1 /* linker.c -- BFD linker routines 2 Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 3 2003, 2004, 2005, 2006, 2007, 2008, 2009 4 Free Software Foundation, Inc. 5 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support 6 7 This file is part of BFD, the Binary File Descriptor library. 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 3 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 22 MA 02110-1301, USA. */ 23 24 #include "sysdep.h" 25 #include "bfd.h" 26 #include "libbfd.h" 27 #include "bfdlink.h" 28 #include "genlink.h" 29 30 /* 31 SECTION 32 Linker Functions 33 34 @cindex Linker 35 The linker uses three special entry points in the BFD target 36 vector. It is not necessary to write special routines for 37 these entry points when creating a new BFD back end, since 38 generic versions are provided. However, writing them can 39 speed up linking and make it use significantly less runtime 40 memory. 41 42 The first routine creates a hash table used by the other 43 routines. The second routine adds the symbols from an object 44 file to the hash table. The third routine takes all the 45 object files and links them together to create the output 46 file. These routines are designed so that the linker proper 47 does not need to know anything about the symbols in the object 48 files that it is linking. The linker merely arranges the 49 sections as directed by the linker script and lets BFD handle 50 the details of symbols and relocs. 51 52 The second routine and third routines are passed a pointer to 53 a <<struct bfd_link_info>> structure (defined in 54 <<bfdlink.h>>) which holds information relevant to the link, 55 including the linker hash table (which was created by the 56 first routine) and a set of callback functions to the linker 57 proper. 58 59 The generic linker routines are in <<linker.c>>, and use the 60 header file <<genlink.h>>. As of this writing, the only back 61 ends which have implemented versions of these routines are 62 a.out (in <<aoutx.h>>) and ECOFF (in <<ecoff.c>>). The a.out 63 routines are used as examples throughout this section. 64 65 @menu 66 @* Creating a Linker Hash Table:: 67 @* Adding Symbols to the Hash Table:: 68 @* Performing the Final Link:: 69 @end menu 70 71 INODE 72 Creating a Linker Hash Table, Adding Symbols to the Hash Table, Linker Functions, Linker Functions 73 SUBSECTION 74 Creating a linker hash table 75 76 @cindex _bfd_link_hash_table_create in target vector 77 @cindex target vector (_bfd_link_hash_table_create) 78 The linker routines must create a hash table, which must be 79 derived from <<struct bfd_link_hash_table>> described in 80 <<bfdlink.c>>. @xref{Hash Tables}, for information on how to 81 create a derived hash table. This entry point is called using 82 the target vector of the linker output file. 83 84 The <<_bfd_link_hash_table_create>> entry point must allocate 85 and initialize an instance of the desired hash table. If the 86 back end does not require any additional information to be 87 stored with the entries in the hash table, the entry point may 88 simply create a <<struct bfd_link_hash_table>>. Most likely, 89 however, some additional information will be needed. 90 91 For example, with each entry in the hash table the a.out 92 linker keeps the index the symbol has in the final output file 93 (this index number is used so that when doing a relocatable 94 link the symbol index used in the output file can be quickly 95 filled in when copying over a reloc). The a.out linker code 96 defines the required structures and functions for a hash table 97 derived from <<struct bfd_link_hash_table>>. The a.out linker 98 hash table is created by the function 99 <<NAME(aout,link_hash_table_create)>>; it simply allocates 100 space for the hash table, initializes it, and returns a 101 pointer to it. 102 103 When writing the linker routines for a new back end, you will 104 generally not know exactly which fields will be required until 105 you have finished. You should simply create a new hash table 106 which defines no additional fields, and then simply add fields 107 as they become necessary. 108 109 INODE 110 Adding Symbols to the Hash Table, Performing the Final Link, Creating a Linker Hash Table, Linker Functions 111 SUBSECTION 112 Adding symbols to the hash table 113 114 @cindex _bfd_link_add_symbols in target vector 115 @cindex target vector (_bfd_link_add_symbols) 116 The linker proper will call the <<_bfd_link_add_symbols>> 117 entry point for each object file or archive which is to be 118 linked (typically these are the files named on the command 119 line, but some may also come from the linker script). The 120 entry point is responsible for examining the file. For an 121 object file, BFD must add any relevant symbol information to 122 the hash table. For an archive, BFD must determine which 123 elements of the archive should be used and adding them to the 124 link. 125 126 The a.out version of this entry point is 127 <<NAME(aout,link_add_symbols)>>. 128 129 @menu 130 @* Differing file formats:: 131 @* Adding symbols from an object file:: 132 @* Adding symbols from an archive:: 133 @end menu 134 135 INODE 136 Differing file formats, Adding symbols from an object file, Adding Symbols to the Hash Table, Adding Symbols to the Hash Table 137 SUBSUBSECTION 138 Differing file formats 139 140 Normally all the files involved in a link will be of the same 141 format, but it is also possible to link together different 142 format object files, and the back end must support that. The 143 <<_bfd_link_add_symbols>> entry point is called via the target 144 vector of the file to be added. This has an important 145 consequence: the function may not assume that the hash table 146 is the type created by the corresponding 147 <<_bfd_link_hash_table_create>> vector. All the 148 <<_bfd_link_add_symbols>> function can assume about the hash 149 table is that it is derived from <<struct 150 bfd_link_hash_table>>. 151 152 Sometimes the <<_bfd_link_add_symbols>> function must store 153 some information in the hash table entry to be used by the 154 <<_bfd_final_link>> function. In such a case the output bfd 155 xvec must be checked to make sure that the hash table was 156 created by an object file of the same format. 157 158 The <<_bfd_final_link>> routine must be prepared to handle a 159 hash entry without any extra information added by the 160 <<_bfd_link_add_symbols>> function. A hash entry without 161 extra information will also occur when the linker script 162 directs the linker to create a symbol. Note that, regardless 163 of how a hash table entry is added, all the fields will be 164 initialized to some sort of null value by the hash table entry 165 initialization function. 166 167 See <<ecoff_link_add_externals>> for an example of how to 168 check the output bfd before saving information (in this 169 case, the ECOFF external symbol debugging information) in a 170 hash table entry. 171 172 INODE 173 Adding symbols from an object file, Adding symbols from an archive, Differing file formats, Adding Symbols to the Hash Table 174 SUBSUBSECTION 175 Adding symbols from an object file 176 177 When the <<_bfd_link_add_symbols>> routine is passed an object 178 file, it must add all externally visible symbols in that 179 object file to the hash table. The actual work of adding the 180 symbol to the hash table is normally handled by the function 181 <<_bfd_generic_link_add_one_symbol>>. The 182 <<_bfd_link_add_symbols>> routine is responsible for reading 183 all the symbols from the object file and passing the correct 184 information to <<_bfd_generic_link_add_one_symbol>>. 185 186 The <<_bfd_link_add_symbols>> routine should not use 187 <<bfd_canonicalize_symtab>> to read the symbols. The point of 188 providing this routine is to avoid the overhead of converting 189 the symbols into generic <<asymbol>> structures. 190 191 @findex _bfd_generic_link_add_one_symbol 192 <<_bfd_generic_link_add_one_symbol>> handles the details of 193 combining common symbols, warning about multiple definitions, 194 and so forth. It takes arguments which describe the symbol to 195 add, notably symbol flags, a section, and an offset. The 196 symbol flags include such things as <<BSF_WEAK>> or 197 <<BSF_INDIRECT>>. The section is a section in the object 198 file, or something like <<bfd_und_section_ptr>> for an undefined 199 symbol or <<bfd_com_section_ptr>> for a common symbol. 200 201 If the <<_bfd_final_link>> routine is also going to need to 202 read the symbol information, the <<_bfd_link_add_symbols>> 203 routine should save it somewhere attached to the object file 204 BFD. However, the information should only be saved if the 205 <<keep_memory>> field of the <<info>> argument is TRUE, so 206 that the <<-no-keep-memory>> linker switch is effective. 207 208 The a.out function which adds symbols from an object file is 209 <<aout_link_add_object_symbols>>, and most of the interesting 210 work is in <<aout_link_add_symbols>>. The latter saves 211 pointers to the hash tables entries created by 212 <<_bfd_generic_link_add_one_symbol>> indexed by symbol number, 213 so that the <<_bfd_final_link>> routine does not have to call 214 the hash table lookup routine to locate the entry. 215 216 INODE 217 Adding symbols from an archive, , Adding symbols from an object file, Adding Symbols to the Hash Table 218 SUBSUBSECTION 219 Adding symbols from an archive 220 221 When the <<_bfd_link_add_symbols>> routine is passed an 222 archive, it must look through the symbols defined by the 223 archive and decide which elements of the archive should be 224 included in the link. For each such element it must call the 225 <<add_archive_element>> linker callback, and it must add the 226 symbols from the object file to the linker hash table. 227 228 @findex _bfd_generic_link_add_archive_symbols 229 In most cases the work of looking through the symbols in the 230 archive should be done by the 231 <<_bfd_generic_link_add_archive_symbols>> function. This 232 function builds a hash table from the archive symbol table and 233 looks through the list of undefined symbols to see which 234 elements should be included. 235 <<_bfd_generic_link_add_archive_symbols>> is passed a function 236 to call to make the final decision about adding an archive 237 element to the link and to do the actual work of adding the 238 symbols to the linker hash table. 239 240 The function passed to 241 <<_bfd_generic_link_add_archive_symbols>> must read the 242 symbols of the archive element and decide whether the archive 243 element should be included in the link. If the element is to 244 be included, the <<add_archive_element>> linker callback 245 routine must be called with the element as an argument, and 246 the elements symbols must be added to the linker hash table 247 just as though the element had itself been passed to the 248 <<_bfd_link_add_symbols>> function. 249 250 When the a.out <<_bfd_link_add_symbols>> function receives an 251 archive, it calls <<_bfd_generic_link_add_archive_symbols>> 252 passing <<aout_link_check_archive_element>> as the function 253 argument. <<aout_link_check_archive_element>> calls 254 <<aout_link_check_ar_symbols>>. If the latter decides to add 255 the element (an element is only added if it provides a real, 256 non-common, definition for a previously undefined or common 257 symbol) it calls the <<add_archive_element>> callback and then 258 <<aout_link_check_archive_element>> calls 259 <<aout_link_add_symbols>> to actually add the symbols to the 260 linker hash table. 261 262 The ECOFF back end is unusual in that it does not normally 263 call <<_bfd_generic_link_add_archive_symbols>>, because ECOFF 264 archives already contain a hash table of symbols. The ECOFF 265 back end searches the archive itself to avoid the overhead of 266 creating a new hash table. 267 268 INODE 269 Performing the Final Link, , Adding Symbols to the Hash Table, Linker Functions 270 SUBSECTION 271 Performing the final link 272 273 @cindex _bfd_link_final_link in target vector 274 @cindex target vector (_bfd_final_link) 275 When all the input files have been processed, the linker calls 276 the <<_bfd_final_link>> entry point of the output BFD. This 277 routine is responsible for producing the final output file, 278 which has several aspects. It must relocate the contents of 279 the input sections and copy the data into the output sections. 280 It must build an output symbol table including any local 281 symbols from the input files and the global symbols from the 282 hash table. When producing relocatable output, it must 283 modify the input relocs and write them into the output file. 284 There may also be object format dependent work to be done. 285 286 The linker will also call the <<write_object_contents>> entry 287 point when the BFD is closed. The two entry points must work 288 together in order to produce the correct output file. 289 290 The details of how this works are inevitably dependent upon 291 the specific object file format. The a.out 292 <<_bfd_final_link>> routine is <<NAME(aout,final_link)>>. 293 294 @menu 295 @* Information provided by the linker:: 296 @* Relocating the section contents:: 297 @* Writing the symbol table:: 298 @end menu 299 300 INODE 301 Information provided by the linker, Relocating the section contents, Performing the Final Link, Performing the Final Link 302 SUBSUBSECTION 303 Information provided by the linker 304 305 Before the linker calls the <<_bfd_final_link>> entry point, 306 it sets up some data structures for the function to use. 307 308 The <<input_bfds>> field of the <<bfd_link_info>> structure 309 will point to a list of all the input files included in the 310 link. These files are linked through the <<link_next>> field 311 of the <<bfd>> structure. 312 313 Each section in the output file will have a list of 314 <<link_order>> structures attached to the <<map_head.link_order>> 315 field (the <<link_order>> structure is defined in 316 <<bfdlink.h>>). These structures describe how to create the 317 contents of the output section in terms of the contents of 318 various input sections, fill constants, and, eventually, other 319 types of information. They also describe relocs that must be 320 created by the BFD backend, but do not correspond to any input 321 file; this is used to support -Ur, which builds constructors 322 while generating a relocatable object file. 323 324 INODE 325 Relocating the section contents, Writing the symbol table, Information provided by the linker, Performing the Final Link 326 SUBSUBSECTION 327 Relocating the section contents 328 329 The <<_bfd_final_link>> function should look through the 330 <<link_order>> structures attached to each section of the 331 output file. Each <<link_order>> structure should either be 332 handled specially, or it should be passed to the function 333 <<_bfd_default_link_order>> which will do the right thing 334 (<<_bfd_default_link_order>> is defined in <<linker.c>>). 335 336 For efficiency, a <<link_order>> of type 337 <<bfd_indirect_link_order>> whose associated section belongs 338 to a BFD of the same format as the output BFD must be handled 339 specially. This type of <<link_order>> describes part of an 340 output section in terms of a section belonging to one of the 341 input files. The <<_bfd_final_link>> function should read the 342 contents of the section and any associated relocs, apply the 343 relocs to the section contents, and write out the modified 344 section contents. If performing a relocatable link, the 345 relocs themselves must also be modified and written out. 346 347 @findex _bfd_relocate_contents 348 @findex _bfd_final_link_relocate 349 The functions <<_bfd_relocate_contents>> and 350 <<_bfd_final_link_relocate>> provide some general support for 351 performing the actual relocations, notably overflow checking. 352 Their arguments include information about the symbol the 353 relocation is against and a <<reloc_howto_type>> argument 354 which describes the relocation to perform. These functions 355 are defined in <<reloc.c>>. 356 357 The a.out function which handles reading, relocating, and 358 writing section contents is <<aout_link_input_section>>. The 359 actual relocation is done in <<aout_link_input_section_std>> 360 and <<aout_link_input_section_ext>>. 361 362 INODE 363 Writing the symbol table, , Relocating the section contents, Performing the Final Link 364 SUBSUBSECTION 365 Writing the symbol table 366 367 The <<_bfd_final_link>> function must gather all the symbols 368 in the input files and write them out. It must also write out 369 all the symbols in the global hash table. This must be 370 controlled by the <<strip>> and <<discard>> fields of the 371 <<bfd_link_info>> structure. 372 373 The local symbols of the input files will not have been 374 entered into the linker hash table. The <<_bfd_final_link>> 375 routine must consider each input file and include the symbols 376 in the output file. It may be convenient to do this when 377 looking through the <<link_order>> structures, or it may be 378 done by stepping through the <<input_bfds>> list. 379 380 The <<_bfd_final_link>> routine must also traverse the global 381 hash table to gather all the externally visible symbols. It 382 is possible that most of the externally visible symbols may be 383 written out when considering the symbols of each input file, 384 but it is still necessary to traverse the hash table since the 385 linker script may have defined some symbols that are not in 386 any of the input files. 387 388 The <<strip>> field of the <<bfd_link_info>> structure 389 controls which symbols are written out. The possible values 390 are listed in <<bfdlink.h>>. If the value is <<strip_some>>, 391 then the <<keep_hash>> field of the <<bfd_link_info>> 392 structure is a hash table of symbols to keep; each symbol 393 should be looked up in this hash table, and only symbols which 394 are present should be included in the output file. 395 396 If the <<strip>> field of the <<bfd_link_info>> structure 397 permits local symbols to be written out, the <<discard>> field 398 is used to further controls which local symbols are included 399 in the output file. If the value is <<discard_l>>, then all 400 local symbols which begin with a certain prefix are discarded; 401 this is controlled by the <<bfd_is_local_label_name>> entry point. 402 403 The a.out backend handles symbols by calling 404 <<aout_link_write_symbols>> on each input BFD and then 405 traversing the global hash table with the function 406 <<aout_link_write_other_symbol>>. It builds a string table 407 while writing out the symbols, which is written to the output 408 file at the end of <<NAME(aout,final_link)>>. 409 */ 410 411 static bfd_boolean generic_link_add_object_symbols 412 (bfd *, struct bfd_link_info *, bfd_boolean collect); 413 static bfd_boolean generic_link_add_symbols 414 (bfd *, struct bfd_link_info *, bfd_boolean); 415 static bfd_boolean generic_link_check_archive_element_no_collect 416 (bfd *, struct bfd_link_info *, bfd_boolean *); 417 static bfd_boolean generic_link_check_archive_element_collect 418 (bfd *, struct bfd_link_info *, bfd_boolean *); 419 static bfd_boolean generic_link_check_archive_element 420 (bfd *, struct bfd_link_info *, bfd_boolean *, bfd_boolean); 421 static bfd_boolean generic_link_add_symbol_list 422 (bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **, 423 bfd_boolean); 424 static bfd_boolean generic_add_output_symbol 425 (bfd *, size_t *psymalloc, asymbol *); 426 static bfd_boolean default_data_link_order 427 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *); 428 static bfd_boolean default_indirect_link_order 429 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *, 430 bfd_boolean); 431 432 /* The link hash table structure is defined in bfdlink.h. It provides 433 a base hash table which the backend specific hash tables are built 434 upon. */ 435 436 /* Routine to create an entry in the link hash table. */ 437 438 struct bfd_hash_entry * 439 _bfd_link_hash_newfunc (struct bfd_hash_entry *entry, 440 struct bfd_hash_table *table, 441 const char *string) 442 { 443 /* Allocate the structure if it has not already been allocated by a 444 subclass. */ 445 if (entry == NULL) 446 { 447 entry = (struct bfd_hash_entry *) 448 bfd_hash_allocate (table, sizeof (struct bfd_link_hash_entry)); 449 if (entry == NULL) 450 return entry; 451 } 452 453 /* Call the allocation method of the superclass. */ 454 entry = bfd_hash_newfunc (entry, table, string); 455 if (entry) 456 { 457 struct bfd_link_hash_entry *h = (struct bfd_link_hash_entry *) entry; 458 459 /* Initialize the local fields. */ 460 h->type = bfd_link_hash_new; 461 memset (&h->u.undef.next, 0, 462 (sizeof (struct bfd_link_hash_entry) 463 - offsetof (struct bfd_link_hash_entry, u.undef.next))); 464 } 465 466 return entry; 467 } 468 469 /* Initialize a link hash table. The BFD argument is the one 470 responsible for creating this table. */ 471 472 bfd_boolean 473 _bfd_link_hash_table_init 474 (struct bfd_link_hash_table *table, 475 bfd *abfd ATTRIBUTE_UNUSED, 476 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *, 477 struct bfd_hash_table *, 478 const char *), 479 unsigned int entsize) 480 { 481 table->undefs = NULL; 482 table->undefs_tail = NULL; 483 table->type = bfd_link_generic_hash_table; 484 485 return bfd_hash_table_init (&table->table, newfunc, entsize); 486 } 487 488 /* Look up a symbol in a link hash table. If follow is TRUE, we 489 follow bfd_link_hash_indirect and bfd_link_hash_warning links to 490 the real symbol. */ 491 492 struct bfd_link_hash_entry * 493 bfd_link_hash_lookup (struct bfd_link_hash_table *table, 494 const char *string, 495 bfd_boolean create, 496 bfd_boolean copy, 497 bfd_boolean follow) 498 { 499 struct bfd_link_hash_entry *ret; 500 501 ret = ((struct bfd_link_hash_entry *) 502 bfd_hash_lookup (&table->table, string, create, copy)); 503 504 if (follow && ret != NULL) 505 { 506 while (ret->type == bfd_link_hash_indirect 507 || ret->type == bfd_link_hash_warning) 508 ret = ret->u.i.link; 509 } 510 511 return ret; 512 } 513 514 /* Look up a symbol in the main linker hash table if the symbol might 515 be wrapped. This should only be used for references to an 516 undefined symbol, not for definitions of a symbol. */ 517 518 struct bfd_link_hash_entry * 519 bfd_wrapped_link_hash_lookup (bfd *abfd, 520 struct bfd_link_info *info, 521 const char *string, 522 bfd_boolean create, 523 bfd_boolean copy, 524 bfd_boolean follow) 525 { 526 bfd_size_type amt; 527 528 if (info->wrap_hash != NULL) 529 { 530 const char *l; 531 char prefix = '\0'; 532 533 l = string; 534 if (*l == bfd_get_symbol_leading_char (abfd) || *l == info->wrap_char) 535 { 536 prefix = *l; 537 ++l; 538 } 539 540 #undef WRAP 541 #define WRAP "__wrap_" 542 543 if (bfd_hash_lookup (info->wrap_hash, l, FALSE, FALSE) != NULL) 544 { 545 char *n; 546 struct bfd_link_hash_entry *h; 547 548 /* This symbol is being wrapped. We want to replace all 549 references to SYM with references to __wrap_SYM. */ 550 551 amt = strlen (l) + sizeof WRAP + 1; 552 n = (char *) bfd_malloc (amt); 553 if (n == NULL) 554 return NULL; 555 556 n[0] = prefix; 557 n[1] = '\0'; 558 strcat (n, WRAP); 559 strcat (n, l); 560 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow); 561 free (n); 562 return h; 563 } 564 565 #undef WRAP 566 567 #undef REAL 568 #define REAL "__real_" 569 570 if (*l == '_' 571 && CONST_STRNEQ (l, REAL) 572 && bfd_hash_lookup (info->wrap_hash, l + sizeof REAL - 1, 573 FALSE, FALSE) != NULL) 574 { 575 char *n; 576 struct bfd_link_hash_entry *h; 577 578 /* This is a reference to __real_SYM, where SYM is being 579 wrapped. We want to replace all references to __real_SYM 580 with references to SYM. */ 581 582 amt = strlen (l + sizeof REAL - 1) + 2; 583 n = (char *) bfd_malloc (amt); 584 if (n == NULL) 585 return NULL; 586 587 n[0] = prefix; 588 n[1] = '\0'; 589 strcat (n, l + sizeof REAL - 1); 590 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow); 591 free (n); 592 return h; 593 } 594 595 #undef REAL 596 } 597 598 return bfd_link_hash_lookup (info->hash, string, create, copy, follow); 599 } 600 601 /* Traverse a generic link hash table. The only reason this is not a 602 macro is to do better type checking. This code presumes that an 603 argument passed as a struct bfd_hash_entry * may be caught as a 604 struct bfd_link_hash_entry * with no explicit cast required on the 605 call. */ 606 607 void 608 bfd_link_hash_traverse 609 (struct bfd_link_hash_table *table, 610 bfd_boolean (*func) (struct bfd_link_hash_entry *, void *), 611 void *info) 612 { 613 bfd_hash_traverse (&table->table, 614 (bfd_boolean (*) (struct bfd_hash_entry *, void *)) func, 615 info); 616 } 617 618 /* Add a symbol to the linker hash table undefs list. */ 619 620 void 621 bfd_link_add_undef (struct bfd_link_hash_table *table, 622 struct bfd_link_hash_entry *h) 623 { 624 BFD_ASSERT (h->u.undef.next == NULL); 625 if (table->undefs_tail != NULL) 626 table->undefs_tail->u.undef.next = h; 627 if (table->undefs == NULL) 628 table->undefs = h; 629 table->undefs_tail = h; 630 } 631 632 /* The undefs list was designed so that in normal use we don't need to 633 remove entries. However, if symbols on the list are changed from 634 bfd_link_hash_undefined to either bfd_link_hash_undefweak or 635 bfd_link_hash_new for some reason, then they must be removed from the 636 list. Failure to do so might result in the linker attempting to add 637 the symbol to the list again at a later stage. */ 638 639 void 640 bfd_link_repair_undef_list (struct bfd_link_hash_table *table) 641 { 642 struct bfd_link_hash_entry **pun; 643 644 pun = &table->undefs; 645 while (*pun != NULL) 646 { 647 struct bfd_link_hash_entry *h = *pun; 648 649 if (h->type == bfd_link_hash_new 650 || h->type == bfd_link_hash_undefweak) 651 { 652 *pun = h->u.undef.next; 653 h->u.undef.next = NULL; 654 if (h == table->undefs_tail) 655 { 656 if (pun == &table->undefs) 657 table->undefs_tail = NULL; 658 else 659 /* pun points at an u.undef.next field. Go back to 660 the start of the link_hash_entry. */ 661 table->undefs_tail = (struct bfd_link_hash_entry *) 662 ((char *) pun - ((char *) &h->u.undef.next - (char *) h)); 663 break; 664 } 665 } 666 else 667 pun = &h->u.undef.next; 668 } 669 } 670 671 /* Routine to create an entry in a generic link hash table. */ 672 673 struct bfd_hash_entry * 674 _bfd_generic_link_hash_newfunc (struct bfd_hash_entry *entry, 675 struct bfd_hash_table *table, 676 const char *string) 677 { 678 /* Allocate the structure if it has not already been allocated by a 679 subclass. */ 680 if (entry == NULL) 681 { 682 entry = (struct bfd_hash_entry *) 683 bfd_hash_allocate (table, sizeof (struct generic_link_hash_entry)); 684 if (entry == NULL) 685 return entry; 686 } 687 688 /* Call the allocation method of the superclass. */ 689 entry = _bfd_link_hash_newfunc (entry, table, string); 690 if (entry) 691 { 692 struct generic_link_hash_entry *ret; 693 694 /* Set local fields. */ 695 ret = (struct generic_link_hash_entry *) entry; 696 ret->written = FALSE; 697 ret->sym = NULL; 698 } 699 700 return entry; 701 } 702 703 /* Create a generic link hash table. */ 704 705 struct bfd_link_hash_table * 706 _bfd_generic_link_hash_table_create (bfd *abfd) 707 { 708 struct generic_link_hash_table *ret; 709 bfd_size_type amt = sizeof (struct generic_link_hash_table); 710 711 ret = (struct generic_link_hash_table *) bfd_malloc (amt); 712 if (ret == NULL) 713 return NULL; 714 if (! _bfd_link_hash_table_init (&ret->root, abfd, 715 _bfd_generic_link_hash_newfunc, 716 sizeof (struct generic_link_hash_entry))) 717 { 718 free (ret); 719 return NULL; 720 } 721 return &ret->root; 722 } 723 724 void 725 _bfd_generic_link_hash_table_free (struct bfd_link_hash_table *hash) 726 { 727 struct generic_link_hash_table *ret 728 = (struct generic_link_hash_table *) hash; 729 730 bfd_hash_table_free (&ret->root.table); 731 free (ret); 732 } 733 734 /* Grab the symbols for an object file when doing a generic link. We 735 store the symbols in the outsymbols field. We need to keep them 736 around for the entire link to ensure that we only read them once. 737 If we read them multiple times, we might wind up with relocs and 738 the hash table pointing to different instances of the symbol 739 structure. */ 740 741 bfd_boolean 742 bfd_generic_link_read_symbols (bfd *abfd) 743 { 744 if (bfd_get_outsymbols (abfd) == NULL) 745 { 746 long symsize; 747 long symcount; 748 749 symsize = bfd_get_symtab_upper_bound (abfd); 750 if (symsize < 0) 751 return FALSE; 752 bfd_get_outsymbols (abfd) = (struct bfd_symbol **) bfd_alloc (abfd, 753 symsize); 754 if (bfd_get_outsymbols (abfd) == NULL && symsize != 0) 755 return FALSE; 756 symcount = bfd_canonicalize_symtab (abfd, bfd_get_outsymbols (abfd)); 757 if (symcount < 0) 758 return FALSE; 759 bfd_get_symcount (abfd) = symcount; 760 } 761 762 return TRUE; 763 } 764 765 /* Generic function to add symbols to from an object file to the 766 global hash table. This version does not automatically collect 767 constructors by name. */ 768 769 bfd_boolean 770 _bfd_generic_link_add_symbols (bfd *abfd, struct bfd_link_info *info) 771 { 772 return generic_link_add_symbols (abfd, info, FALSE); 773 } 774 775 /* Generic function to add symbols from an object file to the global 776 hash table. This version automatically collects constructors by 777 name, as the collect2 program does. It should be used for any 778 target which does not provide some other mechanism for setting up 779 constructors and destructors; these are approximately those targets 780 for which gcc uses collect2 and do not support stabs. */ 781 782 bfd_boolean 783 _bfd_generic_link_add_symbols_collect (bfd *abfd, struct bfd_link_info *info) 784 { 785 return generic_link_add_symbols (abfd, info, TRUE); 786 } 787 788 /* Indicate that we are only retrieving symbol values from this 789 section. We want the symbols to act as though the values in the 790 file are absolute. */ 791 792 void 793 _bfd_generic_link_just_syms (asection *sec, 794 struct bfd_link_info *info ATTRIBUTE_UNUSED) 795 { 796 sec->output_section = bfd_abs_section_ptr; 797 sec->output_offset = sec->vma; 798 } 799 800 /* Copy the type of a symbol assiciated with a linker hast table entry. 801 Override this so that symbols created in linker scripts get their 802 type from the RHS of the assignment. 803 The default implementation does nothing. */ 804 void 805 _bfd_generic_copy_link_hash_symbol_type (bfd *abfd ATTRIBUTE_UNUSED, 806 struct bfd_link_hash_entry * hdest ATTRIBUTE_UNUSED, 807 struct bfd_link_hash_entry * hsrc ATTRIBUTE_UNUSED) 808 { 809 } 810 811 /* Add symbols from an object file to the global hash table. */ 812 813 static bfd_boolean 814 generic_link_add_symbols (bfd *abfd, 815 struct bfd_link_info *info, 816 bfd_boolean collect) 817 { 818 bfd_boolean ret; 819 820 switch (bfd_get_format (abfd)) 821 { 822 case bfd_object: 823 ret = generic_link_add_object_symbols (abfd, info, collect); 824 break; 825 case bfd_archive: 826 ret = (_bfd_generic_link_add_archive_symbols 827 (abfd, info, 828 (collect 829 ? generic_link_check_archive_element_collect 830 : generic_link_check_archive_element_no_collect))); 831 break; 832 default: 833 bfd_set_error (bfd_error_wrong_format); 834 ret = FALSE; 835 } 836 837 return ret; 838 } 839 840 /* Add symbols from an object file to the global hash table. */ 841 842 static bfd_boolean 843 generic_link_add_object_symbols (bfd *abfd, 844 struct bfd_link_info *info, 845 bfd_boolean collect) 846 { 847 bfd_size_type symcount; 848 struct bfd_symbol **outsyms; 849 850 if (!bfd_generic_link_read_symbols (abfd)) 851 return FALSE; 852 symcount = _bfd_generic_link_get_symcount (abfd); 853 outsyms = _bfd_generic_link_get_symbols (abfd); 854 return generic_link_add_symbol_list (abfd, info, symcount, outsyms, collect); 855 } 856 857 /* We build a hash table of all symbols defined in an archive. */ 858 859 /* An archive symbol may be defined by multiple archive elements. 860 This linked list is used to hold the elements. */ 861 862 struct archive_list 863 { 864 struct archive_list *next; 865 unsigned int indx; 866 }; 867 868 /* An entry in an archive hash table. */ 869 870 struct archive_hash_entry 871 { 872 struct bfd_hash_entry root; 873 /* Where the symbol is defined. */ 874 struct archive_list *defs; 875 }; 876 877 /* An archive hash table itself. */ 878 879 struct archive_hash_table 880 { 881 struct bfd_hash_table table; 882 }; 883 884 /* Create a new entry for an archive hash table. */ 885 886 static struct bfd_hash_entry * 887 archive_hash_newfunc (struct bfd_hash_entry *entry, 888 struct bfd_hash_table *table, 889 const char *string) 890 { 891 struct archive_hash_entry *ret = (struct archive_hash_entry *) entry; 892 893 /* Allocate the structure if it has not already been allocated by a 894 subclass. */ 895 if (ret == NULL) 896 ret = (struct archive_hash_entry *) 897 bfd_hash_allocate (table, sizeof (struct archive_hash_entry)); 898 if (ret == NULL) 899 return NULL; 900 901 /* Call the allocation method of the superclass. */ 902 ret = ((struct archive_hash_entry *) 903 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string)); 904 905 if (ret) 906 { 907 /* Initialize the local fields. */ 908 ret->defs = NULL; 909 } 910 911 return &ret->root; 912 } 913 914 /* Initialize an archive hash table. */ 915 916 static bfd_boolean 917 archive_hash_table_init 918 (struct archive_hash_table *table, 919 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *, 920 struct bfd_hash_table *, 921 const char *), 922 unsigned int entsize) 923 { 924 return bfd_hash_table_init (&table->table, newfunc, entsize); 925 } 926 927 /* Look up an entry in an archive hash table. */ 928 929 #define archive_hash_lookup(t, string, create, copy) \ 930 ((struct archive_hash_entry *) \ 931 bfd_hash_lookup (&(t)->table, (string), (create), (copy))) 932 933 /* Allocate space in an archive hash table. */ 934 935 #define archive_hash_allocate(t, size) bfd_hash_allocate (&(t)->table, (size)) 936 937 /* Free an archive hash table. */ 938 939 #define archive_hash_table_free(t) bfd_hash_table_free (&(t)->table) 940 941 /* Generic function to add symbols from an archive file to the global 942 hash file. This function presumes that the archive symbol table 943 has already been read in (this is normally done by the 944 bfd_check_format entry point). It looks through the undefined and 945 common symbols and searches the archive symbol table for them. If 946 it finds an entry, it includes the associated object file in the 947 link. 948 949 The old linker looked through the archive symbol table for 950 undefined symbols. We do it the other way around, looking through 951 undefined symbols for symbols defined in the archive. The 952 advantage of the newer scheme is that we only have to look through 953 the list of undefined symbols once, whereas the old method had to 954 re-search the symbol table each time a new object file was added. 955 956 The CHECKFN argument is used to see if an object file should be 957 included. CHECKFN should set *PNEEDED to TRUE if the object file 958 should be included, and must also call the bfd_link_info 959 add_archive_element callback function and handle adding the symbols 960 to the global hash table. CHECKFN should only return FALSE if some 961 sort of error occurs. 962 963 For some formats, such as a.out, it is possible to look through an 964 object file but not actually include it in the link. The 965 archive_pass field in a BFD is used to avoid checking the symbols 966 of an object files too many times. When an object is included in 967 the link, archive_pass is set to -1. If an object is scanned but 968 not included, archive_pass is set to the pass number. The pass 969 number is incremented each time a new object file is included. The 970 pass number is used because when a new object file is included it 971 may create new undefined symbols which cause a previously examined 972 object file to be included. */ 973 974 bfd_boolean 975 _bfd_generic_link_add_archive_symbols 976 (bfd *abfd, 977 struct bfd_link_info *info, 978 bfd_boolean (*checkfn) (bfd *, struct bfd_link_info *, bfd_boolean *)) 979 { 980 carsym *arsyms; 981 carsym *arsym_end; 982 register carsym *arsym; 983 int pass; 984 struct archive_hash_table arsym_hash; 985 unsigned int indx; 986 struct bfd_link_hash_entry **pundef; 987 988 if (! bfd_has_map (abfd)) 989 { 990 /* An empty archive is a special case. */ 991 if (bfd_openr_next_archived_file (abfd, NULL) == NULL) 992 return TRUE; 993 bfd_set_error (bfd_error_no_armap); 994 return FALSE; 995 } 996 997 arsyms = bfd_ardata (abfd)->symdefs; 998 arsym_end = arsyms + bfd_ardata (abfd)->symdef_count; 999 1000 /* In order to quickly determine whether an symbol is defined in 1001 this archive, we build a hash table of the symbols. */ 1002 if (! archive_hash_table_init (&arsym_hash, archive_hash_newfunc, 1003 sizeof (struct archive_hash_entry))) 1004 return FALSE; 1005 for (arsym = arsyms, indx = 0; arsym < arsym_end; arsym++, indx++) 1006 { 1007 struct archive_hash_entry *arh; 1008 struct archive_list *l, **pp; 1009 1010 arh = archive_hash_lookup (&arsym_hash, arsym->name, TRUE, FALSE); 1011 if (arh == NULL) 1012 goto error_return; 1013 l = ((struct archive_list *) 1014 archive_hash_allocate (&arsym_hash, sizeof (struct archive_list))); 1015 if (l == NULL) 1016 goto error_return; 1017 l->indx = indx; 1018 for (pp = &arh->defs; *pp != NULL; pp = &(*pp)->next) 1019 ; 1020 *pp = l; 1021 l->next = NULL; 1022 } 1023 1024 /* The archive_pass field in the archive itself is used to 1025 initialize PASS, sine we may search the same archive multiple 1026 times. */ 1027 pass = abfd->archive_pass + 1; 1028 1029 /* New undefined symbols are added to the end of the list, so we 1030 only need to look through it once. */ 1031 pundef = &info->hash->undefs; 1032 while (*pundef != NULL) 1033 { 1034 struct bfd_link_hash_entry *h; 1035 struct archive_hash_entry *arh; 1036 struct archive_list *l; 1037 1038 h = *pundef; 1039 1040 /* When a symbol is defined, it is not necessarily removed from 1041 the list. */ 1042 if (h->type != bfd_link_hash_undefined 1043 && h->type != bfd_link_hash_common) 1044 { 1045 /* Remove this entry from the list, for general cleanliness 1046 and because we are going to look through the list again 1047 if we search any more libraries. We can't remove the 1048 entry if it is the tail, because that would lose any 1049 entries we add to the list later on (it would also cause 1050 us to lose track of whether the symbol has been 1051 referenced). */ 1052 if (*pundef != info->hash->undefs_tail) 1053 *pundef = (*pundef)->u.undef.next; 1054 else 1055 pundef = &(*pundef)->u.undef.next; 1056 continue; 1057 } 1058 1059 /* Look for this symbol in the archive symbol map. */ 1060 arh = archive_hash_lookup (&arsym_hash, h->root.string, FALSE, FALSE); 1061 if (arh == NULL) 1062 { 1063 /* If we haven't found the exact symbol we're looking for, 1064 let's look for its import thunk */ 1065 if (info->pei386_auto_import) 1066 { 1067 bfd_size_type amt = strlen (h->root.string) + 10; 1068 char *buf = (char *) bfd_malloc (amt); 1069 if (buf == NULL) 1070 return FALSE; 1071 1072 sprintf (buf, "__imp_%s", h->root.string); 1073 arh = archive_hash_lookup (&arsym_hash, buf, FALSE, FALSE); 1074 free(buf); 1075 } 1076 if (arh == NULL) 1077 { 1078 pundef = &(*pundef)->u.undef.next; 1079 continue; 1080 } 1081 } 1082 /* Look at all the objects which define this symbol. */ 1083 for (l = arh->defs; l != NULL; l = l->next) 1084 { 1085 bfd *element; 1086 bfd_boolean needed; 1087 1088 /* If the symbol has gotten defined along the way, quit. */ 1089 if (h->type != bfd_link_hash_undefined 1090 && h->type != bfd_link_hash_common) 1091 break; 1092 1093 element = bfd_get_elt_at_index (abfd, l->indx); 1094 if (element == NULL) 1095 goto error_return; 1096 1097 /* If we've already included this element, or if we've 1098 already checked it on this pass, continue. */ 1099 if (element->archive_pass == -1 1100 || element->archive_pass == pass) 1101 continue; 1102 1103 /* If we can't figure this element out, just ignore it. */ 1104 if (! bfd_check_format (element, bfd_object)) 1105 { 1106 element->archive_pass = -1; 1107 continue; 1108 } 1109 1110 /* CHECKFN will see if this element should be included, and 1111 go ahead and include it if appropriate. */ 1112 if (! (*checkfn) (element, info, &needed)) 1113 goto error_return; 1114 1115 if (! needed) 1116 element->archive_pass = pass; 1117 else 1118 { 1119 element->archive_pass = -1; 1120 1121 /* Increment the pass count to show that we may need to 1122 recheck object files which were already checked. */ 1123 ++pass; 1124 } 1125 } 1126 1127 pundef = &(*pundef)->u.undef.next; 1128 } 1129 1130 archive_hash_table_free (&arsym_hash); 1131 1132 /* Save PASS in case we are called again. */ 1133 abfd->archive_pass = pass; 1134 1135 return TRUE; 1136 1137 error_return: 1138 archive_hash_table_free (&arsym_hash); 1139 return FALSE; 1140 } 1141 1142 /* See if we should include an archive element. This version is used 1143 when we do not want to automatically collect constructors based on 1144 the symbol name, presumably because we have some other mechanism 1145 for finding them. */ 1146 1147 static bfd_boolean 1148 generic_link_check_archive_element_no_collect ( 1149 bfd *abfd, 1150 struct bfd_link_info *info, 1151 bfd_boolean *pneeded) 1152 { 1153 return generic_link_check_archive_element (abfd, info, pneeded, FALSE); 1154 } 1155 1156 /* See if we should include an archive element. This version is used 1157 when we want to automatically collect constructors based on the 1158 symbol name, as collect2 does. */ 1159 1160 static bfd_boolean 1161 generic_link_check_archive_element_collect (bfd *abfd, 1162 struct bfd_link_info *info, 1163 bfd_boolean *pneeded) 1164 { 1165 return generic_link_check_archive_element (abfd, info, pneeded, TRUE); 1166 } 1167 1168 /* See if we should include an archive element. Optionally collect 1169 constructors. */ 1170 1171 static bfd_boolean 1172 generic_link_check_archive_element (bfd *abfd, 1173 struct bfd_link_info *info, 1174 bfd_boolean *pneeded, 1175 bfd_boolean collect) 1176 { 1177 asymbol **pp, **ppend; 1178 1179 *pneeded = FALSE; 1180 1181 if (!bfd_generic_link_read_symbols (abfd)) 1182 return FALSE; 1183 1184 pp = _bfd_generic_link_get_symbols (abfd); 1185 ppend = pp + _bfd_generic_link_get_symcount (abfd); 1186 for (; pp < ppend; pp++) 1187 { 1188 asymbol *p; 1189 struct bfd_link_hash_entry *h; 1190 1191 p = *pp; 1192 1193 /* We are only interested in globally visible symbols. */ 1194 if (! bfd_is_com_section (p->section) 1195 && (p->flags & (BSF_GLOBAL | BSF_INDIRECT | BSF_WEAK)) == 0) 1196 continue; 1197 1198 /* We are only interested if we know something about this 1199 symbol, and it is undefined or common. An undefined weak 1200 symbol (type bfd_link_hash_undefweak) is not considered to be 1201 a reference when pulling files out of an archive. See the 1202 SVR4 ABI, p. 4-27. */ 1203 h = bfd_link_hash_lookup (info->hash, bfd_asymbol_name (p), FALSE, 1204 FALSE, TRUE); 1205 if (h == NULL 1206 || (h->type != bfd_link_hash_undefined 1207 && h->type != bfd_link_hash_common)) 1208 continue; 1209 1210 /* P is a symbol we are looking for. */ 1211 1212 if (! bfd_is_com_section (p->section)) 1213 { 1214 bfd_size_type symcount; 1215 asymbol **symbols; 1216 1217 /* This object file defines this symbol, so pull it in. */ 1218 if (! (*info->callbacks->add_archive_element) (info, abfd, 1219 bfd_asymbol_name (p))) 1220 return FALSE; 1221 symcount = _bfd_generic_link_get_symcount (abfd); 1222 symbols = _bfd_generic_link_get_symbols (abfd); 1223 if (! generic_link_add_symbol_list (abfd, info, symcount, 1224 symbols, collect)) 1225 return FALSE; 1226 *pneeded = TRUE; 1227 return TRUE; 1228 } 1229 1230 /* P is a common symbol. */ 1231 1232 if (h->type == bfd_link_hash_undefined) 1233 { 1234 bfd *symbfd; 1235 bfd_vma size; 1236 unsigned int power; 1237 1238 symbfd = h->u.undef.abfd; 1239 if (symbfd == NULL) 1240 { 1241 /* This symbol was created as undefined from outside 1242 BFD. We assume that we should link in the object 1243 file. This is for the -u option in the linker. */ 1244 if (! (*info->callbacks->add_archive_element) 1245 (info, abfd, bfd_asymbol_name (p))) 1246 return FALSE; 1247 *pneeded = TRUE; 1248 return TRUE; 1249 } 1250 1251 /* Turn the symbol into a common symbol but do not link in 1252 the object file. This is how a.out works. Object 1253 formats that require different semantics must implement 1254 this function differently. This symbol is already on the 1255 undefs list. We add the section to a common section 1256 attached to symbfd to ensure that it is in a BFD which 1257 will be linked in. */ 1258 h->type = bfd_link_hash_common; 1259 h->u.c.p = (struct bfd_link_hash_common_entry *) 1260 bfd_hash_allocate (&info->hash->table, 1261 sizeof (struct bfd_link_hash_common_entry)); 1262 if (h->u.c.p == NULL) 1263 return FALSE; 1264 1265 size = bfd_asymbol_value (p); 1266 h->u.c.size = size; 1267 1268 power = bfd_log2 (size); 1269 if (power > 4) 1270 power = 4; 1271 h->u.c.p->alignment_power = power; 1272 1273 if (p->section == bfd_com_section_ptr) 1274 h->u.c.p->section = bfd_make_section_old_way (symbfd, "COMMON"); 1275 else 1276 h->u.c.p->section = bfd_make_section_old_way (symbfd, 1277 p->section->name); 1278 h->u.c.p->section->flags = SEC_ALLOC; 1279 } 1280 else 1281 { 1282 /* Adjust the size of the common symbol if necessary. This 1283 is how a.out works. Object formats that require 1284 different semantics must implement this function 1285 differently. */ 1286 if (bfd_asymbol_value (p) > h->u.c.size) 1287 h->u.c.size = bfd_asymbol_value (p); 1288 } 1289 } 1290 1291 /* This archive element is not needed. */ 1292 return TRUE; 1293 } 1294 1295 /* Add the symbols from an object file to the global hash table. ABFD 1296 is the object file. INFO is the linker information. SYMBOL_COUNT 1297 is the number of symbols. SYMBOLS is the list of symbols. COLLECT 1298 is TRUE if constructors should be automatically collected by name 1299 as is done by collect2. */ 1300 1301 static bfd_boolean 1302 generic_link_add_symbol_list (bfd *abfd, 1303 struct bfd_link_info *info, 1304 bfd_size_type symbol_count, 1305 asymbol **symbols, 1306 bfd_boolean collect) 1307 { 1308 asymbol **pp, **ppend; 1309 1310 pp = symbols; 1311 ppend = symbols + symbol_count; 1312 for (; pp < ppend; pp++) 1313 { 1314 asymbol *p; 1315 1316 p = *pp; 1317 1318 if ((p->flags & (BSF_INDIRECT 1319 | BSF_WARNING 1320 | BSF_GLOBAL 1321 | BSF_CONSTRUCTOR 1322 | BSF_WEAK)) != 0 1323 || bfd_is_und_section (bfd_get_section (p)) 1324 || bfd_is_com_section (bfd_get_section (p)) 1325 || bfd_is_ind_section (bfd_get_section (p))) 1326 { 1327 const char *name; 1328 const char *string; 1329 struct generic_link_hash_entry *h; 1330 struct bfd_link_hash_entry *bh; 1331 1332 string = name = bfd_asymbol_name (p); 1333 if (((p->flags & BSF_INDIRECT) != 0 1334 || bfd_is_ind_section (p->section)) 1335 && pp + 1 < ppend) 1336 { 1337 pp++; 1338 string = bfd_asymbol_name (*pp); 1339 } 1340 else if ((p->flags & BSF_WARNING) != 0 1341 && pp + 1 < ppend) 1342 { 1343 /* The name of P is actually the warning string, and the 1344 next symbol is the one to warn about. */ 1345 pp++; 1346 name = bfd_asymbol_name (*pp); 1347 } 1348 1349 bh = NULL; 1350 if (! (_bfd_generic_link_add_one_symbol 1351 (info, abfd, name, p->flags, bfd_get_section (p), 1352 p->value, string, FALSE, collect, &bh))) 1353 return FALSE; 1354 h = (struct generic_link_hash_entry *) bh; 1355 1356 /* If this is a constructor symbol, and the linker didn't do 1357 anything with it, then we want to just pass the symbol 1358 through to the output file. This will happen when 1359 linking with -r. */ 1360 if ((p->flags & BSF_CONSTRUCTOR) != 0 1361 && (h == NULL || h->root.type == bfd_link_hash_new)) 1362 { 1363 p->udata.p = NULL; 1364 continue; 1365 } 1366 1367 /* Save the BFD symbol so that we don't lose any backend 1368 specific information that may be attached to it. We only 1369 want this one if it gives more information than the 1370 existing one; we don't want to replace a defined symbol 1371 with an undefined one. This routine may be called with a 1372 hash table other than the generic hash table, so we only 1373 do this if we are certain that the hash table is a 1374 generic one. */ 1375 if (info->output_bfd->xvec == abfd->xvec) 1376 { 1377 if (h->sym == NULL 1378 || (! bfd_is_und_section (bfd_get_section (p)) 1379 && (! bfd_is_com_section (bfd_get_section (p)) 1380 || bfd_is_und_section (bfd_get_section (h->sym))))) 1381 { 1382 h->sym = p; 1383 /* BSF_OLD_COMMON is a hack to support COFF reloc 1384 reading, and it should go away when the COFF 1385 linker is switched to the new version. */ 1386 if (bfd_is_com_section (bfd_get_section (p))) 1387 p->flags |= BSF_OLD_COMMON; 1388 } 1389 } 1390 1391 /* Store a back pointer from the symbol to the hash 1392 table entry for the benefit of relaxation code until 1393 it gets rewritten to not use asymbol structures. 1394 Setting this is also used to check whether these 1395 symbols were set up by the generic linker. */ 1396 p->udata.p = h; 1397 } 1398 } 1399 1400 return TRUE; 1401 } 1402 1403 /* We use a state table to deal with adding symbols from an object 1404 file. The first index into the state table describes the symbol 1405 from the object file. The second index into the state table is the 1406 type of the symbol in the hash table. */ 1407 1408 /* The symbol from the object file is turned into one of these row 1409 values. */ 1410 1411 enum link_row 1412 { 1413 UNDEF_ROW, /* Undefined. */ 1414 UNDEFW_ROW, /* Weak undefined. */ 1415 DEF_ROW, /* Defined. */ 1416 DEFW_ROW, /* Weak defined. */ 1417 COMMON_ROW, /* Common. */ 1418 INDR_ROW, /* Indirect. */ 1419 WARN_ROW, /* Warning. */ 1420 SET_ROW /* Member of set. */ 1421 }; 1422 1423 /* apparently needed for Hitachi 3050R(HI-UX/WE2)? */ 1424 #undef FAIL 1425 1426 /* The actions to take in the state table. */ 1427 1428 enum link_action 1429 { 1430 FAIL, /* Abort. */ 1431 UND, /* Mark symbol undefined. */ 1432 WEAK, /* Mark symbol weak undefined. */ 1433 DEF, /* Mark symbol defined. */ 1434 DEFW, /* Mark symbol weak defined. */ 1435 COM, /* Mark symbol common. */ 1436 REF, /* Mark defined symbol referenced. */ 1437 CREF, /* Possibly warn about common reference to defined symbol. */ 1438 CDEF, /* Define existing common symbol. */ 1439 NOACT, /* No action. */ 1440 BIG, /* Mark symbol common using largest size. */ 1441 MDEF, /* Multiple definition error. */ 1442 MIND, /* Multiple indirect symbols. */ 1443 IND, /* Make indirect symbol. */ 1444 CIND, /* Make indirect symbol from existing common symbol. */ 1445 SET, /* Add value to set. */ 1446 MWARN, /* Make warning symbol. */ 1447 WARN, /* Issue warning. */ 1448 CWARN, /* Warn if referenced, else MWARN. */ 1449 CYCLE, /* Repeat with symbol pointed to. */ 1450 REFC, /* Mark indirect symbol referenced and then CYCLE. */ 1451 WARNC /* Issue warning and then CYCLE. */ 1452 }; 1453 1454 /* The state table itself. The first index is a link_row and the 1455 second index is a bfd_link_hash_type. */ 1456 1457 static const enum link_action link_action[8][8] = 1458 { 1459 /* current\prev new undef undefw def defw com indr warn */ 1460 /* UNDEF_ROW */ {UND, NOACT, UND, REF, REF, NOACT, REFC, WARNC }, 1461 /* UNDEFW_ROW */ {WEAK, NOACT, NOACT, REF, REF, NOACT, REFC, WARNC }, 1462 /* DEF_ROW */ {DEF, DEF, DEF, MDEF, DEF, CDEF, MDEF, CYCLE }, 1463 /* DEFW_ROW */ {DEFW, DEFW, DEFW, NOACT, NOACT, NOACT, NOACT, CYCLE }, 1464 /* COMMON_ROW */ {COM, COM, COM, CREF, COM, BIG, REFC, WARNC }, 1465 /* INDR_ROW */ {IND, IND, IND, MDEF, IND, CIND, MIND, CYCLE }, 1466 /* WARN_ROW */ {MWARN, WARN, WARN, CWARN, CWARN, WARN, CWARN, NOACT }, 1467 /* SET_ROW */ {SET, SET, SET, SET, SET, SET, CYCLE, CYCLE } 1468 }; 1469 1470 /* Most of the entries in the LINK_ACTION table are straightforward, 1471 but a few are somewhat subtle. 1472 1473 A reference to an indirect symbol (UNDEF_ROW/indr or 1474 UNDEFW_ROW/indr) is counted as a reference both to the indirect 1475 symbol and to the symbol the indirect symbol points to. 1476 1477 A reference to a warning symbol (UNDEF_ROW/warn or UNDEFW_ROW/warn) 1478 causes the warning to be issued. 1479 1480 A common definition of an indirect symbol (COMMON_ROW/indr) is 1481 treated as a multiple definition error. Likewise for an indirect 1482 definition of a common symbol (INDR_ROW/com). 1483 1484 An indirect definition of a warning (INDR_ROW/warn) does not cause 1485 the warning to be issued. 1486 1487 If a warning is created for an indirect symbol (WARN_ROW/indr) no 1488 warning is created for the symbol the indirect symbol points to. 1489 1490 Adding an entry to a set does not count as a reference to a set, 1491 and no warning is issued (SET_ROW/warn). */ 1492 1493 /* Return the BFD in which a hash entry has been defined, if known. */ 1494 1495 static bfd * 1496 hash_entry_bfd (struct bfd_link_hash_entry *h) 1497 { 1498 while (h->type == bfd_link_hash_warning) 1499 h = h->u.i.link; 1500 switch (h->type) 1501 { 1502 default: 1503 return NULL; 1504 case bfd_link_hash_undefined: 1505 case bfd_link_hash_undefweak: 1506 return h->u.undef.abfd; 1507 case bfd_link_hash_defined: 1508 case bfd_link_hash_defweak: 1509 return h->u.def.section->owner; 1510 case bfd_link_hash_common: 1511 return h->u.c.p->section->owner; 1512 } 1513 /*NOTREACHED*/ 1514 } 1515 1516 /* Add a symbol to the global hash table. 1517 ABFD is the BFD the symbol comes from. 1518 NAME is the name of the symbol. 1519 FLAGS is the BSF_* bits associated with the symbol. 1520 SECTION is the section in which the symbol is defined; this may be 1521 bfd_und_section_ptr or bfd_com_section_ptr. 1522 VALUE is the value of the symbol, relative to the section. 1523 STRING is used for either an indirect symbol, in which case it is 1524 the name of the symbol to indirect to, or a warning symbol, in 1525 which case it is the warning string. 1526 COPY is TRUE if NAME or STRING must be copied into locally 1527 allocated memory if they need to be saved. 1528 COLLECT is TRUE if we should automatically collect gcc constructor 1529 or destructor names as collect2 does. 1530 HASHP, if not NULL, is a place to store the created hash table 1531 entry; if *HASHP is not NULL, the caller has already looked up 1532 the hash table entry, and stored it in *HASHP. */ 1533 1534 bfd_boolean 1535 _bfd_generic_link_add_one_symbol (struct bfd_link_info *info, 1536 bfd *abfd, 1537 const char *name, 1538 flagword flags, 1539 asection *section, 1540 bfd_vma value, 1541 const char *string, 1542 bfd_boolean copy, 1543 bfd_boolean collect, 1544 struct bfd_link_hash_entry **hashp) 1545 { 1546 enum link_row row; 1547 struct bfd_link_hash_entry *h; 1548 bfd_boolean cycle; 1549 1550 if (bfd_is_ind_section (section) 1551 || (flags & BSF_INDIRECT) != 0) 1552 row = INDR_ROW; 1553 else if ((flags & BSF_WARNING) != 0) 1554 row = WARN_ROW; 1555 else if ((flags & BSF_CONSTRUCTOR) != 0) 1556 row = SET_ROW; 1557 else if (bfd_is_und_section (section)) 1558 { 1559 if ((flags & BSF_WEAK) != 0) 1560 row = UNDEFW_ROW; 1561 else 1562 row = UNDEF_ROW; 1563 } 1564 else if ((flags & BSF_WEAK) != 0) 1565 row = DEFW_ROW; 1566 else if (bfd_is_com_section (section)) 1567 row = COMMON_ROW; 1568 else 1569 row = DEF_ROW; 1570 1571 if (hashp != NULL && *hashp != NULL) 1572 h = *hashp; 1573 else 1574 { 1575 if (row == UNDEF_ROW || row == UNDEFW_ROW) 1576 h = bfd_wrapped_link_hash_lookup (abfd, info, name, TRUE, copy, FALSE); 1577 else 1578 h = bfd_link_hash_lookup (info->hash, name, TRUE, copy, FALSE); 1579 if (h == NULL) 1580 { 1581 if (hashp != NULL) 1582 *hashp = NULL; 1583 return FALSE; 1584 } 1585 } 1586 1587 if (info->notice_all 1588 || (info->notice_hash != NULL 1589 && bfd_hash_lookup (info->notice_hash, name, FALSE, FALSE) != NULL)) 1590 { 1591 if (! (*info->callbacks->notice) (info, h->root.string, abfd, section, 1592 value)) 1593 return FALSE; 1594 } 1595 1596 if (hashp != NULL) 1597 *hashp = h; 1598 1599 do 1600 { 1601 enum link_action action; 1602 1603 cycle = FALSE; 1604 action = link_action[(int) row][(int) h->type]; 1605 switch (action) 1606 { 1607 case FAIL: 1608 abort (); 1609 1610 case NOACT: 1611 /* Do nothing. */ 1612 break; 1613 1614 case UND: 1615 /* Make a new undefined symbol. */ 1616 h->type = bfd_link_hash_undefined; 1617 h->u.undef.abfd = abfd; 1618 bfd_link_add_undef (info->hash, h); 1619 break; 1620 1621 case WEAK: 1622 /* Make a new weak undefined symbol. */ 1623 h->type = bfd_link_hash_undefweak; 1624 h->u.undef.abfd = abfd; 1625 h->u.undef.weak = abfd; 1626 break; 1627 1628 case CDEF: 1629 /* We have found a definition for a symbol which was 1630 previously common. */ 1631 BFD_ASSERT (h->type == bfd_link_hash_common); 1632 if (! ((*info->callbacks->multiple_common) 1633 (info, h->root.string, 1634 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1635 abfd, bfd_link_hash_defined, 0))) 1636 return FALSE; 1637 /* Fall through. */ 1638 case DEF: 1639 case DEFW: 1640 { 1641 enum bfd_link_hash_type oldtype; 1642 1643 /* Define a symbol. */ 1644 oldtype = h->type; 1645 if (action == DEFW) 1646 h->type = bfd_link_hash_defweak; 1647 else 1648 h->type = bfd_link_hash_defined; 1649 h->u.def.section = section; 1650 h->u.def.value = value; 1651 1652 /* If we have been asked to, we act like collect2 and 1653 identify all functions that might be global 1654 constructors and destructors and pass them up in a 1655 callback. We only do this for certain object file 1656 types, since many object file types can handle this 1657 automatically. */ 1658 if (collect && name[0] == '_') 1659 { 1660 const char *s; 1661 1662 /* A constructor or destructor name starts like this: 1663 _+GLOBAL_[_.$][ID][_.$] where the first [_.$] and 1664 the second are the same character (we accept any 1665 character there, in case a new object file format 1666 comes along with even worse naming restrictions). */ 1667 1668 #define CONS_PREFIX "GLOBAL_" 1669 #define CONS_PREFIX_LEN (sizeof CONS_PREFIX - 1) 1670 1671 s = name + 1; 1672 while (*s == '_') 1673 ++s; 1674 if (s[0] == 'G' && CONST_STRNEQ (s, CONS_PREFIX)) 1675 { 1676 char c; 1677 1678 c = s[CONS_PREFIX_LEN + 1]; 1679 if ((c == 'I' || c == 'D') 1680 && s[CONS_PREFIX_LEN] == s[CONS_PREFIX_LEN + 2]) 1681 { 1682 /* If this is a definition of a symbol which 1683 was previously weakly defined, we are in 1684 trouble. We have already added a 1685 constructor entry for the weak defined 1686 symbol, and now we are trying to add one 1687 for the new symbol. Fortunately, this case 1688 should never arise in practice. */ 1689 if (oldtype == bfd_link_hash_defweak) 1690 abort (); 1691 1692 if (! ((*info->callbacks->constructor) 1693 (info, c == 'I', 1694 h->root.string, abfd, section, value))) 1695 return FALSE; 1696 } 1697 } 1698 } 1699 } 1700 1701 break; 1702 1703 case COM: 1704 /* We have found a common definition for a symbol. */ 1705 if (h->type == bfd_link_hash_new) 1706 bfd_link_add_undef (info->hash, h); 1707 h->type = bfd_link_hash_common; 1708 h->u.c.p = (struct bfd_link_hash_common_entry *) 1709 bfd_hash_allocate (&info->hash->table, 1710 sizeof (struct bfd_link_hash_common_entry)); 1711 if (h->u.c.p == NULL) 1712 return FALSE; 1713 1714 h->u.c.size = value; 1715 1716 /* Select a default alignment based on the size. This may 1717 be overridden by the caller. */ 1718 { 1719 unsigned int power; 1720 1721 power = bfd_log2 (value); 1722 if (power > 4) 1723 power = 4; 1724 h->u.c.p->alignment_power = power; 1725 } 1726 1727 /* The section of a common symbol is only used if the common 1728 symbol is actually allocated. It basically provides a 1729 hook for the linker script to decide which output section 1730 the common symbols should be put in. In most cases, the 1731 section of a common symbol will be bfd_com_section_ptr, 1732 the code here will choose a common symbol section named 1733 "COMMON", and the linker script will contain *(COMMON) in 1734 the appropriate place. A few targets use separate common 1735 sections for small symbols, and they require special 1736 handling. */ 1737 if (section == bfd_com_section_ptr) 1738 { 1739 h->u.c.p->section = bfd_make_section_old_way (abfd, "COMMON"); 1740 h->u.c.p->section->flags = SEC_ALLOC; 1741 } 1742 else if (section->owner != abfd) 1743 { 1744 h->u.c.p->section = bfd_make_section_old_way (abfd, 1745 section->name); 1746 h->u.c.p->section->flags = SEC_ALLOC; 1747 } 1748 else 1749 h->u.c.p->section = section; 1750 break; 1751 1752 case REF: 1753 /* A reference to a defined symbol. */ 1754 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1755 h->u.undef.next = h; 1756 break; 1757 1758 case BIG: 1759 /* We have found a common definition for a symbol which 1760 already had a common definition. Use the maximum of the 1761 two sizes, and use the section required by the larger symbol. */ 1762 BFD_ASSERT (h->type == bfd_link_hash_common); 1763 if (! ((*info->callbacks->multiple_common) 1764 (info, h->root.string, 1765 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1766 abfd, bfd_link_hash_common, value))) 1767 return FALSE; 1768 if (value > h->u.c.size) 1769 { 1770 unsigned int power; 1771 1772 h->u.c.size = value; 1773 1774 /* Select a default alignment based on the size. This may 1775 be overridden by the caller. */ 1776 power = bfd_log2 (value); 1777 if (power > 4) 1778 power = 4; 1779 h->u.c.p->alignment_power = power; 1780 1781 /* Some systems have special treatment for small commons, 1782 hence we want to select the section used by the larger 1783 symbol. This makes sure the symbol does not go in a 1784 small common section if it is now too large. */ 1785 if (section == bfd_com_section_ptr) 1786 { 1787 h->u.c.p->section 1788 = bfd_make_section_old_way (abfd, "COMMON"); 1789 h->u.c.p->section->flags = SEC_ALLOC; 1790 } 1791 else if (section->owner != abfd) 1792 { 1793 h->u.c.p->section 1794 = bfd_make_section_old_way (abfd, section->name); 1795 h->u.c.p->section->flags = SEC_ALLOC; 1796 } 1797 else 1798 h->u.c.p->section = section; 1799 } 1800 break; 1801 1802 case CREF: 1803 { 1804 bfd *obfd; 1805 1806 /* We have found a common definition for a symbol which 1807 was already defined. FIXME: It would nice if we could 1808 report the BFD which defined an indirect symbol, but we 1809 don't have anywhere to store the information. */ 1810 if (h->type == bfd_link_hash_defined 1811 || h->type == bfd_link_hash_defweak) 1812 obfd = h->u.def.section->owner; 1813 else 1814 obfd = NULL; 1815 if (! ((*info->callbacks->multiple_common) 1816 (info, h->root.string, obfd, h->type, 0, 1817 abfd, bfd_link_hash_common, value))) 1818 return FALSE; 1819 } 1820 break; 1821 1822 case MIND: 1823 /* Multiple indirect symbols. This is OK if they both point 1824 to the same symbol. */ 1825 if (strcmp (h->u.i.link->root.string, string) == 0) 1826 break; 1827 /* Fall through. */ 1828 case MDEF: 1829 /* Handle a multiple definition. */ 1830 if (!info->allow_multiple_definition) 1831 { 1832 asection *msec = NULL; 1833 bfd_vma mval = 0; 1834 1835 switch (h->type) 1836 { 1837 case bfd_link_hash_defined: 1838 msec = h->u.def.section; 1839 mval = h->u.def.value; 1840 break; 1841 case bfd_link_hash_indirect: 1842 msec = bfd_ind_section_ptr; 1843 mval = 0; 1844 break; 1845 default: 1846 abort (); 1847 } 1848 1849 /* Ignore a redefinition of an absolute symbol to the 1850 same value; it's harmless. */ 1851 if (h->type == bfd_link_hash_defined 1852 && bfd_is_abs_section (msec) 1853 && bfd_is_abs_section (section) 1854 && value == mval) 1855 break; 1856 1857 if (! ((*info->callbacks->multiple_definition) 1858 (info, h->root.string, msec->owner, msec, mval, 1859 abfd, section, value))) 1860 return FALSE; 1861 } 1862 break; 1863 1864 case CIND: 1865 /* Create an indirect symbol from an existing common symbol. */ 1866 BFD_ASSERT (h->type == bfd_link_hash_common); 1867 if (! ((*info->callbacks->multiple_common) 1868 (info, h->root.string, 1869 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1870 abfd, bfd_link_hash_indirect, 0))) 1871 return FALSE; 1872 /* Fall through. */ 1873 case IND: 1874 /* Create an indirect symbol. */ 1875 { 1876 struct bfd_link_hash_entry *inh; 1877 1878 /* STRING is the name of the symbol we want to indirect 1879 to. */ 1880 inh = bfd_wrapped_link_hash_lookup (abfd, info, string, TRUE, 1881 copy, FALSE); 1882 if (inh == NULL) 1883 return FALSE; 1884 if (inh->type == bfd_link_hash_indirect 1885 && inh->u.i.link == h) 1886 { 1887 (*_bfd_error_handler) 1888 (_("%B: indirect symbol `%s' to `%s' is a loop"), 1889 abfd, name, string); 1890 bfd_set_error (bfd_error_invalid_operation); 1891 return FALSE; 1892 } 1893 if (inh->type == bfd_link_hash_new) 1894 { 1895 inh->type = bfd_link_hash_undefined; 1896 inh->u.undef.abfd = abfd; 1897 bfd_link_add_undef (info->hash, inh); 1898 } 1899 1900 /* If the indirect symbol has been referenced, we need to 1901 push the reference down to the symbol we are 1902 referencing. */ 1903 if (h->type != bfd_link_hash_new) 1904 { 1905 row = UNDEF_ROW; 1906 cycle = TRUE; 1907 } 1908 1909 h->type = bfd_link_hash_indirect; 1910 h->u.i.link = inh; 1911 } 1912 break; 1913 1914 case SET: 1915 /* Add an entry to a set. */ 1916 if (! (*info->callbacks->add_to_set) (info, h, BFD_RELOC_CTOR, 1917 abfd, section, value)) 1918 return FALSE; 1919 break; 1920 1921 case WARNC: 1922 /* Issue a warning and cycle. */ 1923 if (h->u.i.warning != NULL) 1924 { 1925 if (! (*info->callbacks->warning) (info, h->u.i.warning, 1926 h->root.string, abfd, 1927 NULL, 0)) 1928 return FALSE; 1929 /* Only issue a warning once. */ 1930 h->u.i.warning = NULL; 1931 } 1932 /* Fall through. */ 1933 case CYCLE: 1934 /* Try again with the referenced symbol. */ 1935 h = h->u.i.link; 1936 cycle = TRUE; 1937 break; 1938 1939 case REFC: 1940 /* A reference to an indirect symbol. */ 1941 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1942 h->u.undef.next = h; 1943 h = h->u.i.link; 1944 cycle = TRUE; 1945 break; 1946 1947 case WARN: 1948 /* Issue a warning. */ 1949 if (! (*info->callbacks->warning) (info, string, h->root.string, 1950 hash_entry_bfd (h), NULL, 0)) 1951 return FALSE; 1952 break; 1953 1954 case CWARN: 1955 /* Warn if this symbol has been referenced already, 1956 otherwise add a warning. A symbol has been referenced if 1957 the u.undef.next field is not NULL, or it is the tail of the 1958 undefined symbol list. The REF case above helps to 1959 ensure this. */ 1960 if (h->u.undef.next != NULL || info->hash->undefs_tail == h) 1961 { 1962 if (! (*info->callbacks->warning) (info, string, h->root.string, 1963 hash_entry_bfd (h), NULL, 0)) 1964 return FALSE; 1965 break; 1966 } 1967 /* Fall through. */ 1968 case MWARN: 1969 /* Make a warning symbol. */ 1970 { 1971 struct bfd_link_hash_entry *sub; 1972 1973 /* STRING is the warning to give. */ 1974 sub = ((struct bfd_link_hash_entry *) 1975 ((*info->hash->table.newfunc) 1976 (NULL, &info->hash->table, h->root.string))); 1977 if (sub == NULL) 1978 return FALSE; 1979 *sub = *h; 1980 sub->type = bfd_link_hash_warning; 1981 sub->u.i.link = h; 1982 if (! copy) 1983 sub->u.i.warning = string; 1984 else 1985 { 1986 char *w; 1987 size_t len = strlen (string) + 1; 1988 1989 w = (char *) bfd_hash_allocate (&info->hash->table, len); 1990 if (w == NULL) 1991 return FALSE; 1992 memcpy (w, string, len); 1993 sub->u.i.warning = w; 1994 } 1995 1996 bfd_hash_replace (&info->hash->table, 1997 (struct bfd_hash_entry *) h, 1998 (struct bfd_hash_entry *) sub); 1999 if (hashp != NULL) 2000 *hashp = sub; 2001 } 2002 break; 2003 } 2004 } 2005 while (cycle); 2006 2007 return TRUE; 2008 } 2009 2010 /* Generic final link routine. */ 2011 2012 bfd_boolean 2013 _bfd_generic_final_link (bfd *abfd, struct bfd_link_info *info) 2014 { 2015 bfd *sub; 2016 asection *o; 2017 struct bfd_link_order *p; 2018 size_t outsymalloc; 2019 struct generic_write_global_symbol_info wginfo; 2020 2021 bfd_get_outsymbols (abfd) = NULL; 2022 bfd_get_symcount (abfd) = 0; 2023 outsymalloc = 0; 2024 2025 /* Mark all sections which will be included in the output file. */ 2026 for (o = abfd->sections; o != NULL; o = o->next) 2027 for (p = o->map_head.link_order; p != NULL; p = p->next) 2028 if (p->type == bfd_indirect_link_order) 2029 p->u.indirect.section->linker_mark = TRUE; 2030 2031 /* Build the output symbol table. */ 2032 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next) 2033 if (! _bfd_generic_link_output_symbols (abfd, sub, info, &outsymalloc)) 2034 return FALSE; 2035 2036 /* Accumulate the global symbols. */ 2037 wginfo.info = info; 2038 wginfo.output_bfd = abfd; 2039 wginfo.psymalloc = &outsymalloc; 2040 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info), 2041 _bfd_generic_link_write_global_symbol, 2042 &wginfo); 2043 2044 /* Make sure we have a trailing NULL pointer on OUTSYMBOLS. We 2045 shouldn't really need one, since we have SYMCOUNT, but some old 2046 code still expects one. */ 2047 if (! generic_add_output_symbol (abfd, &outsymalloc, NULL)) 2048 return FALSE; 2049 2050 if (info->relocatable) 2051 { 2052 /* Allocate space for the output relocs for each section. */ 2053 for (o = abfd->sections; o != NULL; o = o->next) 2054 { 2055 o->reloc_count = 0; 2056 for (p = o->map_head.link_order; p != NULL; p = p->next) 2057 { 2058 if (p->type == bfd_section_reloc_link_order 2059 || p->type == bfd_symbol_reloc_link_order) 2060 ++o->reloc_count; 2061 else if (p->type == bfd_indirect_link_order) 2062 { 2063 asection *input_section; 2064 bfd *input_bfd; 2065 long relsize; 2066 arelent **relocs; 2067 asymbol **symbols; 2068 long reloc_count; 2069 2070 input_section = p->u.indirect.section; 2071 input_bfd = input_section->owner; 2072 relsize = bfd_get_reloc_upper_bound (input_bfd, 2073 input_section); 2074 if (relsize < 0) 2075 return FALSE; 2076 relocs = (arelent **) bfd_malloc (relsize); 2077 if (!relocs && relsize != 0) 2078 return FALSE; 2079 symbols = _bfd_generic_link_get_symbols (input_bfd); 2080 reloc_count = bfd_canonicalize_reloc (input_bfd, 2081 input_section, 2082 relocs, 2083 symbols); 2084 free (relocs); 2085 if (reloc_count < 0) 2086 return FALSE; 2087 BFD_ASSERT ((unsigned long) reloc_count 2088 == input_section->reloc_count); 2089 o->reloc_count += reloc_count; 2090 } 2091 } 2092 if (o->reloc_count > 0) 2093 { 2094 bfd_size_type amt; 2095 2096 amt = o->reloc_count; 2097 amt *= sizeof (arelent *); 2098 o->orelocation = (struct reloc_cache_entry **) bfd_alloc (abfd, amt); 2099 if (!o->orelocation) 2100 return FALSE; 2101 o->flags |= SEC_RELOC; 2102 /* Reset the count so that it can be used as an index 2103 when putting in the output relocs. */ 2104 o->reloc_count = 0; 2105 } 2106 } 2107 } 2108 2109 /* Handle all the link order information for the sections. */ 2110 for (o = abfd->sections; o != NULL; o = o->next) 2111 { 2112 for (p = o->map_head.link_order; p != NULL; p = p->next) 2113 { 2114 switch (p->type) 2115 { 2116 case bfd_section_reloc_link_order: 2117 case bfd_symbol_reloc_link_order: 2118 if (! _bfd_generic_reloc_link_order (abfd, info, o, p)) 2119 return FALSE; 2120 break; 2121 case bfd_indirect_link_order: 2122 if (! default_indirect_link_order (abfd, info, o, p, TRUE)) 2123 return FALSE; 2124 break; 2125 default: 2126 if (! _bfd_default_link_order (abfd, info, o, p)) 2127 return FALSE; 2128 break; 2129 } 2130 } 2131 } 2132 2133 return TRUE; 2134 } 2135 2136 /* Add an output symbol to the output BFD. */ 2137 2138 static bfd_boolean 2139 generic_add_output_symbol (bfd *output_bfd, size_t *psymalloc, asymbol *sym) 2140 { 2141 if (bfd_get_symcount (output_bfd) >= *psymalloc) 2142 { 2143 asymbol **newsyms; 2144 bfd_size_type amt; 2145 2146 if (*psymalloc == 0) 2147 *psymalloc = 124; 2148 else 2149 *psymalloc *= 2; 2150 amt = *psymalloc; 2151 amt *= sizeof (asymbol *); 2152 newsyms = (asymbol **) bfd_realloc (bfd_get_outsymbols (output_bfd), amt); 2153 if (newsyms == NULL) 2154 return FALSE; 2155 bfd_get_outsymbols (output_bfd) = newsyms; 2156 } 2157 2158 bfd_get_outsymbols (output_bfd) [bfd_get_symcount (output_bfd)] = sym; 2159 if (sym != NULL) 2160 ++ bfd_get_symcount (output_bfd); 2161 2162 return TRUE; 2163 } 2164 2165 /* Handle the symbols for an input BFD. */ 2166 2167 bfd_boolean 2168 _bfd_generic_link_output_symbols (bfd *output_bfd, 2169 bfd *input_bfd, 2170 struct bfd_link_info *info, 2171 size_t *psymalloc) 2172 { 2173 asymbol **sym_ptr; 2174 asymbol **sym_end; 2175 2176 if (!bfd_generic_link_read_symbols (input_bfd)) 2177 return FALSE; 2178 2179 /* Create a filename symbol if we are supposed to. */ 2180 if (info->create_object_symbols_section != NULL) 2181 { 2182 asection *sec; 2183 2184 for (sec = input_bfd->sections; sec != NULL; sec = sec->next) 2185 { 2186 if (sec->output_section == info->create_object_symbols_section) 2187 { 2188 asymbol *newsym; 2189 2190 newsym = bfd_make_empty_symbol (input_bfd); 2191 if (!newsym) 2192 return FALSE; 2193 newsym->name = input_bfd->filename; 2194 newsym->value = 0; 2195 newsym->flags = BSF_LOCAL | BSF_FILE; 2196 newsym->section = sec; 2197 2198 if (! generic_add_output_symbol (output_bfd, psymalloc, 2199 newsym)) 2200 return FALSE; 2201 2202 break; 2203 } 2204 } 2205 } 2206 2207 /* Adjust the values of the globally visible symbols, and write out 2208 local symbols. */ 2209 sym_ptr = _bfd_generic_link_get_symbols (input_bfd); 2210 sym_end = sym_ptr + _bfd_generic_link_get_symcount (input_bfd); 2211 for (; sym_ptr < sym_end; sym_ptr++) 2212 { 2213 asymbol *sym; 2214 struct generic_link_hash_entry *h; 2215 bfd_boolean output; 2216 2217 h = NULL; 2218 sym = *sym_ptr; 2219 if ((sym->flags & (BSF_INDIRECT 2220 | BSF_WARNING 2221 | BSF_GLOBAL 2222 | BSF_CONSTRUCTOR 2223 | BSF_WEAK)) != 0 2224 || bfd_is_und_section (bfd_get_section (sym)) 2225 || bfd_is_com_section (bfd_get_section (sym)) 2226 || bfd_is_ind_section (bfd_get_section (sym))) 2227 { 2228 if (sym->udata.p != NULL) 2229 h = (struct generic_link_hash_entry *) sym->udata.p; 2230 else if ((sym->flags & BSF_CONSTRUCTOR) != 0) 2231 { 2232 /* This case normally means that the main linker code 2233 deliberately ignored this constructor symbol. We 2234 should just pass it through. This will screw up if 2235 the constructor symbol is from a different, 2236 non-generic, object file format, but the case will 2237 only arise when linking with -r, which will probably 2238 fail anyhow, since there will be no way to represent 2239 the relocs in the output format being used. */ 2240 h = NULL; 2241 } 2242 else if (bfd_is_und_section (bfd_get_section (sym))) 2243 h = ((struct generic_link_hash_entry *) 2244 bfd_wrapped_link_hash_lookup (output_bfd, info, 2245 bfd_asymbol_name (sym), 2246 FALSE, FALSE, TRUE)); 2247 else 2248 h = _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info), 2249 bfd_asymbol_name (sym), 2250 FALSE, FALSE, TRUE); 2251 2252 if (h != NULL) 2253 { 2254 /* Force all references to this symbol to point to 2255 the same area in memory. It is possible that 2256 this routine will be called with a hash table 2257 other than a generic hash table, so we double 2258 check that. */ 2259 if (info->output_bfd->xvec == input_bfd->xvec) 2260 { 2261 if (h->sym != NULL) 2262 *sym_ptr = sym = h->sym; 2263 } 2264 2265 switch (h->root.type) 2266 { 2267 default: 2268 case bfd_link_hash_new: 2269 abort (); 2270 case bfd_link_hash_undefined: 2271 break; 2272 case bfd_link_hash_undefweak: 2273 sym->flags |= BSF_WEAK; 2274 break; 2275 case bfd_link_hash_indirect: 2276 h = (struct generic_link_hash_entry *) h->root.u.i.link; 2277 /* fall through */ 2278 case bfd_link_hash_defined: 2279 sym->flags |= BSF_GLOBAL; 2280 sym->flags &=~ BSF_CONSTRUCTOR; 2281 sym->value = h->root.u.def.value; 2282 sym->section = h->root.u.def.section; 2283 break; 2284 case bfd_link_hash_defweak: 2285 sym->flags |= BSF_WEAK; 2286 sym->flags &=~ BSF_CONSTRUCTOR; 2287 sym->value = h->root.u.def.value; 2288 sym->section = h->root.u.def.section; 2289 break; 2290 case bfd_link_hash_common: 2291 sym->value = h->root.u.c.size; 2292 sym->flags |= BSF_GLOBAL; 2293 if (! bfd_is_com_section (sym->section)) 2294 { 2295 BFD_ASSERT (bfd_is_und_section (sym->section)); 2296 sym->section = bfd_com_section_ptr; 2297 } 2298 /* We do not set the section of the symbol to 2299 h->root.u.c.p->section. That value was saved so 2300 that we would know where to allocate the symbol 2301 if it was defined. In this case the type is 2302 still bfd_link_hash_common, so we did not define 2303 it, so we do not want to use that section. */ 2304 break; 2305 } 2306 } 2307 } 2308 2309 /* This switch is straight from the old code in 2310 write_file_locals in ldsym.c. */ 2311 if (info->strip == strip_all 2312 || (info->strip == strip_some 2313 && bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym), 2314 FALSE, FALSE) == NULL)) 2315 output = FALSE; 2316 else if ((sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0) 2317 { 2318 /* If this symbol is marked as occurring now, rather 2319 than at the end, output it now. This is used for 2320 COFF C_EXT FCN symbols. FIXME: There must be a 2321 better way. */ 2322 if (bfd_asymbol_bfd (sym) == input_bfd 2323 && (sym->flags & BSF_NOT_AT_END) != 0) 2324 output = TRUE; 2325 else 2326 output = FALSE; 2327 } 2328 else if (bfd_is_ind_section (sym->section)) 2329 output = FALSE; 2330 else if ((sym->flags & BSF_DEBUGGING) != 0) 2331 { 2332 if (info->strip == strip_none) 2333 output = TRUE; 2334 else 2335 output = FALSE; 2336 } 2337 else if (bfd_is_und_section (sym->section) 2338 || bfd_is_com_section (sym->section)) 2339 output = FALSE; 2340 else if ((sym->flags & BSF_LOCAL) != 0) 2341 { 2342 if ((sym->flags & BSF_WARNING) != 0) 2343 output = FALSE; 2344 else 2345 { 2346 switch (info->discard) 2347 { 2348 default: 2349 case discard_all: 2350 output = FALSE; 2351 break; 2352 case discard_sec_merge: 2353 output = TRUE; 2354 if (info->relocatable 2355 || ! (sym->section->flags & SEC_MERGE)) 2356 break; 2357 /* FALLTHROUGH */ 2358 case discard_l: 2359 if (bfd_is_local_label (input_bfd, sym)) 2360 output = FALSE; 2361 else 2362 output = TRUE; 2363 break; 2364 case discard_none: 2365 output = TRUE; 2366 break; 2367 } 2368 } 2369 } 2370 else if ((sym->flags & BSF_CONSTRUCTOR)) 2371 { 2372 if (info->strip != strip_all) 2373 output = TRUE; 2374 else 2375 output = FALSE; 2376 } 2377 else 2378 abort (); 2379 2380 /* If this symbol is in a section which is not being included 2381 in the output file, then we don't want to output the 2382 symbol. */ 2383 if (!bfd_is_abs_section (sym->section) 2384 && bfd_section_removed_from_list (output_bfd, 2385 sym->section->output_section)) 2386 output = FALSE; 2387 2388 if (output) 2389 { 2390 if (! generic_add_output_symbol (output_bfd, psymalloc, sym)) 2391 return FALSE; 2392 if (h != NULL) 2393 h->written = TRUE; 2394 } 2395 } 2396 2397 return TRUE; 2398 } 2399 2400 /* Set the section and value of a generic BFD symbol based on a linker 2401 hash table entry. */ 2402 2403 static void 2404 set_symbol_from_hash (asymbol *sym, struct bfd_link_hash_entry *h) 2405 { 2406 switch (h->type) 2407 { 2408 default: 2409 abort (); 2410 break; 2411 case bfd_link_hash_new: 2412 /* This can happen when a constructor symbol is seen but we are 2413 not building constructors. */ 2414 if (sym->section != NULL) 2415 { 2416 BFD_ASSERT ((sym->flags & BSF_CONSTRUCTOR) != 0); 2417 } 2418 else 2419 { 2420 sym->flags |= BSF_CONSTRUCTOR; 2421 sym->section = bfd_abs_section_ptr; 2422 sym->value = 0; 2423 } 2424 break; 2425 case bfd_link_hash_undefined: 2426 sym->section = bfd_und_section_ptr; 2427 sym->value = 0; 2428 break; 2429 case bfd_link_hash_undefweak: 2430 sym->section = bfd_und_section_ptr; 2431 sym->value = 0; 2432 sym->flags |= BSF_WEAK; 2433 break; 2434 case bfd_link_hash_defined: 2435 sym->section = h->u.def.section; 2436 sym->value = h->u.def.value; 2437 break; 2438 case bfd_link_hash_defweak: 2439 sym->flags |= BSF_WEAK; 2440 sym->section = h->u.def.section; 2441 sym->value = h->u.def.value; 2442 break; 2443 case bfd_link_hash_common: 2444 sym->value = h->u.c.size; 2445 if (sym->section == NULL) 2446 sym->section = bfd_com_section_ptr; 2447 else if (! bfd_is_com_section (sym->section)) 2448 { 2449 BFD_ASSERT (bfd_is_und_section (sym->section)); 2450 sym->section = bfd_com_section_ptr; 2451 } 2452 /* Do not set the section; see _bfd_generic_link_output_symbols. */ 2453 break; 2454 case bfd_link_hash_indirect: 2455 case bfd_link_hash_warning: 2456 /* FIXME: What should we do here? */ 2457 break; 2458 } 2459 } 2460 2461 /* Write out a global symbol, if it hasn't already been written out. 2462 This is called for each symbol in the hash table. */ 2463 2464 bfd_boolean 2465 _bfd_generic_link_write_global_symbol (struct generic_link_hash_entry *h, 2466 void *data) 2467 { 2468 struct generic_write_global_symbol_info *wginfo = 2469 (struct generic_write_global_symbol_info *) data; 2470 asymbol *sym; 2471 2472 if (h->root.type == bfd_link_hash_warning) 2473 h = (struct generic_link_hash_entry *) h->root.u.i.link; 2474 2475 if (h->written) 2476 return TRUE; 2477 2478 h->written = TRUE; 2479 2480 if (wginfo->info->strip == strip_all 2481 || (wginfo->info->strip == strip_some 2482 && bfd_hash_lookup (wginfo->info->keep_hash, h->root.root.string, 2483 FALSE, FALSE) == NULL)) 2484 return TRUE; 2485 2486 if (h->sym != NULL) 2487 sym = h->sym; 2488 else 2489 { 2490 sym = bfd_make_empty_symbol (wginfo->output_bfd); 2491 if (!sym) 2492 return FALSE; 2493 sym->name = h->root.root.string; 2494 sym->flags = 0; 2495 } 2496 2497 set_symbol_from_hash (sym, &h->root); 2498 2499 sym->flags |= BSF_GLOBAL; 2500 2501 if (! generic_add_output_symbol (wginfo->output_bfd, wginfo->psymalloc, 2502 sym)) 2503 { 2504 /* FIXME: No way to return failure. */ 2505 abort (); 2506 } 2507 2508 return TRUE; 2509 } 2510 2511 /* Create a relocation. */ 2512 2513 bfd_boolean 2514 _bfd_generic_reloc_link_order (bfd *abfd, 2515 struct bfd_link_info *info, 2516 asection *sec, 2517 struct bfd_link_order *link_order) 2518 { 2519 arelent *r; 2520 2521 if (! info->relocatable) 2522 abort (); 2523 if (sec->orelocation == NULL) 2524 abort (); 2525 2526 r = (arelent *) bfd_alloc (abfd, sizeof (arelent)); 2527 if (r == NULL) 2528 return FALSE; 2529 2530 r->address = link_order->offset; 2531 r->howto = bfd_reloc_type_lookup (abfd, link_order->u.reloc.p->reloc); 2532 if (r->howto == 0) 2533 { 2534 bfd_set_error (bfd_error_bad_value); 2535 return FALSE; 2536 } 2537 2538 /* Get the symbol to use for the relocation. */ 2539 if (link_order->type == bfd_section_reloc_link_order) 2540 r->sym_ptr_ptr = link_order->u.reloc.p->u.section->symbol_ptr_ptr; 2541 else 2542 { 2543 struct generic_link_hash_entry *h; 2544 2545 h = ((struct generic_link_hash_entry *) 2546 bfd_wrapped_link_hash_lookup (abfd, info, 2547 link_order->u.reloc.p->u.name, 2548 FALSE, FALSE, TRUE)); 2549 if (h == NULL 2550 || ! h->written) 2551 { 2552 if (! ((*info->callbacks->unattached_reloc) 2553 (info, link_order->u.reloc.p->u.name, NULL, NULL, 0))) 2554 return FALSE; 2555 bfd_set_error (bfd_error_bad_value); 2556 return FALSE; 2557 } 2558 r->sym_ptr_ptr = &h->sym; 2559 } 2560 2561 /* If this is an inplace reloc, write the addend to the object file. 2562 Otherwise, store it in the reloc addend. */ 2563 if (! r->howto->partial_inplace) 2564 r->addend = link_order->u.reloc.p->addend; 2565 else 2566 { 2567 bfd_size_type size; 2568 bfd_reloc_status_type rstat; 2569 bfd_byte *buf; 2570 bfd_boolean ok; 2571 file_ptr loc; 2572 2573 size = bfd_get_reloc_size (r->howto); 2574 buf = (bfd_byte *) bfd_zmalloc (size); 2575 if (buf == NULL) 2576 return FALSE; 2577 rstat = _bfd_relocate_contents (r->howto, abfd, 2578 (bfd_vma) link_order->u.reloc.p->addend, 2579 buf); 2580 switch (rstat) 2581 { 2582 case bfd_reloc_ok: 2583 break; 2584 default: 2585 case bfd_reloc_outofrange: 2586 abort (); 2587 case bfd_reloc_overflow: 2588 if (! ((*info->callbacks->reloc_overflow) 2589 (info, NULL, 2590 (link_order->type == bfd_section_reloc_link_order 2591 ? bfd_section_name (abfd, link_order->u.reloc.p->u.section) 2592 : link_order->u.reloc.p->u.name), 2593 r->howto->name, link_order->u.reloc.p->addend, 2594 NULL, NULL, 0))) 2595 { 2596 free (buf); 2597 return FALSE; 2598 } 2599 break; 2600 } 2601 loc = link_order->offset * bfd_octets_per_byte (abfd); 2602 ok = bfd_set_section_contents (abfd, sec, buf, loc, size); 2603 free (buf); 2604 if (! ok) 2605 return FALSE; 2606 2607 r->addend = 0; 2608 } 2609 2610 sec->orelocation[sec->reloc_count] = r; 2611 ++sec->reloc_count; 2612 2613 return TRUE; 2614 } 2615 2616 /* Allocate a new link_order for a section. */ 2617 2618 struct bfd_link_order * 2619 bfd_new_link_order (bfd *abfd, asection *section) 2620 { 2621 bfd_size_type amt = sizeof (struct bfd_link_order); 2622 struct bfd_link_order *new_lo; 2623 2624 new_lo = (struct bfd_link_order *) bfd_zalloc (abfd, amt); 2625 if (!new_lo) 2626 return NULL; 2627 2628 new_lo->type = bfd_undefined_link_order; 2629 2630 if (section->map_tail.link_order != NULL) 2631 section->map_tail.link_order->next = new_lo; 2632 else 2633 section->map_head.link_order = new_lo; 2634 section->map_tail.link_order = new_lo; 2635 2636 return new_lo; 2637 } 2638 2639 /* Default link order processing routine. Note that we can not handle 2640 the reloc_link_order types here, since they depend upon the details 2641 of how the particular backends generates relocs. */ 2642 2643 bfd_boolean 2644 _bfd_default_link_order (bfd *abfd, 2645 struct bfd_link_info *info, 2646 asection *sec, 2647 struct bfd_link_order *link_order) 2648 { 2649 switch (link_order->type) 2650 { 2651 case bfd_undefined_link_order: 2652 case bfd_section_reloc_link_order: 2653 case bfd_symbol_reloc_link_order: 2654 default: 2655 abort (); 2656 case bfd_indirect_link_order: 2657 return default_indirect_link_order (abfd, info, sec, link_order, 2658 FALSE); 2659 case bfd_data_link_order: 2660 return default_data_link_order (abfd, info, sec, link_order); 2661 } 2662 } 2663 2664 /* Default routine to handle a bfd_data_link_order. */ 2665 2666 static bfd_boolean 2667 default_data_link_order (bfd *abfd, 2668 struct bfd_link_info *info ATTRIBUTE_UNUSED, 2669 asection *sec, 2670 struct bfd_link_order *link_order) 2671 { 2672 bfd_size_type size; 2673 size_t fill_size; 2674 bfd_byte *fill; 2675 file_ptr loc; 2676 bfd_boolean result; 2677 2678 BFD_ASSERT ((sec->flags & SEC_HAS_CONTENTS) != 0); 2679 2680 size = link_order->size; 2681 if (size == 0) 2682 return TRUE; 2683 2684 fill = link_order->u.data.contents; 2685 fill_size = link_order->u.data.size; 2686 if (fill_size != 0 && fill_size < size) 2687 { 2688 bfd_byte *p; 2689 fill = (bfd_byte *) bfd_malloc (size); 2690 if (fill == NULL) 2691 return FALSE; 2692 p = fill; 2693 if (fill_size == 1) 2694 memset (p, (int) link_order->u.data.contents[0], (size_t) size); 2695 else 2696 { 2697 do 2698 { 2699 memcpy (p, link_order->u.data.contents, fill_size); 2700 p += fill_size; 2701 size -= fill_size; 2702 } 2703 while (size >= fill_size); 2704 if (size != 0) 2705 memcpy (p, link_order->u.data.contents, (size_t) size); 2706 size = link_order->size; 2707 } 2708 } 2709 2710 loc = link_order->offset * bfd_octets_per_byte (abfd); 2711 result = bfd_set_section_contents (abfd, sec, fill, loc, size); 2712 2713 if (fill != link_order->u.data.contents) 2714 free (fill); 2715 return result; 2716 } 2717 2718 /* Default routine to handle a bfd_indirect_link_order. */ 2719 2720 static bfd_boolean 2721 default_indirect_link_order (bfd *output_bfd, 2722 struct bfd_link_info *info, 2723 asection *output_section, 2724 struct bfd_link_order *link_order, 2725 bfd_boolean generic_linker) 2726 { 2727 asection *input_section; 2728 bfd *input_bfd; 2729 bfd_byte *contents = NULL; 2730 bfd_byte *new_contents; 2731 bfd_size_type sec_size; 2732 file_ptr loc; 2733 2734 BFD_ASSERT ((output_section->flags & SEC_HAS_CONTENTS) != 0); 2735 2736 input_section = link_order->u.indirect.section; 2737 input_bfd = input_section->owner; 2738 if (input_section->size == 0) 2739 return TRUE; 2740 2741 BFD_ASSERT (input_section->output_section == output_section); 2742 BFD_ASSERT (input_section->output_offset == link_order->offset); 2743 BFD_ASSERT (input_section->size == link_order->size); 2744 2745 if (info->relocatable 2746 && input_section->reloc_count > 0 2747 && output_section->orelocation == NULL) 2748 { 2749 /* Space has not been allocated for the output relocations. 2750 This can happen when we are called by a specific backend 2751 because somebody is attempting to link together different 2752 types of object files. Handling this case correctly is 2753 difficult, and sometimes impossible. */ 2754 (*_bfd_error_handler) 2755 (_("Attempt to do relocatable link with %s input and %s output"), 2756 bfd_get_target (input_bfd), bfd_get_target (output_bfd)); 2757 bfd_set_error (bfd_error_wrong_format); 2758 return FALSE; 2759 } 2760 2761 if (! generic_linker) 2762 { 2763 asymbol **sympp; 2764 asymbol **symppend; 2765 2766 /* Get the canonical symbols. The generic linker will always 2767 have retrieved them by this point, but we are being called by 2768 a specific linker, presumably because we are linking 2769 different types of object files together. */ 2770 if (!bfd_generic_link_read_symbols (input_bfd)) 2771 return FALSE; 2772 2773 /* Since we have been called by a specific linker, rather than 2774 the generic linker, the values of the symbols will not be 2775 right. They will be the values as seen in the input file, 2776 not the values of the final link. We need to fix them up 2777 before we can relocate the section. */ 2778 sympp = _bfd_generic_link_get_symbols (input_bfd); 2779 symppend = sympp + _bfd_generic_link_get_symcount (input_bfd); 2780 for (; sympp < symppend; sympp++) 2781 { 2782 asymbol *sym; 2783 struct bfd_link_hash_entry *h; 2784 2785 sym = *sympp; 2786 2787 if ((sym->flags & (BSF_INDIRECT 2788 | BSF_WARNING 2789 | BSF_GLOBAL 2790 | BSF_CONSTRUCTOR 2791 | BSF_WEAK)) != 0 2792 || bfd_is_und_section (bfd_get_section (sym)) 2793 || bfd_is_com_section (bfd_get_section (sym)) 2794 || bfd_is_ind_section (bfd_get_section (sym))) 2795 { 2796 /* sym->udata may have been set by 2797 generic_link_add_symbol_list. */ 2798 if (sym->udata.p != NULL) 2799 h = (struct bfd_link_hash_entry *) sym->udata.p; 2800 else if (bfd_is_und_section (bfd_get_section (sym))) 2801 h = bfd_wrapped_link_hash_lookup (output_bfd, info, 2802 bfd_asymbol_name (sym), 2803 FALSE, FALSE, TRUE); 2804 else 2805 h = bfd_link_hash_lookup (info->hash, 2806 bfd_asymbol_name (sym), 2807 FALSE, FALSE, TRUE); 2808 if (h != NULL) 2809 set_symbol_from_hash (sym, h); 2810 } 2811 } 2812 } 2813 2814 if ((output_section->flags & (SEC_GROUP | SEC_LINKER_CREATED)) == SEC_GROUP 2815 && input_section->size != 0) 2816 { 2817 /* Group section contents are set by bfd_elf_set_group_contents. */ 2818 if (!output_bfd->output_has_begun) 2819 { 2820 /* FIXME: This hack ensures bfd_elf_set_group_contents is called. */ 2821 if (!bfd_set_section_contents (output_bfd, output_section, "", 0, 1)) 2822 goto error_return; 2823 } 2824 new_contents = output_section->contents; 2825 BFD_ASSERT (new_contents != NULL); 2826 BFD_ASSERT (input_section->output_offset == 0); 2827 } 2828 else 2829 { 2830 /* Get and relocate the section contents. */ 2831 sec_size = (input_section->rawsize > input_section->size 2832 ? input_section->rawsize 2833 : input_section->size); 2834 contents = (bfd_byte *) bfd_malloc (sec_size); 2835 if (contents == NULL && sec_size != 0) 2836 goto error_return; 2837 new_contents = (bfd_get_relocated_section_contents 2838 (output_bfd, info, link_order, contents, 2839 info->relocatable, 2840 _bfd_generic_link_get_symbols (input_bfd))); 2841 if (!new_contents) 2842 goto error_return; 2843 } 2844 2845 /* Output the section contents. */ 2846 loc = input_section->output_offset * bfd_octets_per_byte (output_bfd); 2847 if (! bfd_set_section_contents (output_bfd, output_section, 2848 new_contents, loc, input_section->size)) 2849 goto error_return; 2850 2851 if (contents != NULL) 2852 free (contents); 2853 return TRUE; 2854 2855 error_return: 2856 if (contents != NULL) 2857 free (contents); 2858 return FALSE; 2859 } 2860 2861 /* A little routine to count the number of relocs in a link_order 2862 list. */ 2863 2864 unsigned int 2865 _bfd_count_link_order_relocs (struct bfd_link_order *link_order) 2866 { 2867 register unsigned int c; 2868 register struct bfd_link_order *l; 2869 2870 c = 0; 2871 for (l = link_order; l != NULL; l = l->next) 2872 { 2873 if (l->type == bfd_section_reloc_link_order 2874 || l->type == bfd_symbol_reloc_link_order) 2875 ++c; 2876 } 2877 2878 return c; 2879 } 2880 2881 /* 2882 FUNCTION 2883 bfd_link_split_section 2884 2885 SYNOPSIS 2886 bfd_boolean bfd_link_split_section (bfd *abfd, asection *sec); 2887 2888 DESCRIPTION 2889 Return nonzero if @var{sec} should be split during a 2890 reloceatable or final link. 2891 2892 .#define bfd_link_split_section(abfd, sec) \ 2893 . BFD_SEND (abfd, _bfd_link_split_section, (abfd, sec)) 2894 . 2895 2896 */ 2897 2898 bfd_boolean 2899 _bfd_generic_link_split_section (bfd *abfd ATTRIBUTE_UNUSED, 2900 asection *sec ATTRIBUTE_UNUSED) 2901 { 2902 return FALSE; 2903 } 2904 2905 /* 2906 FUNCTION 2907 bfd_section_already_linked 2908 2909 SYNOPSIS 2910 void bfd_section_already_linked (bfd *abfd, asection *sec, 2911 struct bfd_link_info *info); 2912 2913 DESCRIPTION 2914 Check if @var{sec} has been already linked during a reloceatable 2915 or final link. 2916 2917 .#define bfd_section_already_linked(abfd, sec, info) \ 2918 . BFD_SEND (abfd, _section_already_linked, (abfd, sec, info)) 2919 . 2920 2921 */ 2922 2923 /* Sections marked with the SEC_LINK_ONCE flag should only be linked 2924 once into the output. This routine checks each section, and 2925 arrange to discard it if a section of the same name has already 2926 been linked. This code assumes that all relevant sections have the 2927 SEC_LINK_ONCE flag set; that is, it does not depend solely upon the 2928 section name. bfd_section_already_linked is called via 2929 bfd_map_over_sections. */ 2930 2931 /* The hash table. */ 2932 2933 static struct bfd_hash_table _bfd_section_already_linked_table; 2934 2935 /* Support routines for the hash table used by section_already_linked, 2936 initialize the table, traverse, lookup, fill in an entry and remove 2937 the table. */ 2938 2939 void 2940 bfd_section_already_linked_table_traverse 2941 (bfd_boolean (*func) (struct bfd_section_already_linked_hash_entry *, 2942 void *), void *info) 2943 { 2944 bfd_hash_traverse (&_bfd_section_already_linked_table, 2945 (bfd_boolean (*) (struct bfd_hash_entry *, 2946 void *)) func, 2947 info); 2948 } 2949 2950 struct bfd_section_already_linked_hash_entry * 2951 bfd_section_already_linked_table_lookup (const char *name) 2952 { 2953 return ((struct bfd_section_already_linked_hash_entry *) 2954 bfd_hash_lookup (&_bfd_section_already_linked_table, name, 2955 TRUE, FALSE)); 2956 } 2957 2958 bfd_boolean 2959 bfd_section_already_linked_table_insert 2960 (struct bfd_section_already_linked_hash_entry *already_linked_list, 2961 asection *sec) 2962 { 2963 struct bfd_section_already_linked *l; 2964 2965 /* Allocate the memory from the same obstack as the hash table is 2966 kept in. */ 2967 l = (struct bfd_section_already_linked *) 2968 bfd_hash_allocate (&_bfd_section_already_linked_table, sizeof *l); 2969 if (l == NULL) 2970 return FALSE; 2971 l->sec = sec; 2972 l->next = already_linked_list->entry; 2973 already_linked_list->entry = l; 2974 return TRUE; 2975 } 2976 2977 static struct bfd_hash_entry * 2978 already_linked_newfunc (struct bfd_hash_entry *entry ATTRIBUTE_UNUSED, 2979 struct bfd_hash_table *table, 2980 const char *string ATTRIBUTE_UNUSED) 2981 { 2982 struct bfd_section_already_linked_hash_entry *ret = 2983 (struct bfd_section_already_linked_hash_entry *) 2984 bfd_hash_allocate (table, sizeof *ret); 2985 2986 if (ret == NULL) 2987 return NULL; 2988 2989 ret->entry = NULL; 2990 2991 return &ret->root; 2992 } 2993 2994 bfd_boolean 2995 bfd_section_already_linked_table_init (void) 2996 { 2997 return bfd_hash_table_init_n (&_bfd_section_already_linked_table, 2998 already_linked_newfunc, 2999 sizeof (struct bfd_section_already_linked_hash_entry), 3000 42); 3001 } 3002 3003 void 3004 bfd_section_already_linked_table_free (void) 3005 { 3006 bfd_hash_table_free (&_bfd_section_already_linked_table); 3007 } 3008 3009 /* This is used on non-ELF inputs. */ 3010 3011 void 3012 _bfd_generic_section_already_linked (bfd *abfd, asection *sec, 3013 struct bfd_link_info *info) 3014 { 3015 flagword flags; 3016 const char *name; 3017 struct bfd_section_already_linked *l; 3018 struct bfd_section_already_linked_hash_entry *already_linked_list; 3019 3020 flags = sec->flags; 3021 if ((flags & SEC_LINK_ONCE) == 0) 3022 return; 3023 3024 /* FIXME: When doing a relocatable link, we may have trouble 3025 copying relocations in other sections that refer to local symbols 3026 in the section being discarded. Those relocations will have to 3027 be converted somehow; as of this writing I'm not sure that any of 3028 the backends handle that correctly. 3029 3030 It is tempting to instead not discard link once sections when 3031 doing a relocatable link (technically, they should be discarded 3032 whenever we are building constructors). However, that fails, 3033 because the linker winds up combining all the link once sections 3034 into a single large link once section, which defeats the purpose 3035 of having link once sections in the first place. */ 3036 3037 name = bfd_get_section_name (abfd, sec); 3038 3039 already_linked_list = bfd_section_already_linked_table_lookup (name); 3040 3041 for (l = already_linked_list->entry; l != NULL; l = l->next) 3042 { 3043 bfd_boolean skip = FALSE; 3044 struct coff_comdat_info *s_comdat 3045 = bfd_coff_get_comdat_section (abfd, sec); 3046 struct coff_comdat_info *l_comdat 3047 = bfd_coff_get_comdat_section (l->sec->owner, l->sec); 3048 3049 /* We may have 3 different sections on the list: group section, 3050 comdat section and linkonce section. SEC may be a linkonce or 3051 comdat section. We always ignore group section. For non-COFF 3052 inputs, we also ignore comdat section. 3053 3054 FIXME: Is that safe to match a linkonce section with a comdat 3055 section for COFF inputs? */ 3056 if ((l->sec->flags & SEC_GROUP) != 0) 3057 skip = TRUE; 3058 else if (bfd_get_flavour (abfd) == bfd_target_coff_flavour) 3059 { 3060 if (s_comdat != NULL 3061 && l_comdat != NULL 3062 && strcmp (s_comdat->name, l_comdat->name) != 0) 3063 skip = TRUE; 3064 } 3065 else if (l_comdat != NULL) 3066 skip = TRUE; 3067 3068 if (!skip) 3069 { 3070 /* The section has already been linked. See if we should 3071 issue a warning. */ 3072 switch (flags & SEC_LINK_DUPLICATES) 3073 { 3074 default: 3075 abort (); 3076 3077 case SEC_LINK_DUPLICATES_DISCARD: 3078 break; 3079 3080 case SEC_LINK_DUPLICATES_ONE_ONLY: 3081 (*_bfd_error_handler) 3082 (_("%B: warning: ignoring duplicate section `%A'\n"), 3083 abfd, sec); 3084 break; 3085 3086 case SEC_LINK_DUPLICATES_SAME_CONTENTS: 3087 /* FIXME: We should really dig out the contents of both 3088 sections and memcmp them. The COFF/PE spec says that 3089 the Microsoft linker does not implement this 3090 correctly, so I'm not going to bother doing it 3091 either. */ 3092 /* Fall through. */ 3093 case SEC_LINK_DUPLICATES_SAME_SIZE: 3094 if (sec->size != l->sec->size) 3095 (*_bfd_error_handler) 3096 (_("%B: warning: duplicate section `%A' has different size\n"), 3097 abfd, sec); 3098 break; 3099 } 3100 3101 /* Set the output_section field so that lang_add_section 3102 does not create a lang_input_section structure for this 3103 section. Since there might be a symbol in the section 3104 being discarded, we must retain a pointer to the section 3105 which we are really going to use. */ 3106 sec->output_section = bfd_abs_section_ptr; 3107 sec->kept_section = l->sec; 3108 3109 return; 3110 } 3111 } 3112 3113 /* This is the first section with this name. Record it. */ 3114 if (! bfd_section_already_linked_table_insert (already_linked_list, sec)) 3115 info->callbacks->einfo (_("%F%P: already_linked_table: %E\n")); 3116 } 3117 3118 /* Convert symbols in excluded output sections to use a kept section. */ 3119 3120 static bfd_boolean 3121 fix_syms (struct bfd_link_hash_entry *h, void *data) 3122 { 3123 bfd *obfd = (bfd *) data; 3124 3125 if (h->type == bfd_link_hash_warning) 3126 h = h->u.i.link; 3127 3128 if (h->type == bfd_link_hash_defined 3129 || h->type == bfd_link_hash_defweak) 3130 { 3131 asection *s = h->u.def.section; 3132 if (s != NULL 3133 && s->output_section != NULL 3134 && (s->output_section->flags & SEC_EXCLUDE) != 0 3135 && bfd_section_removed_from_list (obfd, s->output_section)) 3136 { 3137 asection *op, *op1; 3138 3139 h->u.def.value += s->output_offset + s->output_section->vma; 3140 3141 /* Find preceding kept section. */ 3142 for (op1 = s->output_section->prev; op1 != NULL; op1 = op1->prev) 3143 if ((op1->flags & SEC_EXCLUDE) == 0 3144 && !bfd_section_removed_from_list (obfd, op1)) 3145 break; 3146 3147 /* Find following kept section. Start at prev->next because 3148 other sections may have been added after S was removed. */ 3149 if (s->output_section->prev != NULL) 3150 op = s->output_section->prev->next; 3151 else 3152 op = s->output_section->owner->sections; 3153 for (; op != NULL; op = op->next) 3154 if ((op->flags & SEC_EXCLUDE) == 0 3155 && !bfd_section_removed_from_list (obfd, op)) 3156 break; 3157 3158 /* Choose better of two sections, based on flags. The idea 3159 is to choose a section that will be in the same segment 3160 as S would have been if it was kept. */ 3161 if (op1 == NULL) 3162 { 3163 if (op == NULL) 3164 op = bfd_abs_section_ptr; 3165 } 3166 else if (op == NULL) 3167 op = op1; 3168 else if (((op1->flags ^ op->flags) 3169 & (SEC_ALLOC | SEC_THREAD_LOCAL | SEC_LOAD)) != 0) 3170 { 3171 if (((op->flags ^ s->flags) 3172 & (SEC_ALLOC | SEC_THREAD_LOCAL)) != 0 3173 /* We prefer to choose a loaded section. Section S 3174 doesn't have SEC_LOAD set (it being excluded, that 3175 part of the flag processing didn't happen) so we 3176 can't compare that flag to those of OP and OP1. */ 3177 || ((op1->flags & SEC_LOAD) != 0 3178 && (op->flags & SEC_LOAD) == 0)) 3179 op = op1; 3180 } 3181 else if (((op1->flags ^ op->flags) & SEC_READONLY) != 0) 3182 { 3183 if (((op->flags ^ s->flags) & SEC_READONLY) != 0) 3184 op = op1; 3185 } 3186 else if (((op1->flags ^ op->flags) & SEC_CODE) != 0) 3187 { 3188 if (((op->flags ^ s->flags) & SEC_CODE) != 0) 3189 op = op1; 3190 } 3191 else 3192 { 3193 /* Flags we care about are the same. Prefer the following 3194 section if that will result in a positive valued sym. */ 3195 if (h->u.def.value < op->vma) 3196 op = op1; 3197 } 3198 3199 h->u.def.value -= op->vma; 3200 h->u.def.section = op; 3201 } 3202 } 3203 3204 return TRUE; 3205 } 3206 3207 void 3208 _bfd_fix_excluded_sec_syms (bfd *obfd, struct bfd_link_info *info) 3209 { 3210 bfd_link_hash_traverse (info->hash, fix_syms, obfd); 3211 } 3212 3213 /* 3214 FUNCTION 3215 bfd_generic_define_common_symbol 3216 3217 SYNOPSIS 3218 bfd_boolean bfd_generic_define_common_symbol 3219 (bfd *output_bfd, struct bfd_link_info *info, 3220 struct bfd_link_hash_entry *h); 3221 3222 DESCRIPTION 3223 Convert common symbol @var{h} into a defined symbol. 3224 Return TRUE on success and FALSE on failure. 3225 3226 .#define bfd_define_common_symbol(output_bfd, info, h) \ 3227 . BFD_SEND (output_bfd, _bfd_define_common_symbol, (output_bfd, info, h)) 3228 . 3229 */ 3230 3231 bfd_boolean 3232 bfd_generic_define_common_symbol (bfd *output_bfd, 3233 struct bfd_link_info *info ATTRIBUTE_UNUSED, 3234 struct bfd_link_hash_entry *h) 3235 { 3236 unsigned int power_of_two; 3237 bfd_vma alignment, size; 3238 asection *section; 3239 3240 BFD_ASSERT (h != NULL && h->type == bfd_link_hash_common); 3241 3242 size = h->u.c.size; 3243 power_of_two = h->u.c.p->alignment_power; 3244 section = h->u.c.p->section; 3245 3246 /* Increase the size of the section to align the common symbol. 3247 The alignment must be a power of two. */ 3248 alignment = bfd_octets_per_byte (output_bfd) << power_of_two; 3249 BFD_ASSERT (alignment != 0 && (alignment & -alignment) == alignment); 3250 section->size += alignment - 1; 3251 section->size &= -alignment; 3252 3253 /* Adjust the section's overall alignment if necessary. */ 3254 if (power_of_two > section->alignment_power) 3255 section->alignment_power = power_of_two; 3256 3257 /* Change the symbol from common to defined. */ 3258 h->type = bfd_link_hash_defined; 3259 h->u.def.section = section; 3260 h->u.def.value = section->size; 3261 3262 /* Increase the size of the section. */ 3263 section->size += size; 3264 3265 /* Make sure the section is allocated in memory, and make sure that 3266 it is no longer a common section. */ 3267 section->flags |= SEC_ALLOC; 3268 section->flags &= ~SEC_IS_COMMON; 3269 return TRUE; 3270 } 3271 3272 /* 3273 FUNCTION 3274 bfd_find_version_for_sym 3275 3276 SYNOPSIS 3277 struct bfd_elf_version_tree * bfd_find_version_for_sym 3278 (struct bfd_elf_version_tree *verdefs, 3279 const char *sym_name, bfd_boolean *hide); 3280 3281 DESCRIPTION 3282 Search an elf version script tree for symbol versioning 3283 info and export / don't-export status for a given symbol. 3284 Return non-NULL on success and NULL on failure; also sets 3285 the output @samp{hide} boolean parameter. 3286 3287 */ 3288 3289 struct bfd_elf_version_tree * 3290 bfd_find_version_for_sym (struct bfd_elf_version_tree *verdefs, 3291 const char *sym_name, 3292 bfd_boolean *hide) 3293 { 3294 struct bfd_elf_version_tree *t; 3295 struct bfd_elf_version_tree *local_ver, *global_ver, *exist_ver; 3296 struct bfd_elf_version_tree *star_local_ver, *star_global_ver; 3297 3298 local_ver = NULL; 3299 global_ver = NULL; 3300 star_local_ver = NULL; 3301 star_global_ver = NULL; 3302 exist_ver = NULL; 3303 for (t = verdefs; t != NULL; t = t->next) 3304 { 3305 if (t->globals.list != NULL) 3306 { 3307 struct bfd_elf_version_expr *d = NULL; 3308 3309 while ((d = (*t->match) (&t->globals, d, sym_name)) != NULL) 3310 { 3311 if (d->literal || strcmp (d->pattern, "*") != 0) 3312 global_ver = t; 3313 else 3314 star_global_ver = t; 3315 if (d->symver) 3316 exist_ver = t; 3317 d->script = 1; 3318 /* If the match is a wildcard pattern, keep looking for 3319 a more explicit, perhaps even local, match. */ 3320 if (d->literal) 3321 break; 3322 } 3323 3324 if (d != NULL) 3325 break; 3326 } 3327 3328 if (t->locals.list != NULL) 3329 { 3330 struct bfd_elf_version_expr *d = NULL; 3331 3332 while ((d = (*t->match) (&t->locals, d, sym_name)) != NULL) 3333 { 3334 if (d->literal || strcmp (d->pattern, "*") != 0) 3335 local_ver = t; 3336 else 3337 star_local_ver = t; 3338 /* If the match is a wildcard pattern, keep looking for 3339 a more explicit, perhaps even global, match. */ 3340 if (d->literal) 3341 { 3342 /* An exact match overrides a global wildcard. */ 3343 global_ver = NULL; 3344 star_global_ver = NULL; 3345 break; 3346 } 3347 } 3348 3349 if (d != NULL) 3350 break; 3351 } 3352 } 3353 3354 if (global_ver == NULL && local_ver == NULL) 3355 global_ver = star_global_ver; 3356 3357 if (global_ver != NULL) 3358 { 3359 /* If we already have a versioned symbol that matches the 3360 node for this symbol, then we don't want to create a 3361 duplicate from the unversioned symbol. Instead hide the 3362 unversioned symbol. */ 3363 *hide = exist_ver == global_ver; 3364 return global_ver; 3365 } 3366 3367 if (local_ver == NULL) 3368 local_ver = star_local_ver; 3369 3370 if (local_ver != NULL) 3371 { 3372 *hide = TRUE; 3373 return local_ver; 3374 } 3375 3376 return NULL; 3377 } 3378