1 /* linker.c -- BFD linker routines 2 Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 3 2003, 2004, 2005, 2006, 2007, 2008, 2009 4 Free Software Foundation, Inc. 5 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support 6 7 This file is part of BFD, the Binary File Descriptor library. 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 3 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 22 MA 02110-1301, USA. */ 23 24 #include "sysdep.h" 25 #include "bfd.h" 26 #include "libbfd.h" 27 #include "bfdlink.h" 28 #include "genlink.h" 29 30 /* 31 SECTION 32 Linker Functions 33 34 @cindex Linker 35 The linker uses three special entry points in the BFD target 36 vector. It is not necessary to write special routines for 37 these entry points when creating a new BFD back end, since 38 generic versions are provided. However, writing them can 39 speed up linking and make it use significantly less runtime 40 memory. 41 42 The first routine creates a hash table used by the other 43 routines. The second routine adds the symbols from an object 44 file to the hash table. The third routine takes all the 45 object files and links them together to create the output 46 file. These routines are designed so that the linker proper 47 does not need to know anything about the symbols in the object 48 files that it is linking. The linker merely arranges the 49 sections as directed by the linker script and lets BFD handle 50 the details of symbols and relocs. 51 52 The second routine and third routines are passed a pointer to 53 a <<struct bfd_link_info>> structure (defined in 54 <<bfdlink.h>>) which holds information relevant to the link, 55 including the linker hash table (which was created by the 56 first routine) and a set of callback functions to the linker 57 proper. 58 59 The generic linker routines are in <<linker.c>>, and use the 60 header file <<genlink.h>>. As of this writing, the only back 61 ends which have implemented versions of these routines are 62 a.out (in <<aoutx.h>>) and ECOFF (in <<ecoff.c>>). The a.out 63 routines are used as examples throughout this section. 64 65 @menu 66 @* Creating a Linker Hash Table:: 67 @* Adding Symbols to the Hash Table:: 68 @* Performing the Final Link:: 69 @end menu 70 71 INODE 72 Creating a Linker Hash Table, Adding Symbols to the Hash Table, Linker Functions, Linker Functions 73 SUBSECTION 74 Creating a linker hash table 75 76 @cindex _bfd_link_hash_table_create in target vector 77 @cindex target vector (_bfd_link_hash_table_create) 78 The linker routines must create a hash table, which must be 79 derived from <<struct bfd_link_hash_table>> described in 80 <<bfdlink.c>>. @xref{Hash Tables}, for information on how to 81 create a derived hash table. This entry point is called using 82 the target vector of the linker output file. 83 84 The <<_bfd_link_hash_table_create>> entry point must allocate 85 and initialize an instance of the desired hash table. If the 86 back end does not require any additional information to be 87 stored with the entries in the hash table, the entry point may 88 simply create a <<struct bfd_link_hash_table>>. Most likely, 89 however, some additional information will be needed. 90 91 For example, with each entry in the hash table the a.out 92 linker keeps the index the symbol has in the final output file 93 (this index number is used so that when doing a relocatable 94 link the symbol index used in the output file can be quickly 95 filled in when copying over a reloc). The a.out linker code 96 defines the required structures and functions for a hash table 97 derived from <<struct bfd_link_hash_table>>. The a.out linker 98 hash table is created by the function 99 <<NAME(aout,link_hash_table_create)>>; it simply allocates 100 space for the hash table, initializes it, and returns a 101 pointer to it. 102 103 When writing the linker routines for a new back end, you will 104 generally not know exactly which fields will be required until 105 you have finished. You should simply create a new hash table 106 which defines no additional fields, and then simply add fields 107 as they become necessary. 108 109 INODE 110 Adding Symbols to the Hash Table, Performing the Final Link, Creating a Linker Hash Table, Linker Functions 111 SUBSECTION 112 Adding symbols to the hash table 113 114 @cindex _bfd_link_add_symbols in target vector 115 @cindex target vector (_bfd_link_add_symbols) 116 The linker proper will call the <<_bfd_link_add_symbols>> 117 entry point for each object file or archive which is to be 118 linked (typically these are the files named on the command 119 line, but some may also come from the linker script). The 120 entry point is responsible for examining the file. For an 121 object file, BFD must add any relevant symbol information to 122 the hash table. For an archive, BFD must determine which 123 elements of the archive should be used and adding them to the 124 link. 125 126 The a.out version of this entry point is 127 <<NAME(aout,link_add_symbols)>>. 128 129 @menu 130 @* Differing file formats:: 131 @* Adding symbols from an object file:: 132 @* Adding symbols from an archive:: 133 @end menu 134 135 INODE 136 Differing file formats, Adding symbols from an object file, Adding Symbols to the Hash Table, Adding Symbols to the Hash Table 137 SUBSUBSECTION 138 Differing file formats 139 140 Normally all the files involved in a link will be of the same 141 format, but it is also possible to link together different 142 format object files, and the back end must support that. The 143 <<_bfd_link_add_symbols>> entry point is called via the target 144 vector of the file to be added. This has an important 145 consequence: the function may not assume that the hash table 146 is the type created by the corresponding 147 <<_bfd_link_hash_table_create>> vector. All the 148 <<_bfd_link_add_symbols>> function can assume about the hash 149 table is that it is derived from <<struct 150 bfd_link_hash_table>>. 151 152 Sometimes the <<_bfd_link_add_symbols>> function must store 153 some information in the hash table entry to be used by the 154 <<_bfd_final_link>> function. In such a case the output bfd 155 xvec must be checked to make sure that the hash table was 156 created by an object file of the same format. 157 158 The <<_bfd_final_link>> routine must be prepared to handle a 159 hash entry without any extra information added by the 160 <<_bfd_link_add_symbols>> function. A hash entry without 161 extra information will also occur when the linker script 162 directs the linker to create a symbol. Note that, regardless 163 of how a hash table entry is added, all the fields will be 164 initialized to some sort of null value by the hash table entry 165 initialization function. 166 167 See <<ecoff_link_add_externals>> for an example of how to 168 check the output bfd before saving information (in this 169 case, the ECOFF external symbol debugging information) in a 170 hash table entry. 171 172 INODE 173 Adding symbols from an object file, Adding symbols from an archive, Differing file formats, Adding Symbols to the Hash Table 174 SUBSUBSECTION 175 Adding symbols from an object file 176 177 When the <<_bfd_link_add_symbols>> routine is passed an object 178 file, it must add all externally visible symbols in that 179 object file to the hash table. The actual work of adding the 180 symbol to the hash table is normally handled by the function 181 <<_bfd_generic_link_add_one_symbol>>. The 182 <<_bfd_link_add_symbols>> routine is responsible for reading 183 all the symbols from the object file and passing the correct 184 information to <<_bfd_generic_link_add_one_symbol>>. 185 186 The <<_bfd_link_add_symbols>> routine should not use 187 <<bfd_canonicalize_symtab>> to read the symbols. The point of 188 providing this routine is to avoid the overhead of converting 189 the symbols into generic <<asymbol>> structures. 190 191 @findex _bfd_generic_link_add_one_symbol 192 <<_bfd_generic_link_add_one_symbol>> handles the details of 193 combining common symbols, warning about multiple definitions, 194 and so forth. It takes arguments which describe the symbol to 195 add, notably symbol flags, a section, and an offset. The 196 symbol flags include such things as <<BSF_WEAK>> or 197 <<BSF_INDIRECT>>. The section is a section in the object 198 file, or something like <<bfd_und_section_ptr>> for an undefined 199 symbol or <<bfd_com_section_ptr>> for a common symbol. 200 201 If the <<_bfd_final_link>> routine is also going to need to 202 read the symbol information, the <<_bfd_link_add_symbols>> 203 routine should save it somewhere attached to the object file 204 BFD. However, the information should only be saved if the 205 <<keep_memory>> field of the <<info>> argument is TRUE, so 206 that the <<-no-keep-memory>> linker switch is effective. 207 208 The a.out function which adds symbols from an object file is 209 <<aout_link_add_object_symbols>>, and most of the interesting 210 work is in <<aout_link_add_symbols>>. The latter saves 211 pointers to the hash tables entries created by 212 <<_bfd_generic_link_add_one_symbol>> indexed by symbol number, 213 so that the <<_bfd_final_link>> routine does not have to call 214 the hash table lookup routine to locate the entry. 215 216 INODE 217 Adding symbols from an archive, , Adding symbols from an object file, Adding Symbols to the Hash Table 218 SUBSUBSECTION 219 Adding symbols from an archive 220 221 When the <<_bfd_link_add_symbols>> routine is passed an 222 archive, it must look through the symbols defined by the 223 archive and decide which elements of the archive should be 224 included in the link. For each such element it must call the 225 <<add_archive_element>> linker callback, and it must add the 226 symbols from the object file to the linker hash table. (The 227 callback may in fact indicate that a replacement BFD should be 228 used, in which case the symbols from that BFD should be added 229 to the linker hash table instead.) 230 231 @findex _bfd_generic_link_add_archive_symbols 232 In most cases the work of looking through the symbols in the 233 archive should be done by the 234 <<_bfd_generic_link_add_archive_symbols>> function. This 235 function builds a hash table from the archive symbol table and 236 looks through the list of undefined symbols to see which 237 elements should be included. 238 <<_bfd_generic_link_add_archive_symbols>> is passed a function 239 to call to make the final decision about adding an archive 240 element to the link and to do the actual work of adding the 241 symbols to the linker hash table. 242 243 The function passed to 244 <<_bfd_generic_link_add_archive_symbols>> must read the 245 symbols of the archive element and decide whether the archive 246 element should be included in the link. If the element is to 247 be included, the <<add_archive_element>> linker callback 248 routine must be called with the element as an argument, and 249 the element's symbols must be added to the linker hash table 250 just as though the element had itself been passed to the 251 <<_bfd_link_add_symbols>> function. The <<add_archive_element>> 252 callback has the option to indicate that it would like to 253 replace the element archive with a substitute BFD, in which 254 case it is the symbols of that substitute BFD that must be 255 added to the linker hash table instead. 256 257 When the a.out <<_bfd_link_add_symbols>> function receives an 258 archive, it calls <<_bfd_generic_link_add_archive_symbols>> 259 passing <<aout_link_check_archive_element>> as the function 260 argument. <<aout_link_check_archive_element>> calls 261 <<aout_link_check_ar_symbols>>. If the latter decides to add 262 the element (an element is only added if it provides a real, 263 non-common, definition for a previously undefined or common 264 symbol) it calls the <<add_archive_element>> callback and then 265 <<aout_link_check_archive_element>> calls 266 <<aout_link_add_symbols>> to actually add the symbols to the 267 linker hash table - possibly those of a substitute BFD, if the 268 <<add_archive_element>> callback avails itself of that option. 269 270 The ECOFF back end is unusual in that it does not normally 271 call <<_bfd_generic_link_add_archive_symbols>>, because ECOFF 272 archives already contain a hash table of symbols. The ECOFF 273 back end searches the archive itself to avoid the overhead of 274 creating a new hash table. 275 276 INODE 277 Performing the Final Link, , Adding Symbols to the Hash Table, Linker Functions 278 SUBSECTION 279 Performing the final link 280 281 @cindex _bfd_link_final_link in target vector 282 @cindex target vector (_bfd_final_link) 283 When all the input files have been processed, the linker calls 284 the <<_bfd_final_link>> entry point of the output BFD. This 285 routine is responsible for producing the final output file, 286 which has several aspects. It must relocate the contents of 287 the input sections and copy the data into the output sections. 288 It must build an output symbol table including any local 289 symbols from the input files and the global symbols from the 290 hash table. When producing relocatable output, it must 291 modify the input relocs and write them into the output file. 292 There may also be object format dependent work to be done. 293 294 The linker will also call the <<write_object_contents>> entry 295 point when the BFD is closed. The two entry points must work 296 together in order to produce the correct output file. 297 298 The details of how this works are inevitably dependent upon 299 the specific object file format. The a.out 300 <<_bfd_final_link>> routine is <<NAME(aout,final_link)>>. 301 302 @menu 303 @* Information provided by the linker:: 304 @* Relocating the section contents:: 305 @* Writing the symbol table:: 306 @end menu 307 308 INODE 309 Information provided by the linker, Relocating the section contents, Performing the Final Link, Performing the Final Link 310 SUBSUBSECTION 311 Information provided by the linker 312 313 Before the linker calls the <<_bfd_final_link>> entry point, 314 it sets up some data structures for the function to use. 315 316 The <<input_bfds>> field of the <<bfd_link_info>> structure 317 will point to a list of all the input files included in the 318 link. These files are linked through the <<link_next>> field 319 of the <<bfd>> structure. 320 321 Each section in the output file will have a list of 322 <<link_order>> structures attached to the <<map_head.link_order>> 323 field (the <<link_order>> structure is defined in 324 <<bfdlink.h>>). These structures describe how to create the 325 contents of the output section in terms of the contents of 326 various input sections, fill constants, and, eventually, other 327 types of information. They also describe relocs that must be 328 created by the BFD backend, but do not correspond to any input 329 file; this is used to support -Ur, which builds constructors 330 while generating a relocatable object file. 331 332 INODE 333 Relocating the section contents, Writing the symbol table, Information provided by the linker, Performing the Final Link 334 SUBSUBSECTION 335 Relocating the section contents 336 337 The <<_bfd_final_link>> function should look through the 338 <<link_order>> structures attached to each section of the 339 output file. Each <<link_order>> structure should either be 340 handled specially, or it should be passed to the function 341 <<_bfd_default_link_order>> which will do the right thing 342 (<<_bfd_default_link_order>> is defined in <<linker.c>>). 343 344 For efficiency, a <<link_order>> of type 345 <<bfd_indirect_link_order>> whose associated section belongs 346 to a BFD of the same format as the output BFD must be handled 347 specially. This type of <<link_order>> describes part of an 348 output section in terms of a section belonging to one of the 349 input files. The <<_bfd_final_link>> function should read the 350 contents of the section and any associated relocs, apply the 351 relocs to the section contents, and write out the modified 352 section contents. If performing a relocatable link, the 353 relocs themselves must also be modified and written out. 354 355 @findex _bfd_relocate_contents 356 @findex _bfd_final_link_relocate 357 The functions <<_bfd_relocate_contents>> and 358 <<_bfd_final_link_relocate>> provide some general support for 359 performing the actual relocations, notably overflow checking. 360 Their arguments include information about the symbol the 361 relocation is against and a <<reloc_howto_type>> argument 362 which describes the relocation to perform. These functions 363 are defined in <<reloc.c>>. 364 365 The a.out function which handles reading, relocating, and 366 writing section contents is <<aout_link_input_section>>. The 367 actual relocation is done in <<aout_link_input_section_std>> 368 and <<aout_link_input_section_ext>>. 369 370 INODE 371 Writing the symbol table, , Relocating the section contents, Performing the Final Link 372 SUBSUBSECTION 373 Writing the symbol table 374 375 The <<_bfd_final_link>> function must gather all the symbols 376 in the input files and write them out. It must also write out 377 all the symbols in the global hash table. This must be 378 controlled by the <<strip>> and <<discard>> fields of the 379 <<bfd_link_info>> structure. 380 381 The local symbols of the input files will not have been 382 entered into the linker hash table. The <<_bfd_final_link>> 383 routine must consider each input file and include the symbols 384 in the output file. It may be convenient to do this when 385 looking through the <<link_order>> structures, or it may be 386 done by stepping through the <<input_bfds>> list. 387 388 The <<_bfd_final_link>> routine must also traverse the global 389 hash table to gather all the externally visible symbols. It 390 is possible that most of the externally visible symbols may be 391 written out when considering the symbols of each input file, 392 but it is still necessary to traverse the hash table since the 393 linker script may have defined some symbols that are not in 394 any of the input files. 395 396 The <<strip>> field of the <<bfd_link_info>> structure 397 controls which symbols are written out. The possible values 398 are listed in <<bfdlink.h>>. If the value is <<strip_some>>, 399 then the <<keep_hash>> field of the <<bfd_link_info>> 400 structure is a hash table of symbols to keep; each symbol 401 should be looked up in this hash table, and only symbols which 402 are present should be included in the output file. 403 404 If the <<strip>> field of the <<bfd_link_info>> structure 405 permits local symbols to be written out, the <<discard>> field 406 is used to further controls which local symbols are included 407 in the output file. If the value is <<discard_l>>, then all 408 local symbols which begin with a certain prefix are discarded; 409 this is controlled by the <<bfd_is_local_label_name>> entry point. 410 411 The a.out backend handles symbols by calling 412 <<aout_link_write_symbols>> on each input BFD and then 413 traversing the global hash table with the function 414 <<aout_link_write_other_symbol>>. It builds a string table 415 while writing out the symbols, which is written to the output 416 file at the end of <<NAME(aout,final_link)>>. 417 */ 418 419 static bfd_boolean generic_link_add_object_symbols 420 (bfd *, struct bfd_link_info *, bfd_boolean collect); 421 static bfd_boolean generic_link_add_symbols 422 (bfd *, struct bfd_link_info *, bfd_boolean); 423 static bfd_boolean generic_link_check_archive_element_no_collect 424 (bfd *, struct bfd_link_info *, bfd_boolean *); 425 static bfd_boolean generic_link_check_archive_element_collect 426 (bfd *, struct bfd_link_info *, bfd_boolean *); 427 static bfd_boolean generic_link_check_archive_element 428 (bfd *, struct bfd_link_info *, bfd_boolean *, bfd_boolean); 429 static bfd_boolean generic_link_add_symbol_list 430 (bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **, 431 bfd_boolean); 432 static bfd_boolean generic_add_output_symbol 433 (bfd *, size_t *psymalloc, asymbol *); 434 static bfd_boolean default_data_link_order 435 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *); 436 static bfd_boolean default_indirect_link_order 437 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *, 438 bfd_boolean); 439 440 /* The link hash table structure is defined in bfdlink.h. It provides 441 a base hash table which the backend specific hash tables are built 442 upon. */ 443 444 /* Routine to create an entry in the link hash table. */ 445 446 struct bfd_hash_entry * 447 _bfd_link_hash_newfunc (struct bfd_hash_entry *entry, 448 struct bfd_hash_table *table, 449 const char *string) 450 { 451 /* Allocate the structure if it has not already been allocated by a 452 subclass. */ 453 if (entry == NULL) 454 { 455 entry = (struct bfd_hash_entry *) 456 bfd_hash_allocate (table, sizeof (struct bfd_link_hash_entry)); 457 if (entry == NULL) 458 return entry; 459 } 460 461 /* Call the allocation method of the superclass. */ 462 entry = bfd_hash_newfunc (entry, table, string); 463 if (entry) 464 { 465 struct bfd_link_hash_entry *h = (struct bfd_link_hash_entry *) entry; 466 467 /* Initialize the local fields. */ 468 h->type = bfd_link_hash_new; 469 memset (&h->u.undef.next, 0, 470 (sizeof (struct bfd_link_hash_entry) 471 - offsetof (struct bfd_link_hash_entry, u.undef.next))); 472 } 473 474 return entry; 475 } 476 477 /* Initialize a link hash table. The BFD argument is the one 478 responsible for creating this table. */ 479 480 bfd_boolean 481 _bfd_link_hash_table_init 482 (struct bfd_link_hash_table *table, 483 bfd *abfd ATTRIBUTE_UNUSED, 484 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *, 485 struct bfd_hash_table *, 486 const char *), 487 unsigned int entsize) 488 { 489 table->undefs = NULL; 490 table->undefs_tail = NULL; 491 table->type = bfd_link_generic_hash_table; 492 493 return bfd_hash_table_init (&table->table, newfunc, entsize); 494 } 495 496 /* Look up a symbol in a link hash table. If follow is TRUE, we 497 follow bfd_link_hash_indirect and bfd_link_hash_warning links to 498 the real symbol. */ 499 500 struct bfd_link_hash_entry * 501 bfd_link_hash_lookup (struct bfd_link_hash_table *table, 502 const char *string, 503 bfd_boolean create, 504 bfd_boolean copy, 505 bfd_boolean follow) 506 { 507 struct bfd_link_hash_entry *ret; 508 509 ret = ((struct bfd_link_hash_entry *) 510 bfd_hash_lookup (&table->table, string, create, copy)); 511 512 if (follow && ret != NULL) 513 { 514 while (ret->type == bfd_link_hash_indirect 515 || ret->type == bfd_link_hash_warning) 516 ret = ret->u.i.link; 517 } 518 519 return ret; 520 } 521 522 /* Look up a symbol in the main linker hash table if the symbol might 523 be wrapped. This should only be used for references to an 524 undefined symbol, not for definitions of a symbol. */ 525 526 struct bfd_link_hash_entry * 527 bfd_wrapped_link_hash_lookup (bfd *abfd, 528 struct bfd_link_info *info, 529 const char *string, 530 bfd_boolean create, 531 bfd_boolean copy, 532 bfd_boolean follow) 533 { 534 bfd_size_type amt; 535 536 if (info->wrap_hash != NULL) 537 { 538 const char *l; 539 char prefix = '\0'; 540 541 l = string; 542 if (*l == bfd_get_symbol_leading_char (abfd) || *l == info->wrap_char) 543 { 544 prefix = *l; 545 ++l; 546 } 547 548 #undef WRAP 549 #define WRAP "__wrap_" 550 551 if (bfd_hash_lookup (info->wrap_hash, l, FALSE, FALSE) != NULL) 552 { 553 char *n; 554 struct bfd_link_hash_entry *h; 555 556 /* This symbol is being wrapped. We want to replace all 557 references to SYM with references to __wrap_SYM. */ 558 559 amt = strlen (l) + sizeof WRAP + 1; 560 n = (char *) bfd_malloc (amt); 561 if (n == NULL) 562 return NULL; 563 564 n[0] = prefix; 565 n[1] = '\0'; 566 strcat (n, WRAP); 567 strcat (n, l); 568 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow); 569 free (n); 570 return h; 571 } 572 573 #undef WRAP 574 575 #undef REAL 576 #define REAL "__real_" 577 578 if (*l == '_' 579 && CONST_STRNEQ (l, REAL) 580 && bfd_hash_lookup (info->wrap_hash, l + sizeof REAL - 1, 581 FALSE, FALSE) != NULL) 582 { 583 char *n; 584 struct bfd_link_hash_entry *h; 585 586 /* This is a reference to __real_SYM, where SYM is being 587 wrapped. We want to replace all references to __real_SYM 588 with references to SYM. */ 589 590 amt = strlen (l + sizeof REAL - 1) + 2; 591 n = (char *) bfd_malloc (amt); 592 if (n == NULL) 593 return NULL; 594 595 n[0] = prefix; 596 n[1] = '\0'; 597 strcat (n, l + sizeof REAL - 1); 598 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow); 599 free (n); 600 return h; 601 } 602 603 #undef REAL 604 } 605 606 return bfd_link_hash_lookup (info->hash, string, create, copy, follow); 607 } 608 609 /* Traverse a generic link hash table. The only reason this is not a 610 macro is to do better type checking. This code presumes that an 611 argument passed as a struct bfd_hash_entry * may be caught as a 612 struct bfd_link_hash_entry * with no explicit cast required on the 613 call. */ 614 615 void 616 bfd_link_hash_traverse 617 (struct bfd_link_hash_table *table, 618 bfd_boolean (*func) (struct bfd_link_hash_entry *, void *), 619 void *info) 620 { 621 bfd_hash_traverse (&table->table, 622 (bfd_boolean (*) (struct bfd_hash_entry *, void *)) func, 623 info); 624 } 625 626 /* Add a symbol to the linker hash table undefs list. */ 627 628 void 629 bfd_link_add_undef (struct bfd_link_hash_table *table, 630 struct bfd_link_hash_entry *h) 631 { 632 BFD_ASSERT (h->u.undef.next == NULL); 633 if (table->undefs_tail != NULL) 634 table->undefs_tail->u.undef.next = h; 635 if (table->undefs == NULL) 636 table->undefs = h; 637 table->undefs_tail = h; 638 } 639 640 /* The undefs list was designed so that in normal use we don't need to 641 remove entries. However, if symbols on the list are changed from 642 bfd_link_hash_undefined to either bfd_link_hash_undefweak or 643 bfd_link_hash_new for some reason, then they must be removed from the 644 list. Failure to do so might result in the linker attempting to add 645 the symbol to the list again at a later stage. */ 646 647 void 648 bfd_link_repair_undef_list (struct bfd_link_hash_table *table) 649 { 650 struct bfd_link_hash_entry **pun; 651 652 pun = &table->undefs; 653 while (*pun != NULL) 654 { 655 struct bfd_link_hash_entry *h = *pun; 656 657 if (h->type == bfd_link_hash_new 658 || h->type == bfd_link_hash_undefweak) 659 { 660 *pun = h->u.undef.next; 661 h->u.undef.next = NULL; 662 if (h == table->undefs_tail) 663 { 664 if (pun == &table->undefs) 665 table->undefs_tail = NULL; 666 else 667 /* pun points at an u.undef.next field. Go back to 668 the start of the link_hash_entry. */ 669 table->undefs_tail = (struct bfd_link_hash_entry *) 670 ((char *) pun - ((char *) &h->u.undef.next - (char *) h)); 671 break; 672 } 673 } 674 else 675 pun = &h->u.undef.next; 676 } 677 } 678 679 /* Routine to create an entry in a generic link hash table. */ 680 681 struct bfd_hash_entry * 682 _bfd_generic_link_hash_newfunc (struct bfd_hash_entry *entry, 683 struct bfd_hash_table *table, 684 const char *string) 685 { 686 /* Allocate the structure if it has not already been allocated by a 687 subclass. */ 688 if (entry == NULL) 689 { 690 entry = (struct bfd_hash_entry *) 691 bfd_hash_allocate (table, sizeof (struct generic_link_hash_entry)); 692 if (entry == NULL) 693 return entry; 694 } 695 696 /* Call the allocation method of the superclass. */ 697 entry = _bfd_link_hash_newfunc (entry, table, string); 698 if (entry) 699 { 700 struct generic_link_hash_entry *ret; 701 702 /* Set local fields. */ 703 ret = (struct generic_link_hash_entry *) entry; 704 ret->written = FALSE; 705 ret->sym = NULL; 706 } 707 708 return entry; 709 } 710 711 /* Create a generic link hash table. */ 712 713 struct bfd_link_hash_table * 714 _bfd_generic_link_hash_table_create (bfd *abfd) 715 { 716 struct generic_link_hash_table *ret; 717 bfd_size_type amt = sizeof (struct generic_link_hash_table); 718 719 ret = (struct generic_link_hash_table *) bfd_malloc (amt); 720 if (ret == NULL) 721 return NULL; 722 if (! _bfd_link_hash_table_init (&ret->root, abfd, 723 _bfd_generic_link_hash_newfunc, 724 sizeof (struct generic_link_hash_entry))) 725 { 726 free (ret); 727 return NULL; 728 } 729 return &ret->root; 730 } 731 732 void 733 _bfd_generic_link_hash_table_free (struct bfd_link_hash_table *hash) 734 { 735 struct generic_link_hash_table *ret 736 = (struct generic_link_hash_table *) hash; 737 738 bfd_hash_table_free (&ret->root.table); 739 free (ret); 740 } 741 742 /* Grab the symbols for an object file when doing a generic link. We 743 store the symbols in the outsymbols field. We need to keep them 744 around for the entire link to ensure that we only read them once. 745 If we read them multiple times, we might wind up with relocs and 746 the hash table pointing to different instances of the symbol 747 structure. */ 748 749 bfd_boolean 750 bfd_generic_link_read_symbols (bfd *abfd) 751 { 752 if (bfd_get_outsymbols (abfd) == NULL) 753 { 754 long symsize; 755 long symcount; 756 757 symsize = bfd_get_symtab_upper_bound (abfd); 758 if (symsize < 0) 759 return FALSE; 760 bfd_get_outsymbols (abfd) = (struct bfd_symbol **) bfd_alloc (abfd, 761 symsize); 762 if (bfd_get_outsymbols (abfd) == NULL && symsize != 0) 763 return FALSE; 764 symcount = bfd_canonicalize_symtab (abfd, bfd_get_outsymbols (abfd)); 765 if (symcount < 0) 766 return FALSE; 767 bfd_get_symcount (abfd) = symcount; 768 } 769 770 return TRUE; 771 } 772 773 /* Generic function to add symbols to from an object file to the 774 global hash table. This version does not automatically collect 775 constructors by name. */ 776 777 bfd_boolean 778 _bfd_generic_link_add_symbols (bfd *abfd, struct bfd_link_info *info) 779 { 780 return generic_link_add_symbols (abfd, info, FALSE); 781 } 782 783 /* Generic function to add symbols from an object file to the global 784 hash table. This version automatically collects constructors by 785 name, as the collect2 program does. It should be used for any 786 target which does not provide some other mechanism for setting up 787 constructors and destructors; these are approximately those targets 788 for which gcc uses collect2 and do not support stabs. */ 789 790 bfd_boolean 791 _bfd_generic_link_add_symbols_collect (bfd *abfd, struct bfd_link_info *info) 792 { 793 return generic_link_add_symbols (abfd, info, TRUE); 794 } 795 796 /* Indicate that we are only retrieving symbol values from this 797 section. We want the symbols to act as though the values in the 798 file are absolute. */ 799 800 void 801 _bfd_generic_link_just_syms (asection *sec, 802 struct bfd_link_info *info ATTRIBUTE_UNUSED) 803 { 804 sec->output_section = bfd_abs_section_ptr; 805 sec->output_offset = sec->vma; 806 } 807 808 /* Copy the type of a symbol assiciated with a linker hast table entry. 809 Override this so that symbols created in linker scripts get their 810 type from the RHS of the assignment. 811 The default implementation does nothing. */ 812 void 813 _bfd_generic_copy_link_hash_symbol_type (bfd *abfd ATTRIBUTE_UNUSED, 814 struct bfd_link_hash_entry * hdest ATTRIBUTE_UNUSED, 815 struct bfd_link_hash_entry * hsrc ATTRIBUTE_UNUSED) 816 { 817 } 818 819 /* Add symbols from an object file to the global hash table. */ 820 821 static bfd_boolean 822 generic_link_add_symbols (bfd *abfd, 823 struct bfd_link_info *info, 824 bfd_boolean collect) 825 { 826 bfd_boolean ret; 827 828 switch (bfd_get_format (abfd)) 829 { 830 case bfd_object: 831 ret = generic_link_add_object_symbols (abfd, info, collect); 832 break; 833 case bfd_archive: 834 ret = (_bfd_generic_link_add_archive_symbols 835 (abfd, info, 836 (collect 837 ? generic_link_check_archive_element_collect 838 : generic_link_check_archive_element_no_collect))); 839 break; 840 default: 841 bfd_set_error (bfd_error_wrong_format); 842 ret = FALSE; 843 } 844 845 return ret; 846 } 847 848 /* Add symbols from an object file to the global hash table. */ 849 850 static bfd_boolean 851 generic_link_add_object_symbols (bfd *abfd, 852 struct bfd_link_info *info, 853 bfd_boolean collect) 854 { 855 bfd_size_type symcount; 856 struct bfd_symbol **outsyms; 857 858 if (!bfd_generic_link_read_symbols (abfd)) 859 return FALSE; 860 symcount = _bfd_generic_link_get_symcount (abfd); 861 outsyms = _bfd_generic_link_get_symbols (abfd); 862 return generic_link_add_symbol_list (abfd, info, symcount, outsyms, collect); 863 } 864 865 /* We build a hash table of all symbols defined in an archive. */ 866 867 /* An archive symbol may be defined by multiple archive elements. 868 This linked list is used to hold the elements. */ 869 870 struct archive_list 871 { 872 struct archive_list *next; 873 unsigned int indx; 874 }; 875 876 /* An entry in an archive hash table. */ 877 878 struct archive_hash_entry 879 { 880 struct bfd_hash_entry root; 881 /* Where the symbol is defined. */ 882 struct archive_list *defs; 883 }; 884 885 /* An archive hash table itself. */ 886 887 struct archive_hash_table 888 { 889 struct bfd_hash_table table; 890 }; 891 892 /* Create a new entry for an archive hash table. */ 893 894 static struct bfd_hash_entry * 895 archive_hash_newfunc (struct bfd_hash_entry *entry, 896 struct bfd_hash_table *table, 897 const char *string) 898 { 899 struct archive_hash_entry *ret = (struct archive_hash_entry *) entry; 900 901 /* Allocate the structure if it has not already been allocated by a 902 subclass. */ 903 if (ret == NULL) 904 ret = (struct archive_hash_entry *) 905 bfd_hash_allocate (table, sizeof (struct archive_hash_entry)); 906 if (ret == NULL) 907 return NULL; 908 909 /* Call the allocation method of the superclass. */ 910 ret = ((struct archive_hash_entry *) 911 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string)); 912 913 if (ret) 914 { 915 /* Initialize the local fields. */ 916 ret->defs = NULL; 917 } 918 919 return &ret->root; 920 } 921 922 /* Initialize an archive hash table. */ 923 924 static bfd_boolean 925 archive_hash_table_init 926 (struct archive_hash_table *table, 927 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *, 928 struct bfd_hash_table *, 929 const char *), 930 unsigned int entsize) 931 { 932 return bfd_hash_table_init (&table->table, newfunc, entsize); 933 } 934 935 /* Look up an entry in an archive hash table. */ 936 937 #define archive_hash_lookup(t, string, create, copy) \ 938 ((struct archive_hash_entry *) \ 939 bfd_hash_lookup (&(t)->table, (string), (create), (copy))) 940 941 /* Allocate space in an archive hash table. */ 942 943 #define archive_hash_allocate(t, size) bfd_hash_allocate (&(t)->table, (size)) 944 945 /* Free an archive hash table. */ 946 947 #define archive_hash_table_free(t) bfd_hash_table_free (&(t)->table) 948 949 /* Generic function to add symbols from an archive file to the global 950 hash file. This function presumes that the archive symbol table 951 has already been read in (this is normally done by the 952 bfd_check_format entry point). It looks through the undefined and 953 common symbols and searches the archive symbol table for them. If 954 it finds an entry, it includes the associated object file in the 955 link. 956 957 The old linker looked through the archive symbol table for 958 undefined symbols. We do it the other way around, looking through 959 undefined symbols for symbols defined in the archive. The 960 advantage of the newer scheme is that we only have to look through 961 the list of undefined symbols once, whereas the old method had to 962 re-search the symbol table each time a new object file was added. 963 964 The CHECKFN argument is used to see if an object file should be 965 included. CHECKFN should set *PNEEDED to TRUE if the object file 966 should be included, and must also call the bfd_link_info 967 add_archive_element callback function and handle adding the symbols 968 to the global hash table. CHECKFN must notice if the callback 969 indicates a substitute BFD, and arrange to add those symbols instead 970 if it does so. CHECKFN should only return FALSE if some sort of 971 error occurs. 972 973 For some formats, such as a.out, it is possible to look through an 974 object file but not actually include it in the link. The 975 archive_pass field in a BFD is used to avoid checking the symbols 976 of an object files too many times. When an object is included in 977 the link, archive_pass is set to -1. If an object is scanned but 978 not included, archive_pass is set to the pass number. The pass 979 number is incremented each time a new object file is included. The 980 pass number is used because when a new object file is included it 981 may create new undefined symbols which cause a previously examined 982 object file to be included. */ 983 984 bfd_boolean 985 _bfd_generic_link_add_archive_symbols 986 (bfd *abfd, 987 struct bfd_link_info *info, 988 bfd_boolean (*checkfn) (bfd *, struct bfd_link_info *, bfd_boolean *)) 989 { 990 carsym *arsyms; 991 carsym *arsym_end; 992 register carsym *arsym; 993 int pass; 994 struct archive_hash_table arsym_hash; 995 unsigned int indx; 996 struct bfd_link_hash_entry **pundef; 997 998 if (! bfd_has_map (abfd)) 999 { 1000 /* An empty archive is a special case. */ 1001 if (bfd_openr_next_archived_file (abfd, NULL) == NULL) 1002 return TRUE; 1003 bfd_set_error (bfd_error_no_armap); 1004 return FALSE; 1005 } 1006 1007 arsyms = bfd_ardata (abfd)->symdefs; 1008 arsym_end = arsyms + bfd_ardata (abfd)->symdef_count; 1009 1010 /* In order to quickly determine whether an symbol is defined in 1011 this archive, we build a hash table of the symbols. */ 1012 if (! archive_hash_table_init (&arsym_hash, archive_hash_newfunc, 1013 sizeof (struct archive_hash_entry))) 1014 return FALSE; 1015 for (arsym = arsyms, indx = 0; arsym < arsym_end; arsym++, indx++) 1016 { 1017 struct archive_hash_entry *arh; 1018 struct archive_list *l, **pp; 1019 1020 arh = archive_hash_lookup (&arsym_hash, arsym->name, TRUE, FALSE); 1021 if (arh == NULL) 1022 goto error_return; 1023 l = ((struct archive_list *) 1024 archive_hash_allocate (&arsym_hash, sizeof (struct archive_list))); 1025 if (l == NULL) 1026 goto error_return; 1027 l->indx = indx; 1028 for (pp = &arh->defs; *pp != NULL; pp = &(*pp)->next) 1029 ; 1030 *pp = l; 1031 l->next = NULL; 1032 } 1033 1034 /* The archive_pass field in the archive itself is used to 1035 initialize PASS, sine we may search the same archive multiple 1036 times. */ 1037 pass = abfd->archive_pass + 1; 1038 1039 /* New undefined symbols are added to the end of the list, so we 1040 only need to look through it once. */ 1041 pundef = &info->hash->undefs; 1042 while (*pundef != NULL) 1043 { 1044 struct bfd_link_hash_entry *h; 1045 struct archive_hash_entry *arh; 1046 struct archive_list *l; 1047 1048 h = *pundef; 1049 1050 /* When a symbol is defined, it is not necessarily removed from 1051 the list. */ 1052 if (h->type != bfd_link_hash_undefined 1053 && h->type != bfd_link_hash_common) 1054 { 1055 /* Remove this entry from the list, for general cleanliness 1056 and because we are going to look through the list again 1057 if we search any more libraries. We can't remove the 1058 entry if it is the tail, because that would lose any 1059 entries we add to the list later on (it would also cause 1060 us to lose track of whether the symbol has been 1061 referenced). */ 1062 if (*pundef != info->hash->undefs_tail) 1063 *pundef = (*pundef)->u.undef.next; 1064 else 1065 pundef = &(*pundef)->u.undef.next; 1066 continue; 1067 } 1068 1069 /* Look for this symbol in the archive symbol map. */ 1070 arh = archive_hash_lookup (&arsym_hash, h->root.string, FALSE, FALSE); 1071 if (arh == NULL) 1072 { 1073 /* If we haven't found the exact symbol we're looking for, 1074 let's look for its import thunk */ 1075 if (info->pei386_auto_import) 1076 { 1077 bfd_size_type amt = strlen (h->root.string) + 10; 1078 char *buf = (char *) bfd_malloc (amt); 1079 if (buf == NULL) 1080 return FALSE; 1081 1082 sprintf (buf, "__imp_%s", h->root.string); 1083 arh = archive_hash_lookup (&arsym_hash, buf, FALSE, FALSE); 1084 free(buf); 1085 } 1086 if (arh == NULL) 1087 { 1088 pundef = &(*pundef)->u.undef.next; 1089 continue; 1090 } 1091 } 1092 /* Look at all the objects which define this symbol. */ 1093 for (l = arh->defs; l != NULL; l = l->next) 1094 { 1095 bfd *element; 1096 bfd_boolean needed; 1097 1098 /* If the symbol has gotten defined along the way, quit. */ 1099 if (h->type != bfd_link_hash_undefined 1100 && h->type != bfd_link_hash_common) 1101 break; 1102 1103 element = bfd_get_elt_at_index (abfd, l->indx); 1104 if (element == NULL) 1105 goto error_return; 1106 1107 /* If we've already included this element, or if we've 1108 already checked it on this pass, continue. */ 1109 if (element->archive_pass == -1 1110 || element->archive_pass == pass) 1111 continue; 1112 1113 /* If we can't figure this element out, just ignore it. */ 1114 if (! bfd_check_format (element, bfd_object)) 1115 { 1116 element->archive_pass = -1; 1117 continue; 1118 } 1119 1120 /* CHECKFN will see if this element should be included, and 1121 go ahead and include it if appropriate. */ 1122 if (! (*checkfn) (element, info, &needed)) 1123 goto error_return; 1124 1125 if (! needed) 1126 element->archive_pass = pass; 1127 else 1128 { 1129 element->archive_pass = -1; 1130 1131 /* Increment the pass count to show that we may need to 1132 recheck object files which were already checked. */ 1133 ++pass; 1134 } 1135 } 1136 1137 pundef = &(*pundef)->u.undef.next; 1138 } 1139 1140 archive_hash_table_free (&arsym_hash); 1141 1142 /* Save PASS in case we are called again. */ 1143 abfd->archive_pass = pass; 1144 1145 return TRUE; 1146 1147 error_return: 1148 archive_hash_table_free (&arsym_hash); 1149 return FALSE; 1150 } 1151 1152 /* See if we should include an archive element. This version is used 1153 when we do not want to automatically collect constructors based on 1154 the symbol name, presumably because we have some other mechanism 1155 for finding them. */ 1156 1157 static bfd_boolean 1158 generic_link_check_archive_element_no_collect ( 1159 bfd *abfd, 1160 struct bfd_link_info *info, 1161 bfd_boolean *pneeded) 1162 { 1163 return generic_link_check_archive_element (abfd, info, pneeded, FALSE); 1164 } 1165 1166 /* See if we should include an archive element. This version is used 1167 when we want to automatically collect constructors based on the 1168 symbol name, as collect2 does. */ 1169 1170 static bfd_boolean 1171 generic_link_check_archive_element_collect (bfd *abfd, 1172 struct bfd_link_info *info, 1173 bfd_boolean *pneeded) 1174 { 1175 return generic_link_check_archive_element (abfd, info, pneeded, TRUE); 1176 } 1177 1178 /* See if we should include an archive element. Optionally collect 1179 constructors. */ 1180 1181 static bfd_boolean 1182 generic_link_check_archive_element (bfd *abfd, 1183 struct bfd_link_info *info, 1184 bfd_boolean *pneeded, 1185 bfd_boolean collect) 1186 { 1187 asymbol **pp, **ppend; 1188 1189 *pneeded = FALSE; 1190 1191 if (!bfd_generic_link_read_symbols (abfd)) 1192 return FALSE; 1193 1194 pp = _bfd_generic_link_get_symbols (abfd); 1195 ppend = pp + _bfd_generic_link_get_symcount (abfd); 1196 for (; pp < ppend; pp++) 1197 { 1198 asymbol *p; 1199 struct bfd_link_hash_entry *h; 1200 1201 p = *pp; 1202 1203 /* We are only interested in globally visible symbols. */ 1204 if (! bfd_is_com_section (p->section) 1205 && (p->flags & (BSF_GLOBAL | BSF_INDIRECT | BSF_WEAK)) == 0) 1206 continue; 1207 1208 /* We are only interested if we know something about this 1209 symbol, and it is undefined or common. An undefined weak 1210 symbol (type bfd_link_hash_undefweak) is not considered to be 1211 a reference when pulling files out of an archive. See the 1212 SVR4 ABI, p. 4-27. */ 1213 h = bfd_link_hash_lookup (info->hash, bfd_asymbol_name (p), FALSE, 1214 FALSE, TRUE); 1215 if (h == NULL 1216 || (h->type != bfd_link_hash_undefined 1217 && h->type != bfd_link_hash_common)) 1218 continue; 1219 1220 /* P is a symbol we are looking for. */ 1221 1222 if (! bfd_is_com_section (p->section)) 1223 { 1224 bfd_size_type symcount; 1225 asymbol **symbols; 1226 bfd *oldbfd = abfd; 1227 1228 /* This object file defines this symbol, so pull it in. */ 1229 if (!(*info->callbacks 1230 ->add_archive_element) (info, abfd, bfd_asymbol_name (p), 1231 &abfd)) 1232 return FALSE; 1233 /* Potentially, the add_archive_element hook may have set a 1234 substitute BFD for us. */ 1235 if (abfd != oldbfd 1236 && !bfd_generic_link_read_symbols (abfd)) 1237 return FALSE; 1238 symcount = _bfd_generic_link_get_symcount (abfd); 1239 symbols = _bfd_generic_link_get_symbols (abfd); 1240 if (! generic_link_add_symbol_list (abfd, info, symcount, 1241 symbols, collect)) 1242 return FALSE; 1243 *pneeded = TRUE; 1244 return TRUE; 1245 } 1246 1247 /* P is a common symbol. */ 1248 1249 if (h->type == bfd_link_hash_undefined) 1250 { 1251 bfd *symbfd; 1252 bfd_vma size; 1253 unsigned int power; 1254 1255 symbfd = h->u.undef.abfd; 1256 if (symbfd == NULL) 1257 { 1258 /* This symbol was created as undefined from outside 1259 BFD. We assume that we should link in the object 1260 file. This is for the -u option in the linker. */ 1261 if (!(*info->callbacks 1262 ->add_archive_element) (info, abfd, bfd_asymbol_name (p), 1263 &abfd)) 1264 return FALSE; 1265 /* Potentially, the add_archive_element hook may have set a 1266 substitute BFD for us. But no symbols are going to get 1267 registered by anything we're returning to from here. */ 1268 *pneeded = TRUE; 1269 return TRUE; 1270 } 1271 1272 /* Turn the symbol into a common symbol but do not link in 1273 the object file. This is how a.out works. Object 1274 formats that require different semantics must implement 1275 this function differently. This symbol is already on the 1276 undefs list. We add the section to a common section 1277 attached to symbfd to ensure that it is in a BFD which 1278 will be linked in. */ 1279 h->type = bfd_link_hash_common; 1280 h->u.c.p = (struct bfd_link_hash_common_entry *) 1281 bfd_hash_allocate (&info->hash->table, 1282 sizeof (struct bfd_link_hash_common_entry)); 1283 if (h->u.c.p == NULL) 1284 return FALSE; 1285 1286 size = bfd_asymbol_value (p); 1287 h->u.c.size = size; 1288 1289 power = bfd_log2 (size); 1290 if (power > 4) 1291 power = 4; 1292 h->u.c.p->alignment_power = power; 1293 1294 if (p->section == bfd_com_section_ptr) 1295 h->u.c.p->section = bfd_make_section_old_way (symbfd, "COMMON"); 1296 else 1297 h->u.c.p->section = bfd_make_section_old_way (symbfd, 1298 p->section->name); 1299 h->u.c.p->section->flags = SEC_ALLOC; 1300 } 1301 else 1302 { 1303 /* Adjust the size of the common symbol if necessary. This 1304 is how a.out works. Object formats that require 1305 different semantics must implement this function 1306 differently. */ 1307 if (bfd_asymbol_value (p) > h->u.c.size) 1308 h->u.c.size = bfd_asymbol_value (p); 1309 } 1310 } 1311 1312 /* This archive element is not needed. */ 1313 return TRUE; 1314 } 1315 1316 /* Add the symbols from an object file to the global hash table. ABFD 1317 is the object file. INFO is the linker information. SYMBOL_COUNT 1318 is the number of symbols. SYMBOLS is the list of symbols. COLLECT 1319 is TRUE if constructors should be automatically collected by name 1320 as is done by collect2. */ 1321 1322 static bfd_boolean 1323 generic_link_add_symbol_list (bfd *abfd, 1324 struct bfd_link_info *info, 1325 bfd_size_type symbol_count, 1326 asymbol **symbols, 1327 bfd_boolean collect) 1328 { 1329 asymbol **pp, **ppend; 1330 1331 pp = symbols; 1332 ppend = symbols + symbol_count; 1333 for (; pp < ppend; pp++) 1334 { 1335 asymbol *p; 1336 1337 p = *pp; 1338 1339 if ((p->flags & (BSF_INDIRECT 1340 | BSF_WARNING 1341 | BSF_GLOBAL 1342 | BSF_CONSTRUCTOR 1343 | BSF_WEAK)) != 0 1344 || bfd_is_und_section (bfd_get_section (p)) 1345 || bfd_is_com_section (bfd_get_section (p)) 1346 || bfd_is_ind_section (bfd_get_section (p))) 1347 { 1348 const char *name; 1349 const char *string; 1350 struct generic_link_hash_entry *h; 1351 struct bfd_link_hash_entry *bh; 1352 1353 string = name = bfd_asymbol_name (p); 1354 if (((p->flags & BSF_INDIRECT) != 0 1355 || bfd_is_ind_section (p->section)) 1356 && pp + 1 < ppend) 1357 { 1358 pp++; 1359 string = bfd_asymbol_name (*pp); 1360 } 1361 else if ((p->flags & BSF_WARNING) != 0 1362 && pp + 1 < ppend) 1363 { 1364 /* The name of P is actually the warning string, and the 1365 next symbol is the one to warn about. */ 1366 pp++; 1367 name = bfd_asymbol_name (*pp); 1368 } 1369 1370 bh = NULL; 1371 if (! (_bfd_generic_link_add_one_symbol 1372 (info, abfd, name, p->flags, bfd_get_section (p), 1373 p->value, string, FALSE, collect, &bh))) 1374 return FALSE; 1375 h = (struct generic_link_hash_entry *) bh; 1376 1377 /* If this is a constructor symbol, and the linker didn't do 1378 anything with it, then we want to just pass the symbol 1379 through to the output file. This will happen when 1380 linking with -r. */ 1381 if ((p->flags & BSF_CONSTRUCTOR) != 0 1382 && (h == NULL || h->root.type == bfd_link_hash_new)) 1383 { 1384 p->udata.p = NULL; 1385 continue; 1386 } 1387 1388 /* Save the BFD symbol so that we don't lose any backend 1389 specific information that may be attached to it. We only 1390 want this one if it gives more information than the 1391 existing one; we don't want to replace a defined symbol 1392 with an undefined one. This routine may be called with a 1393 hash table other than the generic hash table, so we only 1394 do this if we are certain that the hash table is a 1395 generic one. */ 1396 if (info->output_bfd->xvec == abfd->xvec) 1397 { 1398 if (h->sym == NULL 1399 || (! bfd_is_und_section (bfd_get_section (p)) 1400 && (! bfd_is_com_section (bfd_get_section (p)) 1401 || bfd_is_und_section (bfd_get_section (h->sym))))) 1402 { 1403 h->sym = p; 1404 /* BSF_OLD_COMMON is a hack to support COFF reloc 1405 reading, and it should go away when the COFF 1406 linker is switched to the new version. */ 1407 if (bfd_is_com_section (bfd_get_section (p))) 1408 p->flags |= BSF_OLD_COMMON; 1409 } 1410 } 1411 1412 /* Store a back pointer from the symbol to the hash 1413 table entry for the benefit of relaxation code until 1414 it gets rewritten to not use asymbol structures. 1415 Setting this is also used to check whether these 1416 symbols were set up by the generic linker. */ 1417 p->udata.p = h; 1418 } 1419 } 1420 1421 return TRUE; 1422 } 1423 1424 /* We use a state table to deal with adding symbols from an object 1425 file. The first index into the state table describes the symbol 1426 from the object file. The second index into the state table is the 1427 type of the symbol in the hash table. */ 1428 1429 /* The symbol from the object file is turned into one of these row 1430 values. */ 1431 1432 enum link_row 1433 { 1434 UNDEF_ROW, /* Undefined. */ 1435 UNDEFW_ROW, /* Weak undefined. */ 1436 DEF_ROW, /* Defined. */ 1437 DEFW_ROW, /* Weak defined. */ 1438 COMMON_ROW, /* Common. */ 1439 INDR_ROW, /* Indirect. */ 1440 WARN_ROW, /* Warning. */ 1441 SET_ROW /* Member of set. */ 1442 }; 1443 1444 /* apparently needed for Hitachi 3050R(HI-UX/WE2)? */ 1445 #undef FAIL 1446 1447 /* The actions to take in the state table. */ 1448 1449 enum link_action 1450 { 1451 FAIL, /* Abort. */ 1452 UND, /* Mark symbol undefined. */ 1453 WEAK, /* Mark symbol weak undefined. */ 1454 DEF, /* Mark symbol defined. */ 1455 DEFW, /* Mark symbol weak defined. */ 1456 COM, /* Mark symbol common. */ 1457 REF, /* Mark defined symbol referenced. */ 1458 CREF, /* Possibly warn about common reference to defined symbol. */ 1459 CDEF, /* Define existing common symbol. */ 1460 NOACT, /* No action. */ 1461 BIG, /* Mark symbol common using largest size. */ 1462 MDEF, /* Multiple definition error. */ 1463 MIND, /* Multiple indirect symbols. */ 1464 IND, /* Make indirect symbol. */ 1465 CIND, /* Make indirect symbol from existing common symbol. */ 1466 SET, /* Add value to set. */ 1467 MWARN, /* Make warning symbol. */ 1468 WARN, /* Issue warning. */ 1469 CWARN, /* Warn if referenced, else MWARN. */ 1470 CYCLE, /* Repeat with symbol pointed to. */ 1471 REFC, /* Mark indirect symbol referenced and then CYCLE. */ 1472 WARNC /* Issue warning and then CYCLE. */ 1473 }; 1474 1475 /* The state table itself. The first index is a link_row and the 1476 second index is a bfd_link_hash_type. */ 1477 1478 static const enum link_action link_action[8][8] = 1479 { 1480 /* current\prev new undef undefw def defw com indr warn */ 1481 /* UNDEF_ROW */ {UND, NOACT, UND, REF, REF, NOACT, REFC, WARNC }, 1482 /* UNDEFW_ROW */ {WEAK, NOACT, NOACT, REF, REF, NOACT, REFC, WARNC }, 1483 /* DEF_ROW */ {DEF, DEF, DEF, MDEF, DEF, CDEF, MDEF, CYCLE }, 1484 /* DEFW_ROW */ {DEFW, DEFW, DEFW, NOACT, NOACT, NOACT, NOACT, CYCLE }, 1485 /* COMMON_ROW */ {COM, COM, COM, CREF, COM, BIG, REFC, WARNC }, 1486 /* INDR_ROW */ {IND, IND, IND, MDEF, IND, CIND, MIND, CYCLE }, 1487 /* WARN_ROW */ {MWARN, WARN, WARN, CWARN, CWARN, WARN, CWARN, NOACT }, 1488 /* SET_ROW */ {SET, SET, SET, SET, SET, SET, CYCLE, CYCLE } 1489 }; 1490 1491 /* Most of the entries in the LINK_ACTION table are straightforward, 1492 but a few are somewhat subtle. 1493 1494 A reference to an indirect symbol (UNDEF_ROW/indr or 1495 UNDEFW_ROW/indr) is counted as a reference both to the indirect 1496 symbol and to the symbol the indirect symbol points to. 1497 1498 A reference to a warning symbol (UNDEF_ROW/warn or UNDEFW_ROW/warn) 1499 causes the warning to be issued. 1500 1501 A common definition of an indirect symbol (COMMON_ROW/indr) is 1502 treated as a multiple definition error. Likewise for an indirect 1503 definition of a common symbol (INDR_ROW/com). 1504 1505 An indirect definition of a warning (INDR_ROW/warn) does not cause 1506 the warning to be issued. 1507 1508 If a warning is created for an indirect symbol (WARN_ROW/indr) no 1509 warning is created for the symbol the indirect symbol points to. 1510 1511 Adding an entry to a set does not count as a reference to a set, 1512 and no warning is issued (SET_ROW/warn). */ 1513 1514 /* Return the BFD in which a hash entry has been defined, if known. */ 1515 1516 static bfd * 1517 hash_entry_bfd (struct bfd_link_hash_entry *h) 1518 { 1519 while (h->type == bfd_link_hash_warning) 1520 h = h->u.i.link; 1521 switch (h->type) 1522 { 1523 default: 1524 return NULL; 1525 case bfd_link_hash_undefined: 1526 case bfd_link_hash_undefweak: 1527 return h->u.undef.abfd; 1528 case bfd_link_hash_defined: 1529 case bfd_link_hash_defweak: 1530 return h->u.def.section->owner; 1531 case bfd_link_hash_common: 1532 return h->u.c.p->section->owner; 1533 } 1534 /*NOTREACHED*/ 1535 } 1536 1537 /* Add a symbol to the global hash table. 1538 ABFD is the BFD the symbol comes from. 1539 NAME is the name of the symbol. 1540 FLAGS is the BSF_* bits associated with the symbol. 1541 SECTION is the section in which the symbol is defined; this may be 1542 bfd_und_section_ptr or bfd_com_section_ptr. 1543 VALUE is the value of the symbol, relative to the section. 1544 STRING is used for either an indirect symbol, in which case it is 1545 the name of the symbol to indirect to, or a warning symbol, in 1546 which case it is the warning string. 1547 COPY is TRUE if NAME or STRING must be copied into locally 1548 allocated memory if they need to be saved. 1549 COLLECT is TRUE if we should automatically collect gcc constructor 1550 or destructor names as collect2 does. 1551 HASHP, if not NULL, is a place to store the created hash table 1552 entry; if *HASHP is not NULL, the caller has already looked up 1553 the hash table entry, and stored it in *HASHP. */ 1554 1555 bfd_boolean 1556 _bfd_generic_link_add_one_symbol (struct bfd_link_info *info, 1557 bfd *abfd, 1558 const char *name, 1559 flagword flags, 1560 asection *section, 1561 bfd_vma value, 1562 const char *string, 1563 bfd_boolean copy, 1564 bfd_boolean collect, 1565 struct bfd_link_hash_entry **hashp) 1566 { 1567 enum link_row row; 1568 struct bfd_link_hash_entry *h; 1569 bfd_boolean cycle; 1570 1571 if (bfd_is_ind_section (section) 1572 || (flags & BSF_INDIRECT) != 0) 1573 row = INDR_ROW; 1574 else if ((flags & BSF_WARNING) != 0) 1575 row = WARN_ROW; 1576 else if ((flags & BSF_CONSTRUCTOR) != 0) 1577 row = SET_ROW; 1578 else if (bfd_is_und_section (section)) 1579 { 1580 if ((flags & BSF_WEAK) != 0) 1581 row = UNDEFW_ROW; 1582 else 1583 row = UNDEF_ROW; 1584 } 1585 else if ((flags & BSF_WEAK) != 0) 1586 row = DEFW_ROW; 1587 else if (bfd_is_com_section (section)) 1588 row = COMMON_ROW; 1589 else 1590 row = DEF_ROW; 1591 1592 if (hashp != NULL && *hashp != NULL) 1593 h = *hashp; 1594 else 1595 { 1596 if (row == UNDEF_ROW || row == UNDEFW_ROW) 1597 h = bfd_wrapped_link_hash_lookup (abfd, info, name, TRUE, copy, FALSE); 1598 else 1599 h = bfd_link_hash_lookup (info->hash, name, TRUE, copy, FALSE); 1600 if (h == NULL) 1601 { 1602 if (hashp != NULL) 1603 *hashp = NULL; 1604 return FALSE; 1605 } 1606 } 1607 1608 if (info->notice_all 1609 || (info->notice_hash != NULL 1610 && bfd_hash_lookup (info->notice_hash, name, FALSE, FALSE) != NULL)) 1611 { 1612 if (! (*info->callbacks->notice) (info, h->root.string, abfd, section, 1613 value)) 1614 return FALSE; 1615 } 1616 1617 if (hashp != NULL) 1618 *hashp = h; 1619 1620 do 1621 { 1622 enum link_action action; 1623 1624 cycle = FALSE; 1625 action = link_action[(int) row][(int) h->type]; 1626 switch (action) 1627 { 1628 case FAIL: 1629 abort (); 1630 1631 case NOACT: 1632 /* Do nothing. */ 1633 break; 1634 1635 case UND: 1636 /* Make a new undefined symbol. */ 1637 h->type = bfd_link_hash_undefined; 1638 h->u.undef.abfd = abfd; 1639 bfd_link_add_undef (info->hash, h); 1640 break; 1641 1642 case WEAK: 1643 /* Make a new weak undefined symbol. */ 1644 h->type = bfd_link_hash_undefweak; 1645 h->u.undef.abfd = abfd; 1646 h->u.undef.weak = abfd; 1647 break; 1648 1649 case CDEF: 1650 /* We have found a definition for a symbol which was 1651 previously common. */ 1652 BFD_ASSERT (h->type == bfd_link_hash_common); 1653 if (! ((*info->callbacks->multiple_common) 1654 (info, h->root.string, 1655 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1656 abfd, bfd_link_hash_defined, 0))) 1657 return FALSE; 1658 /* Fall through. */ 1659 case DEF: 1660 case DEFW: 1661 { 1662 enum bfd_link_hash_type oldtype; 1663 1664 /* Define a symbol. */ 1665 oldtype = h->type; 1666 if (action == DEFW) 1667 h->type = bfd_link_hash_defweak; 1668 else 1669 h->type = bfd_link_hash_defined; 1670 h->u.def.section = section; 1671 h->u.def.value = value; 1672 1673 /* If we have been asked to, we act like collect2 and 1674 identify all functions that might be global 1675 constructors and destructors and pass them up in a 1676 callback. We only do this for certain object file 1677 types, since many object file types can handle this 1678 automatically. */ 1679 if (collect && name[0] == '_') 1680 { 1681 const char *s; 1682 1683 /* A constructor or destructor name starts like this: 1684 _+GLOBAL_[_.$][ID][_.$] where the first [_.$] and 1685 the second are the same character (we accept any 1686 character there, in case a new object file format 1687 comes along with even worse naming restrictions). */ 1688 1689 #define CONS_PREFIX "GLOBAL_" 1690 #define CONS_PREFIX_LEN (sizeof CONS_PREFIX - 1) 1691 1692 s = name + 1; 1693 while (*s == '_') 1694 ++s; 1695 if (s[0] == 'G' && CONST_STRNEQ (s, CONS_PREFIX)) 1696 { 1697 char c; 1698 1699 c = s[CONS_PREFIX_LEN + 1]; 1700 if ((c == 'I' || c == 'D') 1701 && s[CONS_PREFIX_LEN] == s[CONS_PREFIX_LEN + 2]) 1702 { 1703 /* If this is a definition of a symbol which 1704 was previously weakly defined, we are in 1705 trouble. We have already added a 1706 constructor entry for the weak defined 1707 symbol, and now we are trying to add one 1708 for the new symbol. Fortunately, this case 1709 should never arise in practice. */ 1710 if (oldtype == bfd_link_hash_defweak) 1711 abort (); 1712 1713 if (! ((*info->callbacks->constructor) 1714 (info, c == 'I', 1715 h->root.string, abfd, section, value))) 1716 return FALSE; 1717 } 1718 } 1719 } 1720 } 1721 1722 break; 1723 1724 case COM: 1725 /* We have found a common definition for a symbol. */ 1726 if (h->type == bfd_link_hash_new) 1727 bfd_link_add_undef (info->hash, h); 1728 h->type = bfd_link_hash_common; 1729 h->u.c.p = (struct bfd_link_hash_common_entry *) 1730 bfd_hash_allocate (&info->hash->table, 1731 sizeof (struct bfd_link_hash_common_entry)); 1732 if (h->u.c.p == NULL) 1733 return FALSE; 1734 1735 h->u.c.size = value; 1736 1737 /* Select a default alignment based on the size. This may 1738 be overridden by the caller. */ 1739 { 1740 unsigned int power; 1741 1742 power = bfd_log2 (value); 1743 if (power > 4) 1744 power = 4; 1745 h->u.c.p->alignment_power = power; 1746 } 1747 1748 /* The section of a common symbol is only used if the common 1749 symbol is actually allocated. It basically provides a 1750 hook for the linker script to decide which output section 1751 the common symbols should be put in. In most cases, the 1752 section of a common symbol will be bfd_com_section_ptr, 1753 the code here will choose a common symbol section named 1754 "COMMON", and the linker script will contain *(COMMON) in 1755 the appropriate place. A few targets use separate common 1756 sections for small symbols, and they require special 1757 handling. */ 1758 if (section == bfd_com_section_ptr) 1759 { 1760 h->u.c.p->section = bfd_make_section_old_way (abfd, "COMMON"); 1761 h->u.c.p->section->flags = SEC_ALLOC; 1762 } 1763 else if (section->owner != abfd) 1764 { 1765 h->u.c.p->section = bfd_make_section_old_way (abfd, 1766 section->name); 1767 h->u.c.p->section->flags = SEC_ALLOC; 1768 } 1769 else 1770 h->u.c.p->section = section; 1771 break; 1772 1773 case REF: 1774 /* A reference to a defined symbol. */ 1775 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1776 h->u.undef.next = h; 1777 break; 1778 1779 case BIG: 1780 /* We have found a common definition for a symbol which 1781 already had a common definition. Use the maximum of the 1782 two sizes, and use the section required by the larger symbol. */ 1783 BFD_ASSERT (h->type == bfd_link_hash_common); 1784 if (! ((*info->callbacks->multiple_common) 1785 (info, h->root.string, 1786 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1787 abfd, bfd_link_hash_common, value))) 1788 return FALSE; 1789 if (value > h->u.c.size) 1790 { 1791 unsigned int power; 1792 1793 h->u.c.size = value; 1794 1795 /* Select a default alignment based on the size. This may 1796 be overridden by the caller. */ 1797 power = bfd_log2 (value); 1798 if (power > 4) 1799 power = 4; 1800 h->u.c.p->alignment_power = power; 1801 1802 /* Some systems have special treatment for small commons, 1803 hence we want to select the section used by the larger 1804 symbol. This makes sure the symbol does not go in a 1805 small common section if it is now too large. */ 1806 if (section == bfd_com_section_ptr) 1807 { 1808 h->u.c.p->section 1809 = bfd_make_section_old_way (abfd, "COMMON"); 1810 h->u.c.p->section->flags = SEC_ALLOC; 1811 } 1812 else if (section->owner != abfd) 1813 { 1814 h->u.c.p->section 1815 = bfd_make_section_old_way (abfd, section->name); 1816 h->u.c.p->section->flags = SEC_ALLOC; 1817 } 1818 else 1819 h->u.c.p->section = section; 1820 } 1821 break; 1822 1823 case CREF: 1824 { 1825 bfd *obfd; 1826 1827 /* We have found a common definition for a symbol which 1828 was already defined. FIXME: It would nice if we could 1829 report the BFD which defined an indirect symbol, but we 1830 don't have anywhere to store the information. */ 1831 if (h->type == bfd_link_hash_defined 1832 || h->type == bfd_link_hash_defweak) 1833 obfd = h->u.def.section->owner; 1834 else 1835 obfd = NULL; 1836 if (! ((*info->callbacks->multiple_common) 1837 (info, h->root.string, obfd, h->type, 0, 1838 abfd, bfd_link_hash_common, value))) 1839 return FALSE; 1840 } 1841 break; 1842 1843 case MIND: 1844 /* Multiple indirect symbols. This is OK if they both point 1845 to the same symbol. */ 1846 if (strcmp (h->u.i.link->root.string, string) == 0) 1847 break; 1848 /* Fall through. */ 1849 case MDEF: 1850 /* Handle a multiple definition. */ 1851 if (!info->allow_multiple_definition) 1852 { 1853 asection *msec = NULL; 1854 bfd_vma mval = 0; 1855 1856 switch (h->type) 1857 { 1858 case bfd_link_hash_defined: 1859 msec = h->u.def.section; 1860 mval = h->u.def.value; 1861 break; 1862 case bfd_link_hash_indirect: 1863 msec = bfd_ind_section_ptr; 1864 mval = 0; 1865 break; 1866 default: 1867 abort (); 1868 } 1869 1870 /* Ignore a redefinition of an absolute symbol to the 1871 same value; it's harmless. */ 1872 if (h->type == bfd_link_hash_defined 1873 && bfd_is_abs_section (msec) 1874 && bfd_is_abs_section (section) 1875 && value == mval) 1876 break; 1877 1878 if (! ((*info->callbacks->multiple_definition) 1879 (info, h->root.string, msec->owner, msec, mval, 1880 abfd, section, value))) 1881 return FALSE; 1882 } 1883 break; 1884 1885 case CIND: 1886 /* Create an indirect symbol from an existing common symbol. */ 1887 BFD_ASSERT (h->type == bfd_link_hash_common); 1888 if (! ((*info->callbacks->multiple_common) 1889 (info, h->root.string, 1890 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size, 1891 abfd, bfd_link_hash_indirect, 0))) 1892 return FALSE; 1893 /* Fall through. */ 1894 case IND: 1895 /* Create an indirect symbol. */ 1896 { 1897 struct bfd_link_hash_entry *inh; 1898 1899 /* STRING is the name of the symbol we want to indirect 1900 to. */ 1901 inh = bfd_wrapped_link_hash_lookup (abfd, info, string, TRUE, 1902 copy, FALSE); 1903 if (inh == NULL) 1904 return FALSE; 1905 if (inh->type == bfd_link_hash_indirect 1906 && inh->u.i.link == h) 1907 { 1908 (*_bfd_error_handler) 1909 (_("%B: indirect symbol `%s' to `%s' is a loop"), 1910 abfd, name, string); 1911 bfd_set_error (bfd_error_invalid_operation); 1912 return FALSE; 1913 } 1914 if (inh->type == bfd_link_hash_new) 1915 { 1916 inh->type = bfd_link_hash_undefined; 1917 inh->u.undef.abfd = abfd; 1918 bfd_link_add_undef (info->hash, inh); 1919 } 1920 1921 /* If the indirect symbol has been referenced, we need to 1922 push the reference down to the symbol we are 1923 referencing. */ 1924 if (h->type != bfd_link_hash_new) 1925 { 1926 row = UNDEF_ROW; 1927 cycle = TRUE; 1928 } 1929 1930 h->type = bfd_link_hash_indirect; 1931 h->u.i.link = inh; 1932 } 1933 break; 1934 1935 case SET: 1936 /* Add an entry to a set. */ 1937 if (! (*info->callbacks->add_to_set) (info, h, BFD_RELOC_CTOR, 1938 abfd, section, value)) 1939 return FALSE; 1940 break; 1941 1942 case WARNC: 1943 /* Issue a warning and cycle. */ 1944 if (h->u.i.warning != NULL) 1945 { 1946 if (! (*info->callbacks->warning) (info, h->u.i.warning, 1947 h->root.string, abfd, 1948 NULL, 0)) 1949 return FALSE; 1950 /* Only issue a warning once. */ 1951 h->u.i.warning = NULL; 1952 } 1953 /* Fall through. */ 1954 case CYCLE: 1955 /* Try again with the referenced symbol. */ 1956 h = h->u.i.link; 1957 cycle = TRUE; 1958 break; 1959 1960 case REFC: 1961 /* A reference to an indirect symbol. */ 1962 if (h->u.undef.next == NULL && info->hash->undefs_tail != h) 1963 h->u.undef.next = h; 1964 h = h->u.i.link; 1965 cycle = TRUE; 1966 break; 1967 1968 case WARN: 1969 /* Issue a warning. */ 1970 if (! (*info->callbacks->warning) (info, string, h->root.string, 1971 hash_entry_bfd (h), NULL, 0)) 1972 return FALSE; 1973 break; 1974 1975 case CWARN: 1976 /* Warn if this symbol has been referenced already, 1977 otherwise add a warning. A symbol has been referenced if 1978 the u.undef.next field is not NULL, or it is the tail of the 1979 undefined symbol list. The REF case above helps to 1980 ensure this. */ 1981 if (h->u.undef.next != NULL || info->hash->undefs_tail == h) 1982 { 1983 if (! (*info->callbacks->warning) (info, string, h->root.string, 1984 hash_entry_bfd (h), NULL, 0)) 1985 return FALSE; 1986 break; 1987 } 1988 /* Fall through. */ 1989 case MWARN: 1990 /* Make a warning symbol. */ 1991 { 1992 struct bfd_link_hash_entry *sub; 1993 1994 /* STRING is the warning to give. */ 1995 sub = ((struct bfd_link_hash_entry *) 1996 ((*info->hash->table.newfunc) 1997 (NULL, &info->hash->table, h->root.string))); 1998 if (sub == NULL) 1999 return FALSE; 2000 *sub = *h; 2001 sub->type = bfd_link_hash_warning; 2002 sub->u.i.link = h; 2003 if (! copy) 2004 sub->u.i.warning = string; 2005 else 2006 { 2007 char *w; 2008 size_t len = strlen (string) + 1; 2009 2010 w = (char *) bfd_hash_allocate (&info->hash->table, len); 2011 if (w == NULL) 2012 return FALSE; 2013 memcpy (w, string, len); 2014 sub->u.i.warning = w; 2015 } 2016 2017 bfd_hash_replace (&info->hash->table, 2018 (struct bfd_hash_entry *) h, 2019 (struct bfd_hash_entry *) sub); 2020 if (hashp != NULL) 2021 *hashp = sub; 2022 } 2023 break; 2024 } 2025 } 2026 while (cycle); 2027 2028 return TRUE; 2029 } 2030 2031 /* Generic final link routine. */ 2032 2033 bfd_boolean 2034 _bfd_generic_final_link (bfd *abfd, struct bfd_link_info *info) 2035 { 2036 bfd *sub; 2037 asection *o; 2038 struct bfd_link_order *p; 2039 size_t outsymalloc; 2040 struct generic_write_global_symbol_info wginfo; 2041 2042 bfd_get_outsymbols (abfd) = NULL; 2043 bfd_get_symcount (abfd) = 0; 2044 outsymalloc = 0; 2045 2046 /* Mark all sections which will be included in the output file. */ 2047 for (o = abfd->sections; o != NULL; o = o->next) 2048 for (p = o->map_head.link_order; p != NULL; p = p->next) 2049 if (p->type == bfd_indirect_link_order) 2050 p->u.indirect.section->linker_mark = TRUE; 2051 2052 /* Build the output symbol table. */ 2053 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next) 2054 if (! _bfd_generic_link_output_symbols (abfd, sub, info, &outsymalloc)) 2055 return FALSE; 2056 2057 /* Accumulate the global symbols. */ 2058 wginfo.info = info; 2059 wginfo.output_bfd = abfd; 2060 wginfo.psymalloc = &outsymalloc; 2061 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info), 2062 _bfd_generic_link_write_global_symbol, 2063 &wginfo); 2064 2065 /* Make sure we have a trailing NULL pointer on OUTSYMBOLS. We 2066 shouldn't really need one, since we have SYMCOUNT, but some old 2067 code still expects one. */ 2068 if (! generic_add_output_symbol (abfd, &outsymalloc, NULL)) 2069 return FALSE; 2070 2071 if (info->relocatable) 2072 { 2073 /* Allocate space for the output relocs for each section. */ 2074 for (o = abfd->sections; o != NULL; o = o->next) 2075 { 2076 o->reloc_count = 0; 2077 for (p = o->map_head.link_order; p != NULL; p = p->next) 2078 { 2079 if (p->type == bfd_section_reloc_link_order 2080 || p->type == bfd_symbol_reloc_link_order) 2081 ++o->reloc_count; 2082 else if (p->type == bfd_indirect_link_order) 2083 { 2084 asection *input_section; 2085 bfd *input_bfd; 2086 long relsize; 2087 arelent **relocs; 2088 asymbol **symbols; 2089 long reloc_count; 2090 2091 input_section = p->u.indirect.section; 2092 input_bfd = input_section->owner; 2093 relsize = bfd_get_reloc_upper_bound (input_bfd, 2094 input_section); 2095 if (relsize < 0) 2096 return FALSE; 2097 relocs = (arelent **) bfd_malloc (relsize); 2098 if (!relocs && relsize != 0) 2099 return FALSE; 2100 symbols = _bfd_generic_link_get_symbols (input_bfd); 2101 reloc_count = bfd_canonicalize_reloc (input_bfd, 2102 input_section, 2103 relocs, 2104 symbols); 2105 free (relocs); 2106 if (reloc_count < 0) 2107 return FALSE; 2108 BFD_ASSERT ((unsigned long) reloc_count 2109 == input_section->reloc_count); 2110 o->reloc_count += reloc_count; 2111 } 2112 } 2113 if (o->reloc_count > 0) 2114 { 2115 bfd_size_type amt; 2116 2117 amt = o->reloc_count; 2118 amt *= sizeof (arelent *); 2119 o->orelocation = (struct reloc_cache_entry **) bfd_alloc (abfd, amt); 2120 if (!o->orelocation) 2121 return FALSE; 2122 o->flags |= SEC_RELOC; 2123 /* Reset the count so that it can be used as an index 2124 when putting in the output relocs. */ 2125 o->reloc_count = 0; 2126 } 2127 } 2128 } 2129 2130 /* Handle all the link order information for the sections. */ 2131 for (o = abfd->sections; o != NULL; o = o->next) 2132 { 2133 for (p = o->map_head.link_order; p != NULL; p = p->next) 2134 { 2135 switch (p->type) 2136 { 2137 case bfd_section_reloc_link_order: 2138 case bfd_symbol_reloc_link_order: 2139 if (! _bfd_generic_reloc_link_order (abfd, info, o, p)) 2140 return FALSE; 2141 break; 2142 case bfd_indirect_link_order: 2143 if (! default_indirect_link_order (abfd, info, o, p, TRUE)) 2144 return FALSE; 2145 break; 2146 default: 2147 if (! _bfd_default_link_order (abfd, info, o, p)) 2148 return FALSE; 2149 break; 2150 } 2151 } 2152 } 2153 2154 return TRUE; 2155 } 2156 2157 /* Add an output symbol to the output BFD. */ 2158 2159 static bfd_boolean 2160 generic_add_output_symbol (bfd *output_bfd, size_t *psymalloc, asymbol *sym) 2161 { 2162 if (bfd_get_symcount (output_bfd) >= *psymalloc) 2163 { 2164 asymbol **newsyms; 2165 bfd_size_type amt; 2166 2167 if (*psymalloc == 0) 2168 *psymalloc = 124; 2169 else 2170 *psymalloc *= 2; 2171 amt = *psymalloc; 2172 amt *= sizeof (asymbol *); 2173 newsyms = (asymbol **) bfd_realloc (bfd_get_outsymbols (output_bfd), amt); 2174 if (newsyms == NULL) 2175 return FALSE; 2176 bfd_get_outsymbols (output_bfd) = newsyms; 2177 } 2178 2179 bfd_get_outsymbols (output_bfd) [bfd_get_symcount (output_bfd)] = sym; 2180 if (sym != NULL) 2181 ++ bfd_get_symcount (output_bfd); 2182 2183 return TRUE; 2184 } 2185 2186 /* Handle the symbols for an input BFD. */ 2187 2188 bfd_boolean 2189 _bfd_generic_link_output_symbols (bfd *output_bfd, 2190 bfd *input_bfd, 2191 struct bfd_link_info *info, 2192 size_t *psymalloc) 2193 { 2194 asymbol **sym_ptr; 2195 asymbol **sym_end; 2196 2197 if (!bfd_generic_link_read_symbols (input_bfd)) 2198 return FALSE; 2199 2200 /* Create a filename symbol if we are supposed to. */ 2201 if (info->create_object_symbols_section != NULL) 2202 { 2203 asection *sec; 2204 2205 for (sec = input_bfd->sections; sec != NULL; sec = sec->next) 2206 { 2207 if (sec->output_section == info->create_object_symbols_section) 2208 { 2209 asymbol *newsym; 2210 2211 newsym = bfd_make_empty_symbol (input_bfd); 2212 if (!newsym) 2213 return FALSE; 2214 newsym->name = input_bfd->filename; 2215 newsym->value = 0; 2216 newsym->flags = BSF_LOCAL | BSF_FILE; 2217 newsym->section = sec; 2218 2219 if (! generic_add_output_symbol (output_bfd, psymalloc, 2220 newsym)) 2221 return FALSE; 2222 2223 break; 2224 } 2225 } 2226 } 2227 2228 /* Adjust the values of the globally visible symbols, and write out 2229 local symbols. */ 2230 sym_ptr = _bfd_generic_link_get_symbols (input_bfd); 2231 sym_end = sym_ptr + _bfd_generic_link_get_symcount (input_bfd); 2232 for (; sym_ptr < sym_end; sym_ptr++) 2233 { 2234 asymbol *sym; 2235 struct generic_link_hash_entry *h; 2236 bfd_boolean output; 2237 2238 h = NULL; 2239 sym = *sym_ptr; 2240 if ((sym->flags & (BSF_INDIRECT 2241 | BSF_WARNING 2242 | BSF_GLOBAL 2243 | BSF_CONSTRUCTOR 2244 | BSF_WEAK)) != 0 2245 || bfd_is_und_section (bfd_get_section (sym)) 2246 || bfd_is_com_section (bfd_get_section (sym)) 2247 || bfd_is_ind_section (bfd_get_section (sym))) 2248 { 2249 if (sym->udata.p != NULL) 2250 h = (struct generic_link_hash_entry *) sym->udata.p; 2251 else if ((sym->flags & BSF_CONSTRUCTOR) != 0) 2252 { 2253 /* This case normally means that the main linker code 2254 deliberately ignored this constructor symbol. We 2255 should just pass it through. This will screw up if 2256 the constructor symbol is from a different, 2257 non-generic, object file format, but the case will 2258 only arise when linking with -r, which will probably 2259 fail anyhow, since there will be no way to represent 2260 the relocs in the output format being used. */ 2261 h = NULL; 2262 } 2263 else if (bfd_is_und_section (bfd_get_section (sym))) 2264 h = ((struct generic_link_hash_entry *) 2265 bfd_wrapped_link_hash_lookup (output_bfd, info, 2266 bfd_asymbol_name (sym), 2267 FALSE, FALSE, TRUE)); 2268 else 2269 h = _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info), 2270 bfd_asymbol_name (sym), 2271 FALSE, FALSE, TRUE); 2272 2273 if (h != NULL) 2274 { 2275 /* Force all references to this symbol to point to 2276 the same area in memory. It is possible that 2277 this routine will be called with a hash table 2278 other than a generic hash table, so we double 2279 check that. */ 2280 if (info->output_bfd->xvec == input_bfd->xvec) 2281 { 2282 if (h->sym != NULL) 2283 *sym_ptr = sym = h->sym; 2284 } 2285 2286 switch (h->root.type) 2287 { 2288 default: 2289 case bfd_link_hash_new: 2290 abort (); 2291 case bfd_link_hash_undefined: 2292 break; 2293 case bfd_link_hash_undefweak: 2294 sym->flags |= BSF_WEAK; 2295 break; 2296 case bfd_link_hash_indirect: 2297 h = (struct generic_link_hash_entry *) h->root.u.i.link; 2298 /* fall through */ 2299 case bfd_link_hash_defined: 2300 sym->flags |= BSF_GLOBAL; 2301 sym->flags &=~ BSF_CONSTRUCTOR; 2302 sym->value = h->root.u.def.value; 2303 sym->section = h->root.u.def.section; 2304 break; 2305 case bfd_link_hash_defweak: 2306 sym->flags |= BSF_WEAK; 2307 sym->flags &=~ BSF_CONSTRUCTOR; 2308 sym->value = h->root.u.def.value; 2309 sym->section = h->root.u.def.section; 2310 break; 2311 case bfd_link_hash_common: 2312 sym->value = h->root.u.c.size; 2313 sym->flags |= BSF_GLOBAL; 2314 if (! bfd_is_com_section (sym->section)) 2315 { 2316 BFD_ASSERT (bfd_is_und_section (sym->section)); 2317 sym->section = bfd_com_section_ptr; 2318 } 2319 /* We do not set the section of the symbol to 2320 h->root.u.c.p->section. That value was saved so 2321 that we would know where to allocate the symbol 2322 if it was defined. In this case the type is 2323 still bfd_link_hash_common, so we did not define 2324 it, so we do not want to use that section. */ 2325 break; 2326 } 2327 } 2328 } 2329 2330 /* This switch is straight from the old code in 2331 write_file_locals in ldsym.c. */ 2332 if (info->strip == strip_all 2333 || (info->strip == strip_some 2334 && bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym), 2335 FALSE, FALSE) == NULL)) 2336 output = FALSE; 2337 else if ((sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0) 2338 { 2339 /* If this symbol is marked as occurring now, rather 2340 than at the end, output it now. This is used for 2341 COFF C_EXT FCN symbols. FIXME: There must be a 2342 better way. */ 2343 if (bfd_asymbol_bfd (sym) == input_bfd 2344 && (sym->flags & BSF_NOT_AT_END) != 0) 2345 output = TRUE; 2346 else 2347 output = FALSE; 2348 } 2349 else if (bfd_is_ind_section (sym->section)) 2350 output = FALSE; 2351 else if ((sym->flags & BSF_DEBUGGING) != 0) 2352 { 2353 if (info->strip == strip_none) 2354 output = TRUE; 2355 else 2356 output = FALSE; 2357 } 2358 else if (bfd_is_und_section (sym->section) 2359 || bfd_is_com_section (sym->section)) 2360 output = FALSE; 2361 else if ((sym->flags & BSF_LOCAL) != 0) 2362 { 2363 if ((sym->flags & BSF_WARNING) != 0) 2364 output = FALSE; 2365 else 2366 { 2367 switch (info->discard) 2368 { 2369 default: 2370 case discard_all: 2371 output = FALSE; 2372 break; 2373 case discard_sec_merge: 2374 output = TRUE; 2375 if (info->relocatable 2376 || ! (sym->section->flags & SEC_MERGE)) 2377 break; 2378 /* FALLTHROUGH */ 2379 case discard_l: 2380 if (bfd_is_local_label (input_bfd, sym)) 2381 output = FALSE; 2382 else 2383 output = TRUE; 2384 break; 2385 case discard_none: 2386 output = TRUE; 2387 break; 2388 } 2389 } 2390 } 2391 else if ((sym->flags & BSF_CONSTRUCTOR)) 2392 { 2393 if (info->strip != strip_all) 2394 output = TRUE; 2395 else 2396 output = FALSE; 2397 } 2398 else 2399 abort (); 2400 2401 /* If this symbol is in a section which is not being included 2402 in the output file, then we don't want to output the 2403 symbol. */ 2404 if (!bfd_is_abs_section (sym->section) 2405 && bfd_section_removed_from_list (output_bfd, 2406 sym->section->output_section)) 2407 output = FALSE; 2408 2409 if (output) 2410 { 2411 if (! generic_add_output_symbol (output_bfd, psymalloc, sym)) 2412 return FALSE; 2413 if (h != NULL) 2414 h->written = TRUE; 2415 } 2416 } 2417 2418 return TRUE; 2419 } 2420 2421 /* Set the section and value of a generic BFD symbol based on a linker 2422 hash table entry. */ 2423 2424 static void 2425 set_symbol_from_hash (asymbol *sym, struct bfd_link_hash_entry *h) 2426 { 2427 switch (h->type) 2428 { 2429 default: 2430 abort (); 2431 break; 2432 case bfd_link_hash_new: 2433 /* This can happen when a constructor symbol is seen but we are 2434 not building constructors. */ 2435 if (sym->section != NULL) 2436 { 2437 BFD_ASSERT ((sym->flags & BSF_CONSTRUCTOR) != 0); 2438 } 2439 else 2440 { 2441 sym->flags |= BSF_CONSTRUCTOR; 2442 sym->section = bfd_abs_section_ptr; 2443 sym->value = 0; 2444 } 2445 break; 2446 case bfd_link_hash_undefined: 2447 sym->section = bfd_und_section_ptr; 2448 sym->value = 0; 2449 break; 2450 case bfd_link_hash_undefweak: 2451 sym->section = bfd_und_section_ptr; 2452 sym->value = 0; 2453 sym->flags |= BSF_WEAK; 2454 break; 2455 case bfd_link_hash_defined: 2456 sym->section = h->u.def.section; 2457 sym->value = h->u.def.value; 2458 break; 2459 case bfd_link_hash_defweak: 2460 sym->flags |= BSF_WEAK; 2461 sym->section = h->u.def.section; 2462 sym->value = h->u.def.value; 2463 break; 2464 case bfd_link_hash_common: 2465 sym->value = h->u.c.size; 2466 if (sym->section == NULL) 2467 sym->section = bfd_com_section_ptr; 2468 else if (! bfd_is_com_section (sym->section)) 2469 { 2470 BFD_ASSERT (bfd_is_und_section (sym->section)); 2471 sym->section = bfd_com_section_ptr; 2472 } 2473 /* Do not set the section; see _bfd_generic_link_output_symbols. */ 2474 break; 2475 case bfd_link_hash_indirect: 2476 case bfd_link_hash_warning: 2477 /* FIXME: What should we do here? */ 2478 break; 2479 } 2480 } 2481 2482 /* Write out a global symbol, if it hasn't already been written out. 2483 This is called for each symbol in the hash table. */ 2484 2485 bfd_boolean 2486 _bfd_generic_link_write_global_symbol (struct generic_link_hash_entry *h, 2487 void *data) 2488 { 2489 struct generic_write_global_symbol_info *wginfo = 2490 (struct generic_write_global_symbol_info *) data; 2491 asymbol *sym; 2492 2493 if (h->root.type == bfd_link_hash_warning) 2494 h = (struct generic_link_hash_entry *) h->root.u.i.link; 2495 2496 if (h->written) 2497 return TRUE; 2498 2499 h->written = TRUE; 2500 2501 if (wginfo->info->strip == strip_all 2502 || (wginfo->info->strip == strip_some 2503 && bfd_hash_lookup (wginfo->info->keep_hash, h->root.root.string, 2504 FALSE, FALSE) == NULL)) 2505 return TRUE; 2506 2507 if (h->sym != NULL) 2508 sym = h->sym; 2509 else 2510 { 2511 sym = bfd_make_empty_symbol (wginfo->output_bfd); 2512 if (!sym) 2513 return FALSE; 2514 sym->name = h->root.root.string; 2515 sym->flags = 0; 2516 } 2517 2518 set_symbol_from_hash (sym, &h->root); 2519 2520 sym->flags |= BSF_GLOBAL; 2521 2522 if (! generic_add_output_symbol (wginfo->output_bfd, wginfo->psymalloc, 2523 sym)) 2524 { 2525 /* FIXME: No way to return failure. */ 2526 abort (); 2527 } 2528 2529 return TRUE; 2530 } 2531 2532 /* Create a relocation. */ 2533 2534 bfd_boolean 2535 _bfd_generic_reloc_link_order (bfd *abfd, 2536 struct bfd_link_info *info, 2537 asection *sec, 2538 struct bfd_link_order *link_order) 2539 { 2540 arelent *r; 2541 2542 if (! info->relocatable) 2543 abort (); 2544 if (sec->orelocation == NULL) 2545 abort (); 2546 2547 r = (arelent *) bfd_alloc (abfd, sizeof (arelent)); 2548 if (r == NULL) 2549 return FALSE; 2550 2551 r->address = link_order->offset; 2552 r->howto = bfd_reloc_type_lookup (abfd, link_order->u.reloc.p->reloc); 2553 if (r->howto == 0) 2554 { 2555 bfd_set_error (bfd_error_bad_value); 2556 return FALSE; 2557 } 2558 2559 /* Get the symbol to use for the relocation. */ 2560 if (link_order->type == bfd_section_reloc_link_order) 2561 r->sym_ptr_ptr = link_order->u.reloc.p->u.section->symbol_ptr_ptr; 2562 else 2563 { 2564 struct generic_link_hash_entry *h; 2565 2566 h = ((struct generic_link_hash_entry *) 2567 bfd_wrapped_link_hash_lookup (abfd, info, 2568 link_order->u.reloc.p->u.name, 2569 FALSE, FALSE, TRUE)); 2570 if (h == NULL 2571 || ! h->written) 2572 { 2573 if (! ((*info->callbacks->unattached_reloc) 2574 (info, link_order->u.reloc.p->u.name, NULL, NULL, 0))) 2575 return FALSE; 2576 bfd_set_error (bfd_error_bad_value); 2577 return FALSE; 2578 } 2579 r->sym_ptr_ptr = &h->sym; 2580 } 2581 2582 /* If this is an inplace reloc, write the addend to the object file. 2583 Otherwise, store it in the reloc addend. */ 2584 if (! r->howto->partial_inplace) 2585 r->addend = link_order->u.reloc.p->addend; 2586 else 2587 { 2588 bfd_size_type size; 2589 bfd_reloc_status_type rstat; 2590 bfd_byte *buf; 2591 bfd_boolean ok; 2592 file_ptr loc; 2593 2594 size = bfd_get_reloc_size (r->howto); 2595 buf = (bfd_byte *) bfd_zmalloc (size); 2596 if (buf == NULL) 2597 return FALSE; 2598 rstat = _bfd_relocate_contents (r->howto, abfd, 2599 (bfd_vma) link_order->u.reloc.p->addend, 2600 buf); 2601 switch (rstat) 2602 { 2603 case bfd_reloc_ok: 2604 break; 2605 default: 2606 case bfd_reloc_outofrange: 2607 abort (); 2608 case bfd_reloc_overflow: 2609 if (! ((*info->callbacks->reloc_overflow) 2610 (info, NULL, 2611 (link_order->type == bfd_section_reloc_link_order 2612 ? bfd_section_name (abfd, link_order->u.reloc.p->u.section) 2613 : link_order->u.reloc.p->u.name), 2614 r->howto->name, link_order->u.reloc.p->addend, 2615 NULL, NULL, 0))) 2616 { 2617 free (buf); 2618 return FALSE; 2619 } 2620 break; 2621 } 2622 loc = link_order->offset * bfd_octets_per_byte (abfd); 2623 ok = bfd_set_section_contents (abfd, sec, buf, loc, size); 2624 free (buf); 2625 if (! ok) 2626 return FALSE; 2627 2628 r->addend = 0; 2629 } 2630 2631 sec->orelocation[sec->reloc_count] = r; 2632 ++sec->reloc_count; 2633 2634 return TRUE; 2635 } 2636 2637 /* Allocate a new link_order for a section. */ 2638 2639 struct bfd_link_order * 2640 bfd_new_link_order (bfd *abfd, asection *section) 2641 { 2642 bfd_size_type amt = sizeof (struct bfd_link_order); 2643 struct bfd_link_order *new_lo; 2644 2645 new_lo = (struct bfd_link_order *) bfd_zalloc (abfd, amt); 2646 if (!new_lo) 2647 return NULL; 2648 2649 new_lo->type = bfd_undefined_link_order; 2650 2651 if (section->map_tail.link_order != NULL) 2652 section->map_tail.link_order->next = new_lo; 2653 else 2654 section->map_head.link_order = new_lo; 2655 section->map_tail.link_order = new_lo; 2656 2657 return new_lo; 2658 } 2659 2660 /* Default link order processing routine. Note that we can not handle 2661 the reloc_link_order types here, since they depend upon the details 2662 of how the particular backends generates relocs. */ 2663 2664 bfd_boolean 2665 _bfd_default_link_order (bfd *abfd, 2666 struct bfd_link_info *info, 2667 asection *sec, 2668 struct bfd_link_order *link_order) 2669 { 2670 switch (link_order->type) 2671 { 2672 case bfd_undefined_link_order: 2673 case bfd_section_reloc_link_order: 2674 case bfd_symbol_reloc_link_order: 2675 default: 2676 abort (); 2677 case bfd_indirect_link_order: 2678 return default_indirect_link_order (abfd, info, sec, link_order, 2679 FALSE); 2680 case bfd_data_link_order: 2681 return default_data_link_order (abfd, info, sec, link_order); 2682 } 2683 } 2684 2685 /* Default routine to handle a bfd_data_link_order. */ 2686 2687 static bfd_boolean 2688 default_data_link_order (bfd *abfd, 2689 struct bfd_link_info *info ATTRIBUTE_UNUSED, 2690 asection *sec, 2691 struct bfd_link_order *link_order) 2692 { 2693 bfd_size_type size; 2694 size_t fill_size; 2695 bfd_byte *fill; 2696 file_ptr loc; 2697 bfd_boolean result; 2698 2699 BFD_ASSERT ((sec->flags & SEC_HAS_CONTENTS) != 0); 2700 2701 size = link_order->size; 2702 if (size == 0) 2703 return TRUE; 2704 2705 fill = link_order->u.data.contents; 2706 fill_size = link_order->u.data.size; 2707 if (fill_size != 0 && fill_size < size) 2708 { 2709 bfd_byte *p; 2710 fill = (bfd_byte *) bfd_malloc (size); 2711 if (fill == NULL) 2712 return FALSE; 2713 p = fill; 2714 if (fill_size == 1) 2715 memset (p, (int) link_order->u.data.contents[0], (size_t) size); 2716 else 2717 { 2718 do 2719 { 2720 memcpy (p, link_order->u.data.contents, fill_size); 2721 p += fill_size; 2722 size -= fill_size; 2723 } 2724 while (size >= fill_size); 2725 if (size != 0) 2726 memcpy (p, link_order->u.data.contents, (size_t) size); 2727 size = link_order->size; 2728 } 2729 } 2730 2731 loc = link_order->offset * bfd_octets_per_byte (abfd); 2732 result = bfd_set_section_contents (abfd, sec, fill, loc, size); 2733 2734 if (fill != link_order->u.data.contents) 2735 free (fill); 2736 return result; 2737 } 2738 2739 /* Default routine to handle a bfd_indirect_link_order. */ 2740 2741 static bfd_boolean 2742 default_indirect_link_order (bfd *output_bfd, 2743 struct bfd_link_info *info, 2744 asection *output_section, 2745 struct bfd_link_order *link_order, 2746 bfd_boolean generic_linker) 2747 { 2748 asection *input_section; 2749 bfd *input_bfd; 2750 bfd_byte *contents = NULL; 2751 bfd_byte *new_contents; 2752 bfd_size_type sec_size; 2753 file_ptr loc; 2754 2755 BFD_ASSERT ((output_section->flags & SEC_HAS_CONTENTS) != 0); 2756 2757 input_section = link_order->u.indirect.section; 2758 input_bfd = input_section->owner; 2759 if (input_section->size == 0) 2760 return TRUE; 2761 2762 BFD_ASSERT (input_section->output_section == output_section); 2763 BFD_ASSERT (input_section->output_offset == link_order->offset); 2764 BFD_ASSERT (input_section->size == link_order->size); 2765 2766 if (info->relocatable 2767 && input_section->reloc_count > 0 2768 && output_section->orelocation == NULL) 2769 { 2770 /* Space has not been allocated for the output relocations. 2771 This can happen when we are called by a specific backend 2772 because somebody is attempting to link together different 2773 types of object files. Handling this case correctly is 2774 difficult, and sometimes impossible. */ 2775 (*_bfd_error_handler) 2776 (_("Attempt to do relocatable link with %s input and %s output"), 2777 bfd_get_target (input_bfd), bfd_get_target (output_bfd)); 2778 bfd_set_error (bfd_error_wrong_format); 2779 return FALSE; 2780 } 2781 2782 if (! generic_linker) 2783 { 2784 asymbol **sympp; 2785 asymbol **symppend; 2786 2787 /* Get the canonical symbols. The generic linker will always 2788 have retrieved them by this point, but we are being called by 2789 a specific linker, presumably because we are linking 2790 different types of object files together. */ 2791 if (!bfd_generic_link_read_symbols (input_bfd)) 2792 return FALSE; 2793 2794 /* Since we have been called by a specific linker, rather than 2795 the generic linker, the values of the symbols will not be 2796 right. They will be the values as seen in the input file, 2797 not the values of the final link. We need to fix them up 2798 before we can relocate the section. */ 2799 sympp = _bfd_generic_link_get_symbols (input_bfd); 2800 symppend = sympp + _bfd_generic_link_get_symcount (input_bfd); 2801 for (; sympp < symppend; sympp++) 2802 { 2803 asymbol *sym; 2804 struct bfd_link_hash_entry *h; 2805 2806 sym = *sympp; 2807 2808 if ((sym->flags & (BSF_INDIRECT 2809 | BSF_WARNING 2810 | BSF_GLOBAL 2811 | BSF_CONSTRUCTOR 2812 | BSF_WEAK)) != 0 2813 || bfd_is_und_section (bfd_get_section (sym)) 2814 || bfd_is_com_section (bfd_get_section (sym)) 2815 || bfd_is_ind_section (bfd_get_section (sym))) 2816 { 2817 /* sym->udata may have been set by 2818 generic_link_add_symbol_list. */ 2819 if (sym->udata.p != NULL) 2820 h = (struct bfd_link_hash_entry *) sym->udata.p; 2821 else if (bfd_is_und_section (bfd_get_section (sym))) 2822 h = bfd_wrapped_link_hash_lookup (output_bfd, info, 2823 bfd_asymbol_name (sym), 2824 FALSE, FALSE, TRUE); 2825 else 2826 h = bfd_link_hash_lookup (info->hash, 2827 bfd_asymbol_name (sym), 2828 FALSE, FALSE, TRUE); 2829 if (h != NULL) 2830 set_symbol_from_hash (sym, h); 2831 } 2832 } 2833 } 2834 2835 if ((output_section->flags & (SEC_GROUP | SEC_LINKER_CREATED)) == SEC_GROUP 2836 && input_section->size != 0) 2837 { 2838 /* Group section contents are set by bfd_elf_set_group_contents. */ 2839 if (!output_bfd->output_has_begun) 2840 { 2841 /* FIXME: This hack ensures bfd_elf_set_group_contents is called. */ 2842 if (!bfd_set_section_contents (output_bfd, output_section, "", 0, 1)) 2843 goto error_return; 2844 } 2845 new_contents = output_section->contents; 2846 BFD_ASSERT (new_contents != NULL); 2847 BFD_ASSERT (input_section->output_offset == 0); 2848 } 2849 else 2850 { 2851 /* Get and relocate the section contents. */ 2852 sec_size = (input_section->rawsize > input_section->size 2853 ? input_section->rawsize 2854 : input_section->size); 2855 contents = (bfd_byte *) bfd_malloc (sec_size); 2856 if (contents == NULL && sec_size != 0) 2857 goto error_return; 2858 new_contents = (bfd_get_relocated_section_contents 2859 (output_bfd, info, link_order, contents, 2860 info->relocatable, 2861 _bfd_generic_link_get_symbols (input_bfd))); 2862 if (!new_contents) 2863 goto error_return; 2864 } 2865 2866 /* Output the section contents. */ 2867 loc = input_section->output_offset * bfd_octets_per_byte (output_bfd); 2868 if (! bfd_set_section_contents (output_bfd, output_section, 2869 new_contents, loc, input_section->size)) 2870 goto error_return; 2871 2872 if (contents != NULL) 2873 free (contents); 2874 return TRUE; 2875 2876 error_return: 2877 if (contents != NULL) 2878 free (contents); 2879 return FALSE; 2880 } 2881 2882 /* A little routine to count the number of relocs in a link_order 2883 list. */ 2884 2885 unsigned int 2886 _bfd_count_link_order_relocs (struct bfd_link_order *link_order) 2887 { 2888 register unsigned int c; 2889 register struct bfd_link_order *l; 2890 2891 c = 0; 2892 for (l = link_order; l != NULL; l = l->next) 2893 { 2894 if (l->type == bfd_section_reloc_link_order 2895 || l->type == bfd_symbol_reloc_link_order) 2896 ++c; 2897 } 2898 2899 return c; 2900 } 2901 2902 /* 2903 FUNCTION 2904 bfd_link_split_section 2905 2906 SYNOPSIS 2907 bfd_boolean bfd_link_split_section (bfd *abfd, asection *sec); 2908 2909 DESCRIPTION 2910 Return nonzero if @var{sec} should be split during a 2911 reloceatable or final link. 2912 2913 .#define bfd_link_split_section(abfd, sec) \ 2914 . BFD_SEND (abfd, _bfd_link_split_section, (abfd, sec)) 2915 . 2916 2917 */ 2918 2919 bfd_boolean 2920 _bfd_generic_link_split_section (bfd *abfd ATTRIBUTE_UNUSED, 2921 asection *sec ATTRIBUTE_UNUSED) 2922 { 2923 return FALSE; 2924 } 2925 2926 /* 2927 FUNCTION 2928 bfd_section_already_linked 2929 2930 SYNOPSIS 2931 void bfd_section_already_linked (bfd *abfd, asection *sec, 2932 struct bfd_link_info *info); 2933 2934 DESCRIPTION 2935 Check if @var{sec} has been already linked during a reloceatable 2936 or final link. 2937 2938 .#define bfd_section_already_linked(abfd, sec, info) \ 2939 . BFD_SEND (abfd, _section_already_linked, (abfd, sec, info)) 2940 . 2941 2942 */ 2943 2944 /* Sections marked with the SEC_LINK_ONCE flag should only be linked 2945 once into the output. This routine checks each section, and 2946 arrange to discard it if a section of the same name has already 2947 been linked. This code assumes that all relevant sections have the 2948 SEC_LINK_ONCE flag set; that is, it does not depend solely upon the 2949 section name. bfd_section_already_linked is called via 2950 bfd_map_over_sections. */ 2951 2952 /* The hash table. */ 2953 2954 static struct bfd_hash_table _bfd_section_already_linked_table; 2955 2956 /* Support routines for the hash table used by section_already_linked, 2957 initialize the table, traverse, lookup, fill in an entry and remove 2958 the table. */ 2959 2960 void 2961 bfd_section_already_linked_table_traverse 2962 (bfd_boolean (*func) (struct bfd_section_already_linked_hash_entry *, 2963 void *), void *info) 2964 { 2965 bfd_hash_traverse (&_bfd_section_already_linked_table, 2966 (bfd_boolean (*) (struct bfd_hash_entry *, 2967 void *)) func, 2968 info); 2969 } 2970 2971 struct bfd_section_already_linked_hash_entry * 2972 bfd_section_already_linked_table_lookup (const char *name) 2973 { 2974 return ((struct bfd_section_already_linked_hash_entry *) 2975 bfd_hash_lookup (&_bfd_section_already_linked_table, name, 2976 TRUE, FALSE)); 2977 } 2978 2979 bfd_boolean 2980 bfd_section_already_linked_table_insert 2981 (struct bfd_section_already_linked_hash_entry *already_linked_list, 2982 asection *sec) 2983 { 2984 struct bfd_section_already_linked *l; 2985 2986 /* Allocate the memory from the same obstack as the hash table is 2987 kept in. */ 2988 l = (struct bfd_section_already_linked *) 2989 bfd_hash_allocate (&_bfd_section_already_linked_table, sizeof *l); 2990 if (l == NULL) 2991 return FALSE; 2992 l->sec = sec; 2993 l->next = already_linked_list->entry; 2994 already_linked_list->entry = l; 2995 return TRUE; 2996 } 2997 2998 static struct bfd_hash_entry * 2999 already_linked_newfunc (struct bfd_hash_entry *entry ATTRIBUTE_UNUSED, 3000 struct bfd_hash_table *table, 3001 const char *string ATTRIBUTE_UNUSED) 3002 { 3003 struct bfd_section_already_linked_hash_entry *ret = 3004 (struct bfd_section_already_linked_hash_entry *) 3005 bfd_hash_allocate (table, sizeof *ret); 3006 3007 if (ret == NULL) 3008 return NULL; 3009 3010 ret->entry = NULL; 3011 3012 return &ret->root; 3013 } 3014 3015 bfd_boolean 3016 bfd_section_already_linked_table_init (void) 3017 { 3018 return bfd_hash_table_init_n (&_bfd_section_already_linked_table, 3019 already_linked_newfunc, 3020 sizeof (struct bfd_section_already_linked_hash_entry), 3021 42); 3022 } 3023 3024 void 3025 bfd_section_already_linked_table_free (void) 3026 { 3027 bfd_hash_table_free (&_bfd_section_already_linked_table); 3028 } 3029 3030 /* This is used on non-ELF inputs. */ 3031 3032 void 3033 _bfd_generic_section_already_linked (bfd *abfd, asection *sec, 3034 struct bfd_link_info *info) 3035 { 3036 flagword flags; 3037 const char *name; 3038 struct bfd_section_already_linked *l; 3039 struct bfd_section_already_linked_hash_entry *already_linked_list; 3040 3041 flags = sec->flags; 3042 if ((flags & SEC_LINK_ONCE) == 0) 3043 return; 3044 3045 /* FIXME: When doing a relocatable link, we may have trouble 3046 copying relocations in other sections that refer to local symbols 3047 in the section being discarded. Those relocations will have to 3048 be converted somehow; as of this writing I'm not sure that any of 3049 the backends handle that correctly. 3050 3051 It is tempting to instead not discard link once sections when 3052 doing a relocatable link (technically, they should be discarded 3053 whenever we are building constructors). However, that fails, 3054 because the linker winds up combining all the link once sections 3055 into a single large link once section, which defeats the purpose 3056 of having link once sections in the first place. */ 3057 3058 name = bfd_get_section_name (abfd, sec); 3059 3060 already_linked_list = bfd_section_already_linked_table_lookup (name); 3061 3062 for (l = already_linked_list->entry; l != NULL; l = l->next) 3063 { 3064 bfd_boolean skip = FALSE; 3065 struct coff_comdat_info *s_comdat 3066 = bfd_coff_get_comdat_section (abfd, sec); 3067 struct coff_comdat_info *l_comdat 3068 = bfd_coff_get_comdat_section (l->sec->owner, l->sec); 3069 3070 /* We may have 3 different sections on the list: group section, 3071 comdat section and linkonce section. SEC may be a linkonce or 3072 comdat section. We always ignore group section. For non-COFF 3073 inputs, we also ignore comdat section. 3074 3075 FIXME: Is that safe to match a linkonce section with a comdat 3076 section for COFF inputs? */ 3077 if ((l->sec->flags & SEC_GROUP) != 0) 3078 skip = TRUE; 3079 else if (bfd_get_flavour (abfd) == bfd_target_coff_flavour) 3080 { 3081 if (s_comdat != NULL 3082 && l_comdat != NULL 3083 && strcmp (s_comdat->name, l_comdat->name) != 0) 3084 skip = TRUE; 3085 } 3086 else if (l_comdat != NULL) 3087 skip = TRUE; 3088 3089 if (!skip) 3090 { 3091 /* The section has already been linked. See if we should 3092 issue a warning. */ 3093 switch (flags & SEC_LINK_DUPLICATES) 3094 { 3095 default: 3096 abort (); 3097 3098 case SEC_LINK_DUPLICATES_DISCARD: 3099 break; 3100 3101 case SEC_LINK_DUPLICATES_ONE_ONLY: 3102 (*_bfd_error_handler) 3103 (_("%B: warning: ignoring duplicate section `%A'\n"), 3104 abfd, sec); 3105 break; 3106 3107 case SEC_LINK_DUPLICATES_SAME_CONTENTS: 3108 /* FIXME: We should really dig out the contents of both 3109 sections and memcmp them. The COFF/PE spec says that 3110 the Microsoft linker does not implement this 3111 correctly, so I'm not going to bother doing it 3112 either. */ 3113 /* Fall through. */ 3114 case SEC_LINK_DUPLICATES_SAME_SIZE: 3115 if (sec->size != l->sec->size) 3116 (*_bfd_error_handler) 3117 (_("%B: warning: duplicate section `%A' has different size\n"), 3118 abfd, sec); 3119 break; 3120 } 3121 3122 /* Set the output_section field so that lang_add_section 3123 does not create a lang_input_section structure for this 3124 section. Since there might be a symbol in the section 3125 being discarded, we must retain a pointer to the section 3126 which we are really going to use. */ 3127 sec->output_section = bfd_abs_section_ptr; 3128 sec->kept_section = l->sec; 3129 3130 return; 3131 } 3132 } 3133 3134 /* This is the first section with this name. Record it. */ 3135 if (! bfd_section_already_linked_table_insert (already_linked_list, sec)) 3136 info->callbacks->einfo (_("%F%P: already_linked_table: %E\n")); 3137 } 3138 3139 /* Convert symbols in excluded output sections to use a kept section. */ 3140 3141 static bfd_boolean 3142 fix_syms (struct bfd_link_hash_entry *h, void *data) 3143 { 3144 bfd *obfd = (bfd *) data; 3145 3146 if (h->type == bfd_link_hash_warning) 3147 h = h->u.i.link; 3148 3149 if (h->type == bfd_link_hash_defined 3150 || h->type == bfd_link_hash_defweak) 3151 { 3152 asection *s = h->u.def.section; 3153 if (s != NULL 3154 && s->output_section != NULL 3155 && (s->output_section->flags & SEC_EXCLUDE) != 0 3156 && bfd_section_removed_from_list (obfd, s->output_section)) 3157 { 3158 asection *op, *op1; 3159 3160 h->u.def.value += s->output_offset + s->output_section->vma; 3161 3162 /* Find preceding kept section. */ 3163 for (op1 = s->output_section->prev; op1 != NULL; op1 = op1->prev) 3164 if ((op1->flags & SEC_EXCLUDE) == 0 3165 && !bfd_section_removed_from_list (obfd, op1)) 3166 break; 3167 3168 /* Find following kept section. Start at prev->next because 3169 other sections may have been added after S was removed. */ 3170 if (s->output_section->prev != NULL) 3171 op = s->output_section->prev->next; 3172 else 3173 op = s->output_section->owner->sections; 3174 for (; op != NULL; op = op->next) 3175 if ((op->flags & SEC_EXCLUDE) == 0 3176 && !bfd_section_removed_from_list (obfd, op)) 3177 break; 3178 3179 /* Choose better of two sections, based on flags. The idea 3180 is to choose a section that will be in the same segment 3181 as S would have been if it was kept. */ 3182 if (op1 == NULL) 3183 { 3184 if (op == NULL) 3185 op = bfd_abs_section_ptr; 3186 } 3187 else if (op == NULL) 3188 op = op1; 3189 else if (((op1->flags ^ op->flags) 3190 & (SEC_ALLOC | SEC_THREAD_LOCAL | SEC_LOAD)) != 0) 3191 { 3192 if (((op->flags ^ s->flags) 3193 & (SEC_ALLOC | SEC_THREAD_LOCAL)) != 0 3194 /* We prefer to choose a loaded section. Section S 3195 doesn't have SEC_LOAD set (it being excluded, that 3196 part of the flag processing didn't happen) so we 3197 can't compare that flag to those of OP and OP1. */ 3198 || ((op1->flags & SEC_LOAD) != 0 3199 && (op->flags & SEC_LOAD) == 0)) 3200 op = op1; 3201 } 3202 else if (((op1->flags ^ op->flags) & SEC_READONLY) != 0) 3203 { 3204 if (((op->flags ^ s->flags) & SEC_READONLY) != 0) 3205 op = op1; 3206 } 3207 else if (((op1->flags ^ op->flags) & SEC_CODE) != 0) 3208 { 3209 if (((op->flags ^ s->flags) & SEC_CODE) != 0) 3210 op = op1; 3211 } 3212 else 3213 { 3214 /* Flags we care about are the same. Prefer the following 3215 section if that will result in a positive valued sym. */ 3216 if (h->u.def.value < op->vma) 3217 op = op1; 3218 } 3219 3220 h->u.def.value -= op->vma; 3221 h->u.def.section = op; 3222 } 3223 } 3224 3225 return TRUE; 3226 } 3227 3228 void 3229 _bfd_fix_excluded_sec_syms (bfd *obfd, struct bfd_link_info *info) 3230 { 3231 bfd_link_hash_traverse (info->hash, fix_syms, obfd); 3232 } 3233 3234 /* 3235 FUNCTION 3236 bfd_generic_define_common_symbol 3237 3238 SYNOPSIS 3239 bfd_boolean bfd_generic_define_common_symbol 3240 (bfd *output_bfd, struct bfd_link_info *info, 3241 struct bfd_link_hash_entry *h); 3242 3243 DESCRIPTION 3244 Convert common symbol @var{h} into a defined symbol. 3245 Return TRUE on success and FALSE on failure. 3246 3247 .#define bfd_define_common_symbol(output_bfd, info, h) \ 3248 . BFD_SEND (output_bfd, _bfd_define_common_symbol, (output_bfd, info, h)) 3249 . 3250 */ 3251 3252 bfd_boolean 3253 bfd_generic_define_common_symbol (bfd *output_bfd, 3254 struct bfd_link_info *info ATTRIBUTE_UNUSED, 3255 struct bfd_link_hash_entry *h) 3256 { 3257 unsigned int power_of_two; 3258 bfd_vma alignment, size; 3259 asection *section; 3260 3261 BFD_ASSERT (h != NULL && h->type == bfd_link_hash_common); 3262 3263 size = h->u.c.size; 3264 power_of_two = h->u.c.p->alignment_power; 3265 section = h->u.c.p->section; 3266 3267 /* Increase the size of the section to align the common symbol. 3268 The alignment must be a power of two. */ 3269 alignment = bfd_octets_per_byte (output_bfd) << power_of_two; 3270 BFD_ASSERT (alignment != 0 && (alignment & -alignment) == alignment); 3271 section->size += alignment - 1; 3272 section->size &= -alignment; 3273 3274 /* Adjust the section's overall alignment if necessary. */ 3275 if (power_of_two > section->alignment_power) 3276 section->alignment_power = power_of_two; 3277 3278 /* Change the symbol from common to defined. */ 3279 h->type = bfd_link_hash_defined; 3280 h->u.def.section = section; 3281 h->u.def.value = section->size; 3282 3283 /* Increase the size of the section. */ 3284 section->size += size; 3285 3286 /* Make sure the section is allocated in memory, and make sure that 3287 it is no longer a common section. */ 3288 section->flags |= SEC_ALLOC; 3289 section->flags &= ~SEC_IS_COMMON; 3290 return TRUE; 3291 } 3292 3293 /* 3294 FUNCTION 3295 bfd_find_version_for_sym 3296 3297 SYNOPSIS 3298 struct bfd_elf_version_tree * bfd_find_version_for_sym 3299 (struct bfd_elf_version_tree *verdefs, 3300 const char *sym_name, bfd_boolean *hide); 3301 3302 DESCRIPTION 3303 Search an elf version script tree for symbol versioning 3304 info and export / don't-export status for a given symbol. 3305 Return non-NULL on success and NULL on failure; also sets 3306 the output @samp{hide} boolean parameter. 3307 3308 */ 3309 3310 struct bfd_elf_version_tree * 3311 bfd_find_version_for_sym (struct bfd_elf_version_tree *verdefs, 3312 const char *sym_name, 3313 bfd_boolean *hide) 3314 { 3315 struct bfd_elf_version_tree *t; 3316 struct bfd_elf_version_tree *local_ver, *global_ver, *exist_ver; 3317 struct bfd_elf_version_tree *star_local_ver, *star_global_ver; 3318 3319 local_ver = NULL; 3320 global_ver = NULL; 3321 star_local_ver = NULL; 3322 star_global_ver = NULL; 3323 exist_ver = NULL; 3324 for (t = verdefs; t != NULL; t = t->next) 3325 { 3326 if (t->globals.list != NULL) 3327 { 3328 struct bfd_elf_version_expr *d = NULL; 3329 3330 while ((d = (*t->match) (&t->globals, d, sym_name)) != NULL) 3331 { 3332 if (d->literal || strcmp (d->pattern, "*") != 0) 3333 global_ver = t; 3334 else 3335 star_global_ver = t; 3336 if (d->symver) 3337 exist_ver = t; 3338 d->script = 1; 3339 /* If the match is a wildcard pattern, keep looking for 3340 a more explicit, perhaps even local, match. */ 3341 if (d->literal) 3342 break; 3343 } 3344 3345 if (d != NULL) 3346 break; 3347 } 3348 3349 if (t->locals.list != NULL) 3350 { 3351 struct bfd_elf_version_expr *d = NULL; 3352 3353 while ((d = (*t->match) (&t->locals, d, sym_name)) != NULL) 3354 { 3355 if (d->literal || strcmp (d->pattern, "*") != 0) 3356 local_ver = t; 3357 else 3358 star_local_ver = t; 3359 /* If the match is a wildcard pattern, keep looking for 3360 a more explicit, perhaps even global, match. */ 3361 if (d->literal) 3362 { 3363 /* An exact match overrides a global wildcard. */ 3364 global_ver = NULL; 3365 star_global_ver = NULL; 3366 break; 3367 } 3368 } 3369 3370 if (d != NULL) 3371 break; 3372 } 3373 } 3374 3375 if (global_ver == NULL && local_ver == NULL) 3376 global_ver = star_global_ver; 3377 3378 if (global_ver != NULL) 3379 { 3380 /* If we already have a versioned symbol that matches the 3381 node for this symbol, then we don't want to create a 3382 duplicate from the unversioned symbol. Instead hide the 3383 unversioned symbol. */ 3384 *hide = exist_ver == global_ver; 3385 return global_ver; 3386 } 3387 3388 if (local_ver == NULL) 3389 local_ver = star_local_ver; 3390 3391 if (local_ver != NULL) 3392 { 3393 *hide = TRUE; 3394 return local_ver; 3395 } 3396 3397 return NULL; 3398 } 3399