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.
340 // The information we keep for a specific place.
343 // The name of sections for this place.
345 // Whether we have a location for this place.
347 // The iterator for this place.
348 Elements_iterator location
;
351 // Initialize one place element.
353 initialize_place(Place_index
, const char*);
356 Place places_
[PLACE_MAX
];
357 // True if this is the first call to output_section_init.
361 // Initialize Orphan_section_placement.
363 Orphan_section_placement::Orphan_section_placement()
366 this->initialize_place(PLACE_TEXT
, ".text");
367 this->initialize_place(PLACE_RODATA
, ".rodata");
368 this->initialize_place(PLACE_DATA
, ".data");
369 this->initialize_place(PLACE_TLS
, NULL
);
370 this->initialize_place(PLACE_TLS_BSS
, NULL
);
371 this->initialize_place(PLACE_BSS
, ".bss");
372 this->initialize_place(PLACE_LAST_ALLOC
, NULL
);
373 this->initialize_place(PLACE_REL
, NULL
);
374 this->initialize_place(PLACE_INTERP
, ".interp");
375 this->initialize_place(PLACE_NONALLOC
, NULL
);
376 this->initialize_place(PLACE_LAST
, NULL
);
379 // Initialize one place element.
382 Orphan_section_placement::initialize_place(Place_index index
, const char* name
)
384 this->places_
[index
].name
= name
;
385 this->places_
[index
].have_location
= false;
388 // While initializing the Orphan_section_placement information, this
389 // is called once for each output section named in the linker script.
390 // If we found an output section during the link, it will be passed in
394 Orphan_section_placement::output_section_init(const std::string
& name
,
396 Elements_iterator location
)
398 bool first_init
= this->first_init_
;
399 this->first_init_
= false;
401 // Remember the last allocated section. Any orphan bss sections
402 // will be placed after it.
404 && (os
->flags() & elfcpp::SHF_ALLOC
) != 0)
406 this->places_
[PLACE_LAST_ALLOC
].location
= location
;
407 this->places_
[PLACE_LAST_ALLOC
].have_location
= true;
410 for (int i
= 0; i
< PLACE_MAX
; ++i
)
412 if (this->places_
[i
].name
!= NULL
&& this->places_
[i
].name
== name
)
414 if (this->places_
[i
].have_location
)
416 // We have already seen a section with this name.
420 this->places_
[i
].location
= location
;
421 this->places_
[i
].have_location
= true;
423 // If we just found the .bss section, restart the search for
424 // an unallocated section. This follows the GNU linker's
427 this->places_
[PLACE_NONALLOC
].have_location
= false;
433 // Relocation sections.
434 if (!this->places_
[PLACE_REL
].have_location
436 && (os
->type() == elfcpp::SHT_REL
|| os
->type() == elfcpp::SHT_RELA
)
437 && (os
->flags() & elfcpp::SHF_ALLOC
) != 0)
439 this->places_
[PLACE_REL
].location
= location
;
440 this->places_
[PLACE_REL
].have_location
= true;
443 // We find the location for unallocated sections by finding the
444 // first debugging or comment section after the BSS section (if
446 if (!this->places_
[PLACE_NONALLOC
].have_location
447 && (name
== ".comment" || Layout::is_debug_info_section(name
.c_str())))
449 // We add orphan sections after the location in PLACES_. We
450 // want to store unallocated sections before LOCATION. If this
451 // is the very first section, we can't use it.
455 this->places_
[PLACE_NONALLOC
].location
= location
;
456 this->places_
[PLACE_NONALLOC
].have_location
= true;
461 // Initialize the last location.
464 Orphan_section_placement::last_init(Elements_iterator location
)
466 this->places_
[PLACE_LAST
].location
= location
;
467 this->places_
[PLACE_LAST
].have_location
= true;
470 // Set *PWHERE to the address of an iterator pointing to the location
471 // to use for an orphan section. Return true if the iterator has a
472 // value, false otherwise.
475 Orphan_section_placement::find_place(Output_section
* os
,
476 Elements_iterator
** pwhere
)
478 // Figure out where OS should go. This is based on the GNU linker
479 // code. FIXME: The GNU linker handles small data sections
480 // specially, but we don't.
481 elfcpp::Elf_Word type
= os
->type();
482 elfcpp::Elf_Xword flags
= os
->flags();
484 if ((flags
& elfcpp::SHF_ALLOC
) == 0
485 && !Layout::is_debug_info_section(os
->name()))
486 index
= PLACE_NONALLOC
;
487 else if ((flags
& elfcpp::SHF_ALLOC
) == 0)
489 else if (type
== elfcpp::SHT_NOTE
)
490 index
= PLACE_INTERP
;
491 else if ((flags
& elfcpp::SHF_TLS
) != 0)
493 if (type
== elfcpp::SHT_NOBITS
)
494 index
= PLACE_TLS_BSS
;
498 else if (type
== elfcpp::SHT_NOBITS
)
500 else if ((flags
& elfcpp::SHF_WRITE
) != 0)
502 else if (type
== elfcpp::SHT_REL
|| type
== elfcpp::SHT_RELA
)
504 else if ((flags
& elfcpp::SHF_EXECINSTR
) == 0)
505 index
= PLACE_RODATA
;
509 // If we don't have a location yet, try to find one based on a
510 // plausible ordering of sections.
511 if (!this->places_
[index
].have_location
)
523 follow
= PLACE_LAST_ALLOC
;
536 if (!this->places_
[PLACE_TLS
].have_location
)
540 if (follow
!= PLACE_MAX
&& this->places_
[follow
].have_location
)
542 // Set the location of INDEX to the location of FOLLOW. The
543 // location of INDEX will then be incremented by the caller,
544 // so anything in INDEX will continue to be after anything
546 this->places_
[index
].location
= this->places_
[follow
].location
;
547 this->places_
[index
].have_location
= true;
551 *pwhere
= &this->places_
[index
].location
;
552 bool ret
= this->places_
[index
].have_location
;
554 // The caller will set the location.
555 this->places_
[index
].have_location
= true;
560 // Return the iterator being used for sections at the very end of the
563 Orphan_section_placement::Elements_iterator
564 Orphan_section_placement::last_place() const
566 gold_assert(this->places_
[PLACE_LAST
].have_location
);
567 return this->places_
[PLACE_LAST
].location
;
570 // An element in a SECTIONS clause.
572 class Sections_element
578 virtual ~Sections_element()
581 // Return whether an output section is relro.
586 // Record that an output section is relro.
591 // Create any required output sections. The only real
592 // implementation is in Output_section_definition.
594 create_sections(Layout
*)
597 // Add any symbol being defined to the symbol table.
599 add_symbols_to_table(Symbol_table
*)
602 // Finalize symbols and check assertions.
604 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*)
607 // Return the output section name to use for an input file name and
608 // section name. This only real implementation is in
609 // Output_section_definition.
611 output_section_name(const char*, const char*, Output_section
***,
612 Script_sections::Section_type
*, bool*)
615 // Initialize OSP with an output section.
617 orphan_section_init(Orphan_section_placement
*,
618 Script_sections::Elements_iterator
)
621 // Set section addresses. This includes applying assignments if the
622 // expression is an absolute value.
624 set_section_addresses(Symbol_table
*, Layout
*, uint64_t*, uint64_t*,
628 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
629 // this section is constrained, and the input sections do not match,
630 // return the constraint, and set *POSD.
631 virtual Section_constraint
632 check_constraint(Output_section_definition
**)
633 { return CONSTRAINT_NONE
; }
635 // See if this is the alternate output section for a constrained
636 // output section. If it is, transfer the Output_section and return
637 // true. Otherwise return false.
639 alternate_constraint(Output_section_definition
*, Section_constraint
)
642 // Get the list of segments to use for an allocated section when
643 // using a PHDRS clause. If this is an allocated section, return
644 // the Output_section, and set *PHDRS_LIST (the first parameter) to
645 // the list of PHDRS to which it should be attached. If the PHDRS
646 // were not specified, don't change *PHDRS_LIST. When not returning
647 // NULL, set *ORPHAN (the second parameter) according to whether
648 // this is an orphan section--one that is not mentioned in the
650 virtual Output_section
*
651 allocate_to_segment(String_list
**, bool*)
654 // Look for an output section by name and return the address, the
655 // load address, the alignment, and the size. This is used when an
656 // expression refers to an output section which was not actually
657 // created. This returns true if the section was found, false
658 // otherwise. The only real definition is for
659 // Output_section_definition.
661 get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
665 // Return the associated Output_section if there is one.
666 virtual Output_section
*
667 get_output_section() const
670 // Set the section's memory regions.
672 set_memory_region(Memory_region
*, bool)
673 { gold_error(_("Attempt to set a memory region for a non-output section")); }
675 // Print the element for debugging purposes.
677 print(FILE* f
) const = 0;
680 // An assignment in a SECTIONS clause outside of an output section.
682 class Sections_element_assignment
: public Sections_element
685 Sections_element_assignment(const char* name
, size_t namelen
,
686 Expression
* val
, bool provide
, bool hidden
)
687 : assignment_(name
, namelen
, false, val
, provide
, hidden
)
690 // Add the symbol to the symbol table.
692 add_symbols_to_table(Symbol_table
* symtab
)
693 { this->assignment_
.add_to_table(symtab
); }
695 // Finalize the symbol.
697 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
,
700 this->assignment_
.finalize_with_dot(symtab
, layout
, *dot_value
, NULL
);
703 // Set the section address. There is no section here, but if the
704 // value is absolute, we set the symbol. This permits us to use
705 // absolute symbols when setting dot.
707 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
,
708 uint64_t* dot_value
, uint64_t*, uint64_t*)
710 this->assignment_
.set_if_absolute(symtab
, layout
, true, *dot_value
, NULL
);
713 // Print for debugging.
718 this->assignment_
.print(f
);
722 Symbol_assignment assignment_
;
725 // An assignment to the dot symbol in a SECTIONS clause outside of an
728 class Sections_element_dot_assignment
: public Sections_element
731 Sections_element_dot_assignment(Expression
* val
)
735 // Finalize the symbol.
737 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
,
740 // We ignore the section of the result because outside of an
741 // output section definition the dot symbol is always considered
743 *dot_value
= this->val_
->eval_with_dot(symtab
, layout
, true, *dot_value
,
744 NULL
, NULL
, NULL
, false);
747 // Update the dot symbol while setting section addresses.
749 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
,
750 uint64_t* dot_value
, uint64_t* dot_alignment
,
751 uint64_t* load_address
)
753 *dot_value
= this->val_
->eval_with_dot(symtab
, layout
, false, *dot_value
,
754 NULL
, NULL
, dot_alignment
, false);
755 *load_address
= *dot_value
;
758 // Print for debugging.
763 this->val_
->print(f
);
771 // An assertion in a SECTIONS clause outside of an output section.
773 class Sections_element_assertion
: public Sections_element
776 Sections_element_assertion(Expression
* check
, const char* message
,
778 : assertion_(check
, message
, messagelen
)
781 // Check the assertion.
783 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
, uint64_t*)
784 { this->assertion_
.check(symtab
, layout
); }
786 // Print for debugging.
791 this->assertion_
.print(f
);
795 Script_assertion assertion_
;
798 // An element in an output section in a SECTIONS clause.
800 class Output_section_element
803 // A list of input sections.
804 typedef std::list
<Output_section::Input_section
> Input_section_list
;
806 Output_section_element()
809 virtual ~Output_section_element()
812 // Return whether this element requires an output section to exist.
814 needs_output_section() const
817 // Add any symbol being defined to the symbol table.
819 add_symbols_to_table(Symbol_table
*)
822 // Finalize symbols and check assertions.
824 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*, Output_section
**)
827 // Return whether this element matches FILE_NAME and SECTION_NAME.
828 // The only real implementation is in Output_section_element_input.
830 match_name(const char*, const char*, bool *) const
833 // Set section addresses. This includes applying assignments if the
834 // expression is an absolute value.
836 set_section_addresses(Symbol_table
*, Layout
*, Output_section
*, uint64_t,
837 uint64_t*, uint64_t*, Output_section
**, std::string
*,
841 // Print the element for debugging purposes.
843 print(FILE* f
) const = 0;
846 // Return a fill string that is LENGTH bytes long, filling it with
849 get_fill_string(const std::string
* fill
, section_size_type length
) const;
853 Output_section_element::get_fill_string(const std::string
* fill
,
854 section_size_type length
) const
856 std::string this_fill
;
857 this_fill
.reserve(length
);
858 while (this_fill
.length() + fill
->length() <= length
)
860 if (this_fill
.length() < length
)
861 this_fill
.append(*fill
, 0, length
- this_fill
.length());
865 // A symbol assignment in an output section.
867 class Output_section_element_assignment
: public Output_section_element
870 Output_section_element_assignment(const char* name
, size_t namelen
,
871 Expression
* val
, bool provide
,
873 : assignment_(name
, namelen
, false, val
, provide
, hidden
)
876 // Add the symbol to the symbol table.
878 add_symbols_to_table(Symbol_table
* symtab
)
879 { this->assignment_
.add_to_table(symtab
); }
881 // Finalize the symbol.
883 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
,
884 uint64_t* dot_value
, Output_section
** dot_section
)
886 this->assignment_
.finalize_with_dot(symtab
, layout
, *dot_value
,
890 // Set the section address. There is no section here, but if the
891 // value is absolute, we set the symbol. This permits us to use
892 // absolute symbols when setting dot.
894 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
, Output_section
*,
895 uint64_t, uint64_t* dot_value
, uint64_t*,
896 Output_section
** dot_section
, std::string
*,
899 this->assignment_
.set_if_absolute(symtab
, layout
, true, *dot_value
,
903 // Print for debugging.
908 this->assignment_
.print(f
);
912 Symbol_assignment assignment_
;
915 // An assignment to the dot symbol in an output section.
917 class Output_section_element_dot_assignment
: public Output_section_element
920 Output_section_element_dot_assignment(Expression
* val
)
924 // An assignment to dot within an output section is enough to force
925 // the output section to exist.
927 needs_output_section() const
930 // Finalize the symbol.
932 finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
,
933 uint64_t* dot_value
, Output_section
** dot_section
)
935 *dot_value
= this->val_
->eval_with_dot(symtab
, layout
, true, *dot_value
,
936 *dot_section
, dot_section
, NULL
,
940 // Update the dot symbol while setting section addresses.
942 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
, Output_section
*,
943 uint64_t, uint64_t* dot_value
, uint64_t*,
944 Output_section
** dot_section
, std::string
*,
945 Input_section_list
*);
947 // Print for debugging.
952 this->val_
->print(f
);
960 // Update the dot symbol while setting section addresses.
963 Output_section_element_dot_assignment::set_section_addresses(
964 Symbol_table
* symtab
,
966 Output_section
* output_section
,
969 uint64_t* dot_alignment
,
970 Output_section
** dot_section
,
974 uint64_t next_dot
= this->val_
->eval_with_dot(symtab
, layout
, false,
975 *dot_value
, *dot_section
,
976 dot_section
, dot_alignment
,
978 if (next_dot
< *dot_value
)
979 gold_error(_("dot may not move backward"));
980 if (next_dot
> *dot_value
&& output_section
!= NULL
)
982 section_size_type length
= convert_to_section_size_type(next_dot
984 Output_section_data
* posd
;
986 posd
= new Output_data_zero_fill(length
, 0);
989 std::string this_fill
= this->get_fill_string(fill
, length
);
990 posd
= new Output_data_const(this_fill
, 0);
992 output_section
->add_output_section_data(posd
);
993 layout
->new_output_section_data_from_script(posd
);
995 *dot_value
= next_dot
;
998 // An assertion in an output section.
1000 class Output_section_element_assertion
: public Output_section_element
1003 Output_section_element_assertion(Expression
* check
, const char* message
,
1005 : assertion_(check
, message
, messagelen
)
1009 print(FILE* f
) const
1012 this->assertion_
.print(f
);
1016 Script_assertion assertion_
;
1019 // We use a special instance of Output_section_data to handle BYTE,
1020 // SHORT, etc. This permits forward references to symbols in the
1023 class Output_data_expression
: public Output_section_data
1026 Output_data_expression(int size
, bool is_signed
, Expression
* val
,
1027 const Symbol_table
* symtab
, const Layout
* layout
,
1028 uint64_t dot_value
, Output_section
* dot_section
)
1029 : Output_section_data(size
, 0, true),
1030 is_signed_(is_signed
), val_(val
), symtab_(symtab
),
1031 layout_(layout
), dot_value_(dot_value
), dot_section_(dot_section
)
1035 // Write the data to the output file.
1037 do_write(Output_file
*);
1039 // Write the data to a buffer.
1041 do_write_to_buffer(unsigned char*);
1043 // Write to a map file.
1045 do_print_to_mapfile(Mapfile
* mapfile
) const
1046 { mapfile
->print_output_data(this, _("** expression")); }
1049 template<bool big_endian
>
1051 endian_write_to_buffer(uint64_t, unsigned char*);
1055 const Symbol_table
* symtab_
;
1056 const Layout
* layout_
;
1057 uint64_t dot_value_
;
1058 Output_section
* dot_section_
;
1061 // Write the data element to the output file.
1064 Output_data_expression::do_write(Output_file
* of
)
1066 unsigned char* view
= of
->get_output_view(this->offset(), this->data_size());
1067 this->write_to_buffer(view
);
1068 of
->write_output_view(this->offset(), this->data_size(), view
);
1071 // Write the data element to a buffer.
1074 Output_data_expression::do_write_to_buffer(unsigned char* buf
)
1076 uint64_t val
= this->val_
->eval_with_dot(this->symtab_
, this->layout_
,
1077 true, this->dot_value_
,
1078 this->dot_section_
, NULL
, NULL
,
1081 if (parameters
->target().is_big_endian())
1082 this->endian_write_to_buffer
<true>(val
, buf
);
1084 this->endian_write_to_buffer
<false>(val
, buf
);
1087 template<bool big_endian
>
1089 Output_data_expression::endian_write_to_buffer(uint64_t val
,
1092 switch (this->data_size())
1095 elfcpp::Swap_unaligned
<8, big_endian
>::writeval(buf
, val
);
1098 elfcpp::Swap_unaligned
<16, big_endian
>::writeval(buf
, val
);
1101 elfcpp::Swap_unaligned
<32, big_endian
>::writeval(buf
, val
);
1104 if (parameters
->target().get_size() == 32)
1107 if (this->is_signed_
&& (val
& 0x80000000) != 0)
1108 val
|= 0xffffffff00000000LL
;
1110 elfcpp::Swap_unaligned
<64, big_endian
>::writeval(buf
, val
);
1117 // A data item in an output section.
1119 class Output_section_element_data
: public Output_section_element
1122 Output_section_element_data(int size
, bool is_signed
, Expression
* val
)
1123 : size_(size
), is_signed_(is_signed
), val_(val
)
1126 // If there is a data item, then we must create an output section.
1128 needs_output_section() const
1131 // Finalize symbols--we just need to update dot.
1133 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t* dot_value
,
1135 { *dot_value
+= this->size_
; }
1137 // Store the value in the section.
1139 set_section_addresses(Symbol_table
*, Layout
*, Output_section
*, uint64_t,
1140 uint64_t* dot_value
, uint64_t*, Output_section
**,
1141 std::string
*, Input_section_list
*);
1143 // Print for debugging.
1148 // The size in bytes.
1150 // Whether the value is signed.
1156 // Store the value in the section.
1159 Output_section_element_data::set_section_addresses(
1160 Symbol_table
* symtab
,
1164 uint64_t* dot_value
,
1166 Output_section
** dot_section
,
1168 Input_section_list
*)
1170 gold_assert(os
!= NULL
);
1171 Output_data_expression
* expression
=
1172 new Output_data_expression(this->size_
, this->is_signed_
, this->val_
,
1173 symtab
, layout
, *dot_value
, *dot_section
);
1174 os
->add_output_section_data(expression
);
1175 layout
->new_output_section_data_from_script(expression
);
1176 *dot_value
+= this->size_
;
1179 // Print for debugging.
1182 Output_section_element_data::print(FILE* f
) const
1185 switch (this->size_
)
1197 if (this->is_signed_
)
1205 fprintf(f
, " %s(", s
);
1206 this->val_
->print(f
);
1210 // A fill value setting in an output section.
1212 class Output_section_element_fill
: public Output_section_element
1215 Output_section_element_fill(Expression
* val
)
1219 // Update the fill value while setting section addresses.
1221 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
, Output_section
*,
1222 uint64_t, uint64_t* dot_value
, uint64_t*,
1223 Output_section
** dot_section
,
1224 std::string
* fill
, Input_section_list
*)
1226 Output_section
* fill_section
;
1227 uint64_t fill_val
= this->val_
->eval_with_dot(symtab
, layout
, false,
1228 *dot_value
, *dot_section
,
1229 &fill_section
, NULL
, false);
1230 if (fill_section
!= NULL
)
1231 gold_warning(_("fill value is not absolute"));
1232 // FIXME: The GNU linker supports fill values of arbitrary length.
1233 unsigned char fill_buff
[4];
1234 elfcpp::Swap_unaligned
<32, true>::writeval(fill_buff
, fill_val
);
1235 fill
->assign(reinterpret_cast<char*>(fill_buff
), 4);
1238 // Print for debugging.
1240 print(FILE* f
) const
1242 fprintf(f
, " FILL(");
1243 this->val_
->print(f
);
1248 // The new fill value.
1252 // An input section specification in an output section
1254 class Output_section_element_input
: public Output_section_element
1257 Output_section_element_input(const Input_section_spec
* spec
, bool keep
);
1259 // Finalize symbols--just update the value of the dot symbol.
1261 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t* dot_value
,
1262 Output_section
** dot_section
)
1264 *dot_value
= this->final_dot_value_
;
1265 *dot_section
= this->final_dot_section_
;
1268 // See whether we match FILE_NAME and SECTION_NAME as an input section.
1269 // If we do then also indicate whether the section should be KEPT.
1271 match_name(const char* file_name
, const char* section_name
, bool* keep
) const;
1273 // Set the section address.
1275 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
, Output_section
*,
1276 uint64_t subalign
, uint64_t* dot_value
, uint64_t*,
1277 Output_section
**, std::string
* fill
,
1278 Input_section_list
*);
1280 // Print for debugging.
1282 print(FILE* f
) const;
1285 // An input section pattern.
1286 struct Input_section_pattern
1288 std::string pattern
;
1289 bool pattern_is_wildcard
;
1292 Input_section_pattern(const char* patterna
, size_t patternlena
,
1293 Sort_wildcard sorta
)
1294 : pattern(patterna
, patternlena
),
1295 pattern_is_wildcard(is_wildcard_string(this->pattern
.c_str())),
1300 typedef std::vector
<Input_section_pattern
> Input_section_patterns
;
1302 // Filename_exclusions is a pair of filename pattern and a bool
1303 // indicating whether the filename is a wildcard.
1304 typedef std::vector
<std::pair
<std::string
, bool> > Filename_exclusions
;
1306 // Return whether STRING matches PATTERN, where IS_WILDCARD_PATTERN
1307 // indicates whether this is a wildcard pattern.
1309 match(const char* string
, const char* pattern
, bool is_wildcard_pattern
)
1311 return (is_wildcard_pattern
1312 ? fnmatch(pattern
, string
, 0) == 0
1313 : strcmp(string
, pattern
) == 0);
1316 // See if we match a file name.
1318 match_file_name(const char* file_name
) const;
1320 // The file name pattern. If this is the empty string, we match all
1322 std::string filename_pattern_
;
1323 // Whether the file name pattern is a wildcard.
1324 bool filename_is_wildcard_
;
1325 // How the file names should be sorted. This may only be
1326 // SORT_WILDCARD_NONE or SORT_WILDCARD_BY_NAME.
1327 Sort_wildcard filename_sort_
;
1328 // The list of file names to exclude.
1329 Filename_exclusions filename_exclusions_
;
1330 // The list of input section patterns.
1331 Input_section_patterns input_section_patterns_
;
1332 // Whether to keep this section when garbage collecting.
1334 // The value of dot after including all matching sections.
1335 uint64_t final_dot_value_
;
1336 // The section where dot is defined after including all matching
1338 Output_section
* final_dot_section_
;
1341 // Construct Output_section_element_input. The parser records strings
1342 // as pointers into a copy of the script file, which will go away when
1343 // parsing is complete. We make sure they are in std::string objects.
1345 Output_section_element_input::Output_section_element_input(
1346 const Input_section_spec
* spec
,
1348 : filename_pattern_(),
1349 filename_is_wildcard_(false),
1350 filename_sort_(spec
->file
.sort
),
1351 filename_exclusions_(),
1352 input_section_patterns_(),
1354 final_dot_value_(0),
1355 final_dot_section_(NULL
)
1357 // The filename pattern "*" is common, and matches all files. Turn
1358 // it into the empty string.
1359 if (spec
->file
.name
.length
!= 1 || spec
->file
.name
.value
[0] != '*')
1360 this->filename_pattern_
.assign(spec
->file
.name
.value
,
1361 spec
->file
.name
.length
);
1362 this->filename_is_wildcard_
= is_wildcard_string(this->filename_pattern_
.c_str());
1364 if (spec
->input_sections
.exclude
!= NULL
)
1366 for (String_list::const_iterator p
=
1367 spec
->input_sections
.exclude
->begin();
1368 p
!= spec
->input_sections
.exclude
->end();
1371 bool is_wildcard
= is_wildcard_string((*p
).c_str());
1372 this->filename_exclusions_
.push_back(std::make_pair(*p
,
1377 if (spec
->input_sections
.sections
!= NULL
)
1379 Input_section_patterns
& isp(this->input_section_patterns_
);
1380 for (String_sort_list::const_iterator p
=
1381 spec
->input_sections
.sections
->begin();
1382 p
!= spec
->input_sections
.sections
->end();
1384 isp
.push_back(Input_section_pattern(p
->name
.value
, p
->name
.length
,
1389 // See whether we match FILE_NAME.
1392 Output_section_element_input::match_file_name(const char* file_name
) const
1394 if (!this->filename_pattern_
.empty())
1396 // If we were called with no filename, we refuse to match a
1397 // pattern which requires a file name.
1398 if (file_name
== NULL
)
1401 if (!match(file_name
, this->filename_pattern_
.c_str(),
1402 this->filename_is_wildcard_
))
1406 if (file_name
!= NULL
)
1408 // Now we have to see whether FILE_NAME matches one of the
1409 // exclusion patterns, if any.
1410 for (Filename_exclusions::const_iterator p
=
1411 this->filename_exclusions_
.begin();
1412 p
!= this->filename_exclusions_
.end();
1415 if (match(file_name
, p
->first
.c_str(), p
->second
))
1423 // See whether we match FILE_NAME and SECTION_NAME. If we do then
1424 // KEEP indicates whether the section should survive garbage collection.
1427 Output_section_element_input::match_name(const char* file_name
,
1428 const char* section_name
,
1431 if (!this->match_file_name(file_name
))
1434 *keep
= this->keep_
;
1436 // If there are no section name patterns, then we match.
1437 if (this->input_section_patterns_
.empty())
1440 // See whether we match the section name patterns.
1441 for (Input_section_patterns::const_iterator p
=
1442 this->input_section_patterns_
.begin();
1443 p
!= this->input_section_patterns_
.end();
1446 if (match(section_name
, p
->pattern
.c_str(), p
->pattern_is_wildcard
))
1450 // We didn't match any section names, so we didn't match.
1454 // Information we use to sort the input sections.
1456 class Input_section_info
1459 Input_section_info(const Output_section::Input_section
& input_section
)
1460 : input_section_(input_section
), section_name_(),
1461 size_(0), addralign_(1)
1464 // Return the simple input section.
1465 const Output_section::Input_section
&
1466 input_section() const
1467 { return this->input_section_
; }
1469 // Return the object.
1472 { return this->input_section_
.relobj(); }
1474 // Return the section index.
1477 { return this->input_section_
.shndx(); }
1479 // Return the section name.
1481 section_name() const
1482 { return this->section_name_
; }
1484 // Set the section name.
1486 set_section_name(const std::string name
)
1488 if (is_compressed_debug_section(name
.c_str()))
1489 this->section_name_
= corresponding_uncompressed_section_name(name
);
1491 this->section_name_
= name
;
1494 // Return the section size.
1497 { return this->size_
; }
1499 // Set the section size.
1501 set_size(uint64_t size
)
1502 { this->size_
= size
; }
1504 // Return the address alignment.
1507 { return this->addralign_
; }
1509 // Set the address alignment.
1511 set_addralign(uint64_t addralign
)
1512 { this->addralign_
= addralign
; }
1515 // Input section, can be a relaxed section.
1516 Output_section::Input_section input_section_
;
1517 // Name of the section.
1518 std::string section_name_
;
1521 // Address alignment.
1522 uint64_t addralign_
;
1525 // A class to sort the input sections.
1527 class Input_section_sorter
1530 Input_section_sorter(Sort_wildcard filename_sort
, Sort_wildcard section_sort
)
1531 : filename_sort_(filename_sort
), section_sort_(section_sort
)
1535 operator()(const Input_section_info
&, const Input_section_info
&) const;
1538 static unsigned long
1539 get_init_priority(const char*);
1541 Sort_wildcard filename_sort_
;
1542 Sort_wildcard section_sort_
;
1545 // Return a relative priority of the section with the specified NAME
1546 // (a lower value meand a higher priority), or 0 if it should be compared
1547 // with others as strings.
1548 // The implementation of this function is copied from ld/ldlang.c.
1551 Input_section_sorter::get_init_priority(const char* name
)
1554 unsigned long init_priority
;
1556 // GCC uses the following section names for the init_priority
1557 // attribute with numerical values 101 and 65535 inclusive. A
1558 // lower value means a higher priority.
1560 // 1: .init_array.NNNN/.fini_array.NNNN: Where NNNN is the
1561 // decimal numerical value of the init_priority attribute.
1562 // The order of execution in .init_array is forward and
1563 // .fini_array is backward.
1564 // 2: .ctors.NNNN/.dtors.NNNN: Where NNNN is 65535 minus the
1565 // decimal numerical value of the init_priority attribute.
1566 // The order of execution in .ctors is backward and .dtors
1569 if (strncmp(name
, ".init_array.", 12) == 0
1570 || strncmp(name
, ".fini_array.", 12) == 0)
1572 init_priority
= strtoul(name
+ 12, &end
, 10);
1573 return *end
? 0 : init_priority
;
1575 else if (strncmp(name
, ".ctors.", 7) == 0
1576 || strncmp(name
, ".dtors.", 7) == 0)
1578 init_priority
= strtoul(name
+ 7, &end
, 10);
1579 return *end
? 0 : 65535 - init_priority
;
1586 Input_section_sorter::operator()(const Input_section_info
& isi1
,
1587 const Input_section_info
& isi2
) const
1589 if (this->section_sort_
== SORT_WILDCARD_BY_INIT_PRIORITY
)
1591 unsigned long ip1
= get_init_priority(isi1
.section_name().c_str());
1592 unsigned long ip2
= get_init_priority(isi2
.section_name().c_str());
1593 if (ip1
!= 0 && ip2
!= 0 && ip1
!= ip2
)
1596 if (this->section_sort_
== SORT_WILDCARD_BY_NAME
1597 || this->section_sort_
== SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1598 || (this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
1599 && isi1
.addralign() == isi2
.addralign())
1600 || this->section_sort_
== SORT_WILDCARD_BY_INIT_PRIORITY
)
1602 if (isi1
.section_name() != isi2
.section_name())
1603 return isi1
.section_name() < isi2
.section_name();
1605 if (this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT
1606 || this->section_sort_
== SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1607 || this->section_sort_
== SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
)
1609 if (isi1
.addralign() != isi2
.addralign())
1610 return isi1
.addralign() < isi2
.addralign();
1612 if (this->filename_sort_
== SORT_WILDCARD_BY_NAME
)
1614 if (isi1
.relobj()->name() != isi2
.relobj()->name())
1615 return (isi1
.relobj()->name() < isi2
.relobj()->name());
1618 // Otherwise we leave them in the same order.
1622 // Set the section address. Look in INPUT_SECTIONS for sections which
1623 // match this spec, sort them as specified, and add them to the output
1627 Output_section_element_input::set_section_addresses(
1630 Output_section
* output_section
,
1632 uint64_t* dot_value
,
1634 Output_section
** dot_section
,
1636 Input_section_list
* input_sections
)
1638 // We build a list of sections which match each
1639 // Input_section_pattern.
1641 // If none of the patterns specify a sort option, we throw all
1642 // matching input sections into a single bin, in the order we
1643 // find them. Otherwise, we put matching input sections into
1644 // a separate bin for each pattern, and sort each one as
1645 // specified. Thus, an input section spec like this:
1647 // will group all .foo and .bar sections in the order seen,
1650 // will group all .foo sections followed by all .bar sections.
1651 // This matches Gnu ld behavior.
1653 // Things get really weird, though, when you add a sort spec
1654 // on some, but not all, of the patterns, like this:
1655 // *(SORT_BY_NAME(.foo) .bar)
1656 // We do not attempt to match Gnu ld behavior in this case.
1658 typedef std::vector
<std::vector
<Input_section_info
> > Matching_sections
;
1659 size_t input_pattern_count
= this->input_section_patterns_
.size();
1660 size_t bin_count
= 1;
1661 bool any_patterns_with_sort
= false;
1662 for (size_t i
= 0; i
< input_pattern_count
; ++i
)
1664 const Input_section_pattern
& isp(this->input_section_patterns_
[i
]);
1665 if (isp
.sort
!= SORT_WILDCARD_NONE
)
1666 any_patterns_with_sort
= true;
1668 if (any_patterns_with_sort
)
1669 bin_count
= input_pattern_count
;
1670 Matching_sections
matching_sections(bin_count
);
1672 // Look through the list of sections for this output section. Add
1673 // each one which matches to one of the elements of
1674 // MATCHING_SECTIONS.
1676 Input_section_list::iterator p
= input_sections
->begin();
1677 while (p
!= input_sections
->end())
1679 Relobj
* relobj
= p
->relobj();
1680 unsigned int shndx
= p
->shndx();
1681 Input_section_info
isi(*p
);
1683 // Calling section_name and section_addralign is not very
1686 // Lock the object so that we can get information about the
1687 // section. This is OK since we know we are single-threaded
1690 const Task
* task
= reinterpret_cast<const Task
*>(-1);
1691 Task_lock_obj
<Object
> tl(task
, relobj
);
1693 isi
.set_section_name(relobj
->section_name(shndx
));
1694 if (p
->is_relaxed_input_section())
1696 // We use current data size because relaxed section sizes may not
1697 // have finalized yet.
1698 isi
.set_size(p
->relaxed_input_section()->current_data_size());
1699 isi
.set_addralign(p
->relaxed_input_section()->addralign());
1703 isi
.set_size(relobj
->section_size(shndx
));
1704 isi
.set_addralign(relobj
->section_addralign(shndx
));
1708 if (!this->match_file_name(relobj
->name().c_str()))
1710 else if (this->input_section_patterns_
.empty())
1712 matching_sections
[0].push_back(isi
);
1713 p
= input_sections
->erase(p
);
1718 for (i
= 0; i
< input_pattern_count
; ++i
)
1720 const Input_section_pattern
&
1721 isp(this->input_section_patterns_
[i
]);
1722 if (match(isi
.section_name().c_str(), isp
.pattern
.c_str(),
1723 isp
.pattern_is_wildcard
))
1727 if (i
>= input_pattern_count
)
1733 matching_sections
[i
].push_back(isi
);
1734 p
= input_sections
->erase(p
);
1739 // Look through MATCHING_SECTIONS. Sort each one as specified,
1740 // using a stable sort so that we get the default order when
1741 // sections are otherwise equal. Add each input section to the
1744 uint64_t dot
= *dot_value
;
1745 for (size_t i
= 0; i
< bin_count
; ++i
)
1747 if (matching_sections
[i
].empty())
1750 gold_assert(output_section
!= NULL
);
1752 const Input_section_pattern
& isp(this->input_section_patterns_
[i
]);
1753 if (isp
.sort
!= SORT_WILDCARD_NONE
1754 || this->filename_sort_
!= SORT_WILDCARD_NONE
)
1755 std::stable_sort(matching_sections
[i
].begin(),
1756 matching_sections
[i
].end(),
1757 Input_section_sorter(this->filename_sort_
,
1760 for (std::vector
<Input_section_info
>::const_iterator p
=
1761 matching_sections
[i
].begin();
1762 p
!= matching_sections
[i
].end();
1765 // Override the original address alignment if SUBALIGN is specified.
1766 // We need to make a copy of the input section to modify the
1768 Output_section::Input_section
sis(p
->input_section());
1770 uint64_t this_subalign
= sis
.addralign();
1771 if (!sis
.is_input_section())
1772 sis
.output_section_data()->finalize_data_size();
1773 uint64_t data_size
= sis
.data_size();
1776 this_subalign
= subalign
;
1777 sis
.set_addralign(subalign
);
1780 uint64_t address
= align_address(dot
, this_subalign
);
1782 if (address
> dot
&& !fill
->empty())
1784 section_size_type length
=
1785 convert_to_section_size_type(address
- dot
);
1786 std::string this_fill
= this->get_fill_string(fill
, length
);
1787 Output_section_data
* posd
= new Output_data_const(this_fill
, 0);
1788 output_section
->add_output_section_data(posd
);
1789 layout
->new_output_section_data_from_script(posd
);
1792 output_section
->add_script_input_section(sis
);
1793 dot
= address
+ data_size
;
1797 // An SHF_TLS/SHT_NOBITS section does not take up any
1799 if (output_section
== NULL
1800 || (output_section
->flags() & elfcpp::SHF_TLS
) == 0
1801 || output_section
->type() != elfcpp::SHT_NOBITS
)
1804 this->final_dot_value_
= *dot_value
;
1805 this->final_dot_section_
= *dot_section
;
1808 // Print for debugging.
1811 Output_section_element_input::print(FILE* f
) const
1816 fprintf(f
, "KEEP(");
1818 if (!this->filename_pattern_
.empty())
1820 bool need_close_paren
= false;
1821 switch (this->filename_sort_
)
1823 case SORT_WILDCARD_NONE
:
1825 case SORT_WILDCARD_BY_NAME
:
1826 fprintf(f
, "SORT_BY_NAME(");
1827 need_close_paren
= true;
1833 fprintf(f
, "%s", this->filename_pattern_
.c_str());
1835 if (need_close_paren
)
1839 if (!this->input_section_patterns_
.empty()
1840 || !this->filename_exclusions_
.empty())
1844 bool need_space
= false;
1845 if (!this->filename_exclusions_
.empty())
1847 fprintf(f
, "EXCLUDE_FILE(");
1848 bool need_comma
= false;
1849 for (Filename_exclusions::const_iterator p
=
1850 this->filename_exclusions_
.begin();
1851 p
!= this->filename_exclusions_
.end();
1856 fprintf(f
, "%s", p
->first
.c_str());
1863 for (Input_section_patterns::const_iterator p
=
1864 this->input_section_patterns_
.begin();
1865 p
!= this->input_section_patterns_
.end();
1871 int close_parens
= 0;
1874 case SORT_WILDCARD_NONE
:
1876 case SORT_WILDCARD_BY_NAME
:
1877 fprintf(f
, "SORT_BY_NAME(");
1880 case SORT_WILDCARD_BY_ALIGNMENT
:
1881 fprintf(f
, "SORT_BY_ALIGNMENT(");
1884 case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
:
1885 fprintf(f
, "SORT_BY_NAME(SORT_BY_ALIGNMENT(");
1888 case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
:
1889 fprintf(f
, "SORT_BY_ALIGNMENT(SORT_BY_NAME(");
1892 case SORT_WILDCARD_BY_INIT_PRIORITY
:
1893 fprintf(f
, "SORT_BY_INIT_PRIORITY(");
1900 fprintf(f
, "%s", p
->pattern
.c_str());
1902 for (int i
= 0; i
< close_parens
; ++i
)
1917 // An output section.
1919 class Output_section_definition
: public Sections_element
1922 typedef Output_section_element::Input_section_list Input_section_list
;
1924 Output_section_definition(const char* name
, size_t namelen
,
1925 const Parser_output_section_header
* header
);
1927 // Finish the output section with the information in the trailer.
1929 finish(const Parser_output_section_trailer
* trailer
);
1931 // Add a symbol to be defined.
1933 add_symbol_assignment(const char* name
, size_t length
, Expression
* value
,
1934 bool provide
, bool hidden
);
1936 // Add an assignment to the special dot symbol.
1938 add_dot_assignment(Expression
* value
);
1940 // Add an assertion.
1942 add_assertion(Expression
* check
, const char* message
, size_t messagelen
);
1944 // Add a data item to the current output section.
1946 add_data(int size
, bool is_signed
, Expression
* val
);
1948 // Add a setting for the fill value.
1950 add_fill(Expression
* val
);
1952 // Add an input section specification.
1954 add_input_section(const Input_section_spec
* spec
, bool keep
);
1956 // Return whether the output section is relro.
1959 { return this->is_relro_
; }
1961 // Record that the output section is relro.
1964 { this->is_relro_
= true; }
1966 // Create any required output sections.
1968 create_sections(Layout
*);
1970 // Add any symbols being defined to the symbol table.
1972 add_symbols_to_table(Symbol_table
* symtab
);
1974 // Finalize symbols and check assertions.
1976 finalize_symbols(Symbol_table
*, const Layout
*, uint64_t*);
1978 // Return the output section name to use for an input file name and
1981 output_section_name(const char* file_name
, const char* section_name
,
1982 Output_section
***, Script_sections::Section_type
*,
1985 // Initialize OSP with an output section.
1987 orphan_section_init(Orphan_section_placement
* osp
,
1988 Script_sections::Elements_iterator p
)
1989 { osp
->output_section_init(this->name_
, this->output_section_
, p
); }
1991 // Set the section address.
1993 set_section_addresses(Symbol_table
* symtab
, Layout
* layout
,
1994 uint64_t* dot_value
, uint64_t*,
1995 uint64_t* load_address
);
1997 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
1998 // this section is constrained, and the input sections do not match,
1999 // return the constraint, and set *POSD.
2001 check_constraint(Output_section_definition
** posd
);
2003 // See if this is the alternate output section for a constrained
2004 // output section. If it is, transfer the Output_section and return
2005 // true. Otherwise return false.
2007 alternate_constraint(Output_section_definition
*, Section_constraint
);
2009 // Get the list of segments to use for an allocated section when
2010 // using a PHDRS clause.
2012 allocate_to_segment(String_list
** phdrs_list
, bool* orphan
);
2014 // Look for an output section by name and return the address, the
2015 // load address, the alignment, and the size. This is used when an
2016 // expression refers to an output section which was not actually
2017 // created. This returns true if the section was found, false
2020 get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
2023 // Return the associated Output_section if there is one.
2025 get_output_section() const
2026 { return this->output_section_
; }
2028 // Print the contents to the FILE. This is for debugging.
2032 // Return the output section type if specified or Script_sections::ST_NONE.
2033 Script_sections::Section_type
2034 section_type() const;
2036 // Store the memory region to use.
2038 set_memory_region(Memory_region
*, bool set_vma
);
2041 set_section_vma(Expression
* address
)
2042 { this->address_
= address
; }
2045 set_section_lma(Expression
* address
)
2046 { this->load_address_
= address
; }
2049 get_section_name() const
2050 { return this->name_
; }
2054 script_section_type_name(Script_section_type
);
2056 typedef std::vector
<Output_section_element
*> Output_section_elements
;
2058 // The output section name.
2060 // The address. This may be NULL.
2061 Expression
* address_
;
2062 // The load address. This may be NULL.
2063 Expression
* load_address_
;
2064 // The alignment. This may be NULL.
2066 // The input section alignment. This may be NULL.
2067 Expression
* subalign_
;
2068 // The constraint, if any.
2069 Section_constraint constraint_
;
2070 // The fill value. This may be NULL.
2072 // The list of segments this section should go into. This may be
2074 String_list
* phdrs_
;
2075 // The list of elements defining the section.
2076 Output_section_elements elements_
;
2077 // The Output_section created for this definition. This will be
2078 // NULL if none was created.
2079 Output_section
* output_section_
;
2080 // The address after it has been evaluated.
2081 uint64_t evaluated_address_
;
2082 // The load address after it has been evaluated.
2083 uint64_t evaluated_load_address_
;
2084 // The alignment after it has been evaluated.
2085 uint64_t evaluated_addralign_
;
2086 // The output section is relro.
2088 // The output section type if specified.
2089 enum Script_section_type script_section_type_
;
2094 Output_section_definition::Output_section_definition(
2097 const Parser_output_section_header
* header
)
2098 : name_(name
, namelen
),
2099 address_(header
->address
),
2100 load_address_(header
->load_address
),
2101 align_(header
->align
),
2102 subalign_(header
->subalign
),
2103 constraint_(header
->constraint
),
2107 output_section_(NULL
),
2108 evaluated_address_(0),
2109 evaluated_load_address_(0),
2110 evaluated_addralign_(0),
2112 script_section_type_(header
->section_type
)
2116 // Finish an output section.
2119 Output_section_definition::finish(const Parser_output_section_trailer
* trailer
)
2121 this->fill_
= trailer
->fill
;
2122 this->phdrs_
= trailer
->phdrs
;
2125 // Add a symbol to be defined.
2128 Output_section_definition::add_symbol_assignment(const char* name
,
2134 Output_section_element
* p
= new Output_section_element_assignment(name
,
2139 this->elements_
.push_back(p
);
2142 // Add an assignment to the special dot symbol.
2145 Output_section_definition::add_dot_assignment(Expression
* value
)
2147 Output_section_element
* p
= new Output_section_element_dot_assignment(value
);
2148 this->elements_
.push_back(p
);
2151 // Add an assertion.
2154 Output_section_definition::add_assertion(Expression
* check
,
2155 const char* message
,
2158 Output_section_element
* p
= new Output_section_element_assertion(check
,
2161 this->elements_
.push_back(p
);
2164 // Add a data item to the current output section.
2167 Output_section_definition::add_data(int size
, bool is_signed
, Expression
* val
)
2169 Output_section_element
* p
= new Output_section_element_data(size
, is_signed
,
2171 this->elements_
.push_back(p
);
2174 // Add a setting for the fill value.
2177 Output_section_definition::add_fill(Expression
* val
)
2179 Output_section_element
* p
= new Output_section_element_fill(val
);
2180 this->elements_
.push_back(p
);
2183 // Add an input section specification.
2186 Output_section_definition::add_input_section(const Input_section_spec
* spec
,
2189 Output_section_element
* p
= new Output_section_element_input(spec
, keep
);
2190 this->elements_
.push_back(p
);
2193 // Create any required output sections. We need an output section if
2194 // there is a data statement here.
2197 Output_section_definition::create_sections(Layout
* layout
)
2199 if (this->output_section_
!= NULL
)
2201 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2202 p
!= this->elements_
.end();
2205 if ((*p
)->needs_output_section())
2207 const char* name
= this->name_
.c_str();
2208 this->output_section_
=
2209 layout
->make_output_section_for_script(name
, this->section_type());
2215 // Add any symbols being defined to the symbol table.
2218 Output_section_definition::add_symbols_to_table(Symbol_table
* symtab
)
2220 for (Output_section_elements::iterator p
= this->elements_
.begin();
2221 p
!= this->elements_
.end();
2223 (*p
)->add_symbols_to_table(symtab
);
2226 // Finalize symbols and check assertions.
2229 Output_section_definition::finalize_symbols(Symbol_table
* symtab
,
2230 const Layout
* layout
,
2231 uint64_t* dot_value
)
2233 if (this->output_section_
!= NULL
)
2234 *dot_value
= this->output_section_
->address();
2237 uint64_t address
= *dot_value
;
2238 if (this->address_
!= NULL
)
2240 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2244 if (this->align_
!= NULL
)
2246 uint64_t align
= this->align_
->eval_with_dot(symtab
, layout
, true,
2249 address
= align_address(address
, align
);
2251 *dot_value
= address
;
2254 Output_section
* dot_section
= this->output_section_
;
2255 for (Output_section_elements::iterator p
= this->elements_
.begin();
2256 p
!= this->elements_
.end();
2258 (*p
)->finalize_symbols(symtab
, layout
, dot_value
, &dot_section
);
2261 // Return the output section name to use for an input section name.
2264 Output_section_definition::output_section_name(
2265 const char* file_name
,
2266 const char* section_name
,
2267 Output_section
*** slot
,
2268 Script_sections::Section_type
* psection_type
,
2271 // Ask each element whether it matches NAME.
2272 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2273 p
!= this->elements_
.end();
2276 if ((*p
)->match_name(file_name
, section_name
, keep
))
2278 // We found a match for NAME, which means that it should go
2279 // into this output section.
2280 *slot
= &this->output_section_
;
2281 *psection_type
= this->section_type();
2282 return this->name_
.c_str();
2286 // We don't know about this section name.
2290 // Return true if memory from START to START + LENGTH is contained
2291 // within a memory region.
2294 Script_sections::block_in_region(Symbol_table
* symtab
, Layout
* layout
,
2295 uint64_t start
, uint64_t length
) const
2297 if (this->memory_regions_
== NULL
)
2300 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2301 mr
!= this->memory_regions_
->end();
2304 uint64_t s
= (*mr
)->start_address()->eval(symtab
, layout
, false);
2305 uint64_t l
= (*mr
)->length()->eval(symtab
, layout
, false);
2308 && (s
+ l
) >= (start
+ length
))
2315 // Find a memory region that should be used by a given output SECTION.
2316 // If provided set PREVIOUS_SECTION_RETURN to point to the last section
2317 // that used the return memory region.
2320 Script_sections::find_memory_region(
2321 Output_section_definition
* section
,
2322 bool find_vma_region
,
2324 Output_section_definition
** previous_section_return
)
2326 if (previous_section_return
!= NULL
)
2327 * previous_section_return
= NULL
;
2329 // Walk the memory regions specified in this script, if any.
2330 if (this->memory_regions_
== NULL
)
2333 // The /DISCARD/ section never gets assigned to any region.
2334 if (section
->get_section_name() == "/DISCARD/")
2337 Memory_region
* first_match
= NULL
;
2339 // First check to see if a region has been assigned to this section.
2340 for (Memory_regions::const_iterator mr
= this->memory_regions_
->begin();
2341 mr
!= this->memory_regions_
->end();
2344 if (find_vma_region
)
2346 for (Memory_region::Section_list::const_iterator s
=
2347 (*mr
)->get_vma_section_list_start();
2348 s
!= (*mr
)->get_vma_section_list_end();
2350 if ((*s
) == section
)
2352 (*mr
)->set_last_section(section
);
2358 for (Memory_region::Section_list::const_iterator s
=
2359 (*mr
)->get_lma_section_list_start();
2360 s
!= (*mr
)->get_lma_section_list_end();
2362 if ((*s
) == section
)
2364 (*mr
)->set_last_section(section
);
2371 // Make a note of the first memory region whose attributes
2372 // are compatible with the section. If we do not find an
2373 // explicit region assignment, then we will return this region.
2374 Output_section
* out_sec
= section
->get_output_section();
2375 if (first_match
== NULL
2377 && (*mr
)->attributes_compatible(out_sec
->flags(),
2383 // With LMA computations, if an explicit region has not been specified then
2384 // we will want to set the difference between the VMA and the LMA of the
2385 // section were searching for to be the same as the difference between the
2386 // VMA and LMA of the last section to be added to first matched region.
2387 // Hence, if it was asked for, we return a pointer to the last section
2388 // known to be used by the first matched region.
2389 if (first_match
!= NULL
2390 && previous_section_return
!= NULL
)
2391 *previous_section_return
= first_match
->get_last_section();
2396 // Set the section address. Note that the OUTPUT_SECTION_ field will
2397 // be NULL if no input sections were mapped to this output section.
2398 // We still have to adjust dot and process symbol assignments.
2401 Output_section_definition::set_section_addresses(Symbol_table
* symtab
,
2403 uint64_t* dot_value
,
2404 uint64_t* dot_alignment
,
2405 uint64_t* load_address
)
2407 Memory_region
* vma_region
= NULL
;
2408 Memory_region
* lma_region
= NULL
;
2409 Script_sections
* script_sections
=
2410 layout
->script_options()->script_sections();
2412 uint64_t old_dot_value
= *dot_value
;
2413 uint64_t old_load_address
= *load_address
;
2415 // If input section sorting is requested via --section-ordering-file or
2416 // linker plugins, then do it here. This is important because we want
2417 // any sorting specified in the linker scripts, which will be done after
2418 // this, to take precedence. The final order of input sections is then
2419 // guaranteed to be according to the linker script specification.
2420 if (this->output_section_
!= NULL
2421 && this->output_section_
->input_section_order_specified())
2422 this->output_section_
->sort_attached_input_sections();
2424 // Decide the start address for the section. The algorithm is:
2425 // 1) If an address has been specified in a linker script, use that.
2426 // 2) Otherwise if a memory region has been specified for the section,
2427 // use the next free address in the region.
2428 // 3) Otherwise if memory regions have been specified find the first
2429 // region whose attributes are compatible with this section and
2430 // install it into that region.
2431 // 4) Otherwise use the current location counter.
2433 if (this->output_section_
!= NULL
2434 // Check for --section-start.
2435 && parameters
->options().section_start(this->output_section_
->name(),
2438 else if (this->address_
== NULL
)
2440 vma_region
= script_sections
->find_memory_region(this, true, false, NULL
);
2441 if (vma_region
!= NULL
)
2442 address
= vma_region
->get_current_address()->eval(symtab
, layout
,
2445 address
= *dot_value
;
2449 vma_region
= script_sections
->find_memory_region(this, true, true, NULL
);
2450 address
= this->address_
->eval_with_dot(symtab
, layout
, true,
2451 *dot_value
, NULL
, NULL
,
2452 dot_alignment
, false);
2453 if (vma_region
!= NULL
)
2454 vma_region
->set_address(address
, symtab
, layout
);
2458 if (this->align_
== NULL
)
2460 if (this->output_section_
== NULL
)
2463 align
= this->output_section_
->addralign();
2467 Output_section
* align_section
;
2468 align
= this->align_
->eval_with_dot(symtab
, layout
, true, *dot_value
,
2469 NULL
, &align_section
, NULL
, false);
2470 if (align_section
!= NULL
)
2471 gold_warning(_("alignment of section %s is not absolute"),
2472 this->name_
.c_str());
2473 if (this->output_section_
!= NULL
)
2474 this->output_section_
->set_addralign(align
);
2478 if (this->subalign_
== NULL
)
2482 Output_section
* subalign_section
;
2483 subalign
= this->subalign_
->eval_with_dot(symtab
, layout
, true,
2485 &subalign_section
, NULL
,
2487 if (subalign_section
!= NULL
)
2488 gold_warning(_("subalign of section %s is not absolute"),
2489 this->name_
.c_str());
2491 // Reserve a value of 0 to mean there is no SUBALIGN property.
2495 // The external alignment of the output section must be at least
2496 // as large as that of the input sections. If there is no
2497 // explicit ALIGN property, we set the output section alignment
2498 // to match the input section alignment.
2499 if (align
< subalign
|| this->align_
== NULL
)
2502 this->output_section_
->set_addralign(align
);
2506 address
= align_address(address
, align
);
2508 uint64_t start_address
= address
;
2510 *dot_value
= address
;
2512 // Except for NOLOAD sections, the address of non-SHF_ALLOC sections is
2513 // forced to zero, regardless of what the linker script wants.
2514 if (this->output_section_
!= NULL
2515 && ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) != 0
2516 || this->output_section_
->is_noload()))
2517 this->output_section_
->set_address(address
);
2519 this->evaluated_address_
= address
;
2520 this->evaluated_addralign_
= align
;
2524 if (this->load_address_
== NULL
)
2526 Output_section_definition
* previous_section
;
2528 // Determine if an LMA region has been set for this section.
2529 lma_region
= script_sections
->find_memory_region(this, false, false,
2532 if (lma_region
!= NULL
)
2534 if (previous_section
== NULL
)
2535 // The LMA address was explicitly set to the given region.
2536 laddr
= lma_region
->get_current_address()->eval(symtab
, layout
,
2540 // We are not going to use the discovered lma_region, so
2541 // make sure that we do not update it in the code below.
2544 if (this->address_
!= NULL
|| previous_section
== this)
2546 // Either an explicit VMA address has been set, or an
2547 // explicit VMA region has been set, so set the LMA equal to
2553 // The LMA address was not explicitly or implicitly set.
2555 // We have been given the first memory region that is
2556 // compatible with the current section and a pointer to the
2557 // last section to use this region. Set the LMA of this
2558 // section so that the difference between its' VMA and LMA
2559 // is the same as the difference between the VMA and LMA of
2560 // the last section in the given region.
2561 laddr
= address
+ (previous_section
->evaluated_load_address_
2562 - previous_section
->evaluated_address_
);
2566 if (this->output_section_
!= NULL
)
2567 this->output_section_
->set_load_address(laddr
);
2571 // Do not set the load address of the output section, if one exists.
2572 // This allows future sections to determine what the load address
2573 // should be. If none is ever set, it will default to being the
2574 // same as the vma address.
2580 laddr
= this->load_address_
->eval_with_dot(symtab
, layout
, true,
2582 this->output_section_
,
2584 if (this->output_section_
!= NULL
)
2585 this->output_section_
->set_load_address(laddr
);
2588 this->evaluated_load_address_
= laddr
;
2591 if (this->fill_
!= NULL
)
2593 // FIXME: The GNU linker supports fill values of arbitrary
2595 Output_section
* fill_section
;
2596 uint64_t fill_val
= this->fill_
->eval_with_dot(symtab
, layout
, true,
2598 NULL
, &fill_section
,
2600 if (fill_section
!= NULL
)
2601 gold_warning(_("fill of section %s is not absolute"),
2602 this->name_
.c_str());
2603 unsigned char fill_buff
[4];
2604 elfcpp::Swap_unaligned
<32, true>::writeval(fill_buff
, fill_val
);
2605 fill
.assign(reinterpret_cast<char*>(fill_buff
), 4);
2608 Input_section_list input_sections
;
2609 if (this->output_section_
!= NULL
)
2611 // Get the list of input sections attached to this output
2612 // section. This will leave the output section with only
2613 // Output_section_data entries.
2614 address
+= this->output_section_
->get_input_sections(address
,
2617 *dot_value
= address
;
2620 Output_section
* dot_section
= this->output_section_
;
2621 for (Output_section_elements::iterator p
= this->elements_
.begin();
2622 p
!= this->elements_
.end();
2624 (*p
)->set_section_addresses(symtab
, layout
, this->output_section_
,
2625 subalign
, dot_value
, dot_alignment
,
2626 &dot_section
, &fill
, &input_sections
);
2628 gold_assert(input_sections
.empty());
2630 if (vma_region
!= NULL
)
2632 // Update the VMA region being used by the section now that we know how
2633 // big it is. Use the current address in the region, rather than
2634 // start_address because that might have been aligned upwards and we
2635 // need to allow for the padding.
2636 Expression
* addr
= vma_region
->get_current_address();
2637 uint64_t size
= *dot_value
- addr
->eval(symtab
, layout
, false);
2639 vma_region
->increment_offset(this->get_section_name(), size
,
2643 // If the LMA region is different from the VMA region, then increment the
2644 // offset there as well. Note that we use the same "dot_value -
2645 // start_address" formula that is used in the load_address assignment below.
2646 if (lma_region
!= NULL
&& lma_region
!= vma_region
)
2647 lma_region
->increment_offset(this->get_section_name(),
2648 *dot_value
- start_address
,
2651 // Compute the load address for the following section.
2652 if (this->output_section_
== NULL
)
2653 *load_address
= *dot_value
;
2654 else if (this->load_address_
== NULL
)
2656 if (lma_region
== NULL
)
2657 *load_address
= *dot_value
;
2660 lma_region
->get_current_address()->eval(symtab
, layout
, false);
2663 *load_address
= (this->output_section_
->load_address()
2664 + (*dot_value
- start_address
));
2666 if (this->output_section_
!= NULL
)
2668 if (this->is_relro_
)
2669 this->output_section_
->set_is_relro();
2671 this->output_section_
->clear_is_relro();
2673 // If this is a NOLOAD section, keep dot and load address unchanged.
2674 if (this->output_section_
->is_noload())
2676 *dot_value
= old_dot_value
;
2677 *load_address
= old_load_address
;
2682 // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
2683 // this section is constrained, and the input sections do not match,
2684 // return the constraint, and set *POSD.
2687 Output_section_definition::check_constraint(Output_section_definition
** posd
)
2689 switch (this->constraint_
)
2691 case CONSTRAINT_NONE
:
2692 return CONSTRAINT_NONE
;
2694 case CONSTRAINT_ONLY_IF_RO
:
2695 if (this->output_section_
!= NULL
2696 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) != 0)
2699 return CONSTRAINT_ONLY_IF_RO
;
2701 return CONSTRAINT_NONE
;
2703 case CONSTRAINT_ONLY_IF_RW
:
2704 if (this->output_section_
!= NULL
2705 && (this->output_section_
->flags() & elfcpp::SHF_WRITE
) == 0)
2708 return CONSTRAINT_ONLY_IF_RW
;
2710 return CONSTRAINT_NONE
;
2712 case CONSTRAINT_SPECIAL
:
2713 if (this->output_section_
!= NULL
)
2714 gold_error(_("SPECIAL constraints are not implemented"));
2715 return CONSTRAINT_NONE
;
2722 // See if this is the alternate output section for a constrained
2723 // output section. If it is, transfer the Output_section and return
2724 // true. Otherwise return false.
2727 Output_section_definition::alternate_constraint(
2728 Output_section_definition
* posd
,
2729 Section_constraint constraint
)
2731 if (this->name_
!= posd
->name_
)
2736 case CONSTRAINT_ONLY_IF_RO
:
2737 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RW
)
2741 case CONSTRAINT_ONLY_IF_RW
:
2742 if (this->constraint_
!= CONSTRAINT_ONLY_IF_RO
)
2750 // We have found the alternate constraint. We just need to move
2751 // over the Output_section. When constraints are used properly,
2752 // THIS should not have an output_section pointer, as all the input
2753 // sections should have matched the other definition.
2755 if (this->output_section_
!= NULL
)
2756 gold_error(_("mismatched definition for constrained sections"));
2758 this->output_section_
= posd
->output_section_
;
2759 posd
->output_section_
= NULL
;
2761 if (this->is_relro_
)
2762 this->output_section_
->set_is_relro();
2764 this->output_section_
->clear_is_relro();
2769 // Get the list of segments to use for an allocated section when using
2773 Output_section_definition::allocate_to_segment(String_list
** phdrs_list
,
2776 // Update phdrs_list even if we don't have an output section. It
2777 // might be used by the following sections.
2778 if (this->phdrs_
!= NULL
)
2779 *phdrs_list
= this->phdrs_
;
2781 if (this->output_section_
== NULL
)
2783 if ((this->output_section_
->flags() & elfcpp::SHF_ALLOC
) == 0)
2786 return this->output_section_
;
2789 // Look for an output section by name and return the address, the load
2790 // address, the alignment, and the size. This is used when an
2791 // expression refers to an output section which was not actually
2792 // created. This returns true if the section was found, false
2796 Output_section_definition::get_output_section_info(const char* name
,
2798 uint64_t* load_address
,
2799 uint64_t* addralign
,
2800 uint64_t* size
) const
2802 if (this->name_
!= name
)
2805 if (this->output_section_
!= NULL
)
2807 *address
= this->output_section_
->address();
2808 if (this->output_section_
->has_load_address())
2809 *load_address
= this->output_section_
->load_address();
2811 *load_address
= *address
;
2812 *addralign
= this->output_section_
->addralign();
2813 *size
= this->output_section_
->current_data_size();
2817 *address
= this->evaluated_address_
;
2818 *load_address
= this->evaluated_load_address_
;
2819 *addralign
= this->evaluated_addralign_
;
2826 // Print for debugging.
2829 Output_section_definition::print(FILE* f
) const
2831 fprintf(f
, " %s ", this->name_
.c_str());
2833 if (this->address_
!= NULL
)
2835 this->address_
->print(f
);
2839 if (this->script_section_type_
!= SCRIPT_SECTION_TYPE_NONE
)
2841 this->script_section_type_name(this->script_section_type_
));
2845 if (this->load_address_
!= NULL
)
2848 this->load_address_
->print(f
);
2852 if (this->align_
!= NULL
)
2854 fprintf(f
, "ALIGN(");
2855 this->align_
->print(f
);
2859 if (this->subalign_
!= NULL
)
2861 fprintf(f
, "SUBALIGN(");
2862 this->subalign_
->print(f
);
2868 for (Output_section_elements::const_iterator p
= this->elements_
.begin();
2869 p
!= this->elements_
.end();
2875 if (this->fill_
!= NULL
)
2878 this->fill_
->print(f
);
2881 if (this->phdrs_
!= NULL
)
2883 for (String_list::const_iterator p
= this->phdrs_
->begin();
2884 p
!= this->phdrs_
->end();
2886 fprintf(f
, " :%s", p
->c_str());
2892 Script_sections::Section_type
2893 Output_section_definition::section_type() const
2895 switch (this->script_section_type_
)
2897 case SCRIPT_SECTION_TYPE_NONE
:
2898 return Script_sections::ST_NONE
;
2899 case SCRIPT_SECTION_TYPE_NOLOAD
:
2900 return Script_sections::ST_NOLOAD
;
2901 case SCRIPT_SECTION_TYPE_COPY
:
2902 case SCRIPT_SECTION_TYPE_DSECT
:
2903 case SCRIPT_SECTION_TYPE_INFO
:
2904 case SCRIPT_SECTION_TYPE_OVERLAY
:
2905 // There are not really support so we treat them as ST_NONE. The
2906 // parse should have issued errors for them already.
2907 return Script_sections::ST_NONE
;
2913 // Return the name of a script section type.
2916 Output_section_definition::script_section_type_name(
2917 Script_section_type script_section_type
)
2919 switch (script_section_type
)
2921 case SCRIPT_SECTION_TYPE_NONE
:
2923 case SCRIPT_SECTION_TYPE_NOLOAD
:
2925 case SCRIPT_SECTION_TYPE_DSECT
:
2927 case SCRIPT_SECTION_TYPE_COPY
:
2929 case SCRIPT_SECTION_TYPE_INFO
:
2931 case SCRIPT_SECTION_TYPE_OVERLAY
:
2939 Output_section_definition::set_memory_region(Memory_region
* mr
, bool set_vma
)
2941 gold_assert(mr
!= NULL
);
2942 // Add the current section to the specified region's list.
2943 mr
->add_section(this, set_vma
);
2946 // An output section created to hold orphaned input sections. These
2947 // do not actually appear in linker scripts. However, for convenience
2948 // when setting the output section addresses, we put a marker to these
2949 // sections in the appropriate place in the list of SECTIONS elements.
2951 class Orphan_output_section
: public Sections_element
2954 Orphan_output_section(Output_section
* os
)
2958 // Return whether the orphan output section is relro. We can just
2959 // check the output section because we always set the flag, if
2960 // needed, just after we create the Orphan_output_section.
2963 { return this->os_
->is_relro(); }
2965 // Initialize OSP with an output section. This should have been
2968 orphan_section_init(Orphan_section_placement
*,
2969 Script_sections::Elements_iterator
)
2970 { gold_unreachable(); }
2972 // Set section addresses.
2974 set_section_addresses(Symbol_table
*, Layout
*, uint64_t*, uint64_t*,
2977 // Get the list of segments to use for an allocated section when
2978 // using a PHDRS clause.
2980 allocate_to_segment(String_list
**, bool*);
2982 // Return the associated Output_section.
2984 get_output_section() const
2985 { return this->os_
; }
2987 // Print for debugging.
2989 print(FILE* f
) const
2991 fprintf(f
, " marker for orphaned output section %s\n",
2996 Output_section
* os_
;
2999 // Set section addresses.
3002 Orphan_output_section::set_section_addresses(Symbol_table
*, Layout
*,
3003 uint64_t* dot_value
,
3005 uint64_t* load_address
)
3007 typedef std::list
<Output_section::Input_section
> Input_section_list
;
3009 bool have_load_address
= *load_address
!= *dot_value
;
3011 uint64_t address
= *dot_value
;
3012 address
= align_address(address
, this->os_
->addralign());
3014 // If input section sorting is requested via --section-ordering-file or
3015 // linker plugins, then do it here. This is important because we want
3016 // any sorting specified in the linker scripts, which will be done after
3017 // this, to take precedence. The final order of input sections is then
3018 // guaranteed to be according to the linker script specification.
3019 if (this->os_
!= NULL
3020 && this->os_
->input_section_order_specified())
3021 this->os_
->sort_attached_input_sections();
3023 // For a relocatable link, all orphan sections are put at
3024 // address 0. In general we expect all sections to be at
3025 // address 0 for a relocatable link, but we permit the linker
3026 // script to override that for specific output sections.
3027 if (parameters
->options().relocatable())
3031 have_load_address
= false;
3034 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) != 0)
3036 this->os_
->set_address(address
);
3037 if (have_load_address
)
3038 this->os_
->set_load_address(align_address(*load_address
,
3039 this->os_
->addralign()));
3042 Input_section_list input_sections
;
3043 address
+= this->os_
->get_input_sections(address
, "", &input_sections
);
3045 for (Input_section_list::iterator p
= input_sections
.begin();
3046 p
!= input_sections
.end();
3049 uint64_t addralign
= p
->addralign();
3050 if (!p
->is_input_section())
3051 p
->output_section_data()->finalize_data_size();
3052 uint64_t size
= p
->data_size();
3053 address
= align_address(address
, addralign
);
3054 this->os_
->add_script_input_section(*p
);
3058 if (parameters
->options().relocatable())
3060 // For a relocatable link, reset DOT_VALUE to 0.
3064 else if (this->os_
== NULL
3065 || (this->os_
->flags() & elfcpp::SHF_TLS
) == 0
3066 || this->os_
->type() != elfcpp::SHT_NOBITS
)
3068 // An SHF_TLS/SHT_NOBITS section does not take up any address space.
3069 if (!have_load_address
)
3070 *load_address
= address
;
3072 *load_address
+= address
- *dot_value
;
3074 *dot_value
= address
;
3078 // Get the list of segments to use for an allocated section when using
3079 // a PHDRS clause. If this is an allocated section, return the
3080 // Output_section. We don't change the list of segments.
3083 Orphan_output_section::allocate_to_segment(String_list
**, bool* orphan
)
3085 if ((this->os_
->flags() & elfcpp::SHF_ALLOC
) == 0)
3091 // Class Phdrs_element. A program header from a PHDRS clause.
3096 Phdrs_element(const char* name
, size_t namelen
, unsigned int type
,
3097 bool includes_filehdr
, bool includes_phdrs
,
3098 bool is_flags_valid
, unsigned int flags
,
3099 Expression
* load_address
)
3100 : name_(name
, namelen
), type_(type
), includes_filehdr_(includes_filehdr
),
3101 includes_phdrs_(includes_phdrs
), is_flags_valid_(is_flags_valid
),
3102 flags_(flags
), load_address_(load_address
), load_address_value_(0),
3106 // Return the name of this segment.
3109 { return this->name_
; }
3111 // Return the type of the segment.
3114 { return this->type_
; }
3116 // Whether to include the file header.
3118 includes_filehdr() const
3119 { return this->includes_filehdr_
; }
3121 // Whether to include the program headers.
3123 includes_phdrs() const
3124 { return this->includes_phdrs_
; }
3126 // Return whether there is a load address.
3128 has_load_address() const
3129 { return this->load_address_
!= NULL
; }
3131 // Evaluate the load address expression if there is one.
3133 eval_load_address(Symbol_table
* symtab
, Layout
* layout
)
3135 if (this->load_address_
!= NULL
)
3136 this->load_address_value_
= this->load_address_
->eval(symtab
, layout
,
3140 // Return the load address.
3142 load_address() const
3144 gold_assert(this->load_address_
!= NULL
);
3145 return this->load_address_value_
;
3148 // Create the segment.
3150 create_segment(Layout
* layout
)
3152 this->segment_
= layout
->make_output_segment(this->type_
, this->flags_
);
3153 return this->segment_
;
3156 // Return the segment.
3159 { return this->segment_
; }
3161 // Release the segment.
3164 { this->segment_
= NULL
; }
3166 // Set the segment flags if appropriate.
3168 set_flags_if_valid()
3170 if (this->is_flags_valid_
)
3171 this->segment_
->set_flags(this->flags_
);
3174 // Print for debugging.
3179 // The name used in the script.
3181 // The type of the segment (PT_LOAD, etc.).
3183 // Whether this segment includes the file header.
3184 bool includes_filehdr_
;
3185 // Whether this segment includes the section headers.
3186 bool includes_phdrs_
;
3187 // Whether the flags were explicitly specified.
3188 bool is_flags_valid_
;
3189 // The flags for this segment (PF_R, etc.) if specified.
3190 unsigned int flags_
;
3191 // The expression for the load address for this segment. This may
3193 Expression
* load_address_
;
3194 // The actual load address from evaluating the expression.
3195 uint64_t load_address_value_
;
3196 // The segment itself.
3197 Output_segment
* segment_
;
3200 // Print for debugging.
3203 Phdrs_element::print(FILE* f
) const
3205 fprintf(f
, " %s 0x%x", this->name_
.c_str(), this->type_
);
3206 if (this->includes_filehdr_
)
3207 fprintf(f
, " FILEHDR");
3208 if (this->includes_phdrs_
)
3209 fprintf(f
, " PHDRS");
3210 if (this->is_flags_valid_
)
3211 fprintf(f
, " FLAGS(%u)", this->flags_
);
3212 if (this->load_address_
!= NULL
)
3215 this->load_address_
->print(f
);
3221 // Add a memory region.
3224 Script_sections::add_memory_region(const char* name
, size_t namelen
,
3225 unsigned int attributes
,
3226 Expression
* start
, Expression
* length
)
3228 if (this->memory_regions_
== NULL
)
3229 this->memory_regions_
= new Memory_regions();
3230 else if (this->find_memory_region(name
, namelen
))
3232 gold_error(_("region '%.*s' already defined"), static_cast<int>(namelen
),
3234 // FIXME: Add a GOLD extension to allow multiple regions with the same
3235 // name. This would amount to a single region covering disjoint blocks
3236 // of memory, which is useful for embedded devices.
3239 // FIXME: Check the length and start values. Currently we allow
3240 // non-constant expressions for these values, whereas LD does not.
3242 // FIXME: Add a GOLD extension to allow NEGATIVE LENGTHS. This would
3243 // describe a region that packs from the end address going down, rather
3244 // than the start address going up. This would be useful for embedded
3247 this->memory_regions_
->push_back(new Memory_region(name
, namelen
, attributes
,
3251 // Find a memory region.
3254 Script_sections::find_memory_region(const char* name
, size_t namelen
)
3256 if (this->memory_regions_
== NULL
)
3259 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
3260 m
!= this->memory_regions_
->end();
3262 if ((*m
)->name_match(name
, namelen
))
3268 // Find a memory region's origin.
3271 Script_sections::find_memory_region_origin(const char* name
, size_t namelen
)
3273 Memory_region
* mr
= find_memory_region(name
, namelen
);
3277 return mr
->start_address();
3280 // Find a memory region's length.
3283 Script_sections::find_memory_region_length(const char* name
, size_t namelen
)
3285 Memory_region
* mr
= find_memory_region(name
, namelen
);
3289 return mr
->length();
3292 // Set the memory region to use for the current section.
3295 Script_sections::set_memory_region(Memory_region
* mr
, bool set_vma
)
3297 gold_assert(!this->sections_elements_
->empty());
3298 this->sections_elements_
->back()->set_memory_region(mr
, set_vma
);
3301 // Class Script_sections.
3303 Script_sections::Script_sections()
3304 : saw_sections_clause_(false),
3305 in_sections_clause_(false),
3306 sections_elements_(NULL
),
3307 output_section_(NULL
),
3308 memory_regions_(NULL
),
3309 phdrs_elements_(NULL
),
3310 orphan_section_placement_(NULL
),
3311 data_segment_align_start_(),
3312 saw_data_segment_align_(false),
3313 saw_relro_end_(false),
3314 saw_segment_start_expression_(false),
3315 segments_created_(false)
3319 // Start a SECTIONS clause.
3322 Script_sections::start_sections()
3324 gold_assert(!this->in_sections_clause_
&& this->output_section_
== NULL
);
3325 this->saw_sections_clause_
= true;
3326 this->in_sections_clause_
= true;
3327 if (this->sections_elements_
== NULL
)
3328 this->sections_elements_
= new Sections_elements
;
3331 // Finish a SECTIONS clause.
3334 Script_sections::finish_sections()
3336 gold_assert(this->in_sections_clause_
&& this->output_section_
== NULL
);
3337 this->in_sections_clause_
= false;
3340 // Add a symbol to be defined.
3343 Script_sections::add_symbol_assignment(const char* name
, size_t length
,
3344 Expression
* val
, bool provide
,
3347 if (this->output_section_
!= NULL
)
3348 this->output_section_
->add_symbol_assignment(name
, length
, val
,
3352 Sections_element
* p
= new Sections_element_assignment(name
, length
,
3355 this->sections_elements_
->push_back(p
);
3359 // Add an assignment to the special dot symbol.
3362 Script_sections::add_dot_assignment(Expression
* val
)
3364 if (this->output_section_
!= NULL
)
3365 this->output_section_
->add_dot_assignment(val
);
3368 // The GNU linker permits assignments to . to appears outside of
3369 // a SECTIONS clause, and treats it as appearing inside, so
3370 // sections_elements_ may be NULL here.
3371 if (this->sections_elements_
== NULL
)
3373 this->sections_elements_
= new Sections_elements
;
3374 this->saw_sections_clause_
= true;
3377 Sections_element
* p
= new Sections_element_dot_assignment(val
);
3378 this->sections_elements_
->push_back(p
);
3382 // Add an assertion.
3385 Script_sections::add_assertion(Expression
* check
, const char* message
,
3388 if (this->output_section_
!= NULL
)
3389 this->output_section_
->add_assertion(check
, message
, messagelen
);
3392 Sections_element
* p
= new Sections_element_assertion(check
, message
,
3394 this->sections_elements_
->push_back(p
);
3398 // Start processing entries for an output section.
3401 Script_sections::start_output_section(
3404 const Parser_output_section_header
* header
)
3406 Output_section_definition
* posd
= new Output_section_definition(name
,
3409 this->sections_elements_
->push_back(posd
);
3410 gold_assert(this->output_section_
== NULL
);
3411 this->output_section_
= posd
;
3414 // Stop processing entries for an output section.
3417 Script_sections::finish_output_section(
3418 const Parser_output_section_trailer
* trailer
)
3420 gold_assert(this->output_section_
!= NULL
);
3421 this->output_section_
->finish(trailer
);
3422 this->output_section_
= NULL
;
3425 // Add a data item to the current output section.
3428 Script_sections::add_data(int size
, bool is_signed
, Expression
* val
)
3430 gold_assert(this->output_section_
!= NULL
);
3431 this->output_section_
->add_data(size
, is_signed
, val
);
3434 // Add a fill value setting to the current output section.
3437 Script_sections::add_fill(Expression
* val
)
3439 gold_assert(this->output_section_
!= NULL
);
3440 this->output_section_
->add_fill(val
);
3443 // Add an input section specification to the current output section.
3446 Script_sections::add_input_section(const Input_section_spec
* spec
, bool keep
)
3448 gold_assert(this->output_section_
!= NULL
);
3449 this->output_section_
->add_input_section(spec
, keep
);
3452 // This is called when we see DATA_SEGMENT_ALIGN. It means that any
3453 // subsequent output sections may be relro.
3456 Script_sections::data_segment_align()
3458 if (this->saw_data_segment_align_
)
3459 gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script"));
3460 gold_assert(!this->sections_elements_
->empty());
3461 Sections_elements::iterator p
= this->sections_elements_
->end();
3463 this->data_segment_align_start_
= p
;
3464 this->saw_data_segment_align_
= true;
3467 // This is called when we see DATA_SEGMENT_RELRO_END. It means that
3468 // any output sections seen since DATA_SEGMENT_ALIGN are relro.
3471 Script_sections::data_segment_relro_end()
3473 if (this->saw_relro_end_
)
3474 gold_error(_("DATA_SEGMENT_RELRO_END may only appear once "
3475 "in a linker script"));
3476 this->saw_relro_end_
= true;
3478 if (!this->saw_data_segment_align_
)
3479 gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN"));
3482 Sections_elements::iterator p
= this->data_segment_align_start_
;
3483 for (++p
; p
!= this->sections_elements_
->end(); ++p
)
3484 (*p
)->set_is_relro();
3488 // Create any required sections.
3491 Script_sections::create_sections(Layout
* layout
)
3493 if (!this->saw_sections_clause_
)
3495 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3496 p
!= this->sections_elements_
->end();
3498 (*p
)->create_sections(layout
);
3501 // Add any symbols we are defining to the symbol table.
3504 Script_sections::add_symbols_to_table(Symbol_table
* symtab
)
3506 if (!this->saw_sections_clause_
)
3508 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3509 p
!= this->sections_elements_
->end();
3511 (*p
)->add_symbols_to_table(symtab
);
3514 // Finalize symbols and check assertions.
3517 Script_sections::finalize_symbols(Symbol_table
* symtab
, const Layout
* layout
)
3519 if (!this->saw_sections_clause_
)
3521 uint64_t dot_value
= 0;
3522 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3523 p
!= this->sections_elements_
->end();
3525 (*p
)->finalize_symbols(symtab
, layout
, &dot_value
);
3528 // Return the name of the output section to use for an input file name
3529 // and section name.
3532 Script_sections::output_section_name(
3533 const char* file_name
,
3534 const char* section_name
,
3535 Output_section
*** output_section_slot
,
3536 Script_sections::Section_type
* psection_type
,
3539 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3540 p
!= this->sections_elements_
->end();
3543 const char* ret
= (*p
)->output_section_name(file_name
, section_name
,
3544 output_section_slot
,
3545 psection_type
, keep
);
3549 // The special name /DISCARD/ means that the input section
3550 // should be discarded.
3551 if (strcmp(ret
, "/DISCARD/") == 0)
3553 *output_section_slot
= NULL
;
3554 *psection_type
= Script_sections::ST_NONE
;
3561 // If we couldn't find a mapping for the name, the output section
3562 // gets the name of the input section.
3564 *output_section_slot
= NULL
;
3565 *psection_type
= Script_sections::ST_NONE
;
3568 return section_name
;
3571 // Place a marker for an orphan output section into the SECTIONS
3575 Script_sections::place_orphan(Output_section
* os
)
3577 Orphan_section_placement
* osp
= this->orphan_section_placement_
;
3580 // Initialize the Orphan_section_placement structure.
3581 osp
= new Orphan_section_placement();
3582 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3583 p
!= this->sections_elements_
->end();
3585 (*p
)->orphan_section_init(osp
, p
);
3586 gold_assert(!this->sections_elements_
->empty());
3587 Sections_elements::iterator last
= this->sections_elements_
->end();
3589 osp
->last_init(last
);
3590 this->orphan_section_placement_
= osp
;
3593 Orphan_output_section
* orphan
= new Orphan_output_section(os
);
3595 // Look for where to put ORPHAN.
3596 Sections_elements::iterator
* where
;
3597 if (osp
->find_place(os
, &where
))
3599 if ((**where
)->is_relro())
3602 os
->clear_is_relro();
3604 // We want to insert ORPHAN after *WHERE, and then update *WHERE
3605 // so that the next one goes after this one.
3606 Sections_elements::iterator p
= *where
;
3607 gold_assert(p
!= this->sections_elements_
->end());
3609 *where
= this->sections_elements_
->insert(p
, orphan
);
3613 os
->clear_is_relro();
3614 // We don't have a place to put this orphan section. Put it,
3615 // and all other sections like it, at the end, but before the
3616 // sections which always come at the end.
3617 Sections_elements::iterator last
= osp
->last_place();
3618 *where
= this->sections_elements_
->insert(last
, orphan
);
3622 // Set the addresses of all the output sections. Walk through all the
3623 // elements, tracking the dot symbol. Apply assignments which set
3624 // absolute symbol values, in case they are used when setting dot.
3625 // Fill in data statement values. As we find output sections, set the
3626 // address, set the address of all associated input sections, and
3627 // update dot. Return the segment which should hold the file header
3628 // and segment headers, if any.
3631 Script_sections::set_section_addresses(Symbol_table
* symtab
, Layout
* layout
)
3633 gold_assert(this->saw_sections_clause_
);
3635 // Implement ONLY_IF_RO/ONLY_IF_RW constraints. These are a pain
3636 // for our representation.
3637 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3638 p
!= this->sections_elements_
->end();
3641 Output_section_definition
* posd
;
3642 Section_constraint failed_constraint
= (*p
)->check_constraint(&posd
);
3643 if (failed_constraint
!= CONSTRAINT_NONE
)
3645 Sections_elements::iterator q
;
3646 for (q
= this->sections_elements_
->begin();
3647 q
!= this->sections_elements_
->end();
3652 if ((*q
)->alternate_constraint(posd
, failed_constraint
))
3657 if (q
== this->sections_elements_
->end())
3658 gold_error(_("no matching section constraint"));
3662 // Force the alignment of the first TLS section to be the maximum
3663 // alignment of all TLS sections.
3664 Output_section
* first_tls
= NULL
;
3665 uint64_t tls_align
= 0;
3666 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
3667 p
!= this->sections_elements_
->end();
3670 Output_section
* os
= (*p
)->get_output_section();
3671 if (os
!= NULL
&& (os
->flags() & elfcpp::SHF_TLS
) != 0)
3673 if (first_tls
== NULL
)
3675 if (os
->addralign() > tls_align
)
3676 tls_align
= os
->addralign();
3679 if (first_tls
!= NULL
)
3680 first_tls
->set_addralign(tls_align
);
3682 // For a relocatable link, we implicitly set dot to zero.
3683 uint64_t dot_value
= 0;
3684 uint64_t dot_alignment
= 0;
3685 uint64_t load_address
= 0;
3687 // Check to see if we want to use any of -Ttext, -Tdata and -Tbss options
3688 // to set section addresses. If the script has any SEGMENT_START
3689 // expression, we do not set the section addresses.
3690 bool use_tsection_options
=
3691 (!this->saw_segment_start_expression_
3692 && (parameters
->options().user_set_Ttext()
3693 || parameters
->options().user_set_Tdata()
3694 || parameters
->options().user_set_Tbss()));
3696 for (Sections_elements::iterator p
= this->sections_elements_
->begin();
3697 p
!= this->sections_elements_
->end();
3700 Output_section
* os
= (*p
)->get_output_section();
3702 // Handle -Ttext, -Tdata and -Tbss options. We do this by looking for
3703 // the special sections by names and doing dot assignments.
3704 if (use_tsection_options
3706 && (os
->flags() & elfcpp::SHF_ALLOC
) != 0)
3708 uint64_t new_dot_value
= dot_value
;
3710 if (parameters
->options().user_set_Ttext()
3711 && strcmp(os
->name(), ".text") == 0)
3712 new_dot_value
= parameters
->options().Ttext();
3713 else if (parameters
->options().user_set_Tdata()
3714 && strcmp(os
->name(), ".data") == 0)
3715 new_dot_value
= parameters
->options().Tdata();
3716 else if (parameters
->options().user_set_Tbss()
3717 && strcmp(os
->name(), ".bss") == 0)
3718 new_dot_value
= parameters
->options().Tbss();
3720 // Update dot and load address if necessary.
3721 if (new_dot_value
< dot_value
)
3722 gold_error(_("dot may not move backward"));
3723 else if (new_dot_value
!= dot_value
)
3725 dot_value
= new_dot_value
;
3726 load_address
= new_dot_value
;
3730 (*p
)->set_section_addresses(symtab
, layout
, &dot_value
, &dot_alignment
,
3734 if (this->phdrs_elements_
!= NULL
)
3736 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
3737 p
!= this->phdrs_elements_
->end();
3739 (*p
)->eval_load_address(symtab
, layout
);
3742 return this->create_segments(layout
, dot_alignment
);
3745 // Sort the sections in order to put them into segments.
3747 class Sort_output_sections
3750 Sort_output_sections(const Script_sections::Sections_elements
* elements
)
3751 : elements_(elements
)
3755 operator()(const Output_section
* os1
, const Output_section
* os2
) const;
3759 script_compare(const Output_section
* os1
, const Output_section
* os2
) const;
3762 const Script_sections::Sections_elements
* elements_
;
3766 Sort_output_sections::operator()(const Output_section
* os1
,
3767 const Output_section
* os2
) const
3769 // Sort first by the load address.
3770 uint64_t lma1
= (os1
->has_load_address()
3771 ? os1
->load_address()
3773 uint64_t lma2
= (os2
->has_load_address()
3774 ? os2
->load_address()
3779 // Then sort by the virtual address.
3780 if (os1
->address() != os2
->address())
3781 return os1
->address() < os2
->address();
3783 // If the linker script says which of these sections is first, go
3784 // with what it says.
3785 int i
= this->script_compare(os1
, os2
);
3789 // Sort PROGBITS before NOBITS.
3790 bool nobits1
= os1
->type() == elfcpp::SHT_NOBITS
;
3791 bool nobits2
= os2
->type() == elfcpp::SHT_NOBITS
;
3792 if (nobits1
!= nobits2
)
3795 // Sort PROGBITS TLS sections to the end, NOBITS TLS sections to the
3797 bool tls1
= (os1
->flags() & elfcpp::SHF_TLS
) != 0;
3798 bool tls2
= (os2
->flags() & elfcpp::SHF_TLS
) != 0;
3800 return nobits1
? tls1
: tls2
;
3802 // Sort non-NOLOAD before NOLOAD.
3803 if (os1
->is_noload() && !os2
->is_noload())
3805 if (!os1
->is_noload() && os2
->is_noload())
3808 // The sections seem practically identical. Sort by name to get a
3810 return os1
->name() < os2
->name();
3813 // Return -1 if OS1 comes before OS2 in ELEMENTS_, 1 if comes after, 0
3814 // if either OS1 or OS2 is not mentioned. This ensures that we keep
3815 // empty sections in the order in which they appear in a linker
3819 Sort_output_sections::script_compare(const Output_section
* os1
,
3820 const Output_section
* os2
) const
3822 if (this->elements_
== NULL
)
3825 bool found_os1
= false;
3826 bool found_os2
= false;
3827 for (Script_sections::Sections_elements::const_iterator
3828 p
= this->elements_
->begin();
3829 p
!= this->elements_
->end();
3832 if (os2
== (*p
)->get_output_section())
3838 else if (os1
== (*p
)->get_output_section())
3849 // Return whether OS is a BSS section. This is a SHT_NOBITS section.
3850 // We treat a section with the SHF_TLS flag set as taking up space
3851 // even if it is SHT_NOBITS (this is true of .tbss), as we allocate
3852 // space for them in the file.
3855 Script_sections::is_bss_section(const Output_section
* os
)
3857 return (os
->type() == elfcpp::SHT_NOBITS
3858 && (os
->flags() & elfcpp::SHF_TLS
) == 0);
3861 // Return the size taken by the file header and the program headers.
3864 Script_sections::total_header_size(Layout
* layout
) const
3866 size_t segment_count
= layout
->segment_count();
3867 size_t file_header_size
;
3868 size_t segment_headers_size
;
3869 if (parameters
->target().get_size() == 32)
3871 file_header_size
= elfcpp::Elf_sizes
<32>::ehdr_size
;
3872 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<32>::phdr_size
;
3874 else if (parameters
->target().get_size() == 64)
3876 file_header_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
3877 segment_headers_size
= segment_count
* elfcpp::Elf_sizes
<64>::phdr_size
;
3882 return file_header_size
+ segment_headers_size
;
3885 // Return the amount we have to subtract from the LMA to accommodate
3886 // headers of the given size. The complication is that the file
3887 // header have to be at the start of a page, as otherwise it will not
3888 // be at the start of the file.
3891 Script_sections::header_size_adjustment(uint64_t lma
,
3892 size_t sizeof_headers
) const
3894 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3895 uint64_t hdr_lma
= lma
- sizeof_headers
;
3896 hdr_lma
&= ~(abi_pagesize
- 1);
3897 return lma
- hdr_lma
;
3900 // Create the PT_LOAD segments when using a SECTIONS clause. Returns
3901 // the segment which should hold the file header and segment headers,
3905 Script_sections::create_segments(Layout
* layout
, uint64_t dot_alignment
)
3907 gold_assert(this->saw_sections_clause_
);
3909 if (parameters
->options().relocatable())
3912 if (this->saw_phdrs_clause())
3913 return create_segments_from_phdrs_clause(layout
, dot_alignment
);
3915 Layout::Section_list sections
;
3916 layout
->get_allocated_sections(§ions
);
3918 // Sort the sections by address.
3919 std::stable_sort(sections
.begin(), sections
.end(),
3920 Sort_output_sections(this->sections_elements_
));
3922 this->create_note_and_tls_segments(layout
, §ions
);
3924 // Walk through the sections adding them to PT_LOAD segments.
3925 const uint64_t abi_pagesize
= parameters
->target().abi_pagesize();
3926 Output_segment
* first_seg
= NULL
;
3927 Output_segment
* current_seg
= NULL
;
3928 bool is_current_seg_readonly
= true;
3929 Layout::Section_list::iterator plast
= sections
.end();
3930 uint64_t last_vma
= 0;
3931 uint64_t last_lma
= 0;
3932 uint64_t last_size
= 0;
3933 for (Layout::Section_list::iterator p
= sections
.begin();
3934 p
!= sections
.end();
3937 const uint64_t vma
= (*p
)->address();
3938 const uint64_t lma
= ((*p
)->has_load_address()
3939 ? (*p
)->load_address()
3941 const uint64_t size
= (*p
)->current_data_size();
3943 bool need_new_segment
;
3944 if (current_seg
== NULL
)
3945 need_new_segment
= true;
3946 else if (lma
- vma
!= last_lma
- last_vma
)
3948 // This section has a different LMA relationship than the
3949 // last one; we need a new segment.
3950 need_new_segment
= true;
3952 else if (align_address(last_lma
+ last_size
, abi_pagesize
)
3953 < align_address(lma
, abi_pagesize
))
3955 // Putting this section in the segment would require
3957 need_new_segment
= true;
3959 else if (is_bss_section(*plast
) && !is_bss_section(*p
))
3961 // A non-BSS section can not follow a BSS section in the
3963 need_new_segment
= true;
3965 else if (is_current_seg_readonly
3966 && ((*p
)->flags() & elfcpp::SHF_WRITE
) != 0
3967 && !parameters
->options().omagic())
3969 // Don't put a writable section in the same segment as a
3970 // non-writable section.
3971 need_new_segment
= true;
3975 // Otherwise, reuse the existing segment.
3976 need_new_segment
= false;
3979 elfcpp::Elf_Word seg_flags
=
3980 Layout::section_flags_to_segment((*p
)->flags());
3982 if (need_new_segment
)
3984 current_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
3986 current_seg
->set_addresses(vma
, lma
);
3987 current_seg
->set_minimum_p_align(dot_alignment
);
3988 if (first_seg
== NULL
)
3989 first_seg
= current_seg
;
3990 is_current_seg_readonly
= true;
3993 current_seg
->add_output_section_to_load(layout
, *p
, seg_flags
);
3995 if (((*p
)->flags() & elfcpp::SHF_WRITE
) != 0)
3996 is_current_seg_readonly
= false;
4004 // An ELF program should work even if the program headers are not in
4005 // a PT_LOAD segment. However, it appears that the Linux kernel
4006 // does not set the AT_PHDR auxiliary entry in that case. It sets
4007 // the load address to p_vaddr - p_offset of the first PT_LOAD
4008 // segment. It then sets AT_PHDR to the load address plus the
4009 // offset to the program headers, e_phoff in the file header. This
4010 // fails when the program headers appear in the file before the
4011 // first PT_LOAD segment. Therefore, we always create a PT_LOAD
4012 // segment to hold the file header and the program headers. This is
4013 // effectively what the GNU linker does, and it is slightly more
4014 // efficient in any case. We try to use the first PT_LOAD segment
4015 // if we can, otherwise we make a new one.
4017 if (first_seg
== NULL
)
4020 // -n or -N mean that the program is not demand paged and there is
4021 // no need to put the program headers in a PT_LOAD segment.
4022 if (parameters
->options().nmagic() || parameters
->options().omagic())
4025 size_t sizeof_headers
= this->total_header_size(layout
);
4027 uint64_t vma
= first_seg
->vaddr();
4028 uint64_t lma
= first_seg
->paddr();
4030 uint64_t subtract
= this->header_size_adjustment(lma
, sizeof_headers
);
4032 if ((lma
& (abi_pagesize
- 1)) >= sizeof_headers
)
4034 first_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
4038 // If there is no room to squeeze in the headers, then punt. The
4039 // resulting executable probably won't run on GNU/Linux, but we
4040 // trust that the user knows what they are doing.
4041 if (lma
< subtract
|| vma
< subtract
)
4044 // If memory regions have been specified and the address range
4045 // we are about to use is not contained within any region then
4046 // issue a warning message about the segment we are going to
4047 // create. It will be outside of any region and so possibly
4048 // using non-existent or protected memory. We test LMA rather
4049 // than VMA since we assume that the headers will never be
4051 if (this->memory_regions_
!= NULL
4052 && !this->block_in_region (NULL
, layout
, lma
- subtract
, subtract
))
4053 gold_warning(_("creating a segment to contain the file and program"
4054 " headers outside of any MEMORY region"));
4056 Output_segment
* load_seg
= layout
->make_output_segment(elfcpp::PT_LOAD
,
4058 load_seg
->set_addresses(vma
- subtract
, lma
- subtract
);
4063 // Create a PT_NOTE segment for each SHT_NOTE section and a PT_TLS
4064 // segment if there are any SHT_TLS sections.
4067 Script_sections::create_note_and_tls_segments(
4069 const Layout::Section_list
* sections
)
4071 gold_assert(!this->saw_phdrs_clause());
4073 bool saw_tls
= false;
4074 for (Layout::Section_list::const_iterator p
= sections
->begin();
4075 p
!= sections
->end();
4078 if ((*p
)->type() == elfcpp::SHT_NOTE
)
4080 elfcpp::Elf_Word seg_flags
=
4081 Layout::section_flags_to_segment((*p
)->flags());
4082 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_NOTE
,
4084 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
4086 // Incorporate any subsequent SHT_NOTE sections, in the
4087 // hopes that the script is sensible.
4088 Layout::Section_list::const_iterator pnext
= p
+ 1;
4089 while (pnext
!= sections
->end()
4090 && (*pnext
)->type() == elfcpp::SHT_NOTE
)
4092 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
4093 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
4099 if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
4102 gold_error(_("TLS sections are not adjacent"));
4104 elfcpp::Elf_Word seg_flags
=
4105 Layout::section_flags_to_segment((*p
)->flags());
4106 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_TLS
,
4108 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
4110 Layout::Section_list::const_iterator pnext
= p
+ 1;
4111 while (pnext
!= sections
->end()
4112 && ((*pnext
)->flags() & elfcpp::SHF_TLS
) != 0)
4114 seg_flags
= Layout::section_flags_to_segment((*pnext
)->flags());
4115 oseg
->add_output_section_to_nonload(*pnext
, seg_flags
);
4123 // If we see a section named .interp then put the .interp section
4124 // in a PT_INTERP segment.
4125 // This is for GNU ld compatibility.
4126 if (strcmp((*p
)->name(), ".interp") == 0)
4128 elfcpp::Elf_Word seg_flags
=
4129 Layout::section_flags_to_segment((*p
)->flags());
4130 Output_segment
* oseg
= layout
->make_output_segment(elfcpp::PT_INTERP
,
4132 oseg
->add_output_section_to_nonload(*p
, seg_flags
);
4136 this->segments_created_
= true;
4139 // Add a program header. The PHDRS clause is syntactically distinct
4140 // from the SECTIONS clause, but we implement it with the SECTIONS
4141 // support because PHDRS is useless if there is no SECTIONS clause.
4144 Script_sections::add_phdr(const char* name
, size_t namelen
, unsigned int type
,
4145 bool includes_filehdr
, bool includes_phdrs
,
4146 bool is_flags_valid
, unsigned int flags
,
4147 Expression
* load_address
)
4149 if (this->phdrs_elements_
== NULL
)
4150 this->phdrs_elements_
= new Phdrs_elements();
4151 this->phdrs_elements_
->push_back(new Phdrs_element(name
, namelen
, type
,
4154 is_flags_valid
, flags
,
4158 // Return the number of segments we expect to create based on the
4159 // SECTIONS clause. This is used to implement SIZEOF_HEADERS.
4162 Script_sections::expected_segment_count(const Layout
* layout
) const
4164 // If we've already created the segments, we won't be adding any more.
4165 if (this->segments_created_
)
4168 if (this->saw_phdrs_clause())
4169 return this->phdrs_elements_
->size();
4171 Layout::Section_list sections
;
4172 layout
->get_allocated_sections(§ions
);
4174 // We assume that we will need two PT_LOAD segments.
4177 bool saw_note
= false;
4178 bool saw_tls
= false;
4179 bool saw_interp
= false;
4180 for (Layout::Section_list::const_iterator p
= sections
.begin();
4181 p
!= sections
.end();
4184 if ((*p
)->type() == elfcpp::SHT_NOTE
)
4186 // Assume that all note sections will fit into a single
4194 else if (((*p
)->flags() & elfcpp::SHF_TLS
) != 0)
4196 // There can only be one PT_TLS segment.
4203 else if (strcmp((*p
)->name(), ".interp") == 0)
4205 // There can only be one PT_INTERP segment.
4217 // Create the segments from a PHDRS clause. Return the segment which
4218 // should hold the file header and program headers, if any.
4221 Script_sections::create_segments_from_phdrs_clause(Layout
* layout
,
4222 uint64_t dot_alignment
)
4224 this->attach_sections_using_phdrs_clause(layout
);
4225 return this->set_phdrs_clause_addresses(layout
, dot_alignment
);
4228 // Create the segments from the PHDRS clause, and put the output
4229 // sections in them.
4232 Script_sections::attach_sections_using_phdrs_clause(Layout
* layout
)
4234 typedef std::map
<std::string
, Output_segment
*> Name_to_segment
;
4235 Name_to_segment name_to_segment
;
4236 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4237 p
!= this->phdrs_elements_
->end();
4239 name_to_segment
[(*p
)->name()] = (*p
)->create_segment(layout
);
4240 this->segments_created_
= true;
4242 // Walk through the output sections and attach them to segments.
4243 // Output sections in the script which do not list segments are
4244 // attached to the same set of segments as the immediately preceding
4247 String_list
* phdr_names
= NULL
;
4248 bool load_segments_only
= false;
4249 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4250 p
!= this->sections_elements_
->end();
4254 String_list
* old_phdr_names
= phdr_names
;
4255 Output_section
* os
= (*p
)->allocate_to_segment(&phdr_names
, &is_orphan
);
4259 elfcpp::Elf_Word seg_flags
=
4260 Layout::section_flags_to_segment(os
->flags());
4262 if (phdr_names
== NULL
)
4264 // Don't worry about empty orphan sections.
4265 if (is_orphan
&& os
->current_data_size() > 0)
4266 gold_error(_("allocated section %s not in any segment"),
4269 // To avoid later crashes drop this section into the first
4271 for (Phdrs_elements::const_iterator ppe
=
4272 this->phdrs_elements_
->begin();
4273 ppe
!= this->phdrs_elements_
->end();
4276 Output_segment
* oseg
= (*ppe
)->segment();
4277 if (oseg
->type() == elfcpp::PT_LOAD
)
4279 oseg
->add_output_section_to_load(layout
, os
, seg_flags
);
4287 // We see a list of segments names. Disable PT_LOAD segment only
4289 if (old_phdr_names
!= phdr_names
)
4290 load_segments_only
= false;
4292 // If this is an orphan section--one that was not explicitly
4293 // mentioned in the linker script--then it should not inherit
4294 // any segment type other than PT_LOAD. Otherwise, e.g., the
4295 // PT_INTERP segment will pick up following orphan sections,
4296 // which does not make sense. If this is not an orphan section,
4297 // we trust the linker script.
4300 // Enable PT_LOAD segments only filtering until we see another
4301 // list of segment names.
4302 load_segments_only
= true;
4305 bool in_load_segment
= false;
4306 for (String_list::const_iterator q
= phdr_names
->begin();
4307 q
!= phdr_names
->end();
4310 Name_to_segment::const_iterator r
= name_to_segment
.find(*q
);
4311 if (r
== name_to_segment
.end())
4312 gold_error(_("no segment %s"), q
->c_str());
4315 if (load_segments_only
4316 && r
->second
->type() != elfcpp::PT_LOAD
)
4319 if (r
->second
->type() != elfcpp::PT_LOAD
)
4320 r
->second
->add_output_section_to_nonload(os
, seg_flags
);
4323 r
->second
->add_output_section_to_load(layout
, os
, seg_flags
);
4324 if (in_load_segment
)
4325 gold_error(_("section in two PT_LOAD segments"));
4326 in_load_segment
= true;
4331 if (!in_load_segment
)
4332 gold_error(_("allocated section not in any PT_LOAD segment"));
4336 // Set the addresses for segments created from a PHDRS clause. Return
4337 // the segment which should hold the file header and program headers,
4341 Script_sections::set_phdrs_clause_addresses(Layout
* layout
,
4342 uint64_t dot_alignment
)
4344 Output_segment
* load_seg
= NULL
;
4345 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4346 p
!= this->phdrs_elements_
->end();
4349 // Note that we have to set the flags after adding the output
4350 // sections to the segment, as adding an output segment can
4351 // change the flags.
4352 (*p
)->set_flags_if_valid();
4354 Output_segment
* oseg
= (*p
)->segment();
4356 if (oseg
->type() != elfcpp::PT_LOAD
)
4358 // The addresses of non-PT_LOAD segments are set from the
4359 // PT_LOAD segments.
4360 if ((*p
)->has_load_address())
4361 gold_error(_("may only specify load address for PT_LOAD segment"));
4365 oseg
->set_minimum_p_align(dot_alignment
);
4367 // The output sections should have addresses from the SECTIONS
4368 // clause. The addresses don't have to be in order, so find the
4369 // one with the lowest load address. Use that to set the
4370 // address of the segment.
4372 Output_section
* osec
= oseg
->section_with_lowest_load_address();
4375 oseg
->set_addresses(0, 0);
4379 uint64_t vma
= osec
->address();
4380 uint64_t lma
= osec
->has_load_address() ? osec
->load_address() : vma
;
4382 // Override the load address of the section with the load
4383 // address specified for the segment.
4384 if ((*p
)->has_load_address())
4386 if (osec
->has_load_address())
4387 gold_warning(_("PHDRS load address overrides "
4388 "section %s load address"),
4391 lma
= (*p
)->load_address();
4394 bool headers
= (*p
)->includes_filehdr() && (*p
)->includes_phdrs();
4395 if (!headers
&& ((*p
)->includes_filehdr() || (*p
)->includes_phdrs()))
4397 // We could support this if we wanted to.
4398 gold_error(_("using only one of FILEHDR and PHDRS is "
4399 "not currently supported"));
4403 size_t sizeof_headers
= this->total_header_size(layout
);
4404 uint64_t subtract
= this->header_size_adjustment(lma
,
4406 if (lma
>= subtract
&& vma
>= subtract
)
4413 gold_error(_("sections loaded on first page without room "
4414 "for file and program headers "
4415 "are not supported"));
4418 if (load_seg
!= NULL
)
4419 gold_error(_("using FILEHDR and PHDRS on more than one "
4420 "PT_LOAD segment is not currently supported"));
4424 oseg
->set_addresses(vma
, lma
);
4430 // Add the file header and segment headers to non-load segments
4431 // specified in the PHDRS clause.
4434 Script_sections::put_headers_in_phdrs(Output_data
* file_header
,
4435 Output_data
* segment_headers
)
4437 gold_assert(this->saw_phdrs_clause());
4438 for (Phdrs_elements::iterator p
= this->phdrs_elements_
->begin();
4439 p
!= this->phdrs_elements_
->end();
4442 if ((*p
)->type() != elfcpp::PT_LOAD
)
4444 if ((*p
)->includes_phdrs())
4445 (*p
)->segment()->add_initial_output_data(segment_headers
);
4446 if ((*p
)->includes_filehdr())
4447 (*p
)->segment()->add_initial_output_data(file_header
);
4452 // Look for an output section by name and return the address, the load
4453 // address, the alignment, and the size. This is used when an
4454 // expression refers to an output section which was not actually
4455 // created. This returns true if the section was found, false
4459 Script_sections::get_output_section_info(const char* name
, uint64_t* address
,
4460 uint64_t* load_address
,
4461 uint64_t* addralign
,
4462 uint64_t* size
) const
4464 if (!this->saw_sections_clause_
)
4466 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4467 p
!= this->sections_elements_
->end();
4469 if ((*p
)->get_output_section_info(name
, address
, load_address
, addralign
,
4475 // Release all Output_segments. This remove all pointers to all
4479 Script_sections::release_segments()
4481 if (this->saw_phdrs_clause())
4483 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4484 p
!= this->phdrs_elements_
->end();
4486 (*p
)->release_segment();
4488 this->segments_created_
= false;
4491 // Print the SECTIONS clause to F for debugging.
4494 Script_sections::print(FILE* f
) const
4496 if (this->phdrs_elements_
!= NULL
)
4498 fprintf(f
, "PHDRS {\n");
4499 for (Phdrs_elements::const_iterator p
= this->phdrs_elements_
->begin();
4500 p
!= this->phdrs_elements_
->end();
4506 if (this->memory_regions_
!= NULL
)
4508 fprintf(f
, "MEMORY {\n");
4509 for (Memory_regions::const_iterator m
= this->memory_regions_
->begin();
4510 m
!= this->memory_regions_
->end();
4516 if (!this->saw_sections_clause_
)
4519 fprintf(f
, "SECTIONS {\n");
4521 for (Sections_elements::const_iterator p
= this->sections_elements_
->begin();
4522 p
!= this->sections_elements_
->end();
4529 } // End namespace gold.