2009-03-23 H.J. Lu <hongjiu.lu@intel.com>
[binutils.git] / gold / output.h
blob6c37dfd0191c3d9e9b560901c424ac204368646f
1 // output.h -- manage the output file for gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
23 #ifndef GOLD_OUTPUT_H
24 #define GOLD_OUTPUT_H
26 #include <list>
27 #include <vector>
29 #include "elfcpp.h"
30 #include "mapfile.h"
31 #include "layout.h"
32 #include "reloc-types.h"
34 namespace gold
37 class General_options;
38 class Object;
39 class Symbol;
40 class Output_file;
41 class Output_section;
42 class Relocatable_relocs;
43 class Target;
44 template<int size, bool big_endian>
45 class Sized_target;
46 template<int size, bool big_endian>
47 class Sized_relobj;
49 // An abtract class for data which has to go into the output file.
51 class Output_data
53 public:
54 explicit Output_data()
55 : address_(0), data_size_(0), offset_(-1),
56 is_address_valid_(false), is_data_size_valid_(false),
57 is_offset_valid_(false),
58 dynamic_reloc_count_(0)
59 { }
61 virtual
62 ~Output_data();
64 // Return the address. For allocated sections, this is only valid
65 // after Layout::finalize is finished.
66 uint64_t
67 address() const
69 gold_assert(this->is_address_valid_);
70 return this->address_;
73 // Return the size of the data. For allocated sections, this must
74 // be valid after Layout::finalize calls set_address, but need not
75 // be valid before then.
76 off_t
77 data_size() const
79 gold_assert(this->is_data_size_valid_);
80 return this->data_size_;
83 // Return the file offset. This is only valid after
84 // Layout::finalize is finished. For some non-allocated sections,
85 // it may not be valid until near the end of the link.
86 off_t
87 offset() const
89 gold_assert(this->is_offset_valid_);
90 return this->offset_;
93 // Reset the address and file offset. This essentially disables the
94 // sanity testing about duplicate and unknown settings.
95 void
96 reset_address_and_file_offset()
98 this->is_address_valid_ = false;
99 this->is_offset_valid_ = false;
100 this->is_data_size_valid_ = false;
101 this->do_reset_address_and_file_offset();
104 // Return the required alignment.
105 uint64_t
106 addralign() const
107 { return this->do_addralign(); }
109 // Return whether this has a load address.
110 bool
111 has_load_address() const
112 { return this->do_has_load_address(); }
114 // Return the load address.
115 uint64_t
116 load_address() const
117 { return this->do_load_address(); }
119 // Return whether this is an Output_section.
120 bool
121 is_section() const
122 { return this->do_is_section(); }
124 // Return whether this is an Output_section of the specified type.
125 bool
126 is_section_type(elfcpp::Elf_Word stt) const
127 { return this->do_is_section_type(stt); }
129 // Return whether this is an Output_section with the specified flag
130 // set.
131 bool
132 is_section_flag_set(elfcpp::Elf_Xword shf) const
133 { return this->do_is_section_flag_set(shf); }
135 // Return the output section that this goes in, if there is one.
136 Output_section*
137 output_section()
138 { return this->do_output_section(); }
140 // Return the output section index, if there is an output section.
141 unsigned int
142 out_shndx() const
143 { return this->do_out_shndx(); }
145 // Set the output section index, if this is an output section.
146 void
147 set_out_shndx(unsigned int shndx)
148 { this->do_set_out_shndx(shndx); }
150 // Set the address and file offset of this data, and finalize the
151 // size of the data. This is called during Layout::finalize for
152 // allocated sections.
153 void
154 set_address_and_file_offset(uint64_t addr, off_t off)
156 this->set_address(addr);
157 this->set_file_offset(off);
158 this->finalize_data_size();
161 // Set the address.
162 void
163 set_address(uint64_t addr)
165 gold_assert(!this->is_address_valid_);
166 this->address_ = addr;
167 this->is_address_valid_ = true;
170 // Set the file offset.
171 void
172 set_file_offset(off_t off)
174 gold_assert(!this->is_offset_valid_);
175 this->offset_ = off;
176 this->is_offset_valid_ = true;
179 // Finalize the data size.
180 void
181 finalize_data_size()
183 if (!this->is_data_size_valid_)
185 // Tell the child class to set the data size.
186 this->set_final_data_size();
187 gold_assert(this->is_data_size_valid_);
191 // Set the TLS offset. Called only for SHT_TLS sections.
192 void
193 set_tls_offset(uint64_t tls_base)
194 { this->do_set_tls_offset(tls_base); }
196 // Return the TLS offset, relative to the base of the TLS segment.
197 // Valid only for SHT_TLS sections.
198 uint64_t
199 tls_offset() const
200 { return this->do_tls_offset(); }
202 // Write the data to the output file. This is called after
203 // Layout::finalize is complete.
204 void
205 write(Output_file* file)
206 { this->do_write(file); }
208 // This is called by Layout::finalize to note that the sizes of
209 // allocated sections must now be fixed.
210 static void
211 layout_complete()
212 { Output_data::allocated_sizes_are_fixed = true; }
214 // Used to check that layout has been done.
215 static bool
216 is_layout_complete()
217 { return Output_data::allocated_sizes_are_fixed; }
219 // Count the number of dynamic relocations applied to this section.
220 void
221 add_dynamic_reloc()
222 { ++this->dynamic_reloc_count_; }
224 // Return the number of dynamic relocations applied to this section.
225 unsigned int
226 dynamic_reloc_count() const
227 { return this->dynamic_reloc_count_; }
229 // Whether the address is valid.
230 bool
231 is_address_valid() const
232 { return this->is_address_valid_; }
234 // Whether the file offset is valid.
235 bool
236 is_offset_valid() const
237 { return this->is_offset_valid_; }
239 // Whether the data size is valid.
240 bool
241 is_data_size_valid() const
242 { return this->is_data_size_valid_; }
244 // Print information to the map file.
245 void
246 print_to_mapfile(Mapfile* mapfile) const
247 { return this->do_print_to_mapfile(mapfile); }
249 protected:
250 // Functions that child classes may or in some cases must implement.
252 // Write the data to the output file.
253 virtual void
254 do_write(Output_file*) = 0;
256 // Return the required alignment.
257 virtual uint64_t
258 do_addralign() const = 0;
260 // Return whether this has a load address.
261 virtual bool
262 do_has_load_address() const
263 { return false; }
265 // Return the load address.
266 virtual uint64_t
267 do_load_address() const
268 { gold_unreachable(); }
270 // Return whether this is an Output_section.
271 virtual bool
272 do_is_section() const
273 { return false; }
275 // Return whether this is an Output_section of the specified type.
276 // This only needs to be implement by Output_section.
277 virtual bool
278 do_is_section_type(elfcpp::Elf_Word) const
279 { return false; }
281 // Return whether this is an Output_section with the specific flag
282 // set. This only needs to be implemented by Output_section.
283 virtual bool
284 do_is_section_flag_set(elfcpp::Elf_Xword) const
285 { return false; }
287 // Return the output section, if there is one.
288 virtual Output_section*
289 do_output_section()
290 { return NULL; }
292 // Return the output section index, if there is an output section.
293 virtual unsigned int
294 do_out_shndx() const
295 { gold_unreachable(); }
297 // Set the output section index, if this is an output section.
298 virtual void
299 do_set_out_shndx(unsigned int)
300 { gold_unreachable(); }
302 // This is a hook for derived classes to set the data size. This is
303 // called by finalize_data_size, normally called during
304 // Layout::finalize, when the section address is set.
305 virtual void
306 set_final_data_size()
307 { gold_unreachable(); }
309 // A hook for resetting the address and file offset.
310 virtual void
311 do_reset_address_and_file_offset()
314 // Set the TLS offset. Called only for SHT_TLS sections.
315 virtual void
316 do_set_tls_offset(uint64_t)
317 { gold_unreachable(); }
319 // Return the TLS offset, relative to the base of the TLS segment.
320 // Valid only for SHT_TLS sections.
321 virtual uint64_t
322 do_tls_offset() const
323 { gold_unreachable(); }
325 // Print to the map file. This only needs to be implemented by
326 // classes which may appear in a PT_LOAD segment.
327 virtual void
328 do_print_to_mapfile(Mapfile*) const
329 { gold_unreachable(); }
331 // Functions that child classes may call.
333 // Set the size of the data.
334 void
335 set_data_size(off_t data_size)
337 gold_assert(!this->is_data_size_valid_);
338 this->data_size_ = data_size;
339 this->is_data_size_valid_ = true;
342 // Get the current data size--this is for the convenience of
343 // sections which build up their size over time.
344 off_t
345 current_data_size_for_child() const
346 { return this->data_size_; }
348 // Set the current data size--this is for the convenience of
349 // sections which build up their size over time.
350 void
351 set_current_data_size_for_child(off_t data_size)
353 gold_assert(!this->is_data_size_valid_);
354 this->data_size_ = data_size;
357 // Return default alignment for the target size.
358 static uint64_t
359 default_alignment();
361 // Return default alignment for a specified size--32 or 64.
362 static uint64_t
363 default_alignment_for_size(int size);
365 private:
366 Output_data(const Output_data&);
367 Output_data& operator=(const Output_data&);
369 // This is used for verification, to make sure that we don't try to
370 // change any sizes of allocated sections after we set the section
371 // addresses.
372 static bool allocated_sizes_are_fixed;
374 // Memory address in output file.
375 uint64_t address_;
376 // Size of data in output file.
377 off_t data_size_;
378 // File offset of contents in output file.
379 off_t offset_;
380 // Whether address_ is valid.
381 bool is_address_valid_;
382 // Whether data_size_ is valid.
383 bool is_data_size_valid_;
384 // Whether offset_ is valid.
385 bool is_offset_valid_;
386 // Count of dynamic relocations applied to this section.
387 unsigned int dynamic_reloc_count_;
390 // Output the section headers.
392 class Output_section_headers : public Output_data
394 public:
395 Output_section_headers(const Layout*,
396 const Layout::Segment_list*,
397 const Layout::Section_list*,
398 const Layout::Section_list*,
399 const Stringpool*,
400 const Output_section*);
402 protected:
403 // Write the data to the file.
404 void
405 do_write(Output_file*);
407 // Return the required alignment.
408 uint64_t
409 do_addralign() const
410 { return Output_data::default_alignment(); }
412 // Write to a map file.
413 void
414 do_print_to_mapfile(Mapfile* mapfile) const
415 { mapfile->print_output_data(this, _("** section headers")); }
417 private:
418 // Write the data to the file with the right size and endianness.
419 template<int size, bool big_endian>
420 void
421 do_sized_write(Output_file*);
423 const Layout* layout_;
424 const Layout::Segment_list* segment_list_;
425 const Layout::Section_list* section_list_;
426 const Layout::Section_list* unattached_section_list_;
427 const Stringpool* secnamepool_;
428 const Output_section* shstrtab_section_;
431 // Output the segment headers.
433 class Output_segment_headers : public Output_data
435 public:
436 Output_segment_headers(const Layout::Segment_list& segment_list);
438 protected:
439 // Write the data to the file.
440 void
441 do_write(Output_file*);
443 // Return the required alignment.
444 uint64_t
445 do_addralign() const
446 { return Output_data::default_alignment(); }
448 // Write to a map file.
449 void
450 do_print_to_mapfile(Mapfile* mapfile) const
451 { mapfile->print_output_data(this, _("** segment headers")); }
453 private:
454 // Write the data to the file with the right size and endianness.
455 template<int size, bool big_endian>
456 void
457 do_sized_write(Output_file*);
459 const Layout::Segment_list& segment_list_;
462 // Output the ELF file header.
464 class Output_file_header : public Output_data
466 public:
467 Output_file_header(const Target*,
468 const Symbol_table*,
469 const Output_segment_headers*,
470 const char* entry);
472 // Add information about the section headers. We lay out the ELF
473 // file header before we create the section headers.
474 void set_section_info(const Output_section_headers*,
475 const Output_section* shstrtab);
477 protected:
478 // Write the data to the file.
479 void
480 do_write(Output_file*);
482 // Return the required alignment.
483 uint64_t
484 do_addralign() const
485 { return Output_data::default_alignment(); }
487 // Write to a map file.
488 void
489 do_print_to_mapfile(Mapfile* mapfile) const
490 { mapfile->print_output_data(this, _("** file header")); }
492 private:
493 // Write the data to the file with the right size and endianness.
494 template<int size, bool big_endian>
495 void
496 do_sized_write(Output_file*);
498 // Return the value to use for the entry address.
499 template<int size>
500 typename elfcpp::Elf_types<size>::Elf_Addr
501 entry();
503 const Target* target_;
504 const Symbol_table* symtab_;
505 const Output_segment_headers* segment_header_;
506 const Output_section_headers* section_header_;
507 const Output_section* shstrtab_;
508 const char* entry_;
511 // Output sections are mainly comprised of input sections. However,
512 // there are cases where we have data to write out which is not in an
513 // input section. Output_section_data is used in such cases. This is
514 // an abstract base class.
516 class Output_section_data : public Output_data
518 public:
519 Output_section_data(off_t data_size, uint64_t addralign)
520 : Output_data(), output_section_(NULL), addralign_(addralign)
521 { this->set_data_size(data_size); }
523 Output_section_data(uint64_t addralign)
524 : Output_data(), output_section_(NULL), addralign_(addralign)
527 // Return the output section.
528 const Output_section*
529 output_section() const
530 { return this->output_section_; }
532 // Record the output section.
533 void
534 set_output_section(Output_section* os);
536 // Add an input section, for SHF_MERGE sections. This returns true
537 // if the section was handled.
538 bool
539 add_input_section(Relobj* object, unsigned int shndx)
540 { return this->do_add_input_section(object, shndx); }
542 // Given an input OBJECT, an input section index SHNDX within that
543 // object, and an OFFSET relative to the start of that input
544 // section, return whether or not the corresponding offset within
545 // the output section is known. If this function returns true, it
546 // sets *POUTPUT to the output offset. The value -1 indicates that
547 // this input offset is being discarded.
548 bool
549 output_offset(const Relobj* object, unsigned int shndx,
550 section_offset_type offset,
551 section_offset_type *poutput) const
552 { return this->do_output_offset(object, shndx, offset, poutput); }
554 // Return whether this is the merge section for the input section
555 // SHNDX in OBJECT. This should return true when output_offset
556 // would return true for some values of OFFSET.
557 bool
558 is_merge_section_for(const Relobj* object, unsigned int shndx) const
559 { return this->do_is_merge_section_for(object, shndx); }
561 // Write the contents to a buffer. This is used for sections which
562 // require postprocessing, such as compression.
563 void
564 write_to_buffer(unsigned char* buffer)
565 { this->do_write_to_buffer(buffer); }
567 // Print merge stats to stderr. This should only be called for
568 // SHF_MERGE sections.
569 void
570 print_merge_stats(const char* section_name)
571 { this->do_print_merge_stats(section_name); }
573 protected:
574 // The child class must implement do_write.
576 // The child class may implement specific adjustments to the output
577 // section.
578 virtual void
579 do_adjust_output_section(Output_section*)
582 // May be implemented by child class. Return true if the section
583 // was handled.
584 virtual bool
585 do_add_input_section(Relobj*, unsigned int)
586 { gold_unreachable(); }
588 // The child class may implement output_offset.
589 virtual bool
590 do_output_offset(const Relobj*, unsigned int, section_offset_type,
591 section_offset_type*) const
592 { return false; }
594 // The child class may implement is_merge_section_for.
595 virtual bool
596 do_is_merge_section_for(const Relobj*, unsigned int) const
597 { return false; }
599 // The child class may implement write_to_buffer. Most child
600 // classes can not appear in a compressed section, and they do not
601 // implement this.
602 virtual void
603 do_write_to_buffer(unsigned char*)
604 { gold_unreachable(); }
606 // Print merge statistics.
607 virtual void
608 do_print_merge_stats(const char*)
609 { gold_unreachable(); }
611 // Return the required alignment.
612 uint64_t
613 do_addralign() const
614 { return this->addralign_; }
616 // Return the output section.
617 Output_section*
618 do_output_section()
619 { return this->output_section_; }
621 // Return the section index of the output section.
622 unsigned int
623 do_out_shndx() const;
625 // Set the alignment.
626 void
627 set_addralign(uint64_t addralign);
629 private:
630 // The output section for this section.
631 Output_section* output_section_;
632 // The required alignment.
633 uint64_t addralign_;
636 // Some Output_section_data classes build up their data step by step,
637 // rather than all at once. This class provides an interface for
638 // them.
640 class Output_section_data_build : public Output_section_data
642 public:
643 Output_section_data_build(uint64_t addralign)
644 : Output_section_data(addralign)
647 // Get the current data size.
648 off_t
649 current_data_size() const
650 { return this->current_data_size_for_child(); }
652 // Set the current data size.
653 void
654 set_current_data_size(off_t data_size)
655 { this->set_current_data_size_for_child(data_size); }
657 protected:
658 // Set the final data size.
659 virtual void
660 set_final_data_size()
661 { this->set_data_size(this->current_data_size_for_child()); }
664 // A simple case of Output_data in which we have constant data to
665 // output.
667 class Output_data_const : public Output_section_data
669 public:
670 Output_data_const(const std::string& data, uint64_t addralign)
671 : Output_section_data(data.size(), addralign), data_(data)
674 Output_data_const(const char* p, off_t len, uint64_t addralign)
675 : Output_section_data(len, addralign), data_(p, len)
678 Output_data_const(const unsigned char* p, off_t len, uint64_t addralign)
679 : Output_section_data(len, addralign),
680 data_(reinterpret_cast<const char*>(p), len)
683 protected:
684 // Write the data to the output file.
685 void
686 do_write(Output_file*);
688 // Write the data to a buffer.
689 void
690 do_write_to_buffer(unsigned char* buffer)
691 { memcpy(buffer, this->data_.data(), this->data_.size()); }
693 // Write to a map file.
694 void
695 do_print_to_mapfile(Mapfile* mapfile) const
696 { mapfile->print_output_data(this, _("** fill")); }
698 private:
699 std::string data_;
702 // Another version of Output_data with constant data, in which the
703 // buffer is allocated by the caller.
705 class Output_data_const_buffer : public Output_section_data
707 public:
708 Output_data_const_buffer(const unsigned char* p, off_t len,
709 uint64_t addralign, const char* map_name)
710 : Output_section_data(len, addralign),
711 p_(p), map_name_(map_name)
714 protected:
715 // Write the data the output file.
716 void
717 do_write(Output_file*);
719 // Write the data to a buffer.
720 void
721 do_write_to_buffer(unsigned char* buffer)
722 { memcpy(buffer, this->p_, this->data_size()); }
724 // Write to a map file.
725 void
726 do_print_to_mapfile(Mapfile* mapfile) const
727 { mapfile->print_output_data(this, _(this->map_name_)); }
729 private:
730 // The data to output.
731 const unsigned char* p_;
732 // Name to use in a map file. Maps are a rarely used feature, but
733 // the space usage is minor as aren't very many of these objects.
734 const char* map_name_;
737 // A place holder for a fixed amount of data written out via some
738 // other mechanism.
740 class Output_data_fixed_space : public Output_section_data
742 public:
743 Output_data_fixed_space(off_t data_size, uint64_t addralign,
744 const char* map_name)
745 : Output_section_data(data_size, addralign),
746 map_name_(map_name)
749 protected:
750 // Write out the data--the actual data must be written out
751 // elsewhere.
752 void
753 do_write(Output_file*)
756 // Write to a map file.
757 void
758 do_print_to_mapfile(Mapfile* mapfile) const
759 { mapfile->print_output_data(this, _(this->map_name_)); }
761 private:
762 // Name to use in a map file. Maps are a rarely used feature, but
763 // the space usage is minor as aren't very many of these objects.
764 const char* map_name_;
767 // A place holder for variable sized data written out via some other
768 // mechanism.
770 class Output_data_space : public Output_section_data_build
772 public:
773 explicit Output_data_space(uint64_t addralign, const char* map_name)
774 : Output_section_data_build(addralign),
775 map_name_(map_name)
778 // Set the alignment.
779 void
780 set_space_alignment(uint64_t align)
781 { this->set_addralign(align); }
783 protected:
784 // Write out the data--the actual data must be written out
785 // elsewhere.
786 void
787 do_write(Output_file*)
790 // Write to a map file.
791 void
792 do_print_to_mapfile(Mapfile* mapfile) const
793 { mapfile->print_output_data(this, _(this->map_name_)); }
795 private:
796 // Name to use in a map file. Maps are a rarely used feature, but
797 // the space usage is minor as aren't very many of these objects.
798 const char* map_name_;
801 // Fill fixed space with zeroes. This is just like
802 // Output_data_fixed_space, except that the map name is known.
804 class Output_data_zero_fill : public Output_section_data
806 public:
807 Output_data_zero_fill(off_t data_size, uint64_t addralign)
808 : Output_section_data(data_size, addralign)
811 protected:
812 // There is no data to write out.
813 void
814 do_write(Output_file*)
817 // Write to a map file.
818 void
819 do_print_to_mapfile(Mapfile* mapfile) const
820 { mapfile->print_output_data(this, "** zero fill"); }
823 // A string table which goes into an output section.
825 class Output_data_strtab : public Output_section_data
827 public:
828 Output_data_strtab(Stringpool* strtab)
829 : Output_section_data(1), strtab_(strtab)
832 protected:
833 // This is called to set the address and file offset. Here we make
834 // sure that the Stringpool is finalized.
835 void
836 set_final_data_size();
838 // Write out the data.
839 void
840 do_write(Output_file*);
842 // Write the data to a buffer.
843 void
844 do_write_to_buffer(unsigned char* buffer)
845 { this->strtab_->write_to_buffer(buffer, this->data_size()); }
847 // Write to a map file.
848 void
849 do_print_to_mapfile(Mapfile* mapfile) const
850 { mapfile->print_output_data(this, _("** string table")); }
852 private:
853 Stringpool* strtab_;
856 // This POD class is used to represent a single reloc in the output
857 // file. This could be a private class within Output_data_reloc, but
858 // the templatization is complex enough that I broke it out into a
859 // separate class. The class is templatized on either elfcpp::SHT_REL
860 // or elfcpp::SHT_RELA, and also on whether this is a dynamic
861 // relocation or an ordinary relocation.
863 // A relocation can be against a global symbol, a local symbol, a
864 // local section symbol, an output section, or the undefined symbol at
865 // index 0. We represent the latter by using a NULL global symbol.
867 template<int sh_type, bool dynamic, int size, bool big_endian>
868 class Output_reloc;
870 template<bool dynamic, int size, bool big_endian>
871 class Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>
873 public:
874 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
875 typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend;
877 static const Address invalid_address = static_cast<Address>(0) - 1;
879 // An uninitialized entry. We need this because we want to put
880 // instances of this class into an STL container.
881 Output_reloc()
882 : local_sym_index_(INVALID_CODE)
885 // We have a bunch of different constructors. They come in pairs
886 // depending on how the address of the relocation is specified. It
887 // can either be an offset in an Output_data or an offset in an
888 // input section.
890 // A reloc against a global symbol.
892 Output_reloc(Symbol* gsym, unsigned int type, Output_data* od,
893 Address address, bool is_relative);
895 Output_reloc(Symbol* gsym, unsigned int type,
896 Sized_relobj<size, big_endian>* relobj,
897 unsigned int shndx, Address address, bool is_relative);
899 // A reloc against a local symbol or local section symbol.
901 Output_reloc(Sized_relobj<size, big_endian>* relobj,
902 unsigned int local_sym_index, unsigned int type,
903 Output_data* od, Address address, bool is_relative,
904 bool is_section_symbol);
906 Output_reloc(Sized_relobj<size, big_endian>* relobj,
907 unsigned int local_sym_index, unsigned int type,
908 unsigned int shndx, Address address, bool is_relative,
909 bool is_section_symbol);
911 // A reloc against the STT_SECTION symbol of an output section.
913 Output_reloc(Output_section* os, unsigned int type, Output_data* od,
914 Address address);
916 Output_reloc(Output_section* os, unsigned int type,
917 Sized_relobj<size, big_endian>* relobj,
918 unsigned int shndx, Address address);
920 // Return TRUE if this is a RELATIVE relocation.
921 bool
922 is_relative() const
923 { return this->is_relative_; }
925 // Return whether this is against a local section symbol.
926 bool
927 is_local_section_symbol() const
929 return (this->local_sym_index_ != GSYM_CODE
930 && this->local_sym_index_ != SECTION_CODE
931 && this->local_sym_index_ != INVALID_CODE
932 && this->is_section_symbol_);
935 // For a local section symbol, return the offset of the input
936 // section within the output section. ADDEND is the addend being
937 // applied to the input section.
938 Address
939 local_section_offset(Addend addend) const;
941 // Get the value of the symbol referred to by a Rel relocation when
942 // we are adding the given ADDEND.
943 Address
944 symbol_value(Addend addend) const;
946 // Write the reloc entry to an output view.
947 void
948 write(unsigned char* pov) const;
950 // Write the offset and info fields to Write_rel.
951 template<typename Write_rel>
952 void write_rel(Write_rel*) const;
954 // This is used when sorting dynamic relocs. Return -1 to sort this
955 // reloc before R2, 0 to sort the same as R2, 1 to sort after R2.
957 compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
958 const;
960 // Return whether this reloc should be sorted before the argument
961 // when sorting dynamic relocs.
962 bool
963 sort_before(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>&
964 r2) const
965 { return this->compare(r2) < 0; }
967 private:
968 // Record that we need a dynamic symbol index.
969 void
970 set_needs_dynsym_index();
972 // Return the symbol index.
973 unsigned int
974 get_symbol_index() const;
976 // Return the output address.
977 Address
978 get_address() const;
980 // Codes for local_sym_index_.
981 enum
983 // Global symbol.
984 GSYM_CODE = -1U,
985 // Output section.
986 SECTION_CODE = -2U,
987 // Invalid uninitialized entry.
988 INVALID_CODE = -3U
991 union
993 // For a local symbol or local section symbol
994 // (this->local_sym_index_ >= 0), the object. We will never
995 // generate a relocation against a local symbol in a dynamic
996 // object; that doesn't make sense. And our callers will always
997 // be templatized, so we use Sized_relobj here.
998 Sized_relobj<size, big_endian>* relobj;
999 // For a global symbol (this->local_sym_index_ == GSYM_CODE, the
1000 // symbol. If this is NULL, it indicates a relocation against the
1001 // undefined 0 symbol.
1002 Symbol* gsym;
1003 // For a relocation against an output section
1004 // (this->local_sym_index_ == SECTION_CODE), the output section.
1005 Output_section* os;
1006 } u1_;
1007 union
1009 // If this->shndx_ is not INVALID CODE, the object which holds the
1010 // input section being used to specify the reloc address.
1011 Sized_relobj<size, big_endian>* relobj;
1012 // If this->shndx_ is INVALID_CODE, the output data being used to
1013 // specify the reloc address. This may be NULL if the reloc
1014 // address is absolute.
1015 Output_data* od;
1016 } u2_;
1017 // The address offset within the input section or the Output_data.
1018 Address address_;
1019 // This is GSYM_CODE for a global symbol, or SECTION_CODE for a
1020 // relocation against an output section, or INVALID_CODE for an
1021 // uninitialized value. Otherwise, for a local symbol
1022 // (this->is_section_symbol_ is false), the local symbol index. For
1023 // a local section symbol (this->is_section_symbol_ is true), the
1024 // section index in the input file.
1025 unsigned int local_sym_index_;
1026 // The reloc type--a processor specific code.
1027 unsigned int type_ : 30;
1028 // True if the relocation is a RELATIVE relocation.
1029 bool is_relative_ : 1;
1030 // True if the relocation is against a section symbol.
1031 bool is_section_symbol_ : 1;
1032 // If the reloc address is an input section in an object, the
1033 // section index. This is INVALID_CODE if the reloc address is
1034 // specified in some other way.
1035 unsigned int shndx_;
1038 // The SHT_RELA version of Output_reloc<>. This is just derived from
1039 // the SHT_REL version of Output_reloc, but it adds an addend.
1041 template<bool dynamic, int size, bool big_endian>
1042 class Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>
1044 public:
1045 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
1046 typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend;
1048 // An uninitialized entry.
1049 Output_reloc()
1050 : rel_()
1053 // A reloc against a global symbol.
1055 Output_reloc(Symbol* gsym, unsigned int type, Output_data* od,
1056 Address address, Addend addend, bool is_relative)
1057 : rel_(gsym, type, od, address, is_relative), addend_(addend)
1060 Output_reloc(Symbol* gsym, unsigned int type,
1061 Sized_relobj<size, big_endian>* relobj,
1062 unsigned int shndx, Address address, Addend addend,
1063 bool is_relative)
1064 : rel_(gsym, type, relobj, shndx, address, is_relative), addend_(addend)
1067 // A reloc against a local symbol.
1069 Output_reloc(Sized_relobj<size, big_endian>* relobj,
1070 unsigned int local_sym_index, unsigned int type,
1071 Output_data* od, Address address,
1072 Addend addend, bool is_relative, bool is_section_symbol)
1073 : rel_(relobj, local_sym_index, type, od, address, is_relative,
1074 is_section_symbol),
1075 addend_(addend)
1078 Output_reloc(Sized_relobj<size, big_endian>* relobj,
1079 unsigned int local_sym_index, unsigned int type,
1080 unsigned int shndx, Address address,
1081 Addend addend, bool is_relative, bool is_section_symbol)
1082 : rel_(relobj, local_sym_index, type, shndx, address, is_relative,
1083 is_section_symbol),
1084 addend_(addend)
1087 // A reloc against the STT_SECTION symbol of an output section.
1089 Output_reloc(Output_section* os, unsigned int type, Output_data* od,
1090 Address address, Addend addend)
1091 : rel_(os, type, od, address), addend_(addend)
1094 Output_reloc(Output_section* os, unsigned int type,
1095 Sized_relobj<size, big_endian>* relobj,
1096 unsigned int shndx, Address address, Addend addend)
1097 : rel_(os, type, relobj, shndx, address), addend_(addend)
1100 // Write the reloc entry to an output view.
1101 void
1102 write(unsigned char* pov) const;
1104 // Return whether this reloc should be sorted before the argument
1105 // when sorting dynamic relocs.
1106 bool
1107 sort_before(const Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>&
1108 r2) const
1110 int i = this->rel_.compare(r2.rel_);
1111 if (i < 0)
1112 return true;
1113 else if (i > 0)
1114 return false;
1115 else
1116 return this->addend_ < r2.addend_;
1119 private:
1120 // The basic reloc.
1121 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian> rel_;
1122 // The addend.
1123 Addend addend_;
1126 // Output_data_reloc is used to manage a section containing relocs.
1127 // SH_TYPE is either elfcpp::SHT_REL or elfcpp::SHT_RELA. DYNAMIC
1128 // indicates whether this is a dynamic relocation or a normal
1129 // relocation. Output_data_reloc_base is a base class.
1130 // Output_data_reloc is the real class, which we specialize based on
1131 // the reloc type.
1133 template<int sh_type, bool dynamic, int size, bool big_endian>
1134 class Output_data_reloc_base : public Output_section_data_build
1136 public:
1137 typedef Output_reloc<sh_type, dynamic, size, big_endian> Output_reloc_type;
1138 typedef typename Output_reloc_type::Address Address;
1139 static const int reloc_size =
1140 Reloc_types<sh_type, size, big_endian>::reloc_size;
1142 // Construct the section.
1143 Output_data_reloc_base(bool sort_relocs)
1144 : Output_section_data_build(Output_data::default_alignment_for_size(size)),
1145 sort_relocs_(sort_relocs)
1148 protected:
1149 // Write out the data.
1150 void
1151 do_write(Output_file*);
1153 // Set the entry size and the link.
1154 void
1155 do_adjust_output_section(Output_section *os);
1157 // Write to a map file.
1158 void
1159 do_print_to_mapfile(Mapfile* mapfile) const
1161 mapfile->print_output_data(this,
1162 (dynamic
1163 ? _("** dynamic relocs")
1164 : _("** relocs")));
1167 // Add a relocation entry.
1168 void
1169 add(Output_data *od, const Output_reloc_type& reloc)
1171 this->relocs_.push_back(reloc);
1172 this->set_current_data_size(this->relocs_.size() * reloc_size);
1173 od->add_dynamic_reloc();
1176 private:
1177 typedef std::vector<Output_reloc_type> Relocs;
1179 // The class used to sort the relocations.
1180 struct Sort_relocs_comparison
1182 bool
1183 operator()(const Output_reloc_type& r1, const Output_reloc_type& r2) const
1184 { return r1.sort_before(r2); }
1187 // The relocations in this section.
1188 Relocs relocs_;
1189 // Whether to sort the relocations when writing them out, to make
1190 // the dynamic linker more efficient.
1191 bool sort_relocs_;
1194 // The class which callers actually create.
1196 template<int sh_type, bool dynamic, int size, bool big_endian>
1197 class Output_data_reloc;
1199 // The SHT_REL version of Output_data_reloc.
1201 template<bool dynamic, int size, bool big_endian>
1202 class Output_data_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>
1203 : public Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, big_endian>
1205 private:
1206 typedef Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size,
1207 big_endian> Base;
1209 public:
1210 typedef typename Base::Output_reloc_type Output_reloc_type;
1211 typedef typename Output_reloc_type::Address Address;
1213 Output_data_reloc(bool sr)
1214 : Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, big_endian>(sr)
1217 // Add a reloc against a global symbol.
1219 void
1220 add_global(Symbol* gsym, unsigned int type, Output_data* od, Address address)
1221 { this->add(od, Output_reloc_type(gsym, type, od, address, false)); }
1223 void
1224 add_global(Symbol* gsym, unsigned int type, Output_data* od,
1225 Sized_relobj<size, big_endian>* relobj,
1226 unsigned int shndx, Address address)
1227 { this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address,
1228 false)); }
1230 // These are to simplify the Copy_relocs class.
1232 void
1233 add_global(Symbol* gsym, unsigned int type, Output_data* od, Address address,
1234 Address addend)
1236 gold_assert(addend == 0);
1237 this->add_global(gsym, type, od, address);
1240 void
1241 add_global(Symbol* gsym, unsigned int type, Output_data* od,
1242 Sized_relobj<size, big_endian>* relobj,
1243 unsigned int shndx, Address address, Address addend)
1245 gold_assert(addend == 0);
1246 this->add_global(gsym, type, od, relobj, shndx, address);
1249 // Add a RELATIVE reloc against a global symbol. The final relocation
1250 // will not reference the symbol.
1252 void
1253 add_global_relative(Symbol* gsym, unsigned int type, Output_data* od,
1254 Address address)
1255 { this->add(od, Output_reloc_type(gsym, type, od, address, true)); }
1257 void
1258 add_global_relative(Symbol* gsym, unsigned int type, Output_data* od,
1259 Sized_relobj<size, big_endian>* relobj,
1260 unsigned int shndx, Address address)
1262 this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address,
1263 true));
1266 // Add a reloc against a local symbol.
1268 void
1269 add_local(Sized_relobj<size, big_endian>* relobj,
1270 unsigned int local_sym_index, unsigned int type,
1271 Output_data* od, Address address)
1273 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od,
1274 address, false, false));
1277 void
1278 add_local(Sized_relobj<size, big_endian>* relobj,
1279 unsigned int local_sym_index, unsigned int type,
1280 Output_data* od, unsigned int shndx, Address address)
1282 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx,
1283 address, false, false));
1286 // Add a RELATIVE reloc against a local symbol.
1288 void
1289 add_local_relative(Sized_relobj<size, big_endian>* relobj,
1290 unsigned int local_sym_index, unsigned int type,
1291 Output_data* od, Address address)
1293 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od,
1294 address, true, false));
1297 void
1298 add_local_relative(Sized_relobj<size, big_endian>* relobj,
1299 unsigned int local_sym_index, unsigned int type,
1300 Output_data* od, unsigned int shndx, Address address)
1302 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx,
1303 address, true, false));
1306 // Add a reloc against a local section symbol. This will be
1307 // converted into a reloc against the STT_SECTION symbol of the
1308 // output section.
1310 void
1311 add_local_section(Sized_relobj<size, big_endian>* relobj,
1312 unsigned int input_shndx, unsigned int type,
1313 Output_data* od, Address address)
1315 this->add(od, Output_reloc_type(relobj, input_shndx, type, od,
1316 address, false, true));
1319 void
1320 add_local_section(Sized_relobj<size, big_endian>* relobj,
1321 unsigned int input_shndx, unsigned int type,
1322 Output_data* od, unsigned int shndx, Address address)
1324 this->add(od, Output_reloc_type(relobj, input_shndx, type, shndx,
1325 address, false, true));
1328 // A reloc against the STT_SECTION symbol of an output section.
1329 // OS is the Output_section that the relocation refers to; OD is
1330 // the Output_data object being relocated.
1332 void
1333 add_output_section(Output_section* os, unsigned int type,
1334 Output_data* od, Address address)
1335 { this->add(od, Output_reloc_type(os, type, od, address)); }
1337 void
1338 add_output_section(Output_section* os, unsigned int type, Output_data* od,
1339 Sized_relobj<size, big_endian>* relobj,
1340 unsigned int shndx, Address address)
1341 { this->add(od, Output_reloc_type(os, type, relobj, shndx, address)); }
1344 // The SHT_RELA version of Output_data_reloc.
1346 template<bool dynamic, int size, bool big_endian>
1347 class Output_data_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>
1348 : public Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, big_endian>
1350 private:
1351 typedef Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size,
1352 big_endian> Base;
1354 public:
1355 typedef typename Base::Output_reloc_type Output_reloc_type;
1356 typedef typename Output_reloc_type::Address Address;
1357 typedef typename Output_reloc_type::Addend Addend;
1359 Output_data_reloc(bool sr)
1360 : Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, big_endian>(sr)
1363 // Add a reloc against a global symbol.
1365 void
1366 add_global(Symbol* gsym, unsigned int type, Output_data* od,
1367 Address address, Addend addend)
1368 { this->add(od, Output_reloc_type(gsym, type, od, address, addend,
1369 false)); }
1371 void
1372 add_global(Symbol* gsym, unsigned int type, Output_data* od,
1373 Sized_relobj<size, big_endian>* relobj,
1374 unsigned int shndx, Address address,
1375 Addend addend)
1376 { this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address,
1377 addend, false)); }
1379 // Add a RELATIVE reloc against a global symbol. The final output
1380 // relocation will not reference the symbol, but we must keep the symbol
1381 // information long enough to set the addend of the relocation correctly
1382 // when it is written.
1384 void
1385 add_global_relative(Symbol* gsym, unsigned int type, Output_data* od,
1386 Address address, Addend addend)
1387 { this->add(od, Output_reloc_type(gsym, type, od, address, addend, true)); }
1389 void
1390 add_global_relative(Symbol* gsym, unsigned int type, Output_data* od,
1391 Sized_relobj<size, big_endian>* relobj,
1392 unsigned int shndx, Address address, Addend addend)
1393 { this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address,
1394 addend, true)); }
1396 // Add a reloc against a local symbol.
1398 void
1399 add_local(Sized_relobj<size, big_endian>* relobj,
1400 unsigned int local_sym_index, unsigned int type,
1401 Output_data* od, Address address, Addend addend)
1403 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, address,
1404 addend, false, false));
1407 void
1408 add_local(Sized_relobj<size, big_endian>* relobj,
1409 unsigned int local_sym_index, unsigned int type,
1410 Output_data* od, unsigned int shndx, Address address,
1411 Addend addend)
1413 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx,
1414 address, addend, false, false));
1417 // Add a RELATIVE reloc against a local symbol.
1419 void
1420 add_local_relative(Sized_relobj<size, big_endian>* relobj,
1421 unsigned int local_sym_index, unsigned int type,
1422 Output_data* od, Address address, Addend addend)
1424 this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, address,
1425 addend, true, false));
1428 void
1429 add_local_relative(Sized_relobj<size, big_endian>* relobj,
1430 unsigned int local_sym_index, unsigned int type,
1431 Output_data* od, unsigned int shndx, Address address,
1432 Addend addend)
1434 this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx,
1435 address, addend, true, false));
1438 // Add a reloc against a local section symbol. This will be
1439 // converted into a reloc against the STT_SECTION symbol of the
1440 // output section.
1442 void
1443 add_local_section(Sized_relobj<size, big_endian>* relobj,
1444 unsigned int input_shndx, unsigned int type,
1445 Output_data* od, Address address, Addend addend)
1447 this->add(od, Output_reloc_type(relobj, input_shndx, type, od, address,
1448 addend, false, true));
1451 void
1452 add_local_section(Sized_relobj<size, big_endian>* relobj,
1453 unsigned int input_shndx, unsigned int type,
1454 Output_data* od, unsigned int shndx, Address address,
1455 Addend addend)
1457 this->add(od, Output_reloc_type(relobj, input_shndx, type, shndx,
1458 address, addend, false, true));
1461 // A reloc against the STT_SECTION symbol of an output section.
1463 void
1464 add_output_section(Output_section* os, unsigned int type, Output_data* od,
1465 Address address, Addend addend)
1466 { this->add(os, Output_reloc_type(os, type, od, address, addend)); }
1468 void
1469 add_output_section(Output_section* os, unsigned int type,
1470 Sized_relobj<size, big_endian>* relobj,
1471 unsigned int shndx, Address address, Addend addend)
1472 { this->add(os, Output_reloc_type(os, type, relobj, shndx, address,
1473 addend)); }
1476 // Output_relocatable_relocs represents a relocation section in a
1477 // relocatable link. The actual data is written out in the target
1478 // hook relocate_for_relocatable. This just saves space for it.
1480 template<int sh_type, int size, bool big_endian>
1481 class Output_relocatable_relocs : public Output_section_data
1483 public:
1484 Output_relocatable_relocs(Relocatable_relocs* rr)
1485 : Output_section_data(Output_data::default_alignment_for_size(size)),
1486 rr_(rr)
1489 void
1490 set_final_data_size();
1492 // Write out the data. There is nothing to do here.
1493 void
1494 do_write(Output_file*)
1497 // Write to a map file.
1498 void
1499 do_print_to_mapfile(Mapfile* mapfile) const
1500 { mapfile->print_output_data(this, _("** relocs")); }
1502 private:
1503 // The relocs associated with this input section.
1504 Relocatable_relocs* rr_;
1507 // Handle a GROUP section.
1509 template<int size, bool big_endian>
1510 class Output_data_group : public Output_section_data
1512 public:
1513 // The constructor clears *INPUT_SHNDXES.
1514 Output_data_group(Sized_relobj<size, big_endian>* relobj,
1515 section_size_type entry_count,
1516 elfcpp::Elf_Word flags,
1517 std::vector<unsigned int>* input_shndxes);
1519 void
1520 do_write(Output_file*);
1522 // Write to a map file.
1523 void
1524 do_print_to_mapfile(Mapfile* mapfile) const
1525 { mapfile->print_output_data(this, _("** group")); }
1527 private:
1528 // The input object.
1529 Sized_relobj<size, big_endian>* relobj_;
1530 // The group flag word.
1531 elfcpp::Elf_Word flags_;
1532 // The section indexes of the input sections in this group.
1533 std::vector<unsigned int> input_shndxes_;
1536 // Output_data_got is used to manage a GOT. Each entry in the GOT is
1537 // for one symbol--either a global symbol or a local symbol in an
1538 // object. The target specific code adds entries to the GOT as
1539 // needed.
1541 template<int size, bool big_endian>
1542 class Output_data_got : public Output_section_data_build
1544 public:
1545 typedef typename elfcpp::Elf_types<size>::Elf_Addr Valtype;
1546 typedef Output_data_reloc<elfcpp::SHT_REL, true, size, big_endian> Rel_dyn;
1547 typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian> Rela_dyn;
1549 Output_data_got()
1550 : Output_section_data_build(Output_data::default_alignment_for_size(size)),
1551 entries_()
1554 // Add an entry for a global symbol to the GOT. Return true if this
1555 // is a new GOT entry, false if the symbol was already in the GOT.
1556 bool
1557 add_global(Symbol* gsym, unsigned int got_type);
1559 // Add an entry for a global symbol to the GOT, and add a dynamic
1560 // relocation of type R_TYPE for the GOT entry.
1561 void
1562 add_global_with_rel(Symbol* gsym, unsigned int got_type,
1563 Rel_dyn* rel_dyn, unsigned int r_type);
1565 void
1566 add_global_with_rela(Symbol* gsym, unsigned int got_type,
1567 Rela_dyn* rela_dyn, unsigned int r_type);
1569 // Add a pair of entries for a global symbol to the GOT, and add
1570 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1571 void
1572 add_global_pair_with_rel(Symbol* gsym, unsigned int got_type,
1573 Rel_dyn* rel_dyn, unsigned int r_type_1,
1574 unsigned int r_type_2);
1576 void
1577 add_global_pair_with_rela(Symbol* gsym, unsigned int got_type,
1578 Rela_dyn* rela_dyn, unsigned int r_type_1,
1579 unsigned int r_type_2);
1581 // Add an entry for a local symbol to the GOT. This returns true if
1582 // this is a new GOT entry, false if the symbol already has a GOT
1583 // entry.
1584 bool
1585 add_local(Sized_relobj<size, big_endian>* object, unsigned int sym_index,
1586 unsigned int got_type);
1588 // Add an entry for a local symbol to the GOT, and add a dynamic
1589 // relocation of type R_TYPE for the GOT entry.
1590 void
1591 add_local_with_rel(Sized_relobj<size, big_endian>* object,
1592 unsigned int sym_index, unsigned int got_type,
1593 Rel_dyn* rel_dyn, unsigned int r_type);
1595 void
1596 add_local_with_rela(Sized_relobj<size, big_endian>* object,
1597 unsigned int sym_index, unsigned int got_type,
1598 Rela_dyn* rela_dyn, unsigned int r_type);
1600 // Add a pair of entries for a local symbol to the GOT, and add
1601 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1602 void
1603 add_local_pair_with_rel(Sized_relobj<size, big_endian>* object,
1604 unsigned int sym_index, unsigned int shndx,
1605 unsigned int got_type, Rel_dyn* rel_dyn,
1606 unsigned int r_type_1, unsigned int r_type_2);
1608 void
1609 add_local_pair_with_rela(Sized_relobj<size, big_endian>* object,
1610 unsigned int sym_index, unsigned int shndx,
1611 unsigned int got_type, Rela_dyn* rela_dyn,
1612 unsigned int r_type_1, unsigned int r_type_2);
1614 // Add a constant to the GOT. This returns the offset of the new
1615 // entry from the start of the GOT.
1616 unsigned int
1617 add_constant(Valtype constant)
1619 this->entries_.push_back(Got_entry(constant));
1620 this->set_got_size();
1621 return this->last_got_offset();
1624 protected:
1625 // Write out the GOT table.
1626 void
1627 do_write(Output_file*);
1629 // Write to a map file.
1630 void
1631 do_print_to_mapfile(Mapfile* mapfile) const
1632 { mapfile->print_output_data(this, _("** GOT")); }
1634 private:
1635 // This POD class holds a single GOT entry.
1636 class Got_entry
1638 public:
1639 // Create a zero entry.
1640 Got_entry()
1641 : local_sym_index_(CONSTANT_CODE)
1642 { this->u_.constant = 0; }
1644 // Create a global symbol entry.
1645 explicit Got_entry(Symbol* gsym)
1646 : local_sym_index_(GSYM_CODE)
1647 { this->u_.gsym = gsym; }
1649 // Create a local symbol entry.
1650 Got_entry(Sized_relobj<size, big_endian>* object,
1651 unsigned int local_sym_index)
1652 : local_sym_index_(local_sym_index)
1654 gold_assert(local_sym_index != GSYM_CODE
1655 && local_sym_index != CONSTANT_CODE);
1656 this->u_.object = object;
1659 // Create a constant entry. The constant is a host value--it will
1660 // be swapped, if necessary, when it is written out.
1661 explicit Got_entry(Valtype constant)
1662 : local_sym_index_(CONSTANT_CODE)
1663 { this->u_.constant = constant; }
1665 // Write the GOT entry to an output view.
1666 void
1667 write(unsigned char* pov) const;
1669 private:
1670 enum
1672 GSYM_CODE = -1U,
1673 CONSTANT_CODE = -2U
1676 union
1678 // For a local symbol, the object.
1679 Sized_relobj<size, big_endian>* object;
1680 // For a global symbol, the symbol.
1681 Symbol* gsym;
1682 // For a constant, the constant.
1683 Valtype constant;
1684 } u_;
1685 // For a local symbol, the local symbol index. This is GSYM_CODE
1686 // for a global symbol, or CONSTANT_CODE for a constant.
1687 unsigned int local_sym_index_;
1690 typedef std::vector<Got_entry> Got_entries;
1692 // Return the offset into the GOT of GOT entry I.
1693 unsigned int
1694 got_offset(unsigned int i) const
1695 { return i * (size / 8); }
1697 // Return the offset into the GOT of the last entry added.
1698 unsigned int
1699 last_got_offset() const
1700 { return this->got_offset(this->entries_.size() - 1); }
1702 // Set the size of the section.
1703 void
1704 set_got_size()
1705 { this->set_current_data_size(this->got_offset(this->entries_.size())); }
1707 // The list of GOT entries.
1708 Got_entries entries_;
1711 // Output_data_dynamic is used to hold the data in SHT_DYNAMIC
1712 // section.
1714 class Output_data_dynamic : public Output_section_data
1716 public:
1717 Output_data_dynamic(Stringpool* pool)
1718 : Output_section_data(Output_data::default_alignment()),
1719 entries_(), pool_(pool)
1722 // Add a new dynamic entry with a fixed numeric value.
1723 void
1724 add_constant(elfcpp::DT tag, unsigned int val)
1725 { this->add_entry(Dynamic_entry(tag, val)); }
1727 // Add a new dynamic entry with the address of output data.
1728 void
1729 add_section_address(elfcpp::DT tag, const Output_data* od)
1730 { this->add_entry(Dynamic_entry(tag, od, false)); }
1732 // Add a new dynamic entry with the address of output data
1733 // plus a constant offset.
1734 void
1735 add_section_plus_offset(elfcpp::DT tag, const Output_data* od,
1736 unsigned int offset)
1737 { this->add_entry(Dynamic_entry(tag, od, offset)); }
1739 // Add a new dynamic entry with the size of output data.
1740 void
1741 add_section_size(elfcpp::DT tag, const Output_data* od)
1742 { this->add_entry(Dynamic_entry(tag, od, true)); }
1744 // Add a new dynamic entry with the address of a symbol.
1745 void
1746 add_symbol(elfcpp::DT tag, const Symbol* sym)
1747 { this->add_entry(Dynamic_entry(tag, sym)); }
1749 // Add a new dynamic entry with a string.
1750 void
1751 add_string(elfcpp::DT tag, const char* str)
1752 { this->add_entry(Dynamic_entry(tag, this->pool_->add(str, true, NULL))); }
1754 void
1755 add_string(elfcpp::DT tag, const std::string& str)
1756 { this->add_string(tag, str.c_str()); }
1758 protected:
1759 // Adjust the output section to set the entry size.
1760 void
1761 do_adjust_output_section(Output_section*);
1763 // Set the final data size.
1764 void
1765 set_final_data_size();
1767 // Write out the dynamic entries.
1768 void
1769 do_write(Output_file*);
1771 // Write to a map file.
1772 void
1773 do_print_to_mapfile(Mapfile* mapfile) const
1774 { mapfile->print_output_data(this, _("** dynamic")); }
1776 private:
1777 // This POD class holds a single dynamic entry.
1778 class Dynamic_entry
1780 public:
1781 // Create an entry with a fixed numeric value.
1782 Dynamic_entry(elfcpp::DT tag, unsigned int val)
1783 : tag_(tag), offset_(DYNAMIC_NUMBER)
1784 { this->u_.val = val; }
1786 // Create an entry with the size or address of a section.
1787 Dynamic_entry(elfcpp::DT tag, const Output_data* od, bool section_size)
1788 : tag_(tag),
1789 offset_(section_size
1790 ? DYNAMIC_SECTION_SIZE
1791 : DYNAMIC_SECTION_ADDRESS)
1792 { this->u_.od = od; }
1794 // Create an entry with the address of a section plus a constant offset.
1795 Dynamic_entry(elfcpp::DT tag, const Output_data* od, unsigned int offset)
1796 : tag_(tag),
1797 offset_(offset)
1798 { this->u_.od = od; }
1800 // Create an entry with the address of a symbol.
1801 Dynamic_entry(elfcpp::DT tag, const Symbol* sym)
1802 : tag_(tag), offset_(DYNAMIC_SYMBOL)
1803 { this->u_.sym = sym; }
1805 // Create an entry with a string.
1806 Dynamic_entry(elfcpp::DT tag, const char* str)
1807 : tag_(tag), offset_(DYNAMIC_STRING)
1808 { this->u_.str = str; }
1810 // Write the dynamic entry to an output view.
1811 template<int size, bool big_endian>
1812 void
1813 write(unsigned char* pov, const Stringpool*) const;
1815 private:
1816 // Classification is encoded in the OFFSET field.
1817 enum Classification
1819 // Section address.
1820 DYNAMIC_SECTION_ADDRESS = 0,
1821 // Number.
1822 DYNAMIC_NUMBER = -1U,
1823 // Section size.
1824 DYNAMIC_SECTION_SIZE = -2U,
1825 // Symbol adress.
1826 DYNAMIC_SYMBOL = -3U,
1827 // String.
1828 DYNAMIC_STRING = -4U
1829 // Any other value indicates a section address plus OFFSET.
1832 union
1834 // For DYNAMIC_NUMBER.
1835 unsigned int val;
1836 // For DYNAMIC_SECTION_SIZE and section address plus OFFSET.
1837 const Output_data* od;
1838 // For DYNAMIC_SYMBOL.
1839 const Symbol* sym;
1840 // For DYNAMIC_STRING.
1841 const char* str;
1842 } u_;
1843 // The dynamic tag.
1844 elfcpp::DT tag_;
1845 // The type of entry (Classification) or offset within a section.
1846 unsigned int offset_;
1849 // Add an entry to the list.
1850 void
1851 add_entry(const Dynamic_entry& entry)
1852 { this->entries_.push_back(entry); }
1854 // Sized version of write function.
1855 template<int size, bool big_endian>
1856 void
1857 sized_write(Output_file* of);
1859 // The type of the list of entries.
1860 typedef std::vector<Dynamic_entry> Dynamic_entries;
1862 // The entries.
1863 Dynamic_entries entries_;
1864 // The pool used for strings.
1865 Stringpool* pool_;
1868 // Output_symtab_xindex is used to handle SHT_SYMTAB_SHNDX sections,
1869 // which may be required if the object file has more than
1870 // SHN_LORESERVE sections.
1872 class Output_symtab_xindex : public Output_section_data
1874 public:
1875 Output_symtab_xindex(size_t symcount)
1876 : Output_section_data(symcount * 4, 4),
1877 entries_()
1880 // Add an entry: symbol number SYMNDX has section SHNDX.
1881 void
1882 add(unsigned int symndx, unsigned int shndx)
1883 { this->entries_.push_back(std::make_pair(symndx, shndx)); }
1885 protected:
1886 void
1887 do_write(Output_file*);
1889 // Write to a map file.
1890 void
1891 do_print_to_mapfile(Mapfile* mapfile) const
1892 { mapfile->print_output_data(this, _("** symtab xindex")); }
1894 private:
1895 template<bool big_endian>
1896 void
1897 endian_do_write(unsigned char*);
1899 // It is likely that most symbols will not require entries. Rather
1900 // than keep a vector for all symbols, we keep pairs of symbol index
1901 // and section index.
1902 typedef std::vector<std::pair<unsigned int, unsigned int> > Xindex_entries;
1904 // The entries we need.
1905 Xindex_entries entries_;
1908 // An output section. We don't expect to have too many output
1909 // sections, so we don't bother to do a template on the size.
1911 class Output_section : public Output_data
1913 public:
1914 // Create an output section, giving the name, type, and flags.
1915 Output_section(const char* name, elfcpp::Elf_Word, elfcpp::Elf_Xword);
1916 virtual ~Output_section();
1918 // Add a new input section SHNDX, named NAME, with header SHDR, from
1919 // object OBJECT. RELOC_SHNDX is the index of a relocation section
1920 // which applies to this section, or 0 if none, or -1 if more than
1921 // one. HAVE_SECTIONS_SCRIPT is true if we have a SECTIONS clause
1922 // in a linker script; in that case we need to keep track of input
1923 // sections associated with an output section. Return the offset
1924 // within the output section.
1925 template<int size, bool big_endian>
1926 off_t
1927 add_input_section(Sized_relobj<size, big_endian>* object, unsigned int shndx,
1928 const char *name,
1929 const elfcpp::Shdr<size, big_endian>& shdr,
1930 unsigned int reloc_shndx, bool have_sections_script);
1932 // Add generated data POSD to this output section.
1933 void
1934 add_output_section_data(Output_section_data* posd);
1936 // Return the section name.
1937 const char*
1938 name() const
1939 { return this->name_; }
1941 // Return the section type.
1942 elfcpp::Elf_Word
1943 type() const
1944 { return this->type_; }
1946 // Return the section flags.
1947 elfcpp::Elf_Xword
1948 flags() const
1949 { return this->flags_; }
1951 // Set the section flags. This may only be used with the Layout
1952 // code when it is prepared to move the section to a different
1953 // segment.
1954 void
1955 set_flags(elfcpp::Elf_Xword flags)
1956 { this->flags_ = flags; }
1958 // Update the output section flags based on input section flags.
1959 void
1960 update_flags_for_input_section(elfcpp::Elf_Xword flags)
1962 this->flags_ |= (flags
1963 & (elfcpp::SHF_WRITE
1964 | elfcpp::SHF_ALLOC
1965 | elfcpp::SHF_EXECINSTR));
1968 // Return the entsize field.
1969 uint64_t
1970 entsize() const
1971 { return this->entsize_; }
1973 // Set the entsize field.
1974 void
1975 set_entsize(uint64_t v);
1977 // Set the load address.
1978 void
1979 set_load_address(uint64_t load_address)
1981 this->load_address_ = load_address;
1982 this->has_load_address_ = true;
1985 // Set the link field to the output section index of a section.
1986 void
1987 set_link_section(const Output_data* od)
1989 gold_assert(this->link_ == 0
1990 && !this->should_link_to_symtab_
1991 && !this->should_link_to_dynsym_);
1992 this->link_section_ = od;
1995 // Set the link field to a constant.
1996 void
1997 set_link(unsigned int v)
1999 gold_assert(this->link_section_ == NULL
2000 && !this->should_link_to_symtab_
2001 && !this->should_link_to_dynsym_);
2002 this->link_ = v;
2005 // Record that this section should link to the normal symbol table.
2006 void
2007 set_should_link_to_symtab()
2009 gold_assert(this->link_section_ == NULL
2010 && this->link_ == 0
2011 && !this->should_link_to_dynsym_);
2012 this->should_link_to_symtab_ = true;
2015 // Record that this section should link to the dynamic symbol table.
2016 void
2017 set_should_link_to_dynsym()
2019 gold_assert(this->link_section_ == NULL
2020 && this->link_ == 0
2021 && !this->should_link_to_symtab_);
2022 this->should_link_to_dynsym_ = true;
2025 // Return the info field.
2026 unsigned int
2027 info() const
2029 gold_assert(this->info_section_ == NULL
2030 && this->info_symndx_ == NULL);
2031 return this->info_;
2034 // Set the info field to the output section index of a section.
2035 void
2036 set_info_section(const Output_section* os)
2038 gold_assert((this->info_section_ == NULL
2039 || (this->info_section_ == os
2040 && this->info_uses_section_index_))
2041 && this->info_symndx_ == NULL
2042 && this->info_ == 0);
2043 this->info_section_ = os;
2044 this->info_uses_section_index_= true;
2047 // Set the info field to the symbol table index of a symbol.
2048 void
2049 set_info_symndx(const Symbol* sym)
2051 gold_assert(this->info_section_ == NULL
2052 && (this->info_symndx_ == NULL
2053 || this->info_symndx_ == sym)
2054 && this->info_ == 0);
2055 this->info_symndx_ = sym;
2058 // Set the info field to the symbol table index of a section symbol.
2059 void
2060 set_info_section_symndx(const Output_section* os)
2062 gold_assert((this->info_section_ == NULL
2063 || (this->info_section_ == os
2064 && !this->info_uses_section_index_))
2065 && this->info_symndx_ == NULL
2066 && this->info_ == 0);
2067 this->info_section_ = os;
2068 this->info_uses_section_index_ = false;
2071 // Set the info field to a constant.
2072 void
2073 set_info(unsigned int v)
2075 gold_assert(this->info_section_ == NULL
2076 && this->info_symndx_ == NULL
2077 && (this->info_ == 0
2078 || this->info_ == v));
2079 this->info_ = v;
2082 // Set the addralign field.
2083 void
2084 set_addralign(uint64_t v)
2085 { this->addralign_ = v; }
2087 // Whether the output section index has been set.
2088 bool
2089 has_out_shndx() const
2090 { return this->out_shndx_ != -1U; }
2092 // Indicate that we need a symtab index.
2093 void
2094 set_needs_symtab_index()
2095 { this->needs_symtab_index_ = true; }
2097 // Return whether we need a symtab index.
2098 bool
2099 needs_symtab_index() const
2100 { return this->needs_symtab_index_; }
2102 // Get the symtab index.
2103 unsigned int
2104 symtab_index() const
2106 gold_assert(this->symtab_index_ != 0);
2107 return this->symtab_index_;
2110 // Set the symtab index.
2111 void
2112 set_symtab_index(unsigned int index)
2114 gold_assert(index != 0);
2115 this->symtab_index_ = index;
2118 // Indicate that we need a dynsym index.
2119 void
2120 set_needs_dynsym_index()
2121 { this->needs_dynsym_index_ = true; }
2123 // Return whether we need a dynsym index.
2124 bool
2125 needs_dynsym_index() const
2126 { return this->needs_dynsym_index_; }
2128 // Get the dynsym index.
2129 unsigned int
2130 dynsym_index() const
2132 gold_assert(this->dynsym_index_ != 0);
2133 return this->dynsym_index_;
2136 // Set the dynsym index.
2137 void
2138 set_dynsym_index(unsigned int index)
2140 gold_assert(index != 0);
2141 this->dynsym_index_ = index;
2144 // Return whether the input sections sections attachd to this output
2145 // section may require sorting. This is used to handle constructor
2146 // priorities compatibly with GNU ld.
2147 bool
2148 may_sort_attached_input_sections() const
2149 { return this->may_sort_attached_input_sections_; }
2151 // Record that the input sections attached to this output section
2152 // may require sorting.
2153 void
2154 set_may_sort_attached_input_sections()
2155 { this->may_sort_attached_input_sections_ = true; }
2157 // Return whether the input sections attached to this output section
2158 // require sorting. This is used to handle constructor priorities
2159 // compatibly with GNU ld.
2160 bool
2161 must_sort_attached_input_sections() const
2162 { return this->must_sort_attached_input_sections_; }
2164 // Record that the input sections attached to this output section
2165 // require sorting.
2166 void
2167 set_must_sort_attached_input_sections()
2168 { this->must_sort_attached_input_sections_ = true; }
2170 // Return whether this section holds relro data--data which has
2171 // dynamic relocations but which may be marked read-only after the
2172 // dynamic relocations have been completed.
2173 bool
2174 is_relro() const
2175 { return this->is_relro_; }
2177 // Record that this section holds relro data.
2178 void
2179 set_is_relro()
2180 { this->is_relro_ = true; }
2182 // Record that this section does not hold relro data.
2183 void
2184 clear_is_relro()
2185 { this->is_relro_ = false; }
2187 // True if this section holds relro local data--relro data for which
2188 // the dynamic relocations are all RELATIVE relocations.
2189 bool
2190 is_relro_local() const
2191 { return this->is_relro_local_; }
2193 // Record that this section holds relro local data.
2194 void
2195 set_is_relro_local()
2196 { this->is_relro_local_ = true; }
2198 // Return whether this section should be written after all the input
2199 // sections are complete.
2200 bool
2201 after_input_sections() const
2202 { return this->after_input_sections_; }
2204 // Record that this section should be written after all the input
2205 // sections are complete.
2206 void
2207 set_after_input_sections()
2208 { this->after_input_sections_ = true; }
2210 // Return whether this section requires postprocessing after all
2211 // relocations have been applied.
2212 bool
2213 requires_postprocessing() const
2214 { return this->requires_postprocessing_; }
2216 // If a section requires postprocessing, return the buffer to use.
2217 unsigned char*
2218 postprocessing_buffer() const
2220 gold_assert(this->postprocessing_buffer_ != NULL);
2221 return this->postprocessing_buffer_;
2224 // If a section requires postprocessing, create the buffer to use.
2225 void
2226 create_postprocessing_buffer();
2228 // If a section requires postprocessing, this is the size of the
2229 // buffer to which relocations should be applied.
2230 off_t
2231 postprocessing_buffer_size() const
2232 { return this->current_data_size_for_child(); }
2234 // Modify the section name. This is only permitted for an
2235 // unallocated section, and only before the size has been finalized.
2236 // Otherwise the name will not get into Layout::namepool_.
2237 void
2238 set_name(const char* newname)
2240 gold_assert((this->flags_ & elfcpp::SHF_ALLOC) == 0);
2241 gold_assert(!this->is_data_size_valid());
2242 this->name_ = newname;
2245 // Return whether the offset OFFSET in the input section SHNDX in
2246 // object OBJECT is being included in the link.
2247 bool
2248 is_input_address_mapped(const Relobj* object, unsigned int shndx,
2249 off_t offset) const;
2251 // Return the offset within the output section of OFFSET relative to
2252 // the start of input section SHNDX in object OBJECT.
2253 section_offset_type
2254 output_offset(const Relobj* object, unsigned int shndx,
2255 section_offset_type offset) const;
2257 // Return the output virtual address of OFFSET relative to the start
2258 // of input section SHNDX in object OBJECT.
2259 uint64_t
2260 output_address(const Relobj* object, unsigned int shndx,
2261 off_t offset) const;
2263 // Look for the merged section for input section SHNDX in object
2264 // OBJECT. If found, return true, and set *ADDR to the address of
2265 // the start of the merged section. This is not necessary the
2266 // output offset corresponding to input offset 0 in the section,
2267 // since the section may be mapped arbitrarily.
2268 bool
2269 find_starting_output_address(const Relobj* object, unsigned int shndx,
2270 uint64_t* addr) const;
2272 // Record that this output section was found in the SECTIONS clause
2273 // of a linker script.
2274 void
2275 set_found_in_sections_clause()
2276 { this->found_in_sections_clause_ = true; }
2278 // Return whether this output section was found in the SECTIONS
2279 // clause of a linker script.
2280 bool
2281 found_in_sections_clause() const
2282 { return this->found_in_sections_clause_; }
2284 // Write the section header into *OPHDR.
2285 template<int size, bool big_endian>
2286 void
2287 write_header(const Layout*, const Stringpool*,
2288 elfcpp::Shdr_write<size, big_endian>*) const;
2290 // The next few calls are for linker script support.
2292 // Store the list of input sections for this Output_section into the
2293 // list passed in. This removes the input sections, leaving only
2294 // any Output_section_data elements. This returns the size of those
2295 // Output_section_data elements. ADDRESS is the address of this
2296 // output section. FILL is the fill value to use, in case there are
2297 // any spaces between the remaining Output_section_data elements.
2298 uint64_t
2299 get_input_sections(uint64_t address, const std::string& fill,
2300 std::list<std::pair<Relobj*, unsigned int > >*);
2302 // Add an input section from a script.
2303 void
2304 add_input_section_for_script(Relobj* object, unsigned int shndx,
2305 off_t data_size, uint64_t addralign);
2307 // Set the current size of the output section.
2308 void
2309 set_current_data_size(off_t size)
2310 { this->set_current_data_size_for_child(size); }
2312 // Get the current size of the output section.
2313 off_t
2314 current_data_size() const
2315 { return this->current_data_size_for_child(); }
2317 // End of linker script support.
2319 // Print merge statistics to stderr.
2320 void
2321 print_merge_stats();
2323 protected:
2324 // Return the output section--i.e., the object itself.
2325 Output_section*
2326 do_output_section()
2327 { return this; }
2329 // Return the section index in the output file.
2330 unsigned int
2331 do_out_shndx() const
2333 gold_assert(this->out_shndx_ != -1U);
2334 return this->out_shndx_;
2337 // Set the output section index.
2338 void
2339 do_set_out_shndx(unsigned int shndx)
2341 gold_assert(this->out_shndx_ == -1U || this->out_shndx_ == shndx);
2342 this->out_shndx_ = shndx;
2345 // Set the final data size of the Output_section. For a typical
2346 // Output_section, there is nothing to do, but if there are any
2347 // Output_section_data objects we need to set their final addresses
2348 // here.
2349 virtual void
2350 set_final_data_size();
2352 // Reset the address and file offset.
2353 void
2354 do_reset_address_and_file_offset();
2356 // Write the data to the file. For a typical Output_section, this
2357 // does nothing: the data is written out by calling Object::Relocate
2358 // on each input object. But if there are any Output_section_data
2359 // objects we do need to write them out here.
2360 virtual void
2361 do_write(Output_file*);
2363 // Return the address alignment--function required by parent class.
2364 uint64_t
2365 do_addralign() const
2366 { return this->addralign_; }
2368 // Return whether there is a load address.
2369 bool
2370 do_has_load_address() const
2371 { return this->has_load_address_; }
2373 // Return the load address.
2374 uint64_t
2375 do_load_address() const
2377 gold_assert(this->has_load_address_);
2378 return this->load_address_;
2381 // Return whether this is an Output_section.
2382 bool
2383 do_is_section() const
2384 { return true; }
2386 // Return whether this is a section of the specified type.
2387 bool
2388 do_is_section_type(elfcpp::Elf_Word type) const
2389 { return this->type_ == type; }
2391 // Return whether the specified section flag is set.
2392 bool
2393 do_is_section_flag_set(elfcpp::Elf_Xword flag) const
2394 { return (this->flags_ & flag) != 0; }
2396 // Set the TLS offset. Called only for SHT_TLS sections.
2397 void
2398 do_set_tls_offset(uint64_t tls_base);
2400 // Return the TLS offset, relative to the base of the TLS segment.
2401 // Valid only for SHT_TLS sections.
2402 uint64_t
2403 do_tls_offset() const
2404 { return this->tls_offset_; }
2406 // This may be implemented by a child class.
2407 virtual void
2408 do_finalize_name(Layout*)
2411 // Print to the map file.
2412 virtual void
2413 do_print_to_mapfile(Mapfile*) const;
2415 // Record that this section requires postprocessing after all
2416 // relocations have been applied. This is called by a child class.
2417 void
2418 set_requires_postprocessing()
2420 this->requires_postprocessing_ = true;
2421 this->after_input_sections_ = true;
2424 // Write all the data of an Output_section into the postprocessing
2425 // buffer.
2426 void
2427 write_to_postprocessing_buffer();
2429 private:
2430 // In some cases we need to keep a list of the input sections
2431 // associated with this output section. We only need the list if we
2432 // might have to change the offsets of the input section within the
2433 // output section after we add the input section. The ordinary
2434 // input sections will be written out when we process the object
2435 // file, and as such we don't need to track them here. We do need
2436 // to track Output_section_data objects here. We store instances of
2437 // this structure in a std::vector, so it must be a POD. There can
2438 // be many instances of this structure, so we use a union to save
2439 // some space.
2440 class Input_section
2442 public:
2443 Input_section()
2444 : shndx_(0), p2align_(0)
2446 this->u1_.data_size = 0;
2447 this->u2_.object = NULL;
2450 // For an ordinary input section.
2451 Input_section(Relobj* object, unsigned int shndx, off_t data_size,
2452 uint64_t addralign)
2453 : shndx_(shndx),
2454 p2align_(ffsll(static_cast<long long>(addralign)))
2456 gold_assert(shndx != OUTPUT_SECTION_CODE
2457 && shndx != MERGE_DATA_SECTION_CODE
2458 && shndx != MERGE_STRING_SECTION_CODE);
2459 this->u1_.data_size = data_size;
2460 this->u2_.object = object;
2463 // For a non-merge output section.
2464 Input_section(Output_section_data* posd)
2465 : shndx_(OUTPUT_SECTION_CODE), p2align_(0)
2467 this->u1_.data_size = 0;
2468 this->u2_.posd = posd;
2471 // For a merge section.
2472 Input_section(Output_section_data* posd, bool is_string, uint64_t entsize)
2473 : shndx_(is_string
2474 ? MERGE_STRING_SECTION_CODE
2475 : MERGE_DATA_SECTION_CODE),
2476 p2align_(0)
2478 this->u1_.entsize = entsize;
2479 this->u2_.posd = posd;
2482 // The required alignment.
2483 uint64_t
2484 addralign() const
2486 if (!this->is_input_section())
2487 return this->u2_.posd->addralign();
2488 return (this->p2align_ == 0
2490 : static_cast<uint64_t>(1) << (this->p2align_ - 1));
2493 // Return the required size.
2494 off_t
2495 data_size() const;
2497 // Whether this is an input section.
2498 bool
2499 is_input_section() const
2501 return (this->shndx_ != OUTPUT_SECTION_CODE
2502 && this->shndx_ != MERGE_DATA_SECTION_CODE
2503 && this->shndx_ != MERGE_STRING_SECTION_CODE);
2506 // Return whether this is a merge section which matches the
2507 // parameters.
2508 bool
2509 is_merge_section(bool is_string, uint64_t entsize,
2510 uint64_t addralign) const
2512 return (this->shndx_ == (is_string
2513 ? MERGE_STRING_SECTION_CODE
2514 : MERGE_DATA_SECTION_CODE)
2515 && this->u1_.entsize == entsize
2516 && this->addralign() == addralign);
2519 // Return the object for an input section.
2520 Relobj*
2521 relobj() const
2523 gold_assert(this->is_input_section());
2524 return this->u2_.object;
2527 // Return the input section index for an input section.
2528 unsigned int
2529 shndx() const
2531 gold_assert(this->is_input_section());
2532 return this->shndx_;
2535 // Set the output section.
2536 void
2537 set_output_section(Output_section* os)
2539 gold_assert(!this->is_input_section());
2540 this->u2_.posd->set_output_section(os);
2543 // Set the address and file offset. This is called during
2544 // Layout::finalize. SECTION_FILE_OFFSET is the file offset of
2545 // the enclosing section.
2546 void
2547 set_address_and_file_offset(uint64_t address, off_t file_offset,
2548 off_t section_file_offset);
2550 // Reset the address and file offset.
2551 void
2552 reset_address_and_file_offset();
2554 // Finalize the data size.
2555 void
2556 finalize_data_size();
2558 // Add an input section, for SHF_MERGE sections.
2559 bool
2560 add_input_section(Relobj* object, unsigned int shndx)
2562 gold_assert(this->shndx_ == MERGE_DATA_SECTION_CODE
2563 || this->shndx_ == MERGE_STRING_SECTION_CODE);
2564 return this->u2_.posd->add_input_section(object, shndx);
2567 // Given an input OBJECT, an input section index SHNDX within that
2568 // object, and an OFFSET relative to the start of that input
2569 // section, return whether or not the output offset is known. If
2570 // this function returns true, it sets *POUTPUT to the offset in
2571 // the output section, relative to the start of the input section
2572 // in the output section. *POUTPUT may be different from OFFSET
2573 // for a merged section.
2574 bool
2575 output_offset(const Relobj* object, unsigned int shndx,
2576 section_offset_type offset,
2577 section_offset_type *poutput) const;
2579 // Return whether this is the merge section for the input section
2580 // SHNDX in OBJECT.
2581 bool
2582 is_merge_section_for(const Relobj* object, unsigned int shndx) const;
2584 // Write out the data. This does nothing for an input section.
2585 void
2586 write(Output_file*);
2588 // Write the data to a buffer. This does nothing for an input
2589 // section.
2590 void
2591 write_to_buffer(unsigned char*);
2593 // Print to a map file.
2594 void
2595 print_to_mapfile(Mapfile*) const;
2597 // Print statistics about merge sections to stderr.
2598 void
2599 print_merge_stats(const char* section_name)
2601 if (this->shndx_ == MERGE_DATA_SECTION_CODE
2602 || this->shndx_ == MERGE_STRING_SECTION_CODE)
2603 this->u2_.posd->print_merge_stats(section_name);
2606 private:
2607 // Code values which appear in shndx_. If the value is not one of
2608 // these codes, it is the input section index in the object file.
2609 enum
2611 // An Output_section_data.
2612 OUTPUT_SECTION_CODE = -1U,
2613 // An Output_section_data for an SHF_MERGE section with
2614 // SHF_STRINGS not set.
2615 MERGE_DATA_SECTION_CODE = -2U,
2616 // An Output_section_data for an SHF_MERGE section with
2617 // SHF_STRINGS set.
2618 MERGE_STRING_SECTION_CODE = -3U
2621 // For an ordinary input section, this is the section index in the
2622 // input file. For an Output_section_data, this is
2623 // OUTPUT_SECTION_CODE or MERGE_DATA_SECTION_CODE or
2624 // MERGE_STRING_SECTION_CODE.
2625 unsigned int shndx_;
2626 // The required alignment, stored as a power of 2.
2627 unsigned int p2align_;
2628 union
2630 // For an ordinary input section, the section size.
2631 off_t data_size;
2632 // For OUTPUT_SECTION_CODE, this is not used. For
2633 // MERGE_DATA_SECTION_CODE or MERGE_STRING_SECTION_CODE, the
2634 // entity size.
2635 uint64_t entsize;
2636 } u1_;
2637 union
2639 // For an ordinary input section, the object which holds the
2640 // input section.
2641 Relobj* object;
2642 // For OUTPUT_SECTION_CODE or MERGE_DATA_SECTION_CODE or
2643 // MERGE_STRING_SECTION_CODE, the data.
2644 Output_section_data* posd;
2645 } u2_;
2648 typedef std::vector<Input_section> Input_section_list;
2650 // This class is used to sort the input sections.
2651 class Input_section_sort_entry;
2653 // This is the sort comparison function.
2654 struct Input_section_sort_compare
2656 bool
2657 operator()(const Input_section_sort_entry&,
2658 const Input_section_sort_entry&) const;
2661 // Fill data. This is used to fill in data between input sections.
2662 // It is also used for data statements (BYTE, WORD, etc.) in linker
2663 // scripts. When we have to keep track of the input sections, we
2664 // can use an Output_data_const, but we don't want to have to keep
2665 // track of input sections just to implement fills.
2666 class Fill
2668 public:
2669 Fill(off_t section_offset, off_t length)
2670 : section_offset_(section_offset),
2671 length_(convert_to_section_size_type(length))
2674 // Return section offset.
2675 off_t
2676 section_offset() const
2677 { return this->section_offset_; }
2679 // Return fill length.
2680 section_size_type
2681 length() const
2682 { return this->length_; }
2684 private:
2685 // The offset within the output section.
2686 off_t section_offset_;
2687 // The length of the space to fill.
2688 section_size_type length_;
2691 typedef std::vector<Fill> Fill_list;
2693 // Add a new output section by Input_section.
2694 void
2695 add_output_section_data(Input_section*);
2697 // Add an SHF_MERGE input section. Returns true if the section was
2698 // handled.
2699 bool
2700 add_merge_input_section(Relobj* object, unsigned int shndx, uint64_t flags,
2701 uint64_t entsize, uint64_t addralign);
2703 // Add an output SHF_MERGE section POSD to this output section.
2704 // IS_STRING indicates whether it is a SHF_STRINGS section, and
2705 // ENTSIZE is the entity size. This returns the entry added to
2706 // input_sections_.
2707 void
2708 add_output_merge_section(Output_section_data* posd, bool is_string,
2709 uint64_t entsize);
2711 // Sort the attached input sections.
2712 void
2713 sort_attached_input_sections();
2715 // Most of these fields are only valid after layout.
2717 // The name of the section. This will point into a Stringpool.
2718 const char* name_;
2719 // The section address is in the parent class.
2720 // The section alignment.
2721 uint64_t addralign_;
2722 // The section entry size.
2723 uint64_t entsize_;
2724 // The load address. This is only used when using a linker script
2725 // with a SECTIONS clause. The has_load_address_ field indicates
2726 // whether this field is valid.
2727 uint64_t load_address_;
2728 // The file offset is in the parent class.
2729 // Set the section link field to the index of this section.
2730 const Output_data* link_section_;
2731 // If link_section_ is NULL, this is the link field.
2732 unsigned int link_;
2733 // Set the section info field to the index of this section.
2734 const Output_section* info_section_;
2735 // If info_section_ is NULL, set the info field to the symbol table
2736 // index of this symbol.
2737 const Symbol* info_symndx_;
2738 // If info_section_ and info_symndx_ are NULL, this is the section
2739 // info field.
2740 unsigned int info_;
2741 // The section type.
2742 const elfcpp::Elf_Word type_;
2743 // The section flags.
2744 elfcpp::Elf_Xword flags_;
2745 // The section index.
2746 unsigned int out_shndx_;
2747 // If there is a STT_SECTION for this output section in the normal
2748 // symbol table, this is the symbol index. This starts out as zero.
2749 // It is initialized in Layout::finalize() to be the index, or -1U
2750 // if there isn't one.
2751 unsigned int symtab_index_;
2752 // If there is a STT_SECTION for this output section in the dynamic
2753 // symbol table, this is the symbol index. This starts out as zero.
2754 // It is initialized in Layout::finalize() to be the index, or -1U
2755 // if there isn't one.
2756 unsigned int dynsym_index_;
2757 // The input sections. This will be empty in cases where we don't
2758 // need to keep track of them.
2759 Input_section_list input_sections_;
2760 // The offset of the first entry in input_sections_.
2761 off_t first_input_offset_;
2762 // The fill data. This is separate from input_sections_ because we
2763 // often will need fill sections without needing to keep track of
2764 // input sections.
2765 Fill_list fills_;
2766 // If the section requires postprocessing, this buffer holds the
2767 // section contents during relocation.
2768 unsigned char* postprocessing_buffer_;
2769 // Whether this output section needs a STT_SECTION symbol in the
2770 // normal symbol table. This will be true if there is a relocation
2771 // which needs it.
2772 bool needs_symtab_index_ : 1;
2773 // Whether this output section needs a STT_SECTION symbol in the
2774 // dynamic symbol table. This will be true if there is a dynamic
2775 // relocation which needs it.
2776 bool needs_dynsym_index_ : 1;
2777 // Whether the link field of this output section should point to the
2778 // normal symbol table.
2779 bool should_link_to_symtab_ : 1;
2780 // Whether the link field of this output section should point to the
2781 // dynamic symbol table.
2782 bool should_link_to_dynsym_ : 1;
2783 // Whether this section should be written after all the input
2784 // sections are complete.
2785 bool after_input_sections_ : 1;
2786 // Whether this section requires post processing after all
2787 // relocations have been applied.
2788 bool requires_postprocessing_ : 1;
2789 // Whether an input section was mapped to this output section
2790 // because of a SECTIONS clause in a linker script.
2791 bool found_in_sections_clause_ : 1;
2792 // Whether this section has an explicitly specified load address.
2793 bool has_load_address_ : 1;
2794 // True if the info_section_ field means the section index of the
2795 // section, false if it means the symbol index of the corresponding
2796 // section symbol.
2797 bool info_uses_section_index_ : 1;
2798 // True if the input sections attached to this output section may
2799 // need sorting.
2800 bool may_sort_attached_input_sections_ : 1;
2801 // True if the input sections attached to this output section must
2802 // be sorted.
2803 bool must_sort_attached_input_sections_ : 1;
2804 // True if the input sections attached to this output section have
2805 // already been sorted.
2806 bool attached_input_sections_are_sorted_ : 1;
2807 // True if this section holds relro data.
2808 bool is_relro_ : 1;
2809 // True if this section holds relro local data.
2810 bool is_relro_local_ : 1;
2811 // For SHT_TLS sections, the offset of this section relative to the base
2812 // of the TLS segment.
2813 uint64_t tls_offset_;
2816 // An output segment. PT_LOAD segments are built from collections of
2817 // output sections. Other segments typically point within PT_LOAD
2818 // segments, and are built directly as needed.
2820 class Output_segment
2822 public:
2823 // Create an output segment, specifying the type and flags.
2824 Output_segment(elfcpp::Elf_Word, elfcpp::Elf_Word);
2826 // Return the virtual address.
2827 uint64_t
2828 vaddr() const
2829 { return this->vaddr_; }
2831 // Return the physical address.
2832 uint64_t
2833 paddr() const
2834 { return this->paddr_; }
2836 // Return the segment type.
2837 elfcpp::Elf_Word
2838 type() const
2839 { return this->type_; }
2841 // Return the segment flags.
2842 elfcpp::Elf_Word
2843 flags() const
2844 { return this->flags_; }
2846 // Return the memory size.
2847 uint64_t
2848 memsz() const
2849 { return this->memsz_; }
2851 // Return the file size.
2852 off_t
2853 filesz() const
2854 { return this->filesz_; }
2856 // Return the file offset.
2857 off_t
2858 offset() const
2859 { return this->offset_; }
2861 // Return the maximum alignment of the Output_data.
2862 uint64_t
2863 maximum_alignment();
2865 // Add an Output_section to this segment.
2866 void
2867 add_output_section(Output_section* os, elfcpp::Elf_Word seg_flags);
2869 // Remove an Output_section from this segment. It is an error if it
2870 // is not present.
2871 void
2872 remove_output_section(Output_section* os);
2874 // Add an Output_data (which is not an Output_section) to the start
2875 // of this segment.
2876 void
2877 add_initial_output_data(Output_data*);
2879 // Return true if this segment has any sections which hold actual
2880 // data, rather than being a BSS section.
2881 bool
2882 has_any_data_sections() const
2883 { return !this->output_data_.empty(); }
2885 // Return the number of dynamic relocations applied to this segment.
2886 unsigned int
2887 dynamic_reloc_count() const;
2889 // Return the address of the first section.
2890 uint64_t
2891 first_section_load_address() const;
2893 // Return whether the addresses have been set already.
2894 bool
2895 are_addresses_set() const
2896 { return this->are_addresses_set_; }
2898 // Set the addresses.
2899 void
2900 set_addresses(uint64_t vaddr, uint64_t paddr)
2902 this->vaddr_ = vaddr;
2903 this->paddr_ = paddr;
2904 this->are_addresses_set_ = true;
2907 // Set the segment flags. This is only used if we have a PHDRS
2908 // clause which explicitly specifies the flags.
2909 void
2910 set_flags(elfcpp::Elf_Word flags)
2911 { this->flags_ = flags; }
2913 // Set the address of the segment to ADDR and the offset to *POFF
2914 // and set the addresses and offsets of all contained output
2915 // sections accordingly. Set the section indexes of all contained
2916 // output sections starting with *PSHNDX. If RESET is true, first
2917 // reset the addresses of the contained sections. Return the
2918 // address of the immediately following segment. Update *POFF and
2919 // *PSHNDX. This should only be called for a PT_LOAD segment.
2920 uint64_t
2921 set_section_addresses(const Layout*, bool reset, uint64_t addr, off_t* poff,
2922 unsigned int* pshndx);
2924 // Set the minimum alignment of this segment. This may be adjusted
2925 // upward based on the section alignments.
2926 void
2927 set_minimum_p_align(uint64_t align)
2928 { this->min_p_align_ = align; }
2930 // Set the offset of this segment based on the section. This should
2931 // only be called for a non-PT_LOAD segment.
2932 void
2933 set_offset();
2935 // Set the TLS offsets of the sections contained in the PT_TLS segment.
2936 void
2937 set_tls_offsets();
2939 // Return the number of output sections.
2940 unsigned int
2941 output_section_count() const;
2943 // Return the section attached to the list segment with the lowest
2944 // load address. This is used when handling a PHDRS clause in a
2945 // linker script.
2946 Output_section*
2947 section_with_lowest_load_address() const;
2949 // Write the segment header into *OPHDR.
2950 template<int size, bool big_endian>
2951 void
2952 write_header(elfcpp::Phdr_write<size, big_endian>*);
2954 // Write the section headers of associated sections into V.
2955 template<int size, bool big_endian>
2956 unsigned char*
2957 write_section_headers(const Layout*, const Stringpool*, unsigned char* v,
2958 unsigned int* pshndx) const;
2960 // Print the output sections in the map file.
2961 void
2962 print_sections_to_mapfile(Mapfile*) const;
2964 private:
2965 Output_segment(const Output_segment&);
2966 Output_segment& operator=(const Output_segment&);
2968 typedef std::list<Output_data*> Output_data_list;
2970 // Find the maximum alignment in an Output_data_list.
2971 static uint64_t
2972 maximum_alignment_list(const Output_data_list*);
2974 // Return whether the first data section is a relro section.
2975 bool
2976 is_first_section_relro() const;
2978 // Set the section addresses in an Output_data_list.
2979 uint64_t
2980 set_section_list_addresses(const Layout*, bool reset, Output_data_list*,
2981 uint64_t addr, off_t* poff, unsigned int* pshndx,
2982 bool* in_tls, bool* in_relro);
2984 // Return the number of Output_sections in an Output_data_list.
2985 unsigned int
2986 output_section_count_list(const Output_data_list*) const;
2988 // Return the number of dynamic relocs in an Output_data_list.
2989 unsigned int
2990 dynamic_reloc_count_list(const Output_data_list*) const;
2992 // Find the section with the lowest load address in an
2993 // Output_data_list.
2994 void
2995 lowest_load_address_in_list(const Output_data_list* pdl,
2996 Output_section** found,
2997 uint64_t* found_lma) const;
2999 // Write the section headers in the list into V.
3000 template<int size, bool big_endian>
3001 unsigned char*
3002 write_section_headers_list(const Layout*, const Stringpool*,
3003 const Output_data_list*, unsigned char* v,
3004 unsigned int* pshdx) const;
3006 // Print a section list to the mapfile.
3007 void
3008 print_section_list_to_mapfile(Mapfile*, const Output_data_list*) const;
3010 // The list of output data with contents attached to this segment.
3011 Output_data_list output_data_;
3012 // The list of output data without contents attached to this segment.
3013 Output_data_list output_bss_;
3014 // The segment virtual address.
3015 uint64_t vaddr_;
3016 // The segment physical address.
3017 uint64_t paddr_;
3018 // The size of the segment in memory.
3019 uint64_t memsz_;
3020 // The maximum section alignment. The is_max_align_known_ field
3021 // indicates whether this has been finalized.
3022 uint64_t max_align_;
3023 // The required minimum value for the p_align field. This is used
3024 // for PT_LOAD segments. Note that this does not mean that
3025 // addresses should be aligned to this value; it means the p_paddr
3026 // and p_vaddr fields must be congruent modulo this value. For
3027 // non-PT_LOAD segments, the dynamic linker works more efficiently
3028 // if the p_align field has the more conventional value, although it
3029 // can align as needed.
3030 uint64_t min_p_align_;
3031 // The offset of the segment data within the file.
3032 off_t offset_;
3033 // The size of the segment data in the file.
3034 off_t filesz_;
3035 // The segment type;
3036 elfcpp::Elf_Word type_;
3037 // The segment flags.
3038 elfcpp::Elf_Word flags_;
3039 // Whether we have finalized max_align_.
3040 bool is_max_align_known_ : 1;
3041 // Whether vaddr and paddr were set by a linker script.
3042 bool are_addresses_set_ : 1;
3045 // This class represents the output file.
3047 class Output_file
3049 public:
3050 Output_file(const char* name);
3052 // Indicate that this is a temporary file which should not be
3053 // output.
3054 void
3055 set_is_temporary()
3056 { this->is_temporary_ = true; }
3058 // Open the output file. FILE_SIZE is the final size of the file.
3059 void
3060 open(off_t file_size);
3062 // Resize the output file.
3063 void
3064 resize(off_t file_size);
3066 // Close the output file (flushing all buffered data) and make sure
3067 // there are no errors.
3068 void
3069 close();
3071 // We currently always use mmap which makes the view handling quite
3072 // simple. In the future we may support other approaches.
3074 // Write data to the output file.
3075 void
3076 write(off_t offset, const void* data, size_t len)
3077 { memcpy(this->base_ + offset, data, len); }
3079 // Get a buffer to use to write to the file, given the offset into
3080 // the file and the size.
3081 unsigned char*
3082 get_output_view(off_t start, size_t size)
3084 gold_assert(start >= 0
3085 && start + static_cast<off_t>(size) <= this->file_size_);
3086 return this->base_ + start;
3089 // VIEW must have been returned by get_output_view. Write the
3090 // buffer to the file, passing in the offset and the size.
3091 void
3092 write_output_view(off_t, size_t, unsigned char*)
3095 // Get a read/write buffer. This is used when we want to write part
3096 // of the file, read it in, and write it again.
3097 unsigned char*
3098 get_input_output_view(off_t start, size_t size)
3099 { return this->get_output_view(start, size); }
3101 // Write a read/write buffer back to the file.
3102 void
3103 write_input_output_view(off_t, size_t, unsigned char*)
3106 // Get a read buffer. This is used when we just want to read part
3107 // of the file back it in.
3108 const unsigned char*
3109 get_input_view(off_t start, size_t size)
3110 { return this->get_output_view(start, size); }
3112 // Release a read bfufer.
3113 void
3114 free_input_view(off_t, size_t, const unsigned char*)
3117 private:
3118 // Map the file into memory and return a pointer to the map.
3119 void
3120 map();
3122 // Unmap the file from memory (and flush to disk buffers).
3123 void
3124 unmap();
3126 // File name.
3127 const char* name_;
3128 // File descriptor.
3129 int o_;
3130 // File size.
3131 off_t file_size_;
3132 // Base of file mapped into memory.
3133 unsigned char* base_;
3134 // True iff base_ points to a memory buffer rather than an output file.
3135 bool map_is_anonymous_;
3136 // True if this is a temporary file which should not be output.
3137 bool is_temporary_;
3140 } // End namespace gold.
3142 #endif // !defined(GOLD_OUTPUT_H)