1 // script-sections.cc -- linker script SECTIONS for gold
3 // Copyright (C) 2008-2016 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 set_address(uint64_t addr
, const Symbol_table
* symtab
, const Layout
* layout
)
100 uint64_t start
= this->start_
->eval(symtab
, layout
, false);
101 uint64_t len
= this->length_
->eval(symtab
, layout
, false);
102 if (addr
< start
|| addr
>= start
+ len
)
103 gold_error(_("address 0x%llx is not within region %s"),
104 static_cast<unsigned long long>(addr
),
105 this->name_
.c_str());
106 else if (addr
< start
+ this->current_offset_
)
107 gold_error(_("address 0x%llx moves dot backwards in region %s"),
108 static_cast<unsigned long long>(addr
),
109 this->name_
.c_str());
110 this->current_offset_
= addr
- start
;
114 increment_offset(std::string section_name
, uint64_t amount
,
115 const Symbol_table
* symtab
, const Layout
* layout
)
117 this->current_offset_
+= amount
;
119 if (this->current_offset_
120 > this->length_
->eval(symtab
, layout
, false))
121 gold_error(_("section %s overflows end of region %s"),
122 section_name
.c_str(), this->name_
.c_str());
125 // Returns true iff there is room left in this region
126 // for AMOUNT more bytes of data.
128 has_room_for(const Symbol_table
* symtab
, const Layout
* layout
,
129 uint64_t amount
) const
131 return (this->current_offset_
+ amount
132 < this->length_
->eval(symtab
, layout
, false));
135 // Return true if the provided section flags
136 // are compatible with this region's attributes.
138 attributes_compatible(elfcpp::Elf_Xword flags
, elfcpp::Elf_Xword type
) const;
141 add_section(Output_section_definition
* sec
, bool vma
)
144 this->vma_sections_
.push_back(sec
);
146 this->lma_sections_
.push_back(sec
);
149 typedef std::vector
<Output_section_definition
*> Section_list
;
151 // Return the start of the list of sections
152 // whose VMAs are taken from this region.
153 Section_list::const_iterator
154 get_vma_section_list_start() const
155 { return this->vma_sections_
.begin(); }
157 // Return the start of the list of sections
158 // whose LMAs are taken from this region.
159 Section_list::const_iterator
160 get_lma_section_list_start() const
161 { return this->lma_sections_
.begin(); }
163 // Return the end of the list of sections
164 // whose VMAs are taken from this region.
165 Section_list::const_iterator
166 get_vma_section_list_end() const
167 { return this->vma_sections_
.end(); }
169 // Return the end of the list of sections
170 // whose LMAs are taken from this region.
171 Section_list::const_iterator
172 get_lma_section_list_end() const
173 { return this->lma_sections_
.end(); }
175 Output_section_definition
*
176 get_last_section() const
177 { return this->last_section_
; }
180 set_last_section(Output_section_definition
* sec
)
181 { this->last_section_
= sec
; }
186 unsigned int attributes_
;
189 // The offset to the next free byte in the region.
190 // Note - for compatibility with GNU LD we only maintain one offset
191 // regardless of whether the region is being used for VMA values,
192 // LMA values, or both.
193 uint64_t current_offset_
;
194 // A list of sections whose VMAs are set inside this region.
195 Section_list vma_sections_
;
196 // A list of sections whose LMAs are set inside this region.
197 Section_list lma_sections_
;
198 // The latest section to make use of this region.
199 Output_section_definition
* last_section_
;
202 // Return true if the provided section flags
203 // are compatible with this region's attributes.
206 Memory_region::attributes_compatible(elfcpp::Elf_Xword flags
,
207 elfcpp::Elf_Xword type
) const
209 unsigned int attrs
= this->attributes_
;
211 // No attributes means that this region is not compatible with anything.
218 switch (attrs
& - attrs
)
221 if ((flags
& elfcpp::SHF_EXECINSTR
) == 0)
226 if ((flags
& elfcpp::SHF_WRITE
) == 0)
231 // All sections are presumed readable.
234 case MEM_ALLOCATABLE
:
235 if ((flags
& elfcpp::SHF_ALLOC
) == 0)
239 case MEM_INITIALIZED
:
240 if ((type
& elfcpp::SHT_NOBITS
) != 0)
244 attrs
&= ~ (attrs
& - attrs
);
251 // Print a memory region.
254 Memory_region::print(FILE* f
) const
256 fprintf(f
, " %s", this->name_
.c_str());
258 unsigned int attrs
= this->attributes_
;
264 switch (attrs
& - attrs
)
266 case MEM_EXECUTABLE
: fputc('x', f
); break;
267 case MEM_WRITEABLE
: fputc('w', f
); break;
268 case MEM_READABLE
: fputc('r', f
); break;
269 case MEM_ALLOCATABLE
: fputc('a', f
); break;
270 case MEM_INITIALIZED
: fputc('i', f
); break;
274 attrs
&= ~ (attrs
& - attrs
);
280 fprintf(f
, " : origin = ");
281 this->start_
->print(f
);
282 fprintf(f
, ", length = ");
283 this->length_
->print(f
);
287 // Manage orphan sections. This is intended to be largely compatible
288 // with the GNU linker. The Linux kernel implicitly relies on
289 // something similar to the GNU linker's orphan placement. We
290 // originally used a simpler scheme here, but it caused the kernel
291 // build to fail, and was also rather inefficient.
293 class Orphan_section_placement
296 typedef Script_sections::Elements_iterator Elements_iterator
;
299 Orphan_section_placement();
301 // Handle an output section during initialization of this mapping.
303 output_section_init(const std::string
& name
, Output_section
*,
304 Elements_iterator location
);
306 // Initialize the last location.
308 last_init(Elements_iterator location
);
310 // Set *PWHERE to the address of an iterator pointing to the
311 // location to use for an orphan section. Return true if the
312 // iterator has a value, false otherwise.
314 find_place(Output_section
*, Elements_iterator
** pwhere
);
316 // Return the iterator being used for sections at the very end of
317 // the linker script.
322 // The places that we specifically recognize. This list is copied
323 // from the GNU linker.
339 // The information we keep for a specific place.
342 // The name of sections for this place.
344 // Whether we have a location for this place.
346 // The iterator for this place.
347 Elements_iterator location
;
350 // Initialize one place element.
352 initialize_place(Place_index
, const char*);
355 Place places_
[PLACE_MAX
];
356 // True if this is the first call to output_section_init.
360 // Initialize Orphan_section_placement.
362 Orphan_section_placement::Orphan_section_placement()
365 this->initialize_place(PLACE_TEXT
, ".text");
366 this->initialize_place(PLACE_RODATA
, ".rodata");
367 this->initialize_place(PLACE_DATA
, ".data");
368 this->initialize_place(PLACE_TLS
, NULL
);
369 this->initialize_place(PLACE_TLS_BSS
, NULL
);
370 this->initialize_place(PLACE_BSS
, ".bss");
371 this->initialize_place(PLACE_REL
, NULL
);
372 this->initialize_place(PLACE_INTERP
, ".interp");
373 this->initialize_place(PLACE_NONALLOC
, NULL
);
374 this->initialize_place(PLACE_LAST
, NULL
);
377 // Initialize one place element.
380 Orphan_section_placement::initialize_place(Place_index index
, const char* name
)
382 this->places_
[index
].name
= name
;
383 this->places_
[index
].have_location
= false;
386 // While initializing the Orphan_section_placement information, this
387 // is called once for each output section named in the linker script.
388 // If we found an output section during the link, it will be passed in
392 Orphan_section_placement::output_section_init(const std::string
& name
,
394 Elements_iterator location
)
396 bool first_init
= this->first_init_
;
397 this->first_init_
= false;
399 for (int i
= 0; i
< PLACE_MAX
; ++i
)
401 if (this->places_
[i
].name
!= NULL
&& this->places_
[i
].name
== name
)
403 if (this->places_
[i
].have_location
)
405 // We have already seen a section with this name.
409 this->places_
[i
].location
= location
;
410 this->places_
[i
].have_location
= true;
412 // If we just found the .bss section, restart the search for
413 // an unallocated section. This follows the GNU linker's
416 this->places_
[PLACE_NONALLOC
].have_location
= false;
422 // Relocation sections.
423 if (!this->places_
[PLACE_REL
].have_location
425 && (os
->type() == elfcpp::SHT_REL
|| os
->type() == elfcpp::SHT_RELA
)
426 && (os
->flags() & elfcpp::SHF_ALLOC
) != 0)
428 this->places_
[PLACE_REL
].location
= location
;
429 this->places_
[PLACE_REL
].have_location
= true;
432 // We find the location for unallocated sections by finding the
433 // first debugging or comment section after the BSS section (if
435 if (!this->places_
[PLACE_NONALLOC
].have_location
436 && (name
== ".comment" || Layout::is_debug_info_section(name
.c_str())))
438 // We add orphan sections after the location in PLACES_. We
439 // want to store unallocated sections before LOCATION. If this
440 // is the very first section, we can't use it.
444 this->places_
[PLACE_NONALLOC
].location
= location
;
445 this->places_
[PLACE_NONALLOC
].have_location
= true;
450 // Initialize the last location.
453 Orphan_section_placement::last_init(Elements_iterator location
)
455 this->places_
[PLACE_LAST
].location
= location
;
456 this->places_
[PLACE_LAST
].have_location
= true;
459 // Set *PWHERE to the address of an iterator pointing to the location
460 // to use for an orphan section. Return true if the iterator has a
461 // value, false otherwise.
464 Orphan_section_placement::find_place(Output_section
* os
,
465 Elements_iterator
** pwhere
)
467 // Figure out where OS should go. This is based on the GNU linker
468 // code. FIXME: The GNU linker handles small data sections
469 // specially, but we don't.
470 elfcpp::Elf_Word type
= os
->type();
471 elfcpp::Elf_Xword flags
= os
->flags();
473 if ((flags
& elfcpp::SHF_ALLOC
) == 0
474 && !Layout::is_debug_info_section(os
->name()))
475 index
= PLACE_NONALLOC
;
476 else if ((flags
& elfcpp::SHF_ALLOC
) == 0)
478 else if (type
== elfcpp::SHT_NOTE
)
479 index
= PLACE_INTERP
;
480 else if ((flags
& elfcpp::SHF_TLS
) != 0)
482 if (type
== elfcpp::SHT_NOBITS
)
483 index
= PLACE_TLS_BSS
;
487 else if (type
== elfcpp::SHT_NOBITS
)
489 else if ((flags
& elfcpp::SHF_WRITE
) != 0)
491 else if (type
== elfcpp::SHT_REL
|| type
== elfcpp::SHT_RELA
)
493 else if ((flags
& elfcpp::SHF_EXECINSTR
) == 0)
494 index
= PLACE_RODATA
;
498 // If we don't have a location yet, try to find one based on a
499 // plausible ordering of sections.
500 if (!this->places_
[index
].have_location
)
525 if (!this->places_
[PLACE_TLS
].have_location
)
529 if (follow
!= PLACE_MAX
&& this->places_
[follow
].have_location
)
531 // Set the location of INDEX to the location of FOLLOW. The
532 // location of INDEX will then be incremented by the caller,
533 // so anything in INDEX will continue to be after anything
535 this->places_
[index
].location
= this->places_
[follow
].location
;
536 this->places_
[index
].have_location
= true;
540 *pwhere
= &this->places_
[index
].location
;
541 bool ret
= this->places_
[index
].have_location
;
543 // The caller will set the location.
544 this->places_
[index
].have_location
= true;
549 // Return the iterator being used for sections at the very end of the
552 Orphan_section_placement::Elements_iterator
553 Orphan_section_placement::last_place() const
555 gold_assert(this->places_
[PLACE_LAST
].have_location
);
556 return this->places_
[PLACE_LAST
].location
;
559 // An element in a SECTIONS clause.
561 class Sections_element
567 virtual ~Sections_element()
570 // Return whether an output section is relro.
575 // Record that an output section is relro.
580 // Create any required output sections. The only real
581 // implementation is in Output_section_definition.
583 create_sections(Layout
*)
586 // Add any symbol being defined to the symbol table.
588 add_symbols_to_table(Symbol_table
*)
591 // Finalize symbols and check assertions.
593 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*)
596 // Return the output section name to use for an input file name and
597 // section name. This only real implementation is in
598 // Output_section_definition.
600 output_section_name(const char*, const char*, Output_section
***,
601 Script_sections::Section_type
*, bool*)
604 // Initialize OSP with an output section.
606 orphan_section_init(Orphan_section_placement
*,
607 Script_sections::Elements_iterator
)
610 // Set section addresses. This includes applying assignments if the
611 // expression is an absolute value.
613 set_section_addresses(Symbol_table
*, Layout
*, uint64_t*, uint64_t*,
617 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
618 // this section is constrained, and the input sections do not match,
619 // return the constraint, and set *POSD.
620 virtual Section_constraint
621 check_constraint(Output_section_definition
**)
622 { return CONSTRAINT_NONE
; }
624 // See if this is the alternate output section for a constrained
625 // output section. If it is, transfer the Output_section and return
626 // true. Otherwise return false.
628 alternate_constraint(Output_section_definition
*, Section_constraint
)
631 // Get the list of segments to use for an allocated section when
632 // using a PHDRS clause. If this is an allocated section, return
633 // the Output_section, and set *PHDRS_LIST (the first parameter) to
634 // the list of PHDRS to which it should be attached. If the PHDRS
635 // were not specified, don't change *PHDRS_LIST. When not returning
636 // NULL, set *ORPHAN (the second parameter) according to whether
637 // this is an orphan section--one that is not mentioned in the
639 virtual Output_section
*
640 allocate_to_segment(String_list
**, bool*)
643 // Look for an output section by name and return the address, the
644 // load address, the alignment, and the size. This is used when an
645 // expression refers to an output section which was not actually
646 // created. This returns true if the section was found, false
647 // otherwise. The only real definition is for
648 // Output_section_definition.
650 get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
654 // Return the associated Output_section if there is one.
655 virtual Output_section
*
656 get_output_section() const
659 // Set the section's memory regions.
661 set_memory_region(Memory_region
*, bool)
662 { gold_error(_("Attempt to set a memory region for a non-output section")); }
664 // Print the element for debugging purposes.
666 print(FILE* f
) const = 0;
669 // An assignment in a SECTIONS clause outside of an output section.
671 class Sections_element_assignment
: public Sections_element
674 Sections_element_assignment(const char* name
, size_t namelen
,
675 Expression
* val
, bool provide
, bool hidden
)
676 : assignment_(name
, namelen
, false, val
, provide
, hidden
)
679 // Add the symbol to the symbol table.
681 add_symbols_to_table(Symbol_table
* symtab
)
682 { this->assignment_
.add_to_table(symtab
); }
684 // Finalize the symbol.
686 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
,
689 this->assignment_
.finalize_with_dot(symtab
, layout
, *dot_value
, NULL
);
692 // Set the section address. There is no section here, but if the
693 // value is absolute, we set the symbol. This permits us to use
694 // absolute symbols when setting dot.
696 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
,
697 uint64_t* dot_value
, uint64_t*, uint64_t*)
699 this->assignment_
.set_if_absolute(symtab
, layout
, true, *dot_value
, NULL
);
702 // Print for debugging.
707 this->assignment_
.print(f
);
711 Symbol_assignment assignment_
;
714 // An assignment to the dot symbol in a SECTIONS clause outside of an
717 class Sections_element_dot_assignment
: public Sections_element
720 Sections_element_dot_assignment(Expression
* val
)
724 // Finalize the symbol.
726 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
,
729 // We ignore the section of the result because outside of an
730 // output section definition the dot symbol is always considered
732 *dot_value
= this->val_
->eval_with_dot(symtab
, layout
, true, *dot_value
,
733 NULL
, NULL
, NULL
, false);
736 // Update the dot symbol while setting section addresses.
738 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
,
739 uint64_t* dot_value
, uint64_t* dot_alignment
,
740 uint64_t* load_address
)
742 *dot_value
= this->val_
->eval_with_dot(symtab
, layout
, false, *dot_value
,
743 NULL
, NULL
, dot_alignment
, false);
744 *load_address
= *dot_value
;
747 // Print for debugging.
752 this->val_
->print(f
);
760 // An assertion in a SECTIONS clause outside of an output section.
762 class Sections_element_assertion
: public Sections_element
765 Sections_element_assertion(Expression
* check
, const char* message
,
767 : assertion_(check
, message
, messagelen
)
770 // Check the assertion.
772 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
, uint64_t*)
773 { this->assertion_
.check(symtab
, layout
); }
775 // Print for debugging.
780 this->assertion_
.print(f
);
784 Script_assertion assertion_
;
787 // An element in an output section in a SECTIONS clause.
789 class Output_section_element
792 // A list of input sections.
793 typedef std::list
<Output_section::Input_section
> Input_section_list
;
795 Output_section_element()
798 virtual ~Output_section_element()
801 // Return whether this element requires an output section to exist.
803 needs_output_section() const
806 // Add any symbol being defined to the symbol table.
808 add_symbols_to_table(Symbol_table
*)
811 // Finalize symbols and check assertions.
813 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*, Output_section
**)
816 // Return whether this element matches FILE_NAME and SECTION_NAME.
817 // The only real implementation is in Output_section_element_input.
819 match_name(const char*, const char*, bool *) const
822 // Set section addresses. This includes applying assignments if the
823 // expression is an absolute value.
825 set_section_addresses(Symbol_table
*, Layout
*, Output_section
*, uint64_t,
826 uint64_t*, uint64_t*, Output_section
**, std::string
*,
830 // Print the element for debugging purposes.
832 print(FILE* f
) const = 0;
835 // Return a fill string that is LENGTH bytes long, filling it with
838 get_fill_string(const std::string
* fill
, section_size_type length
) const;
842 Output_section_element::get_fill_string(const std::string
* fill
,
843 section_size_type length
) const
845 std::string this_fill
;
846 this_fill
.reserve(length
);
847 while (this_fill
.length() + fill
->length() <= length
)
849 if (this_fill
.length() < length
)
850 this_fill
.append(*fill
, 0, length
- this_fill
.length());
854 // A symbol assignment in an output section.
856 class Output_section_element_assignment
: public Output_section_element
859 Output_section_element_assignment(const char* name
, size_t namelen
,
860 Expression
* val
, bool provide
,
862 : assignment_(name
, namelen
, false, val
, provide
, hidden
)
865 // Add the symbol to the symbol table.
867 add_symbols_to_table(Symbol_table
* symtab
)
868 { this->assignment_
.add_to_table(symtab
); }
870 // Finalize the symbol.
872 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
,
873 uint64_t* dot_value
, Output_section
** dot_section
)
875 this->assignment_
.finalize_with_dot(symtab
, layout
, *dot_value
,
879 // Set the section address. There is no section here, but if the
880 // value is absolute, we set the symbol. This permits us to use
881 // absolute symbols when setting dot.
883 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
, Output_section
*,
884 uint64_t, uint64_t* dot_value
, uint64_t*,
885 Output_section
** dot_section
, std::string
*,
888 this->assignment_
.set_if_absolute(symtab
, layout
, true, *dot_value
,
892 // Print for debugging.
897 this->assignment_
.print(f
);
901 Symbol_assignment assignment_
;
904 // An assignment to the dot symbol in an output section.
906 class Output_section_element_dot_assignment
: public Output_section_element
909 Output_section_element_dot_assignment(Expression
* val
)
913 // An assignment to dot within an output section is enough to force
914 // the output section to exist.
916 needs_output_section() const
919 // Finalize the symbol.
921 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
,
922 uint64_t* dot_value
, Output_section
** dot_section
)
924 *dot_value
= this->val_
->eval_with_dot(symtab
, layout
, true, *dot_value
,
925 *dot_section
, dot_section
, NULL
,
929 // Update the dot symbol while setting section addresses.
931 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
, Output_section
*,
932 uint64_t, uint64_t* dot_value
, uint64_t*,
933 Output_section
** dot_section
, std::string
*,
934 Input_section_list
*);
936 // Print for debugging.
941 this->val_
->print(f
);
949 // Update the dot symbol while setting section addresses.
952 Output_section_element_dot_assignment::set_section_addresses(
953 Symbol_table
* symtab
,
955 Output_section
* output_section
,
958 uint64_t* dot_alignment
,
959 Output_section
** dot_section
,
963 uint64_t next_dot
= this->val_
->eval_with_dot(symtab
, layout
, false,
964 *dot_value
, *dot_section
,
965 dot_section
, dot_alignment
,
967 if (next_dot
< *dot_value
)
968 gold_error(_("dot may not move backward"));
969 if (next_dot
> *dot_value
&& output_section
!= NULL
)
971 section_size_type length
= convert_to_section_size_type(next_dot
973 Output_section_data
* posd
;
975 posd
= new Output_data_zero_fill(length
, 0);
978 std::string this_fill
= this->get_fill_string(fill
, length
);
979 posd
= new Output_data_const(this_fill
, 0);
981 output_section
->add_output_section_data(posd
);
982 layout
->new_output_section_data_from_script(posd
);
984 *dot_value
= next_dot
;
987 // An assertion in an output section.
989 class Output_section_element_assertion
: public Output_section_element
992 Output_section_element_assertion(Expression
* check
, const char* message
,
994 : assertion_(check
, message
, messagelen
)
1001 this->assertion_
.print(f
);
1005 Script_assertion assertion_
;
1008 // We use a special instance of Output_section_data to handle BYTE,
1009 // SHORT, etc. This permits forward references to symbols in the
1012 class Output_data_expression
: public Output_section_data
1015 Output_data_expression(int size
, bool is_signed
, Expression
* val
,
1016 const Symbol_table
* symtab
, const Layout
* layout
,
1017 uint64_t dot_value
, Output_section
* dot_section
)
1018 : Output_section_data(size
, 0, true),
1019 is_signed_(is_signed
), val_(val
), symtab_(symtab
),
1020 layout_(layout
), dot_value_(dot_value
), dot_section_(dot_section
)
1024 // Write the data to the output file.
1026 do_write(Output_file
*);
1028 // Write the data to a buffer.
1030 do_write_to_buffer(unsigned char*);
1032 // Write to a map file.
1034 do_print_to_mapfile(Mapfile
* mapfile
) const
1035 { mapfile
->print_output_data(this, _("** expression")); }
1038 template<bool big_endian
>
1040 endian_write_to_buffer(uint64_t, unsigned char*);
1044 const Symbol_table
* symtab_
;
1045 const Layout
* layout_
;
1046 uint64_t dot_value_
;
1047 Output_section
* dot_section_
;
1050 // Write the data element to the output file.
1053 Output_data_expression::do_write(Output_file
* of
)
1055 unsigned char* view
= of
->get_output_view(this->offset(), this->data_size());
1056 this->write_to_buffer(view
);
1057 of
->write_output_view(this->offset(), this->data_size(), view
);
1060 // Write the data element to a buffer.
1063 Output_data_expression::do_write_to_buffer(unsigned char* buf
)
1065 uint64_t val
= this->val_
->eval_with_dot(this->symtab_
, this->layout_
,
1066 true, this->dot_value_
,
1067 this->dot_section_
, NULL
, NULL
,
1070 if (parameters
->target().is_big_endian())
1071 this->endian_write_to_buffer
<true>(val
, buf
);
1073 this->endian_write_to_buffer
<false>(val
, buf
);
1076 template<bool big_endian
>
1078 Output_data_expression::endian_write_to_buffer(uint64_t val
,
1081 switch (this->data_size())
1084 elfcpp::Swap_unaligned
<8, big_endian
>::writeval(buf
, val
);
1087 elfcpp::Swap_unaligned
<16, big_endian
>::writeval(buf
, val
);
1090 elfcpp::Swap_unaligned
<32, big_endian
>::writeval(buf
, val
);
1093 if (parameters
->target().get_size() == 32)
1096 if (this->is_signed_
&& (val
& 0x80000000) != 0)
1097 val
|= 0xffffffff00000000LL
;
1099 elfcpp::Swap_unaligned
<64, big_endian
>::writeval(buf
, val
);
1106 // A data item in an output section.
1108 class Output_section_element_data
: public Output_section_element
1111 Output_section_element_data(int size
, bool is_signed
, Expression
* val
)
1112 : size_(size
), is_signed_(is_signed
), val_(val
)
1115 // If there is a data item, then we must create an output section.
1117 needs_output_section() const
1120 // Finalize symbols--we just need to update dot.
1122 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t* dot_value
,
1124 { *dot_value
+= this->size_
; }
1126 // Store the value in the section.
1128 set_section_addresses(Symbol_table
*, Layout
*, Output_section
*, uint64_t,
1129 uint64_t* dot_value
, uint64_t*, Output_section
**,
1130 std::string
*, Input_section_list
*);
1132 // Print for debugging.
1137 // The size in bytes.
1139 // Whether the value is signed.
1145 // Store the value in the section.
1148 Output_section_element_data::set_section_addresses(
1149 Symbol_table
* symtab
,
1153 uint64_t* dot_value
,
1155 Output_section
** dot_section
,
1157 Input_section_list
*)
1159 gold_assert(os
!= NULL
);
1160 Output_data_expression
* expression
=
1161 new Output_data_expression(this->size_
, this->is_signed_
, this->val_
,
1162 symtab
, layout
, *dot_value
, *dot_section
);
1163 os
->add_output_section_data(expression
);
1164 layout
->new_output_section_data_from_script(expression
);
1165 *dot_value
+= this->size_
;
1168 // Print for debugging.
1171 Output_section_element_data::print(FILE* f
) const
1174 switch (this->size_
)
1186 if (this->is_signed_
)
1194 fprintf(f
, " %s(", s
);
1195 this->val_
->print(f
);
1199 // A fill value setting in an output section.
1201 class Output_section_element_fill
: public Output_section_element
1204 Output_section_element_fill(Expression
* val
)
1208 // Update the fill value while setting section addresses.
1210 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
, Output_section
*,
1211 uint64_t, uint64_t* dot_value
, uint64_t*,
1212 Output_section
** dot_section
,
1213 std::string
* fill
, Input_section_list
*)
1215 Output_section
* fill_section
;
1216 uint64_t fill_val
= this->val_
->eval_with_dot(symtab
, layout
, false,
1217 *dot_value
, *dot_section
,
1218 &fill_section
, NULL
, false);
1219 if (fill_section
!= NULL
)
1220 gold_warning(_("fill value is not absolute"));
1221 // FIXME: The GNU linker supports fill values of arbitrary length.
1222 unsigned char fill_buff
[4];
1223 elfcpp::Swap_unaligned
<32, true>::writeval(fill_buff
, fill_val
);
1224 fill
->assign(reinterpret_cast<char*>(fill_buff
), 4);
1227 // Print for debugging.
1229 print(FILE* f
) const
1231 fprintf(f
, " FILL(");
1232 this->val_
->print(f
);
1237 // The new fill value.
1241 // An input section specification in an output section
1243 class Output_section_element_input
: public Output_section_element
1246 Output_section_element_input(const Input_section_spec
* spec
, bool keep
);
1248 // Finalize symbols--just update the value of the dot symbol.
1250 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t* dot_value
,
1251 Output_section
** dot_section
)
1253 *dot_value
= this->final_dot_value_
;
1254 *dot_section
= this->final_dot_section_
;
1257 // See whether we match FILE_NAME and SECTION_NAME as an input section.
1258 // If we do then also indicate whether the section should be KEPT.
1260 match_name(const char* file_name
, const char* section_name
, bool* keep
) const;
1262 // Set the section address.
1264 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
, Output_section
*,
1265 uint64_t subalign
, uint64_t* dot_value
, uint64_t*,
1266 Output_section
**, std::string
* fill
,
1267 Input_section_list
*);
1269 // Print for debugging.
1271 print(FILE* f
) const;
1274 // An input section pattern.
1275 struct Input_section_pattern
1277 std::string pattern
;
1278 bool pattern_is_wildcard
;
1281 Input_section_pattern(const char* patterna
, size_t patternlena
,
1282 Sort_wildcard sorta
)
1283 : pattern(patterna
, patternlena
),
1284 pattern_is_wildcard(is_wildcard_string(this->pattern
.c_str())),
1289 typedef std::vector
<Input_section_pattern
> Input_section_patterns
;
1291 // Filename_exclusions is a pair of filename pattern and a bool
1292 // indicating whether the filename is a wildcard.
1293 typedef std::vector
<std::pair
<std::string
, bool> > Filename_exclusions
;
1295 // Return whether STRING matches PATTERN, where IS_WILDCARD_PATTERN
1296 // indicates whether this is a wildcard pattern.
1298 match(const char* string
, const char* pattern
, bool is_wildcard_pattern
)
1300 return (is_wildcard_pattern
1301 ? fnmatch(pattern
, string
, 0) == 0
1302 : strcmp(string
, pattern
) == 0);
1305 // See if we match a file name.
1307 match_file_name(const char* file_name
) const;
1309 // The file name pattern. If this is the empty string, we match all
1311 std::string filename_pattern_
;
1312 // Whether the file name pattern is a wildcard.
1313 bool filename_is_wildcard_
;
1314 // How the file names should be sorted. This may only be
1315 // SORT_WILDCARD_NONE or SORT_WILDCARD_BY_NAME.
1316 Sort_wildcard filename_sort_
;
1317 // The list of file names to exclude.
1318 Filename_exclusions filename_exclusions_
;
1319 // The list of input section patterns.
1320 Input_section_patterns input_section_patterns_
;
1321 // Whether to keep this section when garbage collecting.
1323 // The value of dot after including all matching sections.
1324 uint64_t final_dot_value_
;
1325 // The section where dot is defined after including all matching
1327 Output_section
* final_dot_section_
;
1330 // Construct Output_section_element_input. The parser records strings
1331 // as pointers into a copy of the script file, which will go away when
1332 // parsing is complete. We make sure they are in std::string objects.
1334 Output_section_element_input::Output_section_element_input(
1335 const Input_section_spec
* spec
,
1337 : filename_pattern_(),
1338 filename_is_wildcard_(false),
1339 filename_sort_(spec
->file
.sort
),
1340 filename_exclusions_(),
1341 input_section_patterns_(),
1343 final_dot_value_(0),
1344 final_dot_section_(NULL
)
1346 // The filename pattern "*" is common, and matches all files. Turn
1347 // it into the empty string.
1348 if (spec
->file
.name
.length
!= 1 || spec
->file
.name
.value
[0] != '*')
1349 this->filename_pattern_
.assign(spec
->file
.name
.value
,
1350 spec
->file
.name
.length
);
1351 this->filename_is_wildcard_
= is_wildcard_string(this->filename_pattern_
.c_str());
1353 if (spec
->input_sections
.exclude
!= NULL
)
1355 for (String_list::const_iterator p
=
1356 spec
->input_sections
.exclude
->begin();
1357 p
!= spec
->input_sections
.exclude
->end();
1360 bool is_wildcard
= is_wildcard_string((*p
).c_str());
1361 this->filename_exclusions_
.push_back(std::make_pair(*p
,
1366 if (spec
->input_sections
.sections
!= NULL
)
1368 Input_section_patterns
& isp(this->input_section_patterns_
);
1369 for (String_sort_list::const_iterator p
=
1370 spec
->input_sections
.sections
->begin();
1371 p
!= spec
->input_sections
.sections
->end();
1373 isp
.push_back(Input_section_pattern(p
->name
.value
, p
->name
.length
,
1378 // See whether we match FILE_NAME.
1381 Output_section_element_input::match_file_name(const char* file_name
) const
1383 if (!this->filename_pattern_
.empty())
1385 // If we were called with no filename, we refuse to match a
1386 // pattern which requires a file name.
1387 if (file_name
== NULL
)
1390 if (!match(file_name
, this->filename_pattern_
.c_str(),
1391 this->filename_is_wildcard_
))
1395 if (file_name
!= NULL
)
1397 // Now we have to see whether FILE_NAME matches one of the
1398 // exclusion patterns, if any.
1399 for (Filename_exclusions::const_iterator p
=
1400 this->filename_exclusions_
.begin();
1401 p
!= this->filename_exclusions_
.end();
1404 if (match(file_name
, p
->first
.c_str(), p
->second
))
1412 // See whether we match FILE_NAME and SECTION_NAME. If we do then
1413 // KEEP indicates whether the section should survive garbage collection.
1416 Output_section_element_input::match_name(const char* file_name
,
1417 const char* section_name
,
1420 if (!this->match_file_name(file_name
))
1423 *keep
= this->keep_
;
1425 // If there are no section name patterns, then we match.
1426 if (this->input_section_patterns_
.empty())
1429 // See whether we match the section name patterns.
1430 for (Input_section_patterns::const_iterator p
=
1431 this->input_section_patterns_
.begin();
1432 p
!= this->input_section_patterns_
.end();
1435 if (match(section_name
, p
->pattern
.c_str(), p
->pattern_is_wildcard
))
1439 // We didn't match any section names, so we didn't match.
1443 // Information we use to sort the input sections.
1445 class Input_section_info
1448 Input_section_info(const Output_section::Input_section
& input_section
)
1449 : input_section_(input_section
), section_name_(),
1450 size_(0), addralign_(1)
1453 // Return the simple input section.
1454 const Output_section::Input_section
&
1455 input_section() const
1456 { return this->input_section_
; }
1458 // Return the object.
1461 { return this->input_section_
.relobj(); }
1463 // Return the section index.
1466 { return this->input_section_
.shndx(); }
1468 // Return the section name.
1470 section_name() const
1471 { return this->section_name_
; }
1473 // Set the section name.
1475 set_section_name(const std::string name
)
1477 if (is_compressed_debug_section(name
.c_str()))
1478 this->section_name_
= corresponding_uncompressed_section_name(name
);
1480 this->section_name_
= name
;
1483 // Return the section size.
1486 { return this->size_
; }
1488 // Set the section size.
1490 set_size(uint64_t size
)
1491 { this->size_
= size
; }
1493 // Return the address alignment.
1496 { return this->addralign_
; }
1498 // Set the address alignment.
1500 set_addralign(uint64_t addralign
)
1501 { this->addralign_
= addralign
; }
1504 // Input section, can be a relaxed section.
1505 Output_section::Input_section input_section_
;
1506 // Name of the section.
1507 std::string section_name_
;
1510 // Address alignment.
1511 uint64_t addralign_
;
1514 // A class to sort the input sections.
1516 class Input_section_sorter
1519 Input_section_sorter(Sort_wildcard filename_sort
, Sort_wildcard section_sort
)
1520 : filename_sort_(filename_sort
), section_sort_(section_sort
)
1524 operator()(const Input_section_info
&, const Input_section_info
&) const;
1527 Sort_wildcard filename_sort_
;
1528 Sort_wildcard section_sort_
;
1532 Input_section_sorter::operator()(const Input_section_info
& isi1
,
1533 const Input_section_info
& isi2
) const
1535 if (this->section_sort_
== SORT_WILDCARD_BY_NAME
1536 || this->section_sort_
== SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1537 || (this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
1538 && isi1
.addralign() == isi2
.addralign()))
1540 if (isi1
.section_name() != isi2
.section_name())
1541 return isi1
.section_name() < isi2
.section_name();
1543 if (this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT
1544 || this->section_sort_
== SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1545 || this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
)
1547 if (isi1
.addralign() != isi2
.addralign())
1548 return isi1
.addralign() < isi2
.addralign();
1550 if (this->filename_sort_
== SORT_WILDCARD_BY_NAME
)
1552 if (isi1
.relobj()->name() != isi2
.relobj()->name())
1553 return (isi1
.relobj()->name() < isi2
.relobj()->name());
1556 // Otherwise we leave them in the same order.
1560 // Set the section address. Look in INPUT_SECTIONS for sections which
1561 // match this spec, sort them as specified, and add them to the output
1565 Output_section_element_input::set_section_addresses(
1568 Output_section
* output_section
,
1570 uint64_t* dot_value
,
1572 Output_section
** dot_section
,
1574 Input_section_list
* input_sections
)
1576 // We build a list of sections which match each
1577 // Input_section_pattern.
1579 // If none of the patterns specify a sort option, we throw all
1580 // matching input sections into a single bin, in the order we
1581 // find them. Otherwise, we put matching input sections into
1582 // a separate bin for each pattern, and sort each one as
1583 // specified. Thus, an input section spec like this:
1585 // will group all .foo and .bar sections in the order seen,
1588 // will group all .foo sections followed by all .bar sections.
1589 // This matches Gnu ld behavior.
1591 // Things get really weird, though, when you add a sort spec
1592 // on some, but not all, of the patterns, like this:
1593 // *(SORT_BY_NAME(.foo) .bar)
1594 // We do not attempt to match Gnu ld behavior in this case.
1596 typedef std::vector
<std::vector
<Input_section_info
> > Matching_sections
;
1597 size_t input_pattern_count
= this->input_section_patterns_
.size();
1598 size_t bin_count
= 1;
1599 bool any_patterns_with_sort
= false;
1600 for (size_t i
= 0; i
< input_pattern_count
; ++i
)
1602 const Input_section_pattern
& isp(this->input_section_patterns_
[i
]);
1603 if (isp
.sort
!= SORT_WILDCARD_NONE
)
1604 any_patterns_with_sort
= true;
1606 if (any_patterns_with_sort
)
1607 bin_count
= input_pattern_count
;
1608 Matching_sections
matching_sections(bin_count
);
1610 // Look through the list of sections for this output section. Add
1611 // each one which matches to one of the elements of
1612 // MATCHING_SECTIONS.
1614 Input_section_list::iterator p
= input_sections
->begin();
1615 while (p
!= input_sections
->end())
1617 Relobj
* relobj
= p
->relobj();
1618 unsigned int shndx
= p
->shndx();
1619 Input_section_info
isi(*p
);
1621 // Calling section_name and section_addralign is not very
1624 // Lock the object so that we can get information about the
1625 // section. This is OK since we know we are single-threaded
1628 const Task
* task
= reinterpret_cast<const Task
*>(-1);
1629 Task_lock_obj
<Object
> tl(task
, relobj
);
1631 isi
.set_section_name(relobj
->section_name(shndx
));
1632 if (p
->is_relaxed_input_section())
1634 // We use current data size because relaxed section sizes may not
1635 // have finalized yet.
1636 isi
.set_size(p
->relaxed_input_section()->current_data_size());
1637 isi
.set_addralign(p
->relaxed_input_section()->addralign());
1641 isi
.set_size(relobj
->section_size(shndx
));
1642 isi
.set_addralign(relobj
->section_addralign(shndx
));
1646 if (!this->match_file_name(relobj
->name().c_str()))
1648 else if (this->input_section_patterns_
.empty())
1650 matching_sections
[0].push_back(isi
);
1651 p
= input_sections
->erase(p
);
1656 for (i
= 0; i
< input_pattern_count
; ++i
)
1658 const Input_section_pattern
&
1659 isp(this->input_section_patterns_
[i
]);
1660 if (match(isi
.section_name().c_str(), isp
.pattern
.c_str(),
1661 isp
.pattern_is_wildcard
))
1665 if (i
>= input_pattern_count
)
1671 matching_sections
[i
].push_back(isi
);
1672 p
= input_sections
->erase(p
);
1677 // Look through MATCHING_SECTIONS. Sort each one as specified,
1678 // using a stable sort so that we get the default order when
1679 // sections are otherwise equal. Add each input section to the
1682 uint64_t dot
= *dot_value
;
1683 for (size_t i
= 0; i
< bin_count
; ++i
)
1685 if (matching_sections
[i
].empty())
1688 gold_assert(output_section
!= NULL
);
1690 const Input_section_pattern
& isp(this->input_section_patterns_
[i
]);
1691 if (isp
.sort
!= SORT_WILDCARD_NONE
1692 || this->filename_sort_
!= SORT_WILDCARD_NONE
)
1693 std::stable_sort(matching_sections
[i
].begin(),
1694 matching_sections
[i
].end(),
1695 Input_section_sorter(this->filename_sort_
,
1698 for (std::vector
<Input_section_info
>::const_iterator p
=
1699 matching_sections
[i
].begin();
1700 p
!= matching_sections
[i
].end();
1703 // Override the original address alignment if SUBALIGN is specified
1704 // and is greater than the original alignment. We need to make a
1705 // copy of the input section to modify the alignment.
1706 Output_section::Input_section
sis(p
->input_section());
1708 uint64_t this_subalign
= sis
.addralign();
1709 if (!sis
.is_input_section())
1710 sis
.output_section_data()->finalize_data_size();
1711 uint64_t data_size
= sis
.data_size();
1712 if (this_subalign
< subalign
)
1714 this_subalign
= subalign
;
1715 sis
.set_addralign(subalign
);
1718 uint64_t address
= align_address(dot
, this_subalign
);
1720 if (address
> dot
&& !fill
->empty())
1722 section_size_type length
=
1723 convert_to_section_size_type(address
- dot
);
1724 std::string this_fill
= this->get_fill_string(fill
, length
);
1725 Output_section_data
* posd
= new Output_data_const(this_fill
, 0);
1726 output_section
->add_output_section_data(posd
);
1727 layout
->new_output_section_data_from_script(posd
);
1730 output_section
->add_script_input_section(sis
);
1731 dot
= address
+ data_size
;
1735 // An SHF_TLS/SHT_NOBITS section does not take up any
1737 if (output_section
== NULL
1738 || (output_section
->flags() & elfcpp::SHF_TLS
) == 0
1739 || output_section
->type() != elfcpp::SHT_NOBITS
)
1742 this->final_dot_value_
= *dot_value
;
1743 this->final_dot_section_
= *dot_section
;
1746 // Print for debugging.
1749 Output_section_element_input::print(FILE* f
) const
1754 fprintf(f
, "KEEP(");
1756 if (!this->filename_pattern_
.empty())
1758 bool need_close_paren
= false;
1759 switch (this->filename_sort_
)
1761 case SORT_WILDCARD_NONE
:
1763 case SORT_WILDCARD_BY_NAME
:
1764 fprintf(f
, "SORT_BY_NAME(");
1765 need_close_paren
= true;
1771 fprintf(f
, "%s", this->filename_pattern_
.c_str());
1773 if (need_close_paren
)
1777 if (!this->input_section_patterns_
.empty()
1778 || !this->filename_exclusions_
.empty())
1782 bool need_space
= false;
1783 if (!this->filename_exclusions_
.empty())
1785 fprintf(f
, "EXCLUDE_FILE(");
1786 bool need_comma
= false;
1787 for (Filename_exclusions::const_iterator p
=
1788 this->filename_exclusions_
.begin();
1789 p
!= this->filename_exclusions_
.end();
1794 fprintf(f
, "%s", p
->first
.c_str());
1801 for (Input_section_patterns::const_iterator p
=
1802 this->input_section_patterns_
.begin();
1803 p
!= this->input_section_patterns_
.end();
1809 int close_parens
= 0;
1812 case SORT_WILDCARD_NONE
:
1814 case SORT_WILDCARD_BY_NAME
:
1815 fprintf(f
, "SORT_BY_NAME(");
1818 case SORT_WILDCARD_BY_ALIGNMENT
:
1819 fprintf(f
, "SORT_BY_ALIGNMENT(");
1822 case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
:
1823 fprintf(f
, "SORT_BY_NAME(SORT_BY_ALIGNMENT(");
1826 case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
:
1827 fprintf(f
, "SORT_BY_ALIGNMENT(SORT_BY_NAME(");
1834 fprintf(f
, "%s", p
->pattern
.c_str());
1836 for (int i
= 0; i
< close_parens
; ++i
)
1851 // An output section.
1853 class Output_section_definition
: public Sections_element
1856 typedef Output_section_element::Input_section_list Input_section_list
;
1858 Output_section_definition(const char* name
, size_t namelen
,
1859 const Parser_output_section_header
* header
);
1861 // Finish the output section with the information in the trailer.
1863 finish(const Parser_output_section_trailer
* trailer
);
1865 // Add a symbol to be defined.
1867 add_symbol_assignment(const char* name
, size_t length
, Expression
* value
,
1868 bool provide
, bool hidden
);
1870 // Add an assignment to the special dot symbol.
1872 add_dot_assignment(Expression
* value
);
1874 // Add an assertion.
1876 add_assertion(Expression
* check
, const char* message
, size_t messagelen
);
1878 // Add a data item to the current output section.
1880 add_data(int size
, bool is_signed
, Expression
* val
);
1882 // Add a setting for the fill value.
1884 add_fill(Expression
* val
);
1886 // Add an input section specification.
1888 add_input_section(const Input_section_spec
* spec
, bool keep
);
1890 // Return whether the output section is relro.
1893 { return this->is_relro_
; }
1895 // Record that the output section is relro.
1898 { this->is_relro_
= true; }
1900 // Create any required output sections.
1902 create_sections(Layout
*);
1904 // Add any symbols being defined to the symbol table.
1906 add_symbols_to_table(Symbol_table
* symtab
);
1908 // Finalize symbols and check assertions.
1910 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*);
1912 // Return the output section name to use for an input file name and
1915 output_section_name(const char* file_name
, const char* section_name
,
1916 Output_section
***, Script_sections::Section_type
*,
1919 // Initialize OSP with an output section.
1921 orphan_section_init(Orphan_section_placement
* osp
,
1922 Script_sections::Elements_iterator p
)
1923 { osp
->output_section_init(this->name_
, this->output_section_
, p
); }
1925 // Set the section address.
1927 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
,
1928 uint64_t* dot_value
, uint64_t*,
1929 uint64_t* load_address
);
1931 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
1932 // this section is constrained, and the input sections do not match,
1933 // return the constraint, and set *POSD.
1935 check_constraint(Output_section_definition
** posd
);
1937 // See if this is the alternate output section for a constrained
1938 // output section. If it is, transfer the Output_section and return
1939 // true. Otherwise return false.
1941 alternate_constraint(Output_section_definition
*, Section_constraint
);
1943 // Get the list of segments to use for an allocated section when
1944 // using a PHDRS clause.
1946 allocate_to_segment(String_list
** phdrs_list
, bool* orphan
);
1948 // Look for an output section by name and return the address, the
1949 // load address, the alignment, and the size. This is used when an
1950 // expression refers to an output section which was not actually
1951 // created. This returns true if the section was found, false
1954 get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
1957 // Return the associated Output_section if there is one.
1959 get_output_section() const
1960 { return this->output_section_
; }
1962 // Print the contents to the FILE. This is for debugging.
1966 // Return the output section type if specified or Script_sections::ST_NONE.
1967 Script_sections::Section_type
1968 section_type() const;
1970 // Store the memory region to use.
1972 set_memory_region(Memory_region
*, bool set_vma
);
1975 set_section_vma(Expression
* address
)
1976 { this->address_
= address
; }
1979 set_section_lma(Expression
* address
)
1980 { this->load_address_
= address
; }
1983 get_section_name() const
1984 { return this->name_
; }
1988 script_section_type_name(Script_section_type
);
1990 typedef std::vector
<Output_section_element
*> Output_section_elements
;
1992 // The output section name.
1994 // The address. This may be NULL.
1995 Expression
* address_
;
1996 // The load address. This may be NULL.
1997 Expression
* load_address_
;
1998 // The alignment. This may be NULL.
2000 // The input section alignment. This may be NULL.
2001 Expression
* subalign_
;
2002 // The constraint, if any.
2003 Section_constraint constraint_
;
2004 // The fill value. This may be NULL.
2006 // The list of segments this section should go into. This may be
2008 String_list
* phdrs_
;
2009 // The list of elements defining the section.
2010 Output_section_elements elements_
;
2011 // The Output_section created for this definition. This will be
2012 // NULL if none was created.
2013 Output_section
* output_section_
;
2014 // The address after it has been evaluated.
2015 uint64_t evaluated_address_
;
2016 // The load address after it has been evaluated.
2017 uint64_t evaluated_load_address_
;
2018 // The alignment after it has been evaluated.
2019 uint64_t evaluated_addralign_
;
2020 // The output section is relro.
2022 // The output section type if specified.
2023 enum Script_section_type script_section_type_
;
2028 Output_section_definition::Output_section_definition(
2031 const Parser_output_section_header
* header
)
2032 : name_(name
, namelen
),
2033 address_(header
->address
),
2034 load_address_(header
->load_address
),
2035 align_(header
->align
),
2036 subalign_(header
->subalign
),
2037 constraint_(header
->constraint
),
2041 output_section_(NULL
),
2042 evaluated_address_(0),
2043 evaluated_load_address_(0),
2044 evaluated_addralign_(0),
2046 script_section_type_(header
->section_type
)
2050 // Finish an output section.
2053 Output_section_definition::finish(const Parser_output_section_trailer
* trailer
)
2055 this->fill_
= trailer
->fill
;
2056 this->phdrs_
= trailer
->phdrs
;
2059 // Add a symbol to be defined.
2062 Output_section_definition::add_symbol_assignment(const char* name
,
2068 Output_section_element
* p
= new Output_section_element_assignment(name
,
2073 this->elements_
.push_back(p
);
2076 // Add an assignment to the special dot symbol.
2079 Output_section_definition::add_dot_assignment(Expression
* value
)
2081 Output_section_element
* p
= new Output_section_element_dot_assignment(value
);
2082 this->elements_
.push_back(p
);
2085 // Add an assertion.
2088 Output_section_definition::add_assertion(Expression
* check
,
2089 const char* message
,
2092 Output_section_element
* p
= new Output_section_element_assertion(check
,
2095 this->elements_
.push_back(p
);
2098 // Add a data item to the current output section.
2101 Output_section_definition::add_data(int size
, bool is_signed
, Expression
* val
)
2103 Output_section_element
* p
= new Output_section_element_data(size
, is_signed
,
2105 this->elements_
.push_back(p
);
2108 // Add a setting for the fill value.
2111 Output_section_definition::add_fill(Expression
* val
)
2113 Output_section_element
* p
= new Output_section_element_fill(val
);
2114 this->elements_
.push_back(p
);
2117 // Add an input section specification.
2120 Output_section_definition::add_input_section(const Input_section_spec
* spec
,
2123 Output_section_element
* p
= new Output_section_element_input(spec
, keep
);
2124 this->elements_
.push_back(p
);
2127 // Create any required output sections. We need an output section if
2128 // there is a data statement here.
2131 Output_section_definition::create_sections(Layout
* layout
)
2133 if (this->output_section_
!= NULL
)
2135 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2136 p
!= this->elements_
.end();
2139 if ((*p
)->needs_output_section())
2141 const char* name
= this->name_
.c_str();
2142 this->output_section_
=
2143 layout
->make_output_section_for_script(name
, this->section_type());
2149 // Add any symbols being defined to the symbol table.
2152 Output_section_definition::add_symbols_to_table(Symbol_table
* symtab
)
2154 for (Output_section_elements::iterator p
= this->elements_
.begin();
2155 p
!= this->elements_
.end();
2157 (*p
)->add_symbols_to_table(symtab
);
2160 // Finalize symbols and check assertions.
2163 Output_section_definition::finalize_symbols(Symbol_table
* symtab
,
2164 const Layout
* layout
,
2165 uint64_t* dot_value
)
2167 if (this->output_section_
!= NULL
)
2168 *dot_value
= this->output_section_
->address();
2171 uint64_t address
= *dot_value
;
2172 if (this->address_
!= NULL
)
2174 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2178 if (this->align_
!= NULL
)
2180 uint64_t align
= this->align_
->eval_with_dot(symtab
, layout
, true,
2183 address
= align_address(address
, align
);
2185 *dot_value
= address
;
2188 Output_section
* dot_section
= this->output_section_
;
2189 for (Output_section_elements::iterator p
= this->elements_
.begin();
2190 p
!= this->elements_
.end();
2192 (*p
)->finalize_symbols(symtab
, layout
, dot_value
, &dot_section
);
2195 // Return the output section name to use for an input section name.
2198 Output_section_definition::output_section_name(
2199 const char* file_name
,
2200 const char* section_name
,
2201 Output_section
*** slot
,
2202 Script_sections::Section_type
* psection_type
,
2205 // Ask each element whether it matches NAME.
2206 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2207 p
!= this->elements_
.end();
2210 if ((*p
)->match_name(file_name
, section_name
, keep
))
2212 // We found a match for NAME, which means that it should go
2213 // into this output section.
2214 *slot
= &this->output_section_
;
2215 *psection_type
= this->section_type();
2216 return this->name_
.c_str();
2220 // We don't know about this section name.
2224 // Return true if memory from START to START + LENGTH is contained
2225 // within a memory region.
2228 Script_sections::block_in_region(Symbol_table
* symtab
, Layout
* layout
,
2229 uint64_t start
, uint64_t length
) const
2231 if (this->memory_regions_
== NULL
)
2234 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2235 mr
!= this->memory_regions_
->end();
2238 uint64_t s
= (*mr
)->start_address()->eval(symtab
, layout
, false);
2239 uint64_t l
= (*mr
)->length()->eval(symtab
, layout
, false);
2242 && (s
+ l
) >= (start
+ length
))
2249 // Find a memory region that should be used by a given output SECTION.
2250 // If provided set PREVIOUS_SECTION_RETURN to point to the last section
2251 // that used the return memory region.
2254 Script_sections::find_memory_region(
2255 Output_section_definition
* section
,
2256 bool find_vma_region
,
2258 Output_section_definition
** previous_section_return
)
2260 if (previous_section_return
!= NULL
)
2261 * previous_section_return
= NULL
;
2263 // Walk the memory regions specified in this script, if any.
2264 if (this->memory_regions_
== NULL
)
2267 // The /DISCARD/ section never gets assigned to any region.
2268 if (section
->get_section_name() == "/DISCARD/")
2271 Memory_region
* first_match
= NULL
;
2273 // First check to see if a region has been assigned to this section.
2274 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2275 mr
!= this->memory_regions_
->end();
2278 if (find_vma_region
)
2280 for (Memory_region::Section_list::const_iterator s
=
2281 (*mr
)->get_vma_section_list_start();
2282 s
!= (*mr
)->get_vma_section_list_end();
2284 if ((*s
) == section
)
2286 (*mr
)->set_last_section(section
);
2292 for (Memory_region::Section_list::const_iterator s
=
2293 (*mr
)->get_lma_section_list_start();
2294 s
!= (*mr
)->get_lma_section_list_end();
2296 if ((*s
) == section
)
2298 (*mr
)->set_last_section(section
);
2305 // Make a note of the first memory region whose attributes
2306 // are compatible with the section. If we do not find an
2307 // explicit region assignment, then we will return this region.
2308 Output_section
* out_sec
= section
->get_output_section();
2309 if (first_match
== NULL
2311 && (*mr
)->attributes_compatible(out_sec
->flags(),
2317 // With LMA computations, if an explicit region has not been specified then
2318 // we will want to set the difference between the VMA and the LMA of the
2319 // section were searching for to be the same as the difference between the
2320 // VMA and LMA of the last section to be added to first matched region.
2321 // Hence, if it was asked for, we return a pointer to the last section
2322 // known to be used by the first matched region.
2323 if (first_match
!= NULL
2324 && previous_section_return
!= NULL
)
2325 *previous_section_return
= first_match
->get_last_section();
2330 // Set the section address. Note that the OUTPUT_SECTION_ field will
2331 // be NULL if no input sections were mapped to this output section.
2332 // We still have to adjust dot and process symbol assignments.
2335 Output_section_definition::set_section_addresses(Symbol_table
* symtab
,
2337 uint64_t* dot_value
,
2338 uint64_t* dot_alignment
,
2339 uint64_t* load_address
)
2341 Memory_region
* vma_region
= NULL
;
2342 Memory_region
* lma_region
= NULL
;
2343 Script_sections
* script_sections
=
2344 layout
->script_options()->script_sections();
2346 uint64_t old_dot_value
= *dot_value
;
2347 uint64_t old_load_address
= *load_address
;
2349 // If input section sorting is requested via --section-ordering-file or
2350 // linker plugins, then do it here. This is important because we want
2351 // any sorting specified in the linker scripts, which will be done after
2352 // this, to take precedence. The final order of input sections is then
2353 // guaranteed to be according to the linker script specification.
2354 if (this->output_section_
!= NULL
2355 && this->output_section_
->input_section_order_specified())
2356 this->output_section_
->sort_attached_input_sections();
2358 // Decide the start address for the section. The algorithm is:
2359 // 1) If an address has been specified in a linker script, use that.
2360 // 2) Otherwise if a memory region has been specified for the section,
2361 // use the next free address in the region.
2362 // 3) Otherwise if memory regions have been specified find the first
2363 // region whose attributes are compatible with this section and
2364 // install it into that region.
2365 // 4) Otherwise use the current location counter.
2367 if (this->output_section_
!= NULL
2368 // Check for --section-start.
2369 && parameters
->options().section_start(this->output_section_
->name(),
2372 else if (this->address_
== NULL
)
2374 vma_region
= script_sections
->find_memory_region(this, true, false, NULL
);
2375 if (vma_region
!= NULL
)
2376 address
= vma_region
->get_current_address()->eval(symtab
, layout
,
2379 address
= *dot_value
;
2383 vma_region
= script_sections
->find_memory_region(this, true, true, NULL
);
2384 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2385 *dot_value
, NULL
, NULL
,
2386 dot_alignment
, false);
2387 if (vma_region
!= NULL
)
2388 vma_region
->set_address(address
, symtab
, layout
);
2392 if (this->align_
== NULL
)
2394 if (this->output_section_
== NULL
)
2397 align
= this->output_section_
->addralign();
2401 Output_section
* align_section
;
2402 align
= this->align_
->eval_with_dot(symtab
, layout
, true, *dot_value
,
2403 NULL
, &align_section
, NULL
, false);
2404 if (align_section
!= NULL
)
2405 gold_warning(_("alignment of section %s is not absolute"),
2406 this->name_
.c_str());
2407 if (this->output_section_
!= NULL
)
2408 this->output_section_
->set_addralign(align
);
2411 address
= align_address(address
, align
);
2413 uint64_t start_address
= address
;
2415 *dot_value
= address
;
2417 // Except for NOLOAD sections, the address of non-SHF_ALLOC sections is
2418 // forced to zero, regardless of what the linker script wants.
2419 if (this->output_section_
!= NULL
2420 && ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) != 0
2421 || this->output_section_
->is_noload()))
2422 this->output_section_
->set_address(address
);
2424 this->evaluated_address_
= address
;
2425 this->evaluated_addralign_
= align
;
2429 if (this->load_address_
== NULL
)
2431 Output_section_definition
* previous_section
;
2433 // Determine if an LMA region has been set for this section.
2434 lma_region
= script_sections
->find_memory_region(this, false, false,
2437 if (lma_region
!= NULL
)
2439 if (previous_section
== NULL
)
2440 // The LMA address was explicitly set to the given region.
2441 laddr
= lma_region
->get_current_address()->eval(symtab
, layout
,
2445 // We are not going to use the discovered lma_region, so
2446 // make sure that we do not update it in the code below.
2449 if (this->address_
!= NULL
|| previous_section
== this)
2451 // Either an explicit VMA address has been set, or an
2452 // explicit VMA region has been set, so set the LMA equal to
2458 // The LMA address was not explicitly or implicitly set.
2460 // We have been given the first memory region that is
2461 // compatible with the current section and a pointer to the
2462 // last section to use this region. Set the LMA of this
2463 // section so that the difference between its' VMA and LMA
2464 // is the same as the difference between the VMA and LMA of
2465 // the last section in the given region.
2466 laddr
= address
+ (previous_section
->evaluated_load_address_
2467 - previous_section
->evaluated_address_
);
2471 if (this->output_section_
!= NULL
)
2472 this->output_section_
->set_load_address(laddr
);
2476 // Do not set the load address of the output section, if one exists.
2477 // This allows future sections to determine what the load address
2478 // should be. If none is ever set, it will default to being the
2479 // same as the vma address.
2485 laddr
= this->load_address_
->eval_with_dot(symtab
, layout
, true,
2487 this->output_section_
,
2489 if (this->output_section_
!= NULL
)
2490 this->output_section_
->set_load_address(laddr
);
2493 this->evaluated_load_address_
= laddr
;
2496 if (this->subalign_
== NULL
)
2500 Output_section
* subalign_section
;
2501 subalign
= this->subalign_
->eval_with_dot(symtab
, layout
, true,
2503 &subalign_section
, NULL
,
2505 if (subalign_section
!= NULL
)
2506 gold_warning(_("subalign of section %s is not absolute"),
2507 this->name_
.c_str());
2511 if (this->fill_
!= NULL
)
2513 // FIXME: The GNU linker supports fill values of arbitrary
2515 Output_section
* fill_section
;
2516 uint64_t fill_val
= this->fill_
->eval_with_dot(symtab
, layout
, true,
2518 NULL
, &fill_section
,
2520 if (fill_section
!= NULL
)
2521 gold_warning(_("fill of section %s is not absolute"),
2522 this->name_
.c_str());
2523 unsigned char fill_buff
[4];
2524 elfcpp::Swap_unaligned
<32, true>::writeval(fill_buff
, fill_val
);
2525 fill
.assign(reinterpret_cast<char*>(fill_buff
), 4);
2528 Input_section_list input_sections
;
2529 if (this->output_section_
!= NULL
)
2531 // Get the list of input sections attached to this output
2532 // section. This will leave the output section with only
2533 // Output_section_data entries.
2534 address
+= this->output_section_
->get_input_sections(address
,
2537 *dot_value
= address
;
2540 Output_section
* dot_section
= this->output_section_
;
2541 for (Output_section_elements::iterator p
= this->elements_
.begin();
2542 p
!= this->elements_
.end();
2544 (*p
)->set_section_addresses(symtab
, layout
, this->output_section_
,
2545 subalign
, dot_value
, dot_alignment
,
2546 &dot_section
, &fill
, &input_sections
);
2548 gold_assert(input_sections
.empty());
2550 if (vma_region
!= NULL
)
2552 // Update the VMA region being used by the section now that we know how
2553 // big it is. Use the current address in the region, rather than
2554 // start_address because that might have been aligned upwards and we
2555 // need to allow for the padding.
2556 Expression
* addr
= vma_region
->get_current_address();
2557 uint64_t size
= *dot_value
- addr
->eval(symtab
, layout
, false);
2559 vma_region
->increment_offset(this->get_section_name(), size
,
2563 // If the LMA region is different from the VMA region, then increment the
2564 // offset there as well. Note that we use the same "dot_value -
2565 // start_address" formula that is used in the load_address assignment below.
2566 if (lma_region
!= NULL
&& lma_region
!= vma_region
)
2567 lma_region
->increment_offset(this->get_section_name(),
2568 *dot_value
- start_address
,
2571 // Compute the load address for the following section.
2572 if (this->output_section_
== NULL
)
2573 *load_address
= *dot_value
;
2574 else if (this->load_address_
== NULL
)
2576 if (lma_region
== NULL
)
2577 *load_address
= *dot_value
;
2580 lma_region
->get_current_address()->eval(symtab
, layout
, false);
2583 *load_address
= (this->output_section_
->load_address()
2584 + (*dot_value
- start_address
));
2586 if (this->output_section_
!= NULL
)
2588 if (this->is_relro_
)
2589 this->output_section_
->set_is_relro();
2591 this->output_section_
->clear_is_relro();
2593 // If this is a NOLOAD section, keep dot and load address unchanged.
2594 if (this->output_section_
->is_noload())
2596 *dot_value
= old_dot_value
;
2597 *load_address
= old_load_address
;
2602 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
2603 // this section is constrained, and the input sections do not match,
2604 // return the constraint, and set *POSD.
2607 Output_section_definition::check_constraint(Output_section_definition
** posd
)
2609 switch (this->constraint_
)
2611 case CONSTRAINT_NONE
:
2612 return CONSTRAINT_NONE
;
2614 case CONSTRAINT_ONLY_IF_RO
:
2615 if (this->output_section_
!= NULL
2616 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) != 0)
2619 return CONSTRAINT_ONLY_IF_RO
;
2621 return CONSTRAINT_NONE
;
2623 case CONSTRAINT_ONLY_IF_RW
:
2624 if (this->output_section_
!= NULL
2625 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) == 0)
2628 return CONSTRAINT_ONLY_IF_RW
;
2630 return CONSTRAINT_NONE
;
2632 case CONSTRAINT_SPECIAL
:
2633 if (this->output_section_
!= NULL
)
2634 gold_error(_("SPECIAL constraints are not implemented"));
2635 return CONSTRAINT_NONE
;
2642 // See if this is the alternate output section for a constrained
2643 // output section. If it is, transfer the Output_section and return
2644 // true. Otherwise return false.
2647 Output_section_definition::alternate_constraint(
2648 Output_section_definition
* posd
,
2649 Section_constraint constraint
)
2651 if (this->name_
!= posd
->name_
)
2656 case CONSTRAINT_ONLY_IF_RO
:
2657 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RW
)
2661 case CONSTRAINT_ONLY_IF_RW
:
2662 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RO
)
2670 // We have found the alternate constraint. We just need to move
2671 // over the Output_section. When constraints are used properly,
2672 // THIS should not have an output_section pointer, as all the input
2673 // sections should have matched the other definition.
2675 if (this->output_section_
!= NULL
)
2676 gold_error(_("mismatched definition for constrained sections"));
2678 this->output_section_
= posd
->output_section_
;
2679 posd
->output_section_
= NULL
;
2681 if (this->is_relro_
)
2682 this->output_section_
->set_is_relro();
2684 this->output_section_
->clear_is_relro();
2689 // Get the list of segments to use for an allocated section when using
2693 Output_section_definition::allocate_to_segment(String_list
** phdrs_list
,
2696 // Update phdrs_list even if we don't have an output section. It
2697 // might be used by the following sections.
2698 if (this->phdrs_
!= NULL
)
2699 *phdrs_list
= this->phdrs_
;
2701 if (this->output_section_
== NULL
)
2703 if ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) == 0)
2706 return this->output_section_
;
2709 // Look for an output section by name and return the address, the load
2710 // address, the alignment, and the size. This is used when an
2711 // expression refers to an output section which was not actually
2712 // created. This returns true if the section was found, false
2716 Output_section_definition::get_output_section_info(const char* name
,
2718 uint64_t* load_address
,
2719 uint64_t* addralign
,
2720 uint64_t* size
) const
2722 if (this->name_
!= name
)
2725 if (this->output_section_
!= NULL
)
2727 *address
= this->output_section_
->address();
2728 if (this->output_section_
->has_load_address())
2729 *load_address
= this->output_section_
->load_address();
2731 *load_address
= *address
;
2732 *addralign
= this->output_section_
->addralign();
2733 *size
= this->output_section_
->current_data_size();
2737 *address
= this->evaluated_address_
;
2738 *load_address
= this->evaluated_load_address_
;
2739 *addralign
= this->evaluated_addralign_
;
2746 // Print for debugging.
2749 Output_section_definition::print(FILE* f
) const
2751 fprintf(f
, " %s ", this->name_
.c_str());
2753 if (this->address_
!= NULL
)
2755 this->address_
->print(f
);
2759 if (this->script_section_type_
!= SCRIPT_SECTION_TYPE_NONE
)
2761 this->script_section_type_name(this->script_section_type_
));
2765 if (this->load_address_
!= NULL
)
2768 this->load_address_
->print(f
);
2772 if (this->align_
!= NULL
)
2774 fprintf(f
, "ALIGN(");
2775 this->align_
->print(f
);
2779 if (this->subalign_
!= NULL
)
2781 fprintf(f
, "SUBALIGN(");
2782 this->subalign_
->print(f
);
2788 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2789 p
!= this->elements_
.end();
2795 if (this->fill_
!= NULL
)
2798 this->fill_
->print(f
);
2801 if (this->phdrs_
!= NULL
)
2803 for (String_list::const_iterator p
= this->phdrs_
->begin();
2804 p
!= this->phdrs_
->end();
2806 fprintf(f
, " :%s", p
->c_str());
2812 Script_sections::Section_type
2813 Output_section_definition::section_type() const
2815 switch (this->script_section_type_
)
2817 case SCRIPT_SECTION_TYPE_NONE
:
2818 return Script_sections::ST_NONE
;
2819 case SCRIPT_SECTION_TYPE_NOLOAD
:
2820 return Script_sections::ST_NOLOAD
;
2821 case SCRIPT_SECTION_TYPE_COPY
:
2822 case SCRIPT_SECTION_TYPE_DSECT
:
2823 case SCRIPT_SECTION_TYPE_INFO
:
2824 case SCRIPT_SECTION_TYPE_OVERLAY
:
2825 // There are not really support so we treat them as ST_NONE. The
2826 // parse should have issued errors for them already.
2827 return Script_sections::ST_NONE
;
2833 // Return the name of a script section type.
2836 Output_section_definition::script_section_type_name(
2837 Script_section_type script_section_type
)
2839 switch (script_section_type
)
2841 case SCRIPT_SECTION_TYPE_NONE
:
2843 case SCRIPT_SECTION_TYPE_NOLOAD
:
2845 case SCRIPT_SECTION_TYPE_DSECT
:
2847 case SCRIPT_SECTION_TYPE_COPY
:
2849 case SCRIPT_SECTION_TYPE_INFO
:
2851 case SCRIPT_SECTION_TYPE_OVERLAY
:
2859 Output_section_definition::set_memory_region(Memory_region
* mr
, bool set_vma
)
2861 gold_assert(mr
!= NULL
);
2862 // Add the current section to the specified region's list.
2863 mr
->add_section(this, set_vma
);
2866 // An output section created to hold orphaned input sections. These
2867 // do not actually appear in linker scripts. However, for convenience
2868 // when setting the output section addresses, we put a marker to these
2869 // sections in the appropriate place in the list of SECTIONS elements.
2871 class Orphan_output_section
: public Sections_element
2874 Orphan_output_section(Output_section
* os
)
2878 // Return whether the orphan output section is relro. We can just
2879 // check the output section because we always set the flag, if
2880 // needed, just after we create the Orphan_output_section.
2883 { return this->os_
->is_relro(); }
2885 // Initialize OSP with an output section. This should have been
2888 orphan_section_init(Orphan_section_placement
*,
2889 Script_sections::Elements_iterator
)
2890 { gold_unreachable(); }
2892 // Set section addresses.
2894 set_section_addresses(Symbol_table
*, Layout
*, uint64_t*, uint64_t*,
2897 // Get the list of segments to use for an allocated section when
2898 // using a PHDRS clause.
2900 allocate_to_segment(String_list
**, bool*);
2902 // Return the associated Output_section.
2904 get_output_section() const
2905 { return this->os_
; }
2907 // Print for debugging.
2909 print(FILE* f
) const
2911 fprintf(f
, " marker for orphaned output section %s\n",
2916 Output_section
* os_
;
2919 // Set section addresses.
2922 Orphan_output_section::set_section_addresses(Symbol_table
*, Layout
*,
2923 uint64_t* dot_value
,
2925 uint64_t* load_address
)
2927 typedef std::list
<Output_section::Input_section
> Input_section_list
;
2929 bool have_load_address
= *load_address
!= *dot_value
;
2931 uint64_t address
= *dot_value
;
2932 address
= align_address(address
, this->os_
->addralign());
2934 // If input section sorting is requested via --section-ordering-file or
2935 // linker plugins, then do it here. This is important because we want
2936 // any sorting specified in the linker scripts, which will be done after
2937 // this, to take precedence. The final order of input sections is then
2938 // guaranteed to be according to the linker script specification.
2939 if (this->os_
!= NULL
2940 && this->os_
->input_section_order_specified())
2941 this->os_
->sort_attached_input_sections();
2943 // For a relocatable link, all orphan sections are put at
2944 // address 0. In general we expect all sections to be at
2945 // address 0 for a relocatable link, but we permit the linker
2946 // script to override that for specific output sections.
2947 if (parameters
->options().relocatable())
2951 have_load_address
= false;
2954 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) != 0)
2956 this->os_
->set_address(address
);
2957 if (have_load_address
)
2958 this->os_
->set_load_address(align_address(*load_address
,
2959 this->os_
->addralign()));
2962 Input_section_list input_sections
;
2963 address
+= this->os_
->get_input_sections(address
, "", &input_sections
);
2965 for (Input_section_list::iterator p
= input_sections
.begin();
2966 p
!= input_sections
.end();
2969 uint64_t addralign
= p
->addralign();
2970 if (!p
->is_input_section())
2971 p
->output_section_data()->finalize_data_size();
2972 uint64_t size
= p
->data_size();
2973 address
= align_address(address
, addralign
);
2974 this->os_
->add_script_input_section(*p
);
2978 if (parameters
->options().relocatable())
2980 // For a relocatable link, reset DOT_VALUE to 0.
2984 else if (this->os_
== NULL
2985 || (this->os_
->flags() & elfcpp::SHF_TLS
) == 0
2986 || this->os_
->type() != elfcpp::SHT_NOBITS
)
2988 // An SHF_TLS/SHT_NOBITS section does not take up any address space.
2989 if (!have_load_address
)
2990 *load_address
= address
;
2992 *load_address
+= address
- *dot_value
;
2994 *dot_value
= address
;
2998 // Get the list of segments to use for an allocated section when using
2999 // a PHDRS clause. If this is an allocated section, return the
3000 // Output_section. We don't change the list of segments.
3003 Orphan_output_section::allocate_to_segment(String_list
**, bool* orphan
)
3005 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) == 0)
3011 // Class Phdrs_element. A program header from a PHDRS clause.
3016 Phdrs_element(const char* name
, size_t namelen
, unsigned int type
,
3017 bool includes_filehdr
, bool includes_phdrs
,
3018 bool is_flags_valid
, unsigned int flags
,
3019 Expression
* load_address
)
3020 : name_(name
, namelen
), type_(type
), includes_filehdr_(includes_filehdr
),
3021 includes_phdrs_(includes_phdrs
), is_flags_valid_(is_flags_valid
),
3022 flags_(flags
), load_address_(load_address
), load_address_value_(0),
3026 // Return the name of this segment.
3029 { return this->name_
; }
3031 // Return the type of the segment.
3034 { return this->type_
; }
3036 // Whether to include the file header.
3038 includes_filehdr() const
3039 { return this->includes_filehdr_
; }
3041 // Whether to include the program headers.
3043 includes_phdrs() const
3044 { return this->includes_phdrs_
; }
3046 // Return whether there is a load address.
3048 has_load_address() const
3049 { return this->load_address_
!= NULL
; }
3051 // Evaluate the load address expression if there is one.
3053 eval_load_address(Symbol_table
* symtab
, Layout
* layout
)
3055 if (this->load_address_
!= NULL
)
3056 this->load_address_value_
= this->load_address_
->eval(symtab
, layout
,
3060 // Return the load address.
3062 load_address() const
3064 gold_assert(this->load_address_
!= NULL
);
3065 return this->load_address_value_
;
3068 // Create the segment.
3070 create_segment(Layout
* layout
)
3072 this->segment_
= layout
->make_output_segment(this->type_
, this->flags_
);
3073 return this->segment_
;
3076 // Return the segment.
3079 { return this->segment_
; }
3081 // Release the segment.
3084 { this->segment_
= NULL
; }
3086 // Set the segment flags if appropriate.
3088 set_flags_if_valid()
3090 if (this->is_flags_valid_
)
3091 this->segment_
->set_flags(this->flags_
);
3094 // Print for debugging.
3099 // The name used in the script.
3101 // The type of the segment (PT_LOAD, etc.).
3103 // Whether this segment includes the file header.
3104 bool includes_filehdr_
;
3105 // Whether this segment includes the section headers.
3106 bool includes_phdrs_
;
3107 // Whether the flags were explicitly specified.
3108 bool is_flags_valid_
;
3109 // The flags for this segment (PF_R, etc.) if specified.
3110 unsigned int flags_
;
3111 // The expression for the load address for this segment. This may
3113 Expression
* load_address_
;
3114 // The actual load address from evaluating the expression.
3115 uint64_t load_address_value_
;
3116 // The segment itself.
3117 Output_segment
* segment_
;
3120 // Print for debugging.
3123 Phdrs_element::print(FILE* f
) const
3125 fprintf(f
, " %s 0x%x", this->name_
.c_str(), this->type_
);
3126 if (this->includes_filehdr_
)
3127 fprintf(f
, " FILEHDR");
3128 if (this->includes_phdrs_
)
3129 fprintf(f
, " PHDRS");
3130 if (this->is_flags_valid_
)
3131 fprintf(f
, " FLAGS(%u)", this->flags_
);
3132 if (this->load_address_
!= NULL
)
3135 this->load_address_
->print(f
);
3141 // Add a memory region.
3144 Script_sections::add_memory_region(const char* name
, size_t namelen
,
3145 unsigned int attributes
,
3146 Expression
* start
, Expression
* length
)
3148 if (this->memory_regions_
== NULL
)
3149 this->memory_regions_
= new Memory_regions();
3150 else if (this->find_memory_region(name
, namelen
))
3152 gold_error(_("region '%.*s' already defined"), static_cast<int>(namelen
),
3154 // FIXME: Add a GOLD extension to allow multiple regions with the same
3155 // name. This would amount to a single region covering disjoint blocks
3156 // of memory, which is useful for embedded devices.
3159 // FIXME: Check the length and start values. Currently we allow
3160 // non-constant expressions for these values, whereas LD does not.
3162 // FIXME: Add a GOLD extension to allow NEGATIVE LENGTHS. This would
3163 // describe a region that packs from the end address going down, rather
3164 // than the start address going up. This would be useful for embedded
3167 this->memory_regions_
->push_back(new Memory_region(name
, namelen
, attributes
,
3171 // Find a memory region.
3174 Script_sections::find_memory_region(const char* name
, size_t namelen
)
3176 if (this->memory_regions_
== NULL
)
3179 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
3180 m
!= this->memory_regions_
->end();
3182 if ((*m
)->name_match(name
, namelen
))
3188 // Find a memory region's origin.
3191 Script_sections::find_memory_region_origin(const char* name
, size_t namelen
)
3193 Memory_region
* mr
= find_memory_region(name
, namelen
);
3197 return mr
->start_address();
3200 // Find a memory region's length.
3203 Script_sections::find_memory_region_length(const char* name
, size_t namelen
)
3205 Memory_region
* mr
= find_memory_region(name
, namelen
);
3209 return mr
->length();
3212 // Set the memory region to use for the current section.
3215 Script_sections::set_memory_region(Memory_region
* mr
, bool set_vma
)
3217 gold_assert(!this->sections_elements_
->empty());
3218 this->sections_elements_
->back()->set_memory_region(mr
, set_vma
);
3221 // Class Script_sections.
3223 Script_sections::Script_sections()
3224 : saw_sections_clause_(false),
3225 in_sections_clause_(false),
3226 sections_elements_(NULL
),
3227 output_section_(NULL
),
3228 memory_regions_(NULL
),
3229 phdrs_elements_(NULL
),
3230 orphan_section_placement_(NULL
),
3231 data_segment_align_start_(),
3232 saw_data_segment_align_(false),
3233 saw_relro_end_(false),
3234 saw_segment_start_expression_(false),
3235 segments_created_(false)
3239 // Start a SECTIONS clause.
3242 Script_sections::start_sections()
3244 gold_assert(!this->in_sections_clause_
&& this->output_section_
== NULL
);
3245 this->saw_sections_clause_
= true;
3246 this->in_sections_clause_
= true;
3247 if (this->sections_elements_
== NULL
)
3248 this->sections_elements_
= new Sections_elements
;
3251 // Finish a SECTIONS clause.
3254 Script_sections::finish_sections()
3256 gold_assert(this->in_sections_clause_
&& this->output_section_
== NULL
);
3257 this->in_sections_clause_
= false;
3260 // Add a symbol to be defined.
3263 Script_sections::add_symbol_assignment(const char* name
, size_t length
,
3264 Expression
* val
, bool provide
,
3267 if (this->output_section_
!= NULL
)
3268 this->output_section_
->add_symbol_assignment(name
, length
, val
,
3272 Sections_element
* p
= new Sections_element_assignment(name
, length
,
3275 this->sections_elements_
->push_back(p
);
3279 // Add an assignment to the special dot symbol.
3282 Script_sections::add_dot_assignment(Expression
* val
)
3284 if (this->output_section_
!= NULL
)
3285 this->output_section_
->add_dot_assignment(val
);
3288 // The GNU linker permits assignments to . to appears outside of
3289 // a SECTIONS clause, and treats it as appearing inside, so
3290 // sections_elements_ may be NULL here.
3291 if (this->sections_elements_
== NULL
)
3293 this->sections_elements_
= new Sections_elements
;
3294 this->saw_sections_clause_
= true;
3297 Sections_element
* p
= new Sections_element_dot_assignment(val
);
3298 this->sections_elements_
->push_back(p
);
3302 // Add an assertion.
3305 Script_sections::add_assertion(Expression
* check
, const char* message
,
3308 if (this->output_section_
!= NULL
)
3309 this->output_section_
->add_assertion(check
, message
, messagelen
);
3312 Sections_element
* p
= new Sections_element_assertion(check
, message
,
3314 this->sections_elements_
->push_back(p
);
3318 // Start processing entries for an output section.
3321 Script_sections::start_output_section(
3324 const Parser_output_section_header
* header
)
3326 Output_section_definition
* posd
= new Output_section_definition(name
,
3329 this->sections_elements_
->push_back(posd
);
3330 gold_assert(this->output_section_
== NULL
);
3331 this->output_section_
= posd
;
3334 // Stop processing entries for an output section.
3337 Script_sections::finish_output_section(
3338 const Parser_output_section_trailer
* trailer
)
3340 gold_assert(this->output_section_
!= NULL
);
3341 this->output_section_
->finish(trailer
);
3342 this->output_section_
= NULL
;
3345 // Add a data item to the current output section.
3348 Script_sections::add_data(int size
, bool is_signed
, Expression
* val
)
3350 gold_assert(this->output_section_
!= NULL
);
3351 this->output_section_
->add_data(size
, is_signed
, val
);
3354 // Add a fill value setting to the current output section.
3357 Script_sections::add_fill(Expression
* val
)
3359 gold_assert(this->output_section_
!= NULL
);
3360 this->output_section_
->add_fill(val
);
3363 // Add an input section specification to the current output section.
3366 Script_sections::add_input_section(const Input_section_spec
* spec
, bool keep
)
3368 gold_assert(this->output_section_
!= NULL
);
3369 this->output_section_
->add_input_section(spec
, keep
);
3372 // This is called when we see DATA_SEGMENT_ALIGN. It means that any
3373 // subsequent output sections may be relro.
3376 Script_sections::data_segment_align()
3378 if (this->saw_data_segment_align_
)
3379 gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script"));
3380 gold_assert(!this->sections_elements_
->empty());
3381 Sections_elements::iterator p
= this->sections_elements_
->end();
3383 this->data_segment_align_start_
= p
;
3384 this->saw_data_segment_align_
= true;
3387 // This is called when we see DATA_SEGMENT_RELRO_END. It means that
3388 // any output sections seen since DATA_SEGMENT_ALIGN are relro.
3391 Script_sections::data_segment_relro_end()
3393 if (this->saw_relro_end_
)
3394 gold_error(_("DATA_SEGMENT_RELRO_END may only appear once "
3395 "in a linker script"));
3396 this->saw_relro_end_
= true;
3398 if (!this->saw_data_segment_align_
)
3399 gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN"));
3402 Sections_elements::iterator p
= this->data_segment_align_start_
;
3403 for (++p
; p
!= this->sections_elements_
->end(); ++p
)
3404 (*p
)->set_is_relro();
3408 // Create any required sections.
3411 Script_sections::create_sections(Layout
* layout
)
3413 if (!this->saw_sections_clause_
)
3415 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3416 p
!= this->sections_elements_
->end();
3418 (*p
)->create_sections(layout
);
3421 // Add any symbols we are defining to the symbol table.
3424 Script_sections::add_symbols_to_table(Symbol_table
* symtab
)
3426 if (!this->saw_sections_clause_
)
3428 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3429 p
!= this->sections_elements_
->end();
3431 (*p
)->add_symbols_to_table(symtab
);
3434 // Finalize symbols and check assertions.
3437 Script_sections::finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
)
3439 if (!this->saw_sections_clause_
)
3441 uint64_t dot_value
= 0;
3442 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3443 p
!= this->sections_elements_
->end();
3445 (*p
)->finalize_symbols(symtab
, layout
, &dot_value
);
3448 // Return the name of the output section to use for an input file name
3449 // and section name.
3452 Script_sections::output_section_name(
3453 const char* file_name
,
3454 const char* section_name
,
3455 Output_section
*** output_section_slot
,
3456 Script_sections::Section_type
* psection_type
,
3459 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3460 p
!= this->sections_elements_
->end();
3463 const char* ret
= (*p
)->output_section_name(file_name
, section_name
,
3464 output_section_slot
,
3465 psection_type
, keep
);
3469 // The special name /DISCARD/ means that the input section
3470 // should be discarded.
3471 if (strcmp(ret
, "/DISCARD/") == 0)
3473 *output_section_slot
= NULL
;
3474 *psection_type
= Script_sections::ST_NONE
;
3481 // If we couldn't find a mapping for the name, the output section
3482 // gets the name of the input section.
3484 *output_section_slot
= NULL
;
3485 *psection_type
= Script_sections::ST_NONE
;
3487 return section_name
;
3490 // Place a marker for an orphan output section into the SECTIONS
3494 Script_sections::place_orphan(Output_section
* os
)
3496 Orphan_section_placement
* osp
= this->orphan_section_placement_
;
3499 // Initialize the Orphan_section_placement structure.
3500 osp
= new Orphan_section_placement();
3501 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3502 p
!= this->sections_elements_
->end();
3504 (*p
)->orphan_section_init(osp
, p
);
3505 gold_assert(!this->sections_elements_
->empty());
3506 Sections_elements::iterator last
= this->sections_elements_
->end();
3508 osp
->last_init(last
);
3509 this->orphan_section_placement_
= osp
;
3512 Orphan_output_section
* orphan
= new Orphan_output_section(os
);
3514 // Look for where to put ORPHAN.
3515 Sections_elements::iterator
* where
;
3516 if (osp
->find_place(os
, &where
))
3518 if ((**where
)->is_relro())
3521 os
->clear_is_relro();
3523 // We want to insert ORPHAN after *WHERE, and then update *WHERE
3524 // so that the next one goes after this one.
3525 Sections_elements::iterator p
= *where
;
3526 gold_assert(p
!= this->sections_elements_
->end());
3528 *where
= this->sections_elements_
->insert(p
, orphan
);
3532 os
->clear_is_relro();
3533 // We don't have a place to put this orphan section. Put it,
3534 // and all other sections like it, at the end, but before the
3535 // sections which always come at the end.
3536 Sections_elements::iterator last
= osp
->last_place();
3537 *where
= this->sections_elements_
->insert(last
, orphan
);
3541 // Set the addresses of all the output sections. Walk through all the
3542 // elements, tracking the dot symbol. Apply assignments which set
3543 // absolute symbol values, in case they are used when setting dot.
3544 // Fill in data statement values. As we find output sections, set the
3545 // address, set the address of all associated input sections, and
3546 // update dot. Return the segment which should hold the file header
3547 // and segment headers, if any.
3550 Script_sections::set_section_addresses(Symbol_table
* symtab
, Layout
* layout
)
3552 gold_assert(this->saw_sections_clause_
);
3554 // Implement ONLY_IF_RO/ONLY_IF_RW constraints. These are a pain
3555 // for our representation.
3556 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3557 p
!= this->sections_elements_
->end();
3560 Output_section_definition
* posd
;
3561 Section_constraint failed_constraint
= (*p
)->check_constraint(&posd
);
3562 if (failed_constraint
!= CONSTRAINT_NONE
)
3564 Sections_elements::iterator q
;
3565 for (q
= this->sections_elements_
->begin();
3566 q
!= this->sections_elements_
->end();
3571 if ((*q
)->alternate_constraint(posd
, failed_constraint
))
3576 if (q
== this->sections_elements_
->end())
3577 gold_error(_("no matching section constraint"));
3581 // Force the alignment of the first TLS section to be the maximum
3582 // alignment of all TLS sections.
3583 Output_section
* first_tls
= NULL
;
3584 uint64_t tls_align
= 0;
3585 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3586 p
!= this->sections_elements_
->end();
3589 Output_section
* os
= (*p
)->get_output_section();
3590 if (os
!= NULL
&& (os
->flags() & elfcpp::SHF_TLS
) != 0)
3592 if (first_tls
== NULL
)
3594 if (os
->addralign() > tls_align
)
3595 tls_align
= os
->addralign();
3598 if (first_tls
!= NULL
)
3599 first_tls
->set_addralign(tls_align
);
3601 // For a relocatable link, we implicitly set dot to zero.
3602 uint64_t dot_value
= 0;
3603 uint64_t dot_alignment
= 0;
3604 uint64_t load_address
= 0;
3606 // Check to see if we want to use any of -Ttext, -Tdata and -Tbss options
3607 // to set section addresses. If the script has any SEGMENT_START
3608 // expression, we do not set the section addresses.
3609 bool use_tsection_options
=
3610 (!this->saw_segment_start_expression_
3611 && (parameters
->options().user_set_Ttext()
3612 || parameters
->options().user_set_Tdata()
3613 || parameters
->options().user_set_Tbss()));
3615 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3616 p
!= this->sections_elements_
->end();
3619 Output_section
* os
= (*p
)->get_output_section();
3621 // Handle -Ttext, -Tdata and -Tbss options. We do this by looking for
3622 // the special sections by names and doing dot assignments.
3623 if (use_tsection_options
3625 && (os
->flags() & elfcpp::SHF_ALLOC
) != 0)
3627 uint64_t new_dot_value
= dot_value
;
3629 if (parameters
->options().user_set_Ttext()
3630 && strcmp(os
->name(), ".text") == 0)
3631 new_dot_value
= parameters
->options().Ttext();
3632 else if (parameters
->options().user_set_Tdata()
3633 && strcmp(os
->name(), ".data") == 0)
3634 new_dot_value
= parameters
->options().Tdata();
3635 else if (parameters
->options().user_set_Tbss()
3636 && strcmp(os
->name(), ".bss") == 0)
3637 new_dot_value
= parameters
->options().Tbss();
3639 // Update dot and load address if necessary.
3640 if (new_dot_value
< dot_value
)
3641 gold_error(_("dot may not move backward"));
3642 else if (new_dot_value
!= dot_value
)
3644 dot_value
= new_dot_value
;
3645 load_address
= new_dot_value
;
3649 (*p
)->set_section_addresses(symtab
, layout
, &dot_value
, &dot_alignment
,
3653 if (this->phdrs_elements_
!= NULL
)
3655 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
3656 p
!= this->phdrs_elements_
->end();
3658 (*p
)->eval_load_address(symtab
, layout
);
3661 return this->create_segments(layout
, dot_alignment
);
3664 // Sort the sections in order to put them into segments.
3666 class Sort_output_sections
3669 Sort_output_sections(const Script_sections::Sections_elements
* elements
)
3670 : elements_(elements
)
3674 operator()(const Output_section
* os1
, const Output_section
* os2
) const;
3678 script_compare(const Output_section
* os1
, const Output_section
* os2
) const;
3681 const Script_sections::Sections_elements
* elements_
;
3685 Sort_output_sections::operator()(const Output_section
* os1
,
3686 const Output_section
* os2
) const
3688 // Sort first by the load address.
3689 uint64_t lma1
= (os1
->has_load_address()
3690 ? os1
->load_address()
3692 uint64_t lma2
= (os2
->has_load_address()
3693 ? os2
->load_address()
3698 // Then sort by the virtual address.
3699 if (os1
->address() != os2
->address())
3700 return os1
->address() < os2
->address();
3702 // If the linker script says which of these sections is first, go
3703 // with what it says.
3704 int i
= this->script_compare(os1
, os2
);
3708 // Sort PROGBITS before NOBITS.
3709 bool nobits1
= os1
->type() == elfcpp::SHT_NOBITS
;
3710 bool nobits2
= os2
->type() == elfcpp::SHT_NOBITS
;
3711 if (nobits1
!= nobits2
)
3714 // Sort PROGBITS TLS sections to the end, NOBITS TLS sections to the
3716 bool tls1
= (os1
->flags() & elfcpp::SHF_TLS
) != 0;
3717 bool tls2
= (os2
->flags() & elfcpp::SHF_TLS
) != 0;
3719 return nobits1
? tls1
: tls2
;
3721 // Sort non-NOLOAD before NOLOAD.
3722 if (os1
->is_noload() && !os2
->is_noload())
3724 if (!os1
->is_noload() && os2
->is_noload())
3727 // The sections seem practically identical. Sort by name to get a
3729 return os1
->name() < os2
->name();
3732 // Return -1 if OS1 comes before OS2 in ELEMENTS_, 1 if comes after, 0
3733 // if either OS1 or OS2 is not mentioned. This ensures that we keep
3734 // empty sections in the order in which they appear in a linker
3738 Sort_output_sections::script_compare(const Output_section
* os1
,
3739 const Output_section
* os2
) const
3741 if (this->elements_
== NULL
)
3744 bool found_os1
= false;
3745 bool found_os2
= false;
3746 for (Script_sections::Sections_elements::const_iterator
3747 p
= this->elements_
->begin();
3748 p
!= this->elements_
->end();
3751 if (os2
== (*p
)->get_output_section())
3757 else if (os1
== (*p
)->get_output_section())
3768 // Return whether OS is a BSS section. This is a SHT_NOBITS section.
3769 // We treat a section with the SHF_TLS flag set as taking up space
3770 // even if it is SHT_NOBITS (this is true of .tbss), as we allocate
3771 // space for them in the file.
3774 Script_sections::is_bss_section(const Output_section
* os
)
3776 return (os
->type() == elfcpp::SHT_NOBITS
3777 && (os
->flags() & elfcpp::SHF_TLS
) == 0);
3780 // Return the size taken by the file header and the program headers.
3783 Script_sections::total_header_size(Layout
* layout
) const
3785 size_t segment_count
= layout
->segment_count();
3786 size_t file_header_size
;
3787 size_t segment_headers_size
;
3788 if (parameters
->target().get_size() == 32)
3790 file_header_size
= elfcpp::Elf_sizes
<32>::ehdr_size
;
3791 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<32>::phdr_size
;
3793 else if (parameters
->target().get_size() == 64)
3795 file_header_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
3796 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<64>::phdr_size
;
3801 return file_header_size
+ segment_headers_size
;
3804 // Return the amount we have to subtract from the LMA to accommodate
3805 // headers of the given size. The complication is that the file
3806 // header have to be at the start of a page, as otherwise it will not
3807 // be at the start of the file.
3810 Script_sections::header_size_adjustment(uint64_t lma
,
3811 size_t sizeof_headers
) const
3813 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3814 uint64_t hdr_lma
= lma
- sizeof_headers
;
3815 hdr_lma
&= ~(abi_pagesize
- 1);
3816 return lma
- hdr_lma
;
3819 // Create the PT_LOAD segments when using a SECTIONS clause. Returns
3820 // the segment which should hold the file header and segment headers,
3824 Script_sections::create_segments(Layout
* layout
, uint64_t dot_alignment
)
3826 gold_assert(this->saw_sections_clause_
);
3828 if (parameters
->options().relocatable())
3831 if (this->saw_phdrs_clause())
3832 return create_segments_from_phdrs_clause(layout
, dot_alignment
);
3834 Layout::Section_list sections
;
3835 layout
->get_allocated_sections(§ions
);
3837 // Sort the sections by address.
3838 std::stable_sort(sections
.begin(), sections
.end(),
3839 Sort_output_sections(this->sections_elements_
));
3841 this->create_note_and_tls_segments(layout
, §ions
);
3843 // Walk through the sections adding them to PT_LOAD segments.
3844 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3845 Output_segment
* first_seg
= NULL
;
3846 Output_segment
* current_seg
= NULL
;
3847 bool is_current_seg_readonly
= true;
3848 Layout::Section_list::iterator plast
= sections
.end();
3849 uint64_t last_vma
= 0;
3850 uint64_t last_lma
= 0;
3851 uint64_t last_size
= 0;
3852 for (Layout::Section_list::iterator p
= sections
.begin();
3853 p
!= sections
.end();
3856 const uint64_t vma
= (*p
)->address();
3857 const uint64_t lma
= ((*p
)->has_load_address()
3858 ? (*p
)->load_address()
3860 const uint64_t size
= (*p
)->current_data_size();
3862 bool need_new_segment
;
3863 if (current_seg
== NULL
)
3864 need_new_segment
= true;
3865 else if (lma
- vma
!= last_lma
- last_vma
)
3867 // This section has a different LMA relationship than the
3868 // last one; we need a new segment.
3869 need_new_segment
= true;
3871 else if (align_address(last_lma
+ last_size
, abi_pagesize
)
3872 < align_address(lma
, abi_pagesize
))
3874 // Putting this section in the segment would require
3876 need_new_segment
= true;
3878 else if (is_bss_section(*plast
) && !is_bss_section(*p
))
3880 // A non-BSS section can not follow a BSS section in the
3882 need_new_segment
= true;
3884 else if (is_current_seg_readonly
3885 && ((*p
)->flags() & elfcpp::SHF_WRITE
) != 0
3886 && !parameters
->options().omagic())
3888 // Don't put a writable section in the same segment as a
3889 // non-writable section.
3890 need_new_segment
= true;
3894 // Otherwise, reuse the existing segment.
3895 need_new_segment
= false;
3898 elfcpp::Elf_Word seg_flags
=
3899 Layout::section_flags_to_segment((*p
)->flags());
3901 if (need_new_segment
)
3903 current_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
3905 current_seg
->set_addresses(vma
, lma
);
3906 current_seg
->set_minimum_p_align(dot_alignment
);
3907 if (first_seg
== NULL
)
3908 first_seg
= current_seg
;
3909 is_current_seg_readonly
= true;
3912 current_seg
->add_output_section_to_load(layout
, *p
, seg_flags
);
3914 if (((*p
)->flags() & elfcpp::SHF_WRITE
) != 0)
3915 is_current_seg_readonly
= false;
3923 // An ELF program should work even if the program headers are not in
3924 // a PT_LOAD segment. However, it appears that the Linux kernel
3925 // does not set the AT_PHDR auxiliary entry in that case. It sets
3926 // the load address to p_vaddr - p_offset of the first PT_LOAD
3927 // segment. It then sets AT_PHDR to the load address plus the
3928 // offset to the program headers, e_phoff in the file header. This
3929 // fails when the program headers appear in the file before the
3930 // first PT_LOAD segment. Therefore, we always create a PT_LOAD
3931 // segment to hold the file header and the program headers. This is
3932 // effectively what the GNU linker does, and it is slightly more
3933 // efficient in any case. We try to use the first PT_LOAD segment
3934 // if we can, otherwise we make a new one.
3936 if (first_seg
== NULL
)
3939 // -n or -N mean that the program is not demand paged and there is
3940 // no need to put the program headers in a PT_LOAD segment.
3941 if (parameters
->options().nmagic() || parameters
->options().omagic())
3944 size_t sizeof_headers
= this->total_header_size(layout
);
3946 uint64_t vma
= first_seg
->vaddr();
3947 uint64_t lma
= first_seg
->paddr();
3949 uint64_t subtract
= this->header_size_adjustment(lma
, sizeof_headers
);
3951 if ((lma
& (abi_pagesize
- 1)) >= sizeof_headers
)
3953 first_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
3957 // If there is no room to squeeze in the headers, then punt. The
3958 // resulting executable probably won't run on GNU/Linux, but we
3959 // trust that the user knows what they are doing.
3960 if (lma
< subtract
|| vma
< subtract
)
3963 // If memory regions have been specified and the address range
3964 // we are about to use is not contained within any region then
3965 // issue a warning message about the segment we are going to
3966 // create. It will be outside of any region and so possibly
3967 // using non-existent or protected memory. We test LMA rather
3968 // than VMA since we assume that the headers will never be
3970 if (this->memory_regions_
!= NULL
3971 && !this->block_in_region (NULL
, layout
, lma
- subtract
, subtract
))
3972 gold_warning(_("creating a segment to contain the file and program"
3973 " headers outside of any MEMORY region"));
3975 Output_segment
* load_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
3977 load_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
3982 // Create a PT_NOTE segment for each SHT_NOTE section and a PT_TLS
3983 // segment if there are any SHT_TLS sections.
3986 Script_sections::create_note_and_tls_segments(
3988 const Layout::Section_list
* sections
)
3990 gold_assert(!this->saw_phdrs_clause());
3992 bool saw_tls
= false;
3993 for (Layout::Section_list::const_iterator p
= sections
->begin();
3994 p
!= sections
->end();
3997 if ((*p
)->type() == elfcpp::SHT_NOTE
)
3999 elfcpp::Elf_Word seg_flags
=
4000 Layout::section_flags_to_segment((*p
)->flags());
4001 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_NOTE
,
4003 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
4005 // Incorporate any subsequent SHT_NOTE sections, in the
4006 // hopes that the script is sensible.
4007 Layout::Section_list::const_iterator pnext
= p
+ 1;
4008 while (pnext
!= sections
->end()
4009 && (*pnext
)->type() == elfcpp::SHT_NOTE
)
4011 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
4012 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
4018 if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
4021 gold_error(_("TLS sections are not adjacent"));
4023 elfcpp::Elf_Word seg_flags
=
4024 Layout::section_flags_to_segment((*p
)->flags());
4025 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_TLS
,
4027 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
4029 Layout::Section_list::const_iterator pnext
= p
+ 1;
4030 while (pnext
!= sections
->end()
4031 && ((*pnext
)->flags() & elfcpp::SHF_TLS
) != 0)
4033 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
4034 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
4042 // If we see a section named .interp then put the .interp section
4043 // in a PT_INTERP segment.
4044 // This is for GNU ld compatibility.
4045 if (strcmp((*p
)->name(), ".interp") == 0)
4047 elfcpp::Elf_Word seg_flags
=
4048 Layout::section_flags_to_segment((*p
)->flags());
4049 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_INTERP
,
4051 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
4055 this->segments_created_
= true;
4058 // Add a program header. The PHDRS clause is syntactically distinct
4059 // from the SECTIONS clause, but we implement it with the SECTIONS
4060 // support because PHDRS is useless if there is no SECTIONS clause.
4063 Script_sections::add_phdr(const char* name
, size_t namelen
, unsigned int type
,
4064 bool includes_filehdr
, bool includes_phdrs
,
4065 bool is_flags_valid
, unsigned int flags
,
4066 Expression
* load_address
)
4068 if (this->phdrs_elements_
== NULL
)
4069 this->phdrs_elements_
= new Phdrs_elements();
4070 this->phdrs_elements_
->push_back(new Phdrs_element(name
, namelen
, type
,
4073 is_flags_valid
, flags
,
4077 // Return the number of segments we expect to create based on the
4078 // SECTIONS clause. This is used to implement SIZEOF_HEADERS.
4081 Script_sections::expected_segment_count(const Layout
* layout
) const
4083 // If we've already created the segments, we won't be adding any more.
4084 if (this->segments_created_
)
4087 if (this->saw_phdrs_clause())
4088 return this->phdrs_elements_
->size();
4090 Layout::Section_list sections
;
4091 layout
->get_allocated_sections(§ions
);
4093 // We assume that we will need two PT_LOAD segments.
4096 bool saw_note
= false;
4097 bool saw_tls
= false;
4098 bool saw_interp
= false;
4099 for (Layout::Section_list::const_iterator p
= sections
.begin();
4100 p
!= sections
.end();
4103 if ((*p
)->type() == elfcpp::SHT_NOTE
)
4105 // Assume that all note sections will fit into a single
4113 else if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
4115 // There can only be one PT_TLS segment.
4122 else if (strcmp((*p
)->name(), ".interp") == 0)
4124 // There can only be one PT_INTERP segment.
4136 // Create the segments from a PHDRS clause. Return the segment which
4137 // should hold the file header and program headers, if any.
4140 Script_sections::create_segments_from_phdrs_clause(Layout
* layout
,
4141 uint64_t dot_alignment
)
4143 this->attach_sections_using_phdrs_clause(layout
);
4144 return this->set_phdrs_clause_addresses(layout
, dot_alignment
);
4147 // Create the segments from the PHDRS clause, and put the output
4148 // sections in them.
4151 Script_sections::attach_sections_using_phdrs_clause(Layout
* layout
)
4153 typedef std::map
<std::string
, Output_segment
*> Name_to_segment
;
4154 Name_to_segment name_to_segment
;
4155 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4156 p
!= this->phdrs_elements_
->end();
4158 name_to_segment
[(*p
)->name()] = (*p
)->create_segment(layout
);
4159 this->segments_created_
= true;
4161 // Walk through the output sections and attach them to segments.
4162 // Output sections in the script which do not list segments are
4163 // attached to the same set of segments as the immediately preceding
4166 String_list
* phdr_names
= NULL
;
4167 bool load_segments_only
= false;
4168 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4169 p
!= this->sections_elements_
->end();
4173 String_list
* old_phdr_names
= phdr_names
;
4174 Output_section
* os
= (*p
)->allocate_to_segment(&phdr_names
, &is_orphan
);
4178 elfcpp::Elf_Word seg_flags
=
4179 Layout::section_flags_to_segment(os
->flags());
4181 if (phdr_names
== NULL
)
4183 // Don't worry about empty orphan sections.
4184 if (is_orphan
&& os
->current_data_size() > 0)
4185 gold_error(_("allocated section %s not in any segment"),
4188 // To avoid later crashes drop this section into the first
4190 for (Phdrs_elements::const_iterator ppe
=
4191 this->phdrs_elements_
->begin();
4192 ppe
!= this->phdrs_elements_
->end();
4195 Output_segment
* oseg
= (*ppe
)->segment();
4196 if (oseg
->type() == elfcpp::PT_LOAD
)
4198 oseg
->add_output_section_to_load(layout
, os
, seg_flags
);
4206 // We see a list of segments names. Disable PT_LOAD segment only
4208 if (old_phdr_names
!= phdr_names
)
4209 load_segments_only
= false;
4211 // If this is an orphan section--one that was not explicitly
4212 // mentioned in the linker script--then it should not inherit
4213 // any segment type other than PT_LOAD. Otherwise, e.g., the
4214 // PT_INTERP segment will pick up following orphan sections,
4215 // which does not make sense. If this is not an orphan section,
4216 // we trust the linker script.
4219 // Enable PT_LOAD segments only filtering until we see another
4220 // list of segment names.
4221 load_segments_only
= true;
4224 bool in_load_segment
= false;
4225 for (String_list::const_iterator q
= phdr_names
->begin();
4226 q
!= phdr_names
->end();
4229 Name_to_segment::const_iterator r
= name_to_segment
.find(*q
);
4230 if (r
== name_to_segment
.end())
4231 gold_error(_("no segment %s"), q
->c_str());
4234 if (load_segments_only
4235 && r
->second
->type() != elfcpp::PT_LOAD
)
4238 if (r
->second
->type() != elfcpp::PT_LOAD
)
4239 r
->second
->add_output_section_to_nonload(os
, seg_flags
);
4242 r
->second
->add_output_section_to_load(layout
, os
, seg_flags
);
4243 if (in_load_segment
)
4244 gold_error(_("section in two PT_LOAD segments"));
4245 in_load_segment
= true;
4250 if (!in_load_segment
)
4251 gold_error(_("allocated section not in any PT_LOAD segment"));
4255 // Set the addresses for segments created from a PHDRS clause. Return
4256 // the segment which should hold the file header and program headers,
4260 Script_sections::set_phdrs_clause_addresses(Layout
* layout
,
4261 uint64_t dot_alignment
)
4263 Output_segment
* load_seg
= NULL
;
4264 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4265 p
!= this->phdrs_elements_
->end();
4268 // Note that we have to set the flags after adding the output
4269 // sections to the segment, as adding an output segment can
4270 // change the flags.
4271 (*p
)->set_flags_if_valid();
4273 Output_segment
* oseg
= (*p
)->segment();
4275 if (oseg
->type() != elfcpp::PT_LOAD
)
4277 // The addresses of non-PT_LOAD segments are set from the
4278 // PT_LOAD segments.
4279 if ((*p
)->has_load_address())
4280 gold_error(_("may only specify load address for PT_LOAD segment"));
4284 oseg
->set_minimum_p_align(dot_alignment
);
4286 // The output sections should have addresses from the SECTIONS
4287 // clause. The addresses don't have to be in order, so find the
4288 // one with the lowest load address. Use that to set the
4289 // address of the segment.
4291 Output_section
* osec
= oseg
->section_with_lowest_load_address();
4294 oseg
->set_addresses(0, 0);
4298 uint64_t vma
= osec
->address();
4299 uint64_t lma
= osec
->has_load_address() ? osec
->load_address() : vma
;
4301 // Override the load address of the section with the load
4302 // address specified for the segment.
4303 if ((*p
)->has_load_address())
4305 if (osec
->has_load_address())
4306 gold_warning(_("PHDRS load address overrides "
4307 "section %s load address"),
4310 lma
= (*p
)->load_address();
4313 bool headers
= (*p
)->includes_filehdr() && (*p
)->includes_phdrs();
4314 if (!headers
&& ((*p
)->includes_filehdr() || (*p
)->includes_phdrs()))
4316 // We could support this if we wanted to.
4317 gold_error(_("using only one of FILEHDR and PHDRS is "
4318 "not currently supported"));
4322 size_t sizeof_headers
= this->total_header_size(layout
);
4323 uint64_t subtract
= this->header_size_adjustment(lma
,
4325 if (lma
>= subtract
&& vma
>= subtract
)
4332 gold_error(_("sections loaded on first page without room "
4333 "for file and program headers "
4334 "are not supported"));
4337 if (load_seg
!= NULL
)
4338 gold_error(_("using FILEHDR and PHDRS on more than one "
4339 "PT_LOAD segment is not currently supported"));
4343 oseg
->set_addresses(vma
, lma
);
4349 // Add the file header and segment headers to non-load segments
4350 // specified in the PHDRS clause.
4353 Script_sections::put_headers_in_phdrs(Output_data
* file_header
,
4354 Output_data
* segment_headers
)
4356 gold_assert(this->saw_phdrs_clause());
4357 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
4358 p
!= this->phdrs_elements_
->end();
4361 if ((*p
)->type() != elfcpp::PT_LOAD
)
4363 if ((*p
)->includes_phdrs())
4364 (*p
)->segment()->add_initial_output_data(segment_headers
);
4365 if ((*p
)->includes_filehdr())
4366 (*p
)->segment()->add_initial_output_data(file_header
);
4371 // Look for an output section by name and return the address, the load
4372 // address, the alignment, and the size. This is used when an
4373 // expression refers to an output section which was not actually
4374 // created. This returns true if the section was found, false
4378 Script_sections::get_output_section_info(const char* name
, uint64_t* address
,
4379 uint64_t* load_address
,
4380 uint64_t* addralign
,
4381 uint64_t* size
) const
4383 if (!this->saw_sections_clause_
)
4385 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4386 p
!= this->sections_elements_
->end();
4388 if ((*p
)->get_output_section_info(name
, address
, load_address
, addralign
,
4394 // Release all Output_segments. This remove all pointers to all
4398 Script_sections::release_segments()
4400 if (this->saw_phdrs_clause())
4402 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4403 p
!= this->phdrs_elements_
->end();
4405 (*p
)->release_segment();
4409 // Print the SECTIONS clause to F for debugging.
4412 Script_sections::print(FILE* f
) const
4414 if (this->phdrs_elements_
!= NULL
)
4416 fprintf(f
, "PHDRS {\n");
4417 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4418 p
!= this->phdrs_elements_
->end();
4424 if (this->memory_regions_
!= NULL
)
4426 fprintf(f
, "MEMORY {\n");
4427 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
4428 m
!= this->memory_regions_
->end();
4434 if (!this->saw_sections_clause_
)
4437 fprintf(f
, "SECTIONS {\n");
4439 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4440 p
!= this->sections_elements_
->end();
4447 } // End namespace gold.