1 // target.h -- target support for gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 // The abstract class Target is the interface for target specific
24 // support. It defines abstract methods which each target must
25 // implement. Typically there will be one target per processor, but
26 // in some cases it may be necessary to have subclasses.
28 // For speed and consistency we want to use inline functions to handle
29 // relocation processing. So besides implementations of the abstract
30 // methods, each target is expected to define a template
31 // specialization of the relocation functions.
38 #include "parameters.h"
46 template<int size, bool big_endian>
48 template<int size, bool big_endian>
49 class Sized_relobj_file;
50 class Relocatable_relocs;
51 template<int size, bool big_endian>
53 class Reloc_symbol_changes;
59 class Output_data_got_base;
64 // The abstract class for target specific handling.
72 // Return the bit size that this target implements. This should
76 { return this->pti_->size; }
78 // Return whether this target is big-endian.
81 { return this->pti_->is_big_endian; }
83 // Machine code to store in e_machine field of ELF header.
86 { return this->pti_->machine_code; }
88 // Processor specific flags to store in e_flags field of ELF header.
90 processor_specific_flags() const
91 { return this->processor_specific_flags_; }
93 // Whether processor specific flags are set at least once.
95 are_processor_specific_flags_set() const
96 { return this->are_processor_specific_flags_set_; }
98 // Whether this target has a specific make_symbol function.
100 has_make_symbol() const
101 { return this->pti_->has_make_symbol; }
103 // Whether this target has a specific resolve function.
106 { return this->pti_->has_resolve; }
108 // Whether this target has a specific code fill function.
110 has_code_fill() const
111 { return this->pti_->has_code_fill; }
113 // Return the default name of the dynamic linker.
115 dynamic_linker() const
116 { return this->pti_->dynamic_linker; }
118 // Return the default address to use for the text segment.
120 default_text_segment_address() const
121 { return this->pti_->default_text_segment_address; }
123 // Return the ABI specified page size.
127 if (parameters->options().max_page_size() > 0)
128 return parameters->options().max_page_size();
130 return this->pti_->abi_pagesize;
133 // Return the common page size used on actual systems.
135 common_pagesize() const
137 if (parameters->options().common_page_size() > 0)
138 return std::min(parameters->options().common_page_size(),
139 this->abi_pagesize());
141 return std::min(this->pti_->common_pagesize,
142 this->abi_pagesize());
145 // If we see some object files with .note.GNU-stack sections, and
146 // some objects files without them, this returns whether we should
147 // consider the object files without them to imply that the stack
148 // should be executable.
150 is_default_stack_executable() const
151 { return this->pti_->is_default_stack_executable; }
153 // Return a character which may appear as a prefix for a wrap
154 // symbol. If this character appears, we strip it when checking for
155 // wrapping and add it back when forming the final symbol name.
156 // This should be '\0' if not special prefix is required, which is
160 { return this->pti_->wrap_char; }
162 // Return the special section index which indicates a small common
163 // symbol. This will return SHN_UNDEF if there are no small common
166 small_common_shndx() const
167 { return this->pti_->small_common_shndx; }
169 // Return values to add to the section flags for the section holding
170 // small common symbols.
172 small_common_section_flags() const
174 gold_assert(this->pti_->small_common_shndx != elfcpp::SHN_UNDEF);
175 return this->pti_->small_common_section_flags;
178 // Return the special section index which indicates a large common
179 // symbol. This will return SHN_UNDEF if there are no large common
182 large_common_shndx() const
183 { return this->pti_->large_common_shndx; }
185 // Return values to add to the section flags for the section holding
186 // large common symbols.
188 large_common_section_flags() const
190 gold_assert(this->pti_->large_common_shndx != elfcpp::SHN_UNDEF);
191 return this->pti_->large_common_section_flags;
194 // This hook is called when an output section is created.
196 new_output_section(Output_section* os) const
197 { this->do_new_output_section(os); }
199 // This is called to tell the target to complete any sections it is
200 // handling. After this all sections must have their final size.
202 finalize_sections(Layout* layout, const Input_objects* input_objects,
203 Symbol_table* symtab)
204 { return this->do_finalize_sections(layout, input_objects, symtab); }
206 // Return the value to use for a global symbol which needs a special
207 // value in the dynamic symbol table. This will only be called if
208 // the backend first calls symbol->set_needs_dynsym_value().
210 dynsym_value(const Symbol* sym) const
211 { return this->do_dynsym_value(sym); }
213 // Return a string to use to fill out a code section. This is
214 // basically one or more NOPS which must fill out the specified
217 code_fill(section_size_type length) const
218 { return this->do_code_fill(length); }
220 // Return whether SYM is known to be defined by the ABI. This is
221 // used to avoid inappropriate warnings about undefined symbols.
223 is_defined_by_abi(const Symbol* sym) const
224 { return this->do_is_defined_by_abi(sym); }
226 // Adjust the output file header before it is written out. VIEW
227 // points to the header in external form. LEN is the length.
229 adjust_elf_header(unsigned char* view, int len) const
230 { return this->do_adjust_elf_header(view, len); }
232 // Return whether NAME is a local label name. This is used to implement the
233 // --discard-locals options.
235 is_local_label_name(const char* name) const
236 { return this->do_is_local_label_name(name); }
238 // Get the symbol index to use for a target specific reloc.
240 reloc_symbol_index(void* arg, unsigned int type) const
241 { return this->do_reloc_symbol_index(arg, type); }
243 // Get the addend to use for a target specific reloc.
245 reloc_addend(void* arg, unsigned int type, uint64_t addend) const
246 { return this->do_reloc_addend(arg, type, addend); }
248 // Return the PLT address to use for a global symbol. This is used
249 // for STT_GNU_IFUNC symbols. The symbol's plt_offset is relative
250 // to this PLT address.
252 plt_address_for_global(const Symbol* sym) const
253 { return this->do_plt_address_for_global(sym); }
255 // Return the PLT address to use for a local symbol. This is used
256 // for STT_GNU_IFUNC symbols. The symbol's plt_offset is relative
257 // to this PLT address.
259 plt_address_for_local(const Relobj* object, unsigned int symndx) const
260 { return this->do_plt_address_for_local(object, symndx); }
262 // Return whether this target can use relocation types to determine
263 // if a function's address is taken.
265 can_check_for_function_pointers() const
266 { return this->do_can_check_for_function_pointers(); }
268 // Return whether a relocation to a merged section can be processed
269 // to retrieve the contents.
271 can_icf_inline_merge_sections () const
272 { return this->pti_->can_icf_inline_merge_sections; }
274 // Whether a section called SECTION_NAME may have function pointers to
275 // sections not eligible for safe ICF folding.
277 section_may_have_icf_unsafe_pointers(const char* section_name) const
278 { return this->do_section_may_have_icf_unsafe_pointers(section_name); }
280 // Return the base to use for the PC value in an FDE when it is
281 // encoded using DW_EH_PE_datarel. This does not appear to be
282 // documented anywhere, but it is target specific. Any use of
283 // DW_EH_PE_datarel in gcc requires defining a special macro
284 // (ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX) to output the value.
286 ehframe_datarel_base() const
287 { return this->do_ehframe_datarel_base(); }
289 // Return true if a reference to SYM from a reloc of type R_TYPE
290 // means that the current function may call an object compiled
291 // without -fsplit-stack. SYM is known to be defined in an object
292 // compiled without -fsplit-stack.
294 is_call_to_non_split(const Symbol* sym, unsigned int r_type) const
295 { return this->do_is_call_to_non_split(sym, r_type); }
297 // A function starts at OFFSET in section SHNDX in OBJECT. That
298 // function was compiled with -fsplit-stack, but it refers to a
299 // function which was compiled without -fsplit-stack. VIEW is a
300 // modifiable view of the section; VIEW_SIZE is the size of the
301 // view. The target has to adjust the function so that it allocates
304 calls_non_split(Relobj* object, unsigned int shndx,
305 section_offset_type fnoffset, section_size_type fnsize,
306 unsigned char* view, section_size_type view_size,
307 std::string* from, std::string* to) const
309 this->do_calls_non_split(object, shndx, fnoffset, fnsize, view, view_size,
313 // Make an ELF object.
314 template<int size, bool big_endian>
316 make_elf_object(const std::string& name, Input_file* input_file,
317 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
318 { return this->do_make_elf_object(name, input_file, offset, ehdr); }
320 // Make an output section.
322 make_output_section(const char* name, elfcpp::Elf_Word type,
323 elfcpp::Elf_Xword flags)
324 { return this->do_make_output_section(name, type, flags); }
326 // Return true if target wants to perform relaxation.
330 // Run the dummy relaxation pass twice if relaxation debugging is enabled.
331 if (is_debugging_enabled(DEBUG_RELAXATION))
334 return this->do_may_relax();
337 // Perform a relaxation pass. Return true if layout may be changed.
339 relax(int pass, const Input_objects* input_objects, Symbol_table* symtab,
340 Layout* layout, const Task* task)
342 // Run the dummy relaxation pass twice if relaxation debugging is enabled.
343 if (is_debugging_enabled(DEBUG_RELAXATION))
346 return this->do_relax(pass, input_objects, symtab, layout, task);
349 // Return the target-specific name of attributes section. This is
350 // NULL if a target does not use attributes section or if it uses
351 // the default section name ".gnu.attributes".
353 attributes_section() const
354 { return this->pti_->attributes_section; }
356 // Return the vendor name of vendor attributes.
358 attributes_vendor() const
359 { return this->pti_->attributes_vendor; }
361 // Whether a section called NAME is an attribute section.
363 is_attributes_section(const char* name) const
365 return ((this->pti_->attributes_section != NULL
366 && strcmp(name, this->pti_->attributes_section) == 0)
367 || strcmp(name, ".gnu.attributes") == 0);
370 // Return a bit mask of argument types for attribute with TAG.
372 attribute_arg_type(int tag) const
373 { return this->do_attribute_arg_type(tag); }
375 // Return the attribute tag of the position NUM in the list of fixed
376 // attributes. Normally there is no reordering and
377 // attributes_order(NUM) == NUM.
379 attributes_order(int num) const
380 { return this->do_attributes_order(num); }
382 // When a target is selected as the default target, we call this method,
383 // which may be used for expensive, target-specific initialization.
385 select_as_default_target()
386 { this->do_select_as_default_target(); }
388 // Return the value to store in the EI_OSABI field in the ELF
392 { return this->osabi_; }
394 // Set the value to store in the EI_OSABI field in the ELF header.
396 set_osabi(elfcpp::ELFOSABI osabi)
397 { this->osabi_ = osabi; }
399 // Define target-specific standard symbols.
401 define_standard_symbols(Symbol_table* symtab, Layout* layout)
402 { this->do_define_standard_symbols(symtab, layout); }
405 // This struct holds the constant information for a child class. We
406 // use a struct to avoid the overhead of virtual function calls for
407 // simple information.
410 // Address size (32 or 64).
412 // Whether the target is big endian.
414 // The code to store in the e_machine field of the ELF header.
415 elfcpp::EM machine_code;
416 // Whether this target has a specific make_symbol function.
417 bool has_make_symbol;
418 // Whether this target has a specific resolve function.
420 // Whether this target has a specific code fill function.
422 // Whether an object file with no .note.GNU-stack sections implies
423 // that the stack should be executable.
424 bool is_default_stack_executable;
425 // Whether a relocation to a merged section can be processed to
426 // retrieve the contents.
427 bool can_icf_inline_merge_sections;
428 // Prefix character to strip when checking for wrapping.
430 // The default dynamic linker name.
431 const char* dynamic_linker;
432 // The default text segment address.
433 uint64_t default_text_segment_address;
434 // The ABI specified page size.
435 uint64_t abi_pagesize;
436 // The common page size used by actual implementations.
437 uint64_t common_pagesize;
438 // The special section index for small common symbols; SHN_UNDEF
440 elfcpp::Elf_Half small_common_shndx;
441 // The special section index for large common symbols; SHN_UNDEF
443 elfcpp::Elf_Half large_common_shndx;
444 // Section flags for small common section.
445 elfcpp::Elf_Xword small_common_section_flags;
446 // Section flags for large common section.
447 elfcpp::Elf_Xword large_common_section_flags;
448 // Name of attributes section if it is not ".gnu.attributes".
449 const char* attributes_section;
450 // Vendor name of vendor attributes.
451 const char* attributes_vendor;
454 Target(const Target_info* pti)
455 : pti_(pti), processor_specific_flags_(0),
456 are_processor_specific_flags_set_(false), osabi_(elfcpp::ELFOSABI_NONE)
459 // Virtual function which may be implemented by the child class.
461 do_new_output_section(Output_section*) const
464 // Virtual function which may be implemented by the child class.
466 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*)
469 // Virtual function which may be implemented by the child class.
471 do_dynsym_value(const Symbol*) const
472 { gold_unreachable(); }
474 // Virtual function which must be implemented by the child class if
477 do_code_fill(section_size_type) const
478 { gold_unreachable(); }
480 // Virtual function which may be implemented by the child class.
482 do_is_defined_by_abi(const Symbol*) const
485 // Adjust the output file header before it is written out. VIEW
486 // points to the header in external form. LEN is the length, and
487 // will be one of the values of elfcpp::Elf_sizes<size>::ehdr_size.
488 // By default, we set the EI_OSABI field if requested (in
491 do_adjust_elf_header(unsigned char*, int) const = 0;
493 // Virtual function which may be overridden by the child class.
495 do_is_local_label_name(const char*) const;
497 // Virtual function that must be overridden by a target which uses
498 // target specific relocations.
500 do_reloc_symbol_index(void*, unsigned int) const
501 { gold_unreachable(); }
503 // Virtual function that must be overridden by a target which uses
504 // target specific relocations.
506 do_reloc_addend(void*, unsigned int, uint64_t) const
507 { gold_unreachable(); }
509 // Virtual functions that must be overridden by a target that uses
510 // STT_GNU_IFUNC symbols.
512 do_plt_address_for_global(const Symbol*) const
513 { gold_unreachable(); }
516 do_plt_address_for_local(const Relobj*, unsigned int) const
517 { gold_unreachable(); }
519 // Virtual function which may be overriden by the child class.
521 do_can_check_for_function_pointers() const
524 // Virtual function which may be overridden by the child class. We
525 // recognize some default sections for which we don't care whether
526 // they have function pointers.
528 do_section_may_have_icf_unsafe_pointers(const char* section_name) const
530 // We recognize sections for normal vtables, construction vtables and
532 return (!is_prefix_of(".rodata._ZTV", section_name)
533 && !is_prefix_of(".data.rel.ro._ZTV", section_name)
534 && !is_prefix_of(".rodata._ZTC", section_name)
535 && !is_prefix_of(".data.rel.ro._ZTC", section_name)
536 && !is_prefix_of(".eh_frame", section_name));
540 do_ehframe_datarel_base() const
541 { gold_unreachable(); }
543 // Virtual function which may be overridden by the child class. The
544 // default implementation is that any function not defined by the
545 // ABI is a call to a non-split function.
547 do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
549 // Virtual function which may be overridden by the child class.
551 do_calls_non_split(Relobj* object, unsigned int, section_offset_type,
552 section_size_type, unsigned char*, section_size_type,
553 std::string*, std::string*) const;
555 // make_elf_object hooks. There are four versions of these for
556 // different address sizes and endianness.
558 // Set processor specific flags.
560 set_processor_specific_flags(elfcpp::Elf_Word flags)
562 this->processor_specific_flags_ = flags;
563 this->are_processor_specific_flags_set_ = true;
566 #ifdef HAVE_TARGET_32_LITTLE
567 // Virtual functions which may be overridden by the child class.
569 do_make_elf_object(const std::string&, Input_file*, off_t,
570 const elfcpp::Ehdr<32, false>&);
573 #ifdef HAVE_TARGET_32_BIG
574 // Virtual functions which may be overridden by the child class.
576 do_make_elf_object(const std::string&, Input_file*, off_t,
577 const elfcpp::Ehdr<32, true>&);
580 #ifdef HAVE_TARGET_64_LITTLE
581 // Virtual functions which may be overridden by the child class.
583 do_make_elf_object(const std::string&, Input_file*, off_t,
584 const elfcpp::Ehdr<64, false>& ehdr);
587 #ifdef HAVE_TARGET_64_BIG
588 // Virtual functions which may be overridden by the child class.
590 do_make_elf_object(const std::string& name, Input_file* input_file,
591 off_t offset, const elfcpp::Ehdr<64, true>& ehdr);
594 // Virtual functions which may be overridden by the child class.
595 virtual Output_section*
596 do_make_output_section(const char* name, elfcpp::Elf_Word type,
597 elfcpp::Elf_Xword flags);
599 // Virtual function which may be overridden by the child class.
602 { return parameters->options().relax(); }
604 // Virtual function which may be overridden by the child class.
606 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*)
609 // A function for targets to call. Return whether BYTES/LEN matches
610 // VIEW/VIEW_SIZE at OFFSET.
612 match_view(const unsigned char* view, section_size_type view_size,
613 section_offset_type offset, const char* bytes, size_t len) const;
615 // Set the contents of a VIEW/VIEW_SIZE to nops starting at OFFSET
618 set_view_to_nop(unsigned char* view, section_size_type view_size,
619 section_offset_type offset, size_t len) const;
621 // This must be overridden by the child class if it has target-specific
622 // attributes subsection in the attribute section.
624 do_attribute_arg_type(int) const
625 { gold_unreachable(); }
627 // This may be overridden by the child class.
629 do_attributes_order(int num) const
632 // This may be overridden by the child class.
634 do_select_as_default_target()
637 // This may be overridden by the child class.
639 do_define_standard_symbols(Symbol_table*, Layout*)
643 // The implementations of the four do_make_elf_object virtual functions are
644 // almost identical except for their sizes and endianness. We use a template.
645 // for their implementations.
646 template<int size, bool big_endian>
648 do_make_elf_object_implementation(const std::string&, Input_file*, off_t,
649 const elfcpp::Ehdr<size, big_endian>&);
651 Target(const Target&);
652 Target& operator=(const Target&);
654 // The target information.
655 const Target_info* pti_;
656 // Processor-specific flags.
657 elfcpp::Elf_Word processor_specific_flags_;
658 // Whether the processor-specific flags are set at least once.
659 bool are_processor_specific_flags_set_;
660 // If not ELFOSABI_NONE, the value to put in the EI_OSABI field of
661 // the ELF header. This is handled at this level because it is
662 // OS-specific rather than processor-specific.
663 elfcpp::ELFOSABI osabi_;
666 // The abstract class for a specific size and endianness of target.
667 // Each actual target implementation class should derive from an
668 // instantiation of Sized_target.
670 template<int size, bool big_endian>
671 class Sized_target : public Target
674 // Make a new symbol table entry for the target. This should be
675 // overridden by a target which needs additional information in the
676 // symbol table. This will only be called if has_make_symbol()
678 virtual Sized_symbol<size>*
680 { gold_unreachable(); }
682 // Resolve a symbol for the target. This should be overridden by a
683 // target which needs to take special action. TO is the
684 // pre-existing symbol. SYM is the new symbol, seen in OBJECT.
685 // VERSION is the version of SYM. This will only be called if
686 // has_resolve() returns true.
688 resolve(Symbol*, const elfcpp::Sym<size, big_endian>&, Object*,
690 { gold_unreachable(); }
692 // Process the relocs for a section, and record information of the
693 // mapping from source to destination sections. This mapping is later
694 // used to determine unreferenced garbage sections. This procedure is
695 // only called during garbage collection.
697 gc_process_relocs(Symbol_table* symtab,
699 Sized_relobj_file<size, big_endian>* object,
700 unsigned int data_shndx,
701 unsigned int sh_type,
702 const unsigned char* prelocs,
704 Output_section* output_section,
705 bool needs_special_offset_handling,
706 size_t local_symbol_count,
707 const unsigned char* plocal_symbols) = 0;
709 // Scan the relocs for a section, and record any information
710 // required for the symbol. SYMTAB is the symbol table. OBJECT is
711 // the object in which the section appears. DATA_SHNDX is the
712 // section index that these relocs apply to. SH_TYPE is the type of
713 // the relocation section, SHT_REL or SHT_RELA. PRELOCS points to
714 // the relocation data. RELOC_COUNT is the number of relocs.
715 // LOCAL_SYMBOL_COUNT is the number of local symbols.
716 // OUTPUT_SECTION is the output section.
717 // NEEDS_SPECIAL_OFFSET_HANDLING is true if offsets to the output
718 // sections are not mapped as usual. PLOCAL_SYMBOLS points to the
719 // local symbol data from OBJECT. GLOBAL_SYMBOLS is the array of
720 // pointers to the global symbol table from OBJECT.
722 scan_relocs(Symbol_table* symtab,
724 Sized_relobj_file<size, big_endian>* object,
725 unsigned int data_shndx,
726 unsigned int sh_type,
727 const unsigned char* prelocs,
729 Output_section* output_section,
730 bool needs_special_offset_handling,
731 size_t local_symbol_count,
732 const unsigned char* plocal_symbols) = 0;
734 // Relocate section data. SH_TYPE is the type of the relocation
735 // section, SHT_REL or SHT_RELA. PRELOCS points to the relocation
736 // information. RELOC_COUNT is the number of relocs.
737 // OUTPUT_SECTION is the output section.
738 // NEEDS_SPECIAL_OFFSET_HANDLING is true if offsets must be mapped
739 // to correspond to the output section. VIEW is a view into the
740 // output file holding the section contents, VIEW_ADDRESS is the
741 // virtual address of the view, and VIEW_SIZE is the size of the
742 // view. If NEEDS_SPECIAL_OFFSET_HANDLING is true, the VIEW_xx
743 // parameters refer to the complete output section data, not just
744 // the input section data.
746 relocate_section(const Relocate_info<size, big_endian>*,
747 unsigned int sh_type,
748 const unsigned char* prelocs,
750 Output_section* output_section,
751 bool needs_special_offset_handling,
753 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
754 section_size_type view_size,
755 const Reloc_symbol_changes*) = 0;
757 // Scan the relocs during a relocatable link. The parameters are
758 // like scan_relocs, with an additional Relocatable_relocs
759 // parameter, used to record the disposition of the relocs.
761 scan_relocatable_relocs(Symbol_table* symtab,
763 Sized_relobj_file<size, big_endian>* object,
764 unsigned int data_shndx,
765 unsigned int sh_type,
766 const unsigned char* prelocs,
768 Output_section* output_section,
769 bool needs_special_offset_handling,
770 size_t local_symbol_count,
771 const unsigned char* plocal_symbols,
772 Relocatable_relocs*) = 0;
774 // Relocate a section during a relocatable link. The parameters are
775 // like relocate_section, with additional parameters for the view of
776 // the output reloc section.
778 relocate_for_relocatable(const Relocate_info<size, big_endian>*,
779 unsigned int sh_type,
780 const unsigned char* prelocs,
782 Output_section* output_section,
783 off_t offset_in_output_section,
784 const Relocatable_relocs*,
786 typename elfcpp::Elf_types<size>::Elf_Addr
788 section_size_type view_size,
789 unsigned char* reloc_view,
790 section_size_type reloc_view_size) = 0;
792 // Perform target-specific processing in a relocatable link. This is
793 // only used if we use the relocation strategy RELOC_SPECIAL.
794 // RELINFO points to a Relocation_info structure. SH_TYPE is the relocation
795 // section type. PRELOC_IN points to the original relocation. RELNUM is
796 // the index number of the relocation in the relocation section.
797 // OUTPUT_SECTION is the output section to which the relocation is applied.
798 // OFFSET_IN_OUTPUT_SECTION is the offset of the relocation input section
799 // within the output section. VIEW points to the output view of the
800 // output section. VIEW_ADDRESS is output address of the view. VIEW_SIZE
801 // is the size of the output view and PRELOC_OUT points to the new
802 // relocation in the output object.
804 // A target only needs to override this if the generic code in
805 // target-reloc.h cannot handle some relocation types.
808 relocate_special_relocatable(const Relocate_info<size, big_endian>*
810 unsigned int /* sh_type */,
811 const unsigned char* /* preloc_in */,
813 Output_section* /* output_section */,
814 off_t /* offset_in_output_section */,
815 unsigned char* /* view */,
816 typename elfcpp::Elf_types<size>::Elf_Addr
818 section_size_type /* view_size */,
819 unsigned char* /* preloc_out*/)
820 { gold_unreachable(); }
822 // Return the number of entries in the GOT. This is only used for
823 // laying out the incremental link info sections. A target needs
824 // to implement this to support incremental linking.
827 got_entry_count() const
828 { gold_unreachable(); }
830 // Return the number of entries in the PLT. This is only used for
831 // laying out the incremental link info sections. A target needs
832 // to implement this to support incremental linking.
835 plt_entry_count() const
836 { gold_unreachable(); }
838 // Return the offset of the first non-reserved PLT entry. This is
839 // only used for laying out the incremental link info sections.
840 // A target needs to implement this to support incremental linking.
843 first_plt_entry_offset() const
844 { gold_unreachable(); }
846 // Return the size of each PLT entry. This is only used for
847 // laying out the incremental link info sections. A target needs
848 // to implement this to support incremental linking.
851 plt_entry_size() const
852 { gold_unreachable(); }
854 // Create the GOT and PLT sections for an incremental update.
855 // A target needs to implement this to support incremental linking.
857 virtual Output_data_got_base*
858 init_got_plt_for_update(Symbol_table*,
860 unsigned int /* got_count */,
861 unsigned int /* plt_count */)
862 { gold_unreachable(); }
864 // Reserve a GOT entry for a local symbol, and regenerate any
865 // necessary dynamic relocations.
867 reserve_local_got_entry(unsigned int /* got_index */,
868 Sized_relobj<size, big_endian>* /* obj */,
869 unsigned int /* r_sym */,
870 unsigned int /* got_type */)
871 { gold_unreachable(); }
873 // Reserve a GOT entry for a global symbol, and regenerate any
874 // necessary dynamic relocations.
876 reserve_global_got_entry(unsigned int /* got_index */, Symbol* /* gsym */,
877 unsigned int /* got_type */)
878 { gold_unreachable(); }
880 // Register an existing PLT entry for a global symbol.
881 // A target needs to implement this to support incremental linking.
884 register_global_plt_entry(Symbol_table*, Layout*,
885 unsigned int /* plt_index */,
887 { gold_unreachable(); }
889 // Force a COPY relocation for a given symbol.
890 // A target needs to implement this to support incremental linking.
893 emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t)
894 { gold_unreachable(); }
896 // Apply an incremental relocation.
899 apply_relocation(const Relocate_info<size, big_endian>* /* relinfo */,
900 typename elfcpp::Elf_types<size>::Elf_Addr /* r_offset */,
901 unsigned int /* r_type */,
902 typename elfcpp::Elf_types<size>::Elf_Swxword /* r_addend */,
903 const Symbol* /* gsym */,
904 unsigned char* /* view */,
905 typename elfcpp::Elf_types<size>::Elf_Addr /* address */,
906 section_size_type /* view_size */)
907 { gold_unreachable(); }
910 Sized_target(const Target::Target_info* pti)
913 gold_assert(pti->size == size);
914 gold_assert(pti->is_big_endian ? big_endian : !big_endian);
917 // Set the EI_OSABI field if requested.
919 do_adjust_elf_header(unsigned char*, int) const;
922 } // End namespace gold.
924 #endif // !defined(GOLD_TARGET_H)