1 // target.h -- target support for gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 // Free Software Foundation, Inc.
5 // Written by Ian Lance Taylor <iant@google.com>.
7 // This file is part of gold.
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.
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.
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.
24 // The abstract class Target is the interface for target specific
25 // support. It defines abstract methods which each target must
26 // implement. Typically there will be one target per processor, but
27 // in some cases it may be necessary to have subclasses.
29 // For speed and consistency we want to use inline functions to handle
30 // relocation processing. So besides implementations of the abstract
31 // methods, each target is expected to define a template
32 // specialization of the relocation functions.
39 #include "parameters.h"
47 template<int size, bool big_endian>
49 template<int size, bool big_endian>
50 class Sized_relobj_file;
51 class Relocatable_relocs;
52 template<int size, bool big_endian>
54 class Reloc_symbol_changes;
60 class Output_data_got_base;
65 // The abstract class for target specific handling.
73 // Return the bit size that this target implements. This should
77 { return this->pti_->size; }
79 // Return whether this target is big-endian.
82 { return this->pti_->is_big_endian; }
84 // Machine code to store in e_machine field of ELF header.
87 { return this->pti_->machine_code; }
89 // Processor specific flags to store in e_flags field of ELF header.
91 processor_specific_flags() const
92 { return this->processor_specific_flags_; }
94 // Whether processor specific flags are set at least once.
96 are_processor_specific_flags_set() const
97 { return this->are_processor_specific_flags_set_; }
99 // Whether this target has a specific make_symbol function.
101 has_make_symbol() const
102 { return this->pti_->has_make_symbol; }
104 // Whether this target has a specific resolve function.
107 { return this->pti_->has_resolve; }
109 // Whether this target has a specific code fill function.
111 has_code_fill() const
112 { return this->pti_->has_code_fill; }
114 // Return the default name of the dynamic linker.
116 dynamic_linker() const
117 { return this->pti_->dynamic_linker; }
119 // Return the default address to use for the text segment.
121 default_text_segment_address() const
122 { return this->pti_->default_text_segment_address; }
124 // Return the ABI specified page size.
128 if (parameters->options().max_page_size() > 0)
129 return parameters->options().max_page_size();
131 return this->pti_->abi_pagesize;
134 // Return the common page size used on actual systems.
136 common_pagesize() const
138 if (parameters->options().common_page_size() > 0)
139 return std::min(parameters->options().common_page_size(),
140 this->abi_pagesize());
142 return std::min(this->pti_->common_pagesize,
143 this->abi_pagesize());
146 // If we see some object files with .note.GNU-stack sections, and
147 // some objects files without them, this returns whether we should
148 // consider the object files without them to imply that the stack
149 // should be executable.
151 is_default_stack_executable() const
152 { return this->pti_->is_default_stack_executable; }
154 // Return a character which may appear as a prefix for a wrap
155 // symbol. If this character appears, we strip it when checking for
156 // wrapping and add it back when forming the final symbol name.
157 // This should be '\0' if not special prefix is required, which is
161 { return this->pti_->wrap_char; }
163 // Return the special section index which indicates a small common
164 // symbol. This will return SHN_UNDEF if there are no small common
167 small_common_shndx() const
168 { return this->pti_->small_common_shndx; }
170 // Return values to add to the section flags for the section holding
171 // small common symbols.
173 small_common_section_flags() const
175 gold_assert(this->pti_->small_common_shndx != elfcpp::SHN_UNDEF);
176 return this->pti_->small_common_section_flags;
179 // Return the special section index which indicates a large common
180 // symbol. This will return SHN_UNDEF if there are no large common
183 large_common_shndx() const
184 { return this->pti_->large_common_shndx; }
186 // Return values to add to the section flags for the section holding
187 // large common symbols.
189 large_common_section_flags() const
191 gold_assert(this->pti_->large_common_shndx != elfcpp::SHN_UNDEF);
192 return this->pti_->large_common_section_flags;
195 // This hook is called when an output section is created.
197 new_output_section(Output_section* os) const
198 { this->do_new_output_section(os); }
200 // This is called to tell the target to complete any sections it is
201 // handling. After this all sections must have their final size.
203 finalize_sections(Layout* layout, const Input_objects* input_objects,
204 Symbol_table* symtab)
205 { return this->do_finalize_sections(layout, input_objects, symtab); }
207 // Return the value to use for a global symbol which needs a special
208 // value in the dynamic symbol table. This will only be called if
209 // the backend first calls symbol->set_needs_dynsym_value().
211 dynsym_value(const Symbol* sym) const
212 { return this->do_dynsym_value(sym); }
214 // Return a string to use to fill out a code section. This is
215 // basically one or more NOPS which must fill out the specified
218 code_fill(section_size_type length) const
219 { return this->do_code_fill(length); }
221 // Return whether SYM is known to be defined by the ABI. This is
222 // used to avoid inappropriate warnings about undefined symbols.
224 is_defined_by_abi(const Symbol* sym) const
225 { return this->do_is_defined_by_abi(sym); }
227 // Adjust the output file header before it is written out. VIEW
228 // points to the header in external form. LEN is the length.
230 adjust_elf_header(unsigned char* view, int len) const
231 { return this->do_adjust_elf_header(view, len); }
233 // Return whether NAME is a local label name. This is used to implement the
234 // --discard-locals options.
236 is_local_label_name(const char* name) const
237 { return this->do_is_local_label_name(name); }
239 // Get the symbol index to use for a target specific reloc.
241 reloc_symbol_index(void* arg, unsigned int type) const
242 { return this->do_reloc_symbol_index(arg, type); }
244 // Get the addend to use for a target specific reloc.
246 reloc_addend(void* arg, unsigned int type, uint64_t addend) const
247 { return this->do_reloc_addend(arg, type, addend); }
249 // Return the PLT address to use for a global symbol. This is used
250 // for STT_GNU_IFUNC symbols. The symbol's plt_offset is relative
251 // to this PLT address.
253 plt_address_for_global(const Symbol* sym) const
254 { return this->do_plt_address_for_global(sym); }
256 // Return the PLT address to use for a local symbol. This is used
257 // for STT_GNU_IFUNC symbols. The symbol's plt_offset is relative
258 // to this PLT address.
260 plt_address_for_local(const Relobj* object, unsigned int symndx) const
261 { return this->do_plt_address_for_local(object, symndx); }
263 // Return whether this target can use relocation types to determine
264 // if a function's address is taken.
266 can_check_for_function_pointers() const
267 { return this->do_can_check_for_function_pointers(); }
269 // Return whether a relocation to a merged section can be processed
270 // to retrieve the contents.
272 can_icf_inline_merge_sections () const
273 { return this->pti_->can_icf_inline_merge_sections; }
275 // Whether a section called SECTION_NAME may have function pointers to
276 // sections not eligible for safe ICF folding.
278 section_may_have_icf_unsafe_pointers(const char* section_name) const
279 { return this->do_section_may_have_icf_unsafe_pointers(section_name); }
281 // Return the base to use for the PC value in an FDE when it is
282 // encoded using DW_EH_PE_datarel. This does not appear to be
283 // documented anywhere, but it is target specific. Any use of
284 // DW_EH_PE_datarel in gcc requires defining a special macro
285 // (ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX) to output the value.
287 ehframe_datarel_base() const
288 { return this->do_ehframe_datarel_base(); }
290 // Return true if a reference to SYM from a reloc of type R_TYPE
291 // means that the current function may call an object compiled
292 // without -fsplit-stack. SYM is known to be defined in an object
293 // compiled without -fsplit-stack.
295 is_call_to_non_split(const Symbol* sym, unsigned int r_type) const
296 { return this->do_is_call_to_non_split(sym, r_type); }
298 // A function starts at OFFSET in section SHNDX in OBJECT. That
299 // function was compiled with -fsplit-stack, but it refers to a
300 // function which was compiled without -fsplit-stack. VIEW is a
301 // modifiable view of the section; VIEW_SIZE is the size of the
302 // view. The target has to adjust the function so that it allocates
305 calls_non_split(Relobj* object, unsigned int shndx,
306 section_offset_type fnoffset, section_size_type fnsize,
307 unsigned char* view, section_size_type view_size,
308 std::string* from, std::string* to) const
310 this->do_calls_non_split(object, shndx, fnoffset, fnsize, view, view_size,
314 // Make an ELF object.
315 template<int size, bool big_endian>
317 make_elf_object(const std::string& name, Input_file* input_file,
318 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
319 { return this->do_make_elf_object(name, input_file, offset, ehdr); }
321 // Make an output section.
323 make_output_section(const char* name, elfcpp::Elf_Word type,
324 elfcpp::Elf_Xword flags)
325 { return this->do_make_output_section(name, type, flags); }
327 // Return true if target wants to perform relaxation.
331 // Run the dummy relaxation pass twice if relaxation debugging is enabled.
332 if (is_debugging_enabled(DEBUG_RELAXATION))
335 return this->do_may_relax();
338 // Perform a relaxation pass. Return true if layout may be changed.
340 relax(int pass, const Input_objects* input_objects, Symbol_table* symtab,
341 Layout* layout, const Task* task)
343 // Run the dummy relaxation pass twice if relaxation debugging is enabled.
344 if (is_debugging_enabled(DEBUG_RELAXATION))
347 return this->do_relax(pass, input_objects, symtab, layout, task);
350 // Return the target-specific name of attributes section. This is
351 // NULL if a target does not use attributes section or if it uses
352 // the default section name ".gnu.attributes".
354 attributes_section() const
355 { return this->pti_->attributes_section; }
357 // Return the vendor name of vendor attributes.
359 attributes_vendor() const
360 { return this->pti_->attributes_vendor; }
362 // Whether a section called NAME is an attribute section.
364 is_attributes_section(const char* name) const
366 return ((this->pti_->attributes_section != NULL
367 && strcmp(name, this->pti_->attributes_section) == 0)
368 || strcmp(name, ".gnu.attributes") == 0);
371 // Return a bit mask of argument types for attribute with TAG.
373 attribute_arg_type(int tag) const
374 { return this->do_attribute_arg_type(tag); }
376 // Return the attribute tag of the position NUM in the list of fixed
377 // attributes. Normally there is no reordering and
378 // attributes_order(NUM) == NUM.
380 attributes_order(int num) const
381 { return this->do_attributes_order(num); }
383 // When a target is selected as the default target, we call this method,
384 // which may be used for expensive, target-specific initialization.
386 select_as_default_target()
387 { this->do_select_as_default_target(); }
389 // Return the value to store in the EI_OSABI field in the ELF
393 { return this->osabi_; }
395 // Set the value to store in the EI_OSABI field in the ELF header.
397 set_osabi(elfcpp::ELFOSABI osabi)
398 { this->osabi_ = osabi; }
400 // Define target-specific standard symbols.
402 define_standard_symbols(Symbol_table* symtab, Layout* layout)
403 { this->do_define_standard_symbols(symtab, layout); }
406 // This struct holds the constant information for a child class. We
407 // use a struct to avoid the overhead of virtual function calls for
408 // simple information.
411 // Address size (32 or 64).
413 // Whether the target is big endian.
415 // The code to store in the e_machine field of the ELF header.
416 elfcpp::EM machine_code;
417 // Whether this target has a specific make_symbol function.
418 bool has_make_symbol;
419 // Whether this target has a specific resolve function.
421 // Whether this target has a specific code fill function.
423 // Whether an object file with no .note.GNU-stack sections implies
424 // that the stack should be executable.
425 bool is_default_stack_executable;
426 // Whether a relocation to a merged section can be processed to
427 // retrieve the contents.
428 bool can_icf_inline_merge_sections;
429 // Prefix character to strip when checking for wrapping.
431 // The default dynamic linker name.
432 const char* dynamic_linker;
433 // The default text segment address.
434 uint64_t default_text_segment_address;
435 // The ABI specified page size.
436 uint64_t abi_pagesize;
437 // The common page size used by actual implementations.
438 uint64_t common_pagesize;
439 // The special section index for small common symbols; SHN_UNDEF
441 elfcpp::Elf_Half small_common_shndx;
442 // The special section index for large common symbols; SHN_UNDEF
444 elfcpp::Elf_Half large_common_shndx;
445 // Section flags for small common section.
446 elfcpp::Elf_Xword small_common_section_flags;
447 // Section flags for large common section.
448 elfcpp::Elf_Xword large_common_section_flags;
449 // Name of attributes section if it is not ".gnu.attributes".
450 const char* attributes_section;
451 // Vendor name of vendor attributes.
452 const char* attributes_vendor;
455 Target(const Target_info* pti)
456 : pti_(pti), processor_specific_flags_(0),
457 are_processor_specific_flags_set_(false), osabi_(elfcpp::ELFOSABI_NONE)
460 // Virtual function which may be implemented by the child class.
462 do_new_output_section(Output_section*) const
465 // Virtual function which may be implemented by the child class.
467 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*)
470 // Virtual function which may be implemented by the child class.
472 do_dynsym_value(const Symbol*) const
473 { gold_unreachable(); }
475 // Virtual function which must be implemented by the child class if
478 do_code_fill(section_size_type) const
479 { gold_unreachable(); }
481 // Virtual function which may be implemented by the child class.
483 do_is_defined_by_abi(const Symbol*) const
486 // Adjust the output file header before it is written out. VIEW
487 // points to the header in external form. LEN is the length, and
488 // will be one of the values of elfcpp::Elf_sizes<size>::ehdr_size.
489 // By default, we set the EI_OSABI field if requested (in
492 do_adjust_elf_header(unsigned char*, int) const = 0;
494 // Virtual function which may be overridden by the child class.
496 do_is_local_label_name(const char*) const;
498 // Virtual function that must be overridden by a target which uses
499 // target specific relocations.
501 do_reloc_symbol_index(void*, unsigned int) const
502 { gold_unreachable(); }
504 // Virtual function that must be overridden by a target which uses
505 // target specific relocations.
507 do_reloc_addend(void*, unsigned int, uint64_t) const
508 { gold_unreachable(); }
510 // Virtual functions that must be overridden by a target that uses
511 // STT_GNU_IFUNC symbols.
513 do_plt_address_for_global(const Symbol*) const
514 { gold_unreachable(); }
517 do_plt_address_for_local(const Relobj*, unsigned int) const
518 { gold_unreachable(); }
520 // Virtual function which may be overriden by the child class.
522 do_can_check_for_function_pointers() const
525 // Virtual function which may be overridden by the child class. We
526 // recognize some default sections for which we don't care whether
527 // they have function pointers.
529 do_section_may_have_icf_unsafe_pointers(const char* section_name) const
531 // We recognize sections for normal vtables, construction vtables and
533 return (!is_prefix_of(".rodata._ZTV", section_name)
534 && !is_prefix_of(".data.rel.ro._ZTV", section_name)
535 && !is_prefix_of(".rodata._ZTC", section_name)
536 && !is_prefix_of(".data.rel.ro._ZTC", section_name)
537 && !is_prefix_of(".eh_frame", section_name));
541 do_ehframe_datarel_base() const
542 { gold_unreachable(); }
544 // Virtual function which may be overridden by the child class. The
545 // default implementation is that any function not defined by the
546 // ABI is a call to a non-split function.
548 do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
550 // Virtual function which may be overridden by the child class.
552 do_calls_non_split(Relobj* object, unsigned int, section_offset_type,
553 section_size_type, unsigned char*, section_size_type,
554 std::string*, std::string*) const;
556 // make_elf_object hooks. There are four versions of these for
557 // different address sizes and endianness.
559 // Set processor specific flags.
561 set_processor_specific_flags(elfcpp::Elf_Word flags)
563 this->processor_specific_flags_ = flags;
564 this->are_processor_specific_flags_set_ = true;
567 #ifdef HAVE_TARGET_32_LITTLE
568 // Virtual functions which may be overridden by the child class.
570 do_make_elf_object(const std::string&, Input_file*, off_t,
571 const elfcpp::Ehdr<32, false>&);
574 #ifdef HAVE_TARGET_32_BIG
575 // Virtual functions which may be overridden by the child class.
577 do_make_elf_object(const std::string&, Input_file*, off_t,
578 const elfcpp::Ehdr<32, true>&);
581 #ifdef HAVE_TARGET_64_LITTLE
582 // Virtual functions which may be overridden by the child class.
584 do_make_elf_object(const std::string&, Input_file*, off_t,
585 const elfcpp::Ehdr<64, false>& ehdr);
588 #ifdef HAVE_TARGET_64_BIG
589 // Virtual functions which may be overridden by the child class.
591 do_make_elf_object(const std::string& name, Input_file* input_file,
592 off_t offset, const elfcpp::Ehdr<64, true>& ehdr);
595 // Virtual functions which may be overridden by the child class.
596 virtual Output_section*
597 do_make_output_section(const char* name, elfcpp::Elf_Word type,
598 elfcpp::Elf_Xword flags);
600 // Virtual function which may be overridden by the child class.
603 { return parameters->options().relax(); }
605 // Virtual function which may be overridden by the child class.
607 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*)
610 // A function for targets to call. Return whether BYTES/LEN matches
611 // VIEW/VIEW_SIZE at OFFSET.
613 match_view(const unsigned char* view, section_size_type view_size,
614 section_offset_type offset, const char* bytes, size_t len) const;
616 // Set the contents of a VIEW/VIEW_SIZE to nops starting at OFFSET
619 set_view_to_nop(unsigned char* view, section_size_type view_size,
620 section_offset_type offset, size_t len) const;
622 // This must be overridden by the child class if it has target-specific
623 // attributes subsection in the attribute section.
625 do_attribute_arg_type(int) const
626 { gold_unreachable(); }
628 // This may be overridden by the child class.
630 do_attributes_order(int num) const
633 // This may be overridden by the child class.
635 do_select_as_default_target()
638 // This may be overridden by the child class.
640 do_define_standard_symbols(Symbol_table*, Layout*)
644 // The implementations of the four do_make_elf_object virtual functions are
645 // almost identical except for their sizes and endianness. We use a template.
646 // for their implementations.
647 template<int size, bool big_endian>
649 do_make_elf_object_implementation(const std::string&, Input_file*, off_t,
650 const elfcpp::Ehdr<size, big_endian>&);
652 Target(const Target&);
653 Target& operator=(const Target&);
655 // The target information.
656 const Target_info* pti_;
657 // Processor-specific flags.
658 elfcpp::Elf_Word processor_specific_flags_;
659 // Whether the processor-specific flags are set at least once.
660 bool are_processor_specific_flags_set_;
661 // If not ELFOSABI_NONE, the value to put in the EI_OSABI field of
662 // the ELF header. This is handled at this level because it is
663 // OS-specific rather than processor-specific.
664 elfcpp::ELFOSABI osabi_;
667 // The abstract class for a specific size and endianness of target.
668 // Each actual target implementation class should derive from an
669 // instantiation of Sized_target.
671 template<int size, bool big_endian>
672 class Sized_target : public Target
675 // Make a new symbol table entry for the target. This should be
676 // overridden by a target which needs additional information in the
677 // symbol table. This will only be called if has_make_symbol()
679 virtual Sized_symbol<size>*
681 { gold_unreachable(); }
683 // Resolve a symbol for the target. This should be overridden by a
684 // target which needs to take special action. TO is the
685 // pre-existing symbol. SYM is the new symbol, seen in OBJECT.
686 // VERSION is the version of SYM. This will only be called if
687 // has_resolve() returns true.
689 resolve(Symbol*, const elfcpp::Sym<size, big_endian>&, Object*,
691 { gold_unreachable(); }
693 // Process the relocs for a section, and record information of the
694 // mapping from source to destination sections. This mapping is later
695 // used to determine unreferenced garbage sections. This procedure is
696 // only called during garbage collection.
698 gc_process_relocs(Symbol_table* symtab,
700 Sized_relobj_file<size, big_endian>* object,
701 unsigned int data_shndx,
702 unsigned int sh_type,
703 const unsigned char* prelocs,
705 Output_section* output_section,
706 bool needs_special_offset_handling,
707 size_t local_symbol_count,
708 const unsigned char* plocal_symbols) = 0;
710 // Scan the relocs for a section, and record any information
711 // required for the symbol. SYMTAB is the symbol table. OBJECT is
712 // the object in which the section appears. DATA_SHNDX is the
713 // section index that these relocs apply to. SH_TYPE is the type of
714 // the relocation section, SHT_REL or SHT_RELA. PRELOCS points to
715 // the relocation data. RELOC_COUNT is the number of relocs.
716 // LOCAL_SYMBOL_COUNT is the number of local symbols.
717 // OUTPUT_SECTION is the output section.
718 // NEEDS_SPECIAL_OFFSET_HANDLING is true if offsets to the output
719 // sections are not mapped as usual. PLOCAL_SYMBOLS points to the
720 // local symbol data from OBJECT. GLOBAL_SYMBOLS is the array of
721 // pointers to the global symbol table from OBJECT.
723 scan_relocs(Symbol_table* symtab,
725 Sized_relobj_file<size, big_endian>* object,
726 unsigned int data_shndx,
727 unsigned int sh_type,
728 const unsigned char* prelocs,
730 Output_section* output_section,
731 bool needs_special_offset_handling,
732 size_t local_symbol_count,
733 const unsigned char* plocal_symbols) = 0;
735 // Relocate section data. SH_TYPE is the type of the relocation
736 // section, SHT_REL or SHT_RELA. PRELOCS points to the relocation
737 // information. RELOC_COUNT is the number of relocs.
738 // OUTPUT_SECTION is the output section.
739 // NEEDS_SPECIAL_OFFSET_HANDLING is true if offsets must be mapped
740 // to correspond to the output section. VIEW is a view into the
741 // output file holding the section contents, VIEW_ADDRESS is the
742 // virtual address of the view, and VIEW_SIZE is the size of the
743 // view. If NEEDS_SPECIAL_OFFSET_HANDLING is true, the VIEW_xx
744 // parameters refer to the complete output section data, not just
745 // the input section data.
747 relocate_section(const Relocate_info<size, big_endian>*,
748 unsigned int sh_type,
749 const unsigned char* prelocs,
751 Output_section* output_section,
752 bool needs_special_offset_handling,
754 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
755 section_size_type view_size,
756 const Reloc_symbol_changes*) = 0;
758 // Scan the relocs during a relocatable link. The parameters are
759 // like scan_relocs, with an additional Relocatable_relocs
760 // parameter, used to record the disposition of the relocs.
762 scan_relocatable_relocs(Symbol_table* symtab,
764 Sized_relobj_file<size, big_endian>* object,
765 unsigned int data_shndx,
766 unsigned int sh_type,
767 const unsigned char* prelocs,
769 Output_section* output_section,
770 bool needs_special_offset_handling,
771 size_t local_symbol_count,
772 const unsigned char* plocal_symbols,
773 Relocatable_relocs*) = 0;
775 // Relocate a section during a relocatable link. The parameters are
776 // like relocate_section, with additional parameters for the view of
777 // the output reloc section.
779 relocate_for_relocatable(const Relocate_info<size, big_endian>*,
780 unsigned int sh_type,
781 const unsigned char* prelocs,
783 Output_section* output_section,
784 off_t offset_in_output_section,
785 const Relocatable_relocs*,
787 typename elfcpp::Elf_types<size>::Elf_Addr
789 section_size_type view_size,
790 unsigned char* reloc_view,
791 section_size_type reloc_view_size) = 0;
793 // Perform target-specific processing in a relocatable link. This is
794 // only used if we use the relocation strategy RELOC_SPECIAL.
795 // RELINFO points to a Relocation_info structure. SH_TYPE is the relocation
796 // section type. PRELOC_IN points to the original relocation. RELNUM is
797 // the index number of the relocation in the relocation section.
798 // OUTPUT_SECTION is the output section to which the relocation is applied.
799 // OFFSET_IN_OUTPUT_SECTION is the offset of the relocation input section
800 // within the output section. VIEW points to the output view of the
801 // output section. VIEW_ADDRESS is output address of the view. VIEW_SIZE
802 // is the size of the output view and PRELOC_OUT points to the new
803 // relocation in the output object.
805 // A target only needs to override this if the generic code in
806 // target-reloc.h cannot handle some relocation types.
809 relocate_special_relocatable(const Relocate_info<size, big_endian>*
811 unsigned int /* sh_type */,
812 const unsigned char* /* preloc_in */,
814 Output_section* /* output_section */,
815 off_t /* offset_in_output_section */,
816 unsigned char* /* view */,
817 typename elfcpp::Elf_types<size>::Elf_Addr
819 section_size_type /* view_size */,
820 unsigned char* /* preloc_out*/)
821 { gold_unreachable(); }
823 // Return the number of entries in the GOT. This is only used for
824 // laying out the incremental link info sections. A target needs
825 // to implement this to support incremental linking.
828 got_entry_count() const
829 { gold_unreachable(); }
831 // Return the number of entries in the PLT. This is only used for
832 // laying out the incremental link info sections. A target needs
833 // to implement this to support incremental linking.
836 plt_entry_count() const
837 { gold_unreachable(); }
839 // Return the offset of the first non-reserved PLT entry. This is
840 // only used for laying out the incremental link info sections.
841 // A target needs to implement this to support incremental linking.
844 first_plt_entry_offset() const
845 { gold_unreachable(); }
847 // Return the size of each PLT entry. This is only used for
848 // laying out the incremental link info sections. A target needs
849 // to implement this to support incremental linking.
852 plt_entry_size() const
853 { gold_unreachable(); }
855 // Create the GOT and PLT sections for an incremental update.
856 // A target needs to implement this to support incremental linking.
858 virtual Output_data_got_base*
859 init_got_plt_for_update(Symbol_table*,
861 unsigned int /* got_count */,
862 unsigned int /* plt_count */)
863 { gold_unreachable(); }
865 // Reserve a GOT entry for a local symbol, and regenerate any
866 // necessary dynamic relocations.
868 reserve_local_got_entry(unsigned int /* got_index */,
869 Sized_relobj<size, big_endian>* /* obj */,
870 unsigned int /* r_sym */,
871 unsigned int /* got_type */)
872 { gold_unreachable(); }
874 // Reserve a GOT entry for a global symbol, and regenerate any
875 // necessary dynamic relocations.
877 reserve_global_got_entry(unsigned int /* got_index */, Symbol* /* gsym */,
878 unsigned int /* got_type */)
879 { gold_unreachable(); }
881 // Register an existing PLT entry for a global symbol.
882 // A target needs to implement this to support incremental linking.
885 register_global_plt_entry(Symbol_table*, Layout*,
886 unsigned int /* plt_index */,
888 { gold_unreachable(); }
890 // Force a COPY relocation for a given symbol.
891 // A target needs to implement this to support incremental linking.
894 emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t)
895 { gold_unreachable(); }
897 // Apply an incremental relocation.
900 apply_relocation(const Relocate_info<size, big_endian>* /* relinfo */,
901 typename elfcpp::Elf_types<size>::Elf_Addr /* r_offset */,
902 unsigned int /* r_type */,
903 typename elfcpp::Elf_types<size>::Elf_Swxword /* r_addend */,
904 const Symbol* /* gsym */,
905 unsigned char* /* view */,
906 typename elfcpp::Elf_types<size>::Elf_Addr /* address */,
907 section_size_type /* view_size */)
908 { gold_unreachable(); }
911 Sized_target(const Target::Target_info* pti)
914 gold_assert(pti->size == size);
915 gold_assert(pti->is_big_endian ? big_endian : !big_endian);
918 // Set the EI_OSABI field if requested.
920 do_adjust_elf_header(unsigned char*, int) const;
923 } // End namespace gold.
925 #endif // !defined(GOLD_TARGET_H)