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