_types<Address, uint64_t>(address), 1828 false, false, false, false)); 1829 } 1830 1831 void add_local_generic(Relobj * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,unsigned int shndx,uint64_t address,uint64_t addend)1832 add_local_generic(Relobj* relobj, unsigned int local_sym_index, 1833 unsigned int type, Output_data* od, unsigned int shndx, 1834 uint64_t address, uint64_t addend) 1835 { 1836 gold_assert(addend == 0); 1837 Sized_relobj<size, big_endian>* sized_relobj = 1838 static_cast<Sized_relobj<size, big_endian>*>(relobj); 1839 this->add(od, Output_reloc_type(sized_relobj, local_sym_index, type, shndx, 1840 convert_types<Address, uint64_t>(address), 1841 false, false, false, false)); 1842 } 1843 1844 // Add a RELATIVE reloc against a local symbol. 1845 1846 void add_local_relative(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,Address address)1847 add_local_relative(Sized_relobj<size, big_endian>* relobj, 1848 unsigned int local_sym_index, unsigned int type, 1849 Output_data* od, Address address) 1850 { 1851 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, 1852 address, true, true, false, false)); 1853 } 1854 1855 void add_local_relative(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,unsigned int shndx,Address address)1856 add_local_relative(Sized_relobj<size, big_endian>* relobj, 1857 unsigned int local_sym_index, unsigned int type, 1858 Output_data* od, unsigned int shndx, Address address) 1859 { 1860 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, 1861 address, true, true, false, false)); 1862 } 1863 1864 void add_local_relative(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,unsigned int shndx,Address address,bool use_plt_offset)1865 add_local_relative(Sized_relobj<size, big_endian>* relobj, 1866 unsigned int local_sym_index, unsigned int type, 1867 Output_data* od, unsigned int shndx, Address address, 1868 bool use_plt_offset) 1869 { 1870 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, 1871 address, true, true, false, 1872 use_plt_offset)); 1873 } 1874 1875 // Add a local relocation which does not use a symbol for the relocation, 1876 // but which gets its addend from a symbol. 1877 1878 void add_symbolless_local_addend(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,Address address)1879 add_symbolless_local_addend(Sized_relobj<size, big_endian>* relobj, 1880 unsigned int local_sym_index, unsigned int type, 1881 Output_data* od, Address address) 1882 { 1883 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, 1884 address, false, true, false, false)); 1885 } 1886 1887 void add_symbolless_local_addend(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,unsigned int shndx,Address address)1888 add_symbolless_local_addend(Sized_relobj<size, big_endian>* relobj, 1889 unsigned int local_sym_index, unsigned int type, 1890 Output_data* od, unsigned int shndx, 1891 Address address) 1892 { 1893 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, 1894 address, false, true, false, false)); 1895 } 1896 1897 // Add a reloc against a local section symbol. This will be 1898 // converted into a reloc against the STT_SECTION symbol of the 1899 // output section. 1900 1901 void add_local_section(Sized_relobj<size,big_endian> * relobj,unsigned int input_shndx,unsigned int type,Output_data * od,Address address)1902 add_local_section(Sized_relobj<size, big_endian>* relobj, 1903 unsigned int input_shndx, unsigned int type, 1904 Output_data* od, Address address) 1905 { 1906 this->add(od, Output_reloc_type(relobj, input_shndx, type, od, 1907 address, false, false, true, false)); 1908 } 1909 1910 void add_local_section(Sized_relobj<size,big_endian> * relobj,unsigned int input_shndx,unsigned int type,Output_data * od,unsigned int shndx,Address address)1911 add_local_section(Sized_relobj<size, big_endian>* relobj, 1912 unsigned int input_shndx, unsigned int type, 1913 Output_data* od, unsigned int shndx, Address address) 1914 { 1915 this->add(od, Output_reloc_type(relobj, input_shndx, type, shndx, 1916 address, false, false, true, false)); 1917 } 1918 1919 // A reloc against the STT_SECTION symbol of an output section. 1920 // OS is the Output_section that the relocation refers to; OD is 1921 // the Output_data object being relocated. 1922 1923 void add_output_section(Output_section * os,unsigned int type,Output_data * od,Address address)1924 add_output_section(Output_section* os, unsigned int type, 1925 Output_data* od, Address address) 1926 { this->add(od, Output_reloc_type(os, type, od, address, false)); } 1927 1928 void add_output_section(Output_section * os,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address)1929 add_output_section(Output_section* os, unsigned int type, Output_data* od, 1930 Sized_relobj<size, big_endian>* relobj, 1931 unsigned int shndx, Address address) 1932 { this->add(od, Output_reloc_type(os, type, relobj, shndx, address, false)); } 1933 1934 void add_output_section_generic(Output_section * os,unsigned int type,Output_data * od,uint64_t address,uint64_t addend)1935 add_output_section_generic(Output_section* os, unsigned int type, 1936 Output_data* od, uint64_t address, 1937 uint64_t addend) 1938 { 1939 gold_assert(addend == 0); 1940 this->add(od, Output_reloc_type(os, type, od, 1941 convert_types<Address, uint64_t>(address), 1942 false)); 1943 } 1944 1945 void add_output_section_generic(Output_section * os,unsigned int type,Output_data * od,Relobj * relobj,unsigned int shndx,uint64_t address,uint64_t addend)1946 add_output_section_generic(Output_section* os, unsigned int type, 1947 Output_data* od, Relobj* relobj, 1948 unsigned int shndx, uint64_t address, 1949 uint64_t addend) 1950 { 1951 gold_assert(addend == 0); 1952 Sized_relobj<size, big_endian>* sized_relobj = 1953 static_cast<Sized_relobj<size, big_endian>*>(relobj); 1954 this->add(od, Output_reloc_type(os, type, sized_relobj, shndx, 1955 convert_types<Address, uint64_t>(address), 1956 false)); 1957 } 1958 1959 // As above, but the reloc TYPE is relative 1960 1961 void add_output_section_relative(Output_section * os,unsigned int type,Output_data * od,Address address)1962 add_output_section_relative(Output_section* os, unsigned int type, 1963 Output_data* od, Address address) 1964 { this->add(od, Output_reloc_type(os, type, od, address, true)); } 1965 1966 void add_output_section_relative(Output_section * os,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address)1967 add_output_section_relative(Output_section* os, unsigned int type, 1968 Output_data* od, 1969 Sized_relobj<size, big_endian>* relobj, 1970 unsigned int shndx, Address address) 1971 { this->add(od, Output_reloc_type(os, type, relobj, shndx, address, true)); } 1972 1973 // Add an absolute relocation. 1974 1975 void add_absolute(unsigned int type,Output_data * od,Address address)1976 add_absolute(unsigned int type, Output_data* od, Address address) 1977 { this->add(od, Output_reloc_type(type, od, address, false)); } 1978 1979 void add_absolute(unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address)1980 add_absolute(unsigned int type, Output_data* od, 1981 Sized_relobj<size, big_endian>* relobj, 1982 unsigned int shndx, Address address) 1983 { this->add(od, Output_reloc_type(type, relobj, shndx, address, false)); } 1984 1985 // Add a relative relocation 1986 1987 void add_relative(unsigned int type,Output_data * od,Address address)1988 add_relative(unsigned int type, Output_data* od, Address address) 1989 { this->add(od, Output_reloc_type(type, od, address, true)); } 1990 1991 void add_relative(unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address)1992 add_relative(unsigned int type, Output_data* od, 1993 Sized_relobj<size, big_endian>* relobj, 1994 unsigned int shndx, Address address) 1995 { this->add(od, Output_reloc_type(type, relobj, shndx, address, true)); } 1996 1997 // Add a target specific relocation. A target which calls this must 1998 // define the reloc_symbol_index and reloc_addend virtual functions. 1999 2000 void add_target_specific(unsigned int type,void * arg,Output_data * od,Address address)2001 add_target_specific(unsigned int type, void* arg, Output_data* od, 2002 Address address) 2003 { this->add(od, Output_reloc_type(type, arg, od, address)); } 2004 2005 void add_target_specific(unsigned int type,void * arg,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address)2006 add_target_specific(unsigned int type, void* arg, Output_data* od, 2007 Sized_relobj<size, big_endian>* relobj, 2008 unsigned int shndx, Address address) 2009 { this->add(od, Output_reloc_type(type, arg, relobj, shndx, address)); } 2010 }; 2011 2012 // The SHT_RELA version of Output_data_reloc. 2013 2014 template<bool dynamic, int size, bool big_endian> 2015 class Output_data_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian> 2016 : public Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, big_endian> 2017 { 2018 private: 2019 typedef Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, 2020 big_endian> Base; 2021 2022 public: 2023 typedef typename Base::Output_reloc_type Output_reloc_type; 2024 typedef typename Output_reloc_type::Address Address; 2025 typedef typename Output_reloc_type::Addend Addend; 2026 Output_data_reloc(bool sr)2027 Output_data_reloc(bool sr) 2028 : Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, big_endian>(sr) 2029 { } 2030 2031 // Add a reloc against a global symbol. 2032 2033 void add_global(Symbol * gsym,unsigned int type,Output_data * od,Address address,Addend addend)2034 add_global(Symbol* gsym, unsigned int type, Output_data* od, 2035 Address address, Addend addend) 2036 { 2037 this->add(od, Output_reloc_type(gsym, type, od, address, addend, 2038 false, false, false)); 2039 } 2040 2041 void add_global(Symbol * gsym,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend)2042 add_global(Symbol* gsym, unsigned int type, Output_data* od, 2043 Sized_relobj<size, big_endian>* relobj, 2044 unsigned int shndx, Address address, 2045 Addend addend) 2046 { 2047 this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, 2048 addend, false, false, false)); 2049 } 2050 2051 void add_global_generic(Symbol * gsym,unsigned int type,Output_data * od,uint64_t address,uint64_t addend)2052 add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, 2053 uint64_t address, uint64_t addend) 2054 { 2055 this->add(od, Output_reloc_type(gsym, type, od, 2056 convert_types<Address, uint64_t>(address), 2057 convert_types<Addend, uint64_t>(addend), 2058 false, false, false)); 2059 } 2060 2061 void add_global_generic(Symbol * gsym,unsigned int type,Output_data * od,Relobj * relobj,unsigned int shndx,uint64_t address,uint64_t addend)2062 add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, 2063 Relobj* relobj, unsigned int shndx, uint64_t address, 2064 uint64_t addend) 2065 { 2066 Sized_relobj<size, big_endian>* sized_relobj = 2067 static_cast<Sized_relobj<size, big_endian>*>(relobj); 2068 this->add(od, Output_reloc_type(gsym, type, sized_relobj, shndx, 2069 convert_types<Address, uint64_t>(address), 2070 convert_types<Addend, uint64_t>(addend), 2071 false, false, false)); 2072 } 2073 2074 // Add a RELATIVE reloc against a global symbol. The final output 2075 // relocation will not reference the symbol, but we must keep the symbol 2076 // information long enough to set the addend of the relocation correctly 2077 // when it is written. 2078 2079 void add_global_relative(Symbol * gsym,unsigned int type,Output_data * od,Address address,Addend addend,bool use_plt_offset)2080 add_global_relative(Symbol* gsym, unsigned int type, Output_data* od, 2081 Address address, Addend addend, bool use_plt_offset) 2082 { 2083 this->add(od, Output_reloc_type(gsym, type, od, address, addend, true, 2084 true, use_plt_offset)); 2085 } 2086 2087 void add_global_relative(Symbol * gsym,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend,bool use_plt_offset)2088 add_global_relative(Symbol* gsym, unsigned int type, Output_data* od, 2089 Sized_relobj<size, big_endian>* relobj, 2090 unsigned int shndx, Address address, Addend addend, 2091 bool use_plt_offset) 2092 { 2093 this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, 2094 addend, true, true, use_plt_offset)); 2095 } 2096 2097 // Add a global relocation which does not use a symbol for the relocation, 2098 // but which gets its addend from a symbol. 2099 2100 void add_symbolless_global_addend(Symbol * gsym,unsigned int type,Output_data * od,Address address,Addend addend)2101 add_symbolless_global_addend(Symbol* gsym, unsigned int type, Output_data* od, 2102 Address address, Addend addend) 2103 { 2104 this->add(od, Output_reloc_type(gsym, type, od, address, addend, 2105 false, true, false)); 2106 } 2107 2108 void add_symbolless_global_addend(Symbol * gsym,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend)2109 add_symbolless_global_addend(Symbol* gsym, unsigned int type, 2110 Output_data* od, 2111 Sized_relobj<size, big_endian>* relobj, 2112 unsigned int shndx, Address address, 2113 Addend addend) 2114 { 2115 this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, 2116 addend, false, true, false)); 2117 } 2118 2119 // Add a reloc against a local symbol. 2120 2121 void add_local(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,Address address,Addend addend)2122 add_local(Sized_relobj<size, big_endian>* relobj, 2123 unsigned int local_sym_index, unsigned int type, 2124 Output_data* od, Address address, Addend addend) 2125 { 2126 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, address, 2127 addend, false, false, false, false)); 2128 } 2129 2130 void add_local(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,unsigned int shndx,Address address,Addend addend)2131 add_local(Sized_relobj<size, big_endian>* relobj, 2132 unsigned int local_sym_index, unsigned int type, 2133 Output_data* od, unsigned int shndx, Address address, 2134 Addend addend) 2135 { 2136 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, 2137 address, addend, false, false, false, 2138 false)); 2139 } 2140 2141 void add_local_generic(Relobj * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,uint64_t address,uint64_t addend)2142 add_local_generic(Relobj* relobj, unsigned int local_sym_index, 2143 unsigned int type, Output_data* od, uint64_t address, 2144 uint64_t addend) 2145 { 2146 Sized_relobj<size, big_endian>* sized_relobj = 2147 static_cast<Sized_relobj<size, big_endian> *>(relobj); 2148 this->add(od, Output_reloc_type(sized_relobj, local_sym_index, type, od, 2149 convert_types<Address, uint64_t>(address), 2150 convert_types<Addend, uint64_t>(addend), 2151 false, false, false, false)); 2152 } 2153 2154 void add_local_generic(Relobj * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,unsigned int shndx,uint64_t address,uint64_t addend)2155 add_local_generic(Relobj* relobj, unsigned int local_sym_index, 2156 unsigned int type, Output_data* od, unsigned int shndx, 2157 uint64_t address, uint64_t addend) 2158 { 2159 Sized_relobj<size, big_endian>* sized_relobj = 2160 static_cast<Sized_relobj<size, big_endian>*>(relobj); 2161 this->add(od, Output_reloc_type(sized_relobj, local_sym_index, type, shndx, 2162 convert_types<Address, uint64_t>(address), 2163 convert_types<Addend, uint64_t>(addend), 2164 false, false, false, false)); 2165 } 2166 2167 // Add a RELATIVE reloc against a local symbol. 2168 2169 void add_local_relative(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,Address address,Addend addend,bool use_plt_offset)2170 add_local_relative(Sized_relobj<size, big_endian>* relobj, 2171 unsigned int local_sym_index, unsigned int type, 2172 Output_data* od, Address address, Addend addend, 2173 bool use_plt_offset) 2174 { 2175 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, address, 2176 addend, true, true, false, 2177 use_plt_offset)); 2178 } 2179 2180 void add_local_relative(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,unsigned int shndx,Address address,Addend addend,bool use_plt_offset)2181 add_local_relative(Sized_relobj<size, big_endian>* relobj, 2182 unsigned int local_sym_index, unsigned int type, 2183 Output_data* od, unsigned int shndx, Address address, 2184 Addend addend, bool use_plt_offset) 2185 { 2186 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, 2187 address, addend, true, true, false, 2188 use_plt_offset)); 2189 } 2190 2191 // Add a local relocation which does not use a symbol for the relocation, 2192 // but which gets it's addend from a symbol. 2193 2194 void add_symbolless_local_addend(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,Address address,Addend addend)2195 add_symbolless_local_addend(Sized_relobj<size, big_endian>* relobj, 2196 unsigned int local_sym_index, unsigned int type, 2197 Output_data* od, Address address, Addend addend) 2198 { 2199 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, address, 2200 addend, false, true, false, false)); 2201 } 2202 2203 void add_symbolless_local_addend(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,unsigned int shndx,Address address,Addend addend)2204 add_symbolless_local_addend(Sized_relobj<size, big_endian>* relobj, 2205 unsigned int local_sym_index, unsigned int type, 2206 Output_data* od, unsigned int shndx, 2207 Address address, Addend addend) 2208 { 2209 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, 2210 address, addend, false, true, false, 2211 false)); 2212 } 2213 2214 // Add a reloc against a local section symbol. This will be 2215 // converted into a reloc against the STT_SECTION symbol of the 2216 // output section. 2217 2218 void add_local_section(Sized_relobj<size,big_endian> * relobj,unsigned int input_shndx,unsigned int type,Output_data * od,Address address,Addend addend)2219 add_local_section(Sized_relobj<size, big_endian>* relobj, 2220 unsigned int input_shndx, unsigned int type, 2221 Output_data* od, Address address, Addend addend) 2222 { 2223 this->add(od, Output_reloc_type(relobj, input_shndx, type, od, address, 2224 addend, false, false, true, false)); 2225 } 2226 2227 void add_local_section(Sized_relobj<size,big_endian> * relobj,unsigned int input_shndx,unsigned int type,Output_data * od,unsigned int shndx,Address address,Addend addend)2228 add_local_section(Sized_relobj<size, big_endian>* relobj, 2229 unsigned int input_shndx, unsigned int type, 2230 Output_data* od, unsigned int shndx, Address address, 2231 Addend addend) 2232 { 2233 this->add(od, Output_reloc_type(relobj, input_shndx, type, shndx, 2234 address, addend, false, false, true, 2235 false)); 2236 } 2237 2238 // A reloc against the STT_SECTION symbol of an output section. 2239 2240 void add_output_section(Output_section * os,unsigned int type,Output_data * od,Address address,Addend addend)2241 add_output_section(Output_section* os, unsigned int type, Output_data* od, 2242 Address address, Addend addend) 2243 { this->add(od, Output_reloc_type(os, type, od, address, addend, false)); } 2244 2245 void add_output_section(Output_section * os,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend)2246 add_output_section(Output_section* os, unsigned int type, Output_data* od, 2247 Sized_relobj<size, big_endian>* relobj, 2248 unsigned int shndx, Address address, Addend addend) 2249 { 2250 this->add(od, Output_reloc_type(os, type, relobj, shndx, address, 2251 addend, false)); 2252 } 2253 2254 void add_output_section_generic(Output_section * os,unsigned int type,Output_data * od,uint64_t address,uint64_t addend)2255 add_output_section_generic(Output_section* os, unsigned int type, 2256 Output_data* od, uint64_t address, 2257 uint64_t addend) 2258 { 2259 this->add(od, Output_reloc_type(os, type, od, 2260 convert_types<Address, uint64_t>(address), 2261 convert_types<Addend, uint64_t>(addend), 2262 false)); 2263 } 2264 2265 void add_output_section_generic(Output_section * os,unsigned int type,Output_data * od,Relobj * relobj,unsigned int shndx,uint64_t address,uint64_t addend)2266 add_output_section_generic(Output_section* os, unsigned int type, 2267 Output_data* od, Relobj* relobj, 2268 unsigned int shndx, uint64_t address, 2269 uint64_t addend) 2270 { 2271 Sized_relobj<size, big_endian>* sized_relobj = 2272 static_cast<Sized_relobj<size, big_endian>*>(relobj); 2273 this->add(od, Output_reloc_type(os, type, sized_relobj, shndx, 2274 convert_types<Address, uint64_t>(address), 2275 convert_types<Addend, uint64_t>(addend), 2276 false)); 2277 } 2278 2279 // As above, but the reloc TYPE is relative 2280 2281 void add_output_section_relative(Output_section * os,unsigned int type,Output_data * od,Address address,Addend addend)2282 add_output_section_relative(Output_section* os, unsigned int type, 2283 Output_data* od, Address address, Addend addend) 2284 { this->add(od, Output_reloc_type(os, type, od, address, addend, true)); } 2285 2286 void add_output_section_relative(Output_section * os,unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend)2287 add_output_section_relative(Output_section* os, unsigned int type, 2288 Output_data* od, 2289 Sized_relobj<size, big_endian>* relobj, 2290 unsigned int shndx, Address address, 2291 Addend addend) 2292 { 2293 this->add(od, Output_reloc_type(os, type, relobj, shndx, 2294 address, addend, true)); 2295 } 2296 2297 // Add an absolute relocation. 2298 2299 void add_absolute(unsigned int type,Output_data * od,Address address,Addend addend)2300 add_absolute(unsigned int type, Output_data* od, Address address, 2301 Addend addend) 2302 { this->add(od, Output_reloc_type(type, od, address, addend, false)); } 2303 2304 void add_absolute(unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend)2305 add_absolute(unsigned int type, Output_data* od, 2306 Sized_relobj<size, big_endian>* relobj, 2307 unsigned int shndx, Address address, Addend addend) 2308 { 2309 this->add(od, Output_reloc_type(type, relobj, shndx, address, addend, 2310 false)); 2311 } 2312 2313 // Add a relative relocation 2314 2315 void add_relative(unsigned int type,Output_data * od,Address address,Addend addend)2316 add_relative(unsigned int type, Output_data* od, Address address, 2317 Addend addend) 2318 { this->add(od, Output_reloc_type(type, od, address, addend, true)); } 2319 2320 void add_relative(unsigned int type,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend)2321 add_relative(unsigned int type, Output_data* od, 2322 Sized_relobj<size, big_endian>* relobj, 2323 unsigned int shndx, Address address, Addend addend) 2324 { 2325 this->add(od, Output_reloc_type(type, relobj, shndx, address, addend, 2326 true)); 2327 } 2328 2329 // Add a target specific relocation. A target which calls this must 2330 // define the reloc_symbol_index and reloc_addend virtual functions. 2331 2332 void add_target_specific(unsigned int type,void * arg,Output_data * od,Address address,Addend addend)2333 add_target_specific(unsigned int type, void* arg, Output_data* od, 2334 Address address, Addend addend) 2335 { this->add(od, Output_reloc_type(type, arg, od, address, addend)); } 2336 2337 void add_target_specific(unsigned int type,void * arg,Output_data * od,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,Addend addend)2338 add_target_specific(unsigned int type, void* arg, Output_data* od, 2339 Sized_relobj<size, big_endian>* relobj, 2340 unsigned int shndx, Address address, Addend addend) 2341 { 2342 this->add(od, Output_reloc_type(type, arg, relobj, shndx, address, 2343 addend)); 2344 } 2345 }; 2346 2347 // Output_relocatable_relocs represents a relocation section in a 2348 // relocatable link. The actual data is written out in the target 2349 // hook relocate_relocs. This just saves space for it. 2350 2351 template<int sh_type, int size, bool big_endian> 2352 class Output_relocatable_relocs : public Output_section_data 2353 { 2354 public: Output_relocatable_relocs(Relocatable_relocs * rr)2355 Output_relocatable_relocs(Relocatable_relocs* rr) 2356 : Output_section_data(Output_data::default_alignment_for_size(size)), 2357 rr_(rr) 2358 { } 2359 2360 void 2361 set_final_data_size(); 2362 2363 // Write out the data. There is nothing to do here. 2364 void do_write(Output_file *)2365 do_write(Output_file*) 2366 { } 2367 2368 // Write to a map file. 2369 void do_print_to_mapfile(Mapfile * mapfile)2370 do_print_to_mapfile(Mapfile* mapfile) const 2371 { mapfile->print_output_data(this, _("** relocs")); } 2372 2373 private: 2374 // The relocs associated with this input section. 2375 Relocatable_relocs* rr_; 2376 }; 2377 2378 // Handle a GROUP section. 2379 2380 template<int size, bool big_endian> 2381 class Output_data_group : public Output_section_data 2382 { 2383 public: 2384 // The constructor clears *INPUT_SHNDXES. 2385 Output_data_group(Sized_relobj_file<size, big_endian>* relobj, 2386 section_size_type entry_count, 2387 elfcpp::Elf_Word flags, 2388 std::vector<unsigned int>* input_shndxes); 2389 2390 void 2391 do_write(Output_file*); 2392 2393 // Write to a map file. 2394 void do_print_to_mapfile(Mapfile * mapfile)2395 do_print_to_mapfile(Mapfile* mapfile) const 2396 { mapfile->print_output_data(this, _("** group")); } 2397 2398 // Set final data size. 2399 void set_final_data_size()2400 set_final_data_size() 2401 { this->set_data_size((this->input_shndxes_.size() + 1) * 4); } 2402 2403 private: 2404 // The input object. 2405 Sized_relobj_file<size, big_endian>* relobj_; 2406 // The group flag word. 2407 elfcpp::Elf_Word flags_; 2408 // The section indexes of the input sections in this group. 2409 std::vector<unsigned int> input_shndxes_; 2410 }; 2411 2412 // Output_data_got is used to manage a GOT. Each entry in the GOT is 2413 // for one symbol--either a global symbol or a local symbol in an 2414 // object. The target specific code adds entries to the GOT as 2415 // needed. The GOT_SIZE template parameter is the size in bits of a 2416 // GOT entry, typically 32 or 64. 2417 2418 class Output_data_got_base : public Output_section_data_build 2419 { 2420 public: Output_data_got_base(uint64_t align)2421 Output_data_got_base(uint64_t align) 2422 : Output_section_data_build(align) 2423 { } 2424 Output_data_got_base(off_t data_size,uint64_t align)2425 Output_data_got_base(off_t data_size, uint64_t align) 2426 : Output_section_data_build(data_size, align) 2427 { } 2428 2429 // Reserve the slot at index I in the GOT. 2430 void reserve_slot(unsigned int i)2431 reserve_slot(unsigned int i) 2432 { this->do_reserve_slot(i); } 2433 2434 protected: 2435 // Reserve the slot at index I in the GOT. 2436 virtual void 2437 do_reserve_slot(unsigned int i) = 0; 2438 }; 2439 2440 template<int got_size, bool big_endian> 2441 class Output_data_got : public Output_data_got_base 2442 { 2443 public: 2444 typedef typename elfcpp::Elf_types<got_size>::Elf_Addr Valtype; 2445 Output_data_got()2446 Output_data_got() 2447 : Output_data_got_base(Output_data::default_alignment_for_size(got_size)), 2448 entries_(), free_list_() 2449 { } 2450 Output_data_got(off_t data_size)2451 Output_data_got(off_t data_size) 2452 : Output_data_got_base(data_size, 2453 Output_data::default_alignment_for_size(got_size)), 2454 entries_(), free_list_() 2455 { 2456 // For an incremental update, we have an existing GOT section. 2457 // Initialize the list of entries and the free list. 2458 this->entries_.resize(data_size / (got_size / 8)); 2459 this->free_list_.init(data_size, false); 2460 } 2461 2462 // Add an entry for a global symbol to the GOT. Return true if this 2463 // is a new GOT entry, false if the symbol was already in the GOT. 2464 bool 2465 add_global(Symbol* gsym, unsigned int got_type); 2466 2467 // Like add_global, but use the PLT offset of the global symbol if 2468 // it has one. 2469 bool 2470 add_global_plt(Symbol* gsym, unsigned int got_type); 2471 2472 // Like add_global, but for a TLS symbol where the value will be 2473 // offset using Target::tls_offset_for_global. 2474 bool add_global_tls(Symbol * gsym,unsigned int got_type)2475 add_global_tls(Symbol* gsym, unsigned int got_type) 2476 { return add_global_plt(gsym, got_type); } 2477 2478 // Add an entry for a global symbol to the GOT, and add a dynamic 2479 // relocation of type R_TYPE for the GOT entry. 2480 void 2481 add_global_with_rel(Symbol* gsym, unsigned int got_type, 2482 Output_data_reloc_generic* rel_dyn, unsigned int r_type); 2483 2484 // Add a pair of entries for a global symbol to the GOT, and add 2485 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively. 2486 void 2487 add_global_pair_with_rel(Symbol* gsym, unsigned int got_type, 2488 Output_data_reloc_generic* rel_dyn, 2489 unsigned int r_type_1, unsigned int r_type_2); 2490 2491 // Add an entry for a local symbol to the GOT. This returns true if 2492 // this is a new GOT entry, false if the symbol already has a GOT 2493 // entry. 2494 bool 2495 add_local(Relobj* object, unsigned int sym_index, unsigned int got_type); 2496 2497 // Add an entry for a local symbol plus ADDEND to the GOT. This returns 2498 // true if this is a new GOT entry, false if the symbol already has a GOT 2499 // entry. 2500 bool 2501 add_local(Relobj* object, unsigned int sym_index, unsigned int got_type, 2502 uint64_t addend); 2503 2504 // Like add_local, but use the PLT offset of the local symbol if it 2505 // has one. 2506 bool 2507 add_local_plt(Relobj* object, unsigned int sym_index, unsigned int got_type); 2508 2509 // Like add_local, but for a TLS symbol where the value will be 2510 // offset using Target::tls_offset_for_local. 2511 bool add_local_tls(Relobj * object,unsigned int sym_index,unsigned int got_type)2512 add_local_tls(Relobj* object, unsigned int sym_index, unsigned int got_type) 2513 { return add_local_plt(object, sym_index, got_type); } 2514 2515 // Add an entry for a local symbol to the GOT, and add a dynamic 2516 // relocation of type R_TYPE for the GOT entry. 2517 void 2518 add_local_with_rel(Relobj* object, unsigned int sym_index, 2519 unsigned int got_type, Output_data_reloc_generic* rel_dyn, 2520 unsigned int r_type); 2521 2522 // Add an entry for a local symbol plus ADDEND to the GOT, and add a dynamic 2523 // relocation of type R_TYPE for the GOT entry. 2524 void 2525 add_local_with_rel(Relobj* object, unsigned int sym_index, 2526 unsigned int got_type, Output_data_reloc_generic* rel_dyn, 2527 unsigned int r_type, uint64_t addend); 2528 2529 // Add a pair of entries for a local symbol to the GOT, and add 2530 // a dynamic relocation of type R_TYPE using the section symbol of 2531 // the output section to which input section SHNDX maps, on the first. 2532 // The first got entry will have a value of zero, the second the 2533 // value of the local symbol. 2534 void 2535 add_local_pair_with_rel(Relobj* object, unsigned int sym_index, 2536 unsigned int shndx, unsigned int got_type, 2537 Output_data_reloc_generic* rel_dyn, 2538 unsigned int r_type); 2539 2540 // Add a pair of entries for a local symbol plus ADDEND to the GOT, and add 2541 // a dynamic relocation of type R_TYPE using the section symbol of 2542 // the output section to which input section SHNDX maps, on the first. 2543 // The first got entry will have a value of zero, the second the 2544 // value of the local symbol. 2545 void 2546 add_local_pair_with_rel(Relobj* object, unsigned int sym_index, 2547 unsigned int shndx, unsigned int got_type, 2548 Output_data_reloc_generic* rel_dyn, 2549 unsigned int r_type, uint64_t addend); 2550 2551 // Add a pair of entries for a local symbol to the GOT, and add 2552 // a dynamic relocation of type R_TYPE using STN_UNDEF on the first. 2553 // The first got entry will have a value of zero, the second the 2554 // value of the local symbol offset by Target::tls_offset_for_local. 2555 void 2556 add_local_tls_pair(Relobj* object, unsigned int sym_index, 2557 unsigned int got_type, 2558 Output_data_reloc_generic* rel_dyn, 2559 unsigned int r_type); 2560 2561 // Add a constant to the GOT. This returns the offset of the new 2562 // entry from the start of the GOT. 2563 unsigned int add_constant(Valtype constant)2564 add_constant(Valtype constant) 2565 { return this->add_got_entry(Got_entry(constant)); } 2566 2567 // Add a pair of constants to the GOT. This returns the offset of 2568 // the new entry from the start of the GOT. 2569 unsigned int add_constant_pair(Valtype c1,Valtype c2)2570 add_constant_pair(Valtype c1, Valtype c2) 2571 { return this->add_got_entry_pair(Got_entry(c1), Got_entry(c2)); } 2572 2573 // Replace GOT entry I with a new constant. 2574 void replace_constant(unsigned int i,Valtype constant)2575 replace_constant(unsigned int i, Valtype constant) 2576 { 2577 this->replace_got_entry(i, Got_entry(constant)); 2578 } 2579 2580 // Reserve a slot in the GOT for a local symbol. 2581 void 2582 reserve_local(unsigned int i, Relobj* object, unsigned int sym_index, 2583 unsigned int got_type); 2584 2585 // Reserve a slot in the GOT for a global symbol. 2586 void 2587 reserve_global(unsigned int i, Symbol* gsym, unsigned int got_type); 2588 2589 protected: 2590 // Write out the GOT table. 2591 void 2592 do_write(Output_file*); 2593 2594 // Write to a map file. 2595 void do_print_to_mapfile(Mapfile * mapfile)2596 do_print_to_mapfile(Mapfile* mapfile) const 2597 { mapfile->print_output_data(this, _("** GOT")); } 2598 2599 // Reserve the slot at index I in the GOT. 2600 virtual void do_reserve_slot(unsigned int i)2601 do_reserve_slot(unsigned int i) 2602 { this->free_list_.remove(i * got_size / 8, (i + 1) * got_size / 8); } 2603 2604 // Return the number of words in the GOT. 2605 unsigned int num_entries()2606 num_entries () const 2607 { return this->entries_.size(); } 2608 2609 // Return the offset into the GOT of GOT entry I. 2610 unsigned int got_offset(unsigned int i)2611 got_offset(unsigned int i) const 2612 { return i * (got_size / 8); } 2613 2614 private: 2615 // This POD class holds a single GOT entry. 2616 class Got_entry 2617 { 2618 public: 2619 // Create a zero entry. Got_entry()2620 Got_entry() 2621 : local_sym_index_(RESERVED_CODE), use_plt_or_tls_offset_(false), 2622 addend_(0) 2623 { this->u_.constant = 0; } 2624 2625 // Create a global symbol entry. Got_entry(Symbol * gsym,bool use_plt_or_tls_offset)2626 Got_entry(Symbol* gsym, bool use_plt_or_tls_offset) 2627 : local_sym_index_(GSYM_CODE), 2628 use_plt_or_tls_offset_(use_plt_or_tls_offset), addend_(0) 2629 { this->u_.gsym = gsym; } 2630 2631 // Create a local symbol entry. Got_entry(Relobj * object,unsigned int local_sym_index,bool use_plt_or_tls_offset)2632 Got_entry(Relobj* object, unsigned int local_sym_index, 2633 bool use_plt_or_tls_offset) 2634 : local_sym_index_(local_sym_index), 2635 use_plt_or_tls_offset_(use_plt_or_tls_offset), addend_(0) 2636 { 2637 gold_assert(local_sym_index != GSYM_CODE 2638 && local_sym_index != CONSTANT_CODE 2639 && local_sym_index != RESERVED_CODE 2640 && local_sym_index == this->local_sym_index_); 2641 this->u_.object = object; 2642 } 2643 2644 // Create a local symbol entry plus addend. Got_entry(Relobj * object,unsigned int local_sym_index,bool use_plt_or_tls_offset,uint64_t addend)2645 Got_entry(Relobj* object, unsigned int local_sym_index, 2646 bool use_plt_or_tls_offset, uint64_t addend) 2647 : local_sym_index_(local_sym_index), 2648 use_plt_or_tls_offset_(use_plt_or_tls_offset), addend_(addend) 2649 { 2650 gold_assert(local_sym_index != GSYM_CODE 2651 && local_sym_index != CONSTANT_CODE 2652 && local_sym_index != RESERVED_CODE 2653 && local_sym_index == this->local_sym_index_); 2654 this->u_.object = object; 2655 } 2656 2657 // Create a constant entry. The constant is a host value--it will 2658 // be swapped, if necessary, when it is written out. Got_entry(Valtype constant)2659 explicit Got_entry(Valtype constant) 2660 : local_sym_index_(CONSTANT_CODE), use_plt_or_tls_offset_(false) 2661 { this->u_.constant = constant; } 2662 2663 // Write the GOT entry to an output view. 2664 void 2665 write(unsigned int got_indx, unsigned char* pov) const; 2666 2667 private: 2668 enum 2669 { 2670 GSYM_CODE = 0x7fffffff, 2671 CONSTANT_CODE = 0x7ffffffe, 2672 RESERVED_CODE = 0x7ffffffd 2673 }; 2674 2675 union 2676 { 2677 // For a local symbol, the object. 2678 Relobj* object; 2679 // For a global symbol, the symbol. 2680 Symbol* gsym; 2681 // For a constant, the constant. 2682 Valtype constant; 2683 } u_; 2684 // For a local symbol, the local symbol index. This is GSYM_CODE 2685 // for a global symbol, or CONSTANT_CODE for a constant. 2686 unsigned int local_sym_index_ : 31; 2687 // Whether to use the PLT offset of the symbol if it has one. 2688 // For TLS symbols, whether to offset the symbol value. 2689 bool use_plt_or_tls_offset_ : 1; 2690 // The addend. 2691 uint64_t addend_; 2692 }; 2693 2694 typedef std::vector<Got_entry> Got_entries; 2695 2696 // Create a new GOT entry and return its offset. 2697 unsigned int 2698 add_got_entry(Got_entry got_entry); 2699 2700 // Create a pair of new GOT entries and return the offset of the first. 2701 unsigned int 2702 add_got_entry_pair(Got_entry got_entry_1, Got_entry got_entry_2); 2703 2704 // Replace GOT entry I with a new value. 2705 void 2706 replace_got_entry(unsigned int i, Got_entry got_entry); 2707 2708 // Return the offset into the GOT of the last entry added. 2709 unsigned int last_got_offset()2710 last_got_offset() const 2711 { return this->got_offset(this->num_entries() - 1); } 2712 2713 // Set the size of the section. 2714 void set_got_size()2715 set_got_size() 2716 { this->set_current_data_size(this->got_offset(this->num_entries())); } 2717 2718 // The list of GOT entries. 2719 Got_entries entries_; 2720 2721 // List of available regions within the section, for incremental 2722 // update links. 2723 Free_list free_list_; 2724 }; 2725 2726 // Output_data_dynamic is used to hold the data in SHT_DYNAMIC 2727 // section. 2728 2729 class Output_data_dynamic : public Output_section_data 2730 { 2731 public: Output_data_dynamic(Stringpool * pool)2732 Output_data_dynamic(Stringpool* pool) 2733 : Output_section_data(Output_data::default_alignment()), 2734 entries_(), pool_(pool) 2735 { } 2736 2737 // Add a new dynamic entry with a fixed numeric value. 2738 void add_constant(elfcpp::DT tag,unsigned int val)2739 add_constant(elfcpp::DT tag, unsigned int val) 2740 { this->add_entry(Dynamic_entry(tag, val)); } 2741 2742 // Add a new dynamic entry with the address of output data. 2743 void add_section_address(elfcpp::DT tag,const Output_data * od)2744 add_section_address(elfcpp::DT tag, const Output_data* od) 2745 { this->add_entry(Dynamic_entry(tag, od, false)); } 2746 2747 // Add a new dynamic entry with the address of output data 2748 // plus a constant offset. 2749 void add_section_plus_offset(elfcpp::DT tag,const Output_data * od,unsigned int offset)2750 add_section_plus_offset(elfcpp::DT tag, const Output_data* od, 2751 unsigned int offset) 2752 { this->add_entry(Dynamic_entry(tag, od, offset)); } 2753 2754 // Add a new dynamic entry with the size of output data. 2755 void add_section_size(elfcpp::DT tag,const Output_data * od)2756 add_section_size(elfcpp::DT tag, const Output_data* od) 2757 { this->add_entry(Dynamic_entry(tag, od, true)); } 2758 2759 // Add a new dynamic entry with the total size of two output datas. 2760 void add_section_size(elfcpp::DT tag,const Output_data * od,const Output_data * od2)2761 add_section_size(elfcpp::DT tag, const Output_data* od, 2762 const Output_data* od2) 2763 { this->add_entry(Dynamic_entry(tag, od, od2)); } 2764 2765 // Add a new dynamic entry with the address of a symbol. 2766 void add_symbol(elfcpp::DT tag,const Symbol * sym)2767 add_symbol(elfcpp::DT tag, const Symbol* sym) 2768 { this->add_entry(Dynamic_entry(tag, sym)); } 2769 2770 // Add a new dynamic entry with a string. 2771 void add_string(elfcpp::DT tag,const char * str)2772 add_string(elfcpp::DT tag, const char* str) 2773 { this->add_entry(Dynamic_entry(tag, this->pool_->add(str, true, NULL))); } 2774 2775 void add_string(elfcpp::DT tag,const std::string & str)2776 add_string(elfcpp::DT tag, const std::string& str) 2777 { this->add_string(tag, str.c_str()); } 2778 2779 // Add a new dynamic entry with custom value. 2780 void add_custom(elfcpp::DT tag)2781 add_custom(elfcpp::DT tag) 2782 { this->add_entry(Dynamic_entry(tag)); } 2783 2784 // Get a dynamic entry offset. 2785 unsigned int 2786 get_entry_offset(elfcpp::DT tag) const; 2787 2788 protected: 2789 // Adjust the output section to set the entry size. 2790 void 2791 do_adjust_output_section(Output_section*); 2792 2793 // Set the final data size. 2794 void 2795 set_final_data_size(); 2796 2797 // Write out the dynamic entries. 2798 void 2799 do_write(Output_file*); 2800 2801 // Write to a map file. 2802 void do_print_to_mapfile(Mapfile * mapfile)2803 do_print_to_mapfile(Mapfile* mapfile) const 2804 { mapfile->print_output_data(this, _("** dynamic")); } 2805 2806 private: 2807 // This POD class holds a single dynamic entry. 2808 class Dynamic_entry 2809 { 2810 public: 2811 // Create an entry with a fixed numeric value. Dynamic_entry(elfcpp::DT tag,unsigned int val)2812 Dynamic_entry(elfcpp::DT tag, unsigned int val) 2813 : tag_(tag), offset_(DYNAMIC_NUMBER) 2814 { this->u_.val = val; } 2815 2816 // Create an entry with the size or address of a section. Dynamic_entry(elfcpp::DT tag,const Output_data * od,bool section_size)2817 Dynamic_entry(elfcpp::DT tag, const Output_data* od, bool section_size) 2818 : tag_(tag), 2819 offset_(section_size 2820 ? DYNAMIC_SECTION_SIZE 2821 : DYNAMIC_SECTION_ADDRESS) 2822 { 2823 this->u_.od = od; 2824 this->od2 = NULL; 2825 } 2826 2827 // Create an entry with the size of two sections. Dynamic_entry(elfcpp::DT tag,const Output_data * od,const Output_data * od2)2828 Dynamic_entry(elfcpp::DT tag, const Output_data* od, const Output_data* od2) 2829 : tag_(tag), 2830 offset_(DYNAMIC_SECTION_SIZE) 2831 { 2832 this->u_.od = od; 2833 this->od2 = od2; 2834 } 2835 2836 // Create an entry with the address of a section plus a constant offset. Dynamic_entry(elfcpp::DT tag,const Output_data * od,unsigned int offset)2837 Dynamic_entry(elfcpp::DT tag, const Output_data* od, unsigned int offset) 2838 : tag_(tag), 2839 offset_(offset) 2840 { this->u_.od = od; } 2841 2842 // Create an entry with the address of a symbol. Dynamic_entry(elfcpp::DT tag,const Symbol * sym)2843 Dynamic_entry(elfcpp::DT tag, const Symbol* sym) 2844 : tag_(tag), offset_(DYNAMIC_SYMBOL) 2845 { this->u_.sym = sym; } 2846 2847 // Create an entry with a string. Dynamic_entry(elfcpp::DT tag,const char * str)2848 Dynamic_entry(elfcpp::DT tag, const char* str) 2849 : tag_(tag), offset_(DYNAMIC_STRING) 2850 { this->u_.str = str; } 2851 2852 // Create an entry with a custom value. Dynamic_entry(elfcpp::DT tag)2853 Dynamic_entry(elfcpp::DT tag) 2854 : tag_(tag), offset_(DYNAMIC_CUSTOM) 2855 { } 2856 2857 // Return the tag of this entry. 2858 elfcpp::DT tag()2859 tag() const 2860 { return this->tag_; } 2861 2862 // Write the dynamic entry to an output view. 2863 template<int size, bool big_endian> 2864 void 2865 write(unsigned char* pov, const Stringpool*) const; 2866 2867 private: 2868 // Classification is encoded in the OFFSET field. 2869 enum Classification 2870 { 2871 // Section address. 2872 DYNAMIC_SECTION_ADDRESS = 0, 2873 // Number. 2874 DYNAMIC_NUMBER = -1U, 2875 // Section size. 2876 DYNAMIC_SECTION_SIZE = -2U, 2877 // Symbol address. 2878 DYNAMIC_SYMBOL = -3U, 2879 // String. 2880 DYNAMIC_STRING = -4U, 2881 // Custom value. 2882 DYNAMIC_CUSTOM = -5U 2883 // Any other value indicates a section address plus OFFSET. 2884 }; 2885 2886 union 2887 { 2888 // For DYNAMIC_NUMBER. 2889 unsigned int val; 2890 // For DYNAMIC_SECTION_SIZE and section address plus OFFSET. 2891 const Output_data* od; 2892 // For DYNAMIC_SYMBOL. 2893 const Symbol* sym; 2894 // For DYNAMIC_STRING. 2895 const char* str; 2896 } u_; 2897 // For DYNAMIC_SYMBOL with two sections. 2898 const Output_data* od2; 2899 // The dynamic tag. 2900 elfcpp::DT tag_; 2901 // The type of entry (Classification) or offset within a section. 2902 unsigned int offset_; 2903 }; 2904 2905 // Add an entry to the list. 2906 void add_entry(const Dynamic_entry & entry)2907 add_entry(const Dynamic_entry& entry) 2908 { this->entries_.push_back(entry); } 2909 2910 // Sized version of write function. 2911 template<int size, bool big_endian> 2912 void 2913 sized_write(Output_file* of); 2914 2915 // The type of the list of entries. 2916 typedef std::vector<Dynamic_entry> Dynamic_entries; 2917 2918 // The entries. 2919 Dynamic_entries entries_; 2920 // The pool used for strings. 2921 Stringpool* pool_; 2922 }; 2923 2924 // Output_symtab_xindex is used to handle SHT_SYMTAB_SHNDX sections, 2925 // which may be required if the object file has more than 2926 // SHN_LORESERVE sections. 2927 2928 class Output_symtab_xindex : public Output_section_data 2929 { 2930 public: Output_symtab_xindex(size_t symcount)2931 Output_symtab_xindex(size_t symcount) 2932 : Output_section_data(symcount * 4, 4, true), 2933 entries_() 2934 { } 2935 2936 // Add an entry: symbol number SYMNDX has section SHNDX. 2937 void add(unsigned int symndx,unsigned int shndx)2938 add(unsigned int symndx, unsigned int shndx) 2939 { this->entries_.push_back(std::make_pair(symndx, shndx)); } 2940 2941 protected: 2942 void 2943 do_write(Output_file*); 2944 2945 // Write to a map file. 2946 void do_print_to_mapfile(Mapfile * mapfile)2947 do_print_to_mapfile(Mapfile* mapfile) const 2948 { mapfile->print_output_data(this, _("** symtab xindex")); } 2949 2950 private: 2951 template<bool big_endian> 2952 void 2953 endian_do_write(unsigned char*); 2954 2955 // It is likely that most symbols will not require entries. Rather 2956 // than keep a vector for all symbols, we keep pairs of symbol index 2957 // and section index. 2958 typedef std::vector<std::pair<unsigned int, unsigned int> > Xindex_entries; 2959 2960 // The entries we need. 2961 Xindex_entries entries_; 2962 }; 2963 2964 // A relaxed input section. 2965 class Output_relaxed_input_section : public Output_section_data_build 2966 { 2967 public: 2968 // We would like to call relobj->section_addralign(shndx) to get the 2969 // alignment but we do not want the constructor to fail. So callers 2970 // are repsonsible for ensuring that. Output_relaxed_input_section(Relobj * relobj,unsigned int shndx,uint64_t addralign)2971 Output_relaxed_input_section(Relobj* relobj, unsigned int shndx, 2972 uint64_t addralign) 2973 : Output_section_data_build(addralign), relobj_(relobj), shndx_(shndx) 2974 { } 2975 2976 // Return the Relobj of this relaxed input section. 2977 Relobj* relobj()2978 relobj() const 2979 { return this->relobj_; } 2980 2981 // Return the section index of this relaxed input section. 2982 unsigned int shndx()2983 shndx() const 2984 { return this->shndx_; } 2985 2986 protected: 2987 void set_relobj(Relobj * relobj)2988 set_relobj(Relobj* relobj) 2989 { this->relobj_ = relobj; } 2990 2991 void set_shndx(unsigned int shndx)2992 set_shndx(unsigned int shndx) 2993 { this->shndx_ = shndx; } 2994 2995 private: 2996 Relobj* relobj_; 2997 unsigned int shndx_; 2998 }; 2999 3000 // This class describes properties of merge data sections. It is used 3001 // as a key type for maps. 3002 class Merge_section_properties 3003 { 3004 public: Merge_section_properties(bool is_string,uint64_t entsize,uint64_t addralign)3005 Merge_section_properties(bool is_string, uint64_t entsize, 3006 uint64_t addralign) 3007 : is_string_(is_string), entsize_(entsize), addralign_(addralign) 3008 { } 3009 3010 // Whether this equals to another Merge_section_properties MSP. 3011 bool eq(const Merge_section_properties & msp)3012 eq(const Merge_section_properties& msp) const 3013 { 3014 return ((this->is_string_ == msp.is_string_) 3015 && (this->entsize_ == msp.entsize_) 3016 && (this->addralign_ == msp.addralign_)); 3017 } 3018 3019 // Compute a hash value for this using 64-bit FNV-1a hash. 3020 size_t hash_value()3021 hash_value() const 3022 { 3023 uint64_t h = 14695981039346656037ULL; // FNV offset basis. 3024 uint64_t prime = 1099511628211ULL; 3025 h = (h ^ static_cast<uint64_t>(this->is_string_)) * prime; 3026 h = (h ^ static_cast<uint64_t>(this->entsize_)) * prime; 3027 h = (h ^ static_cast<uint64_t>(this->addralign_)) * prime; 3028 return h; 3029 } 3030 3031 // Functors for associative containers. 3032 struct equal_to 3033 { 3034 bool operatorequal_to3035 operator()(const Merge_section_properties& msp1, 3036 const Merge_section_properties& msp2) const 3037 { return msp1.eq(msp2); } 3038 }; 3039 3040 struct hash 3041 { 3042 size_t operatorhash3043 operator()(const Merge_section_properties& msp) const 3044 { return msp.hash_value(); } 3045 }; 3046 3047 private: 3048 // Whether this merge data section is for strings. 3049 bool is_string_; 3050 // Entsize of this merge data section. 3051 uint64_t entsize_; 3052 // Address alignment. 3053 uint64_t addralign_; 3054 }; 3055 3056 // This class is used to speed up look up of special input sections in an 3057 // Output_section. 3058 3059 class Output_section_lookup_maps 3060 { 3061 public: Output_section_lookup_maps()3062 Output_section_lookup_maps() 3063 : is_valid_(true), merge_sections_by_properties_(), 3064 relaxed_input_sections_by_id_() 3065 { } 3066 3067 // Whether the maps are valid. 3068 bool is_valid()3069 is_valid() const 3070 { return this->is_valid_; } 3071 3072 // Invalidate the maps. 3073 void invalidate()3074 invalidate() 3075 { this->is_valid_ = false; } 3076 3077 // Clear the maps. 3078 void clear()3079 clear() 3080 { 3081 this->merge_sections_by_properties_.clear(); 3082 this->relaxed_input_sections_by_id_.clear(); 3083 // A cleared map is valid. 3084 this->is_valid_ = true; 3085 } 3086 3087 // Find a merge section by merge section properties. Return NULL if none 3088 // is found. 3089 Output_merge_base* find_merge_section(const Merge_section_properties & msp)3090 find_merge_section(const Merge_section_properties& msp) const 3091 { 3092 gold_assert(this->is_valid_); 3093 Merge_sections_by_properties::const_iterator p = 3094 this->merge_sections_by_properties_.find(msp); 3095 return p != this->merge_sections_by_properties_.end() ? p->second : NULL; 3096 } 3097 3098 // Add a merge section pointed by POMB with properties MSP. 3099 void add_merge_section(const Merge_section_properties & msp,Output_merge_base * pomb)3100 add_merge_section(const Merge_section_properties& msp, 3101 Output_merge_base* pomb) 3102 { 3103 std::pair<Merge_section_properties, Output_merge_base*> value(msp, pomb); 3104 std::pair<Merge_sections_by_properties::iterator, bool> result = 3105 this->merge_sections_by_properties_.insert(value); 3106 gold_assert(result.second); 3107 } 3108 3109 // Find a relaxed input section of OBJECT with index SHNDX. 3110 Output_relaxed_input_section* find_relaxed_input_section(const Relobj * object,unsigned int shndx)3111 find_relaxed_input_section(const Relobj* object, unsigned int shndx) const 3112 { 3113 gold_assert(this->is_valid_); 3114 Relaxed_input_sections_by_id::const_iterator p = 3115 this->relaxed_input_sections_by_id_.find(Const_section_id(object, shndx)); 3116 return p != this->relaxed_input_sections_by_id_.end() ? p->second : NULL; 3117 } 3118 3119 // Add a relaxed input section pointed by POMB and whose original input 3120 // section is in OBJECT with index SHNDX. 3121 void add_relaxed_input_section(const Relobj * relobj,unsigned int shndx,Output_relaxed_input_section * poris)3122 add_relaxed_input_section(const Relobj* relobj, unsigned int shndx, 3123 Output_relaxed_input_section* poris) 3124 { 3125 Const_section_id csid(relobj, shndx); 3126 std::pair<Const_section_id, Output_relaxed_input_section*> 3127 value(csid, poris); 3128 std::pair<Relaxed_input_sections_by_id::iterator, bool> result = 3129 this->relaxed_input_sections_by_id_.insert(value); 3130 gold_assert(result.second); 3131 } 3132 3133 private: 3134 typedef Unordered_map<Merge_section_properties, Output_merge_base*, 3135 Merge_section_properties::hash, 3136 Merge_section_properties::equal_to> 3137 Merge_sections_by_properties; 3138 3139 typedef Unordered_map<Const_section_id, Output_relaxed_input_section*, 3140 Const_section_id_hash> 3141 Relaxed_input_sections_by_id; 3142 3143 // Whether this is valid 3144 bool is_valid_; 3145 // Merge sections by merge section properties. 3146 Merge_sections_by_properties merge_sections_by_properties_; 3147 // Relaxed sections by section IDs. 3148 Relaxed_input_sections_by_id relaxed_input_sections_by_id_; 3149 }; 3150 3151 // This abstract base class defines the interface for the 3152 // types of methods used to fill free space left in an output 3153 // section during an incremental link. These methods are used 3154 // to insert dummy compilation units into debug info so that 3155 // debug info consumers can scan the debug info serially. 3156 3157 class Output_fill 3158 { 3159 public: Output_fill()3160 Output_fill() 3161 : is_big_endian_(parameters->target().is_big_endian()) 3162 { } 3163 3164 virtual ~Output_fill()3165 ~Output_fill() 3166 { } 3167 3168 // Return the smallest size chunk of free space that can be 3169 // filled with a dummy compilation unit. 3170 size_t minimum_hole_size()3171 minimum_hole_size() const 3172 { return this->do_minimum_hole_size(); } 3173 3174 // Write a fill pattern of length LEN at offset OFF in the file. 3175 void write(Output_file * of,off_t off,size_t len)3176 write(Output_file* of, off_t off, size_t len) const 3177 { this->do_write(of, off, len); } 3178 3179 protected: 3180 virtual size_t 3181 do_minimum_hole_size() const = 0; 3182 3183 virtual void 3184 do_write(Output_file* of, off_t off, size_t len) const = 0; 3185 3186 bool is_big_endian()3187 is_big_endian() const 3188 { return this->is_big_endian_; } 3189 3190 private: 3191 bool is_big_endian_; 3192 }; 3193 3194 // Fill method that introduces a dummy compilation unit in 3195 // a .debug_info or .debug_types section. 3196 3197 class Output_fill_debug_info : public Output_fill 3198 { 3199 public: Output_fill_debug_info(bool is_debug_types)3200 Output_fill_debug_info(bool is_debug_types) 3201 : is_debug_types_(is_debug_types) 3202 { } 3203 3204 protected: 3205 virtual size_t 3206 do_minimum_hole_size() const; 3207 3208 virtual void 3209 do_write(Output_file* of, off_t off, size_t len) const; 3210 3211 private: 3212 // Version of the header. 3213 static const int version = 4; 3214 // True if this is a .debug_types section. 3215 bool is_debug_types_; 3216 }; 3217 3218 // Fill method that introduces a dummy compilation unit in 3219 // a .debug_line section. 3220 3221 class Output_fill_debug_line : public Output_fill 3222 { 3223 public: Output_fill_debug_line()3224 Output_fill_debug_line() 3225 { } 3226 3227 protected: 3228 virtual size_t 3229 do_minimum_hole_size() const; 3230 3231 virtual void 3232 do_write(Output_file* of, off_t off, size_t len) const; 3233 3234 private: 3235 // Version of the header. We write a DWARF-3 header because it's smaller 3236 // and many tools have not yet been updated to understand the DWARF-4 header. 3237 static const int version = 3; 3238 // Length of the portion of the header that follows the header_length 3239 // field. This includes the following fields: 3240 // minimum_instruction_length, default_is_stmt, line_base, line_range, 3241 // opcode_base, standard_opcode_lengths[], include_directories, filenames. 3242 // The standard_opcode_lengths array is 12 bytes long, and the 3243 // include_directories and filenames fields each contain only a single 3244 // null byte. 3245 static const size_t header_length = 19; 3246 }; 3247 3248 // An output section. We don't expect to have too many output 3249 // sections, so we don't bother to do a template on the size. 3250 3251 class Output_section : public Output_data 3252 { 3253 public: 3254 // Create an output section, giving the name, type, and flags. 3255 Output_section(const char* name, elfcpp::Elf_Word, elfcpp::Elf_Xword); 3256 virtual ~Output_section(); 3257 3258 // Add a new input section SHNDX, named NAME, with header SHDR, from 3259 // object OBJECT. RELOC_SHNDX is the index of a relocation section 3260 // which applies to this section, or 0 if none, or -1 if more than 3261 // one. HAVE_SECTIONS_SCRIPT is true if we have a SECTIONS clause 3262 // in a linker script; in that case we need to keep track of input 3263 // sections associated with an output section. Return the offset 3264 // within the output section. 3265 template<int size, bool big_endian> 3266 off_t 3267 add_input_section(Layout* layout, Sized_relobj_file<size, big_endian>* object, 3268 unsigned int shndx, const char* name, 3269 const elfcpp::Shdr<size, big_endian>& shdr, 3270 unsigned int reloc_shndx, bool have_sections_script); 3271 3272 // Add generated data POSD to this output section. 3273 void 3274 add_output_section_data(Output_section_data* posd); 3275 3276 // Add a relaxed input section PORIS called NAME to this output section 3277 // with LAYOUT. 3278 void 3279 add_relaxed_input_section(Layout* layout, 3280 Output_relaxed_input_section* poris, 3281 const std::string& name); 3282 3283 // Return the section name. 3284 const char* name()3285 name() const 3286 { return this->name_; } 3287 3288 // Return the section type. 3289 elfcpp::Elf_Word type()3290 type() const 3291 { return this->type_; } 3292 3293 // Return the section flags. 3294 elfcpp::Elf_Xword flags()3295 flags() const 3296 { return this->flags_; } 3297 3298 typedef std::map<Section_id, unsigned int> Section_layout_order; 3299 3300 void 3301 update_section_layout(const Section_layout_order* order_map); 3302 3303 // Update the output section flags based on input section flags. 3304 void 3305 update_flags_for_input_section(elfcpp::Elf_Xword flags); 3306 3307 // Set the output section flags. 3308 void set_flags(elfcpp::Elf_Xword flags)3309 set_flags(elfcpp::Elf_Xword flags) 3310 { this->flags_ = flags; } 3311 3312 // Return the entsize field. 3313 uint64_t entsize()3314 entsize() const 3315 { return this->entsize_; } 3316 3317 // Set the entsize field. 3318 void 3319 set_entsize(uint64_t v); 3320 3321 // Set the load address. 3322 void set_load_address(uint64_t load_address)3323 set_load_address(uint64_t load_address) 3324 { 3325 this->load_address_ = load_address; 3326 this->has_load_address_ = true; 3327 } 3328 3329 // Set the link field to the output section index of a section. 3330 void set_link_section(const Output_data * od)3331 set_link_section(const Output_data* od) 3332 { 3333 gold_assert(this->link_ == 0 3334 && !this->should_link_to_symtab_ 3335 && !this->should_link_to_dynsym_); 3336 this->link_section_ = od; 3337 } 3338 3339 // Set the link field to a constant. 3340 void set_link(unsigned int v)3341 set_link(unsigned int v) 3342 { 3343 gold_assert(this->link_section_ == NULL 3344 && !this->should_link_to_symtab_ 3345 && !this->should_link_to_dynsym_); 3346 this->link_ = v; 3347 } 3348 3349 // Record that this section should link to the normal symbol table. 3350 void set_should_link_to_symtab()3351 set_should_link_to_symtab() 3352 { 3353 gold_assert(this->link_section_ == NULL 3354 && this->link_ == 0 3355 && !this->should_link_to_dynsym_); 3356 this->should_link_to_symtab_ = true; 3357 } 3358 3359 // Record that this section should link to the dynamic symbol table. 3360 void set_should_link_to_dynsym()3361 set_should_link_to_dynsym() 3362 { 3363 gold_assert(this->link_section_ == NULL 3364 && this->link_ == 0 3365 && !this->should_link_to_symtab_); 3366 this->should_link_to_dynsym_ = true; 3367 } 3368 3369 // Return the info field. 3370 unsigned int info()3371 info() const 3372 { 3373 gold_assert(this->info_section_ == NULL 3374 && this->info_symndx_ == NULL); 3375 return this->info_; 3376 } 3377 3378 // Set the info field to the output section index of a section. 3379 void set_info_section(const Output_section * os)3380 set_info_section(const Output_section* os) 3381 { 3382 gold_assert((this->info_section_ == NULL 3383 || (this->info_section_ == os 3384 && this->info_uses_section_index_)) 3385 && this->info_symndx_ == NULL 3386 && this->info_ == 0); 3387 this->info_section_ = os; 3388 this->info_uses_section_index_= true; 3389 } 3390 3391 // Set the info field to the symbol table index of a symbol. 3392 void set_info_symndx(const Symbol * sym)3393 set_info_symndx(const Symbol* sym) 3394 { 3395 gold_assert(this->info_section_ == NULL 3396 && (this->info_symndx_ == NULL 3397 || this->info_symndx_ == sym) 3398 && this->info_ == 0); 3399 this->info_symndx_ = sym; 3400 } 3401 3402 // Set the info field to the symbol table index of a section symbol. 3403 void set_info_section_symndx(const Output_section * os)3404 set_info_section_symndx(const Output_section* os) 3405 { 3406 gold_assert((this->info_section_ == NULL 3407 || (this->info_section_ == os 3408 && !this->info_uses_section_index_)) 3409 && this->info_symndx_ == NULL 3410 && this->info_ == 0); 3411 this->info_section_ = os; 3412 this->info_uses_section_index_ = false; 3413 } 3414 3415 // Set the info field to a constant. 3416 void set_info(unsigned int v)3417 set_info(unsigned int v) 3418 { 3419 gold_assert(this->info_section_ == NULL 3420 && this->info_symndx_ == NULL 3421 && (this->info_ == 0 3422 || this->info_ == v)); 3423 this->info_ = v; 3424 } 3425 3426 // Set the addralign field. 3427 void set_addralign(uint64_t v)3428 set_addralign(uint64_t v) 3429 { this->addralign_ = v; } 3430 3431 void checkpoint_set_addralign(uint64_t val)3432 checkpoint_set_addralign(uint64_t val) 3433 { 3434 if (this->checkpoint_ != NULL) 3435 this->checkpoint_->set_addralign(val); 3436 } 3437 3438 // Whether the output section index has been set. 3439 bool has_out_shndx()3440 has_out_shndx() const 3441 { return this->out_shndx_ != -1U; } 3442 3443 // Indicate that we need a symtab index. 3444 void set_needs_symtab_index()3445 set_needs_symtab_index() 3446 { this->needs_symtab_index_ = true; } 3447 3448 // Return whether we need a symtab index. 3449 bool needs_symtab_index()3450 needs_symtab_index() const 3451 { return this->needs_symtab_index_; } 3452 3453 // Get the symtab index. 3454 unsigned int symtab_index()3455 symtab_index() const 3456 { 3457 gold_assert(this->symtab_index_ != 0); 3458 return this->symtab_index_; 3459 } 3460 3461 // Set the symtab index. 3462 void set_symtab_index(unsigned int index)3463 set_symtab_index(unsigned int index) 3464 { 3465 gold_assert(index != 0); 3466 this->symtab_index_ = index; 3467 } 3468 3469 // Indicate that we need a dynsym index. 3470 void set_needs_dynsym_index()3471 set_needs_dynsym_index() 3472 { this->needs_dynsym_index_ = true; } 3473 3474 // Return whether we need a dynsym index. 3475 bool needs_dynsym_index()3476 needs_dynsym_index() const 3477 { return this->needs_dynsym_index_; } 3478 3479 // Get the dynsym index. 3480 unsigned int dynsym_index()3481 dynsym_index() const 3482 { 3483 gold_assert(this->dynsym_index_ != 0); 3484 return this->dynsym_index_; 3485 } 3486 3487 // Set the dynsym index. 3488 void set_dynsym_index(unsigned int index)3489 set_dynsym_index(unsigned int index) 3490 { 3491 gold_assert(index != 0); 3492 this->dynsym_index_ = index; 3493 } 3494 3495 // Sort the attached input sections. 3496 void 3497 sort_attached_input_sections(); 3498 3499 // Return whether the input sections sections attachd to this output 3500 // section may require sorting. This is used to handle constructor 3501 // priorities compatibly with GNU ld. 3502 bool may_sort_attached_input_sections()3503 may_sort_attached_input_sections() const 3504 { return this->may_sort_attached_input_sections_; } 3505 3506 // Record that the input sections attached to this output section 3507 // may require sorting. 3508 void set_may_sort_attached_input_sections()3509 set_may_sort_attached_input_sections() 3510 { this->may_sort_attached_input_sections_ = true; } 3511 3512 // Returns true if input sections must be sorted according to the 3513 // order in which their name appear in the --section-ordering-file. 3514 bool input_section_order_specified()3515 input_section_order_specified() 3516 { return this->input_section_order_specified_; } 3517 3518 // Record that input sections must be sorted as some of their names 3519 // match the patterns specified through --section-ordering-file. 3520 void set_input_section_order_specified()3521 set_input_section_order_specified() 3522 { this->input_section_order_specified_ = true; } 3523 3524 // Return whether the input sections attached to this output section 3525 // require sorting. This is used to handle constructor priorities 3526 // compatibly with GNU ld. 3527 bool must_sort_attached_input_sections()3528 must_sort_attached_input_sections() const 3529 { return this->must_sort_attached_input_sections_; } 3530 3531 // Record that the input sections attached to this output section 3532 // require sorting. 3533 void set_must_sort_attached_input_sections()3534 set_must_sort_attached_input_sections() 3535 { this->must_sort_attached_input_sections_ = true; } 3536 3537 // Get the order in which this section appears in the PT_LOAD output 3538 // segment. 3539 Output_section_order order()3540 order() const 3541 { return this->order_; } 3542 3543 // Set the order for this section. 3544 void set_order(Output_section_order order)3545 set_order(Output_section_order order) 3546 { this->order_ = order; } 3547 3548 // Return whether this section holds relro data--data which has 3549 // dynamic relocations but which may be marked read-only after the 3550 // dynamic relocations have been completed. 3551 bool is_relro()3552 is_relro() const 3553 { return this->is_relro_; } 3554 3555 // Record that this section holds relro data. 3556 void set_is_relro()3557 set_is_relro() 3558 { this->is_relro_ = true; } 3559 3560 // Record that this section does not hold relro data. 3561 void clear_is_relro()3562 clear_is_relro() 3563 { this->is_relro_ = false; } 3564 3565 // True if this is a small section: a section which holds small 3566 // variables. 3567 bool is_small_section()3568 is_small_section() const 3569 { return this->is_small_section_; } 3570 3571 // Record that this is a small section. 3572 void set_is_small_section()3573 set_is_small_section() 3574 { this->is_small_section_ = true; } 3575 3576 // True if this is a large section: a section which holds large 3577 // variables. 3578 bool is_large_section()3579 is_large_section() const 3580 { return this->is_large_section_; } 3581 3582 // Record that this is a large section. 3583 void set_is_large_section()3584 set_is_large_section() 3585 { this->is_large_section_ = true; } 3586 3587 // True if this is a large data (not BSS) section. 3588 bool is_large_data_section()3589 is_large_data_section() 3590 { return this->is_large_section_ && this->type_ != elfcpp::SHT_NOBITS; } 3591 3592 // Return whether this section should be written after all the input 3593 // sections are complete. 3594 bool after_input_sections()3595 after_input_sections() const 3596 { return this->after_input_sections_; } 3597 3598 // Record that this section should be written after all the input 3599 // sections are complete. 3600 void set_after_input_sections()3601 set_after_input_sections() 3602 { this->after_input_sections_ = true; } 3603 3604 // Return whether this section requires postprocessing after all 3605 // relocations have been applied. 3606 bool requires_postprocessing()3607 requires_postprocessing() const 3608 { return this->requires_postprocessing_; } 3609 3610 bool is_unique_segment()3611 is_unique_segment() const 3612 { return this->is_unique_segment_; } 3613 3614 void set_is_unique_segment()3615 set_is_unique_segment() 3616 { this->is_unique_segment_ = true; } 3617 extra_segment_flags()3618 uint64_t extra_segment_flags() const 3619 { return this->extra_segment_flags_; } 3620 3621 void set_extra_segment_flags(uint64_t flags)3622 set_extra_segment_flags(uint64_t flags) 3623 { this->extra_segment_flags_ = flags; } 3624 segment_alignment()3625 uint64_t segment_alignment() const 3626 { return this->segment_alignment_; } 3627 3628 void set_segment_alignment(uint64_t align)3629 set_segment_alignment(uint64_t align) 3630 { this->segment_alignment_ = align; } 3631 3632 // If a section requires postprocessing, return the buffer to use. 3633 unsigned char* postprocessing_buffer()3634 postprocessing_buffer() const 3635 { 3636 gold_assert(this->postprocessing_buffer_ != NULL); 3637 return this->postprocessing_buffer_; 3638 } 3639 3640 // If a section requires postprocessing, create the buffer to use. 3641 void 3642 create_postprocessing_buffer(); 3643 3644 // If a section requires postprocessing, this is the size of the 3645 // buffer to which relocations should be applied. 3646 off_t postprocessing_buffer_size()3647 postprocessing_buffer_size() const 3648 { return this->current_data_size_for_child(); } 3649 3650 // Modify the section name. This is only permitted for an 3651 // unallocated section, and only before the size has been finalized. 3652 // Otherwise the name will not get into Layout::namepool_. 3653 void set_name(const char * newname)3654 set_name(const char* newname) 3655 { 3656 gold_assert((this->flags_ & elfcpp::SHF_ALLOC) == 0); 3657 gold_assert(!this->is_data_size_valid()); 3658 this->name_ = newname; 3659 } 3660 3661 // Return whether the offset OFFSET in the input section SHNDX in 3662 // object OBJECT is being included in the link. 3663 bool 3664 is_input_address_mapped(const Relobj* object, unsigned int shndx, 3665 off_t offset) const; 3666 3667 // Return the offset within the output section of OFFSET relative to 3668 // the start of input section SHNDX in object OBJECT. 3669 section_offset_type 3670 output_offset(const Relobj* object, unsigned int shndx, 3671 section_offset_type offset) const; 3672 3673 // Return the output virtual address of OFFSET relative to the start 3674 // of input section SHNDX in object OBJECT. 3675 uint64_t 3676 output_address(const Relobj* object, unsigned int shndx, 3677 off_t offset) const; 3678 3679 // Look for the merged section for input section SHNDX in object 3680 // OBJECT. If found, return true, and set *ADDR to the address of 3681 // the start of the merged section. This is not necessary the 3682 // output offset corresponding to input offset 0 in the section, 3683 // since the section may be mapped arbitrarily. 3684 bool 3685 find_starting_output_address(const Relobj* object, unsigned int shndx, 3686 uint64_t* addr) const; 3687 3688 // Record that this output section was found in the SECTIONS clause 3689 // of a linker script. 3690 void set_found_in_sections_clause()3691 set_found_in_sections_clause() 3692 { this->found_in_sections_clause_ = true; } 3693 3694 // Return whether this output section was found in the SECTIONS 3695 // clause of a linker script. 3696 bool found_in_sections_clause()3697 found_in_sections_clause() const 3698 { return this->found_in_sections_clause_; } 3699 3700 // Write the section header into *OPHDR. 3701 template<int size, bool big_endian> 3702 void 3703 write_header(const Layout*, const Stringpool*, 3704 elfcpp::Shdr_write<size, big_endian>*) const; 3705 3706 // The next few calls are for linker script support. 3707 3708 // In some cases we need to keep a list of the input sections 3709 // associated with this output section. We only need the list if we 3710 // might have to change the offsets of the input section within the 3711 // output section after we add the input section. The ordinary 3712 // input sections will be written out when we process the object 3713 // file, and as such we don't need to track them here. We do need 3714 // to track Output_section_data objects here. We store instances of 3715 // this structure in a std::vector, so it must be a POD. There can 3716 // be many instances of this structure, so we use a union to save 3717 // some space. 3718 class Input_section 3719 { 3720 public: Input_section()3721 Input_section() 3722 : shndx_(0), p2align_(0) 3723 { 3724 this->u1_.data_size = 0; 3725 this->u2_.object = NULL; 3726 } 3727 3728 // For an ordinary input section. Input_section(Relobj * object,unsigned int shndx,off_t data_size,uint64_t addralign)3729 Input_section(Relobj* object, unsigned int shndx, off_t data_size, 3730 uint64_t addralign) 3731 : shndx_(shndx), 3732 p2align_(ffsll(static_cast<long long>(addralign))), 3733 section_order_index_(0) 3734 { 3735 gold_assert(shndx != OUTPUT_SECTION_CODE 3736 && shndx != MERGE_DATA_SECTION_CODE 3737 && shndx != MERGE_STRING_SECTION_CODE 3738 && shndx != RELAXED_INPUT_SECTION_CODE); 3739 this->u1_.data_size = data_size; 3740 this->u2_.object = object; 3741 } 3742 3743 // For a non-merge output section. Input_section(Output_section_data * posd)3744 Input_section(Output_section_data* posd) 3745 : shndx_(OUTPUT_SECTION_CODE), p2align_(0), 3746 section_order_index_(0) 3747 { 3748 this->u1_.data_size = 0; 3749 this->u2_.posd = posd; 3750 } 3751 3752 // For a merge section. Input_section(Output_section_data * posd,bool is_string,uint64_t entsize)3753 Input_section(Output_section_data* posd, bool is_string, uint64_t entsize) 3754 : shndx_(is_string 3755 ? MERGE_STRING_SECTION_CODE 3756 : MERGE_DATA_SECTION_CODE), 3757 p2align_(0), 3758 section_order_index_(0) 3759 { 3760 this->u1_.entsize = entsize; 3761 this->u2_.posd = posd; 3762 } 3763 3764 // For a relaxed input section. Input_section(Output_relaxed_input_section * psection)3765 Input_section(Output_relaxed_input_section* psection) 3766 : shndx_(RELAXED_INPUT_SECTION_CODE), p2align_(0), 3767 section_order_index_(0) 3768 { 3769 this->u1_.data_size = 0; 3770 this->u2_.poris = psection; 3771 } 3772 3773 unsigned int section_order_index()3774 section_order_index() const 3775 { 3776 return this->section_order_index_; 3777 } 3778 3779 void set_section_order_index(unsigned int number)3780 set_section_order_index(unsigned int number) 3781 { 3782 this->section_order_index_ = number; 3783 } 3784 3785 // The required alignment. 3786 uint64_t addralign()3787 addralign() const 3788 { 3789 if (this->p2align_ != 0) 3790 return static_cast<uint64_t>(1) << (this->p2align_ - 1); 3791 else if (!this->is_input_section()) 3792 return this->u2_.posd->addralign(); 3793 else 3794 return 0; 3795 } 3796 3797 // Set the required alignment, which must be either 0 or a power of 2. 3798 // For input sections that are sub-classes of Output_section_data, a 3799 // alignment of zero means asking the underlying object for alignment. 3800 void set_addralign(uint64_t addralign)3801 set_addralign(uint64_t addralign) 3802 { 3803 if (addralign == 0) 3804 this->p2align_ = 0; 3805 else 3806 { 3807 gold_assert((addralign & (addralign - 1)) == 0); 3808 this->p2align_ = ffsll(static_cast<long long>(addralign)); 3809 } 3810 } 3811 3812 // Return the current required size, without finalization. 3813 off_t 3814 current_data_size() const; 3815 3816 // Return the required size. 3817 off_t 3818 data_size() const; 3819 3820 // Whether this is an input section. 3821 bool is_input_section()3822 is_input_section() const 3823 { 3824 return (this->shndx_ != OUTPUT_SECTION_CODE 3825 && this->shndx_ != MERGE_DATA_SECTION_CODE 3826 && this->shndx_ != MERGE_STRING_SECTION_CODE 3827 && this->shndx_ != RELAXED_INPUT_SECTION_CODE); 3828 } 3829 3830 // Return whether this is a merge section which matches the 3831 // parameters. 3832 bool is_merge_section(bool is_string,uint64_t entsize,uint64_t addralign)3833 is_merge_section(bool is_string, uint64_t entsize, 3834 uint64_t addralign) const 3835 { 3836 return (this->shndx_ == (is_string 3837 ? MERGE_STRING_SECTION_CODE 3838 : MERGE_DATA_SECTION_CODE) 3839 && this->u1_.entsize == entsize 3840 && this->addralign() == addralign); 3841 } 3842 3843 // Return whether this is a merge section for some input section. 3844 bool is_merge_section()3845 is_merge_section() const 3846 { 3847 return (this->shndx_ == MERGE_DATA_SECTION_CODE 3848 || this->shndx_ == MERGE_STRING_SECTION_CODE); 3849 } 3850 3851 // Return whether this is a relaxed input section. 3852 bool is_relaxed_input_section()3853 is_relaxed_input_section() const 3854 { return this->shndx_ == RELAXED_INPUT_SECTION_CODE; } 3855 3856 // Return whether this is a generic Output_section_data. 3857 bool is_output_section_data()3858 is_output_section_data() const 3859 { 3860 return this->shndx_ == OUTPUT_SECTION_CODE; 3861 } 3862 3863 // Return the object for an input section. 3864 Relobj* 3865 relobj() const; 3866 3867 // Return the input section index for an input section. 3868 unsigned int 3869 shndx() const; 3870 3871 // For non-input-sections, return the associated Output_section_data 3872 // object. 3873 Output_section_data* output_section_data()3874 output_section_data() const 3875 { 3876 gold_assert(!this->is_input_section()); 3877 return this->u2_.posd; 3878 } 3879 3880 // For a merge section, return the Output_merge_base pointer. 3881 Output_merge_base* output_merge_base()3882 output_merge_base() const 3883 { 3884 gold_assert(this->is_merge_section()); 3885 return this->u2_.pomb; 3886 } 3887 3888 // Return the Output_relaxed_input_section object. 3889 Output_relaxed_input_section* relaxed_input_section()3890 relaxed_input_section() const 3891 { 3892 gold_assert(this->is_relaxed_input_section()); 3893 return this->u2_.poris; 3894 } 3895 3896 // Set the output section. 3897 void set_output_section(Output_section * os)3898 set_output_section(Output_section* os) 3899 { 3900 gold_assert(!this->is_input_section()); 3901 Output_section_data* posd = 3902 this->is_relaxed_input_section() ? this->u2_.poris : this->u2_.posd; 3903 posd->set_output_section(os); 3904 } 3905 3906 // Set the address and file offset. This is called during 3907 // Layout::finalize. SECTION_FILE_OFFSET is the file offset of 3908 // the enclosing section. 3909 void 3910 set_address_and_file_offset(uint64_t address, off_t file_offset, 3911 off_t section_file_offset); 3912 3913 // Reset the address and file offset. 3914 void 3915 reset_address_and_file_offset(); 3916 3917 // Finalize the data size. 3918 void 3919 finalize_data_size(); 3920 3921 // Add an input section, for SHF_MERGE sections. 3922 bool add_input_section(Relobj * object,unsigned int shndx)3923 add_input_section(Relobj* object, unsigned int shndx) 3924 { 3925 gold_assert(this->shndx_ == MERGE_DATA_SECTION_CODE 3926 || this->shndx_ == MERGE_STRING_SECTION_CODE); 3927 return this->u2_.posd->add_input_section(object, shndx); 3928 } 3929 3930 // Given an input OBJECT, an input section index SHNDX within that 3931 // object, and an OFFSET relative to the start of that input 3932 // section, return whether or not the output offset is known. If 3933 // this function returns true, it sets *POUTPUT to the offset in 3934 // the output section, relative to the start of the input section 3935 // in the output section. *POUTPUT may be different from OFFSET 3936 // for a merged section. 3937 bool 3938 output_offset(const Relobj* object, unsigned int shndx, 3939 section_offset_type offset, 3940 section_offset_type* poutput) const; 3941 3942 // Write out the data. This does nothing for an input section. 3943 void 3944 write(Output_file*); 3945 3946 // Write the data to a buffer. This does nothing for an input 3947 // section. 3948 void 3949 write_to_buffer(unsigned char*); 3950 3951 // Print to a map file. 3952 void 3953 print_to_mapfile(Mapfile*) const; 3954 3955 // Print statistics about merge sections to stderr. 3956 void print_merge_stats(const char * section_name)3957 print_merge_stats(const char* section_name) 3958 { 3959 if (this->shndx_ == MERGE_DATA_SECTION_CODE 3960 || this->shndx_ == MERGE_STRING_SECTION_CODE) 3961 this->u2_.posd->print_merge_stats(section_name); 3962 } 3963 3964 private: 3965 // Code values which appear in shndx_. If the value is not one of 3966 // these codes, it is the input section index in the object file. 3967 enum 3968 { 3969 // An Output_section_data. 3970 OUTPUT_SECTION_CODE = -1U, 3971 // An Output_section_data for an SHF_MERGE section with 3972 // SHF_STRINGS not set. 3973 MERGE_DATA_SECTION_CODE = -2U, 3974 // An Output_section_data for an SHF_MERGE section with 3975 // SHF_STRINGS set. 3976 MERGE_STRING_SECTION_CODE = -3U, 3977 // An Output_section_data for a relaxed input section. 3978 RELAXED_INPUT_SECTION_CODE = -4U 3979 }; 3980 3981 // For an ordinary input section, this is the section index in the 3982 // input file. For an Output_section_data, this is 3983 // OUTPUT_SECTION_CODE or MERGE_DATA_SECTION_CODE or 3984 // MERGE_STRING_SECTION_CODE. 3985 unsigned int shndx_; 3986 // The required alignment, stored as a power of 2. 3987 unsigned int p2align_; 3988 union 3989 { 3990 // For an ordinary input section, the section size. 3991 off_t data_size; 3992 // For OUTPUT_SECTION_CODE or RELAXED_INPUT_SECTION_CODE, this is not 3993 // used. For MERGE_DATA_SECTION_CODE or MERGE_STRING_SECTION_CODE, the 3994 // entity size. 3995 uint64_t entsize; 3996 } u1_; 3997 union 3998 { 3999 // For an ordinary input section, the object which holds the 4000 // input section. 4001 Relobj* object; 4002 // For OUTPUT_SECTION_CODE or MERGE_DATA_SECTION_CODE or 4003 // MERGE_STRING_SECTION_CODE, the data. 4004 Output_section_data* posd; 4005 Output_merge_base* pomb; 4006 // For RELAXED_INPUT_SECTION_CODE, the data. 4007 Output_relaxed_input_section* poris; 4008 } u2_; 4009 // The line number of the pattern it matches in the --section-ordering-file 4010 // file. It is 0 if does not match any pattern. 4011 unsigned int section_order_index_; 4012 }; 4013 4014 // Store the list of input sections for this Output_section into the 4015 // list passed in. This removes the input sections, leaving only 4016 // any Output_section_data elements. This returns the size of those 4017 // Output_section_data elements. ADDRESS is the address of this 4018 // output section. FILL is the fill value to use, in case there are 4019 // any spaces between the remaining Output_section_data elements. 4020 uint64_t 4021 get_input_sections(uint64_t address, const std::string& fill, 4022 std::list<Input_section>*); 4023 4024 // Add a script input section. A script input section can either be 4025 // a plain input section or a sub-class of Output_section_data. 4026 void 4027 add_script_input_section(const Input_section& input_section); 4028 4029 // Set the current size of the output section. 4030 void set_current_data_size(off_t size)4031 set_current_data_size(off_t size) 4032 { this->set_current_data_size_for_child(size); } 4033 4034 // End of linker script support. 4035 4036 // Save states before doing section layout. 4037 // This is used for relaxation. 4038 void 4039 save_states(); 4040 4041 // Restore states prior to section layout. 4042 void 4043 restore_states(); 4044 4045 // Discard states. 4046 void 4047 discard_states(); 4048 4049 // Convert existing input sections to relaxed input sections. 4050 void 4051 convert_input_sections_to_relaxed_sections( 4052 const std::vector<Output_relaxed_input_section*>& sections); 4053 4054 // Find a relaxed input section to an input section in OBJECT 4055 // with index SHNDX. Return NULL if none is found. 4056 const Output_relaxed_input_section* 4057 find_relaxed_input_section(const Relobj* object, unsigned int shndx) const; 4058 4059 // Whether section offsets need adjustment due to relaxation. 4060 bool section_offsets_need_adjustment()4061 section_offsets_need_adjustment() const 4062 { return this->section_offsets_need_adjustment_; } 4063 4064 // Set section_offsets_need_adjustment to be true. 4065 void set_section_offsets_need_adjustment()4066 set_section_offsets_need_adjustment() 4067 { this->section_offsets_need_adjustment_ = true; } 4068 4069 // Set section_offsets_need_adjustment to be false. 4070 void clear_section_offsets_need_adjustment()4071 clear_section_offsets_need_adjustment() 4072 { this->section_offsets_need_adjustment_ = false; } 4073 4074 // Adjust section offsets of input sections in this. This is 4075 // requires if relaxation caused some input sections to change sizes. 4076 void 4077 adjust_section_offsets(); 4078 4079 // Whether this is a NOLOAD section. 4080 bool is_noload()4081 is_noload() const 4082 { return this->is_noload_; } 4083 4084 // Set NOLOAD flag. 4085 void set_is_noload()4086 set_is_noload() 4087 { this->is_noload_ = true; } 4088 4089 // Print merge statistics to stderr. 4090 void 4091 print_merge_stats(); 4092 4093 // Set a fixed layout for the section. Used for incremental update links. 4094 void 4095 set_fixed_layout(uint64_t sh_addr, off_t sh_offset, off_t sh_size, 4096 uint64_t sh_addralign); 4097 4098 // Return TRUE if the section has a fixed layout. 4099 bool has_fixed_layout()4100 has_fixed_layout() const 4101 { return this->has_fixed_layout_; } 4102 4103 // Set flag to allow patch space for this section. Used for full 4104 // incremental links. 4105 void set_is_patch_space_allowed()4106 set_is_patch_space_allowed() 4107 { this->is_patch_space_allowed_ = true; } 4108 4109 // Set a fill method to use for free space left in the output section 4110 // during incremental links. 4111 void set_free_space_fill(Output_fill * free_space_fill)4112 set_free_space_fill(Output_fill* free_space_fill) 4113 { 4114 this->free_space_fill_ = free_space_fill; 4115 this->free_list_.set_min_hole_size(free_space_fill->minimum_hole_size()); 4116 } 4117 4118 // Reserve space within the fixed layout for the section. Used for 4119 // incremental update links. 4120 void 4121 reserve(uint64_t sh_offset, uint64_t sh_size); 4122 4123 // Allocate space from the free list for the section. Used for 4124 // incremental update links. 4125 off_t 4126 allocate(off_t len, uint64_t addralign); 4127 4128 typedef std::vector<Input_section> Input_section_list; 4129 4130 // Allow access to the input sections. 4131 const Input_section_list& input_sections()4132 input_sections() const 4133 { return this->input_sections_; } 4134 4135 Input_section_list& input_sections()4136 input_sections() 4137 { return this->input_sections_; } 4138 4139 // For -r and --emit-relocs, we need to keep track of the associated 4140 // relocation section. 4141 Output_section* reloc_section()4142 reloc_section() const 4143 { return this->reloc_section_; } 4144 4145 void set_reloc_section(Output_section * os)4146 set_reloc_section(Output_section* os) 4147 { this->reloc_section_ = os; } 4148 4149 protected: 4150 // Return the output section--i.e., the object itself. 4151 Output_section* do_output_section()4152 do_output_section() 4153 { return this; } 4154 4155 const Output_section* do_output_section()4156 do_output_section() const 4157 { return this; } 4158 4159 // Return the section index in the output file. 4160 unsigned int do_out_shndx()4161 do_out_shndx() const 4162 { 4163 gold_assert(this->out_shndx_ != -1U); 4164 return this->out_shndx_; 4165 } 4166 4167 // Set the output section index. 4168 void do_set_out_shndx(unsigned int shndx)4169 do_set_out_shndx(unsigned int shndx) 4170 { 4171 gold_assert(this->out_shndx_ == -1U || this->out_shndx_ == shndx); 4172 this->out_shndx_ = shndx; 4173 } 4174 4175 // Update the data size of the Output_section. For a typical 4176 // Output_section, there is nothing to do, but if there are any 4177 // Output_section_data objects we need to do a trial layout 4178 // here. 4179 virtual void 4180 update_data_size(); 4181 4182 // Set the final data size of the Output_section. For a typical 4183 // Output_section, there is nothing to do, but if there are any 4184 // Output_section_data objects we need to set their final addresses 4185 // here. 4186 virtual void 4187 set_final_data_size(); 4188 4189 // Reset the address and file offset. 4190 void 4191 do_reset_address_and_file_offset(); 4192 4193 // Return true if address and file offset already have reset values. In 4194 // other words, calling reset_address_and_file_offset will not change them. 4195 bool 4196 do_address_and_file_offset_have_reset_values() const; 4197 4198 // Write the data to the file. For a typical Output_section, this 4199 // does nothing: the data is written out by calling Object::Relocate 4200 // on each input object. But if there are any Output_section_data 4201 // objects we do need to write them out here. 4202 virtual void 4203 do_write(Output_file*); 4204 4205 // Return the address alignment--function required by parent class. 4206 uint64_t do_addralign()4207 do_addralign() const 4208 { return this->addralign_; } 4209 4210 // Return whether there is a load address. 4211 bool do_has_load_address()4212 do_has_load_address() const 4213 { return this->has_load_address_; } 4214 4215 // Return the load address. 4216 uint64_t do_load_address()4217 do_load_address() const 4218 { 4219 gold_assert(this->has_load_address_); 4220 return this->load_address_; 4221 } 4222 4223 // Return whether this is an Output_section. 4224 bool do_is_section()4225 do_is_section() const 4226 { return true; } 4227 4228 // Return whether this is a section of the specified type. 4229 bool do_is_section_type(elfcpp::Elf_Word type)4230 do_is_section_type(elfcpp::Elf_Word type) const 4231 { return this->type_ == type; } 4232 4233 // Return whether the specified section flag is set. 4234 bool do_is_section_flag_set(elfcpp::Elf_Xword flag)4235 do_is_section_flag_set(elfcpp::Elf_Xword flag) const 4236 { return (this->flags_ & flag) != 0; } 4237 4238 // Set the TLS offset. Called only for SHT_TLS sections. 4239 void 4240 do_set_tls_offset(uint64_t tls_base); 4241 4242 // Return the TLS offset, relative to the base of the TLS segment. 4243 // Valid only for SHT_TLS sections. 4244 uint64_t do_tls_offset()4245 do_tls_offset() const 4246 { return this->tls_offset_; } 4247 4248 // This may be implemented by a child class. 4249 virtual void do_finalize_name(Layout *)4250 do_finalize_name(Layout*) 4251 { } 4252 4253 // Print to the map file. 4254 virtual void 4255 do_print_to_mapfile(Mapfile*) const; 4256 4257 // Record that this section requires postprocessing after all 4258 // relocations have been applied. This is called by a child class. 4259 void set_requires_postprocessing()4260 set_requires_postprocessing() 4261 { 4262 this->requires_postprocessing_ = true; 4263 this->after_input_sections_ = true; 4264 } 4265 4266 // Write all the data of an Output_section into the postprocessing 4267 // buffer. 4268 void 4269 write_to_postprocessing_buffer(); 4270 4271 // Whether this always keeps an input section list 4272 bool always_keeps_input_sections()4273 always_keeps_input_sections() const 4274 { return this->always_keeps_input_sections_; } 4275 4276 // Always keep an input section list. 4277 void set_always_keeps_input_sections()4278 set_always_keeps_input_sections() 4279 { 4280 gold_assert(this->current_data_size_for_child() == 0); 4281 this->always_keeps_input_sections_ = true; 4282 } 4283 4284 private: 4285 // We only save enough information to undo the effects of section layout. 4286 class Checkpoint_output_section 4287 { 4288 public: Checkpoint_output_section(uint64_t addralign,elfcpp::Elf_Xword flags,const Input_section_list & input_sections,off_t first_input_offset,bool attached_input_sections_are_sorted)4289 Checkpoint_output_section(uint64_t addralign, elfcpp::Elf_Xword flags, 4290 const Input_section_list& input_sections, 4291 off_t first_input_offset, 4292 bool attached_input_sections_are_sorted) 4293 : addralign_(addralign), flags_(flags), 4294 input_sections_(input_sections), 4295 input_sections_size_(input_sections_.size()), 4296 input_sections_copy_(), first_input_offset_(first_input_offset), 4297 attached_input_sections_are_sorted_(attached_input_sections_are_sorted) 4298 { } 4299 4300 virtual ~Checkpoint_output_section()4301 ~Checkpoint_output_section() 4302 { } 4303 4304 // Return the address alignment. 4305 uint64_t addralign()4306 addralign() const 4307 { return this->addralign_; } 4308 4309 void set_addralign(uint64_t val)4310 set_addralign(uint64_t val) 4311 { this->addralign_ = val; } 4312 4313 // Return the section flags. 4314 elfcpp::Elf_Xword flags()4315 flags() const 4316 { return this->flags_; } 4317 4318 // Return a reference to the input section list copy. 4319 Input_section_list* input_sections()4320 input_sections() 4321 { return &this->input_sections_copy_; } 4322 4323 // Return the size of input_sections at the time when checkpoint is 4324 // taken. 4325 size_t input_sections_size()4326 input_sections_size() const 4327 { return this->input_sections_size_; } 4328 4329 // Whether input sections are copied. 4330 bool input_sections_saved()4331 input_sections_saved() const 4332 { return this->input_sections_copy_.size() == this->input_sections_size_; } 4333 4334 off_t first_input_offset()4335 first_input_offset() const 4336 { return this->first_input_offset_; } 4337 4338 bool attached_input_sections_are_sorted()4339 attached_input_sections_are_sorted() const 4340 { return this->attached_input_sections_are_sorted_; } 4341 4342 // Save input sections. 4343 void save_input_sections()4344 save_input_sections() 4345 { 4346 this->input_sections_copy_.reserve(this->input_sections_size_); 4347 this->input_sections_copy_.clear(); 4348 Input_section_list::const_iterator p = this->input_sections_.begin(); 4349 gold_assert(this->input_sections_size_ >= this->input_sections_.size()); 4350 for(size_t i = 0; i < this->input_sections_size_ ; i++, ++p) 4351 this->input_sections_copy_.push_back(*p); 4352 } 4353 4354 private: 4355 // The section alignment. 4356 uint64_t addralign_; 4357 // The section flags. 4358 elfcpp::Elf_Xword flags_; 4359 // Reference to the input sections to be checkpointed. 4360 const Input_section_list& input_sections_; 4361 // Size of the checkpointed portion of input_sections_; 4362 size_t input_sections_size_; 4363 // Copy of input sections. 4364 Input_section_list input_sections_copy_; 4365 // The offset of the first entry in input_sections_. 4366 off_t first_input_offset_; 4367 // True if the input sections attached to this output section have 4368 // already been sorted. 4369 bool attached_input_sections_are_sorted_; 4370 }; 4371 4372 // This class is used to sort the input sections. 4373 class Input_section_sort_entry; 4374 4375 // This is the sort comparison function for ctors and dtors. 4376 struct Input_section_sort_compare 4377 { 4378 bool 4379 operator()(const Input_section_sort_entry&, 4380 const Input_section_sort_entry&) const; 4381 }; 4382 4383 // This is the sort comparison function for .init_array and .fini_array. 4384 struct Input_section_sort_init_fini_compare 4385 { 4386 bool 4387 operator()(const Input_section_sort_entry&, 4388 const Input_section_sort_entry&) const; 4389 }; 4390 4391 // This is the sort comparison function when a section order is specified 4392 // from an input file. 4393 struct Input_section_sort_section_order_index_compare 4394 { 4395 bool 4396 operator()(const Input_section_sort_entry&, 4397 const Input_section_sort_entry&) const; 4398 }; 4399 4400 // This is the sort comparison function for .text to sort sections with 4401 // prefixes .text.{unlikely,exit,startup,hot} before other sections. 4402 struct Input_section_sort_section_prefix_special_ordering_compare 4403 { 4404 bool 4405 operator()(const Input_section_sort_entry&, 4406 const Input_section_sort_entry&) const; 4407 }; 4408 4409 // This is the sort comparison function for sorting sections by name. 4410 struct Input_section_sort_section_name_compare 4411 { 4412 bool 4413 operator()(const Input_section_sort_entry&, 4414 const Input_section_sort_entry&) const; 4415 }; 4416 4417 // Fill data. This is used to fill in data between input sections. 4418 // It is also used for data statements (BYTE, WORD, etc.) in linker 4419 // scripts. When we have to keep track of the input sections, we 4420 // can use an Output_data_const, but we don't want to have to keep 4421 // track of input sections just to implement fills. 4422 class Fill 4423 { 4424 public: Fill(off_t section_offset,off_t length)4425 Fill(off_t section_offset, off_t length) 4426 : section_offset_(section_offset), 4427 length_(convert_to_section_size_type(length)) 4428 { } 4429 4430 // Return section offset. 4431 off_t section_offset()4432 section_offset() const 4433 { return this->section_offset_; } 4434 4435 // Return fill length. 4436 section_size_type length()4437 length() const 4438 { return this->length_; } 4439 4440 private: 4441 // The offset within the output section. 4442 off_t section_offset_; 4443 // The length of the space to fill. 4444 section_size_type length_; 4445 }; 4446 4447 typedef std::vector<Fill> Fill_list; 4448 4449 // Map used during relaxation of existing sections. This map 4450 // a section id an input section list index. We assume that 4451 // Input_section_list is a vector. 4452 typedef Unordered_map<Section_id, size_t, Section_id_hash> Relaxation_map; 4453 4454 // Add a new output section by Input_section. 4455 void 4456 add_output_section_data(Input_section*); 4457 4458 // Add an SHF_MERGE input section. Returns true if the section was 4459 // handled. If KEEPS_INPUT_SECTIONS is true, the output merge section 4460 // stores information about the merged input sections. 4461 bool 4462 add_merge_input_section(Relobj* object, unsigned int shndx, uint64_t flags, 4463 uint64_t entsize, uint64_t addralign, 4464 bool keeps_input_sections); 4465 4466 // Add an output SHF_MERGE section POSD to this output section. 4467 // IS_STRING indicates whether it is a SHF_STRINGS section, and 4468 // ENTSIZE is the entity size. This returns the entry added to 4469 // input_sections_. 4470 void 4471 add_output_merge_section(Output_section_data* posd, bool is_string, 4472 uint64_t entsize); 4473 4474 // Find the merge section into which an input section with index SHNDX in 4475 // OBJECT has been added. Return NULL if none found. 4476 const Output_section_data* 4477 find_merge_section(const Relobj* object, unsigned int shndx) const; 4478 4479 // Build a relaxation map. 4480 void 4481 build_relaxation_map( 4482 const Input_section_list& input_sections, 4483 size_t limit, 4484 Relaxation_map* map) const; 4485 4486 // Convert input sections in an input section list into relaxed sections. 4487 void 4488 convert_input_sections_in_list_to_relaxed_sections( 4489 const std::vector<Output_relaxed_input_section*>& relaxed_sections, 4490 const Relaxation_map& map, 4491 Input_section_list* input_sections); 4492 4493 // Build the lookup maps for merge and relaxed input sections. 4494 void 4495 build_lookup_maps() const; 4496 4497 // Most of these fields are only valid after layout. 4498 4499 // The name of the section. This will point into a Stringpool. 4500 const char* name_; 4501 // The section address is in the parent class. 4502 // The section alignment. 4503 uint64_t addralign_; 4504 // The section entry size. 4505 uint64_t entsize_; 4506 // The load address. This is only used when using a linker script 4507 // with a SECTIONS clause. The has_load_address_ field indicates 4508 // whether this field is valid. 4509 uint64_t load_address_; 4510 // The file offset is in the parent class. 4511 // Set the section link field to the index of this section. 4512 const Output_data* link_section_; 4513 // If link_section_ is NULL, this is the link field. 4514 unsigned int link_; 4515 // Set the section info field to the index of this section. 4516 const Output_section* info_section_; 4517 // If info_section_ is NULL, set the info field to the symbol table 4518 // index of this symbol. 4519 const Symbol* info_symndx_; 4520 // If info_section_ and info_symndx_ are NULL, this is the section 4521 // info field. 4522 unsigned int info_; 4523 // The section type. 4524 const elfcpp::Elf_Word type_; 4525 // The section flags. 4526 elfcpp::Elf_Xword flags_; 4527 // The order of this section in the output segment. 4528 Output_section_order order_; 4529 // The section index. 4530 unsigned int out_shndx_; 4531 // If there is a STT_SECTION for this output section in the normal 4532 // symbol table, this is the symbol index. This starts out as zero. 4533 // It is initialized in Layout::finalize() to be the index, or -1U 4534 // if there isn't one. 4535 unsigned int symtab_index_; 4536 // If there is a STT_SECTION for this output section in the dynamic 4537 // symbol table, this is the symbol index. This starts out as zero. 4538 // It is initialized in Layout::finalize() to be the index, or -1U 4539 // if there isn't one. 4540 unsigned int dynsym_index_; 4541 // The input sections. This will be empty in cases where we don't 4542 // need to keep track of them. 4543 Input_section_list input_sections_; 4544 // The offset of the first entry in input_sections_. 4545 off_t first_input_offset_; 4546 // The fill data. This is separate from input_sections_ because we 4547 // often will need fill sections without needing to keep track of 4548 // input sections. 4549 Fill_list fills_; 4550 // If the section requires postprocessing, this buffer holds the 4551 // section contents during relocation. 4552 unsigned char* postprocessing_buffer_; 4553 // Whether this output section needs a STT_SECTION symbol in the 4554 // normal symbol table. This will be true if there is a relocation 4555 // which needs it. 4556 bool needs_symtab_index_ : 1; 4557 // Whether this output section needs a STT_SECTION symbol in the 4558 // dynamic symbol table. This will be true if there is a dynamic 4559 // relocation which needs it. 4560 bool needs_dynsym_index_ : 1; 4561 // Whether the link field of this output section should point to the 4562 // normal symbol table. 4563 bool should_link_to_symtab_ : 1; 4564 // Whether the link field of this output section should point to the 4565 // dynamic symbol table. 4566 bool should_link_to_dynsym_ : 1; 4567 // Whether this section should be written after all the input 4568 // sections are complete. 4569 bool after_input_sections_ : 1; 4570 // Whether this section requires post processing after all 4571 // relocations have been applied. 4572 bool requires_postprocessing_ : 1; 4573 // Whether an input section was mapped to this output section 4574 // because of a SECTIONS clause in a linker script. 4575 bool found_in_sections_clause_ : 1; 4576 // Whether this section has an explicitly specified load address. 4577 bool has_load_address_ : 1; 4578 // True if the info_section_ field means the section index of the 4579 // section, false if it means the symbol index of the corresponding 4580 // section symbol. 4581 bool info_uses_section_index_ : 1; 4582 // True if input sections attached to this output section have to be 4583 // sorted according to a specified order. 4584 bool input_section_order_specified_ : 1; 4585 // True if the input sections attached to this output section may 4586 // need sorting. 4587 bool may_sort_attached_input_sections_ : 1; 4588 // True if the input sections attached to this output section must 4589 // be sorted. 4590 bool must_sort_attached_input_sections_ : 1; 4591 // True if the input sections attached to this output section have 4592 // already been sorted. 4593 bool attached_input_sections_are_sorted_ : 1; 4594 // True if this section holds relro data. 4595 bool is_relro_ : 1; 4596 // True if this is a small section. 4597 bool is_small_section_ : 1; 4598 // True if this is a large section. 4599 bool is_large_section_ : 1; 4600 // Whether code-fills are generated at write. 4601 bool generate_code_fills_at_write_ : 1; 4602 // Whether the entry size field should be zero. 4603 bool is_entsize_zero_ : 1; 4604 // Whether section offsets need adjustment due to relaxation. 4605 bool section_offsets_need_adjustment_ : 1; 4606 // Whether this is a NOLOAD section. 4607 bool is_noload_ : 1; 4608 // Whether this always keeps input section. 4609 bool always_keeps_input_sections_ : 1; 4610 // Whether this section has a fixed layout, for incremental update links. 4611 bool has_fixed_layout_ : 1; 4612 // True if we can add patch space to this section. 4613 bool is_patch_space_allowed_ : 1; 4614 // True if this output section goes into a unique segment. 4615 bool is_unique_segment_ : 1; 4616 // For SHT_TLS sections, the offset of this section relative to the base 4617 // of the TLS segment. 4618 uint64_t tls_offset_; 4619 // Additional segment flags, specified via linker plugin, when mapping some 4620 // input sections to unique segments. 4621 uint64_t extra_segment_flags_; 4622 // Segment alignment specified via linker plugin, when mapping some 4623 // input sections to unique segments. 4624 uint64_t segment_alignment_; 4625 // Saved checkpoint. 4626 Checkpoint_output_section* checkpoint_; 4627 // Fast lookup maps for merged and relaxed input sections. 4628 Output_section_lookup_maps* lookup_maps_; 4629 // List of available regions within the section, for incremental 4630 // update links. 4631 Free_list free_list_; 4632 // Method for filling chunks of free space. 4633 Output_fill* free_space_fill_; 4634 // Amount added as patch space for incremental linking. 4635 off_t patch_space_; 4636 // Associated relocation section, when emitting relocations. 4637 Output_section* reloc_section_; 4638 }; 4639 4640 // An output segment. PT_LOAD segments are built from collections of 4641 // output sections. Other segments typically point within PT_LOAD 4642 // segments, and are built directly as needed. 4643 // 4644 // NOTE: We want to use the copy constructor for this class. During 4645 // relaxation, we may try built the segments multiple times. We do 4646 // that by copying the original segment list before lay-out, doing 4647 // a trial lay-out and roll-back to the saved copied if we need to 4648 // to the lay-out again. 4649 4650 class Output_segment 4651 { 4652 public: 4653 // Create an output segment, specifying the type and flags. 4654 Output_segment(elfcpp::Elf_Word, elfcpp::Elf_Word); 4655 4656 // Return the virtual address. 4657 uint64_t vaddr()4658 vaddr() const 4659 { return this->vaddr_; } 4660 4661 // Return the physical address. 4662 uint64_t paddr()4663 paddr() const 4664 { return this->paddr_; } 4665 4666 // Return the segment type. 4667 elfcpp::Elf_Word type()4668 type() const 4669 { return this->type_; } 4670 4671 // Return the segment flags. 4672 elfcpp::Elf_Word flags()4673 flags() const 4674 { return this->flags_; } 4675 4676 // Return the memory size. 4677 uint64_t memsz()4678 memsz() const 4679 { return this->memsz_; } 4680 4681 // Return the file size. 4682 off_t filesz()4683 filesz() const 4684 { return this->filesz_; } 4685 4686 // Return the file offset. 4687 off_t offset()4688 offset() const 4689 { return this->offset_; } 4690 4691 // Return the segment alignment. 4692 uint64_t align()4693 align() const 4694 { return this->align_; } 4695 4696 // Set the segment alignment. 4697 void set_align(uint64_t align)4698 set_align(uint64_t align) 4699 { this->align_ = align; } 4700 4701 // Whether this is a segment created to hold large data sections. 4702 bool is_large_data_segment()4703 is_large_data_segment() const 4704 { return this->is_large_data_segment_; } 4705 4706 // Record that this is a segment created to hold large data 4707 // sections. 4708 void set_is_large_data_segment()4709 set_is_large_data_segment() 4710 { this->is_large_data_segment_ = true; } 4711 4712 bool is_unique_segment()4713 is_unique_segment() const 4714 { return this->is_unique_segment_; } 4715 4716 // Mark segment as unique, happens when linker plugins request that 4717 // certain input sections be mapped to unique segments. 4718 void set_is_unique_segment()4719 set_is_unique_segment() 4720 { this->is_unique_segment_ = true; } 4721 4722 // Return the maximum alignment of the Output_data. 4723 uint64_t 4724 maximum_alignment(); 4725 4726 // Add the Output_section OS to this PT_LOAD segment. SEG_FLAGS is 4727 // the segment flags to use. 4728 void 4729 add_output_section_to_load(Layout* layout, Output_section* os, 4730 elfcpp::Elf_Word seg_flags); 4731 4732 // Add the Output_section OS to this non-PT_LOAD segment. SEG_FLAGS 4733 // is the segment flags to use. 4734 void 4735 add_output_section_to_nonload(Output_section* os, 4736 elfcpp::Elf_Word seg_flags); 4737 4738 // Remove an Output_section from this segment. It is an error if it 4739 // is not present. 4740 void 4741 remove_output_section(Output_section* os); 4742 4743 // Add an Output_data (which need not be an Output_section) to the 4744 // start of this segment. 4745 void 4746 add_initial_output_data(Output_data*); 4747 4748 // Return true if this segment has any sections which hold actual 4749 // data, rather than being a BSS section. 4750 bool 4751 has_any_data_sections() const; 4752 4753 // Whether this segment has a dynamic relocs. 4754 bool 4755 has_dynamic_reloc() const; 4756 4757 // Return the first section. 4758 Output_section* 4759 first_section() const; 4760 4761 // Return the address of the first section. 4762 uint64_t first_section_load_address()4763 first_section_load_address() const 4764 { 4765 const Output_section* os = this->first_section(); 4766 gold_assert(os != NULL); 4767 return os->has_load_address() ? os->load_address() : os->address(); 4768 } 4769 4770 // Return whether the addresses have been set already. 4771 bool are_addresses_set()4772 are_addresses_set() const 4773 { return this->are_addresses_set_; } 4774 4775 // Set the addresses. 4776 void set_addresses(uint64_t vaddr,uint64_t paddr)4777 set_addresses(uint64_t vaddr, uint64_t paddr) 4778 { 4779 this->vaddr_ = vaddr; 4780 this->paddr_ = paddr; 4781 this->are_addresses_set_ = true; 4782 } 4783 4784 // Update the flags for the flags of an output section added to this 4785 // segment. 4786 void update_flags_for_output_section(elfcpp::Elf_Xword flags)4787 update_flags_for_output_section(elfcpp::Elf_Xword flags) 4788 { 4789 // The ELF ABI specifies that a PT_TLS segment should always have 4790 // PF_R as the flags. 4791 if (this->type() != elfcpp::PT_TLS) 4792 this->flags_ |= flags; 4793 } 4794 4795 // Set the segment flags. This is only used if we have a PHDRS 4796 // clause which explicitly specifies the flags. 4797 void set_flags(elfcpp::Elf_Word flags)4798 set_flags(elfcpp::Elf_Word flags) 4799 { this->flags_ = flags; } 4800 4801 // Set the address of the segment to ADDR and the offset to *POFF 4802 // and set the addresses and offsets of all contained output 4803 // sections accordingly. Set the section indexes of all contained 4804 // output sections starting with *PSHNDX. If RESET is true, first 4805 // reset the addresses of the contained sections. Return the 4806 // address of the immediately following segment. Update *POFF and 4807 // *PSHNDX. This should only be called for a PT_LOAD segment. 4808 uint64_t 4809 set_section_addresses(const Target*, Layout*, bool reset, uint64_t addr, 4810 unsigned int* increase_relro, bool* has_relro, 4811 off_t* poff, unsigned int* pshndx); 4812 4813 // Set the minimum alignment of this segment. This may be adjusted 4814 // upward based on the section alignments. 4815 void set_minimum_p_align(uint64_t align)4816 set_minimum_p_align(uint64_t align) 4817 { 4818 if (align > this->min_p_align_) 4819 this->min_p_align_ = align; 4820 } 4821 4822 // Set the memory size of this segment. 4823 void set_size(uint64_t size)4824 set_size(uint64_t size) 4825 { 4826 this->memsz_ = size; 4827 } 4828 4829 // Set the offset of this segment based on the section. This should 4830 // only be called for a non-PT_LOAD segment. 4831 void 4832 set_offset(unsigned int increase); 4833 4834 // Set the TLS offsets of the sections contained in the PT_TLS segment. 4835 void 4836 set_tls_offsets(); 4837 4838 // Return the number of output sections. 4839 unsigned int 4840 output_section_count() const; 4841 4842 // Return the section attached to the list segment with the lowest 4843 // load address. This is used when handling a PHDRS clause in a 4844 // linker script. 4845 Output_section* 4846 section_with_lowest_load_address() const; 4847 4848 // Write the segment header into *OPHDR. 4849 template<int size, bool big_endian> 4850 void 4851 write_header(elfcpp::Phdr_write<size, big_endian>*); 4852 4853 // Write the section headers of associated sections into V. 4854 template<int size, bool big_endian> 4855 unsigned char* 4856 write_section_headers(const Layout*, const Stringpool*, unsigned char* v, 4857 unsigned int* pshndx) const; 4858 4859 // Print the output sections in the map file. 4860 void 4861 print_sections_to_mapfile(Mapfile*) const; 4862 4863 private: 4864 typedef std::vector<Output_data*> Output_data_list; 4865 4866 // Find the maximum alignment in an Output_data_list. 4867 static uint64_t 4868 maximum_alignment_list(const Output_data_list*); 4869 4870 // Return whether the first data section is a relro section. 4871 bool 4872 is_first_section_relro() const; 4873 4874 // Set the section addresses in an Output_data_list. 4875 uint64_t 4876 set_section_list_addresses(Layout*, bool reset, Output_data_list*, 4877 uint64_t addr, off_t* poff, off_t* fpoff, 4878 unsigned int* pshndx, bool* in_tls); 4879 4880 // Return the number of Output_sections in an Output_data_list. 4881 unsigned int 4882 output_section_count_list(const Output_data_list*) const; 4883 4884 // Return whether an Output_data_list has a dynamic reloc. 4885 bool 4886 has_dynamic_reloc_list(const Output_data_list*) const; 4887 4888 // Find the section with the lowest load address in an 4889 // Output_data_list. 4890 void 4891 lowest_load_address_in_list(const Output_data_list* pdl, 4892 Output_section** found, 4893 uint64_t* found_lma) const; 4894 4895 // Find the first and last entries by address. 4896 void 4897 find_first_and_last_list(const Output_data_list* pdl, 4898 const Output_data** pfirst, 4899 const Output_data** plast) const; 4900 4901 // Write the section headers in the list into V. 4902 template<int size, bool big_endian> 4903 unsigned char* 4904 write_section_headers_list(const Layout*, const Stringpool*, 4905 const Output_data_list*, unsigned char* v, 4906 unsigned int* pshdx) const; 4907 4908 // Print a section list to the mapfile. 4909 void 4910 print_section_list_to_mapfile(Mapfile*, const Output_data_list*) const; 4911 4912 // NOTE: We want to use the copy constructor. Currently, shallow copy 4913 // works for us so we do not need to write our own copy constructor. 4914 4915 // The list of output data attached to this segment. 4916 Output_data_list output_lists_[ORDER_MAX]; 4917 // The segment virtual address. 4918 uint64_t vaddr_; 4919 // The segment physical address. 4920 uint64_t paddr_; 4921 // The size of the segment in memory. 4922 uint64_t memsz_; 4923 // The segment alignment. 4924 uint64_t align_; 4925 // The maximum section alignment. The is_max_align_known_ field 4926 // indicates whether this has been finalized. 4927 uint64_t max_align_; 4928 // The required minimum value for the p_align field. This is used 4929 // for PT_LOAD segments. Note that this does not mean that 4930 // addresses should be aligned to this value; it means the p_paddr 4931 // and p_vaddr fields must be congruent modulo this value. For 4932 // non-PT_LOAD segments, the dynamic linker works more efficiently 4933 // if the p_align field has the more conventional value, although it 4934 // can align as needed. 4935 uint64_t min_p_align_; 4936 // The offset of the segment data within the file. 4937 off_t offset_; 4938 // The size of the segment data in the file. 4939 off_t filesz_; 4940 // The segment type; 4941 elfcpp::Elf_Word type_; 4942 // The segment flags. 4943 elfcpp::Elf_Word flags_; 4944 // Whether we have finalized max_align_. 4945 bool is_max_align_known_ : 1; 4946 // Whether vaddr and paddr were set by a linker script. 4947 bool are_addresses_set_ : 1; 4948 // Whether this segment holds large data sections. 4949 bool is_large_data_segment_ : 1; 4950 // Whether this was marked as a unique segment via a linker plugin. 4951 bool is_unique_segment_ : 1; 4952 }; 4953 4954 } // End namespace gold. 4955 4956 #endif // !defined(GOLD_OUTPUT_H) 4957