xref: /freebsd/contrib/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0) 
1 //===- DWARFDie.cpp -------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
10 #include "llvm/ADT/SmallPtrSet.h"
11 #include "llvm/ADT/SmallSet.h"
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/BinaryFormat/Dwarf.h"
14 #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
15 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
16 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
17 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
18 #include "llvm/DebugInfo/DWARF/DWARFExpression.h"
19 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
20 #include "llvm/DebugInfo/DWARF/DWARFTypePrinter.h"
21 #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
22 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
23 #include "llvm/Object/ObjectFile.h"
24 #include "llvm/Support/DataExtractor.h"
25 #include "llvm/Support/Format.h"
26 #include "llvm/Support/FormatVariadic.h"
27 #include "llvm/Support/MathExtras.h"
28 #include "llvm/Support/WithColor.h"
29 #include "llvm/Support/raw_ostream.h"
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 
40 static void dumpApplePropertyAttribute(raw_ostream &OS, uint64_t Val) {
41   OS << " (";
42   do {
43     uint64_t Shift = llvm::countr_zero(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 
58 static void dumpRanges(const DWARFObject &Obj, raw_ostream &OS,
59                        const DWARFAddressRangesVector &Ranges,
60                        unsigned AddressSize, unsigned Indent,
61                        const DIDumpOptions &DumpOpts) {
62   if (!DumpOpts.ShowAddresses)
63     return;
64 
65   for (const DWARFAddressRange &R : Ranges) {
66     OS << '\n';
67     OS.indent(Indent);
68     R.dump(OS, AddressSize, DumpOpts, &Obj);
69   }
70 }
71 
72 static void dumpLocationList(raw_ostream &OS, const DWARFFormValue &FormValue,
73                              DWARFUnit *U, unsigned Indent,
74                              DIDumpOptions DumpOpts) {
75   assert(FormValue.isFormClass(DWARFFormValue::FC_SectionOffset) &&
76          "bad FORM for location list");
77   DWARFContext &Ctx = U->getContext();
78   uint64_t Offset = *FormValue.getAsSectionOffset();
79 
80   if (FormValue.getForm() == DW_FORM_loclistx) {
81     FormValue.dump(OS, DumpOpts);
82 
83     if (auto LoclistOffset = U->getLoclistOffset(Offset))
84       Offset = *LoclistOffset;
85     else
86       return;
87   }
88   U->getLocationTable().dumpLocationList(
89       &Offset, OS, U->getBaseAddress(), Ctx.getDWARFObj(), U, DumpOpts, Indent);
90 }
91 
92 static void dumpLocationExpr(raw_ostream &OS, const DWARFFormValue &FormValue,
93                              DWARFUnit *U, unsigned Indent,
94                              DIDumpOptions DumpOpts) {
95   assert((FormValue.isFormClass(DWARFFormValue::FC_Block) ||
96           FormValue.isFormClass(DWARFFormValue::FC_Exprloc)) &&
97          "bad FORM for location expression");
98   DWARFContext &Ctx = U->getContext();
99   ArrayRef<uint8_t> Expr = *FormValue.getAsBlock();
100   DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
101                      Ctx.isLittleEndian(), 0);
102   DWARFExpression(Data, U->getAddressByteSize(), U->getFormParams().Format)
103       .print(OS, DumpOpts, U);
104 }
105 
106 static DWARFDie resolveReferencedType(DWARFDie D, DWARFFormValue F) {
107   return D.getAttributeValueAsReferencedDie(F).resolveTypeUnitReference();
108 }
109 
110 static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
111                           const DWARFAttribute &AttrValue, unsigned Indent,
112                           DIDumpOptions DumpOpts) {
113   if (!Die.isValid())
114     return;
115   const char BaseIndent[] = "            ";
116   OS << BaseIndent;
117   OS.indent(Indent + 2);
118   dwarf::Attribute Attr = AttrValue.Attr;
119   WithColor(OS, HighlightColor::Attribute) << formatv("{0}", Attr);
120 
121   dwarf::Form Form = AttrValue.Value.getForm();
122   if (DumpOpts.Verbose || DumpOpts.ShowForm)
123     OS << formatv(" [{0}]", Form);
124 
125   DWARFUnit *U = Die.getDwarfUnit();
126   const DWARFFormValue &FormValue = AttrValue.Value;
127 
128   OS << "\t(";
129 
130   StringRef Name;
131   std::string File;
132   auto Color = HighlightColor::Enumerator;
133   if (Attr == DW_AT_decl_file || Attr == DW_AT_call_file) {
134     Color = HighlightColor::String;
135     if (const auto *LT = U->getContext().getLineTableForUnit(U)) {
136       if (std::optional<uint64_t> Val = FormValue.getAsUnsignedConstant()) {
137         if (LT->getFileNameByIndex(
138                 *Val, U->getCompilationDir(),
139                 DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
140                 File)) {
141           File = '"' + File + '"';
142           Name = File;
143         }
144       }
145     }
146   } else if (std::optional<uint64_t> Val = FormValue.getAsUnsignedConstant())
147     Name = AttributeValueString(Attr, *Val);
148 
149   if (!Name.empty())
150     WithColor(OS, Color) << Name;
151   else if (Attr == DW_AT_decl_line || Attr == DW_AT_decl_column ||
152            Attr == DW_AT_call_line || Attr == DW_AT_call_column) {
153     if (std::optional<uint64_t> Val = FormValue.getAsUnsignedConstant())
154       OS << *Val;
155     else
156       FormValue.dump(OS, DumpOpts);
157   } else if (Attr == DW_AT_low_pc &&
158              (FormValue.getAsAddress() ==
159               dwarf::computeTombstoneAddress(U->getAddressByteSize()))) {
160     if (DumpOpts.Verbose) {
161       FormValue.dump(OS, DumpOpts);
162       OS << " (";
163     }
164     OS << "dead code";
165     if (DumpOpts.Verbose)
166       OS << ')';
167   } else if (Attr == DW_AT_high_pc && !DumpOpts.ShowForm && !DumpOpts.Verbose &&
168              FormValue.getAsUnsignedConstant()) {
169     if (DumpOpts.ShowAddresses) {
170       // Print the actual address rather than the offset.
171       uint64_t LowPC, HighPC, Index;
172       if (Die.getLowAndHighPC(LowPC, HighPC, Index))
173         DWARFFormValue::dumpAddress(OS, U->getAddressByteSize(), HighPC);
174       else
175         FormValue.dump(OS, DumpOpts);
176     }
177   } else if (DWARFAttribute::mayHaveLocationList(Attr) &&
178              FormValue.isFormClass(DWARFFormValue::FC_SectionOffset))
179     dumpLocationList(OS, FormValue, U, sizeof(BaseIndent) + Indent + 4,
180                      DumpOpts);
181   else if (FormValue.isFormClass(DWARFFormValue::FC_Exprloc) ||
182            (DWARFAttribute::mayHaveLocationExpr(Attr) &&
183             FormValue.isFormClass(DWARFFormValue::FC_Block)))
184     dumpLocationExpr(OS, FormValue, U, sizeof(BaseIndent) + Indent + 4,
185                      DumpOpts);
186   else
187     FormValue.dump(OS, DumpOpts);
188 
189   std::string Space = DumpOpts.ShowAddresses ? " " : "";
190 
191   // We have dumped the attribute raw value. For some attributes
192   // having both the raw value and the pretty-printed value is
193   // interesting. These attributes are handled below.
194   if (Attr == DW_AT_specification || Attr == DW_AT_abstract_origin ||
195       Attr == DW_AT_call_origin) {
196     if (const char *Name =
197             Die.getAttributeValueAsReferencedDie(FormValue).getName(
198                 DINameKind::LinkageName))
199       OS << Space << "\"" << Name << '\"';
200   } else if (Attr == DW_AT_type || Attr == DW_AT_containing_type) {
201     DWARFDie D = resolveReferencedType(Die, FormValue);
202     if (D && !D.isNULL()) {
203       OS << Space << "\"";
204       dumpTypeQualifiedName(D, OS);
205       OS << '"';
206     }
207   } else if (Attr == DW_AT_APPLE_property_attribute) {
208     if (std::optional<uint64_t> OptVal = FormValue.getAsUnsignedConstant())
209       dumpApplePropertyAttribute(OS, *OptVal);
210   } else if (Attr == DW_AT_ranges) {
211     const DWARFObject &Obj = Die.getDwarfUnit()->getContext().getDWARFObj();
212     // For DW_FORM_rnglistx we need to dump the offset separately, since
213     // we have only dumped the index so far.
214     if (FormValue.getForm() == DW_FORM_rnglistx)
215       if (auto RangeListOffset =
216               U->getRnglistOffset(*FormValue.getAsSectionOffset())) {
217         DWARFFormValue FV = DWARFFormValue::createFromUValue(
218             dwarf::DW_FORM_sec_offset, *RangeListOffset);
219         FV.dump(OS, DumpOpts);
220       }
221     if (auto RangesOrError = Die.getAddressRanges())
222       dumpRanges(Obj, OS, RangesOrError.get(), U->getAddressByteSize(),
223                  sizeof(BaseIndent) + Indent + 4, DumpOpts);
224     else
225       DumpOpts.RecoverableErrorHandler(createStringError(
226           errc::invalid_argument, "decoding address ranges: %s",
227           toString(RangesOrError.takeError()).c_str()));
228   }
229 
230   OS << ")\n";
231 }
232 
233 void DWARFDie::getFullName(raw_string_ostream &OS,
234                            std::string *OriginalFullName) const {
235   const char *NamePtr = getShortName();
236   if (!NamePtr)
237     return;
238   if (getTag() == DW_TAG_GNU_template_parameter_pack)
239     return;
240   dumpTypeUnqualifiedName(*this, OS, OriginalFullName);
241 }
242 
243 bool DWARFDie::isSubprogramDIE() const { return getTag() == DW_TAG_subprogram; }
244 
245 bool DWARFDie::isSubroutineDIE() const {
246   auto Tag = getTag();
247   return Tag == DW_TAG_subprogram || Tag == DW_TAG_inlined_subroutine;
248 }
249 
250 std::optional<DWARFFormValue> DWARFDie::find(dwarf::Attribute Attr) const {
251   if (!isValid())
252     return std::nullopt;
253   auto AbbrevDecl = getAbbreviationDeclarationPtr();
254   if (AbbrevDecl)
255     return AbbrevDecl->getAttributeValue(getOffset(), Attr, *U);
256   return std::nullopt;
257 }
258 
259 std::optional<DWARFFormValue>
260 DWARFDie::find(ArrayRef<dwarf::Attribute> Attrs) const {
261   if (!isValid())
262     return std::nullopt;
263   auto AbbrevDecl = getAbbreviationDeclarationPtr();
264   if (AbbrevDecl) {
265     for (auto Attr : Attrs) {
266       if (auto Value = AbbrevDecl->getAttributeValue(getOffset(), Attr, *U))
267         return Value;
268     }
269   }
270   return std::nullopt;
271 }
272 
273 std::optional<DWARFFormValue>
274 DWARFDie::findRecursively(ArrayRef<dwarf::Attribute> Attrs) const {
275   SmallVector<DWARFDie, 3> Worklist;
276   Worklist.push_back(*this);
277 
278   // Keep track if DIEs already seen to prevent infinite recursion.
279   // Empirically we rarely see a depth of more than 3 when dealing with valid
280   // DWARF. This corresponds to following the DW_AT_abstract_origin and
281   // DW_AT_specification just once.
282   SmallSet<DWARFDie, 3> Seen;
283   Seen.insert(*this);
284 
285   while (!Worklist.empty()) {
286     DWARFDie Die = Worklist.pop_back_val();
287 
288     if (!Die.isValid())
289       continue;
290 
291     if (auto Value = Die.find(Attrs))
292       return Value;
293 
294     if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
295       if (Seen.insert(D).second)
296         Worklist.push_back(D);
297 
298     if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_specification))
299       if (Seen.insert(D).second)
300         Worklist.push_back(D);
301   }
302 
303   return std::nullopt;
304 }
305 
306 DWARFDie
307 DWARFDie::getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const {
308   if (std::optional<DWARFFormValue> F = find(Attr))
309     return getAttributeValueAsReferencedDie(*F);
310   return DWARFDie();
311 }
312 
313 DWARFDie
314 DWARFDie::getAttributeValueAsReferencedDie(const DWARFFormValue &V) const {
315   DWARFDie Result;
316   if (auto SpecRef = V.getAsRelativeReference()) {
317     if (SpecRef->Unit)
318       Result = SpecRef->Unit->getDIEForOffset(SpecRef->Unit->getOffset() +
319                                               SpecRef->Offset);
320     else if (auto SpecUnit =
321                  U->getUnitVector().getUnitForOffset(SpecRef->Offset))
322       Result = SpecUnit->getDIEForOffset(SpecRef->Offset);
323   }
324   return Result;
325 }
326 
327 DWARFDie DWARFDie::resolveTypeUnitReference() const {
328   if (auto Attr = find(DW_AT_signature)) {
329     if (std::optional<uint64_t> Sig = Attr->getAsReferenceUVal()) {
330       if (DWARFTypeUnit *TU = U->getContext().getTypeUnitForHash(
331               U->getVersion(), *Sig, U->isDWOUnit()))
332         return TU->getDIEForOffset(TU->getTypeOffset() + TU->getOffset());
333     }
334   }
335   return *this;
336 }
337 
338 std::optional<uint64_t> DWARFDie::getRangesBaseAttribute() const {
339   return toSectionOffset(find({DW_AT_rnglists_base, DW_AT_GNU_ranges_base}));
340 }
341 
342 std::optional<uint64_t> DWARFDie::getLocBaseAttribute() const {
343   return toSectionOffset(find(DW_AT_loclists_base));
344 }
345 
346 std::optional<uint64_t> DWARFDie::getHighPC(uint64_t LowPC) const {
347   uint64_t Tombstone = dwarf::computeTombstoneAddress(U->getAddressByteSize());
348   if (LowPC == Tombstone)
349     return std::nullopt;
350   if (auto FormValue = find(DW_AT_high_pc)) {
351     if (auto Address = FormValue->getAsAddress()) {
352       // High PC is an address.
353       return Address;
354     }
355     if (auto Offset = FormValue->getAsUnsignedConstant()) {
356       // High PC is an offset from LowPC.
357       return LowPC + *Offset;
358     }
359   }
360   return std::nullopt;
361 }
362 
363 bool DWARFDie::getLowAndHighPC(uint64_t &LowPC, uint64_t &HighPC,
364                                uint64_t &SectionIndex) const {
365   auto F = find(DW_AT_low_pc);
366   auto LowPcAddr = toSectionedAddress(F);
367   if (!LowPcAddr)
368     return false;
369   if (auto HighPcAddr = getHighPC(LowPcAddr->Address)) {
370     LowPC = LowPcAddr->Address;
371     HighPC = *HighPcAddr;
372     SectionIndex = LowPcAddr->SectionIndex;
373     return true;
374   }
375   return false;
376 }
377 
378 Expected<DWARFAddressRangesVector> DWARFDie::getAddressRanges() const {
379   if (isNULL())
380     return DWARFAddressRangesVector();
381   // Single range specified by low/high PC.
382   uint64_t LowPC, HighPC, Index;
383   if (getLowAndHighPC(LowPC, HighPC, Index))
384     return DWARFAddressRangesVector{{LowPC, HighPC, Index}};
385 
386   std::optional<DWARFFormValue> Value = find(DW_AT_ranges);
387   if (Value) {
388     if (Value->getForm() == DW_FORM_rnglistx)
389       return U->findRnglistFromIndex(*Value->getAsSectionOffset());
390     return U->findRnglistFromOffset(*Value->getAsSectionOffset());
391   }
392   return DWARFAddressRangesVector();
393 }
394 
395 bool DWARFDie::addressRangeContainsAddress(const uint64_t Address) const {
396   auto RangesOrError = getAddressRanges();
397   if (!RangesOrError) {
398     llvm::consumeError(RangesOrError.takeError());
399     return false;
400   }
401 
402   for (const auto &R : RangesOrError.get())
403     if (R.LowPC <= Address && Address < R.HighPC)
404       return true;
405   return false;
406 }
407 
408 Expected<DWARFLocationExpressionsVector>
409 DWARFDie::getLocations(dwarf::Attribute Attr) const {
410   std::optional<DWARFFormValue> Location = find(Attr);
411   if (!Location)
412     return createStringError(inconvertibleErrorCode(), "No %s",
413                              dwarf::AttributeString(Attr).data());
414 
415   if (std::optional<uint64_t> Off = Location->getAsSectionOffset()) {
416     uint64_t Offset = *Off;
417 
418     if (Location->getForm() == DW_FORM_loclistx) {
419       if (auto LoclistOffset = U->getLoclistOffset(Offset))
420         Offset = *LoclistOffset;
421       else
422         return createStringError(inconvertibleErrorCode(),
423                                  "Loclist table not found");
424     }
425     return U->findLoclistFromOffset(Offset);
426   }
427 
428   if (std::optional<ArrayRef<uint8_t>> Expr = Location->getAsBlock()) {
429     return DWARFLocationExpressionsVector{
430         DWARFLocationExpression{std::nullopt, to_vector<4>(*Expr)}};
431   }
432 
433   return createStringError(
434       inconvertibleErrorCode(), "Unsupported %s encoding: %s",
435       dwarf::AttributeString(Attr).data(),
436       dwarf::FormEncodingString(Location->getForm()).data());
437 }
438 
439 const char *DWARFDie::getSubroutineName(DINameKind Kind) const {
440   if (!isSubroutineDIE())
441     return nullptr;
442   return getName(Kind);
443 }
444 
445 const char *DWARFDie::getName(DINameKind Kind) const {
446   if (!isValid() || Kind == DINameKind::None)
447     return nullptr;
448   // Try to get mangled name only if it was asked for.
449   if (Kind == DINameKind::LinkageName) {
450     if (auto Name = getLinkageName())
451       return Name;
452   }
453   return getShortName();
454 }
455 
456 const char *DWARFDie::getShortName() const {
457   if (!isValid())
458     return nullptr;
459 
460   return dwarf::toString(findRecursively(dwarf::DW_AT_name), nullptr);
461 }
462 
463 const char *DWARFDie::getLinkageName() const {
464   if (!isValid())
465     return nullptr;
466 
467   return dwarf::toString(findRecursively({dwarf::DW_AT_MIPS_linkage_name,
468                                           dwarf::DW_AT_linkage_name}),
469                          nullptr);
470 }
471 
472 uint64_t DWARFDie::getDeclLine() const {
473   return toUnsigned(findRecursively(DW_AT_decl_line), 0);
474 }
475 
476 std::string
477 DWARFDie::getDeclFile(DILineInfoSpecifier::FileLineInfoKind Kind) const {
478   if (auto FormValue = findRecursively(DW_AT_decl_file))
479     if (auto OptString = FormValue->getAsFile(Kind))
480       return *OptString;
481   return {};
482 }
483 
484 void DWARFDie::getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
485                               uint32_t &CallColumn,
486                               uint32_t &CallDiscriminator) const {
487   CallFile = toUnsigned(find(DW_AT_call_file), 0);
488   CallLine = toUnsigned(find(DW_AT_call_line), 0);
489   CallColumn = toUnsigned(find(DW_AT_call_column), 0);
490   CallDiscriminator = toUnsigned(find(DW_AT_GNU_discriminator), 0);
491 }
492 
493 static std::optional<uint64_t>
494 getTypeSizeImpl(DWARFDie Die, uint64_t PointerSize,
495                 SmallPtrSetImpl<const DWARFDebugInfoEntry *> &Visited) {
496   // Cycle detected?
497   if (!Visited.insert(Die.getDebugInfoEntry()).second)
498     return {};
499   if (auto SizeAttr = Die.find(DW_AT_byte_size))
500     if (std::optional<uint64_t> Size = SizeAttr->getAsUnsignedConstant())
501       return Size;
502 
503   switch (Die.getTag()) {
504   case DW_TAG_pointer_type:
505   case DW_TAG_reference_type:
506   case DW_TAG_rvalue_reference_type:
507     return PointerSize;
508   case DW_TAG_ptr_to_member_type: {
509     if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type))
510       if (BaseType.getTag() == DW_TAG_subroutine_type)
511         return 2 * PointerSize;
512     return PointerSize;
513   }
514   case DW_TAG_const_type:
515   case DW_TAG_immutable_type:
516   case DW_TAG_volatile_type:
517   case DW_TAG_restrict_type:
518   case DW_TAG_typedef: {
519     if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type))
520       return getTypeSizeImpl(BaseType, PointerSize, Visited);
521     break;
522   }
523   case DW_TAG_array_type: {
524     DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type);
525     if (!BaseType)
526       return std::nullopt;
527     std::optional<uint64_t> BaseSize =
528         getTypeSizeImpl(BaseType, PointerSize, Visited);
529     if (!BaseSize)
530       return std::nullopt;
531     uint64_t Size = *BaseSize;
532     for (DWARFDie Child : Die) {
533       if (Child.getTag() != DW_TAG_subrange_type)
534         continue;
535 
536       if (auto ElemCountAttr = Child.find(DW_AT_count))
537         if (std::optional<uint64_t> ElemCount =
538                 ElemCountAttr->getAsUnsignedConstant())
539           Size *= *ElemCount;
540       if (auto UpperBoundAttr = Child.find(DW_AT_upper_bound))
541         if (std::optional<int64_t> UpperBound =
542                 UpperBoundAttr->getAsSignedConstant()) {
543           int64_t LowerBound = 0;
544           if (auto LowerBoundAttr = Child.find(DW_AT_lower_bound))
545             LowerBound = LowerBoundAttr->getAsSignedConstant().value_or(0);
546           Size *= *UpperBound - LowerBound + 1;
547         }
548     }
549     return Size;
550   }
551   default:
552     if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type))
553       return getTypeSizeImpl(BaseType, PointerSize, Visited);
554     break;
555   }
556   return std::nullopt;
557 }
558 
559 std::optional<uint64_t> DWARFDie::getTypeSize(uint64_t PointerSize) {
560   SmallPtrSet<const DWARFDebugInfoEntry *, 4> Visited;
561   return getTypeSizeImpl(*this, PointerSize, Visited);
562 }
563 
564 /// Helper to dump a DIE with all of its parents, but no siblings.
565 static unsigned dumpParentChain(DWARFDie Die, raw_ostream &OS, unsigned Indent,
566                                 DIDumpOptions DumpOpts, unsigned Depth = 0) {
567   if (!Die)
568     return Indent;
569   if (DumpOpts.ParentRecurseDepth > 0 && Depth >= DumpOpts.ParentRecurseDepth)
570     return Indent;
571   Indent = dumpParentChain(Die.getParent(), OS, Indent, DumpOpts, Depth + 1);
572   Die.dump(OS, Indent, DumpOpts);
573   return Indent + 2;
574 }
575 
576 void DWARFDie::dump(raw_ostream &OS, unsigned Indent,
577                     DIDumpOptions DumpOpts) const {
578   if (!isValid())
579     return;
580   DWARFDataExtractor debug_info_data = U->getDebugInfoExtractor();
581   const uint64_t Offset = getOffset();
582   uint64_t offset = Offset;
583   if (DumpOpts.ShowParents) {
584     DIDumpOptions ParentDumpOpts = DumpOpts;
585     ParentDumpOpts.ShowParents = false;
586     ParentDumpOpts.ShowChildren = false;
587     Indent = dumpParentChain(getParent(), OS, Indent, ParentDumpOpts);
588   }
589 
590   if (debug_info_data.isValidOffset(offset)) {
591     uint32_t abbrCode = debug_info_data.getULEB128(&offset);
592     if (DumpOpts.ShowAddresses)
593       WithColor(OS, HighlightColor::Address).get()
594           << format("\n0x%8.8" PRIx64 ": ", Offset);
595 
596     if (abbrCode) {
597       auto AbbrevDecl = getAbbreviationDeclarationPtr();
598       if (AbbrevDecl) {
599         WithColor(OS, HighlightColor::Tag).get().indent(Indent)
600             << formatv("{0}", getTag());
601         if (DumpOpts.Verbose) {
602           OS << format(" [%u] %c", abbrCode,
603                        AbbrevDecl->hasChildren() ? '*' : ' ');
604           if (std::optional<uint32_t> ParentIdx = Die->getParentIdx())
605             OS << format(" (0x%8.8" PRIx64 ")",
606                          U->getDIEAtIndex(*ParentIdx).getOffset());
607         }
608         OS << '\n';
609 
610         // Dump all data in the DIE for the attributes.
611         for (const DWARFAttribute &AttrValue : attributes())
612           dumpAttribute(OS, *this, AttrValue, Indent, DumpOpts);
613 
614         if (DumpOpts.ShowChildren && DumpOpts.ChildRecurseDepth > 0) {
615           DWARFDie Child = getFirstChild();
616           DumpOpts.ChildRecurseDepth--;
617           DIDumpOptions ChildDumpOpts = DumpOpts;
618           ChildDumpOpts.ShowParents = false;
619           while (Child) {
620             Child.dump(OS, Indent + 2, ChildDumpOpts);
621             Child = Child.getSibling();
622           }
623         }
624       } else {
625         OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
626            << abbrCode << '\n';
627       }
628     } else {
629       OS.indent(Indent) << "NULL\n";
630     }
631   }
632 }
633 
634 LLVM_DUMP_METHOD void DWARFDie::dump() const { dump(llvm::errs(), 0); }
635 
636 DWARFDie DWARFDie::getParent() const {
637   if (isValid())
638     return U->getParent(Die);
639   return DWARFDie();
640 }
641 
642 DWARFDie DWARFDie::getSibling() const {
643   if (isValid())
644     return U->getSibling(Die);
645   return DWARFDie();
646 }
647 
648 DWARFDie DWARFDie::getPreviousSibling() const {
649   if (isValid())
650     return U->getPreviousSibling(Die);
651   return DWARFDie();
652 }
653 
654 DWARFDie DWARFDie::getFirstChild() const {
655   if (isValid())
656     return U->getFirstChild(Die);
657   return DWARFDie();
658 }
659 
660 DWARFDie DWARFDie::getLastChild() const {
661   if (isValid())
662     return U->getLastChild(Die);
663   return DWARFDie();
664 }
665 
666 iterator_range<DWARFDie::attribute_iterator> DWARFDie::attributes() const {
667   return make_range(attribute_iterator(*this, false),
668                     attribute_iterator(*this, true));
669 }
670 
671 DWARFDie::attribute_iterator::attribute_iterator(DWARFDie D, bool End)
672     : Die(D), Index(0) {
673   auto AbbrDecl = Die.getAbbreviationDeclarationPtr();
674   assert(AbbrDecl && "Must have abbreviation declaration");
675   if (End) {
676     // This is the end iterator so we set the index to the attribute count.
677     Index = AbbrDecl->getNumAttributes();
678   } else {
679     // This is the begin iterator so we extract the value for this->Index.
680     AttrValue.Offset = D.getOffset() + AbbrDecl->getCodeByteSize();
681     updateForIndex(*AbbrDecl, 0);
682   }
683 }
684 
685 void DWARFDie::attribute_iterator::updateForIndex(
686     const DWARFAbbreviationDeclaration &AbbrDecl, uint32_t I) {
687   Index = I;
688   // AbbrDecl must be valid before calling this function.
689   auto NumAttrs = AbbrDecl.getNumAttributes();
690   if (Index < NumAttrs) {
691     AttrValue.Attr = AbbrDecl.getAttrByIndex(Index);
692     // Add the previous byte size of any previous attribute value.
693     AttrValue.Offset += AttrValue.ByteSize;
694     uint64_t ParseOffset = AttrValue.Offset;
695     if (AbbrDecl.getAttrIsImplicitConstByIndex(Index))
696       AttrValue.Value = DWARFFormValue::createFromSValue(
697           AbbrDecl.getFormByIndex(Index),
698           AbbrDecl.getAttrImplicitConstValueByIndex(Index));
699     else {
700       auto U = Die.getDwarfUnit();
701       assert(U && "Die must have valid DWARF unit");
702       AttrValue.Value = DWARFFormValue::createFromUnit(
703           AbbrDecl.getFormByIndex(Index), U, &ParseOffset);
704     }
705     AttrValue.ByteSize = ParseOffset - AttrValue.Offset;
706   } else {
707     assert(Index == NumAttrs && "Indexes should be [0, NumAttrs) only");
708     AttrValue = {};
709   }
710 }
711 
712 DWARFDie::attribute_iterator &DWARFDie::attribute_iterator::operator++() {
713   if (auto AbbrDecl = Die.getAbbreviationDeclarationPtr())
714     updateForIndex(*AbbrDecl, Index + 1);
715   return *this;
716 }
717 
718 bool DWARFAttribute::mayHaveLocationList(dwarf::Attribute Attr) {
719   switch(Attr) {
720   case DW_AT_location:
721   case DW_AT_string_length:
722   case DW_AT_return_addr:
723   case DW_AT_data_member_location:
724   case DW_AT_frame_base:
725   case DW_AT_static_link:
726   case DW_AT_segment:
727   case DW_AT_use_location:
728   case DW_AT_vtable_elem_location:
729     return true;
730   default:
731     return false;
732   }
733 }
734 
735 bool DWARFAttribute::mayHaveLocationExpr(dwarf::Attribute Attr) {
736   switch (Attr) {
737   // From the DWARF v5 specification.
738   case DW_AT_location:
739   case DW_AT_byte_size:
740   case DW_AT_bit_offset:
741   case DW_AT_bit_size:
742   case DW_AT_string_length:
743   case DW_AT_lower_bound:
744   case DW_AT_return_addr:
745   case DW_AT_bit_stride:
746   case DW_AT_upper_bound:
747   case DW_AT_count:
748   case DW_AT_data_member_location:
749   case DW_AT_frame_base:
750   case DW_AT_segment:
751   case DW_AT_static_link:
752   case DW_AT_use_location:
753   case DW_AT_vtable_elem_location:
754   case DW_AT_allocated:
755   case DW_AT_associated:
756   case DW_AT_data_location:
757   case DW_AT_byte_stride:
758   case DW_AT_rank:
759   case DW_AT_call_value:
760   case DW_AT_call_origin:
761   case DW_AT_call_target:
762   case DW_AT_call_target_clobbered:
763   case DW_AT_call_data_location:
764   case DW_AT_call_data_value:
765   // Extensions.
766   case DW_AT_GNU_call_site_value:
767   case DW_AT_GNU_call_site_target:
768     return true;
769   default:
770     return false;
771   }
772 }
773 
774 namespace llvm {
775 
776 void dumpTypeQualifiedName(const DWARFDie &DIE, raw_ostream &OS) {
777   DWARFTypePrinter(OS).appendQualifiedName(DIE);
778 }
779 
780 void dumpTypeUnqualifiedName(const DWARFDie &DIE, raw_ostream &OS,
781                              std::string *OriginalFullName) {
782   DWARFTypePrinter(OS).appendUnqualifiedName(DIE, OriginalFullName);
783 }
784 
785 } // namespace llvm
786