1/* linker.c -- BFD linker routines 2 Copyright (C) 1993-2017 Free Software Foundation, Inc. 3 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support 4 5 This file is part of BFD, the Binary File Descriptor library. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software 19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 20 MA 02110-1301, USA. */ 21 22#include "sysdep.h" 23#include "bfd.h" 24#include "libbfd.h" 25#include "bfdlink.h" 26#include "genlink.h" 27 28/* 29SECTION 30 Linker Functions 31 32@cindex Linker 33 The linker uses three special entry points in the BFD target 34 vector. It is not necessary to write special routines for 35 these entry points when creating a new BFD back end, since 36 generic versions are provided. However, writing them can 37 speed up linking and make it use significantly less runtime 38 memory. 39 40 The first routine creates a hash table used by the other 41 routines. The second routine adds the symbols from an object 42 file to the hash table. The third routine takes all the 43 object files and links them together to create the output 44 file. These routines are designed so that the linker proper 45 does not need to know anything about the symbols in the object 46 files that it is linking. The linker merely arranges the 47 sections as directed by the linker script and lets BFD handle 48 the details of symbols and relocs. 49 50 The second routine and third routines are passed a pointer to 51 a <<struct bfd_link_info>> structure (defined in 52 <<bfdlink.h>>) which holds information relevant to the link, 53 including the linker hash table (which was created by the 54 first routine) and a set of callback functions to the linker 55 proper. 56 57 The generic linker routines are in <<linker.c>>, and use the 58 header file <<genlink.h>>. As of this writing, the only back 59 ends which have implemented versions of these routines are 60 a.out (in <<aoutx.h>>) and ECOFF (in <<ecoff.c>>). The a.out 61 routines are used as examples throughout this section. 62 63@menu 64@* Creating a Linker Hash Table:: 65@* Adding Symbols to the Hash Table:: 66@* Performing the Final Link:: 67@end menu 68 69INODE 70Creating a Linker Hash Table, Adding Symbols to the Hash Table, Linker Functions, Linker Functions 71SUBSECTION 72 Creating a linker hash table 73 74@cindex _bfd_link_hash_table_create in target vector 75@cindex target vector (_bfd_link_hash_table_create) 76 The linker routines must create a hash table, which must be 77 derived from <<struct bfd_link_hash_table>> described in 78 <<bfdlink.c>>. @xref{Hash Tables}, for information on how to 79 create a derived hash table. This entry point is called using 80 the target vector of the linker output file. 81 82 The <<_bfd_link_hash_table_create>> entry point must allocate 83 and initialize an instance of the desired hash table. If the 84 back end does not require any additional information to be 85 stored with the entries in the hash table, the entry point may 86 simply create a <<struct bfd_link_hash_table>>. Most likely, 87 however, some additional information will be needed. 88 89 For example, with each entry in the hash table the a.out 90 linker keeps the index the symbol has in the final output file 91 (this index number is used so that when doing a relocatable 92 link the symbol index used in the output file can be quickly 93 filled in when copying over a reloc). The a.out linker code 94 defines the required structures and functions for a hash table 95 derived from <<struct bfd_link_hash_table>>. The a.out linker 96 hash table is created by the function 97 <<NAME(aout,link_hash_table_create)>>; it simply allocates 98 space for the hash table, initializes it, and returns a 99 pointer to it. 100 101 When writing the linker routines for a new back end, you will 102 generally not know exactly which fields will be required until 103 you have finished. You should simply create a new hash table 104 which defines no additional fields, and then simply add fields 105 as they become necessary. 106 107INODE 108Adding Symbols to the Hash Table, Performing the Final Link, Creating a Linker Hash Table, Linker Functions 109SUBSECTION 110 Adding symbols to the hash table 111 112@cindex _bfd_link_add_symbols in target vector 113@cindex target vector (_bfd_link_add_symbols) 114 The linker proper will call the <<_bfd_link_add_symbols>> 115 entry point for each object file or archive which is to be 116 linked (typically these are the files named on the command 117 line, but some may also come from the linker script). The 118 entry point is responsible for examining the file. For an 119 object file, BFD must add any relevant symbol information to 120 the hash table. For an archive, BFD must determine which 121 elements of the archive should be used and adding them to the 122 link. 123 124 The a.out version of this entry point is 125 <<NAME(aout,link_add_symbols)>>. 126 127@menu 128@* Differing file formats:: 129@* Adding symbols from an object file:: 130@* Adding symbols from an archive:: 131@end menu 132 133INODE 134Differing file formats, Adding symbols from an object file, Adding Symbols to the Hash Table, Adding Symbols to the Hash Table 135SUBSUBSECTION 136 Differing file formats 137 138 Normally all the files involved in a link will be of the same 139 format, but it is also possible to link together different 140 format object files, and the back end must support that. The 141 <<_bfd_link_add_symbols>> entry point is called via the target 142 vector of the file to be added. This has an important 143 consequence: the function may not assume that the hash table 144 is the type created by the corresponding 145 <<_bfd_link_hash_table_create>> vector. All the 146 <<_bfd_link_add_symbols>> function can assume about the hash 147 table is that it is derived from <<struct 148 bfd_link_hash_table>>. 149 150 Sometimes the <<_bfd_link_add_symbols>> function must store 151 some information in the hash table entry to be used by the 152 <<_bfd_final_link>> function. In such a case the output bfd 153 xvec must be checked to make sure that the hash table was 154 created by an object file of the same format. 155 156 The <<_bfd_final_link>> routine must be prepared to handle a 157 hash entry without any extra information added by the 158 <<_bfd_link_add_symbols>> function. A hash entry without 159 extra information will also occur when the linker script 160 directs the linker to create a symbol. Note that, regardless 161 of how a hash table entry is added, all the fields will be 162 initialized to some sort of null value by the hash table entry 163 initialization function. 164 165 See <<ecoff_link_add_externals>> for an example of how to 166 check the output bfd before saving information (in this 167 case, the ECOFF external symbol debugging information) in a 168 hash table entry. 169 170INODE 171Adding symbols from an object file, Adding symbols from an archive, Differing file formats, Adding Symbols to the Hash Table 172SUBSUBSECTION 173 Adding symbols from an object file 174 175 When the <<_bfd_link_add_symbols>> routine is passed an object 176 file, it must add all externally visible symbols in that 177 object file to the hash table. The actual work of adding the 178 symbol to the hash table is normally handled by the function 179 <<_bfd_generic_link_add_one_symbol>>. The 180 <<_bfd_link_add_symbols>> routine is responsible for reading 181 all the symbols from the object file and passing the correct 182 information to <<_bfd_generic_link_add_one_symbol>>. 183 184 The <<_bfd_link_add_symbols>> routine should not use 185 <<bfd_canonicalize_symtab>> to read the symbols. The point of 186 providing this routine is to avoid the overhead of converting 187 the symbols into generic <<asymbol>> structures. 188 189@findex _bfd_generic_link_add_one_symbol 190 <<_bfd_generic_link_add_one_symbol>> handles the details of 191 combining common symbols, warning about multiple definitions, 192 and so forth. It takes arguments which describe the symbol to 193 add, notably symbol flags, a section, and an offset. The 194 symbol flags include such things as <<BSF_WEAK>> or 195 <<BSF_INDIRECT>>. The section is a section in the object 196 file, or something like <<bfd_und_section_ptr>> for an undefined 197 symbol or <<bfd_com_section_ptr>> for a common symbol. 198 199 If the <<_bfd_final_link>> routine is also going to need to 200 read the symbol information, the <<_bfd_link_add_symbols>> 201 routine should save it somewhere attached to the object file 202 BFD. However, the information should only be saved if the 203 <<keep_memory>> field of the <<info>> argument is TRUE, so 204 that the <<-no-keep-memory>> linker switch is effective. 205 206 The a.out function which adds symbols from an object file is 207 <<aout_link_add_object_symbols>>, and most of the interesting 208 work is in <<aout_link_add_symbols>>. The latter saves 209 pointers to the hash tables entries created by 210 <<_bfd_generic_link_add_one_symbol>> indexed by symbol number, 211 so that the <<_bfd_final_link>> routine does not have to call 212 the hash table lookup routine to locate the entry. 213 214INODE 215Adding symbols from an archive, , Adding symbols from an object file, Adding Symbols to the Hash Table 216SUBSUBSECTION 217 Adding symbols from an archive 218 219 When the <<_bfd_link_add_symbols>> routine is passed an 220 archive, it must look through the symbols defined by the 221 archive and decide which elements of the archive should be 222 included in the link. For each such element it must call the 223 <<add_archive_element>> linker callback, and it must add the 224 symbols from the object file to the linker hash table. (The 225 callback may in fact indicate that a replacement BFD should be 226 used, in which case the symbols from that BFD should be added 227 to the linker hash table instead.) 228 229@findex _bfd_generic_link_add_archive_symbols 230 In most cases the work of looking through the symbols in the 231 archive should be done by the 232 <<_bfd_generic_link_add_archive_symbols>> function. 233 <<_bfd_generic_link_add_archive_symbols>> is passed a function 234 to call to make the final decision about adding an archive 235 element to the link and to do the actual work of adding the 236 symbols to the linker hash table. If the element is to 237 be included, the <<add_archive_element>> linker callback 238 routine must be called with the element as an argument, and 239 the element's symbols must be added to the linker hash table 240 just as though the element had itself been passed to the 241 <<_bfd_link_add_symbols>> function. 242 243 When the a.out <<_bfd_link_add_symbols>> function receives an 244 archive, it calls <<_bfd_generic_link_add_archive_symbols>> 245 passing <<aout_link_check_archive_element>> as the function 246 argument. <<aout_link_check_archive_element>> calls 247 <<aout_link_check_ar_symbols>>. If the latter decides to add 248 the element (an element is only added if it provides a real, 249 non-common, definition for a previously undefined or common 250 symbol) it calls the <<add_archive_element>> callback and then 251 <<aout_link_check_archive_element>> calls 252 <<aout_link_add_symbols>> to actually add the symbols to the 253 linker hash table - possibly those of a substitute BFD, if the 254 <<add_archive_element>> callback avails itself of that option. 255 256 The ECOFF back end is unusual in that it does not normally 257 call <<_bfd_generic_link_add_archive_symbols>>, because ECOFF 258 archives already contain a hash table of symbols. The ECOFF 259 back end searches the archive itself to avoid the overhead of 260 creating a new hash table. 261 262INODE 263Performing the Final Link, , Adding Symbols to the Hash Table, Linker Functions 264SUBSECTION 265 Performing the final link 266 267@cindex _bfd_link_final_link in target vector 268@cindex target vector (_bfd_final_link) 269 When all the input files have been processed, the linker calls 270 the <<_bfd_final_link>> entry point of the output BFD. This 271 routine is responsible for producing the final output file, 272 which has several aspects. It must relocate the contents of 273 the input sections and copy the data into the output sections. 274 It must build an output symbol table including any local 275 symbols from the input files and the global symbols from the 276 hash table. When producing relocatable output, it must 277 modify the input relocs and write them into the output file. 278 There may also be object format dependent work to be done. 279 280 The linker will also call the <<write_object_contents>> entry 281 point when the BFD is closed. The two entry points must work 282 together in order to produce the correct output file. 283 284 The details of how this works are inevitably dependent upon 285 the specific object file format. The a.out 286 <<_bfd_final_link>> routine is <<NAME(aout,final_link)>>. 287 288@menu 289@* Information provided by the linker:: 290@* Relocating the section contents:: 291@* Writing the symbol table:: 292@end menu 293 294INODE 295Information provided by the linker, Relocating the section contents, Performing the Final Link, Performing the Final Link 296SUBSUBSECTION 297 Information provided by the linker 298 299 Before the linker calls the <<_bfd_final_link>> entry point, 300 it sets up some data structures for the function to use. 301 302 The <<input_bfds>> field of the <<bfd_link_info>> structure 303 will point to a list of all the input files included in the 304 link. These files are linked through the <<link.next>> field 305 of the <<bfd>> structure. 306 307 Each section in the output file will have a list of 308 <<link_order>> structures attached to the <<map_head.link_order>> 309 field (the <<link_order>> structure is defined in 310 <<bfdlink.h>>). These structures describe how to create the 311 contents of the output section in terms of the contents of 312 various input sections, fill constants, and, eventually, other 313 types of information. They also describe relocs that must be 314 created by the BFD backend, but do not correspond to any input 315 file; this is used to support -Ur, which builds constructors 316 while generating a relocatable object file. 317 318INODE 319Relocating the section contents, Writing the symbol table, Information provided by the linker, Performing the Final Link 320SUBSUBSECTION 321 Relocating the section contents 322 323 The <<_bfd_final_link>> function should look through the 324 <<link_order>> structures attached to each section of the 325 output file. Each <<link_order>> structure should either be 326 handled specially, or it should be passed to the function 327 <<_bfd_default_link_order>> which will do the right thing 328 (<<_bfd_default_link_order>> is defined in <<linker.c>>). 329 330 For efficiency, a <<link_order>> of type 331 <<bfd_indirect_link_order>> whose associated section belongs 332 to a BFD of the same format as the output BFD must be handled 333 specially. This type of <<link_order>> describes part of an 334 output section in terms of a section belonging to one of the 335 input files. The <<_bfd_final_link>> function should read the 336 contents of the section and any associated relocs, apply the 337 relocs to the section contents, and write out the modified 338 section contents. If performing a relocatable link, the 339 relocs themselves must also be modified and written out. 340 341@findex _bfd_relocate_contents 342@findex _bfd_final_link_relocate 343 The functions <<_bfd_relocate_contents>> and 344 <<_bfd_final_link_relocate>> provide some general support for 345 performing the actual relocations, notably overflow checking. 346 Their arguments include information about the symbol the 347 relocation is against and a <<reloc_howto_type>> argument 348 which describes the relocation to perform. These functions 349 are defined in <<reloc.c>>. 350 351 The a.out function which handles reading, relocating, and 352 writing section contents is <<aout_link_input_section>>. The 353 actual relocation is done in <<aout_link_input_section_std>> 354 and <<aout_link_input_section_ext>>. 355 356INODE 357Writing the symbol table, , Relocating the section contents, Performing the Final Link 358SUBSUBSECTION 359 Writing the symbol table 360 361 The <<_bfd_final_link>> function must gather all the symbols 362 in the input files and write them out. It must also write out 363 all the symbols in the global hash table. This must be 364 controlled by the <<strip>> and <<discard>> fields of the 365 <<bfd_link_info>> structure. 366 367 The local symbols of the input files will not have been 368 entered into the linker hash table. The <<_bfd_final_link>> 369 routine must consider each input file and include the symbols 370 in the output file. It may be convenient to do this when 371 looking through the <<link_order>> structures, or it may be 372 done by stepping through the <<input_bfds>> list. 373 374 The <<_bfd_final_link>> routine must also traverse the global 375 hash table to gather all the externally visible symbols. It 376 is possible that most of the externally visible symbols may be 377 written out when considering the symbols of each input file, 378 but it is still necessary to traverse the hash table since the 379 linker script may have defined some symbols that are not in 380 any of the input files. 381 382 The <<strip>> field of the <<bfd_link_info>> structure 383 controls which symbols are written out. The possible values 384 are listed in <<bfdlink.h>>. If the value is <<strip_some>>, 385 then the <<keep_hash>> field of the <<bfd_link_info>> 386 structure is a hash table of symbols to keep; each symbol 387 should be looked up in this hash table, and only symbols which 388 are present should be included in the output file. 389 390 If the <<strip>> field of the <<bfd_link_info>> structure 391 permits local symbols to be written out, the <<discard>> field 392 is used to further controls which local symbols are included 393 in the output file. If the value is <<discard_l>>, then all 394 local symbols which begin with a certain prefix are discarded; 395 this is controlled by the <<bfd_is_local_label_name>> entry point. 396 397 The a.out backend handles symbols by calling 398 <<aout_link_write_symbols>> on each input BFD and then 399 traversing the global hash table with the function 400 <<aout_link_write_other_symbol>>. It builds a string table 401 while writing out the symbols, which is written to the output 402 file at the end of <<NAME(aout,final_link)>>. 403*/ 404 405static bfd_boolean generic_link_add_object_symbols 406 (bfd *, struct bfd_link_info *); 407static bfd_boolean generic_link_check_archive_element 408 (bfd *, struct bfd_link_info *, struct bfd_link_hash_entry *, const char *, 409 bfd_boolean *); 410static bfd_boolean generic_link_add_symbol_list 411 (bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **); 412static bfd_boolean generic_add_output_symbol 413 (bfd *, size_t *psymalloc, asymbol *); 414static bfd_boolean default_data_link_order 415 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *); 416static bfd_boolean default_indirect_link_order 417 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *, 418 bfd_boolean); 419 420/* The link hash table structure is defined in bfdlink.h. It provides 421 a base hash table which the backend specific hash tables are built 422 upon. */ 423 424/* Routine to create an entry in the link hash table. */ 425 426struct bfd_hash_entry * 427_bfd_link_hash_newfunc (struct bfd_hash_entry *entry, 428 struct bfd_hash_table *table, 429 const char *string) 430{ 431 /* Allocate the structure if it has not already been allocated by a 432 subclass. */ 433 if (entry == NULL) 434 { 435 entry = (struct bfd_hash_entry *) 436 bfd_hash_allocate (table, sizeof (struct bfd_link_hash_entry)); 437 if (entry == NULL) 438 return entry; 439 } 440 441 /* Call the allocation method of the superclass. */ 442 entry = bfd_hash_newfunc (entry, table, string); 443 if (entry) 444 { 445 struct bfd_link_hash_entry *h = (struct bfd_link_hash_entry *) entry; 446 447 /* Initialize the local fields. */ 448 memset ((char *) &h->root + sizeof (h->root), 0, 449 sizeof (*h) - sizeof (h->root)); 450 } 451 452 return entry; 453} 454 455/* Initialize a link hash table. The BFD argument is the one 456 responsible for creating this table. */ 457 458bfd_boolean 459_bfd_link_hash_table_init 460 (struct bfd_link_hash_table *table, 461 bfd *abfd ATTRIBUTE_UNUSED, 462 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *, 463 struct bfd_hash_table *, 464 const char *), 465 unsigned int entsize) 466{ 467 bfd_boolean ret; 468 469 BFD_ASSERT (!abfd->is_linker_output && !abfd->link.hash); 470 table->undefs = NULL; 471 table->undefs_tail = NULL; 472 table->type = bfd_link_generic_hash_table; 473 474 ret = bfd_hash_table_init (&table->table, newfunc, entsize); 475 if (ret) 476 { 477 /* Arrange for destruction of this hash table on closing ABFD. */ 478 table->hash_table_free = _bfd_generic_link_hash_table_free; 479 abfd->link.hash = table; 480 abfd->is_linker_output = TRUE; 481 } 482 return ret; 483} 484 485/* Look up a symbol in a link hash table. If follow is TRUE, we 486 follow bfd_link_hash_indirect and bfd_link_hash_warning links to 487 the real symbol. */ 488 489struct bfd_link_hash_entry * 490bfd_link_hash_lookup (struct bfd_link_hash_table *table, 491 const char *string, 492 bfd_boolean create, 493 bfd_boolean copy, 494 bfd_boolean follow) 495{ 496 struct bfd_link_hash_entry *ret; 497 498 ret = ((struct bfd_link_hash_entry *) 499 bfd_hash_lookup (&table->table, string, create, copy)); 500 501 if (follow && ret != NULL) 502 { 503 while (ret->type == bfd_link_hash_indirect 504 || ret->type == bfd_link_hash_warning) 505 ret = ret->u.i.link; 506 } 507 508 return ret; 509} 510 511/* Look up a symbol in the main linker hash table if the symbol might 512 be wrapped. This should only be used for references to an 513 undefined symbol, not for definitions of a symbol. */ 514 515struct bfd_link_hash_entry * 516bfd_wrapped_link_hash_lookup (bfd *abfd, 517 struct bfd_link_info *info, 518 const char *string, 519 bfd_boolean create, 520 bfd_boolean copy, 521 bfd_boolean follow) 522{ 523 bfd_size_type amt; 524 525 if (info->wrap_hash != NULL) 526 { 527 const char *l; 528 char prefix = '\0'; 529 530 l = string; 531 if (*l == bfd_get_symbol_leading_char (abfd) || *l == info->wrap_char) 532 { 533 prefix = *l; 534 ++l; 535 } 536 537#undef WRAP 538#define WRAP "__wrap_" 539 540 if (bfd_hash_lookup (info->wrap_hash, l, FALSE, FALSE) != NULL) 541 { 542 char *n; 543 struct bfd_link_hash_entry *h; 544 545 /* This symbol is being wrapped. We want to replace all 546 references to SYM with references to __wrap_SYM. */ 547 548 amt = strlen (l) + sizeof WRAP + 1; 549 n = (char *) bfd_malloc (amt); 550 if (n == NULL) 551 return NULL; 552 553 n[0] = prefix; 554 n[1] = '\0'; 555 strcat (n, WRAP); 556 strcat (n, l); 557 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow); 558 free (n); 559 return h; 560 } 561 562#undef REAL 563#define REAL "__real_" 564 565 if (*l == '_' 566 && CONST_STRNEQ (l, REAL) 567 && bfd_hash_lookup (info->wrap_hash, l + sizeof REAL - 1, 568 FALSE, FALSE) != NULL) 569 { 570 char *n; 571 struct bfd_link_hash_entry *h; 572 573 /* This is a reference to __real_SYM, where SYM is being 574 wrapped. We want to replace all references to __real_SYM 575 with references to SYM. */ 576 577 amt = strlen (l + sizeof REAL - 1) + 2; 578 n = (char *) bfd_malloc (amt); 579 if (n == NULL) 580 return NULL; 581 582 n[0] = prefix; 583 n[1] = '\0'; 584 strcat (n, l + sizeof REAL - 1); 585 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow); 586 free (n); 587 return h; 588 } 589 590#undef REAL 591 } 592 593 return bfd_link_hash_lookup (info->hash, string, create, copy, follow); 594} 595 596/* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_" 597 and the remainder is found in wrap_hash, return the real symbol. */ 598 599struct bfd_link_hash_entry * 600unwrap_hash_lookup (struct bfd_link_info *info, 601 bfd *input_bfd, 602 struct bfd_link_hash_entry *h) 603{ 604 const char *l = h->root.string; 605 606 if (*l == bfd_get_symbol_leading_char (input_bfd) 607 || *l == info->wrap_char) 608 ++l; 609 610 if (CONST_STRNEQ (l, WRAP)) 611 { 612 l += sizeof WRAP - 1; 613 614 if (bfd_hash_lookup (info->wrap_hash, l, FALSE, FALSE) != NULL) 615 { 616 char save = 0; 617 if (l - (sizeof WRAP - 1) != h->root.string) 618 { 619 --l; 620 save = *l; 621 *(char *) l = *h->root.string; 622 } 623 h = bfd_link_hash_lookup (info->hash, l, FALSE, FALSE, FALSE); 624 if (save) 625 *(char *) l = save; 626 } 627 } 628 return h; 629} 630#undef WRAP 631 632/* Traverse a generic link hash table. Differs from bfd_hash_traverse 633 in the treatment of warning symbols. When warning symbols are 634 created they replace the real symbol, so you don't get to see the 635 real symbol in a bfd_hash_travere. This traversal calls func with 636 the real symbol. */ 637 638void 639bfd_link_hash_traverse 640 (struct bfd_link_hash_table *htab, 641 bfd_boolean (*func) (struct bfd_link_hash_entry *, void *), 642 void *info) 643{ 644 unsigned int i; 645 646 htab->table.frozen = 1; 647 for (i = 0; i < htab->table.size; i++) 648 { 649 struct bfd_link_hash_entry *p; 650 651 p = (struct bfd_link_hash_entry *) htab->table.table[i]; 652 for (; p != NULL; p = (struct bfd_link_hash_entry *) p->root.next) 653 if (!(*func) (p->type == bfd_link_hash_warning ? p->u.i.link : p, info)) 654 goto out; 655 } 656 out: 657 htab->table.frozen = 0; 658} 659 660/* Add a symbol to the linker hash table undefs list. */ 661 662void 663bfd_link_add_undef (struct bfd_link_hash_table *table, 664 struct bfd_link_hash_entry *h) 665{ 666 BFD_ASSERT (h->u.undef.next == NULL); 667 if (table->undefs_tail != NULL) 668 table->undefs_tail->u.undef.next = h; 669 if (table->undefs == NULL) 670 table->undefs = h; 671 table->undefs_tail = h; 672} 673 674/* The undefs list was designed so that in normal use we don't need to 675 remove entries. However, if symbols on the list are changed from 676 bfd_link_hash_undefined to either bfd_link_hash_undefweak or 677 bfd_link_hash_new for some reason, then they must be removed from the 678 list. Failure to do so might result in the linker attempting to add 679 the symbol to the list again at a later stage. */ 680 681void 682bfd_link_repair_undef_list (struct bfd_link_hash_table *table) 683{ 684 struct bfd_link_hash_entry **pun; 685 686 pun = &table->undefs; 687 while (*pun != NULL) 688 { 689 struct bfd_link_hash_entry *h = *pun; 690 691 if (h->type == bfd_link_hash_new 692 || h->type == bfd_link_hash_undefweak) 693 { 694 *pun = h->u.undef.next; 695 h->u.undef.next = NULL; 696 if (h == table->undefs_tail) 697 { 698 if (pun == &table->undefs) 699 table->undefs_tail = NULL; 700 else 701 /* pun points at an u.undef.next field. Go back to 702 the start of the link_hash_entry. */ 703 table->undefs_tail = (struct bfd_link_hash_entry *) 704 ((char *) pun - ((char *) &h->u.undef.next - (char *) h)); 705 break; 706 } 707 } 708 else 709 pun = &h->u.undef.next; 710 } 711} 712 713/* Routine to create an entry in a generic link hash table. */ 714 715struct bfd_hash_entry * 716_bfd_generic_link_hash_newfunc (struct bfd_hash_entry *entry, 717 struct bfd_hash_table *table, 718 const char *string) 719{ 720 /* Allocate the structure if it has not already been allocated by a 721 subclass. */ 722 if (entry == NULL) 723 { 724 entry = (struct bfd_hash_entry *) 725 bfd_hash_allocate (table, sizeof (struct generic_link_hash_entry)); 726 if (entry == NULL) 727 return entry; 728 } 729 730 /* Call the allocation method of the superclass. */ 731 entry = _bfd_link_hash_newfunc (entry, table, string); 732 if (entry) 733 { 734 struct generic_link_hash_entry *ret; 735 736 /* Set local fields. */ 737 ret = (struct generic_link_hash_entry *) entry; 738 ret->written = FALSE; 739 ret->sym = NULL; 740 } 741 742 return entry; 743} 744 745/* Create a generic link hash table. */ 746 747struct bfd_link_hash_table * 748_bfd_generic_link_hash_table_create (bfd *abfd) 749{ 750 struct generic_link_hash_table *ret; 751 bfd_size_type amt = sizeof (struct generic_link_hash_table); 752 753 ret = (struct generic_link_hash_table *) bfd_malloc (amt); 754 if (ret == NULL) 755 return NULL; 756 if (! _bfd_link_hash_table_init (&ret->root, abfd, 757 _bfd_generic_link_hash_newfunc, 758 sizeof (struct generic_link_hash_entry))) 759 { 760 free (ret); 761 return NULL; 762 } 763 return &ret->root; 764} 765 766void 767_bfd_generic_link_hash_table_free (bfd *obfd) 768{ 769 struct generic_link_hash_table *ret; 770 771 BFD_ASSERT (obfd->is_linker_output && obfd->link.hash); 772 ret = (struct generic_link_hash_table *) obfd->link.hash; 773 bfd_hash_table_free (&ret->root.table); 774 free (ret); 775 obfd->link.hash = NULL; 776 obfd->is_linker_output = FALSE; 777} 778 779/* Grab the symbols for an object file when doing a generic link. We 780 store the symbols in the outsymbols field. We need to keep them 781 around for the entire link to ensure that we only read them once. 782 If we read them multiple times, we might wind up with relocs and 783 the hash table pointing to different instances of the symbol 784 structure. */ 785 786bfd_boolean 787bfd_generic_link_read_symbols (bfd *abfd) 788{ 789 if (bfd_get_outsymbols (abfd) == NULL) 790 { 791 long symsize; 792 long symcount; 793 794 symsize = bfd_get_symtab_upper_bound (abfd); 795 if (symsize < 0) 796 return FALSE; 797 bfd_get_outsymbols (abfd) = (struct bfd_symbol **) bfd_alloc (abfd, 798 symsize); 799 if (bfd_get_outsymbols (abfd) == NULL && symsize != 0) 800 return FALSE; 801 symcount = bfd_canonicalize_symtab (abfd, bfd_get_outsymbols (abfd)); 802 if (symcount < 0) 803 return FALSE; 804 bfd_get_symcount (abfd) = symcount; 805 } 806 807 return TRUE; 808} 809 810/* Indicate that we are only retrieving symbol values from this 811 section. We want the symbols to act as though the values in the 812 file are absolute. */ 813 814void 815_bfd_generic_link_just_syms (asection *sec, 816 struct bfd_link_info *info ATTRIBUTE_UNUSED) 817{ 818 sec->sec_info_type = SEC_INFO_TYPE_JUST_SYMS; 819 sec->output_section = bfd_abs_section_ptr; 820 sec->output_offset = sec->vma; 821} 822 823/* Copy the symbol type and other attributes for a linker script 824 assignment from HSRC to HDEST. 825 The default implementation does nothing. */ 826void 827_bfd_generic_copy_link_hash_symbol_type (bfd *abfd ATTRIBUTE_UNUSED, 828 struct bfd_link_hash_entry *hdest ATTRIBUTE_UNUSED, 829 struct bfd_link_hash_entry *hsrc ATTRIBUTE_UNUSED) 830{ 831} 832 833/* Generic function to add symbols from an object file to the 834 global hash table. */ 835 836bfd_boolean 837_bfd_generic_link_add_symbols (bfd *abfd, struct bfd_link_info *info) 838{ 839 bfd_boolean ret; 840 841 switch (bfd_get_format (abfd)) 842 { 843 case bfd_object: 844 ret = generic_link_add_object_symbols (abfd, info); 845 break; 846 case bfd_archive: 847 ret = (_bfd_generic_link_add_archive_symbols 848 (abfd, info, generic_link_check_archive_element)); 849 break; 850 default: 851 bfd_set_error (bfd_error_wrong_format); 852 ret = FALSE; 853 } 854 855 return ret; 856} 857 858/* Add symbols from an object file to the global hash table. */ 859 860static bfd_boolean 861generic_link_add_object_symbols (bfd *abfd, 862 struct bfd_link_info *info) 863{ 864 bfd_size_type symcount; 865 struct bfd_symbol **outsyms; 866 867 if (!bfd_generic_link_read_symbols (abfd)) 868 return FALSE; 869 symcount = _bfd_generic_link_get_symcount (abfd); 870 outsyms = _bfd_generic_link_get_symbols (abfd); 871 return generic_link_add_symbol_list (abfd, info, symcount, outsyms); 872} 873 874/* Generic function to add symbols from an archive file to the global 875 hash file. This function presumes that the archive symbol table 876 has already been read in (this is normally done by the 877 bfd_check_format entry point). It looks through the archive symbol 878 table for symbols that are undefined or common in the linker global 879 symbol hash table. When one is found, the CHECKFN argument is used 880 to see if an object file should be included. This allows targets 881 to customize common symbol behaviour. CHECKFN should set *PNEEDED 882 to TRUE if the object file should be included, and must also call 883 the bfd_link_info add_archive_element callback function and handle 884 adding the symbols to the global hash table. CHECKFN must notice 885 if the callback indicates a substitute BFD, and arrange to add 886 those symbols instead if it does so. CHECKFN should only return 887 FALSE if some sort of error occurs. */ 888 889bfd_boolean 890_bfd_generic_link_add_archive_symbols 891 (bfd *abfd, 892 struct bfd_link_info *info, 893 bfd_boolean (*checkfn) (bfd *, struct bfd_link_info *, 894 struct bfd_link_hash_entry *, const char *, 895 bfd_boolean *)) 896{ 897 bfd_boolean loop; 898 bfd_size_type amt; 899 unsigned char *included; 900 901 if (! bfd_has_map (abfd)) 902 { 903 /* An empty archive is a special case. */ 904 if (bfd_openr_next_archived_file (abfd, NULL) == NULL) 905 return TRUE; 906 bfd_set_error (bfd_error_no_armap); 907 return FALSE; 908 } 909 910 amt = bfd_ardata (abfd)->symdef_count; 911 if (amt == 0) 912 return TRUE; 913 amt *= sizeof (*included); 914 included = (unsigned char *) bfd_zmalloc (amt); 915 if (included == NULL) 916 return FALSE; 917 918 do 919 { 920 carsym *arsyms; 921 carsym *arsym_end; 922 carsym *arsym; 923 unsigned int indx; 924 file_ptr last_ar_offset = -1; 925 bfd_boolean needed = FALSE; 926 bfd *element = NULL; 927 928 loop = FALSE; 929 arsyms = bfd_ardata (abfd)->symdefs; 930 arsym_end = arsyms + bfd_ardata (abfd)->symdef_count; 931 for (arsym = arsyms, indx = 0; arsym < arsym_end; arsym++, indx++) 932 { 933 struct bfd_link_hash_entry *h; 934 struct bfd_link_hash_entry *undefs_tail; 935 936 if (included[indx]) 937 continue; 938 if (needed && arsym->file_offset == last_ar_offset) 939 { 940 included[indx] = 1; 941 continue; 942 } 943 944 h = bfd_link_hash_lookup (info->hash, arsym->name, 945 FALSE, FALSE, TRUE); 946 947 if (h == NULL 948 && info->pei386_auto_import 949 && CONST_STRNEQ (arsym->name, "__imp_")) 950 h = bfd_link_hash_lookup (info->hash, arsym->name + 6, 951 FALSE, FALSE, TRUE); 952 if (h == NULL) 953 continue; 954 955 if (h->type != bfd_link_hash_undefined 956 && h->type != bfd_link_hash_common) 957 { 958 if (h->type != bfd_link_hash_undefweak) 959 /* Symbol must be defined. Don't check it again. */ 960 included[indx] = 1; 961 continue; 962 } 963 964 if (last_ar_offset != arsym->file_offset) 965 { 966 last_ar_offset = arsym->file_offset; 967 element = _bfd_get_elt_at_filepos (abfd, last_ar_offset); 968 if (element == NULL 969 || !bfd_check_format (element, bfd_object)) 970 goto error_return; 971 } 972 973 undefs_tail = info->hash->undefs_tail; 974 975 /* CHECKFN will see if this element should be included, and 976 go ahead and include it if appropriate. */ 977 if (! (*checkfn) (element, info, h, arsym->name, &needed)) 978 goto error_return; 979 980 if (needed) 981 { 982 unsigned int mark; 983 984 /* Look backward to mark all symbols from this object file 985 which we have already seen in this pass. */ 986 mark = indx; 987 do 988 { 989 included[mark] = 1; 990 if (mark == 0) 991 break; 992 --mark; 993 } 994 while (arsyms[mark].file_offset == last_ar_offset); 995 996 if (undefs_tail != info->hash->undefs_tail) 997 loop = TRUE; 998 } 999 } 1000 } while (loop); 1001 1002 free (included); 1003 return TRUE; 1004 1005 error_return: 1006 free (included); 1007 return FALSE; 1008} 1009 1010/* See if we should include an archive element. */ 1011 1012static bfd_boolean 1013generic_link_check_archive_element (bfd *abfd, 1014 struct bfd_link_info *info, 1015 struct bfd_link_hash_entry *h, 1016 const char *name ATTRIBUTE_UNUSED, 1017 bfd_boolean *pneeded) 1018{ 1019 asymbol **pp, **ppend; 1020 1021 *pneeded = FALSE; 1022 1023 if (!bfd_generic_link_read_symbols (abfd)) 1024 return FALSE; 1025 1026 pp = _bfd_generic_link_get_symbols (abfd); 1027 ppend = pp + _bfd_generic_link_get_symcount (abfd); 1028 for (; pp < ppend; pp++) 1029 { 1030 asymbol *p; 1031 1032 p = *pp; 1033 1034 /* We are only interested in globally visible symbols. */ 1035 if (! bfd_is_com_section (p->section) 1036 && (p->flags & (BSF_GLOBAL | BSF_INDIRECT | BSF_WEAK)) == 0) 1037 continue; 1038 1039 /* We are only interested if we know something about this 1040 symbol, and it is undefined or common. An undefined weak 1041 symbol (type bfd_link_hash_undefweak) is not considered to be 1042 a reference when pulling files out of an archive. See the 1043 SVR4 ABI, p. 4-27. */ 1044 h = bfd_link_hash_lookup (info->hash, bfd_asymbol_name (p), FALSE, 1045 FALSE, TRUE); 1046 if (h == NULL 1047 || (h->type != bfd_link_hash_undefined 1048 && h->type != bfd_link_hash_common)) 1049 continue; 1050 1051 /* P is a symbol we are looking for. */ 1052 1053 if (! bfd_is_com_section (p->section) 1054 || (h->type == bfd_link_hash_undefined 1055 && h->u.undef.abfd == NULL)) 1056 { 1057 /* P is not a common symbol, or an undefined reference was 1058 created from outside BFD such as from a linker -u option. 1059 This object file defines the symbol, so pull it in. */ 1060 *pneeded = TRUE; 1061 if (!(*info->callbacks 1062 ->add_archive_element) (info, abfd, bfd_asymbol_name (p), 1063 &abfd)) 1064 return FALSE; 1065 /* Potentially, the add_archive_element hook may have set a 1066 substitute BFD for us. */ 1067 return bfd_link_add_symbols (abfd, info); 1068 } 1069 1070 /* P is a common symbol. */ 1071 1072 if (h->type == bfd_link_hash_undefined) 1073 { 1074 bfd *symbfd; 1075 bfd_vma size; 1076 unsigned int power; 1077 1078 /* Turn the symbol into a common symbol but do not link in 1079 the object file. This is how a.out works. Object 1080 formats that require different semantics must implement 1081 this function differently. This symbol is already on the 1082 undefs list. We add the section to a common section 1083 attached to symbfd to ensure that it is in a BFD which 1084 will be linked in. */ 1085 symbfd = h->u.undef.abfd; 1086 h->type = bfd_link_hash_common; 1087 h->u.c.p = (struct bfd_link_hash_common_entry *) 1088 bfd_hash_allocate (&info->hash->table, 1089 sizeof (struct bfd_link_hash_common_entry)); 1090 if (h->u.c.p == NULL) 1091 return FALSE; 1092 1093 size = bfd_asymbol_value (p); 1094 h->u.c.size = size; 1095 1096 power = bfd_log2 (size); 1097 if (power > 4) 1098 power = 4; 1099 h->u.c.p->alignment_power = power; 1100 1101 if (p->section == bfd_com_section_ptr) 1102 h->u.c.p->section = bfd_make_section_old_way (symbfd, "COMMON"); 1103 else 1104 h->u.c.p->section = bfd_make_section_old_way (symbfd, 1105 p->section->name); 1106 h->u.c.p->section->flags |= SEC_ALLOC; 1107 } 1108 else 1109 { 1110 /* Adjust the size of the common symbol if necessary. This 1111 is how a.out works. Object formats that require 1112 different semantics must implement this function 1113 differently. */ 1114 if (bfd_asymbol_value (p) > h->u.c.size) 1115 h->u.c.size = bfd_asymbol_value (p); 1116 } 1117 } 1118 1119 /* This archive element is not needed. */ 1120 return TRUE; 1121} 1122 1123/* Add the symbols from an object file to the global hash table. ABFD 1124 is the object file. INFO is the linker information. SYMBOL_COUNT 1125 is the number of symbols. SYMBOLS is the list of symbols. */ 1126 1127static bfd_boolean 1128generic_link_add_symbol_list (bfd *abfd, 1129 struct bfd_link_info *info, 1130 bfd_size_type symbol_count, 1131 asymbol **symbols) 1132{ 1133 asymbol **pp, **ppend; 1134 1135 pp = symbols; 1136 ppend = symbols + symbol_count; 1137 for (; pp < ppend; pp++) 1138 { 1139 asymbol *p; 1140 1141 p = *pp; 1142 1143 if ((p->flags & (BSF_INDIRECT 1144 | BSF_WARNING 1145 | BSF_GLOBAL 1146 | BSF_CONSTRUCTOR 1147 | BSF_WEAK)) != 0 1148 || bfd_is_und_section (bfd_get_section (p)) 1149 || bfd_is_com_section (bfd_get_section (p)) 1150 || bfd_is_ind_section (bfd_get_section (p))) 1151 { 1152 const char *name; 1153 const char *string; 1154 struct generic_link_hash_entry *h; 1155 struct bfd_link_hash_entry *bh; 1156 1157 string = name = bfd_asymbol_name (p); 1158 if (((p->flags & BSF_INDIRECT) != 0 1159 || bfd_is_ind_section (p->section)) 1160 && pp + 1 < ppend) 1161 { 1162 pp++; 1163 string = bfd_asymbol_name (*pp); 1164 } 1165 else if ((p->flags & BSF_WARNING) != 0 1166 && pp + 1 < ppend) 1167 { 1168 /* The name of P is actually the warning string, and the 1169 next symbol is the one to warn about. */ 1170 pp++; 1171 name = bfd_asymbol_name (*pp); 1172 } 1173 1174 bh = NULL; 1175 if (! (_bfd_generic_link_add_one_symbol 1176 (info, abfd, name, p->flags, bfd_get_section (p), 1177 p->value, string, FALSE, FALSE, &bh))) 1178 return FALSE; 1179 h = (struct generic_link_hash_entry *) bh; 1180 1181 /* If this is a constructor symbol, and the linker didn't do 1182 anything with it, then we want to just pass the symbol 1183 through to the output file. This will happen when 1184 linking with -r. */ 1185 if ((p->flags & BSF_CONSTRUCTOR) != 0 1186 && (h == NULL || h->root.type == bfd_link_hash_new)) 1187 { 1188 p->udata.p = NULL; 1189 continue; 1190 } 1191 1192 /* Save the BFD symbol so that we don't lose any backend 1193 specific information that may be attached to it. We only 1194 want this one if it gives more information than the 1195 existing one; we don't want to replace a defined symbol 1196 with an undefined one. This routine may be called with a 1197 hash table other than the generic hash table, so we only 1198 do this if we are certain that the hash table is a 1199 generic one. */ 1200 if (info->output_bfd->xvec == abfd->xvec) 1201 { 1202 if (h->sym == NULL 1203 || (! bfd_is_und_section (bfd_get_section (p)) 1204 && (! bfd_is_com_section (bfd_get_section (p)) 1205 || bfd_is_und_section (bfd_get_section (h->sym))))) 1206 { 1207 h->sym = p; 1208 /* BSF_OLD_COMMON is a hack to support COFF reloc 1209 reading, and it should go away when the COFF 1210 linker is switched to the new version. */ 1211 if (bfd_is_com_section (bfd_get_section (p))) 1212 p->flags |= BSF_OLD_COMMON; 1213 } 1214 } 1215 1216 /* Store a back pointer from the symbol to the hash 1217 table entry for the benefit of relaxation code until 1218 it gets rewritten to not use asymbol structures. 1219 Setting this is also used to check whether these 1220 symbols were set up by the generic linker. */ 1221 p->udata.p = h; 1222 } 1223 } 1224 1225 return TRUE; 1226} 1227 1228/* We use a state table to deal with adding symbols from an object 1229 file. The first index into the state table describes the symbol 1230 from the object file. The second index into the state table is the 1231 type of the symbol in the hash table. */ 1232 1233/* The symbol from the object file is turned into one of these row 1234 values. */ 1235 1236enum link_row 1237{ 1238 UNDEF_ROW, /* Undefined. */ 1239 UNDEFW_ROW, /* Weak undefined. */ 1240 DEF_ROW, /* Defined. */ 1241 DEFW_ROW, /* Weak defined. */ 1242 COMMON_ROW, /* Common. */ 1243 INDR_ROW, /* Indirect. */ 1244 WARN_ROW, /* Warning. */ 1245 SET_ROW /* Member of set. */ 1246}; 1247 1248/* apparently needed for Hitachi 3050R(HI-UX/WE2)? */ 1249#undef FAIL 1250 1251/* The actions to take in the state table. */ 1252 1253enum link_action 1254{ 1255 FAIL, /* Abort. */ 1256 UND, /* Mark symbol undefined. */ 1257 WEAK, /* Mark symbol weak undefined. */ 1258 DEF, /* Mark symbol defined. */ 1259 DEFW, /* Mark symbol weak defined. */ 1260 COM, /* Mark symbol common. */ 1261 REF, /* Mark defined symbol referenced. */ 1262 CREF, /* Possibly warn about common reference to defined symbol. */ 1263 CDEF, /* Define existing common symbol. */ 1264 NOACT, /* No action. */ 1265 BIG, /* Mark symbol common using largest size. */ 1266 MDEF, /* Multiple definition error. */ 1267 MIND, /* Multiple indirect symbols. */ 1268 IND, /* Make indirect symbol. */ 1269 CIND, /* Make indirect symbol from existing common symbol. */ 1270 SET, /* Add value to set. */ 1271 MWARN, /* Make warning symbol. */ 1272 WARN, /* Warn if referenced, else MWARN. */ 1273 CYCLE, /* Repeat with symbol pointed to. */ 1274 REFC, /* Mark indirect symbol referenced and then CYCLE. */ 1275 WARNC /* Issue warning and then CYCLE. */ 1276}; 1277 1278/* The state table itself. The first index is a link_row and the 1279 second index is a bfd_link_hash_type. */ 1280 1281static const enum link_action link_action[8][8] = 1282{ 1283 /* current\prev new undef undefw def defw com indr warn */ 1284 /* UNDEF_ROW */ {UND, NOACT, UND, REF, REF, NOACT, REFC, WARNC }, 1285 /* UNDEFW_ROW */ {WEAK, NOACT, NOACT, REF, REF, NOACT, REFC, WARNC }, 1286 /* DEF_ROW */ {DEF, DEF, DEF, MDEF, DEF, CDEF, MDEF, CYCLE }, 1287 /* DEFW_ROW */ {DEFW, DEFW, DEFW, NOACT, NOACT, NOACT, NOACT, CYCLE }, 1288 /* COMMON_ROW */ {COM, COM, COM, CREF, COM, BIG, REFC, WARNC }, 1289 /* INDR_ROW */ {IND, IND, IND, MDEF, IND, CIND, MIND, CYCLE }, 1290 /* WARN_ROW */ {MWARN, WARN, WARN, WARN, WARN, WARN, WARN, NOACT }, 1291 /* SET_ROW */ {SET, SET, SET, SET, SET, SET, CYCLE, CYCLE } 1292}; 1293 1294/* Most of the entries in the LINK_ACTION table are straightforward, 1295 but a few are somewhat subtle. 1296 1297 A reference to an indirect symbol (UNDEF_ROW/indr or 1298 UNDEFW_ROW/indr) is counted as a reference both to the indirect 1299 symbol and to the symbol the indirect symbol points to. 1300 1301 A reference to a warning symbol (UNDEF_ROW/warn or UNDEFW_ROW/warn) 1302 causes the warning to be issued. 1303 1304 A common definition of an indirect symbol (COMMON_ROW/indr) is 1305 treated as a multiple definition error. Likewise for an indirect 1306 definition of a common symbol (INDR_ROW/com). 1307 1308 An indirect definition of a warning (INDR_ROW/warn) does not cause 1309 the warning to be issued. 1310 1311 If a warning is created for an indirect symbol (WARN_ROW/indr) no 1312 warning is created for the symbol the indirect symbol points to. 1313 1314 Adding an entry to a set does not count as a reference to a set, 1315 and no warning is issued (SET_ROW/warn). */ 1316 1317/* Return the BFD in which a hash entry has been defined, if known. */ 1318 1319static bfd * 1320hash_entry_bfd (struct bfd_link_hash_entry *h) 1321{ 1322 while (h->type == bfd_link_hash_warning) 1323 h = h->u.i.link; 1324 switch (h->type) 1325 { 1326 default: 1327 return NULL; 1328 case bfd_link_hash_undefined: 1329 case bfd_link_hash_undefweak: 1330 return h->u.undef.abfd; 1331 case bfd_link_hash_defined: 1332 case bfd_link_hash_defweak: 1333 return h->u.def.section->owner; 1334 case bfd_link_hash_common: 1335 return h->u.c.p->section->owner; 1336 } 1337 /*NOTREACHED*/ 1338} 1339 1340/* Add a symbol to the global hash table. 1341 ABFD is the BFD the symbol comes from. 1342 NAME is the name of the symbol. 1343 FLAGS is the BSF_* bits associated with the symbol. 1344 SECTION is the section in which the symbol is defined; this may be 1345 bfd_und_section_ptr or bfd_com_section_ptr. 1346 VALUE is the value of the symbol, relative to the section. 1347 STRING is used for either an indirect symbol, in which case it is 1348 the name of the symbol to indirect to, or a warning symbol, in 1349 which case it is the warning string. 1350 COPY is TRUE if NAME or STRING must be copied into locally 1351 allocated memory if they need to be saved. 1352 COLLECT is TRUE if we should automatically collect gcc constructor 1353 or destructor names as collect2 does. 1354 HASHP, if not NULL, is a place to store the created hash table 1355 entry; if *HASHP is not NULL, the caller has already looked up 1356 the hash table entry, and stored it in *HASHP. */ 1357 1358bfd_boolean 1359_bfd_generic_link_add_one_symbol (struct bfd_link_info *info, 1360 bfd *abfd, 1361 const char *name, 1362 flagword flags, 1363 asection *section, 1364 bfd_vma value, 1365 const char *string, 1366 bfd_boolean copy, 1367 bfd_boolean collect, 1368 struct bfd_link_hash_entry **hashp) 1369{ 1370 enum link_row row; 1371 struct bfd_link_hash_entry *h; 1372 struct bfd_link_hash_entry *inh = NULL; 1373 bfd_boolean cycle; 1374 1375 BFD_ASSERT (section != NULL); 1376 1377 if (bfd_is_ind_section (section) 1378 || (flags & BSF_INDIRECT) != 0) 1379 { 1380 row = INDR_ROW; 1381 /* Create the indirect symbol here. This is for the benefit of 1382 the plugin "notice" function. 1383 STRING is the name of the symbol we want to indirect to. */ 1384 inh = bfd_wrapped_link_hash_lookup (abfd, info, string, TRUE, 1385 copy, FALSE); 1386 if (inh == NULL) 1387 return FALSE; 1388 } 1389 else if ((flags & BSF_WARNING) != 0) 1390 row = WARN_ROW; 1391 else if ((flags & BSF_CONSTRUCTOR) != 0) 1392 row = SET_ROW; 1393 else if (bfd_is_und_section (section)) 1394 { 1395 if ((flags & BSF_WEAK) != 0) 1396 row = UNDEFW_ROW; 1397 else 1398 row = UNDEF_ROW; 1399 } 1400 else if ((flags & BSF_WEAK) != 0) 1401 row = DEFW_ROW; 1402 else if (bfd_is_com_section (section)) 1403 { 1404 row = COMMON_ROW; 1405 if (!bfd_link_relocatable (info) 1406 && strcmp (name, "__gnu_lto_slim") == 0) 1407 _bfd_error_handler 1408 (_("%s: plugin needed to handle lto object"), 1409 bfd_get_filename (abfd)); 1410 } 1411 else 1412 row = DEF_ROW; 1413 1414 if (hashp != NULL && *hashp != NULL) 1415 h = *hashp; 1416 else 1417 { 1418 if (row == UNDEF_ROW || row == UNDEFW_ROW) 1419 h = bfd_wrapped_link_hash_lookup (abfd, info, name, TRUE, copy, FALSE); 1420 else 1421 h = bfd_link_hash_lookup (info->hash, name, TRUE, copy, FALSE); 1422 if (h == NULL) 1423 { 1424 if (hashp != NULL) 1425 *hashp = NULL; 1426 return FALSE; 1427 } 1428 } 1429 1430 if (info->notice_all 1431 || (info->notice_hash != NULL 1432 && bfd_hash_lookup (info->notice_hash, name, FALSE, FALSE) != NULL)) 1433 { 1434 if (! (*info->callbacks->notice) (info, h, inh, 1435 abfd, section, value, flags)) 1436 return FALSE; 1437 } 1438 1439 if (hashp != NULL) 1440 *hashp = h; 1441 1442 do 1443 { 1444 enum link_action action; 1445 1446 cycle = FALSE; 1447 action = link_action[(int) row][(int) h->type]; 1448 switch (action) 1449 { 1450 case FAIL: 1451 abort (); 1452 1453 case NOACT: 1454 /* Do nothing. */ 1455 break; 1456 1457 case UND: 1458 /* Make a new undefined symbol. */ 1459 h->type = bfd_link_hash_undefined; 1460 h->u.undef.abfd = abfd; 1461 bfd_link_add_undef (info->hash, h); 1462 break; 1463 1464 case WEAK: 1465 /* Make a new weak undefined symbol. */ 1466 h->type = bfd_link_hash_undefweak; 1467 h->u.undef.abfd = abfd; 1468 break; 1469 1470 case CDEF: 1471 /* We have found a definition for a symbol which was 1472 previously common. */ 1473 BFD_ASSERT (h->type == bfd_link_hash_common); 1474 (*info->callbacks->multiple_common) (info, h, abfd, 1475 bfd_link_hash_defined, 0); 1476 /* Fall through. */ 1477 case DEF: 1478 case DEFW: 1479 { 1480 enum bfd_link_hash_type oldtype; 1481 1482 /* Define a symbol. */ 1483 oldtype = h->type; 1484 if (action == DEFW) 1485 h->type = bfd_link_hash_defweak; 1486 else 1487 h->type = bfd_link_hash_defined; 1488 h->u.def.section = section; 1489 h->u.def.value = value; 1490 h->linker_def = 0; 1491 1492 /* If we have been asked to, we act like collect2 and 1493 identify all functions that might be global 1494 constructors and destructors and pass them up in a 1495 callback. We only do this for certain object file 1496 types, since many object file types can handle this 1497 automatically. */ 1498 if (collect && name[0] == '_') 1499 { 1500 const char *s; 1501 1502 /* A constructor or destructor name starts like this: 1503 _+GLOBAL_[_.$][ID][_.$] where the first [_.$] and 1504 the second are the same character (we accept any 1505 character there, in case a new object file format 1506 comes along with even worse naming restrictions). */ 1507 1508#define CONS_PREFIX "GLOBAL_" 1509#define CONS_PREFIX_LEN (sizeof CONS_PREFIX - 1) 1510 1511 s = name + 1; 1512 while (*s == '_') 1513 ++s; 1514 if (s[0] == 'G' && CONST_STRNEQ (s, CONS_PREFIX)) 1515 { 1516 char c; 1517 1518 c = s[CONS_PREFIX_LEN + 1]; 1519 if ((c == 'I' || c == 'D') 1520 && s[CONS_PREFIX_LEN] == s[CONS_PREFIX_LEN + 2]) 1521 { 1522 /* If this is a definition of a symbol which 1523 was previously weakly defined, we are in 1524 trouble. We have already added a 1525 constructor entry for the weak defined 1526 symbol, and now we are trying to add one 1527 for the new symbol. Fortunately, this case 1528 should never arise in practice. */ 1529 if (oldtype == bfd_link_hash_defweak) 1530 abort (); 1531 1532 (*info->callbacks->constructor) (info, c == 'I', 1533 h->root.string, abfd, 1534 section, value); 1535 } 1536 } 1537 } 1538 } 1539 1540 break; 1541 1542 case COM: 1543 /* We have found a common definition for a symbol. */ 1544 if (h->type == bfd_link_hash_new) 1545 bfd_link_add_undef (info->hash, h); 1546 h->type = bfd_link_hash_common; 1547 h->u.c.p = (struct bfd_link_hash_common_entry *) 1548 bfd_hash_allocate (&info->hash->table, 1549 sizeof (struct bfd_link_hash_common_entry)); 1550 if (h->u.c.p == NULL) 1551 return FALSE; 1552 1553 h->u.c.size = value; 1554 1555 /* Select a default alignment based on the size. This may 1556 be overridden by the caller. */ 1557 { 1558 unsigned int power; 1559 1560 power = bfd_log2 (value); 1561 if (power > 4) 1562 power = 4; 1563 h->u.c.p->alignment_power = power; 1564 } 1565 1566 /* The section of a common symbol is only used if the common 1567 symbol is actually allocated. It basically provides a 1568 hook for the linker script to decide which output section 1569 the common symbols should be put in. In most cases, the 1570 section of a common symbol will be bfd_com_section_ptr, 1571 the code here will choose a common symbol section named 1572 "COMMON", and the linker script will contain *(COMMON) in 1573 the appropriate place. A few targets use separate common 1574 sections for small symbols, and they require special 1575 handling. */ 1576 if (section == bfd_com_section_ptr) 1577 { 1578 h->u.c.p->section = bfd_make_section_old_way (abfd, "COMMON"); 1579 h->u.c.p->section->flags |= SEC_ALLOC; 1580 } 1581 else if (section->owner != abfd) 1582 { 1583 h->u.c.p->section = bfd_make_section_old_way (abfd, 1584 section->name); 1585 h->u.c.p->section->flags |= SEC_ALLOC; 1586 } 1587 else 1588 h->u.c.p->section = section; 1589 h->linker_def = 0; 1590 break; 1591 1592 case REF: 1593 /* A reference to a defined symbol. */ 1594 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1595 h->u.undef.next = h; 1596 break; 1597 1598 case BIG: 1599 /* We have found a common definition for a symbol which 1600 already had a common definition. Use the maximum of the 1601 two sizes, and use the section required by the larger symbol. */ 1602 BFD_ASSERT (h->type == bfd_link_hash_common); 1603 (*info->callbacks->multiple_common) (info, h, abfd, 1604 bfd_link_hash_common, value); 1605 if (value > h->u.c.size) 1606 { 1607 unsigned int power; 1608 1609 h->u.c.size = value; 1610 1611 /* Select a default alignment based on the size. This may 1612 be overridden by the caller. */ 1613 power = bfd_log2 (value); 1614 if (power > 4) 1615 power = 4; 1616 h->u.c.p->alignment_power = power; 1617 1618 /* Some systems have special treatment for small commons, 1619 hence we want to select the section used by the larger 1620 symbol. This makes sure the symbol does not go in a 1621 small common section if it is now too large. */ 1622 if (section == bfd_com_section_ptr) 1623 { 1624 h->u.c.p->section 1625 = bfd_make_section_old_way (abfd, "COMMON"); 1626 h->u.c.p->section->flags |= SEC_ALLOC; 1627 } 1628 else if (section->owner != abfd) 1629 { 1630 h->u.c.p->section 1631 = bfd_make_section_old_way (abfd, section->name); 1632 h->u.c.p->section->flags |= SEC_ALLOC; 1633 } 1634 else 1635 h->u.c.p->section = section; 1636 } 1637 break; 1638 1639 case CREF: 1640 /* We have found a common definition for a symbol which 1641 was already defined. */ 1642 (*info->callbacks->multiple_common) (info, h, abfd, 1643 bfd_link_hash_common, value); 1644 break; 1645 1646 case MIND: 1647 /* Multiple indirect symbols. This is OK if they both point 1648 to the same symbol. */ 1649 if (strcmp (h->u.i.link->root.string, string) == 0) 1650 break; 1651 /* Fall through. */ 1652 case MDEF: 1653 /* Handle a multiple definition. */ 1654 (*info->callbacks->multiple_definition) (info, h, 1655 abfd, section, value); 1656 break; 1657 1658 case CIND: 1659 /* Create an indirect symbol from an existing common symbol. */ 1660 BFD_ASSERT (h->type == bfd_link_hash_common); 1661 (*info->callbacks->multiple_common) (info, h, abfd, 1662 bfd_link_hash_indirect, 0); 1663 /* Fall through. */ 1664 case IND: 1665 if (inh->type == bfd_link_hash_indirect 1666 && inh->u.i.link == h) 1667 { 1668 _bfd_error_handler 1669 /* xgettext:c-format */ 1670 (_("%B: indirect symbol `%s' to `%s' is a loop"), 1671 abfd, name, string); 1672 bfd_set_error (bfd_error_invalid_operation); 1673 return FALSE; 1674 } 1675 if (inh->type == bfd_link_hash_new) 1676 { 1677 inh->type = bfd_link_hash_undefined; 1678 inh->u.undef.abfd = abfd; 1679 bfd_link_add_undef (info->hash, inh); 1680 } 1681 1682 /* If the indirect symbol has been referenced, we need to 1683 push the reference down to the symbol we are referencing. */ 1684 if (h->type != bfd_link_hash_new) 1685 { 1686 /* ??? If inh->type == bfd_link_hash_undefweak this 1687 converts inh to bfd_link_hash_undefined. */ 1688 row = UNDEF_ROW; 1689 cycle = TRUE; 1690 } 1691 1692 h->type = bfd_link_hash_indirect; 1693 h->u.i.link = inh; 1694 /* Not setting h = h->u.i.link here means that when cycle is 1695 set above we'll always go to REFC, and then cycle again 1696 to the indirected symbol. This means that any successful 1697 change of an existing symbol to indirect counts as a 1698 reference. ??? That may not be correct when the existing 1699 symbol was defweak. */ 1700 break; 1701 1702 case SET: 1703 /* Add an entry to a set. */ 1704 (*info->callbacks->add_to_set) (info, h, BFD_RELOC_CTOR, 1705 abfd, section, value); 1706 break; 1707 1708 case WARNC: 1709 /* Issue a warning and cycle, except when the reference is 1710 in LTO IR. */ 1711 if (h->u.i.warning != NULL 1712 && (abfd->flags & BFD_PLUGIN) == 0) 1713 { 1714 (*info->callbacks->warning) (info, h->u.i.warning, 1715 h->root.string, abfd, NULL, 0); 1716 /* Only issue a warning once. */ 1717 h->u.i.warning = NULL; 1718 } 1719 /* Fall through. */ 1720 case CYCLE: 1721 /* Try again with the referenced symbol. */ 1722 h = h->u.i.link; 1723 cycle = TRUE; 1724 break; 1725 1726 case REFC: 1727 /* A reference to an indirect symbol. */ 1728 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1729 h->u.undef.next = h; 1730 h = h->u.i.link; 1731 cycle = TRUE; 1732 break; 1733 1734 case WARN: 1735 /* Warn if this symbol has been referenced already from non-IR, 1736 otherwise add a warning. */ 1737 if ((!info->lto_plugin_active 1738 && (h->u.undef.next != NULL || info->hash->undefs_tail == h)) 1739 || h->non_ir_ref) 1740 { 1741 (*info->callbacks->warning) (info, string, h->root.string, 1742 hash_entry_bfd (h), NULL, 0); 1743 break; 1744 } 1745 /* Fall through. */ 1746 case MWARN: 1747 /* Make a warning symbol. */ 1748 { 1749 struct bfd_link_hash_entry *sub; 1750 1751 /* STRING is the warning to give. */ 1752 sub = ((struct bfd_link_hash_entry *) 1753 ((*info->hash->table.newfunc) 1754 (NULL, &info->hash->table, h->root.string))); 1755 if (sub == NULL) 1756 return FALSE; 1757 *sub = *h; 1758 sub->type = bfd_link_hash_warning; 1759 sub->u.i.link = h; 1760 if (! copy) 1761 sub->u.i.warning = string; 1762 else 1763 { 1764 char *w; 1765 size_t len = strlen (string) + 1; 1766 1767 w = (char *) bfd_hash_allocate (&info->hash->table, len); 1768 if (w == NULL) 1769 return FALSE; 1770 memcpy (w, string, len); 1771 sub->u.i.warning = w; 1772 } 1773 1774 bfd_hash_replace (&info->hash->table, 1775 (struct bfd_hash_entry *) h, 1776 (struct bfd_hash_entry *) sub); 1777 if (hashp != NULL) 1778 *hashp = sub; 1779 } 1780 break; 1781 } 1782 } 1783 while (cycle); 1784 1785 return TRUE; 1786} 1787 1788/* Generic final link routine. */ 1789 1790bfd_boolean 1791_bfd_generic_final_link (bfd *abfd, struct bfd_link_info *info) 1792{ 1793 bfd *sub; 1794 asection *o; 1795 struct bfd_link_order *p; 1796 size_t outsymalloc; 1797 struct generic_write_global_symbol_info wginfo; 1798 1799 bfd_get_outsymbols (abfd) = NULL; 1800 bfd_get_symcount (abfd) = 0; 1801 outsymalloc = 0; 1802 1803 /* Mark all sections which will be included in the output file. */ 1804 for (o = abfd->sections; o != NULL; o = o->next) 1805 for (p = o->map_head.link_order; p != NULL; p = p->next) 1806 if (p->type == bfd_indirect_link_order) 1807 p->u.indirect.section->linker_mark = TRUE; 1808 1809 /* Build the output symbol table. */ 1810 for (sub = info->input_bfds; sub != NULL; sub = sub->link.next) 1811 if (! _bfd_generic_link_output_symbols (abfd, sub, info, &outsymalloc)) 1812 return FALSE; 1813 1814 /* Accumulate the global symbols. */ 1815 wginfo.info = info; 1816 wginfo.output_bfd = abfd; 1817 wginfo.psymalloc = &outsymalloc; 1818 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info), 1819 _bfd_generic_link_write_global_symbol, 1820 &wginfo); 1821 1822 /* Make sure we have a trailing NULL pointer on OUTSYMBOLS. We 1823 shouldn't really need one, since we have SYMCOUNT, but some old 1824 code still expects one. */ 1825 if (! generic_add_output_symbol (abfd, &outsymalloc, NULL)) 1826 return FALSE; 1827 1828 if (bfd_link_relocatable (info)) 1829 { 1830 /* Allocate space for the output relocs for each section. */ 1831 for (o = abfd->sections; o != NULL; o = o->next) 1832 { 1833 o->reloc_count = 0; 1834 for (p = o->map_head.link_order; p != NULL; p = p->next) 1835 { 1836 if (p->type == bfd_section_reloc_link_order 1837 || p->type == bfd_symbol_reloc_link_order) 1838 ++o->reloc_count; 1839 else if (p->type == bfd_indirect_link_order) 1840 { 1841 asection *input_section; 1842 bfd *input_bfd; 1843 long relsize; 1844 arelent **relocs; 1845 asymbol **symbols; 1846 long reloc_count; 1847 1848 input_section = p->u.indirect.section; 1849 input_bfd = input_section->owner; 1850 relsize = bfd_get_reloc_upper_bound (input_bfd, 1851 input_section); 1852 if (relsize < 0) 1853 return FALSE; 1854 relocs = (arelent **) bfd_malloc (relsize); 1855 if (!relocs && relsize != 0) 1856 return FALSE; 1857 symbols = _bfd_generic_link_get_symbols (input_bfd); 1858 reloc_count = bfd_canonicalize_reloc (input_bfd, 1859 input_section, 1860 relocs, 1861 symbols); 1862 free (relocs); 1863 if (reloc_count < 0) 1864 return FALSE; 1865 BFD_ASSERT ((unsigned long) reloc_count 1866 == input_section->reloc_count); 1867 o->reloc_count += reloc_count; 1868 } 1869 } 1870 if (o->reloc_count > 0) 1871 { 1872 bfd_size_type amt; 1873 1874 amt = o->reloc_count; 1875 amt *= sizeof (arelent *); 1876 o->orelocation = (struct reloc_cache_entry **) bfd_alloc (abfd, amt); 1877 if (!o->orelocation) 1878 return FALSE; 1879 o->flags |= SEC_RELOC; 1880 /* Reset the count so that it can be used as an index 1881 when putting in the output relocs. */ 1882 o->reloc_count = 0; 1883 } 1884 } 1885 } 1886 1887 /* Handle all the link order information for the sections. */ 1888 for (o = abfd->sections; o != NULL; o = o->next) 1889 { 1890 for (p = o->map_head.link_order; p != NULL; p = p->next) 1891 { 1892 switch (p->type) 1893 { 1894 case bfd_section_reloc_link_order: 1895 case bfd_symbol_reloc_link_order: 1896 if (! _bfd_generic_reloc_link_order (abfd, info, o, p)) 1897 return FALSE; 1898 break; 1899 case bfd_indirect_link_order: 1900 if (! default_indirect_link_order (abfd, info, o, p, TRUE)) 1901 return FALSE; 1902 break; 1903 default: 1904 if (! _bfd_default_link_order (abfd, info, o, p)) 1905 return FALSE; 1906 break; 1907 } 1908 } 1909 } 1910 1911 return TRUE; 1912} 1913 1914/* Add an output symbol to the output BFD. */ 1915 1916static bfd_boolean 1917generic_add_output_symbol (bfd *output_bfd, size_t *psymalloc, asymbol *sym) 1918{ 1919 if (bfd_get_symcount (output_bfd) >= *psymalloc) 1920 { 1921 asymbol **newsyms; 1922 bfd_size_type amt; 1923 1924 if (*psymalloc == 0) 1925 *psymalloc = 124; 1926 else 1927 *psymalloc *= 2; 1928 amt = *psymalloc; 1929 amt *= sizeof (asymbol *); 1930 newsyms = (asymbol **) bfd_realloc (bfd_get_outsymbols (output_bfd), amt); 1931 if (newsyms == NULL) 1932 return FALSE; 1933 bfd_get_outsymbols (output_bfd) = newsyms; 1934 } 1935 1936 bfd_get_outsymbols (output_bfd) [bfd_get_symcount (output_bfd)] = sym; 1937 if (sym != NULL) 1938 ++ bfd_get_symcount (output_bfd); 1939 1940 return TRUE; 1941} 1942 1943/* Handle the symbols for an input BFD. */ 1944 1945bfd_boolean 1946_bfd_generic_link_output_symbols (bfd *output_bfd, 1947 bfd *input_bfd, 1948 struct bfd_link_info *info, 1949 size_t *psymalloc) 1950{ 1951 asymbol **sym_ptr; 1952 asymbol **sym_end; 1953 1954 if (!bfd_generic_link_read_symbols (input_bfd)) 1955 return FALSE; 1956 1957 /* Create a filename symbol if we are supposed to. */ 1958 if (info->create_object_symbols_section != NULL) 1959 { 1960 asection *sec; 1961 1962 for (sec = input_bfd->sections; sec != NULL; sec = sec->next) 1963 { 1964 if (sec->output_section == info->create_object_symbols_section) 1965 { 1966 asymbol *newsym; 1967 1968 newsym = bfd_make_empty_symbol (input_bfd); 1969 if (!newsym) 1970 return FALSE; 1971 newsym->name = input_bfd->filename; 1972 newsym->value = 0; 1973 newsym->flags = BSF_LOCAL | BSF_FILE; 1974 newsym->section = sec; 1975 1976 if (! generic_add_output_symbol (output_bfd, psymalloc, 1977 newsym)) 1978 return FALSE; 1979 1980 break; 1981 } 1982 } 1983 } 1984 1985 /* Adjust the values of the globally visible symbols, and write out 1986 local symbols. */ 1987 sym_ptr = _bfd_generic_link_get_symbols (input_bfd); 1988 sym_end = sym_ptr + _bfd_generic_link_get_symcount (input_bfd); 1989 for (; sym_ptr < sym_end; sym_ptr++) 1990 { 1991 asymbol *sym; 1992 struct generic_link_hash_entry *h; 1993 bfd_boolean output; 1994 1995 h = NULL; 1996 sym = *sym_ptr; 1997 if ((sym->flags & (BSF_INDIRECT 1998 | BSF_WARNING 1999 | BSF_GLOBAL 2000 | BSF_CONSTRUCTOR 2001 | BSF_WEAK)) != 0 2002 || bfd_is_und_section (bfd_get_section (sym)) 2003 || bfd_is_com_section (bfd_get_section (sym)) 2004 || bfd_is_ind_section (bfd_get_section (sym))) 2005 { 2006 if (sym->udata.p != NULL) 2007 h = (struct generic_link_hash_entry *) sym->udata.p; 2008 else if ((sym->flags & BSF_CONSTRUCTOR) != 0) 2009 { 2010 /* This case normally means that the main linker code 2011 deliberately ignored this constructor symbol. We 2012 should just pass it through. This will screw up if 2013 the constructor symbol is from a different, 2014 non-generic, object file format, but the case will 2015 only arise when linking with -r, which will probably 2016 fail anyhow, since there will be no way to represent 2017 the relocs in the output format being used. */ 2018 h = NULL; 2019 } 2020 else if (bfd_is_und_section (bfd_get_section (sym))) 2021 h = ((struct generic_link_hash_entry *) 2022 bfd_wrapped_link_hash_lookup (output_bfd, info, 2023 bfd_asymbol_name (sym), 2024 FALSE, FALSE, TRUE)); 2025 else 2026 h = _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info), 2027 bfd_asymbol_name (sym), 2028 FALSE, FALSE, TRUE); 2029 2030 if (h != NULL) 2031 { 2032 /* Force all references to this symbol to point to 2033 the same area in memory. It is possible that 2034 this routine will be called with a hash table 2035 other than a generic hash table, so we double 2036 check that. */ 2037 if (info->output_bfd->xvec == input_bfd->xvec) 2038 { 2039 if (h->sym != NULL) 2040 *sym_ptr = sym = h->sym; 2041 } 2042 2043 switch (h->root.type) 2044 { 2045 default: 2046 case bfd_link_hash_new: 2047 abort (); 2048 case bfd_link_hash_undefined: 2049 break; 2050 case bfd_link_hash_undefweak: 2051 sym->flags |= BSF_WEAK; 2052 break; 2053 case bfd_link_hash_indirect: 2054 h = (struct generic_link_hash_entry *) h->root.u.i.link; 2055 /* fall through */ 2056 case bfd_link_hash_defined: 2057 sym->flags |= BSF_GLOBAL; 2058 sym->flags &=~ (BSF_WEAK | BSF_CONSTRUCTOR); 2059 sym->value = h->root.u.def.value; 2060 sym->section = h->root.u.def.section; 2061 break; 2062 case bfd_link_hash_defweak: 2063 sym->flags |= BSF_WEAK; 2064 sym->flags &=~ BSF_CONSTRUCTOR; 2065 sym->value = h->root.u.def.value; 2066 sym->section = h->root.u.def.section; 2067 break; 2068 case bfd_link_hash_common: 2069 sym->value = h->root.u.c.size; 2070 sym->flags |= BSF_GLOBAL; 2071 if (! bfd_is_com_section (sym->section)) 2072 { 2073 BFD_ASSERT (bfd_is_und_section (sym->section)); 2074 sym->section = bfd_com_section_ptr; 2075 } 2076 /* We do not set the section of the symbol to 2077 h->root.u.c.p->section. That value was saved so 2078 that we would know where to allocate the symbol 2079 if it was defined. In this case the type is 2080 still bfd_link_hash_common, so we did not define 2081 it, so we do not want to use that section. */ 2082 break; 2083 } 2084 } 2085 } 2086 2087 /* This switch is straight from the old code in 2088 write_file_locals in ldsym.c. */ 2089 if (info->strip == strip_all 2090 || (info->strip == strip_some 2091 && bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym), 2092 FALSE, FALSE) == NULL)) 2093 output = FALSE; 2094 else if ((sym->flags & (BSF_GLOBAL | BSF_WEAK | BSF_GNU_UNIQUE)) != 0) 2095 { 2096 /* If this symbol is marked as occurring now, rather 2097 than at the end, output it now. This is used for 2098 COFF C_EXT FCN symbols. FIXME: There must be a 2099 better way. */ 2100 if (bfd_asymbol_bfd (sym) == input_bfd 2101 && (sym->flags & BSF_NOT_AT_END) != 0) 2102 output = TRUE; 2103 else 2104 output = FALSE; 2105 } 2106 else if (bfd_is_ind_section (sym->section)) 2107 output = FALSE; 2108 else if ((sym->flags & BSF_DEBUGGING) != 0) 2109 { 2110 if (info->strip == strip_none) 2111 output = TRUE; 2112 else 2113 output = FALSE; 2114 } 2115 else if (bfd_is_und_section (sym->section) 2116 || bfd_is_com_section (sym->section)) 2117 output = FALSE; 2118 else if ((sym->flags & BSF_LOCAL) != 0) 2119 { 2120 if ((sym->flags & BSF_WARNING) != 0) 2121 output = FALSE; 2122 else 2123 { 2124 switch (info->discard) 2125 { 2126 default: 2127 case discard_all: 2128 output = FALSE; 2129 break; 2130 case discard_sec_merge: 2131 output = TRUE; 2132 if (bfd_link_relocatable (info) 2133 || ! (sym->section->flags & SEC_MERGE)) 2134 break; 2135 /* FALLTHROUGH */ 2136 case discard_l: 2137 if (bfd_is_local_label (input_bfd, sym)) 2138 output = FALSE; 2139 else 2140 output = TRUE; 2141 break; 2142 case discard_none: 2143 output = TRUE; 2144 break; 2145 } 2146 } 2147 } 2148 else if ((sym->flags & BSF_CONSTRUCTOR)) 2149 { 2150 if (info->strip != strip_all) 2151 output = TRUE; 2152 else 2153 output = FALSE; 2154 } 2155 else if (sym->flags == 0 2156 && (sym->section->owner->flags & BFD_PLUGIN) != 0) 2157 /* LTO doesn't set symbol information. We get here with the 2158 generic linker for a symbol that was "common" but no longer 2159 needs to be global. */ 2160 output = FALSE; 2161 else 2162 abort (); 2163 2164 /* If this symbol is in a section which is not being included 2165 in the output file, then we don't want to output the 2166 symbol. */ 2167 if (!bfd_is_abs_section (sym->section) 2168 && bfd_section_removed_from_list (output_bfd, 2169 sym->section->output_section)) 2170 output = FALSE; 2171 2172 if (output) 2173 { 2174 if (! generic_add_output_symbol (output_bfd, psymalloc, sym)) 2175 return FALSE; 2176 if (h != NULL) 2177 h->written = TRUE; 2178 } 2179 } 2180 2181 return TRUE; 2182} 2183 2184/* Set the section and value of a generic BFD symbol based on a linker 2185 hash table entry. */ 2186 2187static void 2188set_symbol_from_hash (asymbol *sym, struct bfd_link_hash_entry *h) 2189{ 2190 switch (h->type) 2191 { 2192 default: 2193 abort (); 2194 break; 2195 case bfd_link_hash_new: 2196 /* This can happen when a constructor symbol is seen but we are 2197 not building constructors. */ 2198 if (sym->section != NULL) 2199 { 2200 BFD_ASSERT ((sym->flags & BSF_CONSTRUCTOR) != 0); 2201 } 2202 else 2203 { 2204 sym->flags |= BSF_CONSTRUCTOR; 2205 sym->section = bfd_abs_section_ptr; 2206 sym->value = 0; 2207 } 2208 break; 2209 case bfd_link_hash_undefined: 2210 sym->section = bfd_und_section_ptr; 2211 sym->value = 0; 2212 break; 2213 case bfd_link_hash_undefweak: 2214 sym->section = bfd_und_section_ptr; 2215 sym->value = 0; 2216 sym->flags |= BSF_WEAK; 2217 break; 2218 case bfd_link_hash_defined: 2219 sym->section = h->u.def.section; 2220 sym->value = h->u.def.value; 2221 break; 2222 case bfd_link_hash_defweak: 2223 sym->flags |= BSF_WEAK; 2224 sym->section = h->u.def.section; 2225 sym->value = h->u.def.value; 2226 break; 2227 case bfd_link_hash_common: 2228 sym->value = h->u.c.size; 2229 if (sym->section == NULL) 2230 sym->section = bfd_com_section_ptr; 2231 else if (! bfd_is_com_section (sym->section)) 2232 { 2233 BFD_ASSERT (bfd_is_und_section (sym->section)); 2234 sym->section = bfd_com_section_ptr; 2235 } 2236 /* Do not set the section; see _bfd_generic_link_output_symbols. */ 2237 break; 2238 case bfd_link_hash_indirect: 2239 case bfd_link_hash_warning: 2240 /* FIXME: What should we do here? */ 2241 break; 2242 } 2243} 2244 2245/* Write out a global symbol, if it hasn't already been written out. 2246 This is called for each symbol in the hash table. */ 2247 2248bfd_boolean 2249_bfd_generic_link_write_global_symbol (struct generic_link_hash_entry *h, 2250 void *data) 2251{ 2252 struct generic_write_global_symbol_info *wginfo = 2253 (struct generic_write_global_symbol_info *) data; 2254 asymbol *sym; 2255 2256 if (h->written) 2257 return TRUE; 2258 2259 h->written = TRUE; 2260 2261 if (wginfo->info->strip == strip_all 2262 || (wginfo->info->strip == strip_some 2263 && bfd_hash_lookup (wginfo->info->keep_hash, h->root.root.string, 2264 FALSE, FALSE) == NULL)) 2265 return TRUE; 2266 2267 if (h->sym != NULL) 2268 sym = h->sym; 2269 else 2270 { 2271 sym = bfd_make_empty_symbol (wginfo->output_bfd); 2272 if (!sym) 2273 return FALSE; 2274 sym->name = h->root.root.string; 2275 sym->flags = 0; 2276 } 2277 2278 set_symbol_from_hash (sym, &h->root); 2279 2280 sym->flags |= BSF_GLOBAL; 2281 2282 if (! generic_add_output_symbol (wginfo->output_bfd, wginfo->psymalloc, 2283 sym)) 2284 { 2285 /* FIXME: No way to return failure. */ 2286 abort (); 2287 } 2288 2289 return TRUE; 2290} 2291 2292/* Create a relocation. */ 2293 2294bfd_boolean 2295_bfd_generic_reloc_link_order (bfd *abfd, 2296 struct bfd_link_info *info, 2297 asection *sec, 2298 struct bfd_link_order *link_order) 2299{ 2300 arelent *r; 2301 2302 if (! bfd_link_relocatable (info)) 2303 abort (); 2304 if (sec->orelocation == NULL) 2305 abort (); 2306 2307 r = (arelent *) bfd_alloc (abfd, sizeof (arelent)); 2308 if (r == NULL) 2309 return FALSE; 2310 2311 r->address = link_order->offset; 2312 r->howto = bfd_reloc_type_lookup (abfd, link_order->u.reloc.p->reloc); 2313 if (r->howto == 0) 2314 { 2315 bfd_set_error (bfd_error_bad_value); 2316 return FALSE; 2317 } 2318 2319 /* Get the symbol to use for the relocation. */ 2320 if (link_order->type == bfd_section_reloc_link_order) 2321 r->sym_ptr_ptr = link_order->u.reloc.p->u.section->symbol_ptr_ptr; 2322 else 2323 { 2324 struct generic_link_hash_entry *h; 2325 2326 h = ((struct generic_link_hash_entry *) 2327 bfd_wrapped_link_hash_lookup (abfd, info, 2328 link_order->u.reloc.p->u.name, 2329 FALSE, FALSE, TRUE)); 2330 if (h == NULL 2331 || ! h->written) 2332 { 2333 (*info->callbacks->unattached_reloc) 2334 (info, link_order->u.reloc.p->u.name, NULL, NULL, 0); 2335 bfd_set_error (bfd_error_bad_value); 2336 return FALSE; 2337 } 2338 r->sym_ptr_ptr = &h->sym; 2339 } 2340 2341 /* If this is an inplace reloc, write the addend to the object file. 2342 Otherwise, store it in the reloc addend. */ 2343 if (! r->howto->partial_inplace) 2344 r->addend = link_order->u.reloc.p->addend; 2345 else 2346 { 2347 bfd_size_type size; 2348 bfd_reloc_status_type rstat; 2349 bfd_byte *buf; 2350 bfd_boolean ok; 2351 file_ptr loc; 2352 2353 size = bfd_get_reloc_size (r->howto); 2354 buf = (bfd_byte *) bfd_zmalloc (size); 2355 if (buf == NULL && size != 0) 2356 return FALSE; 2357 rstat = _bfd_relocate_contents (r->howto, abfd, 2358 (bfd_vma) link_order->u.reloc.p->addend, 2359 buf); 2360 switch (rstat) 2361 { 2362 case bfd_reloc_ok: 2363 break; 2364 default: 2365 case bfd_reloc_outofrange: 2366 abort (); 2367 case bfd_reloc_overflow: 2368 (*info->callbacks->reloc_overflow) 2369 (info, NULL, 2370 (link_order->type == bfd_section_reloc_link_order 2371 ? bfd_section_name (abfd, link_order->u.reloc.p->u.section) 2372 : link_order->u.reloc.p->u.name), 2373 r->howto->name, link_order->u.reloc.p->addend, 2374 NULL, NULL, 0); 2375 break; 2376 } 2377 loc = link_order->offset * bfd_octets_per_byte (abfd); 2378 ok = bfd_set_section_contents (abfd, sec, buf, loc, size); 2379 free (buf); 2380 if (! ok) 2381 return FALSE; 2382 2383 r->addend = 0; 2384 } 2385 2386 sec->orelocation[sec->reloc_count] = r; 2387 ++sec->reloc_count; 2388 2389 return TRUE; 2390} 2391 2392/* Allocate a new link_order for a section. */ 2393 2394struct bfd_link_order * 2395bfd_new_link_order (bfd *abfd, asection *section) 2396{ 2397 bfd_size_type amt = sizeof (struct bfd_link_order); 2398 struct bfd_link_order *new_lo; 2399 2400 new_lo = (struct bfd_link_order *) bfd_zalloc (abfd, amt); 2401 if (!new_lo) 2402 return NULL; 2403 2404 new_lo->type = bfd_undefined_link_order; 2405 2406 if (section->map_tail.link_order != NULL) 2407 section->map_tail.link_order->next = new_lo; 2408 else 2409 section->map_head.link_order = new_lo; 2410 section->map_tail.link_order = new_lo; 2411 2412 return new_lo; 2413} 2414 2415/* Default link order processing routine. Note that we can not handle 2416 the reloc_link_order types here, since they depend upon the details 2417 of how the particular backends generates relocs. */ 2418 2419bfd_boolean 2420_bfd_default_link_order (bfd *abfd, 2421 struct bfd_link_info *info, 2422 asection *sec, 2423 struct bfd_link_order *link_order) 2424{ 2425 switch (link_order->type) 2426 { 2427 case bfd_undefined_link_order: 2428 case bfd_section_reloc_link_order: 2429 case bfd_symbol_reloc_link_order: 2430 default: 2431 abort (); 2432 case bfd_indirect_link_order: 2433 return default_indirect_link_order (abfd, info, sec, link_order, 2434 FALSE); 2435 case bfd_data_link_order: 2436 return default_data_link_order (abfd, info, sec, link_order); 2437 } 2438} 2439 2440/* Default routine to handle a bfd_data_link_order. */ 2441 2442static bfd_boolean 2443default_data_link_order (bfd *abfd, 2444 struct bfd_link_info *info ATTRIBUTE_UNUSED, 2445 asection *sec, 2446 struct bfd_link_order *link_order) 2447{ 2448 bfd_size_type size; 2449 size_t fill_size; 2450 bfd_byte *fill; 2451 file_ptr loc; 2452 bfd_boolean result; 2453 2454 BFD_ASSERT ((sec->flags & SEC_HAS_CONTENTS) != 0); 2455 2456 size = link_order->size; 2457 if (size == 0) 2458 return TRUE; 2459 2460 fill = link_order->u.data.contents; 2461 fill_size = link_order->u.data.size; 2462 if (fill_size == 0) 2463 { 2464 fill = abfd->arch_info->fill (size, bfd_big_endian (abfd), 2465 (sec->flags & SEC_CODE) != 0); 2466 if (fill == NULL) 2467 return FALSE; 2468 } 2469 else if (fill_size < size) 2470 { 2471 bfd_byte *p; 2472 fill = (bfd_byte *) bfd_malloc (size); 2473 if (fill == NULL) 2474 return FALSE; 2475 p = fill; 2476 if (fill_size == 1) 2477 memset (p, (int) link_order->u.data.contents[0], (size_t) size); 2478 else 2479 { 2480 do 2481 { 2482 memcpy (p, link_order->u.data.contents, fill_size); 2483 p += fill_size; 2484 size -= fill_size; 2485 } 2486 while (size >= fill_size); 2487 if (size != 0) 2488 memcpy (p, link_order->u.data.contents, (size_t) size); 2489 size = link_order->size; 2490 } 2491 } 2492 2493 loc = link_order->offset * bfd_octets_per_byte (abfd); 2494 result = bfd_set_section_contents (abfd, sec, fill, loc, size); 2495 2496 if (fill != link_order->u.data.contents) 2497 free (fill); 2498 return result; 2499} 2500 2501/* Default routine to handle a bfd_indirect_link_order. */ 2502 2503static bfd_boolean 2504default_indirect_link_order (bfd *output_bfd, 2505 struct bfd_link_info *info, 2506 asection *output_section, 2507 struct bfd_link_order *link_order, 2508 bfd_boolean generic_linker) 2509{ 2510 asection *input_section; 2511 bfd *input_bfd; 2512 bfd_byte *contents = NULL; 2513 bfd_byte *new_contents; 2514 bfd_size_type sec_size; 2515 file_ptr loc; 2516 2517 BFD_ASSERT ((output_section->flags & SEC_HAS_CONTENTS) != 0); 2518 2519 input_section = link_order->u.indirect.section; 2520 input_bfd = input_section->owner; 2521 if (input_section->size == 0) 2522 return TRUE; 2523 2524 BFD_ASSERT (input_section->output_section == output_section); 2525 BFD_ASSERT (input_section->output_offset == link_order->offset); 2526 BFD_ASSERT (input_section->size == link_order->size); 2527 2528 if (bfd_link_relocatable (info) 2529 && input_section->reloc_count > 0 2530 && output_section->orelocation == NULL) 2531 { 2532 /* Space has not been allocated for the output relocations. 2533 This can happen when we are called by a specific backend 2534 because somebody is attempting to link together different 2535 types of object files. Handling this case correctly is 2536 difficult, and sometimes impossible. */ 2537 _bfd_error_handler 2538 /* xgettext:c-format */ 2539 (_("Attempt to do relocatable link with %s input and %s output"), 2540 bfd_get_target (input_bfd), bfd_get_target (output_bfd)); 2541 bfd_set_error (bfd_error_wrong_format); 2542 return FALSE; 2543 } 2544 2545 if (! generic_linker) 2546 { 2547 asymbol **sympp; 2548 asymbol **symppend; 2549 2550 /* Get the canonical symbols. The generic linker will always 2551 have retrieved them by this point, but we are being called by 2552 a specific linker, presumably because we are linking 2553 different types of object files together. */ 2554 if (!bfd_generic_link_read_symbols (input_bfd)) 2555 return FALSE; 2556 2557 /* Since we have been called by a specific linker, rather than 2558 the generic linker, the values of the symbols will not be 2559 right. They will be the values as seen in the input file, 2560 not the values of the final link. We need to fix them up 2561 before we can relocate the section. */ 2562 sympp = _bfd_generic_link_get_symbols (input_bfd); 2563 symppend = sympp + _bfd_generic_link_get_symcount (input_bfd); 2564 for (; sympp < symppend; sympp++) 2565 { 2566 asymbol *sym; 2567 struct bfd_link_hash_entry *h; 2568 2569 sym = *sympp; 2570 2571 if ((sym->flags & (BSF_INDIRECT 2572 | BSF_WARNING 2573 | BSF_GLOBAL 2574 | BSF_CONSTRUCTOR 2575 | BSF_WEAK)) != 0 2576 || bfd_is_und_section (bfd_get_section (sym)) 2577 || bfd_is_com_section (bfd_get_section (sym)) 2578 || bfd_is_ind_section (bfd_get_section (sym))) 2579 { 2580 /* sym->udata may have been set by 2581 generic_link_add_symbol_list. */ 2582 if (sym->udata.p != NULL) 2583 h = (struct bfd_link_hash_entry *) sym->udata.p; 2584 else if (bfd_is_und_section (bfd_get_section (sym))) 2585 h = bfd_wrapped_link_hash_lookup (output_bfd, info, 2586 bfd_asymbol_name (sym), 2587 FALSE, FALSE, TRUE); 2588 else 2589 h = bfd_link_hash_lookup (info->hash, 2590 bfd_asymbol_name (sym), 2591 FALSE, FALSE, TRUE); 2592 if (h != NULL) 2593 set_symbol_from_hash (sym, h); 2594 } 2595 } 2596 } 2597 2598 if ((output_section->flags & (SEC_GROUP | SEC_LINKER_CREATED)) == SEC_GROUP 2599 && input_section->size != 0) 2600 { 2601 /* Group section contents are set by bfd_elf_set_group_contents. */ 2602 if (!output_bfd->output_has_begun) 2603 { 2604 /* FIXME: This hack ensures bfd_elf_set_group_contents is called. */ 2605 if (!bfd_set_section_contents (output_bfd, output_section, "", 0, 1)) 2606 goto error_return; 2607 } 2608 new_contents = output_section->contents; 2609 BFD_ASSERT (new_contents != NULL); 2610 BFD_ASSERT (input_section->output_offset == 0); 2611 } 2612 else 2613 { 2614 /* Get and relocate the section contents. */ 2615 sec_size = (input_section->rawsize > input_section->size 2616 ? input_section->rawsize 2617 : input_section->size); 2618 contents = (bfd_byte *) bfd_malloc (sec_size); 2619 if (contents == NULL && sec_size != 0) 2620 goto error_return; 2621 new_contents = (bfd_get_relocated_section_contents 2622 (output_bfd, info, link_order, contents, 2623 bfd_link_relocatable (info), 2624 _bfd_generic_link_get_symbols (input_bfd))); 2625 if (!new_contents) 2626 goto error_return; 2627 } 2628 2629 /* Output the section contents. */ 2630 loc = input_section->output_offset * bfd_octets_per_byte (output_bfd); 2631 if (! bfd_set_section_contents (output_bfd, output_section, 2632 new_contents, loc, input_section->size)) 2633 goto error_return; 2634 2635 if (contents != NULL) 2636 free (contents); 2637 return TRUE; 2638 2639 error_return: 2640 if (contents != NULL) 2641 free (contents); 2642 return FALSE; 2643} 2644 2645/* A little routine to count the number of relocs in a link_order 2646 list. */ 2647 2648unsigned int 2649_bfd_count_link_order_relocs (struct bfd_link_order *link_order) 2650{ 2651 register unsigned int c; 2652 register struct bfd_link_order *l; 2653 2654 c = 0; 2655 for (l = link_order; l != NULL; l = l->next) 2656 { 2657 if (l->type == bfd_section_reloc_link_order 2658 || l->type == bfd_symbol_reloc_link_order) 2659 ++c; 2660 } 2661 2662 return c; 2663} 2664 2665/* 2666FUNCTION 2667 bfd_link_split_section 2668 2669SYNOPSIS 2670 bfd_boolean bfd_link_split_section (bfd *abfd, asection *sec); 2671 2672DESCRIPTION 2673 Return nonzero if @var{sec} should be split during a 2674 reloceatable or final link. 2675 2676.#define bfd_link_split_section(abfd, sec) \ 2677. BFD_SEND (abfd, _bfd_link_split_section, (abfd, sec)) 2678. 2679 2680*/ 2681 2682bfd_boolean 2683_bfd_generic_link_split_section (bfd *abfd ATTRIBUTE_UNUSED, 2684 asection *sec ATTRIBUTE_UNUSED) 2685{ 2686 return FALSE; 2687} 2688 2689/* 2690FUNCTION 2691 bfd_section_already_linked 2692 2693SYNOPSIS 2694 bfd_boolean bfd_section_already_linked (bfd *abfd, 2695 asection *sec, 2696 struct bfd_link_info *info); 2697 2698DESCRIPTION 2699 Check if @var{data} has been already linked during a reloceatable 2700 or final link. Return TRUE if it has. 2701 2702.#define bfd_section_already_linked(abfd, sec, info) \ 2703. BFD_SEND (abfd, _section_already_linked, (abfd, sec, info)) 2704. 2705 2706*/ 2707 2708/* Sections marked with the SEC_LINK_ONCE flag should only be linked 2709 once into the output. This routine checks each section, and 2710 arrange to discard it if a section of the same name has already 2711 been linked. This code assumes that all relevant sections have the 2712 SEC_LINK_ONCE flag set; that is, it does not depend solely upon the 2713 section name. bfd_section_already_linked is called via 2714 bfd_map_over_sections. */ 2715 2716/* The hash table. */ 2717 2718static struct bfd_hash_table _bfd_section_already_linked_table; 2719 2720/* Support routines for the hash table used by section_already_linked, 2721 initialize the table, traverse, lookup, fill in an entry and remove 2722 the table. */ 2723 2724void 2725bfd_section_already_linked_table_traverse 2726 (bfd_boolean (*func) (struct bfd_section_already_linked_hash_entry *, 2727 void *), void *info) 2728{ 2729 bfd_hash_traverse (&_bfd_section_already_linked_table, 2730 (bfd_boolean (*) (struct bfd_hash_entry *, 2731 void *)) func, 2732 info); 2733} 2734 2735struct bfd_section_already_linked_hash_entry * 2736bfd_section_already_linked_table_lookup (const char *name) 2737{ 2738 return ((struct bfd_section_already_linked_hash_entry *) 2739 bfd_hash_lookup (&_bfd_section_already_linked_table, name, 2740 TRUE, FALSE)); 2741} 2742 2743bfd_boolean 2744bfd_section_already_linked_table_insert 2745 (struct bfd_section_already_linked_hash_entry *already_linked_list, 2746 asection *sec) 2747{ 2748 struct bfd_section_already_linked *l; 2749 2750 /* Allocate the memory from the same obstack as the hash table is 2751 kept in. */ 2752 l = (struct bfd_section_already_linked *) 2753 bfd_hash_allocate (&_bfd_section_already_linked_table, sizeof *l); 2754 if (l == NULL) 2755 return FALSE; 2756 l->sec = sec; 2757 l->next = already_linked_list->entry; 2758 already_linked_list->entry = l; 2759 return TRUE; 2760} 2761 2762static struct bfd_hash_entry * 2763already_linked_newfunc (struct bfd_hash_entry *entry ATTRIBUTE_UNUSED, 2764 struct bfd_hash_table *table, 2765 const char *string ATTRIBUTE_UNUSED) 2766{ 2767 struct bfd_section_already_linked_hash_entry *ret = 2768 (struct bfd_section_already_linked_hash_entry *) 2769 bfd_hash_allocate (table, sizeof *ret); 2770 2771 if (ret == NULL) 2772 return NULL; 2773 2774 ret->entry = NULL; 2775 2776 return &ret->root; 2777} 2778 2779bfd_boolean 2780bfd_section_already_linked_table_init (void) 2781{ 2782 return bfd_hash_table_init_n (&_bfd_section_already_linked_table, 2783 already_linked_newfunc, 2784 sizeof (struct bfd_section_already_linked_hash_entry), 2785 42); 2786} 2787 2788void 2789bfd_section_already_linked_table_free (void) 2790{ 2791 bfd_hash_table_free (&_bfd_section_already_linked_table); 2792} 2793 2794/* Report warnings as appropriate for duplicate section SEC. 2795 Return FALSE if we decide to keep SEC after all. */ 2796 2797bfd_boolean 2798_bfd_handle_already_linked (asection *sec, 2799 struct bfd_section_already_linked *l, 2800 struct bfd_link_info *info) 2801{ 2802 switch (sec->flags & SEC_LINK_DUPLICATES) 2803 { 2804 default: 2805 abort (); 2806 2807 case SEC_LINK_DUPLICATES_DISCARD: 2808 /* If we found an LTO IR match for this comdat group on 2809 the first pass, replace it with the LTO output on the 2810 second pass. We can't simply choose real object 2811 files over IR because the first pass may contain a 2812 mix of LTO and normal objects and we must keep the 2813 first match, be it IR or real. */ 2814 if (sec->owner->lto_output 2815 && (l->sec->owner->flags & BFD_PLUGIN) != 0) 2816 { 2817 l->sec = sec; 2818 return FALSE; 2819 } 2820 break; 2821 2822 case SEC_LINK_DUPLICATES_ONE_ONLY: 2823 info->callbacks->einfo 2824 /* xgettext:c-format */ 2825 (_("%B: ignoring duplicate section `%A'\n"), 2826 sec->owner, sec); 2827 break; 2828 2829 case SEC_LINK_DUPLICATES_SAME_SIZE: 2830 if ((l->sec->owner->flags & BFD_PLUGIN) != 0) 2831 ; 2832 else if (sec->size != l->sec->size) 2833 info->callbacks->einfo 2834 /* xgettext:c-format */ 2835 (_("%B: duplicate section `%A' has different size\n"), 2836 sec->owner, sec); 2837 break; 2838 2839 case SEC_LINK_DUPLICATES_SAME_CONTENTS: 2840 if ((l->sec->owner->flags & BFD_PLUGIN) != 0) 2841 ; 2842 else if (sec->size != l->sec->size) 2843 info->callbacks->einfo 2844 /* xgettext:c-format */ 2845 (_("%B: duplicate section `%A' has different size\n"), 2846 sec->owner, sec); 2847 else if (sec->size != 0) 2848 { 2849 bfd_byte *sec_contents, *l_sec_contents = NULL; 2850 2851 if (!bfd_malloc_and_get_section (sec->owner, sec, &sec_contents)) 2852 info->callbacks->einfo 2853 /* xgettext:c-format */ 2854 (_("%B: could not read contents of section `%A'\n"), 2855 sec->owner, sec); 2856 else if (!bfd_malloc_and_get_section (l->sec->owner, l->sec, 2857 &l_sec_contents)) 2858 info->callbacks->einfo 2859 /* xgettext:c-format */ 2860 (_("%B: could not read contents of section `%A'\n"), 2861 l->sec->owner, l->sec); 2862 else if (memcmp (sec_contents, l_sec_contents, sec->size) != 0) 2863 info->callbacks->einfo 2864 /* xgettext:c-format */ 2865 (_("%B: duplicate section `%A' has different contents\n"), 2866 sec->owner, sec); 2867 2868 if (sec_contents) 2869 free (sec_contents); 2870 if (l_sec_contents) 2871 free (l_sec_contents); 2872 } 2873 break; 2874 } 2875 2876 /* Set the output_section field so that lang_add_section 2877 does not create a lang_input_section structure for this 2878 section. Since there might be a symbol in the section 2879 being discarded, we must retain a pointer to the section 2880 which we are really going to use. */ 2881 sec->output_section = bfd_abs_section_ptr; 2882 sec->kept_section = l->sec; 2883 return TRUE; 2884} 2885 2886/* This is used on non-ELF inputs. */ 2887 2888bfd_boolean 2889_bfd_generic_section_already_linked (bfd *abfd ATTRIBUTE_UNUSED, 2890 asection *sec, 2891 struct bfd_link_info *info) 2892{ 2893 const char *name; 2894 struct bfd_section_already_linked *l; 2895 struct bfd_section_already_linked_hash_entry *already_linked_list; 2896 2897 if ((sec->flags & SEC_LINK_ONCE) == 0) 2898 return FALSE; 2899 2900 /* The generic linker doesn't handle section groups. */ 2901 if ((sec->flags & SEC_GROUP) != 0) 2902 return FALSE; 2903 2904 /* FIXME: When doing a relocatable link, we may have trouble 2905 copying relocations in other sections that refer to local symbols 2906 in the section being discarded. Those relocations will have to 2907 be converted somehow; as of this writing I'm not sure that any of 2908 the backends handle that correctly. 2909 2910 It is tempting to instead not discard link once sections when 2911 doing a relocatable link (technically, they should be discarded 2912 whenever we are building constructors). However, that fails, 2913 because the linker winds up combining all the link once sections 2914 into a single large link once section, which defeats the purpose 2915 of having link once sections in the first place. */ 2916 2917 name = bfd_get_section_name (abfd, sec); 2918 2919 already_linked_list = bfd_section_already_linked_table_lookup (name); 2920 2921 l = already_linked_list->entry; 2922 if (l != NULL) 2923 { 2924 /* The section has already been linked. See if we should 2925 issue a warning. */ 2926 return _bfd_handle_already_linked (sec, l, info); 2927 } 2928 2929 /* This is the first section with this name. Record it. */ 2930 if (!bfd_section_already_linked_table_insert (already_linked_list, sec)) 2931 info->callbacks->einfo (_("%F%P: already_linked_table: %E\n")); 2932 return FALSE; 2933} 2934 2935/* Choose a neighbouring section to S in OBFD that will be output, or 2936 the absolute section if ADDR is out of bounds of the neighbours. */ 2937 2938asection * 2939_bfd_nearby_section (bfd *obfd, asection *s, bfd_vma addr) 2940{ 2941 asection *next, *prev, *best; 2942 2943 /* Find preceding kept section. */ 2944 for (prev = s->prev; prev != NULL; prev = prev->prev) 2945 if ((prev->flags & SEC_EXCLUDE) == 0 2946 && !bfd_section_removed_from_list (obfd, prev)) 2947 break; 2948 2949 /* Find following kept section. Start at prev->next because 2950 other sections may have been added after S was removed. */ 2951 if (s->prev != NULL) 2952 next = s->prev->next; 2953 else 2954 next = s->owner->sections; 2955 for (; next != NULL; next = next->next) 2956 if ((next->flags & SEC_EXCLUDE) == 0 2957 && !bfd_section_removed_from_list (obfd, next)) 2958 break; 2959 2960 /* Choose better of two sections, based on flags. The idea 2961 is to choose a section that will be in the same segment 2962 as S would have been if it was kept. */ 2963 best = next; 2964 if (prev == NULL) 2965 { 2966 if (next == NULL) 2967 best = bfd_abs_section_ptr; 2968 } 2969 else if (next == NULL) 2970 best = prev; 2971 else if (((prev->flags ^ next->flags) 2972 & (SEC_ALLOC | SEC_THREAD_LOCAL | SEC_LOAD)) != 0) 2973 { 2974 if (((next->flags ^ s->flags) 2975 & (SEC_ALLOC | SEC_THREAD_LOCAL)) != 0 2976 /* We prefer to choose a loaded section. Section S 2977 doesn't have SEC_LOAD set (it being excluded, that 2978 part of the flag processing didn't happen) so we 2979 can't compare that flag to those of NEXT and PREV. */ 2980 || ((prev->flags & SEC_LOAD) != 0 2981 && (next->flags & SEC_LOAD) == 0)) 2982 best = prev; 2983 } 2984 else if (((prev->flags ^ next->flags) & SEC_READONLY) != 0) 2985 { 2986 if (((next->flags ^ s->flags) & SEC_READONLY) != 0) 2987 best = prev; 2988 } 2989 else if (((prev->flags ^ next->flags) & SEC_CODE) != 0) 2990 { 2991 if (((next->flags ^ s->flags) & SEC_CODE) != 0) 2992 best = prev; 2993 } 2994 else 2995 { 2996 /* Flags we care about are the same. Prefer the following 2997 section if that will result in a positive valued sym. */ 2998 if (addr < next->vma) 2999 best = prev; 3000 } 3001 3002 return best; 3003} 3004 3005/* Convert symbols in excluded output sections to use a kept section. */ 3006 3007static bfd_boolean 3008fix_syms (struct bfd_link_hash_entry *h, void *data) 3009{ 3010 bfd *obfd = (bfd *) data; 3011 3012 if (h->type == bfd_link_hash_defined 3013 || h->type == bfd_link_hash_defweak) 3014 { 3015 asection *s = h->u.def.section; 3016 if (s != NULL 3017 && s->output_section != NULL 3018 && (s->output_section->flags & SEC_EXCLUDE) != 0 3019 && bfd_section_removed_from_list (obfd, s->output_section)) 3020 { 3021 asection *op; 3022 3023 h->u.def.value += s->output_offset + s->output_section->vma; 3024 op = _bfd_nearby_section (obfd, s->output_section, h->u.def.value); 3025 h->u.def.value -= op->vma; 3026 h->u.def.section = op; 3027 } 3028 } 3029 3030 return TRUE; 3031} 3032 3033void 3034_bfd_fix_excluded_sec_syms (bfd *obfd, struct bfd_link_info *info) 3035{ 3036 bfd_link_hash_traverse (info->hash, fix_syms, obfd); 3037} 3038 3039/* 3040FUNCTION 3041 bfd_generic_define_common_symbol 3042 3043SYNOPSIS 3044 bfd_boolean bfd_generic_define_common_symbol 3045 (bfd *output_bfd, struct bfd_link_info *info, 3046 struct bfd_link_hash_entry *h); 3047 3048DESCRIPTION 3049 Convert common symbol @var{h} into a defined symbol. 3050 Return TRUE on success and FALSE on failure. 3051 3052.#define bfd_define_common_symbol(output_bfd, info, h) \ 3053. BFD_SEND (output_bfd, _bfd_define_common_symbol, (output_bfd, info, h)) 3054. 3055*/ 3056 3057bfd_boolean 3058bfd_generic_define_common_symbol (bfd *output_bfd, 3059 struct bfd_link_info *info ATTRIBUTE_UNUSED, 3060 struct bfd_link_hash_entry *h) 3061{ 3062 unsigned int power_of_two; 3063 bfd_vma alignment, size; 3064 asection *section; 3065 3066 BFD_ASSERT (h != NULL && h->type == bfd_link_hash_common); 3067 3068 size = h->u.c.size; 3069 power_of_two = h->u.c.p->alignment_power; 3070 section = h->u.c.p->section; 3071 3072 /* Increase the size of the section to align the common symbol. 3073 The alignment must be a power of two. */ 3074 alignment = bfd_octets_per_byte (output_bfd) << power_of_two; 3075 BFD_ASSERT (alignment != 0 && (alignment & -alignment) == alignment); 3076 section->size += alignment - 1; 3077 section->size &= -alignment; 3078 3079 /* Adjust the section's overall alignment if necessary. */ 3080 if (power_of_two > section->alignment_power) 3081 section->alignment_power = power_of_two; 3082 3083 /* Change the symbol from common to defined. */ 3084 h->type = bfd_link_hash_defined; 3085 h->u.def.section = section; 3086 h->u.def.value = section->size; 3087 3088 /* Increase the size of the section. */ 3089 section->size += size; 3090 3091 /* Make sure the section is allocated in memory, and make sure that 3092 it is no longer a common section. */ 3093 section->flags |= SEC_ALLOC; 3094 section->flags &= ~SEC_IS_COMMON; 3095 return TRUE; 3096} 3097 3098/* 3099FUNCTION 3100 bfd_find_version_for_sym 3101 3102SYNOPSIS 3103 struct bfd_elf_version_tree * bfd_find_version_for_sym 3104 (struct bfd_elf_version_tree *verdefs, 3105 const char *sym_name, bfd_boolean *hide); 3106 3107DESCRIPTION 3108 Search an elf version script tree for symbol versioning 3109 info and export / don't-export status for a given symbol. 3110 Return non-NULL on success and NULL on failure; also sets 3111 the output @samp{hide} boolean parameter. 3112 3113*/ 3114 3115struct bfd_elf_version_tree * 3116bfd_find_version_for_sym (struct bfd_elf_version_tree *verdefs, 3117 const char *sym_name, 3118 bfd_boolean *hide) 3119{ 3120 struct bfd_elf_version_tree *t; 3121 struct bfd_elf_version_tree *local_ver, *global_ver, *exist_ver; 3122 struct bfd_elf_version_tree *star_local_ver, *star_global_ver; 3123 3124 local_ver = NULL; 3125 global_ver = NULL; 3126 star_local_ver = NULL; 3127 star_global_ver = NULL; 3128 exist_ver = NULL; 3129 for (t = verdefs; t != NULL; t = t->next) 3130 { 3131 if (t->globals.list != NULL) 3132 { 3133 struct bfd_elf_version_expr *d = NULL; 3134 3135 while ((d = (*t->match) (&t->globals, d, sym_name)) != NULL) 3136 { 3137 if (d->literal || strcmp (d->pattern, "*") != 0) 3138 global_ver = t; 3139 else 3140 star_global_ver = t; 3141 if (d->symver) 3142 exist_ver = t; 3143 d->script = 1; 3144 /* If the match is a wildcard pattern, keep looking for 3145 a more explicit, perhaps even local, match. */ 3146 if (d->literal) 3147 break; 3148 } 3149 3150 if (d != NULL) 3151 break; 3152 } 3153 3154 if (t->locals.list != NULL) 3155 { 3156 struct bfd_elf_version_expr *d = NULL; 3157 3158 while ((d = (*t->match) (&t->locals, d, sym_name)) != NULL) 3159 { 3160 if (d->literal || strcmp (d->pattern, "*") != 0) 3161 local_ver = t; 3162 else 3163 star_local_ver = t; 3164 /* If the match is a wildcard pattern, keep looking for 3165 a more explicit, perhaps even global, match. */ 3166 if (d->literal) 3167 { 3168 /* An exact match overrides a global wildcard. */ 3169 global_ver = NULL; 3170 star_global_ver = NULL; 3171 break; 3172 } 3173 } 3174 3175 if (d != NULL) 3176 break; 3177 } 3178 } 3179 3180 if (global_ver == NULL && local_ver == NULL) 3181 global_ver = star_global_ver; 3182 3183 if (global_ver != NULL) 3184 { 3185 /* If we already have a versioned symbol that matches the 3186 node for this symbol, then we don't want to create a 3187 duplicate from the unversioned symbol. Instead hide the 3188 unversioned symbol. */ 3189 *hide = exist_ver == global_ver; 3190 return global_ver; 3191 } 3192 3193 if (local_ver == NULL) 3194 local_ver = star_local_ver; 3195 3196 if (local_ver != NULL) 3197 { 3198 *hide = TRUE; 3199 return local_ver; 3200 } 3201 3202 return NULL; 3203} 3204 3205/* 3206FUNCTION 3207 bfd_hide_sym_by_version 3208 3209SYNOPSIS 3210 bfd_boolean bfd_hide_sym_by_version 3211 (struct bfd_elf_version_tree *verdefs, const char *sym_name); 3212 3213DESCRIPTION 3214 Search an elf version script tree for symbol versioning 3215 info for a given symbol. Return TRUE if the symbol is hidden. 3216 3217*/ 3218 3219bfd_boolean 3220bfd_hide_sym_by_version (struct bfd_elf_version_tree *verdefs, 3221 const char *sym_name) 3222{ 3223 bfd_boolean hidden = FALSE; 3224 bfd_find_version_for_sym (verdefs, sym_name, &hidden); 3225 return hidden; 3226} 3227 3228/* 3229FUNCTION 3230 bfd_link_check_relocs 3231 3232SYNOPSIS 3233 bfd_boolean bfd_link_check_relocs 3234 (bfd *abfd, struct bfd_link_info *info); 3235 3236DESCRIPTION 3237 Checks the relocs in ABFD for validity. 3238 Does not execute the relocs. 3239 Return TRUE if everything is OK, FALSE otherwise. 3240 This is the external entry point to this code. 3241*/ 3242 3243bfd_boolean 3244bfd_link_check_relocs (bfd *abfd, struct bfd_link_info *info) 3245{ 3246 return BFD_SEND (abfd, _bfd_link_check_relocs, (abfd, info)); 3247} 3248 3249/* 3250FUNCTION 3251 _bfd_generic_link_check_relocs 3252 3253SYNOPSIS 3254 bfd_boolean _bfd_generic_link_check_relocs 3255 (bfd *abfd, struct bfd_link_info *info); 3256 3257DESCRIPTION 3258 Stub function for targets that do not implement reloc checking. 3259 Return TRUE. 3260 This is an internal function. It should not be called from 3261 outside the BFD library. 3262*/ 3263 3264bfd_boolean 3265_bfd_generic_link_check_relocs (bfd *abfd ATTRIBUTE_UNUSED, 3266 struct bfd_link_info *info ATTRIBUTE_UNUSED) 3267{ 3268 return TRUE; 3269} 3270 3271/* 3272FUNCTION 3273 bfd_merge_private_bfd_data 3274 3275SYNOPSIS 3276 bfd_boolean bfd_merge_private_bfd_data 3277 (bfd *ibfd, struct bfd_link_info *info); 3278 3279DESCRIPTION 3280 Merge private BFD information from the BFD @var{ibfd} to the 3281 the output file BFD when linking. Return <<TRUE>> on success, 3282 <<FALSE>> on error. Possible error returns are: 3283 3284 o <<bfd_error_no_memory>> - 3285 Not enough memory exists to create private data for @var{obfd}. 3286 3287.#define bfd_merge_private_bfd_data(ibfd, info) \ 3288. BFD_SEND ((info)->output_bfd, _bfd_merge_private_bfd_data, \ 3289. (ibfd, info)) 3290*/ 3291 3292/* 3293INTERNAL_FUNCTION 3294 _bfd_generic_verify_endian_match 3295 3296SYNOPSIS 3297 bfd_boolean _bfd_generic_verify_endian_match 3298 (bfd *ibfd, struct bfd_link_info *info); 3299 3300DESCRIPTION 3301 Can be used from / for bfd_merge_private_bfd_data to check that 3302 endianness matches between input and output file. Returns 3303 TRUE for a match, otherwise returns FALSE and emits an error. 3304*/ 3305 3306bfd_boolean 3307_bfd_generic_verify_endian_match (bfd *ibfd, struct bfd_link_info *info) 3308{ 3309 bfd *obfd = info->output_bfd; 3310 3311 if (ibfd->xvec->byteorder != obfd->xvec->byteorder 3312 && ibfd->xvec->byteorder != BFD_ENDIAN_UNKNOWN 3313 && obfd->xvec->byteorder != BFD_ENDIAN_UNKNOWN) 3314 { 3315 if (bfd_big_endian (ibfd)) 3316 _bfd_error_handler (_("%B: compiled for a big endian system " 3317 "and target is little endian"), ibfd); 3318 else 3319 _bfd_error_handler (_("%B: compiled for a little endian system " 3320 "and target is big endian"), ibfd); 3321 bfd_set_error (bfd_error_wrong_format); 3322 return FALSE; 3323 } 3324 3325 return TRUE; 3326} 3327