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