1 //===- DWARFDie.cpp -------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
11 #include "llvm/ADT/None.h"
12 #include "llvm/ADT/Optional.h"
13 #include "llvm/ADT/SmallSet.h"
14 #include "llvm/ADT/StringRef.h"
15 #include "llvm/BinaryFormat/Dwarf.h"
16 #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
17 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
18 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
19 #include "llvm/DebugInfo/DWARF/DWARFExpression.h"
20 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
21 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
22 #include "llvm/Object/ObjectFile.h"
23 #include "llvm/Support/DataExtractor.h"
24 #include "llvm/Support/Format.h"
25 #include "llvm/Support/FormatVariadic.h"
26 #include "llvm/Support/MathExtras.h"
27 #include "llvm/Support/WithColor.h"
28 #include "llvm/Support/raw_ostream.h"
29 #include <algorithm>
30 #include <cassert>
31 #include <cinttypes>
32 #include <cstdint>
33 #include <string>
34 #include <utility>
35
36 using namespace llvm;
37 using namespace dwarf;
38 using namespace object;
39
dumpApplePropertyAttribute(raw_ostream & OS,uint64_t Val)40 static void dumpApplePropertyAttribute(raw_ostream &OS, uint64_t Val) {
41 OS << " (";
42 do {
43 uint64_t Shift = countTrailingZeros(Val);
44 assert(Shift < 64 && "undefined behavior");
45 uint64_t Bit = 1ULL << Shift;
46 auto PropName = ApplePropertyString(Bit);
47 if (!PropName.empty())
48 OS << PropName;
49 else
50 OS << format("DW_APPLE_PROPERTY_0x%" PRIx64, Bit);
51 if (!(Val ^= Bit))
52 break;
53 OS << ", ";
54 } while (true);
55 OS << ")";
56 }
57
dumpRanges(const DWARFObject & Obj,raw_ostream & OS,const DWARFAddressRangesVector & Ranges,unsigned AddressSize,unsigned Indent,const DIDumpOptions & DumpOpts)58 static void dumpRanges(const DWARFObject &Obj, raw_ostream &OS,
59 const DWARFAddressRangesVector &Ranges,
60 unsigned AddressSize, unsigned Indent,
61 const DIDumpOptions &DumpOpts) {
62 ArrayRef<SectionName> SectionNames;
63 if (DumpOpts.Verbose)
64 SectionNames = Obj.getSectionNames();
65
66 for (const DWARFAddressRange &R : Ranges) {
67
68 OS << '\n';
69 OS.indent(Indent);
70 R.dump(OS, AddressSize);
71
72 if (SectionNames.empty() || R.SectionIndex == -1ULL)
73 continue;
74
75 StringRef Name = SectionNames[R.SectionIndex].Name;
76 OS << " \"" << Name << '\"';
77
78 // Print section index if name is not unique.
79 if (!SectionNames[R.SectionIndex].IsNameUnique)
80 OS << format(" [%" PRIu64 "]", R.SectionIndex);
81 }
82 }
83
dumpLocation(raw_ostream & OS,DWARFFormValue & FormValue,DWARFUnit * U,unsigned Indent,DIDumpOptions DumpOpts)84 static void dumpLocation(raw_ostream &OS, DWARFFormValue &FormValue,
85 DWARFUnit *U, unsigned Indent,
86 DIDumpOptions DumpOpts) {
87 DWARFContext &Ctx = U->getContext();
88 const DWARFObject &Obj = Ctx.getDWARFObj();
89 const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
90 if (FormValue.isFormClass(DWARFFormValue::FC_Block) ||
91 FormValue.isFormClass(DWARFFormValue::FC_Exprloc)) {
92 ArrayRef<uint8_t> Expr = *FormValue.getAsBlock();
93 DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
94 Ctx.isLittleEndian(), 0);
95 DWARFExpression(Data, U->getVersion(), U->getAddressByteSize())
96 .print(OS, MRI);
97 return;
98 }
99
100 FormValue.dump(OS, DumpOpts);
101 if (FormValue.isFormClass(DWARFFormValue::FC_SectionOffset)) {
102 const DWARFSection &LocSection = Obj.getLocSection();
103 const DWARFSection &LocDWOSection = Obj.getLocDWOSection();
104 uint32_t Offset = *FormValue.getAsSectionOffset();
105 if (!LocSection.Data.empty()) {
106 DWARFDebugLoc DebugLoc;
107 DWARFDataExtractor Data(Obj, LocSection, Ctx.isLittleEndian(),
108 Obj.getAddressSize());
109 auto LL = DebugLoc.parseOneLocationList(Data, &Offset);
110 if (LL) {
111 uint64_t BaseAddr = 0;
112 if (Optional<BaseAddress> BA = U->getBaseAddress())
113 BaseAddr = BA->Address;
114 LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, BaseAddr,
115 Indent);
116 } else
117 OS << "error extracting location list.";
118 } else if (!LocDWOSection.Data.empty()) {
119 DataExtractor Data(LocDWOSection.Data, Ctx.isLittleEndian(), 0);
120 auto LL = DWARFDebugLocDWO::parseOneLocationList(Data, &Offset);
121 if (LL)
122 LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, Indent);
123 else
124 OS << "error extracting location list.";
125 }
126 }
127 }
128
129 /// Dump the name encoded in the type tag.
dumpTypeTagName(raw_ostream & OS,dwarf::Tag T)130 static void dumpTypeTagName(raw_ostream &OS, dwarf::Tag T) {
131 StringRef TagStr = TagString(T);
132 if (!TagStr.startswith("DW_TAG_") || !TagStr.endswith("_type"))
133 return;
134 OS << TagStr.substr(7, TagStr.size() - 12) << " ";
135 }
136
137 /// Recursively dump the DIE type name when applicable.
dumpTypeName(raw_ostream & OS,const DWARFDie & Die)138 static void dumpTypeName(raw_ostream &OS, const DWARFDie &Die) {
139 DWARFDie D = Die.getAttributeValueAsReferencedDie(DW_AT_type);
140
141 if (!D.isValid())
142 return;
143
144 if (const char *Name = D.getName(DINameKind::LinkageName)) {
145 OS << Name;
146 return;
147 }
148
149 // FIXME: We should have pretty printers per language. Currently we print
150 // everything as if it was C++ and fall back to the TAG type name.
151 const dwarf::Tag T = D.getTag();
152 switch (T) {
153 case DW_TAG_array_type:
154 case DW_TAG_pointer_type:
155 case DW_TAG_ptr_to_member_type:
156 case DW_TAG_reference_type:
157 case DW_TAG_rvalue_reference_type:
158 break;
159 default:
160 dumpTypeTagName(OS, T);
161 }
162
163 // Follow the DW_AT_type if possible.
164 dumpTypeName(OS, D);
165
166 switch (T) {
167 case DW_TAG_array_type:
168 OS << "[]";
169 break;
170 case DW_TAG_pointer_type:
171 OS << '*';
172 break;
173 case DW_TAG_ptr_to_member_type:
174 OS << '*';
175 break;
176 case DW_TAG_reference_type:
177 OS << '&';
178 break;
179 case DW_TAG_rvalue_reference_type:
180 OS << "&&";
181 break;
182 default:
183 break;
184 }
185 }
186
dumpAttribute(raw_ostream & OS,const DWARFDie & Die,uint32_t * OffsetPtr,dwarf::Attribute Attr,dwarf::Form Form,unsigned Indent,DIDumpOptions DumpOpts)187 static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
188 uint32_t *OffsetPtr, dwarf::Attribute Attr,
189 dwarf::Form Form, unsigned Indent,
190 DIDumpOptions DumpOpts) {
191 if (!Die.isValid())
192 return;
193 const char BaseIndent[] = " ";
194 OS << BaseIndent;
195 OS.indent(Indent + 2);
196 WithColor(OS, HighlightColor::Attribute) << formatv("{0}", Attr);
197
198 if (DumpOpts.Verbose || DumpOpts.ShowForm)
199 OS << formatv(" [{0}]", Form);
200
201 DWARFUnit *U = Die.getDwarfUnit();
202 DWARFFormValue formValue(Form);
203
204 if (!formValue.extractValue(U->getDebugInfoExtractor(), OffsetPtr,
205 U->getFormParams(), U))
206 return;
207
208 OS << "\t(";
209
210 StringRef Name;
211 std::string File;
212 auto Color = HighlightColor::Enumerator;
213 if (Attr == DW_AT_decl_file || Attr == DW_AT_call_file) {
214 Color = HighlightColor::String;
215 if (const auto *LT = U->getContext().getLineTableForUnit(U))
216 if (LT->getFileNameByIndex(
217 formValue.getAsUnsignedConstant().getValue(),
218 U->getCompilationDir(),
219 DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, File)) {
220 File = '"' + File + '"';
221 Name = File;
222 }
223 } else if (Optional<uint64_t> Val = formValue.getAsUnsignedConstant())
224 Name = AttributeValueString(Attr, *Val);
225
226 if (!Name.empty())
227 WithColor(OS, Color) << Name;
228 else if (Attr == DW_AT_decl_line || Attr == DW_AT_call_line)
229 OS << *formValue.getAsUnsignedConstant();
230 else if (Attr == DW_AT_high_pc && !DumpOpts.ShowForm && !DumpOpts.Verbose &&
231 formValue.getAsUnsignedConstant()) {
232 if (DumpOpts.ShowAddresses) {
233 // Print the actual address rather than the offset.
234 uint64_t LowPC, HighPC, Index;
235 if (Die.getLowAndHighPC(LowPC, HighPC, Index))
236 OS << format("0x%016" PRIx64, HighPC);
237 else
238 formValue.dump(OS, DumpOpts);
239 }
240 } else if (Attr == DW_AT_location || Attr == DW_AT_frame_base ||
241 Attr == DW_AT_data_member_location ||
242 Attr == DW_AT_GNU_call_site_value)
243 dumpLocation(OS, formValue, U, sizeof(BaseIndent) + Indent + 4, DumpOpts);
244 else
245 formValue.dump(OS, DumpOpts);
246
247 // We have dumped the attribute raw value. For some attributes
248 // having both the raw value and the pretty-printed value is
249 // interesting. These attributes are handled below.
250 if (Attr == DW_AT_specification || Attr == DW_AT_abstract_origin) {
251 if (const char *Name = Die.getAttributeValueAsReferencedDie(Attr).getName(
252 DINameKind::LinkageName))
253 OS << " \"" << Name << '\"';
254 } else if (Attr == DW_AT_type) {
255 OS << " \"";
256 dumpTypeName(OS, Die);
257 OS << '"';
258 } else if (Attr == DW_AT_APPLE_property_attribute) {
259 if (Optional<uint64_t> OptVal = formValue.getAsUnsignedConstant())
260 dumpApplePropertyAttribute(OS, *OptVal);
261 } else if (Attr == DW_AT_ranges) {
262 const DWARFObject &Obj = Die.getDwarfUnit()->getContext().getDWARFObj();
263 // For DW_FORM_rnglistx we need to dump the offset separately, since
264 // we have only dumped the index so far.
265 Optional<DWARFFormValue> Value = Die.find(DW_AT_ranges);
266 if (Value && Value->getForm() == DW_FORM_rnglistx)
267 if (auto RangeListOffset =
268 U->getRnglistOffset(*Value->getAsSectionOffset())) {
269 DWARFFormValue FV(dwarf::DW_FORM_sec_offset);
270 FV.setUValue(*RangeListOffset);
271 FV.dump(OS, DumpOpts);
272 }
273 if (auto RangesOrError = Die.getAddressRanges())
274 dumpRanges(Obj, OS, RangesOrError.get(), U->getAddressByteSize(),
275 sizeof(BaseIndent) + Indent + 4, DumpOpts);
276 else
277 WithColor::error() << "decoding address ranges: "
278 << toString(RangesOrError.takeError()) << '\n';
279 }
280
281 OS << ")\n";
282 }
283
isSubprogramDIE() const284 bool DWARFDie::isSubprogramDIE() const { return getTag() == DW_TAG_subprogram; }
285
isSubroutineDIE() const286 bool DWARFDie::isSubroutineDIE() const {
287 auto Tag = getTag();
288 return Tag == DW_TAG_subprogram || Tag == DW_TAG_inlined_subroutine;
289 }
290
find(dwarf::Attribute Attr) const291 Optional<DWARFFormValue> DWARFDie::find(dwarf::Attribute Attr) const {
292 if (!isValid())
293 return None;
294 auto AbbrevDecl = getAbbreviationDeclarationPtr();
295 if (AbbrevDecl)
296 return AbbrevDecl->getAttributeValue(getOffset(), Attr, *U);
297 return None;
298 }
299
300 Optional<DWARFFormValue>
find(ArrayRef<dwarf::Attribute> Attrs) const301 DWARFDie::find(ArrayRef<dwarf::Attribute> Attrs) const {
302 if (!isValid())
303 return None;
304 auto AbbrevDecl = getAbbreviationDeclarationPtr();
305 if (AbbrevDecl) {
306 for (auto Attr : Attrs) {
307 if (auto Value = AbbrevDecl->getAttributeValue(getOffset(), Attr, *U))
308 return Value;
309 }
310 }
311 return None;
312 }
313
314 Optional<DWARFFormValue>
findRecursively(ArrayRef<dwarf::Attribute> Attrs) const315 DWARFDie::findRecursively(ArrayRef<dwarf::Attribute> Attrs) const {
316 std::vector<DWARFDie> Worklist;
317 Worklist.push_back(*this);
318
319 // Keep track if DIEs already seen to prevent infinite recursion.
320 // Empirically we rarely see a depth of more than 3 when dealing with valid
321 // DWARF. This corresponds to following the DW_AT_abstract_origin and
322 // DW_AT_specification just once.
323 SmallSet<DWARFDie, 3> Seen;
324
325 while (!Worklist.empty()) {
326 DWARFDie Die = Worklist.back();
327 Worklist.pop_back();
328
329 if (!Die.isValid())
330 continue;
331
332 if (Seen.count(Die))
333 continue;
334
335 Seen.insert(Die);
336
337 if (auto Value = Die.find(Attrs))
338 return Value;
339
340 if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
341 Worklist.push_back(D);
342
343 if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_specification))
344 Worklist.push_back(D);
345 }
346
347 return None;
348 }
349
350 DWARFDie
getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const351 DWARFDie::getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const {
352 if (auto SpecRef = toReference(find(Attr))) {
353 if (auto SpecUnit = U->getUnitSection().getUnitForOffset(*SpecRef))
354 return SpecUnit->getDIEForOffset(*SpecRef);
355 }
356 return DWARFDie();
357 }
358
getRangesBaseAttribute() const359 Optional<uint64_t> DWARFDie::getRangesBaseAttribute() const {
360 return toSectionOffset(find({DW_AT_rnglists_base, DW_AT_GNU_ranges_base}));
361 }
362
getHighPC(uint64_t LowPC) const363 Optional<uint64_t> DWARFDie::getHighPC(uint64_t LowPC) const {
364 if (auto FormValue = find(DW_AT_high_pc)) {
365 if (auto Address = FormValue->getAsAddress()) {
366 // High PC is an address.
367 return Address;
368 }
369 if (auto Offset = FormValue->getAsUnsignedConstant()) {
370 // High PC is an offset from LowPC.
371 return LowPC + *Offset;
372 }
373 }
374 return None;
375 }
376
getLowAndHighPC(uint64_t & LowPC,uint64_t & HighPC,uint64_t & SectionIndex) const377 bool DWARFDie::getLowAndHighPC(uint64_t &LowPC, uint64_t &HighPC,
378 uint64_t &SectionIndex) const {
379 auto F = find(DW_AT_low_pc);
380 auto LowPcAddr = toAddress(F);
381 if (!LowPcAddr)
382 return false;
383 if (auto HighPcAddr = getHighPC(*LowPcAddr)) {
384 LowPC = *LowPcAddr;
385 HighPC = *HighPcAddr;
386 SectionIndex = F->getSectionIndex();
387 return true;
388 }
389 return false;
390 }
391
getAddressRanges() const392 Expected<DWARFAddressRangesVector> DWARFDie::getAddressRanges() const {
393 if (isNULL())
394 return DWARFAddressRangesVector();
395 // Single range specified by low/high PC.
396 uint64_t LowPC, HighPC, Index;
397 if (getLowAndHighPC(LowPC, HighPC, Index))
398 return DWARFAddressRangesVector{{LowPC, HighPC, Index}};
399
400 Optional<DWARFFormValue> Value = find(DW_AT_ranges);
401 if (Value) {
402 if (Value->getForm() == DW_FORM_rnglistx)
403 return U->findRnglistFromIndex(*Value->getAsSectionOffset());
404 return U->findRnglistFromOffset(*Value->getAsSectionOffset());
405 }
406 return DWARFAddressRangesVector();
407 }
408
collectChildrenAddressRanges(DWARFAddressRangesVector & Ranges) const409 void DWARFDie::collectChildrenAddressRanges(
410 DWARFAddressRangesVector &Ranges) const {
411 if (isNULL())
412 return;
413 if (isSubprogramDIE()) {
414 if (auto DIERangesOrError = getAddressRanges())
415 Ranges.insert(Ranges.end(), DIERangesOrError.get().begin(),
416 DIERangesOrError.get().end());
417 else
418 llvm::consumeError(DIERangesOrError.takeError());
419 }
420
421 for (auto Child : children())
422 Child.collectChildrenAddressRanges(Ranges);
423 }
424
addressRangeContainsAddress(const uint64_t Address) const425 bool DWARFDie::addressRangeContainsAddress(const uint64_t Address) const {
426 auto RangesOrError = getAddressRanges();
427 if (!RangesOrError) {
428 llvm::consumeError(RangesOrError.takeError());
429 return false;
430 }
431
432 for (const auto &R : RangesOrError.get())
433 if (R.LowPC <= Address && Address < R.HighPC)
434 return true;
435 return false;
436 }
437
getSubroutineName(DINameKind Kind) const438 const char *DWARFDie::getSubroutineName(DINameKind Kind) const {
439 if (!isSubroutineDIE())
440 return nullptr;
441 return getName(Kind);
442 }
443
getName(DINameKind Kind) const444 const char *DWARFDie::getName(DINameKind Kind) const {
445 if (!isValid() || Kind == DINameKind::None)
446 return nullptr;
447 // Try to get mangled name only if it was asked for.
448 if (Kind == DINameKind::LinkageName) {
449 if (auto Name = dwarf::toString(
450 findRecursively({DW_AT_MIPS_linkage_name, DW_AT_linkage_name}),
451 nullptr))
452 return Name;
453 }
454 if (auto Name = dwarf::toString(findRecursively(DW_AT_name), nullptr))
455 return Name;
456 return nullptr;
457 }
458
getDeclLine() const459 uint64_t DWARFDie::getDeclLine() const {
460 return toUnsigned(findRecursively(DW_AT_decl_line), 0);
461 }
462
getCallerFrame(uint32_t & CallFile,uint32_t & CallLine,uint32_t & CallColumn,uint32_t & CallDiscriminator) const463 void DWARFDie::getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
464 uint32_t &CallColumn,
465 uint32_t &CallDiscriminator) const {
466 CallFile = toUnsigned(find(DW_AT_call_file), 0);
467 CallLine = toUnsigned(find(DW_AT_call_line), 0);
468 CallColumn = toUnsigned(find(DW_AT_call_column), 0);
469 CallDiscriminator = toUnsigned(find(DW_AT_GNU_discriminator), 0);
470 }
471
472 /// Helper to dump a DIE with all of its parents, but no siblings.
dumpParentChain(DWARFDie Die,raw_ostream & OS,unsigned Indent,DIDumpOptions DumpOpts)473 static unsigned dumpParentChain(DWARFDie Die, raw_ostream &OS, unsigned Indent,
474 DIDumpOptions DumpOpts) {
475 if (!Die)
476 return Indent;
477 Indent = dumpParentChain(Die.getParent(), OS, Indent, DumpOpts);
478 Die.dump(OS, Indent, DumpOpts);
479 return Indent + 2;
480 }
481
dump(raw_ostream & OS,unsigned Indent,DIDumpOptions DumpOpts) const482 void DWARFDie::dump(raw_ostream &OS, unsigned Indent,
483 DIDumpOptions DumpOpts) const {
484 if (!isValid())
485 return;
486 DWARFDataExtractor debug_info_data = U->getDebugInfoExtractor();
487 const uint32_t Offset = getOffset();
488 uint32_t offset = Offset;
489 if (DumpOpts.ShowParents) {
490 DIDumpOptions ParentDumpOpts = DumpOpts;
491 ParentDumpOpts.ShowParents = false;
492 ParentDumpOpts.ShowChildren = false;
493 Indent = dumpParentChain(getParent(), OS, Indent, ParentDumpOpts);
494 }
495
496 if (debug_info_data.isValidOffset(offset)) {
497 uint32_t abbrCode = debug_info_data.getULEB128(&offset);
498 if (DumpOpts.ShowAddresses)
499 WithColor(OS, HighlightColor::Address).get()
500 << format("\n0x%8.8x: ", Offset);
501
502 if (abbrCode) {
503 auto AbbrevDecl = getAbbreviationDeclarationPtr();
504 if (AbbrevDecl) {
505 WithColor(OS, HighlightColor::Tag).get().indent(Indent)
506 << formatv("{0}", getTag());
507 if (DumpOpts.Verbose)
508 OS << format(" [%u] %c", abbrCode,
509 AbbrevDecl->hasChildren() ? '*' : ' ');
510 OS << '\n';
511
512 // Dump all data in the DIE for the attributes.
513 for (const auto &AttrSpec : AbbrevDecl->attributes()) {
514 if (AttrSpec.Form == DW_FORM_implicit_const) {
515 // We are dumping .debug_info section ,
516 // implicit_const attribute values are not really stored here,
517 // but in .debug_abbrev section. So we just skip such attrs.
518 continue;
519 }
520 dumpAttribute(OS, *this, &offset, AttrSpec.Attr, AttrSpec.Form,
521 Indent, DumpOpts);
522 }
523
524 DWARFDie child = getFirstChild();
525 if (DumpOpts.ShowChildren && DumpOpts.RecurseDepth > 0 && child) {
526 DumpOpts.RecurseDepth--;
527 DIDumpOptions ChildDumpOpts = DumpOpts;
528 ChildDumpOpts.ShowParents = false;
529 while (child) {
530 child.dump(OS, Indent + 2, ChildDumpOpts);
531 child = child.getSibling();
532 }
533 }
534 } else {
535 OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
536 << abbrCode << '\n';
537 }
538 } else {
539 OS.indent(Indent) << "NULL\n";
540 }
541 }
542 }
543
dump() const544 LLVM_DUMP_METHOD void DWARFDie::dump() const { dump(llvm::errs(), 0); }
545
getParent() const546 DWARFDie DWARFDie::getParent() const {
547 if (isValid())
548 return U->getParent(Die);
549 return DWARFDie();
550 }
551
getSibling() const552 DWARFDie DWARFDie::getSibling() const {
553 if (isValid())
554 return U->getSibling(Die);
555 return DWARFDie();
556 }
557
getPreviousSibling() const558 DWARFDie DWARFDie::getPreviousSibling() const {
559 if (isValid())
560 return U->getPreviousSibling(Die);
561 return DWARFDie();
562 }
563
getFirstChild() const564 DWARFDie DWARFDie::getFirstChild() const {
565 if (isValid())
566 return U->getFirstChild(Die);
567 return DWARFDie();
568 }
569
getLastChild() const570 DWARFDie DWARFDie::getLastChild() const {
571 if (isValid())
572 return U->getLastChild(Die);
573 return DWARFDie();
574 }
575
attributes() const576 iterator_range<DWARFDie::attribute_iterator> DWARFDie::attributes() const {
577 return make_range(attribute_iterator(*this, false),
578 attribute_iterator(*this, true));
579 }
580
attribute_iterator(DWARFDie D,bool End)581 DWARFDie::attribute_iterator::attribute_iterator(DWARFDie D, bool End)
582 : Die(D), AttrValue(0), Index(0) {
583 auto AbbrDecl = Die.getAbbreviationDeclarationPtr();
584 assert(AbbrDecl && "Must have abbreviation declaration");
585 if (End) {
586 // This is the end iterator so we set the index to the attribute count.
587 Index = AbbrDecl->getNumAttributes();
588 } else {
589 // This is the begin iterator so we extract the value for this->Index.
590 AttrValue.Offset = D.getOffset() + AbbrDecl->getCodeByteSize();
591 updateForIndex(*AbbrDecl, 0);
592 }
593 }
594
updateForIndex(const DWARFAbbreviationDeclaration & AbbrDecl,uint32_t I)595 void DWARFDie::attribute_iterator::updateForIndex(
596 const DWARFAbbreviationDeclaration &AbbrDecl, uint32_t I) {
597 Index = I;
598 // AbbrDecl must be valid before calling this function.
599 auto NumAttrs = AbbrDecl.getNumAttributes();
600 if (Index < NumAttrs) {
601 AttrValue.Attr = AbbrDecl.getAttrByIndex(Index);
602 // Add the previous byte size of any previous attribute value.
603 AttrValue.Offset += AttrValue.ByteSize;
604 AttrValue.Value.setForm(AbbrDecl.getFormByIndex(Index));
605 uint32_t ParseOffset = AttrValue.Offset;
606 auto U = Die.getDwarfUnit();
607 assert(U && "Die must have valid DWARF unit");
608 bool b = AttrValue.Value.extractValue(U->getDebugInfoExtractor(),
609 &ParseOffset, U->getFormParams(), U);
610 (void)b;
611 assert(b && "extractValue cannot fail on fully parsed DWARF");
612 AttrValue.ByteSize = ParseOffset - AttrValue.Offset;
613 } else {
614 assert(Index == NumAttrs && "Indexes should be [0, NumAttrs) only");
615 AttrValue.clear();
616 }
617 }
618
operator ++()619 DWARFDie::attribute_iterator &DWARFDie::attribute_iterator::operator++() {
620 if (auto AbbrDecl = Die.getAbbreviationDeclarationPtr())
621 updateForIndex(*AbbrDecl, Index + 1);
622 return *this;
623 }
624