1 // dwarf_reader.cc -- parse dwarf2/3 debug information
3 // Copyright 2007, 2008, 2009, 2010, 2011, 2012 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.
28 #include "elfcpp_swap.h"
32 #include "dwarf_reader.h"
33 #include "int_encoding.h"
34 #include "compressed_output.h"
38 // Class Sized_elf_reloc_mapper
40 // Initialize the relocation tracker for section RELOC_SHNDX.
42 template<int size
, bool big_endian
>
44 Sized_elf_reloc_mapper
<size
, big_endian
>::do_initialize(
45 unsigned int reloc_shndx
, unsigned int reloc_type
)
47 this->reloc_type_
= reloc_type
;
48 return this->track_relocs_
.initialize(this->object_
, reloc_shndx
,
52 // Looks in the symtab to see what section a symbol is in.
54 template<int size
, bool big_endian
>
56 Sized_elf_reloc_mapper
<size
, big_endian
>::symbol_section(
57 unsigned int symndx
, Address
* value
, bool* is_ordinary
)
59 const int symsize
= elfcpp::Elf_sizes
<size
>::sym_size
;
60 gold_assert(static_cast<off_t
>((symndx
+ 1) * symsize
) <= this->symtab_size_
);
61 elfcpp::Sym
<size
, big_endian
> elfsym(this->symtab_
+ symndx
* symsize
);
62 *value
= elfsym
.get_st_value();
63 return this->object_
->adjust_sym_shndx(symndx
, elfsym
.get_st_shndx(),
67 // Return the section index and offset within the section of
68 // the target of the relocation for RELOC_OFFSET.
70 template<int size
, bool big_endian
>
72 Sized_elf_reloc_mapper
<size
, big_endian
>::do_get_reloc_target(
73 off_t reloc_offset
, off_t
* target_offset
)
75 this->track_relocs_
.advance(reloc_offset
);
76 if (reloc_offset
!= this->track_relocs_
.next_offset())
78 unsigned int symndx
= this->track_relocs_
.next_symndx();
79 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
;
81 unsigned int target_shndx
= this->symbol_section(symndx
, &value
,
85 if (this->reloc_type_
== elfcpp::SHT_RELA
)
86 value
+= this->track_relocs_
.next_addend();
87 *target_offset
= value
;
91 static inline Elf_reloc_mapper
*
92 make_elf_reloc_mapper(Relobj
* object
, const unsigned char* symtab
,
95 if (object
->elfsize() == 32)
97 if (object
->is_big_endian())
99 #ifdef HAVE_TARGET_32_BIG
100 return new Sized_elf_reloc_mapper
<32, true>(object
, symtab
,
108 #ifdef HAVE_TARGET_32_LITTLE
109 return new Sized_elf_reloc_mapper
<32, false>(object
, symtab
,
116 else if (object
->elfsize() == 64)
118 if (object
->is_big_endian())
120 #ifdef HAVE_TARGET_64_BIG
121 return new Sized_elf_reloc_mapper
<64, true>(object
, symtab
,
129 #ifdef HAVE_TARGET_64_LITTLE
130 return new Sized_elf_reloc_mapper
<64, false>(object
, symtab
,
141 // class Dwarf_abbrev_table
144 Dwarf_abbrev_table::clear_abbrev_codes()
146 for (unsigned int code
= 0; code
< this->low_abbrev_code_max_
; ++code
)
148 if (this->low_abbrev_codes_
[code
] != NULL
)
150 delete this->low_abbrev_codes_
[code
];
151 this->low_abbrev_codes_
[code
] = NULL
;
154 for (Abbrev_code_table::iterator it
= this->high_abbrev_codes_
.begin();
155 it
!= this->high_abbrev_codes_
.end();
158 if (it
->second
!= NULL
)
161 this->high_abbrev_codes_
.clear();
164 // Read the abbrev table from an object file.
167 Dwarf_abbrev_table::do_read_abbrevs(
169 unsigned int abbrev_shndx
,
172 this->clear_abbrev_codes();
174 // If we don't have relocations, abbrev_shndx will be 0, and
175 // we'll have to hunt for the .debug_abbrev section.
176 if (abbrev_shndx
== 0 && this->abbrev_shndx_
> 0)
177 abbrev_shndx
= this->abbrev_shndx_
;
178 else if (abbrev_shndx
== 0)
180 for (unsigned int i
= 1; i
< object
->shnum(); ++i
)
182 std::string name
= object
->section_name(i
);
183 if (name
== ".debug_abbrev")
186 // Correct the offset. For incremental update links, we have a
187 // relocated offset that is relative to the output section, but
188 // here we need an offset relative to the input section.
189 abbrev_offset
-= object
->output_section_offset(i
);
193 if (abbrev_shndx
== 0)
197 // Get the section contents and decompress if necessary.
198 if (abbrev_shndx
!= this->abbrev_shndx_
)
200 if (this->owns_buffer_
&& this->buffer_
!= NULL
)
202 delete[] this->buffer_
;
203 this->owns_buffer_
= false;
206 section_size_type buffer_size
;
208 object
->decompressed_section_contents(abbrev_shndx
,
210 &this->owns_buffer_
);
211 this->buffer_end_
= this->buffer_
+ buffer_size
;
212 this->abbrev_shndx_
= abbrev_shndx
;
215 this->buffer_pos_
= this->buffer_
+ abbrev_offset
;
219 // Lookup the abbrev code entry for CODE. This function is called
220 // only when the abbrev code is not in the direct lookup table.
221 // It may be in the hash table, it may not have been read yet,
222 // or it may not exist in the abbrev table.
224 const Dwarf_abbrev_table::Abbrev_code
*
225 Dwarf_abbrev_table::do_get_abbrev(unsigned int code
)
227 // See if the abbrev code is already in the hash table.
228 Abbrev_code_table::const_iterator it
= this->high_abbrev_codes_
.find(code
);
229 if (it
!= this->high_abbrev_codes_
.end())
232 // Read and store abbrev code definitions until we find the
233 // one we're looking for.
236 // Read the abbrev code. A zero here indicates the end of the
239 if (this->buffer_pos_
>= this->buffer_end_
)
241 uint64_t nextcode
= read_unsigned_LEB_128(this->buffer_pos_
, &len
);
244 this->buffer_pos_
= this->buffer_end_
;
247 this->buffer_pos_
+= len
;
250 if (this->buffer_pos_
>= this->buffer_end_
)
252 uint64_t tag
= read_unsigned_LEB_128(this->buffer_pos_
, &len
);
253 this->buffer_pos_
+= len
;
255 // Read the has_children flag.
256 if (this->buffer_pos_
>= this->buffer_end_
)
258 bool has_children
= *this->buffer_pos_
== elfcpp::DW_CHILDREN_yes
;
259 this->buffer_pos_
+= 1;
261 // Read the list of (attribute, form) pairs.
262 Abbrev_code
* entry
= new Abbrev_code(tag
, has_children
);
265 // Read the attribute.
266 if (this->buffer_pos_
>= this->buffer_end_
)
268 uint64_t attr
= read_unsigned_LEB_128(this->buffer_pos_
, &len
);
269 this->buffer_pos_
+= len
;
272 if (this->buffer_pos_
>= this->buffer_end_
)
274 uint64_t form
= read_unsigned_LEB_128(this->buffer_pos_
, &len
);
275 this->buffer_pos_
+= len
;
277 // A (0,0) pair terminates the list.
278 if (attr
== 0 && form
== 0)
281 if (attr
== elfcpp::DW_AT_sibling
)
282 entry
->has_sibling_attribute
= true;
284 entry
->add_attribute(attr
, form
);
287 this->store_abbrev(nextcode
, entry
);
288 if (nextcode
== code
)
295 // class Dwarf_ranges_table
297 // Read the ranges table from an object file.
300 Dwarf_ranges_table::read_ranges_table(
302 const unsigned char* symtab
,
304 unsigned int ranges_shndx
)
306 // If we've already read this abbrev table, return immediately.
307 if (this->ranges_shndx_
> 0
308 && this->ranges_shndx_
== ranges_shndx
)
311 // If we don't have relocations, ranges_shndx will be 0, and
312 // we'll have to hunt for the .debug_ranges section.
313 if (ranges_shndx
== 0 && this->ranges_shndx_
> 0)
314 ranges_shndx
= this->ranges_shndx_
;
315 else if (ranges_shndx
== 0)
317 for (unsigned int i
= 1; i
< object
->shnum(); ++i
)
319 std::string name
= object
->section_name(i
);
320 if (name
== ".debug_ranges")
323 this->output_section_offset_
= object
->output_section_offset(i
);
327 if (ranges_shndx
== 0)
331 // Get the section contents and decompress if necessary.
332 if (ranges_shndx
!= this->ranges_shndx_
)
334 if (this->owns_ranges_buffer_
&& this->ranges_buffer_
!= NULL
)
336 delete[] this->ranges_buffer_
;
337 this->owns_ranges_buffer_
= false;
340 section_size_type buffer_size
;
341 this->ranges_buffer_
=
342 object
->decompressed_section_contents(ranges_shndx
,
344 &this->owns_ranges_buffer_
);
345 this->ranges_buffer_end_
= this->ranges_buffer_
+ buffer_size
;
346 this->ranges_shndx_
= ranges_shndx
;
349 if (this->ranges_reloc_mapper_
!= NULL
)
351 delete this->ranges_reloc_mapper_
;
352 this->ranges_reloc_mapper_
= NULL
;
355 // For incremental objects, we have no relocations.
356 if (object
->is_incremental())
359 // Find the relocation section for ".debug_ranges".
360 unsigned int reloc_shndx
= 0;
361 unsigned int reloc_type
= 0;
362 for (unsigned int i
= 0; i
< object
->shnum(); ++i
)
364 reloc_type
= object
->section_type(i
);
365 if ((reloc_type
== elfcpp::SHT_REL
366 || reloc_type
== elfcpp::SHT_RELA
)
367 && object
->section_info(i
) == ranges_shndx
)
374 this->ranges_reloc_mapper_
= make_elf_reloc_mapper(object
, symtab
,
376 this->ranges_reloc_mapper_
->initialize(reloc_shndx
, reloc_type
);
377 this->reloc_type_
= reloc_type
;
382 // Read a range list from section RANGES_SHNDX at offset RANGES_OFFSET.
385 Dwarf_ranges_table::read_range_list(
387 const unsigned char* symtab
,
389 unsigned int addr_size
,
390 unsigned int ranges_shndx
,
393 Dwarf_range_list
* ranges
;
395 if (!this->read_ranges_table(object
, symtab
, symtab_size
, ranges_shndx
))
398 // Correct the offset. For incremental update links, we have a
399 // relocated offset that is relative to the output section, but
400 // here we need an offset relative to the input section.
401 offset
-= this->output_section_offset_
;
403 // Read the range list at OFFSET.
404 ranges
= new Dwarf_range_list();
407 this->ranges_buffer_
+ offset
< this->ranges_buffer_end_
;
408 offset
+= 2 * addr_size
)
413 // Read the raw contents of the section.
416 start
= this->dwinfo_
->read_from_pointer
<32>(this->ranges_buffer_
418 end
= this->dwinfo_
->read_from_pointer
<32>(this->ranges_buffer_
423 start
= this->dwinfo_
->read_from_pointer
<64>(this->ranges_buffer_
425 end
= this->dwinfo_
->read_from_pointer
<64>(this->ranges_buffer_
429 // Check for relocations and adjust the values.
430 unsigned int shndx1
= 0;
431 unsigned int shndx2
= 0;
432 if (this->ranges_reloc_mapper_
!= NULL
)
434 shndx1
= this->lookup_reloc(offset
, &start
);
435 shndx2
= this->lookup_reloc(offset
+ addr_size
, &end
);
438 // End of list is marked by a pair of zeroes.
439 if (shndx1
== 0 && start
== 0 && end
== 0)
442 // A "base address selection entry" is identified by
443 // 0xffffffff for the first value of the pair. The second
444 // value is used as a base for subsequent range list entries.
445 if (shndx1
== 0 && start
== -1)
447 else if (shndx1
== shndx2
)
449 if (shndx1
== 0 || object
->is_section_included(shndx1
))
450 ranges
->add(shndx1
, base
+ start
, base
+ end
);
453 gold_warning(_("%s: DWARF info may be corrupt; offsets in a "
454 "range list entry are in different sections"),
455 object
->name().c_str());
461 // Look for a relocation at offset OFF in the range table,
462 // and return the section index and offset of the target.
465 Dwarf_ranges_table::lookup_reloc(off_t off
, off_t
* target_off
)
469 this->ranges_reloc_mapper_
->get_reloc_target(off
, &value
);
472 if (this->reloc_type_
== elfcpp::SHT_REL
)
473 *target_off
+= value
;
479 // class Dwarf_pubnames_table
481 // Read the pubnames section from the object file.
484 Dwarf_pubnames_table::read_section(Relobj
* object
, const unsigned char* symtab
,
487 section_size_type buffer_size
;
488 unsigned int shndx
= 0;
490 // Find the .debug_pubnames/pubtypes section.
491 const char* name
= (this->is_pubtypes_
493 : ".debug_pubnames");
494 for (unsigned int i
= 1; i
< object
->shnum(); ++i
)
496 if (object
->section_name(i
) == name
)
499 this->output_section_offset_
= object
->output_section_offset(i
);
507 this->buffer_
= object
->decompressed_section_contents(shndx
,
509 &this->owns_buffer_
);
510 if (this->buffer_
== NULL
)
512 this->buffer_end_
= this->buffer_
+ buffer_size
;
514 // For incremental objects, we have no relocations.
515 if (object
->is_incremental())
518 // Find the relocation section
519 unsigned int reloc_shndx
= 0;
520 unsigned int reloc_type
= 0;
521 for (unsigned int i
= 0; i
< object
->shnum(); ++i
)
523 reloc_type
= object
->section_type(i
);
524 if ((reloc_type
== elfcpp::SHT_REL
525 || reloc_type
== elfcpp::SHT_RELA
)
526 && object
->section_info(i
) == shndx
)
533 this->reloc_mapper_
= make_elf_reloc_mapper(object
, symtab
, symtab_size
);
534 this->reloc_mapper_
->initialize(reloc_shndx
, reloc_type
);
535 this->reloc_type_
= reloc_type
;
540 // Read the header for the set at OFFSET.
543 Dwarf_pubnames_table::read_header(off_t offset
)
545 // Make sure we have actually read the section.
546 gold_assert(this->buffer_
!= NULL
);
548 // Correct the offset. For incremental update links, we have a
549 // relocated offset that is relative to the output section, but
550 // here we need an offset relative to the input section.
551 offset
-= this->output_section_offset_
;
553 if (offset
< 0 || offset
+ 14 >= this->buffer_end_
- this->buffer_
)
556 const unsigned char* pinfo
= this->buffer_
+ offset
;
558 // Read the unit_length field.
559 uint64_t unit_length
= this->dwinfo_
->read_from_pointer
<32>(pinfo
);
561 if (unit_length
== 0xffffffff)
563 unit_length
= this->dwinfo_
->read_from_pointer
<64>(pinfo
);
564 this->unit_length_
= unit_length
+ 12;
566 this->offset_size_
= 8;
570 this->unit_length_
= unit_length
+ 4;
571 this->offset_size_
= 4;
574 // Check the version.
575 unsigned int version
= this->dwinfo_
->read_from_pointer
<16>(pinfo
);
580 this->reloc_mapper_
->get_reloc_target(pinfo
- this->buffer_
,
583 // Skip the debug_info_offset and debug_info_size fields.
584 pinfo
+= 2 * this->offset_size_
;
586 if (pinfo
>= this->buffer_end_
)
589 this->pinfo_
= pinfo
;
593 // Read the next name from the set.
596 Dwarf_pubnames_table::next_name()
598 const unsigned char* pinfo
= this->pinfo_
;
600 // Read the offset within the CU. If this is zero, we have reached
601 // the end of the list.
603 if (this->offset_size_
== 4)
604 offset
= this->dwinfo_
->read_from_pointer
<32>(&pinfo
);
606 offset
= this->dwinfo_
->read_from_pointer
<64>(&pinfo
);
610 // Return a pointer to the string at the current location,
611 // and advance the pointer to the next entry.
612 const char* ret
= reinterpret_cast<const char*>(pinfo
);
613 while (pinfo
< this->buffer_end_
&& *pinfo
!= '\0')
615 if (pinfo
< this->buffer_end_
)
618 this->pinfo_
= pinfo
;
624 Dwarf_die::Dwarf_die(
625 Dwarf_info_reader
* dwinfo
,
628 : dwinfo_(dwinfo
), parent_(parent
), die_offset_(die_offset
),
629 child_offset_(0), sibling_offset_(0), abbrev_code_(NULL
), attributes_(),
630 attributes_read_(false), name_(NULL
), name_off_(-1), linkage_name_(NULL
),
631 linkage_name_off_(-1), string_shndx_(0), specification_(0),
635 const unsigned char* pdie
= dwinfo
->buffer_at_offset(die_offset
);
638 unsigned int code
= read_unsigned_LEB_128(pdie
, &len
);
642 parent
->set_sibling_offset(die_offset
+ len
);
645 this->attr_offset_
= len
;
647 // Lookup the abbrev code in the abbrev table.
648 this->abbrev_code_
= dwinfo
->get_abbrev(code
);
651 // Read all the attributes of the DIE.
654 Dwarf_die::read_attributes()
656 if (this->attributes_read_
)
659 gold_assert(this->abbrev_code_
!= NULL
);
661 const unsigned char* pdie
=
662 this->dwinfo_
->buffer_at_offset(this->die_offset_
);
665 const unsigned char* pattr
= pdie
+ this->attr_offset_
;
667 unsigned int nattr
= this->abbrev_code_
->attributes
.size();
668 this->attributes_
.reserve(nattr
);
669 for (unsigned int i
= 0; i
< nattr
; ++i
)
672 unsigned int attr
= this->abbrev_code_
->attributes
[i
].attr
;
673 unsigned int form
= this->abbrev_code_
->attributes
[i
].form
;
674 if (form
== elfcpp::DW_FORM_indirect
)
676 form
= read_unsigned_LEB_128(pattr
, &len
);
679 off_t attr_off
= this->die_offset_
+ (pattr
- pdie
);
680 bool ref_form
= false;
681 Attribute_value attr_value
;
682 attr_value
.attr
= attr
;
683 attr_value
.form
= form
;
684 attr_value
.aux
.shndx
= 0;
687 case elfcpp::DW_FORM_flag_present
:
688 attr_value
.val
.intval
= 1;
690 case elfcpp::DW_FORM_strp
:
693 if (this->dwinfo_
->offset_size() == 4)
694 str_off
= this->dwinfo_
->read_from_pointer
<32>(&pattr
);
696 str_off
= this->dwinfo_
->read_from_pointer
<64>(&pattr
);
698 this->dwinfo_
->lookup_reloc(attr_off
, &str_off
);
699 attr_value
.aux
.shndx
= shndx
;
700 attr_value
.val
.refval
= str_off
;
703 case elfcpp::DW_FORM_sec_offset
:
706 if (this->dwinfo_
->offset_size() == 4)
707 sec_off
= this->dwinfo_
->read_from_pointer
<32>(&pattr
);
709 sec_off
= this->dwinfo_
->read_from_pointer
<64>(&pattr
);
711 this->dwinfo_
->lookup_reloc(attr_off
, &sec_off
);
712 attr_value
.aux
.shndx
= shndx
;
713 attr_value
.val
.refval
= sec_off
;
717 case elfcpp::DW_FORM_addr
:
718 case elfcpp::DW_FORM_ref_addr
:
721 if (this->dwinfo_
->address_size() == 4)
722 sec_off
= this->dwinfo_
->read_from_pointer
<32>(&pattr
);
724 sec_off
= this->dwinfo_
->read_from_pointer
<64>(&pattr
);
726 this->dwinfo_
->lookup_reloc(attr_off
, &sec_off
);
727 attr_value
.aux
.shndx
= shndx
;
728 attr_value
.val
.refval
= sec_off
;
732 case elfcpp::DW_FORM_block1
:
733 attr_value
.aux
.blocklen
= *pattr
++;
734 attr_value
.val
.blockval
= pattr
;
735 pattr
+= attr_value
.aux
.blocklen
;
737 case elfcpp::DW_FORM_block2
:
738 attr_value
.aux
.blocklen
=
739 this->dwinfo_
->read_from_pointer
<16>(&pattr
);
740 attr_value
.val
.blockval
= pattr
;
741 pattr
+= attr_value
.aux
.blocklen
;
743 case elfcpp::DW_FORM_block4
:
744 attr_value
.aux
.blocklen
=
745 this->dwinfo_
->read_from_pointer
<32>(&pattr
);
746 attr_value
.val
.blockval
= pattr
;
747 pattr
+= attr_value
.aux
.blocklen
;
749 case elfcpp::DW_FORM_block
:
750 case elfcpp::DW_FORM_exprloc
:
751 attr_value
.aux
.blocklen
= read_unsigned_LEB_128(pattr
, &len
);
752 attr_value
.val
.blockval
= pattr
+ len
;
753 pattr
+= len
+ attr_value
.aux
.blocklen
;
755 case elfcpp::DW_FORM_data1
:
756 case elfcpp::DW_FORM_flag
:
757 attr_value
.val
.intval
= *pattr
++;
759 case elfcpp::DW_FORM_ref1
:
760 attr_value
.val
.refval
= *pattr
++;
763 case elfcpp::DW_FORM_data2
:
764 attr_value
.val
.intval
=
765 this->dwinfo_
->read_from_pointer
<16>(&pattr
);
767 case elfcpp::DW_FORM_ref2
:
768 attr_value
.val
.refval
=
769 this->dwinfo_
->read_from_pointer
<16>(&pattr
);
772 case elfcpp::DW_FORM_data4
:
775 sec_off
= this->dwinfo_
->read_from_pointer
<32>(&pattr
);
777 this->dwinfo_
->lookup_reloc(attr_off
, &sec_off
);
778 attr_value
.aux
.shndx
= shndx
;
779 attr_value
.val
.intval
= sec_off
;
782 case elfcpp::DW_FORM_ref4
:
785 sec_off
= this->dwinfo_
->read_from_pointer
<32>(&pattr
);
787 this->dwinfo_
->lookup_reloc(attr_off
, &sec_off
);
788 attr_value
.aux
.shndx
= shndx
;
789 attr_value
.val
.refval
= sec_off
;
793 case elfcpp::DW_FORM_data8
:
796 sec_off
= this->dwinfo_
->read_from_pointer
<64>(&pattr
);
798 this->dwinfo_
->lookup_reloc(attr_off
, &sec_off
);
799 attr_value
.aux
.shndx
= shndx
;
800 attr_value
.val
.intval
= sec_off
;
803 case elfcpp::DW_FORM_ref_sig8
:
804 attr_value
.val
.uintval
=
805 this->dwinfo_
->read_from_pointer
<64>(&pattr
);
807 case elfcpp::DW_FORM_ref8
:
810 sec_off
= this->dwinfo_
->read_from_pointer
<64>(&pattr
);
812 this->dwinfo_
->lookup_reloc(attr_off
, &sec_off
);
813 attr_value
.aux
.shndx
= shndx
;
814 attr_value
.val
.refval
= sec_off
;
818 case elfcpp::DW_FORM_ref_udata
:
819 attr_value
.val
.refval
= read_unsigned_LEB_128(pattr
, &len
);
823 case elfcpp::DW_FORM_udata
:
824 case elfcpp::DW_FORM_GNU_addr_index
:
825 case elfcpp::DW_FORM_GNU_str_index
:
826 attr_value
.val
.uintval
= read_unsigned_LEB_128(pattr
, &len
);
829 case elfcpp::DW_FORM_sdata
:
830 attr_value
.val
.intval
= read_signed_LEB_128(pattr
, &len
);
833 case elfcpp::DW_FORM_string
:
834 attr_value
.val
.stringval
= reinterpret_cast<const char*>(pattr
);
835 len
= strlen(attr_value
.val
.stringval
);
842 // Cache the most frequently-requested attributes.
845 case elfcpp::DW_AT_name
:
846 if (form
== elfcpp::DW_FORM_string
)
847 this->name_
= attr_value
.val
.stringval
;
848 else if (form
== elfcpp::DW_FORM_strp
)
850 // All indirect strings should refer to the same
851 // string section, so we just save the last one seen.
852 this->string_shndx_
= attr_value
.aux
.shndx
;
853 this->name_off_
= attr_value
.val
.refval
;
856 case elfcpp::DW_AT_linkage_name
:
857 case elfcpp::DW_AT_MIPS_linkage_name
:
858 if (form
== elfcpp::DW_FORM_string
)
859 this->linkage_name_
= attr_value
.val
.stringval
;
860 else if (form
== elfcpp::DW_FORM_strp
)
862 // All indirect strings should refer to the same
863 // string section, so we just save the last one seen.
864 this->string_shndx_
= attr_value
.aux
.shndx
;
865 this->linkage_name_off_
= attr_value
.val
.refval
;
868 case elfcpp::DW_AT_specification
:
870 this->specification_
= attr_value
.val
.refval
;
872 case elfcpp::DW_AT_abstract_origin
:
874 this->abstract_origin_
= attr_value
.val
.refval
;
876 case elfcpp::DW_AT_sibling
:
877 if (ref_form
&& attr_value
.aux
.shndx
== 0)
878 this->sibling_offset_
= attr_value
.val
.refval
;
883 this->attributes_
.push_back(attr_value
);
886 // Now that we know where the next DIE begins, record the offset
887 // to avoid later recalculation.
888 if (this->has_children())
889 this->child_offset_
= this->die_offset_
+ (pattr
- pdie
);
891 this->sibling_offset_
= this->die_offset_
+ (pattr
- pdie
);
893 this->attributes_read_
= true;
897 // Skip all the attributes of the DIE and return the offset of the next DIE.
900 Dwarf_die::skip_attributes()
902 gold_assert(this->abbrev_code_
!= NULL
);
904 const unsigned char* pdie
=
905 this->dwinfo_
->buffer_at_offset(this->die_offset_
);
908 const unsigned char* pattr
= pdie
+ this->attr_offset_
;
910 for (unsigned int i
= 0; i
< this->abbrev_code_
->attributes
.size(); ++i
)
913 unsigned int form
= this->abbrev_code_
->attributes
[i
].form
;
914 if (form
== elfcpp::DW_FORM_indirect
)
916 form
= read_unsigned_LEB_128(pattr
, &len
);
921 case elfcpp::DW_FORM_flag_present
:
923 case elfcpp::DW_FORM_strp
:
924 case elfcpp::DW_FORM_sec_offset
:
925 pattr
+= this->dwinfo_
->offset_size();
927 case elfcpp::DW_FORM_addr
:
928 case elfcpp::DW_FORM_ref_addr
:
929 pattr
+= this->dwinfo_
->address_size();
931 case elfcpp::DW_FORM_block1
:
934 case elfcpp::DW_FORM_block2
:
937 block_size
= this->dwinfo_
->read_from_pointer
<16>(&pattr
);
941 case elfcpp::DW_FORM_block4
:
944 block_size
= this->dwinfo_
->read_from_pointer
<32>(&pattr
);
948 case elfcpp::DW_FORM_block
:
949 case elfcpp::DW_FORM_exprloc
:
952 block_size
= read_unsigned_LEB_128(pattr
, &len
);
953 pattr
+= len
+ block_size
;
956 case elfcpp::DW_FORM_data1
:
957 case elfcpp::DW_FORM_ref1
:
958 case elfcpp::DW_FORM_flag
:
961 case elfcpp::DW_FORM_data2
:
962 case elfcpp::DW_FORM_ref2
:
965 case elfcpp::DW_FORM_data4
:
966 case elfcpp::DW_FORM_ref4
:
969 case elfcpp::DW_FORM_data8
:
970 case elfcpp::DW_FORM_ref8
:
971 case elfcpp::DW_FORM_ref_sig8
:
974 case elfcpp::DW_FORM_ref_udata
:
975 case elfcpp::DW_FORM_udata
:
976 case elfcpp::DW_FORM_GNU_addr_index
:
977 case elfcpp::DW_FORM_GNU_str_index
:
978 read_unsigned_LEB_128(pattr
, &len
);
981 case elfcpp::DW_FORM_sdata
:
982 read_signed_LEB_128(pattr
, &len
);
985 case elfcpp::DW_FORM_string
:
986 len
= strlen(reinterpret_cast<const char*>(pattr
));
994 return this->die_offset_
+ (pattr
- pdie
);
997 // Get the name of the DIE and cache it.
1000 Dwarf_die::set_name()
1002 if (this->name_
!= NULL
|| !this->read_attributes())
1004 if (this->name_off_
!= -1)
1005 this->name_
= this->dwinfo_
->get_string(this->name_off_
,
1006 this->string_shndx_
);
1009 // Get the linkage name of the DIE and cache it.
1012 Dwarf_die::set_linkage_name()
1014 if (this->linkage_name_
!= NULL
|| !this->read_attributes())
1016 if (this->linkage_name_off_
!= -1)
1017 this->linkage_name_
= this->dwinfo_
->get_string(this->linkage_name_off_
,
1018 this->string_shndx_
);
1021 // Return the value of attribute ATTR.
1023 const Dwarf_die::Attribute_value
*
1024 Dwarf_die::attribute(unsigned int attr
)
1026 if (!this->read_attributes())
1028 for (unsigned int i
= 0; i
< this->attributes_
.size(); ++i
)
1030 if (this->attributes_
[i
].attr
== attr
)
1031 return &this->attributes_
[i
];
1037 Dwarf_die::string_attribute(unsigned int attr
)
1039 const Attribute_value
* attr_val
= this->attribute(attr
);
1040 if (attr_val
== NULL
)
1042 switch (attr_val
->form
)
1044 case elfcpp::DW_FORM_string
:
1045 return attr_val
->val
.stringval
;
1046 case elfcpp::DW_FORM_strp
:
1047 return this->dwinfo_
->get_string(attr_val
->val
.refval
,
1048 attr_val
->aux
.shndx
);
1055 Dwarf_die::int_attribute(unsigned int attr
)
1057 const Attribute_value
* attr_val
= this->attribute(attr
);
1058 if (attr_val
== NULL
)
1060 switch (attr_val
->form
)
1062 case elfcpp::DW_FORM_flag_present
:
1063 case elfcpp::DW_FORM_data1
:
1064 case elfcpp::DW_FORM_flag
:
1065 case elfcpp::DW_FORM_data2
:
1066 case elfcpp::DW_FORM_data4
:
1067 case elfcpp::DW_FORM_data8
:
1068 case elfcpp::DW_FORM_sdata
:
1069 return attr_val
->val
.intval
;
1076 Dwarf_die::uint_attribute(unsigned int attr
)
1078 const Attribute_value
* attr_val
= this->attribute(attr
);
1079 if (attr_val
== NULL
)
1081 switch (attr_val
->form
)
1083 case elfcpp::DW_FORM_flag_present
:
1084 case elfcpp::DW_FORM_data1
:
1085 case elfcpp::DW_FORM_flag
:
1086 case elfcpp::DW_FORM_data4
:
1087 case elfcpp::DW_FORM_data8
:
1088 case elfcpp::DW_FORM_ref_sig8
:
1089 case elfcpp::DW_FORM_udata
:
1090 return attr_val
->val
.uintval
;
1097 Dwarf_die::ref_attribute(unsigned int attr
, unsigned int* shndx
)
1099 const Attribute_value
* attr_val
= this->attribute(attr
);
1100 if (attr_val
== NULL
)
1102 switch (attr_val
->form
)
1104 case elfcpp::DW_FORM_sec_offset
:
1105 case elfcpp::DW_FORM_addr
:
1106 case elfcpp::DW_FORM_ref_addr
:
1107 case elfcpp::DW_FORM_ref1
:
1108 case elfcpp::DW_FORM_ref2
:
1109 case elfcpp::DW_FORM_ref4
:
1110 case elfcpp::DW_FORM_ref8
:
1111 case elfcpp::DW_FORM_ref_udata
:
1112 *shndx
= attr_val
->aux
.shndx
;
1113 return attr_val
->val
.refval
;
1114 case elfcpp::DW_FORM_ref_sig8
:
1115 *shndx
= attr_val
->aux
.shndx
;
1116 return attr_val
->val
.uintval
;
1117 case elfcpp::DW_FORM_data4
:
1118 case elfcpp::DW_FORM_data8
:
1119 *shndx
= attr_val
->aux
.shndx
;
1120 return attr_val
->val
.intval
;
1127 Dwarf_die::address_attribute(unsigned int attr
, unsigned int* shndx
)
1129 const Attribute_value
* attr_val
= this->attribute(attr
);
1130 if (attr_val
== NULL
|| attr_val
->form
!= elfcpp::DW_FORM_addr
)
1133 *shndx
= attr_val
->aux
.shndx
;
1134 return attr_val
->val
.refval
;
1137 // Return the offset of this DIE's first child.
1140 Dwarf_die::child_offset()
1142 gold_assert(this->abbrev_code_
!= NULL
);
1143 if (!this->has_children())
1145 if (this->child_offset_
== 0)
1146 this->child_offset_
= this->skip_attributes();
1147 return this->child_offset_
;
1150 // Return the offset of this DIE's next sibling.
1153 Dwarf_die::sibling_offset()
1155 gold_assert(this->abbrev_code_
!= NULL
);
1157 if (this->sibling_offset_
!= 0)
1158 return this->sibling_offset_
;
1160 if (!this->has_children())
1162 this->sibling_offset_
= this->skip_attributes();
1163 return this->sibling_offset_
;
1166 if (this->has_sibling_attribute())
1168 if (!this->read_attributes())
1170 if (this->sibling_offset_
!= 0)
1171 return this->sibling_offset_
;
1174 // Skip over the children.
1175 off_t child_offset
= this->child_offset();
1176 while (child_offset
> 0)
1178 Dwarf_die
die(this->dwinfo_
, child_offset
, this);
1179 // The Dwarf_die ctor will set this DIE's sibling offset
1180 // when it reads a zero abbrev code.
1183 child_offset
= die
.sibling_offset();
1186 // This should be set by now. If not, there was a problem reading
1187 // the DWARF info, and we return 0.
1188 return this->sibling_offset_
;
1191 // class Dwarf_info_reader
1193 // Begin parsing the debug info. This calls visit_compilation_unit()
1194 // or visit_type_unit() for each compilation or type unit found in the
1195 // section, and visit_die() for each top-level DIE.
1198 Dwarf_info_reader::parse()
1200 if (this->object_
->is_big_endian())
1202 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1203 this->do_parse
<true>();
1210 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1211 this->do_parse
<false>();
1218 template<bool big_endian
>
1220 Dwarf_info_reader::do_parse()
1222 // Get the section contents and decompress if necessary.
1223 section_size_type buffer_size
;
1225 this->buffer_
= this->object_
->decompressed_section_contents(this->shndx_
,
1228 if (this->buffer_
== NULL
|| buffer_size
== 0)
1230 this->buffer_end_
= this->buffer_
+ buffer_size
;
1232 // The offset of this input section in the output section.
1233 off_t section_offset
= this->object_
->output_section_offset(this->shndx_
);
1235 // Start tracking relocations for this section.
1236 this->reloc_mapper_
= make_elf_reloc_mapper(this->object_
, this->symtab_
,
1237 this->symtab_size_
);
1238 this->reloc_mapper_
->initialize(this->reloc_shndx_
, this->reloc_type_
);
1240 // Loop over compilation units (or type units).
1241 unsigned int abbrev_shndx
= this->abbrev_shndx_
;
1242 off_t abbrev_offset
= 0;
1243 const unsigned char* pinfo
= this->buffer_
;
1244 while (pinfo
< this->buffer_end_
)
1246 // Read the compilation (or type) unit header.
1247 const unsigned char* cu_start
= pinfo
;
1248 this->cu_offset_
= cu_start
- this->buffer_
;
1249 this->cu_length_
= this->buffer_end_
- cu_start
;
1251 // Read unit_length (4 or 12 bytes).
1252 if (!this->check_buffer(pinfo
+ 4))
1254 uint32_t unit_length
=
1255 elfcpp::Swap_unaligned
<32, big_endian
>::readval(pinfo
);
1257 if (unit_length
== 0xffffffff)
1259 if (!this->check_buffer(pinfo
+ 8))
1261 unit_length
= elfcpp::Swap_unaligned
<64, big_endian
>::readval(pinfo
);
1263 this->offset_size_
= 8;
1266 this->offset_size_
= 4;
1267 if (!this->check_buffer(pinfo
+ unit_length
))
1269 const unsigned char* cu_end
= pinfo
+ unit_length
;
1270 this->cu_length_
= cu_end
- cu_start
;
1271 if (!this->check_buffer(pinfo
+ 2 + this->offset_size_
+ 1))
1274 // Read version (2 bytes).
1276 elfcpp::Swap_unaligned
<16, big_endian
>::readval(pinfo
);
1279 // Read debug_abbrev_offset (4 or 8 bytes).
1280 if (this->offset_size_
== 4)
1281 abbrev_offset
= elfcpp::Swap_unaligned
<32, big_endian
>::readval(pinfo
);
1283 abbrev_offset
= elfcpp::Swap_unaligned
<64, big_endian
>::readval(pinfo
);
1284 if (this->reloc_shndx_
> 0)
1286 off_t reloc_offset
= pinfo
- this->buffer_
;
1289 this->reloc_mapper_
->get_reloc_target(reloc_offset
, &value
);
1290 if (abbrev_shndx
== 0)
1292 if (this->reloc_type_
== elfcpp::SHT_REL
)
1293 abbrev_offset
+= value
;
1295 abbrev_offset
= value
;
1297 pinfo
+= this->offset_size_
;
1299 // Read address_size (1 byte).
1300 this->address_size_
= *pinfo
++;
1302 // For type units, read the two extra fields.
1303 uint64_t signature
= 0;
1304 off_t type_offset
= 0;
1305 if (this->is_type_unit_
)
1307 if (!this->check_buffer(pinfo
+ 8 + this->offset_size_
))
1310 // Read type_signature (8 bytes).
1311 signature
= elfcpp::Swap_unaligned
<64, big_endian
>::readval(pinfo
);
1314 // Read type_offset (4 or 8 bytes).
1315 if (this->offset_size_
== 4)
1317 elfcpp::Swap_unaligned
<32, big_endian
>::readval(pinfo
);
1320 elfcpp::Swap_unaligned
<64, big_endian
>::readval(pinfo
);
1321 pinfo
+= this->offset_size_
;
1324 // Read the .debug_abbrev table.
1325 this->abbrev_table_
.read_abbrevs(this->object_
, abbrev_shndx
,
1328 // Visit the root DIE.
1329 Dwarf_die
root_die(this,
1330 pinfo
- (this->buffer_
+ this->cu_offset_
),
1332 if (root_die
.tag() != 0)
1334 // Visit the CU or TU.
1335 if (this->is_type_unit_
)
1336 this->visit_type_unit(section_offset
+ this->cu_offset_
,
1337 type_offset
, signature
, &root_die
);
1339 this->visit_compilation_unit(section_offset
+ this->cu_offset_
,
1340 cu_end
- cu_start
, &root_die
);
1343 // Advance to the next CU.
1349 delete[] this->buffer_
;
1350 this->buffer_
= NULL
;
1354 // Read the DWARF string table.
1357 Dwarf_info_reader::do_read_string_table(unsigned int string_shndx
)
1359 Relobj
* object
= this->object_
;
1361 // If we don't have relocations, string_shndx will be 0, and
1362 // we'll have to hunt for the .debug_str section.
1363 if (string_shndx
== 0)
1365 for (unsigned int i
= 1; i
< this->object_
->shnum(); ++i
)
1367 std::string name
= object
->section_name(i
);
1368 if (name
== ".debug_str")
1371 this->string_output_section_offset_
=
1372 object
->output_section_offset(i
);
1376 if (string_shndx
== 0)
1380 if (this->owns_string_buffer_
&& this->string_buffer_
!= NULL
)
1382 delete[] this->string_buffer_
;
1383 this->owns_string_buffer_
= false;
1386 // Get the secton contents and decompress if necessary.
1387 section_size_type buffer_size
;
1388 const unsigned char* buffer
=
1389 object
->decompressed_section_contents(string_shndx
,
1391 &this->owns_string_buffer_
);
1392 this->string_buffer_
= reinterpret_cast<const char*>(buffer
);
1393 this->string_buffer_end_
= this->string_buffer_
+ buffer_size
;
1394 this->string_shndx_
= string_shndx
;
1398 // Read a possibly unaligned integer of SIZE.
1399 template <int valsize
>
1400 inline typename
elfcpp::Valtype_base
<valsize
>::Valtype
1401 Dwarf_info_reader::read_from_pointer(const unsigned char* source
)
1403 typename
elfcpp::Valtype_base
<valsize
>::Valtype return_value
;
1404 if (this->object_
->is_big_endian())
1405 return_value
= elfcpp::Swap_unaligned
<valsize
, true>::readval(source
);
1407 return_value
= elfcpp::Swap_unaligned
<valsize
, false>::readval(source
);
1408 return return_value
;
1411 // Read a possibly unaligned integer of SIZE. Update SOURCE after read.
1412 template <int valsize
>
1413 inline typename
elfcpp::Valtype_base
<valsize
>::Valtype
1414 Dwarf_info_reader::read_from_pointer(const unsigned char** source
)
1416 typename
elfcpp::Valtype_base
<valsize
>::Valtype return_value
;
1417 if (this->object_
->is_big_endian())
1418 return_value
= elfcpp::Swap_unaligned
<valsize
, true>::readval(*source
);
1420 return_value
= elfcpp::Swap_unaligned
<valsize
, false>::readval(*source
);
1421 *source
+= valsize
/ 8;
1422 return return_value
;
1425 // Look for a relocation at offset ATTR_OFF in the dwarf info,
1426 // and return the section index and offset of the target.
1429 Dwarf_info_reader::lookup_reloc(off_t attr_off
, off_t
* target_off
)
1432 attr_off
+= this->cu_offset_
;
1433 unsigned int shndx
= this->reloc_mapper_
->get_reloc_target(attr_off
, &value
);
1436 if (this->reloc_type_
== elfcpp::SHT_REL
)
1437 *target_off
+= value
;
1439 *target_off
= value
;
1443 // Return a string from the DWARF string table.
1446 Dwarf_info_reader::get_string(off_t str_off
, unsigned int string_shndx
)
1448 if (!this->read_string_table(string_shndx
))
1451 // Correct the offset. For incremental update links, we have a
1452 // relocated offset that is relative to the output section, but
1453 // here we need an offset relative to the input section.
1454 str_off
-= this->string_output_section_offset_
;
1456 const char* p
= this->string_buffer_
+ str_off
;
1458 if (p
< this->string_buffer_
|| p
>= this->string_buffer_end_
)
1464 // The following are default, do-nothing, implementations of the
1465 // hook methods normally provided by a derived class. We provide
1466 // default implementations rather than no implementation so that
1467 // a derived class needs to implement only the hooks that it needs
1470 // Process a compilation unit and parse its child DIE.
1473 Dwarf_info_reader::visit_compilation_unit(off_t
, off_t
, Dwarf_die
*)
1477 // Process a type unit and parse its child DIE.
1480 Dwarf_info_reader::visit_type_unit(off_t
, off_t
, uint64_t, Dwarf_die
*)
1484 // Print a warning about a corrupt debug section.
1487 Dwarf_info_reader::warn_corrupt_debug_section() const
1489 gold_warning(_("%s: corrupt debug info in %s"),
1490 this->object_
->name().c_str(),
1491 this->object_
->section_name(this->shndx_
).c_str());
1494 // class Sized_dwarf_line_info
1496 struct LineStateMachine
1502 unsigned int shndx
; // the section address refers to
1503 bool is_stmt
; // stmt means statement.
1509 ResetLineStateMachine(struct LineStateMachine
* lsm
, bool default_is_stmt
)
1514 lsm
->column_num
= 0;
1516 lsm
->is_stmt
= default_is_stmt
;
1517 lsm
->basic_block
= false;
1518 lsm
->end_sequence
= false;
1521 template<int size
, bool big_endian
>
1522 Sized_dwarf_line_info
<size
, big_endian
>::Sized_dwarf_line_info(
1524 unsigned int read_shndx
)
1525 : data_valid_(false), buffer_(NULL
), buffer_start_(NULL
),
1526 reloc_mapper_(NULL
), symtab_buffer_(NULL
), directories_(), files_(),
1527 current_header_index_(-1)
1529 unsigned int debug_shndx
;
1531 for (debug_shndx
= 1; debug_shndx
< object
->shnum(); ++debug_shndx
)
1533 // FIXME: do this more efficiently: section_name() isn't super-fast
1534 std::string name
= object
->section_name(debug_shndx
);
1535 if (name
== ".debug_line" || name
== ".zdebug_line")
1537 section_size_type buffer_size
;
1538 bool is_new
= false;
1539 this->buffer_
= object
->decompressed_section_contents(debug_shndx
,
1543 this->buffer_start_
= this->buffer_
;
1544 this->buffer_end_
= this->buffer_
+ buffer_size
;
1548 if (this->buffer_
== NULL
)
1551 // Find the relocation section for ".debug_line".
1552 // We expect these for relobjs (.o's) but not dynobjs (.so's).
1553 unsigned int reloc_shndx
= 0;
1554 for (unsigned int i
= 0; i
< object
->shnum(); ++i
)
1556 unsigned int reloc_sh_type
= object
->section_type(i
);
1557 if ((reloc_sh_type
== elfcpp::SHT_REL
1558 || reloc_sh_type
== elfcpp::SHT_RELA
)
1559 && object
->section_info(i
) == debug_shndx
)
1562 this->track_relocs_type_
= reloc_sh_type
;
1567 // Finally, we need the symtab section to interpret the relocs.
1568 if (reloc_shndx
!= 0)
1570 unsigned int symtab_shndx
;
1571 for (symtab_shndx
= 0; symtab_shndx
< object
->shnum(); ++symtab_shndx
)
1572 if (object
->section_type(symtab_shndx
) == elfcpp::SHT_SYMTAB
)
1574 this->symtab_buffer_
= object
->section_contents(
1575 symtab_shndx
, &this->symtab_buffer_size_
, false);
1578 if (this->symtab_buffer_
== NULL
)
1582 this->reloc_mapper_
=
1583 new Sized_elf_reloc_mapper
<size
, big_endian
>(object
,
1584 this->symtab_buffer_
,
1585 this->symtab_buffer_size_
);
1586 if (!this->reloc_mapper_
->initialize(reloc_shndx
, this->track_relocs_type_
))
1589 // Now that we have successfully read all the data, parse the debug
1591 this->data_valid_
= true;
1592 this->read_line_mappings(read_shndx
);
1595 // Read the DWARF header.
1597 template<int size
, bool big_endian
>
1598 const unsigned char*
1599 Sized_dwarf_line_info
<size
, big_endian
>::read_header_prolog(
1600 const unsigned char* lineptr
)
1602 uint32_t initial_length
= elfcpp::Swap_unaligned
<32, big_endian
>::readval(lineptr
);
1605 // In DWARF2/3, if the initial length is all 1 bits, then the offset
1606 // size is 8 and we need to read the next 8 bytes for the real length.
1607 if (initial_length
== 0xffffffff)
1609 header_
.offset_size
= 8;
1610 initial_length
= elfcpp::Swap_unaligned
<64, big_endian
>::readval(lineptr
);
1614 header_
.offset_size
= 4;
1616 header_
.total_length
= initial_length
;
1618 gold_assert(lineptr
+ header_
.total_length
<= buffer_end_
);
1620 header_
.version
= elfcpp::Swap_unaligned
<16, big_endian
>::readval(lineptr
);
1623 if (header_
.offset_size
== 4)
1624 header_
.prologue_length
= elfcpp::Swap_unaligned
<32, big_endian
>::readval(lineptr
);
1626 header_
.prologue_length
= elfcpp::Swap_unaligned
<64, big_endian
>::readval(lineptr
);
1627 lineptr
+= header_
.offset_size
;
1629 header_
.min_insn_length
= *lineptr
;
1632 header_
.default_is_stmt
= *lineptr
;
1635 header_
.line_base
= *reinterpret_cast<const signed char*>(lineptr
);
1638 header_
.line_range
= *lineptr
;
1641 header_
.opcode_base
= *lineptr
;
1644 header_
.std_opcode_lengths
.resize(header_
.opcode_base
+ 1);
1645 header_
.std_opcode_lengths
[0] = 0;
1646 for (int i
= 1; i
< header_
.opcode_base
; i
++)
1648 header_
.std_opcode_lengths
[i
] = *lineptr
;
1655 // The header for a debug_line section is mildly complicated, because
1656 // the line info is very tightly encoded.
1658 template<int size
, bool big_endian
>
1659 const unsigned char*
1660 Sized_dwarf_line_info
<size
, big_endian
>::read_header_tables(
1661 const unsigned char* lineptr
)
1663 ++this->current_header_index_
;
1665 // Create a new directories_ entry and a new files_ entry for our new
1666 // header. We initialize each with a single empty element, because
1667 // dwarf indexes directory and filenames starting at 1.
1668 gold_assert(static_cast<int>(this->directories_
.size())
1669 == this->current_header_index_
);
1670 gold_assert(static_cast<int>(this->files_
.size())
1671 == this->current_header_index_
);
1672 this->directories_
.push_back(std::vector
<std::string
>(1));
1673 this->files_
.push_back(std::vector
<std::pair
<int, std::string
> >(1));
1675 // It is legal for the directory entry table to be empty.
1681 const char* dirname
= reinterpret_cast<const char*>(lineptr
);
1682 gold_assert(dirindex
1683 == static_cast<int>(this->directories_
.back().size()));
1684 this->directories_
.back().push_back(dirname
);
1685 lineptr
+= this->directories_
.back().back().size() + 1;
1691 // It is also legal for the file entry table to be empty.
1698 const char* filename
= reinterpret_cast<const char*>(lineptr
);
1699 lineptr
+= strlen(filename
) + 1;
1701 uint64_t dirindex
= read_unsigned_LEB_128(lineptr
, &len
);
1704 if (dirindex
>= this->directories_
.back().size())
1706 int dirindexi
= static_cast<int>(dirindex
);
1708 read_unsigned_LEB_128(lineptr
, &len
); // mod_time
1711 read_unsigned_LEB_128(lineptr
, &len
); // filelength
1714 gold_assert(fileindex
1715 == static_cast<int>(this->files_
.back().size()));
1716 this->files_
.back().push_back(std::make_pair(dirindexi
, filename
));
1725 // Process a single opcode in the .debug.line structure.
1727 template<int size
, bool big_endian
>
1729 Sized_dwarf_line_info
<size
, big_endian
>::process_one_opcode(
1730 const unsigned char* start
, struct LineStateMachine
* lsm
, size_t* len
)
1734 unsigned char opcode
= *start
;
1738 // If the opcode is great than the opcode_base, it is a special
1739 // opcode. Most line programs consist mainly of special opcodes.
1740 if (opcode
>= header_
.opcode_base
)
1742 opcode
-= header_
.opcode_base
;
1743 const int advance_address
= ((opcode
/ header_
.line_range
)
1744 * header_
.min_insn_length
);
1745 lsm
->address
+= advance_address
;
1747 const int advance_line
= ((opcode
% header_
.line_range
)
1748 + header_
.line_base
);
1749 lsm
->line_num
+= advance_line
;
1750 lsm
->basic_block
= true;
1755 // Otherwise, we have the regular opcodes
1758 case elfcpp::DW_LNS_copy
:
1759 lsm
->basic_block
= false;
1763 case elfcpp::DW_LNS_advance_pc
:
1765 const uint64_t advance_address
1766 = read_unsigned_LEB_128(start
, &templen
);
1768 lsm
->address
+= header_
.min_insn_length
* advance_address
;
1772 case elfcpp::DW_LNS_advance_line
:
1774 const uint64_t advance_line
= read_signed_LEB_128(start
, &templen
);
1776 lsm
->line_num
+= advance_line
;
1780 case elfcpp::DW_LNS_set_file
:
1782 const uint64_t fileno
= read_unsigned_LEB_128(start
, &templen
);
1784 lsm
->file_num
= fileno
;
1788 case elfcpp::DW_LNS_set_column
:
1790 const uint64_t colno
= read_unsigned_LEB_128(start
, &templen
);
1792 lsm
->column_num
= colno
;
1796 case elfcpp::DW_LNS_negate_stmt
:
1797 lsm
->is_stmt
= !lsm
->is_stmt
;
1800 case elfcpp::DW_LNS_set_basic_block
:
1801 lsm
->basic_block
= true;
1804 case elfcpp::DW_LNS_fixed_advance_pc
:
1806 int advance_address
;
1807 advance_address
= elfcpp::Swap_unaligned
<16, big_endian
>::readval(start
);
1809 lsm
->address
+= advance_address
;
1813 case elfcpp::DW_LNS_const_add_pc
:
1815 const int advance_address
= (header_
.min_insn_length
1816 * ((255 - header_
.opcode_base
)
1817 / header_
.line_range
));
1818 lsm
->address
+= advance_address
;
1822 case elfcpp::DW_LNS_extended_op
:
1824 const uint64_t extended_op_len
1825 = read_unsigned_LEB_128(start
, &templen
);
1827 oplen
+= templen
+ extended_op_len
;
1829 const unsigned char extended_op
= *start
;
1832 switch (extended_op
)
1834 case elfcpp::DW_LNE_end_sequence
:
1835 // This means that the current byte is the one immediately
1836 // after a set of instructions. Record the current line
1837 // for up to one less than the current address.
1839 lsm
->end_sequence
= true;
1843 case elfcpp::DW_LNE_set_address
:
1846 elfcpp::Swap_unaligned
<size
, big_endian
>::readval(start
);
1847 typename
Reloc_map::const_iterator it
1848 = this->reloc_map_
.find(start
- this->buffer_
);
1849 if (it
!= reloc_map_
.end())
1851 // If this is a SHT_RELA section, then ignore the
1852 // section contents. This assumes that this is a
1853 // straight reloc which just uses the reloc addend.
1854 // The reloc addend has already been included in the
1856 if (this->track_relocs_type_
== elfcpp::SHT_RELA
)
1858 // Add in the symbol value.
1859 lsm
->address
+= it
->second
.second
;
1860 lsm
->shndx
= it
->second
.first
;
1864 // If we're a normal .o file, with relocs, every
1865 // set_address should have an associated relocation.
1866 if (this->input_is_relobj())
1867 this->data_valid_
= false;
1871 case elfcpp::DW_LNE_define_file
:
1873 const char* filename
= reinterpret_cast<const char*>(start
);
1874 templen
= strlen(filename
) + 1;
1877 uint64_t dirindex
= read_unsigned_LEB_128(start
, &templen
);
1879 if (dirindex
>= this->directories_
.back().size())
1881 int dirindexi
= static_cast<int>(dirindex
);
1883 // This opcode takes two additional ULEB128 parameters
1884 // (mod_time and filelength), but we don't use those
1885 // values. Because OPLEN already tells us how far to
1886 // skip to the next opcode, we don't need to read
1889 this->files_
.back().push_back(std::make_pair(dirindexi
,
1899 // Ignore unknown opcode silently
1900 for (int i
= 0; i
< header_
.std_opcode_lengths
[opcode
]; i
++)
1903 read_unsigned_LEB_128(start
, &templen
);
1914 // Read the debug information at LINEPTR and store it in the line
1917 template<int size
, bool big_endian
>
1918 unsigned const char*
1919 Sized_dwarf_line_info
<size
, big_endian
>::read_lines(unsigned const char* lineptr
,
1922 struct LineStateMachine lsm
;
1924 // LENGTHSTART is the place the length field is based on. It is the
1925 // point in the header after the initial length field.
1926 const unsigned char* lengthstart
= buffer_
;
1928 // In 64 bit dwarf, the initial length is 12 bytes, because of the
1929 // 0xffffffff at the start.
1930 if (header_
.offset_size
== 8)
1935 while (lineptr
< lengthstart
+ header_
.total_length
)
1937 ResetLineStateMachine(&lsm
, header_
.default_is_stmt
);
1938 while (!lsm
.end_sequence
)
1941 bool add_line
= this->process_one_opcode(lineptr
, &lsm
, &oplength
);
1943 && (shndx
== -1U || lsm
.shndx
== -1U || shndx
== lsm
.shndx
))
1945 Offset_to_lineno_entry entry
1946 = { static_cast<off_t
>(lsm
.address
),
1947 this->current_header_index_
,
1948 static_cast<unsigned int>(lsm
.file_num
),
1949 true, lsm
.line_num
};
1950 std::vector
<Offset_to_lineno_entry
>&
1951 map(this->line_number_map_
[lsm
.shndx
]);
1952 // If we see two consecutive entries with the same
1953 // offset and a real line number, then mark the first
1954 // one as non-canonical.
1956 && (map
.back().offset
== static_cast<off_t
>(lsm
.address
))
1957 && lsm
.line_num
!= -1
1958 && map
.back().line_num
!= -1)
1959 map
.back().last_line_for_offset
= false;
1960 map
.push_back(entry
);
1962 lineptr
+= oplength
;
1966 return lengthstart
+ header_
.total_length
;
1969 // Read the relocations into a Reloc_map.
1971 template<int size
, bool big_endian
>
1973 Sized_dwarf_line_info
<size
, big_endian
>::read_relocs()
1975 if (this->symtab_buffer_
== NULL
)
1980 while ((reloc_offset
= this->reloc_mapper_
->next_offset()) != -1)
1982 const unsigned int shndx
=
1983 this->reloc_mapper_
->get_reloc_target(reloc_offset
, &value
);
1985 // There is no reason to record non-ordinary section indexes, or
1986 // SHN_UNDEF, because they will never match the real section.
1988 this->reloc_map_
[reloc_offset
] = std::make_pair(shndx
, value
);
1990 this->reloc_mapper_
->advance(reloc_offset
+ 1);
1994 // Read the line number info.
1996 template<int size
, bool big_endian
>
1998 Sized_dwarf_line_info
<size
, big_endian
>::read_line_mappings(unsigned int shndx
)
2000 gold_assert(this->data_valid_
== true);
2002 this->read_relocs();
2003 while (this->buffer_
< this->buffer_end_
)
2005 const unsigned char* lineptr
= this->buffer_
;
2006 lineptr
= this->read_header_prolog(lineptr
);
2007 lineptr
= this->read_header_tables(lineptr
);
2008 lineptr
= this->read_lines(lineptr
, shndx
);
2009 this->buffer_
= lineptr
;
2012 // Sort the lines numbers, so addr2line can use binary search.
2013 for (typename
Lineno_map::iterator it
= line_number_map_
.begin();
2014 it
!= line_number_map_
.end();
2016 // Each vector needs to be sorted by offset.
2017 std::sort(it
->second
.begin(), it
->second
.end());
2020 // Some processing depends on whether the input is a .o file or not.
2021 // For instance, .o files have relocs, and have .debug_lines
2022 // information on a per section basis. .so files, on the other hand,
2023 // lack relocs, and offsets are unique, so we can ignore the section
2026 template<int size
, bool big_endian
>
2028 Sized_dwarf_line_info
<size
, big_endian
>::input_is_relobj()
2030 // Only .o files have relocs and the symtab buffer that goes with them.
2031 return this->symtab_buffer_
!= NULL
;
2034 // Given an Offset_to_lineno_entry vector, and an offset, figure out
2035 // if the offset points into a function according to the vector (see
2036 // comments below for the algorithm). If it does, return an iterator
2037 // into the vector that points to the line-number that contains that
2038 // offset. If not, it returns vector::end().
2040 static std::vector
<Offset_to_lineno_entry
>::const_iterator
2041 offset_to_iterator(const std::vector
<Offset_to_lineno_entry
>* offsets
,
2044 const Offset_to_lineno_entry lookup_key
= { offset
, 0, 0, true, 0 };
2046 // lower_bound() returns the smallest offset which is >= lookup_key.
2047 // If no offset in offsets is >= lookup_key, returns end().
2048 std::vector
<Offset_to_lineno_entry
>::const_iterator it
2049 = std::lower_bound(offsets
->begin(), offsets
->end(), lookup_key
);
2051 // This code is easiest to understand with a concrete example.
2052 // Here's a possible offsets array:
2053 // {{offset = 3211, header_num = 0, file_num = 1, last, line_num = 16}, // 0
2054 // {offset = 3224, header_num = 0, file_num = 1, last, line_num = 20}, // 1
2055 // {offset = 3226, header_num = 0, file_num = 1, last, line_num = 22}, // 2
2056 // {offset = 3231, header_num = 0, file_num = 1, last, line_num = 25}, // 3
2057 // {offset = 3232, header_num = 0, file_num = 1, last, line_num = -1}, // 4
2058 // {offset = 3232, header_num = 0, file_num = 1, last, line_num = 65}, // 5
2059 // {offset = 3235, header_num = 0, file_num = 1, last, line_num = 66}, // 6
2060 // {offset = 3236, header_num = 0, file_num = 1, last, line_num = -1}, // 7
2061 // {offset = 5764, header_num = 0, file_num = 1, last, line_num = 48}, // 8
2062 // {offset = 5764, header_num = 0, file_num = 1,!last, line_num = 47}, // 9
2063 // {offset = 5765, header_num = 0, file_num = 1, last, line_num = 49}, // 10
2064 // {offset = 5767, header_num = 0, file_num = 1, last, line_num = 50}, // 11
2065 // {offset = 5768, header_num = 0, file_num = 1, last, line_num = 51}, // 12
2066 // {offset = 5773, header_num = 0, file_num = 1, last, line_num = -1}, // 13
2067 // {offset = 5787, header_num = 1, file_num = 1, last, line_num = 19}, // 14
2068 // {offset = 5790, header_num = 1, file_num = 1, last, line_num = 20}, // 15
2069 // {offset = 5793, header_num = 1, file_num = 1, last, line_num = 67}, // 16
2070 // {offset = 5793, header_num = 1, file_num = 1, last, line_num = -1}, // 17
2071 // {offset = 5793, header_num = 1, file_num = 1,!last, line_num = 66}, // 18
2072 // {offset = 5795, header_num = 1, file_num = 1, last, line_num = 68}, // 19
2073 // {offset = 5798, header_num = 1, file_num = 1, last, line_num = -1}, // 20
2074 // The entries with line_num == -1 mark the end of a function: the
2075 // associated offset is one past the last instruction in the
2076 // function. This can correspond to the beginning of the next
2077 // function (as is true for offset 3232); alternately, there can be
2078 // a gap between the end of one function and the start of the next
2079 // (as is true for some others, most obviously from 3236->5764).
2081 // Case 1: lookup_key has offset == 10. lower_bound returns
2082 // offsets[0]. Since it's not an exact match and we're
2083 // at the beginning of offsets, we return end() (invalid).
2084 // Case 2: lookup_key has offset 10000. lower_bound returns
2085 // offset[21] (end()). We return end() (invalid).
2086 // Case 3: lookup_key has offset == 3211. lower_bound matches
2087 // offsets[0] exactly, and that's the entry we return.
2088 // Case 4: lookup_key has offset == 3232. lower_bound returns
2089 // offsets[4]. That's an exact match, but indicates
2090 // end-of-function. We check if offsets[5] is also an
2091 // exact match but not end-of-function. It is, so we
2092 // return offsets[5].
2093 // Case 5: lookup_key has offset == 3214. lower_bound returns
2094 // offsets[1]. Since it's not an exact match, we back
2095 // up to the offset that's < lookup_key, offsets[0].
2096 // We note offsets[0] is a valid entry (not end-of-function),
2097 // so that's the entry we return.
2098 // Case 6: lookup_key has offset == 4000. lower_bound returns
2099 // offsets[8]. Since it's not an exact match, we back
2100 // up to offsets[7]. Since offsets[7] indicates
2101 // end-of-function, we know lookup_key is between
2102 // functions, so we return end() (not a valid offset).
2103 // Case 7: lookup_key has offset == 5794. lower_bound returns
2104 // offsets[19]. Since it's not an exact match, we back
2105 // up to offsets[16]. Note we back up to the *first*
2106 // entry with offset 5793, not just offsets[19-1].
2107 // We note offsets[16] is a valid entry, so we return it.
2108 // If offsets[16] had had line_num == -1, we would have
2109 // checked offsets[17]. The reason for this is that
2110 // 16 and 17 can be in an arbitrary order, since we sort
2111 // only by offset and last_line_for_offset. (Note it
2112 // doesn't help to use line_number as a tertiary sort key,
2113 // since sometimes we want the -1 to be first and sometimes
2114 // we want it to be last.)
2116 // This deals with cases (1) and (2).
2117 if ((it
== offsets
->begin() && offset
< it
->offset
)
2118 || it
== offsets
->end())
2119 return offsets
->end();
2121 // This deals with cases (3) and (4).
2122 if (offset
== it
->offset
)
2124 while (it
!= offsets
->end()
2125 && it
->offset
== offset
2126 && it
->line_num
== -1)
2128 if (it
== offsets
->end() || it
->offset
!= offset
)
2129 return offsets
->end();
2134 // This handles the first part of case (7) -- we back up to the
2135 // *first* entry that has the offset that's behind us.
2136 gold_assert(it
!= offsets
->begin());
2137 std::vector
<Offset_to_lineno_entry
>::const_iterator range_end
= it
;
2139 const off_t range_value
= it
->offset
;
2140 while (it
!= offsets
->begin() && (it
-1)->offset
== range_value
)
2143 // This handles cases (5), (6), and (7): if any entry in the
2144 // equal_range [it, range_end) has a line_num != -1, it's a valid
2145 // match. If not, we're not in a function. The line number we saw
2146 // last for an offset will be sorted first, so it'll get returned if
2148 for (; it
!= range_end
; ++it
)
2149 if (it
->line_num
!= -1)
2151 return offsets
->end();
2154 // Returns the canonical filename:lineno for the address passed in.
2155 // If other_lines is not NULL, appends the non-canonical lines
2156 // assigned to the same address.
2158 template<int size
, bool big_endian
>
2160 Sized_dwarf_line_info
<size
, big_endian
>::do_addr2line(
2163 std::vector
<std::string
>* other_lines
)
2165 if (this->data_valid_
== false)
2168 const std::vector
<Offset_to_lineno_entry
>* offsets
;
2169 // If we do not have reloc information, then our input is a .so or
2170 // some similar data structure where all the information is held in
2171 // the offset. In that case, we ignore the input shndx.
2172 if (this->input_is_relobj())
2173 offsets
= &this->line_number_map_
[shndx
];
2175 offsets
= &this->line_number_map_
[-1U];
2176 if (offsets
->empty())
2179 typename
std::vector
<Offset_to_lineno_entry
>::const_iterator it
2180 = offset_to_iterator(offsets
, offset
);
2181 if (it
== offsets
->end())
2184 std::string result
= this->format_file_lineno(*it
);
2185 if (other_lines
!= NULL
)
2186 for (++it
; it
!= offsets
->end() && it
->offset
== offset
; ++it
)
2188 if (it
->line_num
== -1)
2189 continue; // The end of a previous function.
2190 other_lines
->push_back(this->format_file_lineno(*it
));
2195 // Convert the file_num + line_num into a string.
2197 template<int size
, bool big_endian
>
2199 Sized_dwarf_line_info
<size
, big_endian
>::format_file_lineno(
2200 const Offset_to_lineno_entry
& loc
) const
2204 gold_assert(loc
.header_num
< static_cast<int>(this->files_
.size()));
2205 gold_assert(loc
.file_num
2206 < static_cast<unsigned int>(this->files_
[loc
.header_num
].size()));
2207 const std::pair
<int, std::string
>& filename_pair
2208 = this->files_
[loc
.header_num
][loc
.file_num
];
2209 const std::string
& filename
= filename_pair
.second
;
2211 gold_assert(loc
.header_num
< static_cast<int>(this->directories_
.size()));
2212 gold_assert(filename_pair
.first
2213 < static_cast<int>(this->directories_
[loc
.header_num
].size()));
2214 const std::string
& dirname
2215 = this->directories_
[loc
.header_num
][filename_pair
.first
];
2217 if (!dirname
.empty())
2226 char buffer
[64]; // enough to hold a line number
2227 snprintf(buffer
, sizeof(buffer
), "%d", loc
.line_num
);
2234 // Dwarf_line_info routines.
2236 static unsigned int next_generation_count
= 0;
2238 struct Addr2line_cache_entry
2242 Dwarf_line_info
* dwarf_line_info
;
2243 unsigned int generation_count
;
2244 unsigned int access_count
;
2246 Addr2line_cache_entry(Object
* o
, unsigned int s
, Dwarf_line_info
* d
)
2247 : object(o
), shndx(s
), dwarf_line_info(d
),
2248 generation_count(next_generation_count
), access_count(0)
2250 if (next_generation_count
< (1U << 31))
2251 ++next_generation_count
;
2254 // We expect this cache to be small, so don't bother with a hashtable
2255 // or priority queue or anything: just use a simple vector.
2256 static std::vector
<Addr2line_cache_entry
> addr2line_cache
;
2259 Dwarf_line_info::one_addr2line(Object
* object
,
2260 unsigned int shndx
, off_t offset
,
2262 std::vector
<std::string
>* other_lines
)
2264 Dwarf_line_info
* lineinfo
= NULL
;
2265 std::vector
<Addr2line_cache_entry
>::iterator it
;
2267 // First, check the cache. If we hit, update the counts.
2268 for (it
= addr2line_cache
.begin(); it
!= addr2line_cache
.end(); ++it
)
2270 if (it
->object
== object
&& it
->shndx
== shndx
)
2272 lineinfo
= it
->dwarf_line_info
;
2273 it
->generation_count
= next_generation_count
;
2274 // We cap generation_count at 2^31 -1 to avoid overflow.
2275 if (next_generation_count
< (1U << 31))
2276 ++next_generation_count
;
2277 // We cap access_count at 31 so 2^access_count doesn't overflow
2278 if (it
->access_count
< 31)
2284 // If we don't hit the cache, create a new object and insert into the
2286 if (lineinfo
== NULL
)
2288 switch (parameters
->size_and_endianness())
2290 #ifdef HAVE_TARGET_32_LITTLE
2291 case Parameters::TARGET_32_LITTLE
:
2292 lineinfo
= new Sized_dwarf_line_info
<32, false>(object
, shndx
); break;
2294 #ifdef HAVE_TARGET_32_BIG
2295 case Parameters::TARGET_32_BIG
:
2296 lineinfo
= new Sized_dwarf_line_info
<32, true>(object
, shndx
); break;
2298 #ifdef HAVE_TARGET_64_LITTLE
2299 case Parameters::TARGET_64_LITTLE
:
2300 lineinfo
= new Sized_dwarf_line_info
<64, false>(object
, shndx
); break;
2302 #ifdef HAVE_TARGET_64_BIG
2303 case Parameters::TARGET_64_BIG
:
2304 lineinfo
= new Sized_dwarf_line_info
<64, true>(object
, shndx
); break;
2309 addr2line_cache
.push_back(Addr2line_cache_entry(object
, shndx
, lineinfo
));
2312 // Now that we have our object, figure out the answer
2313 std::string retval
= lineinfo
->addr2line(shndx
, offset
, other_lines
);
2315 // Finally, if our cache has grown too big, delete old objects. We
2316 // assume the common (probably only) case is deleting only one object.
2317 // We use a pretty simple scheme to evict: function of LRU and MFU.
2318 while (addr2line_cache
.size() > cache_size
)
2320 unsigned int lowest_score
= ~0U;
2321 std::vector
<Addr2line_cache_entry
>::iterator lowest
2322 = addr2line_cache
.end();
2323 for (it
= addr2line_cache
.begin(); it
!= addr2line_cache
.end(); ++it
)
2325 const unsigned int score
= (it
->generation_count
2326 + (1U << it
->access_count
));
2327 if (score
< lowest_score
)
2329 lowest_score
= score
;
2333 if (lowest
!= addr2line_cache
.end())
2335 delete lowest
->dwarf_line_info
;
2336 addr2line_cache
.erase(lowest
);
2344 Dwarf_line_info::clear_addr2line_cache()
2346 for (std::vector
<Addr2line_cache_entry
>::iterator it
= addr2line_cache
.begin();
2347 it
!= addr2line_cache
.end();
2349 delete it
->dwarf_line_info
;
2350 addr2line_cache
.clear();
2353 #ifdef HAVE_TARGET_32_LITTLE
2355 class Sized_dwarf_line_info
<32, false>;
2358 #ifdef HAVE_TARGET_32_BIG
2360 class Sized_dwarf_line_info
<32, true>;
2363 #ifdef HAVE_TARGET_64_LITTLE
2365 class Sized_dwarf_line_info
<64, false>;
2368 #ifdef HAVE_TARGET_64_BIG
2370 class Sized_dwarf_line_info
<64, true>;
2373 } // End namespace gold.