1 // script-sections.cc -- linker script SECTIONS for gold
3 // Copyright 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
33 #include "parameters.h"
39 #include "script-sections.h"
41 // Support for the SECTIONS clause in linker scripts.
46 // A region of memory.
50 Memory_region(const char* name, size_t namelen, unsigned int attributes,
51 Expression* start, Expression* length)
52 : name_(name, namelen),
53 attributes_(attributes),
62 // Return the name of this region.
65 { return this->name_; }
67 // Return the start address of this region.
70 { return this->start_; }
72 // Return the length of this region.
75 { return this->length_; }
77 // Print the region (when debugging).
81 // Return true if <name,namelen> matches this region.
83 name_match(const char* name, size_t namelen)
85 return (this->name_.length() == namelen
86 && strncmp(this->name_.c_str(), name, namelen) == 0);
90 get_current_address() const
93 script_exp_binary_add(this->start_,
94 script_exp_integer(this->current_offset_));
98 increment_offset(std::string section_name, uint64_t amount,
99 const Symbol_table* symtab, const Layout* layout)
101 this->current_offset_ += amount;
103 if (this->current_offset_
104 > this->length_->eval(symtab, layout, false))
105 gold_error(_("section %s overflows end of region %s"),
106 section_name.c_str(), this->name_.c_str());
109 // Returns true iff there is room left in this region
110 // for AMOUNT more bytes of data.
112 has_room_for(const Symbol_table* symtab, const Layout* layout,
113 uint64_t amount) const
115 return (this->current_offset_ + amount
116 < this->length_->eval(symtab, layout, false));
119 // Return true if the provided section flags
120 // are compatible with this region's attributes.
122 attributes_compatible(elfcpp::Elf_Xword flags, elfcpp::Elf_Xword type) const;
125 add_section(Output_section_definition* sec, bool vma)
128 this->vma_sections_.push_back(sec);
130 this->lma_sections_.push_back(sec);
133 typedef std::vector<Output_section_definition*> Section_list;
135 // Return the start of the list of sections
136 // whose VMAs are taken from this region.
137 Section_list::const_iterator
138 get_vma_section_list_start() const
139 { return this->vma_sections_.begin(); }
141 // Return the start of the list of sections
142 // whose LMAs are taken from this region.
143 Section_list::const_iterator
144 get_lma_section_list_start() const
145 { return this->lma_sections_.begin(); }
147 // Return the end of the list of sections
148 // whose VMAs are taken from this region.
149 Section_list::const_iterator
150 get_vma_section_list_end() const
151 { return this->vma_sections_.end(); }
153 // Return the end of the list of sections
154 // whose LMAs are taken from this region.
155 Section_list::const_iterator
156 get_lma_section_list_end() const
157 { return this->lma_sections_.end(); }
159 Output_section_definition*
160 get_last_section() const
161 { return this->last_section_; }
164 set_last_section(Output_section_definition* sec)
165 { this->last_section_ = sec; }
170 unsigned int attributes_;
173 // The offset to the next free byte in the region.
174 // Note - for compatibility with GNU LD we only maintain one offset
175 // regardless of whether the region is being used for VMA values,
176 // LMA values, or both.
177 uint64_t current_offset_;
178 // A list of sections whose VMAs are set inside this region.
179 Section_list vma_sections_;
180 // A list of sections whose LMAs are set inside this region.
181 Section_list lma_sections_;
182 // The latest section to make use of this region.
183 Output_section_definition* last_section_;
186 // Return true if the provided section flags
187 // are compatible with this region's attributes.
190 Memory_region::attributes_compatible(elfcpp::Elf_Xword flags,
191 elfcpp::Elf_Xword type) const
193 unsigned int attrs = this->attributes_;
195 // No attributes means that this region is not compatible with anything.
202 switch (attrs & - attrs)
205 if ((flags & elfcpp::SHF_EXECINSTR) == 0)
210 if ((flags & elfcpp::SHF_WRITE) == 0)
215 // All sections are presumed readable.
218 case MEM_ALLOCATABLE:
219 if ((flags & elfcpp::SHF_ALLOC) == 0)
223 case MEM_INITIALIZED:
224 if ((type & elfcpp::SHT_NOBITS) != 0)
228 attrs &= ~ (attrs & - attrs);
235 // Print a memory region.
238 Memory_region::print(FILE* f) const
240 fprintf(f, " %s", this->name_.c_str());
242 unsigned int attrs = this->attributes_;
248 switch (attrs & - attrs)
250 case MEM_EXECUTABLE: fputc('x', f); break;
251 case MEM_WRITEABLE: fputc('w', f); break;
252 case MEM_READABLE: fputc('r', f); break;
253 case MEM_ALLOCATABLE: fputc('a', f); break;
254 case MEM_INITIALIZED: fputc('i', f); break;
258 attrs &= ~ (attrs & - attrs);
264 fprintf(f, " : origin = ");
265 this->start_->print(f);
266 fprintf(f, ", length = ");
267 this->length_->print(f);
271 // Manage orphan sections. This is intended to be largely compatible
272 // with the GNU linker. The Linux kernel implicitly relies on
273 // something similar to the GNU linker's orphan placement. We
274 // originally used a simpler scheme here, but it caused the kernel
275 // build to fail, and was also rather inefficient.
277 class Orphan_section_placement
280 typedef Script_sections::Elements_iterator Elements_iterator;
283 Orphan_section_placement();
285 // Handle an output section during initialization of this mapping.
287 output_section_init(const std::string& name, Output_section*,
288 Elements_iterator location);
290 // Initialize the last location.
292 last_init(Elements_iterator location);
294 // Set *PWHERE to the address of an iterator pointing to the
295 // location to use for an orphan section. Return true if the
296 // iterator has a value, false otherwise.
298 find_place(Output_section*, Elements_iterator** pwhere);
300 // Return the iterator being used for sections at the very end of
301 // the linker script.
306 // The places that we specifically recognize. This list is copied
307 // from the GNU linker.
323 // The information we keep for a specific place.
326 // The name of sections for this place.
328 // Whether we have a location for this place.
330 // The iterator for this place.
331 Elements_iterator location;
334 // Initialize one place element.
336 initialize_place(Place_index, const char*);
339 Place places_[PLACE_MAX];
340 // True if this is the first call to output_section_init.
344 // Initialize Orphan_section_placement.
346 Orphan_section_placement::Orphan_section_placement()
349 this->initialize_place(PLACE_TEXT, ".text");
350 this->initialize_place(PLACE_RODATA, ".rodata");
351 this->initialize_place(PLACE_DATA, ".data");
352 this->initialize_place(PLACE_TLS, NULL);
353 this->initialize_place(PLACE_TLS_BSS, NULL);
354 this->initialize_place(PLACE_BSS, ".bss");
355 this->initialize_place(PLACE_REL, NULL);
356 this->initialize_place(PLACE_INTERP, ".interp");
357 this->initialize_place(PLACE_NONALLOC, NULL);
358 this->initialize_place(PLACE_LAST, NULL);
361 // Initialize one place element.
364 Orphan_section_placement::initialize_place(Place_index index, const char* name)
366 this->places_[index].name = name;
367 this->places_[index].have_location = false;
370 // While initializing the Orphan_section_placement information, this
371 // is called once for each output section named in the linker script.
372 // If we found an output section during the link, it will be passed in
376 Orphan_section_placement::output_section_init(const std::string& name,
378 Elements_iterator location)
380 bool first_init = this->first_init_;
381 this->first_init_ = false;
383 for (int i = 0; i < PLACE_MAX; ++i)
385 if (this->places_[i].name != NULL && this->places_[i].name == name)
387 if (this->places_[i].have_location)
389 // We have already seen a section with this name.
393 this->places_[i].location = location;
394 this->places_[i].have_location = true;
396 // If we just found the .bss section, restart the search for
397 // an unallocated section. This follows the GNU linker's
400 this->places_[PLACE_NONALLOC].have_location = false;
406 // Relocation sections.
407 if (!this->places_[PLACE_REL].have_location
409 && (os->type() == elfcpp::SHT_REL || os->type() == elfcpp::SHT_RELA)
410 && (os->flags() & elfcpp::SHF_ALLOC) != 0)
412 this->places_[PLACE_REL].location = location;
413 this->places_[PLACE_REL].have_location = true;
416 // We find the location for unallocated sections by finding the
417 // first debugging or comment section after the BSS section (if
419 if (!this->places_[PLACE_NONALLOC].have_location
420 && (name == ".comment" || Layout::is_debug_info_section(name.c_str())))
422 // We add orphan sections after the location in PLACES_. We
423 // want to store unallocated sections before LOCATION. If this
424 // is the very first section, we can't use it.
428 this->places_[PLACE_NONALLOC].location = location;
429 this->places_[PLACE_NONALLOC].have_location = true;
434 // Initialize the last location.
437 Orphan_section_placement::last_init(Elements_iterator location)
439 this->places_[PLACE_LAST].location = location;
440 this->places_[PLACE_LAST].have_location = true;
443 // Set *PWHERE to the address of an iterator pointing to the location
444 // to use for an orphan section. Return true if the iterator has a
445 // value, false otherwise.
448 Orphan_section_placement::find_place(Output_section* os,
449 Elements_iterator** pwhere)
451 // Figure out where OS should go. This is based on the GNU linker
452 // code. FIXME: The GNU linker handles small data sections
453 // specially, but we don't.
454 elfcpp::Elf_Word type = os->type();
455 elfcpp::Elf_Xword flags = os->flags();
457 if ((flags & elfcpp::SHF_ALLOC) == 0
458 && !Layout::is_debug_info_section(os->name()))
459 index = PLACE_NONALLOC;
460 else if ((flags & elfcpp::SHF_ALLOC) == 0)
462 else if (type == elfcpp::SHT_NOTE)
463 index = PLACE_INTERP;
464 else if ((flags & elfcpp::SHF_TLS) != 0)
466 if (type == elfcpp::SHT_NOBITS)
467 index = PLACE_TLS_BSS;
471 else if (type == elfcpp::SHT_NOBITS)
473 else if ((flags & elfcpp::SHF_WRITE) != 0)
475 else if (type == elfcpp::SHT_REL || type == elfcpp::SHT_RELA)
477 else if ((flags & elfcpp::SHF_EXECINSTR) == 0)
478 index = PLACE_RODATA;
482 // If we don't have a location yet, try to find one based on a
483 // plausible ordering of sections.
484 if (!this->places_[index].have_location)
509 if (!this->places_[PLACE_TLS].have_location)
513 if (follow != PLACE_MAX && this->places_[follow].have_location)
515 // Set the location of INDEX to the location of FOLLOW. The
516 // location of INDEX will then be incremented by the caller,
517 // so anything in INDEX will continue to be after anything
519 this->places_[index].location = this->places_[follow].location;
520 this->places_[index].have_location = true;
524 *pwhere = &this->places_[index].location;
525 bool ret = this->places_[index].have_location;
527 // The caller will set the location.
528 this->places_[index].have_location = true;
533 // Return the iterator being used for sections at the very end of the
536 Orphan_section_placement::Elements_iterator
537 Orphan_section_placement::last_place() const
539 gold_assert(this->places_[PLACE_LAST].have_location);
540 return this->places_[PLACE_LAST].location;
543 // An element in a SECTIONS clause.
545 class Sections_element
551 virtual ~Sections_element()
554 // Return whether an output section is relro.
559 // Record that an output section is relro.
564 // Create any required output sections. The only real
565 // implementation is in Output_section_definition.
567 create_sections(Layout*)
570 // Add any symbol being defined to the symbol table.
572 add_symbols_to_table(Symbol_table*)
575 // Finalize symbols and check assertions.
577 finalize_symbols(Symbol_table*, const Layout*, uint64_t*)
580 // Return the output section name to use for an input file name and
581 // section name. This only real implementation is in
582 // Output_section_definition.
584 output_section_name(const char*, const char*, Output_section***,
585 Script_sections::Section_type*)
588 // Initialize OSP with an output section.
590 orphan_section_init(Orphan_section_placement*,
591 Script_sections::Elements_iterator)
594 // Set section addresses. This includes applying assignments if the
595 // expression is an absolute value.
597 set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*,
601 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
602 // this section is constrained, and the input sections do not match,
603 // return the constraint, and set *POSD.
604 virtual Section_constraint
605 check_constraint(Output_section_definition**)
606 { return CONSTRAINT_NONE; }
608 // See if this is the alternate output section for a constrained
609 // output section. If it is, transfer the Output_section and return
610 // true. Otherwise return false.
612 alternate_constraint(Output_section_definition*, Section_constraint)
615 // Get the list of segments to use for an allocated section when
616 // using a PHDRS clause. If this is an allocated section, return
617 // the Output_section, and set *PHDRS_LIST (the first parameter) to
618 // the list of PHDRS to which it should be attached. If the PHDRS
619 // were not specified, don't change *PHDRS_LIST. When not returning
620 // NULL, set *ORPHAN (the second parameter) according to whether
621 // this is an orphan section--one that is not mentioned in the
623 virtual Output_section*
624 allocate_to_segment(String_list**, bool*)
627 // Look for an output section by name and return the address, the
628 // load address, the alignment, and the size. This is used when an
629 // expression refers to an output section which was not actually
630 // created. This returns true if the section was found, false
631 // otherwise. The only real definition is for
632 // Output_section_definition.
634 get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
638 // Return the associated Output_section if there is one.
639 virtual Output_section*
640 get_output_section() const
643 // Set the section's memory regions.
645 set_memory_region(Memory_region*, bool)
646 { gold_error(_("Attempt to set a memory region for a non-output section")); }
648 // Print the element for debugging purposes.
650 print(FILE* f) const = 0;
653 // An assignment in a SECTIONS clause outside of an output section.
655 class Sections_element_assignment : public Sections_element
658 Sections_element_assignment(const char* name, size_t namelen,
659 Expression* val, bool provide, bool hidden)
660 : assignment_(name, namelen, false, val, provide, hidden)
663 // Add the symbol to the symbol table.
665 add_symbols_to_table(Symbol_table* symtab)
666 { this->assignment_.add_to_table(symtab); }
668 // Finalize the symbol.
670 finalize_symbols(Symbol_table* symtab, const Layout* layout,
673 this->assignment_.finalize_with_dot(symtab, layout, *dot_value, NULL);
676 // Set the section address. There is no section here, but if the
677 // value is absolute, we set the symbol. This permits us to use
678 // absolute symbols when setting dot.
680 set_section_addresses(Symbol_table* symtab, Layout* layout,
681 uint64_t* dot_value, uint64_t*, uint64_t*)
683 this->assignment_.set_if_absolute(symtab, layout, true, *dot_value, NULL);
686 // Print for debugging.
691 this->assignment_.print(f);
695 Symbol_assignment assignment_;
698 // An assignment to the dot symbol in a SECTIONS clause outside of an
701 class Sections_element_dot_assignment : public Sections_element
704 Sections_element_dot_assignment(Expression* val)
708 // Finalize the symbol.
710 finalize_symbols(Symbol_table* symtab, const Layout* layout,
713 // We ignore the section of the result because outside of an
714 // output section definition the dot symbol is always considered
716 *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value,
717 NULL, NULL, NULL, false);
720 // Update the dot symbol while setting section addresses.
722 set_section_addresses(Symbol_table* symtab, Layout* layout,
723 uint64_t* dot_value, uint64_t* dot_alignment,
724 uint64_t* load_address)
726 *dot_value = this->val_->eval_with_dot(symtab, layout, false, *dot_value,
727 NULL, NULL, dot_alignment, false);
728 *load_address = *dot_value;
731 // Print for debugging.
736 this->val_->print(f);
744 // An assertion in a SECTIONS clause outside of an output section.
746 class Sections_element_assertion : public Sections_element
749 Sections_element_assertion(Expression* check, const char* message,
751 : assertion_(check, message, messagelen)
754 // Check the assertion.
756 finalize_symbols(Symbol_table* symtab, const Layout* layout, uint64_t*)
757 { this->assertion_.check(symtab, layout); }
759 // Print for debugging.
764 this->assertion_.print(f);
768 Script_assertion assertion_;
771 // An element in an output section in a SECTIONS clause.
773 class Output_section_element
776 // A list of input sections.
777 typedef std::list<Output_section::Input_section> Input_section_list;
779 Output_section_element()
782 virtual ~Output_section_element()
785 // Return whether this element requires an output section to exist.
787 needs_output_section() const
790 // Add any symbol being defined to the symbol table.
792 add_symbols_to_table(Symbol_table*)
795 // Finalize symbols and check assertions.
797 finalize_symbols(Symbol_table*, const Layout*, uint64_t*, Output_section**)
800 // Return whether this element matches FILE_NAME and SECTION_NAME.
801 // The only real implementation is in Output_section_element_input.
803 match_name(const char*, const char*) const
806 // Set section addresses. This includes applying assignments if the
807 // expression is an absolute value.
809 set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t,
810 uint64_t*, uint64_t*, Output_section**, std::string*,
814 // Print the element for debugging purposes.
816 print(FILE* f) const = 0;
819 // Return a fill string that is LENGTH bytes long, filling it with
822 get_fill_string(const std::string* fill, section_size_type length) const;
826 Output_section_element::get_fill_string(const std::string* fill,
827 section_size_type length) const
829 std::string this_fill;
830 this_fill.reserve(length);
831 while (this_fill.length() + fill->length() <= length)
833 if (this_fill.length() < length)
834 this_fill.append(*fill, 0, length - this_fill.length());
838 // A symbol assignment in an output section.
840 class Output_section_element_assignment : public Output_section_element
843 Output_section_element_assignment(const char* name, size_t namelen,
844 Expression* val, bool provide,
846 : assignment_(name, namelen, false, val, provide, hidden)
849 // Add the symbol to the symbol table.
851 add_symbols_to_table(Symbol_table* symtab)
852 { this->assignment_.add_to_table(symtab); }
854 // Finalize the symbol.
856 finalize_symbols(Symbol_table* symtab, const Layout* layout,
857 uint64_t* dot_value, Output_section** dot_section)
859 this->assignment_.finalize_with_dot(symtab, layout, *dot_value,
863 // Set the section address. There is no section here, but if the
864 // value is absolute, we set the symbol. This permits us to use
865 // absolute symbols when setting dot.
867 set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
868 uint64_t, uint64_t* dot_value, uint64_t*,
869 Output_section** dot_section, std::string*,
872 this->assignment_.set_if_absolute(symtab, layout, true, *dot_value,
876 // Print for debugging.
881 this->assignment_.print(f);
885 Symbol_assignment assignment_;
888 // An assignment to the dot symbol in an output section.
890 class Output_section_element_dot_assignment : public Output_section_element
893 Output_section_element_dot_assignment(Expression* val)
897 // An assignment to dot within an output section is enough to force
898 // the output section to exist.
900 needs_output_section() const
903 // Finalize the symbol.
905 finalize_symbols(Symbol_table* symtab, const Layout* layout,
906 uint64_t* dot_value, Output_section** dot_section)
908 *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value,
909 *dot_section, dot_section, NULL,
913 // Update the dot symbol while setting section addresses.
915 set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
916 uint64_t, uint64_t* dot_value, uint64_t*,
917 Output_section** dot_section, std::string*,
918 Input_section_list*);
920 // Print for debugging.
925 this->val_->print(f);
933 // Update the dot symbol while setting section addresses.
936 Output_section_element_dot_assignment::set_section_addresses(
937 Symbol_table* symtab,
939 Output_section* output_section,
942 uint64_t* dot_alignment,
943 Output_section** dot_section,
947 uint64_t next_dot = this->val_->eval_with_dot(symtab, layout, false,
948 *dot_value, *dot_section,
949 dot_section, dot_alignment,
951 if (next_dot < *dot_value)
952 gold_error(_("dot may not move backward"));
953 if (next_dot > *dot_value && output_section != NULL)
955 section_size_type length = convert_to_section_size_type(next_dot
957 Output_section_data* posd;
959 posd = new Output_data_zero_fill(length, 0);
962 std::string this_fill = this->get_fill_string(fill, length);
963 posd = new Output_data_const(this_fill, 0);
965 output_section->add_output_section_data(posd);
966 layout->new_output_section_data_from_script(posd);
968 *dot_value = next_dot;
971 // An assertion in an output section.
973 class Output_section_element_assertion : public Output_section_element
976 Output_section_element_assertion(Expression* check, const char* message,
978 : assertion_(check, message, messagelen)
985 this->assertion_.print(f);
989 Script_assertion assertion_;
992 // We use a special instance of Output_section_data to handle BYTE,
993 // SHORT, etc. This permits forward references to symbols in the
996 class Output_data_expression : public Output_section_data
999 Output_data_expression(int size, bool is_signed, Expression* val,
1000 const Symbol_table* symtab, const Layout* layout,
1001 uint64_t dot_value, Output_section* dot_section)
1002 : Output_section_data(size, 0, true),
1003 is_signed_(is_signed), val_(val), symtab_(symtab),
1004 layout_(layout), dot_value_(dot_value), dot_section_(dot_section)
1008 // Write the data to the output file.
1010 do_write(Output_file*);
1012 // Write the data to a buffer.
1014 do_write_to_buffer(unsigned char*);
1016 // Write to a map file.
1018 do_print_to_mapfile(Mapfile* mapfile) const
1019 { mapfile->print_output_data(this, _("** expression")); }
1022 template<bool big_endian>
1024 endian_write_to_buffer(uint64_t, unsigned char*);
1028 const Symbol_table* symtab_;
1029 const Layout* layout_;
1030 uint64_t dot_value_;
1031 Output_section* dot_section_;
1034 // Write the data element to the output file.
1037 Output_data_expression::do_write(Output_file* of)
1039 unsigned char* view = of->get_output_view(this->offset(), this->data_size());
1040 this->write_to_buffer(view);
1041 of->write_output_view(this->offset(), this->data_size(), view);
1044 // Write the data element to a buffer.
1047 Output_data_expression::do_write_to_buffer(unsigned char* buf)
1049 uint64_t val = this->val_->eval_with_dot(this->symtab_, this->layout_,
1050 true, this->dot_value_,
1051 this->dot_section_, NULL, NULL,
1054 if (parameters->target().is_big_endian())
1055 this->endian_write_to_buffer<true>(val, buf);
1057 this->endian_write_to_buffer<false>(val, buf);
1060 template<bool big_endian>
1062 Output_data_expression::endian_write_to_buffer(uint64_t val,
1065 switch (this->data_size())
1068 elfcpp::Swap_unaligned<8, big_endian>::writeval(buf, val);
1071 elfcpp::Swap_unaligned<16, big_endian>::writeval(buf, val);
1074 elfcpp::Swap_unaligned<32, big_endian>::writeval(buf, val);
1077 if (parameters->target().get_size() == 32)
1080 if (this->is_signed_ && (val & 0x80000000) != 0)
1081 val |= 0xffffffff00000000LL;
1083 elfcpp::Swap_unaligned<64, big_endian>::writeval(buf, val);
1090 // A data item in an output section.
1092 class Output_section_element_data : public Output_section_element
1095 Output_section_element_data(int size, bool is_signed, Expression* val)
1096 : size_(size), is_signed_(is_signed), val_(val)
1099 // If there is a data item, then we must create an output section.
1101 needs_output_section() const
1104 // Finalize symbols--we just need to update dot.
1106 finalize_symbols(Symbol_table*, const Layout*, uint64_t* dot_value,
1108 { *dot_value += this->size_; }
1110 // Store the value in the section.
1112 set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t,
1113 uint64_t* dot_value, uint64_t*, Output_section**,
1114 std::string*, Input_section_list*);
1116 // Print for debugging.
1121 // The size in bytes.
1123 // Whether the value is signed.
1129 // Store the value in the section.
1132 Output_section_element_data::set_section_addresses(
1133 Symbol_table* symtab,
1137 uint64_t* dot_value,
1139 Output_section** dot_section,
1141 Input_section_list*)
1143 gold_assert(os != NULL);
1144 Output_data_expression* expression =
1145 new Output_data_expression(this->size_, this->is_signed_, this->val_,
1146 symtab, layout, *dot_value, *dot_section);
1147 os->add_output_section_data(expression);
1148 layout->new_output_section_data_from_script(expression);
1149 *dot_value += this->size_;
1152 // Print for debugging.
1155 Output_section_element_data::print(FILE* f) const
1158 switch (this->size_)
1170 if (this->is_signed_)
1178 fprintf(f, " %s(", s);
1179 this->val_->print(f);
1183 // A fill value setting in an output section.
1185 class Output_section_element_fill : public Output_section_element
1188 Output_section_element_fill(Expression* val)
1192 // Update the fill value while setting section addresses.
1194 set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
1195 uint64_t, uint64_t* dot_value, uint64_t*,
1196 Output_section** dot_section,
1197 std::string* fill, Input_section_list*)
1199 Output_section* fill_section;
1200 uint64_t fill_val = this->val_->eval_with_dot(symtab, layout, false,
1201 *dot_value, *dot_section,
1202 &fill_section, NULL, false);
1203 if (fill_section != NULL)
1204 gold_warning(_("fill value is not absolute"));
1205 // FIXME: The GNU linker supports fill values of arbitrary length.
1206 unsigned char fill_buff[4];
1207 elfcpp::Swap_unaligned<32, true>::writeval(fill_buff, fill_val);
1208 fill->assign(reinterpret_cast<char*>(fill_buff), 4);
1211 // Print for debugging.
1213 print(FILE* f) const
1215 fprintf(f, " FILL(");
1216 this->val_->print(f);
1221 // The new fill value.
1225 // An input section specification in an output section
1227 class Output_section_element_input : public Output_section_element
1230 Output_section_element_input(const Input_section_spec* spec, bool keep);
1232 // Finalize symbols--just update the value of the dot symbol.
1234 finalize_symbols(Symbol_table*, const Layout*, uint64_t* dot_value,
1235 Output_section** dot_section)
1237 *dot_value = this->final_dot_value_;
1238 *dot_section = this->final_dot_section_;
1241 // See whether we match FILE_NAME and SECTION_NAME as an input
1244 match_name(const char* file_name, const char* section_name) const;
1246 // Set the section address.
1248 set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
1249 uint64_t subalign, uint64_t* dot_value, uint64_t*,
1250 Output_section**, std::string* fill,
1251 Input_section_list*);
1253 // Print for debugging.
1255 print(FILE* f) const;
1258 // An input section pattern.
1259 struct Input_section_pattern
1261 std::string pattern;
1262 bool pattern_is_wildcard;
1265 Input_section_pattern(const char* patterna, size_t patternlena,
1266 Sort_wildcard sorta)
1267 : pattern(patterna, patternlena),
1268 pattern_is_wildcard(is_wildcard_string(this->pattern.c_str())),
1273 typedef std::vector<Input_section_pattern> Input_section_patterns;
1275 // Filename_exclusions is a pair of filename pattern and a bool
1276 // indicating whether the filename is a wildcard.
1277 typedef std::vector<std::pair<std::string, bool> > Filename_exclusions;
1279 // Return whether STRING matches PATTERN, where IS_WILDCARD_PATTERN
1280 // indicates whether this is a wildcard pattern.
1282 match(const char* string, const char* pattern, bool is_wildcard_pattern)
1284 return (is_wildcard_pattern
1285 ? fnmatch(pattern, string, 0) == 0
1286 : strcmp(string, pattern) == 0);
1289 // See if we match a file name.
1291 match_file_name(const char* file_name) const;
1293 // The file name pattern. If this is the empty string, we match all
1295 std::string filename_pattern_;
1296 // Whether the file name pattern is a wildcard.
1297 bool filename_is_wildcard_;
1298 // How the file names should be sorted. This may only be
1299 // SORT_WILDCARD_NONE or SORT_WILDCARD_BY_NAME.
1300 Sort_wildcard filename_sort_;
1301 // The list of file names to exclude.
1302 Filename_exclusions filename_exclusions_;
1303 // The list of input section patterns.
1304 Input_section_patterns input_section_patterns_;
1305 // Whether to keep this section when garbage collecting.
1307 // The value of dot after including all matching sections.
1308 uint64_t final_dot_value_;
1309 // The section where dot is defined after including all matching
1311 Output_section* final_dot_section_;
1314 // Construct Output_section_element_input. The parser records strings
1315 // as pointers into a copy of the script file, which will go away when
1316 // parsing is complete. We make sure they are in std::string objects.
1318 Output_section_element_input::Output_section_element_input(
1319 const Input_section_spec* spec,
1321 : filename_pattern_(),
1322 filename_is_wildcard_(false),
1323 filename_sort_(spec->file.sort),
1324 filename_exclusions_(),
1325 input_section_patterns_(),
1327 final_dot_value_(0),
1328 final_dot_section_(NULL)
1330 // The filename pattern "*" is common, and matches all files. Turn
1331 // it into the empty string.
1332 if (spec->file.name.length != 1 || spec->file.name.value[0] != '*')
1333 this->filename_pattern_.assign(spec->file.name.value,
1334 spec->file.name.length);
1335 this->filename_is_wildcard_ = is_wildcard_string(this->filename_pattern_.c_str());
1337 if (spec->input_sections.exclude != NULL)
1339 for (String_list::const_iterator p =
1340 spec->input_sections.exclude->begin();
1341 p != spec->input_sections.exclude->end();
1344 bool is_wildcard = is_wildcard_string((*p).c_str());
1345 this->filename_exclusions_.push_back(std::make_pair(*p,
1350 if (spec->input_sections.sections != NULL)
1352 Input_section_patterns& isp(this->input_section_patterns_);
1353 for (String_sort_list::const_iterator p =
1354 spec->input_sections.sections->begin();
1355 p != spec->input_sections.sections->end();
1357 isp.push_back(Input_section_pattern(p->name.value, p->name.length,
1362 // See whether we match FILE_NAME.
1365 Output_section_element_input::match_file_name(const char* file_name) const
1367 if (!this->filename_pattern_.empty())
1369 // If we were called with no filename, we refuse to match a
1370 // pattern which requires a file name.
1371 if (file_name == NULL)
1374 if (!match(file_name, this->filename_pattern_.c_str(),
1375 this->filename_is_wildcard_))
1379 if (file_name != NULL)
1381 // Now we have to see whether FILE_NAME matches one of the
1382 // exclusion patterns, if any.
1383 for (Filename_exclusions::const_iterator p =
1384 this->filename_exclusions_.begin();
1385 p != this->filename_exclusions_.end();
1388 if (match(file_name, p->first.c_str(), p->second))
1396 // See whether we match FILE_NAME and SECTION_NAME.
1399 Output_section_element_input::match_name(const char* file_name,
1400 const char* section_name) const
1402 if (!this->match_file_name(file_name))
1405 // If there are no section name patterns, then we match.
1406 if (this->input_section_patterns_.empty())
1409 // See whether we match the section name patterns.
1410 for (Input_section_patterns::const_iterator p =
1411 this->input_section_patterns_.begin();
1412 p != this->input_section_patterns_.end();
1415 if (match(section_name, p->pattern.c_str(), p->pattern_is_wildcard))
1419 // We didn't match any section names, so we didn't match.
1423 // Information we use to sort the input sections.
1425 class Input_section_info
1428 Input_section_info(const Output_section::Input_section& input_section)
1429 : input_section_(input_section), section_name_(),
1430 size_(0), addralign_(1)
1433 // Return the simple input section.
1434 const Output_section::Input_section&
1435 input_section() const
1436 { return this->input_section_; }
1438 // Return the object.
1441 { return this->input_section_.relobj(); }
1443 // Return the section index.
1446 { return this->input_section_.shndx(); }
1448 // Return the section name.
1450 section_name() const
1451 { return this->section_name_; }
1453 // Set the section name.
1455 set_section_name(const std::string name)
1456 { this->section_name_ = name; }
1458 // Return the section size.
1461 { return this->size_; }
1463 // Set the section size.
1465 set_size(uint64_t size)
1466 { this->size_ = size; }
1468 // Return the address alignment.
1471 { return this->addralign_; }
1473 // Set the address alignment.
1475 set_addralign(uint64_t addralign)
1476 { this->addralign_ = addralign; }
1479 // Input section, can be a relaxed section.
1480 Output_section::Input_section input_section_;
1481 // Name of the section.
1482 std::string section_name_;
1485 // Address alignment.
1486 uint64_t addralign_;
1489 // A class to sort the input sections.
1491 class Input_section_sorter
1494 Input_section_sorter(Sort_wildcard filename_sort, Sort_wildcard section_sort)
1495 : filename_sort_(filename_sort), section_sort_(section_sort)
1499 operator()(const Input_section_info&, const Input_section_info&) const;
1502 Sort_wildcard filename_sort_;
1503 Sort_wildcard section_sort_;
1507 Input_section_sorter::operator()(const Input_section_info& isi1,
1508 const Input_section_info& isi2) const
1510 if (this->section_sort_ == SORT_WILDCARD_BY_NAME
1511 || this->section_sort_ == SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1512 || (this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
1513 && isi1.addralign() == isi2.addralign()))
1515 if (isi1.section_name() != isi2.section_name())
1516 return isi1.section_name() < isi2.section_name();
1518 if (this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT
1519 || this->section_sort_ == SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1520 || this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT_BY_NAME)
1522 if (isi1.addralign() != isi2.addralign())
1523 return isi1.addralign() < isi2.addralign();
1525 if (this->filename_sort_ == SORT_WILDCARD_BY_NAME)
1527 if (isi1.relobj()->name() != isi2.relobj()->name())
1528 return (isi1.relobj()->name() < isi2.relobj()->name());
1531 // Otherwise we leave them in the same order.
1535 // Set the section address. Look in INPUT_SECTIONS for sections which
1536 // match this spec, sort them as specified, and add them to the output
1540 Output_section_element_input::set_section_addresses(
1543 Output_section* output_section,
1545 uint64_t* dot_value,
1547 Output_section** dot_section,
1549 Input_section_list* input_sections)
1551 // We build a list of sections which match each
1552 // Input_section_pattern.
1554 typedef std::vector<std::vector<Input_section_info> > Matching_sections;
1555 size_t input_pattern_count = this->input_section_patterns_.size();
1556 if (input_pattern_count == 0)
1557 input_pattern_count = 1;
1558 Matching_sections matching_sections(input_pattern_count);
1560 // Look through the list of sections for this output section. Add
1561 // each one which matches to one of the elements of
1562 // MATCHING_SECTIONS.
1564 Input_section_list::iterator p = input_sections->begin();
1565 while (p != input_sections->end())
1567 Relobj* relobj = p->relobj();
1568 unsigned int shndx = p->shndx();
1569 Input_section_info isi(*p);
1571 // Calling section_name and section_addralign is not very
1574 // Lock the object so that we can get information about the
1575 // section. This is OK since we know we are single-threaded
1578 const Task* task = reinterpret_cast<const Task*>(-1);
1579 Task_lock_obj<Object> tl(task, relobj);
1581 isi.set_section_name(relobj->section_name(shndx));
1582 if (p->is_relaxed_input_section())
1584 // We use current data size because relaxed section sizes may not
1585 // have finalized yet.
1586 isi.set_size(p->relaxed_input_section()->current_data_size());
1587 isi.set_addralign(p->relaxed_input_section()->addralign());
1591 isi.set_size(relobj->section_size(shndx));
1592 isi.set_addralign(relobj->section_addralign(shndx));
1596 if (!this->match_file_name(relobj->name().c_str()))
1598 else if (this->input_section_patterns_.empty())
1600 matching_sections[0].push_back(isi);
1601 p = input_sections->erase(p);
1606 for (i = 0; i < input_pattern_count; ++i)
1608 const Input_section_pattern&
1609 isp(this->input_section_patterns_[i]);
1610 if (match(isi.section_name().c_str(), isp.pattern.c_str(),
1611 isp.pattern_is_wildcard))
1615 if (i >= this->input_section_patterns_.size())
1619 matching_sections[i].push_back(isi);
1620 p = input_sections->erase(p);
1625 // Look through MATCHING_SECTIONS. Sort each one as specified,
1626 // using a stable sort so that we get the default order when
1627 // sections are otherwise equal. Add each input section to the
1630 uint64_t dot = *dot_value;
1631 for (size_t i = 0; i < input_pattern_count; ++i)
1633 if (matching_sections[i].empty())
1636 gold_assert(output_section != NULL);
1638 const Input_section_pattern& isp(this->input_section_patterns_[i]);
1639 if (isp.sort != SORT_WILDCARD_NONE
1640 || this->filename_sort_ != SORT_WILDCARD_NONE)
1641 std::stable_sort(matching_sections[i].begin(),
1642 matching_sections[i].end(),
1643 Input_section_sorter(this->filename_sort_,
1646 for (std::vector<Input_section_info>::const_iterator p =
1647 matching_sections[i].begin();
1648 p != matching_sections[i].end();
1651 // Override the original address alignment if SUBALIGN is specified
1652 // and is greater than the original alignment. We need to make a
1653 // copy of the input section to modify the alignment.
1654 Output_section::Input_section sis(p->input_section());
1656 uint64_t this_subalign = sis.addralign();
1657 if (!sis.is_input_section())
1658 sis.output_section_data()->finalize_data_size();
1659 uint64_t data_size = sis.data_size();
1660 if (this_subalign < subalign)
1662 this_subalign = subalign;
1663 sis.set_addralign(subalign);
1666 uint64_t address = align_address(dot, this_subalign);
1668 if (address > dot && !fill->empty())
1670 section_size_type length =
1671 convert_to_section_size_type(address - dot);
1672 std::string this_fill = this->get_fill_string(fill, length);
1673 Output_section_data* posd = new Output_data_const(this_fill, 0);
1674 output_section->add_output_section_data(posd);
1675 layout->new_output_section_data_from_script(posd);
1678 output_section->add_script_input_section(sis);
1679 dot = address + data_size;
1683 // An SHF_TLS/SHT_NOBITS section does not take up any
1685 if (output_section == NULL
1686 || (output_section->flags() & elfcpp::SHF_TLS) == 0
1687 || output_section->type() != elfcpp::SHT_NOBITS)
1690 this->final_dot_value_ = *dot_value;
1691 this->final_dot_section_ = *dot_section;
1694 // Print for debugging.
1697 Output_section_element_input::print(FILE* f) const
1702 fprintf(f, "KEEP(");
1704 if (!this->filename_pattern_.empty())
1706 bool need_close_paren = false;
1707 switch (this->filename_sort_)
1709 case SORT_WILDCARD_NONE:
1711 case SORT_WILDCARD_BY_NAME:
1712 fprintf(f, "SORT_BY_NAME(");
1713 need_close_paren = true;
1719 fprintf(f, "%s", this->filename_pattern_.c_str());
1721 if (need_close_paren)
1725 if (!this->input_section_patterns_.empty()
1726 || !this->filename_exclusions_.empty())
1730 bool need_space = false;
1731 if (!this->filename_exclusions_.empty())
1733 fprintf(f, "EXCLUDE_FILE(");
1734 bool need_comma = false;
1735 for (Filename_exclusions::const_iterator p =
1736 this->filename_exclusions_.begin();
1737 p != this->filename_exclusions_.end();
1742 fprintf(f, "%s", p->first.c_str());
1749 for (Input_section_patterns::const_iterator p =
1750 this->input_section_patterns_.begin();
1751 p != this->input_section_patterns_.end();
1757 int close_parens = 0;
1760 case SORT_WILDCARD_NONE:
1762 case SORT_WILDCARD_BY_NAME:
1763 fprintf(f, "SORT_BY_NAME(");
1766 case SORT_WILDCARD_BY_ALIGNMENT:
1767 fprintf(f, "SORT_BY_ALIGNMENT(");
1770 case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT:
1771 fprintf(f, "SORT_BY_NAME(SORT_BY_ALIGNMENT(");
1774 case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME:
1775 fprintf(f, "SORT_BY_ALIGNMENT(SORT_BY_NAME(");
1782 fprintf(f, "%s", p->pattern.c_str());
1784 for (int i = 0; i < close_parens; ++i)
1799 // An output section.
1801 class Output_section_definition : public Sections_element
1804 typedef Output_section_element::Input_section_list Input_section_list;
1806 Output_section_definition(const char* name, size_t namelen,
1807 const Parser_output_section_header* header);
1809 // Finish the output section with the information in the trailer.
1811 finish(const Parser_output_section_trailer* trailer);
1813 // Add a symbol to be defined.
1815 add_symbol_assignment(const char* name, size_t length, Expression* value,
1816 bool provide, bool hidden);
1818 // Add an assignment to the special dot symbol.
1820 add_dot_assignment(Expression* value);
1822 // Add an assertion.
1824 add_assertion(Expression* check, const char* message, size_t messagelen);
1826 // Add a data item to the current output section.
1828 add_data(int size, bool is_signed, Expression* val);
1830 // Add a setting for the fill value.
1832 add_fill(Expression* val);
1834 // Add an input section specification.
1836 add_input_section(const Input_section_spec* spec, bool keep);
1838 // Return whether the output section is relro.
1841 { return this->is_relro_; }
1843 // Record that the output section is relro.
1846 { this->is_relro_ = true; }
1848 // Create any required output sections.
1850 create_sections(Layout*);
1852 // Add any symbols being defined to the symbol table.
1854 add_symbols_to_table(Symbol_table* symtab);
1856 // Finalize symbols and check assertions.
1858 finalize_symbols(Symbol_table*, const Layout*, uint64_t*);
1860 // Return the output section name to use for an input file name and
1863 output_section_name(const char* file_name, const char* section_name,
1864 Output_section***, Script_sections::Section_type*);
1866 // Initialize OSP with an output section.
1868 orphan_section_init(Orphan_section_placement* osp,
1869 Script_sections::Elements_iterator p)
1870 { osp->output_section_init(this->name_, this->output_section_, p); }
1872 // Set the section address.
1874 set_section_addresses(Symbol_table* symtab, Layout* layout,
1875 uint64_t* dot_value, uint64_t*,
1876 uint64_t* load_address);
1878 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
1879 // this section is constrained, and the input sections do not match,
1880 // return the constraint, and set *POSD.
1882 check_constraint(Output_section_definition** posd);
1884 // See if this is the alternate output section for a constrained
1885 // output section. If it is, transfer the Output_section and return
1886 // true. Otherwise return false.
1888 alternate_constraint(Output_section_definition*, Section_constraint);
1890 // Get the list of segments to use for an allocated section when
1891 // using a PHDRS clause.
1893 allocate_to_segment(String_list** phdrs_list, bool* orphan);
1895 // Look for an output section by name and return the address, the
1896 // load address, the alignment, and the size. This is used when an
1897 // expression refers to an output section which was not actually
1898 // created. This returns true if the section was found, false
1901 get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
1904 // Return the associated Output_section if there is one.
1906 get_output_section() const
1907 { return this->output_section_; }
1909 // Print the contents to the FILE. This is for debugging.
1913 // Return the output section type if specified or Script_sections::ST_NONE.
1914 Script_sections::Section_type
1915 section_type() const;
1917 // Store the memory region to use.
1919 set_memory_region(Memory_region*, bool set_vma);
1922 set_section_vma(Expression* address)
1923 { this->address_ = address; }
1926 set_section_lma(Expression* address)
1927 { this->load_address_ = address; }
1930 get_section_name() const
1931 { return this->name_; }
1935 script_section_type_name(Script_section_type);
1937 typedef std::vector<Output_section_element*> Output_section_elements;
1939 // The output section name.
1941 // The address. This may be NULL.
1942 Expression* address_;
1943 // The load address. This may be NULL.
1944 Expression* load_address_;
1945 // The alignment. This may be NULL.
1947 // The input section alignment. This may be NULL.
1948 Expression* subalign_;
1949 // The constraint, if any.
1950 Section_constraint constraint_;
1951 // The fill value. This may be NULL.
1953 // The list of segments this section should go into. This may be
1955 String_list* phdrs_;
1956 // The list of elements defining the section.
1957 Output_section_elements elements_;
1958 // The Output_section created for this definition. This will be
1959 // NULL if none was created.
1960 Output_section* output_section_;
1961 // The address after it has been evaluated.
1962 uint64_t evaluated_address_;
1963 // The load address after it has been evaluated.
1964 uint64_t evaluated_load_address_;
1965 // The alignment after it has been evaluated.
1966 uint64_t evaluated_addralign_;
1967 // The output section is relro.
1969 // The output section type if specified.
1970 enum Script_section_type script_section_type_;
1975 Output_section_definition::Output_section_definition(
1978 const Parser_output_section_header* header)
1979 : name_(name, namelen),
1980 address_(header->address),
1981 load_address_(header->load_address),
1982 align_(header->align),
1983 subalign_(header->subalign),
1984 constraint_(header->constraint),
1988 output_section_(NULL),
1989 evaluated_address_(0),
1990 evaluated_load_address_(0),
1991 evaluated_addralign_(0),
1993 script_section_type_(header->section_type)
1997 // Finish an output section.
2000 Output_section_definition::finish(const Parser_output_section_trailer* trailer)
2002 this->fill_ = trailer->fill;
2003 this->phdrs_ = trailer->phdrs;
2006 // Add a symbol to be defined.
2009 Output_section_definition::add_symbol_assignment(const char* name,
2015 Output_section_element* p = new Output_section_element_assignment(name,
2020 this->elements_.push_back(p);
2023 // Add an assignment to the special dot symbol.
2026 Output_section_definition::add_dot_assignment(Expression* value)
2028 Output_section_element* p = new Output_section_element_dot_assignment(value);
2029 this->elements_.push_back(p);
2032 // Add an assertion.
2035 Output_section_definition::add_assertion(Expression* check,
2036 const char* message,
2039 Output_section_element* p = new Output_section_element_assertion(check,
2042 this->elements_.push_back(p);
2045 // Add a data item to the current output section.
2048 Output_section_definition::add_data(int size, bool is_signed, Expression* val)
2050 Output_section_element* p = new Output_section_element_data(size, is_signed,
2052 this->elements_.push_back(p);
2055 // Add a setting for the fill value.
2058 Output_section_definition::add_fill(Expression* val)
2060 Output_section_element* p = new Output_section_element_fill(val);
2061 this->elements_.push_back(p);
2064 // Add an input section specification.
2067 Output_section_definition::add_input_section(const Input_section_spec* spec,
2070 Output_section_element* p = new Output_section_element_input(spec, keep);
2071 this->elements_.push_back(p);
2074 // Create any required output sections. We need an output section if
2075 // there is a data statement here.
2078 Output_section_definition::create_sections(Layout* layout)
2080 if (this->output_section_ != NULL)
2082 for (Output_section_elements::const_iterator p = this->elements_.begin();
2083 p != this->elements_.end();
2086 if ((*p)->needs_output_section())
2088 const char* name = this->name_.c_str();
2089 this->output_section_ =
2090 layout->make_output_section_for_script(name, this->section_type());
2096 // Add any symbols being defined to the symbol table.
2099 Output_section_definition::add_symbols_to_table(Symbol_table* symtab)
2101 for (Output_section_elements::iterator p = this->elements_.begin();
2102 p != this->elements_.end();
2104 (*p)->add_symbols_to_table(symtab);
2107 // Finalize symbols and check assertions.
2110 Output_section_definition::finalize_symbols(Symbol_table* symtab,
2111 const Layout* layout,
2112 uint64_t* dot_value)
2114 if (this->output_section_ != NULL)
2115 *dot_value = this->output_section_->address();
2118 uint64_t address = *dot_value;
2119 if (this->address_ != NULL)
2121 address = this->address_->eval_with_dot(symtab, layout, true,
2125 if (this->align_ != NULL)
2127 uint64_t align = this->align_->eval_with_dot(symtab, layout, true,
2130 address = align_address(address, align);
2132 *dot_value = address;
2135 Output_section* dot_section = this->output_section_;
2136 for (Output_section_elements::iterator p = this->elements_.begin();
2137 p != this->elements_.end();
2139 (*p)->finalize_symbols(symtab, layout, dot_value, &dot_section);
2142 // Return the output section name to use for an input section name.
2145 Output_section_definition::output_section_name(
2146 const char* file_name,
2147 const char* section_name,
2148 Output_section*** slot,
2149 Script_sections::Section_type* psection_type)
2151 // Ask each element whether it matches NAME.
2152 for (Output_section_elements::const_iterator p = this->elements_.begin();
2153 p != this->elements_.end();
2156 if ((*p)->match_name(file_name, section_name))
2158 // We found a match for NAME, which means that it should go
2159 // into this output section.
2160 *slot = &this->output_section_;
2161 *psection_type = this->section_type();
2162 return this->name_.c_str();
2166 // We don't know about this section name.
2170 // Return true if memory from START to START + LENGTH is contained
2171 // within a memory region.
2174 Script_sections::block_in_region(Symbol_table* symtab, Layout* layout,
2175 uint64_t start, uint64_t length) const
2177 if (this->memory_regions_ == NULL)
2180 for (Memory_regions::const_iterator mr = this->memory_regions_->begin();
2181 mr != this->memory_regions_->end();
2184 uint64_t s = (*mr)->start_address()->eval(symtab, layout, false);
2185 uint64_t l = (*mr)->length()->eval(symtab, layout, false);
2188 && (s + l) >= (start + length))
2195 // Find a memory region that should be used by a given output SECTION.
2196 // If provided set PREVIOUS_SECTION_RETURN to point to the last section
2197 // that used the return memory region.
2200 Script_sections::find_memory_region(
2201 Output_section_definition* section,
2202 bool find_vma_region,
2203 Output_section_definition** previous_section_return)
2205 if (previous_section_return != NULL)
2206 * previous_section_return = NULL;
2208 // Walk the memory regions specified in this script, if any.
2209 if (this->memory_regions_ == NULL)
2212 // The /DISCARD/ section never gets assigned to any region.
2213 if (section->get_section_name() == "/DISCARD/")
2216 Memory_region* first_match = NULL;
2218 // First check to see if a region has been assigned to this section.
2219 for (Memory_regions::const_iterator mr = this->memory_regions_->begin();
2220 mr != this->memory_regions_->end();
2223 if (find_vma_region)
2225 for (Memory_region::Section_list::const_iterator s =
2226 (*mr)->get_vma_section_list_start();
2227 s != (*mr)->get_vma_section_list_end();
2229 if ((*s) == section)
2231 (*mr)->set_last_section(section);
2237 for (Memory_region::Section_list::const_iterator s =
2238 (*mr)->get_lma_section_list_start();
2239 s != (*mr)->get_lma_section_list_end();
2241 if ((*s) == section)
2243 (*mr)->set_last_section(section);
2248 // Make a note of the first memory region whose attributes
2249 // are compatible with the section. If we do not find an
2250 // explicit region assignment, then we will return this region.
2251 Output_section* out_sec = section->get_output_section();
2252 if (first_match == NULL
2254 && (*mr)->attributes_compatible(out_sec->flags(),
2259 // With LMA computations, if an explicit region has not been specified then
2260 // we will want to set the difference between the VMA and the LMA of the
2261 // section were searching for to be the same as the difference between the
2262 // VMA and LMA of the last section to be added to first matched region.
2263 // Hence, if it was asked for, we return a pointer to the last section
2264 // known to be used by the first matched region.
2265 if (first_match != NULL
2266 && previous_section_return != NULL)
2267 *previous_section_return = first_match->get_last_section();
2272 // Set the section address. Note that the OUTPUT_SECTION_ field will
2273 // be NULL if no input sections were mapped to this output section.
2274 // We still have to adjust dot and process symbol assignments.
2277 Output_section_definition::set_section_addresses(Symbol_table* symtab,
2279 uint64_t* dot_value,
2280 uint64_t* dot_alignment,
2281 uint64_t* load_address)
2283 Memory_region* vma_region = NULL;
2284 Memory_region* lma_region = NULL;
2285 Script_sections* script_sections =
2286 layout->script_options()->script_sections();
2288 uint64_t old_dot_value = *dot_value;
2289 uint64_t old_load_address = *load_address;
2291 // Decide the start address for the section. The algorithm is:
2292 // 1) If an address has been specified in a linker script, use that.
2293 // 2) Otherwise if a memory region has been specified for the section,
2294 // use the next free address in the region.
2295 // 3) Otherwise if memory regions have been specified find the first
2296 // region whose attributes are compatible with this section and
2297 // install it into that region.
2298 // 4) Otherwise use the current location counter.
2300 if (this->output_section_ != NULL
2301 // Check for --section-start.
2302 && parameters->options().section_start(this->output_section_->name(),
2305 else if (this->address_ == NULL)
2307 vma_region = script_sections->find_memory_region(this, true, NULL);
2309 if (vma_region != NULL)
2310 address = vma_region->get_current_address()->eval(symtab, layout,
2313 address = *dot_value;
2316 address = this->address_->eval_with_dot(symtab, layout, true,
2317 *dot_value, NULL, NULL,
2318 dot_alignment, false);
2320 if (this->align_ == NULL)
2322 if (this->output_section_ == NULL)
2325 align = this->output_section_->addralign();
2329 Output_section* align_section;
2330 align = this->align_->eval_with_dot(symtab, layout, true, *dot_value,
2331 NULL, &align_section, NULL, false);
2332 if (align_section != NULL)
2333 gold_warning(_("alignment of section %s is not absolute"),
2334 this->name_.c_str());
2335 if (this->output_section_ != NULL)
2336 this->output_section_->set_addralign(align);
2339 address = align_address(address, align);
2341 uint64_t start_address = address;
2343 *dot_value = address;
2345 // Except for NOLOAD sections, the address of non-SHF_ALLOC sections is
2346 // forced to zero, regardless of what the linker script wants.
2347 if (this->output_section_ != NULL
2348 && ((this->output_section_->flags() & elfcpp::SHF_ALLOC) != 0
2349 || this->output_section_->is_noload()))
2350 this->output_section_->set_address(address);
2352 this->evaluated_address_ = address;
2353 this->evaluated_addralign_ = align;
2357 if (this->load_address_ == NULL)
2359 Output_section_definition* previous_section;
2361 // Determine if an LMA region has been set for this section.
2362 lma_region = script_sections->find_memory_region(this, false,
2365 if (lma_region != NULL)
2367 if (previous_section == NULL)
2368 // The LMA address was explicitly set to the given region.
2369 laddr = lma_region->get_current_address()->eval(symtab, layout,
2373 // We are not going to use the discovered lma_region, so
2374 // make sure that we do not update it in the code below.
2377 if (this->address_ != NULL || previous_section == this)
2379 // Either an explicit VMA address has been set, or an
2380 // explicit VMA region has been set, so set the LMA equal to
2386 // The LMA address was not explicitly or implicitly set.
2388 // We have been given the first memory region that is
2389 // compatible with the current section and a pointer to the
2390 // last section to use this region. Set the LMA of this
2391 // section so that the difference between its' VMA and LMA
2392 // is the same as the difference between the VMA and LMA of
2393 // the last section in the given region.
2394 laddr = address + (previous_section->evaluated_load_address_
2395 - previous_section->evaluated_address_);
2399 if (this->output_section_ != NULL)
2400 this->output_section_->set_load_address(laddr);
2404 // Do not set the load address of the output section, if one exists.
2405 // This allows future sections to determine what the load address
2406 // should be. If none is ever set, it will default to being the
2407 // same as the vma address.
2413 laddr = this->load_address_->eval_with_dot(symtab, layout, true,
2415 this->output_section_,
2417 if (this->output_section_ != NULL)
2418 this->output_section_->set_load_address(laddr);
2421 this->evaluated_load_address_ = laddr;
2424 if (this->subalign_ == NULL)
2428 Output_section* subalign_section;
2429 subalign = this->subalign_->eval_with_dot(symtab, layout, true,
2431 &subalign_section, NULL,
2433 if (subalign_section != NULL)
2434 gold_warning(_("subalign of section %s is not absolute"),
2435 this->name_.c_str());
2439 if (this->fill_ != NULL)
2441 // FIXME: The GNU linker supports fill values of arbitrary
2443 Output_section* fill_section;
2444 uint64_t fill_val = this->fill_->eval_with_dot(symtab, layout, true,
2446 NULL, &fill_section,
2448 if (fill_section != NULL)
2449 gold_warning(_("fill of section %s is not absolute"),
2450 this->name_.c_str());
2451 unsigned char fill_buff[4];
2452 elfcpp::Swap_unaligned<32, true>::writeval(fill_buff, fill_val);
2453 fill.assign(reinterpret_cast<char*>(fill_buff), 4);
2456 Input_section_list input_sections;
2457 if (this->output_section_ != NULL)
2459 // Get the list of input sections attached to this output
2460 // section. This will leave the output section with only
2461 // Output_section_data entries.
2462 address += this->output_section_->get_input_sections(address,
2465 *dot_value = address;
2468 Output_section* dot_section = this->output_section_;
2469 for (Output_section_elements::iterator p = this->elements_.begin();
2470 p != this->elements_.end();
2472 (*p)->set_section_addresses(symtab, layout, this->output_section_,
2473 subalign, dot_value, dot_alignment,
2474 &dot_section, &fill, &input_sections);
2476 gold_assert(input_sections.empty());
2478 if (vma_region != NULL)
2480 // Update the VMA region being used by the section now that we know how
2481 // big it is. Use the current address in the region, rather than
2482 // start_address because that might have been aligned upwards and we
2483 // need to allow for the padding.
2484 Expression* addr = vma_region->get_current_address();
2485 uint64_t size = *dot_value - addr->eval(symtab, layout, false);
2487 vma_region->increment_offset(this->get_section_name(), size,
2491 // If the LMA region is different from the VMA region, then increment the
2492 // offset there as well. Note that we use the same "dot_value -
2493 // start_address" formula that is used in the load_address assignment below.
2494 if (lma_region != NULL && lma_region != vma_region)
2495 lma_region->increment_offset(this->get_section_name(),
2496 *dot_value - start_address,
2499 // Compute the load address for the following section.
2500 if (this->output_section_ == NULL)
2501 *load_address = *dot_value;
2502 else if (this->load_address_ == NULL)
2504 if (lma_region == NULL)
2505 *load_address = *dot_value;
2508 lma_region->get_current_address()->eval(symtab, layout, false);
2511 *load_address = (this->output_section_->load_address()
2512 + (*dot_value - start_address));
2514 if (this->output_section_ != NULL)
2516 if (this->is_relro_)
2517 this->output_section_->set_is_relro();
2519 this->output_section_->clear_is_relro();
2521 // If this is a NOLOAD section, keep dot and load address unchanged.
2522 if (this->output_section_->is_noload())
2524 *dot_value = old_dot_value;
2525 *load_address = old_load_address;
2530 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
2531 // this section is constrained, and the input sections do not match,
2532 // return the constraint, and set *POSD.
2535 Output_section_definition::check_constraint(Output_section_definition** posd)
2537 switch (this->constraint_)
2539 case CONSTRAINT_NONE:
2540 return CONSTRAINT_NONE;
2542 case CONSTRAINT_ONLY_IF_RO:
2543 if (this->output_section_ != NULL
2544 && (this->output_section_->flags() & elfcpp::SHF_WRITE) != 0)
2547 return CONSTRAINT_ONLY_IF_RO;
2549 return CONSTRAINT_NONE;
2551 case CONSTRAINT_ONLY_IF_RW:
2552 if (this->output_section_ != NULL
2553 && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0)
2556 return CONSTRAINT_ONLY_IF_RW;
2558 return CONSTRAINT_NONE;
2560 case CONSTRAINT_SPECIAL:
2561 if (this->output_section_ != NULL)
2562 gold_error(_("SPECIAL constraints are not implemented"));
2563 return CONSTRAINT_NONE;
2570 // See if this is the alternate output section for a constrained
2571 // output section. If it is, transfer the Output_section and return
2572 // true. Otherwise return false.
2575 Output_section_definition::alternate_constraint(
2576 Output_section_definition* posd,
2577 Section_constraint constraint)
2579 if (this->name_ != posd->name_)
2584 case CONSTRAINT_ONLY_IF_RO:
2585 if (this->constraint_ != CONSTRAINT_ONLY_IF_RW)
2589 case CONSTRAINT_ONLY_IF_RW:
2590 if (this->constraint_ != CONSTRAINT_ONLY_IF_RO)
2598 // We have found the alternate constraint. We just need to move
2599 // over the Output_section. When constraints are used properly,
2600 // THIS should not have an output_section pointer, as all the input
2601 // sections should have matched the other definition.
2603 if (this->output_section_ != NULL)
2604 gold_error(_("mismatched definition for constrained sections"));
2606 this->output_section_ = posd->output_section_;
2607 posd->output_section_ = NULL;
2609 if (this->is_relro_)
2610 this->output_section_->set_is_relro();
2612 this->output_section_->clear_is_relro();
2617 // Get the list of segments to use for an allocated section when using
2621 Output_section_definition::allocate_to_segment(String_list** phdrs_list,
2624 // Update phdrs_list even if we don't have an output section. It
2625 // might be used by the following sections.
2626 if (this->phdrs_ != NULL)
2627 *phdrs_list = this->phdrs_;
2629 if (this->output_section_ == NULL)
2631 if ((this->output_section_->flags() & elfcpp::SHF_ALLOC) == 0)
2634 return this->output_section_;
2637 // Look for an output section by name and return the address, the load
2638 // address, the alignment, and the size. This is used when an
2639 // expression refers to an output section which was not actually
2640 // created. This returns true if the section was found, false
2644 Output_section_definition::get_output_section_info(const char* name,
2646 uint64_t* load_address,
2647 uint64_t* addralign,
2648 uint64_t* size) const
2650 if (this->name_ != name)
2653 if (this->output_section_ != NULL)
2655 *address = this->output_section_->address();
2656 if (this->output_section_->has_load_address())
2657 *load_address = this->output_section_->load_address();
2659 *load_address = *address;
2660 *addralign = this->output_section_->addralign();
2661 *size = this->output_section_->current_data_size();
2665 *address = this->evaluated_address_;
2666 *load_address = this->evaluated_load_address_;
2667 *addralign = this->evaluated_addralign_;
2674 // Print for debugging.
2677 Output_section_definition::print(FILE* f) const
2679 fprintf(f, " %s ", this->name_.c_str());
2681 if (this->address_ != NULL)
2683 this->address_->print(f);
2687 if (this->script_section_type_ != SCRIPT_SECTION_TYPE_NONE)
2689 this->script_section_type_name(this->script_section_type_));
2693 if (this->load_address_ != NULL)
2696 this->load_address_->print(f);
2700 if (this->align_ != NULL)
2702 fprintf(f, "ALIGN(");
2703 this->align_->print(f);
2707 if (this->subalign_ != NULL)
2709 fprintf(f, "SUBALIGN(");
2710 this->subalign_->print(f);
2716 for (Output_section_elements::const_iterator p = this->elements_.begin();
2717 p != this->elements_.end();
2723 if (this->fill_ != NULL)
2726 this->fill_->print(f);
2729 if (this->phdrs_ != NULL)
2731 for (String_list::const_iterator p = this->phdrs_->begin();
2732 p != this->phdrs_->end();
2734 fprintf(f, " :%s", p->c_str());
2740 Script_sections::Section_type
2741 Output_section_definition::section_type() const
2743 switch (this->script_section_type_)
2745 case SCRIPT_SECTION_TYPE_NONE:
2746 return Script_sections::ST_NONE;
2747 case SCRIPT_SECTION_TYPE_NOLOAD:
2748 return Script_sections::ST_NOLOAD;
2749 case SCRIPT_SECTION_TYPE_COPY:
2750 case SCRIPT_SECTION_TYPE_DSECT:
2751 case SCRIPT_SECTION_TYPE_INFO:
2752 case SCRIPT_SECTION_TYPE_OVERLAY:
2753 // There are not really support so we treat them as ST_NONE. The
2754 // parse should have issued errors for them already.
2755 return Script_sections::ST_NONE;
2761 // Return the name of a script section type.
2764 Output_section_definition::script_section_type_name(
2765 Script_section_type script_section_type)
2767 switch (script_section_type)
2769 case SCRIPT_SECTION_TYPE_NONE:
2771 case SCRIPT_SECTION_TYPE_NOLOAD:
2773 case SCRIPT_SECTION_TYPE_DSECT:
2775 case SCRIPT_SECTION_TYPE_COPY:
2777 case SCRIPT_SECTION_TYPE_INFO:
2779 case SCRIPT_SECTION_TYPE_OVERLAY:
2787 Output_section_definition::set_memory_region(Memory_region* mr, bool set_vma)
2789 gold_assert(mr != NULL);
2790 // Add the current section to the specified region's list.
2791 mr->add_section(this, set_vma);
2794 // An output section created to hold orphaned input sections. These
2795 // do not actually appear in linker scripts. However, for convenience
2796 // when setting the output section addresses, we put a marker to these
2797 // sections in the appropriate place in the list of SECTIONS elements.
2799 class Orphan_output_section : public Sections_element
2802 Orphan_output_section(Output_section* os)
2806 // Return whether the orphan output section is relro. We can just
2807 // check the output section because we always set the flag, if
2808 // needed, just after we create the Orphan_output_section.
2811 { return this->os_->is_relro(); }
2813 // Initialize OSP with an output section. This should have been
2816 orphan_section_init(Orphan_section_placement*,
2817 Script_sections::Elements_iterator)
2818 { gold_unreachable(); }
2820 // Set section addresses.
2822 set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*,
2825 // Get the list of segments to use for an allocated section when
2826 // using a PHDRS clause.
2828 allocate_to_segment(String_list**, bool*);
2830 // Return the associated Output_section.
2832 get_output_section() const
2833 { return this->os_; }
2835 // Print for debugging.
2837 print(FILE* f) const
2839 fprintf(f, " marker for orphaned output section %s\n",
2844 Output_section* os_;
2847 // Set section addresses.
2850 Orphan_output_section::set_section_addresses(Symbol_table*, Layout*,
2851 uint64_t* dot_value,
2853 uint64_t* load_address)
2855 typedef std::list<Output_section::Input_section> Input_section_list;
2857 bool have_load_address = *load_address != *dot_value;
2859 uint64_t address = *dot_value;
2860 address = align_address(address, this->os_->addralign());
2862 // For a relocatable link, all orphan sections are put at
2863 // address 0. In general we expect all sections to be at
2864 // address 0 for a relocatable link, but we permit the linker
2865 // script to override that for specific output sections.
2866 if (parameters->options().relocatable())
2870 have_load_address = false;
2873 if ((this->os_->flags() & elfcpp::SHF_ALLOC) != 0)
2875 this->os_->set_address(address);
2876 if (have_load_address)
2877 this->os_->set_load_address(align_address(*load_address,
2878 this->os_->addralign()));
2881 Input_section_list input_sections;
2882 address += this->os_->get_input_sections(address, "", &input_sections);
2884 for (Input_section_list::iterator p = input_sections.begin();
2885 p != input_sections.end();
2888 uint64_t addralign = p->addralign();
2889 if (!p->is_input_section())
2890 p->output_section_data()->finalize_data_size();
2891 uint64_t size = p->data_size();
2892 address = align_address(address, addralign);
2893 this->os_->add_script_input_section(*p);
2897 // An SHF_TLS/SHT_NOBITS section does not take up any address space.
2898 if (this->os_ == NULL
2899 || (this->os_->flags() & elfcpp::SHF_TLS) == 0
2900 || this->os_->type() != elfcpp::SHT_NOBITS)
2902 if (!have_load_address)
2903 *load_address = address;
2905 *load_address += address - *dot_value;
2907 *dot_value = address;
2911 // Get the list of segments to use for an allocated section when using
2912 // a PHDRS clause. If this is an allocated section, return the
2913 // Output_section. We don't change the list of segments.
2916 Orphan_output_section::allocate_to_segment(String_list**, bool* orphan)
2918 if ((this->os_->flags() & elfcpp::SHF_ALLOC) == 0)
2924 // Class Phdrs_element. A program header from a PHDRS clause.
2929 Phdrs_element(const char* name, size_t namelen, unsigned int type,
2930 bool includes_filehdr, bool includes_phdrs,
2931 bool is_flags_valid, unsigned int flags,
2932 Expression* load_address)
2933 : name_(name, namelen), type_(type), includes_filehdr_(includes_filehdr),
2934 includes_phdrs_(includes_phdrs), is_flags_valid_(is_flags_valid),
2935 flags_(flags), load_address_(load_address), load_address_value_(0),
2939 // Return the name of this segment.
2942 { return this->name_; }
2944 // Return the type of the segment.
2947 { return this->type_; }
2949 // Whether to include the file header.
2951 includes_filehdr() const
2952 { return this->includes_filehdr_; }
2954 // Whether to include the program headers.
2956 includes_phdrs() const
2957 { return this->includes_phdrs_; }
2959 // Return whether there is a load address.
2961 has_load_address() const
2962 { return this->load_address_ != NULL; }
2964 // Evaluate the load address expression if there is one.
2966 eval_load_address(Symbol_table* symtab, Layout* layout)
2968 if (this->load_address_ != NULL)
2969 this->load_address_value_ = this->load_address_->eval(symtab, layout,
2973 // Return the load address.
2975 load_address() const
2977 gold_assert(this->load_address_ != NULL);
2978 return this->load_address_value_;
2981 // Create the segment.
2983 create_segment(Layout* layout)
2985 this->segment_ = layout->make_output_segment(this->type_, this->flags_);
2986 return this->segment_;
2989 // Return the segment.
2992 { return this->segment_; }
2994 // Release the segment.
2997 { this->segment_ = NULL; }
2999 // Set the segment flags if appropriate.
3001 set_flags_if_valid()
3003 if (this->is_flags_valid_)
3004 this->segment_->set_flags(this->flags_);
3007 // Print for debugging.
3012 // The name used in the script.
3014 // The type of the segment (PT_LOAD, etc.).
3016 // Whether this segment includes the file header.
3017 bool includes_filehdr_;
3018 // Whether this segment includes the section headers.
3019 bool includes_phdrs_;
3020 // Whether the flags were explicitly specified.
3021 bool is_flags_valid_;
3022 // The flags for this segment (PF_R, etc.) if specified.
3023 unsigned int flags_;
3024 // The expression for the load address for this segment. This may
3026 Expression* load_address_;
3027 // The actual load address from evaluating the expression.
3028 uint64_t load_address_value_;
3029 // The segment itself.
3030 Output_segment* segment_;
3033 // Print for debugging.
3036 Phdrs_element::print(FILE* f) const
3038 fprintf(f, " %s 0x%x", this->name_.c_str(), this->type_);
3039 if (this->includes_filehdr_)
3040 fprintf(f, " FILEHDR");
3041 if (this->includes_phdrs_)
3042 fprintf(f, " PHDRS");
3043 if (this->is_flags_valid_)
3044 fprintf(f, " FLAGS(%u)", this->flags_);
3045 if (this->load_address_ != NULL)
3048 this->load_address_->print(f);
3054 // Add a memory region.
3057 Script_sections::add_memory_region(const char* name, size_t namelen,
3058 unsigned int attributes,
3059 Expression* start, Expression* length)
3061 if (this->memory_regions_ == NULL)
3062 this->memory_regions_ = new Memory_regions();
3063 else if (this->find_memory_region(name, namelen))
3065 gold_error(_("region '%.*s' already defined"), static_cast<int>(namelen),
3067 // FIXME: Add a GOLD extension to allow multiple regions with the same
3068 // name. This would amount to a single region covering disjoint blocks
3069 // of memory, which is useful for embedded devices.
3072 // FIXME: Check the length and start values. Currently we allow
3073 // non-constant expressions for these values, whereas LD does not.
3075 // FIXME: Add a GOLD extension to allow NEGATIVE LENGTHS. This would
3076 // describe a region that packs from the end address going down, rather
3077 // than the start address going up. This would be useful for embedded
3080 this->memory_regions_->push_back(new Memory_region(name, namelen, attributes,
3084 // Find a memory region.
3087 Script_sections::find_memory_region(const char* name, size_t namelen)
3089 if (this->memory_regions_ == NULL)
3092 for (Memory_regions::const_iterator m = this->memory_regions_->begin();
3093 m != this->memory_regions_->end();
3095 if ((*m)->name_match(name, namelen))
3101 // Find a memory region's origin.
3104 Script_sections::find_memory_region_origin(const char* name, size_t namelen)
3106 Memory_region* mr = find_memory_region(name, namelen);
3110 return mr->start_address();
3113 // Find a memory region's length.
3116 Script_sections::find_memory_region_length(const char* name, size_t namelen)
3118 Memory_region* mr = find_memory_region(name, namelen);
3122 return mr->length();
3125 // Set the memory region to use for the current section.
3128 Script_sections::set_memory_region(Memory_region* mr, bool set_vma)
3130 gold_assert(!this->sections_elements_->empty());
3131 this->sections_elements_->back()->set_memory_region(mr, set_vma);
3134 // Class Script_sections.
3136 Script_sections::Script_sections()
3137 : saw_sections_clause_(false),
3138 in_sections_clause_(false),
3139 sections_elements_(NULL),
3140 output_section_(NULL),
3141 memory_regions_(NULL),
3142 phdrs_elements_(NULL),
3143 orphan_section_placement_(NULL),
3144 data_segment_align_start_(),
3145 saw_data_segment_align_(false),
3146 saw_relro_end_(false),
3147 saw_segment_start_expression_(false)
3151 // Start a SECTIONS clause.
3154 Script_sections::start_sections()
3156 gold_assert(!this->in_sections_clause_ && this->output_section_ == NULL);
3157 this->saw_sections_clause_ = true;
3158 this->in_sections_clause_ = true;
3159 if (this->sections_elements_ == NULL)
3160 this->sections_elements_ = new Sections_elements;
3163 // Finish a SECTIONS clause.
3166 Script_sections::finish_sections()
3168 gold_assert(this->in_sections_clause_ && this->output_section_ == NULL);
3169 this->in_sections_clause_ = false;
3172 // Add a symbol to be defined.
3175 Script_sections::add_symbol_assignment(const char* name, size_t length,
3176 Expression* val, bool provide,
3179 if (this->output_section_ != NULL)
3180 this->output_section_->add_symbol_assignment(name, length, val,
3184 Sections_element* p = new Sections_element_assignment(name, length,
3187 this->sections_elements_->push_back(p);
3191 // Add an assignment to the special dot symbol.
3194 Script_sections::add_dot_assignment(Expression* val)
3196 if (this->output_section_ != NULL)
3197 this->output_section_->add_dot_assignment(val);
3200 // The GNU linker permits assignments to . to appears outside of
3201 // a SECTIONS clause, and treats it as appearing inside, so
3202 // sections_elements_ may be NULL here.
3203 if (this->sections_elements_ == NULL)
3205 this->sections_elements_ = new Sections_elements;
3206 this->saw_sections_clause_ = true;
3209 Sections_element* p = new Sections_element_dot_assignment(val);
3210 this->sections_elements_->push_back(p);
3214 // Add an assertion.
3217 Script_sections::add_assertion(Expression* check, const char* message,
3220 if (this->output_section_ != NULL)
3221 this->output_section_->add_assertion(check, message, messagelen);
3224 Sections_element* p = new Sections_element_assertion(check, message,
3226 this->sections_elements_->push_back(p);
3230 // Start processing entries for an output section.
3233 Script_sections::start_output_section(
3236 const Parser_output_section_header* header)
3238 Output_section_definition* posd = new Output_section_definition(name,
3241 this->sections_elements_->push_back(posd);
3242 gold_assert(this->output_section_ == NULL);
3243 this->output_section_ = posd;
3246 // Stop processing entries for an output section.
3249 Script_sections::finish_output_section(
3250 const Parser_output_section_trailer* trailer)
3252 gold_assert(this->output_section_ != NULL);
3253 this->output_section_->finish(trailer);
3254 this->output_section_ = NULL;
3257 // Add a data item to the current output section.
3260 Script_sections::add_data(int size, bool is_signed, Expression* val)
3262 gold_assert(this->output_section_ != NULL);
3263 this->output_section_->add_data(size, is_signed, val);
3266 // Add a fill value setting to the current output section.
3269 Script_sections::add_fill(Expression* val)
3271 gold_assert(this->output_section_ != NULL);
3272 this->output_section_->add_fill(val);
3275 // Add an input section specification to the current output section.
3278 Script_sections::add_input_section(const Input_section_spec* spec, bool keep)
3280 gold_assert(this->output_section_ != NULL);
3281 this->output_section_->add_input_section(spec, keep);
3284 // This is called when we see DATA_SEGMENT_ALIGN. It means that any
3285 // subsequent output sections may be relro.
3288 Script_sections::data_segment_align()
3290 if (this->saw_data_segment_align_)
3291 gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script"));
3292 gold_assert(!this->sections_elements_->empty());
3293 Sections_elements::iterator p = this->sections_elements_->end();
3295 this->data_segment_align_start_ = p;
3296 this->saw_data_segment_align_ = true;
3299 // This is called when we see DATA_SEGMENT_RELRO_END. It means that
3300 // any output sections seen since DATA_SEGMENT_ALIGN are relro.
3303 Script_sections::data_segment_relro_end()
3305 if (this->saw_relro_end_)
3306 gold_error(_("DATA_SEGMENT_RELRO_END may only appear once "
3307 "in a linker script"));
3308 this->saw_relro_end_ = true;
3310 if (!this->saw_data_segment_align_)
3311 gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN"));
3314 Sections_elements::iterator p = this->data_segment_align_start_;
3315 for (++p; p != this->sections_elements_->end(); ++p)
3316 (*p)->set_is_relro();
3320 // Create any required sections.
3323 Script_sections::create_sections(Layout* layout)
3325 if (!this->saw_sections_clause_)
3327 for (Sections_elements::iterator p = this->sections_elements_->begin();
3328 p != this->sections_elements_->end();
3330 (*p)->create_sections(layout);
3333 // Add any symbols we are defining to the symbol table.
3336 Script_sections::add_symbols_to_table(Symbol_table* symtab)
3338 if (!this->saw_sections_clause_)
3340 for (Sections_elements::iterator p = this->sections_elements_->begin();
3341 p != this->sections_elements_->end();
3343 (*p)->add_symbols_to_table(symtab);
3346 // Finalize symbols and check assertions.
3349 Script_sections::finalize_symbols(Symbol_table* symtab, const Layout* layout)
3351 if (!this->saw_sections_clause_)
3353 uint64_t dot_value = 0;
3354 for (Sections_elements::iterator p = this->sections_elements_->begin();
3355 p != this->sections_elements_->end();
3357 (*p)->finalize_symbols(symtab, layout, &dot_value);
3360 // Return the name of the output section to use for an input file name
3361 // and section name.
3364 Script_sections::output_section_name(
3365 const char* file_name,
3366 const char* section_name,
3367 Output_section*** output_section_slot,
3368 Script_sections::Section_type* psection_type)
3370 for (Sections_elements::const_iterator p = this->sections_elements_->begin();
3371 p != this->sections_elements_->end();
3374 const char* ret = (*p)->output_section_name(file_name, section_name,
3375 output_section_slot,
3380 // The special name /DISCARD/ means that the input section
3381 // should be discarded.
3382 if (strcmp(ret, "/DISCARD/") == 0)
3384 *output_section_slot = NULL;
3385 *psection_type = Script_sections::ST_NONE;
3392 // If we couldn't find a mapping for the name, the output section
3393 // gets the name of the input section.
3395 *output_section_slot = NULL;
3396 *psection_type = Script_sections::ST_NONE;
3398 return section_name;
3401 // Place a marker for an orphan output section into the SECTIONS
3405 Script_sections::place_orphan(Output_section* os)
3407 Orphan_section_placement* osp = this->orphan_section_placement_;
3410 // Initialize the Orphan_section_placement structure.
3411 osp = new Orphan_section_placement();
3412 for (Sections_elements::iterator p = this->sections_elements_->begin();
3413 p != this->sections_elements_->end();
3415 (*p)->orphan_section_init(osp, p);
3416 gold_assert(!this->sections_elements_->empty());
3417 Sections_elements::iterator last = this->sections_elements_->end();
3419 osp->last_init(last);
3420 this->orphan_section_placement_ = osp;
3423 Orphan_output_section* orphan = new Orphan_output_section(os);
3425 // Look for where to put ORPHAN.
3426 Sections_elements::iterator* where;
3427 if (osp->find_place(os, &where))
3429 if ((**where)->is_relro())
3432 os->clear_is_relro();
3434 // We want to insert ORPHAN after *WHERE, and then update *WHERE
3435 // so that the next one goes after this one.
3436 Sections_elements::iterator p = *where;
3437 gold_assert(p != this->sections_elements_->end());
3439 *where = this->sections_elements_->insert(p, orphan);
3443 os->clear_is_relro();
3444 // We don't have a place to put this orphan section. Put it,
3445 // and all other sections like it, at the end, but before the
3446 // sections which always come at the end.
3447 Sections_elements::iterator last = osp->last_place();
3448 *where = this->sections_elements_->insert(last, orphan);
3452 // Set the addresses of all the output sections. Walk through all the
3453 // elements, tracking the dot symbol. Apply assignments which set
3454 // absolute symbol values, in case they are used when setting dot.
3455 // Fill in data statement values. As we find output sections, set the
3456 // address, set the address of all associated input sections, and
3457 // update dot. Return the segment which should hold the file header
3458 // and segment headers, if any.
3461 Script_sections::set_section_addresses(Symbol_table* symtab, Layout* layout)
3463 gold_assert(this->saw_sections_clause_);
3465 // Implement ONLY_IF_RO/ONLY_IF_RW constraints. These are a pain
3466 // for our representation.
3467 for (Sections_elements::iterator p = this->sections_elements_->begin();
3468 p != this->sections_elements_->end();
3471 Output_section_definition* posd;
3472 Section_constraint failed_constraint = (*p)->check_constraint(&posd);
3473 if (failed_constraint != CONSTRAINT_NONE)
3475 Sections_elements::iterator q;
3476 for (q = this->sections_elements_->begin();
3477 q != this->sections_elements_->end();
3482 if ((*q)->alternate_constraint(posd, failed_constraint))
3487 if (q == this->sections_elements_->end())
3488 gold_error(_("no matching section constraint"));
3492 // Force the alignment of the first TLS section to be the maximum
3493 // alignment of all TLS sections.
3494 Output_section* first_tls = NULL;
3495 uint64_t tls_align = 0;
3496 for (Sections_elements::const_iterator p = this->sections_elements_->begin();
3497 p != this->sections_elements_->end();
3500 Output_section* os = (*p)->get_output_section();
3501 if (os != NULL && (os->flags() & elfcpp::SHF_TLS) != 0)
3503 if (first_tls == NULL)
3505 if (os->addralign() > tls_align)
3506 tls_align = os->addralign();
3509 if (first_tls != NULL)
3510 first_tls->set_addralign(tls_align);
3512 // For a relocatable link, we implicitly set dot to zero.
3513 uint64_t dot_value = 0;
3514 uint64_t dot_alignment = 0;
3515 uint64_t load_address = 0;
3517 // Check to see if we want to use any of -Ttext, -Tdata and -Tbss options
3518 // to set section addresses. If the script has any SEGMENT_START
3519 // expression, we do not set the section addresses.
3520 bool use_tsection_options =
3521 (!this->saw_segment_start_expression_
3522 && (parameters->options().user_set_Ttext()
3523 || parameters->options().user_set_Tdata()
3524 || parameters->options().user_set_Tbss()));
3526 for (Sections_elements::iterator p = this->sections_elements_->begin();
3527 p != this->sections_elements_->end();
3530 Output_section* os = (*p)->get_output_section();
3532 // Handle -Ttext, -Tdata and -Tbss options. We do this by looking for
3533 // the special sections by names and doing dot assignments.
3534 if (use_tsection_options
3536 && (os->flags() & elfcpp::SHF_ALLOC) != 0)
3538 uint64_t new_dot_value = dot_value;
3540 if (parameters->options().user_set_Ttext()
3541 && strcmp(os->name(), ".text") == 0)
3542 new_dot_value = parameters->options().Ttext();
3543 else if (parameters->options().user_set_Tdata()
3544 && strcmp(os->name(), ".data") == 0)
3545 new_dot_value = parameters->options().Tdata();
3546 else if (parameters->options().user_set_Tbss()
3547 && strcmp(os->name(), ".bss") == 0)
3548 new_dot_value = parameters->options().Tbss();
3550 // Update dot and load address if necessary.
3551 if (new_dot_value < dot_value)
3552 gold_error(_("dot may not move backward"));
3553 else if (new_dot_value != dot_value)
3555 dot_value = new_dot_value;
3556 load_address = new_dot_value;
3560 (*p)->set_section_addresses(symtab, layout, &dot_value, &dot_alignment,
3564 if (this->phdrs_elements_ != NULL)
3566 for (Phdrs_elements::iterator p = this->phdrs_elements_->begin();
3567 p != this->phdrs_elements_->end();
3569 (*p)->eval_load_address(symtab, layout);
3572 return this->create_segments(layout, dot_alignment);
3575 // Sort the sections in order to put them into segments.
3577 class Sort_output_sections
3580 Sort_output_sections(const Script_sections::Sections_elements* elements)
3581 : elements_(elements)
3585 operator()(const Output_section* os1, const Output_section* os2) const;
3589 script_compare(const Output_section* os1, const Output_section* os2) const;
3592 const Script_sections::Sections_elements* elements_;
3596 Sort_output_sections::operator()(const Output_section* os1,
3597 const Output_section* os2) const
3599 // Sort first by the load address.
3600 uint64_t lma1 = (os1->has_load_address()
3601 ? os1->load_address()
3603 uint64_t lma2 = (os2->has_load_address()
3604 ? os2->load_address()
3609 // Then sort by the virtual address.
3610 if (os1->address() != os2->address())
3611 return os1->address() < os2->address();
3613 // If the linker script says which of these sections is first, go
3614 // with what it says.
3615 int i = this->script_compare(os1, os2);
3619 // Sort PROGBITS before NOBITS.
3620 bool nobits1 = os1->type() == elfcpp::SHT_NOBITS;
3621 bool nobits2 = os2->type() == elfcpp::SHT_NOBITS;
3622 if (nobits1 != nobits2)
3625 // Sort PROGBITS TLS sections to the end, NOBITS TLS sections to the
3627 bool tls1 = (os1->flags() & elfcpp::SHF_TLS) != 0;
3628 bool tls2 = (os2->flags() & elfcpp::SHF_TLS) != 0;
3630 return nobits1 ? tls1 : tls2;
3632 // Sort non-NOLOAD before NOLOAD.
3633 if (os1->is_noload() && !os2->is_noload())
3635 if (!os1->is_noload() && os2->is_noload())
3638 // The sections seem practically identical. Sort by name to get a
3640 return os1->name() < os2->name();
3643 // Return -1 if OS1 comes before OS2 in ELEMENTS_, 1 if comes after, 0
3644 // if either OS1 or OS2 is not mentioned. This ensures that we keep
3645 // empty sections in the order in which they appear in a linker
3649 Sort_output_sections::script_compare(const Output_section* os1,
3650 const Output_section* os2) const
3652 if (this->elements_ == NULL)
3655 bool found_os1 = false;
3656 bool found_os2 = false;
3657 for (Script_sections::Sections_elements::const_iterator
3658 p = this->elements_->begin();
3659 p != this->elements_->end();
3662 if (os2 == (*p)->get_output_section())
3668 else if (os1 == (*p)->get_output_section())
3679 // Return whether OS is a BSS section. This is a SHT_NOBITS section.
3680 // We treat a section with the SHF_TLS flag set as taking up space
3681 // even if it is SHT_NOBITS (this is true of .tbss), as we allocate
3682 // space for them in the file.
3685 Script_sections::is_bss_section(const Output_section* os)
3687 return (os->type() == elfcpp::SHT_NOBITS
3688 && (os->flags() & elfcpp::SHF_TLS) == 0);
3691 // Return the size taken by the file header and the program headers.
3694 Script_sections::total_header_size(Layout* layout) const
3696 size_t segment_count = layout->segment_count();
3697 size_t file_header_size;
3698 size_t segment_headers_size;
3699 if (parameters->target().get_size() == 32)
3701 file_header_size = elfcpp::Elf_sizes<32>::ehdr_size;
3702 segment_headers_size = segment_count * elfcpp::Elf_sizes<32>::phdr_size;
3704 else if (parameters->target().get_size() == 64)
3706 file_header_size = elfcpp::Elf_sizes<64>::ehdr_size;
3707 segment_headers_size = segment_count * elfcpp::Elf_sizes<64>::phdr_size;
3712 return file_header_size + segment_headers_size;
3715 // Return the amount we have to subtract from the LMA to accommodate
3716 // headers of the given size. The complication is that the file
3717 // header have to be at the start of a page, as otherwise it will not
3718 // be at the start of the file.
3721 Script_sections::header_size_adjustment(uint64_t lma,
3722 size_t sizeof_headers) const
3724 const uint64_t abi_pagesize = parameters->target().abi_pagesize();
3725 uint64_t hdr_lma = lma - sizeof_headers;
3726 hdr_lma &= ~(abi_pagesize - 1);
3727 return lma - hdr_lma;
3730 // Create the PT_LOAD segments when using a SECTIONS clause. Returns
3731 // the segment which should hold the file header and segment headers,
3735 Script_sections::create_segments(Layout* layout, uint64_t dot_alignment)
3737 gold_assert(this->saw_sections_clause_);
3739 if (parameters->options().relocatable())
3742 if (this->saw_phdrs_clause())
3743 return create_segments_from_phdrs_clause(layout, dot_alignment);
3745 Layout::Section_list sections;
3746 layout->get_allocated_sections(§ions);
3748 // Sort the sections by address.
3749 std::stable_sort(sections.begin(), sections.end(),
3750 Sort_output_sections(this->sections_elements_));
3752 this->create_note_and_tls_segments(layout, §ions);
3754 // Walk through the sections adding them to PT_LOAD segments.
3755 const uint64_t abi_pagesize = parameters->target().abi_pagesize();
3756 Output_segment* first_seg = NULL;
3757 Output_segment* current_seg = NULL;
3758 bool is_current_seg_readonly = true;
3759 Layout::Section_list::iterator plast = sections.end();
3760 uint64_t last_vma = 0;
3761 uint64_t last_lma = 0;
3762 uint64_t last_size = 0;
3763 for (Layout::Section_list::iterator p = sections.begin();
3764 p != sections.end();
3767 const uint64_t vma = (*p)->address();
3768 const uint64_t lma = ((*p)->has_load_address()
3769 ? (*p)->load_address()
3771 const uint64_t size = (*p)->current_data_size();
3773 bool need_new_segment;
3774 if (current_seg == NULL)
3775 need_new_segment = true;
3776 else if (lma - vma != last_lma - last_vma)
3778 // This section has a different LMA relationship than the
3779 // last one; we need a new segment.
3780 need_new_segment = true;
3782 else if (align_address(last_lma + last_size, abi_pagesize)
3783 < align_address(lma, abi_pagesize))
3785 // Putting this section in the segment would require
3787 need_new_segment = true;
3789 else if (is_bss_section(*plast) && !is_bss_section(*p))
3791 // A non-BSS section can not follow a BSS section in the
3793 need_new_segment = true;
3795 else if (is_current_seg_readonly
3796 && ((*p)->flags() & elfcpp::SHF_WRITE) != 0
3797 && !parameters->options().omagic())
3799 // Don't put a writable section in the same segment as a
3800 // non-writable section.
3801 need_new_segment = true;
3805 // Otherwise, reuse the existing segment.
3806 need_new_segment = false;
3809 elfcpp::Elf_Word seg_flags =
3810 Layout::section_flags_to_segment((*p)->flags());
3812 if (need_new_segment)
3814 current_seg = layout->make_output_segment(elfcpp::PT_LOAD,
3816 current_seg->set_addresses(vma, lma);
3817 current_seg->set_minimum_p_align(dot_alignment);
3818 if (first_seg == NULL)
3819 first_seg = current_seg;
3820 is_current_seg_readonly = true;
3823 current_seg->add_output_section_to_load(layout, *p, seg_flags);
3825 if (((*p)->flags() & elfcpp::SHF_WRITE) != 0)
3826 is_current_seg_readonly = false;
3834 // An ELF program should work even if the program headers are not in
3835 // a PT_LOAD segment. However, it appears that the Linux kernel
3836 // does not set the AT_PHDR auxiliary entry in that case. It sets
3837 // the load address to p_vaddr - p_offset of the first PT_LOAD
3838 // segment. It then sets AT_PHDR to the load address plus the
3839 // offset to the program headers, e_phoff in the file header. This
3840 // fails when the program headers appear in the file before the
3841 // first PT_LOAD segment. Therefore, we always create a PT_LOAD
3842 // segment to hold the file header and the program headers. This is
3843 // effectively what the GNU linker does, and it is slightly more
3844 // efficient in any case. We try to use the first PT_LOAD segment
3845 // if we can, otherwise we make a new one.
3847 if (first_seg == NULL)
3850 // -n or -N mean that the program is not demand paged and there is
3851 // no need to put the program headers in a PT_LOAD segment.
3852 if (parameters->options().nmagic() || parameters->options().omagic())
3855 size_t sizeof_headers = this->total_header_size(layout);
3857 uint64_t vma = first_seg->vaddr();
3858 uint64_t lma = first_seg->paddr();
3860 uint64_t subtract = this->header_size_adjustment(lma, sizeof_headers);
3862 if ((lma & (abi_pagesize - 1)) >= sizeof_headers)
3864 first_seg->set_addresses(vma - subtract, lma - subtract);
3868 // If there is no room to squeeze in the headers, then punt. The
3869 // resulting executable probably won't run on GNU/Linux, but we
3870 // trust that the user knows what they are doing.
3871 if (lma < subtract || vma < subtract)
3874 // If memory regions have been specified and the address range
3875 // we are about to use is not contained within any region then
3876 // issue a warning message about the segment we are going to
3877 // create. It will be outside of any region and so possibly
3878 // using non-existent or protected memory. We test LMA rather
3879 // than VMA since we assume that the headers will never be
3881 if (this->memory_regions_ != NULL
3882 && !this->block_in_region (NULL, layout, lma - subtract, subtract))
3883 gold_warning(_("creating a segment to contain the file and program"
3884 " headers outside of any MEMORY region"));
3886 Output_segment* load_seg = layout->make_output_segment(elfcpp::PT_LOAD,
3888 load_seg->set_addresses(vma - subtract, lma - subtract);
3893 // Create a PT_NOTE segment for each SHT_NOTE section and a PT_TLS
3894 // segment if there are any SHT_TLS sections.
3897 Script_sections::create_note_and_tls_segments(
3899 const Layout::Section_list* sections)
3901 gold_assert(!this->saw_phdrs_clause());
3903 bool saw_tls = false;
3904 for (Layout::Section_list::const_iterator p = sections->begin();
3905 p != sections->end();
3908 if ((*p)->type() == elfcpp::SHT_NOTE)
3910 elfcpp::Elf_Word seg_flags =
3911 Layout::section_flags_to_segment((*p)->flags());
3912 Output_segment* oseg = layout->make_output_segment(elfcpp::PT_NOTE,
3914 oseg->add_output_section_to_nonload(*p, seg_flags);
3916 // Incorporate any subsequent SHT_NOTE sections, in the
3917 // hopes that the script is sensible.
3918 Layout::Section_list::const_iterator pnext = p + 1;
3919 while (pnext != sections->end()
3920 && (*pnext)->type() == elfcpp::SHT_NOTE)
3922 seg_flags = Layout::section_flags_to_segment((*pnext)->flags());
3923 oseg->add_output_section_to_nonload(*pnext, seg_flags);
3929 if (((*p)->flags() & elfcpp::SHF_TLS) != 0)
3932 gold_error(_("TLS sections are not adjacent"));
3934 elfcpp::Elf_Word seg_flags =
3935 Layout::section_flags_to_segment((*p)->flags());
3936 Output_segment* oseg = layout->make_output_segment(elfcpp::PT_TLS,
3938 oseg->add_output_section_to_nonload(*p, seg_flags);
3940 Layout::Section_list::const_iterator pnext = p + 1;
3941 while (pnext != sections->end()
3942 && ((*pnext)->flags() & elfcpp::SHF_TLS) != 0)
3944 seg_flags = Layout::section_flags_to_segment((*pnext)->flags());
3945 oseg->add_output_section_to_nonload(*pnext, seg_flags);
3953 // If we are making a shared library, and we see a section named
3954 // .interp then put the .interp section in a PT_INTERP segment.
3955 // This is for GNU ld compatibility.
3956 if (strcmp((*p)->name(), ".interp") == 0)
3958 elfcpp::Elf_Word seg_flags =
3959 Layout::section_flags_to_segment((*p)->flags());
3960 Output_segment* oseg = layout->make_output_segment(elfcpp::PT_INTERP,
3962 oseg->add_output_section_to_nonload(*p, seg_flags);
3967 // Add a program header. The PHDRS clause is syntactically distinct
3968 // from the SECTIONS clause, but we implement it with the SECTIONS
3969 // support because PHDRS is useless if there is no SECTIONS clause.
3972 Script_sections::add_phdr(const char* name, size_t namelen, unsigned int type,
3973 bool includes_filehdr, bool includes_phdrs,
3974 bool is_flags_valid, unsigned int flags,
3975 Expression* load_address)
3977 if (this->phdrs_elements_ == NULL)
3978 this->phdrs_elements_ = new Phdrs_elements();
3979 this->phdrs_elements_->push_back(new Phdrs_element(name, namelen, type,
3982 is_flags_valid, flags,
3986 // Return the number of segments we expect to create based on the
3987 // SECTIONS clause. This is used to implement SIZEOF_HEADERS.
3990 Script_sections::expected_segment_count(const Layout* layout) const
3992 if (this->saw_phdrs_clause())
3993 return this->phdrs_elements_->size();
3995 Layout::Section_list sections;
3996 layout->get_allocated_sections(§ions);
3998 // We assume that we will need two PT_LOAD segments.
4001 bool saw_note = false;
4002 bool saw_tls = false;
4003 for (Layout::Section_list::const_iterator p = sections.begin();
4004 p != sections.end();
4007 if ((*p)->type() == elfcpp::SHT_NOTE)
4009 // Assume that all note sections will fit into a single
4017 else if (((*p)->flags() & elfcpp::SHF_TLS) != 0)
4019 // There can only be one PT_TLS segment.
4031 // Create the segments from a PHDRS clause. Return the segment which
4032 // should hold the file header and program headers, if any.
4035 Script_sections::create_segments_from_phdrs_clause(Layout* layout,
4036 uint64_t dot_alignment)
4038 this->attach_sections_using_phdrs_clause(layout);
4039 return this->set_phdrs_clause_addresses(layout, dot_alignment);
4042 // Create the segments from the PHDRS clause, and put the output
4043 // sections in them.
4046 Script_sections::attach_sections_using_phdrs_clause(Layout* layout)
4048 typedef std::map<std::string, Output_segment*> Name_to_segment;
4049 Name_to_segment name_to_segment;
4050 for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
4051 p != this->phdrs_elements_->end();
4053 name_to_segment[(*p)->name()] = (*p)->create_segment(layout);
4055 // Walk through the output sections and attach them to segments.
4056 // Output sections in the script which do not list segments are
4057 // attached to the same set of segments as the immediately preceding
4060 String_list* phdr_names = NULL;
4061 bool load_segments_only = false;
4062 for (Sections_elements::const_iterator p = this->sections_elements_->begin();
4063 p != this->sections_elements_->end();
4067 String_list* old_phdr_names = phdr_names;
4068 Output_section* os = (*p)->allocate_to_segment(&phdr_names, &is_orphan);
4072 elfcpp::Elf_Word seg_flags =
4073 Layout::section_flags_to_segment(os->flags());
4075 if (phdr_names == NULL)
4077 // Don't worry about empty orphan sections.
4078 if (is_orphan && os->current_data_size() > 0)
4079 gold_error(_("allocated section %s not in any segment"),
4082 // To avoid later crashes drop this section into the first
4084 for (Phdrs_elements::const_iterator ppe =
4085 this->phdrs_elements_->begin();
4086 ppe != this->phdrs_elements_->end();
4089 Output_segment* oseg = (*ppe)->segment();
4090 if (oseg->type() == elfcpp::PT_LOAD)
4092 oseg->add_output_section_to_load(layout, os, seg_flags);
4100 // We see a list of segments names. Disable PT_LOAD segment only
4102 if (old_phdr_names != phdr_names)
4103 load_segments_only = false;
4105 // If this is an orphan section--one that was not explicitly
4106 // mentioned in the linker script--then it should not inherit
4107 // any segment type other than PT_LOAD. Otherwise, e.g., the
4108 // PT_INTERP segment will pick up following orphan sections,
4109 // which does not make sense. If this is not an orphan section,
4110 // we trust the linker script.
4113 // Enable PT_LOAD segments only filtering until we see another
4114 // list of segment names.
4115 load_segments_only = true;
4118 bool in_load_segment = false;
4119 for (String_list::const_iterator q = phdr_names->begin();
4120 q != phdr_names->end();
4123 Name_to_segment::const_iterator r = name_to_segment.find(*q);
4124 if (r == name_to_segment.end())
4125 gold_error(_("no segment %s"), q->c_str());
4128 if (load_segments_only
4129 && r->second->type() != elfcpp::PT_LOAD)
4132 if (r->second->type() != elfcpp::PT_LOAD)
4133 r->second->add_output_section_to_nonload(os, seg_flags);
4136 r->second->add_output_section_to_load(layout, os, seg_flags);
4137 if (in_load_segment)
4138 gold_error(_("section in two PT_LOAD segments"));
4139 in_load_segment = true;
4144 if (!in_load_segment)
4145 gold_error(_("allocated section not in any PT_LOAD segment"));
4149 // Set the addresses for segments created from a PHDRS clause. Return
4150 // the segment which should hold the file header and program headers,
4154 Script_sections::set_phdrs_clause_addresses(Layout* layout,
4155 uint64_t dot_alignment)
4157 Output_segment* load_seg = NULL;
4158 for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
4159 p != this->phdrs_elements_->end();
4162 // Note that we have to set the flags after adding the output
4163 // sections to the segment, as adding an output segment can
4164 // change the flags.
4165 (*p)->set_flags_if_valid();
4167 Output_segment* oseg = (*p)->segment();
4169 if (oseg->type() != elfcpp::PT_LOAD)
4171 // The addresses of non-PT_LOAD segments are set from the
4172 // PT_LOAD segments.
4173 if ((*p)->has_load_address())
4174 gold_error(_("may only specify load address for PT_LOAD segment"));
4178 oseg->set_minimum_p_align(dot_alignment);
4180 // The output sections should have addresses from the SECTIONS
4181 // clause. The addresses don't have to be in order, so find the
4182 // one with the lowest load address. Use that to set the
4183 // address of the segment.
4185 Output_section* osec = oseg->section_with_lowest_load_address();
4188 oseg->set_addresses(0, 0);
4192 uint64_t vma = osec->address();
4193 uint64_t lma = osec->has_load_address() ? osec->load_address() : vma;
4195 // Override the load address of the section with the load
4196 // address specified for the segment.
4197 if ((*p)->has_load_address())
4199 if (osec->has_load_address())
4200 gold_warning(_("PHDRS load address overrides "
4201 "section %s load address"),
4204 lma = (*p)->load_address();
4207 bool headers = (*p)->includes_filehdr() && (*p)->includes_phdrs();
4208 if (!headers && ((*p)->includes_filehdr() || (*p)->includes_phdrs()))
4210 // We could support this if we wanted to.
4211 gold_error(_("using only one of FILEHDR and PHDRS is "
4212 "not currently supported"));
4216 size_t sizeof_headers = this->total_header_size(layout);
4217 uint64_t subtract = this->header_size_adjustment(lma,
4219 if (lma >= subtract && vma >= subtract)
4226 gold_error(_("sections loaded on first page without room "
4227 "for file and program headers "
4228 "are not supported"));
4231 if (load_seg != NULL)
4232 gold_error(_("using FILEHDR and PHDRS on more than one "
4233 "PT_LOAD segment is not currently supported"));
4237 oseg->set_addresses(vma, lma);
4243 // Add the file header and segment headers to non-load segments
4244 // specified in the PHDRS clause.
4247 Script_sections::put_headers_in_phdrs(Output_data* file_header,
4248 Output_data* segment_headers)
4250 gold_assert(this->saw_phdrs_clause());
4251 for (Phdrs_elements::iterator p = this->phdrs_elements_->begin();
4252 p != this->phdrs_elements_->end();
4255 if ((*p)->type() != elfcpp::PT_LOAD)
4257 if ((*p)->includes_phdrs())
4258 (*p)->segment()->add_initial_output_data(segment_headers);
4259 if ((*p)->includes_filehdr())
4260 (*p)->segment()->add_initial_output_data(file_header);
4265 // Look for an output section by name and return the address, the load
4266 // address, the alignment, and the size. This is used when an
4267 // expression refers to an output section which was not actually
4268 // created. This returns true if the section was found, false
4272 Script_sections::get_output_section_info(const char* name, uint64_t* address,
4273 uint64_t* load_address,
4274 uint64_t* addralign,
4275 uint64_t* size) const
4277 if (!this->saw_sections_clause_)
4279 for (Sections_elements::const_iterator p = this->sections_elements_->begin();
4280 p != this->sections_elements_->end();
4282 if ((*p)->get_output_section_info(name, address, load_address, addralign,
4288 // Release all Output_segments. This remove all pointers to all
4292 Script_sections::release_segments()
4294 if (this->saw_phdrs_clause())
4296 for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
4297 p != this->phdrs_elements_->end();
4299 (*p)->release_segment();
4303 // Print the SECTIONS clause to F for debugging.
4306 Script_sections::print(FILE* f) const
4308 if (this->phdrs_elements_ != NULL)
4310 fprintf(f, "PHDRS {\n");
4311 for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
4312 p != this->phdrs_elements_->end();
4318 if (this->memory_regions_ != NULL)
4320 fprintf(f, "MEMORY {\n");
4321 for (Memory_regions::const_iterator m = this->memory_regions_->begin();
4322 m != this->memory_regions_->end();
4328 if (!this->saw_sections_clause_)
4331 fprintf(f, "SECTIONS {\n");
4333 for (Sections_elements::const_iterator p = this->sections_elements_->begin();
4334 p != this->sections_elements_->end();
4341 } // End namespace gold.