1 // script-sections.cc -- linker script SECTIONS for gold
3 // Copyright 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
33 #include "parameters.h"
39 #include "script-sections.h"
41 // Support for the SECTIONS clause in linker scripts.
46 // A region of memory.
50 Memory_region(const char* name
, size_t namelen
, unsigned int attributes
,
51 Expression
* start
, Expression
* length
)
52 : name_(name
, namelen
),
53 attributes_(attributes
),
62 // Return the name of this region.
65 { return this->name_
; }
67 // Return the start address of this region.
70 { return this->start_
; }
72 // Return the length of this region.
75 { return this->length_
; }
77 // Print the region (when debugging).
81 // Return true if <name,namelen> matches this region.
83 name_match(const char* name
, size_t namelen
)
85 return (this->name_
.length() == namelen
86 && strncmp(this->name_
.c_str(), name
, namelen
) == 0);
90 get_current_address() const
93 script_exp_binary_add(this->start_
,
94 script_exp_integer(this->current_offset_
));
98 increment_offset(std::string section_name
, uint64_t amount
,
99 const Symbol_table
* symtab
, const Layout
* layout
)
101 this->current_offset_
+= amount
;
103 if (this->current_offset_
104 > this->length_
->eval(symtab
, layout
, false))
105 gold_error(_("section %s overflows end of region %s"),
106 section_name
.c_str(), this->name_
.c_str());
109 // Returns true iff there is room left in this region
110 // for AMOUNT more bytes of data.
112 has_room_for(const Symbol_table
* symtab
, const Layout
* layout
,
113 uint64_t amount
) const
115 return (this->current_offset_
+ amount
116 < this->length_
->eval(symtab
, layout
, false));
119 // Return true if the provided section flags
120 // are compatible with this region's attributes.
122 attributes_compatible(elfcpp::Elf_Xword flags
, elfcpp::Elf_Xword type
) const;
125 add_section(Output_section_definition
* sec
, bool vma
)
128 this->vma_sections_
.push_back(sec
);
130 this->lma_sections_
.push_back(sec
);
133 typedef std::vector
<Output_section_definition
*> Section_list
;
135 // Return the start of the list of sections
136 // whose VMAs are taken from this region.
137 Section_list::const_iterator
138 get_vma_section_list_start() const
139 { return this->vma_sections_
.begin(); }
141 // Return the start of the list of sections
142 // whose LMAs are taken from this region.
143 Section_list::const_iterator
144 get_lma_section_list_start() const
145 { return this->lma_sections_
.begin(); }
147 // Return the end of the list of sections
148 // whose VMAs are taken from this region.
149 Section_list::const_iterator
150 get_vma_section_list_end() const
151 { return this->vma_sections_
.end(); }
153 // Return the end of the list of sections
154 // whose LMAs are taken from this region.
155 Section_list::const_iterator
156 get_lma_section_list_end() const
157 { return this->lma_sections_
.end(); }
159 Output_section_definition
*
160 get_last_section() const
161 { return this->last_section_
; }
164 set_last_section(Output_section_definition
* sec
)
165 { this->last_section_
= sec
; }
170 unsigned int attributes_
;
173 // The offset to the next free byte in the region.
174 // Note - for compatibility with GNU LD we only maintain one offset
175 // regardless of whether the region is being used for VMA values,
176 // LMA values, or both.
177 uint64_t current_offset_
;
178 // A list of sections whose VMAs are set inside this region.
179 Section_list vma_sections_
;
180 // A list of sections whose LMAs are set inside this region.
181 Section_list lma_sections_
;
182 // The latest section to make use of this region.
183 Output_section_definition
* last_section_
;
186 // Return true if the provided section flags
187 // are compatible with this region's attributes.
190 Memory_region::attributes_compatible(elfcpp::Elf_Xword flags
,
191 elfcpp::Elf_Xword type
) const
193 unsigned int attrs
= this->attributes_
;
195 // No attributes means that this region is not compatible with anything.
202 switch (attrs
& - attrs
)
205 if ((flags
& elfcpp::SHF_EXECINSTR
) == 0)
210 if ((flags
& elfcpp::SHF_WRITE
) == 0)
215 // All sections are presumed readable.
218 case MEM_ALLOCATABLE
:
219 if ((flags
& elfcpp::SHF_ALLOC
) == 0)
223 case MEM_INITIALIZED
:
224 if ((type
& elfcpp::SHT_NOBITS
) != 0)
228 attrs
&= ~ (attrs
& - attrs
);
235 // Print a memory region.
238 Memory_region::print(FILE* f
) const
240 fprintf(f
, " %s", this->name_
.c_str());
242 unsigned int attrs
= this->attributes_
;
248 switch (attrs
& - attrs
)
250 case MEM_EXECUTABLE
: fputc('x', f
); break;
251 case MEM_WRITEABLE
: fputc('w', f
); break;
252 case MEM_READABLE
: fputc('r', f
); break;
253 case MEM_ALLOCATABLE
: fputc('a', f
); break;
254 case MEM_INITIALIZED
: fputc('i', f
); break;
258 attrs
&= ~ (attrs
& - attrs
);
264 fprintf(f
, " : origin = ");
265 this->start_
->print(f
);
266 fprintf(f
, ", length = ");
267 this->length_
->print(f
);
271 // Manage orphan sections. This is intended to be largely compatible
272 // with the GNU linker. The Linux kernel implicitly relies on
273 // something similar to the GNU linker's orphan placement. We
274 // originally used a simpler scheme here, but it caused the kernel
275 // build to fail, and was also rather inefficient.
277 class Orphan_section_placement
280 typedef Script_sections::Elements_iterator Elements_iterator
;
283 Orphan_section_placement();
285 // Handle an output section during initialization of this mapping.
287 output_section_init(const std::string
& name
, Output_section
*,
288 Elements_iterator location
);
290 // Initialize the last location.
292 last_init(Elements_iterator location
);
294 // Set *PWHERE to the address of an iterator pointing to the
295 // location to use for an orphan section. Return true if the
296 // iterator has a value, false otherwise.
298 find_place(Output_section
*, Elements_iterator
** pwhere
);
300 // Return the iterator being used for sections at the very end of
301 // the linker script.
306 // The places that we specifically recognize. This list is copied
307 // from the GNU linker.
323 // The information we keep for a specific place.
326 // The name of sections for this place.
328 // Whether we have a location for this place.
330 // The iterator for this place.
331 Elements_iterator location
;
334 // Initialize one place element.
336 initialize_place(Place_index
, const char*);
339 Place places_
[PLACE_MAX
];
340 // True if this is the first call to output_section_init.
344 // Initialize Orphan_section_placement.
346 Orphan_section_placement::Orphan_section_placement()
349 this->initialize_place(PLACE_TEXT
, ".text");
350 this->initialize_place(PLACE_RODATA
, ".rodata");
351 this->initialize_place(PLACE_DATA
, ".data");
352 this->initialize_place(PLACE_TLS
, NULL
);
353 this->initialize_place(PLACE_TLS_BSS
, NULL
);
354 this->initialize_place(PLACE_BSS
, ".bss");
355 this->initialize_place(PLACE_REL
, NULL
);
356 this->initialize_place(PLACE_INTERP
, ".interp");
357 this->initialize_place(PLACE_NONALLOC
, NULL
);
358 this->initialize_place(PLACE_LAST
, NULL
);
361 // Initialize one place element.
364 Orphan_section_placement::initialize_place(Place_index index
, const char* name
)
366 this->places_
[index
].name
= name
;
367 this->places_
[index
].have_location
= false;
370 // While initializing the Orphan_section_placement information, this
371 // is called once for each output section named in the linker script.
372 // If we found an output section during the link, it will be passed in
376 Orphan_section_placement::output_section_init(const std::string
& name
,
378 Elements_iterator location
)
380 bool first_init
= this->first_init_
;
381 this->first_init_
= false;
383 for (int i
= 0; i
< PLACE_MAX
; ++i
)
385 if (this->places_
[i
].name
!= NULL
&& this->places_
[i
].name
== name
)
387 if (this->places_
[i
].have_location
)
389 // We have already seen a section with this name.
393 this->places_
[i
].location
= location
;
394 this->places_
[i
].have_location
= true;
396 // If we just found the .bss section, restart the search for
397 // an unallocated section. This follows the GNU linker's
400 this->places_
[PLACE_NONALLOC
].have_location
= false;
406 // Relocation sections.
407 if (!this->places_
[PLACE_REL
].have_location
409 && (os
->type() == elfcpp::SHT_REL
|| os
->type() == elfcpp::SHT_RELA
)
410 && (os
->flags() & elfcpp::SHF_ALLOC
) != 0)
412 this->places_
[PLACE_REL
].location
= location
;
413 this->places_
[PLACE_REL
].have_location
= true;
416 // We find the location for unallocated sections by finding the
417 // first debugging or comment section after the BSS section (if
419 if (!this->places_
[PLACE_NONALLOC
].have_location
420 && (name
== ".comment" || Layout::is_debug_info_section(name
.c_str())))
422 // We add orphan sections after the location in PLACES_. We
423 // want to store unallocated sections before LOCATION. If this
424 // is the very first section, we can't use it.
428 this->places_
[PLACE_NONALLOC
].location
= location
;
429 this->places_
[PLACE_NONALLOC
].have_location
= true;
434 // Initialize the last location.
437 Orphan_section_placement::last_init(Elements_iterator location
)
439 this->places_
[PLACE_LAST
].location
= location
;
440 this->places_
[PLACE_LAST
].have_location
= true;
443 // Set *PWHERE to the address of an iterator pointing to the location
444 // to use for an orphan section. Return true if the iterator has a
445 // value, false otherwise.
448 Orphan_section_placement::find_place(Output_section
* os
,
449 Elements_iterator
** pwhere
)
451 // Figure out where OS should go. This is based on the GNU linker
452 // code. FIXME: The GNU linker handles small data sections
453 // specially, but we don't.
454 elfcpp::Elf_Word type
= os
->type();
455 elfcpp::Elf_Xword flags
= os
->flags();
457 if ((flags
& elfcpp::SHF_ALLOC
) == 0
458 && !Layout::is_debug_info_section(os
->name()))
459 index
= PLACE_NONALLOC
;
460 else if ((flags
& elfcpp::SHF_ALLOC
) == 0)
462 else if (type
== elfcpp::SHT_NOTE
)
463 index
= PLACE_INTERP
;
464 else if ((flags
& elfcpp::SHF_TLS
) != 0)
466 if (type
== elfcpp::SHT_NOBITS
)
467 index
= PLACE_TLS_BSS
;
471 else if (type
== elfcpp::SHT_NOBITS
)
473 else if ((flags
& elfcpp::SHF_WRITE
) != 0)
475 else if (type
== elfcpp::SHT_REL
|| type
== elfcpp::SHT_RELA
)
477 else if ((flags
& elfcpp::SHF_EXECINSTR
) == 0)
478 index
= PLACE_RODATA
;
482 // If we don't have a location yet, try to find one based on a
483 // plausible ordering of sections.
484 if (!this->places_
[index
].have_location
)
509 if (!this->places_
[PLACE_TLS
].have_location
)
513 if (follow
!= PLACE_MAX
&& this->places_
[follow
].have_location
)
515 // Set the location of INDEX to the location of FOLLOW. The
516 // location of INDEX will then be incremented by the caller,
517 // so anything in INDEX will continue to be after anything
519 this->places_
[index
].location
= this->places_
[follow
].location
;
520 this->places_
[index
].have_location
= true;
524 *pwhere
= &this->places_
[index
].location
;
525 bool ret
= this->places_
[index
].have_location
;
527 // The caller will set the location.
528 this->places_
[index
].have_location
= true;
533 // Return the iterator being used for sections at the very end of the
536 Orphan_section_placement::Elements_iterator
537 Orphan_section_placement::last_place() const
539 gold_assert(this->places_
[PLACE_LAST
].have_location
);
540 return this->places_
[PLACE_LAST
].location
;
543 // An element in a SECTIONS clause.
545 class Sections_element
551 virtual ~Sections_element()
554 // Return whether an output section is relro.
559 // Record that an output section is relro.
564 // Create any required output sections. The only real
565 // implementation is in Output_section_definition.
567 create_sections(Layout
*)
570 // Add any symbol being defined to the symbol table.
572 add_symbols_to_table(Symbol_table
*)
575 // Finalize symbols and check assertions.
577 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*)
580 // Return the output section name to use for an input file name and
581 // section name. This only real implementation is in
582 // Output_section_definition.
584 output_section_name(const char*, const char*, Output_section
***,
585 Script_sections::Section_type
*, 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 typedef std::vector
<std::vector
<Input_section_info
> > Matching_sections
;
1559 size_t input_pattern_count
= this->input_section_patterns_
.size();
1560 if (input_pattern_count
== 0)
1561 input_pattern_count
= 1;
1562 Matching_sections
matching_sections(input_pattern_count
);
1564 // Look through the list of sections for this output section. Add
1565 // each one which matches to one of the elements of
1566 // MATCHING_SECTIONS.
1568 Input_section_list::iterator p
= input_sections
->begin();
1569 while (p
!= input_sections
->end())
1571 Relobj
* relobj
= p
->relobj();
1572 unsigned int shndx
= p
->shndx();
1573 Input_section_info
isi(*p
);
1575 // Calling section_name and section_addralign is not very
1578 // Lock the object so that we can get information about the
1579 // section. This is OK since we know we are single-threaded
1582 const Task
* task
= reinterpret_cast<const Task
*>(-1);
1583 Task_lock_obj
<Object
> tl(task
, relobj
);
1585 isi
.set_section_name(relobj
->section_name(shndx
));
1586 if (p
->is_relaxed_input_section())
1588 // We use current data size because relaxed section sizes may not
1589 // have finalized yet.
1590 isi
.set_size(p
->relaxed_input_section()->current_data_size());
1591 isi
.set_addralign(p
->relaxed_input_section()->addralign());
1595 isi
.set_size(relobj
->section_size(shndx
));
1596 isi
.set_addralign(relobj
->section_addralign(shndx
));
1600 if (!this->match_file_name(relobj
->name().c_str()))
1602 else if (this->input_section_patterns_
.empty())
1604 matching_sections
[0].push_back(isi
);
1605 p
= input_sections
->erase(p
);
1610 for (i
= 0; i
< input_pattern_count
; ++i
)
1612 const Input_section_pattern
&
1613 isp(this->input_section_patterns_
[i
]);
1614 if (match(isi
.section_name().c_str(), isp
.pattern
.c_str(),
1615 isp
.pattern_is_wildcard
))
1619 if (i
>= this->input_section_patterns_
.size())
1623 matching_sections
[i
].push_back(isi
);
1624 p
= input_sections
->erase(p
);
1629 // Look through MATCHING_SECTIONS. Sort each one as specified,
1630 // using a stable sort so that we get the default order when
1631 // sections are otherwise equal. Add each input section to the
1634 uint64_t dot
= *dot_value
;
1635 for (size_t i
= 0; i
< input_pattern_count
; ++i
)
1637 if (matching_sections
[i
].empty())
1640 gold_assert(output_section
!= NULL
);
1642 const Input_section_pattern
& isp(this->input_section_patterns_
[i
]);
1643 if (isp
.sort
!= SORT_WILDCARD_NONE
1644 || this->filename_sort_
!= SORT_WILDCARD_NONE
)
1645 std::stable_sort(matching_sections
[i
].begin(),
1646 matching_sections
[i
].end(),
1647 Input_section_sorter(this->filename_sort_
,
1650 for (std::vector
<Input_section_info
>::const_iterator p
=
1651 matching_sections
[i
].begin();
1652 p
!= matching_sections
[i
].end();
1655 // Override the original address alignment if SUBALIGN is specified
1656 // and is greater than the original alignment. We need to make a
1657 // copy of the input section to modify the alignment.
1658 Output_section::Input_section
sis(p
->input_section());
1660 uint64_t this_subalign
= sis
.addralign();
1661 if (!sis
.is_input_section())
1662 sis
.output_section_data()->finalize_data_size();
1663 uint64_t data_size
= sis
.data_size();
1664 if (this_subalign
< subalign
)
1666 this_subalign
= subalign
;
1667 sis
.set_addralign(subalign
);
1670 uint64_t address
= align_address(dot
, this_subalign
);
1672 if (address
> dot
&& !fill
->empty())
1674 section_size_type length
=
1675 convert_to_section_size_type(address
- dot
);
1676 std::string this_fill
= this->get_fill_string(fill
, length
);
1677 Output_section_data
* posd
= new Output_data_const(this_fill
, 0);
1678 output_section
->add_output_section_data(posd
);
1679 layout
->new_output_section_data_from_script(posd
);
1682 output_section
->add_script_input_section(sis
);
1683 dot
= address
+ data_size
;
1687 // An SHF_TLS/SHT_NOBITS section does not take up any
1689 if (output_section
== NULL
1690 || (output_section
->flags() & elfcpp::SHF_TLS
) == 0
1691 || output_section
->type() != elfcpp::SHT_NOBITS
)
1694 this->final_dot_value_
= *dot_value
;
1695 this->final_dot_section_
= *dot_section
;
1698 // Print for debugging.
1701 Output_section_element_input::print(FILE* f
) const
1706 fprintf(f
, "KEEP(");
1708 if (!this->filename_pattern_
.empty())
1710 bool need_close_paren
= false;
1711 switch (this->filename_sort_
)
1713 case SORT_WILDCARD_NONE
:
1715 case SORT_WILDCARD_BY_NAME
:
1716 fprintf(f
, "SORT_BY_NAME(");
1717 need_close_paren
= true;
1723 fprintf(f
, "%s", this->filename_pattern_
.c_str());
1725 if (need_close_paren
)
1729 if (!this->input_section_patterns_
.empty()
1730 || !this->filename_exclusions_
.empty())
1734 bool need_space
= false;
1735 if (!this->filename_exclusions_
.empty())
1737 fprintf(f
, "EXCLUDE_FILE(");
1738 bool need_comma
= false;
1739 for (Filename_exclusions::const_iterator p
=
1740 this->filename_exclusions_
.begin();
1741 p
!= this->filename_exclusions_
.end();
1746 fprintf(f
, "%s", p
->first
.c_str());
1753 for (Input_section_patterns::const_iterator p
=
1754 this->input_section_patterns_
.begin();
1755 p
!= this->input_section_patterns_
.end();
1761 int close_parens
= 0;
1764 case SORT_WILDCARD_NONE
:
1766 case SORT_WILDCARD_BY_NAME
:
1767 fprintf(f
, "SORT_BY_NAME(");
1770 case SORT_WILDCARD_BY_ALIGNMENT
:
1771 fprintf(f
, "SORT_BY_ALIGNMENT(");
1774 case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
:
1775 fprintf(f
, "SORT_BY_NAME(SORT_BY_ALIGNMENT(");
1778 case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
:
1779 fprintf(f
, "SORT_BY_ALIGNMENT(SORT_BY_NAME(");
1786 fprintf(f
, "%s", p
->pattern
.c_str());
1788 for (int i
= 0; i
< close_parens
; ++i
)
1803 // An output section.
1805 class Output_section_definition
: public Sections_element
1808 typedef Output_section_element::Input_section_list Input_section_list
;
1810 Output_section_definition(const char* name
, size_t namelen
,
1811 const Parser_output_section_header
* header
);
1813 // Finish the output section with the information in the trailer.
1815 finish(const Parser_output_section_trailer
* trailer
);
1817 // Add a symbol to be defined.
1819 add_symbol_assignment(const char* name
, size_t length
, Expression
* value
,
1820 bool provide
, bool hidden
);
1822 // Add an assignment to the special dot symbol.
1824 add_dot_assignment(Expression
* value
);
1826 // Add an assertion.
1828 add_assertion(Expression
* check
, const char* message
, size_t messagelen
);
1830 // Add a data item to the current output section.
1832 add_data(int size
, bool is_signed
, Expression
* val
);
1834 // Add a setting for the fill value.
1836 add_fill(Expression
* val
);
1838 // Add an input section specification.
1840 add_input_section(const Input_section_spec
* spec
, bool keep
);
1842 // Return whether the output section is relro.
1845 { return this->is_relro_
; }
1847 // Record that the output section is relro.
1850 { this->is_relro_
= true; }
1852 // Create any required output sections.
1854 create_sections(Layout
*);
1856 // Add any symbols being defined to the symbol table.
1858 add_symbols_to_table(Symbol_table
* symtab
);
1860 // Finalize symbols and check assertions.
1862 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*);
1864 // Return the output section name to use for an input file name and
1867 output_section_name(const char* file_name
, const char* section_name
,
1868 Output_section
***, Script_sections::Section_type
*,
1871 // Initialize OSP with an output section.
1873 orphan_section_init(Orphan_section_placement
* osp
,
1874 Script_sections::Elements_iterator p
)
1875 { osp
->output_section_init(this->name_
, this->output_section_
, p
); }
1877 // Set the section address.
1879 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
,
1880 uint64_t* dot_value
, uint64_t*,
1881 uint64_t* load_address
);
1883 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
1884 // this section is constrained, and the input sections do not match,
1885 // return the constraint, and set *POSD.
1887 check_constraint(Output_section_definition
** posd
);
1889 // See if this is the alternate output section for a constrained
1890 // output section. If it is, transfer the Output_section and return
1891 // true. Otherwise return false.
1893 alternate_constraint(Output_section_definition
*, Section_constraint
);
1895 // Get the list of segments to use for an allocated section when
1896 // using a PHDRS clause.
1898 allocate_to_segment(String_list
** phdrs_list
, bool* orphan
);
1900 // Look for an output section by name and return the address, the
1901 // load address, the alignment, and the size. This is used when an
1902 // expression refers to an output section which was not actually
1903 // created. This returns true if the section was found, false
1906 get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
1909 // Return the associated Output_section if there is one.
1911 get_output_section() const
1912 { return this->output_section_
; }
1914 // Print the contents to the FILE. This is for debugging.
1918 // Return the output section type if specified or Script_sections::ST_NONE.
1919 Script_sections::Section_type
1920 section_type() const;
1922 // Store the memory region to use.
1924 set_memory_region(Memory_region
*, bool set_vma
);
1927 set_section_vma(Expression
* address
)
1928 { this->address_
= address
; }
1931 set_section_lma(Expression
* address
)
1932 { this->load_address_
= address
; }
1935 get_section_name() const
1936 { return this->name_
; }
1940 script_section_type_name(Script_section_type
);
1942 typedef std::vector
<Output_section_element
*> Output_section_elements
;
1944 // The output section name.
1946 // The address. This may be NULL.
1947 Expression
* address_
;
1948 // The load address. This may be NULL.
1949 Expression
* load_address_
;
1950 // The alignment. This may be NULL.
1952 // The input section alignment. This may be NULL.
1953 Expression
* subalign_
;
1954 // The constraint, if any.
1955 Section_constraint constraint_
;
1956 // The fill value. This may be NULL.
1958 // The list of segments this section should go into. This may be
1960 String_list
* phdrs_
;
1961 // The list of elements defining the section.
1962 Output_section_elements elements_
;
1963 // The Output_section created for this definition. This will be
1964 // NULL if none was created.
1965 Output_section
* output_section_
;
1966 // The address after it has been evaluated.
1967 uint64_t evaluated_address_
;
1968 // The load address after it has been evaluated.
1969 uint64_t evaluated_load_address_
;
1970 // The alignment after it has been evaluated.
1971 uint64_t evaluated_addralign_
;
1972 // The output section is relro.
1974 // The output section type if specified.
1975 enum Script_section_type script_section_type_
;
1980 Output_section_definition::Output_section_definition(
1983 const Parser_output_section_header
* header
)
1984 : name_(name
, namelen
),
1985 address_(header
->address
),
1986 load_address_(header
->load_address
),
1987 align_(header
->align
),
1988 subalign_(header
->subalign
),
1989 constraint_(header
->constraint
),
1993 output_section_(NULL
),
1994 evaluated_address_(0),
1995 evaluated_load_address_(0),
1996 evaluated_addralign_(0),
1998 script_section_type_(header
->section_type
)
2002 // Finish an output section.
2005 Output_section_definition::finish(const Parser_output_section_trailer
* trailer
)
2007 this->fill_
= trailer
->fill
;
2008 this->phdrs_
= trailer
->phdrs
;
2011 // Add a symbol to be defined.
2014 Output_section_definition::add_symbol_assignment(const char* name
,
2020 Output_section_element
* p
= new Output_section_element_assignment(name
,
2025 this->elements_
.push_back(p
);
2028 // Add an assignment to the special dot symbol.
2031 Output_section_definition::add_dot_assignment(Expression
* value
)
2033 Output_section_element
* p
= new Output_section_element_dot_assignment(value
);
2034 this->elements_
.push_back(p
);
2037 // Add an assertion.
2040 Output_section_definition::add_assertion(Expression
* check
,
2041 const char* message
,
2044 Output_section_element
* p
= new Output_section_element_assertion(check
,
2047 this->elements_
.push_back(p
);
2050 // Add a data item to the current output section.
2053 Output_section_definition::add_data(int size
, bool is_signed
, Expression
* val
)
2055 Output_section_element
* p
= new Output_section_element_data(size
, is_signed
,
2057 this->elements_
.push_back(p
);
2060 // Add a setting for the fill value.
2063 Output_section_definition::add_fill(Expression
* val
)
2065 Output_section_element
* p
= new Output_section_element_fill(val
);
2066 this->elements_
.push_back(p
);
2069 // Add an input section specification.
2072 Output_section_definition::add_input_section(const Input_section_spec
* spec
,
2075 Output_section_element
* p
= new Output_section_element_input(spec
, keep
);
2076 this->elements_
.push_back(p
);
2079 // Create any required output sections. We need an output section if
2080 // there is a data statement here.
2083 Output_section_definition::create_sections(Layout
* layout
)
2085 if (this->output_section_
!= NULL
)
2087 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2088 p
!= this->elements_
.end();
2091 if ((*p
)->needs_output_section())
2093 const char* name
= this->name_
.c_str();
2094 this->output_section_
=
2095 layout
->make_output_section_for_script(name
, this->section_type());
2101 // Add any symbols being defined to the symbol table.
2104 Output_section_definition::add_symbols_to_table(Symbol_table
* symtab
)
2106 for (Output_section_elements::iterator p
= this->elements_
.begin();
2107 p
!= this->elements_
.end();
2109 (*p
)->add_symbols_to_table(symtab
);
2112 // Finalize symbols and check assertions.
2115 Output_section_definition::finalize_symbols(Symbol_table
* symtab
,
2116 const Layout
* layout
,
2117 uint64_t* dot_value
)
2119 if (this->output_section_
!= NULL
)
2120 *dot_value
= this->output_section_
->address();
2123 uint64_t address
= *dot_value
;
2124 if (this->address_
!= NULL
)
2126 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2130 if (this->align_
!= NULL
)
2132 uint64_t align
= this->align_
->eval_with_dot(symtab
, layout
, true,
2135 address
= align_address(address
, align
);
2137 *dot_value
= address
;
2140 Output_section
* dot_section
= this->output_section_
;
2141 for (Output_section_elements::iterator p
= this->elements_
.begin();
2142 p
!= this->elements_
.end();
2144 (*p
)->finalize_symbols(symtab
, layout
, dot_value
, &dot_section
);
2147 // Return the output section name to use for an input section name.
2150 Output_section_definition::output_section_name(
2151 const char* file_name
,
2152 const char* section_name
,
2153 Output_section
*** slot
,
2154 Script_sections::Section_type
* psection_type
,
2157 // Ask each element whether it matches NAME.
2158 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2159 p
!= this->elements_
.end();
2162 if ((*p
)->match_name(file_name
, section_name
, keep
))
2164 // We found a match for NAME, which means that it should go
2165 // into this output section.
2166 *slot
= &this->output_section_
;
2167 *psection_type
= this->section_type();
2168 return this->name_
.c_str();
2172 // We don't know about this section name.
2176 // Return true if memory from START to START + LENGTH is contained
2177 // within a memory region.
2180 Script_sections::block_in_region(Symbol_table
* symtab
, Layout
* layout
,
2181 uint64_t start
, uint64_t length
) const
2183 if (this->memory_regions_
== NULL
)
2186 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2187 mr
!= this->memory_regions_
->end();
2190 uint64_t s
= (*mr
)->start_address()->eval(symtab
, layout
, false);
2191 uint64_t l
= (*mr
)->length()->eval(symtab
, layout
, false);
2194 && (s
+ l
) >= (start
+ length
))
2201 // Find a memory region that should be used by a given output SECTION.
2202 // If provided set PREVIOUS_SECTION_RETURN to point to the last section
2203 // that used the return memory region.
2206 Script_sections::find_memory_region(
2207 Output_section_definition
* section
,
2208 bool find_vma_region
,
2209 Output_section_definition
** previous_section_return
)
2211 if (previous_section_return
!= NULL
)
2212 * previous_section_return
= NULL
;
2214 // Walk the memory regions specified in this script, if any.
2215 if (this->memory_regions_
== NULL
)
2218 // The /DISCARD/ section never gets assigned to any region.
2219 if (section
->get_section_name() == "/DISCARD/")
2222 Memory_region
* first_match
= NULL
;
2224 // First check to see if a region has been assigned to this section.
2225 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2226 mr
!= this->memory_regions_
->end();
2229 if (find_vma_region
)
2231 for (Memory_region::Section_list::const_iterator s
=
2232 (*mr
)->get_vma_section_list_start();
2233 s
!= (*mr
)->get_vma_section_list_end();
2235 if ((*s
) == section
)
2237 (*mr
)->set_last_section(section
);
2243 for (Memory_region::Section_list::const_iterator s
=
2244 (*mr
)->get_lma_section_list_start();
2245 s
!= (*mr
)->get_lma_section_list_end();
2247 if ((*s
) == section
)
2249 (*mr
)->set_last_section(section
);
2254 // Make a note of the first memory region whose attributes
2255 // are compatible with the section. If we do not find an
2256 // explicit region assignment, then we will return this region.
2257 Output_section
* out_sec
= section
->get_output_section();
2258 if (first_match
== NULL
2260 && (*mr
)->attributes_compatible(out_sec
->flags(),
2265 // With LMA computations, if an explicit region has not been specified then
2266 // we will want to set the difference between the VMA and the LMA of the
2267 // section were searching for to be the same as the difference between the
2268 // VMA and LMA of the last section to be added to first matched region.
2269 // Hence, if it was asked for, we return a pointer to the last section
2270 // known to be used by the first matched region.
2271 if (first_match
!= NULL
2272 && previous_section_return
!= NULL
)
2273 *previous_section_return
= first_match
->get_last_section();
2278 // Set the section address. Note that the OUTPUT_SECTION_ field will
2279 // be NULL if no input sections were mapped to this output section.
2280 // We still have to adjust dot and process symbol assignments.
2283 Output_section_definition::set_section_addresses(Symbol_table
* symtab
,
2285 uint64_t* dot_value
,
2286 uint64_t* dot_alignment
,
2287 uint64_t* load_address
)
2289 Memory_region
* vma_region
= NULL
;
2290 Memory_region
* lma_region
= NULL
;
2291 Script_sections
* script_sections
=
2292 layout
->script_options()->script_sections();
2294 uint64_t old_dot_value
= *dot_value
;
2295 uint64_t old_load_address
= *load_address
;
2297 // Decide the start address for the section. The algorithm is:
2298 // 1) If an address has been specified in a linker script, use that.
2299 // 2) Otherwise if a memory region has been specified for the section,
2300 // use the next free address in the region.
2301 // 3) Otherwise if memory regions have been specified find the first
2302 // region whose attributes are compatible with this section and
2303 // install it into that region.
2304 // 4) Otherwise use the current location counter.
2306 if (this->output_section_
!= NULL
2307 // Check for --section-start.
2308 && parameters
->options().section_start(this->output_section_
->name(),
2311 else if (this->address_
== NULL
)
2313 vma_region
= script_sections
->find_memory_region(this, true, NULL
);
2315 if (vma_region
!= NULL
)
2316 address
= vma_region
->get_current_address()->eval(symtab
, layout
,
2319 address
= *dot_value
;
2322 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2323 *dot_value
, NULL
, NULL
,
2324 dot_alignment
, false);
2326 if (this->align_
== NULL
)
2328 if (this->output_section_
== NULL
)
2331 align
= this->output_section_
->addralign();
2335 Output_section
* align_section
;
2336 align
= this->align_
->eval_with_dot(symtab
, layout
, true, *dot_value
,
2337 NULL
, &align_section
, NULL
, false);
2338 if (align_section
!= NULL
)
2339 gold_warning(_("alignment of section %s is not absolute"),
2340 this->name_
.c_str());
2341 if (this->output_section_
!= NULL
)
2342 this->output_section_
->set_addralign(align
);
2345 address
= align_address(address
, align
);
2347 uint64_t start_address
= address
;
2349 *dot_value
= address
;
2351 // Except for NOLOAD sections, the address of non-SHF_ALLOC sections is
2352 // forced to zero, regardless of what the linker script wants.
2353 if (this->output_section_
!= NULL
2354 && ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) != 0
2355 || this->output_section_
->is_noload()))
2356 this->output_section_
->set_address(address
);
2358 this->evaluated_address_
= address
;
2359 this->evaluated_addralign_
= align
;
2363 if (this->load_address_
== NULL
)
2365 Output_section_definition
* previous_section
;
2367 // Determine if an LMA region has been set for this section.
2368 lma_region
= script_sections
->find_memory_region(this, false,
2371 if (lma_region
!= NULL
)
2373 if (previous_section
== NULL
)
2374 // The LMA address was explicitly set to the given region.
2375 laddr
= lma_region
->get_current_address()->eval(symtab
, layout
,
2379 // We are not going to use the discovered lma_region, so
2380 // make sure that we do not update it in the code below.
2383 if (this->address_
!= NULL
|| previous_section
== this)
2385 // Either an explicit VMA address has been set, or an
2386 // explicit VMA region has been set, so set the LMA equal to
2392 // The LMA address was not explicitly or implicitly set.
2394 // We have been given the first memory region that is
2395 // compatible with the current section and a pointer to the
2396 // last section to use this region. Set the LMA of this
2397 // section so that the difference between its' VMA and LMA
2398 // is the same as the difference between the VMA and LMA of
2399 // the last section in the given region.
2400 laddr
= address
+ (previous_section
->evaluated_load_address_
2401 - previous_section
->evaluated_address_
);
2405 if (this->output_section_
!= NULL
)
2406 this->output_section_
->set_load_address(laddr
);
2410 // Do not set the load address of the output section, if one exists.
2411 // This allows future sections to determine what the load address
2412 // should be. If none is ever set, it will default to being the
2413 // same as the vma address.
2419 laddr
= this->load_address_
->eval_with_dot(symtab
, layout
, true,
2421 this->output_section_
,
2423 if (this->output_section_
!= NULL
)
2424 this->output_section_
->set_load_address(laddr
);
2427 this->evaluated_load_address_
= laddr
;
2430 if (this->subalign_
== NULL
)
2434 Output_section
* subalign_section
;
2435 subalign
= this->subalign_
->eval_with_dot(symtab
, layout
, true,
2437 &subalign_section
, NULL
,
2439 if (subalign_section
!= NULL
)
2440 gold_warning(_("subalign of section %s is not absolute"),
2441 this->name_
.c_str());
2445 if (this->fill_
!= NULL
)
2447 // FIXME: The GNU linker supports fill values of arbitrary
2449 Output_section
* fill_section
;
2450 uint64_t fill_val
= this->fill_
->eval_with_dot(symtab
, layout
, true,
2452 NULL
, &fill_section
,
2454 if (fill_section
!= NULL
)
2455 gold_warning(_("fill of section %s is not absolute"),
2456 this->name_
.c_str());
2457 unsigned char fill_buff
[4];
2458 elfcpp::Swap_unaligned
<32, true>::writeval(fill_buff
, fill_val
);
2459 fill
.assign(reinterpret_cast<char*>(fill_buff
), 4);
2462 Input_section_list input_sections
;
2463 if (this->output_section_
!= NULL
)
2465 // Get the list of input sections attached to this output
2466 // section. This will leave the output section with only
2467 // Output_section_data entries.
2468 address
+= this->output_section_
->get_input_sections(address
,
2471 *dot_value
= address
;
2474 Output_section
* dot_section
= this->output_section_
;
2475 for (Output_section_elements::iterator p
= this->elements_
.begin();
2476 p
!= this->elements_
.end();
2478 (*p
)->set_section_addresses(symtab
, layout
, this->output_section_
,
2479 subalign
, dot_value
, dot_alignment
,
2480 &dot_section
, &fill
, &input_sections
);
2482 gold_assert(input_sections
.empty());
2484 if (vma_region
!= NULL
)
2486 // Update the VMA region being used by the section now that we know how
2487 // big it is. Use the current address in the region, rather than
2488 // start_address because that might have been aligned upwards and we
2489 // need to allow for the padding.
2490 Expression
* addr
= vma_region
->get_current_address();
2491 uint64_t size
= *dot_value
- addr
->eval(symtab
, layout
, false);
2493 vma_region
->increment_offset(this->get_section_name(), size
,
2497 // If the LMA region is different from the VMA region, then increment the
2498 // offset there as well. Note that we use the same "dot_value -
2499 // start_address" formula that is used in the load_address assignment below.
2500 if (lma_region
!= NULL
&& lma_region
!= vma_region
)
2501 lma_region
->increment_offset(this->get_section_name(),
2502 *dot_value
- start_address
,
2505 // Compute the load address for the following section.
2506 if (this->output_section_
== NULL
)
2507 *load_address
= *dot_value
;
2508 else if (this->load_address_
== NULL
)
2510 if (lma_region
== NULL
)
2511 *load_address
= *dot_value
;
2514 lma_region
->get_current_address()->eval(symtab
, layout
, false);
2517 *load_address
= (this->output_section_
->load_address()
2518 + (*dot_value
- start_address
));
2520 if (this->output_section_
!= NULL
)
2522 if (this->is_relro_
)
2523 this->output_section_
->set_is_relro();
2525 this->output_section_
->clear_is_relro();
2527 // If this is a NOLOAD section, keep dot and load address unchanged.
2528 if (this->output_section_
->is_noload())
2530 *dot_value
= old_dot_value
;
2531 *load_address
= old_load_address
;
2536 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
2537 // this section is constrained, and the input sections do not match,
2538 // return the constraint, and set *POSD.
2541 Output_section_definition::check_constraint(Output_section_definition
** posd
)
2543 switch (this->constraint_
)
2545 case CONSTRAINT_NONE
:
2546 return CONSTRAINT_NONE
;
2548 case CONSTRAINT_ONLY_IF_RO
:
2549 if (this->output_section_
!= NULL
2550 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) != 0)
2553 return CONSTRAINT_ONLY_IF_RO
;
2555 return CONSTRAINT_NONE
;
2557 case CONSTRAINT_ONLY_IF_RW
:
2558 if (this->output_section_
!= NULL
2559 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) == 0)
2562 return CONSTRAINT_ONLY_IF_RW
;
2564 return CONSTRAINT_NONE
;
2566 case CONSTRAINT_SPECIAL
:
2567 if (this->output_section_
!= NULL
)
2568 gold_error(_("SPECIAL constraints are not implemented"));
2569 return CONSTRAINT_NONE
;
2576 // See if this is the alternate output section for a constrained
2577 // output section. If it is, transfer the Output_section and return
2578 // true. Otherwise return false.
2581 Output_section_definition::alternate_constraint(
2582 Output_section_definition
* posd
,
2583 Section_constraint constraint
)
2585 if (this->name_
!= posd
->name_
)
2590 case CONSTRAINT_ONLY_IF_RO
:
2591 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RW
)
2595 case CONSTRAINT_ONLY_IF_RW
:
2596 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RO
)
2604 // We have found the alternate constraint. We just need to move
2605 // over the Output_section. When constraints are used properly,
2606 // THIS should not have an output_section pointer, as all the input
2607 // sections should have matched the other definition.
2609 if (this->output_section_
!= NULL
)
2610 gold_error(_("mismatched definition for constrained sections"));
2612 this->output_section_
= posd
->output_section_
;
2613 posd
->output_section_
= NULL
;
2615 if (this->is_relro_
)
2616 this->output_section_
->set_is_relro();
2618 this->output_section_
->clear_is_relro();
2623 // Get the list of segments to use for an allocated section when using
2627 Output_section_definition::allocate_to_segment(String_list
** phdrs_list
,
2630 // Update phdrs_list even if we don't have an output section. It
2631 // might be used by the following sections.
2632 if (this->phdrs_
!= NULL
)
2633 *phdrs_list
= this->phdrs_
;
2635 if (this->output_section_
== NULL
)
2637 if ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) == 0)
2640 return this->output_section_
;
2643 // Look for an output section by name and return the address, the load
2644 // address, the alignment, and the size. This is used when an
2645 // expression refers to an output section which was not actually
2646 // created. This returns true if the section was found, false
2650 Output_section_definition::get_output_section_info(const char* name
,
2652 uint64_t* load_address
,
2653 uint64_t* addralign
,
2654 uint64_t* size
) const
2656 if (this->name_
!= name
)
2659 if (this->output_section_
!= NULL
)
2661 *address
= this->output_section_
->address();
2662 if (this->output_section_
->has_load_address())
2663 *load_address
= this->output_section_
->load_address();
2665 *load_address
= *address
;
2666 *addralign
= this->output_section_
->addralign();
2667 *size
= this->output_section_
->current_data_size();
2671 *address
= this->evaluated_address_
;
2672 *load_address
= this->evaluated_load_address_
;
2673 *addralign
= this->evaluated_addralign_
;
2680 // Print for debugging.
2683 Output_section_definition::print(FILE* f
) const
2685 fprintf(f
, " %s ", this->name_
.c_str());
2687 if (this->address_
!= NULL
)
2689 this->address_
->print(f
);
2693 if (this->script_section_type_
!= SCRIPT_SECTION_TYPE_NONE
)
2695 this->script_section_type_name(this->script_section_type_
));
2699 if (this->load_address_
!= NULL
)
2702 this->load_address_
->print(f
);
2706 if (this->align_
!= NULL
)
2708 fprintf(f
, "ALIGN(");
2709 this->align_
->print(f
);
2713 if (this->subalign_
!= NULL
)
2715 fprintf(f
, "SUBALIGN(");
2716 this->subalign_
->print(f
);
2722 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2723 p
!= this->elements_
.end();
2729 if (this->fill_
!= NULL
)
2732 this->fill_
->print(f
);
2735 if (this->phdrs_
!= NULL
)
2737 for (String_list::const_iterator p
= this->phdrs_
->begin();
2738 p
!= this->phdrs_
->end();
2740 fprintf(f
, " :%s", p
->c_str());
2746 Script_sections::Section_type
2747 Output_section_definition::section_type() const
2749 switch (this->script_section_type_
)
2751 case SCRIPT_SECTION_TYPE_NONE
:
2752 return Script_sections::ST_NONE
;
2753 case SCRIPT_SECTION_TYPE_NOLOAD
:
2754 return Script_sections::ST_NOLOAD
;
2755 case SCRIPT_SECTION_TYPE_COPY
:
2756 case SCRIPT_SECTION_TYPE_DSECT
:
2757 case SCRIPT_SECTION_TYPE_INFO
:
2758 case SCRIPT_SECTION_TYPE_OVERLAY
:
2759 // There are not really support so we treat them as ST_NONE. The
2760 // parse should have issued errors for them already.
2761 return Script_sections::ST_NONE
;
2767 // Return the name of a script section type.
2770 Output_section_definition::script_section_type_name(
2771 Script_section_type script_section_type
)
2773 switch (script_section_type
)
2775 case SCRIPT_SECTION_TYPE_NONE
:
2777 case SCRIPT_SECTION_TYPE_NOLOAD
:
2779 case SCRIPT_SECTION_TYPE_DSECT
:
2781 case SCRIPT_SECTION_TYPE_COPY
:
2783 case SCRIPT_SECTION_TYPE_INFO
:
2785 case SCRIPT_SECTION_TYPE_OVERLAY
:
2793 Output_section_definition::set_memory_region(Memory_region
* mr
, bool set_vma
)
2795 gold_assert(mr
!= NULL
);
2796 // Add the current section to the specified region's list.
2797 mr
->add_section(this, set_vma
);
2800 // An output section created to hold orphaned input sections. These
2801 // do not actually appear in linker scripts. However, for convenience
2802 // when setting the output section addresses, we put a marker to these
2803 // sections in the appropriate place in the list of SECTIONS elements.
2805 class Orphan_output_section
: public Sections_element
2808 Orphan_output_section(Output_section
* os
)
2812 // Return whether the orphan output section is relro. We can just
2813 // check the output section because we always set the flag, if
2814 // needed, just after we create the Orphan_output_section.
2817 { return this->os_
->is_relro(); }
2819 // Initialize OSP with an output section. This should have been
2822 orphan_section_init(Orphan_section_placement
*,
2823 Script_sections::Elements_iterator
)
2824 { gold_unreachable(); }
2826 // Set section addresses.
2828 set_section_addresses(Symbol_table
*, Layout
*, uint64_t*, uint64_t*,
2831 // Get the list of segments to use for an allocated section when
2832 // using a PHDRS clause.
2834 allocate_to_segment(String_list
**, bool*);
2836 // Return the associated Output_section.
2838 get_output_section() const
2839 { return this->os_
; }
2841 // Print for debugging.
2843 print(FILE* f
) const
2845 fprintf(f
, " marker for orphaned output section %s\n",
2850 Output_section
* os_
;
2853 // Set section addresses.
2856 Orphan_output_section::set_section_addresses(Symbol_table
*, Layout
*,
2857 uint64_t* dot_value
,
2859 uint64_t* load_address
)
2861 typedef std::list
<Output_section::Input_section
> Input_section_list
;
2863 bool have_load_address
= *load_address
!= *dot_value
;
2865 uint64_t address
= *dot_value
;
2866 address
= align_address(address
, this->os_
->addralign());
2868 // For a relocatable link, all orphan sections are put at
2869 // address 0. In general we expect all sections to be at
2870 // address 0 for a relocatable link, but we permit the linker
2871 // script to override that for specific output sections.
2872 if (parameters
->options().relocatable())
2876 have_load_address
= false;
2879 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) != 0)
2881 this->os_
->set_address(address
);
2882 if (have_load_address
)
2883 this->os_
->set_load_address(align_address(*load_address
,
2884 this->os_
->addralign()));
2887 Input_section_list input_sections
;
2888 address
+= this->os_
->get_input_sections(address
, "", &input_sections
);
2890 for (Input_section_list::iterator p
= input_sections
.begin();
2891 p
!= input_sections
.end();
2894 uint64_t addralign
= p
->addralign();
2895 if (!p
->is_input_section())
2896 p
->output_section_data()->finalize_data_size();
2897 uint64_t size
= p
->data_size();
2898 address
= align_address(address
, addralign
);
2899 this->os_
->add_script_input_section(*p
);
2903 // An SHF_TLS/SHT_NOBITS section does not take up any address space.
2904 if (this->os_
== NULL
2905 || (this->os_
->flags() & elfcpp::SHF_TLS
) == 0
2906 || this->os_
->type() != elfcpp::SHT_NOBITS
)
2908 if (!have_load_address
)
2909 *load_address
= address
;
2911 *load_address
+= address
- *dot_value
;
2913 *dot_value
= address
;
2917 // Get the list of segments to use for an allocated section when using
2918 // a PHDRS clause. If this is an allocated section, return the
2919 // Output_section. We don't change the list of segments.
2922 Orphan_output_section::allocate_to_segment(String_list
**, bool* orphan
)
2924 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) == 0)
2930 // Class Phdrs_element. A program header from a PHDRS clause.
2935 Phdrs_element(const char* name
, size_t namelen
, unsigned int type
,
2936 bool includes_filehdr
, bool includes_phdrs
,
2937 bool is_flags_valid
, unsigned int flags
,
2938 Expression
* load_address
)
2939 : name_(name
, namelen
), type_(type
), includes_filehdr_(includes_filehdr
),
2940 includes_phdrs_(includes_phdrs
), is_flags_valid_(is_flags_valid
),
2941 flags_(flags
), load_address_(load_address
), load_address_value_(0),
2945 // Return the name of this segment.
2948 { return this->name_
; }
2950 // Return the type of the segment.
2953 { return this->type_
; }
2955 // Whether to include the file header.
2957 includes_filehdr() const
2958 { return this->includes_filehdr_
; }
2960 // Whether to include the program headers.
2962 includes_phdrs() const
2963 { return this->includes_phdrs_
; }
2965 // Return whether there is a load address.
2967 has_load_address() const
2968 { return this->load_address_
!= NULL
; }
2970 // Evaluate the load address expression if there is one.
2972 eval_load_address(Symbol_table
* symtab
, Layout
* layout
)
2974 if (this->load_address_
!= NULL
)
2975 this->load_address_value_
= this->load_address_
->eval(symtab
, layout
,
2979 // Return the load address.
2981 load_address() const
2983 gold_assert(this->load_address_
!= NULL
);
2984 return this->load_address_value_
;
2987 // Create the segment.
2989 create_segment(Layout
* layout
)
2991 this->segment_
= layout
->make_output_segment(this->type_
, this->flags_
);
2992 return this->segment_
;
2995 // Return the segment.
2998 { return this->segment_
; }
3000 // Release the segment.
3003 { this->segment_
= NULL
; }
3005 // Set the segment flags if appropriate.
3007 set_flags_if_valid()
3009 if (this->is_flags_valid_
)
3010 this->segment_
->set_flags(this->flags_
);
3013 // Print for debugging.
3018 // The name used in the script.
3020 // The type of the segment (PT_LOAD, etc.).
3022 // Whether this segment includes the file header.
3023 bool includes_filehdr_
;
3024 // Whether this segment includes the section headers.
3025 bool includes_phdrs_
;
3026 // Whether the flags were explicitly specified.
3027 bool is_flags_valid_
;
3028 // The flags for this segment (PF_R, etc.) if specified.
3029 unsigned int flags_
;
3030 // The expression for the load address for this segment. This may
3032 Expression
* load_address_
;
3033 // The actual load address from evaluating the expression.
3034 uint64_t load_address_value_
;
3035 // The segment itself.
3036 Output_segment
* segment_
;
3039 // Print for debugging.
3042 Phdrs_element::print(FILE* f
) const
3044 fprintf(f
, " %s 0x%x", this->name_
.c_str(), this->type_
);
3045 if (this->includes_filehdr_
)
3046 fprintf(f
, " FILEHDR");
3047 if (this->includes_phdrs_
)
3048 fprintf(f
, " PHDRS");
3049 if (this->is_flags_valid_
)
3050 fprintf(f
, " FLAGS(%u)", this->flags_
);
3051 if (this->load_address_
!= NULL
)
3054 this->load_address_
->print(f
);
3060 // Add a memory region.
3063 Script_sections::add_memory_region(const char* name
, size_t namelen
,
3064 unsigned int attributes
,
3065 Expression
* start
, Expression
* length
)
3067 if (this->memory_regions_
== NULL
)
3068 this->memory_regions_
= new Memory_regions();
3069 else if (this->find_memory_region(name
, namelen
))
3071 gold_error(_("region '%.*s' already defined"), static_cast<int>(namelen
),
3073 // FIXME: Add a GOLD extension to allow multiple regions with the same
3074 // name. This would amount to a single region covering disjoint blocks
3075 // of memory, which is useful for embedded devices.
3078 // FIXME: Check the length and start values. Currently we allow
3079 // non-constant expressions for these values, whereas LD does not.
3081 // FIXME: Add a GOLD extension to allow NEGATIVE LENGTHS. This would
3082 // describe a region that packs from the end address going down, rather
3083 // than the start address going up. This would be useful for embedded
3086 this->memory_regions_
->push_back(new Memory_region(name
, namelen
, attributes
,
3090 // Find a memory region.
3093 Script_sections::find_memory_region(const char* name
, size_t namelen
)
3095 if (this->memory_regions_
== NULL
)
3098 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
3099 m
!= this->memory_regions_
->end();
3101 if ((*m
)->name_match(name
, namelen
))
3107 // Find a memory region's origin.
3110 Script_sections::find_memory_region_origin(const char* name
, size_t namelen
)
3112 Memory_region
* mr
= find_memory_region(name
, namelen
);
3116 return mr
->start_address();
3119 // Find a memory region's length.
3122 Script_sections::find_memory_region_length(const char* name
, size_t namelen
)
3124 Memory_region
* mr
= find_memory_region(name
, namelen
);
3128 return mr
->length();
3131 // Set the memory region to use for the current section.
3134 Script_sections::set_memory_region(Memory_region
* mr
, bool set_vma
)
3136 gold_assert(!this->sections_elements_
->empty());
3137 this->sections_elements_
->back()->set_memory_region(mr
, set_vma
);
3140 // Class Script_sections.
3142 Script_sections::Script_sections()
3143 : saw_sections_clause_(false),
3144 in_sections_clause_(false),
3145 sections_elements_(NULL
),
3146 output_section_(NULL
),
3147 memory_regions_(NULL
),
3148 phdrs_elements_(NULL
),
3149 orphan_section_placement_(NULL
),
3150 data_segment_align_start_(),
3151 saw_data_segment_align_(false),
3152 saw_relro_end_(false),
3153 saw_segment_start_expression_(false)
3157 // Start a SECTIONS clause.
3160 Script_sections::start_sections()
3162 gold_assert(!this->in_sections_clause_
&& this->output_section_
== NULL
);
3163 this->saw_sections_clause_
= true;
3164 this->in_sections_clause_
= true;
3165 if (this->sections_elements_
== NULL
)
3166 this->sections_elements_
= new Sections_elements
;
3169 // Finish a SECTIONS clause.
3172 Script_sections::finish_sections()
3174 gold_assert(this->in_sections_clause_
&& this->output_section_
== NULL
);
3175 this->in_sections_clause_
= false;
3178 // Add a symbol to be defined.
3181 Script_sections::add_symbol_assignment(const char* name
, size_t length
,
3182 Expression
* val
, bool provide
,
3185 if (this->output_section_
!= NULL
)
3186 this->output_section_
->add_symbol_assignment(name
, length
, val
,
3190 Sections_element
* p
= new Sections_element_assignment(name
, length
,
3193 this->sections_elements_
->push_back(p
);
3197 // Add an assignment to the special dot symbol.
3200 Script_sections::add_dot_assignment(Expression
* val
)
3202 if (this->output_section_
!= NULL
)
3203 this->output_section_
->add_dot_assignment(val
);
3206 // The GNU linker permits assignments to . to appears outside of
3207 // a SECTIONS clause, and treats it as appearing inside, so
3208 // sections_elements_ may be NULL here.
3209 if (this->sections_elements_
== NULL
)
3211 this->sections_elements_
= new Sections_elements
;
3212 this->saw_sections_clause_
= true;
3215 Sections_element
* p
= new Sections_element_dot_assignment(val
);
3216 this->sections_elements_
->push_back(p
);
3220 // Add an assertion.
3223 Script_sections::add_assertion(Expression
* check
, const char* message
,
3226 if (this->output_section_
!= NULL
)
3227 this->output_section_
->add_assertion(check
, message
, messagelen
);
3230 Sections_element
* p
= new Sections_element_assertion(check
, message
,
3232 this->sections_elements_
->push_back(p
);
3236 // Start processing entries for an output section.
3239 Script_sections::start_output_section(
3242 const Parser_output_section_header
* header
)
3244 Output_section_definition
* posd
= new Output_section_definition(name
,
3247 this->sections_elements_
->push_back(posd
);
3248 gold_assert(this->output_section_
== NULL
);
3249 this->output_section_
= posd
;
3252 // Stop processing entries for an output section.
3255 Script_sections::finish_output_section(
3256 const Parser_output_section_trailer
* trailer
)
3258 gold_assert(this->output_section_
!= NULL
);
3259 this->output_section_
->finish(trailer
);
3260 this->output_section_
= NULL
;
3263 // Add a data item to the current output section.
3266 Script_sections::add_data(int size
, bool is_signed
, Expression
* val
)
3268 gold_assert(this->output_section_
!= NULL
);
3269 this->output_section_
->add_data(size
, is_signed
, val
);
3272 // Add a fill value setting to the current output section.
3275 Script_sections::add_fill(Expression
* val
)
3277 gold_assert(this->output_section_
!= NULL
);
3278 this->output_section_
->add_fill(val
);
3281 // Add an input section specification to the current output section.
3284 Script_sections::add_input_section(const Input_section_spec
* spec
, bool keep
)
3286 gold_assert(this->output_section_
!= NULL
);
3287 this->output_section_
->add_input_section(spec
, keep
);
3290 // This is called when we see DATA_SEGMENT_ALIGN. It means that any
3291 // subsequent output sections may be relro.
3294 Script_sections::data_segment_align()
3296 if (this->saw_data_segment_align_
)
3297 gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script"));
3298 gold_assert(!this->sections_elements_
->empty());
3299 Sections_elements::iterator p
= this->sections_elements_
->end();
3301 this->data_segment_align_start_
= p
;
3302 this->saw_data_segment_align_
= true;
3305 // This is called when we see DATA_SEGMENT_RELRO_END. It means that
3306 // any output sections seen since DATA_SEGMENT_ALIGN are relro.
3309 Script_sections::data_segment_relro_end()
3311 if (this->saw_relro_end_
)
3312 gold_error(_("DATA_SEGMENT_RELRO_END may only appear once "
3313 "in a linker script"));
3314 this->saw_relro_end_
= true;
3316 if (!this->saw_data_segment_align_
)
3317 gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN"));
3320 Sections_elements::iterator p
= this->data_segment_align_start_
;
3321 for (++p
; p
!= this->sections_elements_
->end(); ++p
)
3322 (*p
)->set_is_relro();
3326 // Create any required sections.
3329 Script_sections::create_sections(Layout
* layout
)
3331 if (!this->saw_sections_clause_
)
3333 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3334 p
!= this->sections_elements_
->end();
3336 (*p
)->create_sections(layout
);
3339 // Add any symbols we are defining to the symbol table.
3342 Script_sections::add_symbols_to_table(Symbol_table
* symtab
)
3344 if (!this->saw_sections_clause_
)
3346 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3347 p
!= this->sections_elements_
->end();
3349 (*p
)->add_symbols_to_table(symtab
);
3352 // Finalize symbols and check assertions.
3355 Script_sections::finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
)
3357 if (!this->saw_sections_clause_
)
3359 uint64_t dot_value
= 0;
3360 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3361 p
!= this->sections_elements_
->end();
3363 (*p
)->finalize_symbols(symtab
, layout
, &dot_value
);
3366 // Return the name of the output section to use for an input file name
3367 // and section name.
3370 Script_sections::output_section_name(
3371 const char* file_name
,
3372 const char* section_name
,
3373 Output_section
*** output_section_slot
,
3374 Script_sections::Section_type
* psection_type
,
3377 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3378 p
!= this->sections_elements_
->end();
3381 const char* ret
= (*p
)->output_section_name(file_name
, section_name
,
3382 output_section_slot
,
3383 psection_type
, keep
);
3387 // The special name /DISCARD/ means that the input section
3388 // should be discarded.
3389 if (strcmp(ret
, "/DISCARD/") == 0)
3391 *output_section_slot
= NULL
;
3392 *psection_type
= Script_sections::ST_NONE
;
3399 // If we couldn't find a mapping for the name, the output section
3400 // gets the name of the input section.
3402 *output_section_slot
= NULL
;
3403 *psection_type
= Script_sections::ST_NONE
;
3405 return section_name
;
3408 // Place a marker for an orphan output section into the SECTIONS
3412 Script_sections::place_orphan(Output_section
* os
)
3414 Orphan_section_placement
* osp
= this->orphan_section_placement_
;
3417 // Initialize the Orphan_section_placement structure.
3418 osp
= new Orphan_section_placement();
3419 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3420 p
!= this->sections_elements_
->end();
3422 (*p
)->orphan_section_init(osp
, p
);
3423 gold_assert(!this->sections_elements_
->empty());
3424 Sections_elements::iterator last
= this->sections_elements_
->end();
3426 osp
->last_init(last
);
3427 this->orphan_section_placement_
= osp
;
3430 Orphan_output_section
* orphan
= new Orphan_output_section(os
);
3432 // Look for where to put ORPHAN.
3433 Sections_elements::iterator
* where
;
3434 if (osp
->find_place(os
, &where
))
3436 if ((**where
)->is_relro())
3439 os
->clear_is_relro();
3441 // We want to insert ORPHAN after *WHERE, and then update *WHERE
3442 // so that the next one goes after this one.
3443 Sections_elements::iterator p
= *where
;
3444 gold_assert(p
!= this->sections_elements_
->end());
3446 *where
= this->sections_elements_
->insert(p
, orphan
);
3450 os
->clear_is_relro();
3451 // We don't have a place to put this orphan section. Put it,
3452 // and all other sections like it, at the end, but before the
3453 // sections which always come at the end.
3454 Sections_elements::iterator last
= osp
->last_place();
3455 *where
= this->sections_elements_
->insert(last
, orphan
);
3459 // Set the addresses of all the output sections. Walk through all the
3460 // elements, tracking the dot symbol. Apply assignments which set
3461 // absolute symbol values, in case they are used when setting dot.
3462 // Fill in data statement values. As we find output sections, set the
3463 // address, set the address of all associated input sections, and
3464 // update dot. Return the segment which should hold the file header
3465 // and segment headers, if any.
3468 Script_sections::set_section_addresses(Symbol_table
* symtab
, Layout
* layout
)
3470 gold_assert(this->saw_sections_clause_
);
3472 // Implement ONLY_IF_RO/ONLY_IF_RW constraints. These are a pain
3473 // for our representation.
3474 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3475 p
!= this->sections_elements_
->end();
3478 Output_section_definition
* posd
;
3479 Section_constraint failed_constraint
= (*p
)->check_constraint(&posd
);
3480 if (failed_constraint
!= CONSTRAINT_NONE
)
3482 Sections_elements::iterator q
;
3483 for (q
= this->sections_elements_
->begin();
3484 q
!= this->sections_elements_
->end();
3489 if ((*q
)->alternate_constraint(posd
, failed_constraint
))
3494 if (q
== this->sections_elements_
->end())
3495 gold_error(_("no matching section constraint"));
3499 // Force the alignment of the first TLS section to be the maximum
3500 // alignment of all TLS sections.
3501 Output_section
* first_tls
= NULL
;
3502 uint64_t tls_align
= 0;
3503 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3504 p
!= this->sections_elements_
->end();
3507 Output_section
* os
= (*p
)->get_output_section();
3508 if (os
!= NULL
&& (os
->flags() & elfcpp::SHF_TLS
) != 0)
3510 if (first_tls
== NULL
)
3512 if (os
->addralign() > tls_align
)
3513 tls_align
= os
->addralign();
3516 if (first_tls
!= NULL
)
3517 first_tls
->set_addralign(tls_align
);
3519 // For a relocatable link, we implicitly set dot to zero.
3520 uint64_t dot_value
= 0;
3521 uint64_t dot_alignment
= 0;
3522 uint64_t load_address
= 0;
3524 // Check to see if we want to use any of -Ttext, -Tdata and -Tbss options
3525 // to set section addresses. If the script has any SEGMENT_START
3526 // expression, we do not set the section addresses.
3527 bool use_tsection_options
=
3528 (!this->saw_segment_start_expression_
3529 && (parameters
->options().user_set_Ttext()
3530 || parameters
->options().user_set_Tdata()
3531 || parameters
->options().user_set_Tbss()));
3533 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3534 p
!= this->sections_elements_
->end();
3537 Output_section
* os
= (*p
)->get_output_section();
3539 // Handle -Ttext, -Tdata and -Tbss options. We do this by looking for
3540 // the special sections by names and doing dot assignments.
3541 if (use_tsection_options
3543 && (os
->flags() & elfcpp::SHF_ALLOC
) != 0)
3545 uint64_t new_dot_value
= dot_value
;
3547 if (parameters
->options().user_set_Ttext()
3548 && strcmp(os
->name(), ".text") == 0)
3549 new_dot_value
= parameters
->options().Ttext();
3550 else if (parameters
->options().user_set_Tdata()
3551 && strcmp(os
->name(), ".data") == 0)
3552 new_dot_value
= parameters
->options().Tdata();
3553 else if (parameters
->options().user_set_Tbss()
3554 && strcmp(os
->name(), ".bss") == 0)
3555 new_dot_value
= parameters
->options().Tbss();
3557 // Update dot and load address if necessary.
3558 if (new_dot_value
< dot_value
)
3559 gold_error(_("dot may not move backward"));
3560 else if (new_dot_value
!= dot_value
)
3562 dot_value
= new_dot_value
;
3563 load_address
= new_dot_value
;
3567 (*p
)->set_section_addresses(symtab
, layout
, &dot_value
, &dot_alignment
,
3571 if (this->phdrs_elements_
!= NULL
)
3573 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
3574 p
!= this->phdrs_elements_
->end();
3576 (*p
)->eval_load_address(symtab
, layout
);
3579 return this->create_segments(layout
, dot_alignment
);
3582 // Sort the sections in order to put them into segments.
3584 class Sort_output_sections
3587 Sort_output_sections(const Script_sections::Sections_elements
* elements
)
3588 : elements_(elements
)
3592 operator()(const Output_section
* os1
, const Output_section
* os2
) const;
3596 script_compare(const Output_section
* os1
, const Output_section
* os2
) const;
3599 const Script_sections::Sections_elements
* elements_
;
3603 Sort_output_sections::operator()(const Output_section
* os1
,
3604 const Output_section
* os2
) const
3606 // Sort first by the load address.
3607 uint64_t lma1
= (os1
->has_load_address()
3608 ? os1
->load_address()
3610 uint64_t lma2
= (os2
->has_load_address()
3611 ? os2
->load_address()
3616 // Then sort by the virtual address.
3617 if (os1
->address() != os2
->address())
3618 return os1
->address() < os2
->address();
3620 // If the linker script says which of these sections is first, go
3621 // with what it says.
3622 int i
= this->script_compare(os1
, os2
);
3626 // Sort PROGBITS before NOBITS.
3627 bool nobits1
= os1
->type() == elfcpp::SHT_NOBITS
;
3628 bool nobits2
= os2
->type() == elfcpp::SHT_NOBITS
;
3629 if (nobits1
!= nobits2
)
3632 // Sort PROGBITS TLS sections to the end, NOBITS TLS sections to the
3634 bool tls1
= (os1
->flags() & elfcpp::SHF_TLS
) != 0;
3635 bool tls2
= (os2
->flags() & elfcpp::SHF_TLS
) != 0;
3637 return nobits1
? tls1
: tls2
;
3639 // Sort non-NOLOAD before NOLOAD.
3640 if (os1
->is_noload() && !os2
->is_noload())
3642 if (!os1
->is_noload() && os2
->is_noload())
3645 // The sections seem practically identical. Sort by name to get a
3647 return os1
->name() < os2
->name();
3650 // Return -1 if OS1 comes before OS2 in ELEMENTS_, 1 if comes after, 0
3651 // if either OS1 or OS2 is not mentioned. This ensures that we keep
3652 // empty sections in the order in which they appear in a linker
3656 Sort_output_sections::script_compare(const Output_section
* os1
,
3657 const Output_section
* os2
) const
3659 if (this->elements_
== NULL
)
3662 bool found_os1
= false;
3663 bool found_os2
= false;
3664 for (Script_sections::Sections_elements::const_iterator
3665 p
= this->elements_
->begin();
3666 p
!= this->elements_
->end();
3669 if (os2
== (*p
)->get_output_section())
3675 else if (os1
== (*p
)->get_output_section())
3686 // Return whether OS is a BSS section. This is a SHT_NOBITS section.
3687 // We treat a section with the SHF_TLS flag set as taking up space
3688 // even if it is SHT_NOBITS (this is true of .tbss), as we allocate
3689 // space for them in the file.
3692 Script_sections::is_bss_section(const Output_section
* os
)
3694 return (os
->type() == elfcpp::SHT_NOBITS
3695 && (os
->flags() & elfcpp::SHF_TLS
) == 0);
3698 // Return the size taken by the file header and the program headers.
3701 Script_sections::total_header_size(Layout
* layout
) const
3703 size_t segment_count
= layout
->segment_count();
3704 size_t file_header_size
;
3705 size_t segment_headers_size
;
3706 if (parameters
->target().get_size() == 32)
3708 file_header_size
= elfcpp::Elf_sizes
<32>::ehdr_size
;
3709 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<32>::phdr_size
;
3711 else if (parameters
->target().get_size() == 64)
3713 file_header_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
3714 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<64>::phdr_size
;
3719 return file_header_size
+ segment_headers_size
;
3722 // Return the amount we have to subtract from the LMA to accommodate
3723 // headers of the given size. The complication is that the file
3724 // header have to be at the start of a page, as otherwise it will not
3725 // be at the start of the file.
3728 Script_sections::header_size_adjustment(uint64_t lma
,
3729 size_t sizeof_headers
) const
3731 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3732 uint64_t hdr_lma
= lma
- sizeof_headers
;
3733 hdr_lma
&= ~(abi_pagesize
- 1);
3734 return lma
- hdr_lma
;
3737 // Create the PT_LOAD segments when using a SECTIONS clause. Returns
3738 // the segment which should hold the file header and segment headers,
3742 Script_sections::create_segments(Layout
* layout
, uint64_t dot_alignment
)
3744 gold_assert(this->saw_sections_clause_
);
3746 if (parameters
->options().relocatable())
3749 if (this->saw_phdrs_clause())
3750 return create_segments_from_phdrs_clause(layout
, dot_alignment
);
3752 Layout::Section_list sections
;
3753 layout
->get_allocated_sections(§ions
);
3755 // Sort the sections by address.
3756 std::stable_sort(sections
.begin(), sections
.end(),
3757 Sort_output_sections(this->sections_elements_
));
3759 this->create_note_and_tls_segments(layout
, §ions
);
3761 // Walk through the sections adding them to PT_LOAD segments.
3762 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3763 Output_segment
* first_seg
= NULL
;
3764 Output_segment
* current_seg
= NULL
;
3765 bool is_current_seg_readonly
= true;
3766 Layout::Section_list::iterator plast
= sections
.end();
3767 uint64_t last_vma
= 0;
3768 uint64_t last_lma
= 0;
3769 uint64_t last_size
= 0;
3770 for (Layout::Section_list::iterator p
= sections
.begin();
3771 p
!= sections
.end();
3774 const uint64_t vma
= (*p
)->address();
3775 const uint64_t lma
= ((*p
)->has_load_address()
3776 ? (*p
)->load_address()
3778 const uint64_t size
= (*p
)->current_data_size();
3780 bool need_new_segment
;
3781 if (current_seg
== NULL
)
3782 need_new_segment
= true;
3783 else if (lma
- vma
!= last_lma
- last_vma
)
3785 // This section has a different LMA relationship than the
3786 // last one; we need a new segment.
3787 need_new_segment
= true;
3789 else if (align_address(last_lma
+ last_size
, abi_pagesize
)
3790 < align_address(lma
, abi_pagesize
))
3792 // Putting this section in the segment would require
3794 need_new_segment
= true;
3796 else if (is_bss_section(*plast
) && !is_bss_section(*p
))
3798 // A non-BSS section can not follow a BSS section in the
3800 need_new_segment
= true;
3802 else if (is_current_seg_readonly
3803 && ((*p
)->flags() & elfcpp::SHF_WRITE
) != 0
3804 && !parameters
->options().omagic())
3806 // Don't put a writable section in the same segment as a
3807 // non-writable section.
3808 need_new_segment
= true;
3812 // Otherwise, reuse the existing segment.
3813 need_new_segment
= false;
3816 elfcpp::Elf_Word seg_flags
=
3817 Layout::section_flags_to_segment((*p
)->flags());
3819 if (need_new_segment
)
3821 current_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
3823 current_seg
->set_addresses(vma
, lma
);
3824 current_seg
->set_minimum_p_align(dot_alignment
);
3825 if (first_seg
== NULL
)
3826 first_seg
= current_seg
;
3827 is_current_seg_readonly
= true;
3830 current_seg
->add_output_section_to_load(layout
, *p
, seg_flags
);
3832 if (((*p
)->flags() & elfcpp::SHF_WRITE
) != 0)
3833 is_current_seg_readonly
= false;
3841 // An ELF program should work even if the program headers are not in
3842 // a PT_LOAD segment. However, it appears that the Linux kernel
3843 // does not set the AT_PHDR auxiliary entry in that case. It sets
3844 // the load address to p_vaddr - p_offset of the first PT_LOAD
3845 // segment. It then sets AT_PHDR to the load address plus the
3846 // offset to the program headers, e_phoff in the file header. This
3847 // fails when the program headers appear in the file before the
3848 // first PT_LOAD segment. Therefore, we always create a PT_LOAD
3849 // segment to hold the file header and the program headers. This is
3850 // effectively what the GNU linker does, and it is slightly more
3851 // efficient in any case. We try to use the first PT_LOAD segment
3852 // if we can, otherwise we make a new one.
3854 if (first_seg
== NULL
)
3857 // -n or -N mean that the program is not demand paged and there is
3858 // no need to put the program headers in a PT_LOAD segment.
3859 if (parameters
->options().nmagic() || parameters
->options().omagic())
3862 size_t sizeof_headers
= this->total_header_size(layout
);
3864 uint64_t vma
= first_seg
->vaddr();
3865 uint64_t lma
= first_seg
->paddr();
3867 uint64_t subtract
= this->header_size_adjustment(lma
, sizeof_headers
);
3869 if ((lma
& (abi_pagesize
- 1)) >= sizeof_headers
)
3871 first_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
3875 // If there is no room to squeeze in the headers, then punt. The
3876 // resulting executable probably won't run on GNU/Linux, but we
3877 // trust that the user knows what they are doing.
3878 if (lma
< subtract
|| vma
< subtract
)
3881 // If memory regions have been specified and the address range
3882 // we are about to use is not contained within any region then
3883 // issue a warning message about the segment we are going to
3884 // create. It will be outside of any region and so possibly
3885 // using non-existent or protected memory. We test LMA rather
3886 // than VMA since we assume that the headers will never be
3888 if (this->memory_regions_
!= NULL
3889 && !this->block_in_region (NULL
, layout
, lma
- subtract
, subtract
))
3890 gold_warning(_("creating a segment to contain the file and program"
3891 " headers outside of any MEMORY region"));
3893 Output_segment
* load_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
3895 load_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
3900 // Create a PT_NOTE segment for each SHT_NOTE section and a PT_TLS
3901 // segment if there are any SHT_TLS sections.
3904 Script_sections::create_note_and_tls_segments(
3906 const Layout::Section_list
* sections
)
3908 gold_assert(!this->saw_phdrs_clause());
3910 bool saw_tls
= false;
3911 for (Layout::Section_list::const_iterator p
= sections
->begin();
3912 p
!= sections
->end();
3915 if ((*p
)->type() == elfcpp::SHT_NOTE
)
3917 elfcpp::Elf_Word seg_flags
=
3918 Layout::section_flags_to_segment((*p
)->flags());
3919 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_NOTE
,
3921 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
3923 // Incorporate any subsequent SHT_NOTE sections, in the
3924 // hopes that the script is sensible.
3925 Layout::Section_list::const_iterator pnext
= p
+ 1;
3926 while (pnext
!= sections
->end()
3927 && (*pnext
)->type() == elfcpp::SHT_NOTE
)
3929 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
3930 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
3936 if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
3939 gold_error(_("TLS sections are not adjacent"));
3941 elfcpp::Elf_Word seg_flags
=
3942 Layout::section_flags_to_segment((*p
)->flags());
3943 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_TLS
,
3945 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
3947 Layout::Section_list::const_iterator pnext
= p
+ 1;
3948 while (pnext
!= sections
->end()
3949 && ((*pnext
)->flags() & elfcpp::SHF_TLS
) != 0)
3951 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
3952 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
3960 // If we are making a shared library, and we see a section named
3961 // .interp then put the .interp section in a PT_INTERP segment.
3962 // This is for GNU ld compatibility.
3963 if (strcmp((*p
)->name(), ".interp") == 0)
3965 elfcpp::Elf_Word seg_flags
=
3966 Layout::section_flags_to_segment((*p
)->flags());
3967 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_INTERP
,
3969 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
3974 // Add a program header. The PHDRS clause is syntactically distinct
3975 // from the SECTIONS clause, but we implement it with the SECTIONS
3976 // support because PHDRS is useless if there is no SECTIONS clause.
3979 Script_sections::add_phdr(const char* name
, size_t namelen
, unsigned int type
,
3980 bool includes_filehdr
, bool includes_phdrs
,
3981 bool is_flags_valid
, unsigned int flags
,
3982 Expression
* load_address
)
3984 if (this->phdrs_elements_
== NULL
)
3985 this->phdrs_elements_
= new Phdrs_elements();
3986 this->phdrs_elements_
->push_back(new Phdrs_element(name
, namelen
, type
,
3989 is_flags_valid
, flags
,
3993 // Return the number of segments we expect to create based on the
3994 // SECTIONS clause. This is used to implement SIZEOF_HEADERS.
3997 Script_sections::expected_segment_count(const Layout
* layout
) const
3999 if (this->saw_phdrs_clause())
4000 return this->phdrs_elements_
->size();
4002 Layout::Section_list sections
;
4003 layout
->get_allocated_sections(§ions
);
4005 // We assume that we will need two PT_LOAD segments.
4008 bool saw_note
= false;
4009 bool saw_tls
= false;
4010 for (Layout::Section_list::const_iterator p
= sections
.begin();
4011 p
!= sections
.end();
4014 if ((*p
)->type() == elfcpp::SHT_NOTE
)
4016 // Assume that all note sections will fit into a single
4024 else if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
4026 // There can only be one PT_TLS segment.
4038 // Create the segments from a PHDRS clause. Return the segment which
4039 // should hold the file header and program headers, if any.
4042 Script_sections::create_segments_from_phdrs_clause(Layout
* layout
,
4043 uint64_t dot_alignment
)
4045 this->attach_sections_using_phdrs_clause(layout
);
4046 return this->set_phdrs_clause_addresses(layout
, dot_alignment
);
4049 // Create the segments from the PHDRS clause, and put the output
4050 // sections in them.
4053 Script_sections::attach_sections_using_phdrs_clause(Layout
* layout
)
4055 typedef std::map
<std::string
, Output_segment
*> Name_to_segment
;
4056 Name_to_segment name_to_segment
;
4057 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4058 p
!= this->phdrs_elements_
->end();
4060 name_to_segment
[(*p
)->name()] = (*p
)->create_segment(layout
);
4062 // Walk through the output sections and attach them to segments.
4063 // Output sections in the script which do not list segments are
4064 // attached to the same set of segments as the immediately preceding
4067 String_list
* phdr_names
= NULL
;
4068 bool load_segments_only
= false;
4069 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4070 p
!= this->sections_elements_
->end();
4074 String_list
* old_phdr_names
= phdr_names
;
4075 Output_section
* os
= (*p
)->allocate_to_segment(&phdr_names
, &is_orphan
);
4079 elfcpp::Elf_Word seg_flags
=
4080 Layout::section_flags_to_segment(os
->flags());
4082 if (phdr_names
== NULL
)
4084 // Don't worry about empty orphan sections.
4085 if (is_orphan
&& os
->current_data_size() > 0)
4086 gold_error(_("allocated section %s not in any segment"),
4089 // To avoid later crashes drop this section into the first
4091 for (Phdrs_elements::const_iterator ppe
=
4092 this->phdrs_elements_
->begin();
4093 ppe
!= this->phdrs_elements_
->end();
4096 Output_segment
* oseg
= (*ppe
)->segment();
4097 if (oseg
->type() == elfcpp::PT_LOAD
)
4099 oseg
->add_output_section_to_load(layout
, os
, seg_flags
);
4107 // We see a list of segments names. Disable PT_LOAD segment only
4109 if (old_phdr_names
!= phdr_names
)
4110 load_segments_only
= false;
4112 // If this is an orphan section--one that was not explicitly
4113 // mentioned in the linker script--then it should not inherit
4114 // any segment type other than PT_LOAD. Otherwise, e.g., the
4115 // PT_INTERP segment will pick up following orphan sections,
4116 // which does not make sense. If this is not an orphan section,
4117 // we trust the linker script.
4120 // Enable PT_LOAD segments only filtering until we see another
4121 // list of segment names.
4122 load_segments_only
= true;
4125 bool in_load_segment
= false;
4126 for (String_list::const_iterator q
= phdr_names
->begin();
4127 q
!= phdr_names
->end();
4130 Name_to_segment::const_iterator r
= name_to_segment
.find(*q
);
4131 if (r
== name_to_segment
.end())
4132 gold_error(_("no segment %s"), q
->c_str());
4135 if (load_segments_only
4136 && r
->second
->type() != elfcpp::PT_LOAD
)
4139 if (r
->second
->type() != elfcpp::PT_LOAD
)
4140 r
->second
->add_output_section_to_nonload(os
, seg_flags
);
4143 r
->second
->add_output_section_to_load(layout
, os
, seg_flags
);
4144 if (in_load_segment
)
4145 gold_error(_("section in two PT_LOAD segments"));
4146 in_load_segment
= true;
4151 if (!in_load_segment
)
4152 gold_error(_("allocated section not in any PT_LOAD segment"));
4156 // Set the addresses for segments created from a PHDRS clause. Return
4157 // the segment which should hold the file header and program headers,
4161 Script_sections::set_phdrs_clause_addresses(Layout
* layout
,
4162 uint64_t dot_alignment
)
4164 Output_segment
* load_seg
= NULL
;
4165 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4166 p
!= this->phdrs_elements_
->end();
4169 // Note that we have to set the flags after adding the output
4170 // sections to the segment, as adding an output segment can
4171 // change the flags.
4172 (*p
)->set_flags_if_valid();
4174 Output_segment
* oseg
= (*p
)->segment();
4176 if (oseg
->type() != elfcpp::PT_LOAD
)
4178 // The addresses of non-PT_LOAD segments are set from the
4179 // PT_LOAD segments.
4180 if ((*p
)->has_load_address())
4181 gold_error(_("may only specify load address for PT_LOAD segment"));
4185 oseg
->set_minimum_p_align(dot_alignment
);
4187 // The output sections should have addresses from the SECTIONS
4188 // clause. The addresses don't have to be in order, so find the
4189 // one with the lowest load address. Use that to set the
4190 // address of the segment.
4192 Output_section
* osec
= oseg
->section_with_lowest_load_address();
4195 oseg
->set_addresses(0, 0);
4199 uint64_t vma
= osec
->address();
4200 uint64_t lma
= osec
->has_load_address() ? osec
->load_address() : vma
;
4202 // Override the load address of the section with the load
4203 // address specified for the segment.
4204 if ((*p
)->has_load_address())
4206 if (osec
->has_load_address())
4207 gold_warning(_("PHDRS load address overrides "
4208 "section %s load address"),
4211 lma
= (*p
)->load_address();
4214 bool headers
= (*p
)->includes_filehdr() && (*p
)->includes_phdrs();
4215 if (!headers
&& ((*p
)->includes_filehdr() || (*p
)->includes_phdrs()))
4217 // We could support this if we wanted to.
4218 gold_error(_("using only one of FILEHDR and PHDRS is "
4219 "not currently supported"));
4223 size_t sizeof_headers
= this->total_header_size(layout
);
4224 uint64_t subtract
= this->header_size_adjustment(lma
,
4226 if (lma
>= subtract
&& vma
>= subtract
)
4233 gold_error(_("sections loaded on first page without room "
4234 "for file and program headers "
4235 "are not supported"));
4238 if (load_seg
!= NULL
)
4239 gold_error(_("using FILEHDR and PHDRS on more than one "
4240 "PT_LOAD segment is not currently supported"));
4244 oseg
->set_addresses(vma
, lma
);
4250 // Add the file header and segment headers to non-load segments
4251 // specified in the PHDRS clause.
4254 Script_sections::put_headers_in_phdrs(Output_data
* file_header
,
4255 Output_data
* segment_headers
)
4257 gold_assert(this->saw_phdrs_clause());
4258 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
4259 p
!= this->phdrs_elements_
->end();
4262 if ((*p
)->type() != elfcpp::PT_LOAD
)
4264 if ((*p
)->includes_phdrs())
4265 (*p
)->segment()->add_initial_output_data(segment_headers
);
4266 if ((*p
)->includes_filehdr())
4267 (*p
)->segment()->add_initial_output_data(file_header
);
4272 // Look for an output section by name and return the address, the load
4273 // address, the alignment, and the size. This is used when an
4274 // expression refers to an output section which was not actually
4275 // created. This returns true if the section was found, false
4279 Script_sections::get_output_section_info(const char* name
, uint64_t* address
,
4280 uint64_t* load_address
,
4281 uint64_t* addralign
,
4282 uint64_t* size
) const
4284 if (!this->saw_sections_clause_
)
4286 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4287 p
!= this->sections_elements_
->end();
4289 if ((*p
)->get_output_section_info(name
, address
, load_address
, addralign
,
4295 // Release all Output_segments. This remove all pointers to all
4299 Script_sections::release_segments()
4301 if (this->saw_phdrs_clause())
4303 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4304 p
!= this->phdrs_elements_
->end();
4306 (*p
)->release_segment();
4310 // Print the SECTIONS clause to F for debugging.
4313 Script_sections::print(FILE* f
) const
4315 if (this->phdrs_elements_
!= NULL
)
4317 fprintf(f
, "PHDRS {\n");
4318 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4319 p
!= this->phdrs_elements_
->end();
4325 if (this->memory_regions_
!= NULL
)
4327 fprintf(f
, "MEMORY {\n");
4328 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
4329 m
!= this->memory_regions_
->end();
4335 if (!this->saw_sections_clause_
)
4338 fprintf(f
, "SECTIONS {\n");
4340 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4341 p
!= this->sections_elements_
->end();
4348 } // End namespace gold.