1 // target-reloc.h -- target specific relocation support -*- C++ -*-
3 // Copyright (C) 2006-2016 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.
23 #ifndef GOLD_TARGET_RELOC_H
24 #define GOLD_TARGET_RELOC_H
30 #include "reloc-types.h"
35 // This function implements the generic part of reloc scanning. The
36 // template parameter Scan must be a class type which provides two
37 // functions: local() and global(). Those functions implement the
38 // machine specific part of scanning. We do it this way to
39 // avoid making a function call for each relocation, and to avoid
40 // repeating the generic code for each target.
42 template<int size
, bool big_endian
, typename Target_type
,
43 typename Scan
, typename Classify_reloc
>
49 Sized_relobj_file
<size
, big_endian
>* object
,
50 unsigned int data_shndx
,
51 const unsigned char* prelocs
,
53 Output_section
* output_section
,
54 bool needs_special_offset_handling
,
56 const unsigned char* plocal_syms
)
58 typedef typename
Classify_reloc::Reltype Reltype
;
59 const int reloc_size
= Classify_reloc::reloc_size
;
60 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
63 for (size_t i
= 0; i
< reloc_count
; ++i
, prelocs
+= reloc_size
)
65 Reltype
reloc(prelocs
);
67 if (needs_special_offset_handling
68 && !output_section
->is_input_address_mapped(object
, data_shndx
,
69 reloc
.get_r_offset()))
72 unsigned int r_sym
= Classify_reloc::get_r_sym(&reloc
);
73 unsigned int r_type
= Classify_reloc::get_r_type(&reloc
);
75 if (r_sym
< local_count
)
77 gold_assert(plocal_syms
!= NULL
);
78 typename
elfcpp::Sym
<size
, big_endian
> lsym(plocal_syms
80 unsigned int shndx
= lsym
.get_st_shndx();
82 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
83 // If RELOC is a relocation against a local symbol in a
84 // section we are discarding then we can ignore it. It will
85 // eventually become a reloc against the value zero.
87 // FIXME: We should issue a warning if this is an
88 // allocated section; is this the best place to do it?
90 // FIXME: The old GNU linker would in some cases look
91 // for the linkonce section which caused this section to
92 // be discarded, and, if the other section was the same
93 // size, change the reloc to refer to the other section.
94 // That seems risky and weird to me, and I don't know of
95 // any case where it is actually required.
96 bool is_discarded
= (is_ordinary
97 && shndx
!= elfcpp::SHN_UNDEF
98 && !object
->is_section_included(shndx
)
99 && !symtab
->is_section_folded(object
, shndx
));
100 scan
.local(symtab
, layout
, target
, object
, data_shndx
,
101 output_section
, reloc
, r_type
, lsym
, is_discarded
);
105 Symbol
* gsym
= object
->global_symbol(r_sym
);
106 gold_assert(gsym
!= NULL
);
107 if (gsym
->is_forwarder())
108 gsym
= symtab
->resolve_forwards(gsym
);
110 scan
.global(symtab
, layout
, target
, object
, data_shndx
,
111 output_section
, reloc
, r_type
, gsym
);
116 // Behavior for relocations to discarded comdat sections.
120 CB_UNDETERMINED
, // Not yet determined -- need to look at section name.
121 CB_PRETEND
, // Attempt to map to the corresponding kept section.
122 CB_IGNORE
, // Ignore the relocation.
123 CB_WARNING
// Print a warning.
126 class Default_comdat_behavior
129 // Decide what the linker should do for relocations that refer to
130 // discarded comdat sections. This decision is based on the name of
131 // the section being relocated.
133 inline Comdat_behavior
134 get(const char* name
)
136 if (Layout::is_debug_info_section(name
))
138 if (strcmp(name
, ".eh_frame") == 0
139 || strcmp(name
, ".gcc_except_table") == 0)
145 // Give an error for a symbol with non-default visibility which is not
149 visibility_error(const Symbol
* sym
)
152 switch (sym
->visibility())
154 case elfcpp::STV_INTERNAL
:
157 case elfcpp::STV_HIDDEN
:
160 case elfcpp::STV_PROTECTED
:
166 gold_error(_("%s symbol '%s' is not defined locally"),
170 // Return true if we are should issue an error saying that SYM is an
171 // undefined symbol. This is called if there is a relocation against
175 issue_undefined_symbol_error(const Symbol
* sym
)
177 // We only report global symbols.
181 // We only report undefined symbols.
182 if (!sym
->is_undefined() && !sym
->is_placeholder())
185 // We don't report weak symbols.
186 if (sym
->is_weak_undefined())
189 // We don't report symbols defined in discarded sections.
190 if (sym
->is_defined_in_discarded_section())
193 // If the target defines this symbol, don't report it here.
194 if (parameters
->target().is_defined_by_abi(sym
))
197 // See if we've been told to ignore whether this symbol is
199 const char* const u
= parameters
->options().unresolved_symbols();
202 if (strcmp(u
, "ignore-all") == 0)
204 if (strcmp(u
, "report-all") == 0)
206 if (strcmp(u
, "ignore-in-object-files") == 0 && !sym
->in_dyn())
208 if (strcmp(u
, "ignore-in-shared-libs") == 0 && !sym
->in_reg())
212 // If the symbol is hidden, report it.
213 if (sym
->visibility() == elfcpp::STV_HIDDEN
)
216 // When creating a shared library, only report unresolved symbols if
218 if (parameters
->options().shared() && !parameters
->options().defs())
221 // Otherwise issue a warning.
225 // This function implements the generic part of relocation processing.
226 // The template parameter Relocate must be a class type which provides
227 // a single function, relocate(), which implements the machine
228 // specific part of a relocation.
230 // The template parameter Relocate_comdat_behavior is a class type
231 // which provides a single function, get(), which determines what the
232 // linker should do for relocations that refer to discarded comdat
235 // SIZE is the ELF size: 32 or 64. BIG_ENDIAN is the endianness of
236 // the data. SH_TYPE is the section type: SHT_REL or SHT_RELA.
237 // RELOCATE implements operator() to do a relocation.
239 // PRELOCS points to the relocation data. RELOC_COUNT is the number
240 // of relocs. OUTPUT_SECTION is the output section.
241 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
242 // mapped to output offsets.
244 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
245 // VIEW_SIZE is the size. These refer to the input section, unless
246 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
247 // the output section.
249 // RELOC_SYMBOL_CHANGES is used for -fsplit-stack support. If it is
250 // not NULL, it is a vector indexed by relocation index. If that
251 // entry is not NULL, it points to a global symbol which used as the
252 // symbol for the relocation, ignoring the symbol index in the
255 template<int size
, bool big_endian
, typename Target_type
,
257 typename Relocate_comdat_behavior
,
258 typename Classify_reloc
>
261 const Relocate_info
<size
, big_endian
>* relinfo
,
263 const unsigned char* prelocs
,
265 Output_section
* output_section
,
266 bool needs_special_offset_handling
,
268 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
269 section_size_type view_size
,
270 const Reloc_symbol_changes
* reloc_symbol_changes
)
272 typedef typename
Classify_reloc::Reltype Reltype
;
273 const int reloc_size
= Classify_reloc::reloc_size
;
275 Relocate_comdat_behavior relocate_comdat_behavior
;
277 Sized_relobj_file
<size
, big_endian
>* object
= relinfo
->object
;
278 unsigned int local_count
= object
->local_symbol_count();
280 Comdat_behavior comdat_behavior
= CB_UNDETERMINED
;
282 for (size_t i
= 0; i
< reloc_count
; ++i
, prelocs
+= reloc_size
)
284 Reltype
reloc(prelocs
);
286 section_offset_type offset
=
287 convert_to_section_size_type(reloc
.get_r_offset());
289 if (needs_special_offset_handling
)
291 offset
= output_section
->output_offset(relinfo
->object
,
298 unsigned int r_sym
= Classify_reloc::get_r_sym(&reloc
);
300 const Sized_symbol
<size
>* sym
;
302 Symbol_value
<size
> symval
;
303 const Symbol_value
<size
> *psymval
;
304 bool is_defined_in_discarded_section
;
306 if (r_sym
< local_count
307 && (reloc_symbol_changes
== NULL
308 || (*reloc_symbol_changes
)[i
] == NULL
))
311 psymval
= object
->local_symbol(r_sym
);
313 // If the local symbol belongs to a section we are discarding,
314 // and that section is a debug section, try to find the
315 // corresponding kept section and map this symbol to its
316 // counterpart in the kept section. The symbol must not
317 // correspond to a section we are folding.
319 shndx
= psymval
->input_shndx(&is_ordinary
);
320 is_defined_in_discarded_section
=
322 && shndx
!= elfcpp::SHN_UNDEF
323 && !object
->is_section_included(shndx
)
324 && !relinfo
->symtab
->is_section_folded(object
, shndx
));
329 if (reloc_symbol_changes
!= NULL
330 && (*reloc_symbol_changes
)[i
] != NULL
)
331 gsym
= (*reloc_symbol_changes
)[i
];
334 gsym
= object
->global_symbol(r_sym
);
335 gold_assert(gsym
!= NULL
);
336 if (gsym
->is_forwarder())
337 gsym
= relinfo
->symtab
->resolve_forwards(gsym
);
340 sym
= static_cast<const Sized_symbol
<size
>*>(gsym
);
341 if (sym
->has_symtab_index() && sym
->symtab_index() != -1U)
342 symval
.set_output_symtab_index(sym
->symtab_index());
344 symval
.set_no_output_symtab_entry();
345 symval
.set_output_value(sym
->value());
346 if (gsym
->type() == elfcpp::STT_TLS
)
347 symval
.set_is_tls_symbol();
348 else if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
349 symval
.set_is_ifunc_symbol();
352 is_defined_in_discarded_section
=
353 (gsym
->is_defined_in_discarded_section()
354 && gsym
->is_undefined());
358 Symbol_value
<size
> symval2
;
359 if (is_defined_in_discarded_section
)
361 if (comdat_behavior
== CB_UNDETERMINED
)
363 std::string name
= object
->section_name(relinfo
->data_shndx
);
364 comdat_behavior
= relocate_comdat_behavior
.get(name
.c_str());
366 if (comdat_behavior
== CB_PRETEND
)
368 // FIXME: This case does not work for global symbols.
369 // We have no place to store the original section index.
370 // Fortunately this does not matter for comdat sections,
371 // only for sections explicitly discarded by a linker
374 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
=
375 object
->map_to_kept_section(shndx
, &found
);
377 symval2
.set_output_value(value
+ psymval
->input_value());
379 symval2
.set_output_value(0);
383 if (comdat_behavior
== CB_WARNING
)
384 gold_warning_at_location(relinfo
, i
, offset
,
385 _("relocation refers to discarded "
387 symval2
.set_output_value(0);
389 symval2
.set_no_output_symtab_entry();
393 // If OFFSET is out of range, still let the target decide to
394 // ignore the relocation. Pass in NULL as the VIEW argument so
395 // that it can return quickly without trashing an invalid memory
397 unsigned char *v
= view
+ offset
;
398 if (offset
< 0 || static_cast<section_size_type
>(offset
) >= view_size
)
401 if (!relocate
.relocate(relinfo
, Classify_reloc::sh_type
, target
,
402 output_section
, i
, prelocs
, sym
, psymval
,
403 v
, view_address
+ offset
, view_size
))
408 gold_error_at_location(relinfo
, i
, offset
,
409 _("reloc has bad offset %zu"),
410 static_cast<size_t>(offset
));
414 if (issue_undefined_symbol_error(sym
))
415 gold_undefined_symbol_at_location(sym
, relinfo
, i
, offset
);
417 && sym
->visibility() != elfcpp::STV_DEFAULT
418 && (sym
->is_strong_undefined() || sym
->is_from_dynobj()))
419 visibility_error(sym
);
421 if (sym
!= NULL
&& sym
->has_warning())
422 relinfo
->symtab
->issue_warning(sym
, relinfo
, i
, offset
);
426 // Apply an incremental relocation.
428 template<int size
, bool big_endian
, typename Target_type
,
431 apply_relocation(const Relocate_info
<size
, big_endian
>* relinfo
,
433 typename
elfcpp::Elf_types
<size
>::Elf_Addr r_offset
,
435 typename
elfcpp::Elf_types
<size
>::Elf_Swxword r_addend
,
438 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
,
439 section_size_type view_size
)
441 // Construct the ELF relocation in a temporary buffer.
442 const int reloc_size
= elfcpp::Elf_sizes
<size
>::rela_size
;
443 unsigned char relbuf
[reloc_size
];
444 elfcpp::Rela_write
<size
, big_endian
> orel(relbuf
);
445 orel
.put_r_offset(r_offset
);
446 orel
.put_r_info(elfcpp::elf_r_info
<size
>(0, r_type
));
447 orel
.put_r_addend(r_addend
);
449 // Setup a Symbol_value for the global symbol.
450 const Sized_symbol
<size
>* sym
= static_cast<const Sized_symbol
<size
>*>(gsym
);
451 Symbol_value
<size
> symval
;
452 gold_assert(sym
->has_symtab_index() && sym
->symtab_index() != -1U);
453 symval
.set_output_symtab_index(sym
->symtab_index());
454 symval
.set_output_value(sym
->value());
455 if (gsym
->type() == elfcpp::STT_TLS
)
456 symval
.set_is_tls_symbol();
457 else if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
458 symval
.set_is_ifunc_symbol();
461 relocate
.relocate(relinfo
, elfcpp::SHT_RELA
, target
, NULL
,
462 -1U, relbuf
, sym
, &symval
,
463 view
+ r_offset
, address
+ r_offset
, view_size
);
466 // A class for inquiring about properties of a relocation,
467 // used while scanning relocs during a relocatable link and
468 // garbage collection. This class may be used as the default
469 // for SHT_RELA targets, but SHT_REL targets must implement
470 // a derived class that overrides get_size_for_reloc.
471 // The MIPS-64 target also needs to override the methods
472 // for accessing the r_sym and r_type fields of a relocation,
473 // due to its non-standard use of the r_info field.
475 template<int sh_type_
, int size
, bool big_endian
>
476 class Default_classify_reloc
479 typedef typename Reloc_types
<sh_type_
, size
, big_endian
>::Reloc
481 typedef typename Reloc_types
<sh_type_
, size
, big_endian
>::Reloc_write
483 static const int reloc_size
=
484 Reloc_types
<sh_type_
, size
, big_endian
>::reloc_size
;
485 static const int sh_type
= sh_type_
;
487 // Return the symbol referred to by the relocation.
488 static inline unsigned int
489 get_r_sym(const Reltype
* reloc
)
490 { return elfcpp::elf_r_sym
<size
>(reloc
->get_r_info()); }
492 // Return the type of the relocation.
493 static inline unsigned int
494 get_r_type(const Reltype
* reloc
)
495 { return elfcpp::elf_r_type
<size
>(reloc
->get_r_info()); }
497 // Return the explicit addend of the relocation (return 0 for SHT_REL).
498 static inline typename
elfcpp::Elf_types
<size
>::Elf_Swxword
499 get_r_addend(const Reltype
* reloc
)
500 { return Reloc_types
<sh_type_
, size
, big_endian
>::get_reloc_addend(reloc
); }
502 // Write the r_info field to a new reloc, using the r_info field from
503 // the original reloc, replacing the r_sym field with R_SYM.
505 put_r_info(Reltype_write
* new_reloc
, Reltype
* reloc
, unsigned int r_sym
)
507 unsigned int r_type
= elfcpp::elf_r_type
<size
>(reloc
->get_r_info());
508 new_reloc
->put_r_info(elfcpp::elf_r_info
<size
>(r_sym
, r_type
));
511 // Write the r_addend field to a new reloc.
513 put_r_addend(Reltype_write
* to
,
514 typename
elfcpp::Elf_types
<size
>::Elf_Swxword addend
)
515 { Reloc_types
<sh_type_
, size
, big_endian
>::set_reloc_addend(to
, addend
); }
517 // Return the size of the addend of the relocation (only used for SHT_REL).
519 get_size_for_reloc(unsigned int, Relobj
*)
526 // This class may be used as a typical class for the
527 // Scan_relocatable_reloc parameter to scan_relocatable_relocs.
528 // This class is intended to capture the most typical target behaviour,
529 // while still permitting targets to define their own independent class
530 // for Scan_relocatable_reloc.
532 template<typename Classify_reloc
>
533 class Default_scan_relocatable_relocs
536 typedef typename
Classify_reloc::Reltype Reltype
;
537 static const int reloc_size
= Classify_reloc::reloc_size
;
538 static const int sh_type
= Classify_reloc::sh_type
;
540 // Return the symbol referred to by the relocation.
541 static inline unsigned int
542 get_r_sym(const Reltype
* reloc
)
543 { return Classify_reloc::get_r_sym(reloc
); }
545 // Return the type of the relocation.
546 static inline unsigned int
547 get_r_type(const Reltype
* reloc
)
548 { return Classify_reloc::get_r_type(reloc
); }
550 // Return the strategy to use for a local symbol which is not a
551 // section symbol, given the relocation type.
552 inline Relocatable_relocs::Reloc_strategy
553 local_non_section_strategy(unsigned int r_type
, Relobj
*, unsigned int r_sym
)
555 // We assume that relocation type 0 is NONE. Targets which are
556 // different must override.
557 if (r_type
== 0 && r_sym
== 0)
558 return Relocatable_relocs::RELOC_DISCARD
;
559 return Relocatable_relocs::RELOC_COPY
;
562 // Return the strategy to use for a local symbol which is a section
563 // symbol, given the relocation type.
564 inline Relocatable_relocs::Reloc_strategy
565 local_section_strategy(unsigned int r_type
, Relobj
* object
)
567 if (sh_type
== elfcpp::SHT_RELA
)
568 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA
;
571 switch (Classify_reloc::get_size_for_reloc(r_type
, object
))
574 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0
;
576 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_1
;
578 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_2
;
580 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4
;
582 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_8
;
589 // Return the strategy to use for a global symbol, given the
590 // relocation type, the object, and the symbol index.
591 inline Relocatable_relocs::Reloc_strategy
592 global_strategy(unsigned int, Relobj
*, unsigned int)
593 { return Relocatable_relocs::RELOC_COPY
; }
596 // This is a strategy class used with scan_relocatable_relocs
597 // and --emit-relocs.
599 template<typename Classify_reloc
>
600 class Default_emit_relocs_strategy
603 typedef typename
Classify_reloc::Reltype Reltype
;
604 static const int reloc_size
= Classify_reloc::reloc_size
;
605 static const int sh_type
= Classify_reloc::sh_type
;
607 // Return the symbol referred to by the relocation.
608 static inline unsigned int
609 get_r_sym(const Reltype
* reloc
)
610 { return Classify_reloc::get_r_sym(reloc
); }
612 // Return the type of the relocation.
613 static inline unsigned int
614 get_r_type(const Reltype
* reloc
)
615 { return Classify_reloc::get_r_type(reloc
); }
617 // A local non-section symbol.
618 inline Relocatable_relocs::Reloc_strategy
619 local_non_section_strategy(unsigned int, Relobj
*, unsigned int)
620 { return Relocatable_relocs::RELOC_COPY
; }
622 // A local section symbol.
623 inline Relocatable_relocs::Reloc_strategy
624 local_section_strategy(unsigned int, Relobj
*)
626 if (sh_type
== elfcpp::SHT_RELA
)
627 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA
;
630 // The addend is stored in the section contents. Since this
631 // is not a relocatable link, we are going to apply the
632 // relocation contents to the section as usual. This means
633 // that we have no way to record the original addend. If the
634 // original addend is not zero, there is basically no way for
635 // the user to handle this correctly. Caveat emptor.
636 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0
;
641 inline Relocatable_relocs::Reloc_strategy
642 global_strategy(unsigned int, Relobj
*, unsigned int)
643 { return Relocatable_relocs::RELOC_COPY
; }
646 // Scan relocs during a relocatable link. This is a default
647 // definition which should work for most targets.
648 // Scan_relocatable_reloc must name a class type which provides three
649 // functions which return a Relocatable_relocs::Reloc_strategy code:
650 // global_strategy, local_non_section_strategy, and
651 // local_section_strategy. Most targets should be able to use
652 // Default_scan_relocatable_relocs as this class.
654 template<int size
, bool big_endian
, typename Scan_relocatable_reloc
>
656 scan_relocatable_relocs(
659 Sized_relobj_file
<size
, big_endian
>* object
,
660 unsigned int data_shndx
,
661 const unsigned char* prelocs
,
663 Output_section
* output_section
,
664 bool needs_special_offset_handling
,
665 size_t local_symbol_count
,
666 const unsigned char* plocal_syms
,
667 Relocatable_relocs
* rr
)
669 typedef typename
Scan_relocatable_reloc::Reltype Reltype
;
670 const int reloc_size
= Scan_relocatable_reloc::reloc_size
;
671 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
672 Scan_relocatable_reloc scan
;
674 for (size_t i
= 0; i
< reloc_count
; ++i
, prelocs
+= reloc_size
)
676 Reltype
reloc(prelocs
);
678 Relocatable_relocs::Reloc_strategy strategy
;
680 if (needs_special_offset_handling
681 && !output_section
->is_input_address_mapped(object
, data_shndx
,
682 reloc
.get_r_offset()))
683 strategy
= Relocatable_relocs::RELOC_DISCARD
;
686 const unsigned int r_sym
= Scan_relocatable_reloc::get_r_sym(&reloc
);
687 const unsigned int r_type
=
688 Scan_relocatable_reloc::get_r_type(&reloc
);
690 if (r_sym
>= local_symbol_count
)
691 strategy
= scan
.global_strategy(r_type
, object
, r_sym
);
694 gold_assert(plocal_syms
!= NULL
);
695 typename
elfcpp::Sym
<size
, big_endian
> lsym(plocal_syms
697 unsigned int shndx
= lsym
.get_st_shndx();
699 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
701 && shndx
!= elfcpp::SHN_UNDEF
702 && !object
->is_section_included(shndx
))
704 // RELOC is a relocation against a local symbol
705 // defined in a section we are discarding. Discard
706 // the reloc. FIXME: Should we issue a warning?
707 strategy
= Relocatable_relocs::RELOC_DISCARD
;
709 else if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
710 strategy
= scan
.local_non_section_strategy(r_type
, object
,
714 strategy
= scan
.local_section_strategy(r_type
, object
);
715 if (strategy
!= Relocatable_relocs::RELOC_DISCARD
)
716 object
->output_section(shndx
)->set_needs_symtab_index();
719 if (strategy
== Relocatable_relocs::RELOC_COPY
)
720 object
->set_must_have_output_symtab_entry(r_sym
);
724 rr
->set_next_reloc_strategy(strategy
);
728 // Relocate relocs. Called for a relocatable link, and for --emit-relocs.
729 // This is a default definition which should work for most targets.
731 template<int size
, bool big_endian
, typename Classify_reloc
>
734 const Relocate_info
<size
, big_endian
>* relinfo
,
735 const unsigned char* prelocs
,
737 Output_section
* output_section
,
738 typename
elfcpp::Elf_types
<size
>::Elf_Off offset_in_output_section
,
740 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
741 section_size_type view_size
,
742 unsigned char* reloc_view
,
743 section_size_type reloc_view_size
)
745 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
746 typedef typename
Classify_reloc::Reltype Reltype
;
747 typedef typename
Classify_reloc::Reltype_write Reltype_write
;
748 const int reloc_size
= Classify_reloc::reloc_size
;
749 const Address invalid_address
= static_cast<Address
>(0) - 1;
751 Sized_relobj_file
<size
, big_endian
>* const object
= relinfo
->object
;
752 const unsigned int local_count
= object
->local_symbol_count();
754 unsigned char* pwrite
= reloc_view
;
756 for (size_t i
= 0; i
< reloc_count
; ++i
, prelocs
+= reloc_size
)
758 Relocatable_relocs::Reloc_strategy strategy
= relinfo
->rr
->strategy(i
);
759 if (strategy
== Relocatable_relocs::RELOC_DISCARD
)
762 if (strategy
== Relocatable_relocs::RELOC_SPECIAL
)
764 // Target wants to handle this relocation.
765 Sized_target
<size
, big_endian
>* target
=
766 parameters
->sized_target
<size
, big_endian
>();
767 target
->relocate_special_relocatable(relinfo
, Classify_reloc::sh_type
,
768 prelocs
, i
, output_section
,
769 offset_in_output_section
,
772 pwrite
+= reloc_size
;
775 Reltype
reloc(prelocs
);
776 Reltype_write
reloc_write(pwrite
);
778 const unsigned int r_sym
= Classify_reloc::get_r_sym(&reloc
);
780 // Get the new symbol index.
782 Output_section
* os
= NULL
;
783 unsigned int new_symndx
;
784 if (r_sym
< local_count
)
788 case Relocatable_relocs::RELOC_COPY
:
793 new_symndx
= object
->symtab_index(r_sym
);
794 gold_assert(new_symndx
!= -1U);
798 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA
:
799 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0
:
800 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_1
:
801 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_2
:
802 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4
:
803 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_8
:
804 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED
:
806 // We are adjusting a section symbol. We need to find
807 // the symbol table index of the section symbol for
808 // the output section corresponding to input section
809 // in which this symbol is defined.
810 gold_assert(r_sym
< local_count
);
813 object
->local_symbol_input_shndx(r_sym
, &is_ordinary
);
814 gold_assert(is_ordinary
);
815 os
= object
->output_section(shndx
);
816 gold_assert(os
!= NULL
);
817 gold_assert(os
->needs_symtab_index());
818 new_symndx
= os
->symtab_index();
828 const Symbol
* gsym
= object
->global_symbol(r_sym
);
829 gold_assert(gsym
!= NULL
);
830 if (gsym
->is_forwarder())
831 gsym
= relinfo
->symtab
->resolve_forwards(gsym
);
833 gold_assert(gsym
->has_symtab_index());
834 new_symndx
= gsym
->symtab_index();
837 // Get the new offset--the location in the output section where
838 // this relocation should be applied.
840 Address offset
= reloc
.get_r_offset();
842 if (offset_in_output_section
!= invalid_address
)
843 new_offset
= offset
+ offset_in_output_section
;
846 section_offset_type sot_offset
=
847 convert_types
<section_offset_type
, Address
>(offset
);
848 section_offset_type new_sot_offset
=
849 output_section
->output_offset(object
, relinfo
->data_shndx
,
851 gold_assert(new_sot_offset
!= -1);
852 new_offset
= new_sot_offset
;
855 // In an object file, r_offset is an offset within the section.
856 // In an executable or dynamic object, generated by
857 // --emit-relocs, r_offset is an absolute address.
858 if (!parameters
->options().relocatable())
860 new_offset
+= view_address
;
861 if (offset_in_output_section
!= invalid_address
)
862 new_offset
-= offset_in_output_section
;
865 reloc_write
.put_r_offset(new_offset
);
866 Classify_reloc::put_r_info(&reloc_write
, &reloc
, new_symndx
);
868 // Handle the reloc addend based on the strategy.
870 if (strategy
== Relocatable_relocs::RELOC_COPY
)
872 if (Classify_reloc::sh_type
== elfcpp::SHT_RELA
)
873 Classify_reloc::put_r_addend(&reloc_write
,
874 Classify_reloc::get_r_addend(&reloc
));
878 // The relocation uses a section symbol in the input file.
879 // We are adjusting it to use a section symbol in the output
880 // file. The input section symbol refers to some address in
881 // the input section. We need the relocation in the output
882 // file to refer to that same address. This adjustment to
883 // the addend is the same calculation we use for a simple
884 // absolute relocation for the input section symbol.
886 const Symbol_value
<size
>* psymval
= object
->local_symbol(r_sym
);
888 unsigned char* padd
= view
+ offset
;
891 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA
:
893 typename
elfcpp::Elf_types
<size
>::Elf_Swxword addend
;
894 addend
= Classify_reloc::get_r_addend(&reloc
);
895 gold_assert(os
!= NULL
);
896 addend
= psymval
->value(object
, addend
) - os
->address();
897 Classify_reloc::put_r_addend(&reloc_write
, addend
);
901 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0
:
904 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_1
:
905 Relocate_functions
<size
, big_endian
>::rel8(padd
, object
,
909 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_2
:
910 Relocate_functions
<size
, big_endian
>::rel16(padd
, object
,
914 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4
:
915 Relocate_functions
<size
, big_endian
>::rel32(padd
, object
,
919 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_8
:
920 Relocate_functions
<size
, big_endian
>::rel64(padd
, object
,
924 case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED
:
925 Relocate_functions
<size
, big_endian
>::rel32_unaligned(padd
,
935 pwrite
+= reloc_size
;
938 gold_assert(static_cast<section_size_type
>(pwrite
- reloc_view
)
942 } // End namespace gold.
944 #endif // !defined(GOLD_TARGET_RELOC_H)