Incorporate ARI web page generator into GDB sources.
[deliverable/binutils-gdb.git] / gold / dwarf_reader.cc
CommitLineData
5c2c6c95
ILT
1// dwarf_reader.cc -- parse dwarf2/3 debug information
2
c1027032 3// Copyright 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
5c2c6c95
ILT
4// Written by Ian Lance Taylor <iant@google.com>.
5
6// This file is part of gold.
7
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.
12
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.
17
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.
22
23#include "gold.h"
24
04bf7072 25#include <algorithm>
e4e5049b 26#include <vector>
04bf7072 27
5c2c6c95
ILT
28#include "elfcpp_swap.h"
29#include "dwarf.h"
24badc65 30#include "object.h"
4c50553d 31#include "reloc.h"
5c2c6c95 32#include "dwarf_reader.h"
4f787271 33#include "int_encoding.h"
a2e47362 34#include "compressed_output.h"
5c2c6c95 35
62b01cb5 36namespace gold {
5c2c6c95 37
c1027032
CC
38// Class Sized_elf_reloc_mapper
39
40// Initialize the relocation tracker for section RELOC_SHNDX.
41
42template<int size, bool big_endian>
43bool
44Sized_elf_reloc_mapper<size, big_endian>::do_initialize(
45 unsigned int reloc_shndx, unsigned int reloc_type)
46{
47 this->reloc_type_ = reloc_type;
48 return this->track_relocs_.initialize(this->object_, reloc_shndx,
49 reloc_type);
50}
51
52// Looks in the symtab to see what section a symbol is in.
53
54template<int size, bool big_endian>
55unsigned int
56Sized_elf_reloc_mapper<size, big_endian>::symbol_section(
57 unsigned int symndx, Address* value, bool* is_ordinary)
58{
59 const int symsize = elfcpp::Elf_sizes<size>::sym_size;
60 gold_assert((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(),
64 is_ordinary);
65}
66
67// Return the section index and offset within the section of
68// the target of the relocation for RELOC_OFFSET.
69
70template<int size, bool big_endian>
71unsigned int
72Sized_elf_reloc_mapper<size, big_endian>::do_get_reloc_target(
73 off_t reloc_offset, off_t* target_offset)
74{
75 this->track_relocs_.advance(reloc_offset);
76 if (reloc_offset != this->track_relocs_.next_offset())
77 return 0;
78 unsigned int symndx = this->track_relocs_.next_symndx();
79 typename elfcpp::Elf_types<size>::Elf_Addr value;
80 bool is_ordinary;
81 unsigned int target_shndx = this->symbol_section(symndx, &value,
82 &is_ordinary);
83 if (!is_ordinary)
84 return 0;
85 if (this->reloc_type_ == elfcpp::SHT_RELA)
86 value += this->track_relocs_.next_addend();
87 *target_offset = value;
88 return target_shndx;
89}
90
91static inline Elf_reloc_mapper*
9fc236f3 92make_elf_reloc_mapper(Relobj* object, const unsigned char* symtab,
c1027032
CC
93 off_t symtab_size)
94{
9fc236f3 95 if (object->elfsize() == 32)
c1027032 96 {
9fc236f3
CC
97 if (object->is_big_endian())
98 {
c1027032 99#ifdef HAVE_TARGET_32_BIG
9fc236f3
CC
100 return new Sized_elf_reloc_mapper<32, true>(object, symtab,
101 symtab_size);
102#else
103 gold_unreachable();
c1027032 104#endif
9fc236f3
CC
105 }
106 else
107 {
108#ifdef HAVE_TARGET_32_LITTLE
109 return new Sized_elf_reloc_mapper<32, false>(object, symtab,
110 symtab_size);
111#else
112 gold_unreachable();
c1027032 113#endif
9fc236f3
CC
114 }
115 }
116 else if (object->elfsize() == 64)
117 {
118 if (object->is_big_endian())
119 {
c1027032 120#ifdef HAVE_TARGET_64_BIG
9fc236f3
CC
121 return new Sized_elf_reloc_mapper<64, true>(object, symtab,
122 symtab_size);
123#else
124 gold_unreachable();
c1027032 125#endif
9fc236f3
CC
126 }
127 else
128 {
129#ifdef HAVE_TARGET_64_LITTLE
130 return new Sized_elf_reloc_mapper<64, false>(object, symtab,
131 symtab_size);
132#else
133 gold_unreachable();
134#endif
135 }
c1027032 136 }
9fc236f3
CC
137 else
138 gold_unreachable();
c1027032
CC
139}
140
141// class Dwarf_abbrev_table
142
143void
144Dwarf_abbrev_table::clear_abbrev_codes()
145{
146 for (unsigned int code = 0; code < this->low_abbrev_code_max_; ++code)
147 {
148 if (this->low_abbrev_codes_[code] != NULL)
149 {
150 delete this->low_abbrev_codes_[code];
151 this->low_abbrev_codes_[code] = NULL;
152 }
153 }
154 for (Abbrev_code_table::iterator it = this->high_abbrev_codes_.begin();
155 it != this->high_abbrev_codes_.end();
156 ++it)
157 {
158 if (it->second != NULL)
159 delete it->second;
160 }
161 this->high_abbrev_codes_.clear();
162}
163
164// Read the abbrev table from an object file.
165
166bool
167Dwarf_abbrev_table::do_read_abbrevs(
168 Relobj* object,
169 unsigned int abbrev_shndx,
170 off_t abbrev_offset)
171{
172 this->clear_abbrev_codes();
173
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)
179 {
180 for (unsigned int i = 1; i < object->shnum(); ++i)
181 {
182 std::string name = object->section_name(i);
183 if (name == ".debug_abbrev")
184 {
185 abbrev_shndx = i;
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);
190 break;
191 }
192 }
193 if (abbrev_shndx == 0)
194 return false;
195 }
196
197 // Get the section contents and decompress if necessary.
198 if (abbrev_shndx != this->abbrev_shndx_)
199 {
200 if (this->owns_buffer_ && this->buffer_ != NULL)
201 {
202 delete[] this->buffer_;
203 this->owns_buffer_ = false;
204 }
205
206 section_size_type buffer_size;
207 this->buffer_ =
208 object->decompressed_section_contents(abbrev_shndx,
209 &buffer_size,
210 &this->owns_buffer_);
211 this->buffer_end_ = this->buffer_ + buffer_size;
212 this->abbrev_shndx_ = abbrev_shndx;
213 }
214
215 this->buffer_pos_ = this->buffer_ + abbrev_offset;
216 return true;
217}
218
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.
223
224const Dwarf_abbrev_table::Abbrev_code*
225Dwarf_abbrev_table::do_get_abbrev(unsigned int code)
226{
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())
230 return it->second;
231
232 // Read and store abbrev code definitions until we find the
233 // one we're looking for.
234 for (;;)
235 {
236 // Read the abbrev code. A zero here indicates the end of the
237 // abbrev table.
238 size_t len;
239 if (this->buffer_pos_ >= this->buffer_end_)
240 return NULL;
241 uint64_t nextcode = read_unsigned_LEB_128(this->buffer_pos_, &len);
242 if (nextcode == 0)
243 {
244 this->buffer_pos_ = this->buffer_end_;
245 return NULL;
246 }
247 this->buffer_pos_ += len;
248
249 // Read the tag.
250 if (this->buffer_pos_ >= this->buffer_end_)
251 return NULL;
252 uint64_t tag = read_unsigned_LEB_128(this->buffer_pos_, &len);
253 this->buffer_pos_ += len;
254
255 // Read the has_children flag.
256 if (this->buffer_pos_ >= this->buffer_end_)
257 return NULL;
258 bool has_children = *this->buffer_pos_ == elfcpp::DW_CHILDREN_yes;
259 this->buffer_pos_ += 1;
260
261 // Read the list of (attribute, form) pairs.
262 Abbrev_code* entry = new Abbrev_code(tag, has_children);
263 for (;;)
264 {
265 // Read the attribute.
266 if (this->buffer_pos_ >= this->buffer_end_)
267 return NULL;
268 uint64_t attr = read_unsigned_LEB_128(this->buffer_pos_, &len);
269 this->buffer_pos_ += len;
270
271 // Read the form.
272 if (this->buffer_pos_ >= this->buffer_end_)
273 return NULL;
274 uint64_t form = read_unsigned_LEB_128(this->buffer_pos_, &len);
275 this->buffer_pos_ += len;
276
277 // A (0,0) pair terminates the list.
278 if (attr == 0 && form == 0)
279 break;
280
281 if (attr == elfcpp::DW_AT_sibling)
282 entry->has_sibling_attribute = true;
283
284 entry->add_attribute(attr, form);
285 }
286
287 this->store_abbrev(nextcode, entry);
288 if (nextcode == code)
289 return entry;
290 }
291
292 return NULL;
293}
294
295// class Dwarf_ranges_table
296
297// Read the ranges table from an object file.
298
299bool
300Dwarf_ranges_table::read_ranges_table(
301 Relobj* object,
302 const unsigned char* symtab,
303 off_t symtab_size,
304 unsigned int ranges_shndx)
305{
306 // If we've already read this abbrev table, return immediately.
307 if (this->ranges_shndx_ > 0
308 && this->ranges_shndx_ == ranges_shndx)
309 return true;
310
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)
316 {
317 for (unsigned int i = 1; i < object->shnum(); ++i)
318 {
319 std::string name = object->section_name(i);
320 if (name == ".debug_ranges")
321 {
322 ranges_shndx = i;
323 this->output_section_offset_ = object->output_section_offset(i);
324 break;
325 }
326 }
327 if (ranges_shndx == 0)
328 return false;
329 }
330
331 // Get the section contents and decompress if necessary.
332 if (ranges_shndx != this->ranges_shndx_)
333 {
334 if (this->owns_ranges_buffer_ && this->ranges_buffer_ != NULL)
335 {
336 delete[] this->ranges_buffer_;
337 this->owns_ranges_buffer_ = false;
338 }
339
340 section_size_type buffer_size;
341 this->ranges_buffer_ =
342 object->decompressed_section_contents(ranges_shndx,
343 &buffer_size,
344 &this->owns_ranges_buffer_);
345 this->ranges_buffer_end_ = this->ranges_buffer_ + buffer_size;
346 this->ranges_shndx_ = ranges_shndx;
347 }
348
349 if (this->ranges_reloc_mapper_ != NULL)
350 {
351 delete this->ranges_reloc_mapper_;
352 this->ranges_reloc_mapper_ = NULL;
353 }
354
355 // For incremental objects, we have no relocations.
356 if (object->is_incremental())
357 return true;
358
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)
363 {
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)
368 {
369 reloc_shndx = i;
370 break;
371 }
372 }
373
374 this->ranges_reloc_mapper_ = make_elf_reloc_mapper(object, symtab,
375 symtab_size);
376 this->ranges_reloc_mapper_->initialize(reloc_shndx, reloc_type);
377
378 return true;
379}
380
381// Read a range list from section RANGES_SHNDX at offset RANGES_OFFSET.
382
383Dwarf_range_list*
384Dwarf_ranges_table::read_range_list(
385 Relobj* object,
386 const unsigned char* symtab,
387 off_t symtab_size,
388 unsigned int addr_size,
389 unsigned int ranges_shndx,
390 off_t offset)
391{
392 Dwarf_range_list* ranges;
393
394 if (!this->read_ranges_table(object, symtab, symtab_size, ranges_shndx))
395 return NULL;
396
397 // Correct the offset. For incremental update links, we have a
398 // relocated offset that is relative to the output section, but
399 // here we need an offset relative to the input section.
400 offset -= this->output_section_offset_;
401
402 // Read the range list at OFFSET.
403 ranges = new Dwarf_range_list();
404 off_t base = 0;
405 for (;
406 this->ranges_buffer_ + offset < this->ranges_buffer_end_;
407 offset += 2 * addr_size)
408 {
409 off_t start;
410 off_t end;
411
412 // Read the raw contents of the section.
413 if (addr_size == 4)
414 {
ed5d6712
CC
415 start = this->dwinfo_->read_from_pointer<32>(this->ranges_buffer_
416 + offset);
417 end = this->dwinfo_->read_from_pointer<32>(this->ranges_buffer_
418 + offset + 4);
c1027032
CC
419 }
420 else
421 {
ed5d6712
CC
422 start = this->dwinfo_->read_from_pointer<64>(this->ranges_buffer_
423 + offset);
424 end = this->dwinfo_->read_from_pointer<64>(this->ranges_buffer_
425 + offset + 8);
c1027032
CC
426 }
427
428 // Check for relocations and adjust the values.
429 unsigned int shndx1 = 0;
430 unsigned int shndx2 = 0;
431 if (this->ranges_reloc_mapper_ != NULL)
432 {
433 shndx1 =
434 this->ranges_reloc_mapper_->get_reloc_target(offset, &start);
435 shndx2 =
436 this->ranges_reloc_mapper_->get_reloc_target(offset + addr_size,
437 &end);
438 }
439
440 // End of list is marked by a pair of zeroes.
441 if (shndx1 == 0 && start == 0 && end == 0)
442 break;
443
444 // A "base address selection entry" is identified by
445 // 0xffffffff for the first value of the pair. The second
446 // value is used as a base for subsequent range list entries.
447 if (shndx1 == 0 && start == -1)
448 base = end;
449 else if (shndx1 == shndx2)
450 {
451 if (shndx1 == 0 || object->is_section_included(shndx1))
452 ranges->add(shndx1, base + start, base + end);
453 }
454 else
455 gold_warning(_("%s: DWARF info may be corrupt; offsets in a "
456 "range list entry are in different sections"),
457 object->name().c_str());
458 }
459
460 return ranges;
461}
462
463// class Dwarf_pubnames_table
464
465// Read the pubnames section SHNDX from the object file.
466
467bool
468Dwarf_pubnames_table::read_section(Relobj* object, unsigned int shndx)
469{
470 section_size_type buffer_size;
471
472 // If we don't have relocations, shndx will be 0, and
473 // we'll have to hunt for the .debug_pubnames/pubtypes section.
474 if (shndx == 0)
475 {
476 const char* name = (this->is_pubtypes_
477 ? ".debug_pubtypes"
478 : ".debug_pubnames");
479 for (unsigned int i = 1; i < object->shnum(); ++i)
480 {
481 if (object->section_name(i) == name)
482 {
483 shndx = i;
484 this->output_section_offset_ = object->output_section_offset(i);
485 break;
486 }
487 }
488 if (shndx == 0)
489 return false;
490 }
491
492 this->buffer_ = object->decompressed_section_contents(shndx,
493 &buffer_size,
494 &this->owns_buffer_);
495 if (this->buffer_ == NULL)
496 return false;
497 this->buffer_end_ = this->buffer_ + buffer_size;
498 return true;
499}
500
501// Read the header for the set at OFFSET.
502
503bool
504Dwarf_pubnames_table::read_header(off_t offset)
505{
506 // Correct the offset. For incremental update links, we have a
507 // relocated offset that is relative to the output section, but
508 // here we need an offset relative to the input section.
509 offset -= this->output_section_offset_;
510
511 if (offset < 0 || offset + 14 >= this->buffer_end_ - this->buffer_)
512 return false;
513
514 const unsigned char* pinfo = this->buffer_ + offset;
515
516 // Read the unit_length field.
ed5d6712 517 uint32_t unit_length = this->dwinfo_->read_from_pointer<32>(pinfo);
c1027032
CC
518 pinfo += 4;
519 if (unit_length == 0xffffffff)
520 {
ed5d6712 521 unit_length = this->dwinfo_->read_from_pointer<64>(pinfo);
c1027032
CC
522 pinfo += 8;
523 this->offset_size_ = 8;
524 }
525 else
526 this->offset_size_ = 4;
527
528 // Check the version.
ed5d6712 529 unsigned int version = this->dwinfo_->read_from_pointer<16>(pinfo);
c1027032
CC
530 pinfo += 2;
531 if (version != 2)
532 return false;
533
534 // Skip the debug_info_offset and debug_info_size fields.
535 pinfo += 2 * this->offset_size_;
536
537 if (pinfo >= this->buffer_end_)
538 return false;
539
540 this->pinfo_ = pinfo;
541 return true;
542}
543
544// Read the next name from the set.
545
546const char*
547Dwarf_pubnames_table::next_name()
548{
549 const unsigned char* pinfo = this->pinfo_;
550
551 // Read the offset within the CU. If this is zero, we have reached
552 // the end of the list.
553 uint32_t offset;
554 if (this->offset_size_ == 4)
ed5d6712 555 offset = this->dwinfo_->read_from_pointer<32>(&pinfo);
c1027032 556 else
ed5d6712 557 offset = this->dwinfo_->read_from_pointer<64>(&pinfo);
c1027032
CC
558 if (offset == 0)
559 return NULL;
560
561 // Return a pointer to the string at the current location,
562 // and advance the pointer to the next entry.
563 const char* ret = reinterpret_cast<const char*>(pinfo);
564 while (pinfo < this->buffer_end_ && *pinfo != '\0')
565 ++pinfo;
566 if (pinfo < this->buffer_end_)
567 ++pinfo;
568
569 this->pinfo_ = pinfo;
570 return ret;
571}
572
573// class Dwarf_die
574
575Dwarf_die::Dwarf_die(
576 Dwarf_info_reader* dwinfo,
577 off_t die_offset,
578 Dwarf_die* parent)
579 : dwinfo_(dwinfo), parent_(parent), die_offset_(die_offset),
580 child_offset_(0), sibling_offset_(0), abbrev_code_(NULL), attributes_(),
581 attributes_read_(false), name_(NULL), name_off_(-1), linkage_name_(NULL),
582 linkage_name_off_(-1), string_shndx_(0), specification_(0),
583 abstract_origin_(0)
584{
585 size_t len;
586 const unsigned char* pdie = dwinfo->buffer_at_offset(die_offset);
587 if (pdie == NULL)
588 return;
589 unsigned int code = read_unsigned_LEB_128(pdie, &len);
590 if (code == 0)
591 {
592 if (parent != NULL)
593 parent->set_sibling_offset(die_offset + len);
594 return;
595 }
596 this->attr_offset_ = len;
597
598 // Lookup the abbrev code in the abbrev table.
599 this->abbrev_code_ = dwinfo->get_abbrev(code);
600}
601
602// Read all the attributes of the DIE.
603
604bool
605Dwarf_die::read_attributes()
606{
607 if (this->attributes_read_)
608 return true;
609
610 gold_assert(this->abbrev_code_ != NULL);
611
612 const unsigned char* pdie =
613 this->dwinfo_->buffer_at_offset(this->die_offset_);
614 if (pdie == NULL)
615 return false;
616 const unsigned char* pattr = pdie + this->attr_offset_;
617
618 unsigned int nattr = this->abbrev_code_->attributes.size();
619 this->attributes_.reserve(nattr);
620 for (unsigned int i = 0; i < nattr; ++i)
621 {
622 size_t len;
623 unsigned int attr = this->abbrev_code_->attributes[i].attr;
624 unsigned int form = this->abbrev_code_->attributes[i].form;
625 if (form == elfcpp::DW_FORM_indirect)
626 {
627 form = read_unsigned_LEB_128(pattr, &len);
628 pattr += len;
629 }
630 off_t attr_off = this->die_offset_ + (pattr - pdie);
631 bool ref_form = false;
632 Attribute_value attr_value;
633 attr_value.attr = attr;
634 attr_value.form = form;
635 attr_value.aux.shndx = 0;
636 switch(form)
637 {
c1027032
CC
638 case elfcpp::DW_FORM_flag_present:
639 attr_value.val.intval = 1;
640 break;
641 case elfcpp::DW_FORM_strp:
642 {
643 off_t str_off;
644 if (this->dwinfo_->offset_size() == 4)
ed5d6712 645 str_off = this->dwinfo_->read_from_pointer<32>(&pattr);
c1027032 646 else
ed5d6712 647 str_off = this->dwinfo_->read_from_pointer<64>(&pattr);
c1027032
CC
648 unsigned int shndx =
649 this->dwinfo_->lookup_reloc(attr_off, &str_off);
650 attr_value.aux.shndx = shndx;
651 attr_value.val.refval = str_off;
652 break;
653 }
654 case elfcpp::DW_FORM_sec_offset:
655 {
656 off_t sec_off;
657 if (this->dwinfo_->offset_size() == 4)
ed5d6712 658 sec_off = this->dwinfo_->read_from_pointer<32>(&pattr);
c1027032 659 else
ed5d6712 660 sec_off = this->dwinfo_->read_from_pointer<64>(&pattr);
c1027032
CC
661 unsigned int shndx =
662 this->dwinfo_->lookup_reloc(attr_off, &sec_off);
663 attr_value.aux.shndx = shndx;
664 attr_value.val.refval = sec_off;
665 ref_form = true;
666 break;
667 }
668 case elfcpp::DW_FORM_addr:
669 case elfcpp::DW_FORM_ref_addr:
670 {
671 off_t sec_off;
672 if (this->dwinfo_->address_size() == 4)
ed5d6712 673 sec_off = this->dwinfo_->read_from_pointer<32>(&pattr);
c1027032 674 else
ed5d6712 675 sec_off = this->dwinfo_->read_from_pointer<64>(&pattr);
c1027032
CC
676 unsigned int shndx =
677 this->dwinfo_->lookup_reloc(attr_off, &sec_off);
678 attr_value.aux.shndx = shndx;
679 attr_value.val.refval = sec_off;
680 ref_form = true;
681 break;
682 }
683 case elfcpp::DW_FORM_block1:
684 attr_value.aux.blocklen = *pattr++;
685 attr_value.val.blockval = pattr;
686 pattr += attr_value.aux.blocklen;
687 break;
688 case elfcpp::DW_FORM_block2:
ed5d6712
CC
689 attr_value.aux.blocklen =
690 this->dwinfo_->read_from_pointer<16>(&pattr);
c1027032
CC
691 attr_value.val.blockval = pattr;
692 pattr += attr_value.aux.blocklen;
693 break;
694 case elfcpp::DW_FORM_block4:
ed5d6712
CC
695 attr_value.aux.blocklen =
696 this->dwinfo_->read_from_pointer<32>(&pattr);
c1027032
CC
697 attr_value.val.blockval = pattr;
698 pattr += attr_value.aux.blocklen;
699 break;
700 case elfcpp::DW_FORM_block:
701 case elfcpp::DW_FORM_exprloc:
702 attr_value.aux.blocklen = read_unsigned_LEB_128(pattr, &len);
703 attr_value.val.blockval = pattr + len;
704 pattr += len + attr_value.aux.blocklen;
705 break;
706 case elfcpp::DW_FORM_data1:
707 case elfcpp::DW_FORM_flag:
708 attr_value.val.intval = *pattr++;
709 break;
710 case elfcpp::DW_FORM_ref1:
711 attr_value.val.refval = *pattr++;
712 ref_form = true;
713 break;
714 case elfcpp::DW_FORM_data2:
ed5d6712
CC
715 attr_value.val.intval =
716 this->dwinfo_->read_from_pointer<16>(&pattr);
c1027032
CC
717 break;
718 case elfcpp::DW_FORM_ref2:
ed5d6712
CC
719 attr_value.val.refval =
720 this->dwinfo_->read_from_pointer<16>(&pattr);
c1027032
CC
721 ref_form = true;
722 break;
723 case elfcpp::DW_FORM_data4:
724 {
725 off_t sec_off;
ed5d6712 726 sec_off = this->dwinfo_->read_from_pointer<32>(&pattr);
c1027032
CC
727 unsigned int shndx =
728 this->dwinfo_->lookup_reloc(attr_off, &sec_off);
729 attr_value.aux.shndx = shndx;
730 attr_value.val.intval = sec_off;
731 break;
732 }
733 case elfcpp::DW_FORM_ref4:
734 {
735 off_t sec_off;
ed5d6712 736 sec_off = this->dwinfo_->read_from_pointer<32>(&pattr);
c1027032
CC
737 unsigned int shndx =
738 this->dwinfo_->lookup_reloc(attr_off, &sec_off);
739 attr_value.aux.shndx = shndx;
740 attr_value.val.refval = sec_off;
741 ref_form = true;
742 break;
743 }
744 case elfcpp::DW_FORM_data8:
745 {
746 off_t sec_off;
ed5d6712 747 sec_off = this->dwinfo_->read_from_pointer<64>(&pattr);
c1027032
CC
748 unsigned int shndx =
749 this->dwinfo_->lookup_reloc(attr_off, &sec_off);
750 attr_value.aux.shndx = shndx;
751 attr_value.val.intval = sec_off;
752 break;
753 }
754 case elfcpp::DW_FORM_ref_sig8:
ed5d6712
CC
755 attr_value.val.uintval =
756 this->dwinfo_->read_from_pointer<64>(&pattr);
c1027032
CC
757 break;
758 case elfcpp::DW_FORM_ref8:
759 {
760 off_t sec_off;
ed5d6712 761 sec_off = this->dwinfo_->read_from_pointer<64>(&pattr);
c1027032
CC
762 unsigned int shndx =
763 this->dwinfo_->lookup_reloc(attr_off, &sec_off);
764 attr_value.aux.shndx = shndx;
765 attr_value.val.refval = sec_off;
766 ref_form = true;
767 break;
768 }
769 case elfcpp::DW_FORM_ref_udata:
770 attr_value.val.refval = read_unsigned_LEB_128(pattr, &len);
771 ref_form = true;
772 pattr += len;
773 break;
774 case elfcpp::DW_FORM_udata:
d2d60eef
CC
775 case elfcpp::DW_FORM_GNU_addr_index:
776 case elfcpp::DW_FORM_GNU_str_index:
c1027032
CC
777 attr_value.val.uintval = read_unsigned_LEB_128(pattr, &len);
778 pattr += len;
779 break;
780 case elfcpp::DW_FORM_sdata:
781 attr_value.val.intval = read_signed_LEB_128(pattr, &len);
782 pattr += len;
783 break;
784 case elfcpp::DW_FORM_string:
785 attr_value.val.stringval = reinterpret_cast<const char*>(pattr);
786 len = strlen(attr_value.val.stringval);
787 pattr += len + 1;
788 break;
789 default:
790 return false;
791 }
792
793 // Cache the most frequently-requested attributes.
794 switch (attr)
795 {
796 case elfcpp::DW_AT_name:
797 if (form == elfcpp::DW_FORM_string)
798 this->name_ = attr_value.val.stringval;
799 else if (form == elfcpp::DW_FORM_strp)
800 {
801 // All indirect strings should refer to the same
802 // string section, so we just save the last one seen.
803 this->string_shndx_ = attr_value.aux.shndx;
804 this->name_off_ = attr_value.val.refval;
805 }
806 break;
807 case elfcpp::DW_AT_linkage_name:
808 case elfcpp::DW_AT_MIPS_linkage_name:
809 if (form == elfcpp::DW_FORM_string)
810 this->linkage_name_ = attr_value.val.stringval;
811 else if (form == elfcpp::DW_FORM_strp)
812 {
813 // All indirect strings should refer to the same
814 // string section, so we just save the last one seen.
815 this->string_shndx_ = attr_value.aux.shndx;
816 this->linkage_name_off_ = attr_value.val.refval;
817 }
818 break;
819 case elfcpp::DW_AT_specification:
820 if (ref_form)
821 this->specification_ = attr_value.val.refval;
822 break;
823 case elfcpp::DW_AT_abstract_origin:
824 if (ref_form)
825 this->abstract_origin_ = attr_value.val.refval;
826 break;
827 case elfcpp::DW_AT_sibling:
828 if (ref_form && attr_value.aux.shndx == 0)
829 this->sibling_offset_ = attr_value.val.refval;
830 default:
831 break;
832 }
833
834 this->attributes_.push_back(attr_value);
835 }
836
837 // Now that we know where the next DIE begins, record the offset
838 // to avoid later recalculation.
839 if (this->has_children())
840 this->child_offset_ = this->die_offset_ + (pattr - pdie);
841 else
842 this->sibling_offset_ = this->die_offset_ + (pattr - pdie);
843
844 this->attributes_read_ = true;
845 return true;
846}
847
848// Skip all the attributes of the DIE and return the offset of the next DIE.
849
850off_t
851Dwarf_die::skip_attributes()
852{
c1027032
CC
853 gold_assert(this->abbrev_code_ != NULL);
854
855 const unsigned char* pdie =
856 this->dwinfo_->buffer_at_offset(this->die_offset_);
857 if (pdie == NULL)
858 return 0;
859 const unsigned char* pattr = pdie + this->attr_offset_;
860
861 for (unsigned int i = 0; i < this->abbrev_code_->attributes.size(); ++i)
862 {
863 size_t len;
864 unsigned int form = this->abbrev_code_->attributes[i].form;
865 if (form == elfcpp::DW_FORM_indirect)
866 {
867 form = read_unsigned_LEB_128(pattr, &len);
868 pattr += len;
869 }
870 switch(form)
871 {
c1027032
CC
872 case elfcpp::DW_FORM_flag_present:
873 break;
874 case elfcpp::DW_FORM_strp:
875 case elfcpp::DW_FORM_sec_offset:
876 pattr += this->dwinfo_->offset_size();
877 break;
878 case elfcpp::DW_FORM_addr:
879 case elfcpp::DW_FORM_ref_addr:
880 pattr += this->dwinfo_->address_size();
881 break;
882 case elfcpp::DW_FORM_block1:
883 pattr += 1 + *pattr;
884 break;
885 case elfcpp::DW_FORM_block2:
886 {
887 uint16_t block_size;
ed5d6712 888 block_size = this->dwinfo_->read_from_pointer<16>(&pattr);
c1027032
CC
889 pattr += block_size;
890 break;
891 }
892 case elfcpp::DW_FORM_block4:
893 {
894 uint32_t block_size;
ed5d6712 895 block_size = this->dwinfo_->read_from_pointer<32>(&pattr);
c1027032
CC
896 pattr += block_size;
897 break;
898 }
899 case elfcpp::DW_FORM_block:
900 case elfcpp::DW_FORM_exprloc:
901 {
902 uint64_t block_size;
903 block_size = read_unsigned_LEB_128(pattr, &len);
904 pattr += len + block_size;
905 break;
906 }
907 case elfcpp::DW_FORM_data1:
908 case elfcpp::DW_FORM_ref1:
909 case elfcpp::DW_FORM_flag:
910 pattr += 1;
911 break;
912 case elfcpp::DW_FORM_data2:
913 case elfcpp::DW_FORM_ref2:
914 pattr += 2;
915 break;
916 case elfcpp::DW_FORM_data4:
917 case elfcpp::DW_FORM_ref4:
918 pattr += 4;
919 break;
920 case elfcpp::DW_FORM_data8:
921 case elfcpp::DW_FORM_ref8:
922 case elfcpp::DW_FORM_ref_sig8:
923 pattr += 8;
924 break;
925 case elfcpp::DW_FORM_ref_udata:
926 case elfcpp::DW_FORM_udata:
d2d60eef
CC
927 case elfcpp::DW_FORM_GNU_addr_index:
928 case elfcpp::DW_FORM_GNU_str_index:
c1027032
CC
929 read_unsigned_LEB_128(pattr, &len);
930 pattr += len;
931 break;
932 case elfcpp::DW_FORM_sdata:
933 read_signed_LEB_128(pattr, &len);
934 pattr += len;
935 break;
936 case elfcpp::DW_FORM_string:
937 len = strlen(reinterpret_cast<const char*>(pattr));
938 pattr += len + 1;
939 break;
940 default:
941 return 0;
942 }
943 }
944
945 return this->die_offset_ + (pattr - pdie);
946}
947
948// Get the name of the DIE and cache it.
949
950void
951Dwarf_die::set_name()
952{
953 if (this->name_ != NULL || !this->read_attributes())
954 return;
955 if (this->name_off_ != -1)
956 this->name_ = this->dwinfo_->get_string(this->name_off_,
957 this->string_shndx_);
958}
959
960// Get the linkage name of the DIE and cache it.
961
962void
963Dwarf_die::set_linkage_name()
964{
965 if (this->linkage_name_ != NULL || !this->read_attributes())
966 return;
967 if (this->linkage_name_off_ != -1)
968 this->linkage_name_ = this->dwinfo_->get_string(this->linkage_name_off_,
969 this->string_shndx_);
970}
971
972// Return the value of attribute ATTR.
973
974const Dwarf_die::Attribute_value*
975Dwarf_die::attribute(unsigned int attr)
976{
977 if (!this->read_attributes())
978 return NULL;
979 for (unsigned int i = 0; i < this->attributes_.size(); ++i)
980 {
981 if (this->attributes_[i].attr == attr)
982 return &this->attributes_[i];
983 }
984 return NULL;
985}
986
987const char*
988Dwarf_die::string_attribute(unsigned int attr)
989{
990 const Attribute_value* attr_val = this->attribute(attr);
991 if (attr_val == NULL)
992 return NULL;
993 switch (attr_val->form)
994 {
995 case elfcpp::DW_FORM_string:
996 return attr_val->val.stringval;
997 case elfcpp::DW_FORM_strp:
998 return this->dwinfo_->get_string(attr_val->val.refval,
999 attr_val->aux.shndx);
1000 default:
1001 return NULL;
1002 }
1003}
1004
1005int64_t
1006Dwarf_die::int_attribute(unsigned int attr)
1007{
1008 const Attribute_value* attr_val = this->attribute(attr);
1009 if (attr_val == NULL)
1010 return 0;
1011 switch (attr_val->form)
1012 {
c1027032
CC
1013 case elfcpp::DW_FORM_flag_present:
1014 case elfcpp::DW_FORM_data1:
1015 case elfcpp::DW_FORM_flag:
1016 case elfcpp::DW_FORM_data2:
1017 case elfcpp::DW_FORM_data4:
1018 case elfcpp::DW_FORM_data8:
1019 case elfcpp::DW_FORM_sdata:
1020 return attr_val->val.intval;
1021 default:
1022 return 0;
1023 }
1024}
1025
1026uint64_t
1027Dwarf_die::uint_attribute(unsigned int attr)
1028{
1029 const Attribute_value* attr_val = this->attribute(attr);
1030 if (attr_val == NULL)
1031 return 0;
1032 switch (attr_val->form)
1033 {
c1027032
CC
1034 case elfcpp::DW_FORM_flag_present:
1035 case elfcpp::DW_FORM_data1:
1036 case elfcpp::DW_FORM_flag:
1037 case elfcpp::DW_FORM_data4:
1038 case elfcpp::DW_FORM_data8:
1039 case elfcpp::DW_FORM_ref_sig8:
1040 case elfcpp::DW_FORM_udata:
1041 return attr_val->val.uintval;
1042 default:
1043 return 0;
1044 }
1045}
1046
1047off_t
1048Dwarf_die::ref_attribute(unsigned int attr, unsigned int* shndx)
1049{
1050 const Attribute_value* attr_val = this->attribute(attr);
1051 if (attr_val == NULL)
1052 return -1;
1053 switch (attr_val->form)
1054 {
1055 case elfcpp::DW_FORM_sec_offset:
1056 case elfcpp::DW_FORM_addr:
1057 case elfcpp::DW_FORM_ref_addr:
1058 case elfcpp::DW_FORM_ref1:
1059 case elfcpp::DW_FORM_ref2:
1060 case elfcpp::DW_FORM_ref4:
1061 case elfcpp::DW_FORM_ref8:
1062 case elfcpp::DW_FORM_ref_udata:
1063 *shndx = attr_val->aux.shndx;
1064 return attr_val->val.refval;
1065 case elfcpp::DW_FORM_ref_sig8:
1066 *shndx = attr_val->aux.shndx;
1067 return attr_val->val.uintval;
1068 case elfcpp::DW_FORM_data4:
1069 case elfcpp::DW_FORM_data8:
1070 *shndx = attr_val->aux.shndx;
1071 return attr_val->val.intval;
1072 default:
1073 return -1;
1074 }
1075}
1076
57923f48
MW
1077off_t
1078Dwarf_die::address_attribute(unsigned int attr, unsigned int* shndx)
1079{
1080 const Attribute_value* attr_val = this->attribute(attr);
1081 if (attr_val == NULL || attr_val->form != elfcpp::DW_FORM_addr)
1082 return -1;
1083
1084 *shndx = attr_val->aux.shndx;
1085 return attr_val->val.refval;
1086}
1087
c1027032
CC
1088// Return the offset of this DIE's first child.
1089
1090off_t
1091Dwarf_die::child_offset()
1092{
1093 gold_assert(this->abbrev_code_ != NULL);
1094 if (!this->has_children())
1095 return 0;
1096 if (this->child_offset_ == 0)
1097 this->child_offset_ = this->skip_attributes();
1098 return this->child_offset_;
1099}
1100
1101// Return the offset of this DIE's next sibling.
1102
1103off_t
1104Dwarf_die::sibling_offset()
1105{
1106 gold_assert(this->abbrev_code_ != NULL);
1107
1108 if (this->sibling_offset_ != 0)
1109 return this->sibling_offset_;
1110
1111 if (!this->has_children())
1112 {
1113 this->sibling_offset_ = this->skip_attributes();
1114 return this->sibling_offset_;
1115 }
1116
1117 if (this->has_sibling_attribute())
1118 {
1119 if (!this->read_attributes())
1120 return 0;
1121 if (this->sibling_offset_ != 0)
1122 return this->sibling_offset_;
1123 }
1124
1125 // Skip over the children.
1126 off_t child_offset = this->child_offset();
1127 while (child_offset > 0)
1128 {
1129 Dwarf_die die(this->dwinfo_, child_offset, this);
1130 // The Dwarf_die ctor will set this DIE's sibling offset
1131 // when it reads a zero abbrev code.
1132 if (die.tag() == 0)
1133 break;
1134 child_offset = die.sibling_offset();
1135 }
1136
1137 // This should be set by now. If not, there was a problem reading
1138 // the DWARF info, and we return 0.
1139 return this->sibling_offset_;
1140}
1141
1142// class Dwarf_info_reader
1143
1144// Check that the pointer P is within the current compilation unit.
1145
1146inline bool
1147Dwarf_info_reader::check_buffer(const unsigned char* p) const
1148{
1149 if (p > this->buffer_ + this->cu_offset_ + this->cu_length_)
1150 {
1151 gold_warning(_("%s: corrupt debug info in %s"),
1152 this->object_->name().c_str(),
1153 this->object_->section_name(this->shndx_).c_str());
1154 return false;
1155 }
1156 return true;
1157}
1158
1159// Begin parsing the debug info. This calls visit_compilation_unit()
1160// or visit_type_unit() for each compilation or type unit found in the
1161// section, and visit_die() for each top-level DIE.
1162
1163void
1164Dwarf_info_reader::parse()
1165{
9fc236f3 1166 if (this->object_->is_big_endian())
c1027032 1167 {
9fc236f3
CC
1168#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1169 this->do_parse<true>();
1170#else
1171 gold_unreachable();
c1027032 1172#endif
9fc236f3
CC
1173 }
1174 else
1175 {
1176#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1177 this->do_parse<false>();
1178#else
1179 gold_unreachable();
c1027032 1180#endif
c1027032
CC
1181 }
1182}
1183
1184template<bool big_endian>
1185void
1186Dwarf_info_reader::do_parse()
1187{
1188 // Get the section contents and decompress if necessary.
1189 section_size_type buffer_size;
1190 bool buffer_is_new;
1191 this->buffer_ = this->object_->decompressed_section_contents(this->shndx_,
1192 &buffer_size,
1193 &buffer_is_new);
1194 if (this->buffer_ == NULL || buffer_size == 0)
1195 return;
1196 this->buffer_end_ = this->buffer_ + buffer_size;
1197
1198 // The offset of this input section in the output section.
1199 off_t section_offset = this->object_->output_section_offset(this->shndx_);
1200
1201 // Start tracking relocations for this section.
1202 this->reloc_mapper_ = make_elf_reloc_mapper(this->object_, this->symtab_,
1203 this->symtab_size_);
1204 this->reloc_mapper_->initialize(this->reloc_shndx_, this->reloc_type_);
1205
1206 // Loop over compilation units (or type units).
8787852d 1207 unsigned int abbrev_shndx = this->abbrev_shndx_;
c1027032
CC
1208 off_t abbrev_offset = 0;
1209 const unsigned char* pinfo = this->buffer_;
1210 while (pinfo < this->buffer_end_)
1211 {
1212 // Read the compilation (or type) unit header.
1213 const unsigned char* cu_start = pinfo;
1214 this->cu_offset_ = cu_start - this->buffer_;
1215 this->cu_length_ = this->buffer_end_ - cu_start;
1216
1217 // Read unit_length (4 or 12 bytes).
1218 if (!this->check_buffer(pinfo + 4))
1219 break;
1220 uint32_t unit_length =
1221 elfcpp::Swap_unaligned<32, big_endian>::readval(pinfo);
1222 pinfo += 4;
1223 if (unit_length == 0xffffffff)
1224 {
1225 if (!this->check_buffer(pinfo + 8))
1226 break;
1227 unit_length = elfcpp::Swap_unaligned<64, big_endian>::readval(pinfo);
1228 pinfo += 8;
1229 this->offset_size_ = 8;
1230 }
1231 else
1232 this->offset_size_ = 4;
1233 if (!this->check_buffer(pinfo + unit_length))
1234 break;
1235 const unsigned char* cu_end = pinfo + unit_length;
1236 this->cu_length_ = cu_end - cu_start;
1237 if (!this->check_buffer(pinfo + 2 + this->offset_size_ + 1))
1238 break;
1239
1240 // Read version (2 bytes).
1241 this->cu_version_ =
1242 elfcpp::Swap_unaligned<16, big_endian>::readval(pinfo);
1243 pinfo += 2;
1244
1245 // Read debug_abbrev_offset (4 or 8 bytes).
1246 if (this->offset_size_ == 4)
1247 abbrev_offset = elfcpp::Swap_unaligned<32, big_endian>::readval(pinfo);
1248 else
1249 abbrev_offset = elfcpp::Swap_unaligned<64, big_endian>::readval(pinfo);
1250 if (this->reloc_shndx_ > 0)
1251 {
1252 off_t reloc_offset = pinfo - this->buffer_;
1253 off_t value;
1254 abbrev_shndx =
1255 this->reloc_mapper_->get_reloc_target(reloc_offset, &value);
1256 if (abbrev_shndx == 0)
1257 return;
1258 if (this->reloc_type_ == elfcpp::SHT_REL)
1259 abbrev_offset += value;
1260 else
1261 abbrev_offset = value;
1262 }
1263 pinfo += this->offset_size_;
1264
1265 // Read address_size (1 byte).
1266 this->address_size_ = *pinfo++;
1267
1268 // For type units, read the two extra fields.
1269 uint64_t signature = 0;
1270 off_t type_offset = 0;
1271 if (this->is_type_unit_)
1272 {
1273 if (!this->check_buffer(pinfo + 8 + this->offset_size_))
1274 break;
1275
1276 // Read type_signature (8 bytes).
1277 signature = elfcpp::Swap_unaligned<64, big_endian>::readval(pinfo);
1278 pinfo += 8;
1279
1280 // Read type_offset (4 or 8 bytes).
1281 if (this->offset_size_ == 4)
1282 type_offset =
1283 elfcpp::Swap_unaligned<32, big_endian>::readval(pinfo);
1284 else
1285 type_offset =
1286 elfcpp::Swap_unaligned<64, big_endian>::readval(pinfo);
1287 pinfo += this->offset_size_;
1288 }
1289
1290 // Read the .debug_abbrev table.
1291 this->abbrev_table_.read_abbrevs(this->object_, abbrev_shndx,
1292 abbrev_offset);
1293
1294 // Visit the root DIE.
1295 Dwarf_die root_die(this,
1296 pinfo - (this->buffer_ + this->cu_offset_),
1297 NULL);
1298 if (root_die.tag() != 0)
1299 {
1300 // Visit the CU or TU.
1301 if (this->is_type_unit_)
1302 this->visit_type_unit(section_offset + this->cu_offset_,
1303 type_offset, signature, &root_die);
1304 else
1305 this->visit_compilation_unit(section_offset + this->cu_offset_,
1306 cu_end - cu_start, &root_die);
1307 }
1308
1309 // Advance to the next CU.
1310 pinfo = cu_end;
1311 }
1312
1313 if (buffer_is_new)
1314 {
1315 delete[] this->buffer_;
1316 this->buffer_ = NULL;
1317 }
1318}
1319
1320// Read the DWARF string table.
1321
1322bool
1323Dwarf_info_reader::do_read_string_table(unsigned int string_shndx)
1324{
1325 Relobj* object = this->object_;
1326
1327 // If we don't have relocations, string_shndx will be 0, and
1328 // we'll have to hunt for the .debug_str section.
1329 if (string_shndx == 0)
1330 {
1331 for (unsigned int i = 1; i < this->object_->shnum(); ++i)
1332 {
1333 std::string name = object->section_name(i);
1334 if (name == ".debug_str")
1335 {
1336 string_shndx = i;
1337 this->string_output_section_offset_ =
1338 object->output_section_offset(i);
1339 break;
1340 }
1341 }
1342 if (string_shndx == 0)
1343 return false;
1344 }
1345
1346 if (this->owns_string_buffer_ && this->string_buffer_ != NULL)
1347 {
1348 delete[] this->string_buffer_;
1349 this->owns_string_buffer_ = false;
1350 }
1351
1352 // Get the secton contents and decompress if necessary.
1353 section_size_type buffer_size;
1354 const unsigned char* buffer =
1355 object->decompressed_section_contents(string_shndx,
1356 &buffer_size,
1357 &this->owns_string_buffer_);
1358 this->string_buffer_ = reinterpret_cast<const char*>(buffer);
1359 this->string_buffer_end_ = this->string_buffer_ + buffer_size;
1360 this->string_shndx_ = string_shndx;
1361 return true;
1362}
1363
ed5d6712
CC
1364// Read a possibly unaligned integer of SIZE.
1365template <int valsize>
1366inline typename elfcpp::Valtype_base<valsize>::Valtype
1367Dwarf_info_reader::read_from_pointer(const unsigned char* source)
1368{
1369 typename elfcpp::Valtype_base<valsize>::Valtype return_value;
1370 if (this->object_->is_big_endian())
1371 return_value = elfcpp::Swap_unaligned<valsize, true>::readval(source);
1372 else
1373 return_value = elfcpp::Swap_unaligned<valsize, false>::readval(source);
1374 return return_value;
1375}
1376
1377// Read a possibly unaligned integer of SIZE. Update SOURCE after read.
1378template <int valsize>
1379inline typename elfcpp::Valtype_base<valsize>::Valtype
1380Dwarf_info_reader::read_from_pointer(const unsigned char** source)
1381{
1382 typename elfcpp::Valtype_base<valsize>::Valtype return_value;
1383 if (this->object_->is_big_endian())
1384 return_value = elfcpp::Swap_unaligned<valsize, true>::readval(*source);
1385 else
1386 return_value = elfcpp::Swap_unaligned<valsize, false>::readval(*source);
1387 *source += valsize / 8;
1388 return return_value;
1389}
1390
c1027032
CC
1391// Look for a relocation at offset ATTR_OFF in the dwarf info,
1392// and return the section index and offset of the target.
1393
1394unsigned int
1395Dwarf_info_reader::lookup_reloc(off_t attr_off, off_t* target_off)
1396{
1397 off_t value;
1398 attr_off += this->cu_offset_;
1399 unsigned int shndx = this->reloc_mapper_->get_reloc_target(attr_off, &value);
1400 if (shndx == 0)
1401 return 0;
1402 if (this->reloc_type_ == elfcpp::SHT_REL)
1403 *target_off += value;
1404 else
1405 *target_off = value;
1406 return shndx;
1407}
1408
1409// Return a string from the DWARF string table.
1410
1411const char*
1412Dwarf_info_reader::get_string(off_t str_off, unsigned int string_shndx)
1413{
1414 if (!this->read_string_table(string_shndx))
1415 return NULL;
1416
1417 // Correct the offset. For incremental update links, we have a
1418 // relocated offset that is relative to the output section, but
1419 // here we need an offset relative to the input section.
1420 str_off -= this->string_output_section_offset_;
1421
1422 const char* p = this->string_buffer_ + str_off;
1423
1424 if (p < this->string_buffer_ || p >= this->string_buffer_end_)
1425 return NULL;
1426
1427 return p;
1428}
1429
1430// The following are default, do-nothing, implementations of the
1431// hook methods normally provided by a derived class. We provide
1432// default implementations rather than no implementation so that
1433// a derived class needs to implement only the hooks that it needs
1434// to use.
1435
1436// Process a compilation unit and parse its child DIE.
1437
1438void
1439Dwarf_info_reader::visit_compilation_unit(off_t, off_t, Dwarf_die*)
1440{
1441}
1442
1443// Process a type unit and parse its child DIE.
1444
1445void
1446Dwarf_info_reader::visit_type_unit(off_t, off_t, uint64_t, Dwarf_die*)
1447{
1448}
1449
1450// class Sized_dwarf_line_info
1451
5c2c6c95
ILT
1452struct LineStateMachine
1453{
1454 int file_num;
1455 uint64_t address;
1456 int line_num;
1457 int column_num;
1458 unsigned int shndx; // the section address refers to
1459 bool is_stmt; // stmt means statement.
1460 bool basic_block;
1461 bool end_sequence;
1462};
1463
1464static void
1465ResetLineStateMachine(struct LineStateMachine* lsm, bool default_is_stmt)
1466{
1467 lsm->file_num = 1;
1468 lsm->address = 0;
1469 lsm->line_num = 1;
1470 lsm->column_num = 0;
338f2eba 1471 lsm->shndx = -1U;
5c2c6c95
ILT
1472 lsm->is_stmt = default_is_stmt;
1473 lsm->basic_block = false;
1474 lsm->end_sequence = false;
1475}
1476
24badc65 1477template<int size, bool big_endian>
5dd8762a
CC
1478Sized_dwarf_line_info<size, big_endian>::Sized_dwarf_line_info(
1479 Object* object,
1480 unsigned int read_shndx)
1481 : data_valid_(false), buffer_(NULL), buffer_start_(NULL),
c1027032
CC
1482 reloc_mapper_(NULL), symtab_buffer_(NULL), directories_(), files_(),
1483 current_header_index_(-1)
24badc65
ILT
1484{
1485 unsigned int debug_shndx;
5dd8762a 1486
ab8056e0
CC
1487 for (debug_shndx = 1; debug_shndx < object->shnum(); ++debug_shndx)
1488 {
1489 // FIXME: do this more efficiently: section_name() isn't super-fast
1490 std::string name = object->section_name(debug_shndx);
1491 if (name == ".debug_line" || name == ".zdebug_line")
1492 {
1493 section_size_type buffer_size;
5dd8762a
CC
1494 bool is_new = false;
1495 this->buffer_ = object->decompressed_section_contents(debug_shndx,
1496 &buffer_size,
1497 &is_new);
1498 if (is_new)
1499 this->buffer_start_ = this->buffer_;
ab8056e0
CC
1500 this->buffer_end_ = this->buffer_ + buffer_size;
1501 break;
1502 }
1503 }
24badc65 1504 if (this->buffer_ == NULL)
c261a0be 1505 return;
24badc65
ILT
1506
1507 // Find the relocation section for ".debug_line".
af674d1d 1508 // We expect these for relobjs (.o's) but not dynobjs (.so's).
c1027032
CC
1509 unsigned int reloc_shndx = 0;
1510 for (unsigned int i = 0; i < object->shnum(); ++i)
24badc65 1511 {
c1027032 1512 unsigned int reloc_sh_type = object->section_type(i);
24badc65
ILT
1513 if ((reloc_sh_type == elfcpp::SHT_REL
1514 || reloc_sh_type == elfcpp::SHT_RELA)
c1027032 1515 && object->section_info(i) == debug_shndx)
24badc65 1516 {
c1027032 1517 reloc_shndx = i;
4dbfafcc 1518 this->track_relocs_type_ = reloc_sh_type;
24badc65
ILT
1519 break;
1520 }
1521 }
24badc65
ILT
1522
1523 // Finally, we need the symtab section to interpret the relocs.
c1027032 1524 if (reloc_shndx != 0)
af674d1d
ILT
1525 {
1526 unsigned int symtab_shndx;
1527 for (symtab_shndx = 0; symtab_shndx < object->shnum(); ++symtab_shndx)
1528 if (object->section_type(symtab_shndx) == elfcpp::SHT_SYMTAB)
1529 {
c1027032
CC
1530 this->symtab_buffer_ = object->section_contents(
1531 symtab_shndx, &this->symtab_buffer_size_, false);
af674d1d
ILT
1532 break;
1533 }
1534 if (this->symtab_buffer_ == NULL)
1535 return;
1536 }
24badc65 1537
c1027032
CC
1538 this->reloc_mapper_ =
1539 new Sized_elf_reloc_mapper<size, big_endian>(object,
1540 this->symtab_buffer_,
1541 this->symtab_buffer_size_);
1542 if (!this->reloc_mapper_->initialize(reloc_shndx, this->track_relocs_type_))
1543 return;
1544
24badc65
ILT
1545 // Now that we have successfully read all the data, parse the debug
1546 // info.
c261a0be 1547 this->data_valid_ = true;
c1027032 1548 this->read_line_mappings(read_shndx);
24badc65
ILT
1549}
1550
5c2c6c95
ILT
1551// Read the DWARF header.
1552
1553template<int size, bool big_endian>
1554const unsigned char*
a55ce7fe 1555Sized_dwarf_line_info<size, big_endian>::read_header_prolog(
e43872e9 1556 const unsigned char* lineptr)
5c2c6c95 1557{
deae2a14 1558 uint32_t initial_length = elfcpp::Swap_unaligned<32, big_endian>::readval(lineptr);
5c2c6c95
ILT
1559 lineptr += 4;
1560
1561 // In DWARF2/3, if the initial length is all 1 bits, then the offset
1562 // size is 8 and we need to read the next 8 bytes for the real length.
1563 if (initial_length == 0xffffffff)
1564 {
1565 header_.offset_size = 8;
deae2a14 1566 initial_length = elfcpp::Swap_unaligned<64, big_endian>::readval(lineptr);
5c2c6c95
ILT
1567 lineptr += 8;
1568 }
1569 else
1570 header_.offset_size = 4;
1571
1572 header_.total_length = initial_length;
1573
1574 gold_assert(lineptr + header_.total_length <= buffer_end_);
1575
deae2a14 1576 header_.version = elfcpp::Swap_unaligned<16, big_endian>::readval(lineptr);
5c2c6c95
ILT
1577 lineptr += 2;
1578
1579 if (header_.offset_size == 4)
deae2a14 1580 header_.prologue_length = elfcpp::Swap_unaligned<32, big_endian>::readval(lineptr);
5c2c6c95 1581 else
deae2a14 1582 header_.prologue_length = elfcpp::Swap_unaligned<64, big_endian>::readval(lineptr);
5c2c6c95
ILT
1583 lineptr += header_.offset_size;
1584
1585 header_.min_insn_length = *lineptr;
1586 lineptr += 1;
1587
1588 header_.default_is_stmt = *lineptr;
1589 lineptr += 1;
1590
1591 header_.line_base = *reinterpret_cast<const signed char*>(lineptr);
1592 lineptr += 1;
1593
1594 header_.line_range = *lineptr;
1595 lineptr += 1;
1596
1597 header_.opcode_base = *lineptr;
1598 lineptr += 1;
1599
a869183f 1600 header_.std_opcode_lengths.resize(header_.opcode_base + 1);
5c2c6c95
ILT
1601 header_.std_opcode_lengths[0] = 0;
1602 for (int i = 1; i < header_.opcode_base; i++)
1603 {
1604 header_.std_opcode_lengths[i] = *lineptr;
1605 lineptr += 1;
1606 }
1607
1608 return lineptr;
1609}
1610
1611// The header for a debug_line section is mildly complicated, because
1612// the line info is very tightly encoded.
1613
e43872e9 1614template<int size, bool big_endian>
5c2c6c95 1615const unsigned char*
a55ce7fe 1616Sized_dwarf_line_info<size, big_endian>::read_header_tables(
e43872e9 1617 const unsigned char* lineptr)
5c2c6c95 1618{
af674d1d
ILT
1619 ++this->current_header_index_;
1620
1621 // Create a new directories_ entry and a new files_ entry for our new
1622 // header. We initialize each with a single empty element, because
1623 // dwarf indexes directory and filenames starting at 1.
1624 gold_assert(static_cast<int>(this->directories_.size())
1625 == this->current_header_index_);
1626 gold_assert(static_cast<int>(this->files_.size())
1627 == this->current_header_index_);
1628 this->directories_.push_back(std::vector<std::string>(1));
1629 this->files_.push_back(std::vector<std::pair<int, std::string> >(1));
1630
5c2c6c95
ILT
1631 // It is legal for the directory entry table to be empty.
1632 if (*lineptr)
1633 {
1634 int dirindex = 1;
1635 while (*lineptr)
1636 {
af674d1d
ILT
1637 const char* dirname = reinterpret_cast<const char*>(lineptr);
1638 gold_assert(dirindex
1639 == static_cast<int>(this->directories_.back().size()));
1640 this->directories_.back().push_back(dirname);
1641 lineptr += this->directories_.back().back().size() + 1;
5c2c6c95
ILT
1642 dirindex++;
1643 }
1644 }
1645 lineptr++;
1646
1647 // It is also legal for the file entry table to be empty.
1648 if (*lineptr)
1649 {
1650 int fileindex = 1;
1651 size_t len;
1652 while (*lineptr)
1653 {
1654 const char* filename = reinterpret_cast<const char*>(lineptr);
1655 lineptr += strlen(filename) + 1;
1656
1657 uint64_t dirindex = read_unsigned_LEB_128(lineptr, &len);
5c2c6c95
ILT
1658 lineptr += len;
1659
af674d1d
ILT
1660 if (dirindex >= this->directories_.back().size())
1661 dirindex = 0;
1662 int dirindexi = static_cast<int>(dirindex);
1663
5c2c6c95
ILT
1664 read_unsigned_LEB_128(lineptr, &len); // mod_time
1665 lineptr += len;
1666
1667 read_unsigned_LEB_128(lineptr, &len); // filelength
1668 lineptr += len;
1669
af674d1d
ILT
1670 gold_assert(fileindex
1671 == static_cast<int>(this->files_.back().size()));
1672 this->files_.back().push_back(std::make_pair(dirindexi, filename));
5c2c6c95
ILT
1673 fileindex++;
1674 }
1675 }
1676 lineptr++;
1677
1678 return lineptr;
1679}
1680
1681// Process a single opcode in the .debug.line structure.
1682
e43872e9 1683template<int size, bool big_endian>
5c2c6c95 1684bool
a55ce7fe 1685Sized_dwarf_line_info<size, big_endian>::process_one_opcode(
e43872e9 1686 const unsigned char* start, struct LineStateMachine* lsm, size_t* len)
5c2c6c95
ILT
1687{
1688 size_t oplen = 0;
1689 size_t templen;
1690 unsigned char opcode = *start;
1691 oplen++;
1692 start++;
1693
1694 // If the opcode is great than the opcode_base, it is a special
1695 // opcode. Most line programs consist mainly of special opcodes.
1696 if (opcode >= header_.opcode_base)
1697 {
1698 opcode -= header_.opcode_base;
1699 const int advance_address = ((opcode / header_.line_range)
1700 * header_.min_insn_length);
1701 lsm->address += advance_address;
1702
1703 const int advance_line = ((opcode % header_.line_range)
1704 + header_.line_base);
1705 lsm->line_num += advance_line;
1706 lsm->basic_block = true;
1707 *len = oplen;
1708 return true;
1709 }
1710
1711 // Otherwise, we have the regular opcodes
1712 switch (opcode)
1713 {
1714 case elfcpp::DW_LNS_copy:
1715 lsm->basic_block = false;
1716 *len = oplen;
1717 return true;
1718
1719 case elfcpp::DW_LNS_advance_pc:
1720 {
1721 const uint64_t advance_address
2ea97941 1722 = read_unsigned_LEB_128(start, &templen);
5c2c6c95
ILT
1723 oplen += templen;
1724 lsm->address += header_.min_insn_length * advance_address;
1725 }
1726 break;
1727
1728 case elfcpp::DW_LNS_advance_line:
1729 {
1730 const uint64_t advance_line = read_signed_LEB_128(start, &templen);
1731 oplen += templen;
1732 lsm->line_num += advance_line;
1733 }
1734 break;
1735
1736 case elfcpp::DW_LNS_set_file:
1737 {
1738 const uint64_t fileno = read_unsigned_LEB_128(start, &templen);
1739 oplen += templen;
1740 lsm->file_num = fileno;
1741 }
1742 break;
1743
1744 case elfcpp::DW_LNS_set_column:
1745 {
1746 const uint64_t colno = read_unsigned_LEB_128(start, &templen);
1747 oplen += templen;
1748 lsm->column_num = colno;
1749 }
1750 break;
1751
1752 case elfcpp::DW_LNS_negate_stmt:
1753 lsm->is_stmt = !lsm->is_stmt;
1754 break;
1755
1756 case elfcpp::DW_LNS_set_basic_block:
1757 lsm->basic_block = true;
1758 break;
1759
1760 case elfcpp::DW_LNS_fixed_advance_pc:
1761 {
1762 int advance_address;
deae2a14 1763 advance_address = elfcpp::Swap_unaligned<16, big_endian>::readval(start);
5c2c6c95
ILT
1764 oplen += 2;
1765 lsm->address += advance_address;
1766 }
1767 break;
1768
1769 case elfcpp::DW_LNS_const_add_pc:
1770 {
1771 const int advance_address = (header_.min_insn_length
1772 * ((255 - header_.opcode_base)
1773 / header_.line_range));
1774 lsm->address += advance_address;
1775 }
1776 break;
1777
1778 case elfcpp::DW_LNS_extended_op:
1779 {
1780 const uint64_t extended_op_len
2ea97941 1781 = read_unsigned_LEB_128(start, &templen);
5c2c6c95
ILT
1782 start += templen;
1783 oplen += templen + extended_op_len;
1784
1785 const unsigned char extended_op = *start;
1786 start++;
1787
1788 switch (extended_op)
1789 {
1790 case elfcpp::DW_LNE_end_sequence:
124dfc89
ILT
1791 // This means that the current byte is the one immediately
1792 // after a set of instructions. Record the current line
1793 // for up to one less than the current address.
79e052ea 1794 lsm->line_num = -1;
5c2c6c95
ILT
1795 lsm->end_sequence = true;
1796 *len = oplen;
1797 return true;
1798
1799 case elfcpp::DW_LNE_set_address:
4c50553d 1800 {
4dbfafcc
ILT
1801 lsm->address =
1802 elfcpp::Swap_unaligned<size, big_endian>::readval(start);
4c50553d 1803 typename Reloc_map::const_iterator it
4dbfafcc 1804 = this->reloc_map_.find(start - this->buffer_);
4c50553d
ILT
1805 if (it != reloc_map_.end())
1806 {
4dbfafcc
ILT
1807 // If this is a SHT_RELA section, then ignore the
1808 // section contents. This assumes that this is a
1809 // straight reloc which just uses the reloc addend.
1810 // The reloc addend has already been included in the
1811 // symbol value.
1812 if (this->track_relocs_type_ == elfcpp::SHT_RELA)
1813 lsm->address = 0;
1814 // Add in the symbol value.
1815 lsm->address += it->second.second;
4c50553d
ILT
1816 lsm->shndx = it->second.first;
1817 }
1818 else
1819 {
af674d1d
ILT
1820 // If we're a normal .o file, with relocs, every
1821 // set_address should have an associated relocation.
1822 if (this->input_is_relobj())
1823 this->data_valid_ = false;
4c50553d
ILT
1824 }
1825 break;
24badc65 1826 }
5c2c6c95
ILT
1827 case elfcpp::DW_LNE_define_file:
1828 {
1829 const char* filename = reinterpret_cast<const char*>(start);
1830 templen = strlen(filename) + 1;
1831 start += templen;
1832
1833 uint64_t dirindex = read_unsigned_LEB_128(start, &templen);
5c2c6c95 1834
af674d1d
ILT
1835 if (dirindex >= this->directories_.back().size())
1836 dirindex = 0;
1837 int dirindexi = static_cast<int>(dirindex);
1838
e8dd54e1
CC
1839 // This opcode takes two additional ULEB128 parameters
1840 // (mod_time and filelength), but we don't use those
1841 // values. Because OPLEN already tells us how far to
1842 // skip to the next opcode, we don't need to read
1843 // them at all.
5c2c6c95 1844
af674d1d 1845 this->files_.back().push_back(std::make_pair(dirindexi,
5c2c6c95
ILT
1846 filename));
1847 }
1848 break;
1849 }
1850 }
1851 break;
1852
1853 default:
1854 {
2ea97941 1855 // Ignore unknown opcode silently
5c2c6c95
ILT
1856 for (int i = 0; i < header_.std_opcode_lengths[opcode]; i++)
1857 {
2ea97941 1858 size_t templen;
5c2c6c95
ILT
1859 read_unsigned_LEB_128(start, &templen);
1860 start += templen;
1861 oplen += templen;
1862 }
1863 }
1864 break;
2ea97941 1865 }
5c2c6c95
ILT
1866 *len = oplen;
1867 return false;
1868}
1869
1870// Read the debug information at LINEPTR and store it in the line
1871// number map.
1872
e43872e9 1873template<int size, bool big_endian>
5c2c6c95 1874unsigned const char*
9430daf8 1875Sized_dwarf_line_info<size, big_endian>::read_lines(unsigned const char* lineptr,
75aea3d0 1876 unsigned int shndx)
5c2c6c95
ILT
1877{
1878 struct LineStateMachine lsm;
1879
1880 // LENGTHSTART is the place the length field is based on. It is the
1881 // point in the header after the initial length field.
1882 const unsigned char* lengthstart = buffer_;
1883
1884 // In 64 bit dwarf, the initial length is 12 bytes, because of the
1885 // 0xffffffff at the start.
1886 if (header_.offset_size == 8)
1887 lengthstart += 12;
1888 else
1889 lengthstart += 4;
1890
1891 while (lineptr < lengthstart + header_.total_length)
1892 {
1893 ResetLineStateMachine(&lsm, header_.default_is_stmt);
1894 while (!lsm.end_sequence)
1895 {
1896 size_t oplength;
e43872e9 1897 bool add_line = this->process_one_opcode(lineptr, &lsm, &oplength);
9430daf8
ILT
1898 if (add_line
1899 && (shndx == -1U || lsm.shndx == -1U || shndx == lsm.shndx))
5c2c6c95
ILT
1900 {
1901 Offset_to_lineno_entry entry
76677ad0
CC
1902 = { static_cast<off_t>(lsm.address),
1903 this->current_header_index_,
1904 static_cast<unsigned int>(lsm.file_num),
1905 true, lsm.line_num };
7500420b
ILT
1906 std::vector<Offset_to_lineno_entry>&
1907 map(this->line_number_map_[lsm.shndx]);
1908 // If we see two consecutive entries with the same
71ff8986
ILT
1909 // offset and a real line number, then mark the first
1910 // one as non-canonical.
7500420b
ILT
1911 if (!map.empty()
1912 && (map.back().offset == static_cast<off_t>(lsm.address))
1913 && lsm.line_num != -1
1914 && map.back().line_num != -1)
71ff8986
ILT
1915 map.back().last_line_for_offset = false;
1916 map.push_back(entry);
5c2c6c95
ILT
1917 }
1918 lineptr += oplength;
1919 }
1920 }
1921
1922 return lengthstart + header_.total_length;
1923}
1924
4c50553d
ILT
1925// Read the relocations into a Reloc_map.
1926
1927template<int size, bool big_endian>
1928void
c1027032 1929Sized_dwarf_line_info<size, big_endian>::read_relocs()
4c50553d
ILT
1930{
1931 if (this->symtab_buffer_ == NULL)
1932 return;
1933
c1027032 1934 off_t value;
4c50553d 1935 off_t reloc_offset;
c1027032 1936 while ((reloc_offset = this->reloc_mapper_->next_offset()) != -1)
4c50553d 1937 {
c1027032
CC
1938 const unsigned int shndx =
1939 this->reloc_mapper_->get_reloc_target(reloc_offset, &value);
d491d34e
ILT
1940
1941 // There is no reason to record non-ordinary section indexes, or
1942 // SHN_UNDEF, because they will never match the real section.
c1027032
CC
1943 if (shndx != 0)
1944 this->reloc_map_[reloc_offset] = std::make_pair(shndx, value);
d491d34e 1945
c1027032 1946 this->reloc_mapper_->advance(reloc_offset + 1);
4c50553d
ILT
1947 }
1948}
1949
1950// Read the line number info.
1951
e43872e9 1952template<int size, bool big_endian>
5c2c6c95 1953void
c1027032 1954Sized_dwarf_line_info<size, big_endian>::read_line_mappings(unsigned int shndx)
5c2c6c95 1955{
c261a0be 1956 gold_assert(this->data_valid_ == true);
24badc65 1957
c1027032 1958 this->read_relocs();
4c50553d 1959 while (this->buffer_ < this->buffer_end_)
e43872e9 1960 {
4c50553d 1961 const unsigned char* lineptr = this->buffer_;
e43872e9
ILT
1962 lineptr = this->read_header_prolog(lineptr);
1963 lineptr = this->read_header_tables(lineptr);
9430daf8 1964 lineptr = this->read_lines(lineptr, shndx);
4c50553d 1965 this->buffer_ = lineptr;
e43872e9
ILT
1966 }
1967
1968 // Sort the lines numbers, so addr2line can use binary search.
1969 for (typename Lineno_map::iterator it = line_number_map_.begin();
5c2c6c95
ILT
1970 it != line_number_map_.end();
1971 ++it)
1972 // Each vector needs to be sorted by offset.
4c50553d 1973 std::sort(it->second.begin(), it->second.end());
5c2c6c95
ILT
1974}
1975
af674d1d
ILT
1976// Some processing depends on whether the input is a .o file or not.
1977// For instance, .o files have relocs, and have .debug_lines
1978// information on a per section basis. .so files, on the other hand,
1979// lack relocs, and offsets are unique, so we can ignore the section
1980// information.
1981
1982template<int size, bool big_endian>
1983bool
a55ce7fe 1984Sized_dwarf_line_info<size, big_endian>::input_is_relobj()
af674d1d
ILT
1985{
1986 // Only .o files have relocs and the symtab buffer that goes with them.
1987 return this->symtab_buffer_ != NULL;
1988}
1989
79e052ea
ILT
1990// Given an Offset_to_lineno_entry vector, and an offset, figure out
1991// if the offset points into a function according to the vector (see
1992// comments below for the algorithm). If it does, return an iterator
1993// into the vector that points to the line-number that contains that
1994// offset. If not, it returns vector::end().
1995
1996static std::vector<Offset_to_lineno_entry>::const_iterator
1997offset_to_iterator(const std::vector<Offset_to_lineno_entry>* offsets,
1998 off_t offset)
1999{
71ff8986 2000 const Offset_to_lineno_entry lookup_key = { offset, 0, 0, true, 0 };
79e052ea
ILT
2001
2002 // lower_bound() returns the smallest offset which is >= lookup_key.
2003 // If no offset in offsets is >= lookup_key, returns end().
2004 std::vector<Offset_to_lineno_entry>::const_iterator it
2005 = std::lower_bound(offsets->begin(), offsets->end(), lookup_key);
2006
2007 // This code is easiest to understand with a concrete example.
2008 // Here's a possible offsets array:
71ff8986
ILT
2009 // {{offset = 3211, header_num = 0, file_num = 1, last, line_num = 16}, // 0
2010 // {offset = 3224, header_num = 0, file_num = 1, last, line_num = 20}, // 1
2011 // {offset = 3226, header_num = 0, file_num = 1, last, line_num = 22}, // 2
2012 // {offset = 3231, header_num = 0, file_num = 1, last, line_num = 25}, // 3
2013 // {offset = 3232, header_num = 0, file_num = 1, last, line_num = -1}, // 4
2014 // {offset = 3232, header_num = 0, file_num = 1, last, line_num = 65}, // 5
2015 // {offset = 3235, header_num = 0, file_num = 1, last, line_num = 66}, // 6
2016 // {offset = 3236, header_num = 0, file_num = 1, last, line_num = -1}, // 7
2017 // {offset = 5764, header_num = 0, file_num = 1, last, line_num = 48}, // 8
2018 // {offset = 5764, header_num = 0, file_num = 1,!last, line_num = 47}, // 9
2019 // {offset = 5765, header_num = 0, file_num = 1, last, line_num = 49}, // 10
2020 // {offset = 5767, header_num = 0, file_num = 1, last, line_num = 50}, // 11
2021 // {offset = 5768, header_num = 0, file_num = 1, last, line_num = 51}, // 12
2022 // {offset = 5773, header_num = 0, file_num = 1, last, line_num = -1}, // 13
2023 // {offset = 5787, header_num = 1, file_num = 1, last, line_num = 19}, // 14
2024 // {offset = 5790, header_num = 1, file_num = 1, last, line_num = 20}, // 15
2025 // {offset = 5793, header_num = 1, file_num = 1, last, line_num = 67}, // 16
2026 // {offset = 5793, header_num = 1, file_num = 1, last, line_num = -1}, // 17
2027 // {offset = 5793, header_num = 1, file_num = 1,!last, line_num = 66}, // 18
2028 // {offset = 5795, header_num = 1, file_num = 1, last, line_num = 68}, // 19
2029 // {offset = 5798, header_num = 1, file_num = 1, last, line_num = -1}, // 20
79e052ea
ILT
2030 // The entries with line_num == -1 mark the end of a function: the
2031 // associated offset is one past the last instruction in the
2032 // function. This can correspond to the beginning of the next
2033 // function (as is true for offset 3232); alternately, there can be
2034 // a gap between the end of one function and the start of the next
ef04e392 2035 // (as is true for some others, most obviously from 3236->5764).
79e052ea
ILT
2036 //
2037 // Case 1: lookup_key has offset == 10. lower_bound returns
2038 // offsets[0]. Since it's not an exact match and we're
ef04e392 2039 // at the beginning of offsets, we return end() (invalid).
79e052ea 2040 // Case 2: lookup_key has offset 10000. lower_bound returns
71ff8986 2041 // offset[21] (end()). We return end() (invalid).
79e052ea
ILT
2042 // Case 3: lookup_key has offset == 3211. lower_bound matches
2043 // offsets[0] exactly, and that's the entry we return.
2044 // Case 4: lookup_key has offset == 3232. lower_bound returns
2045 // offsets[4]. That's an exact match, but indicates
2046 // end-of-function. We check if offsets[5] is also an
2047 // exact match but not end-of-function. It is, so we
2048 // return offsets[5].
2049 // Case 5: lookup_key has offset == 3214. lower_bound returns
2050 // offsets[1]. Since it's not an exact match, we back
2051 // up to the offset that's < lookup_key, offsets[0].
2052 // We note offsets[0] is a valid entry (not end-of-function),
2053 // so that's the entry we return.
2054 // Case 6: lookup_key has offset == 4000. lower_bound returns
2055 // offsets[8]. Since it's not an exact match, we back
2056 // up to offsets[7]. Since offsets[7] indicates
2057 // end-of-function, we know lookup_key is between
ef04e392 2058 // functions, so we return end() (not a valid offset).
79e052ea 2059 // Case 7: lookup_key has offset == 5794. lower_bound returns
71ff8986
ILT
2060 // offsets[19]. Since it's not an exact match, we back
2061 // up to offsets[16]. Note we back up to the *first*
2062 // entry with offset 5793, not just offsets[19-1].
2063 // We note offsets[16] is a valid entry, so we return it.
2064 // If offsets[16] had had line_num == -1, we would have
2065 // checked offsets[17]. The reason for this is that
2066 // 16 and 17 can be in an arbitrary order, since we sort
2067 // only by offset and last_line_for_offset. (Note it
2068 // doesn't help to use line_number as a tertiary sort key,
2069 // since sometimes we want the -1 to be first and sometimes
2070 // we want it to be last.)
79e052ea
ILT
2071
2072 // This deals with cases (1) and (2).
2073 if ((it == offsets->begin() && offset < it->offset)
2074 || it == offsets->end())
2075 return offsets->end();
2076
2077 // This deals with cases (3) and (4).
2078 if (offset == it->offset)
2079 {
2080 while (it != offsets->end()
2081 && it->offset == offset
2082 && it->line_num == -1)
2083 ++it;
2084 if (it == offsets->end() || it->offset != offset)
2085 return offsets->end();
2086 else
2087 return it;
2088 }
2089
2090 // This handles the first part of case (7) -- we back up to the
2091 // *first* entry that has the offset that's behind us.
2092 gold_assert(it != offsets->begin());
2093 std::vector<Offset_to_lineno_entry>::const_iterator range_end = it;
2094 --it;
2095 const off_t range_value = it->offset;
2096 while (it != offsets->begin() && (it-1)->offset == range_value)
2097 --it;
2098
2099 // This handles cases (5), (6), and (7): if any entry in the
2100 // equal_range [it, range_end) has a line_num != -1, it's a valid
71ff8986
ILT
2101 // match. If not, we're not in a function. The line number we saw
2102 // last for an offset will be sorted first, so it'll get returned if
2103 // it's present.
79e052ea
ILT
2104 for (; it != range_end; ++it)
2105 if (it->line_num != -1)
2106 return it;
2107 return offsets->end();
2108}
af674d1d 2109
71ff8986
ILT
2110// Returns the canonical filename:lineno for the address passed in.
2111// If other_lines is not NULL, appends the non-canonical lines
2112// assigned to the same address.
5c2c6c95 2113
e43872e9 2114template<int size, bool big_endian>
5c2c6c95 2115std::string
71ff8986
ILT
2116Sized_dwarf_line_info<size, big_endian>::do_addr2line(
2117 unsigned int shndx,
2118 off_t offset,
2119 std::vector<std::string>* other_lines)
5c2c6c95 2120{
4c50553d
ILT
2121 if (this->data_valid_ == false)
2122 return "";
2123
af674d1d
ILT
2124 const std::vector<Offset_to_lineno_entry>* offsets;
2125 // If we do not have reloc information, then our input is a .so or
2126 // some similar data structure where all the information is held in
2127 // the offset. In that case, we ignore the input shndx.
2128 if (this->input_is_relobj())
2129 offsets = &this->line_number_map_[shndx];
2130 else
2131 offsets = &this->line_number_map_[-1U];
2132 if (offsets->empty())
4c50553d
ILT
2133 return "";
2134
e43872e9 2135 typename std::vector<Offset_to_lineno_entry>::const_iterator it
79e052ea
ILT
2136 = offset_to_iterator(offsets, offset);
2137 if (it == offsets->end())
2138 return "";
5c2c6c95 2139
71ff8986
ILT
2140 std::string result = this->format_file_lineno(*it);
2141 if (other_lines != NULL)
2142 for (++it; it != offsets->end() && it->offset == offset; ++it)
2143 {
2144 if (it->line_num == -1)
2145 continue; // The end of a previous function.
2146 other_lines->push_back(this->format_file_lineno(*it));
2147 }
2148 return result;
2149}
2150
2151// Convert the file_num + line_num into a string.
2152
2153template<int size, bool big_endian>
2154std::string
2155Sized_dwarf_line_info<size, big_endian>::format_file_lineno(
2156 const Offset_to_lineno_entry& loc) const
2157{
5c2c6c95 2158 std::string ret;
af674d1d 2159
71ff8986
ILT
2160 gold_assert(loc.header_num < static_cast<int>(this->files_.size()));
2161 gold_assert(loc.file_num
c1027032 2162 < static_cast<unsigned int>(this->files_[loc.header_num].size()));
af674d1d 2163 const std::pair<int, std::string>& filename_pair
71ff8986 2164 = this->files_[loc.header_num][loc.file_num];
5c2c6c95 2165 const std::string& filename = filename_pair.second;
af674d1d 2166
71ff8986 2167 gold_assert(loc.header_num < static_cast<int>(this->directories_.size()));
af674d1d 2168 gold_assert(filename_pair.first
71ff8986 2169 < static_cast<int>(this->directories_[loc.header_num].size()));
af674d1d 2170 const std::string& dirname
71ff8986 2171 = this->directories_[loc.header_num][filename_pair.first];
af674d1d 2172
5c2c6c95
ILT
2173 if (!dirname.empty())
2174 {
2175 ret += dirname;
2176 ret += "/";
2177 }
2178 ret += filename;
2179 if (ret.empty())
2180 ret = "(unknown)";
2181
2182 char buffer[64]; // enough to hold a line number
71ff8986 2183 snprintf(buffer, sizeof(buffer), "%d", loc.line_num);
5c2c6c95
ILT
2184 ret += ":";
2185 ret += buffer;
2186
2187 return ret;
2188}
2189
a55ce7fe
ILT
2190// Dwarf_line_info routines.
2191
e4e5049b
CS
2192static unsigned int next_generation_count = 0;
2193
2194struct Addr2line_cache_entry
2195{
2196 Object* object;
2197 unsigned int shndx;
2198 Dwarf_line_info* dwarf_line_info;
2199 unsigned int generation_count;
2200 unsigned int access_count;
2201
2202 Addr2line_cache_entry(Object* o, unsigned int s, Dwarf_line_info* d)
2203 : object(o), shndx(s), dwarf_line_info(d),
2204 generation_count(next_generation_count), access_count(0)
2205 {
2206 if (next_generation_count < (1U << 31))
2207 ++next_generation_count;
2208 }
2209};
2210// We expect this cache to be small, so don't bother with a hashtable
2211// or priority queue or anything: just use a simple vector.
2212static std::vector<Addr2line_cache_entry> addr2line_cache;
2213
a55ce7fe
ILT
2214std::string
2215Dwarf_line_info::one_addr2line(Object* object,
e4e5049b 2216 unsigned int shndx, off_t offset,
71ff8986
ILT
2217 size_t cache_size,
2218 std::vector<std::string>* other_lines)
a55ce7fe 2219{
e4e5049b
CS
2220 Dwarf_line_info* lineinfo = NULL;
2221 std::vector<Addr2line_cache_entry>::iterator it;
2222
2223 // First, check the cache. If we hit, update the counts.
2224 for (it = addr2line_cache.begin(); it != addr2line_cache.end(); ++it)
8851ecca 2225 {
e4e5049b
CS
2226 if (it->object == object && it->shndx == shndx)
2227 {
2228 lineinfo = it->dwarf_line_info;
2229 it->generation_count = next_generation_count;
2230 // We cap generation_count at 2^31 -1 to avoid overflow.
2231 if (next_generation_count < (1U << 31))
2232 ++next_generation_count;
2233 // We cap access_count at 31 so 2^access_count doesn't overflow
2234 if (it->access_count < 31)
2235 ++it->access_count;
2236 break;
2237 }
2238 }
2239
2240 // If we don't hit the cache, create a new object and insert into the
2241 // cache.
2242 if (lineinfo == NULL)
2243 {
2244 switch (parameters->size_and_endianness())
2245 {
a55ce7fe 2246#ifdef HAVE_TARGET_32_LITTLE
e4e5049b
CS
2247 case Parameters::TARGET_32_LITTLE:
2248 lineinfo = new Sized_dwarf_line_info<32, false>(object, shndx); break;
a55ce7fe 2249#endif
a55ce7fe 2250#ifdef HAVE_TARGET_32_BIG
e4e5049b
CS
2251 case Parameters::TARGET_32_BIG:
2252 lineinfo = new Sized_dwarf_line_info<32, true>(object, shndx); break;
a55ce7fe 2253#endif
a55ce7fe 2254#ifdef HAVE_TARGET_64_LITTLE
e4e5049b
CS
2255 case Parameters::TARGET_64_LITTLE:
2256 lineinfo = new Sized_dwarf_line_info<64, false>(object, shndx); break;
a55ce7fe 2257#endif
8851ecca 2258#ifdef HAVE_TARGET_64_BIG
e4e5049b
CS
2259 case Parameters::TARGET_64_BIG:
2260 lineinfo = new Sized_dwarf_line_info<64, true>(object, shndx); break;
a55ce7fe 2261#endif
e4e5049b
CS
2262 default:
2263 gold_unreachable();
2264 }
2265 addr2line_cache.push_back(Addr2line_cache_entry(object, shndx, lineinfo));
2266 }
2267
2268 // Now that we have our object, figure out the answer
71ff8986 2269 std::string retval = lineinfo->addr2line(shndx, offset, other_lines);
e4e5049b
CS
2270
2271 // Finally, if our cache has grown too big, delete old objects. We
2272 // assume the common (probably only) case is deleting only one object.
2273 // We use a pretty simple scheme to evict: function of LRU and MFU.
2274 while (addr2line_cache.size() > cache_size)
2275 {
2276 unsigned int lowest_score = ~0U;
2277 std::vector<Addr2line_cache_entry>::iterator lowest
2278 = addr2line_cache.end();
2279 for (it = addr2line_cache.begin(); it != addr2line_cache.end(); ++it)
2280 {
2281 const unsigned int score = (it->generation_count
2282 + (1U << it->access_count));
2283 if (score < lowest_score)
2284 {
2285 lowest_score = score;
2286 lowest = it;
2287 }
2288 }
2289 if (lowest != addr2line_cache.end())
2290 {
2291 delete lowest->dwarf_line_info;
2292 addr2line_cache.erase(lowest);
2293 }
8851ecca 2294 }
e4e5049b
CS
2295
2296 return retval;
2297}
2298
2299void
2300Dwarf_line_info::clear_addr2line_cache()
2301{
2302 for (std::vector<Addr2line_cache_entry>::iterator it = addr2line_cache.begin();
2303 it != addr2line_cache.end();
2304 ++it)
2305 delete it->dwarf_line_info;
2306 addr2line_cache.clear();
a55ce7fe
ILT
2307}
2308
5c2c6c95
ILT
2309#ifdef HAVE_TARGET_32_LITTLE
2310template
a55ce7fe 2311class Sized_dwarf_line_info<32, false>;
5c2c6c95
ILT
2312#endif
2313
2314#ifdef HAVE_TARGET_32_BIG
2315template
a55ce7fe 2316class Sized_dwarf_line_info<32, true>;
5c2c6c95
ILT
2317#endif
2318
2319#ifdef HAVE_TARGET_64_LITTLE
2320template
a55ce7fe 2321class Sized_dwarf_line_info<64, false>;
5c2c6c95
ILT
2322#endif
2323
2324#ifdef HAVE_TARGET_64_BIG
2325template
a55ce7fe 2326class Sized_dwarf_line_info<64, true>;
5c2c6c95
ILT
2327#endif
2328
2329} // End namespace gold.
This page took 0.328396 seconds and 4 git commands to generate.