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