* ld-elf/header.d: Allow arbitrary lines between "Program Header"
[binutils.git] / gold / output.h
blob013a19f1b91028441bfafa2151eebef86db74674
1 // output.h -- manage the output file for gold -*- C++ -*-
3 #ifndef GOLD_OUTPUT_H
4 #define GOLD_OUTPUT_H
6 #include <list>
7 #include <vector>
9 #include "elfcpp.h"
10 #include "layout.h"
11 #include "reloc-types.h"
13 namespace gold
16 class General_options;
17 class Object;
18 class Symbol;
19 class Output_file;
20 class Output_section;
21 class Target;
22 template<int size, bool big_endian>
23 class Sized_target;
24 template<int size, bool big_endian>
25 class Sized_relobj;
27 // An abtract class for data which has to go into the output file.
29 class Output_data
31 public:
32 explicit Output_data(off_t data_size = 0)
33 : address_(0), data_size_(data_size), offset_(-1)
34 { }
36 virtual
37 ~Output_data();
39 // Return the address. This is only valid after Layout::finalize is
40 // finished.
41 uint64_t
42 address() const
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
47 // then.
48 off_t
49 data_size() const
50 { return this->data_size_; }
52 // Return the file offset. This is only valid after
53 // Layout::finalize is finished.
54 off_t
55 offset() const
56 { return this->offset_; }
58 // Return the required alignment.
59 uint64_t
60 addralign() const
61 { return this->do_addralign(); }
63 // Return whether this is an Output_section.
64 bool
65 is_section() const
66 { return this->do_is_section(); }
68 // Return whether this is an Output_section of the specified type.
69 bool
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
74 // set.
75 bool
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.
80 unsigned int
81 out_shndx() const
82 { return this->do_out_shndx(); }
84 // Set the output section index, if this is an output section.
85 void
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.
91 void
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.
96 void
97 write(Output_file* file)
98 { this->do_write(file); }
100 // This is called by Layout::finalize to note that all sizes must
101 // now be fixed.
102 static void
103 layout_complete()
104 { Output_data::sizes_are_fixed = true; }
106 protected:
107 // Functions that child classes may or in some cases must implement.
109 // Write the data to the output file.
110 virtual void
111 do_write(Output_file*) = 0;
113 // Return the required alignment.
114 virtual uint64_t
115 do_addralign() const = 0;
117 // Return whether this is an Output_section.
118 virtual bool
119 do_is_section() const
120 { return false; }
122 // Return whether this is an Output_section of the specified type.
123 // This only needs to be implement by Output_section.
124 virtual bool
125 do_is_section_type(elfcpp::Elf_Word) const
126 { return false; }
128 // Return whether this is an Output_section with the specific flag
129 // set. This only needs to be implemented by Output_section.
130 virtual bool
131 do_is_section_flag_set(elfcpp::Elf_Xword) const
132 { return false; }
134 // Return the output section index, if there is an output section.
135 virtual unsigned int
136 do_out_shndx() const
137 { gold_unreachable(); }
139 // Set the output section index, if this is an output section.
140 virtual void
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.
147 virtual void
148 do_set_address(uint64_t, off_t)
151 // Functions that child classes may call.
153 // Set the size of the data.
154 void
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.
162 static uint64_t
163 default_alignment(int size);
165 private:
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).
174 uint64_t address_;
175 // Size of data in file.
176 off_t data_size_;
177 // Offset within file.
178 off_t offset_;
181 // Output the section headers.
183 class Output_section_headers : public Output_data
185 public:
186 Output_section_headers(int size,
187 bool big_endian,
188 const Layout*,
189 const Layout::Segment_list*,
190 const Layout::Section_list*,
191 const Stringpool*);
193 // Write the data to the file.
194 void
195 do_write(Output_file*);
197 // Return the required alignment.
198 uint64_t
199 do_addralign() const
200 { return Output_data::default_alignment(this->size_); }
202 private:
203 // Write the data to the file with the right size and endianness.
204 template<int size, bool big_endian>
205 void
206 do_sized_write(Output_file*);
208 int size_;
209 bool big_endian_;
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
220 public:
221 Output_segment_headers(int size, bool big_endian,
222 const Layout::Segment_list& segment_list);
224 // Write the data to the file.
225 void
226 do_write(Output_file*);
228 // Return the required alignment.
229 uint64_t
230 do_addralign() const
231 { return Output_data::default_alignment(this->size_); }
233 private:
234 // Write the data to the file with the right size and endianness.
235 template<int size, bool big_endian>
236 void
237 do_sized_write(Output_file*);
239 int size_;
240 bool big_endian_;
241 const Layout::Segment_list& segment_list_;
244 // Output the ELF file header.
246 class Output_file_header : public Output_data
248 public:
249 Output_file_header(int size,
250 bool big_endian,
251 const General_options&,
252 const Target*,
253 const Symbol_table*,
254 const Output_segment_headers*);
256 // Add information about the section headers. We lay out the ELF
257 // file header before we create the section headers.
258 void set_section_info(const Output_section_headers*,
259 const Output_section* shstrtab);
261 // Write the data to the file.
262 void
263 do_write(Output_file*);
265 // Return the required alignment.
266 uint64_t
267 do_addralign() const
268 { return Output_data::default_alignment(this->size_); }
270 // Set the address and offset--we only implement this for error
271 // checking.
272 void
273 do_set_address(uint64_t, off_t off) const
274 { gold_assert(off == 0); }
276 private:
277 // Write the data to the file with the right size and endianness.
278 template<int size, bool big_endian>
279 void
280 do_sized_write(Output_file*);
282 int size_;
283 bool big_endian_;
284 const General_options& options_;
285 const Target* target_;
286 const Symbol_table* symtab_;
287 const Output_segment_headers* segment_header_;
288 const Output_section_headers* section_header_;
289 const Output_section* shstrtab_;
292 // Output sections are mainly comprised of input sections. However,
293 // there are cases where we have data to write out which is not in an
294 // input section. Output_section_data is used in such cases. This is
295 // an abstract base class.
297 class Output_section_data : public Output_data
299 public:
300 Output_section_data(off_t data_size, uint64_t addralign)
301 : Output_data(data_size), output_section_(NULL), addralign_(addralign)
304 Output_section_data(uint64_t addralign)
305 : Output_data(0), output_section_(NULL), addralign_(addralign)
308 // Return the output section.
309 const Output_section*
310 output_section() const
311 { return this->output_section_; }
313 // Record the output section.
314 void
315 set_output_section(Output_section* os);
317 protected:
318 // The child class must implement do_write.
320 // The child class may implement specific adjustments to the output
321 // section.
322 virtual void
323 do_adjust_output_section(Output_section*)
326 // Return the required alignment.
327 uint64_t
328 do_addralign() const
329 { return this->addralign_; }
331 // Return the section index of the output section.
332 unsigned int
333 do_out_shndx() const;
335 // Set the alignment.
336 void
337 set_addralign(uint64_t addralign)
338 { this->addralign_ = addralign; }
340 private:
341 // The output section for this section.
342 const Output_section* output_section_;
343 // The required alignment.
344 uint64_t addralign_;
347 // A simple case of Output_data in which we have constant data to
348 // output.
350 class Output_data_const : public Output_section_data
352 public:
353 Output_data_const(const std::string& data, uint64_t addralign)
354 : Output_section_data(data.size(), addralign), data_(data)
357 Output_data_const(const char* p, off_t len, uint64_t addralign)
358 : Output_section_data(len, addralign), data_(p, len)
361 Output_data_const(const unsigned char* p, off_t len, uint64_t addralign)
362 : Output_section_data(len, addralign),
363 data_(reinterpret_cast<const char*>(p), len)
366 // Add more data.
367 void
368 add_data(const std::string& add)
370 this->data_.append(add);
371 this->set_data_size(this->data_.size());
374 // Write the data to the output file.
375 void
376 do_write(Output_file*);
378 private:
379 std::string data_;
382 // Another version of Output_data with constant data, in which the
383 // buffer is allocated by the caller.
385 class Output_data_const_buffer : public Output_section_data
387 public:
388 Output_data_const_buffer(const unsigned char* p, off_t len,
389 uint64_t addralign)
390 : Output_section_data(len, addralign), p_(p)
393 // Write the data the output file.
394 void
395 do_write(Output_file*);
397 private:
398 const unsigned char* p_;
401 // A place holder for data written out via some other mechanism.
403 class Output_data_space : public Output_section_data
405 public:
406 Output_data_space(off_t data_size, uint64_t addralign)
407 : Output_section_data(data_size, addralign)
410 explicit Output_data_space(uint64_t addralign)
411 : Output_section_data(addralign)
414 // Set the size.
415 void
416 set_space_size(off_t space_size)
417 { this->set_data_size(space_size); }
419 // Set the alignment.
420 void
421 set_space_alignment(uint64_t align)
422 { this->set_addralign(align); }
424 // Write out the data--this must be handled elsewhere.
425 void
426 do_write(Output_file*)
430 // A string table which goes into an output section.
432 class Output_data_strtab : public Output_section_data
434 public:
435 Output_data_strtab(Stringpool* strtab)
436 : Output_section_data(1), strtab_(strtab)
439 // This is called to set the address and file offset. Here we make
440 // sure that the Stringpool is finalized.
441 void
442 do_set_address(uint64_t, off_t);
444 // Write out the data.
445 void
446 do_write(Output_file*);
448 private:
449 Stringpool* strtab_;
452 // This POD class is used to represent a single reloc in the output
453 // file. This could be a private class within Output_data_reloc, but
454 // the templatization is complex enough that I broke it out into a
455 // separate class. The class is templatized on either elfcpp::SHT_REL
456 // or elfcpp::SHT_RELA, and also on whether this is a dynamic
457 // relocation or an ordinary relocation.
459 // A relocation can be against a global symbol, a local symbol, an
460 // output section, or the undefined symbol at index 0. We represent
461 // the latter by using a NULL global symbol.
463 template<int sh_type, bool dynamic, int size, bool big_endian>
464 class Output_reloc;
466 template<bool dynamic, int size, bool big_endian>
467 class Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>
469 public:
470 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
472 // An uninitialized entry. We need this because we want to put
473 // instances of this class into an STL container.
474 Output_reloc()
475 : local_sym_index_(INVALID_CODE)
478 // A reloc against a global symbol.
480 Output_reloc(Symbol* gsym, unsigned int type, Output_data* od,
481 Address address)
482 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
483 shndx_(INVALID_CODE)
485 this->u1_.gsym = gsym;
486 this->u2_.od = od;
489 Output_reloc(Symbol* gsym, unsigned int type, Relobj* relobj,
490 unsigned int shndx, Address address)
491 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
492 shndx_(shndx)
494 gold_assert(shndx != INVALID_CODE);
495 this->u1_.gsym = gsym;
496 this->u2_.relobj = relobj;
499 // A reloc against a local symbol.
501 Output_reloc(Sized_relobj<size, big_endian>* relobj,
502 unsigned int local_sym_index,
503 unsigned int type,
504 Output_data* od,
505 Address address)
506 : address_(address), local_sym_index_(local_sym_index), type_(type),
507 shndx_(INVALID_CODE)
509 gold_assert(local_sym_index != GSYM_CODE
510 && local_sym_index != INVALID_CODE);
511 this->u1_.relobj = relobj;
512 this->u2_.od = od;
515 Output_reloc(Sized_relobj<size, big_endian>* relobj,
516 unsigned int local_sym_index,
517 unsigned int type,
518 unsigned int shndx,
519 Address address)
520 : address_(address), local_sym_index_(local_sym_index), type_(type),
521 shndx_(shndx)
523 gold_assert(local_sym_index != GSYM_CODE
524 && local_sym_index != INVALID_CODE);
525 gold_assert(shndx != INVALID_CODE);
526 this->u1_.relobj = relobj;
527 this->u2_.relobj = relobj;
530 // A reloc against the STT_SECTION symbol of an output section.
532 Output_reloc(Output_section* os, unsigned int type, Output_data* od,
533 Address address)
534 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
535 shndx_(INVALID_CODE)
537 this->u1_.os = os;
538 this->u2_.od = od;
541 Output_reloc(Output_section* os, unsigned int type, Relobj* relobj,
542 unsigned int shndx, Address address)
543 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
544 shndx_(shndx)
546 gold_assert(shndx != INVALID_CODE);
547 this->u1_.os = os;
548 this->u2_.relobj = relobj;
551 // Write the reloc entry to an output view.
552 void
553 write(unsigned char* pov) const;
555 // Write the offset and info fields to Write_rel.
556 template<typename Write_rel>
557 void write_rel(Write_rel*) const;
559 private:
560 // Return the symbol index. We can't do a double template
561 // specialization, so we do a secondary template here.
562 unsigned int
563 get_symbol_index() const;
565 // Codes for local_sym_index_.
566 enum
568 // Global symbol.
569 GSYM_CODE = -1U,
570 // Output section.
571 SECTION_CODE = -2U,
572 // Invalid uninitialized entry.
573 INVALID_CODE = -3U
576 union
578 // For a local symbol, the object. We will never generate a
579 // relocation against a local symbol in a dynamic object; that
580 // doesn't make sense. And our callers will always be
581 // templatized, so we use Sized_relobj here.
582 Sized_relobj<size, big_endian>* relobj;
583 // For a global symbol, the symbol. If this is NULL, it indicates
584 // a relocation against the undefined 0 symbol.
585 Symbol* gsym;
586 // For a relocation against an output section, the output section.
587 Output_section* os;
588 } u1_;
589 union
591 // If shndx_ is not INVALID CODE, the object which holds the input
592 // section being used to specify the reloc address.
593 Relobj* relobj;
594 // If shndx_ is INVALID_CODE, the output data being used to
595 // specify the reloc address. This may be NULL if the reloc
596 // address is absolute.
597 Output_data* od;
598 } u2_;
599 // The address offset within the input section or the Output_data.
600 Address address_;
601 // For a local symbol, the local symbol index. This is GSYM_CODE
602 // for a global symbol, or INVALID_CODE for an uninitialized value.
603 unsigned int local_sym_index_;
604 // The reloc type--a processor specific code.
605 unsigned int type_;
606 // If the reloc address is an input section in an object, the
607 // section index. This is INVALID_CODE if the reloc address is
608 // specified in some other way.
609 unsigned int shndx_;
612 // The SHT_RELA version of Output_reloc<>. This is just derived from
613 // the SHT_REL version of Output_reloc, but it adds an addend.
615 template<bool dynamic, int size, bool big_endian>
616 class Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>
618 public:
619 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
620 typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend;
622 // An uninitialized entry.
623 Output_reloc()
624 : rel_()
627 // A reloc against a global symbol.
629 Output_reloc(Symbol* gsym, unsigned int type, Output_data* od,
630 Address address, Addend addend)
631 : rel_(gsym, type, od, address), addend_(addend)
634 Output_reloc(Symbol* gsym, unsigned int type, Relobj* relobj,
635 unsigned int shndx, Address address, Addend addend)
636 : rel_(gsym, type, relobj, shndx, address), addend_(addend)
639 // A reloc against a local symbol.
641 Output_reloc(Sized_relobj<size, big_endian>* relobj,
642 unsigned int local_sym_index,
643 unsigned int type, Output_data* od, Address address,
644 Addend addend)
645 : rel_(relobj, local_sym_index, type, od, address), addend_(addend)
648 Output_reloc(Sized_relobj<size, big_endian>* relobj,
649 unsigned int local_sym_index,
650 unsigned int type,
651 unsigned int shndx,
652 Address address,
653 Addend addend)
654 : rel_(relobj, local_sym_index, type, shndx, address),
655 addend_(addend)
658 // A reloc against the STT_SECTION symbol of an output section.
660 Output_reloc(Output_section* os, unsigned int type, Output_data* od,
661 Address address, Addend addend)
662 : rel_(os, type, od, address), addend_(addend)
665 Output_reloc(Output_section* os, unsigned int type, Relobj* relobj,
666 unsigned int shndx, Address address, Addend addend)
667 : rel_(os, type, relobj, shndx, address), addend_(addend)
670 // Write the reloc entry to an output view.
671 void
672 write(unsigned char* pov) const;
674 private:
675 // The basic reloc.
676 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian> rel_;
677 // The addend.
678 Addend addend_;
681 // Output_data_reloc is used to manage a section containing relocs.
682 // SH_TYPE is either elfcpp::SHT_REL or elfcpp::SHT_RELA. DYNAMIC
683 // indicates whether this is a dynamic relocation or a normal
684 // relocation. Output_data_reloc_base is a base class.
685 // Output_data_reloc is the real class, which we specialize based on
686 // the reloc type.
688 template<int sh_type, bool dynamic, int size, bool big_endian>
689 class Output_data_reloc_base : public Output_section_data
691 public:
692 typedef Output_reloc<sh_type, dynamic, size, big_endian> Output_reloc_type;
693 typedef typename Output_reloc_type::Address Address;
694 static const int reloc_size =
695 Reloc_types<sh_type, size, big_endian>::reloc_size;
697 // Construct the section.
698 Output_data_reloc_base()
699 : Output_section_data(Output_data::default_alignment(size))
702 // Write out the data.
703 void
704 do_write(Output_file*);
706 protected:
707 // Set the entry size and the link.
708 void
709 do_adjust_output_section(Output_section *os);
711 // Add a relocation entry.
712 void
713 add(const Output_reloc_type& reloc)
715 this->relocs_.push_back(reloc);
716 this->set_data_size(this->relocs_.size() * reloc_size);
719 private:
720 typedef std::vector<Output_reloc_type> Relocs;
722 Relocs relocs_;
725 // The class which callers actually create.
727 template<int sh_type, bool dynamic, int size, bool big_endian>
728 class Output_data_reloc;
730 // The SHT_REL version of Output_data_reloc.
732 template<bool dynamic, int size, bool big_endian>
733 class Output_data_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>
734 : public Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, big_endian>
736 private:
737 typedef Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size,
738 big_endian> Base;
740 public:
741 typedef typename Base::Output_reloc_type Output_reloc_type;
742 typedef typename Output_reloc_type::Address Address;
744 Output_data_reloc()
745 : Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, big_endian>()
748 // Add a reloc against a global symbol.
750 void
751 add_global(Symbol* gsym, unsigned int type, Output_data* od, Address address)
752 { this->add(Output_reloc_type(gsym, type, od, address)); }
754 void
755 add_global(Symbol* gsym, unsigned int type, Relobj* relobj,
756 unsigned int shndx, Address address)
757 { this->add(Output_reloc_type(gsym, type, relobj, shndx, address)); }
759 // Add a reloc against a local symbol.
761 void
762 add_local(Sized_relobj<size, big_endian>* relobj,
763 unsigned int local_sym_index, unsigned int type,
764 Output_data* od, Address address)
765 { this->add(Output_reloc_type(relobj, local_sym_index, type, od, address)); }
767 void
768 add_local(Sized_relobj<size, big_endian>* relobj,
769 unsigned int local_sym_index, unsigned int type,
770 unsigned int shndx, Address address)
771 { this->add(Output_reloc_type(relobj, local_sym_index, type, shndx,
772 address)); }
775 // A reloc against the STT_SECTION symbol of an output section.
777 void
778 add_output_section(Output_section* os, unsigned int type,
779 Output_data* od, Address address)
780 { this->add(Output_reloc_type(os, type, od, address)); }
782 void
783 add_output_section(Output_section* os, unsigned int type,
784 Relobj* relobj, unsigned int shndx, Address address)
785 { this->add(Output_reloc_type(os, type, relobj, shndx, address)); }
788 // The SHT_RELA version of Output_data_reloc.
790 template<bool dynamic, int size, bool big_endian>
791 class Output_data_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>
792 : public Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, big_endian>
794 private:
795 typedef Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size,
796 big_endian> Base;
798 public:
799 typedef typename Base::Output_reloc_type Output_reloc_type;
800 typedef typename Output_reloc_type::Address Address;
801 typedef typename Output_reloc_type::Addend Addend;
803 Output_data_reloc()
804 : Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, big_endian>()
807 // Add a reloc against a global symbol.
809 void
810 add_global(Symbol* gsym, unsigned int type, Output_data* od,
811 Address address, Addend addend)
812 { this->add(Output_reloc_type(gsym, type, od, address, addend)); }
814 void
815 add_global(Symbol* gsym, unsigned int type, Relobj* relobj,
816 unsigned int shndx, Address address, Addend addend)
817 { this->add(Output_reloc_type(gsym, type, relobj, shndx, address, addend)); }
819 // Add a reloc against a local symbol.
821 void
822 add_local(Sized_relobj<size, big_endian>* relobj,
823 unsigned int local_sym_index, unsigned int type,
824 Output_data* od, Address address, Addend addend)
826 this->add(Output_reloc_type(relobj, local_sym_index, type, od, address,
827 addend));
830 void
831 add_local(Sized_relobj<size, big_endian>* relobj,
832 unsigned int local_sym_index, unsigned int type,
833 unsigned int shndx, Address address, Addend addend)
835 this->add(Output_reloc_type(relobj, local_sym_index, type, shndx, address,
836 addend));
839 // A reloc against the STT_SECTION symbol of an output section.
841 void
842 add_output_section(Output_section* os, unsigned int type, Output_data* od,
843 Address address, Addend addend)
844 { this->add(Output_reloc_type(os, type, od, address, addend)); }
846 void
847 add_output_section(Output_section* os, unsigned int type, Relobj* relobj,
848 unsigned int shndx, Address address, Addend addend)
849 { this->add(Output_reloc_type(os, type, relobj, shndx, address, addend)); }
852 // Output_data_got is used to manage a GOT. Each entry in the GOT is
853 // for one symbol--either a global symbol or a local symbol in an
854 // object. The target specific code adds entries to the GOT as
855 // needed.
857 template<int size, bool big_endian>
858 class Output_data_got : public Output_section_data
860 public:
861 typedef typename elfcpp::Elf_types<size>::Elf_Addr Valtype;
863 Output_data_got(const General_options* options)
864 : Output_section_data(Output_data::default_alignment(size)),
865 options_(options), entries_()
868 // Add an entry for a global symbol to the GOT. Return true if this
869 // is a new GOT entry, false if the symbol was already in the GOT.
870 bool
871 add_global(Symbol* gsym);
873 // Add an entry for a local symbol to the GOT. This returns the
874 // offset of the new entry from the start of the GOT.
875 unsigned int
876 add_local(Object* object, unsigned int sym_index)
878 this->entries_.push_back(Got_entry(object, sym_index));
879 this->set_got_size();
880 return this->last_got_offset();
883 // Add a constant to the GOT. This returns the offset of the new
884 // entry from the start of the GOT.
885 unsigned int
886 add_constant(Valtype constant)
888 this->entries_.push_back(Got_entry(constant));
889 this->set_got_size();
890 return this->last_got_offset();
893 // Write out the GOT table.
894 void
895 do_write(Output_file*);
897 private:
898 // This POD class holds a single GOT entry.
899 class Got_entry
901 public:
902 // Create a zero entry.
903 Got_entry()
904 : local_sym_index_(CONSTANT_CODE)
905 { this->u_.constant = 0; }
907 // Create a global symbol entry.
908 explicit Got_entry(Symbol* gsym)
909 : local_sym_index_(GSYM_CODE)
910 { this->u_.gsym = gsym; }
912 // Create a local symbol entry.
913 Got_entry(Object* object, unsigned int local_sym_index)
914 : local_sym_index_(local_sym_index)
916 gold_assert(local_sym_index != GSYM_CODE
917 && local_sym_index != CONSTANT_CODE);
918 this->u_.object = object;
921 // Create a constant entry. The constant is a host value--it will
922 // be swapped, if necessary, when it is written out.
923 explicit Got_entry(Valtype constant)
924 : local_sym_index_(CONSTANT_CODE)
925 { this->u_.constant = constant; }
927 // Write the GOT entry to an output view.
928 void
929 write(const General_options*, unsigned char* pov) const;
931 private:
932 enum
934 GSYM_CODE = -1U,
935 CONSTANT_CODE = -2U
938 union
940 // For a local symbol, the object.
941 Object* object;
942 // For a global symbol, the symbol.
943 Symbol* gsym;
944 // For a constant, the constant.
945 Valtype constant;
946 } u_;
947 // For a local symbol, the local symbol index. This is GSYM_CODE
948 // for a global symbol, or CONSTANT_CODE for a constant.
949 unsigned int local_sym_index_;
952 typedef std::vector<Got_entry> Got_entries;
954 // Return the offset into the GOT of GOT entry I.
955 unsigned int
956 got_offset(unsigned int i) const
957 { return i * (size / 8); }
959 // Return the offset into the GOT of the last entry added.
960 unsigned int
961 last_got_offset() const
962 { return this->got_offset(this->entries_.size() - 1); }
964 // Set the size of the section.
965 void
966 set_got_size()
967 { this->set_data_size(this->got_offset(this->entries_.size())); }
969 // Options.
970 const General_options* options_;
971 // The list of GOT entries.
972 Got_entries entries_;
975 // Output_data_dynamic is used to hold the data in SHT_DYNAMIC
976 // section.
978 class Output_data_dynamic : public Output_section_data
980 public:
981 Output_data_dynamic(const Target* target, Stringpool* pool)
982 : Output_section_data(Output_data::default_alignment(target->get_size())),
983 target_(target), entries_(), pool_(pool)
986 // Add a new dynamic entry with a fixed numeric value.
987 void
988 add_constant(elfcpp::DT tag, unsigned int val)
989 { this->add_entry(Dynamic_entry(tag, val)); }
991 // Add a new dynamic entry with the address of output data.
992 void
993 add_section_address(elfcpp::DT tag, const Output_data* od)
994 { this->add_entry(Dynamic_entry(tag, od, false)); }
996 // Add a new dynamic entry with the size of output data.
997 void
998 add_section_size(elfcpp::DT tag, const Output_data* od)
999 { this->add_entry(Dynamic_entry(tag, od, true)); }
1001 // Add a new dynamic entry with the address of a symbol.
1002 void
1003 add_symbol(elfcpp::DT tag, const Symbol* sym)
1004 { this->add_entry(Dynamic_entry(tag, sym)); }
1006 // Add a new dynamic entry with a string.
1007 void
1008 add_string(elfcpp::DT tag, const char* str)
1009 { this->add_entry(Dynamic_entry(tag, this->pool_->add(str, NULL))); }
1011 // Set the final data size.
1012 void
1013 do_set_address(uint64_t, off_t);
1015 // Write out the dynamic entries.
1016 void
1017 do_write(Output_file*);
1019 protected:
1020 // Adjust the output section to set the entry size.
1021 void
1022 do_adjust_output_section(Output_section*);
1024 private:
1025 // This POD class holds a single dynamic entry.
1026 class Dynamic_entry
1028 public:
1029 // Create an entry with a fixed numeric value.
1030 Dynamic_entry(elfcpp::DT tag, unsigned int val)
1031 : tag_(tag), classification_(DYNAMIC_NUMBER)
1032 { this->u_.val = val; }
1034 // Create an entry with the size or address of a section.
1035 Dynamic_entry(elfcpp::DT tag, const Output_data* od, bool section_size)
1036 : tag_(tag),
1037 classification_(section_size
1038 ? DYNAMIC_SECTION_SIZE
1039 : DYNAMIC_SECTION_ADDRESS)
1040 { this->u_.od = od; }
1042 // Create an entry with the address of a symbol.
1043 Dynamic_entry(elfcpp::DT tag, const Symbol* sym)
1044 : tag_(tag), classification_(DYNAMIC_SYMBOL)
1045 { this->u_.sym = sym; }
1047 // Create an entry with a string.
1048 Dynamic_entry(elfcpp::DT tag, const char* str)
1049 : tag_(tag), classification_(DYNAMIC_STRING)
1050 { this->u_.str = str; }
1052 // Write the dynamic entry to an output view.
1053 template<int size, bool big_endian>
1054 void
1055 write(unsigned char* pov, const Stringpool* ACCEPT_SIZE_ENDIAN) const;
1057 private:
1058 enum Classification
1060 // Number.
1061 DYNAMIC_NUMBER,
1062 // Section address.
1063 DYNAMIC_SECTION_ADDRESS,
1064 // Section size.
1065 DYNAMIC_SECTION_SIZE,
1066 // Symbol adress.
1067 DYNAMIC_SYMBOL,
1068 // String.
1069 DYNAMIC_STRING
1072 union
1074 // For DYNAMIC_NUMBER.
1075 unsigned int val;
1076 // For DYNAMIC_SECTION_ADDRESS and DYNAMIC_SECTION_SIZE.
1077 const Output_data* od;
1078 // For DYNAMIC_SYMBOL.
1079 const Symbol* sym;
1080 // For DYNAMIC_STRING.
1081 const char* str;
1082 } u_;
1083 // The dynamic tag.
1084 elfcpp::DT tag_;
1085 // The type of entry.
1086 Classification classification_;
1089 // Add an entry to the list.
1090 void
1091 add_entry(const Dynamic_entry& entry)
1092 { this->entries_.push_back(entry); }
1094 // Sized version of write function.
1095 template<int size, bool big_endian>
1096 void
1097 sized_write(Output_file* of);
1099 // The type of the list of entries.
1100 typedef std::vector<Dynamic_entry> Dynamic_entries;
1102 // The target.
1103 const Target* target_;
1104 // The entries.
1105 Dynamic_entries entries_;
1106 // The pool used for strings.
1107 Stringpool* pool_;
1110 // An output section. We don't expect to have too many output
1111 // sections, so we don't bother to do a template on the size.
1113 class Output_section : public Output_data
1115 public:
1116 // Create an output section, giving the name, type, and flags.
1117 Output_section(const char* name, elfcpp::Elf_Word, elfcpp::Elf_Xword,
1118 bool may_add_data);
1119 virtual ~Output_section();
1121 // Add a new input section SHNDX, named NAME, with header SHDR, from
1122 // object OBJECT. Return the offset within the output section.
1123 template<int size, bool big_endian>
1124 off_t
1125 add_input_section(Relobj* object, unsigned int shndx, const char *name,
1126 const elfcpp::Shdr<size, big_endian>& shdr);
1128 // Add generated data ODATA to this output section.
1129 void
1130 add_output_section_data(Output_section_data* posd);
1132 // Return the section name.
1133 const char*
1134 name() const
1135 { return this->name_; }
1137 // Return the section type.
1138 elfcpp::Elf_Word
1139 type() const
1140 { return this->type_; }
1142 // Return the section flags.
1143 elfcpp::Elf_Xword
1144 flags() const
1145 { return this->flags_; }
1147 // Return the section index in the output file.
1148 unsigned int
1149 do_out_shndx() const
1150 { return this->out_shndx_; }
1152 // Set the output section index.
1153 void
1154 do_set_out_shndx(unsigned int shndx)
1155 { this->out_shndx_ = shndx; }
1157 // Return the entsize field.
1158 uint64_t
1159 entsize() const
1160 { return this->entsize_; }
1162 // Set the entsize field.
1163 void
1164 set_entsize(uint64_t v);
1166 // Set the link field to the output section index of a section.
1167 void
1168 set_link_section(const Output_data* od)
1170 gold_assert(this->link_ == 0
1171 && !this->should_link_to_symtab_
1172 && !this->should_link_to_dynsym_);
1173 this->link_section_ = od;
1176 // Set the link field to a constant.
1177 void
1178 set_link(unsigned int v)
1180 gold_assert(this->link_section_ == NULL
1181 && !this->should_link_to_symtab_
1182 && !this->should_link_to_dynsym_);
1183 this->link_ = v;
1186 // Record that this section should link to the normal symbol table.
1187 void
1188 set_should_link_to_symtab()
1190 gold_assert(this->link_section_ == NULL
1191 && this->link_ == 0
1192 && !this->should_link_to_dynsym_);
1193 this->should_link_to_symtab_ = true;
1196 // Record that this section should link to the dynamic symbol table.
1197 void
1198 set_should_link_to_dynsym()
1200 gold_assert(this->link_section_ == NULL
1201 && this->link_ == 0
1202 && !this->should_link_to_symtab_);
1203 this->should_link_to_dynsym_ = true;
1206 // Return the info field.
1207 unsigned int
1208 info() const
1210 gold_assert(this->info_section_ == NULL);
1211 return this->info_;
1214 // Set the info field to the output section index of a section.
1215 void
1216 set_info_section(const Output_data* od)
1218 gold_assert(this->info_ == 0);
1219 this->info_section_ = od;
1222 // Set the info field to a constant.
1223 void
1224 set_info(unsigned int v)
1226 gold_assert(this->info_section_ == NULL);
1227 this->info_ = v;
1230 // Set the addralign field.
1231 void
1232 set_addralign(uint64_t v)
1233 { this->addralign_ = v; }
1235 // Indicate that we need a symtab index.
1236 void
1237 set_needs_symtab_index()
1238 { this->needs_symtab_index_ = true; }
1240 // Return whether we need a symtab index.
1241 bool
1242 needs_symtab_index() const
1243 { return this->needs_symtab_index_; }
1245 // Get the symtab index.
1246 unsigned int
1247 symtab_index() const
1249 gold_assert(this->symtab_index_ != 0);
1250 return this->symtab_index_;
1253 // Set the symtab index.
1254 void
1255 set_symtab_index(unsigned int index)
1257 gold_assert(index != 0);
1258 this->symtab_index_ = index;
1261 // Indicate that we need a dynsym index.
1262 void
1263 set_needs_dynsym_index()
1264 { this->needs_dynsym_index_ = true; }
1266 // Return whether we need a dynsym index.
1267 bool
1268 needs_dynsym_index() const
1269 { return this->needs_dynsym_index_; }
1271 // Get the dynsym index.
1272 unsigned int
1273 dynsym_index() const
1275 gold_assert(this->dynsym_index_ != 0);
1276 return this->dynsym_index_;
1279 // Set the dynsym index.
1280 void
1281 set_dynsym_index(unsigned int index)
1283 gold_assert(index != 0);
1284 this->dynsym_index_ = index;
1287 // Set the address of the Output_section. For a typical
1288 // Output_section, there is nothing to do, but if there are any
1289 // Output_section_data objects we need to set the final addresses
1290 // here.
1291 void
1292 do_set_address(uint64_t, off_t);
1294 // Write the data to the file. For a typical Output_section, this
1295 // does nothing: the data is written out by calling Object::Relocate
1296 // on each input object. But if there are any Output_section_data
1297 // objects we do need to write them out here.
1298 void
1299 do_write(Output_file*);
1301 // Return the address alignment--function required by parent class.
1302 uint64_t
1303 do_addralign() const
1304 { return this->addralign_; }
1306 // Return whether this is an Output_section.
1307 bool
1308 do_is_section() const
1309 { return true; }
1311 // Return whether this is a section of the specified type.
1312 bool
1313 do_is_section_type(elfcpp::Elf_Word type) const
1314 { return this->type_ == type; }
1316 // Return whether the specified section flag is set.
1317 bool
1318 do_is_section_flag_set(elfcpp::Elf_Xword flag) const
1319 { return (this->flags_ & flag) != 0; }
1321 // Write the section header into *OPHDR.
1322 template<int size, bool big_endian>
1323 void
1324 write_header(const Layout*, const Stringpool*,
1325 elfcpp::Shdr_write<size, big_endian>*) const;
1327 private:
1328 // In some cases we need to keep a list of the input sections
1329 // associated with this output section. We only need the list if we
1330 // might have to change the offsets of the input section within the
1331 // output section after we add the input section. The ordinary
1332 // input sections will be written out when we process the object
1333 // file, and as such we don't need to track them here. We do need
1334 // to track Output_section_data objects here. We store instances of
1335 // this structure in a std::vector, so it must be a POD. There can
1336 // be many instances of this structure, so we use a union to save
1337 // some space.
1338 class Input_section
1340 public:
1341 Input_section()
1342 : shndx_(0), p2align_(0), data_size_(0)
1343 { this->u_.object = NULL; }
1345 Input_section(Relobj* object, unsigned int shndx, off_t data_size,
1346 uint64_t addralign)
1347 : shndx_(shndx),
1348 p2align_(ffsll(static_cast<long long>(addralign))),
1349 data_size_(data_size)
1351 gold_assert(shndx != -1U);
1352 this->u_.object = object;
1355 Input_section(Output_section_data* posd)
1356 : shndx_(-1U),
1357 p2align_(ffsll(static_cast<long long>(posd->addralign()))),
1358 data_size_(0)
1359 { this->u_.posd = posd; }
1361 // The required alignment.
1362 uint64_t
1363 addralign() const
1365 return (this->p2align_ == 0
1367 : static_cast<uint64_t>(1) << (this->p2align_ - 1));
1370 // Return the required size.
1371 off_t
1372 data_size() const;
1374 // Set the address and file offset. This is called during
1375 // Layout::finalize. SECOFF is the file offset of the enclosing
1376 // section.
1377 void
1378 set_address(uint64_t addr, off_t off, off_t secoff);
1380 // Write out the data. This does nothing for an input section.
1381 void
1382 write(Output_file*);
1384 private:
1385 // Whether this is an input section.
1386 bool
1387 is_input_section() const
1388 { return this->shndx_ != -1U; }
1390 // For an ordinary input section, this is the section index in
1391 // the input file. For an Output_section_data, this is -1U.
1392 unsigned int shndx_;
1393 // The required alignment, stored as a power of 2.
1394 unsigned int p2align_;
1395 // For an ordinary input section, the section size.
1396 off_t data_size_;
1397 union
1399 // If shndx_ != -1U, this points to the object which holds the
1400 // input section.
1401 Relobj* object;
1402 // If shndx_ == -1U, this is the data to write out.
1403 Output_section_data* posd;
1404 } u_;
1407 typedef std::vector<Input_section> Input_section_list;
1409 // Most of these fields are only valid after layout.
1411 // The name of the section. This will point into a Stringpool.
1412 const char* name_;
1413 // The section address is in the parent class.
1414 // The section alignment.
1415 uint64_t addralign_;
1416 // The section entry size.
1417 uint64_t entsize_;
1418 // The file offset is in the parent class.
1419 // Set the section link field to the index of this section.
1420 const Output_data* link_section_;
1421 // If link_section_ is NULL, this is the link field.
1422 unsigned int link_;
1423 // Set the section info field to the index of this section.
1424 const Output_data* info_section_;
1425 // If info_section_ is NULL, this is the section info field.
1426 unsigned int info_;
1427 // The section type.
1428 elfcpp::Elf_Word type_;
1429 // The section flags.
1430 elfcpp::Elf_Xword flags_;
1431 // The section index.
1432 unsigned int out_shndx_;
1433 // If there is a STT_SECTION for this output section in the normal
1434 // symbol table, this is the symbol index. This starts out as zero.
1435 // It is initialized in Layout::finalize() to be the index, or -1U
1436 // if there isn't one.
1437 unsigned int symtab_index_;
1438 // If there is a STT_SECTION for this output section in the dynamic
1439 // symbol table, this is the symbol index. This starts out as zero.
1440 // It is initialized in Layout::finalize() to be the index, or -1U
1441 // if there isn't one.
1442 unsigned int dynsym_index_;
1443 // The input sections. This will be empty in cases where we don't
1444 // need to keep track of them.
1445 Input_section_list input_sections_;
1446 // The offset of the first entry in input_sections_.
1447 off_t first_input_offset_;
1448 // Whether we permit adding data.
1449 bool may_add_data_ : 1;
1450 // Whether this output section needs a STT_SECTION symbol in the
1451 // normal symbol table. This will be true if there is a relocation
1452 // which needs it.
1453 bool needs_symtab_index_ : 1;
1454 // Whether this output section needs a STT_SECTION symbol in the
1455 // dynamic symbol table. This will be true if there is a dynamic
1456 // relocation which needs it.
1457 bool needs_dynsym_index_ : 1;
1458 // Whether the link field of this output section should point to the
1459 // normal symbol table.
1460 bool should_link_to_symtab_ : 1;
1461 // Whether the link field of this output section should point to the
1462 // dynamic symbol table.
1463 bool should_link_to_dynsym_ : 1;
1466 // An output segment. PT_LOAD segments are built from collections of
1467 // output sections. Other segments typically point within PT_LOAD
1468 // segments, and are built directly as needed.
1470 class Output_segment
1472 public:
1473 // Create an output segment, specifying the type and flags.
1474 Output_segment(elfcpp::Elf_Word, elfcpp::Elf_Word);
1476 // Return the virtual address.
1477 uint64_t
1478 vaddr() const
1479 { return this->vaddr_; }
1481 // Return the physical address.
1482 uint64_t
1483 paddr() const
1484 { return this->paddr_; }
1486 // Return the segment type.
1487 elfcpp::Elf_Word
1488 type() const
1489 { return this->type_; }
1491 // Return the segment flags.
1492 elfcpp::Elf_Word
1493 flags() const
1494 { return this->flags_; }
1496 // Return the memory size.
1497 uint64_t
1498 memsz() const
1499 { return this->memsz_; }
1501 // Return the file size.
1502 off_t
1503 filesz() const
1504 { return this->filesz_; }
1506 // Return the maximum alignment of the Output_data.
1507 uint64_t
1508 addralign();
1510 // Add an Output_section to this segment.
1511 void
1512 add_output_section(Output_section* os, elfcpp::Elf_Word seg_flags)
1513 { this->add_output_section(os, seg_flags, false); }
1515 // Add an Output_section to the start of this segment.
1516 void
1517 add_initial_output_section(Output_section* os, elfcpp::Elf_Word seg_flags)
1518 { this->add_output_section(os, seg_flags, true); }
1520 // Add an Output_data (which is not an Output_section) to the start
1521 // of this segment.
1522 void
1523 add_initial_output_data(Output_data*);
1525 // Set the address of the segment to ADDR and the offset to *POFF
1526 // (aligned if necessary), and set the addresses and offsets of all
1527 // contained output sections accordingly. Set the section indexes
1528 // of all contained output sections starting with *PSHNDX. Return
1529 // the address of the immediately following segment. Update *POFF
1530 // and *PSHNDX. This should only be called for a PT_LOAD segment.
1531 uint64_t
1532 set_section_addresses(uint64_t addr, off_t* poff, unsigned int* pshndx);
1534 // Set the offset of this segment based on the section. This should
1535 // only be called for a non-PT_LOAD segment.
1536 void
1537 set_offset();
1539 // Return the number of output sections.
1540 unsigned int
1541 output_section_count() const;
1543 // Write the segment header into *OPHDR.
1544 template<int size, bool big_endian>
1545 void
1546 write_header(elfcpp::Phdr_write<size, big_endian>*);
1548 // Write the section headers of associated sections into V.
1549 template<int size, bool big_endian>
1550 unsigned char*
1551 write_section_headers(const Layout*, const Stringpool*, unsigned char* v,
1552 unsigned int* pshndx ACCEPT_SIZE_ENDIAN) const;
1554 private:
1555 Output_segment(const Output_segment&);
1556 Output_segment& operator=(const Output_segment&);
1558 typedef std::list<Output_data*> Output_data_list;
1560 // Add an Output_section to this segment, specifying front or back.
1561 void
1562 add_output_section(Output_section*, elfcpp::Elf_Word seg_flags,
1563 bool front);
1565 // Find the maximum alignment in an Output_data_list.
1566 static uint64_t
1567 maximum_alignment(const Output_data_list*);
1569 // Set the section addresses in an Output_data_list.
1570 uint64_t
1571 set_section_list_addresses(Output_data_list*, uint64_t addr, off_t* poff,
1572 unsigned int* pshndx);
1574 // Return the number of Output_sections in an Output_data_list.
1575 unsigned int
1576 output_section_count_list(const Output_data_list*) const;
1578 // Write the section headers in the list into V.
1579 template<int size, bool big_endian>
1580 unsigned char*
1581 write_section_headers_list(const Layout*, const Stringpool*,
1582 const Output_data_list*, unsigned char* v,
1583 unsigned int* pshdx ACCEPT_SIZE_ENDIAN) const;
1585 // The list of output data with contents attached to this segment.
1586 Output_data_list output_data_;
1587 // The list of output data without contents attached to this segment.
1588 Output_data_list output_bss_;
1589 // The segment virtual address.
1590 uint64_t vaddr_;
1591 // The segment physical address.
1592 uint64_t paddr_;
1593 // The size of the segment in memory.
1594 uint64_t memsz_;
1595 // The segment alignment.
1596 uint64_t align_;
1597 // The offset of the segment data within the file.
1598 off_t offset_;
1599 // The size of the segment data in the file.
1600 off_t filesz_;
1601 // The segment type;
1602 elfcpp::Elf_Word type_;
1603 // The segment flags.
1604 elfcpp::Elf_Word flags_;
1605 // Whether we have set align_.
1606 bool is_align_known_;
1609 // This class represents the output file.
1611 class Output_file
1613 public:
1614 Output_file(const General_options& options);
1616 // Open the output file. FILE_SIZE is the final size of the file.
1617 void
1618 open(off_t file_size);
1620 // Close the output file and make sure there are no error.
1621 void
1622 close();
1624 // We currently always use mmap which makes the view handling quite
1625 // simple. In the future we may support other approaches.
1627 // Write data to the output file.
1628 void
1629 write(off_t offset, const void* data, off_t len)
1630 { memcpy(this->base_ + offset, data, len); }
1632 // Get a buffer to use to write to the file, given the offset into
1633 // the file and the size.
1634 unsigned char*
1635 get_output_view(off_t start, off_t size)
1637 gold_assert(start >= 0 && size >= 0 && start + size <= this->file_size_);
1638 return this->base_ + start;
1641 // VIEW must have been returned by get_output_view. Write the
1642 // buffer to the file, passing in the offset and the size.
1643 void
1644 write_output_view(off_t, off_t, unsigned char*)
1647 private:
1648 // General options.
1649 const General_options& options_;
1650 // File name.
1651 const char* name_;
1652 // File descriptor.
1653 int o_;
1654 // File size.
1655 off_t file_size_;
1656 // Base of file mapped into memory.
1657 unsigned char* base_;
1660 } // End namespace gold.
1662 #endif // !defined(GOLD_OUTPUT_H)