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1 //===- ELFObjectFile.h - ELF object file implementation ---------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file declares the ELFObjectFile template class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_OBJECT_ELFOBJECTFILE_H
15 #define LLVM_OBJECT_ELFOBJECTFILE_H
16 
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/ADT/iterator_range.h"
22 #include "llvm/MC/SubtargetFeature.h"
23 #include "llvm/Object/Binary.h"
24 #include "llvm/Object/ELF.h"
25 #include "llvm/Object/ELFTypes.h"
26 #include "llvm/Object/Error.h"
27 #include "llvm/Object/ObjectFile.h"
28 #include "llvm/Object/SymbolicFile.h"
29 #include "llvm/Support/Casting.h"
30 #include "llvm/Support/ELF.h"
31 #include "llvm/Support/Endian.h"
32 #include "llvm/Support/Error.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/ErrorOr.h"
35 #include "llvm/Support/MemoryBuffer.h"
36 #include <cassert>
37 #include <cstdint>
38 #include <system_error>
39 
40 namespace llvm {
41 namespace object {
42 
43 class elf_symbol_iterator;
44 class ELFSymbolRef;
45 class ELFRelocationRef;
46 
47 class ELFObjectFileBase : public ObjectFile {
48   friend class ELFSymbolRef;
49   friend class ELFSectionRef;
50   friend class ELFRelocationRef;
51 
52 protected:
53   ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source);
54 
55   virtual uint16_t getEMachine() const = 0;
56   virtual uint64_t getSymbolSize(DataRefImpl Symb) const = 0;
57   virtual uint8_t getSymbolOther(DataRefImpl Symb) const = 0;
58   virtual uint8_t getSymbolELFType(DataRefImpl Symb) const = 0;
59 
60   virtual uint32_t getSectionType(DataRefImpl Sec) const = 0;
61   virtual uint64_t getSectionFlags(DataRefImpl Sec) const = 0;
62 
63   virtual ErrorOr<int64_t> getRelocationAddend(DataRefImpl Rel) const = 0;
64 
65 public:
66   typedef iterator_range<elf_symbol_iterator> elf_symbol_iterator_range;
67   virtual elf_symbol_iterator_range getDynamicSymbolIterators() const = 0;
68 
69   elf_symbol_iterator_range symbols() const;
70 
classof(const Binary * v)71   static inline bool classof(const Binary *v) { return v->isELF(); }
72 
73   SubtargetFeatures getFeatures() const override;
74 };
75 
76 class ELFSectionRef : public SectionRef {
77 public:
ELFSectionRef(const SectionRef & B)78   ELFSectionRef(const SectionRef &B) : SectionRef(B) {
79     assert(isa<ELFObjectFileBase>(SectionRef::getObject()));
80   }
81 
getObject()82   const ELFObjectFileBase *getObject() const {
83     return cast<ELFObjectFileBase>(SectionRef::getObject());
84   }
85 
getType()86   uint32_t getType() const {
87     return getObject()->getSectionType(getRawDataRefImpl());
88   }
89 
getFlags()90   uint64_t getFlags() const {
91     return getObject()->getSectionFlags(getRawDataRefImpl());
92   }
93 };
94 
95 class elf_section_iterator : public section_iterator {
96 public:
elf_section_iterator(const section_iterator & B)97   elf_section_iterator(const section_iterator &B) : section_iterator(B) {
98     assert(isa<ELFObjectFileBase>(B->getObject()));
99   }
100 
101   const ELFSectionRef *operator->() const {
102     return static_cast<const ELFSectionRef *>(section_iterator::operator->());
103   }
104 
105   const ELFSectionRef &operator*() const {
106     return static_cast<const ELFSectionRef &>(section_iterator::operator*());
107   }
108 };
109 
110 class ELFSymbolRef : public SymbolRef {
111 public:
ELFSymbolRef(const SymbolRef & B)112   ELFSymbolRef(const SymbolRef &B) : SymbolRef(B) {
113     assert(isa<ELFObjectFileBase>(SymbolRef::getObject()));
114   }
115 
getObject()116   const ELFObjectFileBase *getObject() const {
117     return cast<ELFObjectFileBase>(BasicSymbolRef::getObject());
118   }
119 
getSize()120   uint64_t getSize() const {
121     return getObject()->getSymbolSize(getRawDataRefImpl());
122   }
123 
getOther()124   uint8_t getOther() const {
125     return getObject()->getSymbolOther(getRawDataRefImpl());
126   }
127 
getELFType()128   uint8_t getELFType() const {
129     return getObject()->getSymbolELFType(getRawDataRefImpl());
130   }
131 };
132 
133 class elf_symbol_iterator : public symbol_iterator {
134 public:
elf_symbol_iterator(const basic_symbol_iterator & B)135   elf_symbol_iterator(const basic_symbol_iterator &B)
136       : symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
137                                   cast<ELFObjectFileBase>(B->getObject()))) {}
138 
139   const ELFSymbolRef *operator->() const {
140     return static_cast<const ELFSymbolRef *>(symbol_iterator::operator->());
141   }
142 
143   const ELFSymbolRef &operator*() const {
144     return static_cast<const ELFSymbolRef &>(symbol_iterator::operator*());
145   }
146 };
147 
148 class ELFRelocationRef : public RelocationRef {
149 public:
ELFRelocationRef(const RelocationRef & B)150   ELFRelocationRef(const RelocationRef &B) : RelocationRef(B) {
151     assert(isa<ELFObjectFileBase>(RelocationRef::getObject()));
152   }
153 
getObject()154   const ELFObjectFileBase *getObject() const {
155     return cast<ELFObjectFileBase>(RelocationRef::getObject());
156   }
157 
getAddend()158   ErrorOr<int64_t> getAddend() const {
159     return getObject()->getRelocationAddend(getRawDataRefImpl());
160   }
161 };
162 
163 class elf_relocation_iterator : public relocation_iterator {
164 public:
elf_relocation_iterator(const relocation_iterator & B)165   elf_relocation_iterator(const relocation_iterator &B)
166       : relocation_iterator(RelocationRef(
167             B->getRawDataRefImpl(), cast<ELFObjectFileBase>(B->getObject()))) {}
168 
169   const ELFRelocationRef *operator->() const {
170     return static_cast<const ELFRelocationRef *>(
171         relocation_iterator::operator->());
172   }
173 
174   const ELFRelocationRef &operator*() const {
175     return static_cast<const ELFRelocationRef &>(
176         relocation_iterator::operator*());
177   }
178 };
179 
180 inline ELFObjectFileBase::elf_symbol_iterator_range
symbols()181 ELFObjectFileBase::symbols() const {
182   return elf_symbol_iterator_range(symbol_begin(), symbol_end());
183 }
184 
185 template <class ELFT> class ELFObjectFile : public ELFObjectFileBase {
186   uint16_t getEMachine() const override;
187   uint64_t getSymbolSize(DataRefImpl Sym) const override;
188 
189 public:
190   LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
191 
192   typedef typename ELFFile<ELFT>::uintX_t uintX_t;
193 
194   typedef typename ELFFile<ELFT>::Elf_Sym Elf_Sym;
195   typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
196   typedef typename ELFFile<ELFT>::Elf_Ehdr Elf_Ehdr;
197   typedef typename ELFFile<ELFT>::Elf_Rel Elf_Rel;
198   typedef typename ELFFile<ELFT>::Elf_Rela Elf_Rela;
199   typedef typename ELFFile<ELFT>::Elf_Dyn Elf_Dyn;
200 
201 protected:
202   ELFFile<ELFT> EF;
203 
204   const Elf_Shdr *DotDynSymSec = nullptr; // Dynamic symbol table section.
205   const Elf_Shdr *DotSymtabSec = nullptr; // Symbol table section.
206   ArrayRef<Elf_Word> ShndxTable;
207 
208   void moveSymbolNext(DataRefImpl &Symb) const override;
209   Expected<StringRef> getSymbolName(DataRefImpl Symb) const override;
210   Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override;
211   uint64_t getSymbolValueImpl(DataRefImpl Symb) const override;
212   uint32_t getSymbolAlignment(DataRefImpl Symb) const override;
213   uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override;
214   uint32_t getSymbolFlags(DataRefImpl Symb) const override;
215   uint8_t getSymbolOther(DataRefImpl Symb) const override;
216   uint8_t getSymbolELFType(DataRefImpl Symb) const override;
217   Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override;
218   Expected<section_iterator> getSymbolSection(const Elf_Sym *Symb,
219                                               const Elf_Shdr *SymTab) const;
220   Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override;
221 
222   void moveSectionNext(DataRefImpl &Sec) const override;
223   std::error_code getSectionName(DataRefImpl Sec,
224                                  StringRef &Res) const override;
225   uint64_t getSectionAddress(DataRefImpl Sec) const override;
226   uint64_t getSectionSize(DataRefImpl Sec) const override;
227   std::error_code getSectionContents(DataRefImpl Sec,
228                                      StringRef &Res) const override;
229   uint64_t getSectionAlignment(DataRefImpl Sec) const override;
230   bool isSectionCompressed(DataRefImpl Sec) const override;
231   bool isSectionText(DataRefImpl Sec) const override;
232   bool isSectionData(DataRefImpl Sec) const override;
233   bool isSectionBSS(DataRefImpl Sec) const override;
234   bool isSectionVirtual(DataRefImpl Sec) const override;
235   relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
236   relocation_iterator section_rel_end(DataRefImpl Sec) const override;
237   section_iterator getRelocatedSection(DataRefImpl Sec) const override;
238 
239   void moveRelocationNext(DataRefImpl &Rel) const override;
240   uint64_t getRelocationOffset(DataRefImpl Rel) const override;
241   symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override;
242   uint64_t getRelocationType(DataRefImpl Rel) const override;
243   void getRelocationTypeName(DataRefImpl Rel,
244                              SmallVectorImpl<char> &Result) const override;
245 
246   uint32_t getSectionType(DataRefImpl Sec) const override;
247   uint64_t getSectionFlags(DataRefImpl Sec) const override;
248   StringRef getRelocationTypeName(uint32_t Type) const;
249 
250   /// \brief Get the relocation section that contains \a Rel.
getRelSection(DataRefImpl Rel)251   const Elf_Shdr *getRelSection(DataRefImpl Rel) const {
252     return *EF.getSection(Rel.d.a);
253   }
254 
toDRI(const Elf_Shdr * SymTable,unsigned SymbolNum)255   DataRefImpl toDRI(const Elf_Shdr *SymTable, unsigned SymbolNum) const {
256     DataRefImpl DRI;
257     if (!SymTable) {
258       DRI.d.a = 0;
259       DRI.d.b = 0;
260       return DRI;
261     }
262     assert(SymTable->sh_type == ELF::SHT_SYMTAB ||
263            SymTable->sh_type == ELF::SHT_DYNSYM);
264 
265     uintptr_t SHT = reinterpret_cast<uintptr_t>(EF.section_begin());
266     unsigned SymTableIndex =
267         (reinterpret_cast<uintptr_t>(SymTable) - SHT) / sizeof(Elf_Shdr);
268 
269     DRI.d.a = SymTableIndex;
270     DRI.d.b = SymbolNum;
271     return DRI;
272   }
273 
toELFShdrIter(DataRefImpl Sec)274   const Elf_Shdr *toELFShdrIter(DataRefImpl Sec) const {
275     return reinterpret_cast<const Elf_Shdr *>(Sec.p);
276   }
277 
toDRI(const Elf_Shdr * Sec)278   DataRefImpl toDRI(const Elf_Shdr *Sec) const {
279     DataRefImpl DRI;
280     DRI.p = reinterpret_cast<uintptr_t>(Sec);
281     return DRI;
282   }
283 
toDRI(const Elf_Dyn * Dyn)284   DataRefImpl toDRI(const Elf_Dyn *Dyn) const {
285     DataRefImpl DRI;
286     DRI.p = reinterpret_cast<uintptr_t>(Dyn);
287     return DRI;
288   }
289 
isExportedToOtherDSO(const Elf_Sym * ESym)290   bool isExportedToOtherDSO(const Elf_Sym *ESym) const {
291     unsigned char Binding = ESym->getBinding();
292     unsigned char Visibility = ESym->getVisibility();
293 
294     // A symbol is exported if its binding is either GLOBAL or WEAK, and its
295     // visibility is either DEFAULT or PROTECTED. All other symbols are not
296     // exported.
297     return ((Binding == ELF::STB_GLOBAL || Binding == ELF::STB_WEAK) &&
298             (Visibility == ELF::STV_DEFAULT ||
299              Visibility == ELF::STV_PROTECTED));
300   }
301 
302   // This flag is used for classof, to distinguish ELFObjectFile from
303   // its subclass. If more subclasses will be created, this flag will
304   // have to become an enum.
305   bool isDyldELFObject;
306 
307 public:
308   ELFObjectFile(MemoryBufferRef Object, std::error_code &EC);
309 
310   const Elf_Rel *getRel(DataRefImpl Rel) const;
311   const Elf_Rela *getRela(DataRefImpl Rela) const;
312 
getSymbol(DataRefImpl Sym)313   const Elf_Sym *getSymbol(DataRefImpl Sym) const {
314     return EF.template getEntry<Elf_Sym>(Sym.d.a, Sym.d.b);
315   }
316 
getSection(DataRefImpl Sec)317   const Elf_Shdr *getSection(DataRefImpl Sec) const {
318     return reinterpret_cast<const Elf_Shdr *>(Sec.p);
319   }
320 
321   basic_symbol_iterator symbol_begin_impl() const override;
322   basic_symbol_iterator symbol_end_impl() const override;
323 
324   elf_symbol_iterator dynamic_symbol_begin() const;
325   elf_symbol_iterator dynamic_symbol_end() const;
326 
327   section_iterator section_begin() const override;
328   section_iterator section_end() const override;
329 
330   ErrorOr<int64_t> getRelocationAddend(DataRefImpl Rel) const override;
331 
332   uint8_t getBytesInAddress() const override;
333   StringRef getFileFormatName() const override;
334   unsigned getArch() const override;
335 
getPlatformFlags(unsigned & Result)336   std::error_code getPlatformFlags(unsigned &Result) const override {
337     Result = EF.getHeader()->e_flags;
338     return std::error_code();
339   }
340 
getELFFile()341   const ELFFile<ELFT> *getELFFile() const { return &EF; }
342 
isDyldType()343   bool isDyldType() const { return isDyldELFObject; }
classof(const Binary * v)344   static inline bool classof(const Binary *v) {
345     return v->getType() == getELFType(ELFT::TargetEndianness == support::little,
346                                       ELFT::Is64Bits);
347   }
348 
349   elf_symbol_iterator_range getDynamicSymbolIterators() const override;
350 
351   bool isRelocatableObject() const override;
352 };
353 
354 typedef ELFObjectFile<ELFType<support::little, false>> ELF32LEObjectFile;
355 typedef ELFObjectFile<ELFType<support::little, true>> ELF64LEObjectFile;
356 typedef ELFObjectFile<ELFType<support::big, false>> ELF32BEObjectFile;
357 typedef ELFObjectFile<ELFType<support::big, true>> ELF64BEObjectFile;
358 
359 template <class ELFT>
moveSymbolNext(DataRefImpl & Sym)360 void ELFObjectFile<ELFT>::moveSymbolNext(DataRefImpl &Sym) const {
361   ++Sym.d.b;
362 }
363 
364 template <class ELFT>
getSymbolName(DataRefImpl Sym)365 Expected<StringRef> ELFObjectFile<ELFT>::getSymbolName(DataRefImpl Sym) const {
366   const Elf_Sym *ESym = getSymbol(Sym);
367   const Elf_Shdr *SymTableSec = *EF.getSection(Sym.d.a);
368   const Elf_Shdr *StringTableSec = *EF.getSection(SymTableSec->sh_link);
369   StringRef SymTable = *EF.getStringTable(StringTableSec);
370   return ESym->getName(SymTable);
371 }
372 
373 template <class ELFT>
getSectionFlags(DataRefImpl Sec)374 uint64_t ELFObjectFile<ELFT>::getSectionFlags(DataRefImpl Sec) const {
375   return getSection(Sec)->sh_flags;
376 }
377 
378 template <class ELFT>
getSectionType(DataRefImpl Sec)379 uint32_t ELFObjectFile<ELFT>::getSectionType(DataRefImpl Sec) const {
380   return getSection(Sec)->sh_type;
381 }
382 
383 template <class ELFT>
getSymbolValueImpl(DataRefImpl Symb)384 uint64_t ELFObjectFile<ELFT>::getSymbolValueImpl(DataRefImpl Symb) const {
385   const Elf_Sym *ESym = getSymbol(Symb);
386   uint64_t Ret = ESym->st_value;
387   if (ESym->st_shndx == ELF::SHN_ABS)
388     return Ret;
389 
390   const Elf_Ehdr *Header = EF.getHeader();
391   // Clear the ARM/Thumb or microMIPS indicator flag.
392   if ((Header->e_machine == ELF::EM_ARM || Header->e_machine == ELF::EM_MIPS) &&
393       ESym->getType() == ELF::STT_FUNC)
394     Ret &= ~1;
395 
396   return Ret;
397 }
398 
399 template <class ELFT>
400 Expected<uint64_t>
getSymbolAddress(DataRefImpl Symb)401 ELFObjectFile<ELFT>::getSymbolAddress(DataRefImpl Symb) const {
402   uint64_t Result = getSymbolValue(Symb);
403   const Elf_Sym *ESym = getSymbol(Symb);
404   switch (ESym->st_shndx) {
405   case ELF::SHN_COMMON:
406   case ELF::SHN_UNDEF:
407   case ELF::SHN_ABS:
408     return Result;
409   }
410 
411   const Elf_Ehdr *Header = EF.getHeader();
412   const Elf_Shdr *SymTab = *EF.getSection(Symb.d.a);
413 
414   if (Header->e_type == ELF::ET_REL) {
415     ErrorOr<const Elf_Shdr *> SectionOrErr =
416         EF.getSection(ESym, SymTab, ShndxTable);
417     if (std::error_code EC = SectionOrErr.getError())
418       return errorCodeToError(EC);
419     const Elf_Shdr *Section = *SectionOrErr;
420     if (Section)
421       Result += Section->sh_addr;
422   }
423 
424   return Result;
425 }
426 
427 template <class ELFT>
getSymbolAlignment(DataRefImpl Symb)428 uint32_t ELFObjectFile<ELFT>::getSymbolAlignment(DataRefImpl Symb) const {
429   const Elf_Sym *Sym = getSymbol(Symb);
430   if (Sym->st_shndx == ELF::SHN_COMMON)
431     return Sym->st_value;
432   return 0;
433 }
434 
435 template <class ELFT>
getEMachine()436 uint16_t ELFObjectFile<ELFT>::getEMachine() const {
437   return EF.getHeader()->e_machine;
438 }
439 
440 template <class ELFT>
getSymbolSize(DataRefImpl Sym)441 uint64_t ELFObjectFile<ELFT>::getSymbolSize(DataRefImpl Sym) const {
442   return getSymbol(Sym)->st_size;
443 }
444 
445 template <class ELFT>
getCommonSymbolSizeImpl(DataRefImpl Symb)446 uint64_t ELFObjectFile<ELFT>::getCommonSymbolSizeImpl(DataRefImpl Symb) const {
447   return getSymbol(Symb)->st_size;
448 }
449 
450 template <class ELFT>
getSymbolOther(DataRefImpl Symb)451 uint8_t ELFObjectFile<ELFT>::getSymbolOther(DataRefImpl Symb) const {
452   return getSymbol(Symb)->st_other;
453 }
454 
455 template <class ELFT>
getSymbolELFType(DataRefImpl Symb)456 uint8_t ELFObjectFile<ELFT>::getSymbolELFType(DataRefImpl Symb) const {
457   return getSymbol(Symb)->getType();
458 }
459 
460 template <class ELFT>
461 Expected<SymbolRef::Type>
getSymbolType(DataRefImpl Symb)462 ELFObjectFile<ELFT>::getSymbolType(DataRefImpl Symb) const {
463   const Elf_Sym *ESym = getSymbol(Symb);
464 
465   switch (ESym->getType()) {
466   case ELF::STT_NOTYPE:
467     return SymbolRef::ST_Unknown;
468   case ELF::STT_SECTION:
469     return SymbolRef::ST_Debug;
470   case ELF::STT_FILE:
471     return SymbolRef::ST_File;
472   case ELF::STT_FUNC:
473     return SymbolRef::ST_Function;
474   case ELF::STT_OBJECT:
475   case ELF::STT_COMMON:
476   case ELF::STT_TLS:
477     return SymbolRef::ST_Data;
478   default:
479     return SymbolRef::ST_Other;
480   }
481 }
482 
483 template <class ELFT>
getSymbolFlags(DataRefImpl Sym)484 uint32_t ELFObjectFile<ELFT>::getSymbolFlags(DataRefImpl Sym) const {
485   const Elf_Sym *ESym = getSymbol(Sym);
486 
487   uint32_t Result = SymbolRef::SF_None;
488 
489   if (ESym->getBinding() != ELF::STB_LOCAL)
490     Result |= SymbolRef::SF_Global;
491 
492   if (ESym->getBinding() == ELF::STB_WEAK)
493     Result |= SymbolRef::SF_Weak;
494 
495   if (ESym->st_shndx == ELF::SHN_ABS)
496     Result |= SymbolRef::SF_Absolute;
497 
498   if (ESym->getType() == ELF::STT_FILE || ESym->getType() == ELF::STT_SECTION ||
499       ESym == EF.symbol_begin(DotSymtabSec) ||
500       ESym == EF.symbol_begin(DotDynSymSec))
501     Result |= SymbolRef::SF_FormatSpecific;
502 
503   if (EF.getHeader()->e_machine == ELF::EM_ARM) {
504     if (Expected<StringRef> NameOrErr = getSymbolName(Sym)) {
505       StringRef Name = *NameOrErr;
506       if (Name.startswith("$d") || Name.startswith("$t") ||
507           Name.startswith("$a"))
508         Result |= SymbolRef::SF_FormatSpecific;
509     } else {
510       // TODO: Actually report errors helpfully.
511       consumeError(NameOrErr.takeError());
512     }
513     if (ESym->getType() == ELF::STT_FUNC && (ESym->st_value & 1) == 1)
514       Result |= SymbolRef::SF_Thumb;
515   }
516 
517   if (ESym->st_shndx == ELF::SHN_UNDEF)
518     Result |= SymbolRef::SF_Undefined;
519 
520   if (ESym->getType() == ELF::STT_COMMON || ESym->st_shndx == ELF::SHN_COMMON)
521     Result |= SymbolRef::SF_Common;
522 
523   if (isExportedToOtherDSO(ESym))
524     Result |= SymbolRef::SF_Exported;
525 
526   if (ESym->getVisibility() == ELF::STV_HIDDEN)
527     Result |= SymbolRef::SF_Hidden;
528 
529   return Result;
530 }
531 
532 template <class ELFT>
533 Expected<section_iterator>
getSymbolSection(const Elf_Sym * ESym,const Elf_Shdr * SymTab)534 ELFObjectFile<ELFT>::getSymbolSection(const Elf_Sym *ESym,
535                                       const Elf_Shdr *SymTab) const {
536   ErrorOr<const Elf_Shdr *> ESecOrErr = EF.getSection(ESym, SymTab, ShndxTable);
537   if (std::error_code EC = ESecOrErr.getError())
538     return errorCodeToError(EC);
539 
540   const Elf_Shdr *ESec = *ESecOrErr;
541   if (!ESec)
542     return section_end();
543 
544   DataRefImpl Sec;
545   Sec.p = reinterpret_cast<intptr_t>(ESec);
546   return section_iterator(SectionRef(Sec, this));
547 }
548 
549 template <class ELFT>
550 Expected<section_iterator>
getSymbolSection(DataRefImpl Symb)551 ELFObjectFile<ELFT>::getSymbolSection(DataRefImpl Symb) const {
552   const Elf_Sym *Sym = getSymbol(Symb);
553   const Elf_Shdr *SymTab = *EF.getSection(Symb.d.a);
554   return getSymbolSection(Sym, SymTab);
555 }
556 
557 template <class ELFT>
moveSectionNext(DataRefImpl & Sec)558 void ELFObjectFile<ELFT>::moveSectionNext(DataRefImpl &Sec) const {
559   const Elf_Shdr *ESec = getSection(Sec);
560   Sec = toDRI(++ESec);
561 }
562 
563 template <class ELFT>
getSectionName(DataRefImpl Sec,StringRef & Result)564 std::error_code ELFObjectFile<ELFT>::getSectionName(DataRefImpl Sec,
565                                                     StringRef &Result) const {
566   ErrorOr<StringRef> Name = EF.getSectionName(&*getSection(Sec));
567   if (!Name)
568     return Name.getError();
569   Result = *Name;
570   return std::error_code();
571 }
572 
573 template <class ELFT>
getSectionAddress(DataRefImpl Sec)574 uint64_t ELFObjectFile<ELFT>::getSectionAddress(DataRefImpl Sec) const {
575   return getSection(Sec)->sh_addr;
576 }
577 
578 template <class ELFT>
getSectionSize(DataRefImpl Sec)579 uint64_t ELFObjectFile<ELFT>::getSectionSize(DataRefImpl Sec) const {
580   return getSection(Sec)->sh_size;
581 }
582 
583 template <class ELFT>
584 std::error_code
getSectionContents(DataRefImpl Sec,StringRef & Result)585 ELFObjectFile<ELFT>::getSectionContents(DataRefImpl Sec,
586                                         StringRef &Result) const {
587   const Elf_Shdr *EShdr = getSection(Sec);
588   Result = StringRef((const char *)base() + EShdr->sh_offset, EShdr->sh_size);
589   return std::error_code();
590 }
591 
592 template <class ELFT>
getSectionAlignment(DataRefImpl Sec)593 uint64_t ELFObjectFile<ELFT>::getSectionAlignment(DataRefImpl Sec) const {
594   return getSection(Sec)->sh_addralign;
595 }
596 
597 template <class ELFT>
isSectionCompressed(DataRefImpl Sec)598 bool ELFObjectFile<ELFT>::isSectionCompressed(DataRefImpl Sec) const {
599   return getSection(Sec)->sh_flags & ELF::SHF_COMPRESSED;
600 }
601 
602 template <class ELFT>
isSectionText(DataRefImpl Sec)603 bool ELFObjectFile<ELFT>::isSectionText(DataRefImpl Sec) const {
604   return getSection(Sec)->sh_flags & ELF::SHF_EXECINSTR;
605 }
606 
607 template <class ELFT>
isSectionData(DataRefImpl Sec)608 bool ELFObjectFile<ELFT>::isSectionData(DataRefImpl Sec) const {
609   const Elf_Shdr *EShdr = getSection(Sec);
610   return EShdr->sh_flags & (ELF::SHF_ALLOC | ELF::SHF_WRITE) &&
611          EShdr->sh_type == ELF::SHT_PROGBITS;
612 }
613 
614 template <class ELFT>
isSectionBSS(DataRefImpl Sec)615 bool ELFObjectFile<ELFT>::isSectionBSS(DataRefImpl Sec) const {
616   const Elf_Shdr *EShdr = getSection(Sec);
617   return EShdr->sh_flags & (ELF::SHF_ALLOC | ELF::SHF_WRITE) &&
618          EShdr->sh_type == ELF::SHT_NOBITS;
619 }
620 
621 template <class ELFT>
isSectionVirtual(DataRefImpl Sec)622 bool ELFObjectFile<ELFT>::isSectionVirtual(DataRefImpl Sec) const {
623   return getSection(Sec)->sh_type == ELF::SHT_NOBITS;
624 }
625 
626 template <class ELFT>
627 relocation_iterator
section_rel_begin(DataRefImpl Sec)628 ELFObjectFile<ELFT>::section_rel_begin(DataRefImpl Sec) const {
629   DataRefImpl RelData;
630   uintptr_t SHT = reinterpret_cast<uintptr_t>(EF.section_begin());
631   RelData.d.a = (Sec.p - SHT) / EF.getHeader()->e_shentsize;
632   RelData.d.b = 0;
633   return relocation_iterator(RelocationRef(RelData, this));
634 }
635 
636 template <class ELFT>
637 relocation_iterator
section_rel_end(DataRefImpl Sec)638 ELFObjectFile<ELFT>::section_rel_end(DataRefImpl Sec) const {
639   const Elf_Shdr *S = reinterpret_cast<const Elf_Shdr *>(Sec.p);
640   relocation_iterator Begin = section_rel_begin(Sec);
641   if (S->sh_type != ELF::SHT_RELA && S->sh_type != ELF::SHT_REL)
642     return Begin;
643   DataRefImpl RelData = Begin->getRawDataRefImpl();
644   const Elf_Shdr *RelSec = getRelSection(RelData);
645 
646   // Error check sh_link here so that getRelocationSymbol can just use it.
647   ErrorOr<const Elf_Shdr *> SymSecOrErr = EF.getSection(RelSec->sh_link);
648   if (std::error_code EC = SymSecOrErr.getError())
649     report_fatal_error(EC.message());
650 
651   RelData.d.b += S->sh_size / S->sh_entsize;
652   return relocation_iterator(RelocationRef(RelData, this));
653 }
654 
655 template <class ELFT>
656 section_iterator
getRelocatedSection(DataRefImpl Sec)657 ELFObjectFile<ELFT>::getRelocatedSection(DataRefImpl Sec) const {
658   if (EF.getHeader()->e_type != ELF::ET_REL)
659     return section_end();
660 
661   const Elf_Shdr *EShdr = getSection(Sec);
662   uintX_t Type = EShdr->sh_type;
663   if (Type != ELF::SHT_REL && Type != ELF::SHT_RELA)
664     return section_end();
665 
666   ErrorOr<const Elf_Shdr *> R = EF.getSection(EShdr->sh_info);
667   if (std::error_code EC = R.getError())
668     report_fatal_error(EC.message());
669   return section_iterator(SectionRef(toDRI(*R), this));
670 }
671 
672 // Relocations
673 template <class ELFT>
moveRelocationNext(DataRefImpl & Rel)674 void ELFObjectFile<ELFT>::moveRelocationNext(DataRefImpl &Rel) const {
675   ++Rel.d.b;
676 }
677 
678 template <class ELFT>
679 symbol_iterator
getRelocationSymbol(DataRefImpl Rel)680 ELFObjectFile<ELFT>::getRelocationSymbol(DataRefImpl Rel) const {
681   uint32_t symbolIdx;
682   const Elf_Shdr *sec = getRelSection(Rel);
683   if (sec->sh_type == ELF::SHT_REL)
684     symbolIdx = getRel(Rel)->getSymbol(EF.isMips64EL());
685   else
686     symbolIdx = getRela(Rel)->getSymbol(EF.isMips64EL());
687   if (!symbolIdx)
688     return symbol_end();
689 
690   // FIXME: error check symbolIdx
691   DataRefImpl SymbolData;
692   SymbolData.d.a = sec->sh_link;
693   SymbolData.d.b = symbolIdx;
694   return symbol_iterator(SymbolRef(SymbolData, this));
695 }
696 
697 template <class ELFT>
getRelocationOffset(DataRefImpl Rel)698 uint64_t ELFObjectFile<ELFT>::getRelocationOffset(DataRefImpl Rel) const {
699   assert(EF.getHeader()->e_type == ELF::ET_REL &&
700          "Only relocatable object files have relocation offsets");
701   const Elf_Shdr *sec = getRelSection(Rel);
702   if (sec->sh_type == ELF::SHT_REL)
703     return getRel(Rel)->r_offset;
704 
705   return getRela(Rel)->r_offset;
706 }
707 
708 template <class ELFT>
getRelocationType(DataRefImpl Rel)709 uint64_t ELFObjectFile<ELFT>::getRelocationType(DataRefImpl Rel) const {
710   const Elf_Shdr *sec = getRelSection(Rel);
711   if (sec->sh_type == ELF::SHT_REL)
712     return getRel(Rel)->getType(EF.isMips64EL());
713   else
714     return getRela(Rel)->getType(EF.isMips64EL());
715 }
716 
717 template <class ELFT>
getRelocationTypeName(uint32_t Type)718 StringRef ELFObjectFile<ELFT>::getRelocationTypeName(uint32_t Type) const {
719   return getELFRelocationTypeName(EF.getHeader()->e_machine, Type);
720 }
721 
722 template <class ELFT>
getRelocationTypeName(DataRefImpl Rel,SmallVectorImpl<char> & Result)723 void ELFObjectFile<ELFT>::getRelocationTypeName(
724     DataRefImpl Rel, SmallVectorImpl<char> &Result) const {
725   uint32_t type = getRelocationType(Rel);
726   EF.getRelocationTypeName(type, Result);
727 }
728 
729 template <class ELFT>
730 ErrorOr<int64_t>
getRelocationAddend(DataRefImpl Rel)731 ELFObjectFile<ELFT>::getRelocationAddend(DataRefImpl Rel) const {
732   if (getRelSection(Rel)->sh_type != ELF::SHT_RELA)
733     return object_error::parse_failed;
734   return (int64_t)getRela(Rel)->r_addend;
735 }
736 
737 template <class ELFT>
738 const typename ELFObjectFile<ELFT>::Elf_Rel *
getRel(DataRefImpl Rel)739 ELFObjectFile<ELFT>::getRel(DataRefImpl Rel) const {
740   assert(getRelSection(Rel)->sh_type == ELF::SHT_REL);
741   return EF.template getEntry<Elf_Rel>(Rel.d.a, Rel.d.b);
742 }
743 
744 template <class ELFT>
745 const typename ELFObjectFile<ELFT>::Elf_Rela *
getRela(DataRefImpl Rela)746 ELFObjectFile<ELFT>::getRela(DataRefImpl Rela) const {
747   assert(getRelSection(Rela)->sh_type == ELF::SHT_RELA);
748   return EF.template getEntry<Elf_Rela>(Rela.d.a, Rela.d.b);
749 }
750 
751 template <class ELFT>
ELFObjectFile(MemoryBufferRef Object,std::error_code & EC)752 ELFObjectFile<ELFT>::ELFObjectFile(MemoryBufferRef Object, std::error_code &EC)
753     : ELFObjectFileBase(
754           getELFType(ELFT::TargetEndianness == support::little, ELFT::Is64Bits),
755           Object),
756       EF(Data.getBuffer(), EC) {
757   if (EC)
758     return;
759   for (const Elf_Shdr &Sec : EF.sections()) {
760     switch (Sec.sh_type) {
761     case ELF::SHT_DYNSYM: {
762       if (DotDynSymSec) {
763         // More than one .dynsym!
764         EC = object_error::parse_failed;
765         return;
766       }
767       DotDynSymSec = &Sec;
768       break;
769     }
770     case ELF::SHT_SYMTAB: {
771       if (DotSymtabSec) {
772         // More than one .dynsym!
773         EC = object_error::parse_failed;
774         return;
775       }
776       DotSymtabSec = &Sec;
777       break;
778     }
779     case ELF::SHT_SYMTAB_SHNDX: {
780       ErrorOr<ArrayRef<Elf_Word>> TableOrErr = EF.getSHNDXTable(Sec);
781       if ((EC = TableOrErr.getError()))
782         return;
783       ShndxTable = *TableOrErr;
784       break;
785     }
786     }
787   }
788 }
789 
790 template <class ELFT>
symbol_begin_impl()791 basic_symbol_iterator ELFObjectFile<ELFT>::symbol_begin_impl() const {
792   DataRefImpl Sym = toDRI(DotSymtabSec, 0);
793   return basic_symbol_iterator(SymbolRef(Sym, this));
794 }
795 
796 template <class ELFT>
symbol_end_impl()797 basic_symbol_iterator ELFObjectFile<ELFT>::symbol_end_impl() const {
798   const Elf_Shdr *SymTab = DotSymtabSec;
799   if (!SymTab)
800     return symbol_begin_impl();
801   DataRefImpl Sym = toDRI(SymTab, SymTab->sh_size / sizeof(Elf_Sym));
802   return basic_symbol_iterator(SymbolRef(Sym, this));
803 }
804 
805 template <class ELFT>
dynamic_symbol_begin()806 elf_symbol_iterator ELFObjectFile<ELFT>::dynamic_symbol_begin() const {
807   DataRefImpl Sym = toDRI(DotDynSymSec, 0);
808   return symbol_iterator(SymbolRef(Sym, this));
809 }
810 
811 template <class ELFT>
dynamic_symbol_end()812 elf_symbol_iterator ELFObjectFile<ELFT>::dynamic_symbol_end() const {
813   const Elf_Shdr *SymTab = DotDynSymSec;
814   DataRefImpl Sym = toDRI(SymTab, SymTab->sh_size / sizeof(Elf_Sym));
815   return basic_symbol_iterator(SymbolRef(Sym, this));
816 }
817 
818 template <class ELFT>
section_begin()819 section_iterator ELFObjectFile<ELFT>::section_begin() const {
820   return section_iterator(SectionRef(toDRI(EF.section_begin()), this));
821 }
822 
823 template <class ELFT>
section_end()824 section_iterator ELFObjectFile<ELFT>::section_end() const {
825   return section_iterator(SectionRef(toDRI(EF.section_end()), this));
826 }
827 
828 template <class ELFT>
getBytesInAddress()829 uint8_t ELFObjectFile<ELFT>::getBytesInAddress() const {
830   return ELFT::Is64Bits ? 8 : 4;
831 }
832 
833 template <class ELFT>
getFileFormatName()834 StringRef ELFObjectFile<ELFT>::getFileFormatName() const {
835   bool IsLittleEndian = ELFT::TargetEndianness == support::little;
836   switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
837   case ELF::ELFCLASS32:
838     switch (EF.getHeader()->e_machine) {
839     case ELF::EM_386:
840       return "ELF32-i386";
841     case ELF::EM_IAMCU:
842       return "ELF32-iamcu";
843     case ELF::EM_X86_64:
844       return "ELF32-x86-64";
845     case ELF::EM_ARM:
846       return (IsLittleEndian ? "ELF32-arm-little" : "ELF32-arm-big");
847     case ELF::EM_AVR:
848       return "ELF32-avr";
849     case ELF::EM_HEXAGON:
850       return "ELF32-hexagon";
851     case ELF::EM_LANAI:
852       return "ELF32-lanai";
853     case ELF::EM_MIPS:
854       return "ELF32-mips";
855     case ELF::EM_PPC:
856       return "ELF32-ppc";
857     case ELF::EM_SPARC:
858     case ELF::EM_SPARC32PLUS:
859       return "ELF32-sparc";
860     case ELF::EM_WEBASSEMBLY:
861       return "ELF32-wasm";
862     case ELF::EM_AMDGPU:
863       return "ELF32-amdgpu";
864     default:
865       return "ELF32-unknown";
866     }
867   case ELF::ELFCLASS64:
868     switch (EF.getHeader()->e_machine) {
869     case ELF::EM_386:
870       return "ELF64-i386";
871     case ELF::EM_X86_64:
872       return "ELF64-x86-64";
873     case ELF::EM_AARCH64:
874       return (IsLittleEndian ? "ELF64-aarch64-little" : "ELF64-aarch64-big");
875     case ELF::EM_PPC64:
876       return "ELF64-ppc64";
877     case ELF::EM_S390:
878       return "ELF64-s390";
879     case ELF::EM_SPARCV9:
880       return "ELF64-sparc";
881     case ELF::EM_MIPS:
882       return "ELF64-mips";
883     case ELF::EM_WEBASSEMBLY:
884       return "ELF64-wasm";
885     case ELF::EM_AMDGPU:
886       return (EF.getHeader()->e_ident[ELF::EI_OSABI] == ELF::ELFOSABI_AMDGPU_HSA
887               && IsLittleEndian) ?
888              "ELF64-amdgpu-hsacobj" : "ELF64-amdgpu";
889     default:
890       return "ELF64-unknown";
891     }
892   default:
893     // FIXME: Proper error handling.
894     report_fatal_error("Invalid ELFCLASS!");
895   }
896 }
897 
898 template <class ELFT>
getArch()899 unsigned ELFObjectFile<ELFT>::getArch() const {
900   bool IsLittleEndian = ELFT::TargetEndianness == support::little;
901   switch (EF.getHeader()->e_machine) {
902   case ELF::EM_386:
903   case ELF::EM_IAMCU:
904     return Triple::x86;
905   case ELF::EM_X86_64:
906     return Triple::x86_64;
907   case ELF::EM_AARCH64:
908     return Triple::aarch64;
909   case ELF::EM_ARM:
910     return Triple::arm;
911   case ELF::EM_AVR:
912     return Triple::avr;
913   case ELF::EM_HEXAGON:
914     return Triple::hexagon;
915   case ELF::EM_LANAI:
916     return Triple::lanai;
917   case ELF::EM_MIPS:
918     switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
919     case ELF::ELFCLASS32:
920       return IsLittleEndian ? Triple::mipsel : Triple::mips;
921     case ELF::ELFCLASS64:
922       return IsLittleEndian ? Triple::mips64el : Triple::mips64;
923     default:
924       report_fatal_error("Invalid ELFCLASS!");
925     }
926   case ELF::EM_PPC:
927     return Triple::ppc;
928   case ELF::EM_PPC64:
929     return IsLittleEndian ? Triple::ppc64le : Triple::ppc64;
930   case ELF::EM_S390:
931     return Triple::systemz;
932 
933   case ELF::EM_SPARC:
934   case ELF::EM_SPARC32PLUS:
935     return IsLittleEndian ? Triple::sparcel : Triple::sparc;
936   case ELF::EM_SPARCV9:
937     return Triple::sparcv9;
938   case ELF::EM_WEBASSEMBLY:
939     switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
940     case ELF::ELFCLASS32: return Triple::wasm32;
941     case ELF::ELFCLASS64: return Triple::wasm64;
942     default: return Triple::UnknownArch;
943     }
944 
945   case ELF::EM_AMDGPU:
946     return (EF.getHeader()->e_ident[ELF::EI_CLASS] == ELF::ELFCLASS64
947          && EF.getHeader()->e_ident[ELF::EI_OSABI] == ELF::ELFOSABI_AMDGPU_HSA
948          && IsLittleEndian) ?
949       Triple::amdgcn : Triple::UnknownArch;
950 
951   default:
952     return Triple::UnknownArch;
953   }
954 }
955 
956 template <class ELFT>
957 ELFObjectFileBase::elf_symbol_iterator_range
getDynamicSymbolIterators()958 ELFObjectFile<ELFT>::getDynamicSymbolIterators() const {
959   return make_range(dynamic_symbol_begin(), dynamic_symbol_end());
960 }
961 
isRelocatableObject()962 template <class ELFT> bool ELFObjectFile<ELFT>::isRelocatableObject() const {
963   return EF.getHeader()->e_type == ELF::ET_REL;
964 }
965 
966 } // end namespace object
967 } // end namespace llvm
968 
969 #endif // LLVM_OBJECT_ELFOBJECTFILE_H
970