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 /* 29 SECTION 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 69 INODE 70 Creating a Linker Hash Table, Adding Symbols to the Hash Table, Linker Functions, Linker Functions 71 SUBSECTION 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. 106 107 INODE 108 Adding Symbols to the Hash Table, Performing the Final Link, Creating a Linker Hash Table, Linker Functions 109 SUBSECTION 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 132 133 INODE 134 Differing file formats, Adding symbols from an object file, Adding Symbols to the Hash Table, Adding Symbols to the Hash Table 135 SUBSUBSECTION 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. 169 170 INODE 171 Adding symbols from an object file, Adding symbols from an archive, Differing file formats, Adding Symbols to the Hash Table 172 SUBSUBSECTION 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. 213 214 INODE 215 Adding symbols from an archive, , Adding symbols from an object file, Adding Symbols to the Hash Table 216 SUBSUBSECTION 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. 265 266 INODE 267 Performing the Final Link, , Adding Symbols to the Hash Table, Linker Functions 268 SUBSECTION 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 297 298 INODE 299 Information provided by the linker, Relocating the section contents, Performing the Final Link, Performing the Final Link 300 SUBSUBSECTION 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. 321 322 INODE 323 Relocating the section contents, Writing the symbol table, Information provided by the linker, Performing the Final Link 324 SUBSUBSECTION 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>>. 359 360 INODE 361 Writing the symbol table, , Relocating the section contents, Performing the Final Link 362 SUBSUBSECTION 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 */ 408 409 static bfd_boolean generic_link_add_object_symbols 410 (bfd *, struct bfd_link_info *, bfd_boolean collect); 411 static bfd_boolean generic_link_add_symbols 412 (bfd *, struct bfd_link_info *, bfd_boolean); 413 static bfd_boolean generic_link_check_archive_element_no_collect 414 (bfd *, struct bfd_link_info *, bfd_boolean *); 415 static bfd_boolean generic_link_check_archive_element_collect 416 (bfd *, struct bfd_link_info *, bfd_boolean *); 417 static bfd_boolean generic_link_check_archive_element 418 (bfd *, struct bfd_link_info *, bfd_boolean *, bfd_boolean); 419 static bfd_boolean generic_link_add_symbol_list 420 (bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **, 421 bfd_boolean); 422 static bfd_boolean generic_add_output_symbol 423 (bfd *, size_t *psymalloc, asymbol *); 424 static bfd_boolean default_data_link_order 425 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *); 426 static 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. */ 435 436 struct 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. */ 468 469 bfd_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. */ 489 490 struct bfd_link_hash_entry * 491 bfd_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. */ 515 516 struct bfd_link_hash_entry * 517 bfd_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 && strncmp (l, REAL, sizeof REAL - 1) == 0 570 && 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. */ 604 605 void 606 bfd_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. */ 617 618 void 619 bfd_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. */ 636 637 void 638 bfd_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. */ 670 671 struct 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. */ 702 703 struct 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 } 721 722 void 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. */ 738 739 static bfd_boolean 740 generic_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. */ 765 766 bfd_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. */ 778 779 bfd_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. */ 788 789 void 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. */ 798 799 static bfd_boolean 800 generic_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. */ 827 828 static bfd_boolean 829 generic_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. */ 847 848 struct archive_list 849 { 850 struct archive_list *next; 851 unsigned int indx; 852 }; 853 854 /* An entry in an archive hash table. */ 855 856 struct 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. */ 864 865 struct archive_hash_table 866 { 867 struct bfd_hash_table table; 868 }; 869 870 /* Create a new entry for an archive hash table. */ 871 872 static struct bfd_hash_entry * 873 archive_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. */ 900 901 static bfd_boolean 902 archive_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. */ 958 959 bfd_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 1132 static bfd_boolean 1133 generic_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 1145 static bfd_boolean 1146 generic_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 1156 static bfd_boolean 1157 generic_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 1286 static bfd_boolean 1287 generic_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 1399 enum 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 1416 enum 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 1445 static 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 1483 static bfd * 1484 hash_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 1522 bfd_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' 1663 && strncmp (s, CONS_PREFIX, CONS_PREFIX_LEN - 1) == 0) 1664 { 1665 char c; 1666 1667 c = s[CONS_PREFIX_LEN + 1]; 1668 if ((c == 'I' || c == 'D') 1669 && s[CONS_PREFIX_LEN] == s[CONS_PREFIX_LEN + 2]) 1670 { 1671 /* If this is a definition of a symbol which 1672 was previously weakly defined, we are in 1673 trouble. We have already added a 1674 constructor entry for the weak defined 1675 symbol, and now we are trying to add one 1676 for the new symbol. Fortunately, this case 1677 should never arise in practice. */ 1678 if (oldtype == bfd_link_hash_defweak) 1679 abort (); 1680 1681 if (! ((*info->callbacks->constructor) 1682 (info, c == 'I', 1683 h->root.string, abfd, section, value))) 1684 return FALSE; 1685 } 1686 } 1687 } 1688 } 1689 1690 break; 1691 1692 case COM: 1693 /* We have found a common definition for a symbol. */ 1694 if (h->type == bfd_link_hash_new) 1695 bfd_link_add_undef (info->hash, h); 1696 h->type = bfd_link_hash_common; 1697 h->u.c.p = 1698 bfd_hash_allocate (&info->hash->table, 1699 sizeof (struct bfd_link_hash_common_entry)); 1700 if (h->u.c.p == NULL) 1701 return FALSE; 1702 1703 h->u.c.size = value; 1704 1705 /* Select a default alignment based on the size. This may 1706 be overridden by the caller. */ 1707 { 1708 unsigned int power; 1709 1710 power = bfd_log2 (value); 1711 if (power > 4) 1712 power = 4; 1713 h->u.c.p->alignment_power = power; 1714 } 1715 1716 /* The section of a common symbol is only used if the common 1717 symbol is actually allocated. It basically provides a 1718 hook for the linker script to decide which output section 1719 the common symbols should be put in. In most cases, the 1720 section of a common symbol will be bfd_com_section_ptr, 1721 the code here will choose a common symbol section named 1722 "COMMON", and the linker script will contain *(COMMON) in 1723 the appropriate place. A few targets use separate common 1724 sections for small symbols, and they require special 1725 handling. */ 1726 if (section == bfd_com_section_ptr) 1727 { 1728 h->u.c.p->section = bfd_make_section_old_way (abfd, "COMMON"); 1729 h->u.c.p->section->flags = SEC_ALLOC; 1730 } 1731 else if (section->owner != abfd) 1732 { 1733 h->u.c.p->section = bfd_make_section_old_way (abfd, 1734 section->name); 1735 h->u.c.p->section->flags = SEC_ALLOC; 1736 } 1737 else 1738 h->u.c.p->section = section; 1739 break; 1740 1741 case REF: 1742 /* A reference to a defined symbol. */ 1743 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1744 h->u.undef.next = h; 1745 break; 1746 1747 case BIG: 1748 /* We have found a common definition for a symbol which 1749 already had a common definition. Use the maximum of the 1750 two sizes, and use the section required by the larger symbol. */ 1751 BFD_ASSERT (h->type == bfd_link_hash_common); 1752 if (! ((*info->callbacks->multiple_common) 1753 (info, h->root.string, 1754 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1755 abfd, bfd_link_hash_common, value))) 1756 return FALSE; 1757 if (value > h->u.c.size) 1758 { 1759 unsigned int power; 1760 1761 h->u.c.size = value; 1762 1763 /* Select a default alignment based on the size. This may 1764 be overridden by the caller. */ 1765 power = bfd_log2 (value); 1766 if (power > 4) 1767 power = 4; 1768 h->u.c.p->alignment_power = power; 1769 1770 /* Some systems have special treatment for small commons, 1771 hence we want to select the section used by the larger 1772 symbol. This makes sure the symbol does not go in a 1773 small common section if it is now too large. */ 1774 if (section == bfd_com_section_ptr) 1775 { 1776 h->u.c.p->section 1777 = bfd_make_section_old_way (abfd, "COMMON"); 1778 h->u.c.p->section->flags = SEC_ALLOC; 1779 } 1780 else if (section->owner != abfd) 1781 { 1782 h->u.c.p->section 1783 = bfd_make_section_old_way (abfd, section->name); 1784 h->u.c.p->section->flags = SEC_ALLOC; 1785 } 1786 else 1787 h->u.c.p->section = section; 1788 } 1789 break; 1790 1791 case CREF: 1792 { 1793 bfd *obfd; 1794 1795 /* We have found a common definition for a symbol which 1796 was already defined. FIXME: It would nice if we could 1797 report the BFD which defined an indirect symbol, but we 1798 don't have anywhere to store the information. */ 1799 if (h->type == bfd_link_hash_defined 1800 || h->type == bfd_link_hash_defweak) 1801 obfd = h->u.def.section->owner; 1802 else 1803 obfd = NULL; 1804 if (! ((*info->callbacks->multiple_common) 1805 (info, h->root.string, obfd, h->type, 0, 1806 abfd, bfd_link_hash_common, value))) 1807 return FALSE; 1808 } 1809 break; 1810 1811 case MIND: 1812 /* Multiple indirect symbols. This is OK if they both point 1813 to the same symbol. */ 1814 if (strcmp (h->u.i.link->root.string, string) == 0) 1815 break; 1816 /* Fall through. */ 1817 case MDEF: 1818 /* Handle a multiple definition. */ 1819 if (!info->allow_multiple_definition) 1820 { 1821 asection *msec = NULL; 1822 bfd_vma mval = 0; 1823 1824 switch (h->type) 1825 { 1826 case bfd_link_hash_defined: 1827 msec = h->u.def.section; 1828 mval = h->u.def.value; 1829 break; 1830 case bfd_link_hash_indirect: 1831 msec = bfd_ind_section_ptr; 1832 mval = 0; 1833 break; 1834 default: 1835 abort (); 1836 } 1837 1838 /* Ignore a redefinition of an absolute symbol to the 1839 same value; it's harmless. */ 1840 if (h->type == bfd_link_hash_defined 1841 && bfd_is_abs_section (msec) 1842 && bfd_is_abs_section (section) 1843 && value == mval) 1844 break; 1845 1846 if (! ((*info->callbacks->multiple_definition) 1847 (info, h->root.string, msec->owner, msec, mval, 1848 abfd, section, value))) 1849 return FALSE; 1850 } 1851 break; 1852 1853 case CIND: 1854 /* Create an indirect symbol from an existing common symbol. */ 1855 BFD_ASSERT (h->type == bfd_link_hash_common); 1856 if (! ((*info->callbacks->multiple_common) 1857 (info, h->root.string, 1858 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1859 abfd, bfd_link_hash_indirect, 0))) 1860 return FALSE; 1861 /* Fall through. */ 1862 case IND: 1863 /* Create an indirect symbol. */ 1864 { 1865 struct bfd_link_hash_entry *inh; 1866 1867 /* STRING is the name of the symbol we want to indirect 1868 to. */ 1869 inh = bfd_wrapped_link_hash_lookup (abfd, info, string, TRUE, 1870 copy, FALSE); 1871 if (inh == NULL) 1872 return FALSE; 1873 if (inh->type == bfd_link_hash_indirect 1874 && inh->u.i.link == h) 1875 { 1876 (*_bfd_error_handler) 1877 (_("%B: indirect symbol `%s' to `%s' is a loop"), 1878 abfd, name, string); 1879 bfd_set_error (bfd_error_invalid_operation); 1880 return FALSE; 1881 } 1882 if (inh->type == bfd_link_hash_new) 1883 { 1884 inh->type = bfd_link_hash_undefined; 1885 inh->u.undef.abfd = abfd; 1886 bfd_link_add_undef (info->hash, inh); 1887 } 1888 1889 /* If the indirect symbol has been referenced, we need to 1890 push the reference down to the symbol we are 1891 referencing. */ 1892 if (h->type != bfd_link_hash_new) 1893 { 1894 row = UNDEF_ROW; 1895 cycle = TRUE; 1896 } 1897 1898 h->type = bfd_link_hash_indirect; 1899 h->u.i.link = inh; 1900 } 1901 break; 1902 1903 case SET: 1904 /* Add an entry to a set. */ 1905 if (! (*info->callbacks->add_to_set) (info, h, BFD_RELOC_CTOR, 1906 abfd, section, value)) 1907 return FALSE; 1908 break; 1909 1910 case WARNC: 1911 /* Issue a warning and cycle. */ 1912 if (h->u.i.warning != NULL) 1913 { 1914 if (! (*info->callbacks->warning) (info, h->u.i.warning, 1915 h->root.string, abfd, 1916 NULL, 0)) 1917 return FALSE; 1918 /* Only issue a warning once. */ 1919 h->u.i.warning = NULL; 1920 } 1921 /* Fall through. */ 1922 case CYCLE: 1923 /* Try again with the referenced symbol. */ 1924 h = h->u.i.link; 1925 cycle = TRUE; 1926 break; 1927 1928 case REFC: 1929 /* A reference to an indirect symbol. */ 1930 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1931 h->u.undef.next = h; 1932 h = h->u.i.link; 1933 cycle = TRUE; 1934 break; 1935 1936 case WARN: 1937 /* Issue a warning. */ 1938 if (! (*info->callbacks->warning) (info, string, h->root.string, 1939 hash_entry_bfd (h), NULL, 0)) 1940 return FALSE; 1941 break; 1942 1943 case CWARN: 1944 /* Warn if this symbol has been referenced already, 1945 otherwise add a warning. A symbol has been referenced if 1946 the u.undef.next field is not NULL, or it is the tail of the 1947 undefined symbol list. The REF case above helps to 1948 ensure this. */ 1949 if (h->u.undef.next != NULL || info->hash->undefs_tail == h) 1950 { 1951 if (! (*info->callbacks->warning) (info, string, h->root.string, 1952 hash_entry_bfd (h), NULL, 0)) 1953 return FALSE; 1954 break; 1955 } 1956 /* Fall through. */ 1957 case MWARN: 1958 /* Make a warning symbol. */ 1959 { 1960 struct bfd_link_hash_entry *sub; 1961 1962 /* STRING is the warning to give. */ 1963 sub = ((struct bfd_link_hash_entry *) 1964 ((*info->hash->table.newfunc) 1965 (NULL, &info->hash->table, h->root.string))); 1966 if (sub == NULL) 1967 return FALSE; 1968 *sub = *h; 1969 sub->type = bfd_link_hash_warning; 1970 sub->u.i.link = h; 1971 if (! copy) 1972 sub->u.i.warning = string; 1973 else 1974 { 1975 char *w; 1976 size_t len = strlen (string) + 1; 1977 1978 w = bfd_hash_allocate (&info->hash->table, len); 1979 if (w == NULL) 1980 return FALSE; 1981 memcpy (w, string, len); 1982 sub->u.i.warning = w; 1983 } 1984 1985 bfd_hash_replace (&info->hash->table, 1986 (struct bfd_hash_entry *) h, 1987 (struct bfd_hash_entry *) sub); 1988 if (hashp != NULL) 1989 *hashp = sub; 1990 } 1991 break; 1992 } 1993 } 1994 while (cycle); 1995 1996 return TRUE; 1997 } 1998 1999 /* Generic final link routine. */ 2000 2001 bfd_boolean 2002 _bfd_generic_final_link (bfd *abfd, struct bfd_link_info *info) 2003 { 2004 bfd *sub; 2005 asection *o; 2006 struct bfd_link_order *p; 2007 size_t outsymalloc; 2008 struct generic_write_global_symbol_info wginfo; 2009 2010 bfd_get_outsymbols (abfd) = NULL; 2011 bfd_get_symcount (abfd) = 0; 2012 outsymalloc = 0; 2013 2014 /* Mark all sections which will be included in the output file. */ 2015 for (o = abfd->sections; o != NULL; o = o->next) 2016 for (p = o->map_head.link_order; p != NULL; p = p->next) 2017 if (p->type == bfd_indirect_link_order) 2018 p->u.indirect.section->linker_mark = TRUE; 2019 2020 /* Build the output symbol table. */ 2021 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next) 2022 if (! _bfd_generic_link_output_symbols (abfd, sub, info, &outsymalloc)) 2023 return FALSE; 2024 2025 /* Accumulate the global symbols. */ 2026 wginfo.info = info; 2027 wginfo.output_bfd = abfd; 2028 wginfo.psymalloc = &outsymalloc; 2029 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info), 2030 _bfd_generic_link_write_global_symbol, 2031 &wginfo); 2032 2033 /* Make sure we have a trailing NULL pointer on OUTSYMBOLS. We 2034 shouldn't really need one, since we have SYMCOUNT, but some old 2035 code still expects one. */ 2036 if (! generic_add_output_symbol (abfd, &outsymalloc, NULL)) 2037 return FALSE; 2038 2039 if (info->relocatable) 2040 { 2041 /* Allocate space for the output relocs for each section. */ 2042 for (o = abfd->sections; o != NULL; o = o->next) 2043 { 2044 o->reloc_count = 0; 2045 for (p = o->map_head.link_order; p != NULL; p = p->next) 2046 { 2047 if (p->type == bfd_section_reloc_link_order 2048 || p->type == bfd_symbol_reloc_link_order) 2049 ++o->reloc_count; 2050 else if (p->type == bfd_indirect_link_order) 2051 { 2052 asection *input_section; 2053 bfd *input_bfd; 2054 long relsize; 2055 arelent **relocs; 2056 asymbol **symbols; 2057 long reloc_count; 2058 2059 input_section = p->u.indirect.section; 2060 input_bfd = input_section->owner; 2061 relsize = bfd_get_reloc_upper_bound (input_bfd, 2062 input_section); 2063 if (relsize < 0) 2064 return FALSE; 2065 relocs = bfd_malloc (relsize); 2066 if (!relocs && relsize != 0) 2067 return FALSE; 2068 symbols = _bfd_generic_link_get_symbols (input_bfd); 2069 reloc_count = bfd_canonicalize_reloc (input_bfd, 2070 input_section, 2071 relocs, 2072 symbols); 2073 free (relocs); 2074 if (reloc_count < 0) 2075 return FALSE; 2076 BFD_ASSERT ((unsigned long) reloc_count 2077 == input_section->reloc_count); 2078 o->reloc_count += reloc_count; 2079 } 2080 } 2081 if (o->reloc_count > 0) 2082 { 2083 bfd_size_type amt; 2084 2085 amt = o->reloc_count; 2086 amt *= sizeof (arelent *); 2087 o->orelocation = bfd_alloc (abfd, amt); 2088 if (!o->orelocation) 2089 return FALSE; 2090 o->flags |= SEC_RELOC; 2091 /* Reset the count so that it can be used as an index 2092 when putting in the output relocs. */ 2093 o->reloc_count = 0; 2094 } 2095 } 2096 } 2097 2098 /* Handle all the link order information for the sections. */ 2099 for (o = abfd->sections; o != NULL; o = o->next) 2100 { 2101 for (p = o->map_head.link_order; p != NULL; p = p->next) 2102 { 2103 switch (p->type) 2104 { 2105 case bfd_section_reloc_link_order: 2106 case bfd_symbol_reloc_link_order: 2107 if (! _bfd_generic_reloc_link_order (abfd, info, o, p)) 2108 return FALSE; 2109 break; 2110 case bfd_indirect_link_order: 2111 if (! default_indirect_link_order (abfd, info, o, p, TRUE)) 2112 return FALSE; 2113 break; 2114 default: 2115 if (! _bfd_default_link_order (abfd, info, o, p)) 2116 return FALSE; 2117 break; 2118 } 2119 } 2120 } 2121 2122 return TRUE; 2123 } 2124 2125 /* Add an output symbol to the output BFD. */ 2126 2127 static bfd_boolean 2128 generic_add_output_symbol (bfd *output_bfd, size_t *psymalloc, asymbol *sym) 2129 { 2130 if (bfd_get_symcount (output_bfd) >= *psymalloc) 2131 { 2132 asymbol **newsyms; 2133 bfd_size_type amt; 2134 2135 if (*psymalloc == 0) 2136 *psymalloc = 124; 2137 else 2138 *psymalloc *= 2; 2139 amt = *psymalloc; 2140 amt *= sizeof (asymbol *); 2141 newsyms = bfd_realloc (bfd_get_outsymbols (output_bfd), amt); 2142 if (newsyms == NULL) 2143 return FALSE; 2144 bfd_get_outsymbols (output_bfd) = newsyms; 2145 } 2146 2147 bfd_get_outsymbols (output_bfd) [bfd_get_symcount (output_bfd)] = sym; 2148 if (sym != NULL) 2149 ++ bfd_get_symcount (output_bfd); 2150 2151 return TRUE; 2152 } 2153 2154 /* Handle the symbols for an input BFD. */ 2155 2156 bfd_boolean 2157 _bfd_generic_link_output_symbols (bfd *output_bfd, 2158 bfd *input_bfd, 2159 struct bfd_link_info *info, 2160 size_t *psymalloc) 2161 { 2162 asymbol **sym_ptr; 2163 asymbol **sym_end; 2164 2165 if (! generic_link_read_symbols (input_bfd)) 2166 return FALSE; 2167 2168 /* Create a filename symbol if we are supposed to. */ 2169 if (info->create_object_symbols_section != NULL) 2170 { 2171 asection *sec; 2172 2173 for (sec = input_bfd->sections; sec != NULL; sec = sec->next) 2174 { 2175 if (sec->output_section == info->create_object_symbols_section) 2176 { 2177 asymbol *newsym; 2178 2179 newsym = bfd_make_empty_symbol (input_bfd); 2180 if (!newsym) 2181 return FALSE; 2182 newsym->name = input_bfd->filename; 2183 newsym->value = 0; 2184 newsym->flags = BSF_LOCAL | BSF_FILE; 2185 newsym->section = sec; 2186 2187 if (! generic_add_output_symbol (output_bfd, psymalloc, 2188 newsym)) 2189 return FALSE; 2190 2191 break; 2192 } 2193 } 2194 } 2195 2196 /* Adjust the values of the globally visible symbols, and write out 2197 local symbols. */ 2198 sym_ptr = _bfd_generic_link_get_symbols (input_bfd); 2199 sym_end = sym_ptr + _bfd_generic_link_get_symcount (input_bfd); 2200 for (; sym_ptr < sym_end; sym_ptr++) 2201 { 2202 asymbol *sym; 2203 struct generic_link_hash_entry *h; 2204 bfd_boolean output; 2205 2206 h = NULL; 2207 sym = *sym_ptr; 2208 if ((sym->flags & (BSF_INDIRECT 2209 | BSF_WARNING 2210 | BSF_GLOBAL 2211 | BSF_CONSTRUCTOR 2212 | BSF_WEAK)) != 0 2213 || bfd_is_und_section (bfd_get_section (sym)) 2214 || bfd_is_com_section (bfd_get_section (sym)) 2215 || bfd_is_ind_section (bfd_get_section (sym))) 2216 { 2217 if (sym->udata.p != NULL) 2218 h = sym->udata.p; 2219 else if ((sym->flags & BSF_CONSTRUCTOR) != 0) 2220 { 2221 /* This case normally means that the main linker code 2222 deliberately ignored this constructor symbol. We 2223 should just pass it through. This will screw up if 2224 the constructor symbol is from a different, 2225 non-generic, object file format, but the case will 2226 only arise when linking with -r, which will probably 2227 fail anyhow, since there will be no way to represent 2228 the relocs in the output format being used. */ 2229 h = NULL; 2230 } 2231 else if (bfd_is_und_section (bfd_get_section (sym))) 2232 h = ((struct generic_link_hash_entry *) 2233 bfd_wrapped_link_hash_lookup (output_bfd, info, 2234 bfd_asymbol_name (sym), 2235 FALSE, FALSE, TRUE)); 2236 else 2237 h = _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info), 2238 bfd_asymbol_name (sym), 2239 FALSE, FALSE, TRUE); 2240 2241 if (h != NULL) 2242 { 2243 /* Force all references to this symbol to point to 2244 the same area in memory. It is possible that 2245 this routine will be called with a hash table 2246 other than a generic hash table, so we double 2247 check that. */ 2248 if (info->hash->creator == input_bfd->xvec) 2249 { 2250 if (h->sym != NULL) 2251 *sym_ptr = sym = h->sym; 2252 } 2253 2254 switch (h->root.type) 2255 { 2256 default: 2257 case bfd_link_hash_new: 2258 abort (); 2259 case bfd_link_hash_undefined: 2260 break; 2261 case bfd_link_hash_undefweak: 2262 sym->flags |= BSF_WEAK; 2263 break; 2264 case bfd_link_hash_indirect: 2265 h = (struct generic_link_hash_entry *) h->root.u.i.link; 2266 /* fall through */ 2267 case bfd_link_hash_defined: 2268 sym->flags |= BSF_GLOBAL; 2269 sym->flags &=~ BSF_CONSTRUCTOR; 2270 sym->value = h->root.u.def.value; 2271 sym->section = h->root.u.def.section; 2272 break; 2273 case bfd_link_hash_defweak: 2274 sym->flags |= BSF_WEAK; 2275 sym->flags &=~ BSF_CONSTRUCTOR; 2276 sym->value = h->root.u.def.value; 2277 sym->section = h->root.u.def.section; 2278 break; 2279 case bfd_link_hash_common: 2280 sym->value = h->root.u.c.size; 2281 sym->flags |= BSF_GLOBAL; 2282 if (! bfd_is_com_section (sym->section)) 2283 { 2284 BFD_ASSERT (bfd_is_und_section (sym->section)); 2285 sym->section = bfd_com_section_ptr; 2286 } 2287 /* We do not set the section of the symbol to 2288 h->root.u.c.p->section. That value was saved so 2289 that we would know where to allocate the symbol 2290 if it was defined. In this case the type is 2291 still bfd_link_hash_common, so we did not define 2292 it, so we do not want to use that section. */ 2293 break; 2294 } 2295 } 2296 } 2297 2298 /* This switch is straight from the old code in 2299 write_file_locals in ldsym.c. */ 2300 if (info->strip == strip_all 2301 || (info->strip == strip_some 2302 && bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym), 2303 FALSE, FALSE) == NULL)) 2304 output = FALSE; 2305 else if ((sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0) 2306 { 2307 /* If this symbol is marked as occurring now, rather 2308 than at the end, output it now. This is used for 2309 COFF C_EXT FCN symbols. FIXME: There must be a 2310 better way. */ 2311 if (bfd_asymbol_bfd (sym) == input_bfd 2312 && (sym->flags & BSF_NOT_AT_END) != 0) 2313 output = TRUE; 2314 else 2315 output = FALSE; 2316 } 2317 else if (bfd_is_ind_section (sym->section)) 2318 output = FALSE; 2319 else if ((sym->flags & BSF_DEBUGGING) != 0) 2320 { 2321 if (info->strip == strip_none) 2322 output = TRUE; 2323 else 2324 output = FALSE; 2325 } 2326 else if (bfd_is_und_section (sym->section) 2327 || bfd_is_com_section (sym->section)) 2328 output = FALSE; 2329 else if ((sym->flags & BSF_LOCAL) != 0) 2330 { 2331 if ((sym->flags & BSF_WARNING) != 0) 2332 output = FALSE; 2333 else 2334 { 2335 switch (info->discard) 2336 { 2337 default: 2338 case discard_all: 2339 output = FALSE; 2340 break; 2341 case discard_sec_merge: 2342 output = TRUE; 2343 if (info->relocatable 2344 || ! (sym->section->flags & SEC_MERGE)) 2345 break; 2346 /* FALLTHROUGH */ 2347 case discard_l: 2348 if (bfd_is_local_label (input_bfd, sym)) 2349 output = FALSE; 2350 else 2351 output = TRUE; 2352 break; 2353 case discard_none: 2354 output = TRUE; 2355 break; 2356 } 2357 } 2358 } 2359 else if ((sym->flags & BSF_CONSTRUCTOR)) 2360 { 2361 if (info->strip != strip_all) 2362 output = TRUE; 2363 else 2364 output = FALSE; 2365 } 2366 else 2367 abort (); 2368 2369 /* If this symbol is in a section which is not being included 2370 in the output file, then we don't want to output the 2371 symbol. */ 2372 if (!bfd_is_abs_section (sym->section) 2373 && bfd_section_removed_from_list (output_bfd, 2374 sym->section->output_section)) 2375 output = FALSE; 2376 2377 if (output) 2378 { 2379 if (! generic_add_output_symbol (output_bfd, psymalloc, sym)) 2380 return FALSE; 2381 if (h != NULL) 2382 h->written = TRUE; 2383 } 2384 } 2385 2386 return TRUE; 2387 } 2388 2389 /* Set the section and value of a generic BFD symbol based on a linker 2390 hash table entry. */ 2391 2392 static void 2393 set_symbol_from_hash (asymbol *sym, struct bfd_link_hash_entry *h) 2394 { 2395 switch (h->type) 2396 { 2397 default: 2398 abort (); 2399 break; 2400 case bfd_link_hash_new: 2401 /* This can happen when a constructor symbol is seen but we are 2402 not building constructors. */ 2403 if (sym->section != NULL) 2404 { 2405 BFD_ASSERT ((sym->flags & BSF_CONSTRUCTOR) != 0); 2406 } 2407 else 2408 { 2409 sym->flags |= BSF_CONSTRUCTOR; 2410 sym->section = bfd_abs_section_ptr; 2411 sym->value = 0; 2412 } 2413 break; 2414 case bfd_link_hash_undefined: 2415 sym->section = bfd_und_section_ptr; 2416 sym->value = 0; 2417 break; 2418 case bfd_link_hash_undefweak: 2419 sym->section = bfd_und_section_ptr; 2420 sym->value = 0; 2421 sym->flags |= BSF_WEAK; 2422 break; 2423 case bfd_link_hash_defined: 2424 sym->section = h->u.def.section; 2425 sym->value = h->u.def.value; 2426 break; 2427 case bfd_link_hash_defweak: 2428 sym->flags |= BSF_WEAK; 2429 sym->section = h->u.def.section; 2430 sym->value = h->u.def.value; 2431 break; 2432 case bfd_link_hash_common: 2433 sym->value = h->u.c.size; 2434 if (sym->section == NULL) 2435 sym->section = bfd_com_section_ptr; 2436 else if (! bfd_is_com_section (sym->section)) 2437 { 2438 BFD_ASSERT (bfd_is_und_section (sym->section)); 2439 sym->section = bfd_com_section_ptr; 2440 } 2441 /* Do not set the section; see _bfd_generic_link_output_symbols. */ 2442 break; 2443 case bfd_link_hash_indirect: 2444 case bfd_link_hash_warning: 2445 /* FIXME: What should we do here? */ 2446 break; 2447 } 2448 } 2449 2450 /* Write out a global symbol, if it hasn't already been written out. 2451 This is called for each symbol in the hash table. */ 2452 2453 bfd_boolean 2454 _bfd_generic_link_write_global_symbol (struct generic_link_hash_entry *h, 2455 void *data) 2456 { 2457 struct generic_write_global_symbol_info *wginfo = data; 2458 asymbol *sym; 2459 2460 if (h->root.type == bfd_link_hash_warning) 2461 h = (struct generic_link_hash_entry *) h->root.u.i.link; 2462 2463 if (h->written) 2464 return TRUE; 2465 2466 h->written = TRUE; 2467 2468 if (wginfo->info->strip == strip_all 2469 || (wginfo->info->strip == strip_some 2470 && bfd_hash_lookup (wginfo->info->keep_hash, h->root.root.string, 2471 FALSE, FALSE) == NULL)) 2472 return TRUE; 2473 2474 if (h->sym != NULL) 2475 sym = h->sym; 2476 else 2477 { 2478 sym = bfd_make_empty_symbol (wginfo->output_bfd); 2479 if (!sym) 2480 return FALSE; 2481 sym->name = h->root.root.string; 2482 sym->flags = 0; 2483 } 2484 2485 set_symbol_from_hash (sym, &h->root); 2486 2487 sym->flags |= BSF_GLOBAL; 2488 2489 if (! generic_add_output_symbol (wginfo->output_bfd, wginfo->psymalloc, 2490 sym)) 2491 { 2492 /* FIXME: No way to return failure. */ 2493 abort (); 2494 } 2495 2496 return TRUE; 2497 } 2498 2499 /* Create a relocation. */ 2500 2501 bfd_boolean 2502 _bfd_generic_reloc_link_order (bfd *abfd, 2503 struct bfd_link_info *info, 2504 asection *sec, 2505 struct bfd_link_order *link_order) 2506 { 2507 arelent *r; 2508 2509 if (! info->relocatable) 2510 abort (); 2511 if (sec->orelocation == NULL) 2512 abort (); 2513 2514 r = bfd_alloc (abfd, sizeof (arelent)); 2515 if (r == NULL) 2516 return FALSE; 2517 2518 r->address = link_order->offset; 2519 r->howto = bfd_reloc_type_lookup (abfd, link_order->u.reloc.p->reloc); 2520 if (r->howto == 0) 2521 { 2522 bfd_set_error (bfd_error_bad_value); 2523 return FALSE; 2524 } 2525 2526 /* Get the symbol to use for the relocation. */ 2527 if (link_order->type == bfd_section_reloc_link_order) 2528 r->sym_ptr_ptr = link_order->u.reloc.p->u.section->symbol_ptr_ptr; 2529 else 2530 { 2531 struct generic_link_hash_entry *h; 2532 2533 h = ((struct generic_link_hash_entry *) 2534 bfd_wrapped_link_hash_lookup (abfd, info, 2535 link_order->u.reloc.p->u.name, 2536 FALSE, FALSE, TRUE)); 2537 if (h == NULL 2538 || ! h->written) 2539 { 2540 if (! ((*info->callbacks->unattached_reloc) 2541 (info, link_order->u.reloc.p->u.name, NULL, NULL, 0))) 2542 return FALSE; 2543 bfd_set_error (bfd_error_bad_value); 2544 return FALSE; 2545 } 2546 r->sym_ptr_ptr = &h->sym; 2547 } 2548 2549 /* If this is an inplace reloc, write the addend to the object file. 2550 Otherwise, store it in the reloc addend. */ 2551 if (! r->howto->partial_inplace) 2552 r->addend = link_order->u.reloc.p->addend; 2553 else 2554 { 2555 bfd_size_type size; 2556 bfd_reloc_status_type rstat; 2557 bfd_byte *buf; 2558 bfd_boolean ok; 2559 file_ptr loc; 2560 2561 size = bfd_get_reloc_size (r->howto); 2562 buf = bfd_zmalloc (size); 2563 if (buf == NULL) 2564 return FALSE; 2565 rstat = _bfd_relocate_contents (r->howto, abfd, 2566 (bfd_vma) link_order->u.reloc.p->addend, 2567 buf); 2568 switch (rstat) 2569 { 2570 case bfd_reloc_ok: 2571 break; 2572 default: 2573 case bfd_reloc_outofrange: 2574 abort (); 2575 case bfd_reloc_overflow: 2576 if (! ((*info->callbacks->reloc_overflow) 2577 (info, NULL, 2578 (link_order->type == bfd_section_reloc_link_order 2579 ? bfd_section_name (abfd, link_order->u.reloc.p->u.section) 2580 : link_order->u.reloc.p->u.name), 2581 r->howto->name, link_order->u.reloc.p->addend, 2582 NULL, NULL, 0))) 2583 { 2584 free (buf); 2585 return FALSE; 2586 } 2587 break; 2588 } 2589 loc = link_order->offset * bfd_octets_per_byte (abfd); 2590 ok = bfd_set_section_contents (abfd, sec, buf, loc, size); 2591 free (buf); 2592 if (! ok) 2593 return FALSE; 2594 2595 r->addend = 0; 2596 } 2597 2598 sec->orelocation[sec->reloc_count] = r; 2599 ++sec->reloc_count; 2600 2601 return TRUE; 2602 } 2603 2604 /* Allocate a new link_order for a section. */ 2605 2606 struct bfd_link_order * 2607 bfd_new_link_order (bfd *abfd, asection *section) 2608 { 2609 bfd_size_type amt = sizeof (struct bfd_link_order); 2610 struct bfd_link_order *new; 2611 2612 new = bfd_zalloc (abfd, amt); 2613 if (!new) 2614 return NULL; 2615 2616 new->type = bfd_undefined_link_order; 2617 2618 if (section->map_tail.link_order != NULL) 2619 section->map_tail.link_order->next = new; 2620 else 2621 section->map_head.link_order = new; 2622 section->map_tail.link_order = new; 2623 2624 return new; 2625 } 2626 2627 /* Default link order processing routine. Note that we can not handle 2628 the reloc_link_order types here, since they depend upon the details 2629 of how the particular backends generates relocs. */ 2630 2631 bfd_boolean 2632 _bfd_default_link_order (bfd *abfd, 2633 struct bfd_link_info *info, 2634 asection *sec, 2635 struct bfd_link_order *link_order) 2636 { 2637 switch (link_order->type) 2638 { 2639 case bfd_undefined_link_order: 2640 case bfd_section_reloc_link_order: 2641 case bfd_symbol_reloc_link_order: 2642 default: 2643 abort (); 2644 case bfd_indirect_link_order: 2645 return default_indirect_link_order (abfd, info, sec, link_order, 2646 FALSE); 2647 case bfd_data_link_order: 2648 return default_data_link_order (abfd, info, sec, link_order); 2649 } 2650 } 2651 2652 /* Default routine to handle a bfd_data_link_order. */ 2653 2654 static bfd_boolean 2655 default_data_link_order (bfd *abfd, 2656 struct bfd_link_info *info ATTRIBUTE_UNUSED, 2657 asection *sec, 2658 struct bfd_link_order *link_order) 2659 { 2660 bfd_size_type size; 2661 size_t fill_size; 2662 bfd_byte *fill; 2663 file_ptr loc; 2664 bfd_boolean result; 2665 2666 BFD_ASSERT ((sec->flags & SEC_HAS_CONTENTS) != 0); 2667 2668 size = link_order->size; 2669 if (size == 0) 2670 return TRUE; 2671 2672 fill = link_order->u.data.contents; 2673 fill_size = link_order->u.data.size; 2674 if (fill_size != 0 && fill_size < size) 2675 { 2676 bfd_byte *p; 2677 fill = bfd_malloc (size); 2678 if (fill == NULL) 2679 return FALSE; 2680 p = fill; 2681 if (fill_size == 1) 2682 memset (p, (int) link_order->u.data.contents[0], (size_t) size); 2683 else 2684 { 2685 do 2686 { 2687 memcpy (p, link_order->u.data.contents, fill_size); 2688 p += fill_size; 2689 size -= fill_size; 2690 } 2691 while (size >= fill_size); 2692 if (size != 0) 2693 memcpy (p, link_order->u.data.contents, (size_t) size); 2694 size = link_order->size; 2695 } 2696 } 2697 2698 loc = link_order->offset * bfd_octets_per_byte (abfd); 2699 result = bfd_set_section_contents (abfd, sec, fill, loc, size); 2700 2701 if (fill != link_order->u.data.contents) 2702 free (fill); 2703 return result; 2704 } 2705 2706 /* Default routine to handle a bfd_indirect_link_order. */ 2707 2708 static bfd_boolean 2709 default_indirect_link_order (bfd *output_bfd, 2710 struct bfd_link_info *info, 2711 asection *output_section, 2712 struct bfd_link_order *link_order, 2713 bfd_boolean generic_linker) 2714 { 2715 asection *input_section; 2716 bfd *input_bfd; 2717 bfd_byte *contents = NULL; 2718 bfd_byte *new_contents; 2719 bfd_size_type sec_size; 2720 file_ptr loc; 2721 2722 BFD_ASSERT ((output_section->flags & SEC_HAS_CONTENTS) != 0); 2723 2724 input_section = link_order->u.indirect.section; 2725 input_bfd = input_section->owner; 2726 if (input_section->size == 0) 2727 return TRUE; 2728 2729 BFD_ASSERT (input_section->output_section == output_section); 2730 BFD_ASSERT (input_section->output_offset == link_order->offset); 2731 BFD_ASSERT (input_section->size == link_order->size); 2732 2733 if (info->relocatable 2734 && input_section->reloc_count > 0 2735 && output_section->orelocation == NULL) 2736 { 2737 /* Space has not been allocated for the output relocations. 2738 This can happen when we are called by a specific backend 2739 because somebody is attempting to link together different 2740 types of object files. Handling this case correctly is 2741 difficult, and sometimes impossible. */ 2742 (*_bfd_error_handler) 2743 (_("Attempt to do relocatable link with %s input and %s output"), 2744 bfd_get_target (input_bfd), bfd_get_target (output_bfd)); 2745 bfd_set_error (bfd_error_wrong_format); 2746 return FALSE; 2747 } 2748 2749 if (! generic_linker) 2750 { 2751 asymbol **sympp; 2752 asymbol **symppend; 2753 2754 /* Get the canonical symbols. The generic linker will always 2755 have retrieved them by this point, but we are being called by 2756 a specific linker, presumably because we are linking 2757 different types of object files together. */ 2758 if (! generic_link_read_symbols (input_bfd)) 2759 return FALSE; 2760 2761 /* Since we have been called by a specific linker, rather than 2762 the generic linker, the values of the symbols will not be 2763 right. They will be the values as seen in the input file, 2764 not the values of the final link. We need to fix them up 2765 before we can relocate the section. */ 2766 sympp = _bfd_generic_link_get_symbols (input_bfd); 2767 symppend = sympp + _bfd_generic_link_get_symcount (input_bfd); 2768 for (; sympp < symppend; sympp++) 2769 { 2770 asymbol *sym; 2771 struct bfd_link_hash_entry *h; 2772 2773 sym = *sympp; 2774 2775 if ((sym->flags & (BSF_INDIRECT 2776 | BSF_WARNING 2777 | BSF_GLOBAL 2778 | BSF_CONSTRUCTOR 2779 | BSF_WEAK)) != 0 2780 || bfd_is_und_section (bfd_get_section (sym)) 2781 || bfd_is_com_section (bfd_get_section (sym)) 2782 || bfd_is_ind_section (bfd_get_section (sym))) 2783 { 2784 /* sym->udata may have been set by 2785 generic_link_add_symbol_list. */ 2786 if (sym->udata.p != NULL) 2787 h = sym->udata.p; 2788 else if (bfd_is_und_section (bfd_get_section (sym))) 2789 h = bfd_wrapped_link_hash_lookup (output_bfd, info, 2790 bfd_asymbol_name (sym), 2791 FALSE, FALSE, TRUE); 2792 else 2793 h = bfd_link_hash_lookup (info->hash, 2794 bfd_asymbol_name (sym), 2795 FALSE, FALSE, TRUE); 2796 if (h != NULL) 2797 set_symbol_from_hash (sym, h); 2798 } 2799 } 2800 } 2801 2802 /* Get and relocate the section contents. */ 2803 sec_size = (input_section->rawsize > input_section->size 2804 ? input_section->rawsize 2805 : input_section->size); 2806 contents = bfd_malloc (sec_size); 2807 if (contents == NULL && sec_size != 0) 2808 goto error_return; 2809 new_contents = (bfd_get_relocated_section_contents 2810 (output_bfd, info, link_order, contents, info->relocatable, 2811 _bfd_generic_link_get_symbols (input_bfd))); 2812 if (!new_contents) 2813 goto error_return; 2814 2815 /* Output the section contents. */ 2816 loc = input_section->output_offset * bfd_octets_per_byte (output_bfd); 2817 if (! bfd_set_section_contents (output_bfd, output_section, 2818 new_contents, loc, input_section->size)) 2819 goto error_return; 2820 2821 if (contents != NULL) 2822 free (contents); 2823 return TRUE; 2824 2825 error_return: 2826 if (contents != NULL) 2827 free (contents); 2828 return FALSE; 2829 } 2830 2831 /* A little routine to count the number of relocs in a link_order 2832 list. */ 2833 2834 unsigned int 2835 _bfd_count_link_order_relocs (struct bfd_link_order *link_order) 2836 { 2837 register unsigned int c; 2838 register struct bfd_link_order *l; 2839 2840 c = 0; 2841 for (l = link_order; l != NULL; l = l->next) 2842 { 2843 if (l->type == bfd_section_reloc_link_order 2844 || l->type == bfd_symbol_reloc_link_order) 2845 ++c; 2846 } 2847 2848 return c; 2849 } 2850 2851 /* 2852 FUNCTION 2853 bfd_link_split_section 2854 2855 SYNOPSIS 2856 bfd_boolean bfd_link_split_section (bfd *abfd, asection *sec); 2857 2858 DESCRIPTION 2859 Return nonzero if @var{sec} should be split during a 2860 reloceatable or final link. 2861 2862 .#define bfd_link_split_section(abfd, sec) \ 2863 . BFD_SEND (abfd, _bfd_link_split_section, (abfd, sec)) 2864 . 2865 2866 */ 2867 2868 bfd_boolean 2869 _bfd_generic_link_split_section (bfd *abfd ATTRIBUTE_UNUSED, 2870 asection *sec ATTRIBUTE_UNUSED) 2871 { 2872 return FALSE; 2873 } 2874 2875 /* 2876 FUNCTION 2877 bfd_section_already_linked 2878 2879 SYNOPSIS 2880 void bfd_section_already_linked (bfd *abfd, asection *sec, 2881 struct bfd_link_info *info); 2882 2883 DESCRIPTION 2884 Check if @var{sec} has been already linked during a reloceatable 2885 or final link. 2886 2887 .#define bfd_section_already_linked(abfd, sec, info) \ 2888 . BFD_SEND (abfd, _section_already_linked, (abfd, sec, info)) 2889 . 2890 2891 */ 2892 2893 /* Sections marked with the SEC_LINK_ONCE flag should only be linked 2894 once into the output. This routine checks each section, and 2895 arrange to discard it if a section of the same name has already 2896 been linked. This code assumes that all relevant sections have the 2897 SEC_LINK_ONCE flag set; that is, it does not depend solely upon the 2898 section name. bfd_section_already_linked is called via 2899 bfd_map_over_sections. */ 2900 2901 /* The hash table. */ 2902 2903 static struct bfd_hash_table _bfd_section_already_linked_table; 2904 2905 /* Support routines for the hash table used by section_already_linked, 2906 initialize the table, traverse, lookup, fill in an entry and remove 2907 the table. */ 2908 2909 void 2910 bfd_section_already_linked_table_traverse 2911 (bfd_boolean (*func) (struct bfd_section_already_linked_hash_entry *, 2912 void *), void *info) 2913 { 2914 bfd_hash_traverse (&_bfd_section_already_linked_table, 2915 (bfd_boolean (*) (struct bfd_hash_entry *, 2916 void *)) func, 2917 info); 2918 } 2919 2920 struct bfd_section_already_linked_hash_entry * 2921 bfd_section_already_linked_table_lookup (const char *name) 2922 { 2923 return ((struct bfd_section_already_linked_hash_entry *) 2924 bfd_hash_lookup (&_bfd_section_already_linked_table, name, 2925 TRUE, FALSE)); 2926 } 2927 2928 void 2929 bfd_section_already_linked_table_insert 2930 (struct bfd_section_already_linked_hash_entry *already_linked_list, 2931 asection *sec) 2932 { 2933 struct bfd_section_already_linked *l; 2934 2935 /* Allocate the memory from the same obstack as the hash table is 2936 kept in. */ 2937 l = bfd_hash_allocate (&_bfd_section_already_linked_table, sizeof *l); 2938 l->sec = sec; 2939 l->next = already_linked_list->entry; 2940 already_linked_list->entry = l; 2941 } 2942 2943 static struct bfd_hash_entry * 2944 already_linked_newfunc (struct bfd_hash_entry *entry ATTRIBUTE_UNUSED, 2945 struct bfd_hash_table *table, 2946 const char *string ATTRIBUTE_UNUSED) 2947 { 2948 struct bfd_section_already_linked_hash_entry *ret = 2949 bfd_hash_allocate (table, sizeof *ret); 2950 2951 ret->entry = NULL; 2952 2953 return &ret->root; 2954 } 2955 2956 bfd_boolean 2957 bfd_section_already_linked_table_init (void) 2958 { 2959 return bfd_hash_table_init_n (&_bfd_section_already_linked_table, 2960 already_linked_newfunc, 2961 sizeof (struct bfd_section_already_linked_hash_entry), 2962 42); 2963 } 2964 2965 void 2966 bfd_section_already_linked_table_free (void) 2967 { 2968 bfd_hash_table_free (&_bfd_section_already_linked_table); 2969 } 2970 2971 /* This is used on non-ELF inputs. */ 2972 2973 void 2974 _bfd_generic_section_already_linked (bfd *abfd, asection *sec, 2975 struct bfd_link_info *info ATTRIBUTE_UNUSED) 2976 { 2977 flagword flags; 2978 const char *name; 2979 struct bfd_section_already_linked *l; 2980 struct bfd_section_already_linked_hash_entry *already_linked_list; 2981 2982 flags = sec->flags; 2983 if ((flags & SEC_LINK_ONCE) == 0) 2984 return; 2985 2986 /* FIXME: When doing a relocatable link, we may have trouble 2987 copying relocations in other sections that refer to local symbols 2988 in the section being discarded. Those relocations will have to 2989 be converted somehow; as of this writing I'm not sure that any of 2990 the backends handle that correctly. 2991 2992 It is tempting to instead not discard link once sections when 2993 doing a relocatable link (technically, they should be discarded 2994 whenever we are building constructors). However, that fails, 2995 because the linker winds up combining all the link once sections 2996 into a single large link once section, which defeats the purpose 2997 of having link once sections in the first place. */ 2998 2999 name = bfd_get_section_name (abfd, sec); 3000 3001 already_linked_list = bfd_section_already_linked_table_lookup (name); 3002 3003 for (l = already_linked_list->entry; l != NULL; l = l->next) 3004 { 3005 bfd_boolean skip = FALSE; 3006 struct coff_comdat_info *s_comdat 3007 = bfd_coff_get_comdat_section (abfd, sec); 3008 struct coff_comdat_info *l_comdat 3009 = bfd_coff_get_comdat_section (l->sec->owner, l->sec); 3010 3011 /* We may have 3 different sections on the list: group section, 3012 comdat section and linkonce section. SEC may be a linkonce or 3013 comdat section. We always ignore group section. For non-COFF 3014 inputs, we also ignore comdat section. 3015 3016 FIXME: Is that safe to match a linkonce section with a comdat 3017 section for COFF inputs? */ 3018 if ((l->sec->flags & SEC_GROUP) != 0) 3019 skip = TRUE; 3020 else if (bfd_get_flavour (abfd) == bfd_target_coff_flavour) 3021 { 3022 if (s_comdat != NULL 3023 && l_comdat != NULL 3024 && strcmp (s_comdat->name, l_comdat->name) != 0) 3025 skip = TRUE; 3026 } 3027 else if (l_comdat != NULL) 3028 skip = TRUE; 3029 3030 if (!skip) 3031 { 3032 /* The section has already been linked. See if we should 3033 issue a warning. */ 3034 switch (flags & SEC_LINK_DUPLICATES) 3035 { 3036 default: 3037 abort (); 3038 3039 case SEC_LINK_DUPLICATES_DISCARD: 3040 break; 3041 3042 case SEC_LINK_DUPLICATES_ONE_ONLY: 3043 (*_bfd_error_handler) 3044 (_("%B: warning: ignoring duplicate section `%A'\n"), 3045 abfd, sec); 3046 break; 3047 3048 case SEC_LINK_DUPLICATES_SAME_CONTENTS: 3049 /* FIXME: We should really dig out the contents of both 3050 sections and memcmp them. The COFF/PE spec says that 3051 the Microsoft linker does not implement this 3052 correctly, so I'm not going to bother doing it 3053 either. */ 3054 /* Fall through. */ 3055 case SEC_LINK_DUPLICATES_SAME_SIZE: 3056 if (sec->size != l->sec->size) 3057 (*_bfd_error_handler) 3058 (_("%B: warning: duplicate section `%A' has different size\n"), 3059 abfd, sec); 3060 break; 3061 } 3062 3063 /* Set the output_section field so that lang_add_section 3064 does not create a lang_input_section structure for this 3065 section. Since there might be a symbol in the section 3066 being discarded, we must retain a pointer to the section 3067 which we are really going to use. */ 3068 sec->output_section = bfd_abs_section_ptr; 3069 sec->kept_section = l->sec; 3070 3071 return; 3072 } 3073 } 3074 3075 /* This is the first section with this name. Record it. */ 3076 bfd_section_already_linked_table_insert (already_linked_list, sec); 3077 } 3078 3079 /* Convert symbols in excluded output sections to absolute. */ 3080 3081 static bfd_boolean 3082 fix_syms (struct bfd_link_hash_entry *h, void *data) 3083 { 3084 bfd *obfd = (bfd *) data; 3085 3086 if (h->type == bfd_link_hash_warning) 3087 h = h->u.i.link; 3088 3089 if (h->type == bfd_link_hash_defined 3090 || h->type == bfd_link_hash_defweak) 3091 { 3092 asection *s = h->u.def.section; 3093 if (s != NULL 3094 && s->output_section != NULL 3095 && (s->output_section->flags & SEC_EXCLUDE) != 0 3096 && bfd_section_removed_from_list (obfd, s->output_section)) 3097 { 3098 h->u.def.value += s->output_offset + s->output_section->vma; 3099 h->u.def.section = bfd_abs_section_ptr; 3100 } 3101 } 3102 3103 return TRUE; 3104 } 3105 3106 void 3107 _bfd_fix_excluded_sec_syms (bfd *obfd, struct bfd_link_info *info) 3108 { 3109 bfd_link_hash_traverse (info->hash, fix_syms, obfd); 3110 } 3111