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
)
1460 { this->section_name_
= name
; }
1462 // Return the section size.
1465 { return this->size_
; }
1467 // Set the section size.
1469 set_size(uint64_t size
)
1470 { this->size_
= size
; }
1472 // Return the address alignment.
1475 { return this->addralign_
; }
1477 // Set the address alignment.
1479 set_addralign(uint64_t addralign
)
1480 { this->addralign_
= addralign
; }
1483 // Input section, can be a relaxed section.
1484 Output_section::Input_section input_section_
;
1485 // Name of the section.
1486 std::string section_name_
;
1489 // Address alignment.
1490 uint64_t addralign_
;
1493 // A class to sort the input sections.
1495 class Input_section_sorter
1498 Input_section_sorter(Sort_wildcard filename_sort
, Sort_wildcard section_sort
)
1499 : filename_sort_(filename_sort
), section_sort_(section_sort
)
1503 operator()(const Input_section_info
&, const Input_section_info
&) const;
1506 Sort_wildcard filename_sort_
;
1507 Sort_wildcard section_sort_
;
1511 Input_section_sorter::operator()(const Input_section_info
& isi1
,
1512 const Input_section_info
& isi2
) const
1514 if (this->section_sort_
== SORT_WILDCARD_BY_NAME
1515 || this->section_sort_
== SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1516 || (this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
1517 && isi1
.addralign() == isi2
.addralign()))
1519 if (isi1
.section_name() != isi2
.section_name())
1520 return isi1
.section_name() < isi2
.section_name();
1522 if (this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT
1523 || this->section_sort_
== SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1524 || this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
)
1526 if (isi1
.addralign() != isi2
.addralign())
1527 return isi1
.addralign() < isi2
.addralign();
1529 if (this->filename_sort_
== SORT_WILDCARD_BY_NAME
)
1531 if (isi1
.relobj()->name() != isi2
.relobj()->name())
1532 return (isi1
.relobj()->name() < isi2
.relobj()->name());
1535 // Otherwise we leave them in the same order.
1539 // Set the section address. Look in INPUT_SECTIONS for sections which
1540 // match this spec, sort them as specified, and add them to the output
1544 Output_section_element_input::set_section_addresses(
1547 Output_section
* output_section
,
1549 uint64_t* dot_value
,
1551 Output_section
** dot_section
,
1553 Input_section_list
* input_sections
)
1555 // We build a list of sections which match each
1556 // Input_section_pattern.
1558 // If none of the patterns specify a sort option, we throw all
1559 // matching input sections into a single bin, in the order we
1560 // find them. Otherwise, we put matching input sections into
1561 // a separate bin for each pattern, and sort each one as
1562 // specified. Thus, an input section spec like this:
1564 // will group all .foo and .bar sections in the order seen,
1567 // will group all .foo sections followed by all .bar sections.
1568 // This matches Gnu ld behavior.
1570 // Things get really weird, though, when you add a sort spec
1571 // on some, but not all, of the patterns, like this:
1572 // *(SORT_BY_NAME(.foo) .bar)
1573 // We do not attempt to match Gnu ld behavior in this case.
1575 typedef std::vector
<std::vector
<Input_section_info
> > Matching_sections
;
1576 size_t input_pattern_count
= this->input_section_patterns_
.size();
1577 bool any_patterns_with_sort
= false;
1578 for (size_t i
= 0; i
< input_pattern_count
; ++i
)
1580 const Input_section_pattern
& isp(this->input_section_patterns_
[i
]);
1581 if (isp
.sort
!= SORT_WILDCARD_NONE
)
1582 any_patterns_with_sort
= true;
1584 if (input_pattern_count
== 0 || !any_patterns_with_sort
)
1585 input_pattern_count
= 1;
1586 Matching_sections
matching_sections(input_pattern_count
);
1588 // Look through the list of sections for this output section. Add
1589 // each one which matches to one of the elements of
1590 // MATCHING_SECTIONS.
1592 Input_section_list::iterator p
= input_sections
->begin();
1593 while (p
!= input_sections
->end())
1595 Relobj
* relobj
= p
->relobj();
1596 unsigned int shndx
= p
->shndx();
1597 Input_section_info
isi(*p
);
1599 // Calling section_name and section_addralign is not very
1602 // Lock the object so that we can get information about the
1603 // section. This is OK since we know we are single-threaded
1606 const Task
* task
= reinterpret_cast<const Task
*>(-1);
1607 Task_lock_obj
<Object
> tl(task
, relobj
);
1609 isi
.set_section_name(relobj
->section_name(shndx
));
1610 if (p
->is_relaxed_input_section())
1612 // We use current data size because relaxed section sizes may not
1613 // have finalized yet.
1614 isi
.set_size(p
->relaxed_input_section()->current_data_size());
1615 isi
.set_addralign(p
->relaxed_input_section()->addralign());
1619 isi
.set_size(relobj
->section_size(shndx
));
1620 isi
.set_addralign(relobj
->section_addralign(shndx
));
1624 if (!this->match_file_name(relobj
->name().c_str()))
1626 else if (this->input_section_patterns_
.empty())
1628 matching_sections
[0].push_back(isi
);
1629 p
= input_sections
->erase(p
);
1634 for (i
= 0; i
< input_pattern_count
; ++i
)
1636 const Input_section_pattern
&
1637 isp(this->input_section_patterns_
[i
]);
1638 if (match(isi
.section_name().c_str(), isp
.pattern
.c_str(),
1639 isp
.pattern_is_wildcard
))
1643 if (i
>= this->input_section_patterns_
.size())
1647 if (!any_patterns_with_sort
)
1649 matching_sections
[i
].push_back(isi
);
1650 p
= input_sections
->erase(p
);
1655 // Look through MATCHING_SECTIONS. Sort each one as specified,
1656 // using a stable sort so that we get the default order when
1657 // sections are otherwise equal. Add each input section to the
1660 uint64_t dot
= *dot_value
;
1661 for (size_t i
= 0; i
< input_pattern_count
; ++i
)
1663 if (matching_sections
[i
].empty())
1666 gold_assert(output_section
!= NULL
);
1668 const Input_section_pattern
& isp(this->input_section_patterns_
[i
]);
1669 if (isp
.sort
!= SORT_WILDCARD_NONE
1670 || this->filename_sort_
!= SORT_WILDCARD_NONE
)
1671 std::stable_sort(matching_sections
[i
].begin(),
1672 matching_sections
[i
].end(),
1673 Input_section_sorter(this->filename_sort_
,
1676 for (std::vector
<Input_section_info
>::const_iterator p
=
1677 matching_sections
[i
].begin();
1678 p
!= matching_sections
[i
].end();
1681 // Override the original address alignment if SUBALIGN is specified
1682 // and is greater than the original alignment. We need to make a
1683 // copy of the input section to modify the alignment.
1684 Output_section::Input_section
sis(p
->input_section());
1686 uint64_t this_subalign
= sis
.addralign();
1687 if (!sis
.is_input_section())
1688 sis
.output_section_data()->finalize_data_size();
1689 uint64_t data_size
= sis
.data_size();
1690 if (this_subalign
< subalign
)
1692 this_subalign
= subalign
;
1693 sis
.set_addralign(subalign
);
1696 uint64_t address
= align_address(dot
, this_subalign
);
1698 if (address
> dot
&& !fill
->empty())
1700 section_size_type length
=
1701 convert_to_section_size_type(address
- dot
);
1702 std::string this_fill
= this->get_fill_string(fill
, length
);
1703 Output_section_data
* posd
= new Output_data_const(this_fill
, 0);
1704 output_section
->add_output_section_data(posd
);
1705 layout
->new_output_section_data_from_script(posd
);
1708 output_section
->add_script_input_section(sis
);
1709 dot
= address
+ data_size
;
1713 // An SHF_TLS/SHT_NOBITS section does not take up any
1715 if (output_section
== NULL
1716 || (output_section
->flags() & elfcpp::SHF_TLS
) == 0
1717 || output_section
->type() != elfcpp::SHT_NOBITS
)
1720 this->final_dot_value_
= *dot_value
;
1721 this->final_dot_section_
= *dot_section
;
1724 // Print for debugging.
1727 Output_section_element_input::print(FILE* f
) const
1732 fprintf(f
, "KEEP(");
1734 if (!this->filename_pattern_
.empty())
1736 bool need_close_paren
= false;
1737 switch (this->filename_sort_
)
1739 case SORT_WILDCARD_NONE
:
1741 case SORT_WILDCARD_BY_NAME
:
1742 fprintf(f
, "SORT_BY_NAME(");
1743 need_close_paren
= true;
1749 fprintf(f
, "%s", this->filename_pattern_
.c_str());
1751 if (need_close_paren
)
1755 if (!this->input_section_patterns_
.empty()
1756 || !this->filename_exclusions_
.empty())
1760 bool need_space
= false;
1761 if (!this->filename_exclusions_
.empty())
1763 fprintf(f
, "EXCLUDE_FILE(");
1764 bool need_comma
= false;
1765 for (Filename_exclusions::const_iterator p
=
1766 this->filename_exclusions_
.begin();
1767 p
!= this->filename_exclusions_
.end();
1772 fprintf(f
, "%s", p
->first
.c_str());
1779 for (Input_section_patterns::const_iterator p
=
1780 this->input_section_patterns_
.begin();
1781 p
!= this->input_section_patterns_
.end();
1787 int close_parens
= 0;
1790 case SORT_WILDCARD_NONE
:
1792 case SORT_WILDCARD_BY_NAME
:
1793 fprintf(f
, "SORT_BY_NAME(");
1796 case SORT_WILDCARD_BY_ALIGNMENT
:
1797 fprintf(f
, "SORT_BY_ALIGNMENT(");
1800 case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
:
1801 fprintf(f
, "SORT_BY_NAME(SORT_BY_ALIGNMENT(");
1804 case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
:
1805 fprintf(f
, "SORT_BY_ALIGNMENT(SORT_BY_NAME(");
1812 fprintf(f
, "%s", p
->pattern
.c_str());
1814 for (int i
= 0; i
< close_parens
; ++i
)
1829 // An output section.
1831 class Output_section_definition
: public Sections_element
1834 typedef Output_section_element::Input_section_list Input_section_list
;
1836 Output_section_definition(const char* name
, size_t namelen
,
1837 const Parser_output_section_header
* header
);
1839 // Finish the output section with the information in the trailer.
1841 finish(const Parser_output_section_trailer
* trailer
);
1843 // Add a symbol to be defined.
1845 add_symbol_assignment(const char* name
, size_t length
, Expression
* value
,
1846 bool provide
, bool hidden
);
1848 // Add an assignment to the special dot symbol.
1850 add_dot_assignment(Expression
* value
);
1852 // Add an assertion.
1854 add_assertion(Expression
* check
, const char* message
, size_t messagelen
);
1856 // Add a data item to the current output section.
1858 add_data(int size
, bool is_signed
, Expression
* val
);
1860 // Add a setting for the fill value.
1862 add_fill(Expression
* val
);
1864 // Add an input section specification.
1866 add_input_section(const Input_section_spec
* spec
, bool keep
);
1868 // Return whether the output section is relro.
1871 { return this->is_relro_
; }
1873 // Record that the output section is relro.
1876 { this->is_relro_
= true; }
1878 // Create any required output sections.
1880 create_sections(Layout
*);
1882 // Add any symbols being defined to the symbol table.
1884 add_symbols_to_table(Symbol_table
* symtab
);
1886 // Finalize symbols and check assertions.
1888 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*);
1890 // Return the output section name to use for an input file name and
1893 output_section_name(const char* file_name
, const char* section_name
,
1894 Output_section
***, Script_sections::Section_type
*,
1897 // Initialize OSP with an output section.
1899 orphan_section_init(Orphan_section_placement
* osp
,
1900 Script_sections::Elements_iterator p
)
1901 { osp
->output_section_init(this->name_
, this->output_section_
, p
); }
1903 // Set the section address.
1905 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
,
1906 uint64_t* dot_value
, uint64_t*,
1907 uint64_t* load_address
);
1909 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
1910 // this section is constrained, and the input sections do not match,
1911 // return the constraint, and set *POSD.
1913 check_constraint(Output_section_definition
** posd
);
1915 // See if this is the alternate output section for a constrained
1916 // output section. If it is, transfer the Output_section and return
1917 // true. Otherwise return false.
1919 alternate_constraint(Output_section_definition
*, Section_constraint
);
1921 // Get the list of segments to use for an allocated section when
1922 // using a PHDRS clause.
1924 allocate_to_segment(String_list
** phdrs_list
, bool* orphan
);
1926 // Look for an output section by name and return the address, the
1927 // load address, the alignment, and the size. This is used when an
1928 // expression refers to an output section which was not actually
1929 // created. This returns true if the section was found, false
1932 get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
1935 // Return the associated Output_section if there is one.
1937 get_output_section() const
1938 { return this->output_section_
; }
1940 // Print the contents to the FILE. This is for debugging.
1944 // Return the output section type if specified or Script_sections::ST_NONE.
1945 Script_sections::Section_type
1946 section_type() const;
1948 // Store the memory region to use.
1950 set_memory_region(Memory_region
*, bool set_vma
);
1953 set_section_vma(Expression
* address
)
1954 { this->address_
= address
; }
1957 set_section_lma(Expression
* address
)
1958 { this->load_address_
= address
; }
1961 get_section_name() const
1962 { return this->name_
; }
1966 script_section_type_name(Script_section_type
);
1968 typedef std::vector
<Output_section_element
*> Output_section_elements
;
1970 // The output section name.
1972 // The address. This may be NULL.
1973 Expression
* address_
;
1974 // The load address. This may be NULL.
1975 Expression
* load_address_
;
1976 // The alignment. This may be NULL.
1978 // The input section alignment. This may be NULL.
1979 Expression
* subalign_
;
1980 // The constraint, if any.
1981 Section_constraint constraint_
;
1982 // The fill value. This may be NULL.
1984 // The list of segments this section should go into. This may be
1986 String_list
* phdrs_
;
1987 // The list of elements defining the section.
1988 Output_section_elements elements_
;
1989 // The Output_section created for this definition. This will be
1990 // NULL if none was created.
1991 Output_section
* output_section_
;
1992 // The address after it has been evaluated.
1993 uint64_t evaluated_address_
;
1994 // The load address after it has been evaluated.
1995 uint64_t evaluated_load_address_
;
1996 // The alignment after it has been evaluated.
1997 uint64_t evaluated_addralign_
;
1998 // The output section is relro.
2000 // The output section type if specified.
2001 enum Script_section_type script_section_type_
;
2006 Output_section_definition::Output_section_definition(
2009 const Parser_output_section_header
* header
)
2010 : name_(name
, namelen
),
2011 address_(header
->address
),
2012 load_address_(header
->load_address
),
2013 align_(header
->align
),
2014 subalign_(header
->subalign
),
2015 constraint_(header
->constraint
),
2019 output_section_(NULL
),
2020 evaluated_address_(0),
2021 evaluated_load_address_(0),
2022 evaluated_addralign_(0),
2024 script_section_type_(header
->section_type
)
2028 // Finish an output section.
2031 Output_section_definition::finish(const Parser_output_section_trailer
* trailer
)
2033 this->fill_
= trailer
->fill
;
2034 this->phdrs_
= trailer
->phdrs
;
2037 // Add a symbol to be defined.
2040 Output_section_definition::add_symbol_assignment(const char* name
,
2046 Output_section_element
* p
= new Output_section_element_assignment(name
,
2051 this->elements_
.push_back(p
);
2054 // Add an assignment to the special dot symbol.
2057 Output_section_definition::add_dot_assignment(Expression
* value
)
2059 Output_section_element
* p
= new Output_section_element_dot_assignment(value
);
2060 this->elements_
.push_back(p
);
2063 // Add an assertion.
2066 Output_section_definition::add_assertion(Expression
* check
,
2067 const char* message
,
2070 Output_section_element
* p
= new Output_section_element_assertion(check
,
2073 this->elements_
.push_back(p
);
2076 // Add a data item to the current output section.
2079 Output_section_definition::add_data(int size
, bool is_signed
, Expression
* val
)
2081 Output_section_element
* p
= new Output_section_element_data(size
, is_signed
,
2083 this->elements_
.push_back(p
);
2086 // Add a setting for the fill value.
2089 Output_section_definition::add_fill(Expression
* val
)
2091 Output_section_element
* p
= new Output_section_element_fill(val
);
2092 this->elements_
.push_back(p
);
2095 // Add an input section specification.
2098 Output_section_definition::add_input_section(const Input_section_spec
* spec
,
2101 Output_section_element
* p
= new Output_section_element_input(spec
, keep
);
2102 this->elements_
.push_back(p
);
2105 // Create any required output sections. We need an output section if
2106 // there is a data statement here.
2109 Output_section_definition::create_sections(Layout
* layout
)
2111 if (this->output_section_
!= NULL
)
2113 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2114 p
!= this->elements_
.end();
2117 if ((*p
)->needs_output_section())
2119 const char* name
= this->name_
.c_str();
2120 this->output_section_
=
2121 layout
->make_output_section_for_script(name
, this->section_type());
2127 // Add any symbols being defined to the symbol table.
2130 Output_section_definition::add_symbols_to_table(Symbol_table
* symtab
)
2132 for (Output_section_elements::iterator p
= this->elements_
.begin();
2133 p
!= this->elements_
.end();
2135 (*p
)->add_symbols_to_table(symtab
);
2138 // Finalize symbols and check assertions.
2141 Output_section_definition::finalize_symbols(Symbol_table
* symtab
,
2142 const Layout
* layout
,
2143 uint64_t* dot_value
)
2145 if (this->output_section_
!= NULL
)
2146 *dot_value
= this->output_section_
->address();
2149 uint64_t address
= *dot_value
;
2150 if (this->address_
!= NULL
)
2152 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2156 if (this->align_
!= NULL
)
2158 uint64_t align
= this->align_
->eval_with_dot(symtab
, layout
, true,
2161 address
= align_address(address
, align
);
2163 *dot_value
= address
;
2166 Output_section
* dot_section
= this->output_section_
;
2167 for (Output_section_elements::iterator p
= this->elements_
.begin();
2168 p
!= this->elements_
.end();
2170 (*p
)->finalize_symbols(symtab
, layout
, dot_value
, &dot_section
);
2173 // Return the output section name to use for an input section name.
2176 Output_section_definition::output_section_name(
2177 const char* file_name
,
2178 const char* section_name
,
2179 Output_section
*** slot
,
2180 Script_sections::Section_type
* psection_type
,
2183 // Ask each element whether it matches NAME.
2184 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2185 p
!= this->elements_
.end();
2188 if ((*p
)->match_name(file_name
, section_name
, keep
))
2190 // We found a match for NAME, which means that it should go
2191 // into this output section.
2192 *slot
= &this->output_section_
;
2193 *psection_type
= this->section_type();
2194 return this->name_
.c_str();
2198 // We don't know about this section name.
2202 // Return true if memory from START to START + LENGTH is contained
2203 // within a memory region.
2206 Script_sections::block_in_region(Symbol_table
* symtab
, Layout
* layout
,
2207 uint64_t start
, uint64_t length
) const
2209 if (this->memory_regions_
== NULL
)
2212 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2213 mr
!= this->memory_regions_
->end();
2216 uint64_t s
= (*mr
)->start_address()->eval(symtab
, layout
, false);
2217 uint64_t l
= (*mr
)->length()->eval(symtab
, layout
, false);
2220 && (s
+ l
) >= (start
+ length
))
2227 // Find a memory region that should be used by a given output SECTION.
2228 // If provided set PREVIOUS_SECTION_RETURN to point to the last section
2229 // that used the return memory region.
2232 Script_sections::find_memory_region(
2233 Output_section_definition
* section
,
2234 bool find_vma_region
,
2235 Output_section_definition
** previous_section_return
)
2237 if (previous_section_return
!= NULL
)
2238 * previous_section_return
= NULL
;
2240 // Walk the memory regions specified in this script, if any.
2241 if (this->memory_regions_
== NULL
)
2244 // The /DISCARD/ section never gets assigned to any region.
2245 if (section
->get_section_name() == "/DISCARD/")
2248 Memory_region
* first_match
= NULL
;
2250 // First check to see if a region has been assigned to this section.
2251 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2252 mr
!= this->memory_regions_
->end();
2255 if (find_vma_region
)
2257 for (Memory_region::Section_list::const_iterator s
=
2258 (*mr
)->get_vma_section_list_start();
2259 s
!= (*mr
)->get_vma_section_list_end();
2261 if ((*s
) == section
)
2263 (*mr
)->set_last_section(section
);
2269 for (Memory_region::Section_list::const_iterator s
=
2270 (*mr
)->get_lma_section_list_start();
2271 s
!= (*mr
)->get_lma_section_list_end();
2273 if ((*s
) == section
)
2275 (*mr
)->set_last_section(section
);
2280 // Make a note of the first memory region whose attributes
2281 // are compatible with the section. If we do not find an
2282 // explicit region assignment, then we will return this region.
2283 Output_section
* out_sec
= section
->get_output_section();
2284 if (first_match
== NULL
2286 && (*mr
)->attributes_compatible(out_sec
->flags(),
2291 // With LMA computations, if an explicit region has not been specified then
2292 // we will want to set the difference between the VMA and the LMA of the
2293 // section were searching for to be the same as the difference between the
2294 // VMA and LMA of the last section to be added to first matched region.
2295 // Hence, if it was asked for, we return a pointer to the last section
2296 // known to be used by the first matched region.
2297 if (first_match
!= NULL
2298 && previous_section_return
!= NULL
)
2299 *previous_section_return
= first_match
->get_last_section();
2304 // Set the section address. Note that the OUTPUT_SECTION_ field will
2305 // be NULL if no input sections were mapped to this output section.
2306 // We still have to adjust dot and process symbol assignments.
2309 Output_section_definition::set_section_addresses(Symbol_table
* symtab
,
2311 uint64_t* dot_value
,
2312 uint64_t* dot_alignment
,
2313 uint64_t* load_address
)
2315 Memory_region
* vma_region
= NULL
;
2316 Memory_region
* lma_region
= NULL
;
2317 Script_sections
* script_sections
=
2318 layout
->script_options()->script_sections();
2320 uint64_t old_dot_value
= *dot_value
;
2321 uint64_t old_load_address
= *load_address
;
2323 // If input section sorting is requested via --section-ordering-file or
2324 // linker plugins, then do it here. This is important because we want
2325 // any sorting specified in the linker scripts, which will be done after
2326 // this, to take precedence. The final order of input sections is then
2327 // guaranteed to be according to the linker script specification.
2328 if (this->output_section_
!= NULL
2329 && this->output_section_
->input_section_order_specified())
2330 this->output_section_
->sort_attached_input_sections();
2332 // Decide the start address for the section. The algorithm is:
2333 // 1) If an address has been specified in a linker script, use that.
2334 // 2) Otherwise if a memory region has been specified for the section,
2335 // use the next free address in the region.
2336 // 3) Otherwise if memory regions have been specified find the first
2337 // region whose attributes are compatible with this section and
2338 // install it into that region.
2339 // 4) Otherwise use the current location counter.
2341 if (this->output_section_
!= NULL
2342 // Check for --section-start.
2343 && parameters
->options().section_start(this->output_section_
->name(),
2346 else if (this->address_
== NULL
)
2348 vma_region
= script_sections
->find_memory_region(this, true, NULL
);
2350 if (vma_region
!= NULL
)
2351 address
= vma_region
->get_current_address()->eval(symtab
, layout
,
2354 address
= *dot_value
;
2357 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2358 *dot_value
, NULL
, NULL
,
2359 dot_alignment
, false);
2361 if (this->align_
== NULL
)
2363 if (this->output_section_
== NULL
)
2366 align
= this->output_section_
->addralign();
2370 Output_section
* align_section
;
2371 align
= this->align_
->eval_with_dot(symtab
, layout
, true, *dot_value
,
2372 NULL
, &align_section
, NULL
, false);
2373 if (align_section
!= NULL
)
2374 gold_warning(_("alignment of section %s is not absolute"),
2375 this->name_
.c_str());
2376 if (this->output_section_
!= NULL
)
2377 this->output_section_
->set_addralign(align
);
2380 address
= align_address(address
, align
);
2382 uint64_t start_address
= address
;
2384 *dot_value
= address
;
2386 // Except for NOLOAD sections, the address of non-SHF_ALLOC sections is
2387 // forced to zero, regardless of what the linker script wants.
2388 if (this->output_section_
!= NULL
2389 && ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) != 0
2390 || this->output_section_
->is_noload()))
2391 this->output_section_
->set_address(address
);
2393 this->evaluated_address_
= address
;
2394 this->evaluated_addralign_
= align
;
2398 if (this->load_address_
== NULL
)
2400 Output_section_definition
* previous_section
;
2402 // Determine if an LMA region has been set for this section.
2403 lma_region
= script_sections
->find_memory_region(this, false,
2406 if (lma_region
!= NULL
)
2408 if (previous_section
== NULL
)
2409 // The LMA address was explicitly set to the given region.
2410 laddr
= lma_region
->get_current_address()->eval(symtab
, layout
,
2414 // We are not going to use the discovered lma_region, so
2415 // make sure that we do not update it in the code below.
2418 if (this->address_
!= NULL
|| previous_section
== this)
2420 // Either an explicit VMA address has been set, or an
2421 // explicit VMA region has been set, so set the LMA equal to
2427 // The LMA address was not explicitly or implicitly set.
2429 // We have been given the first memory region that is
2430 // compatible with the current section and a pointer to the
2431 // last section to use this region. Set the LMA of this
2432 // section so that the difference between its' VMA and LMA
2433 // is the same as the difference between the VMA and LMA of
2434 // the last section in the given region.
2435 laddr
= address
+ (previous_section
->evaluated_load_address_
2436 - previous_section
->evaluated_address_
);
2440 if (this->output_section_
!= NULL
)
2441 this->output_section_
->set_load_address(laddr
);
2445 // Do not set the load address of the output section, if one exists.
2446 // This allows future sections to determine what the load address
2447 // should be. If none is ever set, it will default to being the
2448 // same as the vma address.
2454 laddr
= this->load_address_
->eval_with_dot(symtab
, layout
, true,
2456 this->output_section_
,
2458 if (this->output_section_
!= NULL
)
2459 this->output_section_
->set_load_address(laddr
);
2462 this->evaluated_load_address_
= laddr
;
2465 if (this->subalign_
== NULL
)
2469 Output_section
* subalign_section
;
2470 subalign
= this->subalign_
->eval_with_dot(symtab
, layout
, true,
2472 &subalign_section
, NULL
,
2474 if (subalign_section
!= NULL
)
2475 gold_warning(_("subalign of section %s is not absolute"),
2476 this->name_
.c_str());
2480 if (this->fill_
!= NULL
)
2482 // FIXME: The GNU linker supports fill values of arbitrary
2484 Output_section
* fill_section
;
2485 uint64_t fill_val
= this->fill_
->eval_with_dot(symtab
, layout
, true,
2487 NULL
, &fill_section
,
2489 if (fill_section
!= NULL
)
2490 gold_warning(_("fill of section %s is not absolute"),
2491 this->name_
.c_str());
2492 unsigned char fill_buff
[4];
2493 elfcpp::Swap_unaligned
<32, true>::writeval(fill_buff
, fill_val
);
2494 fill
.assign(reinterpret_cast<char*>(fill_buff
), 4);
2497 Input_section_list input_sections
;
2498 if (this->output_section_
!= NULL
)
2500 // Get the list of input sections attached to this output
2501 // section. This will leave the output section with only
2502 // Output_section_data entries.
2503 address
+= this->output_section_
->get_input_sections(address
,
2506 *dot_value
= address
;
2509 Output_section
* dot_section
= this->output_section_
;
2510 for (Output_section_elements::iterator p
= this->elements_
.begin();
2511 p
!= this->elements_
.end();
2513 (*p
)->set_section_addresses(symtab
, layout
, this->output_section_
,
2514 subalign
, dot_value
, dot_alignment
,
2515 &dot_section
, &fill
, &input_sections
);
2517 gold_assert(input_sections
.empty());
2519 if (vma_region
!= NULL
)
2521 // Update the VMA region being used by the section now that we know how
2522 // big it is. Use the current address in the region, rather than
2523 // start_address because that might have been aligned upwards and we
2524 // need to allow for the padding.
2525 Expression
* addr
= vma_region
->get_current_address();
2526 uint64_t size
= *dot_value
- addr
->eval(symtab
, layout
, false);
2528 vma_region
->increment_offset(this->get_section_name(), size
,
2532 // If the LMA region is different from the VMA region, then increment the
2533 // offset there as well. Note that we use the same "dot_value -
2534 // start_address" formula that is used in the load_address assignment below.
2535 if (lma_region
!= NULL
&& lma_region
!= vma_region
)
2536 lma_region
->increment_offset(this->get_section_name(),
2537 *dot_value
- start_address
,
2540 // Compute the load address for the following section.
2541 if (this->output_section_
== NULL
)
2542 *load_address
= *dot_value
;
2543 else if (this->load_address_
== NULL
)
2545 if (lma_region
== NULL
)
2546 *load_address
= *dot_value
;
2549 lma_region
->get_current_address()->eval(symtab
, layout
, false);
2552 *load_address
= (this->output_section_
->load_address()
2553 + (*dot_value
- start_address
));
2555 if (this->output_section_
!= NULL
)
2557 if (this->is_relro_
)
2558 this->output_section_
->set_is_relro();
2560 this->output_section_
->clear_is_relro();
2562 // If this is a NOLOAD section, keep dot and load address unchanged.
2563 if (this->output_section_
->is_noload())
2565 *dot_value
= old_dot_value
;
2566 *load_address
= old_load_address
;
2571 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
2572 // this section is constrained, and the input sections do not match,
2573 // return the constraint, and set *POSD.
2576 Output_section_definition::check_constraint(Output_section_definition
** posd
)
2578 switch (this->constraint_
)
2580 case CONSTRAINT_NONE
:
2581 return CONSTRAINT_NONE
;
2583 case CONSTRAINT_ONLY_IF_RO
:
2584 if (this->output_section_
!= NULL
2585 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) != 0)
2588 return CONSTRAINT_ONLY_IF_RO
;
2590 return CONSTRAINT_NONE
;
2592 case CONSTRAINT_ONLY_IF_RW
:
2593 if (this->output_section_
!= NULL
2594 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) == 0)
2597 return CONSTRAINT_ONLY_IF_RW
;
2599 return CONSTRAINT_NONE
;
2601 case CONSTRAINT_SPECIAL
:
2602 if (this->output_section_
!= NULL
)
2603 gold_error(_("SPECIAL constraints are not implemented"));
2604 return CONSTRAINT_NONE
;
2611 // See if this is the alternate output section for a constrained
2612 // output section. If it is, transfer the Output_section and return
2613 // true. Otherwise return false.
2616 Output_section_definition::alternate_constraint(
2617 Output_section_definition
* posd
,
2618 Section_constraint constraint
)
2620 if (this->name_
!= posd
->name_
)
2625 case CONSTRAINT_ONLY_IF_RO
:
2626 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RW
)
2630 case CONSTRAINT_ONLY_IF_RW
:
2631 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RO
)
2639 // We have found the alternate constraint. We just need to move
2640 // over the Output_section. When constraints are used properly,
2641 // THIS should not have an output_section pointer, as all the input
2642 // sections should have matched the other definition.
2644 if (this->output_section_
!= NULL
)
2645 gold_error(_("mismatched definition for constrained sections"));
2647 this->output_section_
= posd
->output_section_
;
2648 posd
->output_section_
= NULL
;
2650 if (this->is_relro_
)
2651 this->output_section_
->set_is_relro();
2653 this->output_section_
->clear_is_relro();
2658 // Get the list of segments to use for an allocated section when using
2662 Output_section_definition::allocate_to_segment(String_list
** phdrs_list
,
2665 // Update phdrs_list even if we don't have an output section. It
2666 // might be used by the following sections.
2667 if (this->phdrs_
!= NULL
)
2668 *phdrs_list
= this->phdrs_
;
2670 if (this->output_section_
== NULL
)
2672 if ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) == 0)
2675 return this->output_section_
;
2678 // Look for an output section by name and return the address, the load
2679 // address, the alignment, and the size. This is used when an
2680 // expression refers to an output section which was not actually
2681 // created. This returns true if the section was found, false
2685 Output_section_definition::get_output_section_info(const char* name
,
2687 uint64_t* load_address
,
2688 uint64_t* addralign
,
2689 uint64_t* size
) const
2691 if (this->name_
!= name
)
2694 if (this->output_section_
!= NULL
)
2696 *address
= this->output_section_
->address();
2697 if (this->output_section_
->has_load_address())
2698 *load_address
= this->output_section_
->load_address();
2700 *load_address
= *address
;
2701 *addralign
= this->output_section_
->addralign();
2702 *size
= this->output_section_
->current_data_size();
2706 *address
= this->evaluated_address_
;
2707 *load_address
= this->evaluated_load_address_
;
2708 *addralign
= this->evaluated_addralign_
;
2715 // Print for debugging.
2718 Output_section_definition::print(FILE* f
) const
2720 fprintf(f
, " %s ", this->name_
.c_str());
2722 if (this->address_
!= NULL
)
2724 this->address_
->print(f
);
2728 if (this->script_section_type_
!= SCRIPT_SECTION_TYPE_NONE
)
2730 this->script_section_type_name(this->script_section_type_
));
2734 if (this->load_address_
!= NULL
)
2737 this->load_address_
->print(f
);
2741 if (this->align_
!= NULL
)
2743 fprintf(f
, "ALIGN(");
2744 this->align_
->print(f
);
2748 if (this->subalign_
!= NULL
)
2750 fprintf(f
, "SUBALIGN(");
2751 this->subalign_
->print(f
);
2757 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2758 p
!= this->elements_
.end();
2764 if (this->fill_
!= NULL
)
2767 this->fill_
->print(f
);
2770 if (this->phdrs_
!= NULL
)
2772 for (String_list::const_iterator p
= this->phdrs_
->begin();
2773 p
!= this->phdrs_
->end();
2775 fprintf(f
, " :%s", p
->c_str());
2781 Script_sections::Section_type
2782 Output_section_definition::section_type() const
2784 switch (this->script_section_type_
)
2786 case SCRIPT_SECTION_TYPE_NONE
:
2787 return Script_sections::ST_NONE
;
2788 case SCRIPT_SECTION_TYPE_NOLOAD
:
2789 return Script_sections::ST_NOLOAD
;
2790 case SCRIPT_SECTION_TYPE_COPY
:
2791 case SCRIPT_SECTION_TYPE_DSECT
:
2792 case SCRIPT_SECTION_TYPE_INFO
:
2793 case SCRIPT_SECTION_TYPE_OVERLAY
:
2794 // There are not really support so we treat them as ST_NONE. The
2795 // parse should have issued errors for them already.
2796 return Script_sections::ST_NONE
;
2802 // Return the name of a script section type.
2805 Output_section_definition::script_section_type_name(
2806 Script_section_type script_section_type
)
2808 switch (script_section_type
)
2810 case SCRIPT_SECTION_TYPE_NONE
:
2812 case SCRIPT_SECTION_TYPE_NOLOAD
:
2814 case SCRIPT_SECTION_TYPE_DSECT
:
2816 case SCRIPT_SECTION_TYPE_COPY
:
2818 case SCRIPT_SECTION_TYPE_INFO
:
2820 case SCRIPT_SECTION_TYPE_OVERLAY
:
2828 Output_section_definition::set_memory_region(Memory_region
* mr
, bool set_vma
)
2830 gold_assert(mr
!= NULL
);
2831 // Add the current section to the specified region's list.
2832 mr
->add_section(this, set_vma
);
2835 // An output section created to hold orphaned input sections. These
2836 // do not actually appear in linker scripts. However, for convenience
2837 // when setting the output section addresses, we put a marker to these
2838 // sections in the appropriate place in the list of SECTIONS elements.
2840 class Orphan_output_section
: public Sections_element
2843 Orphan_output_section(Output_section
* os
)
2847 // Return whether the orphan output section is relro. We can just
2848 // check the output section because we always set the flag, if
2849 // needed, just after we create the Orphan_output_section.
2852 { return this->os_
->is_relro(); }
2854 // Initialize OSP with an output section. This should have been
2857 orphan_section_init(Orphan_section_placement
*,
2858 Script_sections::Elements_iterator
)
2859 { gold_unreachable(); }
2861 // Set section addresses.
2863 set_section_addresses(Symbol_table
*, Layout
*, uint64_t*, uint64_t*,
2866 // Get the list of segments to use for an allocated section when
2867 // using a PHDRS clause.
2869 allocate_to_segment(String_list
**, bool*);
2871 // Return the associated Output_section.
2873 get_output_section() const
2874 { return this->os_
; }
2876 // Print for debugging.
2878 print(FILE* f
) const
2880 fprintf(f
, " marker for orphaned output section %s\n",
2885 Output_section
* os_
;
2888 // Set section addresses.
2891 Orphan_output_section::set_section_addresses(Symbol_table
*, Layout
*,
2892 uint64_t* dot_value
,
2894 uint64_t* load_address
)
2896 typedef std::list
<Output_section::Input_section
> Input_section_list
;
2898 bool have_load_address
= *load_address
!= *dot_value
;
2900 uint64_t address
= *dot_value
;
2901 address
= align_address(address
, this->os_
->addralign());
2903 // If input section sorting is requested via --section-ordering-file or
2904 // linker plugins, then do it here. This is important because we want
2905 // any sorting specified in the linker scripts, which will be done after
2906 // this, to take precedence. The final order of input sections is then
2907 // guaranteed to be according to the linker script specification.
2908 if (this->os_
!= NULL
2909 && this->os_
->input_section_order_specified())
2910 this->os_
->sort_attached_input_sections();
2912 // For a relocatable link, all orphan sections are put at
2913 // address 0. In general we expect all sections to be at
2914 // address 0 for a relocatable link, but we permit the linker
2915 // script to override that for specific output sections.
2916 if (parameters
->options().relocatable())
2920 have_load_address
= false;
2923 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) != 0)
2925 this->os_
->set_address(address
);
2926 if (have_load_address
)
2927 this->os_
->set_load_address(align_address(*load_address
,
2928 this->os_
->addralign()));
2931 Input_section_list input_sections
;
2932 address
+= this->os_
->get_input_sections(address
, "", &input_sections
);
2934 for (Input_section_list::iterator p
= input_sections
.begin();
2935 p
!= input_sections
.end();
2938 uint64_t addralign
= p
->addralign();
2939 if (!p
->is_input_section())
2940 p
->output_section_data()->finalize_data_size();
2941 uint64_t size
= p
->data_size();
2942 address
= align_address(address
, addralign
);
2943 this->os_
->add_script_input_section(*p
);
2947 if (parameters
->options().relocatable())
2949 // For a relocatable link, reset DOT_VALUE to 0.
2953 else if (this->os_
== NULL
2954 || (this->os_
->flags() & elfcpp::SHF_TLS
) == 0
2955 || this->os_
->type() != elfcpp::SHT_NOBITS
)
2957 // An SHF_TLS/SHT_NOBITS section does not take up any address space.
2958 if (!have_load_address
)
2959 *load_address
= address
;
2961 *load_address
+= address
- *dot_value
;
2963 *dot_value
= address
;
2967 // Get the list of segments to use for an allocated section when using
2968 // a PHDRS clause. If this is an allocated section, return the
2969 // Output_section. We don't change the list of segments.
2972 Orphan_output_section::allocate_to_segment(String_list
**, bool* orphan
)
2974 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) == 0)
2980 // Class Phdrs_element. A program header from a PHDRS clause.
2985 Phdrs_element(const char* name
, size_t namelen
, unsigned int type
,
2986 bool includes_filehdr
, bool includes_phdrs
,
2987 bool is_flags_valid
, unsigned int flags
,
2988 Expression
* load_address
)
2989 : name_(name
, namelen
), type_(type
), includes_filehdr_(includes_filehdr
),
2990 includes_phdrs_(includes_phdrs
), is_flags_valid_(is_flags_valid
),
2991 flags_(flags
), load_address_(load_address
), load_address_value_(0),
2995 // Return the name of this segment.
2998 { return this->name_
; }
3000 // Return the type of the segment.
3003 { return this->type_
; }
3005 // Whether to include the file header.
3007 includes_filehdr() const
3008 { return this->includes_filehdr_
; }
3010 // Whether to include the program headers.
3012 includes_phdrs() const
3013 { return this->includes_phdrs_
; }
3015 // Return whether there is a load address.
3017 has_load_address() const
3018 { return this->load_address_
!= NULL
; }
3020 // Evaluate the load address expression if there is one.
3022 eval_load_address(Symbol_table
* symtab
, Layout
* layout
)
3024 if (this->load_address_
!= NULL
)
3025 this->load_address_value_
= this->load_address_
->eval(symtab
, layout
,
3029 // Return the load address.
3031 load_address() const
3033 gold_assert(this->load_address_
!= NULL
);
3034 return this->load_address_value_
;
3037 // Create the segment.
3039 create_segment(Layout
* layout
)
3041 this->segment_
= layout
->make_output_segment(this->type_
, this->flags_
);
3042 return this->segment_
;
3045 // Return the segment.
3048 { return this->segment_
; }
3050 // Release the segment.
3053 { this->segment_
= NULL
; }
3055 // Set the segment flags if appropriate.
3057 set_flags_if_valid()
3059 if (this->is_flags_valid_
)
3060 this->segment_
->set_flags(this->flags_
);
3063 // Print for debugging.
3068 // The name used in the script.
3070 // The type of the segment (PT_LOAD, etc.).
3072 // Whether this segment includes the file header.
3073 bool includes_filehdr_
;
3074 // Whether this segment includes the section headers.
3075 bool includes_phdrs_
;
3076 // Whether the flags were explicitly specified.
3077 bool is_flags_valid_
;
3078 // The flags for this segment (PF_R, etc.) if specified.
3079 unsigned int flags_
;
3080 // The expression for the load address for this segment. This may
3082 Expression
* load_address_
;
3083 // The actual load address from evaluating the expression.
3084 uint64_t load_address_value_
;
3085 // The segment itself.
3086 Output_segment
* segment_
;
3089 // Print for debugging.
3092 Phdrs_element::print(FILE* f
) const
3094 fprintf(f
, " %s 0x%x", this->name_
.c_str(), this->type_
);
3095 if (this->includes_filehdr_
)
3096 fprintf(f
, " FILEHDR");
3097 if (this->includes_phdrs_
)
3098 fprintf(f
, " PHDRS");
3099 if (this->is_flags_valid_
)
3100 fprintf(f
, " FLAGS(%u)", this->flags_
);
3101 if (this->load_address_
!= NULL
)
3104 this->load_address_
->print(f
);
3110 // Add a memory region.
3113 Script_sections::add_memory_region(const char* name
, size_t namelen
,
3114 unsigned int attributes
,
3115 Expression
* start
, Expression
* length
)
3117 if (this->memory_regions_
== NULL
)
3118 this->memory_regions_
= new Memory_regions();
3119 else if (this->find_memory_region(name
, namelen
))
3121 gold_error(_("region '%.*s' already defined"), static_cast<int>(namelen
),
3123 // FIXME: Add a GOLD extension to allow multiple regions with the same
3124 // name. This would amount to a single region covering disjoint blocks
3125 // of memory, which is useful for embedded devices.
3128 // FIXME: Check the length and start values. Currently we allow
3129 // non-constant expressions for these values, whereas LD does not.
3131 // FIXME: Add a GOLD extension to allow NEGATIVE LENGTHS. This would
3132 // describe a region that packs from the end address going down, rather
3133 // than the start address going up. This would be useful for embedded
3136 this->memory_regions_
->push_back(new Memory_region(name
, namelen
, attributes
,
3140 // Find a memory region.
3143 Script_sections::find_memory_region(const char* name
, size_t namelen
)
3145 if (this->memory_regions_
== NULL
)
3148 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
3149 m
!= this->memory_regions_
->end();
3151 if ((*m
)->name_match(name
, namelen
))
3157 // Find a memory region's origin.
3160 Script_sections::find_memory_region_origin(const char* name
, size_t namelen
)
3162 Memory_region
* mr
= find_memory_region(name
, namelen
);
3166 return mr
->start_address();
3169 // Find a memory region's length.
3172 Script_sections::find_memory_region_length(const char* name
, size_t namelen
)
3174 Memory_region
* mr
= find_memory_region(name
, namelen
);
3178 return mr
->length();
3181 // Set the memory region to use for the current section.
3184 Script_sections::set_memory_region(Memory_region
* mr
, bool set_vma
)
3186 gold_assert(!this->sections_elements_
->empty());
3187 this->sections_elements_
->back()->set_memory_region(mr
, set_vma
);
3190 // Class Script_sections.
3192 Script_sections::Script_sections()
3193 : saw_sections_clause_(false),
3194 in_sections_clause_(false),
3195 sections_elements_(NULL
),
3196 output_section_(NULL
),
3197 memory_regions_(NULL
),
3198 phdrs_elements_(NULL
),
3199 orphan_section_placement_(NULL
),
3200 data_segment_align_start_(),
3201 saw_data_segment_align_(false),
3202 saw_relro_end_(false),
3203 saw_segment_start_expression_(false)
3207 // Start a SECTIONS clause.
3210 Script_sections::start_sections()
3212 gold_assert(!this->in_sections_clause_
&& this->output_section_
== NULL
);
3213 this->saw_sections_clause_
= true;
3214 this->in_sections_clause_
= true;
3215 if (this->sections_elements_
== NULL
)
3216 this->sections_elements_
= new Sections_elements
;
3219 // Finish a SECTIONS clause.
3222 Script_sections::finish_sections()
3224 gold_assert(this->in_sections_clause_
&& this->output_section_
== NULL
);
3225 this->in_sections_clause_
= false;
3228 // Add a symbol to be defined.
3231 Script_sections::add_symbol_assignment(const char* name
, size_t length
,
3232 Expression
* val
, bool provide
,
3235 if (this->output_section_
!= NULL
)
3236 this->output_section_
->add_symbol_assignment(name
, length
, val
,
3240 Sections_element
* p
= new Sections_element_assignment(name
, length
,
3243 this->sections_elements_
->push_back(p
);
3247 // Add an assignment to the special dot symbol.
3250 Script_sections::add_dot_assignment(Expression
* val
)
3252 if (this->output_section_
!= NULL
)
3253 this->output_section_
->add_dot_assignment(val
);
3256 // The GNU linker permits assignments to . to appears outside of
3257 // a SECTIONS clause, and treats it as appearing inside, so
3258 // sections_elements_ may be NULL here.
3259 if (this->sections_elements_
== NULL
)
3261 this->sections_elements_
= new Sections_elements
;
3262 this->saw_sections_clause_
= true;
3265 Sections_element
* p
= new Sections_element_dot_assignment(val
);
3266 this->sections_elements_
->push_back(p
);
3270 // Add an assertion.
3273 Script_sections::add_assertion(Expression
* check
, const char* message
,
3276 if (this->output_section_
!= NULL
)
3277 this->output_section_
->add_assertion(check
, message
, messagelen
);
3280 Sections_element
* p
= new Sections_element_assertion(check
, message
,
3282 this->sections_elements_
->push_back(p
);
3286 // Start processing entries for an output section.
3289 Script_sections::start_output_section(
3292 const Parser_output_section_header
* header
)
3294 Output_section_definition
* posd
= new Output_section_definition(name
,
3297 this->sections_elements_
->push_back(posd
);
3298 gold_assert(this->output_section_
== NULL
);
3299 this->output_section_
= posd
;
3302 // Stop processing entries for an output section.
3305 Script_sections::finish_output_section(
3306 const Parser_output_section_trailer
* trailer
)
3308 gold_assert(this->output_section_
!= NULL
);
3309 this->output_section_
->finish(trailer
);
3310 this->output_section_
= NULL
;
3313 // Add a data item to the current output section.
3316 Script_sections::add_data(int size
, bool is_signed
, Expression
* val
)
3318 gold_assert(this->output_section_
!= NULL
);
3319 this->output_section_
->add_data(size
, is_signed
, val
);
3322 // Add a fill value setting to the current output section.
3325 Script_sections::add_fill(Expression
* val
)
3327 gold_assert(this->output_section_
!= NULL
);
3328 this->output_section_
->add_fill(val
);
3331 // Add an input section specification to the current output section.
3334 Script_sections::add_input_section(const Input_section_spec
* spec
, bool keep
)
3336 gold_assert(this->output_section_
!= NULL
);
3337 this->output_section_
->add_input_section(spec
, keep
);
3340 // This is called when we see DATA_SEGMENT_ALIGN. It means that any
3341 // subsequent output sections may be relro.
3344 Script_sections::data_segment_align()
3346 if (this->saw_data_segment_align_
)
3347 gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script"));
3348 gold_assert(!this->sections_elements_
->empty());
3349 Sections_elements::iterator p
= this->sections_elements_
->end();
3351 this->data_segment_align_start_
= p
;
3352 this->saw_data_segment_align_
= true;
3355 // This is called when we see DATA_SEGMENT_RELRO_END. It means that
3356 // any output sections seen since DATA_SEGMENT_ALIGN are relro.
3359 Script_sections::data_segment_relro_end()
3361 if (this->saw_relro_end_
)
3362 gold_error(_("DATA_SEGMENT_RELRO_END may only appear once "
3363 "in a linker script"));
3364 this->saw_relro_end_
= true;
3366 if (!this->saw_data_segment_align_
)
3367 gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN"));
3370 Sections_elements::iterator p
= this->data_segment_align_start_
;
3371 for (++p
; p
!= this->sections_elements_
->end(); ++p
)
3372 (*p
)->set_is_relro();
3376 // Create any required sections.
3379 Script_sections::create_sections(Layout
* layout
)
3381 if (!this->saw_sections_clause_
)
3383 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3384 p
!= this->sections_elements_
->end();
3386 (*p
)->create_sections(layout
);
3389 // Add any symbols we are defining to the symbol table.
3392 Script_sections::add_symbols_to_table(Symbol_table
* symtab
)
3394 if (!this->saw_sections_clause_
)
3396 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3397 p
!= this->sections_elements_
->end();
3399 (*p
)->add_symbols_to_table(symtab
);
3402 // Finalize symbols and check assertions.
3405 Script_sections::finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
)
3407 if (!this->saw_sections_clause_
)
3409 uint64_t dot_value
= 0;
3410 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3411 p
!= this->sections_elements_
->end();
3413 (*p
)->finalize_symbols(symtab
, layout
, &dot_value
);
3416 // Return the name of the output section to use for an input file name
3417 // and section name.
3420 Script_sections::output_section_name(
3421 const char* file_name
,
3422 const char* section_name
,
3423 Output_section
*** output_section_slot
,
3424 Script_sections::Section_type
* psection_type
,
3427 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3428 p
!= this->sections_elements_
->end();
3431 const char* ret
= (*p
)->output_section_name(file_name
, section_name
,
3432 output_section_slot
,
3433 psection_type
, keep
);
3437 // The special name /DISCARD/ means that the input section
3438 // should be discarded.
3439 if (strcmp(ret
, "/DISCARD/") == 0)
3441 *output_section_slot
= NULL
;
3442 *psection_type
= Script_sections::ST_NONE
;
3449 // If we couldn't find a mapping for the name, the output section
3450 // gets the name of the input section.
3452 *output_section_slot
= NULL
;
3453 *psection_type
= Script_sections::ST_NONE
;
3455 return section_name
;
3458 // Place a marker for an orphan output section into the SECTIONS
3462 Script_sections::place_orphan(Output_section
* os
)
3464 Orphan_section_placement
* osp
= this->orphan_section_placement_
;
3467 // Initialize the Orphan_section_placement structure.
3468 osp
= new Orphan_section_placement();
3469 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3470 p
!= this->sections_elements_
->end();
3472 (*p
)->orphan_section_init(osp
, p
);
3473 gold_assert(!this->sections_elements_
->empty());
3474 Sections_elements::iterator last
= this->sections_elements_
->end();
3476 osp
->last_init(last
);
3477 this->orphan_section_placement_
= osp
;
3480 Orphan_output_section
* orphan
= new Orphan_output_section(os
);
3482 // Look for where to put ORPHAN.
3483 Sections_elements::iterator
* where
;
3484 if (osp
->find_place(os
, &where
))
3486 if ((**where
)->is_relro())
3489 os
->clear_is_relro();
3491 // We want to insert ORPHAN after *WHERE, and then update *WHERE
3492 // so that the next one goes after this one.
3493 Sections_elements::iterator p
= *where
;
3494 gold_assert(p
!= this->sections_elements_
->end());
3496 *where
= this->sections_elements_
->insert(p
, orphan
);
3500 os
->clear_is_relro();
3501 // We don't have a place to put this orphan section. Put it,
3502 // and all other sections like it, at the end, but before the
3503 // sections which always come at the end.
3504 Sections_elements::iterator last
= osp
->last_place();
3505 *where
= this->sections_elements_
->insert(last
, orphan
);
3509 // Set the addresses of all the output sections. Walk through all the
3510 // elements, tracking the dot symbol. Apply assignments which set
3511 // absolute symbol values, in case they are used when setting dot.
3512 // Fill in data statement values. As we find output sections, set the
3513 // address, set the address of all associated input sections, and
3514 // update dot. Return the segment which should hold the file header
3515 // and segment headers, if any.
3518 Script_sections::set_section_addresses(Symbol_table
* symtab
, Layout
* layout
)
3520 gold_assert(this->saw_sections_clause_
);
3522 // Implement ONLY_IF_RO/ONLY_IF_RW constraints. These are a pain
3523 // for our representation.
3524 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3525 p
!= this->sections_elements_
->end();
3528 Output_section_definition
* posd
;
3529 Section_constraint failed_constraint
= (*p
)->check_constraint(&posd
);
3530 if (failed_constraint
!= CONSTRAINT_NONE
)
3532 Sections_elements::iterator q
;
3533 for (q
= this->sections_elements_
->begin();
3534 q
!= this->sections_elements_
->end();
3539 if ((*q
)->alternate_constraint(posd
, failed_constraint
))
3544 if (q
== this->sections_elements_
->end())
3545 gold_error(_("no matching section constraint"));
3549 // Force the alignment of the first TLS section to be the maximum
3550 // alignment of all TLS sections.
3551 Output_section
* first_tls
= NULL
;
3552 uint64_t tls_align
= 0;
3553 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3554 p
!= this->sections_elements_
->end();
3557 Output_section
* os
= (*p
)->get_output_section();
3558 if (os
!= NULL
&& (os
->flags() & elfcpp::SHF_TLS
) != 0)
3560 if (first_tls
== NULL
)
3562 if (os
->addralign() > tls_align
)
3563 tls_align
= os
->addralign();
3566 if (first_tls
!= NULL
)
3567 first_tls
->set_addralign(tls_align
);
3569 // For a relocatable link, we implicitly set dot to zero.
3570 uint64_t dot_value
= 0;
3571 uint64_t dot_alignment
= 0;
3572 uint64_t load_address
= 0;
3574 // Check to see if we want to use any of -Ttext, -Tdata and -Tbss options
3575 // to set section addresses. If the script has any SEGMENT_START
3576 // expression, we do not set the section addresses.
3577 bool use_tsection_options
=
3578 (!this->saw_segment_start_expression_
3579 && (parameters
->options().user_set_Ttext()
3580 || parameters
->options().user_set_Tdata()
3581 || parameters
->options().user_set_Tbss()));
3583 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3584 p
!= this->sections_elements_
->end();
3587 Output_section
* os
= (*p
)->get_output_section();
3589 // Handle -Ttext, -Tdata and -Tbss options. We do this by looking for
3590 // the special sections by names and doing dot assignments.
3591 if (use_tsection_options
3593 && (os
->flags() & elfcpp::SHF_ALLOC
) != 0)
3595 uint64_t new_dot_value
= dot_value
;
3597 if (parameters
->options().user_set_Ttext()
3598 && strcmp(os
->name(), ".text") == 0)
3599 new_dot_value
= parameters
->options().Ttext();
3600 else if (parameters
->options().user_set_Tdata()
3601 && strcmp(os
->name(), ".data") == 0)
3602 new_dot_value
= parameters
->options().Tdata();
3603 else if (parameters
->options().user_set_Tbss()
3604 && strcmp(os
->name(), ".bss") == 0)
3605 new_dot_value
= parameters
->options().Tbss();
3607 // Update dot and load address if necessary.
3608 if (new_dot_value
< dot_value
)
3609 gold_error(_("dot may not move backward"));
3610 else if (new_dot_value
!= dot_value
)
3612 dot_value
= new_dot_value
;
3613 load_address
= new_dot_value
;
3617 (*p
)->set_section_addresses(symtab
, layout
, &dot_value
, &dot_alignment
,
3621 if (this->phdrs_elements_
!= NULL
)
3623 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
3624 p
!= this->phdrs_elements_
->end();
3626 (*p
)->eval_load_address(symtab
, layout
);
3629 return this->create_segments(layout
, dot_alignment
);
3632 // Sort the sections in order to put them into segments.
3634 class Sort_output_sections
3637 Sort_output_sections(const Script_sections::Sections_elements
* elements
)
3638 : elements_(elements
)
3642 operator()(const Output_section
* os1
, const Output_section
* os2
) const;
3646 script_compare(const Output_section
* os1
, const Output_section
* os2
) const;
3649 const Script_sections::Sections_elements
* elements_
;
3653 Sort_output_sections::operator()(const Output_section
* os1
,
3654 const Output_section
* os2
) const
3656 // Sort first by the load address.
3657 uint64_t lma1
= (os1
->has_load_address()
3658 ? os1
->load_address()
3660 uint64_t lma2
= (os2
->has_load_address()
3661 ? os2
->load_address()
3666 // Then sort by the virtual address.
3667 if (os1
->address() != os2
->address())
3668 return os1
->address() < os2
->address();
3670 // If the linker script says which of these sections is first, go
3671 // with what it says.
3672 int i
= this->script_compare(os1
, os2
);
3676 // Sort PROGBITS before NOBITS.
3677 bool nobits1
= os1
->type() == elfcpp::SHT_NOBITS
;
3678 bool nobits2
= os2
->type() == elfcpp::SHT_NOBITS
;
3679 if (nobits1
!= nobits2
)
3682 // Sort PROGBITS TLS sections to the end, NOBITS TLS sections to the
3684 bool tls1
= (os1
->flags() & elfcpp::SHF_TLS
) != 0;
3685 bool tls2
= (os2
->flags() & elfcpp::SHF_TLS
) != 0;
3687 return nobits1
? tls1
: tls2
;
3689 // Sort non-NOLOAD before NOLOAD.
3690 if (os1
->is_noload() && !os2
->is_noload())
3692 if (!os1
->is_noload() && os2
->is_noload())
3695 // The sections seem practically identical. Sort by name to get a
3697 return os1
->name() < os2
->name();
3700 // Return -1 if OS1 comes before OS2 in ELEMENTS_, 1 if comes after, 0
3701 // if either OS1 or OS2 is not mentioned. This ensures that we keep
3702 // empty sections in the order in which they appear in a linker
3706 Sort_output_sections::script_compare(const Output_section
* os1
,
3707 const Output_section
* os2
) const
3709 if (this->elements_
== NULL
)
3712 bool found_os1
= false;
3713 bool found_os2
= false;
3714 for (Script_sections::Sections_elements::const_iterator
3715 p
= this->elements_
->begin();
3716 p
!= this->elements_
->end();
3719 if (os2
== (*p
)->get_output_section())
3725 else if (os1
== (*p
)->get_output_section())
3736 // Return whether OS is a BSS section. This is a SHT_NOBITS section.
3737 // We treat a section with the SHF_TLS flag set as taking up space
3738 // even if it is SHT_NOBITS (this is true of .tbss), as we allocate
3739 // space for them in the file.
3742 Script_sections::is_bss_section(const Output_section
* os
)
3744 return (os
->type() == elfcpp::SHT_NOBITS
3745 && (os
->flags() & elfcpp::SHF_TLS
) == 0);
3748 // Return the size taken by the file header and the program headers.
3751 Script_sections::total_header_size(Layout
* layout
) const
3753 size_t segment_count
= layout
->segment_count();
3754 size_t file_header_size
;
3755 size_t segment_headers_size
;
3756 if (parameters
->target().get_size() == 32)
3758 file_header_size
= elfcpp::Elf_sizes
<32>::ehdr_size
;
3759 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<32>::phdr_size
;
3761 else if (parameters
->target().get_size() == 64)
3763 file_header_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
3764 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<64>::phdr_size
;
3769 return file_header_size
+ segment_headers_size
;
3772 // Return the amount we have to subtract from the LMA to accommodate
3773 // headers of the given size. The complication is that the file
3774 // header have to be at the start of a page, as otherwise it will not
3775 // be at the start of the file.
3778 Script_sections::header_size_adjustment(uint64_t lma
,
3779 size_t sizeof_headers
) const
3781 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3782 uint64_t hdr_lma
= lma
- sizeof_headers
;
3783 hdr_lma
&= ~(abi_pagesize
- 1);
3784 return lma
- hdr_lma
;
3787 // Create the PT_LOAD segments when using a SECTIONS clause. Returns
3788 // the segment which should hold the file header and segment headers,
3792 Script_sections::create_segments(Layout
* layout
, uint64_t dot_alignment
)
3794 gold_assert(this->saw_sections_clause_
);
3796 if (parameters
->options().relocatable())
3799 if (this->saw_phdrs_clause())
3800 return create_segments_from_phdrs_clause(layout
, dot_alignment
);
3802 Layout::Section_list sections
;
3803 layout
->get_allocated_sections(§ions
);
3805 // Sort the sections by address.
3806 std::stable_sort(sections
.begin(), sections
.end(),
3807 Sort_output_sections(this->sections_elements_
));
3809 this->create_note_and_tls_segments(layout
, §ions
);
3811 // Walk through the sections adding them to PT_LOAD segments.
3812 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3813 Output_segment
* first_seg
= NULL
;
3814 Output_segment
* current_seg
= NULL
;
3815 bool is_current_seg_readonly
= true;
3816 Layout::Section_list::iterator plast
= sections
.end();
3817 uint64_t last_vma
= 0;
3818 uint64_t last_lma
= 0;
3819 uint64_t last_size
= 0;
3820 for (Layout::Section_list::iterator p
= sections
.begin();
3821 p
!= sections
.end();
3824 const uint64_t vma
= (*p
)->address();
3825 const uint64_t lma
= ((*p
)->has_load_address()
3826 ? (*p
)->load_address()
3828 const uint64_t size
= (*p
)->current_data_size();
3830 bool need_new_segment
;
3831 if (current_seg
== NULL
)
3832 need_new_segment
= true;
3833 else if (lma
- vma
!= last_lma
- last_vma
)
3835 // This section has a different LMA relationship than the
3836 // last one; we need a new segment.
3837 need_new_segment
= true;
3839 else if (align_address(last_lma
+ last_size
, abi_pagesize
)
3840 < align_address(lma
, abi_pagesize
))
3842 // Putting this section in the segment would require
3844 need_new_segment
= true;
3846 else if (is_bss_section(*plast
) && !is_bss_section(*p
))
3848 // A non-BSS section can not follow a BSS section in the
3850 need_new_segment
= true;
3852 else if (is_current_seg_readonly
3853 && ((*p
)->flags() & elfcpp::SHF_WRITE
) != 0
3854 && !parameters
->options().omagic())
3856 // Don't put a writable section in the same segment as a
3857 // non-writable section.
3858 need_new_segment
= true;
3862 // Otherwise, reuse the existing segment.
3863 need_new_segment
= false;
3866 elfcpp::Elf_Word seg_flags
=
3867 Layout::section_flags_to_segment((*p
)->flags());
3869 if (need_new_segment
)
3871 current_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
3873 current_seg
->set_addresses(vma
, lma
);
3874 current_seg
->set_minimum_p_align(dot_alignment
);
3875 if (first_seg
== NULL
)
3876 first_seg
= current_seg
;
3877 is_current_seg_readonly
= true;
3880 current_seg
->add_output_section_to_load(layout
, *p
, seg_flags
);
3882 if (((*p
)->flags() & elfcpp::SHF_WRITE
) != 0)
3883 is_current_seg_readonly
= false;
3891 // An ELF program should work even if the program headers are not in
3892 // a PT_LOAD segment. However, it appears that the Linux kernel
3893 // does not set the AT_PHDR auxiliary entry in that case. It sets
3894 // the load address to p_vaddr - p_offset of the first PT_LOAD
3895 // segment. It then sets AT_PHDR to the load address plus the
3896 // offset to the program headers, e_phoff in the file header. This
3897 // fails when the program headers appear in the file before the
3898 // first PT_LOAD segment. Therefore, we always create a PT_LOAD
3899 // segment to hold the file header and the program headers. This is
3900 // effectively what the GNU linker does, and it is slightly more
3901 // efficient in any case. We try to use the first PT_LOAD segment
3902 // if we can, otherwise we make a new one.
3904 if (first_seg
== NULL
)
3907 // -n or -N mean that the program is not demand paged and there is
3908 // no need to put the program headers in a PT_LOAD segment.
3909 if (parameters
->options().nmagic() || parameters
->options().omagic())
3912 size_t sizeof_headers
= this->total_header_size(layout
);
3914 uint64_t vma
= first_seg
->vaddr();
3915 uint64_t lma
= first_seg
->paddr();
3917 uint64_t subtract
= this->header_size_adjustment(lma
, sizeof_headers
);
3919 if ((lma
& (abi_pagesize
- 1)) >= sizeof_headers
)
3921 first_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
3925 // If there is no room to squeeze in the headers, then punt. The
3926 // resulting executable probably won't run on GNU/Linux, but we
3927 // trust that the user knows what they are doing.
3928 if (lma
< subtract
|| vma
< subtract
)
3931 // If memory regions have been specified and the address range
3932 // we are about to use is not contained within any region then
3933 // issue a warning message about the segment we are going to
3934 // create. It will be outside of any region and so possibly
3935 // using non-existent or protected memory. We test LMA rather
3936 // than VMA since we assume that the headers will never be
3938 if (this->memory_regions_
!= NULL
3939 && !this->block_in_region (NULL
, layout
, lma
- subtract
, subtract
))
3940 gold_warning(_("creating a segment to contain the file and program"
3941 " headers outside of any MEMORY region"));
3943 Output_segment
* load_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
3945 load_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
3950 // Create a PT_NOTE segment for each SHT_NOTE section and a PT_TLS
3951 // segment if there are any SHT_TLS sections.
3954 Script_sections::create_note_and_tls_segments(
3956 const Layout::Section_list
* sections
)
3958 gold_assert(!this->saw_phdrs_clause());
3960 bool saw_tls
= false;
3961 for (Layout::Section_list::const_iterator p
= sections
->begin();
3962 p
!= sections
->end();
3965 if ((*p
)->type() == elfcpp::SHT_NOTE
)
3967 elfcpp::Elf_Word seg_flags
=
3968 Layout::section_flags_to_segment((*p
)->flags());
3969 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_NOTE
,
3971 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
3973 // Incorporate any subsequent SHT_NOTE sections, in the
3974 // hopes that the script is sensible.
3975 Layout::Section_list::const_iterator pnext
= p
+ 1;
3976 while (pnext
!= sections
->end()
3977 && (*pnext
)->type() == elfcpp::SHT_NOTE
)
3979 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
3980 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
3986 if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
3989 gold_error(_("TLS sections are not adjacent"));
3991 elfcpp::Elf_Word seg_flags
=
3992 Layout::section_flags_to_segment((*p
)->flags());
3993 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_TLS
,
3995 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
3997 Layout::Section_list::const_iterator pnext
= p
+ 1;
3998 while (pnext
!= sections
->end()
3999 && ((*pnext
)->flags() & elfcpp::SHF_TLS
) != 0)
4001 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
4002 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
4010 // If we are making a shared library, and we see a section named
4011 // .interp then put the .interp section in a PT_INTERP segment.
4012 // This is for GNU ld compatibility.
4013 if (strcmp((*p
)->name(), ".interp") == 0)
4015 elfcpp::Elf_Word seg_flags
=
4016 Layout::section_flags_to_segment((*p
)->flags());
4017 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_INTERP
,
4019 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
4024 // Add a program header. The PHDRS clause is syntactically distinct
4025 // from the SECTIONS clause, but we implement it with the SECTIONS
4026 // support because PHDRS is useless if there is no SECTIONS clause.
4029 Script_sections::add_phdr(const char* name
, size_t namelen
, unsigned int type
,
4030 bool includes_filehdr
, bool includes_phdrs
,
4031 bool is_flags_valid
, unsigned int flags
,
4032 Expression
* load_address
)
4034 if (this->phdrs_elements_
== NULL
)
4035 this->phdrs_elements_
= new Phdrs_elements();
4036 this->phdrs_elements_
->push_back(new Phdrs_element(name
, namelen
, type
,
4039 is_flags_valid
, flags
,
4043 // Return the number of segments we expect to create based on the
4044 // SECTIONS clause. This is used to implement SIZEOF_HEADERS.
4047 Script_sections::expected_segment_count(const Layout
* layout
) const
4049 if (this->saw_phdrs_clause())
4050 return this->phdrs_elements_
->size();
4052 Layout::Section_list sections
;
4053 layout
->get_allocated_sections(§ions
);
4055 // We assume that we will need two PT_LOAD segments.
4058 bool saw_note
= false;
4059 bool saw_tls
= false;
4060 for (Layout::Section_list::const_iterator p
= sections
.begin();
4061 p
!= sections
.end();
4064 if ((*p
)->type() == elfcpp::SHT_NOTE
)
4066 // Assume that all note sections will fit into a single
4074 else if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
4076 // There can only be one PT_TLS segment.
4088 // Create the segments from a PHDRS clause. Return the segment which
4089 // should hold the file header and program headers, if any.
4092 Script_sections::create_segments_from_phdrs_clause(Layout
* layout
,
4093 uint64_t dot_alignment
)
4095 this->attach_sections_using_phdrs_clause(layout
);
4096 return this->set_phdrs_clause_addresses(layout
, dot_alignment
);
4099 // Create the segments from the PHDRS clause, and put the output
4100 // sections in them.
4103 Script_sections::attach_sections_using_phdrs_clause(Layout
* layout
)
4105 typedef std::map
<std::string
, Output_segment
*> Name_to_segment
;
4106 Name_to_segment name_to_segment
;
4107 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4108 p
!= this->phdrs_elements_
->end();
4110 name_to_segment
[(*p
)->name()] = (*p
)->create_segment(layout
);
4112 // Walk through the output sections and attach them to segments.
4113 // Output sections in the script which do not list segments are
4114 // attached to the same set of segments as the immediately preceding
4117 String_list
* phdr_names
= NULL
;
4118 bool load_segments_only
= false;
4119 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4120 p
!= this->sections_elements_
->end();
4124 String_list
* old_phdr_names
= phdr_names
;
4125 Output_section
* os
= (*p
)->allocate_to_segment(&phdr_names
, &is_orphan
);
4129 elfcpp::Elf_Word seg_flags
=
4130 Layout::section_flags_to_segment(os
->flags());
4132 if (phdr_names
== NULL
)
4134 // Don't worry about empty orphan sections.
4135 if (is_orphan
&& os
->current_data_size() > 0)
4136 gold_error(_("allocated section %s not in any segment"),
4139 // To avoid later crashes drop this section into the first
4141 for (Phdrs_elements::const_iterator ppe
=
4142 this->phdrs_elements_
->begin();
4143 ppe
!= this->phdrs_elements_
->end();
4146 Output_segment
* oseg
= (*ppe
)->segment();
4147 if (oseg
->type() == elfcpp::PT_LOAD
)
4149 oseg
->add_output_section_to_load(layout
, os
, seg_flags
);
4157 // We see a list of segments names. Disable PT_LOAD segment only
4159 if (old_phdr_names
!= phdr_names
)
4160 load_segments_only
= false;
4162 // If this is an orphan section--one that was not explicitly
4163 // mentioned in the linker script--then it should not inherit
4164 // any segment type other than PT_LOAD. Otherwise, e.g., the
4165 // PT_INTERP segment will pick up following orphan sections,
4166 // which does not make sense. If this is not an orphan section,
4167 // we trust the linker script.
4170 // Enable PT_LOAD segments only filtering until we see another
4171 // list of segment names.
4172 load_segments_only
= true;
4175 bool in_load_segment
= false;
4176 for (String_list::const_iterator q
= phdr_names
->begin();
4177 q
!= phdr_names
->end();
4180 Name_to_segment::const_iterator r
= name_to_segment
.find(*q
);
4181 if (r
== name_to_segment
.end())
4182 gold_error(_("no segment %s"), q
->c_str());
4185 if (load_segments_only
4186 && r
->second
->type() != elfcpp::PT_LOAD
)
4189 if (r
->second
->type() != elfcpp::PT_LOAD
)
4190 r
->second
->add_output_section_to_nonload(os
, seg_flags
);
4193 r
->second
->add_output_section_to_load(layout
, os
, seg_flags
);
4194 if (in_load_segment
)
4195 gold_error(_("section in two PT_LOAD segments"));
4196 in_load_segment
= true;
4201 if (!in_load_segment
)
4202 gold_error(_("allocated section not in any PT_LOAD segment"));
4206 // Set the addresses for segments created from a PHDRS clause. Return
4207 // the segment which should hold the file header and program headers,
4211 Script_sections::set_phdrs_clause_addresses(Layout
* layout
,
4212 uint64_t dot_alignment
)
4214 Output_segment
* load_seg
= NULL
;
4215 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4216 p
!= this->phdrs_elements_
->end();
4219 // Note that we have to set the flags after adding the output
4220 // sections to the segment, as adding an output segment can
4221 // change the flags.
4222 (*p
)->set_flags_if_valid();
4224 Output_segment
* oseg
= (*p
)->segment();
4226 if (oseg
->type() != elfcpp::PT_LOAD
)
4228 // The addresses of non-PT_LOAD segments are set from the
4229 // PT_LOAD segments.
4230 if ((*p
)->has_load_address())
4231 gold_error(_("may only specify load address for PT_LOAD segment"));
4235 oseg
->set_minimum_p_align(dot_alignment
);
4237 // The output sections should have addresses from the SECTIONS
4238 // clause. The addresses don't have to be in order, so find the
4239 // one with the lowest load address. Use that to set the
4240 // address of the segment.
4242 Output_section
* osec
= oseg
->section_with_lowest_load_address();
4245 oseg
->set_addresses(0, 0);
4249 uint64_t vma
= osec
->address();
4250 uint64_t lma
= osec
->has_load_address() ? osec
->load_address() : vma
;
4252 // Override the load address of the section with the load
4253 // address specified for the segment.
4254 if ((*p
)->has_load_address())
4256 if (osec
->has_load_address())
4257 gold_warning(_("PHDRS load address overrides "
4258 "section %s load address"),
4261 lma
= (*p
)->load_address();
4264 bool headers
= (*p
)->includes_filehdr() && (*p
)->includes_phdrs();
4265 if (!headers
&& ((*p
)->includes_filehdr() || (*p
)->includes_phdrs()))
4267 // We could support this if we wanted to.
4268 gold_error(_("using only one of FILEHDR and PHDRS is "
4269 "not currently supported"));
4273 size_t sizeof_headers
= this->total_header_size(layout
);
4274 uint64_t subtract
= this->header_size_adjustment(lma
,
4276 if (lma
>= subtract
&& vma
>= subtract
)
4283 gold_error(_("sections loaded on first page without room "
4284 "for file and program headers "
4285 "are not supported"));
4288 if (load_seg
!= NULL
)
4289 gold_error(_("using FILEHDR and PHDRS on more than one "
4290 "PT_LOAD segment is not currently supported"));
4294 oseg
->set_addresses(vma
, lma
);
4300 // Add the file header and segment headers to non-load segments
4301 // specified in the PHDRS clause.
4304 Script_sections::put_headers_in_phdrs(Output_data
* file_header
,
4305 Output_data
* segment_headers
)
4307 gold_assert(this->saw_phdrs_clause());
4308 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
4309 p
!= this->phdrs_elements_
->end();
4312 if ((*p
)->type() != elfcpp::PT_LOAD
)
4314 if ((*p
)->includes_phdrs())
4315 (*p
)->segment()->add_initial_output_data(segment_headers
);
4316 if ((*p
)->includes_filehdr())
4317 (*p
)->segment()->add_initial_output_data(file_header
);
4322 // Look for an output section by name and return the address, the load
4323 // address, the alignment, and the size. This is used when an
4324 // expression refers to an output section which was not actually
4325 // created. This returns true if the section was found, false
4329 Script_sections::get_output_section_info(const char* name
, uint64_t* address
,
4330 uint64_t* load_address
,
4331 uint64_t* addralign
,
4332 uint64_t* size
) const
4334 if (!this->saw_sections_clause_
)
4336 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4337 p
!= this->sections_elements_
->end();
4339 if ((*p
)->get_output_section_info(name
, address
, load_address
, addralign
,
4345 // Release all Output_segments. This remove all pointers to all
4349 Script_sections::release_segments()
4351 if (this->saw_phdrs_clause())
4353 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4354 p
!= this->phdrs_elements_
->end();
4356 (*p
)->release_segment();
4360 // Print the SECTIONS clause to F for debugging.
4363 Script_sections::print(FILE* f
) const
4365 if (this->phdrs_elements_
!= NULL
)
4367 fprintf(f
, "PHDRS {\n");
4368 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4369 p
!= this->phdrs_elements_
->end();
4375 if (this->memory_regions_
!= NULL
)
4377 fprintf(f
, "MEMORY {\n");
4378 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
4379 m
!= this->memory_regions_
->end();
4385 if (!this->saw_sections_clause_
)
4388 fprintf(f
, "SECTIONS {\n");
4390 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4391 p
!= this->sections_elements_
->end();
4398 } // End namespace gold.