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