1 //===- ObjectFile.h - File format independent object file -------*- C++ -*-===//
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 // This file declares a file format independent ObjectFile class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_OBJECT_OBJECTFILE_H
14 #define LLVM_OBJECT_OBJECTFILE_H
15 
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/Hashing.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/iterator_range.h"
20 #include "llvm/BinaryFormat/Magic.h"
21 #include "llvm/BinaryFormat/Swift.h"
22 #include "llvm/Object/Binary.h"
23 #include "llvm/Object/Error.h"
24 #include "llvm/Object/SymbolicFile.h"
25 #include "llvm/Support/Casting.h"
26 #include "llvm/Support/Error.h"
27 #include "llvm/Support/MemoryBufferRef.h"
28 #include "llvm/TargetParser/Triple.h"
29 #include <cassert>
30 #include <cstdint>
31 #include <memory>
32 
33 namespace llvm {
34 
35 class SubtargetFeatures;
36 
37 namespace object {
38 
39 class COFFObjectFile;
40 class MachOObjectFile;
41 class ObjectFile;
42 class SectionRef;
43 class SymbolRef;
44 class symbol_iterator;
45 class WasmObjectFile;
46 
47 using section_iterator = content_iterator<SectionRef>;
48 
49 typedef std::function<bool(const SectionRef &)> SectionFilterPredicate;
50 /// This is a value type class that represents a single relocation in the list
51 /// of relocations in the object file.
52 class RelocationRef {
53   DataRefImpl RelocationPimpl;
54   const ObjectFile *OwningObject = nullptr;
55 
56 public:
57   RelocationRef() = default;
58   RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
59 
60   bool operator==(const RelocationRef &Other) const;
61 
62   void moveNext();
63 
64   uint64_t getOffset() const;
65   symbol_iterator getSymbol() const;
66   uint64_t getType() const;
67 
68   /// Get a string that represents the type of this relocation.
69   ///
70   /// This is for display purposes only.
71   void getTypeName(SmallVectorImpl<char> &Result) const;
72 
73   DataRefImpl getRawDataRefImpl() const;
74   const ObjectFile *getObject() const;
75 };
76 
77 using relocation_iterator = content_iterator<RelocationRef>;
78 
79 /// This is a value type class that represents a single section in the list of
80 /// sections in the object file.
81 class SectionRef {
82   friend class SymbolRef;
83 
84   DataRefImpl SectionPimpl;
85   const ObjectFile *OwningObject = nullptr;
86 
87 public:
88   SectionRef() = default;
89   SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
90 
91   bool operator==(const SectionRef &Other) const;
92   bool operator!=(const SectionRef &Other) const;
93   bool operator<(const SectionRef &Other) const;
94 
95   void moveNext();
96 
97   Expected<StringRef> getName() const;
98   uint64_t getAddress() const;
99   uint64_t getIndex() const;
100   uint64_t getSize() const;
101   Expected<StringRef> getContents() const;
102 
103   /// Get the alignment of this section.
104   Align getAlignment() const;
105 
106   bool isCompressed() const;
107   /// Whether this section contains instructions.
108   bool isText() const;
109   /// Whether this section contains data, not instructions.
110   bool isData() const;
111   /// Whether this section contains BSS uninitialized data.
112   bool isBSS() const;
113   bool isVirtual() const;
114   bool isBitcode() const;
115   bool isStripped() const;
116 
117   /// Whether this section will be placed in the text segment, according to the
118   /// Berkeley size format. This is true if the section is allocatable, and
119   /// contains either code or readonly data.
120   bool isBerkeleyText() const;
121   /// Whether this section will be placed in the data segment, according to the
122   /// Berkeley size format. This is true if the section is allocatable and
123   /// contains data (e.g. PROGBITS), but is not text.
124   bool isBerkeleyData() const;
125 
126   /// Whether this section is a debug section.
127   bool isDebugSection() const;
128 
129   bool containsSymbol(SymbolRef S) const;
130 
131   relocation_iterator relocation_begin() const;
132   relocation_iterator relocation_end() const;
133   iterator_range<relocation_iterator> relocations() const {
134     return make_range(relocation_begin(), relocation_end());
135   }
136 
137   /// Returns the related section if this section contains relocations. The
138   /// returned section may or may not have applied its relocations.
139   Expected<section_iterator> getRelocatedSection() const;
140 
141   DataRefImpl getRawDataRefImpl() const;
142   const ObjectFile *getObject() const;
143 };
144 
145 struct SectionedAddress {
146   const static uint64_t UndefSection = UINT64_MAX;
147 
148   uint64_t Address = 0;
149   uint64_t SectionIndex = UndefSection;
150 };
151 
152 inline bool operator<(const SectionedAddress &LHS,
153                       const SectionedAddress &RHS) {
154   return std::tie(LHS.SectionIndex, LHS.Address) <
155          std::tie(RHS.SectionIndex, RHS.Address);
156 }
157 
158 inline bool operator==(const SectionedAddress &LHS,
159                        const SectionedAddress &RHS) {
160   return std::tie(LHS.SectionIndex, LHS.Address) ==
161          std::tie(RHS.SectionIndex, RHS.Address);
162 }
163 
164 raw_ostream &operator<<(raw_ostream &OS, const SectionedAddress &Addr);
165 
166 /// This is a value type class that represents a single symbol in the list of
167 /// symbols in the object file.
168 class SymbolRef : public BasicSymbolRef {
169   friend class SectionRef;
170 
171 public:
172   enum Type {
173     ST_Unknown, // Type not specified
174     ST_Other,
175     ST_Data,
176     ST_Debug,
177     ST_File,
178     ST_Function,
179   };
180 
181   SymbolRef() = default;
182   SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
183   SymbolRef(const BasicSymbolRef &B) : BasicSymbolRef(B) {
184     assert(isa<ObjectFile>(BasicSymbolRef::getObject()));
185   }
186 
187   Expected<StringRef> getName() const;
188   /// Returns the symbol virtual address (i.e. address at which it will be
189   /// mapped).
190   Expected<uint64_t> getAddress() const;
191 
192   /// Return the value of the symbol depending on the object this can be an
193   /// offset or a virtual address.
194   Expected<uint64_t> getValue() const;
195 
196   /// Get the alignment of this symbol as the actual value (not log 2).
197   uint32_t getAlignment() const;
198   uint64_t getCommonSize() const;
199   Expected<SymbolRef::Type> getType() const;
200 
201   /// Get section this symbol is defined in reference to. Result is
202   /// end_sections() if it is undefined or is an absolute symbol.
203   Expected<section_iterator> getSection() const;
204 
205   const ObjectFile *getObject() const;
206 };
207 
208 class symbol_iterator : public basic_symbol_iterator {
209 public:
210   symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
211   symbol_iterator(const basic_symbol_iterator &B)
212       : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
213                                         cast<ObjectFile>(B->getObject()))) {}
214 
215   const SymbolRef *operator->() const {
216     const BasicSymbolRef &P = basic_symbol_iterator::operator *();
217     return static_cast<const SymbolRef*>(&P);
218   }
219 
220   const SymbolRef &operator*() const {
221     const BasicSymbolRef &P = basic_symbol_iterator::operator *();
222     return static_cast<const SymbolRef&>(P);
223   }
224 };
225 
226 /// This class is the base class for all object file types. Concrete instances
227 /// of this object are created by createObjectFile, which figures out which type
228 /// to create.
229 class ObjectFile : public SymbolicFile {
230   virtual void anchor();
231 
232 protected:
233   ObjectFile(unsigned int Type, MemoryBufferRef Source);
234 
235   const uint8_t *base() const {
236     return reinterpret_cast<const uint8_t *>(Data.getBufferStart());
237   }
238 
239   // These functions are for SymbolRef to call internally. The main goal of
240   // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
241   // entry in the memory mapped object file. SymbolPimpl cannot contain any
242   // virtual functions because then it could not point into the memory mapped
243   // file.
244   //
245   // Implementations assume that the DataRefImpl is valid and has not been
246   // modified externally. It's UB otherwise.
247   friend class SymbolRef;
248 
249   virtual Expected<StringRef> getSymbolName(DataRefImpl Symb) const = 0;
250   Error printSymbolName(raw_ostream &OS,
251                                   DataRefImpl Symb) const override;
252   virtual Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const = 0;
253   virtual uint64_t getSymbolValueImpl(DataRefImpl Symb) const = 0;
254   virtual uint32_t getSymbolAlignment(DataRefImpl Symb) const;
255   virtual uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const = 0;
256   virtual Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const = 0;
257   virtual Expected<section_iterator>
258   getSymbolSection(DataRefImpl Symb) const = 0;
259 
260   // Same as above for SectionRef.
261   friend class SectionRef;
262 
263   virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
264   virtual Expected<StringRef> getSectionName(DataRefImpl Sec) const = 0;
265   virtual uint64_t getSectionAddress(DataRefImpl Sec) const = 0;
266   virtual uint64_t getSectionIndex(DataRefImpl Sec) const = 0;
267   virtual uint64_t getSectionSize(DataRefImpl Sec) const = 0;
268   virtual Expected<ArrayRef<uint8_t>>
269   getSectionContents(DataRefImpl Sec) const = 0;
270   virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0;
271   virtual bool isSectionCompressed(DataRefImpl Sec) const = 0;
272   virtual bool isSectionText(DataRefImpl Sec) const = 0;
273   virtual bool isSectionData(DataRefImpl Sec) const = 0;
274   virtual bool isSectionBSS(DataRefImpl Sec) const = 0;
275   // A section is 'virtual' if its contents aren't present in the object image.
276   virtual bool isSectionVirtual(DataRefImpl Sec) const = 0;
277   virtual bool isSectionBitcode(DataRefImpl Sec) const;
278   virtual bool isSectionStripped(DataRefImpl Sec) const;
279   virtual bool isBerkeleyText(DataRefImpl Sec) const;
280   virtual bool isBerkeleyData(DataRefImpl Sec) const;
281   virtual bool isDebugSection(DataRefImpl Sec) const;
282   virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
283   virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
284   virtual Expected<section_iterator> getRelocatedSection(DataRefImpl Sec) const;
285 
286   // Same as above for RelocationRef.
287   friend class RelocationRef;
288   virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
289   virtual uint64_t getRelocationOffset(DataRefImpl Rel) const = 0;
290   virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
291   virtual uint64_t getRelocationType(DataRefImpl Rel) const = 0;
292   virtual void getRelocationTypeName(DataRefImpl Rel,
293                                      SmallVectorImpl<char> &Result) const = 0;
294 
295   virtual llvm::binaryformat::Swift5ReflectionSectionKind
296   mapReflectionSectionNameToEnumValue(StringRef SectionName) const {
297     return llvm::binaryformat::Swift5ReflectionSectionKind::unknown;
298   };
299 
300   Expected<uint64_t> getSymbolValue(DataRefImpl Symb) const;
301 
302 public:
303   ObjectFile() = delete;
304   ObjectFile(const ObjectFile &other) = delete;
305 
306   uint64_t getCommonSymbolSize(DataRefImpl Symb) const {
307     Expected<uint32_t> SymbolFlagsOrErr = getSymbolFlags(Symb);
308     if (!SymbolFlagsOrErr)
309       // TODO: Actually report errors helpfully.
310       report_fatal_error(SymbolFlagsOrErr.takeError());
311     assert(*SymbolFlagsOrErr & SymbolRef::SF_Common);
312     return getCommonSymbolSizeImpl(Symb);
313   }
314 
315   virtual std::vector<SectionRef> dynamic_relocation_sections() const {
316     return std::vector<SectionRef>();
317   }
318 
319   using symbol_iterator_range = iterator_range<symbol_iterator>;
320   symbol_iterator_range symbols() const {
321     return symbol_iterator_range(symbol_begin(), symbol_end());
322   }
323 
324   virtual section_iterator section_begin() const = 0;
325   virtual section_iterator section_end() const = 0;
326 
327   using section_iterator_range = iterator_range<section_iterator>;
328   section_iterator_range sections() const {
329     return section_iterator_range(section_begin(), section_end());
330   }
331 
332   virtual bool hasDebugInfo() const;
333 
334   /// The number of bytes used to represent an address in this object
335   ///        file format.
336   virtual uint8_t getBytesInAddress() const = 0;
337 
338   virtual StringRef getFileFormatName() const = 0;
339   virtual Triple::ArchType getArch() const = 0;
340   virtual Expected<SubtargetFeatures> getFeatures() const = 0;
341   virtual std::optional<StringRef> tryGetCPUName() const {
342     return std::nullopt;
343   };
344   virtual void setARMSubArch(Triple &TheTriple) const { }
345   virtual Expected<uint64_t> getStartAddress() const {
346     return errorCodeToError(object_error::parse_failed);
347   };
348 
349   /// Create a triple from the data in this object file.
350   Triple makeTriple() const;
351 
352   /// Maps a debug section name to a standard DWARF section name.
353   virtual StringRef mapDebugSectionName(StringRef Name) const { return Name; }
354 
355   /// True if this is a relocatable object (.o/.obj).
356   virtual bool isRelocatableObject() const = 0;
357 
358   /// True if the reflection section can be stripped by the linker.
359   bool isReflectionSectionStrippable(
360       llvm::binaryformat::Swift5ReflectionSectionKind ReflectionSectionKind)
361       const;
362 
363   /// @returns Pointer to ObjectFile subclass to handle this type of object.
364   /// @param ObjectPath The path to the object file. ObjectPath.isObject must
365   ///        return true.
366   /// Create ObjectFile from path.
367   static Expected<OwningBinary<ObjectFile>>
368   createObjectFile(StringRef ObjectPath);
369 
370   static Expected<std::unique_ptr<ObjectFile>>
371   createObjectFile(MemoryBufferRef Object, llvm::file_magic Type,
372                    bool InitContent = true);
373   static Expected<std::unique_ptr<ObjectFile>>
374   createObjectFile(MemoryBufferRef Object) {
375     return createObjectFile(Object, llvm::file_magic::unknown);
376   }
377 
378   static bool classof(const Binary *v) {
379     return v->isObject();
380   }
381 
382   static Expected<std::unique_ptr<COFFObjectFile>>
383   createCOFFObjectFile(MemoryBufferRef Object);
384 
385   static Expected<std::unique_ptr<ObjectFile>>
386   createXCOFFObjectFile(MemoryBufferRef Object, unsigned FileType);
387 
388   static Expected<std::unique_ptr<ObjectFile>>
389   createELFObjectFile(MemoryBufferRef Object, bool InitContent = true);
390 
391   static Expected<std::unique_ptr<MachOObjectFile>>
392   createMachOObjectFile(MemoryBufferRef Object, uint32_t UniversalCputype = 0,
393                         uint32_t UniversalIndex = 0,
394                         size_t MachOFilesetEntryOffset = 0);
395 
396   static Expected<std::unique_ptr<ObjectFile>>
397   createGOFFObjectFile(MemoryBufferRef Object);
398 
399   static Expected<std::unique_ptr<WasmObjectFile>>
400   createWasmObjectFile(MemoryBufferRef Object);
401 };
402 
403 /// A filtered iterator for SectionRefs that skips sections based on some given
404 /// predicate.
405 class SectionFilterIterator {
406 public:
407   SectionFilterIterator(SectionFilterPredicate Pred,
408                         const section_iterator &Begin,
409                         const section_iterator &End)
410       : Predicate(std::move(Pred)), Iterator(Begin), End(End) {
411     scanPredicate();
412   }
413   const SectionRef &operator*() const { return *Iterator; }
414   SectionFilterIterator &operator++() {
415     ++Iterator;
416     scanPredicate();
417     return *this;
418   }
419   bool operator!=(const SectionFilterIterator &Other) const {
420     return Iterator != Other.Iterator;
421   }
422 
423 private:
424   void scanPredicate() {
425     while (Iterator != End && !Predicate(*Iterator)) {
426       ++Iterator;
427     }
428   }
429   SectionFilterPredicate Predicate;
430   section_iterator Iterator;
431   section_iterator End;
432 };
433 
434 /// Creates an iterator range of SectionFilterIterators for a given Object and
435 /// predicate.
436 class SectionFilter {
437 public:
438   SectionFilter(SectionFilterPredicate Pred, const ObjectFile &Obj)
439       : Predicate(std::move(Pred)), Object(Obj) {}
440   SectionFilterIterator begin() {
441     return SectionFilterIterator(Predicate, Object.section_begin(),
442                                  Object.section_end());
443   }
444   SectionFilterIterator end() {
445     return SectionFilterIterator(Predicate, Object.section_end(),
446                                  Object.section_end());
447   }
448 
449 private:
450   SectionFilterPredicate Predicate;
451   const ObjectFile &Object;
452 };
453 
454 // Inline function definitions.
455 inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
456     : BasicSymbolRef(SymbolP, Owner) {}
457 
458 inline Expected<StringRef> SymbolRef::getName() const {
459   return getObject()->getSymbolName(getRawDataRefImpl());
460 }
461 
462 inline Expected<uint64_t> SymbolRef::getAddress() const {
463   return getObject()->getSymbolAddress(getRawDataRefImpl());
464 }
465 
466 inline Expected<uint64_t> SymbolRef::getValue() const {
467   return getObject()->getSymbolValue(getRawDataRefImpl());
468 }
469 
470 inline uint32_t SymbolRef::getAlignment() const {
471   return getObject()->getSymbolAlignment(getRawDataRefImpl());
472 }
473 
474 inline uint64_t SymbolRef::getCommonSize() const {
475   return getObject()->getCommonSymbolSize(getRawDataRefImpl());
476 }
477 
478 inline Expected<section_iterator> SymbolRef::getSection() const {
479   return getObject()->getSymbolSection(getRawDataRefImpl());
480 }
481 
482 inline Expected<SymbolRef::Type> SymbolRef::getType() const {
483   return getObject()->getSymbolType(getRawDataRefImpl());
484 }
485 
486 inline const ObjectFile *SymbolRef::getObject() const {
487   const SymbolicFile *O = BasicSymbolRef::getObject();
488   return cast<ObjectFile>(O);
489 }
490 
491 /// SectionRef
492 inline SectionRef::SectionRef(DataRefImpl SectionP,
493                               const ObjectFile *Owner)
494   : SectionPimpl(SectionP)
495   , OwningObject(Owner) {}
496 
497 inline bool SectionRef::operator==(const SectionRef &Other) const {
498   return OwningObject == Other.OwningObject &&
499          SectionPimpl == Other.SectionPimpl;
500 }
501 
502 inline bool SectionRef::operator!=(const SectionRef &Other) const {
503   return !(*this == Other);
504 }
505 
506 inline bool SectionRef::operator<(const SectionRef &Other) const {
507   assert(OwningObject == Other.OwningObject);
508   return SectionPimpl < Other.SectionPimpl;
509 }
510 
511 inline void SectionRef::moveNext() {
512   return OwningObject->moveSectionNext(SectionPimpl);
513 }
514 
515 inline Expected<StringRef> SectionRef::getName() const {
516   return OwningObject->getSectionName(SectionPimpl);
517 }
518 
519 inline uint64_t SectionRef::getAddress() const {
520   return OwningObject->getSectionAddress(SectionPimpl);
521 }
522 
523 inline uint64_t SectionRef::getIndex() const {
524   return OwningObject->getSectionIndex(SectionPimpl);
525 }
526 
527 inline uint64_t SectionRef::getSize() const {
528   return OwningObject->getSectionSize(SectionPimpl);
529 }
530 
531 inline Expected<StringRef> SectionRef::getContents() const {
532   Expected<ArrayRef<uint8_t>> Res =
533       OwningObject->getSectionContents(SectionPimpl);
534   if (!Res)
535     return Res.takeError();
536   return StringRef(reinterpret_cast<const char *>(Res->data()), Res->size());
537 }
538 
539 inline Align SectionRef::getAlignment() const {
540   return MaybeAlign(OwningObject->getSectionAlignment(SectionPimpl))
541       .valueOrOne();
542 }
543 
544 inline bool SectionRef::isCompressed() const {
545   return OwningObject->isSectionCompressed(SectionPimpl);
546 }
547 
548 inline bool SectionRef::isText() const {
549   return OwningObject->isSectionText(SectionPimpl);
550 }
551 
552 inline bool SectionRef::isData() const {
553   return OwningObject->isSectionData(SectionPimpl);
554 }
555 
556 inline bool SectionRef::isBSS() const {
557   return OwningObject->isSectionBSS(SectionPimpl);
558 }
559 
560 inline bool SectionRef::isVirtual() const {
561   return OwningObject->isSectionVirtual(SectionPimpl);
562 }
563 
564 inline bool SectionRef::isBitcode() const {
565   return OwningObject->isSectionBitcode(SectionPimpl);
566 }
567 
568 inline bool SectionRef::isStripped() const {
569   return OwningObject->isSectionStripped(SectionPimpl);
570 }
571 
572 inline bool SectionRef::isBerkeleyText() const {
573   return OwningObject->isBerkeleyText(SectionPimpl);
574 }
575 
576 inline bool SectionRef::isBerkeleyData() const {
577   return OwningObject->isBerkeleyData(SectionPimpl);
578 }
579 
580 inline bool SectionRef::isDebugSection() const {
581   return OwningObject->isDebugSection(SectionPimpl);
582 }
583 
584 inline relocation_iterator SectionRef::relocation_begin() const {
585   return OwningObject->section_rel_begin(SectionPimpl);
586 }
587 
588 inline relocation_iterator SectionRef::relocation_end() const {
589   return OwningObject->section_rel_end(SectionPimpl);
590 }
591 
592 inline Expected<section_iterator> SectionRef::getRelocatedSection() const {
593   return OwningObject->getRelocatedSection(SectionPimpl);
594 }
595 
596 inline DataRefImpl SectionRef::getRawDataRefImpl() const {
597   return SectionPimpl;
598 }
599 
600 inline const ObjectFile *SectionRef::getObject() const {
601   return OwningObject;
602 }
603 
604 /// RelocationRef
605 inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
606                               const ObjectFile *Owner)
607   : RelocationPimpl(RelocationP)
608   , OwningObject(Owner) {}
609 
610 inline bool RelocationRef::operator==(const RelocationRef &Other) const {
611   return RelocationPimpl == Other.RelocationPimpl;
612 }
613 
614 inline void RelocationRef::moveNext() {
615   return OwningObject->moveRelocationNext(RelocationPimpl);
616 }
617 
618 inline uint64_t RelocationRef::getOffset() const {
619   return OwningObject->getRelocationOffset(RelocationPimpl);
620 }
621 
622 inline symbol_iterator RelocationRef::getSymbol() const {
623   return OwningObject->getRelocationSymbol(RelocationPimpl);
624 }
625 
626 inline uint64_t RelocationRef::getType() const {
627   return OwningObject->getRelocationType(RelocationPimpl);
628 }
629 
630 inline void RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const {
631   return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
632 }
633 
634 inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
635   return RelocationPimpl;
636 }
637 
638 inline const ObjectFile *RelocationRef::getObject() const {
639   return OwningObject;
640 }
641 
642 } // end namespace object
643 
644 template <> struct DenseMapInfo<object::SectionRef> {
645   static bool isEqual(const object::SectionRef &A,
646                       const object::SectionRef &B) {
647     return A == B;
648   }
649   static object::SectionRef getEmptyKey() {
650     return object::SectionRef({}, nullptr);
651   }
652   static object::SectionRef getTombstoneKey() {
653     object::DataRefImpl TS;
654     TS.p = (uintptr_t)-1;
655     return object::SectionRef(TS, nullptr);
656   }
657   static unsigned getHashValue(const object::SectionRef &Sec) {
658     object::DataRefImpl Raw = Sec.getRawDataRefImpl();
659     return hash_combine(Raw.p, Raw.d.a, Raw.d.b);
660   }
661 };
662 
663 } // end namespace llvm
664 
665 #endif // LLVM_OBJECT_OBJECTFILE_H
666