1 // script-sections.cc -- linker script SECTIONS for gold
3 // Copyright (C) 2008-2015 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
*, bool*)
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*, bool *) 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 section.
1242 // If we do then also indicate whether the section should be KEPT.
1244 match_name(const char* file_name
, const char* section_name
, bool* keep
) 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. If we do then
1397 // KEEP indicates whether the section should survive garbage collection.
1400 Output_section_element_input::match_name(const char* file_name
,
1401 const char* section_name
,
1404 if (!this->match_file_name(file_name
))
1407 *keep
= this->keep_
;
1409 // If there are no section name patterns, then we match.
1410 if (this->input_section_patterns_
.empty())
1413 // See whether we match the section name patterns.
1414 for (Input_section_patterns::const_iterator p
=
1415 this->input_section_patterns_
.begin();
1416 p
!= this->input_section_patterns_
.end();
1419 if (match(section_name
, p
->pattern
.c_str(), p
->pattern_is_wildcard
))
1423 // We didn't match any section names, so we didn't match.
1427 // Information we use to sort the input sections.
1429 class Input_section_info
1432 Input_section_info(const Output_section::Input_section
& input_section
)
1433 : input_section_(input_section
), section_name_(),
1434 size_(0), addralign_(1)
1437 // Return the simple input section.
1438 const Output_section::Input_section
&
1439 input_section() const
1440 { return this->input_section_
; }
1442 // Return the object.
1445 { return this->input_section_
.relobj(); }
1447 // Return the section index.
1450 { return this->input_section_
.shndx(); }
1452 // Return the section name.
1454 section_name() const
1455 { return this->section_name_
; }
1457 // Set the section name.
1459 set_section_name(const std::string name
)
1461 if (is_compressed_debug_section(name
.c_str()))
1462 this->section_name_
= corresponding_uncompressed_section_name(name
);
1464 this->section_name_
= name
;
1467 // Return the section size.
1470 { return this->size_
; }
1472 // Set the section size.
1474 set_size(uint64_t size
)
1475 { this->size_
= size
; }
1477 // Return the address alignment.
1480 { return this->addralign_
; }
1482 // Set the address alignment.
1484 set_addralign(uint64_t addralign
)
1485 { this->addralign_
= addralign
; }
1488 // Input section, can be a relaxed section.
1489 Output_section::Input_section input_section_
;
1490 // Name of the section.
1491 std::string section_name_
;
1494 // Address alignment.
1495 uint64_t addralign_
;
1498 // A class to sort the input sections.
1500 class Input_section_sorter
1503 Input_section_sorter(Sort_wildcard filename_sort
, Sort_wildcard section_sort
)
1504 : filename_sort_(filename_sort
), section_sort_(section_sort
)
1508 operator()(const Input_section_info
&, const Input_section_info
&) const;
1511 Sort_wildcard filename_sort_
;
1512 Sort_wildcard section_sort_
;
1516 Input_section_sorter::operator()(const Input_section_info
& isi1
,
1517 const Input_section_info
& isi2
) const
1519 if (this->section_sort_
== SORT_WILDCARD_BY_NAME
1520 || this->section_sort_
== SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1521 || (this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
1522 && isi1
.addralign() == isi2
.addralign()))
1524 if (isi1
.section_name() != isi2
.section_name())
1525 return isi1
.section_name() < isi2
.section_name();
1527 if (this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT
1528 || this->section_sort_
== SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1529 || this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
)
1531 if (isi1
.addralign() != isi2
.addralign())
1532 return isi1
.addralign() < isi2
.addralign();
1534 if (this->filename_sort_
== SORT_WILDCARD_BY_NAME
)
1536 if (isi1
.relobj()->name() != isi2
.relobj()->name())
1537 return (isi1
.relobj()->name() < isi2
.relobj()->name());
1540 // Otherwise we leave them in the same order.
1544 // Set the section address. Look in INPUT_SECTIONS for sections which
1545 // match this spec, sort them as specified, and add them to the output
1549 Output_section_element_input::set_section_addresses(
1552 Output_section
* output_section
,
1554 uint64_t* dot_value
,
1556 Output_section
** dot_section
,
1558 Input_section_list
* input_sections
)
1560 // We build a list of sections which match each
1561 // Input_section_pattern.
1563 // If none of the patterns specify a sort option, we throw all
1564 // matching input sections into a single bin, in the order we
1565 // find them. Otherwise, we put matching input sections into
1566 // a separate bin for each pattern, and sort each one as
1567 // specified. Thus, an input section spec like this:
1569 // will group all .foo and .bar sections in the order seen,
1572 // will group all .foo sections followed by all .bar sections.
1573 // This matches Gnu ld behavior.
1575 // Things get really weird, though, when you add a sort spec
1576 // on some, but not all, of the patterns, like this:
1577 // *(SORT_BY_NAME(.foo) .bar)
1578 // We do not attempt to match Gnu ld behavior in this case.
1580 typedef std::vector
<std::vector
<Input_section_info
> > Matching_sections
;
1581 size_t input_pattern_count
= this->input_section_patterns_
.size();
1582 bool any_patterns_with_sort
= false;
1583 for (size_t i
= 0; i
< input_pattern_count
; ++i
)
1585 const Input_section_pattern
& isp(this->input_section_patterns_
[i
]);
1586 if (isp
.sort
!= SORT_WILDCARD_NONE
)
1587 any_patterns_with_sort
= true;
1589 if (input_pattern_count
== 0 || !any_patterns_with_sort
)
1590 input_pattern_count
= 1;
1591 Matching_sections
matching_sections(input_pattern_count
);
1593 // Look through the list of sections for this output section. Add
1594 // each one which matches to one of the elements of
1595 // MATCHING_SECTIONS.
1597 Input_section_list::iterator p
= input_sections
->begin();
1598 while (p
!= input_sections
->end())
1600 Relobj
* relobj
= p
->relobj();
1601 unsigned int shndx
= p
->shndx();
1602 Input_section_info
isi(*p
);
1604 // Calling section_name and section_addralign is not very
1607 // Lock the object so that we can get information about the
1608 // section. This is OK since we know we are single-threaded
1611 const Task
* task
= reinterpret_cast<const Task
*>(-1);
1612 Task_lock_obj
<Object
> tl(task
, relobj
);
1614 isi
.set_section_name(relobj
->section_name(shndx
));
1615 if (p
->is_relaxed_input_section())
1617 // We use current data size because relaxed section sizes may not
1618 // have finalized yet.
1619 isi
.set_size(p
->relaxed_input_section()->current_data_size());
1620 isi
.set_addralign(p
->relaxed_input_section()->addralign());
1624 isi
.set_size(relobj
->section_size(shndx
));
1625 isi
.set_addralign(relobj
->section_addralign(shndx
));
1629 if (!this->match_file_name(relobj
->name().c_str()))
1631 else if (this->input_section_patterns_
.empty())
1633 matching_sections
[0].push_back(isi
);
1634 p
= input_sections
->erase(p
);
1639 for (i
= 0; i
< input_pattern_count
; ++i
)
1641 const Input_section_pattern
&
1642 isp(this->input_section_patterns_
[i
]);
1643 if (match(isi
.section_name().c_str(), isp
.pattern
.c_str(),
1644 isp
.pattern_is_wildcard
))
1648 if (i
>= this->input_section_patterns_
.size())
1652 if (!any_patterns_with_sort
)
1654 matching_sections
[i
].push_back(isi
);
1655 p
= input_sections
->erase(p
);
1660 // Look through MATCHING_SECTIONS. Sort each one as specified,
1661 // using a stable sort so that we get the default order when
1662 // sections are otherwise equal. Add each input section to the
1665 uint64_t dot
= *dot_value
;
1666 for (size_t i
= 0; i
< input_pattern_count
; ++i
)
1668 if (matching_sections
[i
].empty())
1671 gold_assert(output_section
!= NULL
);
1673 const Input_section_pattern
& isp(this->input_section_patterns_
[i
]);
1674 if (isp
.sort
!= SORT_WILDCARD_NONE
1675 || this->filename_sort_
!= SORT_WILDCARD_NONE
)
1676 std::stable_sort(matching_sections
[i
].begin(),
1677 matching_sections
[i
].end(),
1678 Input_section_sorter(this->filename_sort_
,
1681 for (std::vector
<Input_section_info
>::const_iterator p
=
1682 matching_sections
[i
].begin();
1683 p
!= matching_sections
[i
].end();
1686 // Override the original address alignment if SUBALIGN is specified
1687 // and is greater than the original alignment. We need to make a
1688 // copy of the input section to modify the alignment.
1689 Output_section::Input_section
sis(p
->input_section());
1691 uint64_t this_subalign
= sis
.addralign();
1692 if (!sis
.is_input_section())
1693 sis
.output_section_data()->finalize_data_size();
1694 uint64_t data_size
= sis
.data_size();
1695 if (this_subalign
< subalign
)
1697 this_subalign
= subalign
;
1698 sis
.set_addralign(subalign
);
1701 uint64_t address
= align_address(dot
, this_subalign
);
1703 if (address
> dot
&& !fill
->empty())
1705 section_size_type length
=
1706 convert_to_section_size_type(address
- dot
);
1707 std::string this_fill
= this->get_fill_string(fill
, length
);
1708 Output_section_data
* posd
= new Output_data_const(this_fill
, 0);
1709 output_section
->add_output_section_data(posd
);
1710 layout
->new_output_section_data_from_script(posd
);
1713 output_section
->add_script_input_section(sis
);
1714 dot
= address
+ data_size
;
1718 // An SHF_TLS/SHT_NOBITS section does not take up any
1720 if (output_section
== NULL
1721 || (output_section
->flags() & elfcpp::SHF_TLS
) == 0
1722 || output_section
->type() != elfcpp::SHT_NOBITS
)
1725 this->final_dot_value_
= *dot_value
;
1726 this->final_dot_section_
= *dot_section
;
1729 // Print for debugging.
1732 Output_section_element_input::print(FILE* f
) const
1737 fprintf(f
, "KEEP(");
1739 if (!this->filename_pattern_
.empty())
1741 bool need_close_paren
= false;
1742 switch (this->filename_sort_
)
1744 case SORT_WILDCARD_NONE
:
1746 case SORT_WILDCARD_BY_NAME
:
1747 fprintf(f
, "SORT_BY_NAME(");
1748 need_close_paren
= true;
1754 fprintf(f
, "%s", this->filename_pattern_
.c_str());
1756 if (need_close_paren
)
1760 if (!this->input_section_patterns_
.empty()
1761 || !this->filename_exclusions_
.empty())
1765 bool need_space
= false;
1766 if (!this->filename_exclusions_
.empty())
1768 fprintf(f
, "EXCLUDE_FILE(");
1769 bool need_comma
= false;
1770 for (Filename_exclusions::const_iterator p
=
1771 this->filename_exclusions_
.begin();
1772 p
!= this->filename_exclusions_
.end();
1777 fprintf(f
, "%s", p
->first
.c_str());
1784 for (Input_section_patterns::const_iterator p
=
1785 this->input_section_patterns_
.begin();
1786 p
!= this->input_section_patterns_
.end();
1792 int close_parens
= 0;
1795 case SORT_WILDCARD_NONE
:
1797 case SORT_WILDCARD_BY_NAME
:
1798 fprintf(f
, "SORT_BY_NAME(");
1801 case SORT_WILDCARD_BY_ALIGNMENT
:
1802 fprintf(f
, "SORT_BY_ALIGNMENT(");
1805 case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
:
1806 fprintf(f
, "SORT_BY_NAME(SORT_BY_ALIGNMENT(");
1809 case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
:
1810 fprintf(f
, "SORT_BY_ALIGNMENT(SORT_BY_NAME(");
1817 fprintf(f
, "%s", p
->pattern
.c_str());
1819 for (int i
= 0; i
< close_parens
; ++i
)
1834 // An output section.
1836 class Output_section_definition
: public Sections_element
1839 typedef Output_section_element::Input_section_list Input_section_list
;
1841 Output_section_definition(const char* name
, size_t namelen
,
1842 const Parser_output_section_header
* header
);
1844 // Finish the output section with the information in the trailer.
1846 finish(const Parser_output_section_trailer
* trailer
);
1848 // Add a symbol to be defined.
1850 add_symbol_assignment(const char* name
, size_t length
, Expression
* value
,
1851 bool provide
, bool hidden
);
1853 // Add an assignment to the special dot symbol.
1855 add_dot_assignment(Expression
* value
);
1857 // Add an assertion.
1859 add_assertion(Expression
* check
, const char* message
, size_t messagelen
);
1861 // Add a data item to the current output section.
1863 add_data(int size
, bool is_signed
, Expression
* val
);
1865 // Add a setting for the fill value.
1867 add_fill(Expression
* val
);
1869 // Add an input section specification.
1871 add_input_section(const Input_section_spec
* spec
, bool keep
);
1873 // Return whether the output section is relro.
1876 { return this->is_relro_
; }
1878 // Record that the output section is relro.
1881 { this->is_relro_
= true; }
1883 // Create any required output sections.
1885 create_sections(Layout
*);
1887 // Add any symbols being defined to the symbol table.
1889 add_symbols_to_table(Symbol_table
* symtab
);
1891 // Finalize symbols and check assertions.
1893 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*);
1895 // Return the output section name to use for an input file name and
1898 output_section_name(const char* file_name
, const char* section_name
,
1899 Output_section
***, Script_sections::Section_type
*,
1902 // Initialize OSP with an output section.
1904 orphan_section_init(Orphan_section_placement
* osp
,
1905 Script_sections::Elements_iterator p
)
1906 { osp
->output_section_init(this->name_
, this->output_section_
, p
); }
1908 // Set the section address.
1910 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
,
1911 uint64_t* dot_value
, uint64_t*,
1912 uint64_t* load_address
);
1914 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
1915 // this section is constrained, and the input sections do not match,
1916 // return the constraint, and set *POSD.
1918 check_constraint(Output_section_definition
** posd
);
1920 // See if this is the alternate output section for a constrained
1921 // output section. If it is, transfer the Output_section and return
1922 // true. Otherwise return false.
1924 alternate_constraint(Output_section_definition
*, Section_constraint
);
1926 // Get the list of segments to use for an allocated section when
1927 // using a PHDRS clause.
1929 allocate_to_segment(String_list
** phdrs_list
, bool* orphan
);
1931 // Look for an output section by name and return the address, the
1932 // load address, the alignment, and the size. This is used when an
1933 // expression refers to an output section which was not actually
1934 // created. This returns true if the section was found, false
1937 get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
1940 // Return the associated Output_section if there is one.
1942 get_output_section() const
1943 { return this->output_section_
; }
1945 // Print the contents to the FILE. This is for debugging.
1949 // Return the output section type if specified or Script_sections::ST_NONE.
1950 Script_sections::Section_type
1951 section_type() const;
1953 // Store the memory region to use.
1955 set_memory_region(Memory_region
*, bool set_vma
);
1958 set_section_vma(Expression
* address
)
1959 { this->address_
= address
; }
1962 set_section_lma(Expression
* address
)
1963 { this->load_address_
= address
; }
1966 get_section_name() const
1967 { return this->name_
; }
1971 script_section_type_name(Script_section_type
);
1973 typedef std::vector
<Output_section_element
*> Output_section_elements
;
1975 // The output section name.
1977 // The address. This may be NULL.
1978 Expression
* address_
;
1979 // The load address. This may be NULL.
1980 Expression
* load_address_
;
1981 // The alignment. This may be NULL.
1983 // The input section alignment. This may be NULL.
1984 Expression
* subalign_
;
1985 // The constraint, if any.
1986 Section_constraint constraint_
;
1987 // The fill value. This may be NULL.
1989 // The list of segments this section should go into. This may be
1991 String_list
* phdrs_
;
1992 // The list of elements defining the section.
1993 Output_section_elements elements_
;
1994 // The Output_section created for this definition. This will be
1995 // NULL if none was created.
1996 Output_section
* output_section_
;
1997 // The address after it has been evaluated.
1998 uint64_t evaluated_address_
;
1999 // The load address after it has been evaluated.
2000 uint64_t evaluated_load_address_
;
2001 // The alignment after it has been evaluated.
2002 uint64_t evaluated_addralign_
;
2003 // The output section is relro.
2005 // The output section type if specified.
2006 enum Script_section_type script_section_type_
;
2011 Output_section_definition::Output_section_definition(
2014 const Parser_output_section_header
* header
)
2015 : name_(name
, namelen
),
2016 address_(header
->address
),
2017 load_address_(header
->load_address
),
2018 align_(header
->align
),
2019 subalign_(header
->subalign
),
2020 constraint_(header
->constraint
),
2024 output_section_(NULL
),
2025 evaluated_address_(0),
2026 evaluated_load_address_(0),
2027 evaluated_addralign_(0),
2029 script_section_type_(header
->section_type
)
2033 // Finish an output section.
2036 Output_section_definition::finish(const Parser_output_section_trailer
* trailer
)
2038 this->fill_
= trailer
->fill
;
2039 this->phdrs_
= trailer
->phdrs
;
2042 // Add a symbol to be defined.
2045 Output_section_definition::add_symbol_assignment(const char* name
,
2051 Output_section_element
* p
= new Output_section_element_assignment(name
,
2056 this->elements_
.push_back(p
);
2059 // Add an assignment to the special dot symbol.
2062 Output_section_definition::add_dot_assignment(Expression
* value
)
2064 Output_section_element
* p
= new Output_section_element_dot_assignment(value
);
2065 this->elements_
.push_back(p
);
2068 // Add an assertion.
2071 Output_section_definition::add_assertion(Expression
* check
,
2072 const char* message
,
2075 Output_section_element
* p
= new Output_section_element_assertion(check
,
2078 this->elements_
.push_back(p
);
2081 // Add a data item to the current output section.
2084 Output_section_definition::add_data(int size
, bool is_signed
, Expression
* val
)
2086 Output_section_element
* p
= new Output_section_element_data(size
, is_signed
,
2088 this->elements_
.push_back(p
);
2091 // Add a setting for the fill value.
2094 Output_section_definition::add_fill(Expression
* val
)
2096 Output_section_element
* p
= new Output_section_element_fill(val
);
2097 this->elements_
.push_back(p
);
2100 // Add an input section specification.
2103 Output_section_definition::add_input_section(const Input_section_spec
* spec
,
2106 Output_section_element
* p
= new Output_section_element_input(spec
, keep
);
2107 this->elements_
.push_back(p
);
2110 // Create any required output sections. We need an output section if
2111 // there is a data statement here.
2114 Output_section_definition::create_sections(Layout
* layout
)
2116 if (this->output_section_
!= NULL
)
2118 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2119 p
!= this->elements_
.end();
2122 if ((*p
)->needs_output_section())
2124 const char* name
= this->name_
.c_str();
2125 this->output_section_
=
2126 layout
->make_output_section_for_script(name
, this->section_type());
2132 // Add any symbols being defined to the symbol table.
2135 Output_section_definition::add_symbols_to_table(Symbol_table
* symtab
)
2137 for (Output_section_elements::iterator p
= this->elements_
.begin();
2138 p
!= this->elements_
.end();
2140 (*p
)->add_symbols_to_table(symtab
);
2143 // Finalize symbols and check assertions.
2146 Output_section_definition::finalize_symbols(Symbol_table
* symtab
,
2147 const Layout
* layout
,
2148 uint64_t* dot_value
)
2150 if (this->output_section_
!= NULL
)
2151 *dot_value
= this->output_section_
->address();
2154 uint64_t address
= *dot_value
;
2155 if (this->address_
!= NULL
)
2157 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2161 if (this->align_
!= NULL
)
2163 uint64_t align
= this->align_
->eval_with_dot(symtab
, layout
, true,
2166 address
= align_address(address
, align
);
2168 *dot_value
= address
;
2171 Output_section
* dot_section
= this->output_section_
;
2172 for (Output_section_elements::iterator p
= this->elements_
.begin();
2173 p
!= this->elements_
.end();
2175 (*p
)->finalize_symbols(symtab
, layout
, dot_value
, &dot_section
);
2178 // Return the output section name to use for an input section name.
2181 Output_section_definition::output_section_name(
2182 const char* file_name
,
2183 const char* section_name
,
2184 Output_section
*** slot
,
2185 Script_sections::Section_type
* psection_type
,
2188 // Ask each element whether it matches NAME.
2189 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2190 p
!= this->elements_
.end();
2193 if ((*p
)->match_name(file_name
, section_name
, keep
))
2195 // We found a match for NAME, which means that it should go
2196 // into this output section.
2197 *slot
= &this->output_section_
;
2198 *psection_type
= this->section_type();
2199 return this->name_
.c_str();
2203 // We don't know about this section name.
2207 // Return true if memory from START to START + LENGTH is contained
2208 // within a memory region.
2211 Script_sections::block_in_region(Symbol_table
* symtab
, Layout
* layout
,
2212 uint64_t start
, uint64_t length
) const
2214 if (this->memory_regions_
== NULL
)
2217 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2218 mr
!= this->memory_regions_
->end();
2221 uint64_t s
= (*mr
)->start_address()->eval(symtab
, layout
, false);
2222 uint64_t l
= (*mr
)->length()->eval(symtab
, layout
, false);
2225 && (s
+ l
) >= (start
+ length
))
2232 // Find a memory region that should be used by a given output SECTION.
2233 // If provided set PREVIOUS_SECTION_RETURN to point to the last section
2234 // that used the return memory region.
2237 Script_sections::find_memory_region(
2238 Output_section_definition
* section
,
2239 bool find_vma_region
,
2240 Output_section_definition
** previous_section_return
)
2242 if (previous_section_return
!= NULL
)
2243 * previous_section_return
= NULL
;
2245 // Walk the memory regions specified in this script, if any.
2246 if (this->memory_regions_
== NULL
)
2249 // The /DISCARD/ section never gets assigned to any region.
2250 if (section
->get_section_name() == "/DISCARD/")
2253 Memory_region
* first_match
= NULL
;
2255 // First check to see if a region has been assigned to this section.
2256 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2257 mr
!= this->memory_regions_
->end();
2260 if (find_vma_region
)
2262 for (Memory_region::Section_list::const_iterator s
=
2263 (*mr
)->get_vma_section_list_start();
2264 s
!= (*mr
)->get_vma_section_list_end();
2266 if ((*s
) == section
)
2268 (*mr
)->set_last_section(section
);
2274 for (Memory_region::Section_list::const_iterator s
=
2275 (*mr
)->get_lma_section_list_start();
2276 s
!= (*mr
)->get_lma_section_list_end();
2278 if ((*s
) == section
)
2280 (*mr
)->set_last_section(section
);
2285 // Make a note of the first memory region whose attributes
2286 // are compatible with the section. If we do not find an
2287 // explicit region assignment, then we will return this region.
2288 Output_section
* out_sec
= section
->get_output_section();
2289 if (first_match
== NULL
2291 && (*mr
)->attributes_compatible(out_sec
->flags(),
2296 // With LMA computations, if an explicit region has not been specified then
2297 // we will want to set the difference between the VMA and the LMA of the
2298 // section were searching for to be the same as the difference between the
2299 // VMA and LMA of the last section to be added to first matched region.
2300 // Hence, if it was asked for, we return a pointer to the last section
2301 // known to be used by the first matched region.
2302 if (first_match
!= NULL
2303 && previous_section_return
!= NULL
)
2304 *previous_section_return
= first_match
->get_last_section();
2309 // Set the section address. Note that the OUTPUT_SECTION_ field will
2310 // be NULL if no input sections were mapped to this output section.
2311 // We still have to adjust dot and process symbol assignments.
2314 Output_section_definition::set_section_addresses(Symbol_table
* symtab
,
2316 uint64_t* dot_value
,
2317 uint64_t* dot_alignment
,
2318 uint64_t* load_address
)
2320 Memory_region
* vma_region
= NULL
;
2321 Memory_region
* lma_region
= NULL
;
2322 Script_sections
* script_sections
=
2323 layout
->script_options()->script_sections();
2325 uint64_t old_dot_value
= *dot_value
;
2326 uint64_t old_load_address
= *load_address
;
2328 // If input section sorting is requested via --section-ordering-file or
2329 // linker plugins, then do it here. This is important because we want
2330 // any sorting specified in the linker scripts, which will be done after
2331 // this, to take precedence. The final order of input sections is then
2332 // guaranteed to be according to the linker script specification.
2333 if (this->output_section_
!= NULL
2334 && this->output_section_
->input_section_order_specified())
2335 this->output_section_
->sort_attached_input_sections();
2337 // Decide the start address for the section. The algorithm is:
2338 // 1) If an address has been specified in a linker script, use that.
2339 // 2) Otherwise if a memory region has been specified for the section,
2340 // use the next free address in the region.
2341 // 3) Otherwise if memory regions have been specified find the first
2342 // region whose attributes are compatible with this section and
2343 // install it into that region.
2344 // 4) Otherwise use the current location counter.
2346 if (this->output_section_
!= NULL
2347 // Check for --section-start.
2348 && parameters
->options().section_start(this->output_section_
->name(),
2351 else if (this->address_
== NULL
)
2353 vma_region
= script_sections
->find_memory_region(this, true, NULL
);
2355 if (vma_region
!= NULL
)
2356 address
= vma_region
->get_current_address()->eval(symtab
, layout
,
2359 address
= *dot_value
;
2362 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2363 *dot_value
, NULL
, NULL
,
2364 dot_alignment
, false);
2366 if (this->align_
== NULL
)
2368 if (this->output_section_
== NULL
)
2371 align
= this->output_section_
->addralign();
2375 Output_section
* align_section
;
2376 align
= this->align_
->eval_with_dot(symtab
, layout
, true, *dot_value
,
2377 NULL
, &align_section
, NULL
, false);
2378 if (align_section
!= NULL
)
2379 gold_warning(_("alignment of section %s is not absolute"),
2380 this->name_
.c_str());
2381 if (this->output_section_
!= NULL
)
2382 this->output_section_
->set_addralign(align
);
2385 address
= align_address(address
, align
);
2387 uint64_t start_address
= address
;
2389 *dot_value
= address
;
2391 // Except for NOLOAD sections, the address of non-SHF_ALLOC sections is
2392 // forced to zero, regardless of what the linker script wants.
2393 if (this->output_section_
!= NULL
2394 && ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) != 0
2395 || this->output_section_
->is_noload()))
2396 this->output_section_
->set_address(address
);
2398 this->evaluated_address_
= address
;
2399 this->evaluated_addralign_
= align
;
2403 if (this->load_address_
== NULL
)
2405 Output_section_definition
* previous_section
;
2407 // Determine if an LMA region has been set for this section.
2408 lma_region
= script_sections
->find_memory_region(this, false,
2411 if (lma_region
!= NULL
)
2413 if (previous_section
== NULL
)
2414 // The LMA address was explicitly set to the given region.
2415 laddr
= lma_region
->get_current_address()->eval(symtab
, layout
,
2419 // We are not going to use the discovered lma_region, so
2420 // make sure that we do not update it in the code below.
2423 if (this->address_
!= NULL
|| previous_section
== this)
2425 // Either an explicit VMA address has been set, or an
2426 // explicit VMA region has been set, so set the LMA equal to
2432 // The LMA address was not explicitly or implicitly set.
2434 // We have been given the first memory region that is
2435 // compatible with the current section and a pointer to the
2436 // last section to use this region. Set the LMA of this
2437 // section so that the difference between its' VMA and LMA
2438 // is the same as the difference between the VMA and LMA of
2439 // the last section in the given region.
2440 laddr
= address
+ (previous_section
->evaluated_load_address_
2441 - previous_section
->evaluated_address_
);
2445 if (this->output_section_
!= NULL
)
2446 this->output_section_
->set_load_address(laddr
);
2450 // Do not set the load address of the output section, if one exists.
2451 // This allows future sections to determine what the load address
2452 // should be. If none is ever set, it will default to being the
2453 // same as the vma address.
2459 laddr
= this->load_address_
->eval_with_dot(symtab
, layout
, true,
2461 this->output_section_
,
2463 if (this->output_section_
!= NULL
)
2464 this->output_section_
->set_load_address(laddr
);
2467 this->evaluated_load_address_
= laddr
;
2470 if (this->subalign_
== NULL
)
2474 Output_section
* subalign_section
;
2475 subalign
= this->subalign_
->eval_with_dot(symtab
, layout
, true,
2477 &subalign_section
, NULL
,
2479 if (subalign_section
!= NULL
)
2480 gold_warning(_("subalign of section %s is not absolute"),
2481 this->name_
.c_str());
2485 if (this->fill_
!= NULL
)
2487 // FIXME: The GNU linker supports fill values of arbitrary
2489 Output_section
* fill_section
;
2490 uint64_t fill_val
= this->fill_
->eval_with_dot(symtab
, layout
, true,
2492 NULL
, &fill_section
,
2494 if (fill_section
!= NULL
)
2495 gold_warning(_("fill of section %s is not absolute"),
2496 this->name_
.c_str());
2497 unsigned char fill_buff
[4];
2498 elfcpp::Swap_unaligned
<32, true>::writeval(fill_buff
, fill_val
);
2499 fill
.assign(reinterpret_cast<char*>(fill_buff
), 4);
2502 Input_section_list input_sections
;
2503 if (this->output_section_
!= NULL
)
2505 // Get the list of input sections attached to this output
2506 // section. This will leave the output section with only
2507 // Output_section_data entries.
2508 address
+= this->output_section_
->get_input_sections(address
,
2511 *dot_value
= address
;
2514 Output_section
* dot_section
= this->output_section_
;
2515 for (Output_section_elements::iterator p
= this->elements_
.begin();
2516 p
!= this->elements_
.end();
2518 (*p
)->set_section_addresses(symtab
, layout
, this->output_section_
,
2519 subalign
, dot_value
, dot_alignment
,
2520 &dot_section
, &fill
, &input_sections
);
2522 gold_assert(input_sections
.empty());
2524 if (vma_region
!= NULL
)
2526 // Update the VMA region being used by the section now that we know how
2527 // big it is. Use the current address in the region, rather than
2528 // start_address because that might have been aligned upwards and we
2529 // need to allow for the padding.
2530 Expression
* addr
= vma_region
->get_current_address();
2531 uint64_t size
= *dot_value
- addr
->eval(symtab
, layout
, false);
2533 vma_region
->increment_offset(this->get_section_name(), size
,
2537 // If the LMA region is different from the VMA region, then increment the
2538 // offset there as well. Note that we use the same "dot_value -
2539 // start_address" formula that is used in the load_address assignment below.
2540 if (lma_region
!= NULL
&& lma_region
!= vma_region
)
2541 lma_region
->increment_offset(this->get_section_name(),
2542 *dot_value
- start_address
,
2545 // Compute the load address for the following section.
2546 if (this->output_section_
== NULL
)
2547 *load_address
= *dot_value
;
2548 else if (this->load_address_
== NULL
)
2550 if (lma_region
== NULL
)
2551 *load_address
= *dot_value
;
2554 lma_region
->get_current_address()->eval(symtab
, layout
, false);
2557 *load_address
= (this->output_section_
->load_address()
2558 + (*dot_value
- start_address
));
2560 if (this->output_section_
!= NULL
)
2562 if (this->is_relro_
)
2563 this->output_section_
->set_is_relro();
2565 this->output_section_
->clear_is_relro();
2567 // If this is a NOLOAD section, keep dot and load address unchanged.
2568 if (this->output_section_
->is_noload())
2570 *dot_value
= old_dot_value
;
2571 *load_address
= old_load_address
;
2576 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
2577 // this section is constrained, and the input sections do not match,
2578 // return the constraint, and set *POSD.
2581 Output_section_definition::check_constraint(Output_section_definition
** posd
)
2583 switch (this->constraint_
)
2585 case CONSTRAINT_NONE
:
2586 return CONSTRAINT_NONE
;
2588 case CONSTRAINT_ONLY_IF_RO
:
2589 if (this->output_section_
!= NULL
2590 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) != 0)
2593 return CONSTRAINT_ONLY_IF_RO
;
2595 return CONSTRAINT_NONE
;
2597 case CONSTRAINT_ONLY_IF_RW
:
2598 if (this->output_section_
!= NULL
2599 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) == 0)
2602 return CONSTRAINT_ONLY_IF_RW
;
2604 return CONSTRAINT_NONE
;
2606 case CONSTRAINT_SPECIAL
:
2607 if (this->output_section_
!= NULL
)
2608 gold_error(_("SPECIAL constraints are not implemented"));
2609 return CONSTRAINT_NONE
;
2616 // See if this is the alternate output section for a constrained
2617 // output section. If it is, transfer the Output_section and return
2618 // true. Otherwise return false.
2621 Output_section_definition::alternate_constraint(
2622 Output_section_definition
* posd
,
2623 Section_constraint constraint
)
2625 if (this->name_
!= posd
->name_
)
2630 case CONSTRAINT_ONLY_IF_RO
:
2631 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RW
)
2635 case CONSTRAINT_ONLY_IF_RW
:
2636 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RO
)
2644 // We have found the alternate constraint. We just need to move
2645 // over the Output_section. When constraints are used properly,
2646 // THIS should not have an output_section pointer, as all the input
2647 // sections should have matched the other definition.
2649 if (this->output_section_
!= NULL
)
2650 gold_error(_("mismatched definition for constrained sections"));
2652 this->output_section_
= posd
->output_section_
;
2653 posd
->output_section_
= NULL
;
2655 if (this->is_relro_
)
2656 this->output_section_
->set_is_relro();
2658 this->output_section_
->clear_is_relro();
2663 // Get the list of segments to use for an allocated section when using
2667 Output_section_definition::allocate_to_segment(String_list
** phdrs_list
,
2670 // Update phdrs_list even if we don't have an output section. It
2671 // might be used by the following sections.
2672 if (this->phdrs_
!= NULL
)
2673 *phdrs_list
= this->phdrs_
;
2675 if (this->output_section_
== NULL
)
2677 if ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) == 0)
2680 return this->output_section_
;
2683 // Look for an output section by name and return the address, the load
2684 // address, the alignment, and the size. This is used when an
2685 // expression refers to an output section which was not actually
2686 // created. This returns true if the section was found, false
2690 Output_section_definition::get_output_section_info(const char* name
,
2692 uint64_t* load_address
,
2693 uint64_t* addralign
,
2694 uint64_t* size
) const
2696 if (this->name_
!= name
)
2699 if (this->output_section_
!= NULL
)
2701 *address
= this->output_section_
->address();
2702 if (this->output_section_
->has_load_address())
2703 *load_address
= this->output_section_
->load_address();
2705 *load_address
= *address
;
2706 *addralign
= this->output_section_
->addralign();
2707 *size
= this->output_section_
->current_data_size();
2711 *address
= this->evaluated_address_
;
2712 *load_address
= this->evaluated_load_address_
;
2713 *addralign
= this->evaluated_addralign_
;
2720 // Print for debugging.
2723 Output_section_definition::print(FILE* f
) const
2725 fprintf(f
, " %s ", this->name_
.c_str());
2727 if (this->address_
!= NULL
)
2729 this->address_
->print(f
);
2733 if (this->script_section_type_
!= SCRIPT_SECTION_TYPE_NONE
)
2735 this->script_section_type_name(this->script_section_type_
));
2739 if (this->load_address_
!= NULL
)
2742 this->load_address_
->print(f
);
2746 if (this->align_
!= NULL
)
2748 fprintf(f
, "ALIGN(");
2749 this->align_
->print(f
);
2753 if (this->subalign_
!= NULL
)
2755 fprintf(f
, "SUBALIGN(");
2756 this->subalign_
->print(f
);
2762 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2763 p
!= this->elements_
.end();
2769 if (this->fill_
!= NULL
)
2772 this->fill_
->print(f
);
2775 if (this->phdrs_
!= NULL
)
2777 for (String_list::const_iterator p
= this->phdrs_
->begin();
2778 p
!= this->phdrs_
->end();
2780 fprintf(f
, " :%s", p
->c_str());
2786 Script_sections::Section_type
2787 Output_section_definition::section_type() const
2789 switch (this->script_section_type_
)
2791 case SCRIPT_SECTION_TYPE_NONE
:
2792 return Script_sections::ST_NONE
;
2793 case SCRIPT_SECTION_TYPE_NOLOAD
:
2794 return Script_sections::ST_NOLOAD
;
2795 case SCRIPT_SECTION_TYPE_COPY
:
2796 case SCRIPT_SECTION_TYPE_DSECT
:
2797 case SCRIPT_SECTION_TYPE_INFO
:
2798 case SCRIPT_SECTION_TYPE_OVERLAY
:
2799 // There are not really support so we treat them as ST_NONE. The
2800 // parse should have issued errors for them already.
2801 return Script_sections::ST_NONE
;
2807 // Return the name of a script section type.
2810 Output_section_definition::script_section_type_name(
2811 Script_section_type script_section_type
)
2813 switch (script_section_type
)
2815 case SCRIPT_SECTION_TYPE_NONE
:
2817 case SCRIPT_SECTION_TYPE_NOLOAD
:
2819 case SCRIPT_SECTION_TYPE_DSECT
:
2821 case SCRIPT_SECTION_TYPE_COPY
:
2823 case SCRIPT_SECTION_TYPE_INFO
:
2825 case SCRIPT_SECTION_TYPE_OVERLAY
:
2833 Output_section_definition::set_memory_region(Memory_region
* mr
, bool set_vma
)
2835 gold_assert(mr
!= NULL
);
2836 // Add the current section to the specified region's list.
2837 mr
->add_section(this, set_vma
);
2840 // An output section created to hold orphaned input sections. These
2841 // do not actually appear in linker scripts. However, for convenience
2842 // when setting the output section addresses, we put a marker to these
2843 // sections in the appropriate place in the list of SECTIONS elements.
2845 class Orphan_output_section
: public Sections_element
2848 Orphan_output_section(Output_section
* os
)
2852 // Return whether the orphan output section is relro. We can just
2853 // check the output section because we always set the flag, if
2854 // needed, just after we create the Orphan_output_section.
2857 { return this->os_
->is_relro(); }
2859 // Initialize OSP with an output section. This should have been
2862 orphan_section_init(Orphan_section_placement
*,
2863 Script_sections::Elements_iterator
)
2864 { gold_unreachable(); }
2866 // Set section addresses.
2868 set_section_addresses(Symbol_table
*, Layout
*, uint64_t*, uint64_t*,
2871 // Get the list of segments to use for an allocated section when
2872 // using a PHDRS clause.
2874 allocate_to_segment(String_list
**, bool*);
2876 // Return the associated Output_section.
2878 get_output_section() const
2879 { return this->os_
; }
2881 // Print for debugging.
2883 print(FILE* f
) const
2885 fprintf(f
, " marker for orphaned output section %s\n",
2890 Output_section
* os_
;
2893 // Set section addresses.
2896 Orphan_output_section::set_section_addresses(Symbol_table
*, Layout
*,
2897 uint64_t* dot_value
,
2899 uint64_t* load_address
)
2901 typedef std::list
<Output_section::Input_section
> Input_section_list
;
2903 bool have_load_address
= *load_address
!= *dot_value
;
2905 uint64_t address
= *dot_value
;
2906 address
= align_address(address
, this->os_
->addralign());
2908 // If input section sorting is requested via --section-ordering-file or
2909 // linker plugins, then do it here. This is important because we want
2910 // any sorting specified in the linker scripts, which will be done after
2911 // this, to take precedence. The final order of input sections is then
2912 // guaranteed to be according to the linker script specification.
2913 if (this->os_
!= NULL
2914 && this->os_
->input_section_order_specified())
2915 this->os_
->sort_attached_input_sections();
2917 // For a relocatable link, all orphan sections are put at
2918 // address 0. In general we expect all sections to be at
2919 // address 0 for a relocatable link, but we permit the linker
2920 // script to override that for specific output sections.
2921 if (parameters
->options().relocatable())
2925 have_load_address
= false;
2928 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) != 0)
2930 this->os_
->set_address(address
);
2931 if (have_load_address
)
2932 this->os_
->set_load_address(align_address(*load_address
,
2933 this->os_
->addralign()));
2936 Input_section_list input_sections
;
2937 address
+= this->os_
->get_input_sections(address
, "", &input_sections
);
2939 for (Input_section_list::iterator p
= input_sections
.begin();
2940 p
!= input_sections
.end();
2943 uint64_t addralign
= p
->addralign();
2944 if (!p
->is_input_section())
2945 p
->output_section_data()->finalize_data_size();
2946 uint64_t size
= p
->data_size();
2947 address
= align_address(address
, addralign
);
2948 this->os_
->add_script_input_section(*p
);
2952 if (parameters
->options().relocatable())
2954 // For a relocatable link, reset DOT_VALUE to 0.
2958 else if (this->os_
== NULL
2959 || (this->os_
->flags() & elfcpp::SHF_TLS
) == 0
2960 || this->os_
->type() != elfcpp::SHT_NOBITS
)
2962 // An SHF_TLS/SHT_NOBITS section does not take up any address space.
2963 if (!have_load_address
)
2964 *load_address
= address
;
2966 *load_address
+= address
- *dot_value
;
2968 *dot_value
= address
;
2972 // Get the list of segments to use for an allocated section when using
2973 // a PHDRS clause. If this is an allocated section, return the
2974 // Output_section. We don't change the list of segments.
2977 Orphan_output_section::allocate_to_segment(String_list
**, bool* orphan
)
2979 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) == 0)
2985 // Class Phdrs_element. A program header from a PHDRS clause.
2990 Phdrs_element(const char* name
, size_t namelen
, unsigned int type
,
2991 bool includes_filehdr
, bool includes_phdrs
,
2992 bool is_flags_valid
, unsigned int flags
,
2993 Expression
* load_address
)
2994 : name_(name
, namelen
), type_(type
), includes_filehdr_(includes_filehdr
),
2995 includes_phdrs_(includes_phdrs
), is_flags_valid_(is_flags_valid
),
2996 flags_(flags
), load_address_(load_address
), load_address_value_(0),
3000 // Return the name of this segment.
3003 { return this->name_
; }
3005 // Return the type of the segment.
3008 { return this->type_
; }
3010 // Whether to include the file header.
3012 includes_filehdr() const
3013 { return this->includes_filehdr_
; }
3015 // Whether to include the program headers.
3017 includes_phdrs() const
3018 { return this->includes_phdrs_
; }
3020 // Return whether there is a load address.
3022 has_load_address() const
3023 { return this->load_address_
!= NULL
; }
3025 // Evaluate the load address expression if there is one.
3027 eval_load_address(Symbol_table
* symtab
, Layout
* layout
)
3029 if (this->load_address_
!= NULL
)
3030 this->load_address_value_
= this->load_address_
->eval(symtab
, layout
,
3034 // Return the load address.
3036 load_address() const
3038 gold_assert(this->load_address_
!= NULL
);
3039 return this->load_address_value_
;
3042 // Create the segment.
3044 create_segment(Layout
* layout
)
3046 this->segment_
= layout
->make_output_segment(this->type_
, this->flags_
);
3047 return this->segment_
;
3050 // Return the segment.
3053 { return this->segment_
; }
3055 // Release the segment.
3058 { this->segment_
= NULL
; }
3060 // Set the segment flags if appropriate.
3062 set_flags_if_valid()
3064 if (this->is_flags_valid_
)
3065 this->segment_
->set_flags(this->flags_
);
3068 // Print for debugging.
3073 // The name used in the script.
3075 // The type of the segment (PT_LOAD, etc.).
3077 // Whether this segment includes the file header.
3078 bool includes_filehdr_
;
3079 // Whether this segment includes the section headers.
3080 bool includes_phdrs_
;
3081 // Whether the flags were explicitly specified.
3082 bool is_flags_valid_
;
3083 // The flags for this segment (PF_R, etc.) if specified.
3084 unsigned int flags_
;
3085 // The expression for the load address for this segment. This may
3087 Expression
* load_address_
;
3088 // The actual load address from evaluating the expression.
3089 uint64_t load_address_value_
;
3090 // The segment itself.
3091 Output_segment
* segment_
;
3094 // Print for debugging.
3097 Phdrs_element::print(FILE* f
) const
3099 fprintf(f
, " %s 0x%x", this->name_
.c_str(), this->type_
);
3100 if (this->includes_filehdr_
)
3101 fprintf(f
, " FILEHDR");
3102 if (this->includes_phdrs_
)
3103 fprintf(f
, " PHDRS");
3104 if (this->is_flags_valid_
)
3105 fprintf(f
, " FLAGS(%u)", this->flags_
);
3106 if (this->load_address_
!= NULL
)
3109 this->load_address_
->print(f
);
3115 // Add a memory region.
3118 Script_sections::add_memory_region(const char* name
, size_t namelen
,
3119 unsigned int attributes
,
3120 Expression
* start
, Expression
* length
)
3122 if (this->memory_regions_
== NULL
)
3123 this->memory_regions_
= new Memory_regions();
3124 else if (this->find_memory_region(name
, namelen
))
3126 gold_error(_("region '%.*s' already defined"), static_cast<int>(namelen
),
3128 // FIXME: Add a GOLD extension to allow multiple regions with the same
3129 // name. This would amount to a single region covering disjoint blocks
3130 // of memory, which is useful for embedded devices.
3133 // FIXME: Check the length and start values. Currently we allow
3134 // non-constant expressions for these values, whereas LD does not.
3136 // FIXME: Add a GOLD extension to allow NEGATIVE LENGTHS. This would
3137 // describe a region that packs from the end address going down, rather
3138 // than the start address going up. This would be useful for embedded
3141 this->memory_regions_
->push_back(new Memory_region(name
, namelen
, attributes
,
3145 // Find a memory region.
3148 Script_sections::find_memory_region(const char* name
, size_t namelen
)
3150 if (this->memory_regions_
== NULL
)
3153 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
3154 m
!= this->memory_regions_
->end();
3156 if ((*m
)->name_match(name
, namelen
))
3162 // Find a memory region's origin.
3165 Script_sections::find_memory_region_origin(const char* name
, size_t namelen
)
3167 Memory_region
* mr
= find_memory_region(name
, namelen
);
3171 return mr
->start_address();
3174 // Find a memory region's length.
3177 Script_sections::find_memory_region_length(const char* name
, size_t namelen
)
3179 Memory_region
* mr
= find_memory_region(name
, namelen
);
3183 return mr
->length();
3186 // Set the memory region to use for the current section.
3189 Script_sections::set_memory_region(Memory_region
* mr
, bool set_vma
)
3191 gold_assert(!this->sections_elements_
->empty());
3192 this->sections_elements_
->back()->set_memory_region(mr
, set_vma
);
3195 // Class Script_sections.
3197 Script_sections::Script_sections()
3198 : saw_sections_clause_(false),
3199 in_sections_clause_(false),
3200 sections_elements_(NULL
),
3201 output_section_(NULL
),
3202 memory_regions_(NULL
),
3203 phdrs_elements_(NULL
),
3204 orphan_section_placement_(NULL
),
3205 data_segment_align_start_(),
3206 saw_data_segment_align_(false),
3207 saw_relro_end_(false),
3208 saw_segment_start_expression_(false),
3209 segments_created_(false)
3213 // Start a SECTIONS clause.
3216 Script_sections::start_sections()
3218 gold_assert(!this->in_sections_clause_
&& this->output_section_
== NULL
);
3219 this->saw_sections_clause_
= true;
3220 this->in_sections_clause_
= true;
3221 if (this->sections_elements_
== NULL
)
3222 this->sections_elements_
= new Sections_elements
;
3225 // Finish a SECTIONS clause.
3228 Script_sections::finish_sections()
3230 gold_assert(this->in_sections_clause_
&& this->output_section_
== NULL
);
3231 this->in_sections_clause_
= false;
3234 // Add a symbol to be defined.
3237 Script_sections::add_symbol_assignment(const char* name
, size_t length
,
3238 Expression
* val
, bool provide
,
3241 if (this->output_section_
!= NULL
)
3242 this->output_section_
->add_symbol_assignment(name
, length
, val
,
3246 Sections_element
* p
= new Sections_element_assignment(name
, length
,
3249 this->sections_elements_
->push_back(p
);
3253 // Add an assignment to the special dot symbol.
3256 Script_sections::add_dot_assignment(Expression
* val
)
3258 if (this->output_section_
!= NULL
)
3259 this->output_section_
->add_dot_assignment(val
);
3262 // The GNU linker permits assignments to . to appears outside of
3263 // a SECTIONS clause, and treats it as appearing inside, so
3264 // sections_elements_ may be NULL here.
3265 if (this->sections_elements_
== NULL
)
3267 this->sections_elements_
= new Sections_elements
;
3268 this->saw_sections_clause_
= true;
3271 Sections_element
* p
= new Sections_element_dot_assignment(val
);
3272 this->sections_elements_
->push_back(p
);
3276 // Add an assertion.
3279 Script_sections::add_assertion(Expression
* check
, const char* message
,
3282 if (this->output_section_
!= NULL
)
3283 this->output_section_
->add_assertion(check
, message
, messagelen
);
3286 Sections_element
* p
= new Sections_element_assertion(check
, message
,
3288 this->sections_elements_
->push_back(p
);
3292 // Start processing entries for an output section.
3295 Script_sections::start_output_section(
3298 const Parser_output_section_header
* header
)
3300 Output_section_definition
* posd
= new Output_section_definition(name
,
3303 this->sections_elements_
->push_back(posd
);
3304 gold_assert(this->output_section_
== NULL
);
3305 this->output_section_
= posd
;
3308 // Stop processing entries for an output section.
3311 Script_sections::finish_output_section(
3312 const Parser_output_section_trailer
* trailer
)
3314 gold_assert(this->output_section_
!= NULL
);
3315 this->output_section_
->finish(trailer
);
3316 this->output_section_
= NULL
;
3319 // Add a data item to the current output section.
3322 Script_sections::add_data(int size
, bool is_signed
, Expression
* val
)
3324 gold_assert(this->output_section_
!= NULL
);
3325 this->output_section_
->add_data(size
, is_signed
, val
);
3328 // Add a fill value setting to the current output section.
3331 Script_sections::add_fill(Expression
* val
)
3333 gold_assert(this->output_section_
!= NULL
);
3334 this->output_section_
->add_fill(val
);
3337 // Add an input section specification to the current output section.
3340 Script_sections::add_input_section(const Input_section_spec
* spec
, bool keep
)
3342 gold_assert(this->output_section_
!= NULL
);
3343 this->output_section_
->add_input_section(spec
, keep
);
3346 // This is called when we see DATA_SEGMENT_ALIGN. It means that any
3347 // subsequent output sections may be relro.
3350 Script_sections::data_segment_align()
3352 if (this->saw_data_segment_align_
)
3353 gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script"));
3354 gold_assert(!this->sections_elements_
->empty());
3355 Sections_elements::iterator p
= this->sections_elements_
->end();
3357 this->data_segment_align_start_
= p
;
3358 this->saw_data_segment_align_
= true;
3361 // This is called when we see DATA_SEGMENT_RELRO_END. It means that
3362 // any output sections seen since DATA_SEGMENT_ALIGN are relro.
3365 Script_sections::data_segment_relro_end()
3367 if (this->saw_relro_end_
)
3368 gold_error(_("DATA_SEGMENT_RELRO_END may only appear once "
3369 "in a linker script"));
3370 this->saw_relro_end_
= true;
3372 if (!this->saw_data_segment_align_
)
3373 gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN"));
3376 Sections_elements::iterator p
= this->data_segment_align_start_
;
3377 for (++p
; p
!= this->sections_elements_
->end(); ++p
)
3378 (*p
)->set_is_relro();
3382 // Create any required sections.
3385 Script_sections::create_sections(Layout
* layout
)
3387 if (!this->saw_sections_clause_
)
3389 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3390 p
!= this->sections_elements_
->end();
3392 (*p
)->create_sections(layout
);
3395 // Add any symbols we are defining to the symbol table.
3398 Script_sections::add_symbols_to_table(Symbol_table
* symtab
)
3400 if (!this->saw_sections_clause_
)
3402 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3403 p
!= this->sections_elements_
->end();
3405 (*p
)->add_symbols_to_table(symtab
);
3408 // Finalize symbols and check assertions.
3411 Script_sections::finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
)
3413 if (!this->saw_sections_clause_
)
3415 uint64_t dot_value
= 0;
3416 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3417 p
!= this->sections_elements_
->end();
3419 (*p
)->finalize_symbols(symtab
, layout
, &dot_value
);
3422 // Return the name of the output section to use for an input file name
3423 // and section name.
3426 Script_sections::output_section_name(
3427 const char* file_name
,
3428 const char* section_name
,
3429 Output_section
*** output_section_slot
,
3430 Script_sections::Section_type
* psection_type
,
3433 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3434 p
!= this->sections_elements_
->end();
3437 const char* ret
= (*p
)->output_section_name(file_name
, section_name
,
3438 output_section_slot
,
3439 psection_type
, keep
);
3443 // The special name /DISCARD/ means that the input section
3444 // should be discarded.
3445 if (strcmp(ret
, "/DISCARD/") == 0)
3447 *output_section_slot
= NULL
;
3448 *psection_type
= Script_sections::ST_NONE
;
3455 // If we couldn't find a mapping for the name, the output section
3456 // gets the name of the input section.
3458 *output_section_slot
= NULL
;
3459 *psection_type
= Script_sections::ST_NONE
;
3461 return section_name
;
3464 // Place a marker for an orphan output section into the SECTIONS
3468 Script_sections::place_orphan(Output_section
* os
)
3470 Orphan_section_placement
* osp
= this->orphan_section_placement_
;
3473 // Initialize the Orphan_section_placement structure.
3474 osp
= new Orphan_section_placement();
3475 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3476 p
!= this->sections_elements_
->end();
3478 (*p
)->orphan_section_init(osp
, p
);
3479 gold_assert(!this->sections_elements_
->empty());
3480 Sections_elements::iterator last
= this->sections_elements_
->end();
3482 osp
->last_init(last
);
3483 this->orphan_section_placement_
= osp
;
3486 Orphan_output_section
* orphan
= new Orphan_output_section(os
);
3488 // Look for where to put ORPHAN.
3489 Sections_elements::iterator
* where
;
3490 if (osp
->find_place(os
, &where
))
3492 if ((**where
)->is_relro())
3495 os
->clear_is_relro();
3497 // We want to insert ORPHAN after *WHERE, and then update *WHERE
3498 // so that the next one goes after this one.
3499 Sections_elements::iterator p
= *where
;
3500 gold_assert(p
!= this->sections_elements_
->end());
3502 *where
= this->sections_elements_
->insert(p
, orphan
);
3506 os
->clear_is_relro();
3507 // We don't have a place to put this orphan section. Put it,
3508 // and all other sections like it, at the end, but before the
3509 // sections which always come at the end.
3510 Sections_elements::iterator last
= osp
->last_place();
3511 *where
= this->sections_elements_
->insert(last
, orphan
);
3515 // Set the addresses of all the output sections. Walk through all the
3516 // elements, tracking the dot symbol. Apply assignments which set
3517 // absolute symbol values, in case they are used when setting dot.
3518 // Fill in data statement values. As we find output sections, set the
3519 // address, set the address of all associated input sections, and
3520 // update dot. Return the segment which should hold the file header
3521 // and segment headers, if any.
3524 Script_sections::set_section_addresses(Symbol_table
* symtab
, Layout
* layout
)
3526 gold_assert(this->saw_sections_clause_
);
3528 // Implement ONLY_IF_RO/ONLY_IF_RW constraints. These are a pain
3529 // for our representation.
3530 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3531 p
!= this->sections_elements_
->end();
3534 Output_section_definition
* posd
;
3535 Section_constraint failed_constraint
= (*p
)->check_constraint(&posd
);
3536 if (failed_constraint
!= CONSTRAINT_NONE
)
3538 Sections_elements::iterator q
;
3539 for (q
= this->sections_elements_
->begin();
3540 q
!= this->sections_elements_
->end();
3545 if ((*q
)->alternate_constraint(posd
, failed_constraint
))
3550 if (q
== this->sections_elements_
->end())
3551 gold_error(_("no matching section constraint"));
3555 // Force the alignment of the first TLS section to be the maximum
3556 // alignment of all TLS sections.
3557 Output_section
* first_tls
= NULL
;
3558 uint64_t tls_align
= 0;
3559 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3560 p
!= this->sections_elements_
->end();
3563 Output_section
* os
= (*p
)->get_output_section();
3564 if (os
!= NULL
&& (os
->flags() & elfcpp::SHF_TLS
) != 0)
3566 if (first_tls
== NULL
)
3568 if (os
->addralign() > tls_align
)
3569 tls_align
= os
->addralign();
3572 if (first_tls
!= NULL
)
3573 first_tls
->set_addralign(tls_align
);
3575 // For a relocatable link, we implicitly set dot to zero.
3576 uint64_t dot_value
= 0;
3577 uint64_t dot_alignment
= 0;
3578 uint64_t load_address
= 0;
3580 // Check to see if we want to use any of -Ttext, -Tdata and -Tbss options
3581 // to set section addresses. If the script has any SEGMENT_START
3582 // expression, we do not set the section addresses.
3583 bool use_tsection_options
=
3584 (!this->saw_segment_start_expression_
3585 && (parameters
->options().user_set_Ttext()
3586 || parameters
->options().user_set_Tdata()
3587 || parameters
->options().user_set_Tbss()));
3589 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3590 p
!= this->sections_elements_
->end();
3593 Output_section
* os
= (*p
)->get_output_section();
3595 // Handle -Ttext, -Tdata and -Tbss options. We do this by looking for
3596 // the special sections by names and doing dot assignments.
3597 if (use_tsection_options
3599 && (os
->flags() & elfcpp::SHF_ALLOC
) != 0)
3601 uint64_t new_dot_value
= dot_value
;
3603 if (parameters
->options().user_set_Ttext()
3604 && strcmp(os
->name(), ".text") == 0)
3605 new_dot_value
= parameters
->options().Ttext();
3606 else if (parameters
->options().user_set_Tdata()
3607 && strcmp(os
->name(), ".data") == 0)
3608 new_dot_value
= parameters
->options().Tdata();
3609 else if (parameters
->options().user_set_Tbss()
3610 && strcmp(os
->name(), ".bss") == 0)
3611 new_dot_value
= parameters
->options().Tbss();
3613 // Update dot and load address if necessary.
3614 if (new_dot_value
< dot_value
)
3615 gold_error(_("dot may not move backward"));
3616 else if (new_dot_value
!= dot_value
)
3618 dot_value
= new_dot_value
;
3619 load_address
= new_dot_value
;
3623 (*p
)->set_section_addresses(symtab
, layout
, &dot_value
, &dot_alignment
,
3627 if (this->phdrs_elements_
!= NULL
)
3629 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
3630 p
!= this->phdrs_elements_
->end();
3632 (*p
)->eval_load_address(symtab
, layout
);
3635 return this->create_segments(layout
, dot_alignment
);
3638 // Sort the sections in order to put them into segments.
3640 class Sort_output_sections
3643 Sort_output_sections(const Script_sections::Sections_elements
* elements
)
3644 : elements_(elements
)
3648 operator()(const Output_section
* os1
, const Output_section
* os2
) const;
3652 script_compare(const Output_section
* os1
, const Output_section
* os2
) const;
3655 const Script_sections::Sections_elements
* elements_
;
3659 Sort_output_sections::operator()(const Output_section
* os1
,
3660 const Output_section
* os2
) const
3662 // Sort first by the load address.
3663 uint64_t lma1
= (os1
->has_load_address()
3664 ? os1
->load_address()
3666 uint64_t lma2
= (os2
->has_load_address()
3667 ? os2
->load_address()
3672 // Then sort by the virtual address.
3673 if (os1
->address() != os2
->address())
3674 return os1
->address() < os2
->address();
3676 // If the linker script says which of these sections is first, go
3677 // with what it says.
3678 int i
= this->script_compare(os1
, os2
);
3682 // Sort PROGBITS before NOBITS.
3683 bool nobits1
= os1
->type() == elfcpp::SHT_NOBITS
;
3684 bool nobits2
= os2
->type() == elfcpp::SHT_NOBITS
;
3685 if (nobits1
!= nobits2
)
3688 // Sort PROGBITS TLS sections to the end, NOBITS TLS sections to the
3690 bool tls1
= (os1
->flags() & elfcpp::SHF_TLS
) != 0;
3691 bool tls2
= (os2
->flags() & elfcpp::SHF_TLS
) != 0;
3693 return nobits1
? tls1
: tls2
;
3695 // Sort non-NOLOAD before NOLOAD.
3696 if (os1
->is_noload() && !os2
->is_noload())
3698 if (!os1
->is_noload() && os2
->is_noload())
3701 // The sections seem practically identical. Sort by name to get a
3703 return os1
->name() < os2
->name();
3706 // Return -1 if OS1 comes before OS2 in ELEMENTS_, 1 if comes after, 0
3707 // if either OS1 or OS2 is not mentioned. This ensures that we keep
3708 // empty sections in the order in which they appear in a linker
3712 Sort_output_sections::script_compare(const Output_section
* os1
,
3713 const Output_section
* os2
) const
3715 if (this->elements_
== NULL
)
3718 bool found_os1
= false;
3719 bool found_os2
= false;
3720 for (Script_sections::Sections_elements::const_iterator
3721 p
= this->elements_
->begin();
3722 p
!= this->elements_
->end();
3725 if (os2
== (*p
)->get_output_section())
3731 else if (os1
== (*p
)->get_output_section())
3742 // Return whether OS is a BSS section. This is a SHT_NOBITS section.
3743 // We treat a section with the SHF_TLS flag set as taking up space
3744 // even if it is SHT_NOBITS (this is true of .tbss), as we allocate
3745 // space for them in the file.
3748 Script_sections::is_bss_section(const Output_section
* os
)
3750 return (os
->type() == elfcpp::SHT_NOBITS
3751 && (os
->flags() & elfcpp::SHF_TLS
) == 0);
3754 // Return the size taken by the file header and the program headers.
3757 Script_sections::total_header_size(Layout
* layout
) const
3759 size_t segment_count
= layout
->segment_count();
3760 size_t file_header_size
;
3761 size_t segment_headers_size
;
3762 if (parameters
->target().get_size() == 32)
3764 file_header_size
= elfcpp::Elf_sizes
<32>::ehdr_size
;
3765 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<32>::phdr_size
;
3767 else if (parameters
->target().get_size() == 64)
3769 file_header_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
3770 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<64>::phdr_size
;
3775 return file_header_size
+ segment_headers_size
;
3778 // Return the amount we have to subtract from the LMA to accommodate
3779 // headers of the given size. The complication is that the file
3780 // header have to be at the start of a page, as otherwise it will not
3781 // be at the start of the file.
3784 Script_sections::header_size_adjustment(uint64_t lma
,
3785 size_t sizeof_headers
) const
3787 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3788 uint64_t hdr_lma
= lma
- sizeof_headers
;
3789 hdr_lma
&= ~(abi_pagesize
- 1);
3790 return lma
- hdr_lma
;
3793 // Create the PT_LOAD segments when using a SECTIONS clause. Returns
3794 // the segment which should hold the file header and segment headers,
3798 Script_sections::create_segments(Layout
* layout
, uint64_t dot_alignment
)
3800 gold_assert(this->saw_sections_clause_
);
3802 if (parameters
->options().relocatable())
3805 if (this->saw_phdrs_clause())
3806 return create_segments_from_phdrs_clause(layout
, dot_alignment
);
3808 Layout::Section_list sections
;
3809 layout
->get_allocated_sections(§ions
);
3811 // Sort the sections by address.
3812 std::stable_sort(sections
.begin(), sections
.end(),
3813 Sort_output_sections(this->sections_elements_
));
3815 this->create_note_and_tls_segments(layout
, §ions
);
3817 // Walk through the sections adding them to PT_LOAD segments.
3818 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3819 Output_segment
* first_seg
= NULL
;
3820 Output_segment
* current_seg
= NULL
;
3821 bool is_current_seg_readonly
= true;
3822 Layout::Section_list::iterator plast
= sections
.end();
3823 uint64_t last_vma
= 0;
3824 uint64_t last_lma
= 0;
3825 uint64_t last_size
= 0;
3826 for (Layout::Section_list::iterator p
= sections
.begin();
3827 p
!= sections
.end();
3830 const uint64_t vma
= (*p
)->address();
3831 const uint64_t lma
= ((*p
)->has_load_address()
3832 ? (*p
)->load_address()
3834 const uint64_t size
= (*p
)->current_data_size();
3836 bool need_new_segment
;
3837 if (current_seg
== NULL
)
3838 need_new_segment
= true;
3839 else if (lma
- vma
!= last_lma
- last_vma
)
3841 // This section has a different LMA relationship than the
3842 // last one; we need a new segment.
3843 need_new_segment
= true;
3845 else if (align_address(last_lma
+ last_size
, abi_pagesize
)
3846 < align_address(lma
, abi_pagesize
))
3848 // Putting this section in the segment would require
3850 need_new_segment
= true;
3852 else if (is_bss_section(*plast
) && !is_bss_section(*p
))
3854 // A non-BSS section can not follow a BSS section in the
3856 need_new_segment
= true;
3858 else if (is_current_seg_readonly
3859 && ((*p
)->flags() & elfcpp::SHF_WRITE
) != 0
3860 && !parameters
->options().omagic())
3862 // Don't put a writable section in the same segment as a
3863 // non-writable section.
3864 need_new_segment
= true;
3868 // Otherwise, reuse the existing segment.
3869 need_new_segment
= false;
3872 elfcpp::Elf_Word seg_flags
=
3873 Layout::section_flags_to_segment((*p
)->flags());
3875 if (need_new_segment
)
3877 current_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
3879 current_seg
->set_addresses(vma
, lma
);
3880 current_seg
->set_minimum_p_align(dot_alignment
);
3881 if (first_seg
== NULL
)
3882 first_seg
= current_seg
;
3883 is_current_seg_readonly
= true;
3886 current_seg
->add_output_section_to_load(layout
, *p
, seg_flags
);
3888 if (((*p
)->flags() & elfcpp::SHF_WRITE
) != 0)
3889 is_current_seg_readonly
= false;
3897 // An ELF program should work even if the program headers are not in
3898 // a PT_LOAD segment. However, it appears that the Linux kernel
3899 // does not set the AT_PHDR auxiliary entry in that case. It sets
3900 // the load address to p_vaddr - p_offset of the first PT_LOAD
3901 // segment. It then sets AT_PHDR to the load address plus the
3902 // offset to the program headers, e_phoff in the file header. This
3903 // fails when the program headers appear in the file before the
3904 // first PT_LOAD segment. Therefore, we always create a PT_LOAD
3905 // segment to hold the file header and the program headers. This is
3906 // effectively what the GNU linker does, and it is slightly more
3907 // efficient in any case. We try to use the first PT_LOAD segment
3908 // if we can, otherwise we make a new one.
3910 if (first_seg
== NULL
)
3913 // -n or -N mean that the program is not demand paged and there is
3914 // no need to put the program headers in a PT_LOAD segment.
3915 if (parameters
->options().nmagic() || parameters
->options().omagic())
3918 size_t sizeof_headers
= this->total_header_size(layout
);
3920 uint64_t vma
= first_seg
->vaddr();
3921 uint64_t lma
= first_seg
->paddr();
3923 uint64_t subtract
= this->header_size_adjustment(lma
, sizeof_headers
);
3925 if ((lma
& (abi_pagesize
- 1)) >= sizeof_headers
)
3927 first_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
3931 // If there is no room to squeeze in the headers, then punt. The
3932 // resulting executable probably won't run on GNU/Linux, but we
3933 // trust that the user knows what they are doing.
3934 if (lma
< subtract
|| vma
< subtract
)
3937 // If memory regions have been specified and the address range
3938 // we are about to use is not contained within any region then
3939 // issue a warning message about the segment we are going to
3940 // create. It will be outside of any region and so possibly
3941 // using non-existent or protected memory. We test LMA rather
3942 // than VMA since we assume that the headers will never be
3944 if (this->memory_regions_
!= NULL
3945 && !this->block_in_region (NULL
, layout
, lma
- subtract
, subtract
))
3946 gold_warning(_("creating a segment to contain the file and program"
3947 " headers outside of any MEMORY region"));
3949 Output_segment
* load_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
3951 load_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
3956 // Create a PT_NOTE segment for each SHT_NOTE section and a PT_TLS
3957 // segment if there are any SHT_TLS sections.
3960 Script_sections::create_note_and_tls_segments(
3962 const Layout::Section_list
* sections
)
3964 gold_assert(!this->saw_phdrs_clause());
3966 bool saw_tls
= false;
3967 for (Layout::Section_list::const_iterator p
= sections
->begin();
3968 p
!= sections
->end();
3971 if ((*p
)->type() == elfcpp::SHT_NOTE
)
3973 elfcpp::Elf_Word seg_flags
=
3974 Layout::section_flags_to_segment((*p
)->flags());
3975 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_NOTE
,
3977 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
3979 // Incorporate any subsequent SHT_NOTE sections, in the
3980 // hopes that the script is sensible.
3981 Layout::Section_list::const_iterator pnext
= p
+ 1;
3982 while (pnext
!= sections
->end()
3983 && (*pnext
)->type() == elfcpp::SHT_NOTE
)
3985 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
3986 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
3992 if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
3995 gold_error(_("TLS sections are not adjacent"));
3997 elfcpp::Elf_Word seg_flags
=
3998 Layout::section_flags_to_segment((*p
)->flags());
3999 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_TLS
,
4001 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
4003 Layout::Section_list::const_iterator pnext
= p
+ 1;
4004 while (pnext
!= sections
->end()
4005 && ((*pnext
)->flags() & elfcpp::SHF_TLS
) != 0)
4007 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
4008 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
4016 // If we see a section named .interp then put the .interp section
4017 // in a PT_INTERP segment.
4018 // This is for GNU ld compatibility.
4019 if (strcmp((*p
)->name(), ".interp") == 0)
4021 elfcpp::Elf_Word seg_flags
=
4022 Layout::section_flags_to_segment((*p
)->flags());
4023 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_INTERP
,
4025 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
4029 this->segments_created_
= true;
4032 // Add a program header. The PHDRS clause is syntactically distinct
4033 // from the SECTIONS clause, but we implement it with the SECTIONS
4034 // support because PHDRS is useless if there is no SECTIONS clause.
4037 Script_sections::add_phdr(const char* name
, size_t namelen
, unsigned int type
,
4038 bool includes_filehdr
, bool includes_phdrs
,
4039 bool is_flags_valid
, unsigned int flags
,
4040 Expression
* load_address
)
4042 if (this->phdrs_elements_
== NULL
)
4043 this->phdrs_elements_
= new Phdrs_elements();
4044 this->phdrs_elements_
->push_back(new Phdrs_element(name
, namelen
, type
,
4047 is_flags_valid
, flags
,
4051 // Return the number of segments we expect to create based on the
4052 // SECTIONS clause. This is used to implement SIZEOF_HEADERS.
4055 Script_sections::expected_segment_count(const Layout
* layout
) const
4057 // If we've already created the segments, we won't be adding any more.
4058 if (this->segments_created_
)
4061 if (this->saw_phdrs_clause())
4062 return this->phdrs_elements_
->size();
4064 Layout::Section_list sections
;
4065 layout
->get_allocated_sections(§ions
);
4067 // We assume that we will need two PT_LOAD segments.
4070 bool saw_note
= false;
4071 bool saw_tls
= false;
4072 bool saw_interp
= false;
4073 for (Layout::Section_list::const_iterator p
= sections
.begin();
4074 p
!= sections
.end();
4077 if ((*p
)->type() == elfcpp::SHT_NOTE
)
4079 // Assume that all note sections will fit into a single
4087 else if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
4089 // There can only be one PT_TLS segment.
4096 else if (strcmp((*p
)->name(), ".interp") == 0)
4098 // There can only be one PT_INTERP segment.
4110 // Create the segments from a PHDRS clause. Return the segment which
4111 // should hold the file header and program headers, if any.
4114 Script_sections::create_segments_from_phdrs_clause(Layout
* layout
,
4115 uint64_t dot_alignment
)
4117 this->attach_sections_using_phdrs_clause(layout
);
4118 return this->set_phdrs_clause_addresses(layout
, dot_alignment
);
4121 // Create the segments from the PHDRS clause, and put the output
4122 // sections in them.
4125 Script_sections::attach_sections_using_phdrs_clause(Layout
* layout
)
4127 typedef std::map
<std::string
, Output_segment
*> Name_to_segment
;
4128 Name_to_segment name_to_segment
;
4129 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4130 p
!= this->phdrs_elements_
->end();
4132 name_to_segment
[(*p
)->name()] = (*p
)->create_segment(layout
);
4133 this->segments_created_
= true;
4135 // Walk through the output sections and attach them to segments.
4136 // Output sections in the script which do not list segments are
4137 // attached to the same set of segments as the immediately preceding
4140 String_list
* phdr_names
= NULL
;
4141 bool load_segments_only
= false;
4142 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4143 p
!= this->sections_elements_
->end();
4147 String_list
* old_phdr_names
= phdr_names
;
4148 Output_section
* os
= (*p
)->allocate_to_segment(&phdr_names
, &is_orphan
);
4152 elfcpp::Elf_Word seg_flags
=
4153 Layout::section_flags_to_segment(os
->flags());
4155 if (phdr_names
== NULL
)
4157 // Don't worry about empty orphan sections.
4158 if (is_orphan
&& os
->current_data_size() > 0)
4159 gold_error(_("allocated section %s not in any segment"),
4162 // To avoid later crashes drop this section into the first
4164 for (Phdrs_elements::const_iterator ppe
=
4165 this->phdrs_elements_
->begin();
4166 ppe
!= this->phdrs_elements_
->end();
4169 Output_segment
* oseg
= (*ppe
)->segment();
4170 if (oseg
->type() == elfcpp::PT_LOAD
)
4172 oseg
->add_output_section_to_load(layout
, os
, seg_flags
);
4180 // We see a list of segments names. Disable PT_LOAD segment only
4182 if (old_phdr_names
!= phdr_names
)
4183 load_segments_only
= false;
4185 // If this is an orphan section--one that was not explicitly
4186 // mentioned in the linker script--then it should not inherit
4187 // any segment type other than PT_LOAD. Otherwise, e.g., the
4188 // PT_INTERP segment will pick up following orphan sections,
4189 // which does not make sense. If this is not an orphan section,
4190 // we trust the linker script.
4193 // Enable PT_LOAD segments only filtering until we see another
4194 // list of segment names.
4195 load_segments_only
= true;
4198 bool in_load_segment
= false;
4199 for (String_list::const_iterator q
= phdr_names
->begin();
4200 q
!= phdr_names
->end();
4203 Name_to_segment::const_iterator r
= name_to_segment
.find(*q
);
4204 if (r
== name_to_segment
.end())
4205 gold_error(_("no segment %s"), q
->c_str());
4208 if (load_segments_only
4209 && r
->second
->type() != elfcpp::PT_LOAD
)
4212 if (r
->second
->type() != elfcpp::PT_LOAD
)
4213 r
->second
->add_output_section_to_nonload(os
, seg_flags
);
4216 r
->second
->add_output_section_to_load(layout
, os
, seg_flags
);
4217 if (in_load_segment
)
4218 gold_error(_("section in two PT_LOAD segments"));
4219 in_load_segment
= true;
4224 if (!in_load_segment
)
4225 gold_error(_("allocated section not in any PT_LOAD segment"));
4229 // Set the addresses for segments created from a PHDRS clause. Return
4230 // the segment which should hold the file header and program headers,
4234 Script_sections::set_phdrs_clause_addresses(Layout
* layout
,
4235 uint64_t dot_alignment
)
4237 Output_segment
* load_seg
= NULL
;
4238 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4239 p
!= this->phdrs_elements_
->end();
4242 // Note that we have to set the flags after adding the output
4243 // sections to the segment, as adding an output segment can
4244 // change the flags.
4245 (*p
)->set_flags_if_valid();
4247 Output_segment
* oseg
= (*p
)->segment();
4249 if (oseg
->type() != elfcpp::PT_LOAD
)
4251 // The addresses of non-PT_LOAD segments are set from the
4252 // PT_LOAD segments.
4253 if ((*p
)->has_load_address())
4254 gold_error(_("may only specify load address for PT_LOAD segment"));
4258 oseg
->set_minimum_p_align(dot_alignment
);
4260 // The output sections should have addresses from the SECTIONS
4261 // clause. The addresses don't have to be in order, so find the
4262 // one with the lowest load address. Use that to set the
4263 // address of the segment.
4265 Output_section
* osec
= oseg
->section_with_lowest_load_address();
4268 oseg
->set_addresses(0, 0);
4272 uint64_t vma
= osec
->address();
4273 uint64_t lma
= osec
->has_load_address() ? osec
->load_address() : vma
;
4275 // Override the load address of the section with the load
4276 // address specified for the segment.
4277 if ((*p
)->has_load_address())
4279 if (osec
->has_load_address())
4280 gold_warning(_("PHDRS load address overrides "
4281 "section %s load address"),
4284 lma
= (*p
)->load_address();
4287 bool headers
= (*p
)->includes_filehdr() && (*p
)->includes_phdrs();
4288 if (!headers
&& ((*p
)->includes_filehdr() || (*p
)->includes_phdrs()))
4290 // We could support this if we wanted to.
4291 gold_error(_("using only one of FILEHDR and PHDRS is "
4292 "not currently supported"));
4296 size_t sizeof_headers
= this->total_header_size(layout
);
4297 uint64_t subtract
= this->header_size_adjustment(lma
,
4299 if (lma
>= subtract
&& vma
>= subtract
)
4306 gold_error(_("sections loaded on first page without room "
4307 "for file and program headers "
4308 "are not supported"));
4311 if (load_seg
!= NULL
)
4312 gold_error(_("using FILEHDR and PHDRS on more than one "
4313 "PT_LOAD segment is not currently supported"));
4317 oseg
->set_addresses(vma
, lma
);
4323 // Add the file header and segment headers to non-load segments
4324 // specified in the PHDRS clause.
4327 Script_sections::put_headers_in_phdrs(Output_data
* file_header
,
4328 Output_data
* segment_headers
)
4330 gold_assert(this->saw_phdrs_clause());
4331 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
4332 p
!= this->phdrs_elements_
->end();
4335 if ((*p
)->type() != elfcpp::PT_LOAD
)
4337 if ((*p
)->includes_phdrs())
4338 (*p
)->segment()->add_initial_output_data(segment_headers
);
4339 if ((*p
)->includes_filehdr())
4340 (*p
)->segment()->add_initial_output_data(file_header
);
4345 // Look for an output section by name and return the address, the load
4346 // address, the alignment, and the size. This is used when an
4347 // expression refers to an output section which was not actually
4348 // created. This returns true if the section was found, false
4352 Script_sections::get_output_section_info(const char* name
, uint64_t* address
,
4353 uint64_t* load_address
,
4354 uint64_t* addralign
,
4355 uint64_t* size
) const
4357 if (!this->saw_sections_clause_
)
4359 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4360 p
!= this->sections_elements_
->end();
4362 if ((*p
)->get_output_section_info(name
, address
, load_address
, addralign
,
4368 // Release all Output_segments. This remove all pointers to all
4372 Script_sections::release_segments()
4374 if (this->saw_phdrs_clause())
4376 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4377 p
!= this->phdrs_elements_
->end();
4379 (*p
)->release_segment();
4383 // Print the SECTIONS clause to F for debugging.
4386 Script_sections::print(FILE* f
) const
4388 if (this->phdrs_elements_
!= NULL
)
4390 fprintf(f
, "PHDRS {\n");
4391 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4392 p
!= this->phdrs_elements_
->end();
4398 if (this->memory_regions_
!= NULL
)
4400 fprintf(f
, "MEMORY {\n");
4401 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
4402 m
!= this->memory_regions_
->end();
4408 if (!this->saw_sections_clause_
)
4411 fprintf(f
, "SECTIONS {\n");
4413 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4414 p
!= this->sections_elements_
->end();
4421 } // End namespace gold.