xref: /freebsd-src/contrib/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp (revision 0eae32dcef82f6f06de6419a0d623d7def0cc8f6)
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/None.h"
11 #include "llvm/ADT/Optional.h"
12 #include "llvm/ADT/SmallSet.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/BinaryFormat/Dwarf.h"
15 #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
16 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
17 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
18 #include "llvm/DebugInfo/DWARF/DWARFExpression.h"
19 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
20 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
21 #include "llvm/Object/ObjectFile.h"
22 #include "llvm/Support/DataExtractor.h"
23 #include "llvm/Support/Format.h"
24 #include "llvm/Support/FormatAdapters.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 
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 
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   const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
79   uint64_t Offset = *FormValue.getAsSectionOffset();
80 
81   if (FormValue.getForm() == DW_FORM_loclistx) {
82     FormValue.dump(OS, DumpOpts);
83 
84     if (auto LoclistOffset = U->getLoclistOffset(Offset))
85       Offset = *LoclistOffset;
86     else
87       return;
88   }
89   U->getLocationTable().dumpLocationList(&Offset, OS, U->getBaseAddress(), MRI,
90                                          Ctx.getDWARFObj(), U, DumpOpts,
91                                          Indent);
92 }
93 
94 static void dumpLocationExpr(raw_ostream &OS, const DWARFFormValue &FormValue,
95                              DWARFUnit *U, unsigned Indent,
96                              DIDumpOptions DumpOpts) {
97   assert((FormValue.isFormClass(DWARFFormValue::FC_Block) ||
98           FormValue.isFormClass(DWARFFormValue::FC_Exprloc)) &&
99          "bad FORM for location expression");
100   DWARFContext &Ctx = U->getContext();
101   const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
102   ArrayRef<uint8_t> Expr = *FormValue.getAsBlock();
103   DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
104                      Ctx.isLittleEndian(), 0);
105   DWARFExpression(Data, U->getAddressByteSize(), U->getFormParams().Format)
106       .print(OS, DumpOpts, MRI, U);
107 }
108 
109 static DWARFDie resolveReferencedType(DWARFDie D,
110                                       dwarf::Attribute Attr = DW_AT_type) {
111   return D.getAttributeValueAsReferencedDie(Attr).resolveTypeUnitReference();
112 }
113 static DWARFDie resolveReferencedType(DWARFDie D, DWARFFormValue F) {
114   return D.getAttributeValueAsReferencedDie(F).resolveTypeUnitReference();
115 }
116 
117 namespace {
118 
119 // FIXME: We should have pretty printers per language. Currently we print
120 // everything as if it was C++ and fall back to the TAG type name.
121 struct DWARFTypePrinter {
122   raw_ostream &OS;
123   bool Word = true;
124   bool EndedWithTemplate = false;
125 
126   DWARFTypePrinter(raw_ostream &OS) : OS(OS) {}
127 
128   /// Dump the name encoded in the type tag.
129   void appendTypeTagName(dwarf::Tag T) {
130     StringRef TagStr = TagString(T);
131     static constexpr StringRef Prefix = "DW_TAG_";
132     static constexpr StringRef Suffix = "_type";
133     if (!TagStr.startswith(Prefix) || !TagStr.endswith(Suffix))
134       return;
135     OS << TagStr.substr(Prefix.size(),
136                         TagStr.size() - (Prefix.size() + Suffix.size()))
137        << " ";
138   }
139 
140   void appendArrayType(const DWARFDie &D) {
141     for (const DWARFDie &C : D.children()) {
142       if (C.getTag() != DW_TAG_subrange_type)
143         continue;
144       Optional<uint64_t> LB;
145       Optional<uint64_t> Count;
146       Optional<uint64_t> UB;
147       Optional<unsigned> DefaultLB;
148       if (Optional<DWARFFormValue> L = C.find(DW_AT_lower_bound))
149         LB = L->getAsUnsignedConstant();
150       if (Optional<DWARFFormValue> CountV = C.find(DW_AT_count))
151         Count = CountV->getAsUnsignedConstant();
152       if (Optional<DWARFFormValue> UpperV = C.find(DW_AT_upper_bound))
153         UB = UpperV->getAsUnsignedConstant();
154       if (Optional<DWARFFormValue> LV =
155               D.getDwarfUnit()->getUnitDIE().find(DW_AT_language))
156         if (Optional<uint64_t> LC = LV->getAsUnsignedConstant())
157           if ((DefaultLB =
158                    LanguageLowerBound(static_cast<dwarf::SourceLanguage>(*LC))))
159             if (LB && *LB == *DefaultLB)
160               LB = None;
161       if (!LB && !Count && !UB)
162         OS << "[]";
163       else if (!LB && (Count || UB) && DefaultLB)
164         OS << '[' << (Count ? *Count : *UB - *DefaultLB + 1) << ']';
165       else {
166         OS << "[[";
167         if (LB)
168           OS << *LB;
169         else
170           OS << '?';
171         OS << ", ";
172         if (Count)
173           if (LB)
174             OS << *LB + *Count;
175           else
176             OS << "? + " << *Count;
177         else if (UB)
178           OS << *UB + 1;
179         else
180           OS << '?';
181         OS << ")]";
182       }
183     }
184     EndedWithTemplate = false;
185   }
186 
187   DWARFDie skipQualifiers(DWARFDie D) {
188     while (D && (D.getTag() == DW_TAG_const_type ||
189                  D.getTag() == DW_TAG_volatile_type))
190       D = resolveReferencedType(D);
191     return D;
192   }
193 
194   bool needsParens(DWARFDie D) {
195     D = skipQualifiers(D);
196     return D && (D.getTag() == DW_TAG_subroutine_type || D.getTag() == DW_TAG_array_type);
197   }
198 
199   void appendPointerLikeTypeBefore(DWARFDie D, DWARFDie Inner, StringRef Ptr) {
200     appendQualifiedNameBefore(Inner);
201     if (Word)
202       OS << ' ';
203     if (needsParens(Inner))
204       OS << '(';
205     OS << Ptr;
206     Word = false;
207     EndedWithTemplate = false;
208   }
209 
210   DWARFDie
211   appendUnqualifiedNameBefore(DWARFDie D,
212                               std::string *OriginalFullName = nullptr) {
213     Word = true;
214     if (!D) {
215       OS << "void";
216       return DWARFDie();
217     }
218     DWARFDie Inner = resolveReferencedType(D);
219     const dwarf::Tag T = D.getTag();
220     switch (T) {
221     case DW_TAG_pointer_type: {
222       appendPointerLikeTypeBefore(D, Inner, "*");
223       break;
224     }
225     case DW_TAG_subroutine_type: {
226       appendQualifiedNameBefore(Inner);
227       if (Word) {
228         OS << ' ';
229       }
230       Word = false;
231       break;
232     }
233     case DW_TAG_array_type: {
234       appendQualifiedNameBefore(Inner);
235       break;
236     }
237     case DW_TAG_reference_type:
238       appendPointerLikeTypeBefore(D, Inner, "&");
239       break;
240     case DW_TAG_rvalue_reference_type:
241       appendPointerLikeTypeBefore(D, Inner, "&&");
242       break;
243     case DW_TAG_ptr_to_member_type: {
244       appendQualifiedNameBefore(Inner);
245       if (needsParens(Inner))
246         OS << '(';
247       else if (Word)
248         OS << ' ';
249       if (DWARFDie Cont = resolveReferencedType(D, DW_AT_containing_type)) {
250         appendQualifiedName(Cont);
251         OS << "::";
252       }
253       OS << "*";
254       Word = false;
255       break;
256     }
257     case DW_TAG_const_type:
258     case DW_TAG_volatile_type:
259       appendConstVolatileQualifierBefore(D);
260       break;
261     case DW_TAG_namespace: {
262       if (const char *Name = dwarf::toString(D.find(DW_AT_name), nullptr))
263         OS << Name;
264       else
265         OS << "(anonymous namespace)";
266       break;
267     }
268     case DW_TAG_unspecified_type: {
269       StringRef TypeName = D.getShortName();
270       if (TypeName == "decltype(nullptr)")
271         TypeName = "std::nullptr_t";
272       Word = true;
273       OS << TypeName;
274       EndedWithTemplate = false;
275       break;
276     }
277       /*
278     case DW_TAG_structure_type:
279     case DW_TAG_class_type:
280     case DW_TAG_enumeration_type:
281     case DW_TAG_base_type:
282     */
283     default: {
284       const char *NamePtr = dwarf::toString(D.find(DW_AT_name), nullptr);
285       if (!NamePtr) {
286         appendTypeTagName(D.getTag());
287         return Inner;
288       }
289       Word = true;
290       StringRef Name = NamePtr;
291       static constexpr StringRef MangledPrefix = "_STN";
292       if (Name.startswith(MangledPrefix)) {
293         Name = Name.drop_front(MangledPrefix.size());
294         auto Separator = Name.find('|');
295         assert(Separator != StringRef::npos);
296         StringRef BaseName = Name.substr(0, Separator);
297         StringRef TemplateArgs = Name.substr(Separator + 1);
298         if (OriginalFullName)
299           *OriginalFullName = (BaseName + TemplateArgs).str();
300         Name = BaseName;
301       } else
302         EndedWithTemplate = Name.endswith(">");
303       OS << Name;
304       // This check would be insufficient for operator overloads like
305       // "operator>>" - but for now Clang doesn't try to simplify them, so this
306       // is OK. Add more nuanced operator overload handling here if/when needed.
307       if (Name.endswith(">"))
308         break;
309       if (!appendTemplateParameters(D))
310         break;
311 
312       if (EndedWithTemplate)
313         OS << ' ';
314       OS << '>';
315       EndedWithTemplate = true;
316       Word = true;
317       break;
318     }
319     }
320     return Inner;
321   }
322 
323   void appendUnqualifiedNameAfter(DWARFDie D, DWARFDie Inner,
324                                   bool SkipFirstParamIfArtificial = false) {
325     if (!D)
326       return;
327     switch (D.getTag()) {
328     case DW_TAG_subroutine_type: {
329       appendSubroutineNameAfter(D, Inner, SkipFirstParamIfArtificial, false,
330                                 false);
331       break;
332     }
333     case DW_TAG_array_type: {
334       appendArrayType(D);
335       break;
336     }
337     case DW_TAG_const_type:
338     case DW_TAG_volatile_type:
339       appendConstVolatileQualifierAfter(D);
340       break;
341     case DW_TAG_ptr_to_member_type:
342     case DW_TAG_reference_type:
343     case DW_TAG_rvalue_reference_type:
344     case DW_TAG_pointer_type: {
345       if (needsParens(Inner))
346         OS << ')';
347       appendUnqualifiedNameAfter(Inner, resolveReferencedType(Inner),
348                                  /*SkipFirstParamIfArtificial=*/D.getTag() ==
349                                      DW_TAG_ptr_to_member_type);
350       break;
351     }
352       /*
353     case DW_TAG_structure_type:
354     case DW_TAG_class_type:
355     case DW_TAG_enumeration_type:
356     case DW_TAG_base_type:
357     case DW_TAG_namespace:
358     */
359     default:
360       break;
361     }
362   }
363 
364   void appendQualifiedName(DWARFDie D) {
365     if (D)
366       appendScopes(D.getParent());
367     appendUnqualifiedName(D);
368   }
369   DWARFDie appendQualifiedNameBefore(DWARFDie D) {
370     if (D)
371       appendScopes(D.getParent());
372     return appendUnqualifiedNameBefore(D);
373   }
374   bool appendTemplateParameters(DWARFDie D, bool *FirstParameter = nullptr) {
375     bool FirstParameterValue = true;
376     bool IsTemplate = false;
377     if (!FirstParameter)
378       FirstParameter = &FirstParameterValue;
379     for (const DWARFDie &C : D) {
380       auto Sep = [&] {
381         if (*FirstParameter)
382           OS << '<';
383         else
384           OS << ", ";
385         IsTemplate = true;
386         EndedWithTemplate = false;
387         *FirstParameter = false;
388       };
389       if (C.getTag() == dwarf::DW_TAG_GNU_template_parameter_pack) {
390         IsTemplate = true;
391         appendTemplateParameters(C, FirstParameter);
392       }
393       if (C.getTag() == dwarf::DW_TAG_template_value_parameter) {
394         DWARFDie T = resolveReferencedType(C);
395         Sep();
396         if (T.getTag() == DW_TAG_enumeration_type) {
397           auto V = C.find(DW_AT_const_value);
398           bool FoundEnumerator = false;
399           for (const DWARFDie &Enumerator : T) {
400             auto EV = Enumerator.find(DW_AT_const_value);
401             if (V && EV &&
402                 V->getAsSignedConstant() == EV->getAsSignedConstant()) {
403               if (T.find(DW_AT_enum_class)) {
404                 appendQualifiedName(T);
405                 OS << "::";
406               } else
407                 appendScopes(T.getParent());
408               OS << Enumerator.getShortName();
409               FoundEnumerator = true;
410               break;
411             }
412           }
413           if (FoundEnumerator)
414             continue;
415           OS << '(';
416           appendQualifiedName(T);
417           OS << ')';
418           OS << to_string(*V->getAsSignedConstant());
419           continue;
420         }
421         // /Maybe/ we could do pointer type parameters, looking for the
422         // symbol in the ELF symbol table to get back to the variable...
423         // but probably not worth it.
424         if (T.getTag() == DW_TAG_pointer_type)
425           continue;
426         const char *RawName = dwarf::toString(T.find(DW_AT_name), nullptr);
427         assert(RawName);
428         StringRef Name = RawName;
429         auto V = C.find(DW_AT_const_value);
430         bool IsQualifiedChar = false;
431         if (Name == "bool") {
432           OS << (*V->getAsUnsignedConstant() ? "true" : "false");
433         } else if (Name == "short") {
434           OS << "(short)";
435           OS << to_string(*V->getAsSignedConstant());
436         } else if (Name == "unsigned short") {
437           OS << "(unsigned short)";
438           OS << to_string(*V->getAsSignedConstant());
439         } else if (Name == "int")
440           OS << to_string(*V->getAsSignedConstant());
441         else if (Name == "long") {
442           OS << to_string(*V->getAsSignedConstant());
443           OS << "L";
444         } else if (Name == "long long") {
445           OS << to_string(*V->getAsSignedConstant());
446           OS << "LL";
447         } else if (Name == "unsigned int") {
448           OS << to_string(*V->getAsUnsignedConstant());
449           OS << "U";
450         } else if (Name == "unsigned long") {
451           OS << to_string(*V->getAsUnsignedConstant());
452           OS << "UL";
453         } else if (Name == "unsigned long long") {
454           OS << to_string(*V->getAsUnsignedConstant());
455           OS << "ULL";
456         } else if (Name == "char" ||
457                    (IsQualifiedChar =
458                         (Name == "unsigned char" || Name == "signed char"))) {
459           // FIXME: check T's DW_AT_type to see if it's signed or not (since
460           // char signedness is implementation defined).
461           auto Val = *V->getAsSignedConstant();
462           // Copied/hacked up from Clang's CharacterLiteral::print - incomplete
463           // (doesn't actually support different character types/widths, sign
464           // handling's not done, and doesn't correctly test if a character is
465           // printable or needs to use a numeric escape sequence instead)
466           if (IsQualifiedChar) {
467             OS << '(';
468             OS << Name;
469             OS << ')';
470           }
471           switch (Val) {
472           case '\\':
473             OS << "'\\\\'";
474             break;
475           case '\'':
476             OS << "'\\''";
477             break;
478           case '\a':
479             // TODO: K&R: the meaning of '\\a' is different in traditional C
480             OS << "'\\a'";
481             break;
482           case '\b':
483             OS << "'\\b'";
484             break;
485           case '\f':
486             OS << "'\\f'";
487             break;
488           case '\n':
489             OS << "'\\n'";
490             break;
491           case '\r':
492             OS << "'\\r'";
493             break;
494           case '\t':
495             OS << "'\\t'";
496             break;
497           case '\v':
498             OS << "'\\v'";
499             break;
500           default:
501             if ((Val & ~0xFFu) == ~0xFFu)
502               Val &= 0xFFu;
503             if (Val < 127 && Val >= 32) {
504               OS << "'";
505               OS << (char)Val;
506               OS << "'";
507             } else if (Val < 256)
508               OS << to_string(llvm::format("'\\x%02x'", Val));
509             else if (Val <= 0xFFFF)
510               OS << to_string(llvm::format("'\\u%04x'", Val));
511             else
512               OS << to_string(llvm::format("'\\U%08x'", Val));
513           }
514         }
515         continue;
516       }
517       if (C.getTag() == dwarf::DW_TAG_GNU_template_template_param) {
518         const char *RawName =
519             dwarf::toString(C.find(DW_AT_GNU_template_name), nullptr);
520         assert(RawName);
521         StringRef Name = RawName;
522         Sep();
523         OS << Name;
524         continue;
525       }
526       if (C.getTag() != dwarf::DW_TAG_template_type_parameter)
527         continue;
528       auto TypeAttr = C.find(DW_AT_type);
529       Sep();
530       appendQualifiedName(TypeAttr ? resolveReferencedType(C, *TypeAttr)
531                                    : DWARFDie());
532     }
533     if (IsTemplate && *FirstParameter && FirstParameter == &FirstParameterValue)
534       OS << '<';
535     return IsTemplate;
536   }
537   void decomposeConstVolatile(DWARFDie &N, DWARFDie &T, DWARFDie &C,
538                               DWARFDie &V) {
539     (N.getTag() == DW_TAG_const_type ? C : V) = N;
540     T = resolveReferencedType(N);
541     if (T) {
542       auto Tag = T.getTag();
543       if (Tag == DW_TAG_const_type) {
544         C = T;
545         T = resolveReferencedType(T);
546       } else if (Tag == DW_TAG_volatile_type) {
547         V = T;
548         T = resolveReferencedType(T);
549       }
550     }
551   }
552   void appendConstVolatileQualifierAfter(DWARFDie N) {
553     DWARFDie C;
554     DWARFDie V;
555     DWARFDie T;
556     decomposeConstVolatile(N, T, C, V);
557     if (T && T.getTag() == DW_TAG_subroutine_type)
558       appendSubroutineNameAfter(T, resolveReferencedType(T), false, C.isValid(),
559                                 V.isValid());
560     else
561       appendUnqualifiedNameAfter(T, resolveReferencedType(T));
562   }
563   void appendConstVolatileQualifierBefore(DWARFDie N) {
564     DWARFDie C;
565     DWARFDie V;
566     DWARFDie T;
567     decomposeConstVolatile(N, T, C, V);
568     bool Subroutine = T && T.getTag() == DW_TAG_subroutine_type;
569     DWARFDie A = T;
570     while (A && A.getTag() == DW_TAG_array_type)
571       A = resolveReferencedType(A);
572     bool Leading =
573         (!A || (A.getTag() != DW_TAG_pointer_type &&
574                 A.getTag() != llvm::dwarf::DW_TAG_ptr_to_member_type)) &&
575         !Subroutine;
576     if (Leading) {
577       if (C)
578         OS << "const ";
579       if (V)
580         OS << "volatile ";
581     }
582     appendQualifiedNameBefore(T);
583     if (!Leading && !Subroutine) {
584       Word = true;
585       if (C)
586         OS << "const";
587       if (V) {
588         if (C)
589           OS << ' ';
590         OS << "volatile";
591       }
592     }
593   }
594 
595   /// Recursively append the DIE type name when applicable.
596   void appendUnqualifiedName(DWARFDie D,
597                              std::string *OriginalFullName = nullptr) {
598     // FIXME: We should have pretty printers per language. Currently we print
599     // everything as if it was C++ and fall back to the TAG type name.
600     DWARFDie Inner = appendUnqualifiedNameBefore(D, OriginalFullName);
601     appendUnqualifiedNameAfter(D, Inner);
602   }
603 
604   void appendSubroutineNameAfter(DWARFDie D, DWARFDie Inner,
605                                  bool SkipFirstParamIfArtificial, bool Const,
606                                  bool Volatile) {
607     DWARFDie FirstParamIfArtificial;
608     OS << '(';
609     EndedWithTemplate = false;
610     bool First = true;
611     bool RealFirst = true;
612     for (DWARFDie P : D) {
613       if (P.getTag() != DW_TAG_formal_parameter)
614         return;
615       DWARFDie T = resolveReferencedType(P);
616       if (SkipFirstParamIfArtificial && RealFirst && P.find(DW_AT_artificial)) {
617         FirstParamIfArtificial = T;
618         RealFirst = false;
619         continue;
620       }
621       if (!First) {
622         OS << ", ";
623       }
624       First = false;
625       appendQualifiedName(T);
626     }
627     EndedWithTemplate = false;
628     OS << ')';
629     if (FirstParamIfArtificial) {
630       if (DWARFDie P = FirstParamIfArtificial) {
631         if (P.getTag() == DW_TAG_pointer_type) {
632           DWARFDie C;
633           DWARFDie V;
634           auto CVStep = [&](DWARFDie CV) {
635             if (DWARFDie U = resolveReferencedType(CV)) {
636               if (U.getTag() == DW_TAG_const_type)
637                 return C = U;
638               if (U.getTag() == DW_TAG_volatile_type)
639                 return V = U;
640             }
641             return DWARFDie();
642           };
643           if (DWARFDie CV = CVStep(P)) {
644             CVStep(CV);
645           }
646           if (C)
647             OS << " const";
648           if (V)
649             OS << " volatile";
650         }
651       }
652     } else {
653       if (Const)
654         OS << " const";
655       if (Volatile)
656         OS << " volatile";
657     }
658     if (D.find(DW_AT_reference))
659       OS << " &";
660     if (D.find(DW_AT_rvalue_reference))
661       OS << " &&";
662     appendUnqualifiedNameAfter(Inner, resolveReferencedType(Inner));
663   }
664   void appendScopes(DWARFDie D) {
665     if (D.getTag() == DW_TAG_compile_unit)
666       return;
667     if (D.getTag() == DW_TAG_type_unit)
668       return;
669     if (D.getTag() == DW_TAG_skeleton_unit)
670       return;
671     if (D.getTag() == DW_TAG_subprogram)
672       return;
673     if (D.getTag() == DW_TAG_lexical_block)
674       return;
675     D = D.resolveTypeUnitReference();
676     if (DWARFDie P = D.getParent())
677       appendScopes(P);
678     appendUnqualifiedName(D);
679     OS << "::";
680   }
681 };
682 } // anonymous namespace
683 
684 static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
685                           const DWARFAttribute &AttrValue, unsigned Indent,
686                           DIDumpOptions DumpOpts) {
687   if (!Die.isValid())
688     return;
689   const char BaseIndent[] = "            ";
690   OS << BaseIndent;
691   OS.indent(Indent + 2);
692   dwarf::Attribute Attr = AttrValue.Attr;
693   WithColor(OS, HighlightColor::Attribute) << formatv("{0}", Attr);
694 
695   dwarf::Form Form = AttrValue.Value.getForm();
696   if (DumpOpts.Verbose || DumpOpts.ShowForm)
697     OS << formatv(" [{0}]", Form);
698 
699   DWARFUnit *U = Die.getDwarfUnit();
700   const DWARFFormValue &FormValue = AttrValue.Value;
701 
702   OS << "\t(";
703 
704   StringRef Name;
705   std::string File;
706   auto Color = HighlightColor::Enumerator;
707   if (Attr == DW_AT_decl_file || Attr == DW_AT_call_file) {
708     Color = HighlightColor::String;
709     if (const auto *LT = U->getContext().getLineTableForUnit(U))
710       if (LT->getFileNameByIndex(
711               FormValue.getAsUnsignedConstant().getValue(),
712               U->getCompilationDir(),
713               DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, File)) {
714         File = '"' + File + '"';
715         Name = File;
716       }
717   } else if (Optional<uint64_t> Val = FormValue.getAsUnsignedConstant())
718     Name = AttributeValueString(Attr, *Val);
719 
720   if (!Name.empty())
721     WithColor(OS, Color) << Name;
722   else if (Attr == DW_AT_decl_line || Attr == DW_AT_call_line)
723     OS << *FormValue.getAsUnsignedConstant();
724   else if (Attr == DW_AT_low_pc &&
725            (FormValue.getAsAddress() ==
726             dwarf::computeTombstoneAddress(U->getAddressByteSize()))) {
727     if (DumpOpts.Verbose) {
728       FormValue.dump(OS, DumpOpts);
729       OS << " (";
730     }
731     OS << "dead code";
732     if (DumpOpts.Verbose)
733       OS << ')';
734   } else if (Attr == DW_AT_high_pc && !DumpOpts.ShowForm && !DumpOpts.Verbose &&
735              FormValue.getAsUnsignedConstant()) {
736     if (DumpOpts.ShowAddresses) {
737       // Print the actual address rather than the offset.
738       uint64_t LowPC, HighPC, Index;
739       if (Die.getLowAndHighPC(LowPC, HighPC, Index))
740         DWARFFormValue::dumpAddress(OS, U->getAddressByteSize(), HighPC);
741       else
742         FormValue.dump(OS, DumpOpts);
743     }
744   } else if (DWARFAttribute::mayHaveLocationList(Attr) &&
745              FormValue.isFormClass(DWARFFormValue::FC_SectionOffset))
746     dumpLocationList(OS, FormValue, U, sizeof(BaseIndent) + Indent + 4,
747                      DumpOpts);
748   else if (FormValue.isFormClass(DWARFFormValue::FC_Exprloc) ||
749            (DWARFAttribute::mayHaveLocationExpr(Attr) &&
750             FormValue.isFormClass(DWARFFormValue::FC_Block)))
751     dumpLocationExpr(OS, FormValue, U, sizeof(BaseIndent) + Indent + 4,
752                      DumpOpts);
753   else
754     FormValue.dump(OS, DumpOpts);
755 
756   std::string Space = DumpOpts.ShowAddresses ? " " : "";
757 
758   // We have dumped the attribute raw value. For some attributes
759   // having both the raw value and the pretty-printed value is
760   // interesting. These attributes are handled below.
761   if (Attr == DW_AT_specification || Attr == DW_AT_abstract_origin) {
762     if (const char *Name =
763             Die.getAttributeValueAsReferencedDie(FormValue).getName(
764                 DINameKind::LinkageName))
765       OS << Space << "\"" << Name << '\"';
766   } else if (Attr == DW_AT_type) {
767     DWARFDie D = resolveReferencedType(Die, FormValue);
768     if (D && !D.isNULL()) {
769       OS << Space << "\"";
770       DWARFTypePrinter(OS).appendQualifiedName(D);
771       OS << '"';
772     }
773   } else if (Attr == DW_AT_APPLE_property_attribute) {
774     if (Optional<uint64_t> OptVal = FormValue.getAsUnsignedConstant())
775       dumpApplePropertyAttribute(OS, *OptVal);
776   } else if (Attr == DW_AT_ranges) {
777     const DWARFObject &Obj = Die.getDwarfUnit()->getContext().getDWARFObj();
778     // For DW_FORM_rnglistx we need to dump the offset separately, since
779     // we have only dumped the index so far.
780     if (FormValue.getForm() == DW_FORM_rnglistx)
781       if (auto RangeListOffset =
782               U->getRnglistOffset(*FormValue.getAsSectionOffset())) {
783         DWARFFormValue FV = DWARFFormValue::createFromUValue(
784             dwarf::DW_FORM_sec_offset, *RangeListOffset);
785         FV.dump(OS, DumpOpts);
786       }
787     if (auto RangesOrError = Die.getAddressRanges())
788       dumpRanges(Obj, OS, RangesOrError.get(), U->getAddressByteSize(),
789                  sizeof(BaseIndent) + Indent + 4, DumpOpts);
790     else
791       DumpOpts.RecoverableErrorHandler(createStringError(
792           errc::invalid_argument, "decoding address ranges: %s",
793           toString(RangesOrError.takeError()).c_str()));
794   }
795 
796   OS << ")\n";
797 }
798 
799 void DWARFDie::getFullName(raw_string_ostream &OS,
800                            std::string *OriginalFullName) const {
801   const char *NamePtr = getShortName();
802   if (!NamePtr)
803     return;
804   DWARFTypePrinter(OS).appendUnqualifiedName(*this, OriginalFullName);
805 }
806 
807 bool DWARFDie::isSubprogramDIE() const { return getTag() == DW_TAG_subprogram; }
808 
809 bool DWARFDie::isSubroutineDIE() const {
810   auto Tag = getTag();
811   return Tag == DW_TAG_subprogram || Tag == DW_TAG_inlined_subroutine;
812 }
813 
814 Optional<DWARFFormValue> DWARFDie::find(dwarf::Attribute Attr) const {
815   if (!isValid())
816     return None;
817   auto AbbrevDecl = getAbbreviationDeclarationPtr();
818   if (AbbrevDecl)
819     return AbbrevDecl->getAttributeValue(getOffset(), Attr, *U);
820   return None;
821 }
822 
823 Optional<DWARFFormValue>
824 DWARFDie::find(ArrayRef<dwarf::Attribute> Attrs) const {
825   if (!isValid())
826     return None;
827   auto AbbrevDecl = getAbbreviationDeclarationPtr();
828   if (AbbrevDecl) {
829     for (auto Attr : Attrs) {
830       if (auto Value = AbbrevDecl->getAttributeValue(getOffset(), Attr, *U))
831         return Value;
832     }
833   }
834   return None;
835 }
836 
837 Optional<DWARFFormValue>
838 DWARFDie::findRecursively(ArrayRef<dwarf::Attribute> Attrs) const {
839   SmallVector<DWARFDie, 3> Worklist;
840   Worklist.push_back(*this);
841 
842   // Keep track if DIEs already seen to prevent infinite recursion.
843   // Empirically we rarely see a depth of more than 3 when dealing with valid
844   // DWARF. This corresponds to following the DW_AT_abstract_origin and
845   // DW_AT_specification just once.
846   SmallSet<DWARFDie, 3> Seen;
847   Seen.insert(*this);
848 
849   while (!Worklist.empty()) {
850     DWARFDie Die = Worklist.pop_back_val();
851 
852     if (!Die.isValid())
853       continue;
854 
855     if (auto Value = Die.find(Attrs))
856       return Value;
857 
858     if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
859       if (Seen.insert(D).second)
860         Worklist.push_back(D);
861 
862     if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_specification))
863       if (Seen.insert(D).second)
864         Worklist.push_back(D);
865   }
866 
867   return None;
868 }
869 
870 DWARFDie
871 DWARFDie::getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const {
872   if (Optional<DWARFFormValue> F = find(Attr))
873     return getAttributeValueAsReferencedDie(*F);
874   return DWARFDie();
875 }
876 
877 DWARFDie
878 DWARFDie::getAttributeValueAsReferencedDie(const DWARFFormValue &V) const {
879   DWARFDie Result;
880   if (auto SpecRef = V.getAsRelativeReference()) {
881     if (SpecRef->Unit)
882       Result = SpecRef->Unit->getDIEForOffset(SpecRef->Unit->getOffset() +
883                                               SpecRef->Offset);
884     else if (auto SpecUnit =
885                  U->getUnitVector().getUnitForOffset(SpecRef->Offset))
886       Result = SpecUnit->getDIEForOffset(SpecRef->Offset);
887   }
888   return Result;
889 }
890 
891 DWARFDie DWARFDie::resolveTypeUnitReference() const {
892   if (auto Attr = find(DW_AT_signature)) {
893     if (Optional<uint64_t> Sig = Attr->getAsReferenceUVal()) {
894       if (DWARFTypeUnit *TU = U->getContext().getTypeUnitForHash(
895               U->getVersion(), *Sig, U->isDWOUnit()))
896         return TU->getDIEForOffset(TU->getTypeOffset() + TU->getOffset());
897     }
898   }
899   return *this;
900 }
901 
902 Optional<uint64_t> DWARFDie::getRangesBaseAttribute() const {
903   return toSectionOffset(find({DW_AT_rnglists_base, DW_AT_GNU_ranges_base}));
904 }
905 
906 Optional<uint64_t> DWARFDie::getLocBaseAttribute() const {
907   return toSectionOffset(find(DW_AT_loclists_base));
908 }
909 
910 Optional<uint64_t> DWARFDie::getHighPC(uint64_t LowPC) const {
911   uint64_t Tombstone = dwarf::computeTombstoneAddress(U->getAddressByteSize());
912   if (LowPC == Tombstone)
913     return None;
914   if (auto FormValue = find(DW_AT_high_pc)) {
915     if (auto Address = FormValue->getAsAddress()) {
916       // High PC is an address.
917       return Address;
918     }
919     if (auto Offset = FormValue->getAsUnsignedConstant()) {
920       // High PC is an offset from LowPC.
921       return LowPC + *Offset;
922     }
923   }
924   return None;
925 }
926 
927 bool DWARFDie::getLowAndHighPC(uint64_t &LowPC, uint64_t &HighPC,
928                                uint64_t &SectionIndex) const {
929   auto F = find(DW_AT_low_pc);
930   auto LowPcAddr = toSectionedAddress(F);
931   if (!LowPcAddr)
932     return false;
933   if (auto HighPcAddr = getHighPC(LowPcAddr->Address)) {
934     LowPC = LowPcAddr->Address;
935     HighPC = *HighPcAddr;
936     SectionIndex = LowPcAddr->SectionIndex;
937     return true;
938   }
939   return false;
940 }
941 
942 Expected<DWARFAddressRangesVector> DWARFDie::getAddressRanges() const {
943   if (isNULL())
944     return DWARFAddressRangesVector();
945   // Single range specified by low/high PC.
946   uint64_t LowPC, HighPC, Index;
947   if (getLowAndHighPC(LowPC, HighPC, Index))
948     return DWARFAddressRangesVector{{LowPC, HighPC, Index}};
949 
950   Optional<DWARFFormValue> Value = find(DW_AT_ranges);
951   if (Value) {
952     if (Value->getForm() == DW_FORM_rnglistx)
953       return U->findRnglistFromIndex(*Value->getAsSectionOffset());
954     return U->findRnglistFromOffset(*Value->getAsSectionOffset());
955   }
956   return DWARFAddressRangesVector();
957 }
958 
959 bool DWARFDie::addressRangeContainsAddress(const uint64_t Address) const {
960   auto RangesOrError = getAddressRanges();
961   if (!RangesOrError) {
962     llvm::consumeError(RangesOrError.takeError());
963     return false;
964   }
965 
966   for (const auto &R : RangesOrError.get())
967     if (R.LowPC <= Address && Address < R.HighPC)
968       return true;
969   return false;
970 }
971 
972 Expected<DWARFLocationExpressionsVector>
973 DWARFDie::getLocations(dwarf::Attribute Attr) const {
974   Optional<DWARFFormValue> Location = find(Attr);
975   if (!Location)
976     return createStringError(inconvertibleErrorCode(), "No %s",
977                              dwarf::AttributeString(Attr).data());
978 
979   if (Optional<uint64_t> Off = Location->getAsSectionOffset()) {
980     uint64_t Offset = *Off;
981 
982     if (Location->getForm() == DW_FORM_loclistx) {
983       if (auto LoclistOffset = U->getLoclistOffset(Offset))
984         Offset = *LoclistOffset;
985       else
986         return createStringError(inconvertibleErrorCode(),
987                                  "Loclist table not found");
988     }
989     return U->findLoclistFromOffset(Offset);
990   }
991 
992   if (Optional<ArrayRef<uint8_t>> Expr = Location->getAsBlock()) {
993     return DWARFLocationExpressionsVector{
994         DWARFLocationExpression{None, to_vector<4>(*Expr)}};
995   }
996 
997   return createStringError(
998       inconvertibleErrorCode(), "Unsupported %s encoding: %s",
999       dwarf::AttributeString(Attr).data(),
1000       dwarf::FormEncodingString(Location->getForm()).data());
1001 }
1002 
1003 const char *DWARFDie::getSubroutineName(DINameKind Kind) const {
1004   if (!isSubroutineDIE())
1005     return nullptr;
1006   return getName(Kind);
1007 }
1008 
1009 const char *DWARFDie::getName(DINameKind Kind) const {
1010   if (!isValid() || Kind == DINameKind::None)
1011     return nullptr;
1012   // Try to get mangled name only if it was asked for.
1013   if (Kind == DINameKind::LinkageName) {
1014     if (auto Name = getLinkageName())
1015       return Name;
1016   }
1017   return getShortName();
1018 }
1019 
1020 const char *DWARFDie::getShortName() const {
1021   if (!isValid())
1022     return nullptr;
1023 
1024   return dwarf::toString(findRecursively(dwarf::DW_AT_name), nullptr);
1025 }
1026 
1027 const char *DWARFDie::getLinkageName() const {
1028   if (!isValid())
1029     return nullptr;
1030 
1031   return dwarf::toString(findRecursively({dwarf::DW_AT_MIPS_linkage_name,
1032                                           dwarf::DW_AT_linkage_name}),
1033                          nullptr);
1034 }
1035 
1036 uint64_t DWARFDie::getDeclLine() const {
1037   return toUnsigned(findRecursively(DW_AT_decl_line), 0);
1038 }
1039 
1040 std::string
1041 DWARFDie::getDeclFile(DILineInfoSpecifier::FileLineInfoKind Kind) const {
1042   if (auto FormValue = findRecursively(DW_AT_decl_file))
1043     if (auto OptString = FormValue->getAsFile(Kind))
1044       return *OptString;
1045   return {};
1046 }
1047 
1048 void DWARFDie::getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
1049                               uint32_t &CallColumn,
1050                               uint32_t &CallDiscriminator) const {
1051   CallFile = toUnsigned(find(DW_AT_call_file), 0);
1052   CallLine = toUnsigned(find(DW_AT_call_line), 0);
1053   CallColumn = toUnsigned(find(DW_AT_call_column), 0);
1054   CallDiscriminator = toUnsigned(find(DW_AT_GNU_discriminator), 0);
1055 }
1056 
1057 /// Helper to dump a DIE with all of its parents, but no siblings.
1058 static unsigned dumpParentChain(DWARFDie Die, raw_ostream &OS, unsigned Indent,
1059                                 DIDumpOptions DumpOpts, unsigned Depth = 0) {
1060   if (!Die)
1061     return Indent;
1062   if (DumpOpts.ParentRecurseDepth > 0 && Depth >= DumpOpts.ParentRecurseDepth)
1063     return Indent;
1064   Indent = dumpParentChain(Die.getParent(), OS, Indent, DumpOpts, Depth + 1);
1065   Die.dump(OS, Indent, DumpOpts);
1066   return Indent + 2;
1067 }
1068 
1069 void DWARFDie::dump(raw_ostream &OS, unsigned Indent,
1070                     DIDumpOptions DumpOpts) const {
1071   if (!isValid())
1072     return;
1073   DWARFDataExtractor debug_info_data = U->getDebugInfoExtractor();
1074   const uint64_t Offset = getOffset();
1075   uint64_t offset = Offset;
1076   if (DumpOpts.ShowParents) {
1077     DIDumpOptions ParentDumpOpts = DumpOpts;
1078     ParentDumpOpts.ShowParents = false;
1079     ParentDumpOpts.ShowChildren = false;
1080     Indent = dumpParentChain(getParent(), OS, Indent, ParentDumpOpts);
1081   }
1082 
1083   if (debug_info_data.isValidOffset(offset)) {
1084     uint32_t abbrCode = debug_info_data.getULEB128(&offset);
1085     if (DumpOpts.ShowAddresses)
1086       WithColor(OS, HighlightColor::Address).get()
1087           << format("\n0x%8.8" PRIx64 ": ", Offset);
1088 
1089     if (abbrCode) {
1090       auto AbbrevDecl = getAbbreviationDeclarationPtr();
1091       if (AbbrevDecl) {
1092         WithColor(OS, HighlightColor::Tag).get().indent(Indent)
1093             << formatv("{0}", getTag());
1094         if (DumpOpts.Verbose) {
1095           OS << format(" [%u] %c", abbrCode,
1096                        AbbrevDecl->hasChildren() ? '*' : ' ');
1097           if (Optional<uint32_t> ParentIdx = Die->getParentIdx())
1098             OS << format(" (0x%8.8" PRIx64 ")",
1099                          U->getDIEAtIndex(*ParentIdx).getOffset());
1100         }
1101         OS << '\n';
1102 
1103         // Dump all data in the DIE for the attributes.
1104         for (const DWARFAttribute &AttrValue : attributes())
1105           dumpAttribute(OS, *this, AttrValue, Indent, DumpOpts);
1106 
1107         if (DumpOpts.ShowChildren && DumpOpts.ChildRecurseDepth > 0) {
1108           DWARFDie Child = getFirstChild();
1109           DumpOpts.ChildRecurseDepth--;
1110           DIDumpOptions ChildDumpOpts = DumpOpts;
1111           ChildDumpOpts.ShowParents = false;
1112           while (Child) {
1113             Child.dump(OS, Indent + 2, ChildDumpOpts);
1114             Child = Child.getSibling();
1115           }
1116         }
1117       } else {
1118         OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
1119            << abbrCode << '\n';
1120       }
1121     } else {
1122       OS.indent(Indent) << "NULL\n";
1123     }
1124   }
1125 }
1126 
1127 LLVM_DUMP_METHOD void DWARFDie::dump() const { dump(llvm::errs(), 0); }
1128 
1129 DWARFDie DWARFDie::getParent() const {
1130   if (isValid())
1131     return U->getParent(Die);
1132   return DWARFDie();
1133 }
1134 
1135 DWARFDie DWARFDie::getSibling() const {
1136   if (isValid())
1137     return U->getSibling(Die);
1138   return DWARFDie();
1139 }
1140 
1141 DWARFDie DWARFDie::getPreviousSibling() const {
1142   if (isValid())
1143     return U->getPreviousSibling(Die);
1144   return DWARFDie();
1145 }
1146 
1147 DWARFDie DWARFDie::getFirstChild() const {
1148   if (isValid())
1149     return U->getFirstChild(Die);
1150   return DWARFDie();
1151 }
1152 
1153 DWARFDie DWARFDie::getLastChild() const {
1154   if (isValid())
1155     return U->getLastChild(Die);
1156   return DWARFDie();
1157 }
1158 
1159 iterator_range<DWARFDie::attribute_iterator> DWARFDie::attributes() const {
1160   return make_range(attribute_iterator(*this, false),
1161                     attribute_iterator(*this, true));
1162 }
1163 
1164 DWARFDie::attribute_iterator::attribute_iterator(DWARFDie D, bool End)
1165     : Die(D), Index(0) {
1166   auto AbbrDecl = Die.getAbbreviationDeclarationPtr();
1167   assert(AbbrDecl && "Must have abbreviation declaration");
1168   if (End) {
1169     // This is the end iterator so we set the index to the attribute count.
1170     Index = AbbrDecl->getNumAttributes();
1171   } else {
1172     // This is the begin iterator so we extract the value for this->Index.
1173     AttrValue.Offset = D.getOffset() + AbbrDecl->getCodeByteSize();
1174     updateForIndex(*AbbrDecl, 0);
1175   }
1176 }
1177 
1178 void DWARFDie::attribute_iterator::updateForIndex(
1179     const DWARFAbbreviationDeclaration &AbbrDecl, uint32_t I) {
1180   Index = I;
1181   // AbbrDecl must be valid before calling this function.
1182   auto NumAttrs = AbbrDecl.getNumAttributes();
1183   if (Index < NumAttrs) {
1184     AttrValue.Attr = AbbrDecl.getAttrByIndex(Index);
1185     // Add the previous byte size of any previous attribute value.
1186     AttrValue.Offset += AttrValue.ByteSize;
1187     uint64_t ParseOffset = AttrValue.Offset;
1188     if (AbbrDecl.getAttrIsImplicitConstByIndex(Index))
1189       AttrValue.Value = DWARFFormValue::createFromSValue(
1190           AbbrDecl.getFormByIndex(Index),
1191           AbbrDecl.getAttrImplicitConstValueByIndex(Index));
1192     else {
1193       auto U = Die.getDwarfUnit();
1194       assert(U && "Die must have valid DWARF unit");
1195       AttrValue.Value = DWARFFormValue::createFromUnit(
1196           AbbrDecl.getFormByIndex(Index), U, &ParseOffset);
1197     }
1198     AttrValue.ByteSize = ParseOffset - AttrValue.Offset;
1199   } else {
1200     assert(Index == NumAttrs && "Indexes should be [0, NumAttrs) only");
1201     AttrValue = {};
1202   }
1203 }
1204 
1205 DWARFDie::attribute_iterator &DWARFDie::attribute_iterator::operator++() {
1206   if (auto AbbrDecl = Die.getAbbreviationDeclarationPtr())
1207     updateForIndex(*AbbrDecl, Index + 1);
1208   return *this;
1209 }
1210 
1211 bool DWARFAttribute::mayHaveLocationList(dwarf::Attribute Attr) {
1212   switch(Attr) {
1213   case DW_AT_location:
1214   case DW_AT_string_length:
1215   case DW_AT_return_addr:
1216   case DW_AT_data_member_location:
1217   case DW_AT_frame_base:
1218   case DW_AT_static_link:
1219   case DW_AT_segment:
1220   case DW_AT_use_location:
1221   case DW_AT_vtable_elem_location:
1222     return true;
1223   default:
1224     return false;
1225   }
1226 }
1227 
1228 bool DWARFAttribute::mayHaveLocationExpr(dwarf::Attribute Attr) {
1229   switch (Attr) {
1230   // From the DWARF v5 specification.
1231   case DW_AT_location:
1232   case DW_AT_byte_size:
1233   case DW_AT_bit_offset:
1234   case DW_AT_bit_size:
1235   case DW_AT_string_length:
1236   case DW_AT_lower_bound:
1237   case DW_AT_return_addr:
1238   case DW_AT_bit_stride:
1239   case DW_AT_upper_bound:
1240   case DW_AT_count:
1241   case DW_AT_data_member_location:
1242   case DW_AT_frame_base:
1243   case DW_AT_segment:
1244   case DW_AT_static_link:
1245   case DW_AT_use_location:
1246   case DW_AT_vtable_elem_location:
1247   case DW_AT_allocated:
1248   case DW_AT_associated:
1249   case DW_AT_data_location:
1250   case DW_AT_byte_stride:
1251   case DW_AT_rank:
1252   case DW_AT_call_value:
1253   case DW_AT_call_origin:
1254   case DW_AT_call_target:
1255   case DW_AT_call_target_clobbered:
1256   case DW_AT_call_data_location:
1257   case DW_AT_call_data_value:
1258   // Extensions.
1259   case DW_AT_GNU_call_site_value:
1260   case DW_AT_GNU_call_site_target:
1261     return true;
1262   default:
1263     return false;
1264   }
1265 }
1266