1 // reloc.h -- relocate input files for gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
27 #ifdef HAVE_BYTESWAP_H
32 #include "workqueue.h"
37 class General_options
;
40 class Read_relocs_data
;
49 template<int size
, bool big_endian
>
55 template<int sh_type
, bool dynamic
, int size
, bool big_endian
>
56 class Output_data_reloc
;
58 // A class to read the relocations for an object file, and then queue
59 // up a task to see if they require any GOT/PLT/COPY relocations in
62 class Read_relocs
: public Task
65 // THIS_BLOCKER and NEXT_BLOCKER are passed along to a Scan_relocs
66 // or Gc_process_relocs task, so that they run in a deterministic
68 Read_relocs(Symbol_table
* symtab
, Layout
* layout
, Relobj
* object
,
69 Task_token
* this_blocker
, Task_token
* next_blocker
)
70 : symtab_(symtab
), layout_(layout
), object_(object
),
71 this_blocker_(this_blocker
), next_blocker_(next_blocker
)
74 // The standard Task methods.
89 Symbol_table
* symtab_
;
92 Task_token
* this_blocker_
;
93 Task_token
* next_blocker_
;
96 // Process the relocs to figure out which sections are garbage.
97 // Very similar to scan relocs.
99 class Gc_process_relocs
: public Task
102 // THIS_BLOCKER prevents this task from running until the previous
103 // one is finished. NEXT_BLOCKER prevents the next task from
105 Gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Relobj
* object
,
106 Read_relocs_data
* rd
, Task_token
* this_blocker
,
107 Task_token
* next_blocker
)
108 : symtab_(symtab
), layout_(layout
), object_(object
), rd_(rd
),
109 this_blocker_(this_blocker
), next_blocker_(next_blocker
)
112 ~Gc_process_relocs();
114 // The standard Task methods.
129 Symbol_table
* symtab_
;
132 Read_relocs_data
* rd_
;
133 Task_token
* this_blocker_
;
134 Task_token
* next_blocker_
;
137 // Scan the relocations for an object to see if they require any
138 // GOT/PLT/COPY relocations.
140 class Scan_relocs
: public Task
143 // THIS_BLOCKER prevents this task from running until the previous
144 // one is finished. NEXT_BLOCKER prevents the next task from
146 Scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Relobj
* object
,
147 Read_relocs_data
* rd
, Task_token
* this_blocker
,
148 Task_token
* next_blocker
)
149 : symtab_(symtab
), layout_(layout
), object_(object
), rd_(rd
),
150 this_blocker_(this_blocker
), next_blocker_(next_blocker
)
155 // The standard Task methods.
170 Symbol_table
* symtab_
;
173 Read_relocs_data
* rd_
;
174 Task_token
* this_blocker_
;
175 Task_token
* next_blocker_
;
178 // A class to perform all the relocations for an object file.
180 class Relocate_task
: public Task
183 Relocate_task(const Symbol_table
* symtab
, const Layout
* layout
,
184 Relobj
* object
, Output_file
* of
,
185 Task_token
* input_sections_blocker
,
186 Task_token
* output_sections_blocker
, Task_token
* final_blocker
)
187 : symtab_(symtab
), layout_(layout
), object_(object
), of_(of
),
188 input_sections_blocker_(input_sections_blocker
),
189 output_sections_blocker_(output_sections_blocker
),
190 final_blocker_(final_blocker
)
193 // The standard Task methods.
208 const Symbol_table
* symtab_
;
209 const Layout
* layout_
;
212 Task_token
* input_sections_blocker_
;
213 Task_token
* output_sections_blocker_
;
214 Task_token
* final_blocker_
;
217 // During a relocatable link, this class records how relocations
218 // should be handled for a single input reloc section. An instance of
219 // this class is created while scanning relocs, and it is used while
220 // processing relocs.
222 class Relocatable_relocs
225 // We use a vector of unsigned char to indicate how the input relocs
226 // should be handled. Each element is one of the following values.
227 // We create this vector when we initially scan the relocations.
230 // Copy the input reloc. Don't modify it other than updating the
231 // r_offset field and the r_sym part of the r_info field.
233 // Copy the input reloc which is against an STT_SECTION symbol.
234 // Update the r_offset and r_sym part of the r_info field. Adjust
235 // the addend by subtracting the value of the old local symbol and
236 // adding the value of the new local symbol. The addend is in the
237 // SHT_RELA reloc and the contents of the data section do not need
239 RELOC_ADJUST_FOR_SECTION_RELA
,
240 // Like RELOC_ADJUST_FOR_SECTION_RELA but the addend should not be
242 RELOC_ADJUST_FOR_SECTION_0
,
243 // Like RELOC_ADJUST_FOR_SECTION_RELA but the contents of the
244 // section need to be changed. The number indicates the number of
245 // bytes in the addend in the section contents.
246 RELOC_ADJUST_FOR_SECTION_1
,
247 RELOC_ADJUST_FOR_SECTION_2
,
248 RELOC_ADJUST_FOR_SECTION_4
,
249 RELOC_ADJUST_FOR_SECTION_8
,
250 // Discard the input reloc--process it completely when relocating
251 // the data section contents.
253 // An input reloc which is not discarded, but which requires
254 // target specific processing in order to update it.
259 : reloc_strategies_(), output_reloc_count_(0), posd_(NULL
)
262 // Record the number of relocs.
264 set_reloc_count(size_t reloc_count
)
265 { this->reloc_strategies_
.reserve(reloc_count
); }
267 // Record what to do for the next reloc.
269 set_next_reloc_strategy(Reloc_strategy strategy
)
271 this->reloc_strategies_
.push_back(static_cast<unsigned char>(strategy
));
272 if (strategy
!= RELOC_DISCARD
)
273 ++this->output_reloc_count_
;
276 // Record the Output_data associated with this reloc section.
278 set_output_data(Output_data
* posd
)
280 gold_assert(this->posd_
== NULL
);
284 // Return the Output_data associated with this reloc section.
287 { return this->posd_
; }
289 // Return what to do for reloc I.
291 strategy(unsigned int i
) const
293 gold_assert(i
< this->reloc_strategies_
.size());
294 return static_cast<Reloc_strategy
>(this->reloc_strategies_
[i
]);
297 // Return the number of relocations to create in the output file.
299 output_reloc_count() const
300 { return this->output_reloc_count_
; }
303 typedef std::vector
<unsigned char> Reloc_strategies
;
305 // The strategies for the input reloc. There is one entry in this
306 // vector for each relocation in the input section.
307 Reloc_strategies reloc_strategies_
;
308 // The number of relocations to be created in the output file.
309 size_t output_reloc_count_
;
310 // The output data structure associated with this relocation.
314 // Standard relocation routines which are used on many targets. Here
315 // SIZE and BIG_ENDIAN refer to the target, not the relocation type.
317 template<int size
, bool big_endian
>
318 class Relocate_functions
321 // Do a simple relocation with the addend in the section contents.
322 // VALSIZE is the size of the value.
323 template<int valsize
>
325 rel(unsigned char* view
,
326 typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype value
)
328 typedef typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype Valtype
;
329 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
330 Valtype x
= elfcpp::Swap
<valsize
, big_endian
>::readval(wv
);
331 elfcpp::Swap
<valsize
, big_endian
>::writeval(wv
, x
+ value
);
334 // Do a simple relocation using a Symbol_value with the addend in
335 // the section contents. VALSIZE is the size of the value to
337 template<int valsize
>
339 rel(unsigned char* view
,
340 const Sized_relobj
<size
, big_endian
>* object
,
341 const Symbol_value
<size
>* psymval
)
343 typedef typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype Valtype
;
344 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
345 Valtype x
= elfcpp::Swap
<valsize
, big_endian
>::readval(wv
);
346 x
= psymval
->value(object
, x
);
347 elfcpp::Swap
<valsize
, big_endian
>::writeval(wv
, x
);
350 // Do a simple relocation with the addend in the relocation.
351 // VALSIZE is the size of the value.
352 template<int valsize
>
354 rela(unsigned char* view
,
355 typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype value
,
356 typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype addend
)
358 typedef typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype Valtype
;
359 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
360 elfcpp::Swap
<valsize
, big_endian
>::writeval(wv
, value
+ addend
);
363 // Do a simple relocation using a symbol value with the addend in
364 // the relocation. VALSIZE is the size of the value.
365 template<int valsize
>
367 rela(unsigned char* view
,
368 const Sized_relobj
<size
, big_endian
>* object
,
369 const Symbol_value
<size
>* psymval
,
370 typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype addend
)
372 typedef typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype Valtype
;
373 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
374 Valtype x
= psymval
->value(object
, addend
);
375 elfcpp::Swap
<valsize
, big_endian
>::writeval(wv
, x
);
378 // Do a simple PC relative relocation with the addend in the section
379 // contents. VALSIZE is the size of the value.
380 template<int valsize
>
382 pcrel(unsigned char* view
,
383 typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype value
,
384 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
386 typedef typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype Valtype
;
387 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
388 Valtype x
= elfcpp::Swap
<valsize
, big_endian
>::readval(wv
);
389 elfcpp::Swap
<valsize
, big_endian
>::writeval(wv
, x
+ value
- address
);
392 // Do a simple PC relative relocation with a Symbol_value with the
393 // addend in the section contents. VALSIZE is the size of the
395 template<int valsize
>
397 pcrel(unsigned char* view
,
398 const Sized_relobj
<size
, big_endian
>* object
,
399 const Symbol_value
<size
>* psymval
,
400 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
402 typedef typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype Valtype
;
403 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
404 Valtype x
= elfcpp::Swap
<valsize
, big_endian
>::readval(wv
);
405 x
= psymval
->value(object
, x
);
406 elfcpp::Swap
<valsize
, big_endian
>::writeval(wv
, x
- address
);
409 // Do a simple PC relative relocation with the addend in the
410 // relocation. VALSIZE is the size of the value.
411 template<int valsize
>
413 pcrela(unsigned char* view
,
414 typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype value
,
415 typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype addend
,
416 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
418 typedef typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype Valtype
;
419 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
420 elfcpp::Swap
<valsize
, big_endian
>::writeval(wv
, value
+ addend
- address
);
423 // Do a simple PC relative relocation with a Symbol_value with the
424 // addend in the relocation. VALSIZE is the size of the value.
425 template<int valsize
>
427 pcrela(unsigned char* view
,
428 const Sized_relobj
<size
, big_endian
>* object
,
429 const Symbol_value
<size
>* psymval
,
430 typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype addend
,
431 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
433 typedef typename
elfcpp::Swap
<valsize
, big_endian
>::Valtype Valtype
;
434 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
435 Valtype x
= psymval
->value(object
, addend
);
436 elfcpp::Swap
<valsize
, big_endian
>::writeval(wv
, x
- address
);
439 typedef Relocate_functions
<size
, big_endian
> This
;
442 // Do a simple 8-bit REL relocation with the addend in the section
445 rel8(unsigned char* view
, unsigned char value
)
446 { This::template rel
<8>(view
, value
); }
449 rel8(unsigned char* view
,
450 const Sized_relobj
<size
, big_endian
>* object
,
451 const Symbol_value
<size
>* psymval
)
452 { This::template rel
<8>(view
, object
, psymval
); }
454 // Do an 8-bit RELA relocation with the addend in the relocation.
456 rela8(unsigned char* view
, unsigned char value
, unsigned char addend
)
457 { This::template rela
<8>(view
, value
, addend
); }
460 rela8(unsigned char* view
,
461 const Sized_relobj
<size
, big_endian
>* object
,
462 const Symbol_value
<size
>* psymval
,
463 unsigned char addend
)
464 { This::template rela
<8>(view
, object
, psymval
, addend
); }
466 // Do a simple 8-bit PC relative relocation with the addend in the
469 pcrel8(unsigned char* view
, unsigned char value
,
470 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
471 { This::template pcrel
<8>(view
, value
, address
); }
474 pcrel8(unsigned char* view
,
475 const Sized_relobj
<size
, big_endian
>* object
,
476 const Symbol_value
<size
>* psymval
,
477 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
478 { This::template pcrel
<8>(view
, object
, psymval
, address
); }
480 // Do a simple 8-bit PC relative RELA relocation with the addend in
483 pcrela8(unsigned char* view
, unsigned char value
, unsigned char addend
,
484 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
485 { This::template pcrela
<8>(view
, value
, addend
, address
); }
488 pcrela8(unsigned char* view
,
489 const Sized_relobj
<size
, big_endian
>* object
,
490 const Symbol_value
<size
>* psymval
,
491 unsigned char addend
,
492 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
493 { This::template pcrela
<8>(view
, object
, psymval
, addend
, address
); }
495 // Do a simple 16-bit REL relocation with the addend in the section
498 rel16(unsigned char* view
, elfcpp::Elf_Half value
)
499 { This::template rel
<16>(view
, value
); }
502 rel16(unsigned char* view
,
503 const Sized_relobj
<size
, big_endian
>* object
,
504 const Symbol_value
<size
>* psymval
)
505 { This::template rel
<16>(view
, object
, psymval
); }
507 // Do an 16-bit RELA relocation with the addend in the relocation.
509 rela16(unsigned char* view
, elfcpp::Elf_Half value
, elfcpp::Elf_Half addend
)
510 { This::template rela
<16>(view
, value
, addend
); }
513 rela16(unsigned char* view
,
514 const Sized_relobj
<size
, big_endian
>* object
,
515 const Symbol_value
<size
>* psymval
,
516 elfcpp::Elf_Half addend
)
517 { This::template rela
<16>(view
, object
, psymval
, addend
); }
519 // Do a simple 16-bit PC relative REL relocation with the addend in
520 // the section contents.
522 pcrel16(unsigned char* view
, elfcpp::Elf_Half value
,
523 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
524 { This::template pcrel
<16>(view
, value
, address
); }
527 pcrel16(unsigned char* view
,
528 const Sized_relobj
<size
, big_endian
>* object
,
529 const Symbol_value
<size
>* psymval
,
530 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
531 { This::template pcrel
<16>(view
, object
, psymval
, address
); }
533 // Do a simple 16-bit PC relative RELA relocation with the addend in
536 pcrela16(unsigned char* view
, elfcpp::Elf_Half value
,
537 elfcpp::Elf_Half addend
,
538 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
539 { This::template pcrela
<16>(view
, value
, addend
, address
); }
542 pcrela16(unsigned char* view
,
543 const Sized_relobj
<size
, big_endian
>* object
,
544 const Symbol_value
<size
>* psymval
,
545 elfcpp::Elf_Half addend
,
546 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
547 { This::template pcrela
<16>(view
, object
, psymval
, addend
, address
); }
549 // Do a simple 32-bit REL relocation with the addend in the section
552 rel32(unsigned char* view
, elfcpp::Elf_Word value
)
553 { This::template rel
<32>(view
, value
); }
556 rel32(unsigned char* view
,
557 const Sized_relobj
<size
, big_endian
>* object
,
558 const Symbol_value
<size
>* psymval
)
559 { This::template rel
<32>(view
, object
, psymval
); }
561 // Do an 32-bit RELA relocation with the addend in the relocation.
563 rela32(unsigned char* view
, elfcpp::Elf_Word value
, elfcpp::Elf_Word addend
)
564 { This::template rela
<32>(view
, value
, addend
); }
567 rela32(unsigned char* view
,
568 const Sized_relobj
<size
, big_endian
>* object
,
569 const Symbol_value
<size
>* psymval
,
570 elfcpp::Elf_Word addend
)
571 { This::template rela
<32>(view
, object
, psymval
, addend
); }
573 // Do a simple 32-bit PC relative REL relocation with the addend in
574 // the section contents.
576 pcrel32(unsigned char* view
, elfcpp::Elf_Word value
,
577 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
578 { This::template pcrel
<32>(view
, value
, address
); }
581 pcrel32(unsigned char* view
,
582 const Sized_relobj
<size
, big_endian
>* object
,
583 const Symbol_value
<size
>* psymval
,
584 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
585 { This::template pcrel
<32>(view
, object
, psymval
, address
); }
587 // Do a simple 32-bit PC relative RELA relocation with the addend in
590 pcrela32(unsigned char* view
, elfcpp::Elf_Word value
,
591 elfcpp::Elf_Word addend
,
592 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
593 { This::template pcrela
<32>(view
, value
, addend
, address
); }
596 pcrela32(unsigned char* view
,
597 const Sized_relobj
<size
, big_endian
>* object
,
598 const Symbol_value
<size
>* psymval
,
599 elfcpp::Elf_Word addend
,
600 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
601 { This::template pcrela
<32>(view
, object
, psymval
, addend
, address
); }
603 // Do a simple 64-bit REL relocation with the addend in the section
606 rel64(unsigned char* view
, elfcpp::Elf_Xword value
)
607 { This::template rel
<64>(view
, value
); }
610 rel64(unsigned char* view
,
611 const Sized_relobj
<size
, big_endian
>* object
,
612 const Symbol_value
<size
>* psymval
)
613 { This::template rel
<64>(view
, object
, psymval
); }
615 // Do a 64-bit RELA relocation with the addend in the relocation.
617 rela64(unsigned char* view
, elfcpp::Elf_Xword value
,
618 elfcpp::Elf_Xword addend
)
619 { This::template rela
<64>(view
, value
, addend
); }
622 rela64(unsigned char* view
,
623 const Sized_relobj
<size
, big_endian
>* object
,
624 const Symbol_value
<size
>* psymval
,
625 elfcpp::Elf_Xword addend
)
626 { This::template rela
<64>(view
, object
, psymval
, addend
); }
628 // Do a simple 64-bit PC relative REL relocation with the addend in
629 // the section contents.
631 pcrel64(unsigned char* view
, elfcpp::Elf_Xword value
,
632 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
633 { This::template pcrel
<64>(view
, value
, address
); }
636 pcrel64(unsigned char* view
,
637 const Sized_relobj
<size
, big_endian
>* object
,
638 const Symbol_value
<size
>* psymval
,
639 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
640 { This::template pcrel
<64>(view
, object
, psymval
, address
); }
642 // Do a simple 64-bit PC relative RELA relocation with the addend in
645 pcrela64(unsigned char* view
, elfcpp::Elf_Xword value
,
646 elfcpp::Elf_Xword addend
,
647 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
648 { This::template pcrela
<64>(view
, value
, addend
, address
); }
651 pcrela64(unsigned char* view
,
652 const Sized_relobj
<size
, big_endian
>* object
,
653 const Symbol_value
<size
>* psymval
,
654 elfcpp::Elf_Xword addend
,
655 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
)
656 { This::template pcrela
<64>(view
, object
, psymval
, addend
, address
); }
659 // Track relocations while reading a section. This lets you ask for
660 // the relocation at a certain offset, and see how relocs occur
661 // between points of interest.
663 template<int size
, bool big_endian
>
668 : prelocs_(NULL
), len_(0), pos_(0), reloc_size_(0)
671 // Initialize the Track_relocs object. OBJECT is the object holding
672 // the reloc section, RELOC_SHNDX is the section index of the reloc
673 // section, and RELOC_TYPE is the type of the reloc section
674 // (elfcpp::SHT_REL or elfcpp::SHT_RELA). This returns false if
675 // something went wrong.
677 initialize(Object
* object
, unsigned int reloc_shndx
,
678 unsigned int reloc_type
);
680 // Return the offset in the data section to which the next reloc
681 // applies. THis returns -1 if there is no next reloc.
685 // Return the symbol index of the next reloc. This returns -1U if
686 // there is no next reloc.
690 // Advance to OFFSET within the data section, and return the number
691 // of relocs which would be skipped.
693 advance(off_t offset
);
696 // The contents of the input object's reloc section.
697 const unsigned char* prelocs_
;
698 // The length of the reloc section.
699 section_size_type len_
;
700 // Our current position in the reloc section.
701 section_size_type pos_
;
702 // The size of the relocs in the section.
706 } // End namespace gold.
708 #endif // !defined(GOLD_RELOC_H)