1 // output.h -- manage the output file for gold -*- C++ -*-
11 #include "reloc-types.h"
16 class General_options
;
22 template<int size
, bool big_endian
>
24 template<int size
, bool big_endian
>
27 // An abtract class for data which has to go into the output file.
32 explicit Output_data(off_t data_size
= 0)
33 : address_(0), data_size_(data_size
), offset_(-1)
39 // Return the address. This is only valid after Layout::finalize is
43 { return this->address_
; }
45 // Return the size of the data. This must be valid after
46 // Layout::finalize calls set_address, but need not be valid before
50 { return this->data_size_
; }
52 // Return the file offset. This is only valid after
53 // Layout::finalize is finished.
56 { return this->offset_
; }
58 // Return the required alignment.
61 { return this->do_addralign(); }
63 // Return whether this is an Output_section.
66 { return this->do_is_section(); }
68 // Return whether this is an Output_section of the specified type.
70 is_section_type(elfcpp::Elf_Word stt
) const
71 { return this->do_is_section_type(stt
); }
73 // Return whether this is an Output_section with the specified flag
76 is_section_flag_set(elfcpp::Elf_Xword shf
) const
77 { return this->do_is_section_flag_set(shf
); }
79 // Return the output section index, if there is an output section.
82 { return this->do_out_shndx(); }
84 // Set the output section index, if this is an output section.
86 set_out_shndx(unsigned int shndx
)
87 { this->do_set_out_shndx(shndx
); }
89 // Set the address and file offset of this data. This is called
90 // during Layout::finalize.
92 set_address(uint64_t addr
, off_t off
);
94 // Write the data to the output file. This is called after
95 // Layout::finalize is complete.
97 write(Output_file
* file
)
98 { this->do_write(file
); }
100 // This is called by Layout::finalize to note that all sizes must
104 { Output_data::sizes_are_fixed
= true; }
107 // Functions that child classes may or in some cases must implement.
109 // Write the data to the output file.
111 do_write(Output_file
*) = 0;
113 // Return the required alignment.
115 do_addralign() const = 0;
117 // Return whether this is an Output_section.
119 do_is_section() const
122 // Return whether this is an Output_section of the specified type.
123 // This only needs to be implement by Output_section.
125 do_is_section_type(elfcpp::Elf_Word
) const
128 // Return whether this is an Output_section with the specific flag
129 // set. This only needs to be implemented by Output_section.
131 do_is_section_flag_set(elfcpp::Elf_Xword
) const
134 // Return the output section index, if there is an output section.
137 { gold_unreachable(); }
139 // Set the output section index, if this is an output section.
141 do_set_out_shndx(unsigned int)
142 { gold_unreachable(); }
144 // Set the address and file offset of the data. This only needs to
145 // be implemented if the child needs to know. The child class can
146 // set its size in this call.
148 do_set_address(uint64_t, off_t
)
151 // Functions that child classes may call.
153 // Set the size of the data.
155 set_data_size(off_t data_size
)
157 gold_assert(!Output_data::sizes_are_fixed
);
158 this->data_size_
= data_size
;
161 // Return default alignment for a size--32 or 64.
163 default_alignment(int size
);
166 Output_data(const Output_data
&);
167 Output_data
& operator=(const Output_data
&);
169 // This is used for verification, to make sure that we don't try to
170 // change any sizes after we set the section addresses.
171 static bool sizes_are_fixed
;
173 // Memory address in file (not always meaningful).
175 // Size of data in file.
177 // Offset within file.
181 // Output the section headers.
183 class Output_section_headers
: public Output_data
186 Output_section_headers(int size
,
189 const Layout::Segment_list
*,
190 const Layout::Section_list
*,
193 // Write the data to the file.
195 do_write(Output_file
*);
197 // Return the required alignment.
200 { return Output_data::default_alignment(this->size_
); }
203 // Write the data to the file with the right size and endianness.
204 template<int size
, bool big_endian
>
206 do_sized_write(Output_file
*);
210 const Layout
* layout_
;
211 const Layout::Segment_list
* segment_list_
;
212 const Layout::Section_list
* unattached_section_list_
;
213 const Stringpool
* secnamepool_
;
216 // Output the segment headers.
218 class Output_segment_headers
: public Output_data
221 Output_segment_headers(int size
, bool big_endian
,
222 const Layout::Segment_list
& segment_list
);
224 // Write the data to the file.
226 do_write(Output_file
*);
228 // Return the required alignment.
231 { return Output_data::default_alignment(this->size_
); }
234 // Write the data to the file with the right size and endianness.
235 template<int size
, bool big_endian
>
237 do_sized_write(Output_file
*);
241 const Layout::Segment_list
& segment_list_
;
244 // Output the ELF file header.
246 class Output_file_header
: public Output_data
249 Output_file_header(int size
,
253 const Output_segment_headers
*);
255 // Add information about the section headers. We lay out the ELF
256 // file header before we create the section headers.
257 void set_section_info(const Output_section_headers
*,
258 const Output_section
* shstrtab
);
260 // Write the data to the file.
262 do_write(Output_file
*);
264 // Return the required alignment.
267 { return Output_data::default_alignment(this->size_
); }
269 // Set the address and offset--we only implement this for error
272 do_set_address(uint64_t, off_t off
) const
273 { gold_assert(off
== 0); }
276 // Write the data to the file with the right size and endianness.
277 template<int size
, bool big_endian
>
279 do_sized_write(Output_file
*);
283 const Target
* target_
;
284 const Symbol_table
* symtab_
;
285 const Output_segment_headers
* segment_header_
;
286 const Output_section_headers
* section_header_
;
287 const Output_section
* shstrtab_
;
290 // Output sections are mainly comprised of input sections. However,
291 // there are cases where we have data to write out which is not in an
292 // input section. Output_section_data is used in such cases. This is
293 // an abstract base class.
295 class Output_section_data
: public Output_data
298 Output_section_data(off_t data_size
, uint64_t addralign
)
299 : Output_data(data_size
), output_section_(NULL
), addralign_(addralign
)
302 Output_section_data(uint64_t addralign
)
303 : Output_data(0), output_section_(NULL
), addralign_(addralign
)
306 // Return the output section.
307 const Output_section
*
308 output_section() const
309 { return this->output_section_
; }
311 // Record the output section.
313 set_output_section(Output_section
* os
);
315 // Add an input section, for SHF_MERGE sections. This returns true
316 // if the section was handled.
318 add_input_section(Relobj
* object
, unsigned int shndx
)
319 { return this->do_add_input_section(object
, shndx
); }
321 // Given an input OBJECT, an input section index SHNDX within that
322 // object, and an OFFSET relative to the start of that input
323 // section, return whether or not the output address is known.
324 // OUTPUT_SECTION_ADDRESS is the address of the output section which
325 // this is a part of. If this function returns true, it sets
326 // *POUTPUT to the output address.
328 output_address(const Relobj
* object
, unsigned int shndx
, off_t offset
,
329 uint64_t output_section_address
, uint64_t *poutput
) const
331 return this->do_output_address(object
, shndx
, offset
,
332 output_section_address
, poutput
);
336 // The child class must implement do_write.
338 // The child class may implement specific adjustments to the output
341 do_adjust_output_section(Output_section
*)
344 // May be implemented by child class. Return true if the section
347 do_add_input_section(Relobj
*, unsigned int)
348 { gold_unreachable(); }
350 // The child class may implement output_address.
352 do_output_address(const Relobj
*, unsigned int, off_t
, uint64_t,
356 // Return the required alignment.
359 { return this->addralign_
; }
361 // Return the section index of the output section.
363 do_out_shndx() const;
365 // Set the alignment.
367 set_addralign(uint64_t addralign
)
368 { this->addralign_
= addralign
; }
371 // The output section for this section.
372 const Output_section
* output_section_
;
373 // The required alignment.
377 // A simple case of Output_data in which we have constant data to
380 class Output_data_const
: public Output_section_data
383 Output_data_const(const std::string
& data
, uint64_t addralign
)
384 : Output_section_data(data
.size(), addralign
), data_(data
)
387 Output_data_const(const char* p
, off_t len
, uint64_t addralign
)
388 : Output_section_data(len
, addralign
), data_(p
, len
)
391 Output_data_const(const unsigned char* p
, off_t len
, uint64_t addralign
)
392 : Output_section_data(len
, addralign
),
393 data_(reinterpret_cast<const char*>(p
), len
)
398 add_data(const std::string
& add
)
400 this->data_
.append(add
);
401 this->set_data_size(this->data_
.size());
404 // Write the data to the output file.
406 do_write(Output_file
*);
412 // Another version of Output_data with constant data, in which the
413 // buffer is allocated by the caller.
415 class Output_data_const_buffer
: public Output_section_data
418 Output_data_const_buffer(const unsigned char* p
, off_t len
,
420 : Output_section_data(len
, addralign
), p_(p
)
423 // Write the data the output file.
425 do_write(Output_file
*);
428 const unsigned char* p_
;
431 // A place holder for data written out via some other mechanism.
433 class Output_data_space
: public Output_section_data
436 Output_data_space(off_t data_size
, uint64_t addralign
)
437 : Output_section_data(data_size
, addralign
)
440 explicit Output_data_space(uint64_t addralign
)
441 : Output_section_data(addralign
)
446 set_space_size(off_t space_size
)
447 { this->set_data_size(space_size
); }
449 // Set the alignment.
451 set_space_alignment(uint64_t align
)
452 { this->set_addralign(align
); }
454 // Write out the data--this must be handled elsewhere.
456 do_write(Output_file
*)
460 // A string table which goes into an output section.
462 class Output_data_strtab
: public Output_section_data
465 Output_data_strtab(Stringpool
* strtab
)
466 : Output_section_data(1), strtab_(strtab
)
469 // This is called to set the address and file offset. Here we make
470 // sure that the Stringpool is finalized.
472 do_set_address(uint64_t, off_t
);
474 // Write out the data.
476 do_write(Output_file
*);
482 // This POD class is used to represent a single reloc in the output
483 // file. This could be a private class within Output_data_reloc, but
484 // the templatization is complex enough that I broke it out into a
485 // separate class. The class is templatized on either elfcpp::SHT_REL
486 // or elfcpp::SHT_RELA, and also on whether this is a dynamic
487 // relocation or an ordinary relocation.
489 // A relocation can be against a global symbol, a local symbol, an
490 // output section, or the undefined symbol at index 0. We represent
491 // the latter by using a NULL global symbol.
493 template<int sh_type
, bool dynamic
, int size
, bool big_endian
>
496 template<bool dynamic
, int size
, bool big_endian
>
497 class Output_reloc
<elfcpp::SHT_REL
, dynamic
, size
, big_endian
>
500 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
502 // An uninitialized entry. We need this because we want to put
503 // instances of this class into an STL container.
505 : local_sym_index_(INVALID_CODE
)
508 // A reloc against a global symbol.
510 Output_reloc(Symbol
* gsym
, unsigned int type
, Output_data
* od
,
512 : address_(address
), local_sym_index_(GSYM_CODE
), type_(type
),
515 this->u1_
.gsym
= gsym
;
519 Output_reloc(Symbol
* gsym
, unsigned int type
, Relobj
* relobj
,
520 unsigned int shndx
, Address address
)
521 : address_(address
), local_sym_index_(GSYM_CODE
), type_(type
),
524 gold_assert(shndx
!= INVALID_CODE
);
525 this->u1_
.gsym
= gsym
;
526 this->u2_
.relobj
= relobj
;
529 // A reloc against a local symbol.
531 Output_reloc(Sized_relobj
<size
, big_endian
>* relobj
,
532 unsigned int local_sym_index
,
536 : address_(address
), local_sym_index_(local_sym_index
), type_(type
),
539 gold_assert(local_sym_index
!= GSYM_CODE
540 && local_sym_index
!= INVALID_CODE
);
541 this->u1_
.relobj
= relobj
;
545 Output_reloc(Sized_relobj
<size
, big_endian
>* relobj
,
546 unsigned int local_sym_index
,
550 : address_(address
), local_sym_index_(local_sym_index
), type_(type
),
553 gold_assert(local_sym_index
!= GSYM_CODE
554 && local_sym_index
!= INVALID_CODE
);
555 gold_assert(shndx
!= INVALID_CODE
);
556 this->u1_
.relobj
= relobj
;
557 this->u2_
.relobj
= relobj
;
560 // A reloc against the STT_SECTION symbol of an output section.
562 Output_reloc(Output_section
* os
, unsigned int type
, Output_data
* od
,
564 : address_(address
), local_sym_index_(SECTION_CODE
), type_(type
),
571 Output_reloc(Output_section
* os
, unsigned int type
, Relobj
* relobj
,
572 unsigned int shndx
, Address address
)
573 : address_(address
), local_sym_index_(SECTION_CODE
), type_(type
),
576 gold_assert(shndx
!= INVALID_CODE
);
578 this->u2_
.relobj
= relobj
;
581 // Write the reloc entry to an output view.
583 write(unsigned char* pov
) const;
585 // Write the offset and info fields to Write_rel.
586 template<typename Write_rel
>
587 void write_rel(Write_rel
*) const;
590 // Return the symbol index. We can't do a double template
591 // specialization, so we do a secondary template here.
593 get_symbol_index() const;
595 // Codes for local_sym_index_.
602 // Invalid uninitialized entry.
608 // For a local symbol, the object. We will never generate a
609 // relocation against a local symbol in a dynamic object; that
610 // doesn't make sense. And our callers will always be
611 // templatized, so we use Sized_relobj here.
612 Sized_relobj
<size
, big_endian
>* relobj
;
613 // For a global symbol, the symbol. If this is NULL, it indicates
614 // a relocation against the undefined 0 symbol.
616 // For a relocation against an output section, the output section.
621 // If shndx_ is not INVALID CODE, the object which holds the input
622 // section being used to specify the reloc address.
624 // If shndx_ is INVALID_CODE, the output data being used to
625 // specify the reloc address. This may be NULL if the reloc
626 // address is absolute.
629 // The address offset within the input section or the Output_data.
631 // For a local symbol, the local symbol index. This is GSYM_CODE
632 // for a global symbol, or INVALID_CODE for an uninitialized value.
633 unsigned int local_sym_index_
;
634 // The reloc type--a processor specific code.
636 // If the reloc address is an input section in an object, the
637 // section index. This is INVALID_CODE if the reloc address is
638 // specified in some other way.
642 // The SHT_RELA version of Output_reloc<>. This is just derived from
643 // the SHT_REL version of Output_reloc, but it adds an addend.
645 template<bool dynamic
, int size
, bool big_endian
>
646 class Output_reloc
<elfcpp::SHT_RELA
, dynamic
, size
, big_endian
>
649 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
650 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Addend
;
652 // An uninitialized entry.
657 // A reloc against a global symbol.
659 Output_reloc(Symbol
* gsym
, unsigned int type
, Output_data
* od
,
660 Address address
, Addend addend
)
661 : rel_(gsym
, type
, od
, address
), addend_(addend
)
664 Output_reloc(Symbol
* gsym
, unsigned int type
, Relobj
* relobj
,
665 unsigned int shndx
, Address address
, Addend addend
)
666 : rel_(gsym
, type
, relobj
, shndx
, address
), addend_(addend
)
669 // A reloc against a local symbol.
671 Output_reloc(Sized_relobj
<size
, big_endian
>* relobj
,
672 unsigned int local_sym_index
,
673 unsigned int type
, Output_data
* od
, Address address
,
675 : rel_(relobj
, local_sym_index
, type
, od
, address
), addend_(addend
)
678 Output_reloc(Sized_relobj
<size
, big_endian
>* relobj
,
679 unsigned int local_sym_index
,
684 : rel_(relobj
, local_sym_index
, type
, shndx
, address
),
688 // A reloc against the STT_SECTION symbol of an output section.
690 Output_reloc(Output_section
* os
, unsigned int type
, Output_data
* od
,
691 Address address
, Addend addend
)
692 : rel_(os
, type
, od
, address
), addend_(addend
)
695 Output_reloc(Output_section
* os
, unsigned int type
, Relobj
* relobj
,
696 unsigned int shndx
, Address address
, Addend addend
)
697 : rel_(os
, type
, relobj
, shndx
, address
), addend_(addend
)
700 // Write the reloc entry to an output view.
702 write(unsigned char* pov
) const;
706 Output_reloc
<elfcpp::SHT_REL
, dynamic
, size
, big_endian
> rel_
;
711 // Output_data_reloc is used to manage a section containing relocs.
712 // SH_TYPE is either elfcpp::SHT_REL or elfcpp::SHT_RELA. DYNAMIC
713 // indicates whether this is a dynamic relocation or a normal
714 // relocation. Output_data_reloc_base is a base class.
715 // Output_data_reloc is the real class, which we specialize based on
718 template<int sh_type
, bool dynamic
, int size
, bool big_endian
>
719 class Output_data_reloc_base
: public Output_section_data
722 typedef Output_reloc
<sh_type
, dynamic
, size
, big_endian
> Output_reloc_type
;
723 typedef typename
Output_reloc_type::Address Address
;
724 static const int reloc_size
=
725 Reloc_types
<sh_type
, size
, big_endian
>::reloc_size
;
727 // Construct the section.
728 Output_data_reloc_base()
729 : Output_section_data(Output_data::default_alignment(size
))
732 // Write out the data.
734 do_write(Output_file
*);
737 // Set the entry size and the link.
739 do_adjust_output_section(Output_section
*os
);
741 // Add a relocation entry.
743 add(const Output_reloc_type
& reloc
)
745 this->relocs_
.push_back(reloc
);
746 this->set_data_size(this->relocs_
.size() * reloc_size
);
750 typedef std::vector
<Output_reloc_type
> Relocs
;
755 // The class which callers actually create.
757 template<int sh_type
, bool dynamic
, int size
, bool big_endian
>
758 class Output_data_reloc
;
760 // The SHT_REL version of Output_data_reloc.
762 template<bool dynamic
, int size
, bool big_endian
>
763 class Output_data_reloc
<elfcpp::SHT_REL
, dynamic
, size
, big_endian
>
764 : public Output_data_reloc_base
<elfcpp::SHT_REL
, dynamic
, size
, big_endian
>
767 typedef Output_data_reloc_base
<elfcpp::SHT_REL
, dynamic
, size
,
771 typedef typename
Base::Output_reloc_type Output_reloc_type
;
772 typedef typename
Output_reloc_type::Address Address
;
775 : Output_data_reloc_base
<elfcpp::SHT_REL
, dynamic
, size
, big_endian
>()
778 // Add a reloc against a global symbol.
781 add_global(Symbol
* gsym
, unsigned int type
, Output_data
* od
, Address address
)
782 { this->add(Output_reloc_type(gsym
, type
, od
, address
)); }
785 add_global(Symbol
* gsym
, unsigned int type
, Relobj
* relobj
,
786 unsigned int shndx
, Address address
)
787 { this->add(Output_reloc_type(gsym
, type
, relobj
, shndx
, address
)); }
789 // Add a reloc against a local symbol.
792 add_local(Sized_relobj
<size
, big_endian
>* relobj
,
793 unsigned int local_sym_index
, unsigned int type
,
794 Output_data
* od
, Address address
)
795 { this->add(Output_reloc_type(relobj
, local_sym_index
, type
, od
, address
)); }
798 add_local(Sized_relobj
<size
, big_endian
>* relobj
,
799 unsigned int local_sym_index
, unsigned int type
,
800 unsigned int shndx
, Address address
)
801 { this->add(Output_reloc_type(relobj
, local_sym_index
, type
, shndx
,
805 // A reloc against the STT_SECTION symbol of an output section.
808 add_output_section(Output_section
* os
, unsigned int type
,
809 Output_data
* od
, Address address
)
810 { this->add(Output_reloc_type(os
, type
, od
, address
)); }
813 add_output_section(Output_section
* os
, unsigned int type
,
814 Relobj
* relobj
, unsigned int shndx
, Address address
)
815 { this->add(Output_reloc_type(os
, type
, relobj
, shndx
, address
)); }
818 // The SHT_RELA version of Output_data_reloc.
820 template<bool dynamic
, int size
, bool big_endian
>
821 class Output_data_reloc
<elfcpp::SHT_RELA
, dynamic
, size
, big_endian
>
822 : public Output_data_reloc_base
<elfcpp::SHT_RELA
, dynamic
, size
, big_endian
>
825 typedef Output_data_reloc_base
<elfcpp::SHT_RELA
, dynamic
, size
,
829 typedef typename
Base::Output_reloc_type Output_reloc_type
;
830 typedef typename
Output_reloc_type::Address Address
;
831 typedef typename
Output_reloc_type::Addend Addend
;
834 : Output_data_reloc_base
<elfcpp::SHT_RELA
, dynamic
, size
, big_endian
>()
837 // Add a reloc against a global symbol.
840 add_global(Symbol
* gsym
, unsigned int type
, Output_data
* od
,
841 Address address
, Addend addend
)
842 { this->add(Output_reloc_type(gsym
, type
, od
, address
, addend
)); }
845 add_global(Symbol
* gsym
, unsigned int type
, Relobj
* relobj
,
846 unsigned int shndx
, Address address
, Addend addend
)
847 { this->add(Output_reloc_type(gsym
, type
, relobj
, shndx
, address
, addend
)); }
849 // Add a reloc against a local symbol.
852 add_local(Sized_relobj
<size
, big_endian
>* relobj
,
853 unsigned int local_sym_index
, unsigned int type
,
854 Output_data
* od
, Address address
, Addend addend
)
856 this->add(Output_reloc_type(relobj
, local_sym_index
, type
, od
, address
,
861 add_local(Sized_relobj
<size
, big_endian
>* relobj
,
862 unsigned int local_sym_index
, unsigned int type
,
863 unsigned int shndx
, Address address
, Addend addend
)
865 this->add(Output_reloc_type(relobj
, local_sym_index
, type
, shndx
, address
,
869 // A reloc against the STT_SECTION symbol of an output section.
872 add_output_section(Output_section
* os
, unsigned int type
, Output_data
* od
,
873 Address address
, Addend addend
)
874 { this->add(Output_reloc_type(os
, type
, od
, address
, addend
)); }
877 add_output_section(Output_section
* os
, unsigned int type
, Relobj
* relobj
,
878 unsigned int shndx
, Address address
, Addend addend
)
879 { this->add(Output_reloc_type(os
, type
, relobj
, shndx
, address
, addend
)); }
882 // Output_data_got is used to manage a GOT. Each entry in the GOT is
883 // for one symbol--either a global symbol or a local symbol in an
884 // object. The target specific code adds entries to the GOT as
887 template<int size
, bool big_endian
>
888 class Output_data_got
: public Output_section_data
891 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Valtype
;
894 : Output_section_data(Output_data::default_alignment(size
)), entries_()
897 // Add an entry for a global symbol to the GOT. Return true if this
898 // is a new GOT entry, false if the symbol was already in the GOT.
900 add_global(Symbol
* gsym
);
902 // Add an entry for a local symbol to the GOT. This returns the
903 // offset of the new entry from the start of the GOT.
905 add_local(Object
* object
, unsigned int sym_index
)
907 this->entries_
.push_back(Got_entry(object
, sym_index
));
908 this->set_got_size();
909 return this->last_got_offset();
912 // Add a constant to the GOT. This returns the offset of the new
913 // entry from the start of the GOT.
915 add_constant(Valtype constant
)
917 this->entries_
.push_back(Got_entry(constant
));
918 this->set_got_size();
919 return this->last_got_offset();
922 // Write out the GOT table.
924 do_write(Output_file
*);
927 // This POD class holds a single GOT entry.
931 // Create a zero entry.
933 : local_sym_index_(CONSTANT_CODE
)
934 { this->u_
.constant
= 0; }
936 // Create a global symbol entry.
937 explicit Got_entry(Symbol
* gsym
)
938 : local_sym_index_(GSYM_CODE
)
939 { this->u_
.gsym
= gsym
; }
941 // Create a local symbol entry.
942 Got_entry(Object
* object
, unsigned int local_sym_index
)
943 : local_sym_index_(local_sym_index
)
945 gold_assert(local_sym_index
!= GSYM_CODE
946 && local_sym_index
!= CONSTANT_CODE
);
947 this->u_
.object
= object
;
950 // Create a constant entry. The constant is a host value--it will
951 // be swapped, if necessary, when it is written out.
952 explicit Got_entry(Valtype constant
)
953 : local_sym_index_(CONSTANT_CODE
)
954 { this->u_
.constant
= constant
; }
956 // Write the GOT entry to an output view.
958 write(unsigned char* pov
) const;
969 // For a local symbol, the object.
971 // For a global symbol, the symbol.
973 // For a constant, the constant.
976 // For a local symbol, the local symbol index. This is GSYM_CODE
977 // for a global symbol, or CONSTANT_CODE for a constant.
978 unsigned int local_sym_index_
;
981 typedef std::vector
<Got_entry
> Got_entries
;
983 // Return the offset into the GOT of GOT entry I.
985 got_offset(unsigned int i
) const
986 { return i
* (size
/ 8); }
988 // Return the offset into the GOT of the last entry added.
990 last_got_offset() const
991 { return this->got_offset(this->entries_
.size() - 1); }
993 // Set the size of the section.
996 { this->set_data_size(this->got_offset(this->entries_
.size())); }
998 // The list of GOT entries.
999 Got_entries entries_
;
1002 // Output_data_dynamic is used to hold the data in SHT_DYNAMIC
1005 class Output_data_dynamic
: public Output_section_data
1008 Output_data_dynamic(const Target
* target
, Stringpool
* pool
)
1009 : Output_section_data(Output_data::default_alignment(target
->get_size())),
1010 target_(target
), entries_(), pool_(pool
)
1013 // Add a new dynamic entry with a fixed numeric value.
1015 add_constant(elfcpp::DT tag
, unsigned int val
)
1016 { this->add_entry(Dynamic_entry(tag
, val
)); }
1018 // Add a new dynamic entry with the address of output data.
1020 add_section_address(elfcpp::DT tag
, const Output_data
* od
)
1021 { this->add_entry(Dynamic_entry(tag
, od
, false)); }
1023 // Add a new dynamic entry with the size of output data.
1025 add_section_size(elfcpp::DT tag
, const Output_data
* od
)
1026 { this->add_entry(Dynamic_entry(tag
, od
, true)); }
1028 // Add a new dynamic entry with the address of a symbol.
1030 add_symbol(elfcpp::DT tag
, const Symbol
* sym
)
1031 { this->add_entry(Dynamic_entry(tag
, sym
)); }
1033 // Add a new dynamic entry with a string.
1035 add_string(elfcpp::DT tag
, const char* str
)
1036 { this->add_entry(Dynamic_entry(tag
, this->pool_
->add(str
, NULL
))); }
1039 add_string(elfcpp::DT tag
, const std::string
& str
)
1040 { this->add_string(tag
, str
.c_str()); }
1042 // Set the final data size.
1044 do_set_address(uint64_t, off_t
);
1046 // Write out the dynamic entries.
1048 do_write(Output_file
*);
1051 // Adjust the output section to set the entry size.
1053 do_adjust_output_section(Output_section
*);
1056 // This POD class holds a single dynamic entry.
1060 // Create an entry with a fixed numeric value.
1061 Dynamic_entry(elfcpp::DT tag
, unsigned int val
)
1062 : tag_(tag
), classification_(DYNAMIC_NUMBER
)
1063 { this->u_
.val
= val
; }
1065 // Create an entry with the size or address of a section.
1066 Dynamic_entry(elfcpp::DT tag
, const Output_data
* od
, bool section_size
)
1068 classification_(section_size
1069 ? DYNAMIC_SECTION_SIZE
1070 : DYNAMIC_SECTION_ADDRESS
)
1071 { this->u_
.od
= od
; }
1073 // Create an entry with the address of a symbol.
1074 Dynamic_entry(elfcpp::DT tag
, const Symbol
* sym
)
1075 : tag_(tag
), classification_(DYNAMIC_SYMBOL
)
1076 { this->u_
.sym
= sym
; }
1078 // Create an entry with a string.
1079 Dynamic_entry(elfcpp::DT tag
, const char* str
)
1080 : tag_(tag
), classification_(DYNAMIC_STRING
)
1081 { this->u_
.str
= str
; }
1083 // Write the dynamic entry to an output view.
1084 template<int size
, bool big_endian
>
1086 write(unsigned char* pov
, const Stringpool
* ACCEPT_SIZE_ENDIAN
) const;
1094 DYNAMIC_SECTION_ADDRESS
,
1096 DYNAMIC_SECTION_SIZE
,
1105 // For DYNAMIC_NUMBER.
1107 // For DYNAMIC_SECTION_ADDRESS and DYNAMIC_SECTION_SIZE.
1108 const Output_data
* od
;
1109 // For DYNAMIC_SYMBOL.
1111 // For DYNAMIC_STRING.
1116 // The type of entry.
1117 Classification classification_
;
1120 // Add an entry to the list.
1122 add_entry(const Dynamic_entry
& entry
)
1123 { this->entries_
.push_back(entry
); }
1125 // Sized version of write function.
1126 template<int size
, bool big_endian
>
1128 sized_write(Output_file
* of
);
1130 // The type of the list of entries.
1131 typedef std::vector
<Dynamic_entry
> Dynamic_entries
;
1134 const Target
* target_
;
1136 Dynamic_entries entries_
;
1137 // The pool used for strings.
1141 // An output section. We don't expect to have too many output
1142 // sections, so we don't bother to do a template on the size.
1144 class Output_section
: public Output_data
1147 // Create an output section, giving the name, type, and flags.
1148 Output_section(const char* name
, elfcpp::Elf_Word
, elfcpp::Elf_Xword
);
1149 virtual ~Output_section();
1151 // Add a new input section SHNDX, named NAME, with header SHDR, from
1152 // object OBJECT. Return the offset within the output section.
1153 template<int size
, bool big_endian
>
1155 add_input_section(Relobj
* object
, unsigned int shndx
, const char *name
,
1156 const elfcpp::Shdr
<size
, big_endian
>& shdr
);
1158 // Add generated data POSD to this output section.
1160 add_output_section_data(Output_section_data
* posd
);
1162 // Return the section name.
1165 { return this->name_
; }
1167 // Return the section type.
1170 { return this->type_
; }
1172 // Return the section flags.
1175 { return this->flags_
; }
1177 // Return the section index in the output file.
1179 do_out_shndx() const
1180 { return this->out_shndx_
; }
1182 // Set the output section index.
1184 do_set_out_shndx(unsigned int shndx
)
1185 { this->out_shndx_
= shndx
; }
1187 // Return the entsize field.
1190 { return this->entsize_
; }
1192 // Set the entsize field.
1194 set_entsize(uint64_t v
);
1196 // Set the link field to the output section index of a section.
1198 set_link_section(const Output_data
* od
)
1200 gold_assert(this->link_
== 0
1201 && !this->should_link_to_symtab_
1202 && !this->should_link_to_dynsym_
);
1203 this->link_section_
= od
;
1206 // Set the link field to a constant.
1208 set_link(unsigned int v
)
1210 gold_assert(this->link_section_
== NULL
1211 && !this->should_link_to_symtab_
1212 && !this->should_link_to_dynsym_
);
1216 // Record that this section should link to the normal symbol table.
1218 set_should_link_to_symtab()
1220 gold_assert(this->link_section_
== NULL
1222 && !this->should_link_to_dynsym_
);
1223 this->should_link_to_symtab_
= true;
1226 // Record that this section should link to the dynamic symbol table.
1228 set_should_link_to_dynsym()
1230 gold_assert(this->link_section_
== NULL
1232 && !this->should_link_to_symtab_
);
1233 this->should_link_to_dynsym_
= true;
1236 // Return the info field.
1240 gold_assert(this->info_section_
== NULL
);
1244 // Set the info field to the output section index of a section.
1246 set_info_section(const Output_data
* od
)
1248 gold_assert(this->info_
== 0);
1249 this->info_section_
= od
;
1252 // Set the info field to a constant.
1254 set_info(unsigned int v
)
1256 gold_assert(this->info_section_
== NULL
);
1260 // Set the addralign field.
1262 set_addralign(uint64_t v
)
1263 { this->addralign_
= v
; }
1265 // Indicate that we need a symtab index.
1267 set_needs_symtab_index()
1268 { this->needs_symtab_index_
= true; }
1270 // Return whether we need a symtab index.
1272 needs_symtab_index() const
1273 { return this->needs_symtab_index_
; }
1275 // Get the symtab index.
1277 symtab_index() const
1279 gold_assert(this->symtab_index_
!= 0);
1280 return this->symtab_index_
;
1283 // Set the symtab index.
1285 set_symtab_index(unsigned int index
)
1287 gold_assert(index
!= 0);
1288 this->symtab_index_
= index
;
1291 // Indicate that we need a dynsym index.
1293 set_needs_dynsym_index()
1294 { this->needs_dynsym_index_
= true; }
1296 // Return whether we need a dynsym index.
1298 needs_dynsym_index() const
1299 { return this->needs_dynsym_index_
; }
1301 // Get the dynsym index.
1303 dynsym_index() const
1305 gold_assert(this->dynsym_index_
!= 0);
1306 return this->dynsym_index_
;
1309 // Set the dynsym index.
1311 set_dynsym_index(unsigned int index
)
1313 gold_assert(index
!= 0);
1314 this->dynsym_index_
= index
;
1317 // Return the output virtual address of OFFSET relative to the start
1318 // of input section SHNDX in object OBJECT.
1320 output_address(const Relobj
* object
, unsigned int shndx
,
1321 off_t offset
) const;
1323 // Set the address of the Output_section. For a typical
1324 // Output_section, there is nothing to do, but if there are any
1325 // Output_section_data objects we need to set the final addresses
1328 do_set_address(uint64_t, off_t
);
1330 // Write the data to the file. For a typical Output_section, this
1331 // does nothing: the data is written out by calling Object::Relocate
1332 // on each input object. But if there are any Output_section_data
1333 // objects we do need to write them out here.
1335 do_write(Output_file
*);
1337 // Return the address alignment--function required by parent class.
1339 do_addralign() const
1340 { return this->addralign_
; }
1342 // Return whether this is an Output_section.
1344 do_is_section() const
1347 // Return whether this is a section of the specified type.
1349 do_is_section_type(elfcpp::Elf_Word type
) const
1350 { return this->type_
== type
; }
1352 // Return whether the specified section flag is set.
1354 do_is_section_flag_set(elfcpp::Elf_Xword flag
) const
1355 { return (this->flags_
& flag
) != 0; }
1357 // Write the section header into *OPHDR.
1358 template<int size
, bool big_endian
>
1360 write_header(const Layout
*, const Stringpool
*,
1361 elfcpp::Shdr_write
<size
, big_endian
>*) const;
1364 // In some cases we need to keep a list of the input sections
1365 // associated with this output section. We only need the list if we
1366 // might have to change the offsets of the input section within the
1367 // output section after we add the input section. The ordinary
1368 // input sections will be written out when we process the object
1369 // file, and as such we don't need to track them here. We do need
1370 // to track Output_section_data objects here. We store instances of
1371 // this structure in a std::vector, so it must be a POD. There can
1372 // be many instances of this structure, so we use a union to save
1378 : shndx_(0), p2align_(0)
1380 this->u1_
.data_size
= 0;
1381 this->u2_
.object
= NULL
;
1384 // For an ordinary input section.
1385 Input_section(Relobj
* object
, unsigned int shndx
, off_t data_size
,
1388 p2align_(ffsll(static_cast<long long>(addralign
)))
1390 gold_assert(shndx
!= OUTPUT_SECTION_CODE
1391 && shndx
!= MERGE_DATA_SECTION_CODE
1392 && shndx
!= MERGE_STRING_SECTION_CODE
);
1393 this->u1_
.data_size
= data_size
;
1394 this->u2_
.object
= object
;
1397 // For a non-merge output section.
1398 Input_section(Output_section_data
* posd
)
1399 : shndx_(OUTPUT_SECTION_CODE
),
1400 p2align_(ffsll(static_cast<long long>(posd
->addralign())))
1402 this->u1_
.data_size
= 0;
1403 this->u2_
.posd
= posd
;
1406 // For a merge section.
1407 Input_section(Output_section_data
* posd
, bool is_string
, uint64_t entsize
)
1409 ? MERGE_STRING_SECTION_CODE
1410 : MERGE_DATA_SECTION_CODE
),
1411 p2align_(ffsll(static_cast<long long>(posd
->addralign())))
1413 this->u1_
.entsize
= entsize
;
1414 this->u2_
.posd
= posd
;
1417 // The required alignment.
1421 return (this->p2align_
== 0
1423 : static_cast<uint64_t>(1) << (this->p2align_
- 1));
1426 // Return the required size.
1430 // Return whether this is a merge section which matches the
1433 is_merge_section(bool is_string
, uint64_t entsize
) const
1435 return (this->shndx_
== (is_string
1436 ? MERGE_STRING_SECTION_CODE
1437 : MERGE_DATA_SECTION_CODE
)
1438 && this->u1_
.entsize
== entsize
);
1441 // Set the output section.
1443 set_output_section(Output_section
* os
)
1445 gold_assert(!this->is_input_section());
1446 this->u2_
.posd
->set_output_section(os
);
1449 // Set the address and file offset. This is called during
1450 // Layout::finalize. SECOFF is the file offset of the enclosing
1453 set_address(uint64_t addr
, off_t off
, off_t secoff
);
1455 // Add an input section, for SHF_MERGE sections.
1457 add_input_section(Relobj
* object
, unsigned int shndx
)
1459 gold_assert(this->shndx_
== MERGE_DATA_SECTION_CODE
1460 || this->shndx_
== MERGE_STRING_SECTION_CODE
);
1461 return this->u2_
.posd
->add_input_section(object
, shndx
);
1464 // Given an input OBJECT, an input section index SHNDX within that
1465 // object, and an OFFSET relative to the start of that input
1466 // section, return whether or not the output address is known.
1467 // OUTPUT_SECTION_ADDRESS is the address of the output section
1468 // which this is a part of. If this function returns true, it
1469 // sets *POUTPUT to the output address.
1471 output_address(const Relobj
* object
, unsigned int shndx
, off_t offset
,
1472 uint64_t output_section_address
, uint64_t *poutput
) const;
1474 // Write out the data. This does nothing for an input section.
1476 write(Output_file
*);
1479 // Code values which appear in shndx_. If the value is not one of
1480 // these codes, it is the input section index in the object file.
1483 // An Output_section_data.
1484 OUTPUT_SECTION_CODE
= -1U,
1485 // An Output_section_data for an SHF_MERGE section with
1486 // SHF_STRINGS not set.
1487 MERGE_DATA_SECTION_CODE
= -2U,
1488 // An Output_section_data for an SHF_MERGE section with
1490 MERGE_STRING_SECTION_CODE
= -3U
1493 // Whether this is an input section.
1495 is_input_section() const
1497 return (this->shndx_
!= OUTPUT_SECTION_CODE
1498 && this->shndx_
!= MERGE_DATA_SECTION_CODE
1499 && this->shndx_
!= MERGE_STRING_SECTION_CODE
);
1502 // For an ordinary input section, this is the section index in the
1503 // input file. For an Output_section_data, this is
1504 // OUTPUT_SECTION_CODE or MERGE_DATA_SECTION_CODE or
1505 // MERGE_STRING_SECTION_CODE.
1506 unsigned int shndx_
;
1507 // The required alignment, stored as a power of 2.
1508 unsigned int p2align_
;
1511 // For an ordinary input section, the section size.
1513 // For OUTPUT_SECTION_CODE, this is not used. For
1514 // MERGE_DATA_SECTION_CODE or MERGE_STRING_SECTION_CODE, the
1520 // For an ordinary input section, the object which holds the
1523 // For OUTPUT_SECTION_CODE or MERGE_DATA_SECTION_CODE or
1524 // MERGE_STRING_SECTION_CODE, the data.
1525 Output_section_data
* posd
;
1529 typedef std::vector
<Input_section
> Input_section_list
;
1531 // Fill data. This is used to fill in data between input sections.
1532 // When we have to keep track of the input sections, we can use an
1533 // Output_data_const, but we don't want to have to keep track of
1534 // input sections just to implement fills. For a fill we record the
1535 // offset, and the actual data to be written out.
1539 Fill(off_t section_offset
, off_t length
)
1540 : section_offset_(section_offset
), length_(length
)
1543 // Return section offset.
1545 section_offset() const
1546 { return this->section_offset_
; }
1548 // Return fill length.
1551 { return this->length_
; }
1554 // The offset within the output section.
1555 off_t section_offset_
;
1556 // The length of the space to fill.
1560 typedef std::vector
<Fill
> Fill_list
;
1562 // Add a new output section by Input_section.
1564 add_output_section_data(Input_section
*);
1566 // Add an SHF_MERGE input section. Returns true if the section was
1569 add_merge_input_section(Relobj
* object
, unsigned int shndx
, uint64_t flags
,
1570 uint64_t entsize
, uint64_t addralign
);
1572 // Add an output SHF_MERGE section POSD to this output section.
1573 // IS_STRING indicates whether it is a SHF_STRINGS section, and
1574 // ENTSIZE is the entity size. This returns the entry added to
1577 add_output_merge_section(Output_section_data
* posd
, bool is_string
,
1580 // Most of these fields are only valid after layout.
1582 // The name of the section. This will point into a Stringpool.
1584 // The section address is in the parent class.
1585 // The section alignment.
1586 uint64_t addralign_
;
1587 // The section entry size.
1589 // The file offset is in the parent class.
1590 // Set the section link field to the index of this section.
1591 const Output_data
* link_section_
;
1592 // If link_section_ is NULL, this is the link field.
1594 // Set the section info field to the index of this section.
1595 const Output_data
* info_section_
;
1596 // If info_section_ is NULL, this is the section info field.
1598 // The section type.
1599 elfcpp::Elf_Word type_
;
1600 // The section flags.
1601 elfcpp::Elf_Xword flags_
;
1602 // The section index.
1603 unsigned int out_shndx_
;
1604 // If there is a STT_SECTION for this output section in the normal
1605 // symbol table, this is the symbol index. This starts out as zero.
1606 // It is initialized in Layout::finalize() to be the index, or -1U
1607 // if there isn't one.
1608 unsigned int symtab_index_
;
1609 // If there is a STT_SECTION for this output section in the dynamic
1610 // symbol table, this is the symbol index. This starts out as zero.
1611 // It is initialized in Layout::finalize() to be the index, or -1U
1612 // if there isn't one.
1613 unsigned int dynsym_index_
;
1614 // The input sections. This will be empty in cases where we don't
1615 // need to keep track of them.
1616 Input_section_list input_sections_
;
1617 // The offset of the first entry in input_sections_.
1618 off_t first_input_offset_
;
1619 // The fill data. This is separate from input_sections_ because we
1620 // often will need fill sections without needing to keep track of
1623 // Whether this output section needs a STT_SECTION symbol in the
1624 // normal symbol table. This will be true if there is a relocation
1626 bool needs_symtab_index_
: 1;
1627 // Whether this output section needs a STT_SECTION symbol in the
1628 // dynamic symbol table. This will be true if there is a dynamic
1629 // relocation which needs it.
1630 bool needs_dynsym_index_
: 1;
1631 // Whether the link field of this output section should point to the
1632 // normal symbol table.
1633 bool should_link_to_symtab_
: 1;
1634 // Whether the link field of this output section should point to the
1635 // dynamic symbol table.
1636 bool should_link_to_dynsym_
: 1;
1639 // An output segment. PT_LOAD segments are built from collections of
1640 // output sections. Other segments typically point within PT_LOAD
1641 // segments, and are built directly as needed.
1643 class Output_segment
1646 // Create an output segment, specifying the type and flags.
1647 Output_segment(elfcpp::Elf_Word
, elfcpp::Elf_Word
);
1649 // Return the virtual address.
1652 { return this->vaddr_
; }
1654 // Return the physical address.
1657 { return this->paddr_
; }
1659 // Return the segment type.
1662 { return this->type_
; }
1664 // Return the segment flags.
1667 { return this->flags_
; }
1669 // Return the memory size.
1672 { return this->memsz_
; }
1674 // Return the file size.
1677 { return this->filesz_
; }
1679 // Return the maximum alignment of the Output_data.
1683 // Add an Output_section to this segment.
1685 add_output_section(Output_section
* os
, elfcpp::Elf_Word seg_flags
)
1686 { this->add_output_section(os
, seg_flags
, false); }
1688 // Add an Output_section to the start of this segment.
1690 add_initial_output_section(Output_section
* os
, elfcpp::Elf_Word seg_flags
)
1691 { this->add_output_section(os
, seg_flags
, true); }
1693 // Add an Output_data (which is not an Output_section) to the start
1696 add_initial_output_data(Output_data
*);
1698 // Set the address of the segment to ADDR and the offset to *POFF
1699 // (aligned if necessary), and set the addresses and offsets of all
1700 // contained output sections accordingly. Set the section indexes
1701 // of all contained output sections starting with *PSHNDX. Return
1702 // the address of the immediately following segment. Update *POFF
1703 // and *PSHNDX. This should only be called for a PT_LOAD segment.
1705 set_section_addresses(uint64_t addr
, off_t
* poff
, unsigned int* pshndx
);
1707 // Set the minimum alignment of this segment. This may be adjusted
1708 // upward based on the section alignments.
1710 set_minimum_addralign(uint64_t align
)
1712 gold_assert(!this->is_align_known_
);
1713 this->align_
= align
;
1716 // Set the offset of this segment based on the section. This should
1717 // only be called for a non-PT_LOAD segment.
1721 // Return the number of output sections.
1723 output_section_count() const;
1725 // Write the segment header into *OPHDR.
1726 template<int size
, bool big_endian
>
1728 write_header(elfcpp::Phdr_write
<size
, big_endian
>*);
1730 // Write the section headers of associated sections into V.
1731 template<int size
, bool big_endian
>
1733 write_section_headers(const Layout
*, const Stringpool
*, unsigned char* v
,
1734 unsigned int* pshndx ACCEPT_SIZE_ENDIAN
) const;
1737 Output_segment(const Output_segment
&);
1738 Output_segment
& operator=(const Output_segment
&);
1740 typedef std::list
<Output_data
*> Output_data_list
;
1742 // Add an Output_section to this segment, specifying front or back.
1744 add_output_section(Output_section
*, elfcpp::Elf_Word seg_flags
,
1747 // Find the maximum alignment in an Output_data_list.
1749 maximum_alignment(const Output_data_list
*);
1751 // Set the section addresses in an Output_data_list.
1753 set_section_list_addresses(Output_data_list
*, uint64_t addr
, off_t
* poff
,
1754 unsigned int* pshndx
);
1756 // Return the number of Output_sections in an Output_data_list.
1758 output_section_count_list(const Output_data_list
*) const;
1760 // Write the section headers in the list into V.
1761 template<int size
, bool big_endian
>
1763 write_section_headers_list(const Layout
*, const Stringpool
*,
1764 const Output_data_list
*, unsigned char* v
,
1765 unsigned int* pshdx ACCEPT_SIZE_ENDIAN
) const;
1767 // The list of output data with contents attached to this segment.
1768 Output_data_list output_data_
;
1769 // The list of output data without contents attached to this segment.
1770 Output_data_list output_bss_
;
1771 // The segment virtual address.
1773 // The segment physical address.
1775 // The size of the segment in memory.
1777 // The segment alignment. The is_align_known_ field indicates
1778 // whether this has been finalized. It can be set to a minimum
1779 // value before it is finalized.
1781 // The offset of the segment data within the file.
1783 // The size of the segment data in the file.
1785 // The segment type;
1786 elfcpp::Elf_Word type_
;
1787 // The segment flags.
1788 elfcpp::Elf_Word flags_
;
1789 // Whether we have finalized align_.
1790 bool is_align_known_
;
1793 // This class represents the output file.
1798 Output_file(const General_options
& options
, Target
*);
1800 // Get a pointer to the target.
1803 { return this->target_
; }
1805 // Open the output file. FILE_SIZE is the final size of the file.
1807 open(off_t file_size
);
1809 // Close the output file and make sure there are no error.
1813 // We currently always use mmap which makes the view handling quite
1814 // simple. In the future we may support other approaches.
1816 // Write data to the output file.
1818 write(off_t offset
, const void* data
, off_t len
)
1819 { memcpy(this->base_
+ offset
, data
, len
); }
1821 // Get a buffer to use to write to the file, given the offset into
1822 // the file and the size.
1824 get_output_view(off_t start
, off_t size
)
1826 gold_assert(start
>= 0 && size
>= 0 && start
+ size
<= this->file_size_
);
1827 return this->base_
+ start
;
1830 // VIEW must have been returned by get_output_view. Write the
1831 // buffer to the file, passing in the offset and the size.
1833 write_output_view(off_t
, off_t
, unsigned char*)
1838 const General_options
& options_
;
1847 // Base of file mapped into memory.
1848 unsigned char* base_
;
1851 } // End namespace gold.
1853 #endif // !defined(GOLD_OUTPUT_H)