1/* Copyright (C) 2001, 2002, 2003 Red Hat, Inc. 2 Written by Ulrich Drepper <drepper@redhat.com>, 2001. 3 4 This program is Open Source software; you can redistribute it and/or 5 modify it under the terms of the Open Software License version 1.0 as 6 published by the Open Source Initiative. 7 8 You should have received a copy of the Open Software License along 9 with this program; if not, you may obtain a copy of the Open Software 10 License version 1.0 from http://www.opensource.org/licenses/osl.php or 11 by writing the Open Source Initiative c/o Lawrence Rosen, Esq., 12 3001 King Ranch Road, Ukiah, CA 95482. */ 13 14#ifndef LD_H 15#define LD_H 1 16 17#include <dlfcn.h> 18#include <obstack.h> 19#include <stdbool.h> 20#include <stdio.h> 21#include "xelf.h" 22 23 24/* Recommended size of the buffer passed to ld_strerror. */ 25#define ERRBUFSIZE (512) 26 27/* Character used to introduce version name after symbol. */ 28#define VER_CHR '@' 29 30 31/* Methods for handling archives. */ 32enum extract_rule 33 { 34 defaultextract, /* Weak references don't cause archive member to 35 be used. */ 36 weakextract, /* Weak references cause archive member to be 37 extracted. */ 38 allextract /* Extract all archive members regardless of 39 references (aka whole-archive). */ 40 }; 41 42 43/* Type of output file. */ 44enum file_type 45 { 46 no_file_type = 0, /* None selected so far. */ 47 executable_file_type, /* Executable. */ 48 dso_file_type, /* DSO. */ 49 dso_needed_file_type, /* DSO introduced by DT_NEEDED. */ 50 relocatable_file_type, /* Relocatable object file. */ 51 archive_file_type /* Archive (input only). */ 52 }; 53 54 55struct usedfiles 56{ 57 /* The next file given at the command line. */ 58 struct usedfiles *next; 59 /* Nonzero if this file is the beginning of a group. */ 60 bool group_start; 61 /* Nonzero if this file is the end of a group. */ 62 bool group_end; 63 /* Pointer to the beginning of the group. It is necessary to 64 explain why we cannot simply use the 'next' pointer and have a 65 circular single-linked list like in many cases. The problem is 66 that the last archive of the group, if it is the last file of the 67 group, contains the only existing pointer to the next file we 68 have to look at. All files are initially connected via the 69 'next' pointer in a single-linked list. Therefore we cannot 70 overwrite this value. It instead will be used once the group is 71 handled and we go on processing the rest of the files. */ 72 struct usedfiles *group_backref; 73 74 /* Name/path of the file. */ 75 const char *fname; 76 /* Resolved file name. */ 77 const char *rfname; 78 /* Name used as reference in DT_NEEDED entries. This is normally 79 the SONAME. If it is missing it's normally the fname above. */ 80 const char *soname; 81 /* Handle for the SONAME in the string table. */ 82 struct Ebl_Strent *sonameent; 83 84 /* Help to identify duplicates. */ 85 dev_t dev; 86 ino_t ino; 87 88 enum 89 { 90 not_opened, 91 opened, 92 in_archive, 93 closed 94 } status; 95 96 /* How to extract elements from archives. */ 97 enum extract_rule extract_rule; 98 99 /* Lazy-loading rule. */ 100 bool lazyload; 101 102 /* If this is a DSO the flag indicates whether the file is directly 103 used in a reference. */ 104 bool used; 105 106 /* If nonzero this is the archive sequence number which can be used to 107 determine whether back refernces from -( -) or GROUP statements 108 have to be followed. */ 109 int archive_seq; 110 111 /* Pointer to the record for the archive containing this file. */ 112 struct usedfiles *archive_file; 113 114 /* Type of file. We have to distinguish these types since they 115 are searched for differently. */ 116 enum file_type file_type; 117 /* This is the ELF library handle for this file. */ 118 Elf *elf; 119 120 /* The ELF header. */ 121#if NATIVE_ELF != 0 122 XElf_Ehdr *ehdr; 123# define FILEINFO_EHDR(fi) (*(fi)) 124#else 125 XElf_Ehdr ehdr; 126# define FILEINFO_EHDR(fi) (fi) 127#endif 128 129 /* Index of the section header string table section. We use a 130 separate field and not the e_shstrndx field in the ELF header 131 since in case of a file with more than 64000 sections the index 132 might be stored in the section header of section zero. The 133 elf_getshstrndx() function can find the value but it is too 134 costly to repeat this call over and over. */ 135 size_t shstrndx; 136 137 /* Info about the sections of the file. */ 138 struct scninfo 139 { 140 /* Handle for the section. Note that we can store a section 141 handle here because the file is not changing. This together 142 with the knowledge about the libelf library is enough for us to 143 assume the section reference remains valid at all times. */ 144 Elf_Scn *scn; 145 /* Section header. */ 146#if NATIVE_ELF != 0 147 XElf_Shdr *shdr; 148# define SCNINFO_SHDR(si) (*(si)) 149#else 150 XElf_Shdr shdr; 151# define SCNINFO_SHDR(si) (si) 152#endif 153 /* Offset of this files section in the combined section. */ 154 XElf_Off offset; 155 /* Index of the section in the output file. */ 156 Elf32_Word outscnndx; 157 /* Index of the output section in the 'allsection' array. */ 158 Elf32_Word allsectionsidx; 159 /* True if the section is used. */ 160 bool used; 161 /* Section group number. This is the index of the SHT_GROUP section. */ 162 Elf32_Word grpid; 163 /* Pointer back to the containing file information structure. */ 164 struct usedfiles *fileinfo; 165 /* List of symbols in this section (set only for merge-able sections). */ 166 struct symbol *symbols; 167 /* Size of relocations in this section. Only used for relocation 168 sections. */ 169 size_t relsize; 170 /* Pointer to next section which is put in the given output 171 section. */ 172 struct scninfo *next; 173 } *scninfo; 174 175 /* List of section group sections. */ 176 struct scninfo *groups; 177 178 /* The symbol table section. 179 180 XXX Maybe support for more than one symbol table is needed. */ 181 Elf_Data *symtabdata; 182 /* Extra section index table section. */ 183 Elf_Data *xndxdata; 184 /* Dynamic symbol table section. */ 185 Elf_Data *dynsymtabdata; 186 /* The version number section. */ 187 Elf_Data *versymdata; 188 /* The defined versions. */ 189 Elf_Data *verdefdata; 190 /* Number of versions defined. */ 191 size_t nverdef; 192 /* True if the version with the given index number is used in the 193 output. */ 194 XElf_Versym *verdefused; 195 /* How many versions are used. */ 196 size_t nverdefused; 197 /* Handle for name of the version. */ 198 struct Ebl_Strent **verdefent; 199 /* The needed versions. */ 200 Elf_Data *verneeddata; 201 /* String table section associated with the symbol table. */ 202 Elf32_Word symstridx; 203 /* String table section associated with the dynamic symbol table. */ 204 Elf32_Word dynsymstridx; 205 /* Number of entries in the symbol table. */ 206 size_t nsymtab; 207 size_t nlocalsymbols; 208 size_t ndynsymtab; 209 /* Dynamic section. */ 210 Elf_Scn *dynscn; 211 212 /* Indirection table for the symbols defined here. */ 213 Elf32_Word *symindirect; 214 Elf32_Word *dynsymindirect; 215 /* For undefined or common symbols we need a reference to the symbol 216 record. */ 217 struct symbol **symref; 218 struct symbol **dynsymref; 219 220 /* This is the file descriptor. The value is -1 if the descriptor 221 was already closed. This can happen if we needed file descriptors 222 to open new files. */ 223 int fd; 224 /* This flag is true if the descriptor was passed to the generic 225 functions from somewhere else. This is an implementation detail; 226 no machine-specific code must use this flag. */ 227 bool fd_passed; 228 229 /* True if any of the sections is merge-able. */ 230 bool has_merge_sections; 231}; 232 233 234/* Functions to test for the various types of files we handle. */ 235static inline int 236ld_file_rel_p (struct usedfiles *file) 237{ 238 return (elf_kind (file->elf) == ELF_K_ELF 239 && FILEINFO_EHDR (file->ehdr).e_type == ET_REL); 240} 241 242static inline int 243ld_file_dso_p (struct usedfiles *file) 244{ 245 return (elf_kind (file->elf) == ELF_K_ELF 246 && FILEINFO_EHDR (file->ehdr).e_type == ET_DYN); 247} 248 249static inline int 250ld_file_ar_p (struct usedfiles *file) 251{ 252 return elf_kind (file->elf) == ELF_K_AR; 253} 254 255 256struct pathelement 257{ 258 /* The next path to search. */ 259 struct pathelement *next; 260 /* The path name. */ 261 const char *pname; 262 /* Larger than zero if the directory exists, smaller than zero if not, 263 zero if it is not yet known. */ 264 int exist; 265}; 266 267 268/* Forward declaration. */ 269struct ld_state; 270 271 272/* Callback functions. */ 273struct callbacks 274{ 275 /* Library names passed to the linker as -lXXX represent files named 276 libXXX.YY. The YY part can have different forms, depending on the 277 architecture. The generic set is .so and .a (in this order). */ 278 const char **(*lib_extensions) (struct ld_state *) 279 __attribute__ ((__const__)); 280#define LIB_EXTENSION(state) \ 281 DL_CALL_FCT ((state)->callbacks.lib_extensions, (state)) 282 283 /* Process the given file. If the file is not yet open, open it. 284 The first parameter is a file descriptor for the file which can 285 be -1 to indicate the file has not yet been found. The second 286 parameter describes the file to be opened, the last one is the 287 state of the linker which among other information contain the 288 paths we look at.*/ 289 int (*file_process) (int fd, struct usedfiles *, struct ld_state *, 290 struct usedfiles **); 291#define FILE_PROCESS(fd, file, state, nextp) \ 292 DL_CALL_FCT ((state)->callbacks.file_process, (fd, file, state, nextp)) 293 294 /* Close the given file. */ 295 int (*file_close) (struct usedfiles *, struct ld_state *); 296#define FILE_CLOSE(file, state) \ 297 DL_CALL_FCT ((state)->callbacks.file_close, (file, state)) 298 299 /* Create the output sections now. This requires knowledge about 300 all the sections we will need. It may be necessary to sort the 301 sections in the order they are supposed to appear in the 302 executable. The sorting use many different kinds of information 303 to optimize the resulting binary. Important is to respect 304 segment boundaries and the needed alignment. The mode of the 305 segments will be determined afterwards automatically by the 306 output routines. */ 307 void (*create_sections) (struct ld_state *); 308#define CREATE_SECTIONS(state) \ 309 DL_CALL_FCT ((state)->callbacks.create_sections, (state)) 310 311 /* Determine whether we have any non-weak unresolved references left. */ 312 int (*flag_unresolved) (struct ld_state *); 313#define FLAG_UNRESOLVED(state) \ 314 DL_CALL_FCT ((state)->callbacks.flag_unresolved, (state)) 315 316 /* Create the sections which are generated by the linker and are not 317 present in the input file. */ 318 void (*generate_sections) (struct ld_state *); 319#define GENERATE_SECTIONS(state) \ 320 DL_CALL_FCT ((state)->callbacks.generate_sections, (state)) 321 322 /* Open the output file. The file name is given or "a.out". We 323 create as much of the ELF structure as possible. */ 324 int (*open_outfile) (struct ld_state *, int, int, int); 325#define OPEN_OUTFILE(state, machine, class, data) \ 326 DL_CALL_FCT ((state)->callbacks.open_outfile, (state, machine, class, data)) 327 328 /* Create the data for the output file. */ 329 int (*create_outfile) (struct ld_state *); 330#define CREATE_OUTFILE(state) \ 331 DL_CALL_FCT ((state)->callbacks.create_outfile, (state)) 332 333 /* Process a relocation section. */ 334 void (*relocate_section) (struct ld_state *, Elf_Scn *, struct scninfo *, 335 const Elf32_Word *); 336#define RELOCATE_SECTION(state, outscn, first, dblindirect) \ 337 DL_CALL_FCT ((state)->callbacks.relocate_section, (state, outscn, first, \ 338 dblindirect)) 339 340 /* Allocate a data buffer for the relocations of the given output 341 section. */ 342 void (*count_relocations) (struct ld_state *, struct scninfo *); 343#define COUNT_RELOCATIONS(state, scninfo) \ 344 DL_CALL_FCT ((state)->callbacks.count_relocations, (state, scninfo)) 345 346 /* Create relocations for executable or DSO. */ 347 void (*create_relocations) (struct ld_state *, const Elf32_Word *); 348#define CREATE_RELOCATIONS(state, dlbindirect) \ 349 DL_CALL_FCT ((state)->callbacks.create_relocations, (state, dblindirect)) 350 351 /* Finalize the output file. */ 352 int (*finalize) (struct ld_state *); 353#define FINALIZE(state) \ 354 DL_CALL_FCT ((state)->callbacks.finalize, (state)) 355 356 /* Check whether special section number is known. */ 357 bool (*special_section_number_p) (struct ld_state *, size_t); 358#define SPECIAL_SECTION_NUMBER_P(state, number) \ 359 DL_CALL_FCT ((state)->callbacks.special_section_number_p, (state, number)) 360 361 /* Check whether section type is known. */ 362 bool (*section_type_p) (struct ld_state *, XElf_Word); 363#define SECTION_TYPE_P(state, type) \ 364 DL_CALL_FCT ((state)->callbacks.section_type_p, (state, type)) 365 366 /* Return section flags for .dynamic section. */ 367 XElf_Xword (*dynamic_section_flags) (struct ld_state *); 368#define DYNAMIC_SECTION_FLAGS(state) \ 369 DL_CALL_FCT ((state)->callbacks.dynamic_section_flags, (state)) 370 371 /* Create the data structures for the .plt section and initialize it. */ 372 void (*initialize_plt) (struct ld_state *, Elf_Scn *scn); 373#define INITIALIZE_PLT(state, scn) \ 374 DL_CALL_FCT ((state)->callbacks.initialize_plt, (state, scn)) 375 376 /* Create the data structures for the .rel.plt section and initialize it. */ 377 void (*initialize_pltrel) (struct ld_state *, Elf_Scn *scn); 378#define INITIALIZE_PLTREL(state, scn) \ 379 DL_CALL_FCT ((state)->callbacks.initialize_pltrel, (state, scn)) 380 381 /* Finalize the .plt section the what belongs to them. */ 382 void (*finalize_plt) (struct ld_state *, size_t, size_t); 383#define FINALIZE_PLT(state, nsym, nsym_dyn) \ 384 DL_CALL_FCT ((state)->callbacks.finalize_plt, (state, nsym, nsym_dyn)) 385 386 /* Create the data structures for the .got section and initialize it. */ 387 void (*initialize_got) (struct ld_state *, Elf_Scn *scn); 388#define INITIALIZE_GOT(state, scn) \ 389 DL_CALL_FCT ((state)->callbacks.initialize_got, (state, scn)) 390 391 /* Return the tag corresponding to the native relocation type for 392 the platform. */ 393 int (*rel_type) (struct ld_state *); 394#define REL_TYPE(state) \ 395 DL_CALL_FCT ((state)->callbacks.rel_type, (state)) 396}; 397 398 399/* Structure for symbol representation. This data structure is used a 400 lot, so size is important. */ 401struct symbol 402{ 403 /* Symbol name. */ 404 const char *name; 405 /* Size of the object. */ 406 XElf_Xword size; 407 /* Index of the symbol in the symbol table of the object. */ 408 size_t symidx; 409 /* Index of the symbol in the symbol table of the output file. */ 410 size_t outsymidx; 411 412 /* Description where the symbol is found/needed. */ 413 size_t scndx; 414 struct usedfiles *file; 415 /* Index of the symbol table. */ 416 Elf32_Word symscndx; 417 418 /* Index of the symbol in the dynamic symbol table of the output 419 file. Note that the value only needs to be 16 bit wide since 420 there cannot be more sections in an executable or DSO. */ 421 unsigned int outdynsymidx:16; 422 423 /* Type of the symbol. */ 424 unsigned int type:4; 425 /* Various flags. */ 426 unsigned int defined:1; 427 unsigned int common:1; 428 unsigned int weak:1; 429 unsigned int added:1; 430 unsigned int merged:1; 431 /* Nonzero if the symbol is on the from_dso list. */ 432 unsigned int on_dsolist:1; 433 /* Nonzero if symbol needs copy relocation, reset when the 434 relocation has been created. */ 435 unsigned int need_copy:1; 436 unsigned int in_dso:1; 437 438 union 439 { 440 /* Pointer to the handle created by the functions which create 441 merged section contents. We use 'void *' because there are 442 different implementations used. */ 443 void *handle; 444 XElf_Addr value; 445 } merge; 446 447 /* Pointer to next/previous symbol on whatever list the symbol is. */ 448 struct symbol *next; 449 struct symbol *previous; 450 /* Pointer to next symbol of the same section (only set for merge-able 451 sections). */ 452 struct symbol *next_in_scn; 453}; 454 455 456/* Get the definition for the symbol table. */ 457#include <symbolhash.h> 458 459/* Simple single linked list of file names. */ 460struct filename_list 461{ 462 const char *name; 463 struct usedfiles *real; 464 struct filename_list *next; 465 bool group_start; 466 bool group_end; 467}; 468 469 470/* Data structure to describe expression in linker script. */ 471struct expression 472{ 473 enum expression_tag 474 { 475 exp_num, 476 exp_sizeof_headers, 477 exp_pagesize, 478 exp_id, 479 exp_mult, 480 exp_div, 481 exp_mod, 482 exp_plus, 483 exp_minus, 484 exp_and, 485 exp_or, 486 exp_align 487 } tag; 488 489 union 490 { 491 uintmax_t num; 492 struct expression *child; 493 struct 494 { 495 struct expression *left; 496 struct expression *right; 497 } binary; 498 const char *str; 499 } val; 500}; 501 502 503/* Data structure for section name with flags. */ 504struct input_section_name 505{ 506 const char *name; 507 bool sort_flag; 508}; 509 510/* File name mask with section name. */ 511struct filemask_section_name 512{ 513 const char *filemask; 514 const char *excludemask; 515 struct input_section_name *section_name; 516 bool keep_flag; 517}; 518 519/* Data structure for assignments. */ 520struct assignment 521{ 522 const char *variable; 523 struct expression *expression; 524 struct symbol *sym; 525 bool provide_flag; 526}; 527 528 529/* Data structure describing input for an output section. */ 530struct input_rule 531{ 532 enum 533 { 534 input_section, 535 input_assignment 536 } tag; 537 538 union 539 { 540 struct assignment *assignment; 541 struct filemask_section_name *section; 542 } val; 543 544 struct input_rule *next; 545}; 546 547 548/* Data structure to describe output section. */ 549struct output_section 550{ 551 const char *name; 552 struct input_rule *input; 553 XElf_Addr max_alignment; 554 bool ignored; 555}; 556 557 558/* Data structure to describe output file format. */ 559struct output_rule 560{ 561 enum 562 { 563 output_section, 564 output_assignment 565 } tag; 566 567 union 568 { 569 struct assignment *assignment; 570 struct output_section section; 571 } val; 572 573 struct output_rule *next; 574}; 575 576 577/* List of all the segments the linker script describes. */ 578struct output_segment 579{ 580 int mode; 581 struct output_rule *output_rules; 582 struct output_segment *next; 583 584 XElf_Off offset; 585 XElf_Addr addr; 586 XElf_Xword align; 587}; 588 589 590/* List of identifiers. */ 591struct id_list 592{ 593 union 594 { 595 enum id_type 596 { 597 id_str, /* Normal string. */ 598 id_all, /* "*", matches all. */ 599 id_wild /* Globbing wildcard string. */ 600 } id_type; 601 struct 602 { 603 bool local; 604 const char *versionname; 605 } s; 606 } u; 607 const char *id; 608 struct id_list *next; 609}; 610 611 612/* Version information. */ 613struct version 614{ 615 struct version *next; 616 struct id_list *local_names; 617 struct id_list *global_names; 618 const char *versionname; 619 const char *parentname; 620}; 621 622 623/* Head for list of sections. */ 624struct scnhead 625{ 626 /* Name of the sections. */ 627 const char *name; 628 629 /* Accumulated flags for the sections. */ 630 XElf_Xword flags; 631 632 /* Type of the sections. */ 633 XElf_Word type; 634 635 /* Entry size. If there are differencs between the sections with 636 the same name this field contains 1. */ 637 XElf_Word entsize; 638 639 /* If non-NULL pointer to group signature. */ 640 const char *grp_signature; 641 642 /* Maximum alignment for all sections. */ 643 XElf_Word align; 644 645 /* Distinguish between normal sections coming from the input file 646 and sections generated by the linker. */ 647 enum scn_kind 648 { 649 scn_normal, /* Section from the input file(s). */ 650 scn_dot_interp, /* Generated .interp section. */ 651 scn_dot_got, /* Generated .got section. */ 652 scn_dot_dynrel, /* Generated .rel.dyn section. */ 653 scn_dot_dynamic, /* Generated .dynamic section. */ 654 scn_dot_dynsym, /* Generated .dynsym section. */ 655 scn_dot_dynstr, /* Generated .dynstr section. */ 656 scn_dot_hash, /* Generated .hash section. */ 657 scn_dot_plt, /* Generated .plt section. */ 658 scn_dot_pltrel, /* Generated .rel.plt section. */ 659 scn_dot_version, /* Generated .gnu.version section. */ 660 scn_dot_version_r /* Generated .gnu.version_r section. */ 661 } kind; 662 663 /* True is the section is used in the output. */ 664 bool used; 665 666 /* Total size (only determined this way for relocation sections). */ 667 size_t relsize; 668 669 /* Filled in by the section sorting to indicate which segment the 670 section goes in. */ 671 int segment_nr; 672 673 /* Index of the output section. We cannot store the section handle 674 directly here since the handle is a pointer in a dynamically 675 allocated table which might move if it becomes too small for all 676 the sections. Using the index the correct value can be found at 677 all times. */ 678 XElf_Word scnidx; 679 680 /* Index of the STT_SECTION entry for this section in the symbol 681 table. */ 682 XElf_Word scnsymidx; 683 684 /* Address of the section in the output file. */ 685 XElf_Addr addr; 686 687 /* Handle for the section name in the output file's section header 688 string table. */ 689 struct Ebl_Strent *nameent; 690 691 /* Tail of list of symbols for this section. Only set if the 692 section is merge-able. */ 693 struct symbol *symbols; 694 695 /* Pointer to last section. */ 696 struct scninfo *last; 697}; 698 699 700/* Define hash table for sections. */ 701#include <sectionhash.h> 702 703/* Define hash table for version symbols. */ 704#include <versionhash.h> 705 706 707/* State of the linker. */ 708struct ld_state 709{ 710 /* ELF backend library handle. */ 711 Ebl *ebl; 712 713 /* List of all archives participating, in this order. */ 714 struct usedfiles *archives; 715 /* End of the list. */ 716 struct usedfiles *tailarchives; 717 /* If nonzero we are looking for the beginning of a group. */ 718 bool group_start_requested; 719 /* Pointer to the archive starting the group. */ 720 struct usedfiles *group_start_archive; 721 722 /* List of the DSOs we found. */ 723 struct usedfiles *dsofiles; 724 /* Number of DSO files. */ 725 size_t ndsofiles; 726 /* Ultimate list of object files which are linked in. */ 727 struct usedfiles *relfiles; 728 729 /* List the DT_NEEDED DSOs. */ 730 struct usedfiles *needed; 731 732 /* Temporary storage for the parser. */ 733 struct filename_list *srcfiles; 734 735 /* List of all the paths to look at. */ 736 struct pathelement *paths; 737 /* Tail of the list. */ 738 struct pathelement *tailpaths; 739 740 /* User provided paths for lookup of DSOs. */ 741 struct pathelement *rpath; 742 struct pathelement *rpath_link; 743 struct pathelement *runpath; 744 struct pathelement *runpath_link; 745 struct Ebl_Strent *rxxpath_strent; 746 int rxxpath_tag; 747 748 /* From the environment variable LD_LIBRARY_PATH. */ 749 struct pathelement *ld_library_path1; 750 struct pathelement *ld_library_path2; 751 752 /* Name of the output file. */ 753 const char *outfname; 754 /* Name of the temporary file we initially create. */ 755 const char *tempfname; 756 /* File descriptor opened for the output file. */ 757 int outfd; 758 /* The ELF descriptor for the output file. */ 759 Elf *outelf; 760 761 /* Type of output file. */ 762 enum file_type file_type; 763 764 /* Is this a system library or not. */ 765 bool is_system_library; 766 767 /* Page size to be assumed for the binary. */ 768 size_t pagesize; 769 770 /* Name of the interpreter for dynamically linked objects. */ 771 const char *interp; 772 /* Index of the .interp section. */ 773 Elf32_Word interpscnidx; 774 775 /* Optimization level. */ 776 unsigned long int optlevel; 777 778 /* If true static linking is requested. */ 779 bool statically; 780 781 /* How to extract elements from archives. */ 782 enum extract_rule extract_rule; 783 784 /* Sequence number of the last archive we used. */ 785 int last_archive_used; 786 787 /* If true print to stdout information about the files we are 788 trying to open. */ 789 bool trace_files; 790 791 /* If true multiple definitions are not considered an error; the 792 first is used. */ 793 bool muldefs; 794 795 /* If true undefined symbols when building DSOs are not fatal. */ 796 bool nodefs; 797 798 /* If true add line indentifying link-editor to .comment section. */ 799 bool add_ld_comment; 800 801 /* Stripping while linking. */ 802 enum 803 { 804 strip_none, 805 strip_debug, 806 strip_all, 807 strip_everything 808 } strip; 809 810 /* The callback function vector. */ 811 struct callbacks callbacks; 812 813 /* Name of the entry symbol. Can also be a numeric value. */ 814 const char *entry; 815 816 /* The description of the segments in the output file. */ 817 struct output_segment *output_segments; 818 819 /* List of the symbols we created from linker script definitions. */ 820 struct symbol *lscript_syms; 821 size_t nlscript_syms; 822 823 /* Table with known symbols. */ 824 ld_symbol_tab symbol_tab; 825 826 /* Table with used sections. */ 827 ld_section_tab section_tab; 828 829 /* The list of sections once we collected them. */ 830 struct scnhead **allsections; 831 size_t nallsections; 832 size_t nusedsections; 833 size_t nnotesections; 834 835 /* Beginning of the list of symbols which are still unresolved. */ 836 struct symbol *unresolved; 837 /* Number of truely unresolved entries in the list. */ 838 size_t nunresolved; 839 /* Number of truely unresolved, non-weak entries in the list. */ 840 size_t nunresolved_nonweak; 841 842 /* List of common symbols. */ 843 struct symbol *common_syms; 844 /* Section for the common symbols. */ 845 struct scninfo *common_section; 846 847 /* List of symbols defined in DSOs and used in a relocatable file. 848 DSO symbols not referenced in the relocatable files are not on 849 the list. If a symbol is on the list the on_dsolist field in the 850 'struct symbol' is nonzero. */ 851 struct symbol *from_dso; 852 /* Number of entries in from_dso. */ 853 size_t nfrom_dso; 854 /* Number of entries in the dynamic symbol table. */ 855 size_t ndynsym; 856 /* Number of PLT entries from DSO references. */ 857 size_t nplt; 858 /* Number of PLT entries from DSO references. */ 859 size_t ngot; 860 /* Number of copy relocations. */ 861 size_t ncopy; 862 /* Section for copy relocations. */ 863 struct scninfo *copy_section; 864 865 /* Keeping track of the number of symbols in the output file. */ 866 size_t nsymtab; 867 size_t nlocalsymbols; 868 869 /* Special symbols. */ 870 struct symbol *init_symbol; 871 struct symbol *fini_symbol; 872 873 /* The description of the segments in the output file as described 874 in the default linker script. This information will be used in 875 addition to the user-provided information. */ 876 struct output_segment *default_output_segments; 877 /* Search paths added by the default linker script. */ 878 struct pathelement *default_paths; 879 880#ifndef BASE_ELF_NAME 881 /* The handle of the ld backend library. */ 882 void *ldlib; 883#endif 884 885 /* String table for the section headers. */ 886 struct Ebl_Strtab *shstrtab; 887 888 /* True if output file should contain symbol table. */ 889 bool need_symtab; 890 /* Symbol table section. */ 891 Elf32_Word symscnidx; 892 /* Extended section table section. */ 893 Elf32_Word xndxscnidx; 894 /* Symbol string table section. */ 895 Elf32_Word strscnidx; 896 897 /* True if output file should contain dynamic symbol table. */ 898 bool need_dynsym; 899 /* Dynamic symbol table section. */ 900 Elf32_Word dynsymscnidx; 901 /* Dynamic symbol string table section. */ 902 Elf32_Word dynstrscnidx; 903 /* Dynamic symbol hash table. */ 904 size_t hashscnidx; 905 906 /* Procedure linkage table section. */ 907 Elf32_Word pltscnidx; 908 /* Number of entries already in the PLT section. */ 909 size_t nplt_used; 910 /* Relocation for procedure linkage table section. */ 911 Elf32_Word pltrelscnidx; 912 913 /* Global offset table section. */ 914 Elf32_Word gotscnidx; 915 916 /* This section will hole all non-PLT relocations. */ 917 Elf32_Word reldynscnidx; 918 919 /* Index of the sections to handle versioning. */ 920 Elf32_Word versymscnidx; 921 Elf32_Word verneedscnidx; 922 /* XXX Should the following names be verneed...? */ 923 /* Number of version definitions in input DSOs used. */ 924 int nverdefused; 925 /* Number of input DSOs using versioning. */ 926 int nverdeffile; 927 /* Index of next version. */ 928 int nextveridx; 929 930 /* Hash table for version symbol strings. Only strings without 931 special characters are hashed here. */ 932 ld_version_str_tab version_str_tab; 933 /* At most one of the following two variables is set to true if either 934 global or local symbol binding is selected as the default. */ 935 bool default_bind_local; 936 bool default_bind_global; 937 938 /* True if only used sections are used. */ 939 bool gc_sections; 940 941 /* Array to determine final index of symbol. */ 942 Elf32_Word *dblindirect; 943 944 /* Section group handling. */ 945 struct scngroup 946 { 947 Elf32_Word outscnidx; 948 int nscns; 949 struct member 950 { 951 struct scnhead *scn; 952 struct member *next; 953 } *member; 954 struct Ebl_Strent *nameent; 955 struct symbol *symbol; 956 struct scngroup *next; 957 } *groups; 958 959 /* True if the output file needs a .got section. */ 960 bool need_got; 961 /* Number of relocations for GOT section caused. */ 962 size_t nrel_got; 963 964 /* Number of entries needed in the .dynamic section. */ 965 int ndynamic; 966 /* To keep track of added entries. */ 967 int ndynamic_filled; 968 /* Index for the dynamic section. */ 969 Elf32_Word dynamicscnidx; 970 971 /* Flags set in the DT_FLAGS word. */ 972 Elf32_Word dt_flags; 973 /* Flags set in the DT_FLAGS_1 word. */ 974 Elf32_Word dt_flags_1; 975 /* Flags set in the DT_FEATURE_1 word. */ 976 Elf32_Word dt_feature_1; 977 978 /* Lazy-loading state for dependencies. */ 979 bool lazyload; 980 981 /* True is DSOs which are not used in the linking process are not 982 recorded. */ 983 bool ignore_unused_dsos; 984 985 986 /* True if in executables all global symbols should be exported in 987 the dynamic symbol table. */ 988 bool export_all_dynamic; 989 990 /* If DSO is generated, this is the SONAME. */ 991 const char *soname; 992 993 /* List of all relocation sections. */ 994 struct scninfo *rellist; 995 /* Total size of non-PLT relocations. */ 996 size_t relsize_total; 997 998 /* Record for the GOT symbol, if known. */ 999 struct symbol *got_symbol; 1000 /* Record for the dynamic section symbol, if known. */ 1001 struct symbol *dyn_symbol; 1002 1003 /* Obstack used for small objects which will not be deleted. */ 1004 struct obstack smem; 1005}; 1006 1007 1008/* The interface to the scanner. */ 1009 1010/* Parser entry point. */ 1011extern int ldparse (void); 1012 1013/* The input file. */ 1014extern FILE *ldin; 1015 1016/* Name of the input file. */ 1017extern const char *ldin_fname; 1018 1019/* Current line number. Must be reset for a new file. */ 1020extern int ldlineno; 1021 1022/* If nonzero we are currently parsing a version script. */ 1023extern int ld_scan_version_script; 1024 1025/* Flags defined in ld.c. */ 1026extern int verbose; 1027extern int conserve_memory; 1028 1029 1030/* Linker state. This contains all global information. */ 1031extern struct ld_state ld_state; 1032 1033 1034/* Generic ld helper functions. */ 1035 1036/* Append a new directory to search libraries in. */ 1037extern void ld_new_searchdir (const char *dir); 1038 1039/* Append a new file to the list of input files. */ 1040extern struct usedfiles *ld_new_inputfile (const char *fname, 1041 enum file_type type); 1042 1043 1044/* These are the generic implementations for the callbacks used by ld. */ 1045 1046/* Initialize state object. This callback function is called after the 1047 parameters are parsed but before any file is searched for. */ 1048extern int ld_prepare_state (const char *emulation); 1049 1050 1051/* Function to determine whether an object will be dynamically linked. */ 1052extern bool dynamically_linked_p (void); 1053 1054/* Helper functions for the architecture specific code. */ 1055 1056/* Checked whether the symbol is undefined and referenced from a DSO. */ 1057extern bool linked_from_dso_p (struct scninfo *scninfo, int symidx); 1058extern inline bool 1059linked_from_dso_p (struct scninfo *scninfo, int symidx) 1060{ 1061 struct usedfiles *file = scninfo->fileinfo; 1062 1063 /* If this symbol is not undefined in this file it cannot come from 1064 a DSO. */ 1065 if (symidx < file->nlocalsymbols) 1066 return false; 1067 1068 struct symbol *sym = file->symref[symidx]; 1069 1070 return sym->defined && sym->in_dso; 1071} 1072 1073#endif /* ld.h */ 1074