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