1/* linker.c -- BFD linker routines 2 Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 3 2003, 2004, 2005, 2006, 2007 4 Free Software Foundation, Inc. 5 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support 6 7 This file is part of BFD, the Binary File Descriptor library. 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 3 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 22 MA 02110-1301, USA. */ 23 24#include "sysdep.h" 25#include "bfd.h" 26#include "libbfd.h" 27#include "bfdlink.h" 28#include "genlink.h" 29 30/* 31SECTION 32 Linker Functions 33 34@cindex Linker 35 The linker uses three special entry points in the BFD target 36 vector. It is not necessary to write special routines for 37 these entry points when creating a new BFD back end, since 38 generic versions are provided. However, writing them can 39 speed up linking and make it use significantly less runtime 40 memory. 41 42 The first routine creates a hash table used by the other 43 routines. The second routine adds the symbols from an object 44 file to the hash table. The third routine takes all the 45 object files and links them together to create the output 46 file. These routines are designed so that the linker proper 47 does not need to know anything about the symbols in the object 48 files that it is linking. The linker merely arranges the 49 sections as directed by the linker script and lets BFD handle 50 the details of symbols and relocs. 51 52 The second routine and third routines are passed a pointer to 53 a <<struct bfd_link_info>> structure (defined in 54 <<bfdlink.h>>) which holds information relevant to the link, 55 including the linker hash table (which was created by the 56 first routine) and a set of callback functions to the linker 57 proper. 58 59 The generic linker routines are in <<linker.c>>, and use the 60 header file <<genlink.h>>. As of this writing, the only back 61 ends which have implemented versions of these routines are 62 a.out (in <<aoutx.h>>) and ECOFF (in <<ecoff.c>>). The a.out 63 routines are used as examples throughout this section. 64 65@menu 66@* Creating a Linker Hash Table:: 67@* Adding Symbols to the Hash Table:: 68@* Performing the Final Link:: 69@end menu 70 71INODE 72Creating a Linker Hash Table, Adding Symbols to the Hash Table, Linker Functions, Linker Functions 73SUBSECTION 74 Creating a linker hash table 75 76@cindex _bfd_link_hash_table_create in target vector 77@cindex target vector (_bfd_link_hash_table_create) 78 The linker routines must create a hash table, which must be 79 derived from <<struct bfd_link_hash_table>> described in 80 <<bfdlink.c>>. @xref{Hash Tables}, for information on how to 81 create a derived hash table. This entry point is called using 82 the target vector of the linker output file. 83 84 The <<_bfd_link_hash_table_create>> entry point must allocate 85 and initialize an instance of the desired hash table. If the 86 back end does not require any additional information to be 87 stored with the entries in the hash table, the entry point may 88 simply create a <<struct bfd_link_hash_table>>. Most likely, 89 however, some additional information will be needed. 90 91 For example, with each entry in the hash table the a.out 92 linker keeps the index the symbol has in the final output file 93 (this index number is used so that when doing a relocatable 94 link the symbol index used in the output file can be quickly 95 filled in when copying over a reloc). The a.out linker code 96 defines the required structures and functions for a hash table 97 derived from <<struct bfd_link_hash_table>>. The a.out linker 98 hash table is created by the function 99 <<NAME(aout,link_hash_table_create)>>; it simply allocates 100 space for the hash table, initializes it, and returns a 101 pointer to it. 102 103 When writing the linker routines for a new back end, you will 104 generally not know exactly which fields will be required until 105 you have finished. You should simply create a new hash table 106 which defines no additional fields, and then simply add fields 107 as they become necessary. 108 109INODE 110Adding Symbols to the Hash Table, Performing the Final Link, Creating a Linker Hash Table, Linker Functions 111SUBSECTION 112 Adding symbols to the hash table 113 114@cindex _bfd_link_add_symbols in target vector 115@cindex target vector (_bfd_link_add_symbols) 116 The linker proper will call the <<_bfd_link_add_symbols>> 117 entry point for each object file or archive which is to be 118 linked (typically these are the files named on the command 119 line, but some may also come from the linker script). The 120 entry point is responsible for examining the file. For an 121 object file, BFD must add any relevant symbol information to 122 the hash table. For an archive, BFD must determine which 123 elements of the archive should be used and adding them to the 124 link. 125 126 The a.out version of this entry point is 127 <<NAME(aout,link_add_symbols)>>. 128 129@menu 130@* Differing file formats:: 131@* Adding symbols from an object file:: 132@* Adding symbols from an archive:: 133@end menu 134 135INODE 136Differing file formats, Adding symbols from an object file, Adding Symbols to the Hash Table, Adding Symbols to the Hash Table 137SUBSUBSECTION 138 Differing file formats 139 140 Normally all the files involved in a link will be of the same 141 format, but it is also possible to link together different 142 format object files, and the back end must support that. The 143 <<_bfd_link_add_symbols>> entry point is called via the target 144 vector of the file to be added. This has an important 145 consequence: the function may not assume that the hash table 146 is the type created by the corresponding 147 <<_bfd_link_hash_table_create>> vector. All the 148 <<_bfd_link_add_symbols>> function can assume about the hash 149 table is that it is derived from <<struct 150 bfd_link_hash_table>>. 151 152 Sometimes the <<_bfd_link_add_symbols>> function must store 153 some information in the hash table entry to be used by the 154 <<_bfd_final_link>> function. In such a case the <<creator>> 155 field of the hash table must be checked to make sure that the 156 hash table was created by an object file of the same format. 157 158 The <<_bfd_final_link>> routine must be prepared to handle a 159 hash entry without any extra information added by the 160 <<_bfd_link_add_symbols>> function. A hash entry without 161 extra information will also occur when the linker script 162 directs the linker to create a symbol. Note that, regardless 163 of how a hash table entry is added, all the fields will be 164 initialized to some sort of null value by the hash table entry 165 initialization function. 166 167 See <<ecoff_link_add_externals>> for an example of how to 168 check the <<creator>> field before saving information (in this 169 case, the ECOFF external symbol debugging information) in a 170 hash table entry. 171 172INODE 173Adding symbols from an object file, Adding symbols from an archive, Differing file formats, Adding Symbols to the Hash Table 174SUBSUBSECTION 175 Adding symbols from an object file 176 177 When the <<_bfd_link_add_symbols>> routine is passed an object 178 file, it must add all externally visible symbols in that 179 object file to the hash table. The actual work of adding the 180 symbol to the hash table is normally handled by the function 181 <<_bfd_generic_link_add_one_symbol>>. The 182 <<_bfd_link_add_symbols>> routine is responsible for reading 183 all the symbols from the object file and passing the correct 184 information to <<_bfd_generic_link_add_one_symbol>>. 185 186 The <<_bfd_link_add_symbols>> routine should not use 187 <<bfd_canonicalize_symtab>> to read the symbols. The point of 188 providing this routine is to avoid the overhead of converting 189 the symbols into generic <<asymbol>> structures. 190 191@findex _bfd_generic_link_add_one_symbol 192 <<_bfd_generic_link_add_one_symbol>> handles the details of 193 combining common symbols, warning about multiple definitions, 194 and so forth. It takes arguments which describe the symbol to 195 add, notably symbol flags, a section, and an offset. The 196 symbol flags include such things as <<BSF_WEAK>> or 197 <<BSF_INDIRECT>>. The section is a section in the object 198 file, or something like <<bfd_und_section_ptr>> for an undefined 199 symbol or <<bfd_com_section_ptr>> for a common symbol. 200 201 If the <<_bfd_final_link>> routine is also going to need to 202 read the symbol information, the <<_bfd_link_add_symbols>> 203 routine should save it somewhere attached to the object file 204 BFD. However, the information should only be saved if the 205 <<keep_memory>> field of the <<info>> argument is TRUE, so 206 that the <<-no-keep-memory>> linker switch is effective. 207 208 The a.out function which adds symbols from an object file is 209 <<aout_link_add_object_symbols>>, and most of the interesting 210 work is in <<aout_link_add_symbols>>. The latter saves 211 pointers to the hash tables entries created by 212 <<_bfd_generic_link_add_one_symbol>> indexed by symbol number, 213 so that the <<_bfd_final_link>> routine does not have to call 214 the hash table lookup routine to locate the entry. 215 216INODE 217Adding symbols from an archive, , Adding symbols from an object file, Adding Symbols to the Hash Table 218SUBSUBSECTION 219 Adding symbols from an archive 220 221 When the <<_bfd_link_add_symbols>> routine is passed an 222 archive, it must look through the symbols defined by the 223 archive and decide which elements of the archive should be 224 included in the link. For each such element it must call the 225 <<add_archive_element>> linker callback, and it must add the 226 symbols from the object file to the linker hash table. 227 228@findex _bfd_generic_link_add_archive_symbols 229 In most cases the work of looking through the symbols in the 230 archive should be done by the 231 <<_bfd_generic_link_add_archive_symbols>> function. This 232 function builds a hash table from the archive symbol table and 233 looks through the list of undefined symbols to see which 234 elements should be included. 235 <<_bfd_generic_link_add_archive_symbols>> is passed a function 236 to call to make the final decision about adding an archive 237 element to the link and to do the actual work of adding the 238 symbols to the linker hash table. 239 240 The function passed to 241 <<_bfd_generic_link_add_archive_symbols>> must read the 242 symbols of the archive element and decide whether the archive 243 element should be included in the link. If the element is to 244 be included, the <<add_archive_element>> linker callback 245 routine must be called with the element as an argument, and 246 the elements symbols must be added to the linker hash table 247 just as though the element had itself been passed to the 248 <<_bfd_link_add_symbols>> function. 249 250 When the a.out <<_bfd_link_add_symbols>> function receives an 251 archive, it calls <<_bfd_generic_link_add_archive_symbols>> 252 passing <<aout_link_check_archive_element>> as the function 253 argument. <<aout_link_check_archive_element>> calls 254 <<aout_link_check_ar_symbols>>. If the latter decides to add 255 the element (an element is only added if it provides a real, 256 non-common, definition for a previously undefined or common 257 symbol) it calls the <<add_archive_element>> callback and then 258 <<aout_link_check_archive_element>> calls 259 <<aout_link_add_symbols>> to actually add the symbols to the 260 linker hash table. 261 262 The ECOFF back end is unusual in that it does not normally 263 call <<_bfd_generic_link_add_archive_symbols>>, because ECOFF 264 archives already contain a hash table of symbols. The ECOFF 265 back end searches the archive itself to avoid the overhead of 266 creating a new hash table. 267 268INODE 269Performing the Final Link, , Adding Symbols to the Hash Table, Linker Functions 270SUBSECTION 271 Performing the final link 272 273@cindex _bfd_link_final_link in target vector 274@cindex target vector (_bfd_final_link) 275 When all the input files have been processed, the linker calls 276 the <<_bfd_final_link>> entry point of the output BFD. This 277 routine is responsible for producing the final output file, 278 which has several aspects. It must relocate the contents of 279 the input sections and copy the data into the output sections. 280 It must build an output symbol table including any local 281 symbols from the input files and the global symbols from the 282 hash table. When producing relocatable output, it must 283 modify the input relocs and write them into the output file. 284 There may also be object format dependent work to be done. 285 286 The linker will also call the <<write_object_contents>> entry 287 point when the BFD is closed. The two entry points must work 288 together in order to produce the correct output file. 289 290 The details of how this works are inevitably dependent upon 291 the specific object file format. The a.out 292 <<_bfd_final_link>> routine is <<NAME(aout,final_link)>>. 293 294@menu 295@* Information provided by the linker:: 296@* Relocating the section contents:: 297@* Writing the symbol table:: 298@end menu 299 300INODE 301Information provided by the linker, Relocating the section contents, Performing the Final Link, Performing the Final Link 302SUBSUBSECTION 303 Information provided by the linker 304 305 Before the linker calls the <<_bfd_final_link>> entry point, 306 it sets up some data structures for the function to use. 307 308 The <<input_bfds>> field of the <<bfd_link_info>> structure 309 will point to a list of all the input files included in the 310 link. These files are linked through the <<link_next>> field 311 of the <<bfd>> structure. 312 313 Each section in the output file will have a list of 314 <<link_order>> structures attached to the <<map_head.link_order>> 315 field (the <<link_order>> structure is defined in 316 <<bfdlink.h>>). These structures describe how to create the 317 contents of the output section in terms of the contents of 318 various input sections, fill constants, and, eventually, other 319 types of information. They also describe relocs that must be 320 created by the BFD backend, but do not correspond to any input 321 file; this is used to support -Ur, which builds constructors 322 while generating a relocatable object file. 323 324INODE 325Relocating the section contents, Writing the symbol table, Information provided by the linker, Performing the Final Link 326SUBSUBSECTION 327 Relocating the section contents 328 329 The <<_bfd_final_link>> function should look through the 330 <<link_order>> structures attached to each section of the 331 output file. Each <<link_order>> structure should either be 332 handled specially, or it should be passed to the function 333 <<_bfd_default_link_order>> which will do the right thing 334 (<<_bfd_default_link_order>> is defined in <<linker.c>>). 335 336 For efficiency, a <<link_order>> of type 337 <<bfd_indirect_link_order>> whose associated section belongs 338 to a BFD of the same format as the output BFD must be handled 339 specially. This type of <<link_order>> describes part of an 340 output section in terms of a section belonging to one of the 341 input files. The <<_bfd_final_link>> function should read the 342 contents of the section and any associated relocs, apply the 343 relocs to the section contents, and write out the modified 344 section contents. If performing a relocatable link, the 345 relocs themselves must also be modified and written out. 346 347@findex _bfd_relocate_contents 348@findex _bfd_final_link_relocate 349 The functions <<_bfd_relocate_contents>> and 350 <<_bfd_final_link_relocate>> provide some general support for 351 performing the actual relocations, notably overflow checking. 352 Their arguments include information about the symbol the 353 relocation is against and a <<reloc_howto_type>> argument 354 which describes the relocation to perform. These functions 355 are defined in <<reloc.c>>. 356 357 The a.out function which handles reading, relocating, and 358 writing section contents is <<aout_link_input_section>>. The 359 actual relocation is done in <<aout_link_input_section_std>> 360 and <<aout_link_input_section_ext>>. 361 362INODE 363Writing the symbol table, , Relocating the section contents, Performing the Final Link 364SUBSUBSECTION 365 Writing the symbol table 366 367 The <<_bfd_final_link>> function must gather all the symbols 368 in the input files and write them out. It must also write out 369 all the symbols in the global hash table. This must be 370 controlled by the <<strip>> and <<discard>> fields of the 371 <<bfd_link_info>> structure. 372 373 The local symbols of the input files will not have been 374 entered into the linker hash table. The <<_bfd_final_link>> 375 routine must consider each input file and include the symbols 376 in the output file. It may be convenient to do this when 377 looking through the <<link_order>> structures, or it may be 378 done by stepping through the <<input_bfds>> list. 379 380 The <<_bfd_final_link>> routine must also traverse the global 381 hash table to gather all the externally visible symbols. It 382 is possible that most of the externally visible symbols may be 383 written out when considering the symbols of each input file, 384 but it is still necessary to traverse the hash table since the 385 linker script may have defined some symbols that are not in 386 any of the input files. 387 388 The <<strip>> field of the <<bfd_link_info>> structure 389 controls which symbols are written out. The possible values 390 are listed in <<bfdlink.h>>. If the value is <<strip_some>>, 391 then the <<keep_hash>> field of the <<bfd_link_info>> 392 structure is a hash table of symbols to keep; each symbol 393 should be looked up in this hash table, and only symbols which 394 are present should be included in the output file. 395 396 If the <<strip>> field of the <<bfd_link_info>> structure 397 permits local symbols to be written out, the <<discard>> field 398 is used to further controls which local symbols are included 399 in the output file. If the value is <<discard_l>>, then all 400 local symbols which begin with a certain prefix are discarded; 401 this is controlled by the <<bfd_is_local_label_name>> entry point. 402 403 The a.out backend handles symbols by calling 404 <<aout_link_write_symbols>> on each input BFD and then 405 traversing the global hash table with the function 406 <<aout_link_write_other_symbol>>. It builds a string table 407 while writing out the symbols, which is written to the output 408 file at the end of <<NAME(aout,final_link)>>. 409*/ 410 411static bfd_boolean generic_link_add_object_symbols 412 (bfd *, struct bfd_link_info *, bfd_boolean collect); 413static bfd_boolean generic_link_add_symbols 414 (bfd *, struct bfd_link_info *, bfd_boolean); 415static bfd_boolean generic_link_check_archive_element_no_collect 416 (bfd *, struct bfd_link_info *, bfd_boolean *); 417static bfd_boolean generic_link_check_archive_element_collect 418 (bfd *, struct bfd_link_info *, bfd_boolean *); 419static bfd_boolean generic_link_check_archive_element 420 (bfd *, struct bfd_link_info *, bfd_boolean *, bfd_boolean); 421static bfd_boolean generic_link_add_symbol_list 422 (bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **, 423 bfd_boolean); 424static bfd_boolean generic_add_output_symbol 425 (bfd *, size_t *psymalloc, asymbol *); 426static bfd_boolean default_data_link_order 427 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *); 428static bfd_boolean default_indirect_link_order 429 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *, 430 bfd_boolean); 431 432/* The link hash table structure is defined in bfdlink.h. It provides 433 a base hash table which the backend specific hash tables are built 434 upon. */ 435 436/* Routine to create an entry in the link hash table. */ 437 438struct bfd_hash_entry * 439_bfd_link_hash_newfunc (struct bfd_hash_entry *entry, 440 struct bfd_hash_table *table, 441 const char *string) 442{ 443 /* Allocate the structure if it has not already been allocated by a 444 subclass. */ 445 if (entry == NULL) 446 { 447 entry = bfd_hash_allocate (table, sizeof (struct bfd_link_hash_entry)); 448 if (entry == NULL) 449 return entry; 450 } 451 452 /* Call the allocation method of the superclass. */ 453 entry = bfd_hash_newfunc (entry, table, string); 454 if (entry) 455 { 456 struct bfd_link_hash_entry *h = (struct bfd_link_hash_entry *) entry; 457 458 /* Initialize the local fields. */ 459 h->type = bfd_link_hash_new; 460 memset (&h->u.undef.next, 0, 461 (sizeof (struct bfd_link_hash_entry) 462 - offsetof (struct bfd_link_hash_entry, u.undef.next))); 463 } 464 465 return entry; 466} 467 468/* Initialize a link hash table. The BFD argument is the one 469 responsible for creating this table. */ 470 471bfd_boolean 472_bfd_link_hash_table_init 473 (struct bfd_link_hash_table *table, 474 bfd *abfd, 475 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *, 476 struct bfd_hash_table *, 477 const char *), 478 unsigned int entsize) 479{ 480 table->creator = abfd->xvec; 481 table->undefs = NULL; 482 table->undefs_tail = NULL; 483 table->type = bfd_link_generic_hash_table; 484 485 return bfd_hash_table_init (&table->table, newfunc, entsize); 486} 487 488/* Look up a symbol in a link hash table. If follow is TRUE, we 489 follow bfd_link_hash_indirect and bfd_link_hash_warning links to 490 the real symbol. */ 491 492struct bfd_link_hash_entry * 493bfd_link_hash_lookup (struct bfd_link_hash_table *table, 494 const char *string, 495 bfd_boolean create, 496 bfd_boolean copy, 497 bfd_boolean follow) 498{ 499 struct bfd_link_hash_entry *ret; 500 501 ret = ((struct bfd_link_hash_entry *) 502 bfd_hash_lookup (&table->table, string, create, copy)); 503 504 if (follow && ret != NULL) 505 { 506 while (ret->type == bfd_link_hash_indirect 507 || ret->type == bfd_link_hash_warning) 508 ret = ret->u.i.link; 509 } 510 511 return ret; 512} 513 514/* Look up a symbol in the main linker hash table if the symbol might 515 be wrapped. This should only be used for references to an 516 undefined symbol, not for definitions of a symbol. */ 517 518struct bfd_link_hash_entry * 519bfd_wrapped_link_hash_lookup (bfd *abfd, 520 struct bfd_link_info *info, 521 const char *string, 522 bfd_boolean create, 523 bfd_boolean copy, 524 bfd_boolean follow) 525{ 526 bfd_size_type amt; 527 528 if (info->wrap_hash != NULL) 529 { 530 const char *l; 531 char prefix = '\0'; 532 533 l = string; 534 if (*l == bfd_get_symbol_leading_char (abfd) || *l == info->wrap_char) 535 { 536 prefix = *l; 537 ++l; 538 } 539 540#undef WRAP 541#define WRAP "__wrap_" 542 543 if (bfd_hash_lookup (info->wrap_hash, l, FALSE, FALSE) != NULL) 544 { 545 char *n; 546 struct bfd_link_hash_entry *h; 547 548 /* This symbol is being wrapped. We want to replace all 549 references to SYM with references to __wrap_SYM. */ 550 551 amt = strlen (l) + sizeof WRAP + 1; 552 n = bfd_malloc (amt); 553 if (n == NULL) 554 return NULL; 555 556 n[0] = prefix; 557 n[1] = '\0'; 558 strcat (n, WRAP); 559 strcat (n, l); 560 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow); 561 free (n); 562 return h; 563 } 564 565#undef WRAP 566 567#undef REAL 568#define REAL "__real_" 569 570 if (*l == '_' 571 && CONST_STRNEQ (l, REAL) 572 && bfd_hash_lookup (info->wrap_hash, l + sizeof REAL - 1, 573 FALSE, FALSE) != NULL) 574 { 575 char *n; 576 struct bfd_link_hash_entry *h; 577 578 /* This is a reference to __real_SYM, where SYM is being 579 wrapped. We want to replace all references to __real_SYM 580 with references to SYM. */ 581 582 amt = strlen (l + sizeof REAL - 1) + 2; 583 n = bfd_malloc (amt); 584 if (n == NULL) 585 return NULL; 586 587 n[0] = prefix; 588 n[1] = '\0'; 589 strcat (n, l + sizeof REAL - 1); 590 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow); 591 free (n); 592 return h; 593 } 594 595#undef REAL 596 } 597 598 return bfd_link_hash_lookup (info->hash, string, create, copy, follow); 599} 600 601/* Traverse a generic link hash table. The only reason this is not a 602 macro is to do better type checking. This code presumes that an 603 argument passed as a struct bfd_hash_entry * may be caught as a 604 struct bfd_link_hash_entry * with no explicit cast required on the 605 call. */ 606 607void 608bfd_link_hash_traverse 609 (struct bfd_link_hash_table *table, 610 bfd_boolean (*func) (struct bfd_link_hash_entry *, void *), 611 void *info) 612{ 613 bfd_hash_traverse (&table->table, 614 (bfd_boolean (*) (struct bfd_hash_entry *, void *)) func, 615 info); 616} 617 618/* Add a symbol to the linker hash table undefs list. */ 619 620void 621bfd_link_add_undef (struct bfd_link_hash_table *table, 622 struct bfd_link_hash_entry *h) 623{ 624 BFD_ASSERT (h->u.undef.next == NULL); 625 if (table->undefs_tail != NULL) 626 table->undefs_tail->u.undef.next = h; 627 if (table->undefs == NULL) 628 table->undefs = h; 629 table->undefs_tail = h; 630} 631 632/* The undefs list was designed so that in normal use we don't need to 633 remove entries. However, if symbols on the list are changed from 634 bfd_link_hash_undefined to either bfd_link_hash_undefweak or 635 bfd_link_hash_new for some reason, then they must be removed from the 636 list. Failure to do so might result in the linker attempting to add 637 the symbol to the list again at a later stage. */ 638 639void 640bfd_link_repair_undef_list (struct bfd_link_hash_table *table) 641{ 642 struct bfd_link_hash_entry **pun; 643 644 pun = &table->undefs; 645 while (*pun != NULL) 646 { 647 struct bfd_link_hash_entry *h = *pun; 648 649 if (h->type == bfd_link_hash_new 650 || h->type == bfd_link_hash_undefweak) 651 { 652 *pun = h->u.undef.next; 653 h->u.undef.next = NULL; 654 if (h == table->undefs_tail) 655 { 656 if (pun == &table->undefs) 657 table->undefs_tail = NULL; 658 else 659 /* pun points at an u.undef.next field. Go back to 660 the start of the link_hash_entry. */ 661 table->undefs_tail = (struct bfd_link_hash_entry *) 662 ((char *) pun - ((char *) &h->u.undef.next - (char *) h)); 663 break; 664 } 665 } 666 else 667 pun = &h->u.undef.next; 668 } 669} 670 671/* Routine to create an entry in a generic link hash table. */ 672 673struct bfd_hash_entry * 674_bfd_generic_link_hash_newfunc (struct bfd_hash_entry *entry, 675 struct bfd_hash_table *table, 676 const char *string) 677{ 678 /* Allocate the structure if it has not already been allocated by a 679 subclass. */ 680 if (entry == NULL) 681 { 682 entry = 683 bfd_hash_allocate (table, sizeof (struct generic_link_hash_entry)); 684 if (entry == NULL) 685 return entry; 686 } 687 688 /* Call the allocation method of the superclass. */ 689 entry = _bfd_link_hash_newfunc (entry, table, string); 690 if (entry) 691 { 692 struct generic_link_hash_entry *ret; 693 694 /* Set local fields. */ 695 ret = (struct generic_link_hash_entry *) entry; 696 ret->written = FALSE; 697 ret->sym = NULL; 698 } 699 700 return entry; 701} 702 703/* Create a generic link hash table. */ 704 705struct bfd_link_hash_table * 706_bfd_generic_link_hash_table_create (bfd *abfd) 707{ 708 struct generic_link_hash_table *ret; 709 bfd_size_type amt = sizeof (struct generic_link_hash_table); 710 711 ret = bfd_malloc (amt); 712 if (ret == NULL) 713 return NULL; 714 if (! _bfd_link_hash_table_init (&ret->root, abfd, 715 _bfd_generic_link_hash_newfunc, 716 sizeof (struct generic_link_hash_entry))) 717 { 718 free (ret); 719 return NULL; 720 } 721 return &ret->root; 722} 723 724void 725_bfd_generic_link_hash_table_free (struct bfd_link_hash_table *hash) 726{ 727 struct generic_link_hash_table *ret 728 = (struct generic_link_hash_table *) hash; 729 730 bfd_hash_table_free (&ret->root.table); 731 free (ret); 732} 733 734/* Grab the symbols for an object file when doing a generic link. We 735 store the symbols in the outsymbols field. We need to keep them 736 around for the entire link to ensure that we only read them once. 737 If we read them multiple times, we might wind up with relocs and 738 the hash table pointing to different instances of the symbol 739 structure. */ 740 741static bfd_boolean 742generic_link_read_symbols (bfd *abfd) 743{ 744 if (bfd_get_outsymbols (abfd) == NULL) 745 { 746 long symsize; 747 long symcount; 748 749 symsize = bfd_get_symtab_upper_bound (abfd); 750 if (symsize < 0) 751 return FALSE; 752 bfd_get_outsymbols (abfd) = bfd_alloc (abfd, symsize); 753 if (bfd_get_outsymbols (abfd) == NULL && symsize != 0) 754 return FALSE; 755 symcount = bfd_canonicalize_symtab (abfd, bfd_get_outsymbols (abfd)); 756 if (symcount < 0) 757 return FALSE; 758 bfd_get_symcount (abfd) = symcount; 759 } 760 761 return TRUE; 762} 763 764/* Generic function to add symbols to from an object file to the 765 global hash table. This version does not automatically collect 766 constructors by name. */ 767 768bfd_boolean 769_bfd_generic_link_add_symbols (bfd *abfd, struct bfd_link_info *info) 770{ 771 return generic_link_add_symbols (abfd, info, FALSE); 772} 773 774/* Generic function to add symbols from an object file to the global 775 hash table. This version automatically collects constructors by 776 name, as the collect2 program does. It should be used for any 777 target which does not provide some other mechanism for setting up 778 constructors and destructors; these are approximately those targets 779 for which gcc uses collect2 and do not support stabs. */ 780 781bfd_boolean 782_bfd_generic_link_add_symbols_collect (bfd *abfd, struct bfd_link_info *info) 783{ 784 return generic_link_add_symbols (abfd, info, TRUE); 785} 786 787/* Indicate that we are only retrieving symbol values from this 788 section. We want the symbols to act as though the values in the 789 file are absolute. */ 790 791void 792_bfd_generic_link_just_syms (asection *sec, 793 struct bfd_link_info *info ATTRIBUTE_UNUSED) 794{ 795 sec->output_section = bfd_abs_section_ptr; 796 sec->output_offset = sec->vma; 797} 798 799/* Add symbols from an object file to the global hash table. */ 800 801static bfd_boolean 802generic_link_add_symbols (bfd *abfd, 803 struct bfd_link_info *info, 804 bfd_boolean collect) 805{ 806 bfd_boolean ret; 807 808 switch (bfd_get_format (abfd)) 809 { 810 case bfd_object: 811 ret = generic_link_add_object_symbols (abfd, info, collect); 812 break; 813 case bfd_archive: 814 ret = (_bfd_generic_link_add_archive_symbols 815 (abfd, info, 816 (collect 817 ? generic_link_check_archive_element_collect 818 : generic_link_check_archive_element_no_collect))); 819 break; 820 default: 821 bfd_set_error (bfd_error_wrong_format); 822 ret = FALSE; 823 } 824 825 return ret; 826} 827 828/* Add symbols from an object file to the global hash table. */ 829 830static bfd_boolean 831generic_link_add_object_symbols (bfd *abfd, 832 struct bfd_link_info *info, 833 bfd_boolean collect) 834{ 835 bfd_size_type symcount; 836 struct bfd_symbol **outsyms; 837 838 if (! generic_link_read_symbols (abfd)) 839 return FALSE; 840 symcount = _bfd_generic_link_get_symcount (abfd); 841 outsyms = _bfd_generic_link_get_symbols (abfd); 842 return generic_link_add_symbol_list (abfd, info, symcount, outsyms, collect); 843} 844 845/* We build a hash table of all symbols defined in an archive. */ 846 847/* An archive symbol may be defined by multiple archive elements. 848 This linked list is used to hold the elements. */ 849 850struct archive_list 851{ 852 struct archive_list *next; 853 unsigned int indx; 854}; 855 856/* An entry in an archive hash table. */ 857 858struct archive_hash_entry 859{ 860 struct bfd_hash_entry root; 861 /* Where the symbol is defined. */ 862 struct archive_list *defs; 863}; 864 865/* An archive hash table itself. */ 866 867struct archive_hash_table 868{ 869 struct bfd_hash_table table; 870}; 871 872/* Create a new entry for an archive hash table. */ 873 874static struct bfd_hash_entry * 875archive_hash_newfunc (struct bfd_hash_entry *entry, 876 struct bfd_hash_table *table, 877 const char *string) 878{ 879 struct archive_hash_entry *ret = (struct archive_hash_entry *) entry; 880 881 /* Allocate the structure if it has not already been allocated by a 882 subclass. */ 883 if (ret == NULL) 884 ret = bfd_hash_allocate (table, sizeof (struct archive_hash_entry)); 885 if (ret == NULL) 886 return NULL; 887 888 /* Call the allocation method of the superclass. */ 889 ret = ((struct archive_hash_entry *) 890 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string)); 891 892 if (ret) 893 { 894 /* Initialize the local fields. */ 895 ret->defs = NULL; 896 } 897 898 return &ret->root; 899} 900 901/* Initialize an archive hash table. */ 902 903static bfd_boolean 904archive_hash_table_init 905 (struct archive_hash_table *table, 906 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *, 907 struct bfd_hash_table *, 908 const char *), 909 unsigned int entsize) 910{ 911 return bfd_hash_table_init (&table->table, newfunc, entsize); 912} 913 914/* Look up an entry in an archive hash table. */ 915 916#define archive_hash_lookup(t, string, create, copy) \ 917 ((struct archive_hash_entry *) \ 918 bfd_hash_lookup (&(t)->table, (string), (create), (copy))) 919 920/* Allocate space in an archive hash table. */ 921 922#define archive_hash_allocate(t, size) bfd_hash_allocate (&(t)->table, (size)) 923 924/* Free an archive hash table. */ 925 926#define archive_hash_table_free(t) bfd_hash_table_free (&(t)->table) 927 928/* Generic function to add symbols from an archive file to the global 929 hash file. This function presumes that the archive symbol table 930 has already been read in (this is normally done by the 931 bfd_check_format entry point). It looks through the undefined and 932 common symbols and searches the archive symbol table for them. If 933 it finds an entry, it includes the associated object file in the 934 link. 935 936 The old linker looked through the archive symbol table for 937 undefined symbols. We do it the other way around, looking through 938 undefined symbols for symbols defined in the archive. The 939 advantage of the newer scheme is that we only have to look through 940 the list of undefined symbols once, whereas the old method had to 941 re-search the symbol table each time a new object file was added. 942 943 The CHECKFN argument is used to see if an object file should be 944 included. CHECKFN should set *PNEEDED to TRUE if the object file 945 should be included, and must also call the bfd_link_info 946 add_archive_element callback function and handle adding the symbols 947 to the global hash table. CHECKFN should only return FALSE if some 948 sort of error occurs. 949 950 For some formats, such as a.out, it is possible to look through an 951 object file but not actually include it in the link. The 952 archive_pass field in a BFD is used to avoid checking the symbols 953 of an object files too many times. When an object is included in 954 the link, archive_pass is set to -1. If an object is scanned but 955 not included, archive_pass is set to the pass number. The pass 956 number is incremented each time a new object file is included. The 957 pass number is used because when a new object file is included it 958 may create new undefined symbols which cause a previously examined 959 object file to be included. */ 960 961bfd_boolean 962_bfd_generic_link_add_archive_symbols 963 (bfd *abfd, 964 struct bfd_link_info *info, 965 bfd_boolean (*checkfn) (bfd *, struct bfd_link_info *, bfd_boolean *)) 966{ 967 carsym *arsyms; 968 carsym *arsym_end; 969 register carsym *arsym; 970 int pass; 971 struct archive_hash_table arsym_hash; 972 unsigned int indx; 973 struct bfd_link_hash_entry **pundef; 974 975 if (! bfd_has_map (abfd)) 976 { 977 /* An empty archive is a special case. */ 978 if (bfd_openr_next_archived_file (abfd, NULL) == NULL) 979 return TRUE; 980 bfd_set_error (bfd_error_no_armap); 981 return FALSE; 982 } 983 984 arsyms = bfd_ardata (abfd)->symdefs; 985 arsym_end = arsyms + bfd_ardata (abfd)->symdef_count; 986 987 /* In order to quickly determine whether an symbol is defined in 988 this archive, we build a hash table of the symbols. */ 989 if (! archive_hash_table_init (&arsym_hash, archive_hash_newfunc, 990 sizeof (struct archive_hash_entry))) 991 return FALSE; 992 for (arsym = arsyms, indx = 0; arsym < arsym_end; arsym++, indx++) 993 { 994 struct archive_hash_entry *arh; 995 struct archive_list *l, **pp; 996 997 arh = archive_hash_lookup (&arsym_hash, arsym->name, TRUE, FALSE); 998 if (arh == NULL) 999 goto error_return; 1000 l = ((struct archive_list *) 1001 archive_hash_allocate (&arsym_hash, sizeof (struct archive_list))); 1002 if (l == NULL) 1003 goto error_return; 1004 l->indx = indx; 1005 for (pp = &arh->defs; *pp != NULL; pp = &(*pp)->next) 1006 ; 1007 *pp = l; 1008 l->next = NULL; 1009 } 1010 1011 /* The archive_pass field in the archive itself is used to 1012 initialize PASS, sine we may search the same archive multiple 1013 times. */ 1014 pass = abfd->archive_pass + 1; 1015 1016 /* New undefined symbols are added to the end of the list, so we 1017 only need to look through it once. */ 1018 pundef = &info->hash->undefs; 1019 while (*pundef != NULL) 1020 { 1021 struct bfd_link_hash_entry *h; 1022 struct archive_hash_entry *arh; 1023 struct archive_list *l; 1024 1025 h = *pundef; 1026 1027 /* When a symbol is defined, it is not necessarily removed from 1028 the list. */ 1029 if (h->type != bfd_link_hash_undefined 1030 && h->type != bfd_link_hash_common) 1031 { 1032 /* Remove this entry from the list, for general cleanliness 1033 and because we are going to look through the list again 1034 if we search any more libraries. We can't remove the 1035 entry if it is the tail, because that would lose any 1036 entries we add to the list later on (it would also cause 1037 us to lose track of whether the symbol has been 1038 referenced). */ 1039 if (*pundef != info->hash->undefs_tail) 1040 *pundef = (*pundef)->u.undef.next; 1041 else 1042 pundef = &(*pundef)->u.undef.next; 1043 continue; 1044 } 1045 1046 /* Look for this symbol in the archive symbol map. */ 1047 arh = archive_hash_lookup (&arsym_hash, h->root.string, FALSE, FALSE); 1048 if (arh == NULL) 1049 { 1050 /* If we haven't found the exact symbol we're looking for, 1051 let's look for its import thunk */ 1052 if (info->pei386_auto_import) 1053 { 1054 bfd_size_type amt = strlen (h->root.string) + 10; 1055 char *buf = bfd_malloc (amt); 1056 if (buf == NULL) 1057 return FALSE; 1058 1059 sprintf (buf, "__imp_%s", h->root.string); 1060 arh = archive_hash_lookup (&arsym_hash, buf, FALSE, FALSE); 1061 free(buf); 1062 } 1063 if (arh == NULL) 1064 { 1065 pundef = &(*pundef)->u.undef.next; 1066 continue; 1067 } 1068 } 1069 /* Look at all the objects which define this symbol. */ 1070 for (l = arh->defs; l != NULL; l = l->next) 1071 { 1072 bfd *element; 1073 bfd_boolean needed; 1074 1075 /* If the symbol has gotten defined along the way, quit. */ 1076 if (h->type != bfd_link_hash_undefined 1077 && h->type != bfd_link_hash_common) 1078 break; 1079 1080 element = bfd_get_elt_at_index (abfd, l->indx); 1081 if (element == NULL) 1082 goto error_return; 1083 1084 /* If we've already included this element, or if we've 1085 already checked it on this pass, continue. */ 1086 if (element->archive_pass == -1 1087 || element->archive_pass == pass) 1088 continue; 1089 1090 /* If we can't figure this element out, just ignore it. */ 1091 if (! bfd_check_format (element, bfd_object)) 1092 { 1093 element->archive_pass = -1; 1094 continue; 1095 } 1096 1097 /* CHECKFN will see if this element should be included, and 1098 go ahead and include it if appropriate. */ 1099 if (! (*checkfn) (element, info, &needed)) 1100 goto error_return; 1101 1102 if (! needed) 1103 element->archive_pass = pass; 1104 else 1105 { 1106 element->archive_pass = -1; 1107 1108 /* Increment the pass count to show that we may need to 1109 recheck object files which were already checked. */ 1110 ++pass; 1111 } 1112 } 1113 1114 pundef = &(*pundef)->u.undef.next; 1115 } 1116 1117 archive_hash_table_free (&arsym_hash); 1118 1119 /* Save PASS in case we are called again. */ 1120 abfd->archive_pass = pass; 1121 1122 return TRUE; 1123 1124 error_return: 1125 archive_hash_table_free (&arsym_hash); 1126 return FALSE; 1127} 1128 1129/* See if we should include an archive element. This version is used 1130 when we do not want to automatically collect constructors based on 1131 the symbol name, presumably because we have some other mechanism 1132 for finding them. */ 1133 1134static bfd_boolean 1135generic_link_check_archive_element_no_collect ( 1136 bfd *abfd, 1137 struct bfd_link_info *info, 1138 bfd_boolean *pneeded) 1139{ 1140 return generic_link_check_archive_element (abfd, info, pneeded, FALSE); 1141} 1142 1143/* See if we should include an archive element. This version is used 1144 when we want to automatically collect constructors based on the 1145 symbol name, as collect2 does. */ 1146 1147static bfd_boolean 1148generic_link_check_archive_element_collect (bfd *abfd, 1149 struct bfd_link_info *info, 1150 bfd_boolean *pneeded) 1151{ 1152 return generic_link_check_archive_element (abfd, info, pneeded, TRUE); 1153} 1154 1155/* See if we should include an archive element. Optionally collect 1156 constructors. */ 1157 1158static bfd_boolean 1159generic_link_check_archive_element (bfd *abfd, 1160 struct bfd_link_info *info, 1161 bfd_boolean *pneeded, 1162 bfd_boolean collect) 1163{ 1164 asymbol **pp, **ppend; 1165 1166 *pneeded = FALSE; 1167 1168 if (! generic_link_read_symbols (abfd)) 1169 return FALSE; 1170 1171 pp = _bfd_generic_link_get_symbols (abfd); 1172 ppend = pp + _bfd_generic_link_get_symcount (abfd); 1173 for (; pp < ppend; pp++) 1174 { 1175 asymbol *p; 1176 struct bfd_link_hash_entry *h; 1177 1178 p = *pp; 1179 1180 /* We are only interested in globally visible symbols. */ 1181 if (! bfd_is_com_section (p->section) 1182 && (p->flags & (BSF_GLOBAL | BSF_INDIRECT | BSF_WEAK)) == 0) 1183 continue; 1184 1185 /* We are only interested if we know something about this 1186 symbol, and it is undefined or common. An undefined weak 1187 symbol (type bfd_link_hash_undefweak) is not considered to be 1188 a reference when pulling files out of an archive. See the 1189 SVR4 ABI, p. 4-27. */ 1190 h = bfd_link_hash_lookup (info->hash, bfd_asymbol_name (p), FALSE, 1191 FALSE, TRUE); 1192 if (h == NULL 1193 || (h->type != bfd_link_hash_undefined 1194 && h->type != bfd_link_hash_common)) 1195 continue; 1196 1197 /* P is a symbol we are looking for. */ 1198 1199 if (! bfd_is_com_section (p->section)) 1200 { 1201 bfd_size_type symcount; 1202 asymbol **symbols; 1203 1204 /* This object file defines this symbol, so pull it in. */ 1205 if (! (*info->callbacks->add_archive_element) (info, abfd, 1206 bfd_asymbol_name (p))) 1207 return FALSE; 1208 symcount = _bfd_generic_link_get_symcount (abfd); 1209 symbols = _bfd_generic_link_get_symbols (abfd); 1210 if (! generic_link_add_symbol_list (abfd, info, symcount, 1211 symbols, collect)) 1212 return FALSE; 1213 *pneeded = TRUE; 1214 return TRUE; 1215 } 1216 1217 /* P is a common symbol. */ 1218 1219 if (h->type == bfd_link_hash_undefined) 1220 { 1221 bfd *symbfd; 1222 bfd_vma size; 1223 unsigned int power; 1224 1225 symbfd = h->u.undef.abfd; 1226 if (symbfd == NULL) 1227 { 1228 /* This symbol was created as undefined from outside 1229 BFD. We assume that we should link in the object 1230 file. This is for the -u option in the linker. */ 1231 if (! (*info->callbacks->add_archive_element) 1232 (info, abfd, bfd_asymbol_name (p))) 1233 return FALSE; 1234 *pneeded = TRUE; 1235 return TRUE; 1236 } 1237 1238 /* Turn the symbol into a common symbol but do not link in 1239 the object file. This is how a.out works. Object 1240 formats that require different semantics must implement 1241 this function differently. This symbol is already on the 1242 undefs list. We add the section to a common section 1243 attached to symbfd to ensure that it is in a BFD which 1244 will be linked in. */ 1245 h->type = bfd_link_hash_common; 1246 h->u.c.p = 1247 bfd_hash_allocate (&info->hash->table, 1248 sizeof (struct bfd_link_hash_common_entry)); 1249 if (h->u.c.p == NULL) 1250 return FALSE; 1251 1252 size = bfd_asymbol_value (p); 1253 h->u.c.size = size; 1254 1255 power = bfd_log2 (size); 1256 if (power > 4) 1257 power = 4; 1258 h->u.c.p->alignment_power = power; 1259 1260 if (p->section == bfd_com_section_ptr) 1261 h->u.c.p->section = bfd_make_section_old_way (symbfd, "COMMON"); 1262 else 1263 h->u.c.p->section = bfd_make_section_old_way (symbfd, 1264 p->section->name); 1265 h->u.c.p->section->flags = SEC_ALLOC; 1266 } 1267 else 1268 { 1269 /* Adjust the size of the common symbol if necessary. This 1270 is how a.out works. Object formats that require 1271 different semantics must implement this function 1272 differently. */ 1273 if (bfd_asymbol_value (p) > h->u.c.size) 1274 h->u.c.size = bfd_asymbol_value (p); 1275 } 1276 } 1277 1278 /* This archive element is not needed. */ 1279 return TRUE; 1280} 1281 1282/* Add the symbols from an object file to the global hash table. ABFD 1283 is the object file. INFO is the linker information. SYMBOL_COUNT 1284 is the number of symbols. SYMBOLS is the list of symbols. COLLECT 1285 is TRUE if constructors should be automatically collected by name 1286 as is done by collect2. */ 1287 1288static bfd_boolean 1289generic_link_add_symbol_list (bfd *abfd, 1290 struct bfd_link_info *info, 1291 bfd_size_type symbol_count, 1292 asymbol **symbols, 1293 bfd_boolean collect) 1294{ 1295 asymbol **pp, **ppend; 1296 1297 pp = symbols; 1298 ppend = symbols + symbol_count; 1299 for (; pp < ppend; pp++) 1300 { 1301 asymbol *p; 1302 1303 p = *pp; 1304 1305 if ((p->flags & (BSF_INDIRECT 1306 | BSF_WARNING 1307 | BSF_GLOBAL 1308 | BSF_CONSTRUCTOR 1309 | BSF_WEAK)) != 0 1310 || bfd_is_und_section (bfd_get_section (p)) 1311 || bfd_is_com_section (bfd_get_section (p)) 1312 || bfd_is_ind_section (bfd_get_section (p))) 1313 { 1314 const char *name; 1315 const char *string; 1316 struct generic_link_hash_entry *h; 1317 struct bfd_link_hash_entry *bh; 1318 1319 string = name = bfd_asymbol_name (p); 1320 if (((p->flags & BSF_INDIRECT) != 0 1321 || bfd_is_ind_section (p->section)) 1322 && pp + 1 < ppend) 1323 { 1324 pp++; 1325 string = bfd_asymbol_name (*pp); 1326 } 1327 else if ((p->flags & BSF_WARNING) != 0 1328 && pp + 1 < ppend) 1329 { 1330 /* The name of P is actually the warning string, and the 1331 next symbol is the one to warn about. */ 1332 pp++; 1333 name = bfd_asymbol_name (*pp); 1334 } 1335 1336 bh = NULL; 1337 if (! (_bfd_generic_link_add_one_symbol 1338 (info, abfd, name, p->flags, bfd_get_section (p), 1339 p->value, string, FALSE, collect, &bh))) 1340 return FALSE; 1341 h = (struct generic_link_hash_entry *) bh; 1342 1343 /* If this is a constructor symbol, and the linker didn't do 1344 anything with it, then we want to just pass the symbol 1345 through to the output file. This will happen when 1346 linking with -r. */ 1347 if ((p->flags & BSF_CONSTRUCTOR) != 0 1348 && (h == NULL || h->root.type == bfd_link_hash_new)) 1349 { 1350 p->udata.p = NULL; 1351 continue; 1352 } 1353 1354 /* Save the BFD symbol so that we don't lose any backend 1355 specific information that may be attached to it. We only 1356 want this one if it gives more information than the 1357 existing one; we don't want to replace a defined symbol 1358 with an undefined one. This routine may be called with a 1359 hash table other than the generic hash table, so we only 1360 do this if we are certain that the hash table is a 1361 generic one. */ 1362 if (info->hash->creator == abfd->xvec) 1363 { 1364 if (h->sym == NULL 1365 || (! bfd_is_und_section (bfd_get_section (p)) 1366 && (! bfd_is_com_section (bfd_get_section (p)) 1367 || bfd_is_und_section (bfd_get_section (h->sym))))) 1368 { 1369 h->sym = p; 1370 /* BSF_OLD_COMMON is a hack to support COFF reloc 1371 reading, and it should go away when the COFF 1372 linker is switched to the new version. */ 1373 if (bfd_is_com_section (bfd_get_section (p))) 1374 p->flags |= BSF_OLD_COMMON; 1375 } 1376 } 1377 1378 /* Store a back pointer from the symbol to the hash 1379 table entry for the benefit of relaxation code until 1380 it gets rewritten to not use asymbol structures. 1381 Setting this is also used to check whether these 1382 symbols were set up by the generic linker. */ 1383 p->udata.p = h; 1384 } 1385 } 1386 1387 return TRUE; 1388} 1389 1390/* We use a state table to deal with adding symbols from an object 1391 file. The first index into the state table describes the symbol 1392 from the object file. The second index into the state table is the 1393 type of the symbol in the hash table. */ 1394 1395/* The symbol from the object file is turned into one of these row 1396 values. */ 1397 1398enum link_row 1399{ 1400 UNDEF_ROW, /* Undefined. */ 1401 UNDEFW_ROW, /* Weak undefined. */ 1402 DEF_ROW, /* Defined. */ 1403 DEFW_ROW, /* Weak defined. */ 1404 COMMON_ROW, /* Common. */ 1405 INDR_ROW, /* Indirect. */ 1406 WARN_ROW, /* Warning. */ 1407 SET_ROW /* Member of set. */ 1408}; 1409 1410/* apparently needed for Hitachi 3050R(HI-UX/WE2)? */ 1411#undef FAIL 1412 1413/* The actions to take in the state table. */ 1414 1415enum link_action 1416{ 1417 FAIL, /* Abort. */ 1418 UND, /* Mark symbol undefined. */ 1419 WEAK, /* Mark symbol weak undefined. */ 1420 DEF, /* Mark symbol defined. */ 1421 DEFW, /* Mark symbol weak defined. */ 1422 COM, /* Mark symbol common. */ 1423 REF, /* Mark defined symbol referenced. */ 1424 CREF, /* Possibly warn about common reference to defined symbol. */ 1425 CDEF, /* Define existing common symbol. */ 1426 NOACT, /* No action. */ 1427 BIG, /* Mark symbol common using largest size. */ 1428 MDEF, /* Multiple definition error. */ 1429 MIND, /* Multiple indirect symbols. */ 1430 IND, /* Make indirect symbol. */ 1431 CIND, /* Make indirect symbol from existing common symbol. */ 1432 SET, /* Add value to set. */ 1433 MWARN, /* Make warning symbol. */ 1434 WARN, /* Issue warning. */ 1435 CWARN, /* Warn if referenced, else MWARN. */ 1436 CYCLE, /* Repeat with symbol pointed to. */ 1437 REFC, /* Mark indirect symbol referenced and then CYCLE. */ 1438 WARNC /* Issue warning and then CYCLE. */ 1439}; 1440 1441/* The state table itself. The first index is a link_row and the 1442 second index is a bfd_link_hash_type. */ 1443 1444static const enum link_action link_action[8][8] = 1445{ 1446 /* current\prev new undef undefw def defw com indr warn */ 1447 /* UNDEF_ROW */ {UND, NOACT, UND, REF, REF, NOACT, REFC, WARNC }, 1448 /* UNDEFW_ROW */ {WEAK, NOACT, NOACT, REF, REF, NOACT, REFC, WARNC }, 1449 /* DEF_ROW */ {DEF, DEF, DEF, MDEF, DEF, CDEF, MDEF, CYCLE }, 1450 /* DEFW_ROW */ {DEFW, DEFW, DEFW, NOACT, NOACT, NOACT, NOACT, CYCLE }, 1451 /* COMMON_ROW */ {COM, COM, COM, CREF, COM, BIG, REFC, WARNC }, 1452 /* INDR_ROW */ {IND, IND, IND, MDEF, IND, CIND, MIND, CYCLE }, 1453 /* WARN_ROW */ {MWARN, WARN, WARN, CWARN, CWARN, WARN, CWARN, NOACT }, 1454 /* SET_ROW */ {SET, SET, SET, SET, SET, SET, CYCLE, CYCLE } 1455}; 1456 1457/* Most of the entries in the LINK_ACTION table are straightforward, 1458 but a few are somewhat subtle. 1459 1460 A reference to an indirect symbol (UNDEF_ROW/indr or 1461 UNDEFW_ROW/indr) is counted as a reference both to the indirect 1462 symbol and to the symbol the indirect symbol points to. 1463 1464 A reference to a warning symbol (UNDEF_ROW/warn or UNDEFW_ROW/warn) 1465 causes the warning to be issued. 1466 1467 A common definition of an indirect symbol (COMMON_ROW/indr) is 1468 treated as a multiple definition error. Likewise for an indirect 1469 definition of a common symbol (INDR_ROW/com). 1470 1471 An indirect definition of a warning (INDR_ROW/warn) does not cause 1472 the warning to be issued. 1473 1474 If a warning is created for an indirect symbol (WARN_ROW/indr) no 1475 warning is created for the symbol the indirect symbol points to. 1476 1477 Adding an entry to a set does not count as a reference to a set, 1478 and no warning is issued (SET_ROW/warn). */ 1479 1480/* Return the BFD in which a hash entry has been defined, if known. */ 1481 1482static bfd * 1483hash_entry_bfd (struct bfd_link_hash_entry *h) 1484{ 1485 while (h->type == bfd_link_hash_warning) 1486 h = h->u.i.link; 1487 switch (h->type) 1488 { 1489 default: 1490 return NULL; 1491 case bfd_link_hash_undefined: 1492 case bfd_link_hash_undefweak: 1493 return h->u.undef.abfd; 1494 case bfd_link_hash_defined: 1495 case bfd_link_hash_defweak: 1496 return h->u.def.section->owner; 1497 case bfd_link_hash_common: 1498 return h->u.c.p->section->owner; 1499 } 1500 /*NOTREACHED*/ 1501} 1502 1503/* Add a symbol to the global hash table. 1504 ABFD is the BFD the symbol comes from. 1505 NAME is the name of the symbol. 1506 FLAGS is the BSF_* bits associated with the symbol. 1507 SECTION is the section in which the symbol is defined; this may be 1508 bfd_und_section_ptr or bfd_com_section_ptr. 1509 VALUE is the value of the symbol, relative to the section. 1510 STRING is used for either an indirect symbol, in which case it is 1511 the name of the symbol to indirect to, or a warning symbol, in 1512 which case it is the warning string. 1513 COPY is TRUE if NAME or STRING must be copied into locally 1514 allocated memory if they need to be saved. 1515 COLLECT is TRUE if we should automatically collect gcc constructor 1516 or destructor names as collect2 does. 1517 HASHP, if not NULL, is a place to store the created hash table 1518 entry; if *HASHP is not NULL, the caller has already looked up 1519 the hash table entry, and stored it in *HASHP. */ 1520 1521bfd_boolean 1522_bfd_generic_link_add_one_symbol (struct bfd_link_info *info, 1523 bfd *abfd, 1524 const char *name, 1525 flagword flags, 1526 asection *section, 1527 bfd_vma value, 1528 const char *string, 1529 bfd_boolean copy, 1530 bfd_boolean collect, 1531 struct bfd_link_hash_entry **hashp) 1532{ 1533 enum link_row row; 1534 struct bfd_link_hash_entry *h; 1535 bfd_boolean cycle; 1536 1537 if (bfd_is_ind_section (section) 1538 || (flags & BSF_INDIRECT) != 0) 1539 row = INDR_ROW; 1540 else if ((flags & BSF_WARNING) != 0) 1541 row = WARN_ROW; 1542 else if ((flags & BSF_CONSTRUCTOR) != 0) 1543 row = SET_ROW; 1544 else if (bfd_is_und_section (section)) 1545 { 1546 if ((flags & BSF_WEAK) != 0) 1547 row = UNDEFW_ROW; 1548 else 1549 row = UNDEF_ROW; 1550 } 1551 else if ((flags & BSF_WEAK) != 0) 1552 row = DEFW_ROW; 1553 else if (bfd_is_com_section (section)) 1554 row = COMMON_ROW; 1555 else 1556 row = DEF_ROW; 1557 1558 if (hashp != NULL && *hashp != NULL) 1559 h = *hashp; 1560 else 1561 { 1562 if (row == UNDEF_ROW || row == UNDEFW_ROW) 1563 h = bfd_wrapped_link_hash_lookup (abfd, info, name, TRUE, copy, FALSE); 1564 else 1565 h = bfd_link_hash_lookup (info->hash, name, TRUE, copy, FALSE); 1566 if (h == NULL) 1567 { 1568 if (hashp != NULL) 1569 *hashp = NULL; 1570 return FALSE; 1571 } 1572 } 1573 1574 if (info->notice_all 1575 || (info->notice_hash != NULL 1576 && bfd_hash_lookup (info->notice_hash, name, FALSE, FALSE) != NULL)) 1577 { 1578 if (! (*info->callbacks->notice) (info, h->root.string, abfd, section, 1579 value)) 1580 return FALSE; 1581 } 1582 1583 if (hashp != NULL) 1584 *hashp = h; 1585 1586 do 1587 { 1588 enum link_action action; 1589 1590 cycle = FALSE; 1591 action = link_action[(int) row][(int) h->type]; 1592 switch (action) 1593 { 1594 case FAIL: 1595 abort (); 1596 1597 case NOACT: 1598 /* Do nothing. */ 1599 break; 1600 1601 case UND: 1602 /* Make a new undefined symbol. */ 1603 h->type = bfd_link_hash_undefined; 1604 h->u.undef.abfd = abfd; 1605 bfd_link_add_undef (info->hash, h); 1606 break; 1607 1608 case WEAK: 1609 /* Make a new weak undefined symbol. */ 1610 h->type = bfd_link_hash_undefweak; 1611 h->u.undef.abfd = abfd; 1612 h->u.undef.weak = abfd; 1613 break; 1614 1615 case CDEF: 1616 /* We have found a definition for a symbol which was 1617 previously common. */ 1618 BFD_ASSERT (h->type == bfd_link_hash_common); 1619 if (! ((*info->callbacks->multiple_common) 1620 (info, h->root.string, 1621 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1622 abfd, bfd_link_hash_defined, 0))) 1623 return FALSE; 1624 /* Fall through. */ 1625 case DEF: 1626 case DEFW: 1627 { 1628 enum bfd_link_hash_type oldtype; 1629 1630 /* Define a symbol. */ 1631 oldtype = h->type; 1632 if (action == DEFW) 1633 h->type = bfd_link_hash_defweak; 1634 else 1635 h->type = bfd_link_hash_defined; 1636 h->u.def.section = section; 1637 h->u.def.value = value; 1638 1639 /* If we have been asked to, we act like collect2 and 1640 identify all functions that might be global 1641 constructors and destructors and pass them up in a 1642 callback. We only do this for certain object file 1643 types, since many object file types can handle this 1644 automatically. */ 1645 if (collect && name[0] == '_') 1646 { 1647 const char *s; 1648 1649 /* A constructor or destructor name starts like this: 1650 _+GLOBAL_[_.$][ID][_.$] where the first [_.$] and 1651 the second are the same character (we accept any 1652 character there, in case a new object file format 1653 comes along with even worse naming restrictions). */ 1654 1655#define CONS_PREFIX "GLOBAL_" 1656#define CONS_PREFIX_LEN (sizeof CONS_PREFIX - 1) 1657 1658 s = name + 1; 1659 while (*s == '_') 1660 ++s; 1661 if (s[0] == 'G' && CONST_STRNEQ (s, CONS_PREFIX)) 1662 { 1663 char c; 1664 1665 c = s[CONS_PREFIX_LEN + 1]; 1666 if ((c == 'I' || c == 'D') 1667 && s[CONS_PREFIX_LEN] == s[CONS_PREFIX_LEN + 2]) 1668 { 1669 /* If this is a definition of a symbol which 1670 was previously weakly defined, we are in 1671 trouble. We have already added a 1672 constructor entry for the weak defined 1673 symbol, and now we are trying to add one 1674 for the new symbol. Fortunately, this case 1675 should never arise in practice. */ 1676 if (oldtype == bfd_link_hash_defweak) 1677 abort (); 1678 1679 if (! ((*info->callbacks->constructor) 1680 (info, c == 'I', 1681 h->root.string, abfd, section, value))) 1682 return FALSE; 1683 } 1684 } 1685 } 1686 } 1687 1688 break; 1689 1690 case COM: 1691 /* We have found a common definition for a symbol. */ 1692 if (h->type == bfd_link_hash_new) 1693 bfd_link_add_undef (info->hash, h); 1694 h->type = bfd_link_hash_common; 1695 h->u.c.p = 1696 bfd_hash_allocate (&info->hash->table, 1697 sizeof (struct bfd_link_hash_common_entry)); 1698 if (h->u.c.p == NULL) 1699 return FALSE; 1700 1701 h->u.c.size = value; 1702 1703 /* Select a default alignment based on the size. This may 1704 be overridden by the caller. */ 1705 { 1706 unsigned int power; 1707 1708 power = bfd_log2 (value); 1709 if (power > 4) 1710 power = 4; 1711 h->u.c.p->alignment_power = power; 1712 } 1713 1714 /* The section of a common symbol is only used if the common 1715 symbol is actually allocated. It basically provides a 1716 hook for the linker script to decide which output section 1717 the common symbols should be put in. In most cases, the 1718 section of a common symbol will be bfd_com_section_ptr, 1719 the code here will choose a common symbol section named 1720 "COMMON", and the linker script will contain *(COMMON) in 1721 the appropriate place. A few targets use separate common 1722 sections for small symbols, and they require special 1723 handling. */ 1724 if (section == bfd_com_section_ptr) 1725 { 1726 h->u.c.p->section = bfd_make_section_old_way (abfd, "COMMON"); 1727 h->u.c.p->section->flags = SEC_ALLOC; 1728 } 1729 else if (section->owner != abfd) 1730 { 1731 h->u.c.p->section = bfd_make_section_old_way (abfd, 1732 section->name); 1733 h->u.c.p->section->flags = SEC_ALLOC; 1734 } 1735 else 1736 h->u.c.p->section = section; 1737 break; 1738 1739 case REF: 1740 /* A reference to a defined symbol. */ 1741 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1742 h->u.undef.next = h; 1743 break; 1744 1745 case BIG: 1746 /* We have found a common definition for a symbol which 1747 already had a common definition. Use the maximum of the 1748 two sizes, and use the section required by the larger symbol. */ 1749 BFD_ASSERT (h->type == bfd_link_hash_common); 1750 if (! ((*info->callbacks->multiple_common) 1751 (info, h->root.string, 1752 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1753 abfd, bfd_link_hash_common, value))) 1754 return FALSE; 1755 if (value > h->u.c.size) 1756 { 1757 unsigned int power; 1758 1759 h->u.c.size = value; 1760 1761 /* Select a default alignment based on the size. This may 1762 be overridden by the caller. */ 1763 power = bfd_log2 (value); 1764 if (power > 4) 1765 power = 4; 1766 h->u.c.p->alignment_power = power; 1767 1768 /* Some systems have special treatment for small commons, 1769 hence we want to select the section used by the larger 1770 symbol. This makes sure the symbol does not go in a 1771 small common section if it is now too large. */ 1772 if (section == bfd_com_section_ptr) 1773 { 1774 h->u.c.p->section 1775 = bfd_make_section_old_way (abfd, "COMMON"); 1776 h->u.c.p->section->flags = SEC_ALLOC; 1777 } 1778 else if (section->owner != abfd) 1779 { 1780 h->u.c.p->section 1781 = bfd_make_section_old_way (abfd, section->name); 1782 h->u.c.p->section->flags = SEC_ALLOC; 1783 } 1784 else 1785 h->u.c.p->section = section; 1786 } 1787 break; 1788 1789 case CREF: 1790 { 1791 bfd *obfd; 1792 1793 /* We have found a common definition for a symbol which 1794 was already defined. FIXME: It would nice if we could 1795 report the BFD which defined an indirect symbol, but we 1796 don't have anywhere to store the information. */ 1797 if (h->type == bfd_link_hash_defined 1798 || h->type == bfd_link_hash_defweak) 1799 obfd = h->u.def.section->owner; 1800 else 1801 obfd = NULL; 1802 if (! ((*info->callbacks->multiple_common) 1803 (info, h->root.string, obfd, h->type, 0, 1804 abfd, bfd_link_hash_common, value))) 1805 return FALSE; 1806 } 1807 break; 1808 1809 case MIND: 1810 /* Multiple indirect symbols. This is OK if they both point 1811 to the same symbol. */ 1812 if (strcmp (h->u.i.link->root.string, string) == 0) 1813 break; 1814 /* Fall through. */ 1815 case MDEF: 1816 /* Handle a multiple definition. */ 1817 if (!info->allow_multiple_definition) 1818 { 1819 asection *msec = NULL; 1820 bfd_vma mval = 0; 1821 1822 switch (h->type) 1823 { 1824 case bfd_link_hash_defined: 1825 msec = h->u.def.section; 1826 mval = h->u.def.value; 1827 break; 1828 case bfd_link_hash_indirect: 1829 msec = bfd_ind_section_ptr; 1830 mval = 0; 1831 break; 1832 default: 1833 abort (); 1834 } 1835 1836 /* Ignore a redefinition of an absolute symbol to the 1837 same value; it's harmless. */ 1838 if (h->type == bfd_link_hash_defined 1839 && bfd_is_abs_section (msec) 1840 && bfd_is_abs_section (section) 1841 && value == mval) 1842 break; 1843 1844 if (! ((*info->callbacks->multiple_definition) 1845 (info, h->root.string, msec->owner, msec, mval, 1846 abfd, section, value))) 1847 return FALSE; 1848 } 1849 break; 1850 1851 case CIND: 1852 /* Create an indirect symbol from an existing common symbol. */ 1853 BFD_ASSERT (h->type == bfd_link_hash_common); 1854 if (! ((*info->callbacks->multiple_common) 1855 (info, h->root.string, 1856 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1857 abfd, bfd_link_hash_indirect, 0))) 1858 return FALSE; 1859 /* Fall through. */ 1860 case IND: 1861 /* Create an indirect symbol. */ 1862 { 1863 struct bfd_link_hash_entry *inh; 1864 1865 /* STRING is the name of the symbol we want to indirect 1866 to. */ 1867 inh = bfd_wrapped_link_hash_lookup (abfd, info, string, TRUE, 1868 copy, FALSE); 1869 if (inh == NULL) 1870 return FALSE; 1871 if (inh->type == bfd_link_hash_indirect 1872 && inh->u.i.link == h) 1873 { 1874 (*_bfd_error_handler) 1875 (_("%B: indirect symbol `%s' to `%s' is a loop"), 1876 abfd, name, string); 1877 bfd_set_error (bfd_error_invalid_operation); 1878 return FALSE; 1879 } 1880 if (inh->type == bfd_link_hash_new) 1881 { 1882 inh->type = bfd_link_hash_undefined; 1883 inh->u.undef.abfd = abfd; 1884 bfd_link_add_undef (info->hash, inh); 1885 } 1886 1887 /* If the indirect symbol has been referenced, we need to 1888 push the reference down to the symbol we are 1889 referencing. */ 1890 if (h->type != bfd_link_hash_new) 1891 { 1892 row = UNDEF_ROW; 1893 cycle = TRUE; 1894 } 1895 1896 h->type = bfd_link_hash_indirect; 1897 h->u.i.link = inh; 1898 } 1899 break; 1900 1901 case SET: 1902 /* Add an entry to a set. */ 1903 if (! (*info->callbacks->add_to_set) (info, h, BFD_RELOC_CTOR, 1904 abfd, section, value)) 1905 return FALSE; 1906 break; 1907 1908 case WARNC: 1909 /* Issue a warning and cycle. */ 1910 if (h->u.i.warning != NULL) 1911 { 1912 if (! (*info->callbacks->warning) (info, h->u.i.warning, 1913 h->root.string, abfd, 1914 NULL, 0)) 1915 return FALSE; 1916 /* Only issue a warning once. */ 1917 h->u.i.warning = NULL; 1918 } 1919 /* Fall through. */ 1920 case CYCLE: 1921 /* Try again with the referenced symbol. */ 1922 h = h->u.i.link; 1923 cycle = TRUE; 1924 break; 1925 1926 case REFC: 1927 /* A reference to an indirect symbol. */ 1928 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1929 h->u.undef.next = h; 1930 h = h->u.i.link; 1931 cycle = TRUE; 1932 break; 1933 1934 case WARN: 1935 /* Issue a warning. */ 1936 if (! (*info->callbacks->warning) (info, string, h->root.string, 1937 hash_entry_bfd (h), NULL, 0)) 1938 return FALSE; 1939 break; 1940 1941 case CWARN: 1942 /* Warn if this symbol has been referenced already, 1943 otherwise add a warning. A symbol has been referenced if 1944 the u.undef.next field is not NULL, or it is the tail of the 1945 undefined symbol list. The REF case above helps to 1946 ensure this. */ 1947 if (h->u.undef.next != NULL || info->hash->undefs_tail == h) 1948 { 1949 if (! (*info->callbacks->warning) (info, string, h->root.string, 1950 hash_entry_bfd (h), NULL, 0)) 1951 return FALSE; 1952 break; 1953 } 1954 /* Fall through. */ 1955 case MWARN: 1956 /* Make a warning symbol. */ 1957 { 1958 struct bfd_link_hash_entry *sub; 1959 1960 /* STRING is the warning to give. */ 1961 sub = ((struct bfd_link_hash_entry *) 1962 ((*info->hash->table.newfunc) 1963 (NULL, &info->hash->table, h->root.string))); 1964 if (sub == NULL) 1965 return FALSE; 1966 *sub = *h; 1967 sub->type = bfd_link_hash_warning; 1968 sub->u.i.link = h; 1969 if (! copy) 1970 sub->u.i.warning = string; 1971 else 1972 { 1973 char *w; 1974 size_t len = strlen (string) + 1; 1975 1976 w = bfd_hash_allocate (&info->hash->table, len); 1977 if (w == NULL) 1978 return FALSE; 1979 memcpy (w, string, len); 1980 sub->u.i.warning = w; 1981 } 1982 1983 bfd_hash_replace (&info->hash->table, 1984 (struct bfd_hash_entry *) h, 1985 (struct bfd_hash_entry *) sub); 1986 if (hashp != NULL) 1987 *hashp = sub; 1988 } 1989 break; 1990 } 1991 } 1992 while (cycle); 1993 1994 return TRUE; 1995} 1996 1997/* Generic final link routine. */ 1998 1999bfd_boolean 2000_bfd_generic_final_link (bfd *abfd, struct bfd_link_info *info) 2001{ 2002 bfd *sub; 2003 asection *o; 2004 struct bfd_link_order *p; 2005 size_t outsymalloc; 2006 struct generic_write_global_symbol_info wginfo; 2007 2008 bfd_get_outsymbols (abfd) = NULL; 2009 bfd_get_symcount (abfd) = 0; 2010 outsymalloc = 0; 2011 2012 /* Mark all sections which will be included in the output file. */ 2013 for (o = abfd->sections; o != NULL; o = o->next) 2014 for (p = o->map_head.link_order; p != NULL; p = p->next) 2015 if (p->type == bfd_indirect_link_order) 2016 p->u.indirect.section->linker_mark = TRUE; 2017 2018 /* Build the output symbol table. */ 2019 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next) 2020 if (! _bfd_generic_link_output_symbols (abfd, sub, info, &outsymalloc)) 2021 return FALSE; 2022 2023 /* Accumulate the global symbols. */ 2024 wginfo.info = info; 2025 wginfo.output_bfd = abfd; 2026 wginfo.psymalloc = &outsymalloc; 2027 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info), 2028 _bfd_generic_link_write_global_symbol, 2029 &wginfo); 2030 2031 /* Make sure we have a trailing NULL pointer on OUTSYMBOLS. We 2032 shouldn't really need one, since we have SYMCOUNT, but some old 2033 code still expects one. */ 2034 if (! generic_add_output_symbol (abfd, &outsymalloc, NULL)) 2035 return FALSE; 2036 2037 if (info->relocatable) 2038 { 2039 /* Allocate space for the output relocs for each section. */ 2040 for (o = abfd->sections; o != NULL; o = o->next) 2041 { 2042 o->reloc_count = 0; 2043 for (p = o->map_head.link_order; p != NULL; p = p->next) 2044 { 2045 if (p->type == bfd_section_reloc_link_order 2046 || p->type == bfd_symbol_reloc_link_order) 2047 ++o->reloc_count; 2048 else if (p->type == bfd_indirect_link_order) 2049 { 2050 asection *input_section; 2051 bfd *input_bfd; 2052 long relsize; 2053 arelent **relocs; 2054 asymbol **symbols; 2055 long reloc_count; 2056 2057 input_section = p->u.indirect.section; 2058 input_bfd = input_section->owner; 2059 relsize = bfd_get_reloc_upper_bound (input_bfd, 2060 input_section); 2061 if (relsize < 0) 2062 return FALSE; 2063 relocs = bfd_malloc (relsize); 2064 if (!relocs && relsize != 0) 2065 return FALSE; 2066 symbols = _bfd_generic_link_get_symbols (input_bfd); 2067 reloc_count = bfd_canonicalize_reloc (input_bfd, 2068 input_section, 2069 relocs, 2070 symbols); 2071 free (relocs); 2072 if (reloc_count < 0) 2073 return FALSE; 2074 BFD_ASSERT ((unsigned long) reloc_count 2075 == input_section->reloc_count); 2076 o->reloc_count += reloc_count; 2077 } 2078 } 2079 if (o->reloc_count > 0) 2080 { 2081 bfd_size_type amt; 2082 2083 amt = o->reloc_count; 2084 amt *= sizeof (arelent *); 2085 o->orelocation = bfd_alloc (abfd, amt); 2086 if (!o->orelocation) 2087 return FALSE; 2088 o->flags |= SEC_RELOC; 2089 /* Reset the count so that it can be used as an index 2090 when putting in the output relocs. */ 2091 o->reloc_count = 0; 2092 } 2093 } 2094 } 2095 2096 /* Handle all the link order information for the sections. */ 2097 for (o = abfd->sections; o != NULL; o = o->next) 2098 { 2099 for (p = o->map_head.link_order; p != NULL; p = p->next) 2100 { 2101 switch (p->type) 2102 { 2103 case bfd_section_reloc_link_order: 2104 case bfd_symbol_reloc_link_order: 2105 if (! _bfd_generic_reloc_link_order (abfd, info, o, p)) 2106 return FALSE; 2107 break; 2108 case bfd_indirect_link_order: 2109 if (! default_indirect_link_order (abfd, info, o, p, TRUE)) 2110 return FALSE; 2111 break; 2112 default: 2113 if (! _bfd_default_link_order (abfd, info, o, p)) 2114 return FALSE; 2115 break; 2116 } 2117 } 2118 } 2119 2120 return TRUE; 2121} 2122 2123/* Add an output symbol to the output BFD. */ 2124 2125static bfd_boolean 2126generic_add_output_symbol (bfd *output_bfd, size_t *psymalloc, asymbol *sym) 2127{ 2128 if (bfd_get_symcount (output_bfd) >= *psymalloc) 2129 { 2130 asymbol **newsyms; 2131 bfd_size_type amt; 2132 2133 if (*psymalloc == 0) 2134 *psymalloc = 124; 2135 else 2136 *psymalloc *= 2; 2137 amt = *psymalloc; 2138 amt *= sizeof (asymbol *); 2139 newsyms = bfd_realloc (bfd_get_outsymbols (output_bfd), amt); 2140 if (newsyms == NULL) 2141 return FALSE; 2142 bfd_get_outsymbols (output_bfd) = newsyms; 2143 } 2144 2145 bfd_get_outsymbols (output_bfd) [bfd_get_symcount (output_bfd)] = sym; 2146 if (sym != NULL) 2147 ++ bfd_get_symcount (output_bfd); 2148 2149 return TRUE; 2150} 2151 2152/* Handle the symbols for an input BFD. */ 2153 2154bfd_boolean 2155_bfd_generic_link_output_symbols (bfd *output_bfd, 2156 bfd *input_bfd, 2157 struct bfd_link_info *info, 2158 size_t *psymalloc) 2159{ 2160 asymbol **sym_ptr; 2161 asymbol **sym_end; 2162 2163 if (! generic_link_read_symbols (input_bfd)) 2164 return FALSE; 2165 2166 /* Create a filename symbol if we are supposed to. */ 2167 if (info->create_object_symbols_section != NULL) 2168 { 2169 asection *sec; 2170 2171 for (sec = input_bfd->sections; sec != NULL; sec = sec->next) 2172 { 2173 if (sec->output_section == info->create_object_symbols_section) 2174 { 2175 asymbol *newsym; 2176 2177 newsym = bfd_make_empty_symbol (input_bfd); 2178 if (!newsym) 2179 return FALSE; 2180 newsym->name = input_bfd->filename; 2181 newsym->value = 0; 2182 newsym->flags = BSF_LOCAL | BSF_FILE; 2183 newsym->section = sec; 2184 2185 if (! generic_add_output_symbol (output_bfd, psymalloc, 2186 newsym)) 2187 return FALSE; 2188 2189 break; 2190 } 2191 } 2192 } 2193 2194 /* Adjust the values of the globally visible symbols, and write out 2195 local symbols. */ 2196 sym_ptr = _bfd_generic_link_get_symbols (input_bfd); 2197 sym_end = sym_ptr + _bfd_generic_link_get_symcount (input_bfd); 2198 for (; sym_ptr < sym_end; sym_ptr++) 2199 { 2200 asymbol *sym; 2201 struct generic_link_hash_entry *h; 2202 bfd_boolean output; 2203 2204 h = NULL; 2205 sym = *sym_ptr; 2206 if ((sym->flags & (BSF_INDIRECT 2207 | BSF_WARNING 2208 | BSF_GLOBAL 2209 | BSF_CONSTRUCTOR 2210 | BSF_WEAK)) != 0 2211 || bfd_is_und_section (bfd_get_section (sym)) 2212 || bfd_is_com_section (bfd_get_section (sym)) 2213 || bfd_is_ind_section (bfd_get_section (sym))) 2214 { 2215 if (sym->udata.p != NULL) 2216 h = sym->udata.p; 2217 else if ((sym->flags & BSF_CONSTRUCTOR) != 0) 2218 { 2219 /* This case normally means that the main linker code 2220 deliberately ignored this constructor symbol. We 2221 should just pass it through. This will screw up if 2222 the constructor symbol is from a different, 2223 non-generic, object file format, but the case will 2224 only arise when linking with -r, which will probably 2225 fail anyhow, since there will be no way to represent 2226 the relocs in the output format being used. */ 2227 h = NULL; 2228 } 2229 else if (bfd_is_und_section (bfd_get_section (sym))) 2230 h = ((struct generic_link_hash_entry *) 2231 bfd_wrapped_link_hash_lookup (output_bfd, info, 2232 bfd_asymbol_name (sym), 2233 FALSE, FALSE, TRUE)); 2234 else 2235 h = _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info), 2236 bfd_asymbol_name (sym), 2237 FALSE, FALSE, TRUE); 2238 2239 if (h != NULL) 2240 { 2241 /* Force all references to this symbol to point to 2242 the same area in memory. It is possible that 2243 this routine will be called with a hash table 2244 other than a generic hash table, so we double 2245 check that. */ 2246 if (info->hash->creator == input_bfd->xvec) 2247 { 2248 if (h->sym != NULL) 2249 *sym_ptr = sym = h->sym; 2250 } 2251 2252 switch (h->root.type) 2253 { 2254 default: 2255 case bfd_link_hash_new: 2256 abort (); 2257 case bfd_link_hash_undefined: 2258 break; 2259 case bfd_link_hash_undefweak: 2260 sym->flags |= BSF_WEAK; 2261 break; 2262 case bfd_link_hash_indirect: 2263 h = (struct generic_link_hash_entry *) h->root.u.i.link; 2264 /* fall through */ 2265 case bfd_link_hash_defined: 2266 sym->flags |= BSF_GLOBAL; 2267 sym->flags &=~ BSF_CONSTRUCTOR; 2268 sym->value = h->root.u.def.value; 2269 sym->section = h->root.u.def.section; 2270 break; 2271 case bfd_link_hash_defweak: 2272 sym->flags |= BSF_WEAK; 2273 sym->flags &=~ BSF_CONSTRUCTOR; 2274 sym->value = h->root.u.def.value; 2275 sym->section = h->root.u.def.section; 2276 break; 2277 case bfd_link_hash_common: 2278 sym->value = h->root.u.c.size; 2279 sym->flags |= BSF_GLOBAL; 2280 if (! bfd_is_com_section (sym->section)) 2281 { 2282 BFD_ASSERT (bfd_is_und_section (sym->section)); 2283 sym->section = bfd_com_section_ptr; 2284 } 2285 /* We do not set the section of the symbol to 2286 h->root.u.c.p->section. That value was saved so 2287 that we would know where to allocate the symbol 2288 if it was defined. In this case the type is 2289 still bfd_link_hash_common, so we did not define 2290 it, so we do not want to use that section. */ 2291 break; 2292 } 2293 } 2294 } 2295 2296 /* This switch is straight from the old code in 2297 write_file_locals in ldsym.c. */ 2298 if (info->strip == strip_all 2299 || (info->strip == strip_some 2300 && bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym), 2301 FALSE, FALSE) == NULL)) 2302 output = FALSE; 2303 else if ((sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0) 2304 { 2305 /* If this symbol is marked as occurring now, rather 2306 than at the end, output it now. This is used for 2307 COFF C_EXT FCN symbols. FIXME: There must be a 2308 better way. */ 2309 if (bfd_asymbol_bfd (sym) == input_bfd 2310 && (sym->flags & BSF_NOT_AT_END) != 0) 2311 output = TRUE; 2312 else 2313 output = FALSE; 2314 } 2315 else if (bfd_is_ind_section (sym->section)) 2316 output = FALSE; 2317 else if ((sym->flags & BSF_DEBUGGING) != 0) 2318 { 2319 if (info->strip == strip_none) 2320 output = TRUE; 2321 else 2322 output = FALSE; 2323 } 2324 else if (bfd_is_und_section (sym->section) 2325 || bfd_is_com_section (sym->section)) 2326 output = FALSE; 2327 else if ((sym->flags & BSF_LOCAL) != 0) 2328 { 2329 if ((sym->flags & BSF_WARNING) != 0) 2330 output = FALSE; 2331 else 2332 { 2333 switch (info->discard) 2334 { 2335 default: 2336 case discard_all: 2337 output = FALSE; 2338 break; 2339 case discard_sec_merge: 2340 output = TRUE; 2341 if (info->relocatable 2342 || ! (sym->section->flags & SEC_MERGE)) 2343 break; 2344 /* FALLTHROUGH */ 2345 case discard_l: 2346 if (bfd_is_local_label (input_bfd, sym)) 2347 output = FALSE; 2348 else 2349 output = TRUE; 2350 break; 2351 case discard_none: 2352 output = TRUE; 2353 break; 2354 } 2355 } 2356 } 2357 else if ((sym->flags & BSF_CONSTRUCTOR)) 2358 { 2359 if (info->strip != strip_all) 2360 output = TRUE; 2361 else 2362 output = FALSE; 2363 } 2364 else 2365 abort (); 2366 2367 /* If this symbol is in a section which is not being included 2368 in the output file, then we don't want to output the 2369 symbol. */ 2370 if (!bfd_is_abs_section (sym->section) 2371 && bfd_section_removed_from_list (output_bfd, 2372 sym->section->output_section)) 2373 output = FALSE; 2374 2375 if (output) 2376 { 2377 if (! generic_add_output_symbol (output_bfd, psymalloc, sym)) 2378 return FALSE; 2379 if (h != NULL) 2380 h->written = TRUE; 2381 } 2382 } 2383 2384 return TRUE; 2385} 2386 2387/* Set the section and value of a generic BFD symbol based on a linker 2388 hash table entry. */ 2389 2390static void 2391set_symbol_from_hash (asymbol *sym, struct bfd_link_hash_entry *h) 2392{ 2393 switch (h->type) 2394 { 2395 default: 2396 abort (); 2397 break; 2398 case bfd_link_hash_new: 2399 /* This can happen when a constructor symbol is seen but we are 2400 not building constructors. */ 2401 if (sym->section != NULL) 2402 { 2403 BFD_ASSERT ((sym->flags & BSF_CONSTRUCTOR) != 0); 2404 } 2405 else 2406 { 2407 sym->flags |= BSF_CONSTRUCTOR; 2408 sym->section = bfd_abs_section_ptr; 2409 sym->value = 0; 2410 } 2411 break; 2412 case bfd_link_hash_undefined: 2413 sym->section = bfd_und_section_ptr; 2414 sym->value = 0; 2415 break; 2416 case bfd_link_hash_undefweak: 2417 sym->section = bfd_und_section_ptr; 2418 sym->value = 0; 2419 sym->flags |= BSF_WEAK; 2420 break; 2421 case bfd_link_hash_defined: 2422 sym->section = h->u.def.section; 2423 sym->value = h->u.def.value; 2424 break; 2425 case bfd_link_hash_defweak: 2426 sym->flags |= BSF_WEAK; 2427 sym->section = h->u.def.section; 2428 sym->value = h->u.def.value; 2429 break; 2430 case bfd_link_hash_common: 2431 sym->value = h->u.c.size; 2432 if (sym->section == NULL) 2433 sym->section = bfd_com_section_ptr; 2434 else if (! bfd_is_com_section (sym->section)) 2435 { 2436 BFD_ASSERT (bfd_is_und_section (sym->section)); 2437 sym->section = bfd_com_section_ptr; 2438 } 2439 /* Do not set the section; see _bfd_generic_link_output_symbols. */ 2440 break; 2441 case bfd_link_hash_indirect: 2442 case bfd_link_hash_warning: 2443 /* FIXME: What should we do here? */ 2444 break; 2445 } 2446} 2447 2448/* Write out a global symbol, if it hasn't already been written out. 2449 This is called for each symbol in the hash table. */ 2450 2451bfd_boolean 2452_bfd_generic_link_write_global_symbol (struct generic_link_hash_entry *h, 2453 void *data) 2454{ 2455 struct generic_write_global_symbol_info *wginfo = data; 2456 asymbol *sym; 2457 2458 if (h->root.type == bfd_link_hash_warning) 2459 h = (struct generic_link_hash_entry *) h->root.u.i.link; 2460 2461 if (h->written) 2462 return TRUE; 2463 2464 h->written = TRUE; 2465 2466 if (wginfo->info->strip == strip_all 2467 || (wginfo->info->strip == strip_some 2468 && bfd_hash_lookup (wginfo->info->keep_hash, h->root.root.string, 2469 FALSE, FALSE) == NULL)) 2470 return TRUE; 2471 2472 if (h->sym != NULL) 2473 sym = h->sym; 2474 else 2475 { 2476 sym = bfd_make_empty_symbol (wginfo->output_bfd); 2477 if (!sym) 2478 return FALSE; 2479 sym->name = h->root.root.string; 2480 sym->flags = 0; 2481 } 2482 2483 set_symbol_from_hash (sym, &h->root); 2484 2485 sym->flags |= BSF_GLOBAL; 2486 2487 if (! generic_add_output_symbol (wginfo->output_bfd, wginfo->psymalloc, 2488 sym)) 2489 { 2490 /* FIXME: No way to return failure. */ 2491 abort (); 2492 } 2493 2494 return TRUE; 2495} 2496 2497/* Create a relocation. */ 2498 2499bfd_boolean 2500_bfd_generic_reloc_link_order (bfd *abfd, 2501 struct bfd_link_info *info, 2502 asection *sec, 2503 struct bfd_link_order *link_order) 2504{ 2505 arelent *r; 2506 2507 if (! info->relocatable) 2508 abort (); 2509 if (sec->orelocation == NULL) 2510 abort (); 2511 2512 r = bfd_alloc (abfd, sizeof (arelent)); 2513 if (r == NULL) 2514 return FALSE; 2515 2516 r->address = link_order->offset; 2517 r->howto = bfd_reloc_type_lookup (abfd, link_order->u.reloc.p->reloc); 2518 if (r->howto == 0) 2519 { 2520 bfd_set_error (bfd_error_bad_value); 2521 return FALSE; 2522 } 2523 2524 /* Get the symbol to use for the relocation. */ 2525 if (link_order->type == bfd_section_reloc_link_order) 2526 r->sym_ptr_ptr = link_order->u.reloc.p->u.section->symbol_ptr_ptr; 2527 else 2528 { 2529 struct generic_link_hash_entry *h; 2530 2531 h = ((struct generic_link_hash_entry *) 2532 bfd_wrapped_link_hash_lookup (abfd, info, 2533 link_order->u.reloc.p->u.name, 2534 FALSE, FALSE, TRUE)); 2535 if (h == NULL 2536 || ! h->written) 2537 { 2538 if (! ((*info->callbacks->unattached_reloc) 2539 (info, link_order->u.reloc.p->u.name, NULL, NULL, 0))) 2540 return FALSE; 2541 bfd_set_error (bfd_error_bad_value); 2542 return FALSE; 2543 } 2544 r->sym_ptr_ptr = &h->sym; 2545 } 2546 2547 /* If this is an inplace reloc, write the addend to the object file. 2548 Otherwise, store it in the reloc addend. */ 2549 if (! r->howto->partial_inplace) 2550 r->addend = link_order->u.reloc.p->addend; 2551 else 2552 { 2553 bfd_size_type size; 2554 bfd_reloc_status_type rstat; 2555 bfd_byte *buf; 2556 bfd_boolean ok; 2557 file_ptr loc; 2558 2559 size = bfd_get_reloc_size (r->howto); 2560 buf = bfd_zmalloc (size); 2561 if (buf == NULL) 2562 return FALSE; 2563 rstat = _bfd_relocate_contents (r->howto, abfd, 2564 (bfd_vma) link_order->u.reloc.p->addend, 2565 buf); 2566 switch (rstat) 2567 { 2568 case bfd_reloc_ok: 2569 break; 2570 default: 2571 case bfd_reloc_outofrange: 2572 abort (); 2573 case bfd_reloc_overflow: 2574 if (! ((*info->callbacks->reloc_overflow) 2575 (info, NULL, 2576 (link_order->type == bfd_section_reloc_link_order 2577 ? bfd_section_name (abfd, link_order->u.reloc.p->u.section) 2578 : link_order->u.reloc.p->u.name), 2579 r->howto->name, link_order->u.reloc.p->addend, 2580 NULL, NULL, 0))) 2581 { 2582 free (buf); 2583 return FALSE; 2584 } 2585 break; 2586 } 2587 loc = link_order->offset * bfd_octets_per_byte (abfd); 2588 ok = bfd_set_section_contents (abfd, sec, buf, loc, size); 2589 free (buf); 2590 if (! ok) 2591 return FALSE; 2592 2593 r->addend = 0; 2594 } 2595 2596 sec->orelocation[sec->reloc_count] = r; 2597 ++sec->reloc_count; 2598 2599 return TRUE; 2600} 2601 2602/* Allocate a new link_order for a section. */ 2603 2604struct bfd_link_order * 2605bfd_new_link_order (bfd *abfd, asection *section) 2606{ 2607 bfd_size_type amt = sizeof (struct bfd_link_order); 2608 struct bfd_link_order *new; 2609 2610 new = bfd_zalloc (abfd, amt); 2611 if (!new) 2612 return NULL; 2613 2614 new->type = bfd_undefined_link_order; 2615 2616 if (section->map_tail.link_order != NULL) 2617 section->map_tail.link_order->next = new; 2618 else 2619 section->map_head.link_order = new; 2620 section->map_tail.link_order = new; 2621 2622 return new; 2623} 2624 2625/* Default link order processing routine. Note that we can not handle 2626 the reloc_link_order types here, since they depend upon the details 2627 of how the particular backends generates relocs. */ 2628 2629bfd_boolean 2630_bfd_default_link_order (bfd *abfd, 2631 struct bfd_link_info *info, 2632 asection *sec, 2633 struct bfd_link_order *link_order) 2634{ 2635 switch (link_order->type) 2636 { 2637 case bfd_undefined_link_order: 2638 case bfd_section_reloc_link_order: 2639 case bfd_symbol_reloc_link_order: 2640 default: 2641 abort (); 2642 case bfd_indirect_link_order: 2643 return default_indirect_link_order (abfd, info, sec, link_order, 2644 FALSE); 2645 case bfd_data_link_order: 2646 return default_data_link_order (abfd, info, sec, link_order); 2647 } 2648} 2649 2650/* Default routine to handle a bfd_data_link_order. */ 2651 2652static bfd_boolean 2653default_data_link_order (bfd *abfd, 2654 struct bfd_link_info *info ATTRIBUTE_UNUSED, 2655 asection *sec, 2656 struct bfd_link_order *link_order) 2657{ 2658 bfd_size_type size; 2659 size_t fill_size; 2660 bfd_byte *fill; 2661 file_ptr loc; 2662 bfd_boolean result; 2663 2664 BFD_ASSERT ((sec->flags & SEC_HAS_CONTENTS) != 0); 2665 2666 size = link_order->size; 2667 if (size == 0) 2668 return TRUE; 2669 2670 fill = link_order->u.data.contents; 2671 fill_size = link_order->u.data.size; 2672 if (fill_size != 0 && fill_size < size) 2673 { 2674 bfd_byte *p; 2675 fill = bfd_malloc (size); 2676 if (fill == NULL) 2677 return FALSE; 2678 p = fill; 2679 if (fill_size == 1) 2680 memset (p, (int) link_order->u.data.contents[0], (size_t) size); 2681 else 2682 { 2683 do 2684 { 2685 memcpy (p, link_order->u.data.contents, fill_size); 2686 p += fill_size; 2687 size -= fill_size; 2688 } 2689 while (size >= fill_size); 2690 if (size != 0) 2691 memcpy (p, link_order->u.data.contents, (size_t) size); 2692 size = link_order->size; 2693 } 2694 } 2695 2696 loc = link_order->offset * bfd_octets_per_byte (abfd); 2697 result = bfd_set_section_contents (abfd, sec, fill, loc, size); 2698 2699 if (fill != link_order->u.data.contents) 2700 free (fill); 2701 return result; 2702} 2703 2704/* Default routine to handle a bfd_indirect_link_order. */ 2705 2706static bfd_boolean 2707default_indirect_link_order (bfd *output_bfd, 2708 struct bfd_link_info *info, 2709 asection *output_section, 2710 struct bfd_link_order *link_order, 2711 bfd_boolean generic_linker) 2712{ 2713 asection *input_section; 2714 bfd *input_bfd; 2715 bfd_byte *contents = NULL; 2716 bfd_byte *new_contents; 2717 bfd_size_type sec_size; 2718 file_ptr loc; 2719 2720 BFD_ASSERT ((output_section->flags & SEC_HAS_CONTENTS) != 0); 2721 2722 input_section = link_order->u.indirect.section; 2723 input_bfd = input_section->owner; 2724 if (input_section->size == 0) 2725 return TRUE; 2726 2727 BFD_ASSERT (input_section->output_section == output_section); 2728 BFD_ASSERT (input_section->output_offset == link_order->offset); 2729 BFD_ASSERT (input_section->size == link_order->size); 2730 2731 if (info->relocatable 2732 && input_section->reloc_count > 0 2733 && output_section->orelocation == NULL) 2734 { 2735 /* Space has not been allocated for the output relocations. 2736 This can happen when we are called by a specific backend 2737 because somebody is attempting to link together different 2738 types of object files. Handling this case correctly is 2739 difficult, and sometimes impossible. */ 2740 (*_bfd_error_handler) 2741 (_("Attempt to do relocatable link with %s input and %s output"), 2742 bfd_get_target (input_bfd), bfd_get_target (output_bfd)); 2743 bfd_set_error (bfd_error_wrong_format); 2744 return FALSE; 2745 } 2746 2747 if (! generic_linker) 2748 { 2749 asymbol **sympp; 2750 asymbol **symppend; 2751 2752 /* Get the canonical symbols. The generic linker will always 2753 have retrieved them by this point, but we are being called by 2754 a specific linker, presumably because we are linking 2755 different types of object files together. */ 2756 if (! generic_link_read_symbols (input_bfd)) 2757 return FALSE; 2758 2759 /* Since we have been called by a specific linker, rather than 2760 the generic linker, the values of the symbols will not be 2761 right. They will be the values as seen in the input file, 2762 not the values of the final link. We need to fix them up 2763 before we can relocate the section. */ 2764 sympp = _bfd_generic_link_get_symbols (input_bfd); 2765 symppend = sympp + _bfd_generic_link_get_symcount (input_bfd); 2766 for (; sympp < symppend; sympp++) 2767 { 2768 asymbol *sym; 2769 struct bfd_link_hash_entry *h; 2770 2771 sym = *sympp; 2772 2773 if ((sym->flags & (BSF_INDIRECT 2774 | BSF_WARNING 2775 | BSF_GLOBAL 2776 | BSF_CONSTRUCTOR 2777 | BSF_WEAK)) != 0 2778 || bfd_is_und_section (bfd_get_section (sym)) 2779 || bfd_is_com_section (bfd_get_section (sym)) 2780 || bfd_is_ind_section (bfd_get_section (sym))) 2781 { 2782 /* sym->udata may have been set by 2783 generic_link_add_symbol_list. */ 2784 if (sym->udata.p != NULL) 2785 h = sym->udata.p; 2786 else if (bfd_is_und_section (bfd_get_section (sym))) 2787 h = bfd_wrapped_link_hash_lookup (output_bfd, info, 2788 bfd_asymbol_name (sym), 2789 FALSE, FALSE, TRUE); 2790 else 2791 h = bfd_link_hash_lookup (info->hash, 2792 bfd_asymbol_name (sym), 2793 FALSE, FALSE, TRUE); 2794 if (h != NULL) 2795 set_symbol_from_hash (sym, h); 2796 } 2797 } 2798 } 2799 2800 /* Get and relocate the section contents. */ 2801 sec_size = (input_section->rawsize > input_section->size 2802 ? input_section->rawsize 2803 : input_section->size); 2804 contents = bfd_malloc (sec_size); 2805 if (contents == NULL && sec_size != 0) 2806 goto error_return; 2807 new_contents = (bfd_get_relocated_section_contents 2808 (output_bfd, info, link_order, contents, info->relocatable, 2809 _bfd_generic_link_get_symbols (input_bfd))); 2810 if (!new_contents) 2811 goto error_return; 2812 2813 /* Output the section contents. */ 2814 loc = input_section->output_offset * bfd_octets_per_byte (output_bfd); 2815 if (! bfd_set_section_contents (output_bfd, output_section, 2816 new_contents, loc, input_section->size)) 2817 goto error_return; 2818 2819 if (contents != NULL) 2820 free (contents); 2821 return TRUE; 2822 2823 error_return: 2824 if (contents != NULL) 2825 free (contents); 2826 return FALSE; 2827} 2828 2829/* A little routine to count the number of relocs in a link_order 2830 list. */ 2831 2832unsigned int 2833_bfd_count_link_order_relocs (struct bfd_link_order *link_order) 2834{ 2835 register unsigned int c; 2836 register struct bfd_link_order *l; 2837 2838 c = 0; 2839 for (l = link_order; l != NULL; l = l->next) 2840 { 2841 if (l->type == bfd_section_reloc_link_order 2842 || l->type == bfd_symbol_reloc_link_order) 2843 ++c; 2844 } 2845 2846 return c; 2847} 2848 2849/* 2850FUNCTION 2851 bfd_link_split_section 2852 2853SYNOPSIS 2854 bfd_boolean bfd_link_split_section (bfd *abfd, asection *sec); 2855 2856DESCRIPTION 2857 Return nonzero if @var{sec} should be split during a 2858 reloceatable or final link. 2859 2860.#define bfd_link_split_section(abfd, sec) \ 2861. BFD_SEND (abfd, _bfd_link_split_section, (abfd, sec)) 2862. 2863 2864*/ 2865 2866bfd_boolean 2867_bfd_generic_link_split_section (bfd *abfd ATTRIBUTE_UNUSED, 2868 asection *sec ATTRIBUTE_UNUSED) 2869{ 2870 return FALSE; 2871} 2872 2873/* 2874FUNCTION 2875 bfd_section_already_linked 2876 2877SYNOPSIS 2878 void bfd_section_already_linked (bfd *abfd, asection *sec, 2879 struct bfd_link_info *info); 2880 2881DESCRIPTION 2882 Check if @var{sec} has been already linked during a reloceatable 2883 or final link. 2884 2885.#define bfd_section_already_linked(abfd, sec, info) \ 2886. BFD_SEND (abfd, _section_already_linked, (abfd, sec, info)) 2887. 2888 2889*/ 2890 2891/* Sections marked with the SEC_LINK_ONCE flag should only be linked 2892 once into the output. This routine checks each section, and 2893 arrange to discard it if a section of the same name has already 2894 been linked. This code assumes that all relevant sections have the 2895 SEC_LINK_ONCE flag set; that is, it does not depend solely upon the 2896 section name. bfd_section_already_linked is called via 2897 bfd_map_over_sections. */ 2898 2899/* The hash table. */ 2900 2901static struct bfd_hash_table _bfd_section_already_linked_table; 2902 2903/* Support routines for the hash table used by section_already_linked, 2904 initialize the table, traverse, lookup, fill in an entry and remove 2905 the table. */ 2906 2907void 2908bfd_section_already_linked_table_traverse 2909 (bfd_boolean (*func) (struct bfd_section_already_linked_hash_entry *, 2910 void *), void *info) 2911{ 2912 bfd_hash_traverse (&_bfd_section_already_linked_table, 2913 (bfd_boolean (*) (struct bfd_hash_entry *, 2914 void *)) func, 2915 info); 2916} 2917 2918struct bfd_section_already_linked_hash_entry * 2919bfd_section_already_linked_table_lookup (const char *name) 2920{ 2921 return ((struct bfd_section_already_linked_hash_entry *) 2922 bfd_hash_lookup (&_bfd_section_already_linked_table, name, 2923 TRUE, FALSE)); 2924} 2925 2926bfd_boolean 2927bfd_section_already_linked_table_insert 2928 (struct bfd_section_already_linked_hash_entry *already_linked_list, 2929 asection *sec) 2930{ 2931 struct bfd_section_already_linked *l; 2932 2933 /* Allocate the memory from the same obstack as the hash table is 2934 kept in. */ 2935 l = bfd_hash_allocate (&_bfd_section_already_linked_table, sizeof *l); 2936 if (l == NULL) 2937 return FALSE; 2938 l->sec = sec; 2939 l->next = already_linked_list->entry; 2940 already_linked_list->entry = l; 2941 return TRUE; 2942} 2943 2944static struct bfd_hash_entry * 2945already_linked_newfunc (struct bfd_hash_entry *entry ATTRIBUTE_UNUSED, 2946 struct bfd_hash_table *table, 2947 const char *string ATTRIBUTE_UNUSED) 2948{ 2949 struct bfd_section_already_linked_hash_entry *ret = 2950 bfd_hash_allocate (table, sizeof *ret); 2951 2952 if (ret == NULL) 2953 return NULL; 2954 2955 ret->entry = NULL; 2956 2957 return &ret->root; 2958} 2959 2960bfd_boolean 2961bfd_section_already_linked_table_init (void) 2962{ 2963 return bfd_hash_table_init_n (&_bfd_section_already_linked_table, 2964 already_linked_newfunc, 2965 sizeof (struct bfd_section_already_linked_hash_entry), 2966 42); 2967} 2968 2969void 2970bfd_section_already_linked_table_free (void) 2971{ 2972 bfd_hash_table_free (&_bfd_section_already_linked_table); 2973} 2974 2975/* This is used on non-ELF inputs. */ 2976 2977void 2978_bfd_generic_section_already_linked (bfd *abfd, asection *sec, 2979 struct bfd_link_info *info) 2980{ 2981 flagword flags; 2982 const char *name; 2983 struct bfd_section_already_linked *l; 2984 struct bfd_section_already_linked_hash_entry *already_linked_list; 2985 2986 flags = sec->flags; 2987 if ((flags & SEC_LINK_ONCE) == 0) 2988 return; 2989 2990 /* FIXME: When doing a relocatable link, we may have trouble 2991 copying relocations in other sections that refer to local symbols 2992 in the section being discarded. Those relocations will have to 2993 be converted somehow; as of this writing I'm not sure that any of 2994 the backends handle that correctly. 2995 2996 It is tempting to instead not discard link once sections when 2997 doing a relocatable link (technically, they should be discarded 2998 whenever we are building constructors). However, that fails, 2999 because the linker winds up combining all the link once sections 3000 into a single large link once section, which defeats the purpose 3001 of having link once sections in the first place. */ 3002 3003 name = bfd_get_section_name (abfd, sec); 3004 3005 already_linked_list = bfd_section_already_linked_table_lookup (name); 3006 3007 for (l = already_linked_list->entry; l != NULL; l = l->next) 3008 { 3009 bfd_boolean skip = FALSE; 3010 struct coff_comdat_info *s_comdat 3011 = bfd_coff_get_comdat_section (abfd, sec); 3012 struct coff_comdat_info *l_comdat 3013 = bfd_coff_get_comdat_section (l->sec->owner, l->sec); 3014 3015 /* We may have 3 different sections on the list: group section, 3016 comdat section and linkonce section. SEC may be a linkonce or 3017 comdat section. We always ignore group section. For non-COFF 3018 inputs, we also ignore comdat section. 3019 3020 FIXME: Is that safe to match a linkonce section with a comdat 3021 section for COFF inputs? */ 3022 if ((l->sec->flags & SEC_GROUP) != 0) 3023 skip = TRUE; 3024 else if (bfd_get_flavour (abfd) == bfd_target_coff_flavour) 3025 { 3026 if (s_comdat != NULL 3027 && l_comdat != NULL 3028 && strcmp (s_comdat->name, l_comdat->name) != 0) 3029 skip = TRUE; 3030 } 3031 else if (l_comdat != NULL) 3032 skip = TRUE; 3033 3034 if (!skip) 3035 { 3036 /* The section has already been linked. See if we should 3037 issue a warning. */ 3038 switch (flags & SEC_LINK_DUPLICATES) 3039 { 3040 default: 3041 abort (); 3042 3043 case SEC_LINK_DUPLICATES_DISCARD: 3044 break; 3045 3046 case SEC_LINK_DUPLICATES_ONE_ONLY: 3047 (*_bfd_error_handler) 3048 (_("%B: warning: ignoring duplicate section `%A'\n"), 3049 abfd, sec); 3050 break; 3051 3052 case SEC_LINK_DUPLICATES_SAME_CONTENTS: 3053 /* FIXME: We should really dig out the contents of both 3054 sections and memcmp them. The COFF/PE spec says that 3055 the Microsoft linker does not implement this 3056 correctly, so I'm not going to bother doing it 3057 either. */ 3058 /* Fall through. */ 3059 case SEC_LINK_DUPLICATES_SAME_SIZE: 3060 if (sec->size != l->sec->size) 3061 (*_bfd_error_handler) 3062 (_("%B: warning: duplicate section `%A' has different size\n"), 3063 abfd, sec); 3064 break; 3065 } 3066 3067 /* Set the output_section field so that lang_add_section 3068 does not create a lang_input_section structure for this 3069 section. Since there might be a symbol in the section 3070 being discarded, we must retain a pointer to the section 3071 which we are really going to use. */ 3072 sec->output_section = bfd_abs_section_ptr; 3073 sec->kept_section = l->sec; 3074 3075 return; 3076 } 3077 } 3078 3079 /* This is the first section with this name. Record it. */ 3080 if (! bfd_section_already_linked_table_insert (already_linked_list, sec)) 3081 info->callbacks->einfo (_("%F%P: already_linked_table: %E")); 3082} 3083 3084/* Convert symbols in excluded output sections to use a kept section. */ 3085 3086static bfd_boolean 3087fix_syms (struct bfd_link_hash_entry *h, void *data) 3088{ 3089 bfd *obfd = (bfd *) data; 3090 3091 if (h->type == bfd_link_hash_warning) 3092 h = h->u.i.link; 3093 3094 if (h->type == bfd_link_hash_defined 3095 || h->type == bfd_link_hash_defweak) 3096 { 3097 asection *s = h->u.def.section; 3098 if (s != NULL 3099 && s->output_section != NULL 3100 && (s->output_section->flags & SEC_EXCLUDE) != 0 3101 && bfd_section_removed_from_list (obfd, s->output_section)) 3102 { 3103 asection *op, *op1; 3104 3105 h->u.def.value += s->output_offset + s->output_section->vma; 3106 3107 /* Find preceding kept section. */ 3108 for (op1 = s->output_section->prev; op1 != NULL; op1 = op1->prev) 3109 if ((op1->flags & SEC_EXCLUDE) == 0 3110 && !bfd_section_removed_from_list (obfd, op1)) 3111 break; 3112 3113 /* Find following kept section. Start at prev->next because 3114 other sections may have been added after S was removed. */ 3115 if (s->output_section->prev != NULL) 3116 op = s->output_section->prev->next; 3117 else 3118 op = s->output_section->owner->sections; 3119 for (; op != NULL; op = op->next) 3120 if ((op->flags & SEC_EXCLUDE) == 0 3121 && !bfd_section_removed_from_list (obfd, op)) 3122 break; 3123 3124 /* Choose better of two sections, based on flags. The idea 3125 is to choose a section that will be in the same segment 3126 as S would have been if it was kept. */ 3127 if (op1 == NULL) 3128 { 3129 if (op == NULL) 3130 op = bfd_abs_section_ptr; 3131 } 3132 else if (op == NULL) 3133 op = op1; 3134 else if (((op1->flags ^ op->flags) 3135 & (SEC_ALLOC | SEC_THREAD_LOCAL)) != 0) 3136 { 3137 if (((op->flags ^ s->flags) 3138 & (SEC_ALLOC | SEC_THREAD_LOCAL)) != 0) 3139 op = op1; 3140 } 3141 else if (((op1->flags ^ op->flags) & SEC_READONLY) != 0) 3142 { 3143 if (((op->flags ^ s->flags) & SEC_READONLY) != 0) 3144 op = op1; 3145 } 3146 else if (((op1->flags ^ op->flags) & SEC_CODE) != 0) 3147 { 3148 if (((op->flags ^ s->flags) & SEC_CODE) != 0) 3149 op = op1; 3150 } 3151 else 3152 { 3153 /* Flags we care about are the same. Prefer the following 3154 section if that will result in a positive valued sym. */ 3155 if (h->u.def.value < op->vma) 3156 op = op1; 3157 } 3158 3159 h->u.def.value -= op->vma; 3160 h->u.def.section = op; 3161 } 3162 } 3163 3164 return TRUE; 3165} 3166 3167void 3168_bfd_fix_excluded_sec_syms (bfd *obfd, struct bfd_link_info *info) 3169{ 3170 bfd_link_hash_traverse (info->hash, fix_syms, obfd); 3171} 3172