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